Technical Field
[000 I] The present disclosure relates to a manufacturing method for a pressed component, a
pressed component, and a press apparatus.
Background Art
[0002] Automotive bodies are assembled by superimposing edges of multiple formed panels,
joining the formed panels together by spot welding to configure a box body, and joining
structural members to required locations on the box body by spot welding. Examples of
structural members employed at a side section of an automotive body (body side) include side
sills joined to the two sides of a floor panel, an A-pillar lower and an A-pillar upper provided
standing upward from a front portion of the side sill, a roof rail joined to an upper end portion
of the A-pillar upper, and a B-pillar joining the side sill and the roof rail together.
[0003] Generally speaking, configuration elements (such as respective outer panels) of
structural members including A-pillar lowers, A-pillar uppers, and roof rails often have a
substantially hat-shaped lateral cross-section profile configured by a top plate extending in a
length direction, two convex ridge lines respectively connected to the two sides of the top
plate, two vertical walls respectively connected to the two convex ridge lines, two concave
ridge lines respectively connected to the two vertical walls, and two flanges respectively
connected to the two concave ridge lines.
SUMMARY OF INVENTION
Technical Problem
[0004] The configuration elements described above have comparatively complex lateral
cross-section profiles and are elongated. In order to suppress an increase in manufacturing
costs, the above configuration elements are generally manufactured by cold pressing.
Moreover, in order to both increase strength and achieve a reduction in vehicle body weight in
the interests of improving fuel consumption, thickness reduction of the above structural
members through the use of, for example, high tensile sheet steel having a tensile strength of
440 MPa or greater is being promoted.
[0005] However, when a high tensile sheet steel blank is cold pressed in an attempt to
manufacture configuration elements that curve along their length direction, such as roof rail
outer panels (referred to below as "roof members"; roof members are automotive structural
members), spring-back occurs during press mold release, leading to concerns of twisting in
the top plate. This gives rise to issues with regard to shape fixability, whereby roof members
cannot be formed in a desired shape.
[0006] For example, Japanese Patent Application Laid-Open (JP-A) No. 2004-314123
(refen·ed to below as "Patent Document 1 ") describes an invention in which a pressed
component having a uniform hat-shaped lateral cross-section along its length direction is
applied with a step during manufacture in order to suppress opening-out, and thus improve the
shape fixability.
[0007] Moreover, the specification of Japanese Patent No. 5382281 (referred to below as
"Patent Document 2") describes an invention in which, during the manufacture of a pressed
component that includes a top plate, vertical walls, and flanges, and that curves along its
length direction, a flange formed in a first process is bent back in a second process so as to
reduce residual stress in the flange, thereby improving the shape fixability.
[0008] When the invention described in Patent Document 1 is used to manufacture pressed
components shaped so as to curve along a length direction, for example in configuration
elements of configuration members such as A-pillar lowers, A-pillar uppers, or roof rails,
bending occurs in curved walls as a result of spring-back after removal from the mold, such
that the desired shape cannot be formed.
[0009] According to the invention described in Patent Document 2, when manufacturing
pressed components that curve along their length direction and height direction and that
include a bent portion in the vicinity of the length direction center, residual stress arises in the
flange, residual stress arises at inner faces of the vertical walls and the top plate, and
deviatoric residual stress arises at inner faces of the vertical walls and the top plate. As a
result, as viewed from the top plate side, bending occurs as a result of spring-back in the
pressed component after removal from the mold, such that the desired shape cannot be
formed.
[00 l 0] An object of the present disclosure is to provide a manufacturing method for a
specific pressed component in which the occurrence of bending as viewed from a top plate
side is suppressed. Note that in the present specification, a "specific pressed component"
refers to a pressed component configured including an elongated top plate, ridge lines at both
short direction ends of the top plate, and vertical walls facing each other in a state extending
from the respective ridge lines and at least one of the ve1iical walls configuring a curved wall
curving as viewed from an upper side of the top plate.
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Solution to Problem
[00 II] A pressed component manufacturing method of a first aspect according to the present
disclosure is a manufacturing method for a pressed component configured including an
elongated top plate, ridge lines at both short direction ends of the top plate, and vertical walls
facing each other in a state extending from the respective ridge lines and at least one of the
vertical walls configuring a curved wall curving as viewed from an upper side ofthe top plate.
The manufacturing method includes a first process of pressing a blank to form an intermediate
formed component configured including the top plate, the ridge lines at both ends, and the
vertical walls, and in which a step projecting toward an opposite side to a side on which the
vertical walls face each other is formed to the curved wall so as to run along a length direction
of the top plate. The manufacturing method further includes a second process of perfmming
at least one out of pressing the intermediate formed component so as to narrow a projection
width of the step, or pressing the intermediate formed component so as to move a portion of
the curved wall on an opposite side of the step to a portion of the curved wall on the top plate
side of the step toward the opposite side to the side on which the vertical walls face each
other.
[0012] A pressed component manufacturing method of a second aspect according to the
present disclosure is the pressed component manufacturing method of the first aspect
according to the present disclosure, wherein, in the first process, taking a position of the top
plate as a reference, a portion of the curved wall at a distance of not less than 40% of a height
from the top plate position to a lower end of the curved wall is formed with a step having the
projection width of not more than 20% of a short direction width of the top plate.
[0013] A pressed component manufacturing method of a third aspect according to the
present disclosure is the pressed component manufacturing method of either the first aspect or
the second aspect according to the present disclosure, wherein, in cases in which at least the
projection width of the step is narrowed in the second process, in the second process an angle
of a pmtion of the curved wall further to the top plate side than the step is changed in order to
narrow the projection width of the step formed in the first process.
[00 14] A pressed component according to the present disclosure is configured including: an
elongated top plate; ridge lines at both short direction ends of the top plate; and ve1tical walls
facing each other in a state extending from the respective ridge lines and at least one of the
vertical walls configuring a curved wall curving as viewed from an upper side of the top plate.
In the pressed component according to the present disclosure, a pmtion of the curved wall at a
distance of not less than 40% of a height of the curved wall from a position of the top plate is
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formed with a step running along a length direction of the top plate, the step projecting out
with a projection width of not more than 20% of a short direction width of the top plate on an
opposite side to a facing side on which the vertical walls face each other. Moreover, a
Vickers hardness value of an end pmtion on the facing side of the step is greater than a
Vickers hardness value of an end portion on the opposite side of the step.
[00 15] A press apparatus of a first aspect according to the present disclosure includes a first
press device and a second press device. The first press device presses a blank to form an
intermediate formed component that is configured including an elongated top plate, ridge
lines at both short direction ends of the top plate, and vertical walls facing each other in a
state extending from the respective ridge lines and at least one of the vertical walls
configuring a curved wall curving as viewed from an upper side of the top plate, with a step
projecting out toward an opposite side to the side on which the vertical walls face each other
being formed to the curved wall so as to run along a length direction of the top plate. The
second press device presses the intermediate formed component so as to narrow a projection
width of the step.
[0016] A press apparatus of a second aspect according to the present disclosure includes a
first press device that presses a blank using a first die and a first punch so as to form an
intermediate formed component, and a second press device that presses the intermediate
formed component with a second die and a second punch. In the first press device, an
elongated first groove configured including an elongated first groove-bottom face and first
side faces connected to both short direction ends of the first groove-bottom face is formed in
the first die. Moreover, in the first press device, at least one of the first side faces configures
a first curved face that is curved as viewed along a mold closing direction, and that is formed
with a first step at a position at a specific depth at a distance of not less than 40% of a depth of
the first groove from the first groove-bottom face, the first step having a width of not more
than 20% of a short direction width of the first groove-bottom face and rurming along a length
direction of the first side face, and the shape of the first punch is a shape that fits together with
the shape of the first groove during mold closure. In the second press device, an elongated
second groove configured including an elongated second groove-bottom face and second side
faces connected to both short direction ends of the second groove-bottom face is formed in
the second die. Moreover, in the second press device, at least one of the second side faces
configures a second curved face that is curved as viewed along the mold closing direction,
and that is formed with a second step at a position at the specific depth from the second
groove-bottom face, the step running along a length direction of the second side face.
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Furthermore, the second step is narrower in width than the first step, and a separation distance
between the second groove-bottom face and the second step in the short direction of the
second groove-bottom face is longer than a separation distance between the first
groove-bottom face and the first step in the short direction of the first groove-bottom face.
The shape of the second punch is a shape that fits together with the shape of the second
groove during mold closure.
[00 17] A press apparatus of a third aspect according to the present disclosure is the press
apparatus of the second aspect according to the present disclosure, wherein, in a cross-section
of the second die projected onto a cross-section of the first die, at least part of a portion of the
second curved face at an opposite side of the second step to a portion on the second
groove-bottom face side is located further outside than a portion of the first curved face at an
opposite side of the first step to a portion on the second groove-bottom face side.
Advantageous Effects of Invention
[00 18] Employing the pressed component manufacturing method according to the present
disclosure enables a specific pressed component to be manufactured in which the occurrence
of bending is suppressed as viewed from the top plate side.
[00 19] The pressed component according to the present disclosure undergoes little bending
as viewed from the top plate side.
[0020] Employing the press apparatus according to the present disclosure enables a specific
pressed component to be manufactured in which the occurrence of bending is suppressed as
viewed from the top plate side.
BRIEF DESCRIPTION OF DRAWINGS
[0021] Fig. 1 A is a plan view illustrating a roof member (pressed component) of a first
exemplaty embodiment.
Fig. 1 B is aside view illustrating a roof member of the first exemplary embodiment.
Fig. 1 C is a cross-section along 1 C-1 C in Fig. lA.
Fig. lD is a cross-section along !D-ID in Fig. lA.
Fig. 2A is a perspective view of a mold of a first press device employed in a first
process of a roof member manufacturing method of the first exemplary embodiment.
Fig. 2B is a vertical cross-section of a first press device employed in the first process
of the roof member manufacturing method of the first exemplary embodiment.
Fig. 3A is a perspective view of a mold of a second press device employed in a
second process of the roof member manufacturing method of the first exemplary embodiment.
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Fig. 3B is a vertical cross-section of a second press device employed in the second
process of the roof member manufacturing method of the first exemplary embodiment.
Fig. 4A is a cross-section along 1 C-1 C in Fig. lA for an intermediate formed
component formed by the first process of the first exemplary embodiment.
Fig. 4B is a cross-section along lD-lD in Fig. lA for an intermediate formed
component formed by the first process of the first exemplary embodiment.
Fig. 4C is a cross-section along 1 C-1 C in Fig. 1 A for a roof member manufactured
by undergoing the second process of the first exemplary embodiment.
Fig. 4D is a cross-section along 1 D-1 D in Fig. lA for an intermediate formed
component formed by the second process of the first exemplary embodiment.
Fig. SA is a cross-section illustrating the cross-section along 1 C-1 C in Fig. lA for the
intermediate formed component formed by the first process of the first exemplary
embodiment in more detail.
Fig. 5B is a cross-section illustrating the cross-section along lD-lD in Fig. lA for the
intermediate formed component formed by the first process of the first exemplary
embodiment in more detail.
Fig. 5C is a cross-section illustrating the cross-section along 1 C-1 C in Fig. lA for the
roof member manufactured by undergoing the second process of the first exemplary
embodiment in more detail.
Fig. 5D is a cross-section illustrating the cross-section along 1 D-1 D in Fig. lA for
the roof member manufactured by undergoing the second process of the first exemplary
embodiment in more detail.
Fig. 6A is a cross-section of a length direction central portion of an intermediate
formed component formed by the first process of the first exemplary embodiment.
Fig. 6B is a cross-section of a portion corresponding to the cross-section along
lC-1 C in Fig. lA for the" intermediate formed component formed by the first process of the
first exemplary embodiment.
Fig. 6C is a cross-section of a length direction central pmiion of a roof member
manufactured by undergoing the second process of the first exemplary embodiment.
Fig. 6D is a cross-section along 1 C-1 C in Fig. lA for a roof member manufactured
by undergoing the second process of the first exemplary embodiment.
Fig. 7 A is a cross-section along 1 C-1 C in Fig. lA for an intermediate fmmed
component formed by the first process of the first exemplary embodiment, and is a
cross-section illustrating an angle formed between a vertical wall and a flange in detail.
6
Fig. 7B is a cross-section along lD-lD in Fig. lA for an intermediate formed
component formed by the first process of the first ex em platy embodiment, and is a
cross-section illustrating an angle fmmed between a vertical wall and a flange in detail.
Fig. 7C is a cross-section along lC-lC in Fig. lA for a roof member manufactured
by undergoing the second process of the first ex em platy embodiment, and is a cross-section
illustrating an angle formed between a vertical wall and a flange in detail.
Fig. 7D is a cross-section along lD-lD in Fig. 1 A for a roof member manufactured
by undergoing the second process of the first exemplary embodiment, and is a cross-section
illustrating an angle formed between a vertical wall and a flange in detail.
Fig. 8A is a plan view illustrating a roof member of a second exemplary embodiment.
Fig. 8B is a side view illustrating a roof member of the second exemplary
embodiment.
Fig. 8C is a cross-section along 8C-8C in Fig. 8A.
Fig. 8D is a cross-section along 8D-8D in Fig. SA.
Fig. 9 is a vertical cross-section of a first press device employed in a first process of a
roof member manufacturing method of the second exemplary embodiment.
Fig. 10 is a vertical cross-section of a second press device employed in a second
process of the roof member manufacturing method of the second exemplmy embodiment.
Fig. 11 is a diagram to explain the definition of a projection width of a step in the
first exemplary embodiment.
Fig. 12 is a schematic diagram illustrating a state in which part of a vertical
cross-section of a length direction central portion of an intermediate formed component 30 of
the first exemplmy embodiment is overlaid on part of a vertical cross-section of a length
direction central portion of a roof member 1.
Fig. 13 is a schematic diagram illustrating a state in which an intermediate formed
component has been set "in a mold in the second process ofthe first exemplary embodiment,
prior to mold closure.
Fig. 14 is a diagram to explain evaluation methods for twisting and bending in the
first exemplary embodiment.
Fig. 15 is a table illustrating evaluation results for simulations of bending of roof
members of Examples (Examples lA to SA) of the first exemplary embodiment and bending
of roof members of Comparative Examples (Comparative Examples lA to SA).
Fig. 16 is a table illustrating evaluation results for simulations of bending of roof
members of Examples (Examples lOA to 16A) of the second exemplary embodiment and
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bending of roof members of Comparative Examples (Comparative Examples 6A to lOA).
Fig. 17 is a graph illustrating evaluation results of Vickers hardness testing of a
vertical wall for Comparative Example lA.
Fig. 18 is a graph illustrating evaluation results of Vickers hardness testing of a
vertical wall for Example 4A.
Fig. 19 is a perspective view illustrating a roof member of a third exemplary
embodiment, and includes a lateral cross-section across a length direction.
Fig. 20 is a cross-section along line 2-2 in Fig. 19, and illustrates a roof member of
the third exemplary embodiment in cross-section.
Fig. 21 is a perspective view illustrating an intermediate formed component ofthe
third exemplary embodiment, and includes a lateral cross-section across a length direction.
Fig. 22 is a cross-section along line 4-4 in Fig. 21, and illustrates a lateral
cross-section of an intermediate formed component of the third exemplary embodiment in
lateral cross-section.
Fig. 23 is a schematic diagram in which part of the lateral cross-section of Fig. 22
(solid line) is overlaid with part of the cross-section of Fig. 20 (double-dotted dashed line).
Fig. 24 is a perspective view of a mold of a first press device employed in a first
process of the roof member manufacturing method of the third exemplary embodiment.
Fig. 25 is a lateral cross-section of a first press device employed in the first process
of the roof member manufacturing method of the third exemplary embodiment, and a blank.
Fig. 26 is a perspective view of a mold of a second press device employed in a
second process of the roof member manufacturing method of the third exemplary
embodiment.
Fig. 27 is a lateral cross-section of a second press device employed in the second
process of the roof member manufacturing method of the third exemplary embodiment, and
an intermediate formed component.
Fig. 28 is a diagram to explain an evaluation method for bending in the third
exemplary embodiment.
Fig. 29 is a perspective view illustrating a roof member of a foruih exemplary
embodiment, and includes a lateral cross-section across a length direction.
Fig. 30 is a cross-section taken along line 12-12 in Fig. 29, and illustrates a roof
member of the foruih exemplary embodiment in cross-section.
Fig. 31 is a diagram to explain an outside vertical wall change start point and an
inside vertical wall change start point in an Example and a Comparative Example of the third
8
exemplary embodiment.
Fig. 32 is a table illustrating evaluation results of a simulation for bending of roof
members of Examples 1B to 19B, these being Examples of the third exemplary embodiment,
and for bending of roof members of Comparative Examples 1 B to 6B, these being
Comparative Examples relating to the third exemplary embodiment.
Fig. 33 is a table illustrating evaluation results of a simulation for bending of roof
members of Examples 20B to 37B, these being Examples of the fourth exemplary
embodiment, and for bending of roof members of Comparative Examples 7B to 12B, these
being Comparative Examples relating to the fourth exemplary embodiment.
DESCRIPTION OF EMBODIMENTS
[0022] Summary
Explanation follows regarding four exemplary embodiments (a first to a fourth
exemplary embodiment) and Examples thereof as embodiments for implementing the present
disclosure. First, explanation follows regarding the first and second exemplary
embodiments and Examples of the first and second exemplary embodiments. This will be
followed by explanation regarding the third and fourth exemplary embodiments and
Examples of the third and fourth exemplary embodiments. Note that in the present
specification, exemplary embodiments refer to embodiments for implementing the present
disclosure.
[0023] First Exemplary Embodiment
Explanation follows regarding the first exemplary embodiment. First, explanation
follows regarding configuration of a roof member 1 of the present exemplary embodiment
illustrated in Fig. 1A, Fig. 1 B, Fig. 1 C, and Fig. 1 D. Next, explanation follows regarding
configuration of a press apparatus 17 of the present exemplary embodiment, illustrated in Fig.
2A, Fig. 2B, Fig. 3A, and Fig. 3B. This will be followed by explanation regarding a
manufacturing method of the roof member 1 of the present exemplary embodiment. This
will then be followed by explanation regarding advantageous effects of the present exemplary
embodiment.
[0024] Roof Member Configuration
First, explanation follows regarding configuration of the roof member 1 of the
present exemplary embodiment, with reference to the drawings. Note that the roof member
1 is an example of a pressed component and a specific pressed component.
[0025] As illustrated in Fig. 1 A, Fig. lB, Fig. I C, and Fig. 1 D, the roof member 1 is an
9
elongated member integrally confignred including a top plate 2, two convex ridge lines 3a, 3b,
two vertical walls 4a, 4b, two concave ridge lines 5a, 5b, and two flanges 6a, 6b, and having a
substantially hat-shaped cross-section profile. Note that the convex ridge lines 3a, 3b are an
example of ridge lines. The roof member 1. is, for example, configured by a component cold
pressed from a high tensile steel stock sheet having 131 0 MPa grade tensile strength.
Namely, the roof member 1 of the present exemplary embodiment is, for example, confignred
by a component cold pressed from a high tensile steel stock sheet having a tensile strength of
from 440 MPa to 1600 MPa.
[0026] As illustrated in Fig. 1A and Fig. 1, the top plate 2 is elongated. Moreover, as
illustrated in Fig. 1A, as viewed from the upper side of the top plate 2, the top plate 2 is
curved along its length direction. The two convex ridge lines 3a, 3b are formed at both short
direction ends of the top plate 2. The two vertical walls 4a, 4b face each other in a state
extending from the respective convex ridge lines 3a, 3b. Namely, the roof member 1 of the
present exemplary embodiment is confignred including the elongated top plate 2, the convex
ridge lines 3a, 3b at both short direction ends of the top plate 2, and the vertical walls 4a, 4b
facing each other in a state extending from the convex ridge lines 3a, 3b. Moreover, as
illustrated in Fig. 1 A, the two vertical walls 4a, 4b are curved along the length direction of the
top plate 2 as viewed from the upper side of the top plate 2. Namely, the two vertical walls
4a, 4b of the present exemplary embodiment face each other in a state extending from the
respective convex ridge lines 3a, 3b, and at least one out of the vertical walls 4a, 4b is
configured as a curved wall curving as viewed from the upper side of the top plate 2. Note
that the vertical walls 4a, 4b are an example of curved walls. Note that in the present
exemplary embodiment, as an example, the vertical wall 4a is curved in a concave shape
opening toward the opposite side to the vertical wall 4b side, namely the side facing the
vertical wall 4b side, and the vertical wall4b is curved in a convex shape bowing toward the
opposite side to the vertical wall 4a side, namely the side facing the vertical wall 4a side.
Note that in the present exemplary embodiment, the two vertical walls 4a, 4b, namely both the
vertical walls 4a, 4b, are curved as viewed from the upper side of the top plate 2.
[0027] In the present exemplary embodiment, for example, respective cross-sections
perpendicular to the length direction of the top plate 2 extend in a straight line shape along the
short direction at each length direction position. Namely, when the top plate 2 of the present
exemplary embodiment is viewed in respective cross-sections perpendicular to the length
direction, as illustrated in Fig. 1 C and Fig. lD, the top plate 2 is flat at each length direction
position. Moreover, as illustrated in Fig. 1 B, the roof member 1 is curved in a convex shape
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bowing toward the top plate 2 side along its length direction. Note that as illustrated in Fig.
lD, the convex ridge line 3a is a portion that connects the top plate 2 and the vertical wall4a
together, and is a curved portion when viewed in the respective cross-sections taken
perpendicularly to the length direction of the top plate 2. The two dashed lines in the
drawings respectively indicate the two ends of the convex ridge line 3a connected to the top
plate 2 and the vertical wall4a. Illustration of the two ends of the convex ridge line 3b using
dashed lines is omitted from the drawings; however, the convex ridge line 3b is a portion that
connects the top plate 2 and the vertical wall 4b together, and is a curved portion when viewed
in the respective cross-sections taken perpendicularly to the length direction of the top plate 2.
[0028] The two concave ridge lines Sa, Sb are respectively formed at end portions of the two
vertical walls 4a, 4b on the opposite side to the side connected to the top plate 2. The two
flanges 6a, 6b are connected to the two respective concave ridge lines Sa, Sb. Illustration of
the two ends of the concave ridge line Sa using dashed lines is omitted from the drawings;
however, the concave ridge line Sa is a portion that connects the vertical wall4a and the
flange 6a together, and is a curved portion when viewed in the respective cross-sections taken
perpendicularly to the length direction of the top plate 2. Illustration of the two ends of the
concave ridge line 5b using dashed lines is omitted from the drawings; however, the concave
ridge line 5b is a portion that connects the vertical wall 4b and the flange 6b together, and is a
curved portion when viewed in the respective cross-sections taken perpendicularly to the
length direction of the top plate 2.
[0029] As illustrated in Fig. !A, as viewed from the top plate 2 side in a state in which the
top plate 2 is disposed so as to be orientated at a position on the upper side, the roof member 1
is curved from a front end portion 1 a configuring one length direction end portion to a rear
end portion 1 b configuring another length direction end portion. From another perspective,
as illustrated in Fig. 1 A and Fig. IB, the roof member 1 may be described as being integrally
configured including a first portion 8 including the one end portion 1 a, a third portion 1 0
including the other end portion 1 b, and a second potiion 9 connecting the first portion 8 and
the third portion 1 0 together.
[0030] Note that in the present exemplary embodiment, in plan view, namely, as viewed
from the upper side of the top plate 2, the radius of curvature R of the first portion 8 is, for
example, set to from 2000 mm to 9000 mm, the radius of curvature R of the second portion 9
is, for example, set to fi·om SOO mm to 2000 mm, and the radius of curvature R of the third
portion 10 is, for example, set to from 2SOO mm to 9000 mm. Moreover, as illustrated in Fig.
lB, in the present exemplary embodiment, in side view, namely as viewed from a width
11
direction side of the top plate 2, the radius of curvature R of the first portion 8 is, for example,
set to from 3000 mm to 15000 mm, the radius of curvature R of the second portion 9 is, for
example, set to from 1000 mm at 15000 mm, and the radius of curvature R of the third portion
I 0 is, for example, set to from 3000 mm at 15000 mm. As described above, the radius of
curvature R of the first portion 8 and the radius of curvature R of the third portion 10 are
larger than the radius of curvature R of the second portion 9.
[0031] Note that as illustrated in Fig. lD, the height of a plate thickness center of an arc end
configuring an arc start point on the top plate 2 side of the convex ridge line 3a, namely from
the plate thickness center of the top plate 2, to a lower end of the vertical wall 4a configuring
a concave ridge line Sa side end of the vertical wall4a configures a height h. At not less
than 40% of the height h from the plate thickness center of the top plate 2, the vertical wall 4a
is formed along its length direction with a step lla having a step amount a2 (mm).
Moreover, as illustrated in Fig. lD, the height from a plate thickness center of an arc end
configuring an arc start point on the top plate 2 side of the convex ridge line 3b, namely from
the plate thickness center of the top plate 2, to a lower end of the vertical wall 4b configures a
height h'. The vertical wall 4b is also formed along its length direction with a step 11 a'
having a step amount a2' (mm) at a portion at a distance of not less than 40% of the height h'
from the plate thickness center of the top plate 2. In the present specification, the plate
thickness center of the top plate 2 is taken as the height direction position of the top plate 2.
Note that as illustrated in Fig. lD, the projection widths a2, a2' of the steps lla, lla' are set to
not more than 20% of a short direction width W of the top plate 2 at each position out of the
respective positions in the length direction of the top plate 2.
[0032] Out of the two ends of the step lla, the end on the side closer to the top plate 2,
namely an upper side location of the step 11 a, configures a recess 11 al, and the end on the
side frnther from the top plate 2, namely a lower side location of the step lla, configures a
protrusion 11 a2. Moreover, out of the two ends of the step 11 b, the end on the side closer to
the top plate 2, namely an upper side location of the step 11 a', configures a recess lla' 1, and
the end on the side frnther from the top plate 2, namely a lower side location of the step 11 a',
configures a protrusion 11 a'2. Moreover, in the present exemplary embodiment, as can be
seen in Fig. 18, described later, a Vickers hardness value of the protrusion 11 a2 is lower than a
Vickers hardness value of the recess 11 al by 10 HV or greater at each position along the
length direction of the vertical wall 4a. Moreover, as can be seen in Fig. 18, described later,
a Vickers hardness value of the protrusion 11 a'2 is lower than a Vickers hardness value of the
recess 11 a' 1 by I 0 HV or greater at each position along the length direction of the vertical
12
wall4b.
[0033] Note that the following generalized statements may also be made about the two ends
of each of the steps lla, 11a'. Namely, out of the two ends of the step lla, the recess llal
configuring the end on the side closer to the top plate 2 is configured as a location formed
with a radius of curvature that forms the largest protrusion toward an inner surface side of an
inner surface of the vertical wall4a. The protmsion lla2 configuring the end on the side
further from the top plate 2 is configured as a location formed with a radius of curvature that
forms the largest protmsion toward an outer surface side of the inner surface of the vertical
wall 4a. Moreover, out of the two ends of the step 11 a', the recess 11 a' 1 configuring the end
on the side closer to the top plate 2 is configured as a location formed with a radius of
curvature that forms the largest protrusion toward an inner surface side of an inner surface of
the vertical wall4b. Out of the two ends of the step lla', the protrusion 11a'2 configuring
the end on the side further from the top plate 2 is configured as a location formed with a
radius of curvature that forms the largest protmsion toward an outer surface side of the inner
surface of the vertical wall 4b. Accordingly, it may be said that the two ends of each of the
steps 11 a, 11 a' are defined even in cases in which, as viewed in cross-sections perpendicular
to the length direction of the vertical wa114a, there is no location with an incline of 45° at the
two ends of the steps, or at one end out of the two ends of the steps, namely even in cases
differing from that of the present exemplary embodiment.
[0034] Fig. 11 is a diagram to explain the projection width a2 of the steps 11a, 11a'. As
illustrated in Fig. 11, the projection width a2 of the step lla refers, for example, to a
separation width between a vertical line L2 passing through the protrusion 11 a2 and a vertical
line L3 passing through the recess 11al, with respect to a hypothetical line L1 joining together
the two ends of the top plate 2 when viewed in cross-section perpendicular to the length
direction of the roof member 1. Note that the hypothetical line L1 joining together the two
ends of the top plate 2 is a hypothetical line L1 joining together the convex ridge line 3a and
the convex ridge line 3b, as illustrated in Fig. 11.
[0035] As illustrated in Fig. lC and Fig. lD, in the roof member 1, the cross-section profile
of the flanges 6a, 6b differs between the front end portion la and the rear end portion lb.
Specifically, the angle between the vertical wall 4b and the flange 6b is set to 30° at the front
end portion 1 a, and is set to 40° at the rear end portion 1 b. Note that the respective angles
between the flanges 6a, 6b and the vertical wall 4a change progressively along the length
direction. Moreover, the short direction width of the top plate 2 changes so as to become
progressively wider, namely larger, from the front end portion la to the rear end portion lb
13
along the length direction. Note that as illustrated in Fig. I A to Fig. 1 D, an angle formed
between the vertical wall4b and the flange 6b at the first portion 8 is preferably the angle
formed between the vertical wall4b and the flange 6b at the third portion 10 or greater.
[0036] The foregoing was an explanation regarding configuration of the roof member 1 of
the present exemplary embodiment.
[0037] Press Apparatus Configuration
Next, explanation follows regarding the press apparatus 17 of the present exemplary
embodiment, with reference to the drawings. The press apparatus 17 of the present
exemplary embodiment is used to manufacture the roof member 1 of the present exemplary
embodiment. As illustrated in Fig. 2A, Fig. 2B, Fig. 3A, and Fig. 3B, the press apparatus 17
is configured including a first press device 18 and a second press device 19. The press
apparatus 17 of the present exemplary embodiment employs the first press device 18 to draw
a blank BL, illustrated in Fig. 2B, for example, so as to press the blank BL to form an
intermediate formed component 30, illustrated in Fig. 3B, for example, and then uses the
second press device 19 to press the intermediate formed component 30 to manufacture a
manufactured component, namely the roof member I. Note that the blank BL is configured
by elongated high tensile sheet steel as a base material for manufacturing the roof member L
[0038] Note that as illustrated in Fig. 3B, the intermediate formed component 30 is a
substantially hat-shaped member configured including the top plate 2, two ridge lines 32a,
32b, two vertical walls 33a, 33b, two concave ridge lines 34a, 34b, and two flanges 35a, 35b.
Moreover, in the present specification, "pressing" refers to a process spanning, for example,
setting a forming target such as the blank BL or the intermediate formed component 30 in a
mold such as a first mold 20 or a second mold 40, described later, closing the mold, and then
opening the mold. Namely, in the present specification, "pressing" refers to forming by
pressing (applying pressure to) a forming target.
[0039] First Press Device
The first press device 18 has a function of pressing the blank BL, this being the
forming target, to form the intermediate formed component 30.
[0040] The first press device 18 is configured including the first mold 20 and a first moving
device 25. As illustrated in Fig. 2B, the first mold 20 includes an upper mold 21, a lower
mold 22, a first holder 23, and a second holder 24. Note that the upper mold 21 is an
example of a first die. Moreover, the lower mold 22 is an example of a first punch. The
upper mold 21 is disposed at the upper side, and the lower mold 22 is disposed at the lower
side. When forming the blank BL into the intermediate formed component 30, the first press
14
device 18 sandwiches a portion of the blank BL that will form the top plate 2 between the
upper mold 21 and the lower mold 22, and indents the portion of the blank BL that will form
the top plate 2 from the upper mold 21 side toward the lower mold 22 side.
[0041] As illustrated in Fig. 2A, the upper mold 21 and the lower mold 22 are both
elongated. When the upper mold 21 and the lower mold 22 are viewed along the direction in
which the upper mold 21 and the lower mold 22 face each other, as illustrated in Fig. 2A and
Fig. 2B, the lower mold 22 projects out in a curve along its length direction, and the upper
mold 21 is formed with a groove that curves following the lower mold 22. As illustrated in
Fig. 2A and Fig. 2B, when the upper mold 21 and the lower mold 22 are viewed along a
direction orthogonal to the direction in which the upper mold 21 and the lower mold 22 face
each other, namely across the short direction of the upper mold 21 and the lower mold 22, the
lower mold 22 is curved in a convex shape bowing toward the upper mold 21 side, and the
upper mold 21 is formed with a groove that curves following the lower mold 22. Moreover,
as illustrated in Fig. 2B, as viewed along its length direction, the bottom of the groove in the
upper mold 21 projects toward the lower mold 22 side with a radius of curvature R (rnrn), and
a portion of the lower mold 22 facing the bottom of the groove in the upper mold 21 is
indented so as to open toward the upper mold 21 side with the radius of curvature R (rnrn).
Note that the radius of curvature R (rnrn) of the present exemplary embodiment is, for
example, set to 100 rnrn. Moreover, when viewed across the short direction of the upper
mold 21, the width ofthe groove in the upper mold 21 becomes progressively wider from the
groove bottom toward the open side of the groove, namely from the upper side toward the
lower side. When the lower mold 22 is viewed across the short direction of the lower mold
22, the width of a first projection, described later, configuring the projecting portion becomes
progressively narrower from the lower side toward the upper side.
[0042] Moreover, as illustrated in Fig. 2B, as viewed along the length direction of the lower
mold 22, the two side facesofthe lower mold 22 are respectively formed with steps 22a.
The two side faces of the groove in the upper mold 21 are formed with steps 21 a that
respectively follow the steps 22a.
[0043] The first holder 23 and the second holder 24 are elongated so as to follow the upper
mold 21 and the lower mold 22. As illustrated in Fig. 2B, the first holder 23 and the second
holder 24 are respectively disposed at the two short direction sides of the lower mold 22.
Moreover, the first holder 23 and the second holder 24 are biased toward the upper side by
springs 26, 27.
[0044] The first moving device 25 is configured to move the upper mold 21 toward the
15
lower mold 22. Namely, the first moving device is configured to move the upper mold 21
relative to the lower mold 22.
[0045] In a state in which the blank BL has been disposed at a predetermined position in a
gap between the upper mold 21 and the lower mold 22, the first moving device 25 moves the
upper mold 21 toward the lower mold 22, as illustrated in Fig. 2B, thereby pressing the blank
BL to form the intermediate formed component 30 in a state in which the two short direction
end sides of the blank BLare respectively sandwiched between the first holder 23 and the
upper mold 21, and the second holder 24 and the upper mold 21. Moreover, the blank BL is
pressed by the steps 22a and the steps 21 a accompanying formation of the intermediate
formed component 30, such that portions of the vertical walls 33a, 33b at a distance of not
less than 40% of the height of the vertical walls 33a, 33b from the position of the top plate 2
are formed with the steps 11 a, lla' having the projection width al (mm), as illustrated in Fig.
SA, Fig. 5B, Fig. 6A, and Fig. 6B. Note that as a result configuring the shape of the groove
in the upper mold 21 and the shape of the first projection configuring the projection of the
lower mold 22 as described above, the steps lla, lla' are inclined such that a spacing across
which the steps lla, 11 a' face each other is larger at the opening side than at the top plate 2
side as viewed across the short direction of the top plate 2. From another perspective, it may
be said that since the steps lla, lla' are inclined such that the spacing across which the steps
11 a, 11 a' face each other is larger at the opening side than at the top plate 2 side, the
intermediate formed component 30 formed with the steps lla, 11 a' is formed by pressing.
[0046] Explanation has been given above regarding the first press device 18. However,
from another perspective, the first press device 18 may be described in the following manner.
Namely, the upper mold 21 is formed with a fust groove, this being an elongated groove
configured including a first groove-bottom face configured as an elongated groove-bottom
face, and first side faces configured by side faces connected to the two short direction ends of
the first groove-bottom face. Moreover, each first side face is curved as viewed along a
mold closing direction, namely the direction in which the upper mold 21 and the lower mold
22 face each other, and a first curved face configured by a curved face in which the steps 11 a,
11 a' having a width of not more than 20% of the short direction width of the first
groove-bottom face are respectively formed along the length direction of the first side face at
a position at a specific depth that is at a distance of not less than 40% of the depth of the first
groove from the first groove-bottom face. Moreover, the lower mold 22 fits into the first
groove during mold closure. Note that the steps lla, lla' are an example of a first step.
[0047] Second Press Device
16
The second press device 19 has a function of pressing the intermediate formed
component 30, this being a forming target, so as to narrow the projection width of steps 36a,
36a' formed to the vertical walls 33a, 33b of the intetmediate formed component 30 with the
projection width al. Namely, the second press device 19 has a function of setting the
projection width of the steps 36a, 36a' to a projection width a2 that is narrower than the
projection width al.
[0048] The second press device 19 is configured including the second mold 40 and a second
moving device 45. As illustrated in Fig. 3B, the second mold 40 includes an upper mold 41,
a lower mold 43, and a holder 42. Note that the upper mold 41 is an example of a second die.
Moreover, the lower mold 42 is an example of a second punch. The upper mold 41 is
disposed at the upper side, and the lower mold 43 is disposed at the lower side. The lower
mold 43 is biased from the lower side by a spring 46. Moreover, in the second press device
19, in a state in which the intermediate f01med component 30 has been fitted onto the lower
mold 43, the upper mold 41 is moved toward the lower mold 43 side by the second moving
device so as to change the angles of the two flanges 35a, 35b of the intermediate formed
component 30.
[0049] As illustrated in Fig. 3B, when the lower mold 43 is viewed across its short direction,
steps 43a are respectively formed on the two side faces of the lower mold 43. The two side
faces of a groove in the upper mold 41 are respectively f01med with steps 41 a that follow the
steps 43a. The width of the steps 43a, namely the width in the short direction of the lower
mold 43, is narrower than the width of the steps 22a of the first press device 18. Moreover,
the width of the steps 4la, namely the width in the short direction of the lower mold 43, is
narrower than the width of the steps 2la of the first press device 18. Note that when the
upper mold 41 is viewed across the short direction of the upper mold 43, the groove width
becomes progressively wider from the groove bottom toward the open side of the groove,
namely from the uppei· side toward the lower side. When the lower mold 43 is viewed
across the short direction of the lower mold 43, the width of a second projection, described
later, configured by a projecting portion becomes progressively narrower from the lower side
toward the upper side.
[0050] Moreover, when the first moving device moves the upper mold 41 toward the lower
mold 43 in a state in which the blank BL has been disposed on the lower mold 43, the
intermediate formed component 30 is pressed so as to form the roof member 1. Note that
accompanying formation of the intermediate formed component 30, a portion of the vertical
wall 33a further toward the upper side than the step 36a, namely a portion on the top plate 2
17
side, is bent toward the opposite side to the side on which the vertical walls 33a, 33b face
each other, namely the opposite side to the facing side, namely, toward the outside.
Moreover, the projection width of the step 36a having the projection width al is set to the
projection width a2 that is narrower than the projection width al. Moreover, accompanying
formation of the intermediate formed component 30, a portion of the vertical wall33b further
toward the upper side than the step 36a', namely a portion on the top plate 2 side, is bent
toward the opposite side to the side on which the vertical walls 33a, 33b face each other,
namely the opposite side to the facing side, namely, toward the outside. Moreover, the
projection width of the step 36a' having the projection width al is set to the projection width
a2 that is narrower than the projection width a1. Note that as a result of configuring the
shape of the groove in the upper mold 41 and the shape ofthe second projection configuring
the projection of the lower mold 43 as described above, the steps 43a, 41a are inclined such
that a spacing across which the steps 4 3a, 41 a face each other is larger at the opening side
than at the top plate 2 side as viewed across the short direction of the top plate 2. From
another perspective, it may be said that since the steps lla, lla' are inclined such that the
spacing across which the steps 11 a, 11 a' face each other is larger at the opening side than at
the top plate 2 side, the roof member 1 formed with the steps 11a, lla' is formed by pressing.
[0051] Explanation has been given above regarding the second press device 19. However,
from another perspective, the second press device 19 may be described in the following
manner. Namely, the upper mold 41 is formed with a second groove, this being an elongated
groove configured including a second groove-bottom face configuring a groove-bottom face
having the same shape as the first groove-bottom face configuring the groove-bottom face of
the upper mold 21 of the first press device 18 as viewed along the mold closing direction, and
second side faces configured by side faces connected to the two short direction ends of the
second groove-bottom face. Moreover, each second side face is curved as viewed along the
mold closing direction, namely the direction in which the upper mold 41 and the lower mold
43 face each other, and configures a second curved face formed with second steps along the
length direction of the second side face at a position at the specific depth described above
from the second groove-bottom face. Moreover, the second steps are nanower in width
(here, "width" refers to the width in the short direction of the first groove-bottom face or the
second groove-bottom face) than the first steps of the upper mold 21 of the first press device
18, and the separation distance fi"om the second groove-bottom face in the short direction of
the second groove-bottom face is longer than the separation distance between the first
groove-bottom face and the first steps in the short direction of the first groove-bottom face.
18
Moreover, the lower mold 43 is adapted so as to fit together with the shape of the second
groove during mold closure. Namely, the shape of the lower mold 43 is configured as a
shape that fits together with the second groove during mold closure.
[0052] The foregoing was an explanation regarding the configuration of the press apparatus
17 of the present exemplary embodiment.
[0053] Roof Member Manufacturing Method
Next, explanation follows regarding a manufacturing method of the roof member 1
of the present exemplary embodiment, with reference to the drawings. The manufacturing
method of the roof member 1 of the present exemplary embodiment is performed employing
the press apparatus 17. Moreover, the manufacturing method of the roof member 1 of the
present exemplary embodiment includes a first process, this being a process performed using
the first press device 18, and a second process, this being a process performed using the
second press device 19.
[0054] First Process
In the first process, the blank BL is disposed at a predetermined position in the gap
between the upper mold 21 and the lower mold 22. Next, an operator operates the first press
device 18 such that the upper mold 21 is moved toward the lower mold 22 side by the first
moving device, and the blank BL is drawn so as to press the blank BL. Namely, in the first
process, the upper mold 21 and the lower mold 22 are employed to press the blank BL, this
being a forming target. The intermediate formed component 30 is formed from the blank BL
as a result.
[0055] Specifically, in the first process, as illustrated in Fig. SA, Fig. 5B, Fig. 6A, and Fig.
6B, the two vertical walls 33a, 33b of the intermediate fmmed component 30 are formed with
the steps 36a, 36a' having the projection width al defined by Equation (1) and Equation (2)
below, at a portion in a range ofless than 60% of the height h fi·om the respective flanges 35a,
35b. In other words, itithe first process, the steps lla, lla' having the projection width al
defined by Equation (1) and Equation (2) below, are formed at portions of the two vertical
walls 33a, 33b of the intermediate formed component 30 at a distance of not less than 40% of
the height of the vertical walls 33a, 33b from the position of the top plate 2. Namely,
according to Equation (1) below, the projection width al of the steps 36a, 36a' fmmed in the
first process is wider than the projection width a2 in the roof member 1 configuring a
manufactured component, and is a width that is not more than 20% of the width W of the roof
member 1 in the short direction of the top plate 2.
[0056] al ::: a2 ... (1)
19
a1 :<: 0.2W ... (2)
Note that the reference sign a1 is the projection width (nnn) of the steps 33a, 33b of
the intermediate formed component 30, the reference sign a2 is the projection width (nnn) of
the steps lla, 11a' of the roof member 1, and the reference sign W is the width (nnn) of the
roof member 1 in the short direction of the top plate 2.
[0057] Moreover, in the first process, as illustrated in Fig. 7 A and Fig. 7B, the vertical wall
33a and the flange 35a are formed such that an angle Dll formed between the vertical wall
33a and the flange 35a of the intermediate formed component 3 satisfies the following
Equation (3).
[0058] 1.0 X DI2 :<: Dil :<: 1.2 X DI2 ... (3)
The reference sign Dll is the angle formed between the vertical wall 33a and the
flange 35a of the intermediate formed component 30, and the reference sign DI2 is the angle
formed between the vertical wall 4a and the flange 6a of the roof member 1.
[0059] Moreover, in the first process, the vertical wall33b and the flange 35b of the
intermediate formed component 30 are formed so as to satisfY the following Equation (4).
[0060] 0.9 :<: DOFl/ DORl :<: 1 ... (4)
Note that DOFl is the angle formed between the flange 35b and the vertical wall33b
at the front end portion la of the intermediate formed component 30, and DORl is the angle
formed between flange 35b and the vertical wall33b at the rear end portion 1 b of the
intermediate formed component 30.
[0061] Moreover, in the first process, an edge of the material of the blank BL flows in and
the blank BL is flexed so as to form the flange 35b at the outside of the intermediate formed
component 30.
[0062] The intermediate formed component 30 is then removed from the first mold 20,
thereby completing the first process.
[0063] Note that wben the first mold 20 is opened, namely, when the first process is
completed, as illustrated in Fig. 4A and Fig. 4B, a cross-section of the intermediate formed
component 30 orthogonal to the length direction of the top plate 2 deforms into a flatter shape
than when the mold was closed, namely, in a state in which the radius of curvature has been
enlarged. In other words, in the first process, the blank BL is deformed so as to protrude
toward the upper side by the time that the mold closes, and then the portion of the blank BL
that will form the top plate 2 is deformed so as to protrude toward the lower side when the
mold is closed. The intermediate formed component 30 is then formed when the mold is
opened. Accordingly, the top plate 2 and the convex ridge lines 3a, 3b of the intetmediate
20
formed component 30 of the present exemplary embodiment are subjected to a load from the
upper side toward the lower side after being plastically deformed toward the upper side,
thereby attaining a state in which the Bauschinger effect acts.
[0064] Second Process
The inte1mediate formed component 30 is then fitted onto the lower mold 43 of the
second mold 40 of the second press device 19. Next, the operator operates the second press
device 19 such that the upper mold 41 is moved toward the lower mold 43 side by the second
moving device, thereby pressing the intermediate formed component 30. Namely, in the
second process, the blank BL that has been formed using the upper mold 21 and the lower
mold 22 in the first process is pressed. The roof member 1 is thereby formed from the
intermediate formed component 30 as a result.
[0065] Specifically, in the second process, the angles of the two flanges 3 Sa, 3 5b of the
intermediate formed component 30 are changed. Moreover, in the second process, as
illustrated in Fig. 6A, Fig. 6B, Fig. 6C, Fig. 6D, and Fig. 12, the angles of respective portions
of the vertical walls 33a, 33b of the intermediate formed component 30 further toward the
upper side than the steps 36a, 36a', namely of portions on the top plate 2 side of the vertical
walls 33a, 33b, are changed such that the projection width of the steps 36a, 36a' is set to the
projection width a2 that is narrower than the projection width a1. Note that in the present
exemplary embodiment, as illustrated in Fig. 12, in the vertical wall33a of the intermediate
formed component 30 formed in the first process, the portion further toward the upper side
than the step 36a is rotated about an axis of the convex ridge line 3a or the convex ridge line
32a toward the opposite direction to the direction in which the vertical walls 33a, 33b face
each other, namely toward the arrow A direction side illustrated in Fig. 12. As a result, in the
second process, the recess 11 a 1 is moved toward the arrow A direction side by the upper mold
41 without moving the protrusion 11 a2 of the step 11 a while the intermediate formed
component 30 is restrained by the lower mold 43. Although not illustrated in the drawings,
in the vertical wall33b of the intermediate formed component 30 formed in the first process,
a portion further toward the upper side than the step 3 6b is rotated toward the opposite side to
the arrow A direction about an axis of the convex ridge line 3b or the convex ridge line 32b.
As a result, in the second process, the recess 11 a 1 is moved toward the opposite side to the
arrow A direction without moving the protrusion 11 a2 of the step 11 a' of the intermediate
fom1ed component 30. In the above mam1er, in the second process, the projection widths of
the steps 11 a, 11 a' of the intermediate formed component 30 are respectively set to the
projection widths a2, a2', these being narrower than the projection widths a1, a1'.
21
Accompanying this process, in the second process, in the vertical wall 33a of the intermediate
formed component 30, a portion further toward the upper side than the recess llal, namely
than the step 36a, is moved in the opposite direction to the direction facing the vertical wall
33b. Moreover, in the second process, in the vertical wall33b of the intermediate formed
component 30, a portion further toward the upper side than the recess lla'l, namely than the
step 36a', is moved in the opposite direction to the direction facing the vertical wall 33a.
Note that Fig. 13 schematically illustrates a state in which the intermediate formed component
30 has been fitted onto the lower mold 43 prior to closing the second mold 40 in the second
process. Here, when the angle of inclination, namely the angle between the top plate 2 and
the portion of the vertical wall33a further toward the upper side than the step 36a is taken to
be 81, then an angle of inclination 82 of portions ofthe upper mold 41 and the lower mold 43
on either side of the portion of the vertical wall33a further toward the upper side than the step
36a is larger than the angle of inclination 81. Moreover, although not illustrated in the
drawings, the angle of inclination of portions of the upper mold 41 and the lower mold 4 3 on
either side of the portion of the vertical wall33b further toward the upper side than the step
36b is larger than the angle between the portion of the vertical wall 33b further toward the
upper side than the step 36b and the top plate 2. As a result, in the second process of the
present exemplary embodiment, the angles of the portions of the vertical walls 33a, 33b of the
intermediate formed component 30 further toward the upper side than the steps 36a, 36a' are
changed such that the projection width of the steps 36a, 36a' is set to the projection width a2,
this being narrower than the projection width al. Moreover, as illustrated in Fig. 7 A, Fig.
7B, Fig. 7C, and Fig. 7D, in the second process, the intermediate formed component 30 is
pressed such that the vertical wall 33a and the flange 35a of the intermediate formed
component 30 become the vertical wall 4a and the flange 6a of the roof member I.
Moreover, as illustrated in Fig. 7 A, Fig. 7B, Fig. 7C, and Fig. 7D, in the second process, the
intermediate formed component 30 is pressed such that the vertical wall 33b and the flange
35b of the intermediate formed component 30 become the vertical wall4b and the flange 6b
of the roof member 1.
[0066] The foregoing was an explanation regarding the manufacturing method of the roof
member 1 of the present exemplmy embodiment.
[0067] Advantageous Effects
Next, explanation follows regarding advantageous effects of the present exemplmy
embodiment, with reference to the drawings.
[0068] First Advantageous effect
22
Generally, when pressing a blank to manufacture a formed component, not illustrated
in the drawings, configured including a curved wall that curves in a concave shape opening
toward the side of another wall as viewed from an upper side, namely as viewed from a top
plate side, residual compressive stress is liable to occur in the curved wall that is formed.
The formed component is then liable to bend as viewed from the top plate side when the
residual compressive stress in the curved wall of the formed component is released. Note
that in the present specification, "residual stress", namely residual compressive stress and
residual tensile stress, refer to stress that remains in the material at the pressing bottom dead
center.
[0069) By contrast, in the present exemplary embodiment, as illustrated in Fig. 2B, Fig. 4A,
and Fig. 4B, in the first process, the step 36a having the projection width al is formed in the
vertical wall 33a that curves in a concave shape opening toward the vertical wall 33b side, and
then, as illustrated in Fig. 3B, Fig. 4C, and Fig. 4D, in the second process, the projection
width of the step 36a is changed from the projection width a1 to a2, this being narrower than
a!. Note that in the roof member 1 manufactured by performing the second process, the
vertical wall 33a and the step 33a respectively become the vertical wall4a and the step 11a.
[0070] Moreover, as illustrated in the table of Fig. 15, described later, as viewed from the
top plate 2 side, the roof member 1 of the present exemplary embodiment may be said to be
less prone to bending, and exhibit a smaller bend amount, than Comparative Examples 1A to
4A in the table of Fig. 15, these being configured by a comparative embodiment in which
steps are not formed. This is speculated to be due to the following mechanism. Namely, in
the present exemplary embodiment, in the first process, the vertical wall33a undergoes plastic
deformation as a result of forming the vertical wall 3 3a with the step 36a. Then, in the
second process, the projection width of the step 36a is narrowed. Accordingly, it is
speculated that since the step 11 a of the roof member 1 is formed as a result of being
subjected to a load in the opposite'direction to that of the first process, a state is attained in
which the Bauschinger effect acts on the step 11 a of the roof member 1.
[0071] Therefore, according to the present exemplary embodiment, the occurrence of
bending in the roof member 1 is suppressed in comparison to cases in which the curved wall
of a formed component configured including a curved wall curved in a concave shape
opening toward the side of another wall as viewed from the upper side of the top plate is not
formed with a step.
[0072] Moreover, in the present exemplary embodiment, as illustrated in Fig. 11, in the
second process, accompanying the nanowing of the projection width of the step 36a, the
23
portion of the vertical wall 33a further toward the top plate 2 side than the step 36a, namely
the upper side portion of the vertical wall33a, is moved in the opposite direction to the
direction facing the vertical wa1133b such that the vertical wall33a becomes the two vertical
wall4a. Moreover, in the second process, accompanying the narrowing of the projection
width of the step 36a, the portion of the vertical wall33b further toward the top plate 2 side
than the step 36a', namely the upper side portion of the vertical wall33b, is moved in the
opposite direction to the direction facing the vertical wall33a, such that the vertical wall 33b
becomes the vertical wall 4b. Accordingly, in the present exemplary embodiment, residual
tensile stress in a portion of the vertical wall 4a further toward the upper side than the step II a
can be reduced in comparison to cases in which a step is not formed to the curved wall of a
formed component configured including a curved wall curved in a concave shape opening
toward the side of another wall as viewed from the upper side ofthe top plate. Moreover,
according to the present exemplary embodiment, residual compressive stress in a portion of
the vertical wall4b further toward the upper side than the step lla' can be reduced in
comparison to cases in which a step is not formed to the curved wall of a formed component
configured including a curved wall curved in a concave shape opening toward the side of
another wall as viewed from the upper side of the top plate. From another perspective, for
example, in the case of an intermediate formed component in which the vertical walls are not
formed with steps, when the vertical walls are moved in the opposite direction to the direction
in which the vertical walls face each other in the second process, residual stress carrnot be
selectively reduced at specific portions of the vertical walls 4a, 4b (portions at the top plate
side, for example). However, it may be said that the present exemplary embodiment is
capable of reducing residual stress in the portions of the vertical walls 4a, 4b further toward
the upper side than the steps !Ia, lla', namely in specific portions of the vertical walls 4a, 4b.
In particular, the present exemplary embodiment may be said to be effective in the point that
residual stress can be selectively reduced in the upper side portions of the overall vertical
walls 4a, 4b in cases in which a large residual stress arises in the portions further toward the
upper side than the steps !Ia, lla'. Note that in the present exemplary embodiment, in the
second process, the projection width of the step 36a is narrowed by changing the angle of the
portion of the vertical wal133a further toward the top plate 2 side than the step 36a.
Accordingly, the present exemplary embodiment may be said to suppress the occurrence of
bending of the roof member 1 without changing the angle of the portion of the vertical wall
33a on the opposite side of the step 36a to the top plate 2 side, namely a lower end side
portion of the vertical wal133a.
24
[0073] Second Advantageous Effect
Moreover, generally, when pressing a blank to manufacture a formed component, not
illustrated in the drawings, configured including a curved wall that curves in a convex shape
bowing toward the side of another wall as viewed from au upper side, namely as viewed from
a top plate side, residual tensile stress is liable to occur in the curved wall that is formed.
The formed component is then liable to bend as viewed from the top plate side when the
residual tensile stress in the curved wall of the formed component is released.
[0074] By contrast, in the present exemplary embodiment, in the first process, as illustrated
in Fig. 2B, Fig. 4A, and Fig. 4B, the step 36a' having the projection width al is formed in the
vertical wall 33b that curves in a convex shape bowing toward the vertical wall 33a side, and
then, in the second process, as illustrated in Fig. 3B, Fig. 4C, and Fig. 4D, the projection
width of the step 36a' is changed from the projection width al to a2, this being narrower than
al. Note that in the roof member 1 manufactured by performing the second process, the
vertical wall33b and the step 33b respectively become the vertical wall4b and the step 11a'.
[0075] Moreover, as illustrated in the table of Fig. 15, described later, the roof member 1 of
the present exemplary embodiment may be said to be less prone to bending and have a
smaller bend amount than Comparative Examples lA to 4A in the table of Fig. 15, these being
configured by the comparative embodiment in which a step is not formed. This is speculated
to be due to the following mechanism. Namely, in the present exemplary embodiment, in
the first process, the vertical wall 33b undergoes plastic deformation as a result of forming the
vertical wall33b with the step 36a'. Then, in the second process, the angle of the portion of
the vertical wall 33b further toward the top plate 2 side than the step 36a' is changed so as to
narrow the projection width of the step 36a'. Accordingly, it is speculated that since the step
11 a' of the roof member 1 is formed as a result of being subjected to a load in the opposite
direction to that of the first process, a state is achieved in which the Bauschinger effect acts on
the step 11 a' of the roof member 1.
[0076] Accordingly, according to the present exemplary embodiment, the occurrence of
bending in the roof member 1 is suppressed in comparison to cases in which a step is not
formed in the curved wall of a formed component configured including a curved wall curved
in a convex shape bowing toward the side of another wall as viewed from the upper side of a
top plate.
[0077] Third Advantageous Effect
The first and second advantageous effects have been explained separately above for
the two vertical walls 4a, 4b configuring the curved walls. However, in the present
25
exemplary embodiment, the two vertical walls 4a, 4b are respectively formed with the steps
II a, II a' through the first process and the second process.
[0078] Accordingly, in the present exemplary embodiment, as illustrated in the table in Fig.
15, residual stress is easily reduced in the two vertical walls 4a, 4b, and deviatoric residual
stress is easily reduced in the two vertical walls 4a, 4b. The occurrence of bending in the
roof member I is suppressed as a result.
[0079] The foregoing was an explanation regarding the advantageous effect of the present
exemplary embodiment.
[0080] Second Exemplary Embodiment
Next, explanation follows regarding the second exemplary embodiment. First,
explanation follows regarding configuration of a roof member lA ofthe present exemplary
embodiment illustrated in Fig. 8A, Fig. 8B, Fig. 8C, and Fig. 8D. Explanation then follows
regarding configuration of a press apparatus 17 A of the present exemplary embodiment
illustrated in Fig. 9 and Fig. I 0. This will be followed by explanation regarding a
manufacturing method of the roof member of the present exemplary embodiment. This will
then be followed by explanation regarding advantageous effects of the present exemplary
embodiment. Note that the following explanation concerns portions of the present
exemplary embodiment differing from those of the frrst exemplary embodiment.
[0081] Roof Member Configuration
First, explanation follows regarding configuration of the roof member lA of the
present exemplary embodiment, with reference to the drawings. Note that the roof member
I A is an example of a pressed component and a specific pressed component.
[0082] As illustrated in Fig. 8A, Fig. 8B, Fig. 8C, and Fig. 8D, the roof member lA of the
present exemplary embodiment is not provided with the flanges 6a, 6b of the first exemplary
embodiment illustrated in Fig. lA, Fig. IB, Fig. IC, and Fig. !D. The roof member lA of
the present exemplary embodiment has the same configuration as the roof member l of the
first exemplary embodiment with the exception of this point.
[0083] Press Apparatus Configuration
Explanation follows regarding the press apparatus 17 A of the present exemplary
embodiment, with reference to the drawings. The press apparatus 17 A of the present
exemplary embodiment is used to manufacture the roof member lA of the present exemplary
embodiment.
[0084] A first press device 18A of the present exemplary embodiment, illustrated in Fig. 9,
is not provided with the holders 23, 24 illustrated in Fig. 2B. Note that the first press device
26
18A is an example of a press device. The press apparatus 17 A of the present exemplary
embodiment has the same configuration as the press apparatus 17 of the first exemplary
embodiment with the exception of this point. An intermediate formed component 3 OA has
the same configuration as the intermediate formed component 30 of the first exemplary
embodiment, with the exception of the point that the two flanges 35a, 35b are not provided.
Namely, the intermediate formed component 30A of the present exemplary embodiment is
configured as a gutter-shaped member.
[0085] Roof Member Manufacturing Method
Next, explanation follows regarding a manufacturing method of the roof member lA
of the present exemplary embodiment. The manufacturing method of the roof member lA
of the present exemplary embodiment is performed employing the press apparatus 17 A.
Moreover, in the manufacturing method of the roof member 1 A of the present exemplary
embodiment, a first process is the same as that of the first exemplary embodiment, with the
exception of the point that it is performed using the first press device 18A. Note that in the
present exemplary embodiment, in the first process, the blank BL is pressed by bending to
form the intermediate formed component 30A illustrated in Fig. 10.
[0086] Advantageous Effects
Advantageous effects of the present exemplary embodiment are similar to the
advantageous effects of the first exemplary embodiment.
[0087] Examples of the First and Second Exemplary Embodiments
Next, explanation follows regarding first and second simulations, and a third test, of
Examples of the first and second exemplary embodiments and of Comparative Examples,
with reference to the drawings. Note that in the following explanation, when the reference
signs used for components and the like are similar to the reference signs used for components
and the like in the first and second exemplary embodiments and the comparative embodiment
thereof, the reference signs for these components and the like are carried over as-is.
[0088] First Simulation
In the first simulation, bending was evaluated at the fi·ont end 1 a side and the rear
end lb side of roof members 1 of Examples lA to 8Aproduced using simulations based on
the roof member manufacturing method of the first exemplary embodiment, and for roof
members of Comparative Examples lA to SA produced using simulations based on the roof
member manufacture described below. Specifically, in the evaluation method of the present
simulation, a computer, not illustrated in the drawings, was used to compare data SD for the
roof members 1 of Examples lA to 8A and for the roof members of Comparative Examples
27
lA to SA against design data DD. Specifically, as illustrated in Fig. 14, the cross-sections
length direction central portions of the top plate 2 were aligned, namely, a best fit was found,
and bending was evaluated as the amount of offset in the width direction of center positions of
the front end face and a rear end face in measured data with respect to the center position of a
front end face and a rear end face in the design data DD.
[0089] Explanation Regarding Table of Fig. lS
The table of Fig. lSlists simulation parameters and evaluation results for Examples
lA to 8A and Comparative Examples lA to SA. Note that in the table of Fig. lS, "plate
thickness" is the thickness of the blank BL employed in the simulation. "Strength" is the
tensile strength of the blank BL employed in the simulation. The "curve-inside offset
amount" refers to a value obtained by subtracting the projection width a2 of the step lla
narrowed in the second process from the projection width al of the step 36a formed in the
first process. The "curve-outside offset amount" refers to a value obtained by subtracting the
projection width a2 of the step lla' after narrowing in the second process from the projection
width al of the step 36a' formed in the first process. The "evaluation of bending at
cross-section 1 (mm)" is the bending of a portion 10 mm toward the length direction central
side from the front end la. The "evaluation of bending at cross-section 2 (mm)" is the
bending of a portion 10 mm toward the length direction central side from the rear end 1 b.
The "average bend amount" is the average of the evaluation of bending at cross-section 1 and
the evaluation of bending at cross-section 2.
[0090] Roof Members of Comparative Examples lA to SA
In the roof members of Comparative Example lA to 4A, the vertical walls 4a, 4b
were not formed with steps. Specifically, the roof members of Comparative Examples lA to
4A were not formed with steps in either the first process or the second process. With the
exception of this point, the roof members of Comparative Examples lA to 4A were produced
by simulations assumingthe manufacturing method of the roof member 1 of the first
exemplary embodiment, namely assuming drawing. Moreover, in Comparative Example SA,
in the first process, the projection width al of the respective steps 36a, 36b was set to S mm,
and in the second process, the projection width a2 of the respective steps lla, lla' remained at
S mm. Namely, in Comparative Example SA, in the second process, the steps 36a, 36b were
left unchanged, with the same shape as that in which they were formed in the first process.
[0091] Roof Members of Examples lA to 8A
The roof members of Examples lA to 8A were produced by simulations assuming
the manufacturing method of the roof member 1 of the first exemplary embodiment, namely
28
assuming drawing. Note that in Examples lA to 8A, in the first process, the projection
width a! of the steps 36a, 36b was set to S mm.
[0092] Evaluation Results and Interpretation
From the table of Fig. IS, it is apparent that the roof members of Examples lA to 8A
underwent less bending or experienced smaller amounts of bending than the roof members of
Comparative Examples lA to SA. For example, Examples lA to 4A and Comparative
Example lA each have the same simulation parameters for plate thickness and strength.
When the simulation results for evaluation of bending at cross-section 1 are compared, it is
apparent that the roof members of Examples lA to 4A underwent less bending than the roof
member of Comparative Example lA. Moreover, when the simulation results for evaluation
of bending at cross-section 2 are compared, it is apparent that the roof members of Examples
lA to 4A underwent less bending than the roof member of Comparative Example I A. Note
that the evaluation of bending at cross-section 2 for Example 1A was -1.12 mm. The minus
sign is in reference to the fact that bending occurred in the opposite direction to that in Fig. 14,
this being a diagram to explain bending. Accordingly, when the absolute values of the
angles are compared, it can be said that the roof member of Example lA underwent less
bending than the roof member of Comparative Example 1A. It may therefore be considered
that Examples 1A to SA, these being Examples of the first exemplary embodiment, exhibit the
third advantageous effect to a greater extent than Comparative Examples lA to 4A in which
the vertical walls were not formed with steps.
[0093] Moreover in Examples lA and 2, in the second process, the projection width a! was
only narrowed in of one out of the steps 36a, 36b formed in the first process. However,
Examples lA and 2 still underwent less bending than Comparative Example lA. It may
therefore be considered that Examples I A and 2, these being Examples of the first exemplary
embodiment, underwent less bending, namely, exhibit the first and second advantageous
effects to a greater extent, than the Comparative Example (Comparative Example lA) in
which the vertical walls were not formed with steps.
[0094] Moreover, it is apparent that Example 7 A underwent less bending than Comparative
Example SA that has the same simulation parameters for plate thickness and strength. It may
therefore be considered that Example 7 A exhibits the first, second, and third advantageous
effects to a greater extent than Comparative Example SA.
[009S] Moreover, when comparing combinations having the same simulation parameters for
plate thickness and strength, such as Example lA and Comparative Example lA, Example SA
and Comparative Example 2A, and the like, it is apparent that Example lA and Example SA
29
/
have smaller average bend amounts than the respective Comparative Examples !A and 2A.
It may therefore be considered Examples !A to 8A exhibit the first, second, and third
advantageous effects to a greater extent than the Comparative Examples !A to SA, regardless
of differences in the tensile strength of the blank BL.
[0096] Second Simulation
In the second simulation, bending was evaluated at a front end side and a rear end
side for roof members 1 of Examples 9 A to !6A produced using simulations based on the roof
member manufacturing method of the second exemplary embodiment, and for roof members
of Comparative Examples 6A to I OA produced using simulations based on the roof member
manufacture described below.
[0097] Explanation Regarding Table of Fig. 16
The table of Fig. 16 lists simulation parameters and evaluation results for Examples
lOA to 16A and Comparative Examples 6A to lOA. Note that interpretation of the table of
Fig. 16 and the definition of bending are the same as those of the first simulation.
[0098] Roof Members of Comparative Examples 6A to I OA
In the roof members of Comparative Examples 6A to 1 OA, in the first process, the
projection width al of the respective steps 36a, 36b was set to 5 mm, and in the second
process, the projection width a2 of the respective steps lla, lla' was left unchanged at 5 mm.
Namely, in Comparative Examples 6A to I OA, in the second process, the shapes of the steps
36a, 36b were left unchanged from when they were formed in the first process. Note that
with the exception of the above point, Comparative Examples 6A to I OA are configured as
gutter-shaped members formed by bending similarly to the roof member I A of the second
exemplary embodiment.
[0099] Roof Members of Examples 9A to !6A
The roof members of Examples 9A to !6A were produced by simulations assuming
the bending of the manufacturing method of the roof member I of the first exemplary
embodiment. Note that in Examples 9A to 16A, in the first process, the projection width a1
of the respective steps 36a, 36b was set to 5 mm.
[0100] Evaluation Results and Interpretation
From the table of Fig. 16, it is apparent that the roof members of Examples 9A to 12
underwent less bending or experienced a smaller amount of bending than the roof member of
Comparative Example 6A that has the same simulation parameters for plate thickness and
strength. It may therefore be considered that Examples 9A to 12, these being Examples of
the first exemplary embodiment, exhibit the third advantageous effects to a greater extent than
30
Comparative Examples lA to 4A in which the vertical walls were not formed with steps.
[0101] Moreover, in Examples 9A and lOA, in the second process, the projection width al
was only narrowed in of one out of the steps 36a, 36b formed in the first process. However,
Examples 9 A and 1 OA still underwent less bending than Comparative Example 6A. It may
thereby be considered that Examples 9 A and 1 OA, these being Examples of the second
exemplary embodiment, underwent less bending, namely exhibited the first and second
advantageous effects to a greater extent, than in Comparative Example 6A in which the steps
formed in the vertical walls in the first process were not narrowed in the second process.
[01 02] It is also apparent that Example 7 A underwent less bending than Comparative
Example SA that has the same simulation parameters for plate thickness and strength. It may
therefore be considered that Example 7 A exhibits the first, second, and third advantageous
effects to a greater extent than Comparative Example SA.
[0 1 03] Moreover, when comparing combinations having the same simulation parameters for
plate thickness and strength, such as Example 9 A and Comparative Example 6A, Example
13A and Comparative Example 7A, and so on, it is apparent that Examples 9A and 13A
experienced smaller amounts of bending than the respective Comparative Examples 6A and
7 A. It may therefore be considered that Examples 9A to 16A exhibit the first, second, and
third advantageous effects to a greater extent than Comparative Examples 6A of the 1 OA,
regardless of differences in the tensile strength of the blank BL.
[0104] Third Test
In a third test, Vickers hardness values for the vertical wall 4a of the roof member of
Example 4A and Vickers hardness values for the vertical wall 4a of the roof member of
Comparative Example lA were measured and compared. Note that in the third test, the
Vickers hardness values were measured in accordance with the Vickers hardness measurement
method set out in Japanese Industrial Standard JIS Z 2244. However, the Vickers hardness
values are not limited to the Vickers hardness measurement method set out in Japanese
Industrial Standard JIS Z 2244, and measurements may be taken using another method and
converted using a hardness conversion table, not illustrated in the drawings, in order to find
the Vickers hardness values. Note that JIS Z 2244 cotTesponds to the International Standard
ISO 6S07-2: 2005.
[01 OS] According to the measurement results for Comparative Example lA illustrated in the
graph of Fig. 17 and the measurement results for Example 4A illustrated in the graph of Fig.
18, it is apparent that the Vickers hardness values of the protrusion lla2 are lower than the
Vickers hardness value for the recess llal in each case, namely, for both Comparative
31
Example lA and Example 4A. Note that in the measurement results for Comparative
Example lA, the difference between the Vickers hardness value for the recess llal and the
Vickers hardness value for the protrusion 11 a2 (the difference between the Vickers hardness
value for the recess 11 al and the Vickers hardness value for the protrusion 11 a2 is denoted the
"difference A" hereafter) was 7 HV. By contrast, in the measurement results for Example 4A,
the difference A was 10 HV: The difference A in Example 4A was thus greater than the
difference A in Comparative Example 1 A. In other words, the protrusion 11 a2 may be said
to be softer than the recess 11al to a greater extent in Example 4A than in Comparative
Example lA. The reason for this is speculated to be as follows. Namely, when the blank
BL is pressed in the first process, the step 36a is formed, and the protrusion lla2 is pulled
toward an outer surface side. Namely, tensile stress acts toward the outer side. Then, when
the projection width of the step 36a of the intermediate formed component 30 narrows in the
second process, the recess llal moves toward the protrusion lla2 side. This results in a
more compressed state at the inner surface side of the protrusion 11 a2 than in a state at a point
in time following the first process and prior to the second process. However, the recess 11 a!
is in a pulled state both following the first process and prior to the second process, and
following the second process. The protrusion 1la2 is accordingly softened to a greater
extent than the recess llal. From another perspective, it may be said that the recess llal is
harder than the protrusion lla2, namely the roof members 1, lA of the first exemplary
embodiment and the second exemplary embodiment have higher precision, namely bending is
better suppressed, than in Comparative Example 6A. Note that although the measurement
results are not illustrated, the difference A measured for Comparative Example 2A was, for
example, 8 HV. Moreover, the differences A measured for all of the Comparative Examples
other than Comparative Example lA and Comparative Example 2A were under 10 HV. By
contrast, for example, the differences A measured for Example SA and Comparative Example
7 A were respectively 30 HV and 20 HV. Moreover, the differences A measured for all of the
Examples other than Example SA and Example 7 A were all 10 HV or greater. Namely, it is
apparent that the difference A is I 0 HV or greater for the roof members 1, lA of the first
exemplary embodiment, the second exemplary embodiment, and each of the Examples.
[0 106] Note that in the above results, the roof members I, lA of any of the Examples are
results reflecting better dimensional precision than those for the roof members of any of the
Comparative Examples. For example, when the roof member I, I A of any one Example is
welded and joined to another member, not illustrated in the drawings, the roof member is not
conected during welding, or if the roof members were to be conected, the conection amount,
32
namely the defmmation amount, would be smaller than when the roof members of any one of
the Comparative Examples and the roof members of the respective Comparative Examples
were welded and joined. Accordingly, the Examples have the advantageous effect of having
higher dimensional precision than the Comparative Examples when joined to such other
members. Moreover, in the Examples, in comparison to the Comparative Examples, stress
does not remain, or is not liable to remain, in portions welded to such joined members, such
that the Examples exhibit the advantageous effect of exhibiting good strength with such
joined members.
[0107] The foregoing was an explanation regarding Examples of the first and second
exemplary embodiments.
[0108] Third Exemplmy Embodiment
Next, explanation follows regarding the third exemplary embodiment. First,
explanation follows regarding configuration of a roof member 1 B of the present exemplary
embodiment, illustrated in Fig. 19 and Fig. 20. Explanation then follows regarding
configuration of a press apparatus 17B of the present exemplary embodiment, illustrated in
Fig. 24, Fig. 25, Fig. 26, and Fig. 27. This will be followed by explanation regarding a
manufacturing method of the roof member lB of the present exemplmy embodiment. This
will then be followed by explanation regarding advantageous effects of the present exemplary
embodiment. Note that the roof member 1 B of the present exemplary embodiment
corresponds to Example 9B in Fig. 32, described later. In the following explanation of the
present exemplary embodiment, when the reference signs used for components and the like
are similar to the reference signs used for components and the like in the first and second
exemplary embodiments, the reference signs for these components and the like are carried
over as-is.
[0109] Roof Member Configuration
First, explanation follows regarding configuration of the roof member lB of the
present exemplary embodiment, with reference to the drawings. Note that the roof member
lB is an example of a pressed component and a specific pressed component.
[0 11 OJ As illustrated in Fig. 19 and Fig. 20, the roof member lB is an elongated member
integrally configured including a top plate 2, two convex ridge lines 3a, 3b, two vertical walls
4a, 4b, two concave ridge lines 5a, 5b, and two flanges 6a, 6b, and having a substantially
hat-shaped cross-section profile. Note that the convex ridge lines 3a, 3b are an example of
ridge lines. The roof member lB is, for example, configured by a component cold pressed
from a high tensile steel stock sheet having 14 70 MPa grade tensile strength.
33
[0111] Note that the configuration of the roof member lB of the present exemplary
embodiment illustrated in Fig. 19 and Fig. 20 is the same as the configuration of the roof
member 1 of the first exemplary embodiment illustrated in Fig. lA, Fig. 1 B, Fig. 1 C, and Fig.
lD.
[0112] The foregoing was an explanation regarding configuration of the roof member lB of
the present exemplary embodiment.
[0113] Press Apparatus Configuration
Next, explanation follows regarding the press apparatus 17B of the present
exemplary embodiment, with reference to the drawings. The press apparatus 17B of the
present exemplary embodiment is used to manufacture the roof member 1 B of the present
exemplary embodiment. As illustrated in Fig. 24, Fig. 25, Fig. 26, and Fig. 27, the press
apparatus 17B is configured including a first press device 18 and a second press device 19B.
The press apparatus 17B of the present exemplary embodiment employs the first press device
18 to draw the blank BL illustrated in Fig. 25 so as to press the blank BL to form the
intermediate formed component 30 illustrated in Fig. 21 and Fig. 22, and then uses the second
press device 19B to press the intermediate formed component 30 to manufacture a
manufactured component, namely the roof member 1 B. Note that the blank BL is
configured by an elongated high tensile sheet steel as a base material for manufacturing the
roof member lB.
[0114] First Press Device
The first press device 18 has a function of pressing the blank BL, this being the
forming target, to form the intermediate formed component 30.
[0115] As illustrated in Fig. 25, the first press device 18 is configured including a first mold
20 and a first moving device 25. As illustrated in Fig. 24 and Fig. 25, the first mold 20
includes an upper mold 21, a lower mold 22, a first holder 23, and a second holder 24. Note
that the upper mold 21 is an example of a first die. Moreover, the lower mold 22 is an
example of a first punch. The upper mold 21 is disposed at an upper side, and the lower
mold 22 is disposed at a lower side.
[0116] As illustrated in Fig. 24, the upper mold 21 and the lower mold 22 are both elongated.
When the upper mold 21 and the lower mold 22 are viewed along the direction in which the
upper mold 21 and the lower mold 22 face each other, the lower mold 22 projects out in a
curve along its length direction, and the upper mold 21 is formed with a groove that curves
following the lower mold 22. Moreover, when the upper mold 21 is viewed across the short
direction of the upper mold 21, the groove width becomes progressively wider from the
34
groove bottom toward the open side of the groove, namely from the upper side toward the
lower side. When the lower mold 22 is viewed across the short direction of the lower mold
22, the width of the projecting portion becomes progressively narrower from the lower side
toward the upper side. Moreover, the shape of the lower mold 22 is configured as a shape
that fits together with the shape of the groove in the upper mold 21 during mold closure.
[0117] Moreover, as illustrated in Fig. 25, as viewed along the length direction of the lower
mold 22, the two side faces of the lower mold 22 are respectively formed with steps 22a.
The two side faces of the groove in the upper mold 21 are formed with steps 2la, 2la' that
respectively follow the steps 22a. Moreover, an angle of inclination of a portion further
toward the lower side than the step 21 a in the side face formed with the step 21 a with respect
to the up-down direction, namely with respect to the direction in which the upper mold 21 and
the lower mold 22 face each other, is taken to be e 1.
[0118] The first holder 23 and the second holder 24 are elongated so as to follow the upper
mold 21 and the lower mold 22. As illustrated in Fig. 24 and Fig. 25, the first holder 23 and
the second holder 24 are disposed at both short direction sides of the lower mold 22.
Moreover, as illustrated in Fig. 25, the first holder 23 and the second holder 24 are
respectively biased toward the upper side by springs 26, 27.
[0 119] The first moving device 25 is configured to move the upper mold 21 toward the
lower mold 22. Namely, the first moving device moves the upper mold 21 relative to the
lower mold 22.
[0120] In a state in which the blank BL has been disposed at a predetermined position in a
gap between the upper mold 21 and the lower mold 22, the first moving device moves the
upper mold 21 toward the lower mold 22, as illustrated in Fig. 25, thereby pressing the blank
BL to form the intermediate formed component 30 in a state in which the two end sides in the
short direction of the blank BLare respectively sandwiched between the first holder 23 and
the upper mold 21, and the second holder 24 and the upper mold 21. Moreover, as illustrated
in Fig. 22, the blank BL is pressed by the step 22a and the step 2la accompanying formation
of the intermediate formed component 30, such that a portion ofthe vertical wall33a at a
distance of not less than 40% of the height of the vertical wall33a from the position ofthe top
plate 2 is formed with the step lla having the projection width al (mm). Moreover, as
illustrated in Fig. 22, the blank BL is pressed by the step 22a' and the step 21 a' accompanying
formation of the intermediate formed component 30, such that a portion of the vertical wall
33b at a distance of not less than 40% of the height of the vertical wall33b from the position
of the top plate 2 is fo1med with the step 11 a' having the projection width a 1 (mm). Note
35
that as a result of configuring the shape of the groove in the upper mold 21 and the shape of
the projection portion of the lower mold 22 as described above, the steps 2la, 2la' are
inclined such that a spacing across which the steps 21 a, 21 a' face each other is wider at the
opening side than at the top plate 2 side, namely, such that the gap facing width widens as
viewed along the length direction of the top plate 2. From another perspective, the steps 2la,
2la' are inclined such that the spacing across which the steps 21a, 21a' face each other is
larger at the opening side than at the top plate 2 side.
[0 121] Explanation has been given above regarding the first press device 18. However,
from another perspective, the first press device 18 may be described in the following manner.
Namely, the upper mold 21 is formed with a first groove, this being an elongated groove
configured including a first groove-bottom face configuring an elongated groove-bottom face,
and first side faces configured by side faces facing each other in a state in which one end of
each is connected at one end to one of the two short direction ends of the groove-bottom face.
Moreover, each first side face is curved as viewed along the mold closing direction, namely
the direction in which the upper mold 21 and the lower mold 22 face each other, and the
respective first side faces are configured by first curved faces in which the steps lla, lla'
having a width of not more than 20% of the short direction width of the first groove-bottom
face are respectively formed along the length direction of the first side faces, at portions at a
specific depth of not less than 40% of the depth of the first groove from the first
groove-bottom face. Moreover, the lower mold 22 fits together with the first groove during
mold closure. Namely, an angle of inclination of a portion of the lower mold 22 further
toward the lower side than the step 22a with respect to the up-down direction, namely the
direction in which the upper mold 21 and the lower mold 22 face each other, is taken as e 1.
Note that the steps lla, lla' are an example of a first step.
[0122] Second Press Device
As illustrated in Fig. 21, Fig. 22, and Fig. 23, the second press device 19B has a
function of pressing the intermediate fmmed component 30, this being a forming target, so as
to move a portion 33al of the intermediate formed component 30 further to the other end side
than the step lla formed to the vertical wall33a, namely on the concave ridge line 34a side,
toward the opposite side to the side on which the vertical walls 33a, 33b face each other,
namely the opposite side to the facing side, and namely the arrow A direction side in the
drawings.
[0123] As illustrated in Fig. 27, the second press device 19B is configured including a
second mold 40B and a second moving device 45. As illustrated in Fig. 26 and Fig. 27, the
36
second mold 40B includes an upper mold 41, a lower mold 43B, and a holder 42. The upper
mold 41 is disposed on the upper side, and the lower mold 43B is disposed on the lower side.
The lower mold 43B is biased from the lower side by a spring 46. Moreover, in the second
press device 19B, in a state in which the intermediate formed component 30 has been fitted
onto the lower mold 43B, the upper mold 41 is moved toward the lower mold 43B side by the
second moving device 45 so as to change the angles of the two flanges 35a, 35b of the
intermediate formed component 30.
[0124] Moreover, as illustrated in Fig. 27, as viewed along the length direction of the lower
mold 43B, both side faces of the lower mold 43B are formed with respective steps 43a.
Moreover, curved faces configuring the two side faces ofthe groove in the upper mold 41 are
respectively formed with steps 4la following the steps 43a. Note that the steps 4la are an
example of a second step. The shapes of the steps 43a are the same as the shapes of the
steps 22a of the first press device 18. The steps 43a are formed at positions corresponding to
the steps 22a, namely at positions overlapping the steps lla, lla' of the intermediate formed
component 30. Moreover, the shapes of the steps 4la are the same as the shapes of the steps
2la of the first press device 18. The steps 4la are formed at positions corresponding to the
step 22a', namely at positions overlapping the steps lla, lla' of the intermediate formed
component 30. Note that as illustrated in Fig. 27, when the upper mold 41 is viewed along
the length direction of the upper mold 41, the groove width becomes progressively wider
from the groove bottom toward the open side of the groove, namely from the upper side
toward the lower side. When the lower mold 43B is viewed along the length direction of the
lower mold 43B, the width of the projecting portion becomes progressively narrower from the
lower side toward the upper side. Moreover, the shape of the lower mold 43B is a shape that
fits together with the shape of the groove in the upper mold 41 during mold closure.
[0125] In a state in which the intermediate formed component 30 has been fitted onto the
lower mold 43B, when the second moving device 45 moves the upper mold 41 toward the
lower mold 43B, the intermediate formed component 30 is pressed so as to form the roof
member lB. Accompanying formation of the intermediate formed component 30, the
portion 33al of the vertical wall33a further toward the other end side than the step 36a is
moved toward the opposite side to (outer side of) the side on which the vertical walls 33a, 33b
face each other (facing side). Accordingly, the angle of inclination 92 of a pmiion of the
lower mold 43B further toward the lower side than the step 43a with respect to the up-down
direction, namely with respect to the direction in which the upper mold 21 and the lower mold
22 face each other, is greater than the angle of inclination 91. Note that since the shape of
37
the groove in the upper mold 41 and the shape of the projection portion of the lower mold
43B are configured as described above, the steps 43a, 4la are inclined such that as viewed
across the short direction of the top plate 2, spacings across which the respective steps 43a,
4la face each other are larger, namely such that a facing width becomes wider, at the opening
side than at the top plate 2 side. From another perspective, the steps 41 a, 41 a' are inclined
such that the spacing across which the steps 4la, 41a' face each other is larger at the opening
side than at the top plate 2 side.
[0126] Explanation has been given above regarding the second press device 19B. However,
from another perspective, the second press device 19B can be described in the following
manner. Namely, the upper mold 41 is formed with an example of a second groove, this
being an elongated groove configured including a second groove-bottom face configuring a
groove-bottom face having the same shape as the first groove-bottom configuring the
groove-bottom face of the upper mold 21 of the first press device 18 as viewed along the
mold closing direction, and second side faces configured by side faces each having one end
connected to one of the two short direction ends of the second groove-bottom face and facing
each other. Moreover, a second curved face configuring at least one of the second side faces
is a second curved face that curves as viewed along the mold closing direction, namely, the
direction in which the upper mold 41 and the lower mold 43B face each other, and that is
formed with a second step at a position corresponding to the first step. Moreover, the angle
92 by which a portion of the second curved face further toward the other end side than the
second step is inclined with respect to the mold closing direction is larger than the angle e 1 by
which the portion of the first curved face further toward the other end side than the first step is
inclined with respect to the mold closing direction. Moreover, the lower mold 43B is
configured so as to fit together with the shape of the second groove during mold closure.
Namely, the shape of the lower mold 43B is a shape that fits together with the second groove
during mold closure.
[0127] The foregoing was an explanation regarding configuration of the press apparatus 17B
of the present exemplary embodiment.
[0128] Roof Member Manufacturing Method
Next, explanation follows regarding a manufacturing method of the roof member lB
of the present exemplary embodiment, with reference to the drawings. The manufacturing
method of the roof member lB of the present exemplary embodiment is performed employing
the press apparatus 17B. Moreover, the manufacturing method of the roof member lB of the
present exemplary embodiment includes a first process, this being a process performed using
38
the first press device 18, and a second process, this being a process performed using the
second press device 19B.
[0 129] First Process
In the first process, the blank BL is disposed in the gap between the upper mold 21
and the lower mold 22. Next, an operator operates the first press device 18 such that the
upper mold 21 is moved toward the lower mold 22 side by the first moving device, and the
blank BL is drawn so as to press the blank BL. Namely, in the first process, the upper mold
21 and the lower mold 22 are employed to press the blank BL, this being a forming target.
The intermediate formed component 30 is formed from the blank BL as a result. The
intermediate formed component 30 is then removed from the first mold 20, thereby
completing the first process.
[0130] Second Process
The intermediate formed component 30 is then fitted onto the lower mold 43B of the
second mold 40B of the second press device 19B. Next, the operator operates the second
press device 19B such that the upper mold 41 is moved toward the lower mold 43B side by
the second moving device, thereby pressing the intermediate formed component 30. Namely,
in the second process, the blank BL that was formed using the upper mold 21 and the lower
mold 22 in the first process is pressed. The roof member lB is thereby formed from the
intermediate formed component 30 as a result. Namely, in the second process, the
intermediate formed component 30 is pressed, and of the vertical walls 4a, 4b configuring the
curved walls, portions on the opposite side of the steps 11 b, 11 b' to the side connected to the
convex ridge lines 3a, 3b are moved toward the opposite side to the facing side on which the
vertical walls 4a, 4b face each other. The roof member 1 B is then removed from the second
mold 40B, thereby completing the second process. With this, the manufacturing method of
the roof member 1 B of the present exemplary embodiment is completed.
[0131] The foregoing was an explanation concerns the manufacturing method of the roof
member lB of the present exemplary embodiment.
[0132] Advantageous Effects
Next, explanation follows regarding advantageous effects of the present exemplmy
embodiment, described later, drawing comparison to a non-illustrated comparative
embodiment, described later, of the present exemplary embodiment. In the following
explanation of the comparative embodiment, when the components and the like employed are
the same as the components and the like employed in the present exemplary embodiment, the
reference signs for these components and the like are carried over as-is, even though they are
39
not illustrated in the drawings. Note that a roof member of the comparative embodiment
corresponds to Comparative Example 5B in the table of Fig. 27, described later.
[0133] In the comparative embodiment, the blank BL is pressed by the second press device
19B to form the roof member. The comparative embodiment is the same as the present
exemplary embodiment with the exception of this point.
[0134] According to the evaluation results for Comparative Example 5B, as illustrated in the
table in Fig. 32, leading end portion bending was 4.38 mm, rear end portion bending was 5.85
mm, and the average bend amount was 5.12 mm.
[0 135] Note that in the evaluation of leading end portion bending and rear end portion
bending, data SD for roof members produced using simulations based on the roof member
manufacturing method of the comparative embodiment, and data SD for roof members lB
produced using simulations based on the roof member manufacturing method of the present
exemplary embodiment, was compared against design data DD. Specifically, using a
computer, not illustrated in the drawings, cross-sections of length direction central portions of
the top plate 2 were aligned, namely, a best fit was found. As illustrated in Fig. 28, bending
was taken to be the amount of offset in the width direction of center positions of a leading end
portion and a rear end portion in the measured data SD from center positions of the leading
end portion and rear end portion in the design data DD. The average value of the leading
end portion bending value and the rear end portion bending value was taken as the average
bend amount.
[0136] By contrast, according to the evaluation of Example 9B of the present exemplary
embodiment, as illustrated in the table of Fig. 32, for a roof member 1 B produced using a
simulation based on the manufacture of a roof member of the present exemplary embodiment,
leading end portion bending was 5.02 mm, rear end portion bending was 4.34 mm, and the
average bend amount was 4.68 mm. Namely, it may be said that Example 9B suppresses the
occurrence of short directioifbending of the top plate 2 caused by spring-back better than
Comparative Example 5B.
[0137] The reason that the occurrence of bending as viewed from the top plate 2 side is
better suppressed in the present exemplary embodiment than in the comparative embodiment
is speculated to be as follows. Namely, in the comparative embodiment, as described above,
the blank BL is pressed by the second press device 19B to form the roof member. As viewed
from the top plate 2 side, the vertical wall 4a of the roof member is configured by a curved
face curving in a convex shape bowing toward the opposite side to the side facing the vertical
wall4b. Moreover, the vertical wall 4b is inclined with respect to the up-down direction,
40
namely the plate thickness direction of the top plate 2. Accordingly, in the comparative
embodiment, when the roof member is pressed and removed from the second mold 40B,
compressive stress in the length direction of the top plate 2 acts at the outer surface of the
vertical wa114a. In particular, as illustrated in Fig. 19 and Fig. 20, a portion 4a1 of the
vertical wall4a located further to the concave ridge line Sa side than the step lla is further
from the convex ridge line 3a than a portion 4a2 of the vertical wall4a located further to the
convex ridge line 3a side than the step lla. Accordingly, compressive stress acting in the
length direction of the top plate 2 is greater at the outer surface of the portion 4a1 than at the
outer surface of the portion 4a2. It is speculated that the occurrence of bending of the roof
member ofthe comparative embodiment as viewed from the top plate 2 side is as a result of
the above. By contrast, as illustrated in Fig. 23, in the present exemplary embodiment, in the
second process, further toward the other end side than the step 11 a formed in the vertical wall
33a of the intermediate formed component 30, namely the portion 33al on the concave ridge
line 34a side, is moved toward the opposite side to the side on which the vertical walls 33a,
33b face each other, namely the opposite side to the facing side, namely the arrow A direction
side in the drawings, and becomes the portion 4a1. Accordingly, the present exemplary
embodiment attains a state in which compressive stress acting in the length direction of the
portion 4al is reduced in comparison to in the comparative embodiment. As a result, in the
present exemplary embodiment, the desired shape is easier to achieve than in the comparative
embodiment following bending caused by compressive stress acting at the outer surface of the
portion 4al. In other words, compared to the comparative embodiment, the present
exemplary embodiment facilitates formation within permissible bending values following
bending caused by compressive stress acting at the outer surface of the portion 4al.
[0138] Accordingly, according to the present exemplary embodiment, in the second process,
the occurrence of short direction bending of the top plate 2 as a result of spring-back is better
suppressed than in cases in which the vertical wall33a of the intermediate formed component
30 is not moved toward the opposite side to the side on which the vertical walls 33a, 33b face
each other. Moreover, in the present exemplary embodiment, as illustrated in Fig. 31,
residual tensile stress in a portion of the vertical wall 4a further toward the lower side than the
step 1la and residual compressive stress in a portion of the ve1iical wall4b further to the
lower side than the step 11 a' can be reduced in comparison to in cases in which the vertical
wall 33a of the intermediate formed component 30 is not moved toward the opposite side to
the side on which the vertical walls 33a, 33b face each other. From another perspective, in
cases in which the vertical wall33a of the intermediate formed component 30 is not moved
41
toward the opposite side to the side on which the vertical walls 33a, 33b face each other, for
example, it is not possible to selectively reduce residual stress in a specific portion ofthe
vertical wall (for example, a portion at the lower side of the vertical wall). However, the
present exemplary embodiment may be said to enable a reduction in residual compressive
stress at the portions of the vertical walls 4a, 4b further to the lower side than the steps 11 a,
lla', namely at specific portions of the vertical walls 4a, 4b. In particular, the present
exemplary embodiment may be said to be effective in the point of enabling a selective
reduction in residual stress in this lower side portion across the entirety of the vertical walls
4a, 4b in cases in which a large residual stress occurs at portions further to the lower side than
the steps 11 a, 11 a'. Moreover, in the present exemplary embodiment, in the second process,
out of the vertical wall4a, the portion 33al located further away from the convex ridge line
3a is moved toward the opposite side to the side on which the vertical walls 33a, 33b face
each other, such that the advantageous effect of suppressing short direction bending of the top
plate 2 as a result of spring-back becomes even more apparent.
[0139] The foregoing was an explanation regarding the advantageous effects of the present
exemplary embodiment.
[0140] Fourth Exemplary Embodiment
Next, explanation follows regarding the fourth exemplary embodiment. First,
explanation follows regarding configuration of a roof member 1 C of the present exemplary
embodiment illustrated in Fig. 29 and Fig. 30. Explanation then follows regarding
configuration of a press apparatus, not illustrated in the drawings, of the present exemplary
embodiment. This will be followed by explanation regarding a manufacturing method of the
roof member of the present exemplary embodiment. This will then be followed by
explanation regarding advantageous effects of the present exemplary embodiment. Note that
the following explanation concerns portions ofthe present exemplary embodiment differing
from those of the third exemplary embodiment. In the following explanation, when the
reference signs used for components and the like in the present exemplary embodiment are
similar to the reference signs used for components and the like in the first to the third
exemplary embodiments, the reference signs for these components and the like are carried
over as-Js.
[0141] Roof Member Configuration
First, explanation follows regarding configuration of the roof member 1 C of the
present exemplary embodiment, with reference to the drawings. Note that the roof member
1 C is an example of a pressed component and a specific pressed component.
42
[0142] As illustrated in Fig. 29 and Fig. 30, the roof member lC of the present exemplary
embodiment does not include the flanges 6a, 6b of the third exemplary embodiment,
illustrated in Fig. 19 and Fig. 20. With the exception of this point, the roof member lC of
the present exemplary embodiment has the same configuration as the roof member lB of the
third exemplary embodiment.
[0 14 3] Press Apparatus Configuration
Next, explanation follows regarding the press apparatus of the present exemplary
embodiment. The press apparatus, not illustrated in the drawings, of the present exemplary
embodiment, is used to manufacture the roof member 1 C.
[0144] A first press device, not illustrated in the drawings, of the present exemplary
embodiment differs from the first press device 18 of the third exemplary embodiment
illustrated in Fig. 24 and Fig. 25 in that it does not include the holders 23, 24. With the
exception of this point, the first press device of the present exemplary embodiment has the
same configuration as the press apparatus 17B of the third exemplary embodiment.
Moreover, an intermediate formed component formed by the first press device has the same
configuration as the intermediate formed component 30A of the second exemplary
embodiment. Namely, the intermediate formed component of the present exemplary
embodiment is configured by a member having a gutter-shaped lateral cross-section profile as
viewed along the length direction of the top plate 2.
[0145] Roof Member Manufacturing Method
Next, explanation follows regarding the manufacturing method of the roof member
1 C of the present exemplary embodiment. The manufacturing method of the roof member
1 C of the present exemplary embodiment is the same as that of the third exemplary
embodiment, with the exception of the point that the first press device of the present
exemplary embodiment is employed instead of the first press device 18 of the third exemplary
embodiment. Note1hat in the present exemplm·y embodiment, in the first process, the blank
BL is pressed by bending to fmm the intermediate formed component, and in the second
process, the intermediate formed component is pressed by bending to form the roof member
lC.
[0146] Advantageous Effects
Advantageous effects of the present exemplary embodiment is the same as the
advantageous effects of the third exemplary embodiment, as illustrated in the table of Fig. 33,
described later.
[0147] The foregoing was an explanation regm·ding the advantageous effects of the present
43
exemplary embodiment.
[0148] Examples of the Third and Fourth Exemplary Embodiments
Next, explanation follows regarding simulations of Examples and Comparative
Examples of the third and fourth exemplary embodiments, with reference to the drawings.
Note that in the following explanation, when the reference signs used for components and the
like are similar to the reference signs used for components and the like in the third and fourth
exemplary embodiments and in the comparative embodiments, the reference signs for these
components and the like are carried over as-is.
[0149] As illustrated in the table of Fig. 32, in the present simulation, bending at the front
end I a and the rear end 1 b, as well as the average bend amount, were evaluated for roof
members lB of Examples IB to 19B, these being produced using simulations based on the
roof member manufacturing method ofthe third exemplary embodiment, and for roof
members of Comparative Examples lB to 6B, these being produced using simulations based
on the roof member manufacturing method of the comparative embodiment described above.
Moreover, in the present simulation, as illustrated in the table of Fig. 33, bending at the front
end Ia and the rear end 1 b, as well as the average bend amount, were evaluated for roof
members 1 of Examples 20B to 37B, these being produced using simulations based on the
roof member manufacturing method of the fourth exemplary embodiment, and for roof
members of Comparative Examples 7B to 12B, these being produced using simulations based
on the roof member manufacturing method of the comparative embodiment described above.
[0150] Explanation regarding the Table of Fig. 32
The table of Fig. 32lists simulation parameters and evaluation results for Examples
!B to 19B and Comparative Examples 1B to 6B, each of which is configured with a hat-shape.
Note that in the table of Fig. 32, "plate thickness" is the thickness of the blank BL employed
in the simulation. "Strength" is the tensile strength of the blank BL employed in the
simulation. The "outside vertical wall change start point(%)" represents the start position of
the portion 33al when the protrusion lla2 of the intermediate formed component 30 is taken
as a reference (0%), and the height direction position of the other end of the pmiion 33al,
namely the end pmiion cmmected to the concave ridge line 34a, is taken as 100%. For
example, Fig. 31 illustrates a case in which the outside vertical wall change start point is 50%.
Moreover, when the outside vertical wall change start point(%) is given as"-", this is in
reference to the fact that there is no change start point, namely that the portion 33al is not
moved in the second process. The "inside vertical wall change start point(%)" represents
the stmi position of a portion 33b 1 further toward the lower side than the protrusion lla'2
44
when the protrusion 11 a'2 of the intermediate formed component 30 is taken as a reference
(0%) and the height direction position of the other end ofthe portion 33bl, namely of the end
portion connected to the concave ridge line 34b, is taken as 100%. For example, Fig. 31
illustrates a case in which the inside vertical wall change start point is 50%. Moreover, when
the inside vertical wall change start point (%) is given as "-", this is in reference to the fact
that there is no change start point, namely that the portion 33bl is not moved in the second
process. Accordingly, when forming the roof member lB illustrated in Fig. 31, only the
second press device differs from the second press device 19B of the press apparatus 17 of the
third exemplary embodiment. More specifically, the second press device is configured such
that when a cross-section of the second die is projected onto a cross-section of the first die, on
the second curved face of the second die, at least a portion located further toward the other
end side than the second step is further toward the outside than a portion of the first curved
face located further toward the other end side than the first step. Namely, the second press
device has a function of pressing the intermediate formed component 30, this being a forming
target, and moving the portion 33bllocated further to the other end side than the step lla'
formed to the vertical wall33b of the intermediate formed component 30, namely located on
the concave ridge line 34b side, toward the opposite side to the side on which the vertical
walls 33a, 33b face each other, namely toward the opposite side to the facing side.
[0151] The roof members of Comparative Examples 1B to 4B are examples of the
comparative embodiment of the third exemplary embodiment described above. The roof
members of Examples lB to 19B are examples of the roof member lB of the third exemplary
embodiment.
[0152] Evaluation Results and Interpretation
From the table of Fig. 32, it is apparent that the roof members lB of the Examples
underwent less bending or experienced smaller amounts of bending than the roof members of
the Comparative Examples when the Examples and the Comparative Examples have the same
parameters for plate thickness and strength. For example, when Example lB is compared
against Comparative Example IB, or when Example 3B is compared against Comparative
Example 2B, in each case the Example underwent less bending or experienced a smaller
amount of bending than the conesponding Comparative Example. Namely, these examples
may be considered to exhibit the operation and advantageous effects of the third exemplary
embodiment.
[0153] Moreover, when Example 14B is compared against Comparative Example SB,
Example 14B underwent less bending or experienced a smaller amount of bending than
45
Comparative Example 5B. In Example 14B, the portion 33bl of the vertical wall4b located
further to the lower side than the step !Ia' is moved toward the opposite direction to the
facing direction of the vertical walls 33a, 33b. The vertical wall4b configures a curved face
curving in a concave shape opening toward the opposite side to the side facing the vertical
wall4b as viewed from the top plate 2. Moreover, in the roof member of Example 14B, it
may be expected that after tensile stress has acted in and caused bending of the outer surface
of the portion 33bl that has been moved, the desired shape would be easier to achieve than in
Comparative Example 5B, and in the roof members of Example 5B and Example 9B it may
be expected that after tensile stress has acted in and caused bending of the outer surface of the
portion 33bl that has been moved, the desired shape would be easier to achieve than in
Comparative Example 5B. In other words, in the case of the roof member of Example 14B
and in the cases of the roof members of Example 5B and Example 9B, in comparison to
Comparative Example 5B, the outer surface of the portion 33bl that has been moved is easier
to form within the permissible bending value range after being acted on and bent by tensile
stress.
[0154] Explanation regarding the Table of Fig. 33
The table of Fig. 33 lists simulation parameters and evaluation results for Examples
20B to 37B and for Comparative Examples 7B to 12B, each of which is configured with a
gutter-shaped profile.
[0155) The roof members of Comparative Examples 7B to 12B are examples of a
comparative embodiment of the third exemplary embodiment described above. The roof
members of Examples 20B to 37B are examples of the roof member lB of the third
exemplary embodiment.
[0 !56) Evaluation Results and Interpretation
From the table of Fig. 33, it is apparent that the roof members of the Examples
underwent less bending or experienced a smaller amount of bending than the roof members of
the Comparative Examples when the Examples and the Comparative Examples have the same
parameters for plate thickness and strength. For example, when Example 20B is compared
against Comparative Example 7B, or when Example 21B is compared against Comparative
Example 8B, in each case, the Example underwent less bending or experienced a smaller
amount of bending than the con·esponding Comparative Example. Namely, Example 20B
and Example 21B may be considered to exhibit the operation and advantageous effects of the
fourth exemplary embodiment.
[OJ 57] Moreover, when Example 31B is compared against Comparative Example liB,
46
Example 31 B underwent less bending or experienced a smaller amount of bending than
Comparative Example liB. In Example 31 B, the portion 33bl of the vertical wall 4b
located further to the lower side than the step 11 a' is moved toward the opposite direction to
the facing direction of the vertical walls 33a, 33b. The vertical wall 4b configures a curved
face curving in a concave shape toward the opposite side to the side facing the vertical wall 4b
as viewed from the top plate 2. Moreover, in the roof member of Example 31 B, it may be
expected that after tensile stress has acted in and caused bending of the outer surface of the
portion 33b 1 that has been moved, the desired shape would be easier to achieve than in
Comparative Example liB. In other words, in the case of the roof member of Example 31B,
in comparison to Comparative Example liB, the outer surface of the portion 33bl that has
been moved is easier to form within the permissible bending value range after being acted on
and bent by tensile stress.
[0158] The foregoing was an explanation regarding Examples of the third and fourth
exemplary embodiments.
[0159] The present disclosure has been explained above using the first to fourth exemplary
embodiments, these being specific exemplary embodiments. However, configurations other
than those of the first to fourth exemplary embodiments described above are also included
within the technical scope of the present disclosure. For example, the following
configurations are also included within the technical scope of the present disclosure.
[0160] In the first and second exemplary embodiments and the Examples, explanation has
been given using the roof members 1, 1 A as examples of the pressed component. However,
the pressed component may be an automotive component other than the roof members 1, lA
as long as it is manufactured by pressing so as to satisfy the conditions of Equation 1.
Moreover, the pressed component may also be a component other than an automotive
component as long as it is manufactured by pressing so as to satisfy the conditions of
Equation 1.
[0161] In the first and second exemplary embodiments and in the Examples thereof,
explanation has been given in which the vertical walls 4a, 4b configuring curved walls are
respectively formed with the steps lla, 11 a'. However, as long as the step 36a or 36a' is
formed to either one of the vertical walls 4a, 4b, the step 36a or 36a' need not be formed to the
other of the vertical walls 4a, 4b.
[0162] In the first and second exemplary embodiments and in the Examples thereof,
explanation has been given in which the vertical walls 4a, 4b are configured as curved walls.
However, as long as either one of the ve1iical walls 4a, 4b is a curved wall, and the step lla or
47
11 a' manufactured by the manufacturing method of the roof member 1 or 1 A of the respective
exemplmy embodiments is formed as a step on that curved wall, then there is no need for the
other of the vertical walls 4a, 4b to be a curved wall. For exmnple, the other of the vertical
walls 4a, 4b may be a wall running along the length direction in a straight line shape.
[0 163] In the first and second exemplary embodiments and in the Examples thereof,
explanation has been given in which the projection width al of the step of the curved wall
formed in the first process is narrowed in the second process to a2, this being narrower than
a1. However, in the second process, as long as the projection width a1 of the step formed in
the first process is narrowed, the step formed in the first process may be eliminated in the
second process. Nmnely, in the present disclosure, "nan·owing the projection width of the
step" encompasses eliminating the projection width of the step, in other words, eliminating
the step itself.
[0164] In the third and fourth exemplary embodiments and their Exmnples, explanation has
been given using the roof members lB, lC as examples of the pressed component. However,
the pressed component may be an automotive component other than the roof members 1B, 1 C
as long as its manufacture includes a process in which an intermediate formed component is
pressed such that a portion of a curved wall further toward another end side than a step is
moved toward the opposite side to a facing side. Moreover, the pressed component may also
be a component other than an automotive component as long as it includes a process in which
an intermediate formed component is pressed such that a portion of a curved wall further
toward another end side than a step is moved toward the opposite side to a facing side.
[0165] In the third and fourth exemplary embodiments and their Examples, explanation has
been given in which the vertical walls 4a, 4b are configured as curved walls. However, as
long as either one of the vertical walls 4a, 4b is a curved wall, and its formation includes a
process of pressing an intermediate formed component such that a portion of the curved wall
further toward another end side than a step is moved toward the opposite side to a facing side,
the other out of the vertical walls 4a, 4b need not be a curved wall. For example, the other
out of the vertical walls 4a, 4b may be a wall running along the length direction in a straight
line shape.
[0166] In the first and second exemplary embodiments and in the Exmnples thereof, as
illustrated in Fig. 12, explanation has been given in which the intermediate formed component
30 is pressed so as to narrow the width of the projection width a1 of the steps 11a, lla' of the
vertical walls 33a, 33b in the second process that follows the first process. However, other
forming may also be performed in the second process as long as, at a minimum, the
48
intermediate formed component 30 is pressed so as to narrow the width of the projection
width a! of the steps lla, lla' of the vertical walls 33a, 33b in the second process of the first
and second exemplary embodiments and of the Examples thereof. For example, in the
second process of the first and second exemplary embodiments and the Examples thereof, the
second process of the third and fourth exemplary embodiments and the Examples thereof may
be performed. Namely, after the blank BL is pressed to form the intermediate formed
component 30 in the first process, in the second process, the width of the projection width al
of the steps !Ia, !Ia' of the intermediate formed component 30 may be narrowed, and the
portions 33al of the vertical walls 33a, 33b further toward the other end side (concave ridge
line 34a side) than the steps lla, lla' of the vertical walls 33a, 33b may be moved towm·d the
opposite side (the arrow A direction side in the drawings) to the side on which the vertical
walls 33a, 33b face each other (the facing side). Such modified examples may be said to
exhibit the first and second advantageous effects of the first and second exemplary
embodiments as well as the advantageous effects of the third and fourth exemplary
embodiments.
[0167] As illustrated in Fig. 12, in the first and second exemplary embodiments and the
Examples thereof, explanation has been given in which the intermediate formed component
30 is pressed so as to narrow the width of the projection width al of the steps lla, lla' of the
vertical walls 33a, 33b in the second process that follows the first process. However, in the
second process of the first and second exemplary embodiments and the Examples thereof,
other forming may be performed after the first process and before the second process, or after
the second process, as long as at a minimum, the intermediate formed component 30 is
pressed so as to nauow the width of the projection width al of the steps lla, lla' of the
vertical walls 33a, 33b of the intermediate formed component 30. For example, the second
process of the third and fourth exemplary embodiment and the Examples thereof may be
performed after the first process and before the second process of the first and second
exemplary embodiments and the Examples thereof. Moreover, for example, the second
process of the third and fourth exemplary embodiments and the Examples thereof may be
performed after the second process of the first and second exemplary embodiments and the
Examples thereof. Such modified examples may be said to exhibit the first and second
advantageous effects of the first and second exemplary embodiments as well as the
advantageous effects of the third and fomih exemplary embodiments.
[0 168] Supplement
The following additional disclosure is a generalization from the present specification.
49
Namely, a first aspect of the additional disclosure is
"A manufacturing method for a pressed component in which:
a blank configured by sheet steel having a tensile strength of from 440 MPa to 1600
MPa is subjected to a first pressing using a punch, a die, and a holder so as to manufacture an
intermediate formed component that has a substantially hat-shaped lateral cross-section
profile configured by
a top plate present extending along a length direction,
two ridge lines respectively connected to both sides of the top plate,
two vertical walls respectively connected to the two ridge lines,
two concave ridge line portions respectively connected to the two vertical
walls, and
two flanges respectively connected to the two concave ridge line portions,
and that includes a curved portion curved from one end portion to another end
portion in the length direction in both plan view and side view when disposed in an
orientation in which the top plate is positioned at an upper portion; and
the intermediate formed component is subjected to a second pressing employing a
punch, a die, and a holder,
wherein the pressed component:
has a substantially hat -shaped lateral cross-section profile configured by
a top plate present extending along a length direction and having a
widthW,
two ridge lines respectively connected to both sides of the top plate,
two vertical walls respectively connected to the two ridge lines,
two concave ridge line portions respectively connected to the two
vertical walls, and
two flanges respectively connected to the two concave ridge line
portions,
includes a curved portion curved from one end portion to another end
portion in the length direction in both plan view and side view when disposed in an
orientation in which the top plate is positioned at an upper portion;
is configured by a first portion on a side in the length direction including the
one end portion, a third portion on a side in. the length direction including the other
end portion, and a second portion contiguously connected to both the first portion
and the third pmiion, the radius of curvature being smaller than the radius of
50
curvature of the first portion and the radius of curvature of the third portion; and
is fmmed with a step on at least one vertical wall out of the two vertical
walls, the step being formed in a range within 60% of a total height fi·om the flange,
having a step amount a2, and running along the length direction; and wherein
in the first pressing, at least one veriical wall out of the two vertical walls of the
intermediate formed component is formed with a step, the step being formed within a range of
60% of a total height from the flange, and having a step amount al as defined by Equation
(A) and Equation (B) below, and
in the second pressing, forming is performed such that the step amount of the step
becomes a2.
al ::: a2
al :S 0.2W
. .. (A)
... (B)"
[0169] Moreover, a second aspect of the additional disclosure is
"A manufacturing method for a pressed component in which:
a blank configured by sheet steel having a tensile strength of from 440 MPa to 1600
MPa is subjected to a first pressing using a punch, a die, and a holder so as to manufacture an
intermediate formed component that has a substantially hat-shaped lateral cross-section
profile configured by
a top plate present extending along a length direction,
two ridge lines respectively connected to both sides of the top plate,
two vertical walls respectively connected to the two ridge lines,
two concave ridge line portions respectively connected to the two vertical
walls, and
two flanges respectively connected to the two concave ridge line portions,
and that includes a curved portion curved from one end portion to another end
portion in the length direction iil both plan view and side view when disposed in an
orientation in which the top plate is positioned at an upper portion; and
the intermediate formed component is subjected to a second pressing employing a
punch, a die, and a holder,
wherein the pressed component:
has a substantially hat-shaped lateral cross-section profile configured by
a top plate present extending along a length direction,
two ridge lines respectively connected to both sides of the top plate,
two vertical walls respectively corutected to the two ridge lines,
51
two concave ridge line portions respectively connected to the two
vertical walls, and
two flanges respectively connected to the two concave ridge line
portions,
includes a curved portion curved from one end portion to another end
portion in the length direction in both plan view and side view when disposed in an
orientation in which the top plate is positioned at an upper portion;
is configured by a first portion on a side in the length direction including the
one end portion, a third portion on a side in the length direction including the other
end portion, and a second portion contiguously connecting the first portion and the
third portion together, the radius of curvature being smaller than the radius of
curvature of the first portion and the radius of curvature of the third portion; and
is formed with a step on at least one vertical wall out of the two vertical
walls, the step being formed in a range within 60% of a total height from the flange,
having a step amount a2, and running along the length direction; and wherein
in the first pressing, the vertical wall and the flange on an inner side of the curved
portion are formed such that an angle DII formed between the vertical wall and the flange on
the inner side of the curved portion of the intermediate formed component satisfies Equation
(C) below, and
in the second pressing, the vertical wall formed on the inner side of the curved
portion of the intermediate fmmed component forms the vertical wall on an inner
side of the curved portion of the pressed component, and the flange on the inner side
of the curved portion of the intermediate formed component fmms the flange on the
inner side of the curved portion .
1.0 X DI2 < DI! :S 1.2 X DI2 ... (C)
wherein DI2 refers to an angle formed between the vertical wall and the flange on the
inner side of the curved portion of the pressed component."
[0 170] Moreover, a third aspect of the additional disclosure is
"A manufacturing method for a pressed component configured including an
elongated top plate, ridge line portions at both shmi direction ends of the top plate, and a pair
of vertical walls facing each other in a state in which one end of each of the vertical walls is
connected to the respective ridge line portions and at least one of the vertical walls
configuring a curved wall curving as viewed from an upper side of the top plate, the
manufacturing method comprising:
52
a first process of pressing a blank to form an intermediate formed component
configured including the top plate, the ridge line portions at both ends, and a pair of vertical
walls facing each other in a state in which one end of each of the vetiical walls is connected to
the respective ridge line and at least one of the vertical walls configuring a curved wall
curving as viewed from the upper side of the top plate, such that a step projecting out toward
the opposite side to a facing side on which the vertical walls face each other is formed to the
curving wall so as to run along the length direction of the top plate; and
a second process of pressing the intermediate formed component such that a portion
of the curved wall on another end side of the step is moved toward the opposite side to the
facing side."
[0171] The disclosures of Japanese PatentApp1ication Nos. 2015-087504 and 2015-087505,
filed onApril22, 2015, the disclosure of Japanese Patent Application No. 2016-056041, filed
on March 18,2016, and the disclosure ofJapanese Patent Application No. 2016-057267, filed
on March 22, 2016, are incorporated in their entirety by reference herein.
All cited documents, patent applications, and technical standards mentioned in the
present specification are incorporated by reference in the present specification to the same
extent as if the individual cited document, patent application, or technical standard was
specifically and individually indicated to be incorporated by reference.

CLAIMS
1. A manufacturing method for a pressed component configured including an elongated top
plate, ridge lines at both short direction ends of the top plate, and vertical walls facing each
other in a state extending from the respective ridge lines and at least one of the vertical walls
configuring a curved wall curving as viewed from an upper side of the top plate, the
manufacturing method comprising:
a first process of pressing a blank to form an intermediate formed component
configured including the top plate, the ridge lines at both ends, and the vertical walls, and in
which a step projecting toward an opposite side to a side on which the vertical walls face each
other is formed to the curved wall so as to run along a length direction of the top plate; and
a second process of performing at least one out of
pressing the intermediate formed component so as to narrow a projection
width of the step, or
pressing the intermediate formed component so as to move a portion of the
curved wall on an opposite side of the step to a portion of the curved wall on the top plate side
of the step toward the opposite side to the side on which the vertical walls face each other.
2. The pressed component manufacturing method of claim 1, wherein, in the first process,
taking a position of the top plate as a reference, a portion of the curved wall at a distance of
not less than 40% of a height from the top plate position to a lower end of the curved wall is
formed with a step having the projection width of not more than 20% of a short direction
width of the top plate.
3. The pressed component manufacturing method of either claim I or claim 2, wherein, in
cases in which at least the projection width of the step is narrowed in the second process, in
the second process an angle of a portion of the curved wall further to the top plate side than
the step is changed in order to nanow the projection width of the step formed in the first
process.
4. A pressed component comprising:
an elongated top plate;
ridge lines at both short direction ends of the top plate; and
vertical walls facing each other in a state extending from the respective ridge lines
and at least one of the vertical walls configuring a curved wall curving as viewed from an
54
upper side of the top plate; and wherein
a portion of the curved wall at a distance of not less than 40% of a height of the
curved wall from a position of the top plate is formed with a step running along a length
direction of the top plate, the step projecting out with a projection width of not more than 20%
of a short direction width of the top plate on an opposite side to a facing side on which the
vertical walls face each other; and
a Vickers hardness value of an end portion on the facing side of the step is greater
than a Vickers hardness value of an end portion on the opposite side of the step by 10 HV or
more.
5. A press apparatus comprising:
a first press device that presses a blank to form an intermediate formed component
that is configured including an elongated top plate, ridge lines at both short direction ends of
the top plate, and vertical walls facing each other in a state extending from the respective
ridge lines and at least one of the vertical walls configuring a curved wall curving as viewed
from an upper side of the top plate, with a step projecting out toward an opposite side to the
side on which the vertical walls face each other being formed to the curved wall so as to run
along a length direction ofthe top plate; and
a second press device that presses the intermediate formed component so as to
narrow a projection width of the step.
6. A press apparatus comprising:
a first press device that presses a blank using a first die and a first punch so as to
form an intermediate formed component; and
a second press device that presses the intermediate formed component with a second
die and a second punch; wherein
in the first press device,
an elongated first groove configured including an elongated first
groove-bottom face and first side faces connected to both short direction ends of the
first groove-bottom face is formed in the first die,
at least one of the first side faces configures a first curved face that is curved
as viewed along a mold closing direction, and that is formed with a first step at a
position at a specific depth at a distance of not less than 40% of a depth of the first
groove from the first groove-bottom face, the first step having a width of not more
55
than 20% of a short direction width of the first groove-bottom face and running along
a length direction of the first side face, and
the shape of the first punch is a shape that fits together with the shape of the
first groove during mold closure; and
in the second press device,
an elongated second groove configured including an elongated second
groove-bottom face and second side faces connected to both short direction ends of
the second groove-bottom face is formed in the second die,
at least one ofthe second side faces configures a second curved face that is
curved as viewed along the mold closing direction, and that is formed with a second
step at a position at the specific depth from the second groove-bottom face, the step
running along a length direction of the second side face,
the second step is narrower in width than the first step, and a separation
distance between the second groove-bottom face and the second step in the short
direction of the second groove-bottom face is longer than a separation distance
between the first groove-bottom face and the first step in the short direction of the
first groove-bottom face, and
the shape of the second punch is a shape that fits together with the shape of
the second groove during mold closure.
7. The press apparatus of claim 6, wherein, in a cross-section of the second die projected
onto a cross-section of the first die, at least part of a portion of the second curved face at an
opposite side of the second step to a portion on the second groove-bottom face side is located
further outside than a portion of the first curved face at an opposite side of the first step to a
portion on the second groove-bottom face side.