The present invention relates to a blank, and a tnanufacturing method for a pressed
article that employs the blank.
Background Art
[0002] Antotnotive body shells include unit construction structures (monocoque structurcs)
in \vhich fiamework mcnlbers such as front pillars, center pillars, side sills, roof rails, side
members, and the like are joined together with various fonned panels such as hood ridges,
dash panels, fiotit floor panels, rear floor front panels, and rear floor rear panels. Framework
members that generally have a closed cross-section, such as fiont pillars, center pillars, and
side sills, are assembled by joining configuration members such as fiatit pillar reinforcement,
center pillar reinforcement, and side sill outer reinforcement, to other configuration members
such as outer panels and inner panels.
[0003] Fig. 19 is an explanatory diagratn illustrating an example of a framework tilember 1
formed by joining configuration members 2,3,4, and 5 together by spot welding. As
illustrated in Fig. 19, the configuration member 2 has a substantially hat-shaped lateral
cross-section profile including a top plate 2a, a pair of left and right vertical walls 2b, 2b, and
flanges 2c, 2c linked to the vertical walls 2b, 2b. The top plate 2a has a T-shaped outer
profile in plan view (components wit11 such an outer profile are also refelxed to as "T-shaped
profile components" below), tl~erebys ecuring the strength and rigidity of the framework
member 1.
[0004] Fig. 20 is an explanatory diagram illustrating a T-shaped profile conlponent 2
including a top plate with a T-shaped outer profile in plan view. As illustrated in Fig. 20, the
T-shaped profile component 2 is configured including a first formed section 12 extending in a
length direction, and a second formed section 14 configuring one length direction end portion
of the T-shaped profile component 2. Moreover, in the T-shaped profile component 2, a
width dimension of the top plate in the second formed section 14 is set larger than a width
dimension of the top plate in the first formed section 12, and a length direction end portion of
the second formed section 14 is formed \vitli a T-shape in plan vie~v. Note that as
modifications of the T-shaped profile component 2, there are also Y-shaped profile
components (not illustrated in the drawings) in which the top plate has a Y-shaped outer
profile in plan view, and L-shaped profilc components (not illustrated in the drawings) in
\vhich the top plate bas an L-shaped outer profile in plan vie\v.
[0005] Pressing that en~ployds rawing is enlployed in order to suppress creasing from
I
occurring when manufacturing the T-shaped profile compo~icn2t , Y-sliapcd profile
components, or L-shaped profile co~nponentsb y pressing.
[0006] However; in order to manufacture a pressed article by pressing employing drawing, a
wide trim region is inevitably required at tlie periphery of a11 intermediate pressed article,
thereby reducing the yield of the pressed article, and increasing the manufacturing cost.
[0007] In order to prevent the occurrence of creasing and cracking in pressed articles,
conventionally, metal sheets having excellent ductility but comparatively low strength have
been employed in blanks for T-shaped profile components such as center pillar reinforceme~lt.
It is accordingly necessary to iricrease the sheet thickness of the blank in order to secure
strength, making an increase in weight and all increase in cost unavoidable.
[0008] Methods for pressing by bending to manufacture components with simple
cross-section profiles such as hat shapes or 2-shapes running along the entire length direction
are, for exainple, described in Japanese Patent Applicatioli Laid-Open (JP-A) Nos.
2003-103306,2004-154859,2006-015404, and 2008-307557. However, none of these
methods can be applied when manufacturing components with complex shapes, such as
T-shaped profile components, Y-shaped profile components, or L-shaped profile components.
[0009] Recently, high tensile sheet steel is being employed in framework merilbers in order
to reduce weight and increase strength. High tensile sheet steel has lower ductility than
general sheet steel, and so there is demand for methods to suppress the occurrence of creases,
cracking, and the like during pressing. The pamphlet of International Publication (WO) No.
201 11145679 describes a n~anufacturingm ethod (free betiding method) for a pressed article
enabling T-shaped profile components, Y-shaped profile coniponents, and L-shaped profile
components to be manufaetured wliile suppressing the occurrence of creases, cracking, and
the like, even when employing a blank configured by high tensile sheet steel with low
ductility.
[0010] In this pressed article mannfacturirig method (fiee bending method), a T-shaped
component 2 is manufaetured by causing the top plate 2a of tlie second formed section 14 to
move in-plane (slide) inside the mold when fanning the vertical walls 2b and tlie flanges 2c of
tlie second formed section 14.
[0011] However, even in the above free bending method, if a width dimensio~oi f the top
plate 2a of the secotid formed section 14 is large, sometitiles cracking can occur due to a
reduction'in sheet thickness of the blank becoming large. Specifically, new issues particular
to free bending methods have emerged, namely cracking occurring at portions of the second
formed section 14 linking from the vertical \valls 2b to the flanges 2c (region A in Fig. 20)
(this cracking is referred to below as "flange cracking"), atid crackirig occurring at an edge at
2
one length direction end oftlie top plate 2a of tlie second forn~eds ection 14 (region B in Fig.
20) (this cracking is referred to below as "top plate edge cracking").
[0012] As a coontcrmcasure, in WO No. 20141050973, excess po~tionsfo rming bulges
toward the length direction outer side are provided to edges at both length direction ends of a
blank it1 order to avoid top plate edge cracking (see paragraph 0035 and Fig. 3 of WO No.
20 141050973). Specifically, thc excess portions forn bulges projecting toward the Ietigt11
direction outer side with respect to edges at both length direction ends of the blank.
SUMMARY OF INVENTION
Technical Problem
[0013] However, even in blanks with excess portions provided to tlie edges, there is still
room for i~nprovementin the follo\ving regard. Namelj: at both length direction ends of the
blank, portions of the edges adjacent to the excess portions on both sides in the width
direction (referred to below as "adjacent edges" for convenience) are fonned in substantially
straight line shapes. In other words, the substantially straight line shaped adjacent edges and
the curved excess portions intersect with each other at boundary portions between the adjacent
edges and the excess portions. Accordingly, even when the T-shaped profile cotnponent 2 is
manufactured using the free bending method employing the blank described in WO No.
2014-050973, if the width dimension of the top plate 2a of the second formed section 14 of
the T-shaped profile component 2 is large, a reduction in sheet thickness at the boundary
portions between the adjacent edges and the excess portions beconies large, and there is a
possibility of top plate edge cracking occui~inga t these boundaly portions.
[0014] The present invention relates to obtaining a blank and a pressed article manufacturing
method capable of suppressing top plate edge cracking.
Sohition to Problem
[0015] A blank of the present disclosure is a blank for forming a pressed article that includes
a top plate formed in an elongated shape with a length direction along a first direction and
including a pair of outer edges extending along the length direction in plan view, the top plate
being laid out with at least one of the outer edges curving so as to extend out toward a width
direction outer side at an end portion on one length direction side of the top plate so that the
one outer edge is separated toward another length direction side from an edge on the one
length direction side, a pair of vertical \valls extending out from the pair of outer edges toward
a lower side, and a pair of flanges, each extending out from a lo\~eern d portion of one of the
vertical walls toward an opposite side from the top plate in plan view. The blank includes a
flat pattern edge configuring an edge on the one length direction side of the blank, and an
3
excess portion formed at the flat pattern edge. An edge of the excess portion includes a first
convex portion that protrudes toward the one length direction side of the bla~lkw ith respect to
thc flat pattern edge, a first concave portion that is adjacent to the first convex portion at a
width direction outer side of the blank, that is formed in a concave shape opening toward the
one length direction side of the blank, and that connects the flat patteni edge and the first
convex portion together, and a second concave portion that is adjacent to the first convex
portion at a width direction inner side of the blank, that is fornled in a concave shape opening
toward the one length direction side of the blank, and that connects the flat pattern edge and
the first convex portion together
[0016] According to the blank addressing tlie above issue, the blank is configured as a blank
for the pressed article including the top plate, the pair of vertical walls, and the pair of flanges.
The top plate of the pressed article is formed in an elongated shape with its length direction
along the first direction. Moreover, tlie top plate includes the pair of outer edges extending
along the length direction in plan view. At least one of the outer edges is laid out cu~ving
toward the width direction outer side at tlie end portion on the one length direction side of the
top plate so as to be separated toward the other length direction side from the edge on the one
length direction side. One length direction side end portion of the pressed article is thereby
fornied with a T-shaped profile or an L-shaped profile in plan view, and the pressed article is
configured as a T-shaped profile component or an L-shaped profile component.
[0017] In the pressed article, the pair of vertical walls extend out from the pair of outer
edges of the top plate toward the lower side, and the pair of flanges extend out from lower end
portions of the respective vertical walls toward the opposite sides to the top plate in plan view.
The pressed article is thereby formed with a hat shape opening toward the lower side as
viewed from the other length direction side.
(00181 The blank includes the flat pattern edge configuring an edge on the one length
direction side of the blank, and the excess portion formed at the flat pattern edge.
[0019] The edge of the excess portion includes the first convex portion that protrudes toward
the one length direction side of tlie blank with respect to the flat pattern edge. The flat
pattern edge is accordingly configured so as to be thickened toward the one length direction
side by the excess portion. Accordingly, during the fornling process of the pressed article, a
reduction in sheet tluekness at the edge of the blank on the one length direction side (nan~el>:
the flat pattern edge and the edge of the excess portion) can be suppressed even when the flat
pattern edge and the edge of tlie excess portion rnove in-plane (slide) inside the mold.
[0020] Moreover, the edge of the excess portion includes the first concave portion that is
adjacent to the first convex portion at the width direction outer side of the blank, and the
4
second concave portion that is adjacent to tlie first convex portion at the width direction itlucr
side of the blank. The first concave poltion and the second concave portion are each foniied
in concave shapes opening toward the one length direction side of the pressed article, and
colulect the flat pattern edge and the first convex portion together. Boundary portions
between the first convex portion and the flat pattern edge can accordingly be connected
smoothly by the first concave portion and the second concave portion. This thereby enables
a localized reduction in sheet thichiess at the boundary portions between tlie first convex
portion and the flat pattern edge of the blank to bc suppressed, and enables top plate edge
cracking at the bo~nidaryp o~tionsto be suppressed.
Advantageous Effects of I~lvetition
[0021] The blank of the present disclosure has the excellent advantageous effect of enabling
top plate edge cracking to be suppressed.
BRIEF DESCRIPTION OF DRAWINGS
[0022] Fig. 1 is a perspective view schematically illustrating a pressed article formed
employing a blank according to a first exenlpla~ye mbodiment.
Fig. 2 is an explatiatoty diagram illustrating an example of dunensions of relevant portions of
the pressed article illustrated in Fig. 1.
Fig. 3 is an enlarged perspective view illustrating a portion on one width direction side of the
pressed article illusttated in Fig. 1.
Fig. 4 is a plan view schematically illustrating a blank according to the first exernpla~y
embodiment.
Fig. 5 is an explanatoty diagram to explain imaginary ridge lines illustrated in Fig. 4.
Fig. 6 is an explanatory diagram in which an out-of-plane defonnation suppression region of
the blank illustrated in Fig. 4 is indicated by hatching.
Fig. 7 is an explanatory diagram scben~aticallyil lustrating a mold unit eriiployed in
manufacture of the pressed article illustrated in Fig. 1, in an exploded state.
Fig. 8A is an explatiatoly diagram to explain the outline of a pressing process of the mold unit
illustrated in Fig. 7 at the a-a cross-section position in Fig. 3.
Fig. 8B is an explanatory diagratn to explain the outline of a pressing process of the mold unit
illustrated in Fig. 7 at the b-b cross-section position in Fig. 3.
Fig. 9 is a perspective view illustrating a state in which a blank has been placed over a die.
Fig. 10 is a perspective view illustrating a state after a blank has been formed into a pressed
article.
Fig. 11A is an explanato~yd iagram to explain proportional reduction in sheet thickness in the
5
vicinity of a blank edge after pressing a blank of Comparative Example 1.
Fig. 11B is an explanatoty diagram to explain propol-tional rcduction in sheet thickness in the
vicinity of a blank edge after pressing a blank of Comparative Example 2.
Fig. 11C is an explanatory diagram to explain proportional reduction in sheet thickness in the
vicinity ofa blank edge arter pressing a blank of the first exemplary embodiment.
Fig. 12 is a plan view to explain material in-flow paths when pressing a pressed article.
Fig. 13 is a perspective view to explain material in-flow paths when pressing a pressed a~ticle.
Fig. 14A is a plan view schematically illustrating a blank of Conlparative Example 3.
Fig. 14B is a plan view schen~aticallyil lustrating a blank of Comparative Example 4.
Fig. 14C is a plan view schen~aticallyi llustrating a blank of Comparative Example 5.
Fig. 14D is a plan view schen~aticallyil lustrating a blank of Comparative Example 6.
Fig. 14E is a plan view schetnatically illustrating a blank of the first exemplary embodiment.
Fig. 15 is a view in two planes illnstrating the shape of a pressed article when a pressed article
of the first exemplary etilbodiment is employed as a vehicle framework component.
Fig. 16 is a perspective view schematically illustrating a pressed article formed employing a
blank according to a second exemplary embodiment.
Fig. 17 is a plan view schematically illt~stratinga blank according to the second exempla~y
embodiment.
Fig. 18 is a view in two plates illustrating the shape of a pressed article when a pressed article
of the second exemplary embodiment is employed as a vehicle fsamework component.
Fig. 19 is an explanatoly diagram illustrating an example of a framework member formed by
joining together configuration members by spot welding.
Fig. 20 is an explanatoly diagram illustrating a T-shaped profile component in which a top
plate has a T-shaped outer profile in plan view.
DESCRIPTION OF EMBODIMENTS
[0023] First Exemplary Embodiment
First, explanation follows regarding a pressed article 20 manufactured using a blank
30 according to a first exemplary embodin~ent. Explanation will then be given regarding a
mold unit 40 employed when forming the pressed article 20, followed by explanation
regarding the blank 30. In the following explanation, an example is described in which the
pressed article 20 is configured as a T-shaped profile component. The blank 30 that is the
stock material for the pressed article 20 is not limited to a specific material, as long as it is a
metal sheet suited for pressing. The blank 30 is preferably a sheet nletal suited for pressing,
such as sheet steel, sheet aluminum, or a sheet of an alloy with steel or alumintnn as a main
6
component. In the present eseniplary embodiment, explanation is givcn regarding a case in
\vhich tlie blank 30 is sheet steel.
[0024] Pressed Article 20
The stock material for tlie pressed article 20 is the blank 30, described latcr, or a
for~nitigs heet resulting froin pre-processing the blank 30. The pressed article 20 is obtained
by pressing using a pressing niethod (free bending method) described later, tusing the tnold
unit 40, described later.
[0025] As illustrated in Fig. 1, the pressed article 20 is formed in an elongated shape with its
length direction along a first direction (the arrow Dl direction and tlie arrow D2 direction in
Fig. 1). Note that the arrow Dl and the arrow D2, illustrated as appropriate in the drawings,
indicate the length direction of the pressed article 20. Moreover, the arrow Dl indicates one
length direction side of the pressed alticle 20, and the arrow D2 indicates the other length
direction side of the pressed article 20. The arrow D3 and the arrow D4, illustrated as
appropriate in the drawings, indicate a width direction of the pressed article 20, this being
orthogonal to the length direction of the pressed article 20 in plan view. In the following
explanation, unless specifically indicated otherwise, reference in the explanation simply to the
length direction and the width direction refers to the length direction and the width direction
of the pressed article 20.
[0026] An end portion at one length direction side of the pressed article 20 projects out
toward the width direction outer sides (the arrow D3 direction and the anow D4 direction it1
Fig. 1) so as to form a substantially T-shape, arid the pressed article 20 has left-right symmetry
about a width direction center line (not illustrated in the drawings). The pressed article 20 is
configured including a first formed section 21 extending along the length direction, and a
second formed section 22 configuring an end section on one length direction side of tlie
pressed aiticle 20, and adjacent to the first formed section 21 on the one length direction side.
Note that the width direction outer sides of the pressed article 20 refer to sides in directions
heading away from each other with respect to the width direction center line (not illustrated in
the drawings) of the first formed section 21. Width direction inner sides of the pressed
article 20 refer to sides in directions approaching each other with respect to the width
direction center line of the first formed section 21.
[0027] As viewed from the length direction other side, the pressed article 20 is formed with
a substantially hat shaped cross-section profile opening toward the lower side (the arrow D5
side in Fig. 1). The pressed article 20 is thus configured including a top plate 20a, a pair of
ridge lines 20b, a pair of vertical walls 20c, and a pair of flanges 20d. These will be
described in detail belo\\.
7
[0028] The top plate 20a is formed in a substantially T-shaped plate shape in plan view as
\rie\ved from tlie uppcr sidc (the side of arrow D6 in Fig. 1). Specifically, tlie top plate 20a
includes a pair of outer edges 20aA extending along the length direction. Portions of the
outer edgcs 20aA corresponding to the first fonncd section 21 configure first outcr edges
20aA-1, and the pair of first outer cdges 20aA-1 are disposed substantially parallel to each
other along the length direction. The portion of the top plate 20a corresponding to tlie first
formed section 21 is accordingly set with a substantially uniform width W1.
[0029] Portions of the outer edges 20aA that correspond to the second formed section 22 and
that are portions adjacent to the first outer edges 20aA-1 configure second outer edges 20aA-2.
The second outer edges 20aA-2 extend out fro111 one length direction ends of the respective
first outer edges 20aA-1 toward the width direction outer sides. Specifically, the second
outer edges 20aA-2 are curved into arc shapes protnlding toward the one length direction side
and the width direction inner side of the pressed article 20 in plan view. Accordingly, at a
portion of tlie top plate 20a corresponding to the second formed section 22 and adjacent to the
first formed section 21, a width W2 of the top plate 20a is set so as to become larger (wider)
on progression toward the one length direction side of the pressed article 20. Moreover, the
second outer edges 20aA-2 are disposed so as to be separated toward the other length
direction side from an edge on the one length direction side of the top plate 20a.
[0030] The outer edges 20aA further include third outer edges 20aA-3. The third outer
edges 2 0 a ~ - 3ex tend out from width direction outer side ends of the respective second outer
edges 20aA-2 toward the width direction outer side of the pressed article 20. Note that the
third outer edges 20aA-3 may be omitted fiotn the outer edges 20aA.
[0031] The pair of vertical walls 20c respectively extend out toward the lower side from the
first outer edges 20aA-1, the second outer edges 20aA-2, and the third outer edges 20aA-3 of
the top plate 20a, with the ridge lines 20b interposed therebetween. The vertical walls 20c
accordingly extend so as to follow the first outer edges 20aA-1, the second outer edges
20aA-2, and the third outer edges 20aA-3, and the vertical walls 20c cullre in arc shapes in
plan view where connected to the second outer edges 20aA-2. Namely, the pair of vertical
walls 20c are not formed at the one length direction side edge of the top plate 20a, nor at
width direction outer side edges of the top plate 20a at the second formed section 22, and are
disposed so as to be separated toward the one length direction side from the one length
direction side edge of the top plate 20a.
[0032] The pair of flanges 20d respectively extend out from leading edges (lower edges) of
the vertical walls 20c toward the opposite sidc from the top plate 20a in plan view, and are
disposed substantially parallel to the top plate 20a. Accordingly, in plan view, the flanges
8
20d also extend so as to follow tlic first outer edges 20aA-1, the second outer edges 20aA-2,
atid the third outer edges 20aA-3, and \\rhere they are connected to the scco~ldo uter edges
20aA-2 through tlie vc~ticawl alls 20c, the respective flanges 20d are cunred in arc shapes in
plan view.
[0033] ?'he ridge lines 20b are fomled at bou~idaryp ortions between the top plate 20a and
the vertical walls 20c. Where they correspond to the first outer edges 20aA-1, the ridge lilies
20b cotlfigure first ridge lines 20b-1, where they correspond to the second outer edges 20aA-2,
the ridge lines 20b configure second ridge lincs 20b-2, and where they correspond to the third
outer edges 20aA-3, the ridgc lilies 20b configure third ridge lines 20b-3. The locations of
the vertical walls 20c and the flanges 20d that are connected to the curved second ridge lines
20b-2 are collectively refesred to as curved portions 23.
[0034] Note that as viewed from tlie upper side of the top plate 20a, the respective second
ridge lities 20b-2 (second outer edges 20aA-2) may have a shape with uniforni curvature, an
elliptical arc shape, or a shape including plural curvatures. Namely, in plan view, in the
pressed article 20, the top plate 20a is present at a radial direction outer side of the arc shaped
curved second ridge lines 20b-2, and the flanges 20d are present at the radial direction inner
side of the second ridge lines 20b-2 (on the side toward the center of cut-vature of the arc).
Moreover, the top plate 20a need not be perfectly flat, and the top plate 20a may be applied
with various additional shapes (such as recesses or protrusions) according to the design of the
pressed component or the like.
[0035] As illustrated in Fig. 3, a base end portion of each of tlie second ridge lines 20b-2 of
the pressed article 20 (an end portion adjacent to the first ridge line 20b-1, an end portion at a
position further in the length direction from a blank edge 30a on the one length direction side
of the blank 30, described later) configures an end portion PA (a first end portion). A
tertninal end portion of each second ridge litie 20b-2 (an end portion adjacent to the third
ridge line 20b-3) configures an end portion PB (a second end portion). I11 plan view, tlie first
ridge line 20b-1 is colmected to the second ridge line 20b-2 so as to meet the second ridge line
20b-2 at the end portion PA. The third ridge line 20b-3 extends out from the end portion PI3
toward the width direction outer side.
[0036] Next, explanation follows regarding dimensions of the pressed article 20, with
reference to Fig. 2. A length direction dimension of the pressed article 20 is set within a
range of fiom 100 llun to 1600 mm (for example, 300 nlm in the present exemplary
embodiment). Awidth W1 of the top plate 20a at the first formed sectiorl 21 is set in a range
of fi.011150 nlm to 200 tnnl (for example, 100 tntn in the present exemplary embodiment). A
width W3 of the top plate 20a at one length direction side end portion of the pressed article 20
9
is set in a range of fro111 70 nnn to 2000 rnm (for example, 320 mnl in the present exenlplary
entbodiment).
[0037] The height of the pair of vertical walls 20c is set in a range of from 20 inn1 to 120
~ n ~(fioir example, 50 11nn in the present exe~nplarye mbodiment). Note that there is a
tendency for creases to form Inore readily in the vertical walls 20c if the height of the vertical
walls 20c is set to less than 0.2 titiles the peripheral length of the arc shaped cui-ved second
ridge lines 20b-2, or if set to less than 20 nnn. Accordingly, the height of the vertical walls
20c is preferably 0.2 times or greater the periphcral length of the second ridge lines 20b-2, or
20 ~lnnor greater.
[0038] Moreover, the radii of cun~atureo f the curved portions of the vertical walls 20c are
set in a range of from 5 tnrn to 500 mm (100 nun in the present exemplaiy embodiment). If
the radius of curvature of tlie nlaxin~utnc urvature portion were to be less than 5 nnn, the
periphery of the maximuni curvature portion would jut out locally and therefore tend to be
more vult~erableto cracking. Conversely, if the radius of curvature of the tnaximum
curvature portion were to exceed 500 mm, a length obtained by subtracting the width W1 of
tlie first formed section 21 from the width W3 of the top plate 20a at the one length direction
side end portion of the pressed article 20 would become long. Accordingly, the pulling in
distance toward the vertical walls 20c during the pressing process would become longer,
increasing the distance of sliding between tlie mold unit 40 and the blank 30, described later,
exacerbating abrasion of the mold unit 40, and shortening the life of the mold. It is
accordingly preferable for the radius of curvature of the maximum curvature portion to be 300
nnn or less.
[0039] Moreover, the widths of the pair of flanges 20d are both set within a range of from 10
mm to 100 mtn (for example 30 mm in the present exemplay embodiment). Moreover, as
illustrated in Fig. 3, it is sufficient that a width hi of the flanges 20d at a side further to the end
portion PA side than a peripheral direction (extension direction) center line C of the cullred
flanges 20d is from 25 mm to 100 mm.
[0040] More specifically, during pressing, described later, pressing is preferably performed
such that tlie width lii of each of tlie flanges 20d is from 25 mm to 100 illm in a region
spanning from the center line C and past the end portion PA as far as a position 50 nlm away
from the etid portion PA on tlie other letigth direction side (see the hatched region in Fig. 3).
Namely, if locations are present in tlie above region where the width lii is less than 25 tnm,
there is a large reduction in sheet thickness orthe flange 20d during pressing, and cracking is
liable to occur. This is due to force pulling in the one length direction end portion of the top
plate 20a at the second formed section 22 (in the vicinity of region B in Fig. 1) toward the
10
vertical wall 20c sidc being concentrated in the proxiniity of the flange 20d during tlie
pressing process.
[0041] Coii\~ersely,i f locations are present in the above region \vlierc tlie width /ti exceeds
100 mm, a peripheral direction (extension direction) compression amount of the flange 20d
becomes large, and creasing of the flange 20d is liable to occur Accordingly, setting the
width hi of tlie above region to fiom 25 mni to 100 tmn enables the occusrence of creasing
and cracking of the flange 20d to be suppressed.
[0042] Note that the width lti of the flange 20d is defined as the length of the flange 20d in a
direction orthogonal to a tangent to any given position along the edge of the flange 20d.
Moreover, in cases in \vliich a manufactured component has a sliape in which tlie width hi of
tlie flanges 20d is less than 25 mm, preferably an intermediate pressed body in whicli the
flanges 20d have a width of 25 tnrn or greater is manufactured by pressing, after wliicli the
unwanted portions are cut away.
[0043] Mold Unit 40
Next, explanation follo\vs regarding the mold unit 40, serving as a "mold" for
manufacturing the pressed article 20, with reference to Fig. 7. Note that Fig. 7 illustrates the
mold unit 40 corresponding to a portion on one width direction side of the pressed article 20,
and illustration of the mold unit 40 corresponding to a portion on the other width direction
side of the pressed article 20 is omitted. As illustsated in Fig. 7, the mold unit 40 is
configured including a die 41, a pad 42, and a pair of bending molds 43 (only one of the
bending molds 43 is illustrated in Fig. 7).
[0044] The die 41 confignres a lower section of the mold unit 40. The die 41 is fortned
with recesses for forming the ve~ticawl alls 20c and the flanges 20d of tlie pressed article 20.
In other words, the die 41 is formed with a prot~usionp rojecting out from bottoril faces of the
recesses. The protrusion is formed in a substantially T-shape in plan view, and outer faces of
the protrusion are formed corresponding to tlie shape of inner faces of the top plate 20a, the
ridge lines 20b, and the vertical walls 20c.
[0045] The pad 42 configures an upper section of the mold unit 40. The pad 42 is disposed
facing the die 41 in an up-down direction at a position on the upper side of the die 41
(specifically, tlie substantially T-shaped protrusion). The pad 42 is formed in a substatitially
T-shape in plan view, corresponditig to tlie shape of the top plate 20a. A lower face of the
pad 42 is formed in a sliape corresponding to an outer face of the top plate 20a.
[0046] The bending molds 43 configure an upper section of the mold unit 40 together with
the pad 42. The respective bending molds 43 are disposed at the width direction outer sides
of the pad 42, and are disposed at positions facing the die 41 in tlie up-down direction at tlie
11
upper side of tlie recess of the die 41. The bending molds 43 are formed in shapes
corresponding to tlie vet-tical walls 20c and the flanges 20d of the pressed article 20.
Specifically, side faces ol:tlie bending tilolds 43 configure vertical wall forming faces 43Afor
forming the vertical walls 20c. Each of the vertical wall for~niligfa ces 43A is configured
including a first vertical wall forming face 43A-1 extending along the length direction in plan
view, a second vertical \vall forming face 43A-2 for forming the vertical wall 20c at the
cu~vcdp ortion 23, and a third vertical wall fomiing face 43A-3 extending from tlie second
vertical wall forming face 43A-2 toward tlie width direction outer side. Moreover, a lower
face of each of the bending molds 43 configures a flange for~liingfa ce 43B for forming the
respective flange 20d. The flange forming face 43B is formed in a shapc corresponding to
an outer face of the corresponding flange 20d.
[0047] A boutidary portion between the vertical wall forming face 43A and the flange
forming face 43B of each bending mold 43 configures a shoulder portion 43C of the bending
mold 43. The shoulder portion 43C is configured by a first shoulder portion 43C-1, a second
shoulder portion (cut-ved shoulder portion) 43C-2, and a third shoulder portion 43C-3,
corresponding to where the shoulder portion 43C is respectively connected to the first vet-tical
wall forming face 43A-1, the second vertical wall forming face 43A-2, and the third vertical
wall fornling face 43A-3.
[0048] According to a first manufacturing method of the pressed al-ticle 20, described later,
tlie pad 42 of the rnold unit 40 applies pressure toward the lower side (namely, toward the die
41 side) to the blank 30 at a degree that permits in-plane movement of the blank 30.
Specifically, a drive ~iiechanismth at drives the pad 42 is configured by a spring drive
mechanism, a hydraulic drive mechanism, a gas cushion, or the like.
[0049] In cases in which tlie pressed article 20 is manufactured by a second manufacturing
method, described later, configuration is made to give a state in which a gap between tlie die
41 and the pad 42 is maintained at no less than the sheet thickness of the blank 30, and no
more than 1 .I times tlie sheet thickness of the blank 30. In such cases, tlie drive mechanism
that drives the pad 42 is configured by an electric cylinder, a hydraulic senlo device, or the
like. Note that the above/below positional relationship of the die 41 and the bending molds
43 is not limited.
[0050] Blank 30
Fig. 4 is a plan view schematically illustrating the blank 30 for forming the pressed
article 20 described above. The blank 30 is manufactured in the following shape by
processing a sheet steel stock material as appropriate (for exatiiple, by laser cutting).
[005 11 Using the nlold unit 40, the pressed article 20 described above is obtained by using
12
tlie prcssing method (free bending inethod) describcd later to press the blank 30, or a forming
sheet resulting from pre-processing the blank 30, as a stock material.
[0052] The pre-processing performed on the blank 30 includes, for esample, bending to
for~nsl ight protrusions in tlie interior of the blank 30, pressing by drawing, and hole cutting.
Such pre-processing may be performed on tlie blank 30 as appropriate, in consideration of the
di~nensionsa nd shape of the pressed article 20.
[0053] The breaking strength of the blank 30 or the forming sheet is, as an example, set from
400 MPa to I600 MPa, and tlie tensile strength of tlie blank 30 or the forming sheet is, as an
csample, set from 590 MPa to either 980 MPa or 1180 MPa. Note tliat a blank 30 of lower
strength or higher strength than tlis may also be c~nployed.
[0054] The blank 30 is for~nedin a substantially T-shape in plan view. Note that a length
direction of the blank 30 matches the length direction of the pressed article 20, and a width
direction of the blank 30 matches the width direction of the pressed article 20. The blank 30
includes a blank base 3 1 configuring a base of the blank 30, and the blank base 3 1 has a shape
corresponding to the pressed article 20 when opened out flat (the shape illustrated by
single-dotted dashed lines in Fig. 4, also referred to as the "flat pattern" in the present
specification). Namely, the blank base 31 is formed in a shape combining a first blank
section 3 la corresponding to the top plate 20a of the pressed article 20, and a pair of second
blank sections 31c corresponding to the pair of vertical walls 20c and the pair of flanges 20d.
Moreover, the first blank section 3 la and the second blank sections 31c are disposed adjacent
to each other, on either side of imaginary ridge lines 31b. Moreover, an end (edge) on the
one length direction side of the blank base 31 is configured by a base edge 31d, serving as a
"flat pattern edge". Note that the blank base 31 is configured in the shape of a flat pattern
found using calculations from the shape set for the pressed article 20. Specifically, JSTAMP
software manufactured by JSOL Corporation is employed to find the flat pattern of the
pressed article 20, and this flat pattern is set as the shape of the blank base 3 1. Note tliat the
shape of the blank base 3 1 may be found using software other than that mentioned above.
[0055] In each of the imaginary ridge lines 31b of the blank base 3 1, a portion
corresponding to the first ridge line 20b-1 of the pressed article 20 configures a first
imaginary ridge line 31b-1, serving as an "adjacent imaginary line", a portion corresponding
to the second ridge line 20b-2 configures a second imaginary ridge line 3 1b-2 serving as a
"curved imaginary line", and a portion corresponding to the third ridge line 20b-3 configures a
third imaginary ridge line 3 1 b-3. The imaginary ridge lines 3 1 b are sct in the following
matmee Namely, in a state in which the blank 30 bas been disposed in the mold unit 40 (the
blank 30 has been set in a state positioned on tlie die 41), and the (flange forming faces 43B
13
of tlic) bc~lditlgn lolds 43 contact an upper face of the blank 30 (the state illustrated on the left
sides of Fig. 8A and Fig. 8B. This statc is rcferred to below as the "set state"), imaginary
lines extending along tlie shoulder portions 43C of the respective bending molds 43 in plan
view arc set as tlic itilagiriary ridge lines 3 Ib. Specifically, the first imaginary ridge line
3 l b- 1, the second itnaginary ridge line 3 1 b-2, and the third imaginary ridge line 3 l b-3 are
respectively configured by itliaginary lines corresponding to tlie first shoulder poltion 43C-1,
the second shoulder portion 43C-2, arid the third shoulder portion 43C-3 of each of the
bending molds 43 in plan view. Moreover, although not illustrated in the drawings, a
positio~li~pigin is provided to the die 41 described above so as to project out toward the upper
side, and the blank 30 is fornlcd with a hole into which the positioning pin is inserted. The
blank 30 is thereby positioned with respect to the mold unit 40. Note that instead of the
positio~lingp in described above, a guide section to guide the outer profile of the blank 30 may
be formed at the die 41 in order to position the blatlk 30 with respect to the 11101d unit 40.
Moreovel; as will he described in detail later, in the pressing method described below, the
ve~ticawl alls 20c and the flanges 20d are formed wvhile the first blank section 3 la undergoes
in-plane movement (slides) inside the mold unit 40. Accordingly, the imaginary ridge lines
3 lb of the blank base 31 do not match the ridge lines 20b of the pressed article 20.
[0056] Moreover, one length direction side end portion of the blank base 31 is curved in an
arc shape opening toward the one length direction side in plan view. In other words, the base
edge 3 1d is curved in an arc shape opening toward the one lengtll direction side. As will be
described in detail later, in the pressing method (free bending method) of the pressed article
20, the vertical walls 20c and the flanges 20d corresponding to the second formed section 22
are formed while a portion of the first blank section 3 la corresponding to the second formed
section 22 undergoes in-plane tnovement (slides) toward the other length direction side inner
side the mold unit 40. Accordingly, the one length direction side end portion of the blank
base 31 is curved in an arc shape opening toward the one length direction side in plan view so
as to cossespond to the in-plane movement of the first blank section 31a.
[0057] Apair of excess portions 32 (see the excess portions 32 illustrated by dashed lines in
Fig. 4) that bulge out (project) from the base edge 3 1d toward the one length direction side in
plan view are applied to the blank base 3 1 of the blank 30. The excess portions 32 are
provided at positions with left-right symmetry about a width direction center line of the blank
30. Moreover, (outer peripheral) edges of tlie excess portions 32 are formed in specific
shapes (see the excess portions 32 illustrated by continuous lines in Fig. 4), and are connected
to the base edge 31d. Accordingly, one length direction side edge (this edge is referred to
below as the blank edge 30a) of the blank 30 is configured by the base edge 3 id of the blank
14
base 3 1 and tlie edges of the pair of excess portions 32. Explanation follows regarding the
edges of the excess po~-tions3 2. Notc that since the pair of cxcess portions 32 are fornled
with left-right symmetry about the width direction center line of the blank 30, as described
above, explanation follows regarding the excess portion 32 disposed on the one width
direction side (the arrow D3 direction side in Fig. 4).
[0058] The edge of each excess portion 32 is configured including a first convex portion 34
configuring a width direction intermediate pol-tion of the edge, a first concave portion 33
disposed on the width direction outer side of the first convex portion 34, and a second
concave portion 35 disposed on the width direction inner side of the first convex portion 34.
The first convex portion 34, the first concave portion 33, and the second concave portion 35
are formed so as to satisfy the following conditions.
[0059] Narnely, the first convex portion 34 is formed so as to protrude toward the one length
direction side of the base edge 3 Id. The first concave portion 33 is adjacent to the first
convex portion 34 on the width direction outer side, is formed in a concave shape opening
toward the one length direction side, and is connected to the base edge 3 1d and the first
convex portion 34. The second concave portion 35 is adjacent to the first convex portion 34
on the width direction inner side, is formed in a concave shape opening toward the one length
direction side, and is connected to the base edge 3 1d and the first convex portion 34.
[0060] More specifically, taking curvature toward an inner side direction of the blank 30 as
negative, and taking curvature toward an opposite direction to the inner side direction as
positive, the first convex portion 34 is formed in an arc shape with positive curvature.
[0061] The first concave portion 33 is formed in an arc shape with negative curvature, and
connects smoothly between the first convex portion 34 and the base edge 3 1d disposed at the
width direction outer side of the first convex portion 34. Namely, in the bla~lke dge 30a, a
tangent to the first convex pottion 34 and a tangent to the first concave portion 33 match each
other at an inflection point between the first convex portion 34 and the first concave portion
33, and a tangent to the first concave portion 33 and a tangent to the base edge 3 Id match
each other at an inflection point between the first concave portion 33 and the base edge 3 1d.
[0062] The second concave portion 35 is formed in an arc shape with negative curvature,
and connects smoothly between the first convex portion 34 and the base edge 3 1d disposed at
the width direction inner side of the first convex portion 34. Namely, in the blank edge 30a,
a tangent to the first convex portion 34 and a tangent to the second concave portion 35 match
each other at an inflection point between the first convex portion 34 and the second concave
poi-tion 35, and a tangent to the second concave portion 35 and a tangent to the base edge 3 1d
match each other at an inflection point between tlie second concave portion 35 and the base
15
edge 3 1 d.
[0063] In this mannel; the first concave portion 33, the first convex portion 34, and the
second concave portion 35 are disposed side-by-side in this sequence along the edge of the
excess portion 32 on progression fsotll the width direction outer side toward the width
direction inner side (width direction center side).
[0064] Maxi~nutnv alues of the absolute values of the curvatttres of the first concave poi-tion
33, the first convex poi-tion 34, and the second concave portion 35 are set to 0.5 (llmm) or
lower. Namely, the first concave portion 33 and the second concave portion 35 are provided
in order to suppress flange edge cracking when forming the pressed article 20. When
fonning the pressed article 20, the first concave portion 33 and the second concave portion 35
stretch out along the width direction of the blank 30, thereby encouraging the blank 30 to flow
into the mold unit 40 during pressing. Accordingly, if the absolute values of the co~vatures
of the first concave portion 33 and the second concave portion 35 were large, a concentration
of stress would arise at the first concave portion 33 and the second concave portion 35 (in
other words, a proportional reduction in the sheet thickness of the first concave portion 33 and
the second concave portion 35 would become large), and top plate edge cracking would tend
to occur readily at the first concave portion 33 and the second concave portion 35.
Accordingly, the absolute values of the curvatures of the first concave portion 33 and the
second concave portion 35 are preferably 0.5 (lltnm) or lower.
[0065] The maximum value of the absolute value of the curvature of the base edge 31d
between the second concave portion 35 of the excess portion 32 disposed on the right side of
the width direction center line of the blank 30, and the second concave portion 35 of the
excess portion 32 disposed on the left side of the width direction center line, is set to 0.1
(llmm) or lower.
[0066] Next, explanation follows regarding the positions of the first convex portions 34 in
the width direction of the blank 30, with reference to Fig. 5. Note that in Fig. 5, the blank 30
is sho~vnw ith the first convex postion 34 (excess portion 32) omitted. As illustrated in Fig.
5, a first imaginary line AL1 denotes an imaginary line passing through a base end portion of
the second imaginary ridge line 3 1b-2 (namely, through the end portion PA) and extending
along the width direction. A second imaginary line AL2 denotes an imaginary line passing
througl~a terminal end portion of the second imaginary ridge line 3 lb-2 (natnely, tkougl~th e
end portion PB) and extending along the length direction. An inclined imaginary line AL3
denotes an imaginary line passing through an intersection E between the first imaginary line
ALl and the second imaginary lineAL2, and rotated clockwise with respect to the first
imaginary line AL1. An angle a formed between the first imaginary line AL1 and the
16
inclined imaginary line AL3 is set at 22.5O. Note that in Fig. 5, for the sake of convcnicncc,
the angle u is shown larger than 22.5".
[0067] The first convex portion 34 is set between the inclined i~naginarpli ncAL3 and the
second itnaginary line AL2 (in tlie range G in Fig. 5). Namely, as describetl in detail latcr, in
the pressing method (free bending method) described later, when for~ningth e vertical walls
20c and the flanges 20d of the ctu~vedp o~tions2 3, the first blank section 31a correspotiding to
the second formed section 22 is drawn in (flows in) substantially toward tlie other length
direction side (the arrow J direction side in Fig. 9). Moreover, it has been found that \$hen
this occurs, in the vicinity of the base edge 3 id of the blank base 3 1, the reduction in sheet
thickness of the blank 30 tends to he distributed in tlie range G between the inclined
imaginary line AL3 and the second imaginary line AL2. Accordingly, the first convex
portion 34 is set between the inclined imaginary line AL3 and the second imaginary line AL2.
Note that the first convex portion 34 is set as appropriate between the inclined imaginary line
AL3 and the second i111agina1-y line AL2 according to the width dimensions of respective
locations of the pressed article 20, and according to the shape of the second formed section 22
(T-shape or L-shape). Namely, it1 cases in which the pressed article 20 is a T-shaped profile
component, as in the present exemplary embodiment, a pair of the excess portions 32 are
applied to the blank base 3 1, with each excess portion 32 being set from the width direction
center line of the blank 30, up to the corresponding second iniaginary line AL2.
[0068] In the present exemplary embodiment, the first convex portion 34 (specifically, an
apex of the first convex portion 34 (an apex portion of the first convex portion 34 in the
length direction of the blank 30)) is disposed on an extension line L running along the first
inlaginary ridge line 3 lb-1 of the blank 30 and extending from the end portion PA toward the
one length direction side. In other words, since the first imaginary ridge line 31b-1 meets
the second imaginary ridge line 31b-2 at the end portion PA, the first convex portion 34 is
disposed on a tangent that meets the second imaginary ridge line 3 1b-2 at the end portion PA.
[0069] As illustrated in Fig. 4, the edge of each excess pottion 32 is forriled in a shape that is
left-right asymmetrical about the extension line L in the width direction. Specifically, the
ctlrvatilre of the first concave portion 33 is set s~nalletrh an tlie curvature of the second
concave portion 35 at the edge of the excess portion 32. In other words, the radius of
curvature of the first concave po~tion3 3 is set larger than the radius of curvature of the second
concave portion 35. Note that in Fig. 4, the excess portion 32 is shoivn in an exaggerated
nianner in order to facilitate understanding of the shape of tlie excess portion 32.
[0070] A width dimension W4 of the excess portion 32 on the width direction outer side of
tlie extension line L (a width dimension from tlie extension line L to the intersection between
17
the first concave portion 33 and tlie base edge 31d) is set longer than a width diulension W5
of the excess poitiotl 32 on the width directioi~in ner side of the exte~lsionli ne L (a dimension
fionl thc extension linc L to thc i~ltersectionb etween the second concave portion 35 and the
base edge 3 Id).
[0071] Moreovel; a width dinlension of the excess portion 32 (width ditnension co~nbining
the width dinlension W4 and the width di~nensionW 5) is set to 1 nnn or greater, and no
greater than three times the peripheral length of the second ridge line 20b-2 that is curved in
an arc shape. This is since if the width dimension of the excess portion 32 is less than 1 mm,
the reduction it1 sheet thickness of the blank edge 30a during pressing, described latel;
beconles large, and there is a possibility of top plate edge cracking occurring. Conversely, if
the width di~nensiono f the excess portion 32 is more than three times the peripheral length of
the second ridge line 20b-2, in-plane movement (sliding) of the blank 30 during pressing,
described later, is suppressed, and there is a possibility of flange cracking or vertical wall
cracking occurring. Namelj: the excess portions 32 are essentially portions for suppressing
flange cracking and top plate edge cracking, and so the forniation rauge aud size of the excess
portions 32 are determined fiom this perspective.
[0072] In the blank 30, it is desirable for the blank edge 30a to have a shape that lies in the
same plane as the first blank section 3 la (namely, a shape in which the blank edge 30a of the
blank 30 is not pulled between the pad 42 and the die 41 during pressing, described later).
Namely, as illustrated in Fig. 6, the blank edge 30a at a location of the blank 30 corresponding
to an out-of-plane defornlation suppression region (region F) (the hatched region in Fig. 6) is
preferably in the same plane as the first blank section 31a. Put another way, a portion of the
blank edge 30a of the blank 30 lying on tlie one length direction side of the second imagina~y
ridge line 31 b-2 and the third ilnagina~yri dge line 3 lb-3 within the location of the blank 30
corresponding to the out-of-plane deformation suppression region, is preferably present in the
sarne plane as the first blank section 3 la.
[0073] Explanation follo\\~sr egarding the out-of-plane deformation suppression region
(region F). In the manufacturing method of the pressed article 20, described later, the
out-of-plane deformation suppression region (region F) is set in order to suppress the
occurrence of creases in the top plate 20a and the vertical walls 20c when fornling the pressed
article 20. Out-of-plane deformation is suppressed in the out-of-plane defonnation
suppression region (region F) during manufacture of the pressed article 20. The out-of-plane
deformation suppressiotl region (region F) is set in the following manner. Namely, a portion
of the first blank section 3 la of the blank 30 on the width direction outer side of the extension
line L and on the one length direction side of the second imaginary ridge line 31b-2 and the
18
third imaginary ridge line 3 1 b-3 is set as the out-of-plane deformation snppression region
(region F). The out-of-plane deformation suppression region (region F) is in contact with a
top plate face of the die 41 (spccificall~~a ,f ace aligned with the first blank scction 3la of tlie
blank 30).
[0074] Next, explanation follows regarding operation and advaritagcous effects of tlie
present exemplary embodiment, while explaining the manufacturing method of thc pressed
article 20.
[0075] Pressed Article 20 Manufacturing Methods (Free Bending Methods)
The pressed article 20 is manufactured using either a first tnatiufacturirig rnethod or a
second mannfacturing method, described below. The first manufacturing method and the
second manufacturing method are both methods for nlariufact~tringth e prcsscd article 20 by
cold bending the blank 30.
[0076] First Manufacturing Method of the Pressed Article 20
The first manufacturing method of the pressed article 20 includes the processes 1-1,
1-2 below.
Process 1-1
The blank 30, or the forming sheet resulting from pre-processing the blank 30, is set
in the mold unit 40. Namely, as illustrated in Fig. 9, the blank 30 or the forming sheet is set
on the die 41 in a positioned state.
[0077] Process 1-2
Then, in a state in which the blank edge 30a of the blank 30 or the fonning sheet is
present in tlie same plane as the first blank section 31a of the blank 30 or the forming sheet,
tlie out-of-plane deformation suppression region (region F), this being part of the first blank
section 3 la, is applied with pressure by the pad 42 (see the respective left sides of Fig. 8(A)
and Fig. 8(B)). 111 this state, either one or both out of the die 41 or the bending molds 43 are
moved in a direction relatively approaching each other. When this is perfomled, the blank
edge 30a on the one length direction side of the blatlk 30 or the forming sheet is bent so as to
be pressed into tlie pair of vertical walls 20c and the pair of flanges 20d of the pressed article
20 (see the respective right sides of Fig. 8(A) and Fig. 8(B), and also Fig. lo), while being
moved in-plane (moved toward the arrow J direction side in Fig. 9) with respect to a location
of the die 41 corresponding to the top plate 20a.
[0078] In this manner, in the first manufacturing tnethod, the occurrence of cracking of the
flanges 20d and creasitlg of the top plate 20a is suppressed due to configuting part of the
blank 30 as the out-of-planc deformation suppression region (region F), and applying a
specific load pressure to the out-of-plane deformation suppression region (region F) using the
19
pad 42.
[0079] If the load pressure of the pad 42 is set too high, thc first blank section 3 la of the
blank 30 in contact with the die 41 is unable to undergo sufficient in-plane movenient
(sliding) between the die 41 and the pad 42 during pressing. Cracking of the flanges 20d
occurs in such cases.
[0080] Conversely, if the load pressure of the pad 42 is set too low, out-of-plane deforniation
of the first blaok section 31a of the blank 30 in contact with the die 41 cannot be restrained
during pressing. Creasing of the top plate 20a occurs in such cases.
[0081] Moreover, when fom~ingsh eet steel with a tensile strength of from 200 MPa to 1600
MPa, such as is generally employed in automobile co~llponentsa nd the like, cracking of the
flanges 20d occurs if the pad 42 applies pressure to the blank 30 at a load pressure greater
than 30 MPa. Conversely, if the pad 42 applies pressure to the blank 30 at a load pressure of
less than 0.1 MPa, out-of-plane deformation of the first blank section 31a of the blank 30
cannot be sufficiently suppressed, and creasing of the top plate 20a occurs. Accordingly, it is
desirable to set the pad 42 to apply pressure of from 0.1 MPa to 30 MPa when fo~mingth e
sheet steel described above.
[0082] Moreover, when presses and mold units such as are generally etnployed in
automobile component manufacture are considered, if the load pressure of the pad 42 is below
0.4 MPa, stable pressure application with the pad 42 using a gas cushion or the like becomes
difficult, due to the load pressure being small. Conversely, if the load pressure of the pad 42
is above 15 MPa, high pressure application apparatus becomes necessary due to the load
pressure being large, thereby increasing equipment costs. Accordingly, it is desirable for
pressure application by the pad 42 to be performed at from 0.4 MPa to 15 MPa.
[0083] Note that here, the "pressure" refers to the average pressure over a plane, and is
found by dividing the force of the pad pressure by the surface area of the contact region
between the pad 42 and the blank 30, and some localized variation may be present.
[0084] In the above manufacturing method, for the pad pressure application, the pad 42
enlployed preferably has a shape covering the entire portion of the blank 30 that contacts the
top plate face of the die 41, or covering part of the portion of the blank 30 that contacts the top
plate face of the die 41, including the entirety of the out-of-plane deformation suppression
region (region F). However, in cases in which due, for example, to the design of the
manofactused component, an additional shape has been added to the out-of-plane deformation
suppression region (region F), the pad 42 rnay have a shape such as the follo\ving. Namely,
the pad 42 may be fornled so as to avoid the additional shape portion, and the pad 42 may be
fornled with a shape that at least includes a region up to 5 tntn to the inside of the second
20
imaginary ridge line 3 Ib-2 at a location \\?liere the out-of-plane deforniation suppression
region (region F) meets tlie second imaginary ridge line 3 1 b-2, and that covers 50% or nlore
of the surface area of tlie out-of-plane deforniation suppression region (region F). This is
since creasing of the top plate 20a is liable to occur if, for examplc, the pad 42 only applies
pressnrc in a region of the first blank section 3 la up to 4 mtil to the inside of this boundary
line.
[0085] Second Manufacturing Method
The second ~natiufacturingm ethod of tlie pressed article 20 includes the processes
2-1,2-2 described below.
Process 2- 1
Similarly to in the first manufacturing method, the blank 30 or the forming sheet is
set on the die 41 in a positioned state.
[0086] Process 2-2
Then, in a state in which the blank edge 30a of the blank 30 or the forming slieet is
present in the same plane as the first blank section 3 la of the blank 30 or the forming sheet,
the pad 42 is placed in the vicinity of, or in contact with, the out-of-plane deformation
suppression region (region F), this being part of the first blank section 3 la, to attain a state in
which a gap between the pad 42 and the die 41 is maintained at no less than the sheet
thickness, and no greater than 1.1 times the slieet thickness, of the blank 30 or the forming
slieet. I11 this state, either one or both out of the die 41 or the bending molds 43 are moved in
a direction relatively approaching each other. When this is performed, the blank edge 30a of
the blank 30 or the forming sheet is bent so as to be pressed into the vertical walls 20c and the
flanges 20d of the second formed sectiori 22, while being moved in-plane (moved toward the
arrow J direction side in Fig. 9) with respect to a location of tlie die 41 corresponding to the
top plate 20a.
[0087] In this manner, in the second manufacturing ~nettiodo f the pressed article 20, the gap
between the pad 42 and the die 41 is maintained at no less than the sheet thickness, and no
greater than 1.1 times the sheet thickness, of the blank 30 or the forming sheet. Accordingly,
excessive surface pressure does not act on the blank 30. This thereby allo\vs the blank 30 to
undergo sufficient in-plane movement (slide) within the mold unit 40 during pressing.
Moreover, in cases in which surplus material arises in the first blank section 3 1 a and a force
attempting to cause out-of-plane deformation of the blank 30 acts as pressing advances, such
out-of-plane deformation of tlie blank 30 is restrained by tlie pad 42. This thereby enables
the occurrence of cracking and creasing of the pressed article 20 to be suppressed.
[0088] Namely, were forming of tlie blank 30 to be performed with the gap between the pad
21
42 and the die 41 set to less than the sheet thickness of tlie bla~ik 30, excessive surface
pressurc would act between tlie blank 30 and tlie die 41. The blank 30 would therefore be
unable to u~idergos ufficient in-plane tnove~i~e(nstl ide) within thc lllold unit 40, leading to
cracking of the flanges 20d.
[0089] Conversely, were forming of the blank 30 to be perfor~lledw ith the gap between the
pad 42 and the die 41 set to 1.1 tinles the sheet thickness of the blank 30 or greatel;
out-of-plane deformation of the blank 30 could not be sufficiently restrained during pressing.
Accordingly, as pressing advanced, obvious creasing \vould occur in the top plate 20a due to
far too niuch of the blank 30 remaining at the top plate 20a. Moreover, buckling woold also
occur, ~illakingi t inlpossible to form a specific shape.
[0090] Moreover, it has been found that when forming sheet steel having a tensile strength
of froxn 200 MPa to 1600 MPa, such as is generally employed in automobilc components and
the like, creasing occurs to some extent when the gap between the pad 42 and the die 41 is
1.03 times the sheet thicktiess of the blank 30 or greater. Accordingly, in such cases, it is
even more desirable to set the gap behveen the pad 42 and the die 41 at no less than the sheet
thickness and no greater than 1.03 times the sheet thicktiess.
[0091] Note that in tlie second nianufacturing method, a "state in which the pad 42 has been
placed in the vicinity of the blank 30" rneans a state in which the blank 30 and the pad 42 do
not contact each other when the blank 30 moves in-plane (slides) over the location of the die
41 corresponding to the top plate 204 but the blank 30 and the pad 42 do contact each other if
the blank 30 is displaced towvard a direction so as to deform out-of-plane (or buckle) over this
location. More strictly speaking, the "state in which the pad 42 has been placed in the
vicinity of the blank 30" tneatis a state in which the gap between the pad 42 and the die 41 is
maintained at greater than 1.0 times the sheet thickness of the blank 30, and no gseater than
1 .I titnes the sheet thickness of the blank 30.
[0092] In the second manufacturing method, sitnilarly to in the first manufacturing method,
the vertical walls 20c atid the flanges 20d of the second formed section 22 of the pressed
article 20 are preferably formed by tnaking the pad 42 approacli or contact a region of the
blank 30 lying within the first blank section 31a arid up to at least 5 mtn to the inside of the
second imagina~yri dge line 3 1b -2. Namely, this is since creasing of the top plate 20a is
liable to occur if, for example, the pad 42 only applies pressure in a region of the first blank
section 3 la up to 4 nun inside the second imaginary ridge line 3 1 b-2.
[0093] Note that in a pressed article 20 manufactured using the first manufacturing tilethod
or tlie secolid ~nanufacturingm ethod described above, the outer profile is trimmed to a desired
shape, and hole forming and the like are performed in order to inanufacture a pressed body as
22
the rna~lufacturedc omponent.
[0094] As illustrated in Fig. 4, tlie blank 30 includes tlie excess portions 32. Thc cxccss
portions 32 bulge out toward tthc onc lcngth direction side froin the base edge 3 ld configuring
the one lengtli direction side edge of tlie blank base 31. The edges of each of the respective
excess portions 32 are configured including tlie first convex portion 34 that protrudes toward
the one length direction side of the base edge 3 Id. Accordingly, the blank edge 30a of the
blank 30 is fomled by using the excess portions 32 to increase the thickness of the base edge
3 id toward tlie one length direction side. This thereby enables a reduction in the slieet
thickness of the blank edge 30a (namely the edge of the base edge 3 id and the excess portions
32) to be suppressed even if the blank edge 30a liloves in-plane (slides) inside the niold unit
40 during the for~ilingp rocess of the pressed article 20.
[0095] Moreover, the edge of each excess portion 32 includes the first concave portion 33
adjacent on the width direction outer side of tile first convex portion 34, and the second
concave portion 35 adjacent on the width direction inner side (center side) of the first convex
portion 34. The first concave portion 33 and the second concave portion 35 are respectively
fonned in concave shapes opening toward the one length direction side, and connect the base
edge 31d and the first convex portion 34 together. Boundary portiotis between the first
convex portion 34 and the base edge 3 Id can accordingly be smoothly connected through the
first concave portion 33 and the second concave portion 35. This thereby enables a localized
reduction in sheet thickness at boundary portions between the first convex pottion 34 and the
base edge 31d in the blank 30 to be suppressed, and enables top plate edge cracking at these
boundary portions to be siippressed.
[0096] Explanation follows regarding these points, with reference to comparative exanlples.
Fig. 1lA illustrates a pressed article of a Comparative Example 1, with dots illustrating a
proportional reduction in sheet thicktiess in the vicinity of a blank edge. Fig. 11B illustrates
a pressed article of a Comparative Example 2, with dots illustrating a proportional reduction
in sheet thickness in the vicinity of a blank edge. Fig. 11C illustrates the pressed article 20
of the present exemplary embodiment, with dots illustrating reduction in sheet thickness in the
vicinity of the blank edge 30a. In Fig. 11A to Fig. 11 C, tlie dot density is greater in regions
with a higher proportional reduction in sheet thicktiess in the pressed article. First,
explatlation follows regarding the blanks employed in Comparative Example 1 and
Comparative Exanlple 2. Note that in the following explanation, the blanks and pressed
articles of Comparative Example 1 and Comparative Example 2 are described using the same
reference numerals as in the present exemplary embodiment.
[0097] In Comparative Example 1 illustrated in Fig. l lA, tlie excess portions 32 of the
23
present exen~plarpe tnbodiment are omitted from the blatlk 30. Namely, in the blank 30 of
Comparative Example 1, the blank edge 30a is configured by only the base edge 3 1 (1.
Moreover, in Co~uparativeE xanlple 2 illustrated in Fig. 1 IB, the first concave portions 33 and
the second concave portions 35 are omitted fro111 the edges of the excess portiolts 32 of the
blank 30 of the present exemplary embodimetlt. Namel): in the blatlk 30 of Comparative
Example 2, the blank edge 30a is configured by the base edge 3 1d and the first convex
portions 34.
[0098] As illustrated in Fig. 11 A, in Comparative Exa~nple1 , due to omittiug the excess
portions 32 from the blank 30, in the pressed article 20, there is a tendency for a large
reduction in sheet thickless of the blank 30 to occur in the vicinity of two locations P1 on the
blank edge 30a. Explauation follows regarding this point. In the blank 30, each second
blank section 3 1c is disposed adjacent to, and on the other length direction side of, the second
imaginary ridge line 3 1b-2 and the third imaginary ridge lule 3 1b-3 (see Fig. 4).
Accordingly, when the vertical walls 20c and the flanges 20d of the second formed section 22
are formed as illustrated in Fig. 9 using the first ~nanufacturingm ethod or the second
manufacturing method, the out-of-plane deformation suppression region (region F) of the first
blank section 3 la in particular moves in-plane (slides) toward the other length direction side
(toward the arrow D2 side in Fig. 9). Namely, in the first blank section 31a of the blank 30,
portions at the width direction outer sides of the extension lines L in particular ut~dergo
in-plane movement (slide) toward the other length direction side.
[0099] In Fig. 12 and Fig. 13, arrows are used to indicate in-flow paths of the material of the
top plate 20a flowing toward the side of the vertical wall 20c and the flange 20d when the first
blank section 31a moves in-plane (slides). As illustrated in Fig. 12 and Fig. 13, in the
in-flow paths of the material of the top plate 20a, the in-flow paths of the material of the top
plate 20a become longer on progression from the end portion PA on the second ridge line
20b-2 toward the end portion PB side. Namely, the in-flow paths of the material of the top
plate 20a become longer on progression toward the width direction outer side of the second
ridge line 20b-2. Accordingly, the out-of-plane deformation suppression region F (the
portion of the first blank section 3 la on the width direction outer side of the extension line L)
moves in-plane (slides) so as to sweep around toward the other length direction side about an
origin in the vicinity of the intersection PI behveen the extension line L, this being a tangent
to the second ridge line 20b-2 at the end portion PA, aud the blank edge 30a (see arrow J in
Fig. 9).
[0100] When the material of the top plate 20a flows in toward the side of the vertical wall
20c and the flange 20d, the material is gathered along the peripheral directiotl of the cutved
24
ridgc line at a portion of the top plate 20a in the vicinity of the second ridge line 20b-2 (see
tlie arrow K in Fig. 12), and the top plate 20a accordingly attetilpts to undcrgo out-of-plane
defor~nation. However, as described above, in the frce bending tuethod, out-or-plane
defor~nationo f the top plate 20a is restrained by the pad 42. Accordingly, force arising when
the top plate 2021 is being restrained propagates such that the top plate 20a (first blank section
31a) is pulled substantially along the width direction. Namely, in the first blank section 31a,
the out-of-plane deforntation suppression region F in particular is pulled substantially in the
width direction while moving in-plane so as to sweep around toward the other length direction
side. Accordingly, in Comparative Example 1, as illustrated in Fig. 11 A, tensile stress
concentrates in the vicinity of the intersections PI, and the reduction in sheet thickness of the
blank edge 30a is coricentrated in the vicinity of the intersections PI. As a result, in
Comparative Exatiiple I, there is a large reduction in the sheet thickness of the blank 30 in the
vicinity of the hvo intersections PI, and there is a possibility of top plate edge cracking
occurring.
[0101] By contrast, in Comparative Example 2, the first convex portions 34are formed at
the blank edge 30a as illustrated in Fig. 1 lB. Accordingly, the first convex portions 34 bulge
out toward the one length direction side in the vicinity of tlie intersections PI on the blank
edge 30a (in other words, the blank edge 30a is thickened toward the one length direction side ,
in the vicinity of the locations PI). This alleviates the concet~trationo f tensile stress in the
vicinity of the intersections PI at the blank edge 30a when the blank edge 30a undergoes
in-plane movement, suppressing the reduction in sheet thickness from becoming large in the
vicinity of the intersections PI on the blank edge 30a. As a result, in Comparative Example
2, top plate edge cracking is suppressed from occurring in the pressed article at the hvo
intersections PI.
[0102] I-Iowever, in Comparative Example 2, the first concave portions 33 and the second
concave po~tions3 5 of the present exempla~ye mbodiment are omitted fro111 tlie edges of the
excess portions 32. The curvature of the blank edge 30a is therefore discontinuous about
intersections P2 beheen tlie respective first convex portions 34 and the base edge 3 Id.
Accordingly, in the blank edge 30a, localized concentration of tensile stress occurs at the
intersections P2 when the blank edge 30a undergoes in-plane movement (slides). There is
accordingly a localized reduction in the sheet thickness of the blank 30 at tlie intersections P2
between the first convex portions 34 and the base edge 31d. As a result, there is a possibility
of top plate edge cracking occurring at the intersections P2.
[0103] By contrast, in the present exemplary embodiment illustrated in Fig. 11 C, the edge of
each excess portion 32 is configured by the first convex portion 34, the first concave portion
25
33, and the second concave portion 35. Accordinglj: in comparison to Comparative
Example 2, discontin~~iitny the curvature of the blank edgc 30a at the boundary portion
between the first convex portion 34 and tlie base edge 3 1 d is suppressed by the first concave
portion 33 and the second concave portion 35. Accordingly, when the blank edge 30a moves
in-plane (slides), tensile stress acting at the blatlk edge 30a becomes substantially uniform
along the width direction. hl other words, localized concentration of the tensile stress at the
intersection P2 described above is suppressed. As a result, a localized reduction in the sheet
thickness of the blank 30 at the boundary portion between the first convex portion 34 and tlie
base edge 3 Id is suppressed, and the proportional reduction in sheet tliicktless of the blank
edge 30a becomes substantially utliform along the width direction. This thereby enables top
plate edgc cracking of the blank edge 30a to be su~ppressed..
[0104] Doe to the above, fonning the pressed article 20 with the free bending method using
the blatlk 30 of the present exe~nplatye mbodiment enables the occurrence of top plate edge
cracking of the pressed article 20 to be suppressed.
[0105] Moreover, as described above, when formit~gth e pressed article 20, the blank edge
30a moves in-plane (slides) toward the other length direction side, and the first concave
portions 33 and the second concave portions 35 of the edges of the respective excess portions
32 are stretched out along the width direction. Accordingly, in comparison to Comparative
Example 2, the blank edge 30a of the blank 30 can be encouraged to flow inside the mold unit
40 when forming the pressed article 20. The displacement amount of the first blank section
31a of the blank 30 toward the side of the vertical walls 20c and the flanges 20d is thereby
increased, thus enabling the occurrence of flange edge cracking of the pressed article 20 to be
suppressed during pressing.
[0106] Regarding this point, explariatiori follows regarding the occurrence of top plate edge
cracking and flange edge cracking when pressed articles are manufactured from blanks of
various shapes, as illustrated in Fig. 14A to Fig. 14E, with reference to Table 1 below. Note
that the variously shaped blanks illustrated in Fig. 14A to Fig. 14E each e~nployh igh tensile
sheet steel with a tensile strength of 1180 MPa and a sheet thickness of 1.6 mm. Moreover,
in manufacture of the various pressed articles mentioned above, blank top plate portions of the
blanks are held down by the pad 42, and then the respective pressed articles are ~natlufactured
using a free bending method (the first manufacturing method described above) using the die
41 and the bending tnolds 43 for bending.
[0107] First, explanation follows regarding blanks 53 to 56 of Comparative Exatnple 3 to
Comparative Example 6 illustrated in Fig. 14A to Fig. 14D, and an example of the blank 30 of
the present exemplary embodiment illustrated in Fig. 14E. As illustrated in Fig. 14A, in the
26
blank 53 oSCornparative Example 3, the excess portions 32 of the present exemplary
emboditnent are omitted (namely, this is a blank with the same specifications as Comparative
Exa~nplc 1 above). As illustrated in Fig. 14B, in the blank 54 of Cotnparative Example 4, an
excess portion 32 having an edge with negative curvature is formed at one length direction
end of the blank 30, and the radius of curvature of the cxccss poi-tion 32 is set to 300 mm.
As illustrated in Fig. 14C, the blatlk 55 of Comparative Example 5 is for~nedw ith an excess
portion 32 having an edge extending in a straight line along the width direction. As
illustrated in Fig. 14D, the blank 56 of Comparative Exa~nple6 is formed with a pair of
excess portions 32 having edges with positive curvature, and the radii of curvature of the
excess portions 32 are set to 150 innl. In the blank 56 of Comparative Example 6, the first
concave portions 33 and the second concave portions 35 of the present exemplaiy
embodiment are omitted (namely, this is a blank with the same specifications as Comparative
Example 2). As illustrated in Fig. 14E, in the example of the blank 30 of the present
exempla~ye mbodiment, the respective radii of curvature of the first convex portions 34, the
first concave portions 33, and the secol~dc oncave portions 35 of the pair of excess portions 32
are each set to 100 mm. Moreover, the surface area of the excess pot-tions 32 is set smaller
than in Comparative Example 5.
[0108] Table 1
[0109] As shown in Table 1, in Comparative Example 3, although flange cracking did not
occur at regions A (see Fig. I), top plate edge cracking did occur at region B (see Fig. l),
Blank Shape
Flange
Cracking at
Regions A
Edge Cracking
at Region B
similarly to in Comparative Example 1 above. In Comparative Example 4, the surface area
at the one length direction end portion of the blank 54 is larger than in Cotnparative Example
3 by the atnount added by the excess portion 32. Accordingly, the proportional reduction it1
sheet thickness at region B was reduced, but top plate edge cracking still occurred at region B.
Moreover, in Comparative Example 5, the surface area of the one length direction end portion
of the blank 55 is larger than in Comparative Example 4. Accordingly, the proportional
27
Comparative
Exatnple 3 (53)
Absent
Present
Comparative
Exatnple 4 (54)
Absent
Present
Comparative
Example 5 (55)
Present
Absent
Comparative
Example 6 (56)
Absent
Present
Present
Exemplary
Embodiment
(30)
Absent
Absent
reduction in sheet thickness at rcgion B was reduced, and top plate edge cracking at region B
could be averted. However, in Conlparative Exatnplc 5, the largcr surface arca at the one
length direction end portion of the blank 55 makes it difficult for the blank edge to undergo
in-plane rnovelilelit during pressing, and the displacelne~lat nlouut from the portion of the
blank 55 that forms the top plate toward tlie side of the vertical walls a~idth e flanges is small.
Flange cracking therefore occusred in tlie pressed article. In Comparative Exatnple 6,
similarly to in Comparative Example 2 above, there were localized reductions in tlie sheet
thickness of the blank 56 at the intersections between the first convex portioils and the base
edge, and top plate edge cracking occurred at these intersections (inflection points).
[0110] By contrast, the exaniple illustrated in Fig. 14E, this being an exa~npleo f the present
exemplary emboditnent, enables the proportional reduction in sheet thickness at the blank
edge 30a to be reduced. Moreover, the surface area of the excess portions 32 is smaller than
in the blank 55 of Comparative Example 5, and there is good in-plane movement of the blank
edge 30a. This thereby enables the proportional reduction in sheet thickness at regions A to
be kept sniall. Accordingly, the present exempla~ye mbodiment is capable of preventing not
only flange edge cracking at regions A, but also top plate edge cracking at region B.
[Olll] As described above, forming the pressed aticle 20 with a free bending method using
the blank 30 of the present exemplaly embodiment enables top plate edge cracking to be
suppressed, and also enables flange cracking to be suppressed in the pressed article 20.
[0112] In the blank 30 of the present exemnpla~ye mbodiment, the excess portions 32 are
disposed on tangents to the end portions PA of the second ridge lines 20b-2 (in other words,
on the extension lines L). Specifically, the apex portions (apexes) of the excess portions 32
are disposed on tangents to the end portions PA of the second ridge lines 20b-2 (in other
words, on the extension lines L). Accordingly, the blank 30 is tl~ickenedt o\vard the one
length direction side in the vicinity of the iritersections P1, where would othenvise be a large
proportional reduction in sheet thickness of the blank 30 during the pressing process. This
thereby enables a reduction in sheet thickness of the blank 30 in the vicinity of the
intersections P1 to be effectively suppressed, and enables top plate edge cracking to be
effectively suppressed.
[0113] Moreover, in tlie present exemplary embodiment, in plan view, each of the excess
portions 32 is formed with left-right asymmetry about the extension line L in the width
direction. Specifically, the curvature of the fist coticave portion 33 is set smaller than the
curvature of the second concave portion 35. In other words, the radius of curvature of the
first concave portion 33 is set larger than the radius of cul-vature of the second concave
portion 35. Accordingly, the difference behveen the curvature of the first convex poltion 34
28
and the curvature of thc first c~nca\p~oer tion 33 can be made smaller than the difference
between the curvature oftl~efi rst convcx portion 34 and the curvature oftthe second concave
portion 35. This thereby enables the proportional reduction in sheet thickness to be lnade
cvcn nlore uniform at thc excess portions 32, and enables top plate edge cracking of the
pressed article 20 to be even more effectively suppressed.
[0114] Moreover, in the present exempla~ye mbodiment, the width dimension W4 of each
excess portion 32 on the width dircction outer side of the extension line L is set longer than
the widtli dimension W5 of the excess portion 32 on the width direction inner side of the
extension line L. This thereby enables top plate edge cracking of the pressed article 20 to be
effectively suppressed. Namclj: as described above, when the blank edge 30a tlloves
in-plane (slides) toward the arrow J direction side in Fig. 9 during pressing, the blank edge
30a corresponding to the out-of-plane deforn~ations uppression region (region F) in particular
moves in-plane (slides) toward the other length direction side. Namely, in particular, the
portion of each excess portion 32 011 the width direction outer side of the extension line L
moves in-plane (slides) toward the other length direction side. Accordingly, setting the
width dimension W4 of each excess portion 32 at a portion on the width direction outer side
of the extension line L longer than the width dimension W5 of the excess portion 32 at a
portion on the width direction itmer side of the extension line L enables the reduction in sheet
thickness to be effectively suppressed at the portion on the width direction outer side of the
extension line L. This thereby enables top plate edge cracking of the pressed article 20 to be
effectively suppressed.
[0115] Moreover, in the present exemplary embodiment, performing a free bending method
using the blank 30 enables the occurrence of flange cracking and top plate edge cracking to be
prevented in the pressed article 20, wvlile securing a width W3 of 300 mnl or greater or 400
mm or greater at the one length direction side end portion of the pressed article 20.
Accordingly, the present excmplaly embodiment enables the manufacture of a fiamework
configuration con~ponent6 0 configuring a vehicle framework component, such as that
illustrated in Fig. 15 (Fig. 15 illustrates a framework configuration corilponent configuring a
vehicle center pillar). Explanation follows regarding examples of dinlensions of the
framework configuration component 60.
[0116] Namely, the framework configuration cotnponent 60 illustrated in Fig. 15 has an
overall length of 1105 tnm, and the width of a top plate corresponding to the first fornled
section 21 is from 65 mm to 70 IIUII. The widths of the top plate at an upper end portion and
a lower end portion corresponding to second formed sections 22 (namel): length direction end
po~lions)a re respcctivcly 260 nlnl and 490 ~nma, nd the height of the vertical walls is 65 mm
29
at its maxirnu~np oint. The flange width is 25 nnn. Blanks for the fia~neworkc onfiguration
component 60 are tmanufachired frotn three types of high tensile sheet steel of590 MPa grade,
980 MPa grade, and 1180 MPa grade tensile strength, and each has a sheet thickness of 1.6
trim. Accordingly, in the example illustrated in Fig. 15, the frame\vork configuration
co~nponen6t 0 secures a width at thc lower end po~tiont,h is being a length direction end
portion, of 400 nun or greater.
[0117] In the fratnework cot~figuratiotc~o tnponent 60 illustrated in Fig. 15, the length
direction end portions (the upper end poltion and the lower end portion) configure joints with
other members (for example, a roof rail or a side sill). Moreover, the framework
configuration component 60 is joined to the other members through the joints by nleans such
as spot welding or laser welding. Accordingly, enlploying the blank 30 of the present
exeinpla~ye n~bodi~neennta bles the joint surface area of the locations configuring joints with
other members to be increased (secured) in the fratnework configuration component 60.
This thereby enables the joint strength to other components to be increased. In particular,
this enables bending rigidity and twisting rigidity of a vehicle body shell to be in~provedin
cases in which the pressed article is a vehicle body configuration member such as the
fiamexvork configuration component 60 (for example various pillar outer reinforcement and
sill outer reinforcement).
[0118] Moreover, in the present exempla~yem bodiment, the pressed article 20 is configured
as a T-shaped profile component. However, the pressed article 20 may be configured as a
Y-shaped profile component. In such cases, the pressed ai-ticle 20 is applied to autornobile
rear ~netnbere inforcement or the like.
[0119] Second Exemplary Etnbodinnent
As illustrated in Fig. 16, in a second exetnpla~ye tnbodiment, a pressed article 70 is
configured as an L-shaped profile component. Explanation follows regarding the pressed
article 70 and a blank 80 of the second exemplary embodiment. Note that in the following
explanation, portions of the pressed article 70 and the blank 80 with similar configuration to
the pressed article 20 and the blank 30 of the first exemplary embodiment are allocated the
satne reference numerals.
[0120] Namely, as illustrated in Fig. 16, the pressed article 70 includes the top plate 20a, the
ridge lines 20b, the vertical walls 20c, and the flanges 20d. Moreover, in the pressed article
70, only one of the vertical walls 20c is curved to extend out toward the width direction outer
side in [he second formed section 22. Namely, the other vettical wall 20c is formed wit11 a
flat plane shape along the entirc length direction, and the curved portion 23 is only formed at
a single location in the pressed article 70.
30
[0121] The followi~igd iti~cnsio~airsc examples of the dimensions of the pressed article 70.
Namely, a length direction di~nensiono f the pressed article 70 is set in a range of fiom 100
111n1 to 1600 111til (for example, 300 turn in the present exeriiplary c~nboditnent). The width
W1 of tlie top plate 20a is sct in a range of fiotn 50 mm to 200 mm (for example 100 rim1 in
the present exemplary embodiment), and the width W3 at the one length direction end portion
of the top plate 20a is set in a range of from 70 mm to 1000 ~ n m(fo r exaaiple, 210 mm in the
present exemplary etnbodiment). The height of the vertical walls 20c, the radius of
curvature of the curved vertical wall 20c, and the width of tlie flanges 20d are set sinlilarly to
in the first exc~ilpla~emy bodiment.
[0122] Moreover, as illustrated in Fig. 17, in the blank 80 of the second cxcmplary
embodiment, the base edge 3 1d is curved so as to incline toward the one length direction side
(the arrow Dl direction side in Fig. 17) on progression toward the one width direction side
(the arrow D3 direction side in Fig. 17). Similarly to in tile first exemplary embodiment, the
excess portion 32 is fonned at tile base edge 3 1d and disposed over the extension line L.
[0123] I11 the second exemplary embodiment, the excess portion 32 is provided to the blank
80 si~nilarlyto in the first exemplary embodiment, thereby enabling top plate edge cracking
and flange edge cracking to be snppressed when forming the pressed article 70. Moreover,
forming an end portion in an L-shape, as in the pressed article 70, enables a htnework
configuration component 90 configuring the vehicle fixmework component illustrated in Fig.
18 to be manufactured (Fig. 18 illustrates a framework configt~rationc otnponent configuring a
vehicle front pillar). Simple explanation follows regarding dimensions of the framework
configuration co~nponent9 0 illustrated in Fig. 18.
[0124] The framework configuration component 90 has at1 overall length of 1150 tnm, atid
the width of a top plate corresponding to the first formed section 21 is 130 mm. The width
of a top plate at an end portion corresponding to tlie second formed section 22 is 340 mm, and
tlie maximum height of the vertical walls is 75 mm. The flange width is 25 nm. Blanks
for the pressed article 50 are formed from three types of high tensile sheet steel of 590 MPa
grade, 980 MPa grade, and 1180 MPa grade tensile strength, and each has a sheet thickness of
1.6 mm.
[0125] Note that in the first exemnplaly embodiment and the second exemplary embodiment
described above, the first concave portion 33, tlie first convex portioti 34, and the second
concave portion 35 of each excess portion 32 are disposed adjacent to each other in the width
direction. Alternatively, straight line portions extending in straight line sliapes may be
present at least at one location out of between the first concave portion 33 and tlie first convex
portion 34, or between the second concave portion 35 and the first convex portion 34.
31
Moreover, a straight line portioti extending ill a straight line shape may be present between the
second concave portion 35 and the first concave portion 33 of ad.jacc~ict xcess portious 32 it1
thc width direction. l'his thereby enables the first cotlcave portions 33, the first convex
portions 34, the secoud coricave portions 35, and third concave portions 36 to be formed as
desired at the blank edge 30a without setting large radii of curvature in cases in which snlall
radii of curvature would suffice for the first coucave portions 33, the first convex portions 34,
and the second concave portions 35.
[OI 261 In the first exetnplary embodiment and the second exemplary emhodimelit, in plan
vie\\: each excess portion 32 is fornied in a shape that is left-right asynitnetrical about the
extension liue L in the width direction. Alternatively, i ~pila t1 view, each excess portion 32
nlay be fortned in a shape with left-right sytnmetty about the extension line L in the width
direction.
[0127] In the first exetnplary en~bodi~neanntd the second exemplary embodiment, in plat1
view, the apex portion (apex) of each excess portion 32 (first convex portion 34) is set so as to
be positioned on the extension line L. Alternatively, the apex portion (apex) of each excess
portion 32 (first convex portion 34) may be disposed on the width direction outer side or the
width direction inner side of the extension line L. Namely, the first convex poition 34 is
disposed as appropriate between the inclined imaginaly line AL3 and the second imaginary
line AL2 according to the shape, material, and the like of the pressed article.
[0128] The disclosure of Japanese Patent Application No. 2014-100619, filed on May 14,
2014, and tlie disclosure of Japanese Patent Application No. 2014-203316, filed on October I,
2014, are iiicorporated in their entirety by reference herein.
[0129] Suppletnentary Explanation
A blank of the present disclosure is a blank for forming a pressed article that includes
a top plate formed in an elongated shape with a length direction along a first direction and
including a pair of outer edges extending along the length direction in plat1 view, the top plate
being laid out with at least one of tlie outer edges curving so as to extend out toward a width
direction outer side at an end portion on one length direction side of the top plate so that the
one outer edge is separated toward another length direction side from an edge 011 the one
length direction side, a pair of vertical walls extending out from the pair of outer edges toward
a lower side, and a pair of flanges, each extending out fiom a lower end portion of one of the
vertical \valls toward an opposite side from the top plate in plan view. The blank includes a
flat pattern edge configuring an edge on the one length direction side of the blank, and an
excess portion formed at the flat pattern edge. An edge of the excess portioti includes a first
coilvex portiori that protrudes toward the one length direction side of the blank with respect to
32
the flat pattern edge, a first concave pot-tion that is adjacent to thc first co~lvcxp ortion at a
\vidth direction outer side of tlie blank, that is for~ncdin a concave shape opening to\vard the
one length direction side of the blank, and that connects the flat pattern edge and the first
convex portion together, and a second concave portion that is adjacent to the first co~~vcx
portion at a width direction inner side of the blank, that is formed in a concave shape opening
toward the one length direction side of the blank, and that connects the flat patten1 edge and
the first convex portion together.
[013q Configuration may preferably be made in which, in a state in which the blank has
been disposed in a mold for fonning tlie pressed article, and a bending mold for for~ningth e
vertical walls and the flanges of the pressed article is in contact with an upper face of the
blank, and given that, in plan view, a curved imaginary line is defined as an imaginary line
running along a curved shoulder portion of the bending mold for fonning the vertical wall that
is curved, a first imagina~yli ne is defmed as an imaginary line passing though a base end
portion of the cul-ved imaginary line and extending in the width direction of the blank, and a
second imaginary line is defined as an imaginary line passing though a terminal end portion
of the curved imaginary line and extending in the length direction of the blank, the first
convex portion is disposed between the second imaginary line and an inclined itnaginary line
that passes through an intersection betwveen the first imaginary line and the second imaginary
line and is inclined at 22.5O toward the one length direction side of the blank with respect to
the first imaginary line.
[0131] Configuration may preferably be made in which, in a state in which the blank has
been disposed in the mold for forming the pressed article and the bending mold is in contact
with the upper face of the blank, and given that, in plan view, an adjacent imaginary line is
defined as an imaginary line n~ntlit~algo ng the shoulder portion of the bending mold for
forming the vertical wall and is an imaginary line adjacent to the base end portion of the
curved imaginary line, the first convex portion is disposed on an extension line extended from
the adjacent imaginary line toward the one length direction side of the blank.
[0132] Configuration may preferably be made in which the edge of the excess portion is
formed in a shape that is left-right asymmetrical about tlie extension line in the width
direction of the blank.
LO1331 Configuration may preferably be made in which a curvature of the first concave
portion is set smaller than a curvature of the second concave portion.
LO1341 A pressed article manufacturing method of the present disclosure is a pressed article
manufacturing method that employs pressing using cold bending to manufacture a pressed
article that includes a top plate formed in an elongated shape with a length direction along a
33
first direction and including a pair of outer edges extending along tlie length direction in plan
view, the top plate being laid out with at least one of the outer edges c u ~ ~ ~sion ags t o extend
out toward a width direction outer side at an end portion on one length direction side of the
top plate so that the one outer edge is separated toward another length direction side from at1
edge on tlie one length direction side, a pair of vertical walls extending out ftom the pair of
outer edges toward a lower side, and a pair of flanges, each extending out from a lower end
portion of one of the vertical walls towvard an opposite side ftom the top plate in plan view.
The manufacturing n~etliodin cludes: disposing the blank of any one of claim 1 to clainl5, or
a for~nirigs heet resulting from pre-processing the blank, between a die, and a pad and a
bending mold; and, in a state in which the flat pattern edge and the edge of the excess portion
are present in tlie same plane as a portion that will form the top plate, bending so as to press
the vertical walls and the flanges of the pressed article \vhile moving the flat pattern edge and
the edge of the excess portion in-plane with respect to a location of the die corresponding to
the top plate, by relatively moving either the die or the bending mold, or both the die and the
bending mold, in a direction so as to approach each other in a state in which an out-of-plane
deformation suppression region that is part of the portion of the blank, or of the forming sheet,
that will form the top plate is being applied with pressure by the pad.
[0135] A pressed article manufacturing method of the present disclosure is a pressed article
manufacturing method that enlploys pressing using cold bending to manufacture a pressed
article that includes a top plate fo~medin an elongated shape with a length direction along a
first direction and including a pair of outer edges extending along the length direction in plan
view, the top plate being laid out with at least one of the outer edges curving so as to extend
out toward a width direction outer side at an end po~-tiono n one length direction side of the
top plate so that the one outer edge is separated toward another length direction side from an
edge on the one length direction side, a pair of vertical walls extending out from the pair of
outer edges toward a lower side, and a pair of flanges, each extending out from a lower end
portion of one of the vertical walls toward an opposite side from the top plate in plan view.
The manufacturing method includes: disposing the blank of any one of claitn 1 to claim 5, or
a forming sheet resulting from pre-processing the blank, between a die, and a pad arid a
bending mold; and, in a state in which the flat pattern edge and the edge of the excess portion
are in the same plane as a portion that will forn~th e top plate, bending so as to press the
vertical walls and the flanges of tlie pressed article wvliile moving the flat patter11 edge and the
edge of the excess portion in-plane with respect to a location of the die cor~espondingto the
top plate, by placing the pad in the vicinity of, or in contact with, an out-of-planc deformation
suppression region that is part of a region of the blank, or of the forming sheet, tliat \vill fonn
34
the top plate, and relatively moving citl~ctrh c die or the beading mold, or both the die and the
bending mold, in a direction so as to approach each other while maintaining a gap between the
pad and the dic of no less than a sheet thickness of the blank, or of the fornling sheet, and no
more than 1.1 times the sheet tllickt~csso f the blank, or of the forming sheet.
[0136] Moreover, configuration may preferably be made in which thc breaking strength of
the blank, or of the forming sheet, is from 400 MPa to 1600 MPa.
[0137] Moreover, a blank of the present disclosure is a stock nlaterial for an elongated
pressed article obtained by performing pressing in wvhich the blank or a forlning sheet
resulting from pre-processing the blank is bent using a pressing machine including a die, a
bending mold, and a pad. The elongated pressed article has a substantially hat shaped lateral
cross-section profile including a top plate that is present extending in one direction and that
has a specific width in a direction intersecting the one direction, two ridge lines that are
respectively linked to both edges of the top plate in a width direction that is a direction
intersecting the one direction, two vertical walls that are respectively linked to the twvo ridge
lines, and two flanges that are respectively linked to the two vertical walls. The elongated
pressed article is configured by a first section in which the vertical walls are formed in flat
plane shapes along the one direction, and a second section that is linked to the first section,
and that includes a curved portion where the two vertical walls, and the ridge lines and the
flanges that are respectively linked to the vertical walls, all curve substantially toward a sheet
thickness direction of the vertical walls, and the width of the top plate gradually increases in
comparison to the width of the top plate in the first section, such that the top plate exhibits a
T-shape or a Y-shape in plan view. The blank has a shape in which a flat pattern of the
pressed article is additionally provided with an excess portion at an edge at a location that will
form the top plate in the second section, an edge of the excess portion being provided with a
first concave portion, a first convex portion and a second concave portion, a third concave
portion, and a second convex portion and a fourth concave portion, that satisfy the following
condition 1.
Condition 1: Taking a cu~vatureto ward an inward direction of the blank as
negative, and taking a curvature toward the opposite direction to the inward direction as
positive, the first concave portion with negative curvature, the first convex portion with
positive curvature, the second concave portion with negative curvature, the third concave
portion with negative curvature, the second convex portion with positive cut~aturea, nd the
fourth concave portion wit11 negative curvature are formed in tllis sequence side-by-side along
the edge of the excess portion.
[0138] Moreover, a blank of the present disclosure is a stock material for an elongated
35
pressed ailicle obtained by perfomling pressing in which the blank or a forming shcct
resulting from pre-processing the blank is bent using a pressing machine including a die, a
bending mold, and a pad. The elongated pressed article has a substantially hat shaped lateral
cross-section profile including a top plate that is present extending in one direction and that
has a specific width in a direction intersecting the one direction, two ridge lines that are
respectivelp linked to both edges of the top plate in a width direction, two vertical walls that
are respectively linked to the two ridge lines, and two flanges that are respectively linked to
the two vertical walls. The elongated pressed article is configured by a first section in which
the vertical walls are formed in flat plane shapes along the one direction, and a secoild section
that is linked to the first section, and that includes a curved portion where one vertical wall
out of the two vertical walls, and the ridge line and the flange linked to this vertical wall, all
curve substantially toward a sheet thickness direction of this vertical wall, and the width of
the top plate gradually increases in co~nparisonto the width of the top plate in the first section,
such that the top plate exhibits an L-shape in plan view. The blank has a shape in which a
flat pattern of the pressed article is additionally provided with an excess portion at an edge at
a location that will form the top plate in the second section, an edge of the excess portion
being provided with a first concave portion, a convex portion, and a second concave portion
that satisfy the following condition 1.
Condition 1: Taking a curvature toward an inward direction of the blank as negative, and
taking a curvature toward the opposite direction to the inward direction as positive, the first
concave portion with negative curvature, the convex portion with positive curvature, and the
second concave portion with negative curvature are formed in this sequence side-by-side
along the edge of the excess portion.

CLAIMS
1. A blank for fornling a pressed article that includes:
a top plate forriled in an elongated shape with a length direction along a first direction
and including a pair of outer edges extending along tlie length direction in plat1 view, the top
plate being laid out with at least one of the outer edges curving so as to extend out toward a
width direction outer side at an end portion on one length direction side of the top plate so that
tlie one outer edge is separated toward another length direction side fsom an edge on the one
length direction side,
a pair of vertical walls extending out fsotn tlie pair of outer edges toward a lower side,
aud
a pair of flanges, each extending out fro111 a lower end portion of one of the vertical
walls toward an opposite side from the top plate in plan view,
the blank comprising:
a flat pattern edge configuring an edge on the one length direction side of
the blank; and
an excess postion formed at tile flat pattern edge, wherein an edge of the
excess portion includes:
a first convex portion that protrudes toward the one length direction side of
the blank with respect to the flat pattern edge,
a first concave portion that is adjacent to the fist convex portion at a width
direction outer side of the blank, that is formed in a concave shape opening toward
tlie one length direction side of the blank, and that connects the flat pattern edge and
the first convex portion together, and
a second concave portion that is adjacent to the first convex portion at a
width direction inner side of tlie blank, that is formed in a concave shape opening
toward the one length direction side of the blank, and that connects the flat pattern
edge and the first convex portion together.
2. The blank of claim 1, wherein:
in a state in which the blank has been disposed in a ~iloldfo r forming the pressed
article, and in which a bending nlold for fornling the vertical walls and the flanges of the
pressed article is in contact with an upper face of the blank, and
given that, in plan view, a cul-ved imaginary linc is defined as an imaginasy line
running along a cutved shoulder pottion of the bending mold for fornling the ve~tica\l \dl that
is curved, a first imaginaty line is defined as an imaginary line passing through a base end
37
portion of the curved imaginary line and extending in tlie width direction of tlie blank, and a
second imaginary line is defined as an imagioar)' line passing through a tertiiinal cnd portion
of the curved imaginary line arid extending in thc length direction of the blank,
the first convex portion is disposed between the second iniaginarp line aid an
inclined iniaginary line that passes tlnougli an intersection between the first imaginary line
and the second imaginary line atid is inclined at 22.5' toward tlie one length direction side of
the blank with respect to the first itnaginary line.
3. The blank of clairn 2, wherein:
in a slate in which the blank has been disposed in the nlold for for~iiingth e pressed
article and thc bending mold is in contact with the upper face of tlie blank, arid
given that, in plan view, an adjacent imaginary line is defined as at1 itnaginary line
running along the shoulder pottion of the bending mold for forming the vertical wall and an
itnaginary line adjacent to the base end poltion of the curved iniaginary line,
the first convex portion is disposed on an extension line extended from tlie adjacent
imaginary line toward the one length direction side of the blank.
4. The blank of claim 3, wherein the edge of the excess portion is fornied in a shape that is
left-right asynunetrical about the extension line in the width direction of the blank.
5. The blank of any one of claim 1 to claini 4, wherein a curvature of the first concave
pottion is set smaller than a curvature of the second concave portion.
6. A pressed article manufacturing method that employs pressing using cold bending to
manufacture a pressed article that includes:
a top plate formed in an elongated shape with a length direction along a first direction
and including a pair of outer edges extending along the length direction in plat1 view, the top
plate being laid out with at least one of the outer edges curving so as to extend out toward a
width direction outer side at an end poition on one length direction side of tlie top plate so that
the one outer edge is separated toward another length direction side fro~nan edge on the one
length direction side,
a pair of vertical walls extending out from the pair of outer edges toward a lower side,
a pair of flanges, each extending out from a lo\vcr end pol-tion of one of tlie vertical
walls toward an opposite side frotn tlie top plate in plan view, the manufacturing method
38
disposing the blank of any one of clai~i1l to clailil 5, or a forming sheet resulting
from pre-processi~igth e blank, between a die, and a pad and a bending mold; and
in a state in which the flat patter11 edge and the edge of the excess portion arc present
in a same plane as a portioli that will form the top plate,
bendi~igs o as to press the vertical walls aud the flanges of the pressed article while
moving the flat pattern edge and the edge of the excess portion in-plane with respect to a
locatiori of the die corresponding to tlie top plate, by relatively moving either the die or the
bending inold, or both the die and the bellding mold, in a direction so as to approach each
other in a state in wllich at1 out-of-plane deforlllation suppressioil region that is part of the
portion of the blank, or of the forming sheet, that will form the top plate is being applied with
pressure by the pad.
7. A pressed article manufacturing xilethod that ernploys pressing using cold bending to
manufacture a pressed article that includes:
a top plate formed in an elongated shape with a length direction along a first direction
and including a pair of outer edges extending along the length direction in plan view, the top
plate being laid out with at least one of the outer edges cu~vingso as to extend out toward a
width direction outer side at an end portioti on one length direction side of the top plate so that
the one outer edge is separated toward another length direction side from an edge on the one
le~igthd irection side,
a pair of vertical walls extending out from the pair of outer edges toward a lower side,
and
a pair of flanges, each extending out fiom a lower end portion of one of the vertical
walls toward an opposite side fiom the top plate in plan vie\+; the manufacturi~igm ethod
conlprising:
disposing the blank of any orie of claim 1 to claitn 5, or a fortning sheet resulting
from pre-processing the blank, between a die, and a pad and a bending mold; and
in a state in which the flat pattern edge atid the edge of the excess portion are in a
same plane as a portion that will form the top plate,
bending so as to press the vertical walls and tlie flanges of the pressed article while
tnovitig the flat pattern edge and the edge of the excess portion in-plane with respect to a
location ofthe die corresponding to the top plate, by placing the pad in a vicinity of, or in
coutact with, an out-of-plane defor~ilations uppression region that is part of a regioil of the
blank, or of the forming sheet, that will form the top plate, and relatively moving either the
3 9
die or the bending mold, or both the die and the bending mold, in a direction so as to approach
.t -, each other while maintaining a gap hetween the pad atid the die of no less than a sheet
thickness of the blank, or of the forming sheet, and no Inore than 1.1 times the sheet thickness
of the blank, or of the forming sheet.
8. The pressed article manufacturing lnetllod of either claim 6 or claim 7, wherein a
breaking strength of the blank, or of the forming sheet, is from 400 MPa to 1600 MPa.