The present invention relates to an automobile member.
Priority is claimed on Japanese Patent Application No. 2014-181190, filed
September 05,2014, and Japanese Patent Application No. 2015-015694, filed January
29,2015, the contents of which are incorporated herein by reference.
[Related Art]
[0002]
Most of body shells of automobile vehicle bodies having the so-called
monocoque structure are equipped with a platform, left and right body sides, and an
engine compartment provided at a body shell front part. The platform has a floor
panel. The left and right body sides are mounted on both sides of the platform. The
engine compartment has a frontside member as a constituent member.
(0003]
Each body side has an A pillar, a B pillar, a roof rail side, and a side sill
(kicker). The roof rail side is welded to respective upper end portions of the A pillar
and the B pillar. Resistance spot welding (it abbreviates to spot welding hereafter),
laser welding, and the like are mainly used for welding of an automobile member.
The side sill is welded to respective lower end portions of the A pillar and the B pillar,
and the front end portion of a rear wheel housing outer.
[0004]
- 1 -
Generally, the side sill is equipped with a side sill inner panel having a
substantially hat-shaped cross-sectional shape, and a side sill outer panel having a
substantially hat-shaped cross-sectional shape. Both of the side sill inner panel and
the side sill outer panel have a top plate, two side walls connected to this top plate, and
outward flanges connected to the two side walls, respectively. An integral side sill is
formed by spot-welding the two outward flanges of the side sill inner panel and the
two outward flanges of the side sill outer panel to each other in an overlapped state.
The side sill formed in this way is an elongated hollow tubular body.
The side sill is spot-welded to the floor panel via the upward flanges formed
on both sides of a front floor panel. Any deflection resulting from elastic defonnation
of the floor panel during traveling of a vehicle is suppressed by the side sill. In this
way, the side sill gives desired bending rigidity and torsional rigidity to a body shell.
Moreover, atthe time of collision of the vehicle, the side sill is deformed due to an
impact load, and absorbs striking energy. As a result, a passenger's safety is ensured
at the time of the collision of the vehicle.
[0005]
The side sill is a member that absorbs the striking energy by causing so-called
three-point bending deformation mainly at the time of a side collision. For this
reason, in the related art, design and development of the side sill have been performed
by adopting increasing impact energy absorption amount (EA) with respect to the
three-point bending deformation as a main design target.
Meanwhile, in recent years, in order to further improve the collision safety
performance ofthe vehicle, a front collision test or a rear collision test in which small
overlap (SOl) is supposed begins to be adopted. In the small overlap front collision
- 2 -
test, the vehicle is made to collide against a fixed barrier at 64 km/h such that a 25%
part of the overall vehicle width in a front end portion of the vehicle hits a fixed barrier.
In such a small overlap front collision, the fixed barrier collides outside an impactabsorbing
structure (for example, a irontside member or the like) provided at a front
part of the vehicle. Therefore, it is difficult to sufficiently absorb the striking energy
due to the impact-absorbing structure of the front part of the vehicle.
However, as a result of the small overlap front collision test, it turned out that
the axial crushing deformation occurs in the side sill at the time of a collision, and
thereby the striking energy is absorbed by the side silL For this reason, from a
viewpoint of improvement in the collision safety performance of the vehicle,
increasing impact energy absorption amounts with respect to two different deformation
modes such as the three-point bending defonnation and the axial crushing deformation
are strongly required for recent side sills.
[0006]
As described above, the front end portion of the side sill is spot-welded to a
lower end portion (lower A pillar) of an A pillar, a substantially central portion of the
side sill in its longitudinal direction is spot-welded to a lower end portion of the B
pillar, and a rear end portion ofthe side sill is spot -welded to a front end portion of the
wheel housing outer. At the time of the collision of the vehicle, early breaking (spot
breaking) often occurs with each of a welded spot between the side sill and the lower A
pillar, a welded spot between the side sill and the B pillar, and a welded spot between
the side sill and the wheel housing outer as a starting point. It is known that, due to
this early spot breaking, the design philosophy of a load path for propagating the
striking energy sequentially to structural members and absorbing the striking energy
- 3 -
cannot be sufficiently realized, and the impact energy absorption amount decreases.
[0007]
A vehicle body front part structure configured such that a cross section of a
side sill in a vertical direction of a vehicle varies in a longitudinal direction of the
vehicle in order to improve the front collision safety performance of the vehicle is
disclosed in Patent Document 1. Additionally, a teclmique of forming an integral side
sill by welding a cut and raised portion formed in an upper surface of a side sill inner
panel and a cutout formed in an upper surface of a side sill outer panel in a state where
are made to coincide with each other in order to improve the assemblability and
weldability of the side sill inner panel and the side sill outer panel is disclosed in Patent
Document2.
[0008]
FIG. 16 is a top view partially illustrating an arrangement situation of a
frontside member 40 in a simplified manner. An A-A cross section is altogether
illustrated in FIG. 16. FIG. 17 is a top view illustrating a deformation behavior ofthe
frontside member 40 in a front collision in a simplified manner.
[0009]
As illustrated in FIG. 16, generally, the frontside member 40 has a hat-shaped
panel 41 having a constant cross-sectional shape (hat shape) in a material axis direction,
and a flat plate-shaped closing plate 42. The hat-shaped panel41 has a top plate 41a,
two side walls 4lb connected to the top plate 4la, and outward flanges 4lc connected
to the two side walls 41 b, respectively. The integral frontside member 40 is formed
by spot-welding the nvo outward flanges 4lc of the hat-shaped panel41 and the
closing plate 42 in an overlapped state. The frontside member 40 formed in this way
- 4 -
is an elongated hollow tubular body. The fronts ide member 40 is disposed inside an
engine compartment 43 of the vehicle body front part.
[0010]
The two outward t1anges 41 c of the hat -shaped panel 41 are disposed on a
vehicle outside. For this reason, a wide t1at side wall41b of the frontside member 40
can be used as a mounting surface of an engine mount bracket 46. Accordingly,
components ncar the engine compartment 43, such as the engine mount bracket 46 that
supports the transverse-mounted engine 44, can be certainly fixed to an upper surface
(side wall 41 b) of the frontside member 40. Additionally, at the time of a front
collision, as illustrated by a circled portion in FIG. 17, the frontside member 40 can be
bent and deformed toward a vehicle inside. Additionally, in a case where the outward
t1anges 41 care disposed on the vehicle inside, the frontside member 40 can be bent
toward the vehicle inside at the time of the front collision.
[0011]
In this way, the frontside member 40 gives desired bending rigidity and
torsional rigidity to the body shell, and supports important components, such as heavy
goods such as the engine 44, and a suspension. Additionally, at the time of the front
collision of the vehicle, the fronts ide member 40 is deformed due to an impact load
applied via a front crash box 45 (refer to FIG. 16) disposed at a front end portion
thereof, and absorbs collision energy. As a result, deformation of a passenger
compartment is suppressed and a passenger's safety is ensured.
[0012]
Afrontside member having a hat-shaped panel located on a vehicle inside and
a closing plate located on a vehicle outside is disclosed in Patent Document 3. In the
- 5
technique disclosed in Patent Document 3, the ti·ontside member is prevented from
buckling easily due to an impact force at a front collision by devising the structure of a
bending portion that is present in a longitudinal direction of the fronts ide member.
According to this technique, the impact force at the front collision is effectively
relieved, and the deformation of a vehicle body is suppressed.
[Prior Art Document]
[Patent Literature]
[0013]
Patent Document I: Japanese Patent No. 2689595
Patent Document 2: Japanese Unexamined Patent Application, First
Publication No. I-13-184685
· Patent Document3: Japanese Unexamined Patent Application, First
Publication No. 2014-40209
[Disclosure of the Invention]
[Problems to be Solved by the Invention]
[0014]
The side sill disclosed in Patent Document 1 is not developed for the purpose
of improving the side collision safety performance of the vehicle, and has room for an
improvement from a viewpoint of improvement in safety against a side collision.
Additionally, the side sill disclosed in Patent Document 2 cannot improve the impact
energy absorption amount with respect to the two different deformation modes such as
the three-point bending deformation and the axial crushing defonnation.
- 6 -
[00 15]
FIG. 18 is an explanatory view schematically illustrating problems ofthe
frontside member 40 illustrated in FIG. 16. In addition, the frontside member
disclosed in Patent Document 3 also has the same problems.
[0016]
If an impact load is applied to the frontside member 40 via the crash box 45 at
the time of a front collision, as illustrated by a circled portion in FIG. 18, a spot-welded
portion (a site joined by spot welding) between the outward flanges 41 c of the hatshaped
panel41 and the closing plate 42 is broken at an early stage on a front end side
of the frontside member 40, and the closing plate 42 is cut apart from the hat-shaped
panel41. If such a phenomenon (spot breaking) occurs on the front end side of the
frontside member 40, the impact energy absorption amount in the remaining sites of
the frontside member 40 decreases.
[0017]
In this way, in the related-art side sills, the impact energy absorption amount
with respect to the two different deformation modes such as the three-point bending
deformation and the axial crushing deformation cannot be improved. Additionally, in
the related-art fronts ide member, suppressing the occurrence of the spot breaking at the
time of a front collision while maintaining the mountability of the engine mount
bracket is not possible.
[0018]
The invention has been made in view of the above circumstances, and an
object thereof is to provide an automobile member in which the two properties that
could not be compatible with each other in the related art are compatible with each
- 7 -
other.
[Means for Solving the Problem]
[0019]
The present inventors repeated keen study in order to solve the above
problems, and consequently could obtain the knowledge listed below, and further
repeated the study to complete the invention.
[0020]
(A) By making the overlapped joining positions of the side sill inner panel
(inner panel) and the side sill outer panel (outer panel) different from each other in the
longitudinal direction of the side sill, the impact energy absorption amount with
respect to the three-point bending defonnation occurring in the side sill at the time of a
side collision can be increased. Even in a case where the axial crushing deformation
occurs in the side sill at the time of a front collision or a rear collision including a small
overlap collision, the occurrence of the spot breaking can be suppressed. Accordingly,
the impact energy absorption amount with respect to the axial crushing deformation of
the side sill is increased.
[0021]
(B) By making the overlapped joining positions of the two outward flanges of
the frontside member inner panel (inner panel) constituting the frontside member and
the two outward flanges of the frontside member outer panel (outer panel) different
from each other in a portion on the front end side in the longitudinal direction of the
frontside member and the other portion, the occurrence of the spot breaking at the time
of a front collision can be suppressed while reliably secnring the mounting snrface of
- 8 -
the engine mount bracket.
[0022]
The invention adopts the following means in order to solve the above
problems to achieve the relevant object.
(I) An automobile member related to an aspect of the invention is an
automobile member of a closed cross section including an inner panel having a top
plate and two side walls connected to the top plate, and an outer panel having a top
plate and two side walls connected to the top plate, and joint portions in which edge
portions of the two side walls of the inner panel are respectively joined to edge
portions of the two side walls ofthe outer panel. The automobile member includes a
first region extending rearward from a front end portion of the automobile member; a
first transition region extending rearward continuously with the first region; and a
second region extending rearward continuously with the first transition region. When
the height of the side walls of the outer panel in the first region is defined as a first
region outer height hot, and the height of the side walls of the inner panel in the first
region is defined as a first region inner height hi~, when the height of the side walls of
the outer panel in the second region is defined as a second region outer height ho2, and
the height of the side walls of the inner panel in the second region is defined as a
second region inner height hi2, and when the height of the side walls of the outer panel
in the first transition region is defined as a first transition region outer height hoH, and
the height of the side walls of the inner panel in the first transition region is defined as
a first transition region inner height hit-2, in the first region, the first region outer
height hot and the first region inner height hit have constant values, and a difference
between the first region outer height hot and the first region inner height hit is smaller
- 9 -
than a difference between the second region outer height ho2 and the second region
inner height hi2, in the second region, the second region outer height ho2 has a constant
value larger than the second region inner height hb, or the second region outer height
ho2 has a constant value smaller than the second region inner height hh, and in the tirst
transition region, the first transition region outer height ho1-2 continuously varies
between the first region outer height ho 1 and the second region outer height ho2, and
the first transition region inner height hi 1_2 continuously varies between the first region
inner height hi1 and the second region inner height hb.
[0023]
(2) The automobile member described in the above (1) may be a skeleton
member of an automobile vehicle body.
[0024]
(3) In the automobile member described in the above (2), the inner panel may
be a side sill inner panel, the outer panel may be a side sill outer panel, and the
skeleton member may be a side sill.
[0025]
(4) In the automobile member described in the above (3), a lower A pillar
connecting portion that is a site to which a lower A pillar is connected may be provided
in a region including the front end portion in the first region, and a B pillar connecting
portion that is a site to which a B pillar is connected may be provided in at least a
portion ofthe second region. The first region may be a region to a position that is
150 mm or less apart rearward from a rear end of the lower A pillar connecting portion
of the skeleton member, and the second region may be a region between a position that
is 150 mm or less apart forward from the B pillar connecting portion, and a position
- 10 -
that is 150 mm or less apart rearward from the B pillar connecting portion.
[0026]
(5) In the automobile member described in the above (3) or (4), the following
Relational Expression (a) may be satisfied in the first region, and the following
Relational Expression (b) may be satisfied in the second region.
0.40 x (hi1 + ho1) :S ho1 :S 0.60 x (hh + ho1) (a)
0.10 x (hi2 + ho2) :S hi2 :S 0.40 x (hi2 + ho2) (b)
[0027]
(6) The automobile member described in any one of the above (3) to (5) may
further include a second transition region extending rearward continuously with the
second region; and a third region extending to a rear end portion of the automobile
member rearward continuously with the second transition region. When the height of
the side walls of the outer panel in the third region is defined as a third region outer
height ho3, and the height of the side walls of the inner panel in the third region is
defined as a third region inner height hb, and when the height of the side walls of the
outer panel in the second transition region is defined as a second transition region outer
height ho2-3 and the height of the side walls of the inner panel in the second transition
region is defined as the second transition region inner height hh-3, in the third region,
the third region outer height ho3 and the third region inner height hi3 may have
constant values, and a difference between the third region outer height ho3 and the third
region inner height hb may be smaller than a difference between the second region
outer height ho2 and the second region inner height hi2, and in the second transition
region, the second transition region outer height ho2-3 may continuously vary between
the second region outer height ho2 and the third region outer height ho3, and the second
- 11 -
transition region inner height hh-3 may continuously vary between the second region
inner height hiz and the third region inner height hi3.
[0028]
(7) In the automobile member described in the above (6), the following
Relational Expression (c) may be satisfied in the third region.
0.40 x (hi3 + ho3) <:: ho3 <:: 0.60 x (hb + ho3) ··· (c)
[0029]
(8) In the automobile member described in any one of the above (4) to (7), the
lower A pillar may be connected to the lower A pillar connecting portion, and the B
pillar may be connected to the B pillar connecting portion.
[0030]
(9) In the automobile member described in the above (2), the inner panel may
be a frontside member inner panel, the outer panel may be a frontside member outer
panel, and the skeleton member may be a frontside member.
[0031]
(1 0) In the automobile member described in the above (9), the following
Relational Expression (a) may be satisfied in the first region.
0.40 x (hi1 + ho1) <:: ho1 <:: 0.60 x (hi1 + ho1) ··· (a)
[0032]
(11) In the automobile member described in the above (9) or (10), the first
region is a region between the front end portion and a position that is 400 mm or less
apart rearward from the front end portion.
[0033]
(12) In the automobile member described in any one of the above (9) to (11),
- 12 -
the second region may be a region that is present behind a position that is !50 nun or
more apart from the front end portion.
[0034]
(13) In the automobile member described in any one of the above (9) to (12),
the following Relational Expression (d) or the following Relational Expression (e) may
be satisfied in the second region.
0 -s: hb -s: 0.40 x (hb + ho2) (d)
0 -s; ho2 -s: 0.40 x (hb + ho2) (e)
[0035]
(14) In the automobile member described in any one of the above (I) to (13),
in at least portions of the joint portions, the edge portions may be flanges that are
connected so as to be formed in the two side walls of each of the inner panel and the
outer panel.
[0036]
(15) In the automobile member described in the above (14), in at least
portions of the joint portions, the flanges formed in the inner panel may be subjected to
hemming working so as to cover the flanges formed in the outer panel, or the flanges
formed in the outer panel may be subjected to hemming working so as to cover the
flanges formed in the inner panel.
[0037]
(16) In the automobile member described in any one of the above (1) to (13),
in at least portions of the joint portion, edge portions of the two side walls of the inner
panel may be respectively overlapped on and joined to edge portions of the two side
walls of the outer panel.
- 13 -
[0038]
( 17) In the automobile member described in any one of the above (1) to (16),
the joining may be performed nsing resistance spot welding.
[0039]
( 18) In the automobile member described in any one of the above (l) to ( 17),
when the tensile strength of the outer panel is defined as TSo (MPa), the plate
thickness of the outer panel is defined as to (mm), the tensile strength of the inner
panel is defined as TSi (MPa), and the plate thickness of the inner panel is defined as ti
(mm), the following Relational Expression (f) may be satisfied in a case where the
second region outer height ho2 is larger than the second region inner height hh, and the
following Relational Expression (g) may be satisfied in a case where the second region
outer height ho2 is smaller than the second region inner height hh.
TSo x to< TSi x ti (f)
TSo x to > TSi x ti (g)
[0040]
(19)An automobile member related to another aspect of the invention is an
automobile member of a closed cross section including an inner panel having a top
plate and two side walls connected to the top plate, and an outer panel having a top
plate and two side walls connected to the top plate, and joint portions in which edge
portions of the two side walls of the inner panel are respectively joined to edge
portions of the two side walls of the outer panel. When the tensile strength of the
outer panel is defined as TSo (MPa), and the plate thickness of the outer panel is
defined as to (mm), the tensile strength of the inner panel is defined as TSi (MPa), the
plate thickness of the inner panel is defined as ti (mm), the height of the side walls of
- 14 -
the outer panel is defined as outer height ho, and the height of the side walls of the
inner panel is defined is defined as inner height hi, the outer height ho and the inner
height hi have constant values, respectively, in a length direction of the automobile
member, the following Relational Expression (f) is satisfied in a case where the outer
height ho is larger than the inner height hi, and the following Relational Expression (g)
is satisfied in a case where the outer height ho is smaller than the inner height hi.
TSo x to < TSi x ti (f)
TSo x to > TSi x ti (g)
[0041]
(20) In the automobile member described in the above (19), the automobile
member is a side sill, and the side sill may have a side sill inner panel as the inner
panel and have a side sill outer panel as the outer panel.
[0042]
(21) In the automobile member described in the above (19), the automobile
member may be a frontside member, and the frontside member may have a frontside
member outer panel as the outer panel and may have a frontside member inner panel as
the inner panel.
(0043]
(22) In the automobile member according to any one of the above (I) to (21 ),
the automobile member may be formed by a tailored welding blank, a tailored rolled
blank, or combinations of these materials.
Here, a tailored welding blank (TWB) means one obtained by integrating two
or more types of steel sheets having different plate thicknesses, tensile strengths, and
the like in a material state with each other through welding (for example, butt welding).
- 15 -
Additionally, a tailored rolled blank (TRB) means one obtained by changing the
intervals of rolling rolls, thereby changing the plate thickness of a material, when
manufacturing the material.
[0044]
In the invention, the "front end portion" means an end portion of the
automobile member related to the invention on a front side in a traveling direction of a
vehicle equipped with the vehicle body on which the automobile member is mounted,
and the "rear" means the rear in the traveling direction.
[0045]
The height of the side walls in the invention means a distance in a direction
orthogonal to the top plate from an outer surface of the top plate to an outer surface of
the flanges.
[0046]
The "automobile member" related to the invention means a member used for
automobiles, for example, includes the skeleton member that forms the skeleton of the
automobile vehicle body, or a member other than the skeleton member mounted on the
automobile vehicle body. The "automobile member" related to the invention includes
a center pillar (B pillar), a roof rail, an A pillar, or the like as the skeleton member of
the automobile vehicle body in addition to the above side sill and the frontside member,
and includes a subframe constituent member that supports a suspension as a member
other than the skeleton member of the automobile vehicle body.
[Effects of the Invention]
[0047]
- 16 -
According to the above aspects of the invention, the automobile member in
which the two properties that could not be compatible with each other in the related art
are compatible with each other can be provided.
[0048]
Specifically, according to the above aspects of the invention, the skeleton
members of the automobile vehicle body such as the side sill that in which both impact
energy absorption amounts with respect to two different deformation modes such as
the three-point bending defonnation and the axial crushing defonnation are increased,
and the frontside member in which the occurrence ofthe spot breaking at the time of a
front collision can be suppressed while maintaining the mountability of the engine
mount bracket can be provided.
[0049]
More specifically regarding the side sill, according to the above aspects of the
invention, the impact energy absorption amount with respect to the three-point bending
deformation occurring in the side sill at the time of a side collision can be increased.
Even in a case where the axial crushing defonnation occurs in the side sill at the time
of a front collision or a rear collision including a small overlap collision, the
occurrence of the spot breaking can be suppressed. Accordingly, the impact energy
absorption amount with respect to the axial crushing deformation of the side sill can be
increased.
[Brief Description of Drawings]
[0050]
FIG. 1 is a perspective view illustrating a schematic configuration of a side sill
- 17 -
related to a first embodiment of the invention.
FIG. 2 is an explanatory view schematically illustrating cross-sectional shapes
of side sills of a present invention example and a comparative example used for
numerical analysis of axial crushing deformation.
FIG. 3 is an explanatory view schematically illustrating numerical analysis
conditions of the axial crushing deformation.
FIG. 4 is a graph illustrating impact energy absorbed amount EA (kJ) that is a
numerical analysis result of the axial crushing deformation.
FIG. 5 is an explanatory view illustrating numerical analysis conditions of
three-point bending deformation of a side sill adopted in a side collision test in which a
case where a side collision has occurred in a B pillar joint portion of the side sill is
supposed.
FIG. 6 is an explanatory view illustrating the numerical analysis conditions of
the three-point bending deformation of the side sill adopted in the side collision test in
which the case where the side collision has occurred in the B pillar joint portion of the
side sill is supposed.
FIG. 7 is an explanatory view illustrating a test piece of a comparative
example in which a ratio of heights (a second region outer height ho2 and a second
region inner height hh) of side walls in a second region is ho2:hi2 = l: l, and a test
piece of a present invention example that is ho2:hh = 3:1.
FIG. 8 is a graph illustrating collision absorbed energy EA (kJ) that is a
numerical analysis result of the three-point bending deformation of the side collision
test.
FIG. 9A is an explanatory view illustrating a first modification example of a
- 18 -
mating structure of joint portions of a side sill inner panel and a side sill outer panel.
FIG. 98 is an explanatory view illustrating a second modification example of
the mating structure of the joint portions of the side sill inner panel and the side sill
outer panel.
FIG. l 0 is a perspective view illustrating a schematic configuration of a
frontside member related to a second embodiment of the invention.
FIG. II is a top view partially illustrating an arrangement situation of a
fronts ide member related to the second embodiment of the invention in a simplified
manner.
FIG. I2A is a plan view illustrating a schematic configuration of a side sill
related to a third embodiment of the invention.
FIG. I 28 is an E-E arrow cross-sectional view of the side sill illustrated in FIG.
12A.
FIG. 13A is an explanatory view schematically illustrating the numerical
analysis conditions of the axial crushing deformation.
FIG. 138 is a view graphing a correspondence relationship between a
multiplication value (TSo x to) of tensile strength TSo and plate thickness to of a hatshaped
panel on a larger hat side (side sill outer panel), and the plate thickness to.
FIG. 14 is a plan view illustrating a schematic configuration of a side sill lA
related to a fourth embodiment of the invention.
FIG. 15 is a plan view illustrating a schematic configuration of a frontside
member 31A related to a fifth embodiment of the invention.
FIG. 16 is a top view partially illustrating an arrangement situation of a
frontside member in a simplified manner in the related art.
- 19 -
FIG. 17 is a top view illustrating a deformation behavior of the frontside
member in a tront collision in a simplified manner.
FIG. 18 is an explanatory view schematically illustrating problems of a
fronts ide member disclosed in Patent Document 3 and the frontside member illustrated
in FIG 16.
[Description ofEmbodiments]
[0051]
Hereinafter, embodiments of the invention will be described in detail with
reference to the drawings.
[First Embodiment]
A first embodiment of the invention will first be described. In the first
embodiment, a side sill that is a skeleton member of an automobile vehicle body is
exemplified as an automobile member related to the invention. This side sill has a
side sill inner panel as an inner panel and has a side sill outer panel as an outer panel.
Although a case where the automobile member related to the invention has a
substantially quadrangular cross-sectional shape is exemplified in the subsequent
description, the invention can also be applied to an automobile member having, for
example, a polygonal cross-sectional shape, such as a hexagon or an octagon, which
has an upper side and a lower side that face each other.
[0052]
FIG. 1 is a perspective view illustrating a schematic configuration of a side sill
1 related to the first embodiment of the invention.
The side sill! has at least a side sill inner panel2 and a side sill outer panel3.
- 20 -
The side sill inner panel2 and the side sill outer panel 3 are respectively shape steels
fom1ed from high-tensile steel sheets having a plate thickness of 1.0 mm or more.
Although not illustrated in FIG. 1, the side sill I usually further has a side sill outer
panel that is a low-strength material having a plate thickness of 1.0 mm or less as an
outer plate. A side sill reinforcement (reinforcing plate) may be provided between the
side sill inner panel 2 and the side sill outer panel 3 or between the side sill outer panel
3 and the side sill outer panel serving as the outer plate.
[0053]
The side sill inner panel 2 has at least a top plate 4 and two side walls 6a and
6b connected to the top plate 4. Since the side sill inner panel 2 is manufactured by
press working using ordinary bending forming or throttle forming, and roll working
using bending forming, the side sill inner panel 2 has ridgelines Sa and 5b connected to
the top plate 4 and the side walls 6a and 6b.
[0054]
Additionally, edge portions of the side sill inner panel 2 are provided with
outward flanges 8a and 8b connected to the two side walls 6a and 6b. The outward
flanges 8a and 8b are joining margins joined by, for example, resistance spot welding
or the like in a state where the outward flanges 8a and 8b are overlapped on outward
flanges 13a and 13b provided at edge portions of the side sill outer panel3. For this
reason, the side sill inner panel 2 further has curved portions 7a and 7b connected to
the side walls 6a and 6b and the outward flanges 8a and 8b.
[0055]
The respective curvature radii of the ridgelines 5a and 5b and the curved
portions 7 a and 7b are values such that manufacture is performed by the above-
- 21 -
described ordinary working methods, and are usually 3 to 20 nun.
[0056]
Moreover, the side sill inner panel2 is joined to a front floor panel30 via an
upward flange 30a that is resistance spot welded to the top plate 4.
[0057]
Meanwhile, the side sill outer panel 3 has at least a top plate 9, and two side
walls II a and II b connected to the top plate 9, similar to the side sill inner panel 2.
Since the side sill outer panel 3 is manufactured by the press working using the
ordinary bending forming or throttle forming or the roll working using the bending
forming, the side sill outer panel 3 has ridge! ines 1 Oa and 1 Ob connected to the top
plate 9 and the side walls lla and !lb.
[0058]
Additionally, the edge portions of the side sill outer panel 3 are provided with
the outward flanges 13a and 13b connected to the two side walls II a and II b. The
outward flanges 13a and 13b are joining margins joined by, for example, the resistance
spot welding or the like in a state where the outward flanges 13a and 13b are
overlapped on the outward flanges 8a and 8b provided at the edge portions of the side
sill inner panel 2. For this reason, the side sill outer panel 3 further has curved
portions 12a and 12b connected to the side walls lla and llb and the outward flanges
13a and 13b.
[0059]
The respective curvature radii of the ridgelines lOa and 1 Ob and the curved
portions 12a and 12b are values such that manufacture is performed by the abovedescribed
ordinary working methods, and are usually 3 to 20 mm.
- 22 -
[0060]
Although a case where the outward flanges Sa and 8b are joined to the
outward flanges 13a and 13b by the resistance spot welding has been exemplified in
the above description, for example, it is also possible to use other joining methods,
such as other kinds of welding such as laser welding or electric arc welding other than
the resistance spot welding, bonding, and brazing.
(0061]
The side sill! has a first region 14, a first transition region 15, a second
region 16, a second transition region 17, and a third region 18.
[0062]
The first region 14 extends rearward from a front end portion 1 a of the side
sill 1. The first transition region 15 extends rearward continuously with the first
region 14. The second region 16 extends rearward continuously with the first
transition region 15. The second transition region 17 extends rearward continuously
with the second region 16. Moreover, the third region 18 extends to a rear end
portion lb of the side sill 1 rearward continuously with the second transition region 17.
The rear end portion 1 b of the third region 18 is connected to a rear wheel housing
outer panel2L
[0063]
In the following, the height of the side walls lla and 11 b of the side sill outer
panel 3 in the first region 14 is defined as a first region outer height hor, and the height
of the side walls 6a and 6b of the side sill inner panel2 in the first region 14 is defined
as a first region inner height hi1.
The height of the side walls 11 a and 11 b of the side sill outer panel 3 in the
- 23 -
second region 16 is defined as a second region outer height ho2, and the height of the
side walls 6a and 6b of the side sill inner panel 2 in the second region 16 is defined as a
second region inner height hh. The height of the side walls 11 a and II b of the side
sill outer panel 3 in the first transition region 15 is defined as a first transition region
outer height ho1-2, and the height of the side walls 6a and 6b of the side sill inner panel
2 in the first transition region 15 is defined as a first transition region inner height hi 1_2.
The height of the side walls !Ia and Jib of the side sill outer panel3 in the
third region 18 is defined as a third region outer height ho3, and the height of the side
walls 6a and 6b of the side sill inner panel2 in the third region 18 is defined as a third
region inner height hb. The height of the side walls !Ia and lib of the side sill outer
panel 3 in the second transition region 17 is defined as a second transition region outer
height hoz-3, and the height of the side walls 6a and 6b of the side sill inner panel 2 in
the second transition region 17 is defined as a second transition region inner height
hiz-3.
[0064]
In the first region 14, the first region outer height ho1 and the first region inner
height hh have constant values, and a difference between the first region outer height
hot and the first region inner height hh is smaller than a difference between the second
region outer height hoz and the second region inner height hiz.
[0065]
In the second region 16, the second region outer height ho2 has a constant
value larger than the second region inner height hh.
[0066]
In the first transition region 15, the first transition region outer height ho1-2
- 24 -
continuously varies between the first region outer height ho1 and the second region
outer height ho2, and the first transition region inner height hi 1_2 continuously varies
between the tlrst region inner height hh and the second region inner height hh.
[0067]
A lower A pillar connecting portion21, which is a site to which a lower A
pillar 19 illustrated with a two-dot chain line is com1ected, is provided in a region,
including the front end portion Ia of the side sill!, in the first region 14.
Additionally, at least a portion of the second region 16 is provided with B pillar
connecting portions (a B pillar front connecting portion 22 and a B pillar rear
connecting portion 23), which is a site to which a B pillar 20 illustrated with a two-dot
chain line is connected.
[0068]
The first region 14 is a region up to a position that is !50 mm or less apart
rearward from a rear end of the lower A pillar connecting portion 21 of the side sill !.
Although the lower A pillar I 9 hangs over the side sill I in the example illustrated in
FIG. !, a rear end portion of the lower A pillar 19 and the front end portion !a of the
side sill 1 may be butted against and connected to each other. In any case, the first
region 14 is the region up to the position that is 150 mm or less apart reatward from the
rear end of the lower A pillar connecting portion 21.
[0069]
Additionally, the second region 16 is a region between a position that is 150
mm or less apart forward from the B pillar connecting portion (B pillar front
connecting portion 22), and a position that is 150 mm or less apart rearward from the B
pillar cmmecting portion (the B pillar rear connecting portion 23).
- 25 -
[0070]
Meanwhile, in the third region 18, the third region outer height ho3 and the
third region inner height hh have constant values, and a difference between the third
region outer height ho3 and the third region inner height hi3 is smaller than a difference
between the second region outer height ho2 and the second region inner height hh.
[0071]
In the second transition region 17, the second transition region outer height
hoH continuously varies between the second region outer height ho2 and the third
region outer height ho3, and the second transition region inner height hi 2~3 continuously
varies between the second region inner height hh and the third region inner height hh.
[0072]
By setting the first region outer height ho1, the first region inner height hi1, the
second region outer height ho2, the second region inner height hh, the first transition
region outer height ho 1~2, fhe first transition region inner height hiH, the third region
outer height ho3, the third region inner height hh, the second transition region outer
height ho2~3, and the second transition region inner height hiH as described above, an
impact energy absorption amount with respect to three-point bending deformation of
the side sill 1 caused at the time of a side collision can be increased. Even in a case
where axial crushing deformation occurs in fhe side sill 1 at the time of a front
collision or a rear collision including a small overlap collision, occurrence of spot
breaking can also be suppressed, and accordingly, the impact energy absorption
amount with respect to the axial crushing deformation of the side sill1 can be
increased. Hereinafter, the reasons will be described.
[0073]
- 26 -
As described above, the first region 14 and the third region 18 are required to
have excellent axial crushing properties. However, these excellent axial crushing
properties are required not only in a case where an input direction of an impact load
coincides with a material axis direction (length direction) of the side sill I but also in a
case where the input direction is a direction inclined, for example, about 10 degrees
from this material axis direction.
[0074]
FIG. 2(a) and FIG. 2(b) are explanatory views schematically illustrating crosssectional
shapes of a test piece 24 of a side sill of a present invention example, and a
test piece 25 of a side sill of a comparative example used for numerical analysis of the
axial crushing deformation performed by present inventors. Additionally, FIG. 3(a) to
FIG. 3(e) are explanatory views schematically illustrating numerical analysis
conditions of the axial crushing deformation.
[0075]
The present inventors performs a numerical analysis test for the axial crushing
deformation in which a front end section ofthe side sill is supposed as illustrated in
FIG. 3(a) to 3(e), using the test piece 24 of the present invention example in which a
ratio of the first region outer height ho1 and the first region inner height hi1 is ho1:hi1 =
1: l and the test piece 25 of the comparative example in which the ratio is ho1:hi1 = 3: I,
as illustrated in FIG. 2(a) and FIG. 2(b).
In addition, the plate thickness t of the test pieces 24 and 25 was 1.4 mm, the
tensile strength thereof was 980 MPa, and the total length thereof was 350 mm. The
resistance spot welding was performed at nine points set at intervals of 40 mm in the
material axis direction ofthe test pieces 24 and 25. A welding condition was set such
- 27 -
that the nugget diameter of welding nuggets formed by the resistance spot welding
became 4,lt (mm).
(0076]
In the numerical analysis test for the axial crushing deformation, after lower
end portions of the test pieces 24 and 25 were fixed, a flat plate-shaped rigid body 26
was made to collide against upper end portions of the test pieces 24 and 25 in a state
where the rigid body was parallel to or inclined at I oo with respect to a width direction
of the test pieces 24 and 25. The collision speed of the rigid body 26 against the test
pieces 24 and 25 was 20 km/h. Regarding the respective analysis conditions
illustrated in FIG. 3(a) to FIG. 3(e), the presence/absence of the spot breaking in a case
where the axial crushing deformation was caused within a range of !50 mm in the
material axis direction of the test pieces 24 and 25 due to the collision of the rigid body
26 was investigated. Additionally, regarding the respective analysis conditions
illustrated in FIG. 3(a) to FIG. 3(e), the impact energy absorbed amount EA (kJ) in a
case where the axial crushing deformation was caused within a range of 150 mm in the
material axis direction of the test pieces 24 and 25 due to the collision of the rigid body
26 was analyzed.
[0077]
Table l shows test results of the presence/absence of the spot breaking. FIG.
4 is a graph illustrating analysis results of the impact energy absorbed amount EA (kJ)
with respect to the axial crushing deformation.
(0078]
[Table I]
Present Invention Example Comparative Example
FIG. 3(a) to FIG. 3(e) a I b c I d I e
- 28 -
1-Pre.sence/ Absence of
L_Spot Breaking
[0079]
No No
As shown in Table 1 and FIG. 4, in the test piece 25 of the comparative
example subjected to testing on the analysis conditions illustrated in FIG. 3(e), the 10°-
inclined rigid body 26 collided against a hat-shaped panel closer to a larger hat side (a
hat-shaped side sill outer panel of which the height of the side walls was large) than a
hat-shaped panel on a smaller hat sill (a hat-shaped side sill inner panel of which the
height of the side walls was small). Accordingly, the spot breaking occurred, and
consequently, the impact energy absorbed amount EA decreased.
[0080]
In contrast, in the test piece 24 of the present invention example subjected to
testing on the analysis conditions illustrated in FIG. 3(a) and FIG. 3(b), in any of a case
where the rigid body 26 was made to collide against the test piece in a state where the
rigid body was parallel to the width direction of the test piece 24, and a case where the
rigid body 26 was made to collide against the test piece in a state where the rigid body
was inclined at 10° with respect to the width direction of the test piece 24, the spot
breaking did not occur. As illustrated in such test results, it turned out that the test
piece 24 of the present invention example had high robustness with respect to the axial
crushing deformation, as compared to the test piece 25 ofthe comparative example.
[0081]
The reasons are considered as follows. That is, in the test piece 25 of the
comparative example, the height of the side walls of the side sill outer panel (the hatshaped
panel on the larger hat side) is larger than the height of the side walls of the
side sill inner panel (the hat-shaped panel on the smaller hat side), the surface rigidity
- 29 -
of the side walls is lower than the test piece 24 of the present invention example. For
this reason, particularly as illustrated in FIG. 3(e), if an impact load is firstly input to
the side sill outer panel having the side walls with low surface rigidity, the side sill
outer panel is largely deformed, shear deformation in a welded spot (flange) welded
with the side sill inner panel becomes excessive. As a result, the spot breaking occurs
at an early stage.
[0082]
In this way, in the first region I 4 and the third region I 8 of the side sill I, the
first region outer height ho1, the first region inner height hi 1, the third region outer
height ho3, and the third region inner height hh have constant values, respectively.
Accordingly, even if the axial crushing deformation occurs due to an impact load in the
first region 14 and the third region 18 of the side sill 1, the occurrence ofthe spot
breaking can be markedly suppressed. As a result, a decrease in the impact energy
absorbed amount EA with respect to the axial crushing deformation can be suppressed.
[0083]
FIGS. 5 and 6 are explanatory views illustrating the numerical analysis
conditions of the three-point bending deformation of a side si1127 adopted in a side
collision test in which a case where a side collision has occurred in a B pillar joint
portion of the side sill is supposed.
[0084]
Additionally, FIG. 7 is an explanatory view illustrating a test piece 29 of the
comparative example in which a ratio of the second region outer height ho2 and the
second region inner height hi2 that is ho2:hh = 1:1, and a test piece 30 of the present
invention example that is ho2:hh = 3:1.
- 30 -
[0085]
The plate thickness of the test pieces 29 and 30 was 1.4mm, and the tensile
strength thereof was 980 MPa. The plate thickness of the B pillar 20 was 1.4mm,
and the tensile strength thereof was 590 MPa. The B pillar 20 was joined to a top
plate of the side sill27. Constraint conditions of both ends of the side sill27 were
complete constraint of entire circumferences of both the ends, and constraint
conditions of a vehicle upper end of the B pillar 20 was allowance of rotational
displacement and allowance of displacement of only a vehicle upper side from an
initial position. As illustrated in FIG. 6, a rigid body 28 was made to collide against
the horizontally disposed test pieces 29 and 30 at a speed of20 km/h from above.
Regarding the respective test pieces 29 and 30, the impact energy absorbed amount EA
(kJ) in case the stroke of the rigid body 28 is 170 mm was analyzed.
[0086]
FIG. 8 illustrates analysis results of the impact energy absorbed amount EA
with respect to the three-point bending deformation analyzed regarding the respective
test pieces 29 and 30. As illustrated in FIG. 8, it can be seen that the impact energy
absorbed amount EA of the test piece 30 of the present invention example is markedly
higher than the impact energy absorbed amount EA of the test piece 29 of the
comparative example.
[0087]
The reasons are considered as follows. That is, if an impact load resulting
from a side collision is applied, a bending moment is applied to the side sill outer panel
via a joining region joined to the B pillar. If the test piece 29 of the comparative
example and the test piece 30 of the present invention example are compared with each
- 31 -
other regarding the second region outer height ho2 of the side sill outer panel, the
second region outer height ho2 of the test piece 29 of the comparative example is
smaller than the second region outer height ho2 of the test piece 30 of the present
invention example. For that reason, in a case where a bending moment is applied to
the side sill outer panel of the test piece 29 of the comparative example, large
deformation occurs in a welded spot (flange) welded with the side sill inner panel. As
a result, it is believed that the impact energy absorbed amount EA of the test piece 29
of the comparative example becomes smaller than the impact energy absorbed amount
EA of the test piece 30 of the present invention example.
[0088]
According to the present embodiment based on the above analysis results, the
impact energy absorption amount with respect to the three-point bending deformation
of the side sill I caused at the time of a side collision can be increased. Even in a
case where axial crushing deformation occurs in the side sill I at the time of a front
collision or a rear collision, the occurrence of the spot breaking can also be suppressed.
Accordingly, the impact energy absorption amount with respect to the axial crushing
deformation of the side sill 1 can be increased.
[0089]
It is desirable that the first region 14 is a region up to the position that is 150
mm or less apart rearward from the rear end of the lower A pillar connecting portion 21
of the side sill 1. Since the first region 14 is a portion that is within a range close to a
passenger's ankle and cmmected to a lower end portion of the lower A pillar 19 by the
resistance spot welding, it is necessary to prevent the spot breaking from occurring in
the first region 14 at the time of input of an impact load. For that reason, it is
- 32 -
desirable that the region up to the position that is 150 mm or less apart rearward from
the rear end of the lower A pillar connecting portion 21 of the side sill I is the first
region 14.
[0090]
Additionally, it is desirable that the second region 16 is the region between the
position that is 150 mm apart from the B pillar front connecting portion 22 toward the
vehicle front and the position that is 150 mm apart from the B pillar rear connecting
portion 23 toward the vehicle rear. A lower end portion ofthe B pillar 20 is fixed to a
portion of the second region 16 by the resistance spot welding. However, at the time
of a side collision, the three-point bending deformation occurs in the second region 16
in the side walls lla and lib ofthe side sill outer panel3. In this way, in order to
increase resistance with respect to the three-point bending deformation caused in the
second region 16 to increase the impact energy absorption amount with respect to the
three-point bending deformation, it is desirable that the above region is the second
region 16.
[0091]
In the tlrst region 14, it is preferable to satisfY the following Relational
Expression (a).
0.40 x (hi1 + ho1) :S ho1 :S 0.60 x (hi1 + ho1) ... (a)
[0092]
In the second region 16, it is preferable to satisfY the following Relational
Expression (b).
0.1 x (hh + hoz) :S hh :S 0.4 x (hiz + hoz) (b)
[0093]
- 33 -
In the third region 18, it is preferable to satisfY the following Relational
Expression (c).
0.40 x (hh + ho3) :S ho3 :S 0.60 x (hb + ho3) (c)
[0094]
By satisfYing the above Relational Expressions (a) and (c), the occurrence of
the spot breaking in the first region 14 and the third region 18 is suppressed even if the
axial crushing deformation occurs in the side sill! at the time of a front collision or a
rear collision. As a result, the impact energy absorption amount with respect to the
axial crushing deformation of the side sill 1 increases. Additionally, by satisfying the
above Relational Expression (b), the occurrence of the three-point bending
deformation in the side sill outer panel 3 at the time of a side collision is suppressed.
As a result, the impact energy absorption amount with respect to the three-point
bending deformation increases.
[0095]
As described above, although the side sill 1 equipped with the first region 14,
the second region 16, the third region 18, the first transition region 15, and the second
transition region 16 has been exemplified in the first embodiment, this side sill may be
a side sill equipped with at least the first region 14, the second region 16, and the first
transition region 15. For example, the rear end portion may be included in the second
region 16.
[0096]
FIG. 9A is an explanatory view illustrating a first modification example of a
mating structure of the joint portions of the side sill inner pane12 and the side sill outer
pane13. FIG. 9B is an explanatory view illustrating a second modification example of
- 34 -
a mating structure of the joint portions of the side sill inner panel2 and the side sill
outer panel 3.
[0097]
As illustrated in FIG. 9A, in a side silll-1 of the first modification example, in
at least portions of the joint portions, and the tlange width of the outward flanges 13a
and 13b is set to be longer than the flange width of the outward flanges Sa and Sb.
The outward tlanges 13a and 13b are bent by hemming working (hemming work) so as
to cover the outward flanges Sa and Sb. For example, an effect of suppressing the
spot breaking at the time of the occurrence of the axial crushing deformation is
improved by adopting the above configuration in the first region 14 or the third region
lS.
In addition, the flange width of the outward flanges Sa and 8b may be set to
be longer than the flange width of the outward flanges 13a and 13b, and the outward
flanges 8a and 8b may be bent by the hemming working so as to cover the outward
flanges 13a and 13b.
[0098]
As illustrated in FIG. 9B, in a side sill 1-2 of the second modification example,
in at least portions of the joint portions, the outward flanges 8a and 8b are not provided
in the side sill inner panel2, and the outward flanges 13a and 13b are not provided in
the side sill outerpanel3. The edge portions of the two side walls 6a and 6b of the
side sill inner panel2 and edge portions oftwo side walls 13a and 13b of the side sill
outer panel 3 are joined to each other in an overlapped state. For example, an effect
of suppressing the spot breaking at the time of the occurrence of the axial crushing
deformation is improved by adopting the above configuration in the first region 14 or
- 35 -
the third region 18.
[0099]
[Second Embodiment]
Next, a second embodiment of the invention will be described. In the second
embodiment, a fronts ide member that is a skeleton member of the automobile vehicle
body is exemplified as an automobile member related to the invention. This frontside
member has a fronts ide member inner panel as an inner panel and has a fronts ide
member outer panel as an outer panel.
[0 I 00]
FIG 10 is a perspective view illustrating a schematic configuration of a
frontside member 31 related to the second embodiment of the invention. FIG 11 is a
top view partially illustrating an arrangement situation of the frontside member 31 in a
simplified manner. A B-B cross section and a C-C cross section are altogether
illustrated in FIG II.
[0101]
The frontside member 31 has at least a frontside member inner panel 32 and a
frontside member outer panel33. The frontside member inner panel32 and the
frontside member outer panel 33 are respectively shape steels formed from high-tensile
steel sheets having a plate thickness of 1.0 mm or more. A reinforcement (reinforcing
plate) may be provided between the fronts ide member inner panel 32 and the frontside
member outer panel 33.
[0 I 02]
The frontside member inner panel 32 has at least the top plate 4 and the two
side walls 6a and 6b connected to the top plate 4. Since the frontside member inner
- 36 -
panel 32 is formed and manufactured by the press working using the ordinary bending
fanning or throttle forming or the roll working using the bending fom1ing, the
t!·ontside member inner panel 32 has the ridgelines Sa and Sb connected to the top plate
4 and the side walls 6a and 6b.
[0103]
Additionally, edge portions of the frontside member inner panel 32 are
provided with the outward flanges Sa and Sb connected to the two side walls 6a and 6b.
The outward flanges Sa and Sb are joining margins joined by, for example, the
resistance spot welding or the like in a state where the outward flanges Sa and Sb are
overlapped on outward flanges 13a and 13b provided at edge portions ofthe fronts ide
member outer panel33. For this reason, the frontside member inner panel32 further
has the curved portions 7 a and 7b connected to the side walls 6a and 6b and the
outward flanges Sa and Sb.
[0104]
The respective curvature radii of the ridgelines Sa and Sb and the curved
portions 7a and 7b are values such that manufacture is performed by the abovedescribed
ordinary working methods, and are usually 3 to 20 mm.
[OlOS]
Meanwhile, the frontside member outer panel 33 has at least the top plate 9,
and two side walls II a and II b connected to the top plate 9, similar to the frontside
member inner panel 32. Since the fronts ide member outer panel 33 is manufactured
by the press working using the ordinary bending forming or throttle forming or the roll
working using the bending forming, the frontside member outer panel 33 has the
ridgelines lOa and lOb connected to the top plate 9 and the side walls lla and !lb.
- 37 -
[0 1 06]
Additionally, the edge portions of the fronts ide member outer panel 33 are
provided with the outward flanges l3a and 13b connected to the two side walls lla and
II b. The outward flanges l3a and l3b are the joining margins joined by, for example,
the resistance spot welding or the like in a state where the outward flanges 13a and 13b
are overlapped on the outward flanges 8a and 8b provided at the edge portions of the
irontside member inner panel 32. For this reason, the fronts ide member outer panel
33 further has the curved portions 12a and 12b connected to the side walls 11 a and II b
and the outward flanges 13a and l3b.
[01 07]
The respective curvature radii of the ridgelines 1 Oa and 1 Ob and the curved
portions 12a and 12b are values such that manufacture is performed by the abovedescribed
ordinary working methods, and are usually 3 to 20 mm.
[0108]
Although a case where the outward flanges Sa and 8b are joined to the
outward flanges 13a and l3b by the resistance spot welding has been exemplified in
the above description, for example, it is also possible to use other joining methods,
such as other kinds of welding such as laser welding or electric arc welding other than
the resistance spot welding, bonding, and brazing.
[0109]
The frontside member 31 has the first region 14, the first transition region 15,
and the second region 16.
[0110]
The first region 14 extends rearward from a front end portion 31 a of the
- 38 -
fronts ide member 31. The first transition region 15 extends rearward continuously
with the first region 14. Moreover, the second region 16 extends rearward
continuously with the first transition region 15.
[Olll]
In the following, the height of the side walls 11 a and 11 b of the trontside
member outer panel 33 in the first region 14 is defined as the first region outer height
ho~, and the height of the side walls 6a and 6b of the frontside member inner panel 32
in the first region 14 is defined as the first region inner height hi 1.
The height of the side walls !Ia and lib of the frontside member outer panel
33 in the second region 16 is defined as the second region outer height ho2, and the
height of the side walls 6a and 6b of the frontside member inner panel32 in the second
region 16 is defined as the second region inner height hh. The height of the side
walls 11a and II b of the frontside member outer panel 33 in the first transition region
15 is defined as the first transition region outer height ho1-2, and the height of the side
walls 6a and 6b of the frontside member inner panel 32 in the first transition region 15
is defined as the first transition region inner height hi 1-2.
[0112]
In the first region 14, the first region outer height ho 1 and the first region irmer
height hit have the constant values, and the difference between the first region outer
height ho1 and the first region inner height hi1 is smaller than the difference between
the second region outer height ho2 and the second region itmer height hh. In the
frontside member 31 illustrated in FIG. I 0, the first region outer height ho1 and the first
region inner height hit are substantially equal to each other.
[0113]
- 39 -
In this way, in the first region 14 located on a front end side of the irontside
member 31, the first region outer height ho1 and the first region inner height hi 1 are
substantially equal to each other. Therefore, as described in the first embodiment, the
occurrence of the spot breaking at the lime of a front collision can be suppressed.
[0114]
In the second region 16, the second region outer height ho2 has a constant
value smaller than the second region inner height hi2. In the frontside member 31
illustrated in FIG. I 0, the second region outer height ho2 is zero. That is, in the
second region 16, the side walls lla and Ilb of the frontside member outer panel 33
are not present.
[0115]
In the first transition region 15, the first transition region outer height ho1-2
continuously varies between the first region outer height ho1 and the second region
outer height ho2, and the first transition region inner height hi1-2 continuously varies
between the first region inner height hi1 and the second region inner height hh.
[0116]
An engine mount bracket 46 that supports a transverse-mounted engine 44 is
fixed to the side wall 6a of the frontside member inner panel32 in the second region
16. In the second region 16, the side walls 11a and llb of the frontside member outer
panel 33 are not present. Thus, the height (second region inner height hh) of the side
walls 6a and 6b of the frontside member inner panel32 is sufficiently secured. For
this reason, since the mountability of the engine mount bracket 46 is sufficiently
secured, and as illustrated in FIG. 17, the frontside member 31 bends to a vehicle inside
at the time of a front col! is ion, the impact energy absorption amount can be increased.
- 40 -
[0117]
For this reason, the first region 14 and the second region 16 are fonned nearer
the front end portion 31 a of the frontside member 31 than a mounting position of the
engine mount bracket 46.
[0118]
As described above, by setting the first region outer height ho1, the first region
inner height hi1, the second region outer height ho2, the second region inner height hh,
the first transition region outer height ho1-2, and the first transition region inner height
hiH, the mountability of the engine mount bracket 46 can be maintained, and the
occurrence of the spot breaking at the time of a front collision can be suppressed.
[0119]
In the first region 14, it is preferable to satis.ty the following Relational
Expression (a). Accordingly, since the occurrence of the spot breaking is suppressed
even in a case where the axial crushing defom1ation occurs in the fronts ide member 31
at the time of a front collision or a rear collision, the impact energy absorption amount
with respect to the axial crushing deformation increases.
0.40 x (hi1 + ho1) S ho1 S 0.60 x (hi1 + ho1) (a)
[0120]
It is desirable that the first region 14 is a region between the front end portion
31a of the frontside member 31 and a position that is 400 mm or less apart rearward
from the front end portion 31 a. Accordingly, it is possible to avoid that the spot
breaking occurs in a welded spot between the outward flanges 8a and l3a. As a result,
a decrease in the impact energy absorption amount can be avoided.
[0121]
- 41 -
It is desirable that the second region 16 is a region that is present behind a
position that is 150 mm or more apart Jrom the tront end portion 31 a. Accordingly,
not only the engine 44 can be effectively mounted but also the frontside member 31
can be effectively folded at the time of a collision and the impact energy absorption
amount can be improved.
[0122]
Moreover, in the second region 16, it is desirable to satisfy the following
Relational Expression (d) or Relational Expression (e). Accordingly, not only the
engine 44 can be effectively mounted but also the frontside member 31 can be
effectively folded at the time of a collision and the impact energy absorption amount
can be improved.
0 <; hh <; 0.40 x (hh + ho2) (d)
0 <; ho2 :S 0.40 x(hh + ho2) (e)
Moreover, similar to the first embodiment, the mating structure of the joint
portion of the frontside member 31 may be the same structure as the modification
example described referring to FIGS. 9A and 98.
[0123]
A case where the outward flanges 8a and 8b of the fronts ide member inner
panel32 and the outward flanges 13a and 13b of the frontside member outer panel33
are disposed on a vehicle outside in the second region 16 has been exemplified in the
above description. However, in a case where the outward flanges Sa, 8b, 13a, and
13b are disposed on the vehicle inside, an engine mount bracket having a shape that
reaches the side walls over the outward flanges Sa, Sb, 13a, and 13b may be used.
[0124]
- 42 -
[Third Embodiment]
Next, a third embodiment of the invention will be described. In the third
embodiment, a side sill that is a skeleton member of an automobile vehicle body is
exemplified as an automobile member related to the invention. This side sill has a
side sill inner panel as an inner panel and has a side sill outer panel as an outer panel.
[0125]
FIG 12A is a plan view of a side sill I 00 related to the third embodiment of
the invention. FIG. 128 is an E-E arrow cross-sectional view of the side sill I 00
illustrated in FIG. 12A. As illustrated in FIGS. 12Aand 128, the side siliiOO has a
side sill outer panel II 0 and a side sill inner panel 120. The side sill outer panel II 0
and the side sill inner panel 120 are hat -shaped steels formed from high-tensile steel
sheets.
[0126]
The side sill outer panel 110 has a top plate Ill, a pair of side walls 112 and
113, and a pair of outward flanges 114 and 115. The top plate Ill, the side walls 112
and 113, and the outward flanges 114 and 115 are rectangular flat plates extending in a
material axis direction (length direction) of the side sill 100, respectively.
[0127]
As illustrated in FIG. 128, when the side sill 100 is seen in a cross section
orthogonal to the material axis direction, one width-direction end portion of the side
wall112 is connected to one width-direction end portion of the top plate 111 such that
an angle between the top plate 111 and the side wall112 becomes substantially rightangled.
Similarly, one width-direction end portion of the side wall113 is connected
to the other width-direction end portion of the top plate Ill such that an angle between
- 43 -
the top plate 111 and the side wallll3 becomes substantially right-angled.
In addition, in a case where the side sill outer panel 110 is fom1ed by pressworking
one steel sheet, the ridgelines described in the first embodiment are present at
a connecting site between the top plate 111 and the side wall 112 and at a connecting
site between the top plate 111 and the side wall 113, but the illustration thereof is
omitted in FIG 12B.
[0128]
Additionally, as illustrated in FIG 12B, when the side sill 100 is seen in the
section orthogonal to the material axis direction, an angle between the side wall 112
and the outward flange 114 becomes substantially right-angled and the outward flange
114, and one width-direction end portion of the outward flange 114 is connected to the
other width-direction end portion of the side wall 112 so as to protrude toward the
outside of the side sill 100 from the side wall 112.
Similarly, an angle between the side wall 113 and the outward flange 115
becomes substantially right-angled, and one width-direction end portion of the outward
flange 115 is connected to the other width-direction end portion of the side wall 113
such that the outward flange 115 protrudes toward the outside of the side sill 100 from
the side wall 113.
In addition, in a case where the side sill outer panel 110 is formed by pressworking
one steel sheet, the curved portions described in the first embodiment are
present at a connecting site between the side wall 112 and the outward flange 114 and a
connecting site between the side wall 113 and the outward flange 115, but the
Illustration thereof is omitted in FIG 12B.
[0129]
- 44 -
The length of the side walls 112 and 113 and the length ofthe outward flanges
114 and 115 arc the same as the length of the top plate Ill. The width (equivalent to
"the height of the side walls" described in the first embodiment) of the side wallll2 is
the same as the width of the side walll13. The width of the outward flange 114 is the
same as the width of the outward flange 115.
[0130]
The side sill inner panell20 has a top plate 121, a pair of side walls 122 and
123, and a pair of outward flanges 124 and 125. The top plate 121, the side walls 122
and 123, and the outward flanges 124 and 125 are rectangular flat plates extending in
the material axis direction of the side sill I 00, respectively.
[0131]
As illustrated in FIG. 128, when the side silllOO is seen in the section
orthogonal to the material axis direction, the top plate 121 faces the top plate Ill.
The length and width of the top plate 121 are the same as the length and width of the
top plate Ill. One width-direction end portion of the side wall 122 is connected to
one width-direction end portion of the top plate 121 such that an angle between the top
plate 121 and the side wall 122 becomes substantially right-angled. Similarly, one
width-direction end portion of the side walll23 is connected to the other widthdirection
end portion of the top plate 121 such that an angle between the top plate 121
and the side wall 123 becomes substantially right-angled.
In addition, in a case where the side sill inner panel 120 is formed by pressworking
one steel sheet, the ridgelines described in the first embodiment is present are
at a connecting site between the top plate 121 and the side wall 122 and at a connecting
site between the top plate 121 and the side wall 123, but the illustration thereof is
- 45 -
omitted in FIG. I 28.
[0132]
Additionally, as illustrated in FIG. 128, when the side sill 100 is seen in the
section orthogonal to the material axis direction, an angle between the side wall 122
and the outward flange 124 becomes substantially right-angled and the outward flange
124, and one width-direction end portion of the outward flange 124 is connected to the
other width-direction end portion of the side wall 122 so as to protrude toward the
outside of the side sill 100 from the side wall 122.
Similarly, an angle between the side wall 123 and the outward flange 125
becomes substantially right-angled, and one width-direction end portion of the outward
flange 125 is connected to the other width-direction end portion of the side wall 123
such that the outward flange 125 protrudes toward the outside of the side sill 100 from
the side wall 123. ·
In addition, in a case where the side sill inner panel 120 is formed by pressworking
one steel sheet, the curved portions described in the first embodiment are
present at a connecting site between the side wall 123 and the outward flange 124 and
a connecting site between the side wall 122 and the outward flange 125, but the
illustration thereof is omitted in FIG 12B.
[0133]
The length ofthe side walls 122 and 123 and the length of the outward flanges
124 and 125 are the same as the length of the top plate 121. The width of the side
wall122 is the same as the width of the side wall 123. The width of the outward
flange 124 is the same as the width of the outward flange 125. The width of the
outward flanges 124 and 125 is the same as the width of the out\vard t1anges 114 and
- 46 -
115.
[0134]
As described above, the side sill outer panel 110 and the side sill inner panel
120 have a hat-shaped cross-sectional shape, respectively. The outward flanges 114
and 115 of the side sill outer panel110 and the outward flanges 124 and 125 of the side
sill inner panel120 are joined to each other by the resistance spot welding or the like in
an overlapped state.
[0135]
In the following, the height (width) ofthe side walls 112 and 113 of the side
sill outer panel 110 is defined as the outer height ho, and the height (width) of the side
walls 122 and 123 of the side sill inner panell20 is defined as the inner height hi.
Additionally, the tensile strength of the side sill outer panel II 0 is defined as
TSo (MPa) and the plate thickness thereof is defined as to (mm), and the tensile
strength of the side sill inner panel 120 is defined as TSi (MPa) and the plate thickness
thereof is defined as ti (mm).
[0136]
In the side sill I 00 of the third embodiment, the outer height ho and the inner
height hi have constant values, respectively, in the length direction of the side sili!OO,
and the outer height ho is larger than the inner height hi. In snch the side sill I 00, the
tensile strength TSo and the plate thickness to of the side sill outer panell!O, and the
tensile strength TSi and the plate thickness ti of the side sill inner panel 120 are set so
as to satisfy the following Relational Expression (f).
TSo x to< TSi x ti ... (f)
[0137]
- 47 -
According to the side sill I 00 of the third embodiment having the above
configuration, both the impact energy absorption amount with respect to the axial
crushing deformation and the impact energy absorption amount with respect to the
three-point bending defonnation can be increased similar to the side sill 1 of the first
embodiment. Hereinafter, the reasons will be described.
[0138]
As illustrated in FIG. 13A, a test piece 200 that imitated the side sill I 00 of the
third embodiment was prepared, and an analysis test for the axial crushing deformation
was performed similar to the first embodiment. That is in this test, after a lower end
portion of the test piece 200 was fixed, a flat plate-shaped rigid body 300 was made to
collide against an upper end portion of the test piece 200 in a state where the rigid
body was parallel to or inclined at I oo with respect to a width direction of the test piece
200. Here, the inclined state of the rigid body 300 was adjusted such that the rigid
body 300 firstly collide against a hat-shaped panel closer to a larger hat side (a hatshaped
side sill outer panel of which the height of the side walls was large) rather than
a hat-shaped panel220 (a side sill inner panel of which the height of the side walls was
small) on a smaller hat side. The collision speed of the rigid body 300 against the test
piece 200 was 20 km/h.
[0139]
Under the conditions in which the tensile strength TSi of the hat-shaped panel
220 on the smaller hat side (side sill inner panel) was fixed at 780 (MPa) and the plate
thickness ti was fixed at 1.4 (mm), the combination of the tensile strength TSo and the
plate thickness to of the hat-shaped panel210 on the larger hat side (side sill outer
panel) was set according to combinations illustrated in Table 2. The rigid body 300
- 48 -
was made to collide against to the test piece 200 in which the combinations illustrated
in Table 2 were adopted, on the above collision conditions, and the presence/absence of
the spot breaking was investigated.
[0140]
The investigation results of the presence/absence of the spot breaking are
illustrated in Table 2. Additionally, FIG. 13B is a view graphing a correspondence
relationship between a multiplication value (TSo x to) of the tensile strength TSo and
the plate thickness to of the hat-shaped panel 210 on the larger hat side (side sill outer
panel), and the plate thickness to, on the basis of Table 2.
[0141]
[Table 2]
Tensile Strength on Plate Thickness on Large Hat side (mrn)
Larger Hat Side 2.0 1.8 1.6 1.4 1.2 1.0 0.8
590 (MPa) Yes No No No No No No
780 (MPa) Yes Yes Yes Yes No No No
980 (MPa) Yes Yes Yes Yes Yes No No
[0142]
As illustrated in FIG 13B, in a case where the multiplication value (TSo x to)
ofthe tensile strength TSo and the plate thickness to of the hat-shaped panel210 on the
larger hat side (side sill outer panel) was equal to or larger than a multiplication value
(fixed at TSi x ti = I 092 (MPa·mm)) of the tensile strength TSi and the plate thickness
ti of the hat-shaped panel220 on the smaller hat side (side sill inner panel), it tumed
out that the spot breaking occurs and the impact energy absorbed amount EA with
respect to the axial crushing deformation decreases.
On the other hand, in a case where the multiplication value (TSo x to) of the
tensile strength TSo and the plate thickness to ofthe hat-shaped panel210 on the larger
- 49 -
hat side (side sill outer panel) was smaller than a multiplication value (fixed at TSi x ti
= 1092 (MPa·mm)) ofthe tensile strength TSi and the plate thickness ti ofthe hatshaped
panel 220 on the smaller hat side (side sill inner panel), it turned out that the
spot breaking does not occur and the impact energy absorbed amount EA with respect
to the axial crushing deformation does not decrease.
[0143]
From the above analysis results, in a case where the outer height ho of the side
sill I 00 is larger than the inner height hi, the tensile strength TSo and the plate
thickness to of the side sill outer panel 110 and the tensile strength TSi and the plate
thickness ti of the side sill inner panel 120 are set so as to satisfY the above Relational
Expression (f). Accordingly, the occurrence of the spot breaking can be suppressed
even in a case where the axial crushing deformation occurs in the side sill 100 at the
time of a front collision or a rear collision including a small overlap collision. As a
result, the impact energy absorption amount that with respect to the axial crushing
deformation of the side sill 100 can be increased.
Additionally, the configuration of the side sill I 00 is the same as the
configuration of the second region I 6 of the side sill 1 in the first embodiment. Thus,
according to the side sill I 00, the impact energy absorption amount with respect to the
three-point bending deformation occurring at the time of a side collision can also be
increased.
[0144]
In addition, a case where the outer height ho and the im1er height hi have
constant values, respectively, in the length direction of the side silllOO and the outer
height ho is larger than the ilmer height hi has been exemplified in the above third
- 50 -
embodiment. However, for example, in a case where the outer height ho and the
inner heigh! hi have constant values, respectively, in the length direction of the side sill
and the outer height ho is smaller than the inner height hi, the tensile strength TSo and
the plate thickness to ofthe side sill outer panel and the tensile strength TSi and the
plate thickness ti of the side sill i1mer panel may be set so as to satisfy the following
Relational Expression (g).
TSo x to> TSi x ti ... (g)
[0 145]
Additionally, in the above third embodiment, the side sill I 00 is exemplified
as an automobile member. However, the automobile member may be a frontside
member. In this case, the fiontside member has a fronts ide member outer panel of the
same configuration as the above side sill outer panel 110 as an outer panel, and has a
fronts ide member inner panel of the same configuration as the above side sill inner
panel I 20 as an inner panel.
[0146]
[Fourth Embodiment]
FIG. 14 is a plan view illustrating a schematic configuration of a side sill lA
related to a fourth embodiment of the invention. The side silllArelated to a fourth
embodiment is equipped with the side sill inner panel 2 and the side sill outer panel 3
having the same configurations as the first embodiment. For that reason, in the
following, only differences from the configuration of the side silll of the first
embodiment in the configuration of the side sill lA of the fourth embodiment will be
described.
[0147]
- 51 -
Additionally, in the following, in the side sill !A, the tensile strength of the
side sill outer panel 3 is defined as TSo (MPa) and the plate thickness thereof is
defined as to (mm), and the tensile strength of the side sill inner panel2 is defined as
TSi (MPa) and the plate thickness thereof is defined as ti (mm).
[0148]
As illustrated in FIG. 14, similar to the side sill! ofthe first embodiment, also
in the side sill I A, the second region outer height ho2 is larger than the second region
inner height hi2. In such the side sill 1A, the tensile strength TSo and the plate
thickness to of the side sill outer panel 3, and the tensile strength TSi and the plate
thickness ti ofthe side sill inner panel 2 are set so as to satisfy the following Relational
Expression (f).
TSoxto TSi x ti ... (g)
[0153]
According to the fronts ide member 31A of the fifth embodiment having the
above configuration, the features of both the second embodiment and the third
embodiment are included. Thus, the occurrence of the spot breaking at the time of a
front collision can be more effectively suppressed while maintaining the mountability
of the engine mount bracket.
[0154]
- 53 -
Although the first to fitlh embodiments of the invention have been described
above, the automobile members (the side sills and the frontside members) described in
the respective embodiments may be formed of a tailored welding blank (TWB) in
which two or more types of steel sheets having different plate thicknesses, tensile
strengths, and the like in a material state are integrated with each other by welding (for
example, butt welding), a tailored rolled blank (TRB) in which the plate thickness of a
material is changed by changing the intervals of rolling rolls when manufacturing the
material, or a combination of the TWB and the TRB.
[Brief Description of the Reference Symbols]
[0155]
I, lA: SIDE SILL
2: SIDE SILL INNER PANEL
3: SIDE SILL OUTER PANEL
6a, 6b: SIDE WALL
lla, llb: SIDE WALL
14: FIRSTREGION
15: FIRST TRANSITION REGION
16: SECOND REGION
17: SECOND TRANSITION REGION
18: THIRD REGION
19: LOWERAPILLAR
20: B PILLAR
21: REAR WHEEL HOUSING OUTER
- 54 -
31, 31A: FRONTSIDE MEMBER
32: FRONTSJDE MEMBER INNER PANEL
33: FRONTSIDE MEMBER OUTER PANEL
44: TRANSVERSE-MOUNTED ENGINE
46: ENGINE MOUNT BRACKET
100: SIDE SILL
110: SIDE SILL OUTER PANEL
120: SIDE SILL INNER PANEL
Ill, 121: TOP PLATE
112, 113: SIDE WALL
122, 123: SIDE WALL
- 55 -

Claims
1. An automobile member of a closed cross section including an inner panel
having a top plate and two side walls connected to the top plate, an outer panel having
a top plate and two side walls connected to the top plate, and joint portions in which
edge portions of the two side walls of the inner panel are respectively joined to edge
portions of the two side walls of the outer panel, the automobile member comprising:
a first region extending rearward from a front end portion of the automobile
member;
a first transition region extending rearward continuously with the first region;
and
a second region extending rearward continuously with the first transition
regiOn,
wherein when the height of the side walls ofthe outer panel in the first region
is defined as a first region outer height ho1; the height ofthe side walls of the inner
panel in the first region is defined as a first region inner height hh; the height of the
side walls of the outer panel in the second region is defined as a second region outer
height ho2; the height of the side walls of the inner panel in the second region is
defined as a second region inner height hi2 ; the height of the side walls of the outer
panel in the first transition region is defined as a first transition region outer height
ho~-2; and the height of the side walls of the inner panel in the first transition region is
defined as a first transition region inner height hi1-2,
in the first region, the first region outer height ho1 and the first region inner
height hi1 have constant values, and a difference between the first region outer height
- 56 -
hot and the first region inner height hit is smaller than a difference between the second
region outer height ho2 and the second region inner height hh,
in the second region, the second region outer height 1m2 has a constant value
larger than the second region inner height hi2, or the second region outer height ho2 has
a constant value smaller than the second region inner height hh, and
in the first transition region, the first transition region outer height ho1-2
continuously varies between the first region outer height hot and the second region
outer height ho2, and the first transition region inner height hi1-2 continuously varies
between the first region inner height hi1 and the second region inner height hh.
2. The automobile member according to claim 1,
wherein the automobile member is a skeleton member of an automobile
vehicle body.
3. The automobile member according to claim 2,
wherein the inner panel is a side sill inner panel, the outer panel is a side sill
outer panel, and the skeleton member is a side sill.
4. The automobile member according to claim 3,
wherein a lower A pillar connecting portion that is a site to which a lower A
pillar is connected is provided in a region including the front end portion in the first
region, and a B pillar connecting portion that is a site to which a B pillar is connected
is provided in at least a portion of the second region,
wherein the first region is a region to a position that is 150 mm or less apart
- 57 -
rearward trom a rear end of the lower A pillar connecting portion of the skeleton
member, and
wherein the second region is a region between a position that is 150 mm or
less apart forward from the B pillar connecting portion, and a position that is 150 mm
or less apart rearward trom the B pillar cmmecting portion.
5. The automobile member according to claim 3 or 4,
wherein the following Relational Expression (a) is satisfied in the first region,
and the following Relational Expression (b) is satisfied in the second region.
0.40 x (hh + ho1) :S ho, :S 0.60 x (hi1 + ho1) (a)
0.10 x (hh + hoz) :S hiz :S 0.40 x (hiz + hoz) (b)
6. The automobile member according to any one of claims 3 to 5, further
compnsmg:
a second transition region extending rearward continuously with the second
region; and
a third region extending to a rear end portion of the automobile member
rearward continuously with the second transition region,
wherein when the height of the side walls of the outer panel in the third region
is defined as a third region outer height ho3; the height of the side walls ofthe inner
panel in the third region is defined as a third region inner height hb; the height of the
side walls of the outer panel in the second transition region is defined as a second
transition region outer height ho2- 3; and the height of the side walls of the inner panel
in the second transition region is defined as the second transition region inner height
- 58 -
in the third region, the third region outer height ho3 and the third region inner
height hi3 have constant values, and a difference between the third region outer height
ho3 and the third region inner height hb is smaller than a difference between the second
region outer height ho2 and the second region inner height hiz, and
in the second transition region, the second transition region outer height hoz-3
continnously varies between the second region outer height ho2 and the third region
outer height ho3, and the second transition region inner height hi 2_3 continuously varies
between the second region inner height hiz and the third region inner height hb.
7. The automobile member according to claim 6,
wherein the following Relational Expression (c) is satisfied in the third region.
0.40 x (hb + ho3) :S ho3 :S 0.60 x (hi3 + ho3) (c)
8. The automobile member according to any one of claims 4 to 7,
wherein the lower A pillar is connected to the lower A pillar connecting
portion, and the B pillar is connected to the B pillar connecting portion.
9. The automobile member according to claim 2,
wherein the inner panel is a frontside member inner panel, the outer panel is a
frontside member outer panel, and the skeleton member is a frontside member.
10. The automobile member according to claim 9,
wherein the following Relational Expression (a) is satisfied in the first region.
- 59 -
0.40 x (hi1 + ho1) <:; ho1 S 0.60 x (hi1 + ho1) (a)
II. The automobile member according to claim 9 or I 0,
wherein the !lrst region is a region between the front end portion and a
position that is 400 mm or less apart rearward from the front end portion.
12. The automobile member according to any one of claims 9 to II,
wherein the second region is a region that is present behind a position that is
150 mm or more apart from the front end portion.
13. The automobile member according to any one of claims 9 to 12,
wherein the following Relational Expression (d) or the following Relational
Expression (e) is satisfied in the second region.
0 <:; hi2 <:; 0.40 x (hh + ho2) (d)
0 S ho2 <:; 0.40 x (hh + ho2) (e)
14. The automobile member according to any one of claims 1 to 13,
wherein, in at least portions of the joint portions, the edge portions are flanges
that are connected so as to be formed in the two side walls of each of the inner panel
and the outer panel.
15. The automobile member according to claim14,
wherein in at least portions of the joint portions, the flanges formed in the
inner panel are subjected to hemming working so as to cover the flanges formed in the
- 60 -
outer panel, or the flanges formed in the outer panel are subjected to hemming working
so as to cover the flanges formed in the inner panel.
16. The automobile member according to any one of claims l to 13,
wherein in at least portions of the joint portion, edge portions of the two side
walls of the inner panel are respectively overlapped on and joined to edge portions of
the two side walls of the outer panel.
17. The automobile member according to any one of claims l to 16,
wherein the joining is performed using resistance spot welding.
18. The automobile member according to any one of claims I to 17,
wherein when the tensile strength of the outer panel is defined as TSo (MPa),
the plate thickness of the outer panel is defined as to (mm), the tensile strength of the
inner panel is defined as TSi (MPa), and the plate thickness of the inner panel is
defined as ti (mm),
the following Relational Expression (f) is satisfied in a case where the second
region outer height ho2 is larger than the second region inner height hh, and
the following Relational Expression (g) is satisfied in a case where the second
region outer height ho2 is smaller than the second region inner height hh.
TSo x to < TSi x ti (f)
TSo x to > TSi x ti (g)
19. An automobile member of a closed cross section including an inner
- 61 -
panel having a top plate and two side walls connected to the top plate, and an outer
panel having a top plate and two side walls connected to the top plate, and joint
portions in which edge portions of the two side walls of the inner panel are
respectively joined to edge portions of the two side walls of the outer panel,
wherein when the tensile strength of the outer panel is defined as TSo (MPa),
the plate thickness of the outer panel is defined as to (mm), the tensile strength of the
inner panel is defined as TSi (MPa), and the plate thickness of the inner panel is
defined as ti (mm), the height of the side walls of the outer panel is defined as outer
height ho, and the height of the side walls of the inner panel is defined is defined as
inner height hi,
the outer height ho and the inner height hi have constant values, respectively,
in a length direction of the automobile member,
the following Relational Expression (f) is satisfied in a case where the outer
height ho is larger than the inner height hi, and
the following Relational Expression (g) is satisfied in a case where the outer
height ho is smaller than the inner height hi.
TSoxto TSi x ti (g)
20. The automobile member according to claim 19,
wherein the automobile member is a side sill, and
wherein the side sill has a side sill inner panel as the inner panel and has a
side sill outer panel as the outer panel.
- 62 -
21. The automobile member according to claim 19,
wherein the automobile member is a frontside member, and
wherein the fronts ide member has a frontside member outer panel as the outer
panel and has a frontside member inner panel as the inner panel.
22. The automobile member according to any one of claims 1 to 21,
wherein the automobile member is formed by a tailored welding blank, a
tailored rolled blank, or combinations of these materials.