Title of the invention : Body side member structure
Technical field
[0001]
The present invention relates to a vehicle body side member structure.
This application claims priority based on Japanese Patent Application No. 2020-017225 filed in Japan on February 4, 2020, the content of which is hereby incorporated by reference.
Background technology
[0002]
In the past, there was a structure that could absorb shocks in the side member structure of the car body.
[0003]
However, the conventional side member structure does not meet the demand for protecting the battery pack mounted under the floor of an electrified vehicle from the impact caused by the collision of an obstacle from the side of the vehicle body, and the impact absorption capacity is insufficient. There is room for improvement in suppressing local deformation that affects the battery pack while maintaining the
prior art documents
patent literature
[0004]
Patent Document 1: Japanese Patent Application Laid-Open No. 2018-192868
Patent Document 2: JP 2015-003715 A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0005]
An object of the present invention is to provide a vehicle body side member structure capable of suppressing local deformation while maintaining impact absorption capability in view of the problems of the background art described above.
Means to solve problems
[0006]
The gist of the present invention is as follows.
[0007]
(1) A vehicle body side member structure according to an aspect of the present invention includes a tubular body extending in the front-rear direction of the vehicle body, and a shock absorbing member disposed inside the tubular body, the shock absorbing member comprising: a web that extends along the longitudinal direction and is flat in the vehicle width direction; a vehicle-exterior flange that is joined to an outer end of the web and extends along the longitudinal direction; and an outer flange that is joined to the inner end of the web. and a vehicle interior flange extending along the longitudinal direction, wherein the vehicle exterior flange and the vehicle interior flange have ribs arranged to sandwich the web from above and below and extending along the longitudinal direction.
(2) In (1) above, the web may be vertically compressed while being sandwiched between the ribs.
(3) In (1) or (2) above, the thickness of the web may be equal to or less than the thickness of the vehicle-exterior flange and the vehicle-interior flange.
(4) In any one of (1) to (3) above, the rib and the web are joined to each other.
(5) In any one of (1) to (4) above, the web may be a corrugated plate that alternately bends up and down along the front-rear direction.
(6) In any one of (1) to (4) above, the web may be a metal porous body.
(7) In any one of (1) to (4) above, the web may be formed by arranging a plurality of pipes having central axes along the vehicle width direction and arranging them along the front-rear direction.
(8) In (7) above, adjacent first and second pipes of the plurality of pipes may be joined together.
(9) In any one of (1) to (8) above, the cylindrical body has a support portion supported in the vehicle width direction by a cross member that crosses the vehicle body in the vehicle width direction, and the vehicle outer flange and the thickness of the vehicle-interior flange, when a load is applied in the vehicle width direction to the intermediate portion of the cylinder excluding the support portion, the cross section of the cylinder perpendicular to the front-rear direction Depending on the resulting bending moment distribution, it may have different portions in the longitudinal direction.
Effect of the invention
[0008]
The side member structure of the vehicle body of the present invention can suppress local deformation while maintaining impact absorption capability.
Brief description of the drawing
[0009]
1 is an exploded perspective view showing part of a vehicle body; FIG.
2 is a cross-sectional view taken along the arrow A in FIG. 1, showing the side member structure according to the first embodiment;
3 is a cross-sectional perspective view showing part of the side member structure according to the first embodiment; FIG.
4 is an exploded perspective view showing part of the side member structure according to the first embodiment; FIG.
5 is a side view showing part of the web according to the first embodiment; FIG.
[Fig. 6] Fig. 6 is a diagram for explaining the bending moment distribution acting on the side member structure and the deformation mode of the side member structure according to the first embodiment, Fig. 6(A) is a plan view, and Fig. 6(B) is a It is a side view.
7 is a cross-sectional view taken along the arrow A in FIG. 1, showing a side member structure according to a second embodiment; FIG.
8 is a cross-sectional perspective view showing part of a side member structure according to a second embodiment; FIG.
9 is an exploded perspective view showing part of a side member structure according to a second embodiment; FIG.
10 is a side view showing part of a web according to a second embodiment; FIG.
11 is a diagram showing results of numerical analysis of penetration amount; FIG.
MODE FOR CARRYING OUT THE INVENTION
[0010]
(First embodiment)
FIG. 1 is an exploded perspective view showing part of the vehicle body 1 including the side member structure 100 according to the first embodiment. FIG. 2 is a cross-sectional view taken along arrow A in FIG. 1, showing the side member structure 100 according to the first embodiment. Note that FIG. 2 shows a structure in which the battery case 20 and the side member structure 100 are integrated. Hereinafter, the direction along the traveling direction of the vehicle body (vehicle) is referred to as the front-rear direction or X direction, the traveling direction of the vehicle body is referred to as the front side, the opposite side is referred to as the rear side, and the direction along the direction of gravity is referred to as the vertical direction or Z direction. The direction along the horizontal direction is called the vehicle width direction or the Y direction, the direction away from the center of the vehicle body in the vehicle width direction is called the vehicle outer side, and the opposite direction is sometimes called the vehicle inner side.
[0011]
As shown in FIG. 1, the vehicle body 1 includes a frame 10 that constitutes the framework of the vehicle body 1, and a battery case 20 that houses a battery pack 21 such as a lithium ion battery. The vehicle body 1, such as an electric vehicle, is driven by a battery as a power source.
The frame 10 extends along the longitudinal direction of the vehicle body 1 and has a side member structure 100 (also referred to as a "side sill") located under the door of the side opening. The frame 10 also has a cross member 200 that extends along the vehicle width direction of the vehicle body 1 and bridges between the pair of side member structures 100 .
[0012]
The side member structure 100 of the vehicle body 1 according to the first embodiment protects the battery pack 21 from a side collision with a utility pole (pole side collision) and protects the occupant. On the outside (on the right side in FIG. 2), it is arranged with its longitudinal direction facing the longitudinal direction of the vehicle body 1 .
[0013]
As shown in FIG. 2, the side member structure 100 is supported by cross members 200 in the vehicle width direction (lateral direction). Cross member 200 supports floor panel 300 . The side member structure 100 is connected to the battery case 20 via fasteners 160 .
[0014]
A pair of side member structures 100 are normally provided on the left and right sides of the vehicle body 1 in the vehicle width direction. The side member structure 100 is supported in the vehicle width direction by the cross member 200 at the supporting portion 100S (see FIG. 1). That is, the cylindrical body 110 of the side member structure 100 has a support portion 100S that is supported in the vehicle width direction by the cross member 200 that crosses the vehicle body 1 in the vehicle width direction. As a result, a bending moment around the Z direction acting on the side member structure 100 that is generated when an obstacle collides with the side surface of the side member structure 100 of the vehicle body 1 can be suppressed. Therefore, the amount of bending deformation of the side member structure 100 in the vehicle width direction, particularly toward the vehicle interior side, can be suppressed.
[0015]
The cross member 200 spans between the pair of side member structures 100 . Both ends of the cross member 200 are joined to the support portions 100S of the side member structure 100 . A plurality of crossing members 200 are appropriately provided.
[0016]
The structures of the left and right side member structures 100 in the pair of side member structures 100 are symmetrical in the vehicle width direction. Below, as a representative, the side member structure 100 on the left side when viewed in the traveling direction will be described.
[0017]
FIG. 3 is a cross-sectional perspective view showing part of the side member structure 100 according to the first embodiment. FIG. 4 is an exploded perspective view showing part of the side member structure 100 according to the first embodiment. FIG. 5 is a side view showing part of the web 121 according to the first embodiment.
As shown in FIGS. 3 to 5 , the side member structure 100 according to the first embodiment includes a cylindrical body 110 (a hollow beam) extending in the front-rear direction of the vehicle body 1 and an impact absorbing member disposed inside the cylindrical body 110 . A member 120 is provided.
[0018]
(cylinder)
The cylindrical body 110 is a hollow elongated structure. The cylindrical body 110 is arranged with its longitudinal direction along the longitudinal direction of the vehicle body 1 . The cylindrical body 110 is made of, for example, a high-strength steel plate having a tensile strength of 980 MPa, and has desired performance including bending rigidity around the Z direction and buckling strength in the vehicle width direction. The tubular body 110 is divided into two, and has a vehicle-exterior tubular body 110A and a vehicle-interior tubular body 110B. The vehicle-exterior tubular body 110A and the vehicle-interior tubular body 110B each have a hat-shaped cross section with flanges on the upper and lower sides. The vehicle-exterior tubular body 110A and the vehicle-interior tubular body 110B are joined together by appropriate joining means such as welding and bolts, with their flanges facing each other. In addition, the cylindrical body 110 may not be divided into two parts, and may be divided into three parts or more.
[0019]
(Impact absorbing member)
The shock absorbing member 120 is arranged inside the tubular body 110 with its longitudinal direction along the longitudinal direction of the vehicle body 1 . The impact absorbing member 120 is made of, for example, a high-strength steel plate. When the shock absorbing member 120 is made of a high-strength steel plate, it can absorb high energy with a low mass, has high mass efficiency, and is suitable for a vehicle member that requires weight reduction.
[0020]
The impact absorbing member 120 extends along the front-rear direction of the vehicle body 1, is joined to a web 121 that is flat in the vehicle width direction of the vehicle body 1, and a vehicle-outer end portion 121e of the web 121, and extends along the front-rear direction. 122 and a vehicle-interior flange 123 joined to the vehicle-interior end 121i of the web 121 and extending in the front-rear direction. The vehicle-exterior flange 122 and the vehicle-interior flange 123 have ribs 122R and 123R arranged to sandwich the web 121 from above and below and extending in the front-rear direction.
[0021]
Since the impact absorbing member 120 has such a structure, the web 121 undergoes buckling deformation in the vehicle width direction toward the vehicle interior when an impact load is applied. As a result, the web 121 is crushed and deformed while resisting an averagely high load (reaction force) while suppressing the peak load (reaction force) generated when an impact load acts, so that the impact energy can be efficiently absorbed. Absorbable.
In addition, since the vehicle-exterior flange 122 and the vehicle-interior flange 123 are joined to both ends of the web 121 in the vehicle width direction, the deformation mode when the web 121 undergoes buckling deformation is set to a high-order mode with a short buckling wavelength. can be maintained. The vehicle-exterior flange 122 and the vehicle-interior flange 123 are joined to both ends of the web 121 in the vehicle width direction. Also, in the process of transmitting the impact load from the side member structure 100 to the web 121 via the vehicle exterior flange 122, the impact load can be dispersed in the front-rear direction, and the impact energy can be absorbed over a wide area in the front-rear direction. Therefore, it is possible to reduce the maximum value of local deformation of the side member structure 100 toward the vehicle interior due to a concentrated impact load. Since the vehicle-exterior flange 122 and the vehicle-interior flange 123 can efficiently increase the geometrical moment of inertia of the impact-absorbing member 120 around the Z-direction, bending deformation of the impact-absorbing member 120 in the vehicle-interior direction in the vehicle width direction (Bending deformation around the Z direction) can be efficiently resisted. Therefore, it is possible to suppress the deformation of the impact absorbing member 120 toward the inside of the vehicle.
Furthermore, the vehicle-exterior flange 122 and the vehicle-interior flange 123 are arranged to sandwich the web 121 from above and below, and have ribs 122R and 123R extending in the front-rear direction. The secondary polar moment of area around the direction can be increased. Therefore, it is difficult to bend and deform around the Y direction, that is, it is difficult to bend up and down, and it is difficult to twist around the X direction. Therefore, when a shock load acts, the shock absorbing member 120 It can be compactly deformed without causing large deformation.
In this way, even if an impact load acts from the vehicle width direction, the impact absorbing member 120 can efficiently absorb impact energy and suppress deformation toward the vehicle interior. Therefore, the battery case 20 that accommodates the battery pack 21 can be effectively protected.
[0022]
Specifically, the vehicle-exterior flange 122 and the vehicle-interior flange 123 are made of steel, for example. From the viewpoint of restraining deformation of the web 121, the vehicle-exterior flange 122 and the vehicle-interior flange 123 desirably have a tensile strength of 590 MPa or more, preferably 780 MPa or more, and more preferably 980 MPa or more.
As shown in FIG. 2, the cross-section of the vehicle-exterior flange 122 perpendicular to the front-rear direction is formed by a base portion 122B extending in the vertical direction, and upper ribs 122RU and lower ribs 122RD extending toward the vehicle interior from both upper and lower ends of the base portion 122B. It is approximately C-shaped. The cross-sectional shape of the vehicle-exterior flange 122 may be uniform along the front-rear direction.
Similarly, the cross section perpendicular to the front-rear direction of the vehicle-interior flange 123 is formed by a base portion 123B extending in the vertical direction, and an upper rib 123RU and a lower rib 123RD extending outward from the upper and lower ends of the base portion 123B. It is C-shaped. The cross-sectional shape of the vehicle inner side flange 123 may be uniform along the front-rear direction.
Both the vehicle-exterior flange 122 and the vehicle-interior flange 123 sandwich the web 121 inside the substantially C-shaped cross section. That is, the web 121 is sandwiched between the upper rib 122RU and the lower rib 122RD of the vehicle-interior flange 122, and the web 121 is sandwiched between the upper rib 123RU and the lower rib 123RD of the vehicle-interior flange 123. It is possible to more efficiently resist bending deformation in the vehicle width direction toward the vehicle interior (bending deformation around the Z direction), and further suppress deformation from the shock absorbing member 120 toward the vehicle interior.
[0023]
Specifically, the vehicle-exterior flange 122 is joined to the vehicle-exterior end 121e of the web 121 by arc welding, for example. Specifically, the shock absorbing member 120 forms a joint portion 124 at the boundary portion between the vehicle-exterior flange 122 and the web 121 . In order to obtain high weldability, that is, from the viewpoint of reducing the number of welding man-hours and ensuring the soundness of the welded portion, the joint portion 124 is formed by, for example, fillet welding the rib 122R of the vehicle outer flange 122 and the web 121. may be formed only at the boundary between That is, the first vertical surface portion 121b (see FIG. 5) and the second vertical surface portion 121d (see FIG. 5) of the web 121 and the vehicle exterior flange 122 do not have to be directly joined.
Similarly, the vehicle-interior flange 123 is joined to the vehicle-interior end 121i of the web 121 by, for example, welding. Specifically, the shock absorbing member 120 forms a joint 125 at the boundary between the vehicle interior flange 123 and the web 121 .
Here, even if the web 121 has a corrugated shape without the first horizontal surface portion 121a and the second horizontal surface portion 121c as shown in FIG. It is sufficient if the web 121 can be sufficiently joined. When the web 121 is provided with the first horizontal surface portion 121a and the second horizontal surface portion 121c, the first horizontal surface portion 121a is connected to the upper rib 122RU and the upper rib 123RU, and the second horizontal surface portion 121c is connected to the lower rib 122RD and the lower rib. Bonding with 123RD can be made easier and stronger.
[0024]
The web 121 and the rib 122R or the web 121 and the rib 123R are joined together. Thereby, the dimensional error of the positional relationship between the web 121 and the vehicle-exterior flange 122 or the vehicle-interior flange 123 can be absorbed. Also, after assembling the web 121 and the rib 122R or the rib 123R, they can be joined together. Therefore, it is easy to manufacture. Further, cross-sectional stress can be continuously and reliably transmitted between the web 121 and the vehicle-exterior flange 122 or the vehicle-interior flange 123 via the rib 122R or the rib 123R.
From the viewpoint of reducing the number of welding man-hours, the joint 125 may be formed only at the boundary between the rib 123R of the vehicle inner flange 123 and the web 121 by, for example, fillet welding.
The vehicle-interior surface of the base portion 122B of the vehicle-exterior flange 122 and the vehicle-exterior end surface of the web 121 may be in contact with each other or may be separated from each other. If there is a gap between the vehicle-interior side surface of the base portion 122B of the vehicle-exterior flange 122 and the vehicle-exterior end surface of the web 121, the dimensional tolerance of the web 121 in the vehicle width direction can be absorbed by the gap, and the width of the cylindrical body 110 in the vehicle width direction can be absorbed. It is possible to easily adjust the dimension of the impact absorbing member 120 in the vehicle width direction so as to match the inner dimension. Similarly, the vehicle-exterior surface of the base portion 123B of the vehicle-interior flange 123 and the vehicle-interior end surface of the web 121 may be in contact with each other or may be separated from each other.
Here, as shown in FIG. 2, the upper rib 122RU of the vehicle-exterior flange 122 and the upper rib 123RU of the vehicle-interior flange 123 are configured such that the respective lower surfaces 122CU, 123CU constrain the upward deformation of the web 121. , along the upper end of the web 121 (here, the upper surface of the first horizontal surface portion 121a). That is, the lower surfaces 122CU and 123CU of the upper rib 122RU and the upper rib 123RU may be parallel to the upper surface of the first horizontal surface portion 121a without any gap.
Also, the lower surfaces 122CU, 123CU of the upper rib 122RU of the vehicle-interior flange 122 and the upper rib 123RU of the vehicle-interior flange 123 are preferably in contact with the upper surface of the first horizontal surface portion 121a.
Further, the lower surface 122CU of the upper rib 122RU is in contact with at least the outermost end P1 of the first horizontal surface portion 121a, and the lower surface 123CU of the upper rib 123RU is in contact with at least the innermost end P2 of the first horizontal surface portion 121a. is preferred.
Similarly, the lower rib 122RD of the vehicle-interior flange 122 and the lower rib 123RD of the vehicle-interior flange 123 are arranged at the lower end of the web 121 (here Then, it is preferably provided along the lower surface of the second horizontal surface portion 121c. That is, the upper surfaces 122CD and 123CD of the lower ribs 122RD and 123RD may be parallel to the lower surface of the second horizontal surface portion 121c without any gap.
Further, it is preferable that the upper surfaces 122CD, 123CD of the lower rib 122RD of the vehicle-exterior flange 122 and the lower rib 123RD of the vehicle-interior flange 123 are in contact with the lower surface of the second horizontal surface portion 121c.
Further, the upper surface 122CD of the lower rib 122RD is in contact with at least the outermost end P3 of the second horizontal surface portion 121c, and the upper surface 123CD of the lower rib 123RD is in contact with at least the innermost end P4 of the second horizontal surface portion 121c. is preferred.
As a result, the vehicle-exterior flange 122 and the vehicle-interior flange 123 appropriately restrain the deformation of both ends of the web 121 in the vehicle width direction, so that the buckling load of the web 121 can be increased.
[0025]
As shown in FIG. 4, the web 121 of the shock absorbing member 120 is, for example, a corrugated plate that alternately bends up and down along the longitudinal direction of the vehicle body 1 . The web 121 is made of steel, for example. The web 121 should have a tensile strength of 590 MPa or more, preferably 780 MPa or more, more preferably 980 MPa or more, from the viewpoint of suppressing deformation and increasing buckling strength to obtain high energy absorption performance. desirable. When the shock absorbing member 120 has a ridgeline RL, the direction of the ridgeline RL is substantially parallel to the vehicle width direction. The shock absorbing member 120 has a wavy shape when viewed in the vehicle width direction, that is, when viewed from the side, as shown in FIG. 5, and when viewed vertically as shown in FIG. That is, in plan view, it has a rectangular shape that is long in the front-rear direction and has a predetermined width. In this way, the shock absorbing member 120 is a corrugated plate that alternately bends up and down along the longitudinal direction of the vehicle body 1, so that the flexural rigidity around the X direction (cross-sectional two-dimensional second moment) is high. Therefore, in the elastic region, the shock absorbing member 120 is less likely to bend in the X direction, and the buckling strength in the vehicle width direction can be enhanced. In addition, even if an impact load due to a pole side collision is input to any local area in the front-rear direction of the side member structure 100, the impact-absorbing member 120 at that local area is deformed by being crushed, and the impact-absorbing member 120 at that local area. Since 120 is also interlocked and deformed and crushed, the impact energy can be dispersed and absorbed in the front-rear direction of the impact-absorbing member 120 . Therefore, even if an impact such as a pole side collision is applied to any part in the front-rear direction, deformation of the entire impact-absorbing member 120 is suppressed, and local large impact energy is efficiently absorbed by the impact-absorbing member 120 as a whole. Absorbable. In addition, since the direction of the ridgeline RL is substantially parallel to the vehicle width direction along the direction of the impact load, when the impact load acts, the impact absorbing member 120 is configured to have a high energy absorption capacity, which will be described later. can be buckled in a lantern buckling mode such as
[0026]
As shown in FIG. 5, the wavy shape of the web 121 of the shock absorbing member 120 has a predetermined pitch 2D (twice the length D, for example, 120 mm) and a predetermined height when viewed from the vehicle width direction. Alternately bent up and down at H (distance from the center of the plate thickness tw at the upper end of the shock absorbing member 120 to the center of the plate thickness tw at the lower end of the shock absorbing member 120, twice the amplitude, for example, 30 mm) It is a shape that repeats
Specifically, the web 121 has a first horizontal surface portion 121a extending in the front-rear direction (extending left and right when viewed in the vehicle width direction) with a predetermined length. Further, following the first horizontal surface portion 121a, a first vertical surface portion 121b is bent downward (for example, at an angle of about 120 degrees) and obliquely extends at a predetermined height H (for example, 30 mm). have. In addition, following the lower part of the first vertical surface portion 121b, there is a second horizontal surface portion 121c that bends in the front-rear direction and extends in the front-rear direction for a predetermined length. Further, following the second horizontal surface portion 121c, it bends upward (for example, at an angle of about 120 degrees), extends obliquely at a predetermined height H, and continues to the next horizontal surface portion 121c. It has a vertical surface portion 121d.
These first horizontal surface portion 121a, first vertical surface portion 121b, second horizontal surface portion 121c, and second vertical surface portion 121d are periodically repeated in the front-rear direction to form a wave shape. The bent portion may be formed to draw an arc with a predetermined radius of curvature (eg, 5 mm).
Here, under the condition that each joint portion between the web 121 and the vehicle-exterior flange 122 and the vehicle-interior flange 123 is provided at 70% or more of the length of each of the first horizontal surface portion 121a and the second horizontal surface portion 121c. If so, it is possible to sufficiently ensure the amount of impact absorption energy to be absorbed, which will be described later, within the following numerical range regarding the dimensions of the impact absorbing member 120 .
Here, as the numerical range described above, the pitch 2D is within the range of 60 mm or more and 180 mm or less. The height H is in the range of 20 mm to 60 mm, preferably 20 mm to 50 mm. The first horizontal surface portion 121a and the second horizontal surface portion 121c are 30 mm or more and 90 mm or less. The angle formed by the first horizontal surface portion 121a with the first vertical surface portion 121b or the second vertical surface portion 121d is ±2.0° maximum from the angle formed with the second horizontal surface portion 121c with the first vertical surface portion 121b or the second vertical surface portion 121d. They match within the range of the difference, and the angle formed is within the range of 45° or more and 135° or less. The overall width of the shock absorbing member 120 is 120 mm or more and 180 mm or less.
In addition, the wave shape is not limited to the above. For example, each joint between the web 121 and the vehicle-exterior flange 122 and the vehicle-interior flange 123 ensures that the line length ratio of the ends of the web 121 on the vehicle-exterior flange 122 side and the vehicle-interior flange 123 side is at least 40% or more. Under such conditions as possible, for example, when viewed in the vehicle width direction, the shape may be such that upwardly convex arcs and downwardly convex arcs are alternately repeated.It may be shaped like a sine curve. Dimensions such as the pitch 2D and the height H of the corrugation may not be constant over the longitudinal direction. The values ​​of D/H and D/tw are set to appropriate values ​​from the viewpoint of obtaining high absorbed energy by crushing in an appropriate buckling mode.
[0027]
The web 121 of the shock absorbing member 120 has a predetermined plate thickness tw (for example, 1.0 mm, 1.2 mm, 1.6 mm, 2.0 mm, 2.3 mm) and a predetermined width B (depending on the dimensions of the vehicle body 1). , 100 mm or more and 200 mm or less, for example, 150 mm), and a predetermined total length L (1,500 mm or more and 3,000 mm or less, for example, 2,000 mm, depending on the dimensions of the vehicle body 1). It can be easily formed by pressing with a mold or by repeatedly bending up and down alternately. The plate thickness tw of the web 121 is preferably 0.7 mm or more and 2.6 mm or less from the viewpoint of suppressing bending deformation around the Z direction while ensuring the amount of energy absorption due to crushing. Moreover, the plate thickness tw of the web 121 is preferably 1.2 mm or more and 2.6 mm or less. Further, the plate thickness tw of the web 121 is desirably 1.0 mm or more and 2.3 mm or less from the viewpoint of energy absorption stability and weight reduction. Further, the plate thickness tw of the web 121 is desirably 1.2 mm or more and 2.0 mm or less from the viewpoint of further improving energy absorption stability and formability.
In addition, from the viewpoint of suppressing bending deformation in the Z direction while ensuring the amount of energy absorption due to crushing, the plate thickness tw of the web 121 is preferably equal to or less than the plate thickness tf of the vehicle outer flange 122 and the vehicle inner flange 123. preferable.
In particular, the structure of the web 121 and the vehicle-exterior flange 122 and the vehicle-interior flange 123 are the same except for the plate thickness, and the weight-equivalent structural condition that the weight per unit length along the longitudinal direction of the shock absorbing member 120 is equal. , when the input conditions such as the impact load to the side member structure 100 are the same, the thickness tf of the vehicle-exterior flange 122 and the vehicle-interior flange 123 becomes thicker than the thickness tw of the web 121, the more the side member The penetration amount d (see FIG. 6A), which is the maximum amount of deformation of the structure 100 toward the vehicle interior side, is reduced.
Here, as shown in FIGS. 6A and 6B, the side member structure 100 having the impact absorbing member 120 is supported by cross members 200, and the side member structure 100 is supported by cross members 200. Including the intrusion amount d when a load F is applied in the vehicle width direction from the vehicle outer side to the vehicle inner side to the rigid body RB in a state where a cylindrical rigid body RB imitating an obstacle is in contact with the side surface of An experiment was conducted to measure deformation and the like.
For example, the shock absorbing member 120 has a steel web 121 having a tensile strength of 980 MPa with a thickness tw of 2.0 mm, and a steel vehicle-exterior flange 122 and a vehicle-interior flange 123 having a tensile strength of 980 MPa. tf is 3.6 mm.
As a result of the experiment, the penetration amount d was 57 mm. Further, for example, without changing other conditions, the thickness tw of the web 121 is 3.1 mm, and the thickness tf of the vehicle-exterior flange 122 and the vehicle-interior flange 123 is 1.8 mm. As a result, the penetration amount d was 91 mm.
Therefore, from the viewpoint of protecting the battery case 20 by reducing the intrusion amount d, it is preferable that the thickness tf of the vehicle-exterior flange 122 and the vehicle-interior flange 123 is equal to or greater than the thickness tw of the web 121 . Further, from the viewpoint of further ensuring rigidity and further reducing weight, tf is desirably 3.0 mm or more and 4.5 mm or less under the condition of tf≧tw. Furthermore, from the viewpoint of further improving the energy absorption stability, it is more desirable that the length is 3.3 mm or more and 4.2 mm or less.
[0028]
In addition, the web 121 has a shape in which, when viewed in the vehicle width direction, it alternately bends up and down at a predetermined pitch 2D and a predetermined height H. Therefore, without causing buckling deformation (whole buckling mode) in which the entire shock absorbing member 120 is locally bent around the X direction in the vehicle width direction, a bellows-shaped, paper lantern-shaped, or intestinal structure ( boudinage-like buckling deformation (lantern buckling mode) can be generated. Therefore, the buckling strength of the shock absorbing member 120 can be efficiently used in a wide area of ​​the cross section perpendicular to the vehicle width direction, and the load is reduced immediately after reaching the maximum load (peak load) like the overall buckling mode. Buckling deformation can be performed while maintaining a high load without the deformation progressing. Therefore, it is possible to suppress the amount of deformation while maintaining a large amount of energy absorption. Note that the lantern buckling mode is a buckling deformation in which undulations occur continuously in small increments in the longitudinal and vertical directions along the width of the vehicle, and expansion and contraction are repeated in the direction perpendicular to the width of the vehicle. be.
[0029]
A vehicle-exterior end 121 e of the web 121 is joined to the vehicle-exterior flange 122 . As a result, when an impact load is input from the outside of the vehicle to the tubular body 110, the impact load is locally biased from the tubular body 110 to the outside edge 121e of the web 121 via the outside flange 122. It is possible to disperse and uniformly transmit the cross section perpendicular to the vehicle width direction. Therefore, the lantern buckling mode can be stably generated in the impact absorbing member 120, and high absorption energy can be obtained. Further, when an impact load acts on the impact absorbing member 120 in the vehicle width direction, the vehicle outer flange 122, on which compressive stress mainly acts, resists the bending moment. Furthermore, the second moment of area of ​​the shock absorbing member 120 around the Z direction is efficiently increased. Therefore, bending deformation of the shock absorbing member 120 around the Z direction can be suppressed.
[0030]
A vehicle-interior end 121 i of the web 121 is joined to the vehicle-interior flange 123 . As a result, when an impact load is input from the vehicle exterior side of the tubular body 110 , the load transmitted from the tubular body 110 via the vehicle exterior flange 122 and the web 121 is distributed to the front and rear of the vehicle interior flange 123 without being locally biased. As a tensile force acting on a cross section perpendicular to the direction, it can be dispersed and uniformly transmitted in the front-rear direction. Therefore, when an impact load acts on the impact absorbing member 120 in the vehicle width direction, the vehicle inner flange 123, on which tensile stress mainly acts, resists the bending moment around the Z direction. Furthermore, the second moment of area of ​​the shock absorbing member 120 around the Z direction is efficiently increased. Therefore, bending deformation of the shock absorbing member 120 around the Z direction can be suppressed.
[0031]
The web 121 is vertically compressed while being sandwiched between the ribs 122R. Similarly, the web 121 is vertically compressed while being sandwiched between the ribs 123R. For example, by fitting the vehicle-exterior end 121e and the vehicle-interior end 121i of the web 121 into the vehicle-exterior flange 122 and the vehicle-interior flange 123, respectively, the web 121 is sandwiched between the ribs 122R and 123R from above and below. Can be compressed vertically.
Since the web 121 is thus compressed in the vertical direction, the web 121, the vehicle-exterior flange 122, and the vehicle-interior flange 123 are less likely to be misaligned due to mutual friction, and can be easily joined together. . Therefore, the shock absorbing member 120 can be easily assembled. Moreover, since the web 121 is compressed in the vertical direction, it is possible to increase the buckling load in the vehicle width direction. Therefore, impact energy can be efficiently absorbed.
[0032]
The web 121 may have different tensile strengths on the vehicle inner side and on the vehicle outer side. For example, the web 121 may have a higher tensile strength on the vehicle exterior side than on the vehicle interior side. Alternatively, the web 121 may have a higher tensile strength on the vehicle interior side than on the vehicle exterior side.
[0033]
The impact-absorbing member 120 may be joined at its front-rear end to the front-rear end of the tubular body 110 . Thereby, the shock absorbing member 120 can be joined to the cylindrical body 110 after the shock absorbing member 120 is inserted into the cylindrical body 110 . In addition, shock absorbing member 120 does not have an intermediate portion other than the ends in the front-rear direction joined to cylindrical body 110, and only the ends in the front-rear direction of shock absorbing member 120 are attached to the ends of cylindrical body 110 in the front-rear direction. may be joined to As a result, after the shock absorbing member 120 is inserted into the cylindrical body 110, only the end portions of the shock absorbing member 120 need not be bonded to the cylindrical body 110, and the intermediate portion does not need to be bonded. Therefore, manufacturing efficiency can be improved.
[0034]
The thickness tfe of the vehicle-exterior flange 122 and the thickness tfi of the vehicle-interior flange 123 may be uniform in the front-rear direction. The optimum dimensions of the plate thickness tfe of the vehicle-exterior flange 122 and the plate thickness tfi of the vehicle-interior flange 123 may vary depending on design conditions. Under general design conditions, the thickness tfe of the vehicle-exterior flange 122 and the thickness tfi of the vehicle-interior flange 123 are 1.3 times or more and 3.8 times or less, preferably 1.6 times, the thickness of the web 121tw. It is found that the mass efficiency of impact absorption energy is improved when the ratio is 2.0 times or more and 3.0 times or less, more preferably 2.0 times or more and 2.5 times or less, which is desirable.
[0035]
(action)
Next, the action when the vehicle body 1 collides with a pole-shaped obstacle such as a utility pole installed on the ground and an impact load (impact energy) is input to the side member structure 100 from the outside of the vehicle will be described.
6A and 6B are diagrams for explaining the bending moment distribution MD acting on the side member structure 100 according to the first embodiment and the deformation mode Q of the shock absorbing member 120. FIG. (B) is a side view. In addition, in FIG. 6, the solid line indicates the shape of the shock absorbing member 120 before deformation. A two-dot chain line indicates the shape of the shock absorbing member 120 after deformation and a rigid body RB imitating an obstacle.
When the vehicle body 1 collides with a pole-shaped obstacle such as a utility pole installed on the ground surface, first, the pole-shaped obstacle comes into contact with the outer side of the cylindrical body 110, and the cylindrical body 110 is pushed locally toward the inner side of the vehicle. transform.
Then, following the deformation of the cylindrical body 110, the vehicle-exterior flange 122 of the impact-absorbing member 120 is pushed toward the vehicle interior and bends in the Z direction. Following the deformation, the vehicle-exterior end 121e of the web 121 of the shock absorbing member 120 deforms so as to be locally crushed. At this time, if the web 121 is deformed while resisting a certain load, buckling occurs in the vehicle width direction. Here, the buckling mode is a higher-order mode, and the buckling occurs uniformly in the cross section perpendicular to the vehicle width direction when viewed locally, so the web 121 is in a state of receiving a high load. , and further transform.
As the deformation progresses, high-order mode buckling occurs continuously in the vehicle width direction, and the web 121 is locally crushed into a lantern shape that continuously undulates in the vehicle width direction. A portion adjacent to the local area in the front-rear direction is also involved in the local deformation and crushed.
Here, as shown in FIG. 6, the impact energy causes the impact absorbing member 120 to bend toward the vehicle interior while being locally crushed in a shape (deformation mode Q) indicated by a chain double-dashed line. transform. At this time, the deformation in the Z direction increases the moment of inertia of area around the Y direction and around the Z direction and the polar moment of area around the X direction in the shock absorbing member 120 by the vehicle outer flange 122 and the vehicle inner flange 123. suppressed by the effect. In this way, since the deformation in the Z direction can be suppressed, the impact absorbing member 120 effectively absorbs the impact energy and is crushed in the vehicle width direction, while maintaining the bending rigidity around the Z direction. Inward deformation can be suppressed.
In this way, the side member structure 100 suppresses the deformation of the side member structure 100 toward the vehicle interior by cooperating with the cylindrical body 110 and the shock absorbing member 120, and absorbs the impact energy due to the local pole side collision. can be absorbed. Therefore, it is possible to effectively protect the battery pack 21 arranged inside the vehicle from the side member structure 100 .
[0036]
Here, the plate thickness tfe of the vehicle-interior flange 122 and the plate thickness tfi of the vehicle-interior flange 123 are such that when a load is applied in the vehicle width direction to an intermediate portion of the cylinder 110 excluding the support portion 100S, the cylinder 110 Depending on the bending moment distribution MD (see FIG. 6) occurring in the cross section perpendicular to the front-back direction, even if it has different parts in the front-back direction good. For example, when a load is applied in the vehicle width direction to an intermediate portion of the cylindrical body 110 excluding the support portion 100S, the bending moment around the Z direction generated in the cross section perpendicular to the front-rear direction of the cylindrical body 110 is the maximum bending. The plate thickness tfe of the vehicle-exterior flange 122 and the plate thickness tfi of the vehicle-interior flange 123 at the portion N that becomes the moment MM may be relatively large. As a result, the maximum value of bending deformation (deformation toward the vehicle interior) of the shock absorbing member 120 in the Z direction can be efficiently suppressed. Therefore, the maximum bending deformation of the side member structure 100 can be efficiently suppressed.
[0037]
(Production method)
Next, a method for manufacturing the side member structure 100 will be described.
(1) First, the cylinder 110 is prepared (cylinder preparation step). Specifically, the vehicle-exterior tubular body 110A and the vehicle-interior tubular body 110B are combined to form the tubular body 110 extending in the front-rear direction.
(2) Next, the impact absorbing member 120 is prepared (impact absorbing member preparing step). Specifically, a vehicle-exterior flange 122 and a vehicle-interior flange 123 are provided at both ends of the web 121 . Then, the ribs 123R of the vehicle outer flange 122 and the vehicle inner flange 123 and the web 121 are welded and joined by arc welding or the like.
(3) Next, the impact absorbing member 120 is inserted into the cylindrical body 110 from at least one end of the cylindrical body 110 (insertion step).
(4) Finally, the end portion of the cylindrical body and the end portion of the shock absorbing member, which is at least one end portion of the shock absorbing member 120, are joined together (joining step).
Thus, it is not essential to join the intermediate portion of the cylindrical body 110 and the intermediate portion of the shock absorbing member 120, and it is only necessary to join the end portions of the cylindrical body 110 and the end portions of the shock absorbing member 120. , the tubular body 110 and the impact absorbing member 120 can be assembled. Therefore, the side member structure 100 can be manufactured by inserting the shock absorbing member 120 after completing the cylindrical body 110 . Therefore, the side member structure 100 having high impact absorption energy absorption and high bending rigidity can be easily manufactured.
[0038]
(Second embodiment)
Next, the side member structure 500 according to the second embodiment will be described. Compared to the side member structure 100 according to the first embodiment, the side member structure 500 according to the second embodiment mainly includes a plurality of pipes 521p having central axes along the vehicle width direction. They are different in that they are arranged side by side in the front-rear direction. Hereinafter, descriptions of common parts between the first embodiment and the second embodiment may be omitted.
FIG. 7 is a cross-sectional view taken along arrow A in FIG. 1, showing the side member structure 500 according to the second embodiment. FIG. 8 is a cross-sectional perspective view showing a portion of the side member structure 500 according to the second embodiment. FIG. 9 is an exploded perspective view showing part of the side member structure 500 according to the second embodiment. FIG. 10 is a side view showing part of the web 521 according to the second embodiment.
[0039]
As shown in FIG. 7, the side member structure 500 is supported by the cross member 200 in the vehicle width direction (lateral direction). Cross member 200 supports floor panel 300 . The side member structure 500 is connected to the battery case 20 via fasteners 560 .
[0040]
As shown in FIGS. 8 to 10, the side member structure 500 according to the second embodiment includes a tubular body 510 extending in the longitudinal direction of the vehicle body 1 and an impact absorbing member 520 arranged inside the tubular body 510. ing.
[0041]
(cylinder)
The tubular body 510 is a hollow elongated structure. The cylindrical body 510 is arranged with its longitudinal direction along the longitudinal direction of the vehicle body 1 . The tubular body 510 is divided into two, and has a vehicle-exterior tubular body 510A and a vehicle-interior tubular body 510B.
[0042]
(Impact absorbing member)
The shock absorbing member 520 is arranged inside the tubular body 510 with its longitudinal direction along the longitudinal direction of the vehicle body 1 .
[0043]
The shock absorbing member 520 extends along the front-rear direction of the vehicle body 1, is joined to a web 521 that is flat in the vehicle width direction of the vehicle body 1, and a vehicle-outer end portion 521e of the web 521, and extends along the front-rear direction with a vehicle-outer flange. 522, and a vehicle-interior flange 523 joined to the vehicle-interior end 521i of the web 521 and extending in the front-rear direction. The vehicle-exterior flange 522 and the vehicle-interior flange 523 have ribs 522R and 523R arranged to sandwich the web 521 from above and below and extending in the front-rear direction.
[0044]
Specifically, as shown in FIG. 7, the cross section perpendicular to the front-rear direction of the vehicle-exterior flange 522 includes a base portion 522B extending in the vertical direction, upper ribs 522RU extending toward the vehicle interior from both upper and lower ends of the base portion 522B, and lower ribs. 522RD and has a substantially C-shaped (grooved) shape. The cross-sectional shape of the vehicle-exterior flange 522 may be uniform along the front-rear direction.
Similarly, the section perpendicular to the front-rear direction of the vehicle-interior flange 523 is formed from a base portion 523B extending in the vertical direction, and an upper rib 523RU and a lower rib 523RD extending outward from the upper and lower ends of the base portion 523B. It is C-shaped. The cross-sectional shape of the vehicle inner side flange 523 may be uniform along the front-rear direction.
[0045]
The vehicle-exterior flange 522 is joined to the vehicle-exterior end 521e of the web 521 by, for example, welding. Specifically, the impact absorbing member 520 forms a joint portion 524 at the boundary portion between the vehicle-exterior flange 522 and the web 521 .
Similarly, the vehicle-interior flange 523 is joined to the vehicle-interior end 521i of the web 521 by, for example, welding. Specifically, the shock absorbing member 520 forms a joint portion 525 at the boundary portion between the vehicle interior flange 523 and the web 521 .
[0046]
The web 521 and the rib 522R or the web 521 and the rib 523R are joined together. Thereby, the dimensional error of the positional relationship between the web 521 and the vehicle-exterior flange 522 or the vehicle-interior flange 523 can be absorbed. Also, after assembling the web 521 and the rib 522R or the rib 523R, they can be joined together. Therefore, it is easy to manufacture. Further, cross-sectional stress can be continuously and reliably transmitted between the web 521 and the vehicle-exterior flange 522 or the vehicle-interior flange 523 via the rib 522R or the rib 523R.
From the viewpoint of reducing the number of welding man-hours, the joint 525 may be formed only at the boundary between the rib 523R of the vehicle interior flange 523 and the web 521 by, for example, fillet welding.
The vehicle-interior side surface of the base portion 522B of the vehicle-exterior flange 522 and the vehicle-exterior end surface of the web 521 may be in contact with each other or may be separated from each other. If there is a gap between the vehicle-interior side surface of the base portion 522B of the vehicle-exterior flange 522 and the vehicle-exterior end surface of the web 521, the dimensional tolerance of the web 521 in the vehicle width direction can be absorbed by the gap, and the dimensional tolerance of the tubular body 510 in the vehicle width direction can be absorbed. It is possible to easily adjust the dimension of the impact absorbing member 520 in the vehicle width direction so as to match the inner dimension. Similarly, the vehicle-outside surface of the base portion 523B of the vehicle-interior flange 523 and the vehicle-interior end surface of the web 521 may be in contact with each other or may be separated from each other.
Here, as shown in FIG. 7, the upper rib 522RU of the vehicle-interior flange 522 and the upper rib 523RU of the vehicle-interior flange 523 are configured such that the respective lower surfaces 522CU, 523CU constrain the upward deformation of the web 521. , along the upper end of the web 521 (here, the upper surface of the first horizontal surface portion 521a). That is, the lower surfaces 522CU and 523CU of the upper rib 522RU and the upper rib 523RU may be parallel to the upper surface of the first horizontal surface portion 521a without any gap.
Also, the lower surfaces 522CU, 523CU of the upper rib 522RU of the vehicle-interior flange 522 and the upper rib 523RU of the vehicle-interior flange 523 are preferably in contact with the upper surface of the first horizontal surface portion 521a.
Furthermore, the lower surface 522CU of the upper rib 522RU is in contact with at least the outermost end Q1 of the first horizontal surface portion 521a, and the lower surface 523CU of the upper rib 523RU is in contact with at least the innermost end Q2 of the first horizontal surface portion 521a. is preferred.
Similarly, the lower rib 522RD of the vehicle-interior flange 522 and the lower rib 523RD of the vehicle-interior flange 523 are arranged at the lower end of the web 521 (here Then, it is preferably provided along the lower surface of the second horizontal surface portion 521c. That is, the upper surfaces 522CD and 523CD of the lower ribs 522RD and 523RD may be parallel to the lower surface of the second horizontal surface portion 521c without any gap.
Further, it is preferable that the upper surfaces 522CD, 523CD of the lower rib 522RD of the vehicle-exterior flange 522 and the lower rib 523RD of the vehicle-interior flange 523 are in contact with the lower surface of the second horizontal surface portion 521c.
Furthermore, the upper surface 522CD of the lower rib 522RD is in contact with at least the outermost end Q3 of the second horizontal surface portion 521c, and the upper surface 523CD of the lower rib 523RD is in contact with at least the innermost end Q4 of the second horizontal surface portion 521c. is preferred.
As a result, the vehicle-exterior flange 522 and the vehicle-interior flange 523 appropriately restrain the deformation of both ends of the web 521 in the vehicle width direction, so that the buckling load of the web 521 can be increased.
[0047]
As shown in FIGS. 9 and 10, the web 521 of the impact absorbing member 520 is formed by arranging a plurality of pipes 521p having a central axis along the vehicle width direction and arranging them along the front-rear direction.
Each pipe 521p has, for example, a rectangular cross section perpendicular to the central axis along the vehicle width direction. The cross section has a rectangular shape flattened in the front-rear direction. Each pipe 521p has a plate thickness tp of about 1 mm, for example. Each pipe 521p is made of steel, for example, and has a tensile strength of 980 MPa.
[0048]
As described above, the web 521 of the impact absorbing member 520 is formed by arranging a plurality of pipes 521p having a center axis along the vehicle width direction and arranging them along the front-rear direction. bending rigidity (geometric moment of inertia) is high. Therefore, in the elastic region, the shock absorbing member 520 is less likely to bend in the X direction, and the buckling strength in the vehicle width direction can be enhanced. In addition, since the central axis of the pipe 521p is substantially parallel to the vehicle width direction along the direction of the impact load, when the impact load is applied, the impact absorbing member 520 is configured to absorb a large amount of energy. It can be buckled in buckling mode.
[0049]
Adjacent pipes 521p are joined to each other in a state where the flat surfaces of the respective pipes 521p in the front-rear direction are in contact with each other. That is, the adjacent first pipe 521p1 and second pipe 521p2 are joined to each other. As a result, even if an impact load due to a pole side collision is input to any local area in the front-rear direction of the side member structure 500, the adjacent first pipe 521p1 and second pipe 521p2 are joined to each other. Along with the crushing deformation of the group of pipes 521p at , the groups of pipes 521p before and after the local area are also deformed and crushed in conjunction. Therefore, the impact energy can be dispersed and absorbed in the longitudinal direction of the impact absorbing member 520 . Therefore, even if an impact such as a pole side collision is applied to any part in the front-rear direction, deformation of the entire impact absorbing member 520 is suppressed, and local large impact energy is efficiently absorbed by the entire impact absorbing member 520. Absorbable.
[0050]
(Other embodiments)
The form of the web in the shock absorbing member is not limited to the web 121 in the first embodiment or the web 521 in the second embodiment. The web in the shock absorbing member may be, for example, a porous body made of metal, preferably steel.
In addition, in the above-described first and second embodiments, the impact absorbing member 120 or the impact absorbing member 520 is described as being used alone. On the other hand, a plurality of shock absorbing members 120 may be used, a plurality of shock absorbing members 520 may be used, and a plurality of shock absorbing members 120 and shock absorbing members 520 may be used in combination. You can At this time, the plurality of shock absorbing members 120 or shock absorbing members 520 may be arranged vertically so as to be parallel to each other.
[0051]
(Example)
Next, the results of numerical analysis performed on the side member structure 100 of the example will be described. The side member structure 100 of the first embodiment as shown in FIGS. 1 to 6 was taken as an example. In addition, a comparative example was a side member structure in which a web-only shock absorbing member having a mass equivalent to that of the shock absorbing member of the example was used, and other structures were the same as those of the example. Numerical analysis was performed on the structural model for Examples and Comparative Examples.
FIG. 11 is a diagram showing numerical analysis results of the intrusion amount d.
[0052]
Specifically, as an embodiment, as shown in FIGS. 1 to 6, a web 121 having a plate thickness tw and a vehicle-exterior flange 122 and a vehicle-interior flange 123 having a plate thickness tf are assembled into a shock absorbing member. A structural model of the side member structure 100 with 120 was prepared.
The web 121, the vehicle-exterior flange 122, and the vehicle-interior flange 123 are all made of steel with a tensile strength of 980 MPa.
The thickness tfe of the vehicle-exterior flange 122 and the thickness tfi of the vehicle-interior flange 123 are set to be the same thickness tf. The height H of the web 121 was set to 27 mm.
The full width of the shock absorbing member 120 is set to 137 mm.
The upper surfaces of all the first horizontal surface portions 121a of the web 121 are fillet-welded to the vehicle-interior end surfaces of the upper ribs 122RU of the vehicle-interior flange 122 and the vehicle-exterior end surfaces of the upper ribs 123RU of the vehicle-interior flange 123.
The lower surfaces of all the second horizontal surface portions 121c of the web 121 are fillet-welded to the vehicle-interior end surfaces of the lower ribs 122RD of the vehicle-interior flange 122 and the vehicle-exterior end surfaces of the lower ribs 123RD of the vehicle-interior flange 123. A plurality of structural models including shock absorbing members 120 having different combinations of plate thickness tw and plate thickness tf as shown in FIG. 11 were prepared. The plate thickness tw of the web 121 and the plate thickness of the flanges 122 and 123 are set so that the mass of the shock absorbing member 120, which is the combination of the vehicle-exterior flange 122 and the vehicle-interior flange 123, and the web 121, is the same in any structural model. tf.
The combination of the plate thickness tw of the web 121 and the plate thickness tf of the flanges 122 and 123 is (tw, tf); 3.9 mm), (1.8 mm, 3.6 mm), (2.0 mm, 3.3 mm), (2.2 mm, 3.0 mm), (2.4 mm, 2.7 mm), (2.6 mm, 2.4 mm).
[0053]
Further, specifically, as a comparative example, except that the vehicle-interior flange 123 and the vehicle-exterior flange 122 are excluded, and that the web has the same full width as the impact-absorbing member 120 of the embodiment, We prepared a structural model of the side member structure including the shock absorbing member of the same structure. That is, the shape of the impact absorbing member of the comparative example when viewed in the vehicle width direction was made the same as the shape of the web 121 of the example. Then, a plurality of comparative examples having different web thicknesses tw were prepared, and the web thicknesses tw of the respective comparative examples were set to 1.2 mm, 1.4 mm, 1.6 mm, 1.2 mm, 1.6 mm, 1.2 mm, 1.6 mm, 1.2 mm, 1.6 mm, 1.2 mm, 1.6 mm, 1.2 mm, 1.6 mm, 1.2 mm, 1.6 mm, 1.2 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.2 mm, 1.6 mm, 1.2 mm, 1.6 mm, and 1.2 mm. 8 mm, 2.0 mm, 2.2 mm, 2.4 mm, and 2.6 mm.
[0054]
Then, with respect to the side member structure 100 of the embodiment, as shown in FIGS. Deformation including the penetration amount d when a load F is applied to the rigid body RB in the vehicle width direction from the vehicle outer side to the vehicle inner side in a state where a cylindrical rigid body RB imitating an obstacle is in contact with the A numerical analysis was performed to calculate the response. Similarly, numerical analysis was performed on the side member structure of the comparative example.
[0055]
As a result, as shown in FIG. 11, the penetration amount d in the example when (tw, tf) was (1.2 mm, 4.5 mm) was 65 mm. Similarly, the penetration amount d is 63 mm when (tw, tf) is (1.4 mm, 4.2 mm), and 59 mm when (tw, tf) is (1.6 mm, 3.9 mm). is 60 mm when (tw, tf) is (1.8 mm, 3.6 mm), 67 mm when (tw, tf) is (2.0 mm, 3.3 mm), and (tw, 63 mm when tf) is (2.2 mm, 3.0 mm), 74 mm when (tw, tf) is (2.4 mm, 2.7 mm), and (tw, tf) is (2. 6 mm, 2.4 mm) was 78 mm.
[0056]
On the other hand, the penetration amount d in the comparative example exceeded 90 mm at any web thickness tw corresponding to the example, and was larger than the penetration amount d in the example.
As described above, the side member structure 100 of the embodiment has the vehicle-exterior flange joined to the vehicle-exterior end of the web 121 and the vehicle-interior flange joined to the vehicle-interior end of the web 121. , the intrusion amount d can be reliably reduced. Moreover, since the vehicle-exterior flange 122 and the vehicle-interior flange 123 in the side member structure 100 of the embodiment have the ribs 122R and 123R arranged to sandwich the web 121 from above and below, the intrusion amount d can be reliably increased. can be reduced.
Industrial applicability
[0057]
The side member structure of the vehicle body according to one aspect of the embodiment is suitable for a side sill, which is a member positioned under the door of the side opening of the frame that constitutes the skeleton of the vehicle body that is driven by a battery, such as an electric vehicle. Applicable. An object to be protected by the vehicle body side member structure according to one aspect of the embodiment may be anything other than the battery pack as long as it is arranged inside the vehicle from the side member structure.
Code explanation
[0058]
1 Body
2D pitch
10 frames
20 battery case
21 Battery pack
100, 500 side member structure
100S support part
110,510 cylinder
110A, 510A outer cylinder
110B, 510B cylinder inside the vehicle
120, 520 Shock absorbing member
121,521 Web
121a First horizontal surface part
121b First vertical surface portion
121c second horizontal surface part
121d Second vertical surface portion
121e, 521e Vehicle outside end
121i, 521i end inside the vehicle
122, 522 outside flange
122B, 522B base
122R, 522R ribs
122RD, 522RD lower rib
122RU, 522RU upper rib
123, 523 Inside flange
123B, 523B base
123R, 523R ribs
123RD, 523RD lower rib
123RU, 523RU upper rib
124 joint
125 joint
160, 560 fasteners
200 Cross member
300 floor panel
521p pipe
521p1 first pipe
521p2 second pipe
524, 525 joint
B width
L Total length
MD moment distribution
MM Maximum bending moment
N part
Q Transformation mode
RL Ridgeline
t, tf, tfe, tfi, tp, tw Plate thickness
d Amount of penetration
RB rigid body
F Load
P1, P2, P3, P4 ends
The scope of the claims
[Claim 1]
The side member structure of the car body,
A cylindrical body extending in the longitudinal direction of the vehicle body, and a shock absorbing member disposed inside the cylindrical body,
The shock absorbing member extends along the front-rear direction and includes a web that is flat in the vehicle width direction,
a vehicle-exterior flange joined to the vehicle-exterior end of the web and extending along the longitudinal direction;
a vehicle-interior flange joined to the vehicle-interior end of the web and extending along the longitudinal direction;
The vehicle-exterior flange and the vehicle-interior flange are arranged to sandwich the web from above and below, and have ribs extending along the front-rear direction.
A vehicle body side member structure characterized by:
[Claim 2]
The web is vertically compressed while being sandwiched between the ribs
The side member structure for a vehicle body according to claim 1, characterized in that:
[Claim 3]
The thickness of the web is equal to or less than the thickness of the vehicle-exterior flange and the vehicle-interior flange
The vehicle body side member structure according to claim 1 or 2, characterized in that:
[Claim 4]
　The ribs and the web are joined to each other
The side member structure for a vehicle body according to any one of claims 1 to 3, characterized in that:
[Claim 5]
The web is a corrugated plate that alternately bends up and down along the front-back direction.
The side member structure for a vehicle body according to any one of claims 1 to 4, characterized in that:
[Claim 6]
The web is a metallic porous body
The side member structure for a vehicle body according to any one of claims 1 to 4, characterized in that:
[Claim 7]
The web is formed by arranging a plurality of pipes having a central axis along the vehicle width direction and arranging them along the front-rear direction.
The side member structure for a vehicle body according to any one of claims 1 to 4, characterized in that:
[Claim 8]
Adjacent first and second pipes in the plurality of pipes are joined together
The vehicle body side member structure according to claim 7, characterized in that:
[Claim 9]
The tubular body has a support portion that is supported in the vehicle width direction by a cross member that crosses the vehicle body in the vehicle width direction,
The plate thickness of the vehicle-exterior flange and the plate thickness of the vehicle-interior flange are such that when a load acts in the vehicle width direction on an intermediate portion of the cylinder excluding the support portion, the thickness of the cylinder increases in the longitudinal direction. Having different parts in the front-back direction according to the bending moment distribution occurring in the vertical cross section
The side member structure for a vehicle body according to any one of claims 1 to 8, characterized in that: