Impact absorbing member

Abstract

To absorb a larger impact by an impact absorbing member when the impact is applied to the impact absorbing member and to prevent a buckled part from interfering with a peripheral member.SOLUTION: An impact absorbing member of the present disclosure, which absorbs an impact acting on a vehicle, includes: a cylindrical peripheral wall portion extending in a predetermined direction; a plurality of partition wall portions respectively extending in the predetermined direction and disposed at intervals in an impact absorbing direction so as to define a plurality of hollow portions inside the peripheral wall portion; and a plurality of deformation trigger portions respectively extending in the predetermined direction and formed on an upper wall portion and a lower wall portion of the peripheral wall portion so as to cause a buckling mode in the impact absorbing direction of at least one of portions defining a predetermined hollow portion of the upper wall portion and the lower wall portion, to be a second order or higher.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an impact absorbing member that absorbs an impact acting on a vehicle. [Background technology]

[0002] A conventional rocker structure includes a closed cross-section portion extending along the longitudinal direction of the vehicle on the outer side of a vehicle floor panel in the vehicle width direction (see, for example, Patent Document 1). Within the closed cross-section portion of this rocker structure, a horizontal plate is installed along the vehicle width direction between an outer wall located on the outer side of the closed cross-section portion in the vehicle width direction and an inner wall located on the inner side of the closed cross-section portion in the vehicle width direction. Furthermore, the horizontal plate has convex portions that protrude upward in the vehicle vertical direction and concave portions that concave downward in the vehicle vertical direction, alternately formed along the vehicle width direction. Furthermore, the protrusion amounts of the convex portions and the concave amounts of the concave portions change from the outer wall side to the inner wall side. Furthermore, a plurality of vertical plates are installed along the vertical direction of the vehicle between the horizontal plate and a lower wall portion located on the lower side of the closed cross-section portion in the vehicle vertical direction. The vertical plates are arranged at approximately equal intervals between the outer wall and the inner wall, and each extends from between the apex of the convex portion and the apex of the concave portion of the horizontal plate toward the lower wall portion. In such a rocker structure, the buckling mode in the vehicle width direction of the horizontal plate and the portion between the outer wall of the lower wall portion and the vertical plate, the portion between adjacent vertical plates, and the portion between the inner wall and the vertical plate is first-order. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-137256 Summary of the Invention [Problem to be solved by the invention]

[0004] In the rocker structure described above, depending on the distance between a pair of adjacent vertical plates (including the outer and inner walls), i.e., the length of the hollow space between the vertical plates in the vehicle width direction, an impact applied to the rocker structure may cause the horizontal plate and the lower wall between the pair of vertical plates to bend toward the hollow space and come into contact with each other, making it impossible to absorb large impact energy. Furthermore, if an impact applied to the rocker structure causes the horizontal plate and the lower wall between the pair of vertical plates to bend upward or downward and buckle in the primary mode, the buckled horizontal plate and lower wall may interfere with surrounding components.

[0005] Therefore, the main object of the present disclosure is to enable a shock absorbing member to absorb a larger impact when an impact is applied to the shock absorbing member, and to suppress interference of the buckled portion with surrounding members. [Means for solving the problem]

[0006] The impact absorbing member of the present disclosure is an impact absorbing member that absorbs impact acting on a vehicle and includes a cylindrical peripheral wall portion extending in a predetermined direction, a plurality of partition wall portions that each extend in the predetermined direction and are arranged at intervals in the impact absorbing direction so as to define a plurality of hollow portions inside the peripheral wall portion, and a plurality of deformation trigger portions that each extend in the predetermined direction and are formed in the upper wall portion and the lower wall portion so as to make the buckling mode in the impact absorbing direction of at least one of the portions that define the predetermined hollow portions in the upper wall portion and the lower wall portion of the peripheral wall portion second or higher.

[0007] In the shock-absorbing member of the present disclosure, when an impact is applied to the shock-absorbing member, at least one of the portions defining the predetermined hollow portion in the upper wall portion and the lower wall portion of the peripheral wall portion can be buckled (collapsed) in the shock-absorbing direction in a secondary buckling mode starting from the multiple deformation trigger portions. This prevents the portions defining the predetermined hollow portion in the upper wall portion and the lower wall portion from bending and contacting each other in the predetermined hollow portion due to the impact applied to the shock-absorbing member, even if the portions defining the predetermined hollow portion in the upper wall portion and the lower wall portion bend and buckle upward or downward (toward the opposite side from the predetermined hollow portion) due to the impact applied to the shock-absorbing member. This minimizes the amount of upward protrusion of the upper wall portion and the amount of downward protrusion of the lower wall portion. As a result, when an impact is applied to the shock-absorbing member, the shock-absorbing member can absorb a larger impact and prevent the buckled portions from interfering with surrounding components. The deformation trigger portion may extend continuously in a predetermined direction, or may extend intermittently in a predetermined direction. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a vehicle body structure including an impact absorbing member according to the present disclosure. [Figure 2] 1 is a front view showing a vehicle body structure including an impact absorbing member according to the present disclosure. [Figure 3] FIG. 2 is a cross-sectional view showing the impact absorbing member of the present disclosure. [Figure 4] FIG. 2 is a plan view showing the impact absorbing member of the present disclosure. [Figure 5] FIG. 10 is a cross-sectional view showing another impact absorbing member of the present disclosure. [Figure 6] FIG. 10 is a cross-sectional view showing yet another impact absorbing member of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0010] Fig. 1 is a perspective view showing a main part of a vehicle 1 to which an energy absorbing member 10 of the present disclosure is applied. The vehicle 1 shown in the figure is an electric vehicle such as a battery electric vehicle or a hybrid vehicle, and includes a battery (battery pack) 2 mounted (placed) below a floor panel (not shown). The battery 2 includes a number of battery cells (not shown), such as lithium ion secondary batteries or nickel-metal hydride secondary batteries, and a battery case 2c that houses the number of battery cells.

[0011] In this embodiment, the impact absorbing members 10 are fixed to both side portions of the battery case 2c in the vehicle width direction of the vehicle 1, one on each side, and extend in the front-to-rear direction (predetermined direction) of the vehicle 1, in order to protect the battery 2 when a side collision (crash) occurs on the vehicle 1. When a side collision occurs on the vehicle 1, the impact absorbing members 10 buckle due to the impact in the vehicle width direction caused by the side collision, thereby absorbing the impact of the side collision so as not to transmit it to the battery 2. In other words, the impact absorbing direction of the impact absorbing members 10 coincides with the vehicle width direction.

[0012] As shown in Fig. 1, each impact absorbing member 10 is suspended and supported by left and right rocker members (under-reinforcements) 4 of the vehicle 1 via a plurality of brackets 3 (for example, six each in this embodiment) and bolts B. The rocker members 4 are arranged to extend in the longitudinal direction (predetermined direction) of the vehicle 1, and are curved so as to approach the center of the vehicle 1 in the vehicle width direction as they move from the front side (left side in Fig. 1) to the rear side (right side in Fig. 1). As a result, as shown in Fig. 2, the plurality of brackets 3 are also arranged so as to approach the center of the vehicle 1 in the vehicle width direction as they move from the front side to the rear side of the vehicle 1.

[0013] FIG. 3 is a cross-sectional view of an impact-absorbing member 10. The impact-absorbing member 10 shown in the figure is formed by extrusion molding of an aluminum alloy or the like. It includes a peripheral wall portion 11 in the shape of a flat, elongated rectangular tube having a rectangular cross-section, and a plurality of partition walls 16, 17, and 18 that are integrated with the peripheral wall portion 11 and extend from one end to the other in the longitudinal direction of the peripheral wall portion 11 (impact-absorbing member 10). As shown in FIG. 3, the peripheral wall portion 11 includes an upper wall portion 12, a lower wall portion 13, an outer wall portion 14, and an inner wall portion 15 that are integrated with each other. The upper wall portion 12 and the lower wall portion 13 of the peripheral wall portion 11 are all formed in a flat plate shape, extend parallel to each other, and face each other at a predetermined distance. The outer wall portion 14 extends in the vertical direction between the outer end of the upper wall portion 12 (the right end in the figure) and the outer end of the lower wall portion 13 (the right end in the figure). The inner wall portion 15 extends in the vertical direction between the inner end (left end in the figure) of the upper wall portion 12 and the inner end (left end in the figure) of the lower wall portion 13.

[0014] The partition walls 16-18 are formed integrally with the peripheral wall 11 so as to extend vertically between the upper wall 12 and the lower wall 13 of the peripheral wall 11 and be spaced apart along the vehicle width direction (the impact absorption direction) of the vehicle 1. As a result, hollow portions 110, 111, 112, and 113 are defined inside the peripheral wall 11, each extending in the longitudinal direction of the peripheral wall 11. That is, the hollow portion 110 is defined between the outer wall 14 and the partition wall 16. The hollow portion 111 is defined between the partition wall 16 and the partition wall 17. The hollow portion 112 is defined between the partition wall 17 and the partition wall 18. The hollow portion 113 is defined between the partition wall 18 and the inner wall 15.

[0015] 2 and 4, a plurality of (for example, six in this embodiment) cylindrical (hollow) collars 19 are fixed to the impact absorbing member 10 by upsetting, offset in the width direction (vehicle width direction) of the peripheral wall portion 11 so as to be aligned at intervals in the longitudinal direction (front-rear direction of the vehicle 1) of the peripheral wall portion 11. In this embodiment, each collar 19 is press-fitted and fixed to the upper wall portion 12 so that one end (lower end in the figure) abuts against the bottom surface (inner surface) of the lower wall portion 13 of the impact absorbing member 10 and the other end (upper end in the figure) protrudes from the upper surface 12U of the upper wall portion 12. However, each collar 19 may also be fixed to the impact absorbing member 10 by welding.

[0016] Furthermore, a plurality of (for example, six in this embodiment) bolt insertion holes 13B are formed in the lower wall portion 13 of the impact absorbing member 10 so as to align with the through holes 19h of each collar 19. The plurality of bolt insertion holes 13B are also arranged in the lower wall portion 13 at intervals in the longitudinal direction of the peripheral wall portion 11 (the front-to-rear direction of the vehicle 1) and offset in the width direction of the peripheral wall portion 11 (the vehicle width direction of the vehicle 1). A bolt B is inserted through each bolt insertion hole 13B in the lower wall portion 13 of the impact absorbing member 10 and through holes 19h in each collar 19. Then, each bolt B is screwed into a corresponding bracket 3 fixed to the rocker member 4, thereby fixing the impact absorbing member 10 to the rocker member 4.

[0017] As described above, in vehicle 1, rocker member 4 is curved so as to approach the center in the vehicle width direction as it moves from the front to the rear of vehicle 1, and multiple brackets 3 are arranged so as to approach the center in the vehicle width direction of vehicle 1 as it moves from the front to the rear of vehicle 1. For this reason, in impact absorbing member 10, multiple collars 19 are arranged offset in the width direction of peripheral wall portion 11 (vehicle width direction of vehicle 1), and therefore the spacing in the vehicle width direction of multiple partition walls 16-18 is adjusted so as not to interfere with the multiple collars 19.

[0018] 3, in the impact absorbing member 10, the distance between the partition walls 16 and 17 in the vehicle width direction (impact absorbing direction) is set to be larger than the distance between the outer wall portion 14 and the partition wall 16, the distance between the partition walls 17 and 18, and the distance between the partition wall 18 and the inner wall portion 15. As a result, the length of the hollow portion 111 (predetermined hollow portion) in the vehicle width direction is longer than the lengths of the hollow portions 110, 112, and 113 in the vehicle width direction (impact absorbing direction). In addition, in this embodiment, four collars 19 on the front side of the vehicle 1 are disposed within the hollow portion 111.

[0019] Here, if the distance between partition walls 16 and 17 in the vehicle width direction (impact absorbing direction), i.e., the length (buckling length) of hollow portion 111 in the vehicle width direction, is increased as described above, the buckling load of the portion of upper wall portion 12 and lower wall portion 13 of peripheral wall portion 11 that defines hollow portion 111 will be smaller than the portions of upper wall portion 12 and lower wall portion 13 that define hollow portions 110, 112, or 13. Furthermore, if the length of hollow portion 111 in the vehicle width direction is relatively long, the impact of a side collision applied to outer wall portion 14 of impact absorbing member 10 will cause upper wall portion 12 and lower wall portion 13 to bend toward hollow portion 111 and come into contact with each other, which may result in a large impact energy not being absorbed. Furthermore, if the impact of a side collision applied to the impact absorbing member 10 causes the upper wall portion 12 and the lower wall portion 13 to bend upward or downward and buckle in the primary mode, there is a risk that the buckled upper wall portion 12 will interfere with the rocker member 4.

[0020] In consideration of these, in impact absorbing member 10, a plurality of deformation trigger portions 121, 122, 131, and 132 are formed in upper wall portion 12 and lower wall portion 13 of peripheral wall portion 11 so as to make the buckling mode in the vehicle width direction (impact absorbing direction) of the portion defining hollow portion 111 therein secondary. Each deformation trigger portion 121, 122, 131, and 132 is a thin-walled portion that is simultaneously formed in upper wall portion 12 or lower wall portion 13 when impact absorbing member 10 is extruded so as to extend in the longitudinal direction of peripheral wall portion 11, i.e., the front-to-rear direction of vehicle 1. This makes it possible to further increase the buckling load of the portion defining hollow portion 111 in upper wall portion 12 and lower wall portion 13.

[0021] 3, the deformation trigger portion 121 (first upper thin portion) of the upper wall portion 12 is an elongated recess recessed from the lower surface 12L toward the upper surface 12U between the partition wall 16 and the center in the vehicle width direction of the hollow portion 111. The deformation trigger portion 122 (second upper thin portion) of the upper wall portion 12 is an elongated recess formed at a distance from the deformation trigger portion 121 in the vehicle width direction (impact absorption direction), and is recessed from the upper surface 12U toward the lower surface 12L between the center in the vehicle width direction of the hollow portion 111 and the partition wall 17.

[0022] The deformation trigger portion 131 (first lower thin portion) of the lower wall portion 13 is an elongated recess recessed from the lower surface 13L toward the upper surface 13U between the partition wall 16 and the center in the vehicle width direction of the hollow portion 111. The deformation trigger portion 132 (second lower thin portion) of the lower wall portion 13 is an elongated recess formed at a distance from the deformation trigger portion 131 in the vehicle width direction (impact absorption direction), and is recessed from the upper surface 13U toward the lower surface 13L between the center in the vehicle width direction of the hollow portion 111 and the partition wall 17.

[0023] Furthermore, the deformation trigger portions 121, 122, 131, 132 all have a width (length in the vehicle width direction) that is smaller than the inner diameter of the bolt insertion hole 13B in the lower wall portion 13 and the inner diameter of the through hole 19h in the collar 19. Furthermore, as can be seen from FIG. 3, the deformation trigger portion 122 of the upper wall portion 12 is divided by the corresponding collar 19 and through hole 19h, and extends intermittently in the longitudinal direction of the peripheral wall portion 11, i.e., in the front-to-rear direction of the vehicle 1. Furthermore, as can be seen from FIG. 3, the deformation trigger portion 132 of the lower wall portion 13 is divided by the corresponding bolt insertion hole 13B formed in the lower wall portion 13, and extends intermittently in the longitudinal direction of the peripheral wall portion 11, i.e., in the front-to-rear direction of the vehicle 1. In contrast, the deforming trigger portions 121, 131 extend continuously in the longitudinal direction of the peripheral wall portion 11, that is, in the front-rear direction of the vehicle 1, without being divided by the collar 19 (through hole 19h) and the bolt insertion hole 13B.

[0024] In the impact absorbing member 10 configured as described above, when an impact due to a side collision is applied to the outer wall portion 14, the portions that define the hollow portion 111 (predetermined hollow portion) in the upper wall portion 12 and the lower wall portion 13 of the peripheral wall portion 11 can be buckled (crushed) in the impact absorbing direction in a secondary buckling mode starting from the plurality of deformation trigger portions 121, 122, 131, 132. In other words, in the impact absorbing member 10, when an impact due to a side collision is applied to the outer wall portion 14, the portions that define the hollow portion 111 in the upper wall portion 12 and the lower wall portion 13 can be buckled (crushed into an accordion-like shape) so as to form wavefronts of one wavelength that are substantially parallel to each other.

[0025] More specifically, when an impact from a side collision is applied to the outer wall portion 14, the upper wall portion 12 bends upward, starting from a deformation trigger portion 121 (first upper thin-walled portion) that is recessed from the lower surface 12L toward the upper surface 12U, as shown by the dotted line in Figure 3, and also bends downward (towards the hollow portion 111) from a deformation trigger portion 122 (second upper thin-walled portion) that is formed at a distance from the deformation trigger portion 121 in the vehicle width direction and that is recessed from the upper surface 12U toward the lower surface 12L. Furthermore, when an impact is applied to the outer wall portion 14 due to a side collision, the lower wall portion 13 bends upward (toward the hollow portion 111) starting from a deformation trigger portion 131 (first lower thin portion) that is recessed from the lower surface 13L toward the upper surface 13U, as shown by the dotted line in Figure 3, and also bends downward starting from a deformation trigger portion 132 (second lower thin portion) that is formed at a distance from the deformation trigger portion 131 in the vehicle width direction and that is recessed from the upper surface 13U toward the lower surface 13L.

[0026] As a result, even if the length of hollow portion 111 in the vehicle width direction (impact absorbing direction) is relatively long, it is possible to prevent the portions of upper wall portion 12 and lower wall portion 13 that define hollow portion 111 from bending and coming into contact with each other at hollow portion 111 due to the impact of a side collision applied to impact absorbing member 10. Furthermore, even if the portions of upper wall portion 12 and lower wall portion 13 that define hollow portion 111 bend upward or downward (toward the opposite side from hollow portion 111) due to the impact of a side collision applied to impact absorbing member 10, it is possible to reduce the amount of upward protrusion of upper wall portion 12 and the amount of downward protrusion of lower wall portion 13. As a result, when a side collision impact is applied to impact absorbing member 10, a larger impact can be absorbed by impact absorbing member 10, and interference of the buckled portions with rocker member 4 (surrounding members) can be prevented. In addition, in the impact absorbing member 10, multiple deformation trigger portions may be formed on the upper wall portion 12 and the lower wall portion 13 so as to buckle at least one of the portions defining the hollow portion 111 of the upper wall portion 12 and the lower wall portion 13 in the impact absorbing direction in a third or higher buckling mode.

[0027] Furthermore, in the vehicle 1, a plurality of collars 19 are arranged in the hollow portion 111 of the impact absorbing member 10, offset in the vehicle width direction (impact absorbing direction) so as to be spaced apart in the longitudinal direction of the vehicle 1. Furthermore, a plurality of bolt insertion holes 13B are formed in the lower wall portion 13 so as to align with the plurality of collars 19 (through holes 19h). Furthermore, the peripheral wall portion 11 is fastened to the rocker member 4 (another member) via a plurality of bolts B that are inserted into the corresponding bolt insertion holes 13B and the corresponding collars 19 (through holes 19h).

[0028] That is, in the impact absorbing member 10, multiple collars 19 are disposed in the hollow portion 111 offset in the vehicle width direction, which increases the length (buckling length) of the hollow portion 111 in the vehicle width direction, thereby reducing the buckling load of the portion of the upper wall portion 12 and the lower wall portion 13 of the peripheral wall portion 11 that defines the hollow portion 111. In contrast, if multiple deformation trigger portions 121, 122, 131, 132 are provided in the upper wall portion 12 and the lower wall portion 13, it is possible to increase the buckling load of the portion of the upper wall portion 12 and the lower wall portion 13 that defines the hollow portion 111. As a result, it is possible for the impact absorbing member 10 to absorb a larger impact, and to suppress interference of the portion of the impact absorbing member 10 that buckles due to the impact with surrounding members such as the rocker member 4.

[0029] Furthermore, the deformation trigger portions 121, 122, 131, and 132 each extend in the longitudinal direction of the peripheral wall portion 11, i.e., in the front-to-rear direction (predetermined direction) of the vehicle 1, and have a width smaller than the inner diameter of the bolt insertion hole 13B. One of the bolt insertion holes 13B of the impact absorbing member 10 is formed in the lower wall portion 13 so as to divide the deformation trigger portion 132. This ensures good strength around the bolt insertion hole 13B of the lower wall portion 13, and makes it possible to firmly fasten the peripheral wall portion 11 of the impact absorbing member 10 to the rocker member 4 (another member) via the bolt B.

[0030] The deformation trigger portions 121, 122, 131, and 132 are thin-walled portions recessed from one of the upper surfaces 12U, 13U and the lower surfaces 12L, 13L of the upper wall portion 12 and the lower wall portion 13 toward the other. The upper wall portion 12 is formed with a deformation trigger portion 121 recessed from the lower surface 12L toward the upper surface 12U, and a deformation trigger portion 122 recessed from the upper surface 12U toward the lower surface 12L, while the lower wall portion 13 is formed with a deformation trigger portion 131 recessed from the lower surface 13L toward the upper surface 13U, and a deformation trigger portion 132 recessed from the upper surface 13U toward the lower surface 13L. This makes it possible to easily form the deformation trigger portions 121, 122, 131, and 132 by extrusion molding and to increase the buckling load of the portion of the upper wall portion 12 and the lower wall portion 13 that defines the hollow portion 111.

[0031] Furthermore, the impact absorbing members 10 are arranged on both sides of the battery 2 mounted on the vehicle 1 in the vehicle width direction so as to extend in the longitudinal direction of the vehicle 1. This makes it possible, in the event of a so-called side collision, for the impact to be absorbed in the vehicle width direction by the impact absorbing members 10, thereby providing good protection for the battery 2. However, the impact absorbing direction of the impact absorbing members 10 is not limited to the vehicle width direction of the vehicle 1. In other words, the impact absorbing members 10 may be mounted on the vehicle 1 so as to absorb impact in the longitudinal direction of the vehicle 1.

[0032] Furthermore, by manufacturing the impact absorbing member 10 by extrusion molding, it is possible to suppress an increase in the cost of the impact absorbing member 10. However, the impact absorbing member 10 is not limited to being manufactured by extrusion molding, and may be manufactured by drawing, pressing, roll forming, or the like.

[0033] In the impact absorbing member 10, the deformation trigger portion 121 (first upper thin portion) of the upper wall portion 12 may be recessed from the upper surface 12U toward the lower surface 12L, and the deformation trigger portion 122 (second upper thin portion) of the upper wall portion 12 may be recessed from the lower surface 12L toward the upper surface 12U. In this case, the deformation trigger portion 131 (first lower thin portion) of the lower wall portion 13 may be an elongated recess recessed from the upper surface 13U toward the lower surface 13L, and the deformation trigger portion 132 (second lower thin portion) of the lower wall portion 13 may be recessed from the lower surface 13L toward the upper surface 13U.

[0034] 5 is a cross-sectional view showing another impact absorbing member 10B of the present disclosure. Note that, among the components of the impact absorbing member 10B, the same components as those of the impact absorbing member 10 described above are given the same reference numerals, and redundant explanations will be omitted.

[0035] As shown in Fig. 5, the deformation trigger portion 121 (first upper thin portion) of the upper wall portion 12 of the impact absorbing member 10B is an elongated recess recessed from the upper surface 12U toward the lower surface 12L between the partition wall 16 and the center of the hollow portion 111 in the vehicle width direction. The deformation trigger portion 122 (second upper thin portion) of the upper wall portion 12 of the impact absorbing member 10B is an elongated recess formed at a distance from the deformation trigger portion 121 in the vehicle width direction (impact absorbing direction), and recessed from the lower surface 12L toward the upper surface 12U between the center of the hollow portion 111 in the vehicle width direction and the partition wall 17. The deformation trigger portion 131 (first lower thin portion) of the lower wall portion 13 of the impact absorbing member 10B is an elongated recess recessed from the lower surface 13L toward the upper surface 13U between the partition wall 16 and the center of the hollow portion 111 in the vehicle width direction. The deformation trigger portion 132 (second lower thin portion) of the lower wall portion 13 of the impact absorbing member 10B is a long recess formed at a distance from the deformation trigger portion 131 in the vehicle width direction (impact absorbing direction), and is recessed from the upper surface 13U toward the lower surface 13L between the center of the hollow portion 111 in the vehicle width direction and the partition wall 17.

[0036] When an impact due to a side collision is applied to the outer wall portion 14 of such an impact absorbing member 10B, the upper wall portion 12 bends downward (towards the hollow portion 111) from a deformation trigger portion 121 (first upper thin portion) that is recessed from the upper surface 12U toward the lower surface 12L, as shown by the two-dot chain line in Figure 5, and also bends upward from a deformation trigger portion 122 (second upper thin portion) that is recessed from the lower surface 12L toward the upper surface 12U. Furthermore, when an impact from a side collision is applied to the outer wall portion 14, the lower wall portion 13 of the impact absorbing member 10B bends upward (toward the hollow portion 111) starting from a deformation trigger portion 131 (first lower thin portion) that is recessed from the lower surface 13L toward the upper surface 13U, as shown by the two-dot chain line in Figure 5, and also bends downward starting from a deformation trigger portion 132 (second lower thin portion) that is recessed from the upper surface 13U toward the lower surface 13L.

[0037] That is, in shock absorbing member 10B, upper wall portion 12 and lower wall portion 13 can be deflected toward hollow portion 111 starting from deformation trigger portion 121 or 131, and upper wall portion 12 and lower wall portion 13 can be deflected upward or downward starting from deformation trigger portion 122 or 133. As a result, shock absorbing member 10B can absorb a larger shock, and interference of the portion that buckles starting from deformation trigger portion 121 or 131 with rocker member 4 (surrounding member) can be extremely effectively suppressed.

[0038] In the impact absorbing member 10B, the deformation trigger portion 121 (first upper thin portion) of the upper wall portion 12 may be recessed from the lower surface 12L toward the upper surface 12U, and the deformation trigger portion 122 (second upper thin portion) of the upper wall portion 12 may be recessed from the upper surface 12U toward the lower surface 12L. In this case, the deformation trigger portion 131 (first lower thin portion) of the lower wall portion 13 of the impact absorbing member 10B may be recessed from the upper surface 13U toward the lower surface 13L, and the deformation trigger portion 132 (second lower thin portion) of the lower wall portion 13 of the impact absorbing member 10B may be recessed from the lower surface 13L toward the upper surface 13U. In addition, in the impact absorbing member 10B, multiple deformation trigger portions may be formed on the upper wall portion 12 and the lower wall portion 13 so as to buckle at least one of the portions defining the hollow portion 111 of the upper wall portion 12 and the lower wall portion 13 in the impact absorbing direction in a third or higher buckling mode.

[0039] 6 is a cross-sectional view showing another impact absorbing member 10 of the present disclosure. Note that, among the components of the impact absorbing member 10C, the same components as those of the impact absorbing member 10 described above are given the same reference numerals, and redundant explanations will be omitted.

[0040] 6, the deformation trigger portion 121 (first thin portion) of the upper wall portion 12 of the impact absorbing member 10C is an elongated recess recessed from the lower surface 12L to the upper surface 12U between the partition wall 16 and the center of the hollow portion 111 in the vehicle width direction. The deformation trigger portion 122 (second upper thin portion) of the upper wall portion 12 of the impact absorbing member 10C is an elongated recess formed at a distance from the deformation trigger portion 121 in the vehicle width direction (impact absorbing direction), and recessed from the upper surface 12U to the lower surface 12L between the center of the hollow portion 111 in the vehicle width direction and the partition wall 17. The lower wall portion 13 of the impact absorbing member 10C also includes a deformation trigger portion 130 (middle thin portion) that extends in the longitudinal direction of the peripheral wall portion 11 and is an elongated recess recessed from the upper surface 13U to the lower surface 13L at the center of the hollow portion 111 in the vehicle width direction.

[0041] 6, when an impact due to a side collision is applied to outer wall portion 14 of impact absorbing member 10C, upper wall portion 12 bends upward from deformation trigger portion 121 (first thin-walled portion) that is recessed from lower surface 12L toward upper surface 12U as a starting point, and also bends downward (toward hollow portion 111) from deformation trigger portion 122 (second thin-walled portion) that is formed at a distance in the vehicle width direction from deformation trigger portion 121 and recessed from upper surface 12U toward lower surface 12L. Furthermore, when an impact due to a side collision is applied to outer wall portion 14, lower wall portion 13 bends downward (toward the opposite side from hollow portion 111) from deformation trigger portion 130 that is recessed from upper surface 13U toward lower surface 13L at the center of hollow portion 111 in the vehicle width direction.

[0042] In this way, in the shock absorbing member 10C, the upper wall portion 12 can be buckled in the shock absorbing direction in a secondary buckling mode, and the lower wall portion 13 can be buckled in the shock absorbing direction in a primary buckling mode. As a result, a larger shock can be absorbed by the shock absorbing member 10C, and interference of the buckled portion starting from the deformation trigger portions 121, 122, 130 with the rocker member 4 (surrounding member) can be extremely effectively suppressed.

[0043] In the impact absorbing member 10C, the deformation trigger portion 121 (first thin portion) of the upper wall portion 12 may be an elongated recess recessed from the upper surface 12U toward the lower surface 12L, and the deformation trigger portion 122 (second thin portion) of the upper wall portion 12 of the impact absorbing member 10C may be recessed from the lower surface 12L toward the upper surface 12U. Furthermore, the lower wall portion 13 of the impact absorbing member 10C may be recessed from the lower surface 13L toward the upper surface 13U at the center of the hollow portion 111 in the vehicle width direction.

[0044] Furthermore, the upper wall portion 12 of the impact absorbing member 10C may be formed with a deformation trigger portion (intermediate thin portion) recessed from one of the upper surface 12U and the lower surface 12L toward the other at the center of the hollow portion 111 in the vehicle width direction. In this case, the lower wall portion 13 of the impact absorbing member 10C may include a deformation trigger portion (first thin portion) recessed from one of the upper surface 13U and the lower surface 13L toward the other, and a deformation trigger portion (second thin portion) formed at a distance from the deformation trigger portion in the vehicle width direction (impact absorbing direction) and recessed from the other of the upper surface 13U and the lower surface 13L toward the one side. Also, in the impact absorbing member 10C, multiple deformation trigger portions may be formed in the upper wall portion 12 and the lower wall portion 13 so as to buckle at least one of the portions defining the hollow portion 111 of the upper wall portion 12 and the lower wall portion 13 in the impact absorbing direction in a third or higher buckling mode.

[0045] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present disclosure. Furthermore, the above-described embodiment is merely a specific form of the invention described in the Summary of the Invention, and does not limit the elements of the invention described in the Summary of the Invention. [Industrial Applicability]

[0046] The invention of the present disclosure can be used in the industry of manufacturing impact absorbing members, etc. [Explanation of symbols]

[0047] 1 vehicle, 2 battery, 3 bracket, 4 rocker member, 10, 10B, 10C impact absorbing member, 11 peripheral wall portion, 12 upper wall portion, 12L, 13L lower surface, 12U, 13U upper surface, 13 lower wall portion, 13B bolt insertion hole, 14 outer wall portion, 15 inner wall portion, 16, 17, 18 partition wall, 19 collar, 19h through hole, 110, 113, 113 hollow portion, 111 hollow portion (predetermined hollow portion), 121, 122, 130, 131, 132 deformation trigger portion, B bolt.

Claims

1. In a shock absorbing member that absorbs shock acting on a vehicle, a cylindrical peripheral wall portion extending in a predetermined direction; a plurality of partition wall portions each extending in the predetermined direction and arranged at intervals in the impact absorbing direction so as to define a plurality of hollow portions inside the peripheral wall portion; a plurality of deformation trigger portions each extending in the predetermined direction and formed on the upper wall portion and the lower wall portion so as to cause a buckling mode of at least one of portions defining a predetermined hollow portion of the upper wall portion and the lower wall portion of the peripheral wall portion in the shock absorbing direction to be second or higher order; A shock absorbing member comprising:

2. The impact absorbing member according to claim 1, a plurality of collars are disposed in the predetermined hollow portion, offset in the impact absorbing direction so as to be spaced apart in the predetermined direction; a plurality of bolt insertion holes are formed in at least one of the upper wall portion and the lower wall portion so as to align with the plurality of collars; The peripheral wall portion is an impact absorbing member that is fastened to another member via a plurality of bolts that are inserted into corresponding bolt insertion holes and corresponding collars.

3. The impact absorbing member according to claim 2, the deformed trigger portion has a width smaller than an inner diameter of the bolt insertion hole, At least one of the bolt insertion holes is an impact absorbing member formed in the upper wall portion or the lower wall portion so as to separate the deformation trigger portion.

4. The impact absorbing member according to any one of claims 1 to 3, The deformation trigger portion is a thin-walled portion recessed from one of the upper and lower surfaces of the upper wall portion and the lower wall portion toward the other, and at least one of the upper wall portion and the lower wall portion is formed with the thin-walled portion recessed from the upper surface toward the lower surface and the thin-walled portion recessed from the lower surface toward the upper surface, forming an impact absorbing member.

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