JP2009274663A - Vehicle energy absorbing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To absorb energy by a lightweight and highly efficient energy absorbing member by suppressing the breakage of the root section of the energy absorbing member without increasing the mass of the energy absorbing member. <P>SOLUTION: In this vehicle energy absorbing structure 10, a crash box 16 is installed between a bumper reinforcement 12 and side members 14 in the vehicle longitudinal direction. The crash box 16 has an open cross section when viewed in the vehicle longitudinal direction. The pair of free ends 16A, 16B of the crash box 16 in the vehicle longitudinal direction are disposed in respective areas B and C on the inside of the centroid O of the open cross section when viewed in the vehicle lateral direction. In other words, the free ends are disposed in those areas other than the areas A and D in which the maximum compressive stresses are produced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle energy absorption structure, and more particularly to a vehicle energy absorption structure including an energy absorption member.

Conventionally, the following is known as this kind of vehicle energy absorption structure (for example, refer to patent documents 1). That is, Patent Document 1 discloses an example in which a cylindrical CFRP is provided as an energy absorbing member.
JP 2005-233263 A JP 2005-195155 A

  However, in the example described in Patent Document 1, the cylindrical CFRP is formed in a cylindrical shape. For this reason, an impact load acts on the cylindrical CFRP, and when the impact load is absorbed by the destruction of the cylindrical CFRP, there is a possibility that crushing waste accumulates inside the cylindrical CFRP and becomes clogged. In this case, there is a possibility that the impact absorbing performance of the cylindrical CFRP may be impaired by the crushing waste clogged inside.

  As a means for solving this, for example, it is conceivable to form the energy absorbing member in an open cross-sectional shape when viewed in the vehicle front-rear direction. However, in general, when the energy absorbing member is formed in an open cross-sectional shape when viewed in the vehicle front-rear direction, the proof stress of the energy absorbing member tends to decrease compared to the case where it is formed in a closed cross-sectional shape. is there.

  For this reason, when the energy absorbing member is formed in an open cross-sectional shape when viewed in the vehicle longitudinal direction, the bending moment is maximized when an impact load is applied to the energy absorbing member from a direction at an angle with respect to the vehicle longitudinal direction. In order to suppress the occurrence of breakage in the root portion of the energy absorbing member (that is, the joint portion of the energy absorbing member with the vehicle skeleton member), it is necessary to sufficiently ensure the proof strength of this portion.

  As measures for sufficiently securing the proof strength of the root portion of the energy absorbing member, for example, increasing the plate thickness of the root portion or partially forming the root portion in a closed cross-sectional shape may be considered. However, in this case, the mass of the energy absorbing member increases.

  The present invention has been made in view of the above-described problems, and can suppress the bending of the root portion of the energy absorbing member without increasing the mass of the energy absorbing member, and can absorb energy by a light and highly efficient energy absorbing member. It is an object of the present invention to provide a vehicle energy absorption structure that can be made to operate.

  In order to solve the above-mentioned problem, the vehicle energy absorption structure according to claim 1 includes a load input member extending in the vehicle width direction and a vehicle width of the load input member extending in the vehicle longitudinal direction. A pair of vehicle skeleton members disposed on both sides in the vehicle width direction with respect to the center in the direction and on one side in the vehicle longitudinal direction, and provided between the load input member and the vehicle skeleton member in the vehicle longitudinal direction, respectively. One side in the direction is coupled to the vehicle skeleton member, the other side in the vehicle front-rear direction is coupled to the load input member, and is formed in an open cross-sectional shape when viewed from the vehicle front-rear direction. At least one of them includes a pair of energy absorbing members disposed in a region outside the centroid of the open section in the vehicle width direction.

  In the vehicle energy absorption structure according to the first aspect, the energy absorption member is provided between the load input member and the vehicle skeleton member in the vehicle front-rear direction. For example, a colliding body that moves relative to the load input member in one side in the vehicle front-rear direction collides with the load input member from the other side in the vehicle front-rear direction, and an impact load is input to the load input member in one side in the vehicle front-rear direction. Then, the impact load is transmitted to the energy absorbing member, and the energy of the impact load is absorbed by breaking the energy absorbing member.

  Here, in the vehicle energy absorption structure according to the first aspect, the energy absorption member is formed in an open cross-sectional shape as viewed in the vehicle front-rear direction. Therefore, when an impact load is applied to the energy absorbing member and this impact load is absorbed by breaking the energy absorbing member, it is possible to suppress crushing dust from accumulating inside the energy absorbing member. Thereby, the impact absorption performance of the energy absorbing member can be ensured.

  By the way, in the collision mode of the vehicle, for example, when the colliding body collides perpendicularly with the load input member, or when the colliding body is oblique to the load input member with respect to the vehicle front-rear direction from the direction having an angle outward in the vehicle width direction. There may be a collision. For example, when the colliding body obliquely collides with the load input member from a direction with an angle outward in the vehicle width direction with respect to the vehicle front-rear direction, the base portion of the energy absorbing member (energy absorption) that maximizes the bending moment. The maximum compressive stress is generated in the inner part of the member in the vehicle width direction among the connecting part of the member to the vehicle skeleton member).

  In this regard, in the vehicle energy absorbing structure according to claim 1, at least one of the pair of free ends of the energy absorbing member as viewed in the vehicle front-rear direction is disposed in a region outside the vehicle width direction with respect to the centroid of the open section. In other words, in other words, it is disposed in a portion other than the portion on the inner side in the vehicle width direction where the maximum compressive stress is generated in the root portion of the energy absorbing member where the bending moment is maximized. Therefore, for example, compared to a configuration in which both of the pair of free ends having a low yield strength against cross-sectional deformation are arranged in the vehicle width direction inner side portion where the maximum compressive stress is generated in the root portion of the energy absorbing member, the energy absorbing member It is possible to suppress the occurrence of folds at the root portion.

  Moreover, in the vehicle energy absorption structure according to claim 1, as described above, only the positions of the pair of free ends of the energy absorption member formed in an open cross-sectional shape when viewed in the vehicle longitudinal direction are set optimally. Further, since the thickness of the base portion is not increased or the base portion is not partially formed in a closed cross section, an increase in the mass of the energy absorbing member can be prevented.

  As described above, according to the vehicle energy absorption structure of the first aspect, the bending of the root portion of the energy absorption member can be suppressed without increasing the mass of the energy absorption member, and the energy absorption member is lightweight and highly efficient. Energy can be absorbed.

  The vehicle energy absorption structure according to claim 2 is the vehicle energy absorption structure according to claim 1, wherein the pair of free ends is a region other than a region on the inner side in the vehicle width direction and a lower side in the vehicle vertical direction with respect to the centroid of the open section. It is the configuration which is arranged in.

  For example, when the position of the load input member is relatively low with respect to the collision body, the collision body not only has an angle on the outer side in the vehicle width direction with respect to the vehicle longitudinal direction but also has an angle on the upper side in the vehicle vertical direction. May collide diagonally with the load input member. In this case, the maximum compressive stress is generated in the vehicle width direction inner side and the vehicle vertical direction lower side of the root part of the energy absorbing member where the bending moment is maximized.

  In this regard, in the vehicle energy absorption structure according to claim 2, the pair of free ends of the energy absorption member in the vehicle front-rear direction view is other than the region on the vehicle width direction inner side and the vehicle vertical direction lower side with respect to the centroid of the open section. In other words, in other words, in the root portion of the energy absorbing member where the bending moment is maximized, it is disposed in a portion other than the portion on the vehicle width direction inner side and the vehicle vertical direction lower side where the maximum compressive stress is generated. Therefore, for example, at least one of a pair of free ends having a low yield strength against cross-sectional deformation is arranged in the vehicle width direction inner side and the vehicle vertical direction lower side of the root part of the energy absorbing member where the maximum compressive stress is generated. In comparison, it is possible to suppress the folding of the root portion of the energy absorbing member.

  The vehicle energy absorption structure according to claim 3 is the vehicle energy absorption structure according to claim 1, wherein the pair of free ends is other than the region on the vehicle width direction inner side and the vehicle vertical direction upper side with respect to the centroid of the open section. This is a configuration arranged in the area.

  For example, when the position of the load input member is relatively high with respect to the collision body, the vehicle collides from not only the angle in the vehicle width direction outside the vehicle longitudinal direction but also the angle in the vehicle vertical direction lower side. The body may collide with the load input member at an angle. In this case, in the root portion of the energy absorbing member where the bending moment is maximized, the portion on the vehicle width direction inner side and the vehicle vertical direction upper side, that is, the vehicle width direction inner side and the vehicle vertical direction upper side in the centroid of the open section Maximum compressive stress is generated.

  In this respect, in the vehicle energy absorbing structure according to claim 3, the pair of free ends of the energy absorbing member in the vehicle front-rear direction view is a region other than the region on the vehicle width direction inner side and the vehicle vertical direction upper side with respect to the centroid of the open section That is, in other words, the energy absorbing member having the maximum bending moment is disposed at a portion other than the portion on the vehicle width direction inner side and the vehicle vertical direction upper side where the maximum compressive stress is generated. Therefore, for example, at least one of a pair of free ends having a low yield strength against cross-sectional deformation is compared with a configuration in which the maximum compressive stress is generated in the root portion of the energy absorbing member and the vehicle width direction inner side and the vehicle vertical direction upper side part. And it can suppress that a fold arises in the root part of an energy absorption member.

  The vehicle energy absorption structure according to claim 4 is the vehicle energy absorption structure according to any one of claims 1 to 3, wherein one of the pair of free ends is a vehicle width with respect to the centroid of the open section. This is a configuration in which the other of the pair of free ends is arranged in a vehicle width direction outside and a vehicle vertical direction lower side with respect to the centroid of the open section.

  According to the vehicle energy absorption structure of the fourth aspect, the pair of free ends are located on the vehicle width direction outer side and the vehicle vertical direction upper side with respect to the centroid of the open section, and on the vehicle width direction outer side and the vehicle vertical direction lower side. In other words, in other words, it is disposed in the vehicle width direction outside portion where the compressive stress is small in the root portion of the energy absorbing member. Therefore, for example, a configuration in which only one of the pair of free ends is disposed in the vehicle width direction outer side where the compressive stress is small in the root portion of the energy absorbing member (or, for example, the pair of free ends is the root of the energy absorbing member. It is possible to effectively prevent the root portion of the energy absorbing member from being bent as compared with a configuration in which the portion of the energy absorbing member is disposed in the portion in the vehicle width direction having a large compressive stress.

  The vehicle energy absorbing structure according to claim 5 is the vehicle energy absorbing structure according to claim 4, wherein the energy absorbing member is a vehicle with respect to the centroid of the open section between the pair of free ends in the vehicle vertical direction. Between at least one peak portion disposed in the outer region in the width direction and one of the free ends in the vehicle vertical direction and the peak portion, the vehicle width direction inner side and the vehicle vertical direction upper side with respect to the centroid of the open section. Between the first valley portion disposed in the region, the other free end in the vehicle vertical direction and the mountain portion, the vehicle is disposed in the vehicle width direction inner side and the vehicle vertical direction lower side with respect to the centroid of the open section. And having a second trough.

  According to the vehicle energy absorption structure of the fifth aspect, at least one peak portion, the first valley portion, and the second valley portion are formed in the energy absorption member. Therefore, since the rigidity of the energy absorbing member is improved by the peak portion, the first valley portion, and the second valley portion, it is possible to more effectively suppress the bending of the root portion of the energy absorbing member. be able to.

  In particular, the first valley portion and the second valley portion are the vehicle width direction inner side and the vehicle vertical direction upper side region and the vehicle width direction inner side and the vehicle vertical direction lower side region with respect to the centroid of the open section, in other words, It arrange | positions in the vehicle width direction inside part with a big compressive stress among the root parts of an energy absorption member. Therefore, the proof stress of the inner part in the vehicle width direction of the root part of the energy absorbing member can be ensured by the first valley part and the second valley part.

  As described above in detail, according to the present invention, it is possible to suppress the bending of the root portion of the energy absorbing member without increasing the mass of the energy absorbing member, and to absorb energy by the light energy efficient member. it can.

[First embodiment]
First, a first embodiment of the present invention will be described.

  FIG. 1 is a perspective view of a vehicle energy absorption structure 10 according to a first embodiment of the present invention. Note that an arrow UP, an arrow FR, and an arrow OUT shown in these drawings and the following drawings respectively indicate the vehicle up-down direction upper side, the vehicle front-rear direction front side, and the vehicle width direction outer side.

  As shown in FIG. 1, a vehicle energy absorption structure 10 according to a first embodiment of the present invention is applied to a front portion of a vehicle, and includes a bumper reinforcement 12 as a load input member and a pair of vehicle skeleton members. The side member 14 (front side member) and the crash box 16 as an energy absorbing member are provided as main components.

  The bumper reinforcement 12 is for supporting a front bumper cover (not shown), and extends in the vehicle width direction. The side members 14 are respectively extended in the vehicle front-rear direction, and are disposed on both sides in the vehicle width direction with respect to the center portion of the bumper reinforcement 12 in the vehicle width direction and on the rear side in the vehicle front-rear direction.

  The crash box 16 is provided between the bumper reinforcement 12 and the side member 14 in the vehicle front-rear direction. The rear side of the vehicle front-rear direction is coupled to the side member 14, and the front side of the vehicle front-rear direction is a bumper. It is coupled to the reinforcement 12. The crash box 16 is made of, for example, CFRP, and is configured to be able to absorb energy of an impact load that acts in the vehicle longitudinal direction.

  Here, in FIG. 2, the cross section of the crash box 16 is shown in detail by the cross section taken along line 2-2 of FIG. As shown in this figure, the crash box 16 has a so-called wave shape when viewed in the vehicle longitudinal direction and has a pair of free ends 16A and 16B when viewed in the vehicle longitudinal direction. It is formed in an open cross section.

  That is, one free end 16A is arranged in a vehicle width direction outer side and vehicle vertical direction upper side region (hereinafter referred to as region B) with respect to the centroid O of the open section, and the other free end 16B has an open section. It is arranged in a region (hereinafter referred to as region C) on the outer side in the vehicle width direction with respect to the centroid O and on the lower side in the vehicle vertical direction.

  Moreover, the mountain part 18 is arrange | positioned so that the area | region B and the area | region C may be straddled between a pair of free ends 16A and 16B in a vehicle up-down direction. On the other hand, between one free end 16A and the mountain portion 18 in the vehicle vertical direction, it is located in an area (hereinafter referred to as area A) on the vehicle width direction inner side and the vehicle vertical direction upper side with respect to the centroid O of the open section. 1st trough part 20 is arrange | positioned. Further, between the other free end 16B and the mountain portion 18 in the vehicle vertical direction, the vehicle is located in the vehicle width direction inner side and the vehicle vertical direction lower side region (hereinafter referred to as region D) with respect to the centroid O of the open section. As such, the second valley portion 22 is arranged.

  Next, the operation and effect of the first embodiment of the present invention will be described.

  In the vehicle energy absorption structure 10 according to the first embodiment of the present invention, a crash box 16 is provided between the bumper reinforcement 12 and the side member 14 in the vehicle longitudinal direction. Then, for example, a collision body 70 that moves relative to the bumper reinforcement 12 rearward in the vehicle front-rear direction collides with the bumper reinforcement 12 from the front side of the vehicle front-rear direction, and the bumper reinforcement 12 impacts from the front side in the vehicle front-rear direction. Is input, the impact load is transmitted to the crash box 16, and the crash box 16 is destroyed to absorb the energy of the impact load.

  Here, in the vehicle energy absorption structure 10 according to the first embodiment of the present invention, the crash box 16 is formed in an open cross-sectional shape when viewed in the vehicle front-rear direction. Therefore, when an impact load is applied to the crash box 16 and this impact load is absorbed by the crash box 16 being destroyed, it is possible to suppress crushing debris from accumulating and clogging inside the crash box 16. Thereby, the impact absorption performance of the energy absorbing member can be ensured.

  By the way, as the collision mode of the vehicle, for example, when the collision body 70 collides perpendicularly to the bumper reinforcement 12, or the collision body 70 has an angle outward in the vehicle width direction with respect to the vehicle front-rear direction. There are cases where the vehicle collides diagonally from the direction. For example, when the collision object 70 collides with the bumper reinforcement 12 obliquely from a direction with an angle outward in the vehicle width direction with respect to the vehicle longitudinal direction at a position substantially the same height as the bumper reinforcement 12, the crash occurs. An axial compression load Fx in the vehicle front-rear direction and a bending load Fy inward in the vehicle width direction act on the root portion of the box 16 (the connection portion between the crash box 16 and the side member 14). As a result, as shown in Table 1 below, the maximum compressive stress is applied to the inner portion of the crush box 16 where the bending moment due to the bending load Fy is maximized, that is, the inner portion in the vehicle width direction. appear.

  In this regard, in the vehicle energy absorbing structure 10 according to the first embodiment of the present invention, the pair of free ends 16A and 16B in the vehicle longitudinal direction view of the crash box 16 are respectively disposed in the region B and the region C. In other words, they are arranged in areas other than the areas A and D where the maximum compressive stress occurs. Therefore, compared with a configuration in which a pair of free ends 16A and 16B having a low resistance to cross-sectional deformation are arranged in the region A and the region D (for example, the crash box 116 of the comparative example shown in FIG. 14), It is possible to prevent the root portion from being bent.

  Moreover, in the vehicle energy absorption structure 10 according to the first embodiment of the present invention, as described above, the positions of the pair of free ends 16A and 16B of the crash box 16 formed in an open cross-sectional shape when viewed in the vehicle longitudinal direction are set. It is merely set optimally, and the thickness of the crush box 16 can be prevented from increasing because the thickness of the base portion is not increased or the base portion is not partially formed in a closed cross section.

  Thus, according to the vehicle energy absorption structure 10 according to the first embodiment of the present invention, the root portion of the crash box 16 can be prevented from being bent without increasing the mass of the crash box 16, and it is lightweight and highly efficient. Energy can be absorbed by the crash box 16.

  Moreover, according to the vehicle energy absorption structure 10 which concerns on 1st embodiment of this invention, the crest box 16 is formed with the peak part 18, the 1st trough part 20, and the 2nd trough part 22. FIG. Therefore, since the rigidity of the crash box 16 is improved by the peak portion 18, the first valley portion 20, and the second valley portion 22, it is more effective that the root portion of the crash box 16 is broken. Can be suppressed.

  In particular, since the first valley portion 20 and the second valley portion 22 are respectively arranged in the region A and the region D, the first valley portion 20 and the second valley portion 22 of the root portion of the crash box 16 The proof stress of the part in which the area | region A and the area | region D with a large compressive stress are located can be ensured.

  By the way, for example, because the position of the bumper reinforcement 12 is relatively low with respect to the collision body 70, there is an angle not only on the vehicle width direction outside with respect to the vehicle longitudinal direction but also on the vehicle vertical direction upper side. The collision body 70 may collide with the bumper reinforcement 12 obliquely from the direction. In this case, the axial compression load Fx in the vehicle longitudinal direction, the bending load Fy in the vehicle width direction inner side, and the bending load Fz in the vehicle vertical direction lower side act on the root portion of the crash box 16. . As a result, the portion of the root portion of the crash box 16 where the bending moment due to the bending loads Fy and Fz is maximized in the vehicle width direction inner side and the vehicle vertical direction lower side, that is, the region D is shown in Table 2 below. Thus, the maximum compressive stress is generated.

  On the other hand, for example, the position of the bumper reinforcement 12 is relatively high with respect to the collision body 70, so that not only the vehicle width direction outer side has an angle with respect to the vehicle longitudinal direction but also the vehicle vertical direction lower side. In other cases, the colliding body 70 may collide with the bumper reinforcement 12 obliquely from a direction with an angle. In this case, the axial compression load Fx in the vehicle longitudinal direction, the bending load Fy in the vehicle width direction inner side, and the bending load −Fz in the vehicle vertical direction upper side act on the root portion of the crash box 16. . As a result, of the root portion of the crash box 16 where the bending moment due to the bending loads Fy and -Fz is maximized, the vehicle width direction inner side and the vehicle vertical direction upper side, that is, the region A is shown in Table 3 below. Thus, the maximum compressive stress is generated.

  In this regard, in the vehicle energy absorption structure 10 according to the first embodiment of the present invention, as described above, the pair of free ends 16A and 16B has a region other than the region A and the region D where the compressive stress is large, that is, in other words. The region B and the region C where the compressive stress is small are disposed. Therefore, even when the collision body 70 obliquely collides with the bumper reinforcement 12 from a direction in which there is an angle not only on the vehicle width direction outside with respect to the vehicle longitudinal direction but also on the vehicle vertical direction upper side or lower side, It is possible to suppress the folding of the root portion of the crash box 16.

  As mentioned above, although 1st embodiment of this invention was described, this invention is not limited above, Of course, it can change and implement variously in the range which does not deviate from the main point. is there.

  For example, in the said embodiment, although the vehicle energy absorption structure 10 was applied to the front part of a vehicle, you may be applied to the rear part of a vehicle.

  Moreover, in the said embodiment, although the crush box 16 was set as the structure which has the one peak part 18, the 1st trough part 20, and the 2nd trough part 22, the several peak part 18 and several 1st trough part You may be set as the structure which has the 1 trough part 20 and the 2nd trough part 22. FIG.

  Moreover, in the said embodiment, the crash box 16 may be set as the structure which has the trough part 24 arrange | positioned so that the area | region A and the area | region D may be straddled, as FIG. 3 shows.

  Moreover, in the said embodiment, as long as a pair of free end 16A, 16B is each arrange | positioned in the area | region B and the area | region C, the crash box 16 may be made into another shape.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  FIG. 4 is a sectional view showing a vehicle energy absorption structure 30 according to the second embodiment of the present invention. The vehicle energy absorption structure 30 according to the second embodiment of the present invention is configured to include a crash box 36 instead of the crash box 16 with respect to the vehicle energy absorption structure 10 according to the first embodiment of the present invention. Yes.

  In the vehicle energy absorption structure 30 according to the second embodiment of the present invention, the crash box 36 has a configuration in which a pair of free ends 36A and 36B are arranged in a region other than the region D. The free ends 36A and 36B are arranged in the area A and the area B, respectively. Further, the crash box 36 is configured to have a valley portion 38 that is disposed so as to straddle the region C and the region D. Note that the crash box 36 is made of, for example, CFRP and is configured to be able to absorb the energy of an impact load acting in the vehicle longitudinal direction, which is the same as the crash box 16 described above.

  Next, the operation and effect of the second embodiment of the present invention will be described.

  For example, the vehicle to which the vehicle energy absorption structure 30 according to the second embodiment of the present invention is applied is a vehicle type such as a sports type having a low vehicle height, so that the position of the bumper reinforcement 12 is relative to the collision body 70. In the case where the distance is relatively low, the collision body 70 obliquely collides with the bumper reinforcement 12 from a direction having an angle not only on the vehicle width direction outside with respect to the vehicle longitudinal direction but also on the vehicle vertical direction upper side. There is. In this case, the axial compression load Fx in the vehicle longitudinal direction, the bending load Fy in the vehicle width direction inner side, and the bending load Fz in the vehicle vertical direction lower side act on the root portion of the crash box 36. . As a result, the portion of the root portion of the crash box 36 where the bending moment due to the bending loads Fy and Fz is maximized inside the vehicle width direction and below the vehicle vertical direction, that is, the region D is shown in Table 2 above. Thus, the maximum compressive stress is generated.

  In this regard, in the vehicle energy absorption structure 30 according to the second embodiment of the present invention, the pair of free ends 36A and 36B are arranged in a region other than the region D as described above. Accordingly, even when the collision body 70 obliquely collides with the bumper reinforcement 12 from a direction having an angle on the vehicle width direction outer side and the vehicle vertical direction upper side with respect to the vehicle longitudinal direction, the root portion of the crash box 36 is bent. Can be suppressed.

  Moreover, in the vehicle energy absorption structure 30 according to the second embodiment of the present invention, as described above, the positions of the pair of free ends 36A and 36B of the crash box 36 formed in an open cross-sectional shape when viewed in the vehicle longitudinal direction are determined. Since the thickness of the base portion is not increased or the base portion is not partially formed in a closed cross section, an increase in the mass of the crash box 36 can be prevented.

  Thus, according to the vehicle energy absorption structure 30 according to the second embodiment of the present invention, the root portion of the crash box 36 can be prevented from being bent without increasing the mass of the crash box 36, and is lightweight and highly efficient. Energy can be absorbed by the crash box 36.

  Further, according to the vehicle energy absorption structure 30 according to the second embodiment of the present invention, the crush box 36 has the valley portion 38 formed therein. Accordingly, since the rigidity of the crash box 36 is improved by the valley portion 38, it is possible to more effectively suppress the occurrence of the fold at the root portion of the crash box 36.

  In particular, since the valley portion 38 is disposed so as to straddle the region D, the valley portion 38 can ensure the proof stress of the portion where the region D where the compressive stress is large is located in the root portion of the crash box 36. .

  As mentioned above, although 2nd embodiment of this invention was described, this invention is not limited above, Of course, it can change and implement variously within the range which does not deviate from the main point. is there.

  For example, in the above embodiment, the crash box 36 is configured such that the pair of free ends 36A and 36B are arranged in the region A and the region B as regions other than the region D, for example, as shown in FIG. As described above, the pair of free ends 36 </ b> A and 36 </ b> B may be arranged in the region A and the region C as regions other than the region D, respectively.

  In the modification shown in FIG. 5, the crash box 36 is configured to have a peak portion 40 mainly disposed in the region B and a valley portion 42 mainly disposed in the region D. Even if comprised in this way, the rigidity of the crash box 36 can be improved.

  In particular, since the valley portion 42 is mainly disposed in the region D, the valley portion 42 can ensure the yield strength of the portion where the region D where the compressive stress is large is located in the root portion of the crash box 36. .

  In addition to the modified example shown in FIG. 5 described above, the crash box 36 has a pair of free ends 36A and 36B disposed in the region A as regions other than the region D, as shown in FIG. For example, as shown in FIG. 7, a pair of free ends 36A and 36B may be arranged in the region B as regions other than the region D. For example, as shown in FIG. 8, a pair of free ends 36 </ b> A and 36 </ b> B may be arranged in the region C as regions other than the region D, respectively.

  Of course, the vehicle energy absorption structure 30 according to the second embodiment of the present invention may be applied to the rear portion of the vehicle.

[Third embodiment]
Next, a third embodiment of the present invention will be described.

  FIG. 9 is a sectional view showing a vehicle energy absorption structure 50 according to the third embodiment of the present invention. The vehicle energy absorption structure 50 according to the third embodiment of the present invention is configured to include a crash box 56 instead of the crash box 16 with respect to the vehicle energy absorption structure 10 according to the first embodiment of the present invention. Yes.

  In the vehicle energy absorption structure 50 according to the third embodiment of the present invention, the crash box 56 has a configuration in which a pair of free ends 56A and 56B are arranged in a region other than the region A. The free ends 56A and 56B are arranged in the region C and the region D, respectively. Further, the crash box 56 is configured to have a mountain portion 58 disposed so as to straddle the region A and the region B. Note that the crash box 56 is made of, for example, CFRP, and is configured to be able to absorb the energy of an impact load acting in the vehicle longitudinal direction, which is the same as the crash box 16 described above.

  Next, the operation and effect of the third embodiment of the present invention will be described.

  For example, when the vehicle to which the vehicle energy absorption structure 50 according to the third embodiment of the present invention is applied is a vehicle type such as SUV or RV having a high vehicle height, the position of the bumper reinforcement 12 is relative to the collision body 70. If the vehicle is relatively high, the collision body 70 collides obliquely with the bumper reinforcement 12 from a direction that has an angle not only on the vehicle width direction outside with respect to the vehicle longitudinal direction but also on the vehicle vertical direction lower side. There is a case. In this case, the axial compression load Fx in the vehicle longitudinal direction, the bending load Fy in the vehicle width direction inner side, and the bending load −Fz in the vehicle vertical direction upper side act on the root portion of the crash box 56. . As a result, in the base portion of the crash box 56 where the bending moment due to the bending loads Fy and -Fz is maximum, the vehicle width direction inner side and the vehicle vertical direction upper side portion, that is, the region A is shown in Table 3 above. Thus, the maximum compressive stress is generated.

  In this regard, in the vehicle energy absorbing structure 50 according to the third embodiment of the present invention, the pair of free ends 56A and 56B are arranged in a region other than the region A as described above. Therefore, even when the collision body 70 obliquely collides with the bumper reinforcement 12 from a direction having an angle on the vehicle width direction outer side and the vehicle vertical direction lower side with respect to the vehicle front-rear direction, the root portion of the crash box 56 is bent. This can be suppressed.

  Moreover, in the vehicle energy absorption structure 50 according to the third embodiment of the present invention, as described above, the positions of the pair of free ends 56A and 56B of the crash box 56 formed in an open cross-sectional shape when viewed in the vehicle longitudinal direction are set. Since the thickness of the base portion is not increased or the base portion is not partially formed in a closed cross section, an increase in the mass of the crash box 56 can be prevented.

  As described above, according to the vehicle energy absorption structure 50 according to the third embodiment of the present invention, the root portion of the crash box 56 can be prevented from being bent without increasing the mass of the crash box 56, and is lightweight and highly efficient. Energy can be absorbed by the crash box 56.

  Moreover, according to the vehicle energy absorption structure 50 which concerns on 3rd embodiment of this invention, the peak part 58 is formed in the crash box 56. FIG. Therefore, since the rigidity of the crash box 56 is improved by the peak portion 58, it is possible to more effectively suppress the folding of the root portion of the crash box 56.

  In particular, since the peak portion 58 is disposed so as to straddle the region A, the peak portion 58 of the crest box 56 can secure the yield strength of the portion where the region A where the compressive stress is large is located. .

  The third embodiment of the present invention has been described above. However, the present invention is not limited to the above, and it is needless to say that various modifications can be made without departing from the spirit of the present invention. is there.

  For example, in the above-described embodiment, the crash box 56 is configured such that the pair of free ends 56A and 56B are arranged in the region C and the region D as regions other than the region A, for example, as shown in FIG. As described above, the pair of free ends 56 </ b> A and 56 </ b> B may be arranged in the region B and the region D as regions other than the region A, respectively.

  In the modification shown in FIG. 10, the crash box 56 is configured to have a valley portion 60 mainly disposed in the region A and a mountain portion 62 mainly disposed in the region C. Even if comprised in this way, the rigidity of the crash box 56 can be improved.

  In particular, since the valley portion 60 is mainly disposed in the region A, the valley portion 60 can ensure the proof stress of the portion where the region A where the compressive stress is large is located in the root portion of the crash box 56. .

  In addition to the modified example shown in FIG. 10 described above, the crash box 56 has a pair of free ends 56A and 56B arranged in the region D as regions other than the region A, as shown in FIG. Further, for example, as shown in FIG. 12, a pair of free ends 56A and 56B may be arranged in the region C as regions other than the region A, For example, as shown in FIG. 13, a pair of free ends 56 </ b> A and 56 </ b> B may be arranged in the region B as regions other than the region A.

  Needless to say, the vehicle energy absorbing structure 50 according to the third embodiment of the present invention may be applied to the rear portion of the vehicle.

1 is a perspective view showing a vehicle energy absorption structure according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a figure which shows the modification of the vehicle energy absorption structure which concerns on 1st embodiment of this invention. It is sectional drawing which shows the vehicle energy absorption structure which concerns on 2nd embodiment of this invention. It is a figure which shows the modification of the vehicle energy absorption structure which concerns on 2nd embodiment of this invention. It is a figure which shows the modification of the vehicle energy absorption structure which concerns on 2nd embodiment of this invention. It is a figure which shows the modification of the vehicle energy absorption structure which concerns on 2nd embodiment of this invention. It is a figure which shows the modification of the vehicle energy absorption structure which concerns on 2nd embodiment of this invention. It is sectional drawing which shows the vehicle energy absorption structure which concerns on 3rd embodiment of this invention. It is a figure which shows the modification of the vehicle energy absorption structure which concerns on 3rd embodiment of this invention. It is a figure which shows the modification of the vehicle energy absorption structure which concerns on 3rd embodiment of this invention. It is a figure which shows the modification of the vehicle energy absorption structure which concerns on 3rd embodiment of this invention. It is a figure which shows the modification of the vehicle energy absorption structure which concerns on 3rd embodiment of this invention. It is sectional drawing which shows the vehicle energy absorption structure which concerns on the comparative example of this invention.

Explanation of symbols

10, 30, 50 Vehicle energy absorption structure 12 Bumper reinforcement (load input member)
14 Side member (vehicle frame member)
16 Crash box (energy absorbing member)
16A, 16B Free end 18 Mountain part 20 First valley part 22 Second valley part

Claims (5)

A load input member extending in the vehicle width direction;
A pair of vehicle skeleton members, each extending in the vehicle longitudinal direction, disposed on both sides in the vehicle width direction with respect to the vehicle width direction central portion of the load input member and on one side in the vehicle longitudinal direction;
Each provided between the load input member and the vehicle skeleton member in the vehicle longitudinal direction, one side in the vehicle longitudinal direction is coupled to the vehicle skeleton member, and the other side in the vehicle longitudinal direction is coupled to the load input member; A pair of energies that are formed in an open cross-sectional shape when viewed in the vehicle longitudinal direction and at least one of the pair of free ends when viewed in the vehicle longitudinal direction is disposed in a region outside the vehicle width direction with respect to the centroid of the open cross-section. An absorbent member;
A vehicle energy absorption structure. The pair of free ends are arranged in a region other than the region on the vehicle width direction inner side and the vehicle vertical direction lower side with respect to the centroid of the open section,
The vehicle energy absorption structure according to claim 1. The pair of free ends are arranged in a region other than the region on the vehicle width direction inner side and the vehicle vertical direction upper side with respect to the centroid of the open section,
The vehicle energy absorption structure according to claim 1. One of the pair of free ends is disposed in a region on the vehicle width direction outer side and the vehicle vertical direction upper side with respect to the centroid of the open section,
The other of the pair of free ends is disposed in a vehicle width direction outer side and a vehicle vertical direction lower side with respect to the centroid of the open section,
The vehicle energy absorption structure according to any one of claims 1 to 3. The energy absorbing member is
At least one peak portion disposed in a region outside the vehicle width direction with respect to the centroid of the open section between the pair of free ends in the vehicle vertical direction;
A first trough disposed in a region on the vehicle width direction inner side and the vehicle vertical direction upper side with respect to the centroid of the open cross section between one of the free ends in the vehicle vertical direction and the mountain portion;
A second trough disposed in a vehicle width direction inner side and a vehicle vertical direction lower side region with respect to the centroid of the open cross section between the other free end in the vehicle vertical direction and the mountain portion,
The vehicle energy absorption structure according to claim 4.

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