JP2009292340A - Vehicle body structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To bring F-S characteristics close to the characteristics of a rectangular shape that is ideal upon vehicle collision. <P>SOLUTION: A crash box 30 includes a body part 54 that has a roughly C-shaped sectional shape and opens toward outward in a vehicle width direction, and an auxiliary part 58 that connects the upper part and the lower part of the opening part 56 of the body part 54. Six ridgelines 60, 62, 64, 66, 68, 70 are provided at the body part 54, and the ridgelines are positioned more inward than a center G1 of a figure of the sectional shape in a vehicle width direction when viewed from a vehicle body front/rear direction of a front part 12A of a front side member 12. Therefore, collision load from the bumper reinforcement upon vehicle collision is divided into the six ridgelines of the body part 54 and two ridgelines 71, 73 of the auxiliary part 58 positioned more outward than the center G1 of a figure in the vehicle width direction, and when the collision load is more than a predetermined value, each ridgeline is buckling-deformed in the vehicle body front/rear direction, thus restraining energy loss due to a drop of load F in the F-S characteristics of the crash box 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle body structure, and more particularly to a vehicle body structure for absorbing collision energy from a bumper of a vehicle such as an automobile.

2. Description of the Related Art Conventionally, a vehicle body structure for absorbing collision energy from a bumper of a vehicle such as an automobile is known (Patent Document 1). This body structure has a crash box shaft by forming a notch at the rear end of the middle rib of the crash box with a flange part that is formed in the shape of figure 8 when viewed from the front. The load resistance in the latter half of the compressive deformation (buckling deformation) can be reduced, and the crush box remains uncrushed.
JP 2006-327463 A

  However, in the above-described prior art, when the crash box is buckled and deformed in a bellows shape (accordion shape) at the time of collision, every time the crash box is buckled by one wavelength, an FS characteristic (change characteristic of load with respect to displacement) is obtained. The load F decreases. For this reason, there is a need for a vehicle body structure that reduces energy loss due to the drop in the load F, and approximates the FS characteristic at the time of vehicle collision to a rectangular characteristic that is an ideal characteristic.

  In view of the above fact, an object of the present invention is to obtain a vehicle body structure that can approximate the FS characteristic at the time of a vehicle collision to a rectangular characteristic that is an ideal characteristic.

  The vehicle body structure of the present invention according to claim 1 is a bumper reinforcement disposed along a vehicle width direction at a longitudinal end portion of the vehicle body, a skeleton member disposed along the vehicle longitudinal direction, and the skeleton. A main body portion having a substantially C-shaped cross section with the front end portion of the member and the bumper reinforcement being connected to each other along the longitudinal direction of the vehicle body and the opening portion facing outward in the vehicle width direction, and upper and lower portions of the opening portion of the main body portion An auxiliary portion that closes the opening, and the main body portion is provided with six ridge lines along the vehicle body longitudinal direction, and the six ridge lines are cross-sections of the skeleton member viewed from the vehicle body longitudinal direction. And an impact absorbing member located on the inner side in the vehicle width direction than the centroid.

  Therefore, when a collision load is applied to the bumper reinforcement arranged along the vehicle width direction at the longitudinal end portion of the vehicle body, the collision load is arranged along the vehicle body longitudinal direction via the shock absorbing member. Transmitted to the skeletal member. In this case, in the present invention, the shock absorbing member includes a main body portion having a substantially C-shaped cross section that opens outward in the vehicle width direction, and an auxiliary portion that connects the upper and lower portions of the opening portion of the main body portion and closes the opening portion. The main body portion is provided with six ridge lines along the longitudinal direction of the vehicle body, and these six ridge lines are located on the inner side in the vehicle width direction from the centroid of the cross section viewed from the longitudinal direction of the skeleton member. Yes. For this reason, the six ridge lines located on the inner side in the vehicle width direction from the centroid of the skeleton member support the collision load, and when the collision load exceeds a predetermined value, the six ridge lines are seated in the vehicle longitudinal direction. Bends and deforms. As a result, energy loss due to load drop in the FS characteristic (change characteristic of load with respect to displacement) of the entire shock absorbing member is suppressed, so that the FS characteristic of the shock absorbing member is an ideal characteristic. Close to the characteristics of the shape.

  According to a second aspect of the present invention, in the vehicle body structure according to the first aspect, at least two wall portions of the seven wall portions partitioned by the six ridge lines in the main body portion of the shock absorbing member are respectively provided on the vehicle body. A plurality of beads serving as starting points of buckling deformation are provided at predetermined intervals in the front-rear direction, and the position of the bead on at least one wall portion is shifted in the front-rear direction of the vehicle body with respect to the position of the bead on the other wall portion.

  Therefore, at the time of a vehicle collision, starting from a plurality of beads provided at predetermined intervals in the longitudinal direction of the vehicle body on at least two wall portions among seven wall portions partitioned by six ridge lines in the main body portion of the shock absorbing member The shock absorbing member is buckled and deformed. At this time, the position of the bead of at least one wall portion is shifted in the vehicle longitudinal direction with respect to the position of the bead of the other wall portion, so that the buckling timing of one wall portion and the buckling timing of the other wall portion are The load increase / decrease timing of each ridge line is also different. For this reason, by superimposing the FS characteristics (FS waveform) of each ridge line, the cycle of increasing / decreasing the maximum load is reduced in the FS characteristics of the shock absorbing member, and the energy absorption amount per displacement amount is reduced. To increase.

  According to a third aspect of the present invention, in the vehicle body structure according to the second aspect, at least one of the six ridge lines does not intersect the plurality of beads.

  Therefore, at the time of a vehicle collision, the load drop in the FS characteristic of the shock absorbing member is suppressed by supporting the collision load by at least one ridge line that does not intersect with the plurality of beads among the six ridge lines.

  According to a fourth aspect of the present invention, in the vehicle body structure according to the third aspect, the plurality of beads cross all ridge lines except the uppermost ridge line and the lowermost ridge line among the six ridge lines. .

  Therefore, at the time of a vehicle collision, all the ridge lines except the uppermost ridge line and the lowermost ridge line that intersect with a plurality of beads among the six ridge lines are buckled and deformed, so that in the FS characteristic of the shock absorbing member. Maximum load is controlled. In addition, when a vehicle collides, the load drop in the FS characteristic of the shock absorbing member is suppressed by supporting the collision load by the uppermost ridgeline and the lowermost ridgeline that do not intersect with a plurality of beads among the six ridgelines. Is done.

  According to a fifth aspect of the present invention, in the vehicle body structure according to any one of the second to fourth aspects, each of the auxiliary portions facing the plurality of beads provided in the main body portion is buckled. A bead was provided as a starting point for deformation.

  Therefore, at the time of a vehicle collision, the auxiliary portion buckles and deforms starting from the beads provided in the respective portions of the auxiliary portion facing the plurality of beads provided in the main body portion, so that the maximum in the FS characteristic of the shock absorbing member. The load is controlled.

  According to a sixth aspect of the present invention, in the vehicle body structure according to the fifth aspect, the plurality of beads formed in the auxiliary portion include a concave bead that is concave toward the outer side in the vehicle width direction, and a vehicle width direction. Convex beads, which are convex toward the outside, are alternately arranged along the longitudinal direction of the vehicle body.

  Therefore, at the time of a vehicle collision, the impact absorbing member is buckled and deformed starting from the concave beads and the convex beads alternately arranged along the longitudinal direction of the vehicle body formed in the auxiliary portion, so that the FS of the impact absorbing member. The period of increase / decrease of the maximum load becomes small, and the amount of energy absorption per displacement increases.

  According to a seventh aspect of the present invention, in the vehicle body structure according to any one of the first to sixth aspects, the thickness of the main body portion of the shock absorbing member is thicker than the thickness of the auxiliary portion of the shock absorbing member. .

  Therefore, since the plate thickness of the main body part constituting the inner side in the vehicle width direction of the shock absorbing member is thicker than the plate thickness of the auxiliary part constituting the outer side in the vehicle width direction of the shock absorbing member, the inner side in the vehicle width direction of the shock absorbing member is It becomes difficult to deform compared to the vehicle width direction outside. As a result, the bending moment inward in the vehicle width direction acting on the skeleton member provided on the inner side in the vehicle longitudinal direction of the shock absorbing member is suppressed, so that deformation of the skeleton member in the vehicle width direction is suppressed. .

  According to the first aspect of the present invention, the FS characteristic of the shock absorbing member can be brought close to a rectangular characteristic which is an ideal characteristic at the time of a vehicle collision.

  The present invention according to claim 2 can increase the energy absorption amount per displacement amount of the shock absorbing member.

  The present invention according to claim 3 can suppress a drop in load in the FS characteristic of the shock absorbing member.

  According to the fourth aspect of the present invention, the maximum load in the FS characteristic of the shock absorbing member can be controlled and the drop of the load can be suppressed.

  The present invention according to claim 5 can control the maximum load in the FS characteristic of the shock absorbing member.

  According to the sixth aspect of the present invention, the energy absorption amount per displacement amount of the shock absorbing member can be increased.

  The present invention according to claim 7 can suppress deformation of the skeleton member inward in the vehicle width direction.

  An embodiment of a vehicle body structure according to the present invention will be described with reference to FIGS. In these drawings, an arrow FR appropriately shown indicates the vehicle body front side, an arrow UP indicates the vehicle body upper side, and an arrow IN indicates the vehicle width direction inner side.

  FIG. 3 is a plan view showing the vehicle body structure according to this embodiment. 2 is an exploded perspective view of the crash box of the vehicle body structure according to the present embodiment as viewed from the obliquely forward inner side of the vehicle body. FIG. 1 is an enlarged cross-sectional view taken along line 1-1 of FIG. It is shown.

  As shown in FIG. 3, in the automobile body of the present embodiment, the front part of a pair of left and right front side members 12 as a skeleton member constituting the vehicle body is provided at the lower part of both ends in the vehicle width direction of the engine room 10 which is the vehicle body front part. 12A is arranged along the longitudinal direction of the vehicle body in the longitudinal direction. Note that the rear portions 12B of the pair of left and right front side members 12 are displaced (curved) inward in the vehicle width direction in plan view.

  As shown by a broken line in FIG. 1, the front side member 12 has a closed cross-sectional structure including a closed cross-sectional portion 13 extending in the longitudinal direction of the vehicle body.

  1 and 2 show only the front side member 12 on the left side of the vehicle body. In addition, the closed cross-sectional structure is a cross-sectional structure in which the opening outer periphery of the target cross section is substantially continuous and has high strength and high rigidity, and substantially the target cross section is the outer periphery. This means that even if a hole or the like smaller than the length is partially formed, there is no hole on the front side or the back side in the direction perpendicular to the cross section, and a configuration in which members around the opening are continuous is included. .

  As shown in FIG. 1, the front side member 12 includes a front side member inner panel 14 that forms an inner portion in the vehicle width direction of the front side member 12, and a front side member that forms an outer portion in the vehicle width direction of the front side member 12. And an outer panel 16. The cross-sectional shape of the front side member inner panel 14 viewed from the front-rear direction of the vehicle body is a hat cross-sectional shape with the opening facing outward in the vehicle width direction, and an upper flange 14A extending upward from the vehicle body at the upper end of the opening. However, a lower flange 14B extending downward from the vehicle body is formed at the lower end of the opening. On the other hand, the front side member outer panel 16 has a flat plate shape along the vertical direction of the vehicle body. The upper edge 16A is the upper flange 14A of the front side member inner panel 14 and the lower edge 16B is the front side member inner panel 14. The lower flange 14B is coupled by welding or the like.

  As shown in FIG. 3, a bumper reinforcement 20 serving as a skeleton of a front bumper (not shown) is disposed at the front end portion of the vehicle body along the vehicle width direction. The outer end 20A in the width direction has an arc shape in which the front side of the vehicle body is the outer peripheral side on both the left and right sides. A mounting hole 22 for mounting a crash box 30 as an impact absorbing member is formed in the rear wall portion 20B of the bumper reinforcement 20, and a bolt 24 is mounted on the front wall portion 20C of the bumper reinforcement 20. A work hole 26 for performing the fastening work is formed.

  Although not shown, the cross-sectional shape of the bumper reinforcement 20 viewed from the vehicle width direction has a substantially rectangular closed cross-sectional structure with the vertical direction of the vehicle body as the longitudinal direction.

  As shown in FIG. 2, the crash box 30 as an impact absorbing member is arranged with its longitudinal direction along the vehicle body longitudinal direction. A mounting plate 36 is attached to the front end of the crash box 30 by welding or the like, and a pair of upper and lower mounting holes 40 are formed in the mounting plate 36.

  As shown in FIG. 3, the bumper reinforcement 20 is fixed to the left and right crash boxes 30 with bolts 24 and nuts 42. More specifically, the bolt 24 inserted into the mounting hole 22 of the bumper reinforcement 20 from the front side of the vehicle body passes through the mounting hole 40 of the mounting plate 36 of the crash box 30, and on the vehicle body rear side of the mounting plate 36. The nut 42 is screwed.

  As shown in FIG. 2, an attachment plate 38 is attached to the rear end portion of the crash box 30 by welding or the like. The mounting plate 38 is rectangular, and mounting holes 44 are formed at the four corners.

  As shown in FIG. 3, the left and right crash boxes 30 connect the front end portions of the left and right front side members 12 to the left and right vehicle width direction outer end portions 20 </ b> A of the bumper reinforcement 20. More specifically, a mounting plate 46 is attached to the front end of the front side member 12 by welding or the like. The mounting plate 46 is rectangular, and mounting holes 48 are formed at the four corners. Further, a mounting plate 38 provided at the rear end of the crash box 30 and a mounting plate 46 provided at the front end of the front side member 12 are a bolt 50 inserted through the mounting hole 44 and the mounting hole 48, and a bolt The nuts 52 are screwed together and are connected to each other.

  As shown in FIG. 2, the crash box 30 includes a main body portion 54 that forms an inner portion in the vehicle width direction of the crash box 30 and an auxiliary portion 58 that forms an outer portion in the vehicle width direction of the crash box 30. . The main body portion 54 of the crash box 30 has a substantially C-shaped cross section that opens toward the outside in the vehicle width direction, and the auxiliary portion 58 connects the upper and lower sides of the opening portion 56 of the main body portion 54. The closed cross section 13 is formed.

  In addition, six ridge lines 60, 62, 64, 66, 68, 70 are formed in the main body portion 54 of the crash box 30 along the longitudinal direction of the vehicle body. On the other hand, the cross-sectional shape of the auxiliary portion 58 viewed from the front-rear direction of the vehicle body is a U-shape with the opening facing outward in the vehicle width direction. Ridge lines 71 and 73 are formed along the front-rear direction.

  An upper flange 58B is formed from the upper end of the vertical wall portion 58A of the auxiliary portion 58 toward the outer side in the vehicle width direction, and the upper flange 58B is formed on the first wall portion (upper wall portion) 54A of the main body portion 54. It is joined to the lower surface of the vehicle width direction outer side end portion 54B by welding or the like. Further, a lower flange 58C is formed from the lower end of the vertical wall portion 58A of the auxiliary portion 58 toward the outer side in the vehicle width direction and obliquely downward, and this lower flange 58C is the seventh wall portion (lower wall portion) of the main body portion 54. It is coupled to the upper surface of the outer end 54D in the vehicle width direction of 54C by welding or the like.

  As shown in FIG. 1, ridge lines 60, 62, 64, 66, 68, 70 provided on the main body portion 54 of the crash box 30 are all vehicle bodies of the front side member 12 connected to the vehicle body rear side of the crash box 30. It is located on the inner side in the vehicle width direction than the centroid G1 of the cross section viewed from the front-rear direction. Further, in the main body portion 54 of the crash box 30, the distance between the ridge line 60 and the ridge line 62 is between the second wall part 54E, the distance between the ridge line 62 and the ridge line 64 is between the third wall part 54F, and the distance between the ridge line 64 and the ridge line 66. Between the fourth wall 54G, the ridgeline 66 and the ridgeline 68 is a fifth wall 54H, and between the ridgeline 68 and the ridgeline 70 is a sixth wall 54J. That is, the main body portion 54 of the crash box 30 has a first wall portion (upper wall portion) 54A, a second wall portion 54E, and a third wall portion 54F from the vehicle width direction outer side upper end P1 toward the vehicle width direction outer side lower end P2. The fourth wall 54G, the fifth wall 54H, the sixth wall 54J, and the seventh wall (lower wall) 54C are provided in this order.

  Further, the two ridgelines 71 and 73 of the auxiliary portion 58 of the crash box 30 are located on the outer side in the vehicle width direction from the centroid G1 of the cross section viewed from the front and rear direction of the front portion 12A of the front side member 12.

  Therefore, the collision load F is shared by the six ridge lines 60, 62, 64, 66, 68, and 70 of the main body portion 54 of the crash box 30 and the two ridge lines 71 and 73 of the auxiliary portion 58 of the crash box 30. At the same time, when the collision load F exceeds a predetermined value, the ridges 60, 62, 64, 66, 68, 70, 71, 73 are buckled and deformed in the longitudinal direction of the vehicle body, so that the FS characteristic indicated by the solid line in FIG. As in (change characteristics of the load F with respect to the displacement S), energy loss due to the drop of the load F of the crash box 30 is suppressed.

  That is, as shown in FIG. 4, in the FS characteristic (FS characteristic shown by a two-dot chain line) by the ridge lines 60, 62, 68, 70, 71, 73, the energy loss due to the drop of the load F is represented by the ridge line 64, By adding energy absorption by 66 (shaded portion in FIG. 4), it can be suppressed.

  In the present embodiment, as shown in FIG. 1, the upper half and the lower half of the main body portion 54 and the auxiliary portion 58 of the crash box 30 are symmetrical. In addition, the vertical length of the vehicle width direction outer upper end P1 and the vehicle width direction outer lower end P2 that is the maximum vertical length of the crash box 30 is H, the maximum width of the crash box 30 in the vehicle width direction is W, and the ridgeline 64 The distance between the edge line 66 and the edge line 66 is L1, the distance between the edge line 64 and the edge line 62 and the distance between the edge line 66 and the edge line 68 are L2, the distance between the edge line 62 and the edge line 60, and the distance between the edge line 68 and the edge line 70 are L3, and the edge line. 60 and W4 in the vehicle width direction outer side upper end P1 and the distance between the ridgeline 70 and the vehicle width direction outer side lower end P2 are L4, W = 0.82, L3 = 0.25 to 0.30 with respect to H = 1. , L4 = 0.45 to 0.53 (there is no relationship between L1 and L2 and H).

  In the present embodiment, the plate thickness M1 of the main body portion 54 of the crash box 30 is set to be thicker than the plate thickness M2 of the auxiliary portion 58 (M1> M2). For example, M2 = 1.4 for M1 = 2.0, M2 = 1.2 for M1 = 1.8, and M2 = 1.0 for M1 = 1.6.

  Accordingly, the front side member 12 is displaced inward in the vehicle width direction in a plan view at the rear part 12B on the rear side of the vehicle body, and is easily deformed by bending input inward in the vehicle width direction. Since the plate thickness M1 of the main body portion 54 constituting the inner side in the direction is thicker than the plate thickness M2 of the auxiliary portion 58 constituting the outer side in the vehicle width direction of the crash box 30, the inner side in the vehicle width direction of the crash box 30 is the outer side in the vehicle width direction. It becomes difficult to deform compared to. As a result, the bending moment inward in the vehicle width direction acting on the front side member 12 provided on the vehicle body rear side of the crash box 30 is suppressed, so that the front side member 12 is deformed inward in the vehicle width direction. It is supposed to be suppressed.

  Further, in the present embodiment, the ridge lines 60, 62, 64, 66, 68, 70 provided on the main body portion 54 of the crash box 30 are more than the centroid G1 of the cross section when the front side member 12 is viewed from the front-rear direction of the vehicle body. Located inside the vehicle width direction. For this reason, the load sharing of all the ridgelines 60, 62, 64, 66, 68, 70, 71, 73 of the crash box 30 is increased in the vehicle width direction inside of the crash box 30 (the vehicle width direction inner side of the crash box 30 is It becomes difficult to deform compared to the outside in the vehicle width direction). As a result, also in this respect, deformation of the front side member 12 provided on the rear side of the vehicle body of the crash box 30 in the vehicle width direction is suppressed.

  As shown in FIG. 2, the fourth wall 54G of the main body 54 of the crash box 30 has a plurality of beads 74 having a V-shaped cross section that protrudes outward in the vehicle width direction with a predetermined interval in the longitudinal direction of the vehicle body. Is formed. These beads 74 are formed such that the longitudinal direction thereof is perpendicular to the axial direction (vehicle body longitudinal direction) of the crash box 30, and both longitudinal end portions 74 </ b> A intersect the ridge line 64 and the ridge line 66.

  A plurality of beads 76 are formed on the third wall portion 54F of the main body portion 54 of the crash box 30 in a V-shaped cross section that protrudes outward in the vehicle width direction with a predetermined interval in the longitudinal direction of the vehicle body. These beads 76 are formed such that the longitudinal direction thereof is perpendicular to the axial direction (vehicle body longitudinal direction) of the crash box 30, and both longitudinal end portions 76 </ b> A intersect the ridge line 64 and the ridge line 62.

  A plurality of beads 78 are formed on the fifth wall portion 54H of the main body portion 54 of the crash box 30 in a V-shaped cross section that protrudes outward in the vehicle width direction with a predetermined interval in the longitudinal direction of the vehicle body. The beads 78 are formed such that the longitudinal direction thereof is perpendicular to the axial direction (vehicle body longitudinal direction) of the crash box 30, and both longitudinal ends 78 </ b> A intersect the ridge line 66 and the ridge line 68.

  The bead 78 is formed at the same position as the bead 76 in the front-rear direction of the vehicle body, and the bead 74 is formed at a position (a position shifted by 1/2 pitch) that is the center of the adjacent bead 76 in the front-rear direction of the vehicle body. Yes.

  Therefore, the crash box 30 is buckled and deformed starting from the beads 74, 76, and 78.

  On the other hand, on the vertical wall portion 58A of the auxiliary portion 58 of the crash box 30, a plurality of beads 80 as concave beads are provided outward in the vehicle width direction at predetermined positions in the longitudinal direction of the vehicle body at positions facing the beads 76 and 78. It is formed in a convex arcuate cross section. These beads 80 are formed such that the longitudinal direction thereof is perpendicular to the axial direction of the crush box 30 (the longitudinal direction of the vehicle body), and both longitudinal ends 80A reach the upper and lower ends of the vertical wall portion 58A.

  Also, on the vertical wall portion 58A of the auxiliary portion 58 of the crash box 30, beads 82 as a plurality of convex beads are projected inward in the vehicle width direction at predetermined positions in the vehicle body front-rear direction at positions facing the beads 74. The cross section is formed in an arc shape. These beads 82 are formed such that the longitudinal direction thereof is perpendicular to the axial direction of the crush box 30 (the vehicle longitudinal direction), and both longitudinal ends 82A reach the upper and lower ends of the vertical wall portion 58A.

  The bead 82 is formed at a position (a position shifted by 1/2 pitch) that is a central portion of adjacent beads 80 in the longitudinal direction of the vehicle body.

  Accordingly, beads 74, 76, and 78 are formed in the main body portion 54 of the crash box 30 along the vehicle body longitudinal direction, and the concave beads 80 and the convex beads 82 are formed in the auxiliary portion 58 of the crash box 30 along the vehicle body longitudinal direction. Are formed alternately. For this reason, the buckling timing of the wall portion starting from the beads 76, 78, and 80 is different from the buckling timing of the wall portion starting from the beads 74, 82, and the load increasing / decreasing timing of each ridge line is also different. For this reason, the FS characteristic (FS waveform) of each ridgeline is superimposed, and the period of increase / decrease in the maximum load in the FS characteristic of the crash box 30 can be shortened.

  Next, the operation of this embodiment will be described.

  For example, when the left front part of the vehicle body collides with the inclined barrier at a low speed and a collision load (arrow F in FIG. 3) acts on the bumper reinforcement 20 from the vehicle body front side to the vehicle body rear side. The collision load F is transmitted to the front side member 12 on the left side of the vehicle through the crash box 30 on the left side of the vehicle, and part of the collision energy is absorbed by the buckling deformation of the crash box 30.

  At this time, in this embodiment, the crash box 30 includes a main body portion 54 having a substantially C-shaped cross section that opens toward the outside in the vehicle width direction, and an auxiliary portion 58 that connects the upper and lower sides of the opening portion 56 of the main body portion 54. The main body portion 54 is provided with six ridge lines 60, 62, 64, 66, 68, 70 along the longitudinal direction of the vehicle body. Furthermore, these ridgelines 60, 62, 64, 66, 68, 70 are located on the inner side in the vehicle width direction from the centroid G1 of the cross section of the front portion 12A of the front side member 12 as viewed from the front-rear direction of the vehicle body.

  For this reason, the six ridge lines 60, 62, 64, 66, 68, 70 of the main body portion 54 of the crash box 30 located on the inner side in the vehicle width direction from the centroid G1 of the front portion 12A of the front side member 12 and The collision load F is shared by the two ridge lines 71 and 73 of the auxiliary portion 58 of the crash box 30 located outside the centroid G1 of the front portion 12A of the front side member 12 and the collision. When the load F exceeds a predetermined value, the ridgelines 60, 62, 64, 66, 68, 70, 71, 73 are buckled and deformed in the longitudinal direction of the vehicle body. As a result, energy loss due to the drop in the load F of the crash box 30 is suppressed as in the FS characteristic indicated by the solid line in FIG.

  That is, as shown in FIG. 4, in the FS characteristic (FS characteristic shown by a two-dot chain line) by the ridge lines 60, 62, 68, 70, 71, 73, the energy loss due to the drop of the load F is represented by the ridge line 64, It can suppress by adding the energy absorption by 66 (shaded part of FIG. 4). For this reason, the FS characteristic of the crash box 30 approaches the rectangular characteristic which is an ideal characteristic. As a result, it is difficult to transmit the collision load at the time of a light vehicle collision to the front side member 12, and damage to the front side member 12 can be suppressed.

  In the present embodiment, the rear portion 12B of the front side member 12 is displaced inward in the vehicle width direction in plan view, and is easily deformed by bending input inward in the vehicle width direction. On the other hand, the plate thickness M1 of the main body 54 constituting the inner side in the vehicle width direction of the crash box 30 is thicker than the plate thickness M2 of the auxiliary portion 58 constituting the outer side in the vehicle width direction of the crash box 30. The inner side in the vehicle width direction of 30 is less likely to be deformed than the outer side in the vehicle width direction. As a result, the bending moment inward in the vehicle width direction acting on the front side member 12 provided on the vehicle body rear side of the crash box 30 is suppressed, so that the front side member 12 is deformed inward in the vehicle width direction. Can be suppressed.

  Further, in the present embodiment, seven wall portions partitioned by six ridge lines 60, 62, 64, 66, 68, 70 in the main body portion 54 of the crash box 30, that is, the second wall portion 54E and the third wall portion. 54F, the fourth wall 54G, the fifth wall 54H, and the sixth wall 54J, the third wall 54F, the fourth wall 54G, and the fifth wall 54H are beaded at predetermined intervals in the longitudinal direction of the vehicle body. 74, 76, 78 are provided, and the positions of the beads 76, 78 provided in the third wall portion 54F and the fifth wall portion 54H in the vehicle longitudinal direction and the vehicle body longitudinal directions of the plurality of beads 74 provided in the fourth wall portion 54G are provided. Is shifted in the longitudinal direction of the vehicle body. Therefore, the buckling timing of the fourth wall portion 54G provided with the beads 74 is different from the buckling timing of the third wall portion 54F and the fifth wall portion 54H provided with the beads 76 and 78. The timing of increase / decrease in the load on each ridgeline 60, 62, 64, 66, 68, 70 varies depending on the deviation. As a result, the FS characteristics of the ridge lines 60, 62, 64, 66, 68, and 70 are overlapped, so that the FS characteristics of the crash box 30 are further approximated to the rectangular characteristics that are ideal characteristics.

  In the present embodiment, two ridge lines 60 and 70 out of the six ridge lines 60, 62, 64, 66, 68 and 70 of the main body 54 of the crash box 30 intersect with a plurality of beads 74, 76 and 78. Therefore, by receiving the collision load F by these ridge lines 60 and 70, it is possible to suppress a drop in the load in the FS characteristic of the crash box 30.

  Furthermore, in this embodiment, the ridgelines 62, 64, 66, and 68 that intersect with the beads 74, 76, and 78 except the ridgeline 60 at the uppermost end and the ridgeline 70 at the lowermost end buckle starting from the beads 74, 76, and 78. Deform. For this reason, the maximum load in the FS characteristic of the crash box 30 can be controlled. Further, by receiving the collision load F by the uppermost ridgeline 60 and the lowermost ridgeline 70 that do not intersect with the plurality of beads 74, 76, 78 among the six ridgelines 60, 62, 64, 66, 68, 70. Moreover, the fall of the load in the FS characteristic of the crash box 30 can be suppressed.

  In the present embodiment, the auxiliary portion 58 is buckled and deformed starting from the beads 80 and 82 of the auxiliary portion 58 provided at positions facing the plurality of beads 74, 76, and 78 provided in the main body portion 54 of the crash box 30. By doing so, the maximum load in the FS characteristic of the crash box 30 can be further controlled.

  In the present embodiment, the concave beads 80 and the convex beads 82 are alternately formed in the auxiliary portion 58 of the crash box 30 along the longitudinal direction of the vehicle body. For this reason, these beads 80 and 82 bring the FS characteristic of the crash box 30 closer to the ideal rectangular characteristic.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art. For example, the dimensions H, W, L1, L2, L3, and L4 of the crash box 30 set in the above embodiment may be other dimensions.

  Further, the plate thickness M1 of the main body portion 54 and the plate thickness M2 of the auxiliary portion 58 of the crash box 30 set in the above embodiment may be other plate thicknesses.

  In the above embodiment, the beads 74, 76, and 78 are formed on the third wall portion 54 </ b> F, the fourth wall portion 54 </ b> G, and the fifth wall portion 54 </ b> H of the crash box 30. A plurality of at least two wall portions among the seven wall portions partitioned by six ridge lines are provided at predetermined intervals in the longitudinal direction of the vehicle body, and the position of the bead of at least one wall portion is the position of the bead of the other wall portion. On the other hand, any configuration that deviates in the longitudinal direction of the vehicle body may be used.

  Further, in the above embodiment, the bead 78 is formed at the same position as the bead 76 in the longitudinal direction of the vehicle body, and the bead 74 is located at a position (a position shifted by 1/2 pitch) that is the center of the adjacent bead 76 in the longitudinal direction of the vehicle body. Although formed, the position of each bead should just shift | deviate in the vehicle body front-back direction with respect to the position of the bead of at least one wall part with respect to the position of the bead of another wall part.

  Moreover, in the said embodiment, although it was set as the structure where the ridgeline 60 of an upper end and the ridgeline 70 of a lower end among the six ridgelines of the main-body part 54 of the crash box 30 do not cross | intersect a bead, it replaces with this, It is good also as a structure in which at least 1 does not cross | intersect a bead among the six ridgelines of the main-body part 54. FIG.

  Moreover, in the said embodiment, although bead 74, 76, 78 was provided in the main-body part 54 of the crash box 30, it is good also as a structure which does not provide a bead in the main-body part 54 of the crash box 30 instead.

  Further, in the above embodiment, the beads 80 and 82 are provided in the respective portions of the auxiliary portion 58 facing the beads 74, 76 and 78 provided in the main body portion 54 of the crash box 30. 58 may be configured without a bead.

  In the above embodiment, the cross-sectional shape of the front side member 12 viewed from the front-rear direction of the vehicle body is rectangular. However, the cross-sectional shape of the front side member 12 viewed from the front-rear direction of the vehicle body is not limited to a rectangular shape. It is good also as other shapes, such as a shape and another polygonal shape.

  Moreover, in the said embodiment, although the main-body part 54 and the auxiliary | assistant part 58 of the crash box 30 were used as a separate member, it is good also as a structure which integrally molded the main-body part 54 and the auxiliary | assistant part 58 of the crash box 30. FIG.

  Moreover, in the said embodiment, although the vehicle width direction outer side edge part 20A of the bumper reinforcement 20 was made into the circular arc shape from which the vehicle body front side becomes an outer peripheral side on both right and left sides, the vehicle width direction outer side edge part 20A of the bumper reinforcement 20 is curved. Instead, the shape of the bumper reinforcement 20 in plan view may be a linear shape.

  Moreover, in the said embodiment, although this invention was applied to the front side member as a frame member, this invention is applicable also to other frame members, such as a rear side member.

FIG. 4 is an enlarged view taken along a section line 1-1 in FIG. 3. It is the disassembled perspective view seen from the vehicle body diagonally forward inner side which shows the crash box of the vehicle body structure which concerns on one Embodiment of this invention. It is a top view which shows the vehicle body structure which concerns on one Embodiment of this invention. It is a graph which shows the FS characteristic of the vehicle body structure which concerns on one Embodiment of this invention.

Explanation of symbols

12 Front side member (frame member)
20 Bumper reinforcement 30 Crash box (shock absorbing member)
54 Crash box body 54A First wall (upper wall)
54C 7th wall (lower wall)
54E 2nd wall part 54F 3rd wall part 54G 4th wall part 54H 5th wall part 54J 6th wall part 56 Opening part of main-body part 58 Crash box auxiliary part 60 Ridge line 62 Ridge line 64 Ridge line 66 Ridge line 68 Ridge line 70 Ridge line 71 Ridge 73 Ridge 74 Bead 76 Bead 78 Bead 80 Bead 82 Bead

Claims (7)

Bumper reinforcement arranged along the vehicle width direction at the longitudinal end of the vehicle body,
A skeleton member arranged along the longitudinal direction of the vehicle body;
A main body portion having a substantially C-shaped cross section in which the distal end portion of the skeleton member and the bumper reinforcement are connected to each other along the longitudinal direction of the vehicle body and the opening portion is directed outward in the vehicle width direction, and the opening portion of the main body portion And an auxiliary portion that closes the opening, and the main body portion is provided with six ridge lines along the vehicle body longitudinal direction, and the six ridge lines are viewed from the vehicle body longitudinal direction of the skeleton member. An impact absorbing member located on the inner side in the vehicle width direction from the centroid of the cross section;
A vehicle body structure. A bead serving as a starting point of a plurality of buckling deformations is provided at predetermined intervals in the longitudinal direction of the vehicle body on at least two wall portions among the seven wall portions partitioned by the six ridge lines in the main body portion of the shock absorbing member, The vehicle body structure according to claim 1, wherein a position of the bead of at least one wall portion is shifted in a longitudinal direction of the vehicle body with respect to a position of the bead of the other wall portion. The vehicle body structure according to claim 2, wherein at least one of the six ridge lines does not intersect with the plurality of beads. The vehicle body structure according to claim 3, wherein the plurality of beads intersect all ridge lines except the uppermost ridge line and the lowermost ridge line among the six ridge lines. The vehicle body structure according to any one of claims 2 to 4, wherein a bead serving as a starting point of buckling deformation is provided in each portion of the auxiliary portion facing the plurality of beads provided in the main body. The plurality of beads formed in the auxiliary portion include concave beads that are concave outward in the vehicle width direction and convex beads that are convex outward in the vehicle width direction along the longitudinal direction of the vehicle body. The vehicle body structure according to claim 5, wherein The vehicle body structure according to any one of claims 1 to 6, wherein a thickness of a main body portion of the shock absorbing member is thicker than a thickness of an auxiliary portion of the shock absorbing member.

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