JP6344664B2 - Vehicle shock absorption structure - Google Patents

Description

  The present invention includes a pair of left and right fiber reinforced resin impact absorbing members including a plurality of reinforcing fibers continuously extending in the front-rear direction, and a bumper reinforcement attached to the distal ends of the pair of impact absorbing members. The present invention relates to a shock absorbing structure for a vehicle.

Conventionally, a pair of left and right front side frames or a pair of left and right rear side frames has been provided at the front or rear of the vehicle body, and a pair of left and right crashes that can absorb impact energy at the time of collision at the front end of these side frames. A structure for attaching a bumper reinforcement extending in the vehicle width direction through a can (also referred to as a crash box) is known.
The pair of crash cans is usually formed of a metal material, and absorbs impact energy transmitted to the passenger compartment by elastic-plastic deformation accompanied by axial buckling at the time of a vehicle collision.

Since the crash can is a large component, it is also known that it is composed of a fiber reinforced resin molded body for the purpose of reducing the weight of the vehicle body.
The reinforcing fiber used as the reinforcing material includes glass fiber, carbon fiber, metal fiber, and the like, and a fiber reinforced resin is formed by combining with a base material (matrix).
In such a fiber reinforced resin, the reinforced fiber shares mechanical properties such as strength, and the base material resin shares the function of transmitting stress between fibers and the function of protecting fibers.
In particular, carbon fiber resin (Carbon-Fiber-Reinforced-Plastic: CFRP) is a characteristic that combines high specific strength (strength / specific gravity) and high specific rigidity (stiffness / specific gravity), so-called lightness, strength and rigidity. Widely used as a structural material for aircraft and vehicles.

The performance required for the impact absorbing member is that the amount of energy absorption (hereinafter referred to as EA (Energy Absorption) amount) is large. To absorb.
Therefore, an impact absorbing structure that can be sequentially broken at the time of a vehicle collision has already been proposed.
The shock absorbing structure for a vehicle of Patent Document 1 includes a crush can made of CFRP and having one end in the longitudinal direction coupled to the front end of the front side frame. The crush can has an open cross section orthogonal to the longitudinal direction. A part of the connecting side with the front side frame in the longitudinal direction is formed in a reinforcing portion reinforced from both sides in the thickness direction.

JP 2010-195068 A

The impact absorbing structure for a vehicle disclosed in Patent Document 1 can increase the amount of EA compared to a steel plate crash can by using sequential destruction due to a collision load at the time of a vehicle collision.
However, there is a possibility that sequential destruction by the fiber reinforced resin cannot effectively contribute to the amount of EA.
In the vehicle shock absorbing structure of Patent Document 1, the base end portion of the crash can is fastened and fixed to the front end portion of the front side frame via fastening means such as bolts. The fiber cutting part accompanying the formation of the bolt hole is formed.
And when the fiber cutting part is formed in the base end part (bolt hole part) of the crash can, the strength difference between the base end side part which is the support side end part and the front end side part which is the end part in the collision load input direction Based on the above, there is a possibility that the breakage of the base end side portion may be started earlier than the breakage of the distal end side portion by the fiber cut portion as the starting point of the breakage.

On the other hand, at the time of an oblique collision (oblique projection) in which a collision load that intersects the axis of the crash can is input, a bending moment directed inward in the vehicle width direction due to the collision load is applied to the base end portion of the crash can side wall. Because it acts, it is also possible that the crash can falls over.
When the base side of the crash can starts to break early, or when the crash can falls down, the axis direction of the crash can and the input direction of the impact load shift, resulting in a crash due to the impact load. There is a possibility that the can cannot be crushed sufficiently.
That is, there is room for improvement in structure in order to ensure stable EA performance in a crash can that absorbs impact energy using sequential fracture.

  An object of the present invention is to provide a vehicle impact absorbing structure and the like that can ensure stable EA performance regardless of the collision mode at the time of a vehicle collision.

  The invention according to claim 1 is a pair of left and right fiber reinforced resin shock absorbing members including a plurality of reinforcing fibers disposed at the front end portion of the vehicle body in the longitudinal direction and arranged so as to extend continuously in the longitudinal direction, In a shock absorbing structure for a vehicle including a bumper reinforcement that extends in the vehicle width direction and is attached to the front ends of a pair of shock absorbing members, the shock absorbing member has a base end portion that is 1 from both sides in the vehicle width direction. A side wall portion sandwiched between a pair of sandwiching members and fixed to the vehicle body; and an open cross-section member provided with a front end wall portion provided at a front end portion of the side wall portion and attached with the bumper reinforcement, The thickness of the sandwiched portion of the side wall portion sandwiched by the pair of sandwiching members is formed to be thicker toward the proximal end portion side, and the step is locked to the sandwiched portion of the sidewall portion by the sandwiching member. Part formed Is, the step portion is characterized by having a portion extending portion and the vehicle width direction and extending in the vertical direction of the vehicle.

According to the first aspect of the present invention, the shock absorbing member has a base end portion sandwiched by a pair of sandwiching members from both sides in the vehicle width direction and fixed to the vehicle body, and a distal end portion of the side wall portion. The shock absorbing member can be fixed to the vehicle body without forming a fiber cutting portion, because it is configured as an open section member provided with a tip wall portion to which the bumper reinforcement is attached. At the time of the collision, the fiber reinforced resin that is sequentially broken can be discharged from the inside of the impact absorbing member.
Since the thickness of the sandwiched portion of the side wall portion sandwiched by the pair of sandwiching members is formed to be thicker toward the proximal end portion, it is possible to ensure the sequential destruction start from the distal end portion, and to absorb shock during oblique collision Stable EA performance can be ensured by preventing the members from falling sideways.
Further, the step portion formed in the sandwiched portion has a portion extending in the vehicle vertical direction and a portion extending in the vehicle width direction. Since the step portion is locked by the sandwiching member, a load is applied to the shock absorbing member. When acting, it is possible to prevent the posture from changing in any direction by the stepped portion.

The invention of claim 2 is characterized in that, in the invention of claim 1, the thickness of the base end portion of the side wall portion is increased toward the inner side in the vehicle width direction .
According to this configuration, although a compressive load is generated on the inner side in the vehicle width direction of the side wall portion at the time of the oblique projection, the base end portion is thick, so that the compressive deformation acting on the side wall portion can be suppressed, and the side of the shock absorbing member can be suppressed. The fall can be suppressed.
The invention of claim 3 is the invention of claim 1 or 2, wherein the impact absorbing member is constituted by a laminate of a plurality of fiber reinforced resin sheets, and the laminate of the plurality of fiber reinforced resin sheets is the impact absorbing member. It is characterized by being comprised with the fiber reinforced resin sheet | seat whose front-back length is short, so that it separates from the surface of the inner surface side of this side wall part.
According to this configuration, the thickness of the side wall can be increased toward the base end while suppressing an increase in weight.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the impact absorbing member is separated from the front end portion of the side wall portion after the front end wall portion is broken from the side wall portion at the time of collision. It is characterized by being formed to be destroyed sequentially.
According to this configuration, it is possible to reliably generate sequential destruction starting from the tip portion of the side wall at the time of a vehicle collision.

  According to the shock absorbing structure for a vehicle of the present invention, it is possible to suppress the crashing of the crash can and ensure stable EA performance at the time of a vehicle collision regardless of the collision mode.

1 is a perspective view of a rear part of a vehicle body including an impact absorbing structure according to Embodiment 1. FIG. It is a top view of the left vehicle body rear part. It is the side view seen from the left side. It is the perspective view seen from the right side back. It is a perspective view of a crash can. It is a figure explaining the manufacturing process of a crash can. It is the VII-VII sectional view taken on the line of FIG. It is the VIII-VIII sectional view taken on the line of FIG. FIG. 9 is a view corresponding to FIG. 8 at the time of a vehicle collision. It is a disassembled perspective view of a crash can, an outer side clamping member, an inner side clamping member, and a bumper rain.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following description exemplifies a case where the present invention is applied to an impact absorbing structure at the rear of a vehicle body, and does not limit the present invention, its application, or its use.
In the drawing, the arrow F indicates the front, the arrow L indicates the left, and the arrow U indicates the upper side.

Embodiment 1 of the present invention will be described below with reference to FIGS.
As shown in FIGS. 1 to 4, the vehicle V includes a pair of left and right rear side frames 1, a floor panel 2 provided so as to span between the pair of rear side frames 1, and a bumper fascia (not shown). ) A bumper reinforcement (hereinafter abbreviated as “bumper rain”) 3 that covers the rear outer periphery and extends to the left and right, and a pair of left and right crashes disposed between the pair of rear side frames 1 and the bumper rain 3. A can 4 (impact absorbing member) is provided.
Since the pair of left and right members have a bilaterally symmetric structure, the left side member will be mainly described below.

The rear side frame 1 is formed as an integral part by extrusion molding of an aluminum alloy material. The rear side frame 1 forms a closed cross section that supports the floor panel 2 and the like and extends in a substantially horizontal straight line.
As shown in FIG. 10, the rear side frame 1 is formed in a substantially trapezoidal cross section, and is arranged parallel to the lower wall portion orthogonal to the vertical direction and the upper position of the lower wall portion, and left and right of the lower wall portion. The upper wall part with a small dimension, the outer wall part which connects the left end parts of a lower wall part and an upper wall part, and the inner wall part which connects the lower wall part and the right end parts of an upper wall part are provided. The outer wall portion is formed in an inclined shape so as to move downward toward the left side, and the inner wall portion is formed in an inclined shape so as to move downward toward the right side.

  The floor panel 2 is disposed in front of the rear end of the rear side frame 1, and a rear seat (not shown) is mounted on the front end side portion. The left and right end portions of the floor panel 2 are joined to the respective inner wall portions 1b of the pair of rear side frames 1 by welding. A spare tire pan 2 a capable of storing a spare tire (not shown) is formed at the rear end portion of the floor panel 2. The spare tire pan 2a is formed so as to be recessed downward at a portion corresponding to the luggage compartment of the floor panel 2.

Next, the bumper rain 3 will be described.
The bumper rain 3 is formed as an integral part by extrusion molding of an aluminum alloy material.
As shown in FIGS. 1 to 4 and 8 to 10, the bumper rain 3 is formed in a substantially trapezoidal cross section, and is formed in a gently curved shape that protrudes rearward inward in the vehicle width direction in plan view. ing.
The bumper rain 3 includes a rear wall portion 3a orthogonal to the front-rear direction, a front wall portion 3b arranged in parallel at the front side position of the rear wall portion 3a and having a vertical dimension larger than the rear wall portion 3a, and a rear wall portion 3a and the upper wall part 3c which connects the upper end parts of the front wall part 3b, the lower wall part 3d which connects the lower wall parts of the rear wall part 3a and the front wall part 3b, the middle step part of the rear wall part 3a and the front A node wall portion 3e for connecting the middle portion of the wall portion 3b is provided.

A pair of upper and lower working holes 3h are formed at both left and right end portions of the rear wall 3a.
The upper wall portion 3c is formed in an inclined shape so as to move upward toward the front side, and its front end portion extends to the front of the front wall portion 3b. The lower wall portion 3d is formed in an inclined shape so as to move downward toward the front side, and its front end portion extends to the front side of the front wall portion 3b.
As described above, the bumper rain 3 has two upper and lower closed sections that are substantially horizontal and gently curved in the left-right direction. When the vehicle V collides, the input impact energy is transferred to the pair of crash cans 4. Communicating.

Next, the crash can 4 will be described.
As shown in FIGS. 1 to 5, the crash can 4 is formed by forming a carbon fiber resin (CFRP) molded body using carbon fibers, which are long fibers, as a reinforcing material (for example, an autoclave method), and the left side when viewed from the front of the vehicle. It is integrally formed as an open section member having an opening in the vehicle width direction outside.
The pair of left and right crush cans 4 are arranged so that the distance between the axial centers of the crush cans 4 increases substantially in the shape of a letter C in a plan view.
Each of the pair of crash cans 4 includes a side wall portion 4a having a substantially W-shaped cross section extending in the front-rear direction and a front end wall portion 4b that is bent substantially orthogonally from the rear end of the side wall portion 4a and extends outward in the vehicle width direction. I have.

The side wall portion 4a of the crash can 4 is formed such that the thickness (plate thickness) of the wall portion increases toward the front side (base end side).
As shown in FIG. 6 (a), a plurality of prepreg sheets (fiber reinforced resin sheets) made of carbon fiber and a base resin are prepared, and a plurality of types (for example, three types) of prepreg sheets having different front and rear dimensions are laminated. Layers s1 to s3 are formed respectively.
As shown in FIG. 6 (b), the front and rear dimensions are gradually shortened step by step from the prepreg sheet layer s1 having a long front and rear dimension with the front end portions (base end portions) of the prepreg sheet layers s1 to s3 aligned. Each of the prepreg sheet layers s1 to s3 is overlapped to form a laminate S.
As shown in FIG. 6C, after crushing the laminated body S, each crush can 4 is formed by molding and curing with an autoclave pot.

Therefore, the laminate S is constituted by the prepreg sheet layers s2 and s3 whose front and rear dimensions are shorter as they are separated from the left inner surface (the inner space of the crash can 4) of the side wall 4a.
Thereby, this crush can 4 secures the volume of carbon fiber resin located in the right side rather than the left inner surface of the side wall part 4a compared with the crush can comprised by the prepreg sheet | seat whose front-and-back dimension is long on the outer surface side of the side wall part 4a. The resistance force against the compressive load at the time of oblique projection, that is, the supporting force to support the left inner surface of the so-called side wall portion 4a is increased.
Hereinafter, for the sake of convenience, the convex side (inner side in the vehicle width direction) of the side wall 4a will be described as the outer surface side, and the concave side (outer side in the vehicle width direction) will be described as the inner surface side.

Here, the carbon fiber resin contained in the prepreg sheets s1 to s3 will be described.
The first carbon fiber corresponding to most of the carbon fibers contained in the carbon fiber resin is a single fiber (filament) that extends continuously in the front-rear direction from the front end to the rear end of the carbon fiber resin molded body. The second carbon fiber corresponding to a part of the carbon fiber included in the carbon fiber resin is formed from a predetermined number (for example, 12 k) of bundled fiber bundles (tows), extending from the upper end to the lower end of the carbon fiber resin molded body. And a bundle of fibers in which a predetermined number of single fibers extending continuously and uniformly are bundled.
The diameter of the single fiber of carbon fiber is 7-10 micrometers, for example. A thermosetting epoxy synthetic resin is used as a base material resin of the carbon fiber resin molded body.

1st carbon fiber is arrange | positioned 1 layer at a time on the surface layer of the outer surface side of the side wall part 4a, and the surface layer of an inner surface side, and the 2nd carbon fiber orthogonal to the 1st carbon fiber is arrange | positioned 2 layers at the inside.
And the 1st carbon fiber of the multilayer which becomes the main body between both right and left 2nd carbon fibers is arrange | positioned.
Thereby, at the time of a vehicle collision, the function corresponding to the 1st carbon fiber arrange | positioned at the outer surface side surface layer and the inner surface side surface layer can be given the function of a front part, and it arrange | positions in the intermediate part between an outer surface side and an inner surface side. Each of the portions corresponding to the first carbon fibers can have the function of the pillar portion.
Therefore, when a collision load in the compression direction parallel to the side wall portion 4a is applied, the first carbon fiber portion corresponding to the front portion is peeled and broken before the first carbon fiber portion corresponding to the pillar portion, and then The first carbon fiber portion corresponding to the pillar portion is compressed and broken. Sequential fracture in which the peeling fracture and the compression fracture proceed sequentially forward from the rear end portion toward the front end portion is performed.
Accordingly, a pillar portion having a large width (thickness) in the direction orthogonal to the side wall portion 4a is stably formed, and a large amount of EA is ensured.
In addition, when the first carbon fiber portion corresponding to the front part is peeled and broken, the second carbon fiber forms a fiber bridge between the plurality of first carbon fibers, so that the second carbon fiber is cut by a tensile load. Cutting energy is used to increase the amount of EA.

As shown in FIGS. 5 and 8, the front end wall portion 4 b is formed so as to close substantially the entire region from the upper end portion to the lower end portion at the rear end of the side wall portion 4 a. Thereby, the collision load input via the bumper rain 3 is uniformly distributed and transmitted across the entire bent portion of the crash can 4 (the boundary portion between the side wall portion 4a and the tip wall portion 4b) by the tip wall portion 4b.
As shown in FIG. 8, a pair of upper and lower nut members 5 are attached to the tip wall portion 4 b, and the bolt 6 inserted through the work hole 3 h of the bumper rain 3 is fastened to the nut member 5. The bumper rain 3 is fixed to the rear end portion of the crash can 4 in a state where the front wall portion 3 b is in surface contact with the front wall portion 3 b of the crash can 4.

As shown in FIG. 8, the side wall 4a is fixed so as to be substantially orthogonal to the front wall 3b facing the side wall 4a.
Therefore, when a collision load directed forward is applied to the bumper rain 3, the central portion in the vehicle width direction of the bumper rain 3 is displaced forward, and the angle formed between the side wall 4a and the front wall 3b facing the side wall 4a is reduced. In addition, the angle formed between the side wall portion 4a and the tip wall portion 4b increases.
As shown in FIG. 9, at the time of a vehicle collision, after the stress concentrates on the boundary portion between the side wall portion 4a and the front end wall portion 4b, the side wall portion 4a and the front end wall portion 4b are broken, and then on the rear end portion of the side wall portion 4a. Impact load is applied. Thereby, destruction is started sequentially from the rear end portion of the side wall portion 4a.

Next, the inner surface side clamping member 7 and the outer surface side clamping member 8 constituting the clamping member will be described.
The inner surface side clamping member 7 and the outer surface side clamping member 8 are integrally formed by aluminum die casting, respectively, and the front end portion (the sandwiched portion 4p) of the side wall portion 4a is sandwiched from the inner surface side and the outer surface side so that the crash can 4 is placed in the rear side frame 1. It is fixed against.
Thereby, the crush can 4 is attached to the rear end portion of the rear side frame 1 without forming a fiber cutting portion in the front end side portion of the crush can 4.

As shown in FIGS. 1 to 4, 7, and 10, the inner surface side clamping member 7 includes an inner surface side flange portion 7 a and an inner surface side clamping portion 7 b that protrudes rearward from the inner surface side flange portion 7 a. .
The inner surface side flange portion 7a is formed so that the front surface portion is fixed to the rear end portion of the rear side frame 1 by welding and projects from the inner surface side clamping portion 7b to the outer surface side.
The inner surface side flange portion 7a is formed with a pair of left and right bolt holes 7h penetrating front and rear in the upper end portion and the lower end portion.

The inner surface side clamping portion 7b is formed in a substantially W-shaped cross section, and is configured to protrude rearward from the rear surface portion of the inner surface side flange portion 7a. The rear end side portion of the inner surface side clamping portion 7b is formed with a step so as to shift to the inner surface side, and an extension portion 7c having a thickness smaller than that of the front end side portion is formed.
The surface on the outer surface side of the extension portion 7c is in surface contact with the surface on the inner surface side of the base end portion of the side wall portion 4a.
As shown in FIG. 7, the inner surface side clamping portion 7b is configured to be inclined slightly toward the inner surface side toward the rear side, and forms an obtuse angle in cooperation with the inner surface side flange portion 7a.

As shown in FIGS. 1 to 4, 7, and 10, the outer surface side clamping member 8 includes an outer surface side flange portion 8 a and an outer surface side clamping portion 8 b that protrudes rearward from the outer surface side flange portion 8 a. .
The outer surface side flange portion 8a is formed so that the front surface portion is fixed to the rear end portion of the inner surface side flange portion 7a and projects outward from the outer surface side clamping portion 8b.
The outer surface side flange portion 8a is formed with a pair of left and right bolt holes 8h penetrating back and forth in the upper end portion and the lower end portion.

The outer surface side clamping portion 8b is formed in a substantially W-shaped cross section, and is configured to protrude rearward from the rear surface portion of the outer surface side flange portion 8a. In the rear end side portion of the outer surface side clamping portion 8b, an extension portion 8c disposed on the inner surface side as compared with the front end side portion is formed. The surface on the inner surface side of the extension portion 8c is in surface contact with the outer surface surface of the front end portion of the side wall portion 4a.
The rear end portion of the extension portion 8c extends rearward from the rear end portion of the extension portion 7c.
As shown in FIG. 7, a stepped portion 4s is formed at the rear end of the sandwiched portion 4p by the outer surface side sandwiched portion 8b, and the stepped portion 4s extends in the vehicle vertical direction as shown in FIG. It has a portion and a portion extending in the vehicle width direction.
As a result, in the case of an oblique collision in which a collision load intersecting the front-rear direction is input to the crash can 4, the extension portion 8 c supports the compressive load toward the right side caused by the collision load. The fall is prevented.

As shown in FIG. 7, the outer surface side clamping portion 8b is configured to be slightly inclined toward the inner surface side toward the rear side, and forms an obtuse angle in cooperation with the outer surface side flange portion 8a.
Thereby, when the bolt hole 7h and the bolt hole 8h are fastened by the bolt 9, the inner surface side clamping portion 7b and the outer surface side clamping portion 8b are synchronized with the decrease in the separation distance between the inner surface side flange portion 7a and the outer surface side flange portion 8a. The separation distance can be reduced. Therefore, the fastening bolt 9 of the inner surface side flange portion 7a and the outer surface side flange portion 8a is also used as a crimping bolt at the front end portion of the side wall portion 4a.

Based on FIG. 10, the assembly procedure of the crash can 4 will be described.
As a preparation process, a vehicle body side unit and a bumper rain side unit are formed.
A vehicle body side unit is formed by joining the inner surface side flange portion 7a of the inner surface side clamping member 7 to the rear ends of the left and right rear side frames 1, and the front wall 4b of the pair of left and right crash cans 4 and the front wall of the bumper rain 3 The bumper rain side unit is formed by fastening and fixing the portion 3b to the bolt 3 inserted through the bolt hole 3h.

Next, the surface on the outer surface side of the extension portion 7c of the inner surface side clamping member 7 is brought into surface contact with the surface on the inner surface side of the front end portion of the side wall portion 4a. The stepped surface of the inner surface side clamping part 7b receives and positions the front end part of the side wall part 4a.
At the same time as the surface on the inner surface side of the extension portion 8c of the outer surface side clamping member 8 is overlapped with the outer surface surface of the front end portion of the side wall portion 4a, the inner surface side flange portion in a state where the bolt holes 7h and the bolt holes 8h are superimposed. 7a and the outer surface side flange portion 8a are overlapped. Finally, the four bolt holes 7h and the four bolt holes 8h are fastened and fixed via the four bolts 9.

Next, functions and effects of the shock absorbing structure for the vehicle V according to the present embodiment will be described.
According to this shock absorbing structure, the crash can 4 is provided at the rear end portion of the side wall portion 4a, the side wall portion 4a being fixed to the vehicle body with the front end portion sandwiched from both sides in the vehicle width direction, and the bumper rain 3 being attached. The crush can 4 can be fixed to the vehicle body without forming a fiber cutting portion, and the fiber reinforcement that is sequentially broken at the time of a vehicle collision. The resin can be discharged from the inside of the crash can 4 to the outside.
Since the thickness of the side wall portion 4a is increased toward the front end portion, it is possible to ensure sequential destruction from the rear end portion, and to ensure stable EA performance by suppressing the sideways collapse of the crash can 4 at the time of oblique collision. be able to.

The thickness of the side wall portion 4a leading end portion of the (proximal portion) is that is formed to be thicker as the vehicle width direction inside.
As a result, a compressive load is generated on the inner side in the vehicle width direction of the side wall portion 4a at the time of the oblique collision, but since the front end portion is thick, it is possible to suppress the compressive deformation acting on the side wall portion 4a and Can be suppressed.
The crash can 4 is constituted by a laminate S of a plurality of prepreg sheet layers s1 to s3, and the laminate S of the plurality of prepreg sheet layers s1 to s3 is separated from the surface on the inner surface side of the side wall portion 4a of the crash can 4. Since it is comprised by the prepreg sheet layers s1-s3 with short front-back length, the thickness of the side wall part 4a can be made thicker toward the front end part side, suppressing an increase in weight.

The holding member that holds the front end portion of the side wall portion 4a includes an outer surface side holding member 8 that contacts the front end portion of the side wall portion 4a from the inner side in the vehicle width direction, and an inner surface side that contacts the front end portion of the side wall portion 4a from the outer side in the vehicle width direction. The outer surface side clamping member 8 and the inner surface side clamping member 7 have flange portions 8a and 7a and clamping portions 8b and 7b, respectively, and the front and rear lengths of the inner surface side clamping portion 7b of the inner surface side clamping member 7 are provided. However, it is formed shorter than the front-rear length of the outer surface side clamping portion 8b of the outer surface side clamping member 8.
Thereby, the compression load which acts on the side wall part 4a by the outer surface side clamping member 8 which comprises a clamping member at the time of a diagonal collision can be suppressed, and the side collapse of the crash can 4 can be suppressed.

  The outer surface side clamping portion 8 of the outer surface side clamping member 8 is disposed closer to the outer surface side of the crash can 4 than the outer surface side clamping portion 8b and forms an obtuse angle in cooperation with the outer surface side clamping portion 8b. 7 is disposed on the outer surface side of the crash can 4 with respect to the inner surface side holding portion 7b and forms an obtuse angle in cooperation with the inner surface side holding portion 7b. By using the fastening force of the side flange portion 7a, the interval between the outer surface side clamping portion 8b and the inner surface side clamping portion 7b can be narrowed, and the clamping force of the crash can 4 can be increased.

  The crash can 4 is formed so as to be sequentially broken from the rear end portion of the side wall portion 4a after the front end wall portion 4b is broken from the side wall portion 4a at the time of collision. Sequential destruction starting from the portion can be reliably generated.

Next, a modified example in which the embodiment is partially changed will be described.
1) In the above-described embodiment, an example in which the present invention is applied to a rear crash can attached to a rear side frame has been described. However, the present invention may be applied to a front crash can attached to a front side frame.
Moreover, although the example applied to the crush can comprised in the partial cylinder-shaped open cross-section member by which the vehicle width direction outer side was open | released, you may comprise in the open cross-section member by which the vehicle width direction inner side was open | released, The longitudinal section perpendicular to the front-rear direction may be rectangular, and the so-called side wall may be plate-shaped.

2] In the above embodiment, an example of a crush can using a carbon fiber resin has been described, but at least a general-purpose reinforcing fiber such as glass fiber or metal fiber may be used.
Also, the base material resin can be arbitrarily selected according to the specifications of the crash can.

3] In the above embodiment, the second carbon fiber has been described as being disposed so as to be orthogonal to the first carbon fiber. However, the second carbon fiber may be at least crossed with respect to the first carbon fiber. It is also possible to use a second carbon fiber having a crossing angle of 45 ° or 60 °.

4] In the above embodiment, an example of molding by an autoclave method using an autoclave pot has been described. However, instead of curing by an autoclave pot, an RFI method that cures in an oven may be used. A hot pressing method in which the bagging process is omitted and heat pressing is performed with a press die may be used.
It is also possible to use an RTM method in which a carbon fiber preform is set in a mold and a molten resin is injected into the mold without forming a prepreg sheet.

5] In the above embodiment, an example in which three types of prepreg sheet layers are laminated and the thickness of the base end portion of the side wall portion of the crash can is formed stepwise in the vehicle width direction inside is described. You may form so that the thickness of a part may become linearly thick in the vehicle width direction inner side.

6) In addition, those skilled in the art can implement the present invention in a form in which various modifications are added to the above-described embodiment or in a form in which each embodiment is combined without departing from the gist of the present invention. Various modifications are also included.

3 Bumper rain 4 Crash can 4a Side wall part 4b Tip wall part 4s Step part 4p Clamping part
7 inner surface side clamping member 7a inner surface side flange portion 7b inner surface side clamping portion 8 outer surface side clamping member 8a outer surface side flange portion 8b outer surface side clamping portion V vehicle s1 to s3 prepreg sheet layer S laminate

Claims (4)

A pair of left and right fiber reinforced resin impact absorbing members including a plurality of reinforcing fibers disposed at the front end in the longitudinal direction of the vehicle body and arranged so as to extend continuously in the longitudinal direction; and the pair of impact absorbing members In the shock absorbing structure for a vehicle, including a bumper reinforcement attached in the vehicle width direction attached to the tip portion,
The shock absorbing member is provided at a side wall portion of which the base end portion is clamped by a pair of clamping members from both sides in the vehicle width direction and fixed to the vehicle body, at the tip end portion of the side wall portion, and the bumper reinforcement is provided It is configured as an open cross-section member with an attached tip wall,
Formed so that the thickness of the sandwiched portion of the side wall portion sandwiched by the pair of sandwiching members becomes thicker toward the proximal end side,
A stepped portion that is locked by the clamping member is formed in the sandwiched portion of the side wall portion,
The shock absorbing structure for a vehicle, wherein the step portion has a portion extending in a vehicle vertical direction and a portion extending in a vehicle width direction. 2. The shock absorbing structure for a vehicle according to claim 1, wherein a thickness of a base end portion of the side wall portion is formed so as to increase toward an inner side in the vehicle width direction . The impact absorbing member is constituted by a laminate of a plurality of fiber reinforced resin sheets,
The laminate of the plurality of fiber reinforced resin sheets is composed of a fiber reinforced resin sheet having a short front-rear length as it is separated from the inner surface of the side wall portion of the shock absorbing member. 2. A shock absorbing structure for a vehicle according to 2. The shock absorbing member is formed such that, at the time of a collision, the front end wall portion is broken from the side wall portion, and then is sequentially broken from the front end portion of the side wall portion. The shock absorbing structure for a vehicle according to claim 1.