JP2012166688A - Impact absorbing member and bumper device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impact absorbing member having excellent mass productivity, and impact absorption characteristics when attached to a reinforcement, and to provide a bumper device using the impact absorbing member.SOLUTION: The impact absorption member 1 has a bottom part 11, a flange part 12 and a nearly square tube-shaped impact absorption part 13 which is provided between the bottom part 11 and the flange part 12 and is composed of four flat side wall surfaces 13a, 13b, 13c, 13d. The bottom part 11, the flange part 12 and the impact absorption part 13 are integrally formed by press-forming one piece of an aluminum plate material. The side wall part 13a arranged at an inside WI in the vehicle width direction is an inclined surface formed in such a way that the inside WI in the vehicle width direction and the flange part 12 side enlarge in the range of 5°-15° with respect to the longitudinal vehicle direction. The bumper device 2 is fixed to the reinforcement 3 at the bottom part 11 while the incline surface 13a of the impact absorption member 1 is arranged in the inside WI in the vehicle width direction.

Description

  The present invention relates to an impact absorbing member and a bumper device.

  Conventionally, bumpers are provided in front and rear of a vehicle such as an automobile in order to absorb an impact at the time of the collision of the vehicle and reduce an impact energy transmitted to the vehicle. Generally, the bumper has a resin outer cover, a reinforcement extending in the vehicle width direction, and a foamed resin that fills a gap between the outer cover and the reinforcement. The reinforcement is attached to the frame of the vehicle main body via an impact absorbing member that absorbs impact energy by buckling deformation.

  As the impact absorbing member, for example, as described in Patent Document 1 and the like, an extruded shape made of an aluminum alloy having a predetermined cross-sectional shape considering impact absorption is widely used.

  In addition, in Patent Document 2, an aluminum plate material is pressed deep-drawn to form a bottomed cylinder, and then the bottomed cylinder is axially pressed to form a spiral step on the outer wall surface. A formed shock absorbing member has been proposed. In this document, the impact absorbing member can be attached to the vehicle without using the reinforcement, and when the impact absorbing member is attached between the reinforcement and the frame of the vehicle body, The point etc. which can be attached irrespective of the direction of the vehicle front-back direction are disclosed.

JP 2007-30647 A JP 2007-261557 A

  However, the prior art still has room for improvement in the following points. That is, when an extruded shape is used as the impact absorbing member, three parts are required: an impact absorbing portion made of the extruded shape, a fixing member for fixing to the reinforcement, and a fixing member for fixing to the vehicle frame. It becomes. For this reason, the number of manufacturing processes such as cutting of each part and assembly by line welding (all-around welding) between the parts increase. In particular, wire welding between members increases costs. Further, in order to reduce the initial load, it is necessary to perform processing for forming a bead on the outer wall surface of the impact absorbing portion made of the extruded profile. Thus, the impact-absorbing member using an extruded profile has a problem that it is inferior in mass productivity.

  On the other hand, the impact absorbing member of Patent Document 2 needs to perform press work for forming a spiral step on the outer wall surface, in addition to the press deep drawing process for forming the bottomed cylindrical body. Therefore, it cannot be said that the advantage of the press molding which increases a manufacturing process and is excellent in mass productivity is fully utilized. Moreover, it is difficult to form a spiral stepped portion on the outer wall surface of the bottomed cylindrical body by pressing. Furthermore, little consideration is given to the impact absorption characteristics when attached to the reinforcement, and there is room for improving the impact absorption characteristics from the shape.

  The present invention has been made in view of such problems, and intends to provide a shock absorbing member excellent in shock absorption characteristics when mounted on a mass productivity and a reinforcement, and a bumper device using the same. It is.

  The present invention is provided between a bottom portion for fixing to a reinforcement for reinforcing a bumper of a vehicle, a flange portion for fixing to a frame of a vehicle body, and the four flat portions. A substantially square tube-shaped shock absorbing portion composed of a side wall surface, and the bottom portion, the flange portion, and the shock absorbing portion are integrally formed by press-molding a single aluminum plate. Among the side wall surfaces of the impact absorbing portion, the side wall surface arranged on the inner side in the vehicle width direction has an inner side in the vehicle width direction within the range of 5 ° to 15 ° with respect to the vehicle front-rear direction and the flange portion side. The shock absorbing member is an inclined surface formed so as to expand (claim 1).

  The present invention also includes a reinforcement for reinforcing a bumper of a vehicle and the impact absorbing member, and the impact absorbing member is arranged in the state in which the inclined surface is disposed on the inner side in the vehicle width direction. A bumper device characterized in that the bottom portion is fixed to a force (claim 5).

Since the shock absorbing member of the present invention has the above-described configuration, it is excellent in mass productivity and shock absorbing characteristics when attached to a reinforcement.
Specifically, the bottom portion, the flange portion, and the impact absorbing portion are integrally formed by press-molding a single aluminum plate material. Therefore, the number of parts is reduced as compared with the case where an extruded profile is used, and manufacturing processes such as cutting of each part and assembly by wire welding of parts are not required. Further, it is not necessary to form a bead on the outer wall surface of the impact absorbing portion made of an extruded profile, or to form a stepped portion on the side wall surface as described in Patent Document 2. Therefore, it is excellent in mass productivity. In particular, the fact that a wire welding process is not required for forming the impact absorbing member is advantageous in terms of cost reduction.

  Of the side wall surfaces of the shock absorbing portion, the side wall surface arranged on the inner side in the vehicle width direction expands on the inner side in the vehicle width direction and on the flange side within a range of 5 ° to 15 ° with respect to the vehicle longitudinal direction. The inclined surface is formed as described above. For this reason, when receiving an impact load from the front direction of the vehicle (when applied to the front bumper side) or the rear direction of the vehicle (when applied to the rear bumper side), the balance between the initial buckling load and the prevention of falling down is achieved. Excellent and excellent shock absorption characteristics can be exhibited.

  Since the bumper device of the present invention uses the shock absorbing member, it is excellent in mass productivity and shock absorbing characteristics at the time of vehicle collision.

It is explanatory drawing which shows the structure of the impact-absorbing member in Example 1. FIG. It is explanatory drawing which shows the structure (however, the left half at the time of applying to a vehicle front direction, ie, a front bumper side), in Example 1. FIG. It is explanatory drawing which expands and shows the cross-sectional shape of the impact-absorbing member of a bumper apparatus in Example 1. In Example 1, it is explanatory drawing which shows the cross-sectional shape of the reinforcement of a bumper apparatus. It is explanatory drawing which shows the outline of the evaluation method by simulation. It is explanatory drawing which shows the structure (however, the left half at the time of applying to a vehicle front direction, ie, the front bumper side), in the comparative example 1. It is explanatory drawing which shows the structure (however, the left half at the time of applying to a vehicle front direction, ie, the front bumper side), in the comparative example 2. It is a simulation result which shows the relationship between jig | tool displacement-load.

  As described above, the shock absorbing member is provided between the bottom portion for fixing to the reinforcement for reinforcing the bumper of the vehicle, the flange portion for fixing to the vehicle body frame, and the bottom portion and the flange portion. And an impact absorbing portion. In the shock absorbing member, the method for fixing the bottom portion to the reinforcement and the method for fixing the flange portion to the frame of the vehicle main body are not particularly limited. Examples of the fixing method include fastening with a fastening member such as a bolt or nut, mechanical joining with caulking or FSW, or spot welding.

  The shape of the bottom portion is preferably a substantially rectangular shape because of the relationship with the shape of the edge portion on the bottom side of the substantially square cylindrical shock absorbing portion. Moreover, what is necessary is just to form a bottom part in the shape along the side wall surface arrange | positioned inside the vehicle front-back direction of the reinforcement for fixing a bottom part.

  The shape of the flange portion is not particularly limited, and may be a substantially polygonal shape such as a substantially square shape, a substantially circular shape, or the like. The shape of the flange portion is preferably substantially rectangular from the viewpoint of ease of attachment to the frame. More preferably, the shape of the flange portion is formed in a substantially rectangular shape such that the four side surfaces of the impact absorbing portion and the four sides of the connecting portion between the flange portion and the four sides of the flange portion are substantially parallel to each other. Good. This is because it is excellent in ease of attachment to the frame, and it is easy to arrange an attachment hole through which a bolt is inserted when it is fixed by a fastening member.

  The impact absorbing portion is formed in a substantially rectangular tube shape composed of four flat side wall surfaces. Under the present circumstances, the intersection part of side wall surfaces may be rounded so that there may be no corner | angular, and the corner | angular part may be attached. The intersecting portion is preferably rounded so as to have no corners from the viewpoint of excellent demoldability during press molding and contributing to improvement of press moldability.

  The bottom part, the flange part, and the shock absorbing part are integrally formed by press-molding a single aluminum plate. There is no seam due to caulking or joining between the bottom and the flange, or between the flange and the shock absorber. The “aluminum” referred to in the present application is a general term for metals and alloys mainly composed of aluminum, and is a concept including pure aluminum and aluminum alloys.

  As the press molding method, deep drawing can be suitably used. The thickness of the bottom portion and the flange portion is preferably in the range of 2 to 4 mm from the viewpoint of traction characteristics and the thickness of the impact absorbing section is preferably in the range of 2 to 4 mm from the viewpoint of impact energy absorption characteristics. The length of the impact absorbing portion in the vehicle front-rear direction can be appropriately determined according to the distance between the reinforcement and the frame of the vehicle body.

  Here, among the side wall surfaces of the impact absorbing portion, the side wall surface arranged on the inner side in the vehicle width direction is an inner side in the vehicle width direction within the range of 5 ° to 15 ° with respect to the vehicle longitudinal direction and the flange portion It is set as the inclined surface formed so that the side might expand. That is, of the side wall surfaces of the shock absorbing portion, the angle formed between the side wall surface arranged on the inner side in the vehicle width direction and the vehicle front-rear direction is in the range of 5 ° to 15 °, and the inner side in the vehicle width direction. The side wall surface arranged in is formed obliquely so that the inner side in the vehicle width direction and the flange portion side expand. Thus, as for the said impact-absorbing part, the side wall surface arrange | positioned inside a vehicle width direction is positively inclined.

Of the side wall surfaces of the impact absorbing portion, the side wall surface arranged on the inner side in the vehicle width direction is formed so as to extend to the inner side in the vehicle width direction and the flange portion side in a range exceeding 15 ° with respect to the vehicle front-rear direction. In the case of an inclined surface, the side wall surface arranged on the inner side in the vehicle width direction buckles with a relatively low load and falls down, resulting in deterioration of shock absorption characteristics. The upper limit value of the angle is preferably 12 °.
On the other hand, among the side wall surfaces of the impact absorbing portion, the side wall surface arranged on the inner side in the vehicle width direction extends toward the inner side in the vehicle width direction and the flange portion side in a range of 0 ° or more and less than 5 ° with respect to the vehicle longitudinal direction. In the case of the inclined surface formed as described above, the initial buckling load increases, so that the side wall surface disposed on the inner side in the vehicle front-rear direction of the reinforcement undergoes shear deformation, and the shock absorption characteristics deteriorate. . The lower limit value of the angle is preferably 7 °.

Of the side wall surfaces of the impact absorbing portion, the three side wall surfaces other than the side wall surfaces arranged on the inner side in the vehicle width direction are preferably parallel surfaces formed so as to be substantially parallel to the vehicle front-rear direction ( Claim 2).
In this case, it is easy to make it excellent in the balance between the initial buckling load and the prevention of the lateral falling, and it is easy to exhibit excellent shock absorption characteristics.
The term “substantially parallel to the vehicle front-rear direction” mentioned above is not only when the vehicle front-rear direction is completely parallel, but also when the angle between the vehicle front-rear direction and the side wall surface is 0 ° to less than 5 °. Including. This means that it can include manufacturing variations, clearance during press molding, and the like.

In the shock absorbing member, it is preferable that the bottom portion can be fixed to the reinforcement by fastening, and the flange portion can be fixed to the frame by fastening.
Fixing by wire welding increases the cost and may cause fluctuations in the design buckling load due to the heat affected zone. If it is fixed by fastening, it can be attached to the frame of the reinforcement or the vehicle body relatively easily, and the design buckling load can be easily maintained.

  Bolts, nuts and the like can be suitably used for the fastening means. In this case, a plurality of attachment holes for inserting bolts into the bottom part and the flange part may be formed. The position of the mounting hole is not particularly limited, but may be set to an optimal position in consideration of the mounting balance. For example, when the flange portion has a substantially quadrangular shape, the attachment holes may be formed at the corner portions (four corners) of the substantially square shape. This is because it is relatively easy to form and has an excellent mounting balance.

In the shock absorbing member, the aluminum plate material is preferably made of a 6000 series aluminum alloy (hereinafter referred to as “6000 series alloy”).
6000 series alloys are less prone to bending cracks. Therefore, it is difficult for cracks to occur when the shock absorbing portion buckles and deforms in a substantially bellows shape, and it is difficult to deteriorate the shock absorbing characteristics. Specific examples of the 6000 series alloy include 6009, 6016, and 6111.

  When press-molding the shock absorbing member from a single aluminum plate, the shape is determined by press-molding using an aluminum plate made of an O material or a T4 material, and then heat treatment is performed so that it becomes a T6 material. preferable. The press working to the shape of the shock absorbing member in which the bottom part, the flange part, and the shock absorbing part are integrated is a strong work. Therefore, when press molding is performed using an aluminum plate made of a relatively soft O material or T4 material, the shape workability is excellent. In addition, when the heat treatment is performed so as to finally become a T6 material after determining the shape, it is easy to improve the shock absorption.

  In the above bumper device, the reinforcement is preferably hollow from the viewpoint of improving the impact absorption characteristics of the bumper device. In this case, one or more ribs for connecting the inner surfaces of the side wall surfaces may be provided. The cross-sectional shape when the reinforcement is cut in the vehicle longitudinal direction is preferably a substantially rectangular shape, a substantially “day” character shape, a substantially “eye” character shape, a substantially “rice” character shape, or the like. be able to. However, in this case, the side wall surface substantially parallel to the vehicle vertical direction may protrude from the side wall surface substantially parallel to the vehicle front-rear direction.

  In addition, the reinforcement is usually formed by bending both end portions on the design of the vehicle. Also in the bumper device, the reinforcement may have bent portions at both ends. In the above bumper device, the shock absorbing member can be attached to the frame of the vehicle main body on the left and right sides of the vehicle main body in the vehicle front-rear direction, etc. Two are preferably attached to the force.

  The shock absorbing member and the bumper device can be applied to either the front bumper side or the rear bumper side of the vehicle.

Example 1
An impact absorbing member and a bumper device according to an embodiment of the present invention will be described with reference to FIGS. In all the drawings, FR means the vehicle front-rear direction, FRI means the vehicle inner side in the vehicle front-rear direction, and FRO means the vehicle outer side in the vehicle front-rear direction. W represents the vehicle width direction, WI represents the vehicle inner side in the vehicle width direction, and WO represents the vehicle outer side in the vehicle width direction. Moreover, UD means the vehicle vertical direction, U means the vehicle upper side, and D means the vehicle lower side. These symbols are used as appropriate in the following description. The shock absorbing member and bumper device of this example are assumed to be applied to the front bumper side of the vehicle. However, the shock absorbing member and bumper device of this example are not limited to this, and It can also be applied to the bumper side.

<Shock absorbing member>
As shown in FIGS. 1 and 2, the impact absorbing member 1 of this example is fixed to a bottom 11 for fixing to a reinforcement 3 for reinforcing a bumper of a vehicle and to a frame (not shown) of a vehicle main body. The flange portion 12 is provided between the bottom portion 11 and the flange portion 12, and has a substantially rectangular tube-shaped shock absorbing portion 13 composed of four flat side wall surfaces 13 a, 13 b, 13 c, and 13 d. Yes. That is, the shock absorbing member 1 of this example is formed in a bottomed substantially rectangular tube as a whole, and the outer periphery of the bottomed substantially rectangular tube on the side opposite to the bottom 11 is outside the bottomed substantially rectangular tube. The flange portion 12 protrudes from

  The bottom part 11, the flange part 12, and the impact absorbing part 13 are integrally formed by drawing a single aluminum plate material by press molding. As an aluminum plate material, a plate material of A6016 which is a 6000 series aluminum alloy was used. In press molding, first, the aluminum plate material (thickness 2.5 mm) made of the O material was press-molded to determine the shape, and then heat-treated to obtain a T6 material.

  In the impact absorbing member 1 of the present example, the bottom 11 is for fixing to the side wall surface 32a of the inner FRI in the vehicle longitudinal direction in the reinforcement 3. Moreover, the reinforcement 3 has the bending part 31 which bend | folds toward the inner side FRI of a vehicle front-back direction on the design of a vehicle in many cases. In this example, it is assumed that the bottom 11 is fixed to the side wall surface 32a of the inner FRI in the vehicle front-rear direction in the bent portion 31 of the reinforcement 3 as described above. Therefore, the bottom 11 is formed to be inclined in an oblique direction so as to follow the bent portion 31 of the reinforcement 3.

  The bottom part 11 is formed in a substantially square shape. Moreover, although the corner | angular part of the four corners of the bottom part 11 is formed in the shape curved so that it may become roundish, it may be formed in the shape which was square in addition to this. The outer shape of the bottom portion 11 can be determined in consideration of the outer shape on the bottom portion 11 side of the substantially square cylindrical shock absorbing portion 13.

  The bottom 11 can be fixed to the reinforcement 3 by fastening. Specifically, mounting holes (not shown) are provided at the four corners of the bottom 11 and can be fixed to the side wall surface 32a of the reinforcement 3 using bolts and nuts as fastening members. ing.

  In the impact absorbing member 1 of the present example, the flange portion 12 is for fixing to a frame of the vehicle body, specifically, to a frame of the vehicle body disposed on the outer side WO in the vehicle width direction. The flange portion 12 is formed in a substantially square shape larger than the outer shape of the end portion on the side opposite to the bottom portion 11 of the shock absorbing portion 13. The shape of the flange portion 12 can be determined in consideration of the shape of the attachment portion of the flange portion 12 in the frame of the vehicle main body. Moreover, although the corner | angular part of the four corners of the flange part 12 is formed in the shape curved so that it may become roundish, it may be formed in the shape which was square in addition to this. Further, the flange portion 12 has four sides of the connection portion between the four side wall surfaces 13a, 13b, 13c, 13d of the substantially square cylindrical shock absorbing portion 13 and the flange portion 12, and the four sides of the flange portion are substantially parallel to each other. It is arranged to be.

  The flange portion 12 can be fixed to the frame of the vehicle main body by fastening. Specifically, attachment holes (not shown) are respectively provided at four corners of the flange portion 12 and can be fixed to the frame of the vehicle body using bolts and nuts as fastening members.

  In the shock absorbing member 1 of this example, the shock absorbing portion 13 is formed in a substantially rectangular tube shape, and is composed of four flat side wall surfaces 13a, 13b, 13c, and 13d. Note that none of the side wall surfaces 13a, 13b, 13c, and 13d has a stepped portion on the outer surface. The bottom 11 is integrally connected to one end of the substantially square cylindrical shock absorber 13, and the flange 12 is integrally connected to the other end.

  Here, in the impact absorbing member 1 of the present example, among the side wall surfaces 13a, 13b, 13c, and 13d of the shock absorbing portion 13, the side wall surface 13a disposed on the inner side WI in the vehicle width direction is enlarged in FIG. As shown, the inner surface WI of the vehicle width direction and the flange portion 12 side are formed so as to expand within a range of 5 ° to 15 ° with respect to the vehicle longitudinal direction. That is, of the side wall surfaces 13a, 13b, 13c, and 13d of the shock absorbing portion 13, the angle θ between the side wall surface 13a disposed on the inner side WI in the vehicle width direction and the vehicle front-rear direction is in the range of 5 ° to 15 °. The side wall surface 13a located on the inner side WI in the vehicle width direction is formed obliquely so that the inner side WI in the vehicle width direction and the flange portion 12 side expand.

  As described above, the side wall surface 13a arranged on the inner side WI in the vehicle width direction has a direction inclined from the vehicle longitudinal direction FR to the inner side WI in the vehicle width direction within an angle range of 5 ° to 15 ° and the vehicle vertical direction UD. It is formed as a flat surface including. In this example, the angle θ formed by the inclined surface 13a and the vehicle longitudinal direction FR is set to 10 °.

  Of the side wall surfaces 13a, 13b, 13c, and 13d of the shock absorber 13, three side wall surfaces 13b, 13c, and 13d other than the side wall surface 13a (inclined surface) disposed on the inner side WI in the vehicle width direction are the vehicle The parallel surface is formed so as to be substantially parallel to the front-rear direction FR. That is, the side wall surface 13b disposed opposite to the inclined surface 13a on the outer side WO in the vehicle width direction is formed as a flat surface including the vehicle longitudinal direction FR and the vehicle vertical direction UD. That is, in this example, the angle formed between the side wall surface 13b and the vehicle longitudinal direction FR is set to 0 °. Further, the side wall surfaces 13c and 13d disposed on the upper side U and the lower side D in the vehicle vertical direction are formed as flat surfaces including the vehicle longitudinal direction FR and the vehicle width direction W. That is, in this example, the angle formed by the side wall surface 13c and the vehicle longitudinal direction FR and the angle formed by the side wall surface 13d and the vehicle longitudinal direction FR are both set to 0 °.

  In this example, the shock absorbing portion 13 has the above-described inclined surface 13a, so that a substantially square cross-sectional shape when cut in the vehicle width direction W is changed from the bottom portion 11 toward the flange portion 12 in the vehicle width direction. The diameter is gradually expanded so as to project to the inner WI of the. In addition, the substantially square cross-sectional shape immediately above the flange portion 12 was set such that the outer dimension in the vehicle width direction W was 110 mm and the outer dimension in the vehicle vertical direction UD was 90 mm. The dimension LI of the inclined surface 13a when projected in the vehicle longitudinal direction FR was set to 100 mm. In this example, the shock absorbing portion 13 is formed in a curved shape so that the intersections of the side wall surfaces 13a, 13b, 13c, and 13d are rounded. You can also.

<Bumper device>
As shown in FIG. 2, the bumper device 2 of this example includes a reinforcement 3 for reinforcing a bumper of the vehicle and the impact absorbing member 1 described above. The shock absorbing member 1 has the bottom 11 fixed to the reinforcement 3 by fastening in a state where the inclined surface 13a is disposed on the inner side WI in the vehicle width direction (the fastening member is omitted). FIG. 2 shows the left half of the bumper device 2 when applied to the front bumper side, but on the right side of the center line S is a bumper symmetrical to the left half of the bumper device 2 in the vehicle front direction. There is a right half (not shown) of the device 2 in the vehicle front direction. Therefore, in this example, the two impact absorbing members 1 described above are provided.

  The reinforcement 3 extends in the vehicle width direction W, and includes a bent portion 31 that is bent at both ends toward the inner FRI in the vehicle longitudinal direction so as to have an angle of 10 ° with the vehicle width direction W. Have. The bottom 11 of the shock absorbing member 1 is fixed to the side wall surface 32a of the inner FRI in the vehicle front-rear direction at the bent portion 31 of the reinforcement 3.

  As shown in FIG. 4A, the reinforcement 3 is formed of an aluminum hollow shape whose cross-sectional shape when cut in the vehicle front-rear direction FR is a substantially “day” shape. As shown in FIG. 4 (b), the side wall surface 32b of the outer FRO in the vehicle front-rear direction and the side wall surface 32a of the inner FRI in the vehicle front-rear direction are from the upper U side and the lower D side wall surfaces 32c, 32d in the vehicle vertical direction. It may be protruding. In addition, A7N01-T6 was used as said aluminum hollow shape material.

<Collision performance evaluation>
Hereinafter, in order to evaluate the collision performance, a simulation using commercially available FEM analysis software was performed on the bumper device 2 having the shape shown in FIG.

First, the bumper device 2 having the shape shown in FIG. 2 was converted into a mesh model to create an analysis model. Next, the following characteristics were input to the analysis model.
That is, it is assumed that the reinforcement 3 is made of a hollow shape material of an aluminum alloy (A7N01-T6) having a proof stress of 320 MPa, and the impact absorbing member 1 is made of an aluminum alloy (A6016-T6) having a proof strength of 280 MPa. The stress-strain characteristics assuming each proof stress were input to the analysis model.

  The cross-sectional shape when the reinforcement 3 was cut in the vehicle front-rear direction FR was substantially “Sun”. In a substantially “day” -shaped cross-sectional shape, the side wall surfaces 32a and 32b arranged in the vehicle longitudinal direction FR have dimensions of 100 mm, the thickness is 4 mm, and the side wall surfaces 32c and 3d arranged in the vehicle vertical direction UD have a size of 80 mm. The thickness of the central rib 33 was 2 mm. In addition, the reinforcement 3 was in a state where both ends were bent so as to have an angle of 10 ° with the vehicle width direction.

  In the shock absorbing member 1, the angle θ formed by the inclined surface 13a disposed on the inner side WI in the vehicle width direction and the vehicle longitudinal direction FR is set to 10 °. Further, the substantially square cross-sectional shape directly above the flange portion 12 has an outer dimension in the vehicle width direction W of 110 mm and an outer dimension in the vehicle vertical direction UD of 90 mm. Moreover, the dimension when projecting in the vehicle front-back direction FR of the inclined surface 13a arrange | positioned at the inner side WI of a vehicle width direction was 100 mm.

  Next, as shown in FIG. 5, a simulation was performed by causing the load jig 4 made into a mesh model to collide with the analysis model to which the above characteristics were input. In addition, the bumper apparatus 5 in FIG. 5 is for description of the evaluation method. A condition referring to ODB (Offset Deformable Barrier) was input as an analysis condition based on the analysis model. Specifically, the flange portion side end of the shock absorbing member 51 of the bumper device 5 is completely restrained, and the load jig 4 is set to a region of 40% of the total length T of the reinforcement 53 at a speed setting of 1000 mm / s. A simulation was performed to output the reaction force to the load jig 4 due to the collision with the bumper device 5 with respect to the displacement amount of the load jig 4.

  For comparison, as shown in FIG. 6, the same impact as in FIG. 1 except that the angle θ formed between the side wall surface 911a disposed on the inner side WI in the vehicle width direction and the vehicle longitudinal direction FR is 0 °. A simulation similar to the above was performed for the bumper device 91 (Comparative Product 1) using the absorbing member 911. Further, as shown in FIG. 7, the impact absorbing member 921 is the same as that shown in FIG. 1 except that the angle θ formed between the side wall surface 921a disposed on the inner side WI in the vehicle width direction and the vehicle longitudinal direction FR is 25 °. The same simulation as described above was performed for the bumper device 92 (Comparative product 2) using the above.

  The simulation result is shown in FIG. In FIG. 8, the impact energy absorption amount is calculated by the amount of displacement of the load jig 4 × the area of the load. As shown in FIG. 8, the bumper device 91 of the comparative product 1 was cracked in the reinforcement 3. In the bumper device 92 of the comparative product 2, the impact absorbing member 921 fell sideways and the load decreased.

  On the other hand, the bumper device 2 of the invention did not buckle in the reinforcement 3 and could hold a high load, and the impact was reliably transmitted to the shock absorbing member 1. The impact absorbing member 1 was buckled and deformed in the vehicle front-rear direction without falling down. Thus, it was confirmed that the shock absorbing performance was excellent.

From the above, it can be said that the impact absorbing member 1 of this example is excellent in mass productivity and impact absorbing characteristics when attached to the reinforcement 3.
Specifically, the bottom part 11, the flange part 12, and the impact absorbing part 13 are integrally formed by press-molding a single aluminum plate material. Therefore, the number of parts is reduced as compared with the case where an extruded profile is used, and manufacturing processes such as cutting of each part and assembly by wire welding of parts are not required. Further, it is not necessary to form a bead on the outer wall surface of the impact absorbing portion made of the extruded profile or to form a step on the side wall surface. Therefore, it is excellent in mass productivity.

  Of the side wall surfaces 13a, 13b, 13c, and 13d of the shock absorbing portion 13, the side wall surface 13a disposed on the inner side WI in the vehicle width direction is within a range of 5 ° to 15 ° with respect to the vehicle longitudinal direction FR. The inclined surface is formed so that the inner side WI and the flange portion 12 side in the vehicle width direction are expanded. With the bottom 11 fixed to the reinforcement 3 and the flange 12 fixed to the frame of the vehicle main body, the vehicle forward direction (when applied to the front bumper side) or the vehicle rear direction (applied to the rear bumper side) The impact load from the reinforcement 3 is transmitted to the impact absorbing portion 13. The impact absorbing portion 13 to which the impact load is transmitted buckles and deforms in a substantially bellows shape without falling down, and absorbs impact energy. Therefore, it is excellent in the balance between the initial buckling load and the prevention of falling down, and can exhibit excellent shock absorption characteristics.

  Further, since the bumper device 2 of this example uses the shock absorbing member 1 of this example, it can be said that the bumper device 2 is excellent in mass productivity and shock absorbing characteristics at the time of vehicle collision.

  Although the embodiments have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Shock absorption member 11 Bottom part 12 Flange part 13 Shock absorption part 13a Side wall surface (vehicle inner side, inclined surface)
13b Side wall surface (vehicle outside)
13c Side wall surface (vehicle upper side)
13d Side wall (vehicle lower side)
2 Bumper device 3 Reinforcement 31 Bending part 32a Side wall surface (vehicle inside)
32b Side wall surface (vehicle outside)
32c Side wall (upper side of vehicle)
32d Side wall surface (vehicle lower side)
33 Central rib

Claims (5)

A bottom for fixing to a reinforcement for reinforcing a vehicle bumper;
A flange for fixing to the frame of the vehicle body;
A shock absorber having a substantially rectangular tube shape, which is provided between the bottom and the flange, and includes four flat side wall surfaces;
The bottom part, the flange part, and the shock absorbing part are integrally formed by press-molding a single aluminum plate,
Of the side wall surfaces of the impact absorbing portion, the side wall surface arranged on the inner side in the vehicle width direction is such that the inner side in the vehicle width direction and the flange portion side expand within a range of 5 ° to 15 ° with respect to the vehicle longitudinal direction. An impact-absorbing member, characterized by being an inclined surface formed on the surface. The impact-absorbing member according to claim 1,
Of the side wall surfaces of the impact absorbing portion, the three side wall surfaces other than the side wall surfaces arranged on the inner side in the vehicle width direction are parallel surfaces formed so as to be substantially parallel to the vehicle longitudinal direction. Shock absorbing member. The impact absorbing member according to claim 1 or 2,
The bottom can be fixed to the reinforcement by fastening,
The shock absorbing member, wherein the flange portion can be fixed to the frame by fastening. In the impact-absorbing member according to any one of claims 1 to 3,
The said aluminum plate material consists of a 6000 series aluminum alloy, The impact-absorbing member characterized by the above-mentioned. Reinforcement for vehicle bumper reinforcement,
The shock absorbing member according to any one of claims 1 to 4,
The bumper device, wherein the impact absorbing member has the bottom portion fixed to the reinforcement in a state where the inclined surface is disposed on the inner side in the vehicle width direction.

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