WO2013172137A1

WO2013172137A1 - Shock absorbing member

Info

Publication number: WO2013172137A1
Application number: PCT/JP2013/061148
Authority: WO
Inventors: 山下　洋介; 大地木下; 成司西尾
Original assignee: 日産自動車株式会社
Priority date: 2012-05-15
Filing date: 2013-04-15
Publication date: 2013-11-21

Abstract

In the present invention, an energy absorbing body (1) attached to the front surface (7a) of a bumper reinforcement (7) at the rear of a bumper fascia (5) is provided with: a front wall (9) that faces the bumper fascia (5); a top surface wall (11) and bottom surface wall (13); and an attachment flange (19) that is joined to the bumper reinforcement (7). The top surface wall (11) and the bottom surface wall (13) have a wavy shape that undulates vertically along the direction of vehicle width, and an inclined surface (23, 25) is provided between the attachment flange (19) and the top surface wall (11) and bottom surface wall (13).

Description

Shock absorbing member

The present invention relates to an impact absorbing member provided in an automobile.

2. Description of the Related Art A front bumper of an automobile composed of a bumper fascia, a bumper reinforcement, and an energy absorber disposed therebetween is known (for example, see Patent Document 1).

The energy absorber includes a flange on the outer peripheral side, an upper wall, a lower wall, and a side wall extending forward from the flange, and a front connecting the front ends of the upper wall, the lower wall, and the side wall. And a wall. The energy absorber is attached to the bumper reinforcement by fastening the flange to the bumper reinforcement.

Further, a predetermined portion of the upper wall protrudes upward, and a portion of the lower wall corresponding to the lower side of the predetermined portion protrudes downward, thereby forming a crushing lobe. Each crushing lobe is composed of a front lobe portion disposed on the front side, a rear lobe portion disposed on the rear side, and a crushing start portion formed therebetween. A plurality of crushing lobes are formed at predetermined intervals along the vehicle width direction.

Then, when an impact load is input to the crushing lobe from the front, the front lobe part moves rearward and deforms into the rear lobe part to absorb the impact load.

JP 2005-536392 A

However, when an impact load is input to a portion between a predetermined crushing lobe and another crushing lobe adjacent to the predetermined crushing lobe, the adjacent crushing lobes are deformed to be pushed out in the vehicle width direction. To do. Therefore, since the deformation | transformation which a front lobe part moves to the back side and enters inward of a back lobe part is suppressed, there exists a possibility that an impact load cannot be absorbed efficiently.

Therefore, an object of the present invention is to provide an impact absorbing member that can efficiently absorb an impact load.

The impact absorbing member according to the present invention includes a vertical surface portion extending in the vehicle width direction and the vertical direction, and extending from the upper portion of the vertical surface portion toward the center side in the vehicle front-rear direction and vertically along the vehicle width direction. An upper surface formed in a wave shape that repeats undulations, and a lower surface formed in a wave shape that extends from the lower part of the vertical surface part toward the center in the vehicle longitudinal direction and repeats the undulations vertically along the vehicle width direction And an upper mounting base that is bent from the center end of the upper surface portion in the vehicle front-rear direction and extends along the vertical direction and is attached to the vehicle body member, and the vehicle front-rear direction center side in the lower surface portion A lower mounting base portion that is bent from the end portion and extends along the vertical direction and is attached to the vehicle body member, and the cross section is formed in a hat shape,
In the bent boundary part between the upper surface part and the upper mounting base part, an upper inclined part rising from the upper mounting base part toward the vertical surface part is provided,
In the bent boundary portion between the lower surface portion and the lower mounting base, a lower inclined portion that rises from the lower mounting base toward the vertical surface portion is provided,
When the vertical surface portion receives an impact load toward the center in the longitudinal direction of the vehicle and the upper surface portion deforms to bulge upward and the lower surface portion deforms to bulge downward, the upper inclined portion The lower inclined portion is inclined toward the vertical surface portion of the vehicle body member and contacts the vertical surface portion.

It is a perspective view which shows the energy absorber which concerns on one Embodiment of this invention. It is a disassembled perspective view of the front bumper containing the energy absorber of FIG. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 2 is an operation explanatory view showing a state in which the energy absorber shown in FIG. 1 is deformed by receiving an impact load from the front, where (a) shows a state before deformation, (b) shows an early stage of deformation, and (c) shows a late stage of deformation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The energy absorber 1 as an impact absorbing member shown in FIG. 1 is interposed between a bumper fascia 5 and a bumper reinforcement 7 as a vehicle body member, as shown in FIG. That is, the front bumper 3 of the automobile is disposed on the front side of the vehicle (outside in the vehicle front-rear direction) and the resin bumper fascia 5 and on the rear side of the bumper fascia 5 (center side in the front-rear direction of the vehicle). Energy absorber 1 and metal bumper reinforcement 7 disposed on the vehicle rear side of energy absorber 1. The bumper reinforcement 7 is fixed to a front end of a front side member that is a skeleton member of the vehicle body. The bumper fascia 5, the bumper reinforcement 7, and the energy absorber 1 all extend long along the vehicle width direction.

As shown in FIG. 3, the energy absorber 1 described above includes a front wall 9 as a vertical surface portion, an upper surface wall 11 as an upper surface portion, a lower surface wall 13 as a lower surface portion, and a front surface 7a ( And an attachment flange 19 as an attachment base attached to the vertical wall surface.

The front wall 9 faces the front surface 5a of the bumper fascia 5 in a state of being separated in the vehicle front-rear direction and extends in the vehicle width direction and the vertical direction. The upper surface wall 11 extends from the upper end of the front wall 9 toward the rear of the vehicle (center side in the vehicle front-rear direction), and the lower surface wall 13 extends from the lower end of the front wall 9 to the rear side of the vehicle (center side in the vehicle front-rear direction). It extends toward. The mounting flange 19 includes an upper flange 19a serving as an upper mounting base, a lower flange 19b serving as a lower mounting base, a left flange 19c and a right flange 19d respectively continuous with the left and

right side walls

15 and 17, respectively. Is provided.

Further, the energy absorber 1 has left and

right side walls

15 and 17 that are located at both ends in the vehicle width direction and face the side surface 5b of the bumper fascia 5 in a separated state.

Such an energy absorber 1 has a convex portion including a front wall 9, an upper wall 11, a lower wall 13, and left and

right side walls

15, 17 projecting forward from a mounting flange 19, for example, made of PP (polypropylene). It is integrally molded with. The energy absorber 1 has a hat-shaped cross section by the front wall 9, the upper surface wall 11 and the lower surface wall 13, and the upper flange 19 a and the lower flange 19 b.

As shown in FIG. 3, a closed space 21 is formed by the front wall 9, the upper wall 11 and the lower wall 13, the left and

right side walls

15, 17, and the front surface 7 a of the bumper reinforcement 7. The mounting flange 19 is closed from each end edge of the upper surface wall 11, the lower surface wall 13, and the left and

right side walls

15, 17 on the vehicle rear side (opposite side to the bumper fascia 5, that is, the center side in the vehicle front-rear direction). It is bent toward the outside of the space 21. Bolt insertion holes 19 e are provided at the four corners of the peripheral edge of the mounting flange 19. The energy absorber 1 is attached to the bumper reinforcement 7 by inserting a bolt (not shown) into the bolt insertion hole 19 e and fastening it to the bumper reinforcement 7.

Thus, in a state where the attachment flange 19 is attached to the front surface 7a of the bumper reinforcement 7, the opening located on the opposite side of the front wall 9 is blocked by the front surface 7a of the bumper reinforcement 7.

As shown in FIG. 1, the upper wall 11 and the lower wall 13 both have a wave shape that repeatedly undulates along the vehicle width direction. That is, the upper surface wall 11 is formed with arc-shaped convex portions 11a projecting upward and arc-shaped concave portions 11b recessed downward along the vehicle width direction. Similarly, the lower surface wall 13 is alternately formed with arc-shaped convex portions 13a protruding downward and arc-shaped concave portions 13b recessed upward along the vehicle width direction.

The convex part 11a of the upper surface wall 11 and the convex part 13a of the lower surface wall 13 are in positions facing each other, and are provided at the same position in the vehicle width direction. Further, the concave portion 11b of the upper surface wall 11 and the concave portion 13b of the lower surface wall 13 are provided at positions facing each other and at the same position in the vehicle width direction. These upper surface wall 11 and lower surface wall 13 are formed in the circular arc surface curved so that it may each become convex upward and downward. Such a circular arc surface has both convex

portions

11a and 13a and

concave portions

11b and 13b.

As shown in FIG. 3, the upper wall 11 has an end on the front wall 9 side positioned lower than an end on the mounting flange 19 side, and the lower wall 13 has an end on the front wall 9 side. Is located above the end on the mounting flange 19 side. In other words, the vertical interval between the end portions on the front wall 9 side of the upper surface wall 11 and the lower surface wall 13 is smaller than the vertical interval between the end portions on the mounting flange 19 side. Such a difference in the vertical spacing is provided for both the part corresponding to the

convex parts

11a and 13a and the part corresponding to the

concave parts

11b and 13b.

And the upper inclination which rises toward the front wall 9 side from the upper flange 19a in the bent boundary part between the upper surface wall 11 which has these convex part 11a and the recessed part 11b, and the upper flange 19a of the attachment flange 19 An upper inclined surface 23 as a part is formed. The upper inclined surface 23 is disposed between the upper first bent portion 27 and the upper second bent portion 29. The upper first bent portion 27 is a portion bent from the lower end portion of the upper flange 19a toward the front wall 9. The upper second bent portion 29 is a portion bent so as to protrude toward the closed space 21 between the lower end portion of the upper inclined surface 23 and the rear end portion of the upper surface wall 11. That is, the upper first bent portion 27 and the upper second bent portion 29 are bent such that the outer surface (the vehicle front side surface) is concave. Further, the outer angle formed by the upper inclined surface 23 and the upper flange 19a (the vehicle front side) and the outer angle formed by the upper inclined surface 23 and the upper surface wall 11 (the vehicle front side) are both obtuse angles. It is.

Similarly, in the bent boundary portion between the lower surface wall 13 having the convex portion 13a and the concave portion 13b and the lower flange 19b of the mounting flange 19, a downward inclination rising from the lower flange 19b toward the front wall 9 side. A lower inclined surface 25 as a part is formed. The lower inclined surface 25 is also disposed between the lower first bent portion 31 and the lower second bent portion 33. The lower first bent portion 31 is a portion bent from the upper end portion of the lower flange 19 b toward the front wall 9. The lower second bent portion 33 is a portion bent so as to protrude toward the closed space 21 between the upper end portion of the lower inclined surface 25 and the rear end portion of the lower surface wall 13. Also, the outer angle (vehicle front side) formed by the lower inclined surface 25 and the lower flange 19b and the outer angle (vehicle front side) formed by the lower inclined surface 25 and the lower wall 13 are both obtuse angles. It is.

Next, the deformation of the energy absorber 1 when the automobile has a frontal collision and the front bumper 3 receives an impact load from the front will be described. At this time, the bumper fascia 5 is deformed to absorb the impact load, and the energy absorber 1 behind the bumper fascia 5 is also deformed to absorb the impact load. Here, the upper surface wall 11 and the lower surface wall 13 are both formed in a curved shape so as to protrude upward and downward in a state before deformation.

First, as shown in FIG. 4A, the energy absorber 1 receives an impact load F from the obstacle N toward the rear. Specifically, the obstacle N hits the front wall 9 of the energy absorber 1. Then, as shown in FIG. 4B, the upper surface wall 11 is deformed so as to be greatly curved (bulged) upward, and the lower wall 13 is largely curved (bulged) downward. Deform. That is, when the impact load F is received, the energy absorber 1 is deformed so that the distance between the upper and

lower walls

11 and 13 is increased.

The deformation of the curved shape is not limited to the portions corresponding to the convex portions 11a and the convex portions 13a, but also the portions corresponding to the

concave portions

11b and 13b, that is, between the convex portions 11a formed in plural along the vehicle width direction. It also occurs at the part corresponding to the part 13a).

FIG. 4 shows the deformation of the portions corresponding to the convex portions 11a and the convex portions 13a, but the same applies to the portions corresponding to the

concave portions

11b and 13b.

In the following description following the deformation of the curved shape, the deformation on the upper surface wall 11 side will be described, but the deformation on the lower surface wall 13 side is also deformed in a substantially symmetrical shape with respect to the upper surface wall 11.

4B, a force F1 acting toward the upper first bent portion 27 is generated at the force point P (the front end of the upper surface wall 11) at which a load acts on the upper surface wall 11 in FIG.

At that time, when the energy absorber 1 is further deformed from the state shown in FIG. 4B, the shape shown in FIG. 4C is obtained. Specifically, the upper second bent portion 29 is bent while moving rearward, and the upper inclined surface 23 is rearward with the upper first bent portion 27 as a fulcrum (in FIG. 4B). Tilt to rotate counterclockwise. Then, as shown in FIG. 4C, the upper inclined surface 23 is in a state of being in close contact with and in contact with the front surface 7 a of the bumper reinforcement 7. Next, the upper surface wall 11 is bent rearward from the end portion (upper second bent portion 29) of the upper inclined surface 23 in contact with the upper surface wall 11 side as a base point.

At this time, the upper surface wall 11 bends around the vicinity of the maximum bending portion Q of the upper surface wall 11 in FIG. 4B, and the maximum bending portion Q becomes the power point Pa as shown in FIG. 4C. The force point Pa is a force point at which a load acts on the upper surface wall 11.

Here, an angle formed by the perpendicular B and the upper surface wall 11 with respect to the front surface 7a of the bumper reinforcement 7 in FIG. 4C is an opening angle θ of the upper surface wall 11. This opening angle θ is larger than the opening angle θ1 in the comparative example in which the inclined surface 23 is not provided.

In addition, the upper surface wall 11 which concerns on a comparative example is shown with a dashed-two dotted line. In the comparative example, the inclined surface 23 is not provided, and the connection point R of the upper wall 11 to the front surface 7a of the bumper reinforcement 7 is used as a fulcrum. Therefore, since the amount of tilting upward with the connection point R as a fulcrum is smaller than in the present embodiment in which the inclined surface 23 is provided, the opening angle θ1 is smaller than the opening angle θ.

When the opening angle θ <b> 1 is small, the upper surface wall 11 is more upright with respect to the front surface 7 a of the bumper reinforcement 7. Therefore, in the comparative example, the upper surface wall 11 is easily subjected to an excessive force, and after the buckling deformation at the maximum bending portion Q, the upper surface wall 11 is buckled and deformed between the force point Pa and the connection point R, and the impact load is effectively reduced. Cannot absorb well.

On the other hand, in the present embodiment in which the inclined surface 23 is provided, the opening angle θ of the upper surface wall 11 is larger than the opening angle θ1 of the comparative example, so that the upper surface wall 11 is closer to the front surface 7a of the bumper reinforcement 7. Fall into. This makes it difficult for an excessive force to act on the upper surface wall 11, can suppress the buckling deformation between the force point Pa and the second bent portion 29, and the impact load is reduced when the upper surface wall 11 falls. It can be absorbed efficiently.

Such an effect is not only the position corresponding to the

convex portions

11a and 13a that are in the position facing each other in the vertical direction, but also the position corresponding to the

concave portions

11b and 13b that are in the position facing each other in the vertical direction. Can be obtained as well.

In the above-described embodiment, the

inclined surfaces

23 and 25 are formed as the inclined portions between the upper surface wall 11 and the lower surface wall 13 and the mounting flange 19. You may form in the curved surface from which the surface side becomes concave. That is, you may make it the upper surface wall 11 and the lower surface wall 13, and the attachment flange 19 continue with a concave curved surface.

Even when the inclined portion is a concave curved surface as described above, as in the case of the

inclined surfaces

23 and 25, when the state shown in FIG. 4B is shifted to the state shown in FIG. The part formed in the concave curved surface which replaces the

inclined surfaces

23 and 25 will be in the state which contact | adhered and contact | adhered to the front surface 7a of the bumper reinforcement 7 substantially. As a result, the opening angle θ becomes larger, the buckling deformation of the upper surface wall 11 between the force point Pa and the end portion of the close contact portion on the upper surface wall 11 side is suppressed, and the impact load is absorbed efficiently. be able to.

The inclined surfaces 23 and 25 are easier to bend with the second

bent portions

29 and 33 as base points than the inclined surfaces are concave curved surfaces, and the opening angle θ is compared. The opening angle θ1 of the example can be increased more reliably.

Further, in the energy absorber 1 according to the present embodiment, the upper surface wall 11 and the lower surface wall 13 have a wave shape. Thereby, since the rigidity of the upper surface wall 11 and the lower surface wall 13 increases compared with what does not provide a wave shape, board thickness can be made thin and weight reduction can be achieved.

The entire contents of Japanese Patent Application No. 2012-111369 (filing date: May 15, 2012) are incorporated herein by reference.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, although the energy absorber 1 is provided on the front bumper 3 in the above-described embodiment, it may be provided on the rear bumper.

According to the present invention, when an impact load is applied from the front-rear direction of the vehicle body, the upper surface portion is deformed so that the upper surface portion opens upward and the lower surface portion opens downward. The inclined portion is in contact with the front surface of the vehicle body member, so that the opening angle of the wave-shaped upper surface portion and the lower surface portion is increased, and the upper surface portion and the lower surface portion are prevented from buckling and deforming in the middle, and the impact load is reduced. It can be absorbed efficiently.

1 Energy absorber (shock absorbing member)
7 Bumper reinforcement (body parts)
7a Bumper reinforcement front (vertical wall)
9 Front wall of energy absorber (vertical surface)
11 Upper wall of the energy absorber (upper surface)
13 Lower wall of energy absorber (lower surface)
19a Upper flange of energy absorber (upper mounting base)
19b Lower flange of energy absorber (lower mounting base)
23,25 Inclined surface of energy absorber (inclined part)
27, 31 The first bent portion of the

energy absorber

29, 33 The second bent portion of the energy absorber

Claims

A vertical surface portion that extends in the vehicle width direction and the vertical direction, and a wave shape that extends from the upper portion of the vertical surface portion toward the center side in the vehicle front-rear direction and repeats ups and downs along the vehicle width direction. An upper surface portion, a lower surface portion formed in a wave shape extending from the lower portion of the vertical surface portion toward the center in the vehicle front-rear direction and undulating vertically along the vehicle width direction, and the vehicle front-rear in the upper surface portion Bending from the center side end of the direction and extending along the vertical direction, and attached to the vehicle body member, and bent from the center side end in the vehicle front-rear direction of the lower surface portion to the vertical direction And a lower mounting base that is attached to the vehicle body member and has a cross section formed in a hat shape,
In the bent boundary part between the upper surface part and the upper mounting base part, an upper inclined part rising from the upper mounting base part toward the vertical surface part is provided,
In the bent boundary portion between the lower surface portion and the lower mounting base, a lower inclined portion that rises from the lower mounting base toward the vertical surface portion is provided,
When the vertical surface portion receives an impact load toward the center in the longitudinal direction of the vehicle and the upper surface portion deforms to bulge upward and the lower surface portion deforms to bulge downward, the upper inclined portion The shock absorbing member, wherein the lower inclined portion is deformed to be inclined toward the vertical surface portion of the vehicle body member and abuts on the vertical surface portion.
The upper inclined portion includes an upper first bent portion that is bent at a lower end portion of the upper mounting base portion, and an upper first bent portion that is bent so that an upper surface is concave at an end portion of the upper surface portion on the vehicle center side. An upper inclined surface formed between the two bent portions,
The lower inclined portion includes a lower first bent portion bent at an upper end portion of the lower mounting base portion, and a lower lower portion bent so that a lower surface is concave at an end portion of the lower surface portion on the vehicle center side. The shock absorbing member according to claim 1, wherein the shock absorbing member is a lower inclined surface formed between the two bent portions.