JP2018016159A - Bumper reinforcement for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bumper reinforcement for vehicle that is lightweight and can sufficiently absorb an impact load.SOLUTION: A bumper reinforcement 10 for vehicle is arranged before or behind a passenger compartment. The bumper reinforcement 10 for vehicle comprises: a plate-like front wall part 11 extended in a vehicle width direction and arranged to face the passenger compartment; and an upper wall part 12 and a lower wall part 13 extended in the vehicle width direction respectively, the upper wall part 12 and lower wall part 13 extending from an upper end part and a lower end part of the front wall part 11 toward the passenger compartment, respectively and being plate-like. A predetermined part extending in the vehicle width direction at an intermediate part of the front wall part 11 in a vehicle height direction is set to be larger in rigidity than other parts of the front wall part 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bumper reinforcement for a vehicle.

  As described in Patent Document 1 below, a bumper reinforcement for a vehicle that absorbs an impact when an object collides with the front end (or the rear end) of the vehicle while the vehicle is running is known. The vehicle bumper reinforcement is formed in a cylindrical shape extending in the vehicle width direction. Moreover, as shown in FIG. 8, the bumper reinforcement 20 for vehicles open | released back (vehicle compartment side) is also known. Both end portions in the longitudinal direction of these vehicle bumper reinforcements are respectively attached to and supported by support members (side members) of the vehicle body.

Japanese Patent Laid-Open No. 2002-225652

  When an impact load is applied to the front wall portion 21 of the conventional vehicle bumper reinforcement 20 shown in FIG. 8, the vehicle bumper reinforcement 20 is bent by the impact load and absorbs the impact. At this time, each of the upper wall portion 22, the lower wall portion 23, the upper rear wall portion 24, and the lower rear wall portion 25 of the vehicle bumper reinforcement 20 has a longitudinal direction (see FIG. 8). Stress in a direction parallel to the direction perpendicular to the paper surface acts. Here, in a state where the front wall portion 21 is bent, compressive stress is applied to the front side portions of the upper wall portion 22, the lower wall portion 23, the upper rear wall portion 24, and the lower rear wall portion 25 of the vehicle bumper reinforcement 20. A tensile stress acts on the rear side portion. Therefore, as the front wall portion 21 is bent, the upper rear wall portion 24 and the lower rear wall portion 25 of the vehicle bumper reinforcement are cracked, and then the upper wall portion 22 and the lower wall portion 23 are cracked. Then, the vehicle bumper reinforcement 20 is broken (see FIG. 9). In the conventional bumper reinforcement 20 for a vehicle, the above-described breakage occurs in the initial stage of bending of the front wall portion 21 (with a small amount of deformation) (see FIGS. 6A and 6B). Therefore, the wall thickness of each wall portion of the vehicle bumper reinforcement 20 is set to be relatively large so that the impact is sufficiently absorbed by the bending of the vehicle bumper reinforcement 20 before the vehicle bumper reinforcement 20 breaks. There was a need to do. That is, it was necessary to set the breaking strength with respect to the impact load received by the vehicle bumper reinforcement 20 to be relatively large (see FIG. 6A). Therefore, it was difficult to reduce the weight of the bumper reinforcement 20 for the vehicle.

  The present invention has been made to address the above-described problems, and an object of the present invention is to provide a vehicle bumper reinforcement that is lightweight and can sufficiently absorb an impact load. In addition, in the description of each constituent element of the present invention below, in order to facilitate understanding of the present invention, reference numerals of corresponding portions of the embodiment are described in parentheses, but each constituent element of the present invention is The present invention should not be construed as being limited to the configurations of the corresponding portions indicated by the reference numerals of the embodiments.

In order to achieve the above object, a feature of the present invention is a bumper reinforcement (10, 10A) for a vehicle disposed in front or rear of a passenger compartment, which extends in the vehicle width direction and faces the passenger compartment. A plate-like first wall portion (11) arranged to extend in the vehicle width direction, and a second wall portion and a third wall portion respectively extending in the vehicle width direction, the upper end portion and the lower end portion of the first wall portion Plate-like second wall portion (12) and third wall portion (13) respectively extending from the first portion toward the vehicle compartment side, and extending in the vehicle width direction at an intermediate portion in the vehicle height direction of the first wall portion. The bumper reinforcement for the vehicle is set such that the rigidity of the predetermined part (P ₁₁ , Q ₁₁ ) is set lower than the rigidity of the other part of the first wall part (the part excluding the predetermined part). is there. In addition, said intermediate part is a part of 1st wall part, Comprising: It is located below the upper end part 2nd wall part of a 1st wall part, and is higher than the lower end part 3rd wall part of a 1st wall part. Means the part that is located.

  In this case, the thickness of the predetermined portion may be smaller than the thickness of the other portion of the first wall portion.

  In this case, the surface on the passenger compartment side of the predetermined portion and the surface on the passenger compartment side of the first wall portion that is continuous with the upper end and the lower end of the predetermined portion are located in the same plane. It is good to have.

  In this case, the vehicle bumper reinforcement is preferably opened toward the passenger compartment.

  In this case, the first wall portion preferably has a vertically symmetrical shape with the center portion in the vehicle height direction as the center.

  When an impact load is applied to the front surface of the vehicle bumper reinforcement according to the present invention, the vehicle bumper reinforcement is bent and deformed around a portion where the impact load acts. By this bending deformation, the second wall portion and the third wall portion in the bending deformation portion are deformed so as to open from the predetermined portion having low rigidity formed in the first wall portion in the bending deformation portion. (See FIG. 4). Thereby, the 1st wall part in the bending deformation part thru / or the 3rd wall part will be in the state (one plate shape) in a substantially parallel. As described above, the bending deformation portion is deformed into a plate shape in the process of bending the bumper reinforcement for the vehicle (that is, the bending deformation portion is deformed so that the dimension of the bending deformation portion in the vehicle front-rear direction becomes small). The vehicle bumper reinforcement according to the present invention can be bent more greatly than the conventional vehicle bumper reinforcement without breaking. That is, the vehicle bumper reinforcement can be prevented from breaking immediately after the collision. Therefore, even if the thickness of the vehicle bumper reinforcement according to the present invention is not so large, the shock absorption amount can be set to be equal to that of the conventional vehicle bumper reinforcement. That is, according to the present invention, it is possible to provide a bumper reinforcement for a vehicle that is lighter than the conventional one but has a shock absorbing performance equivalent to the conventional one.

It is the schematic of the vehicle to which the bumper reinforcement for vehicles which concerns on this invention was applied. It is sectional drawing which shows a cross section perpendicular | vertical to the longitudinal direction of the bumper reinforcement for vehicles of FIG. It is a top view which shows the stress which acts on an upper wall part and a lower wall part when the bumper reinforcement for vehicles is bent a little. It is II sectional drawing of FIG. 3A. It is the schematic which shows the process in which the intermediate part of bumper reinforcement for vehicles deform | transforms into plate shape. It is the perspective view which looked at the bumper reinforcement for vehicles bent by applying an impact load from diagonally back. It is a graph which shows the impact load applied to the bumper reinforcement for vehicles. It is a graph which shows the amount of impact absorbed by bumper reinforcement for vehicles. It is sectional drawing which shows a cross section perpendicular | vertical to the longitudinal direction of the bumper reinforcement for vehicles which concerns on the modification of this invention. It is sectional drawing which shows a cross section perpendicular | vertical to the longitudinal direction of the conventional bumper reinforcement for vehicles. It is the perspective view which looked at the conventional bumper reinforcement for vehicles which applied the impact load and fractured from the slanting back.

  A vehicle bumper reinforcement 10 according to an embodiment of the present invention will be described. The vehicle bumper reinforcement 10 is extended in the vehicle width direction at the front end of the vehicle V as shown in FIG. The vehicle V includes side members SL and SR extending in the vehicle front-rear direction. The side members SL and SR are disposed at the left end portion and the right end portion of the vehicle V, respectively. The left end and the right end of the vehicle bumper reinforcement 10 are respectively attached to the front end of the side member SL and the front end of the side member SR.

  The configuration of the vehicle bumper reinforcement 10 is substantially the same as the configuration of the conventional vehicle bumper reinforcement 20 shown in FIG. However, as described below, the configuration of the front wall portion 11 of the vehicle bumper reinforcement 10 is different from the configuration of the front wall portion 21 of the vehicle bumper reinforcement 20.

  Next, the configuration of the vehicle bumper reinforcement 10 will be described in detail. In a plan view, the bumper reinforcement 10 for a vehicle is curved in a bow shape (see FIG. 1). That is, both end portions in the longitudinal direction are located slightly behind the central portion in the longitudinal direction (vehicle width direction) of the vehicle bumper reinforcement 10. The curvature of the vehicle bumper reinforcement 10 is determined according to the design of the front end portion of the vehicle (the shape of the bumper cover). Moreover, the bumper reinforcement 10 for vehicles exhibits a vertically symmetrical shape centering on the center part in the vehicle height direction. As shown in FIG. 2, the vehicle bumper reinforcement 10 includes a front wall portion 11, an upper wall portion 12, a lower wall portion 13, an upper rear wall portion 14, and a lower rear wall portion 15. FIG. 2 shows a cross section perpendicular to the longitudinal direction of the vehicle bumper reinforcement 10, but the shape thereof is constant regardless of the position of the cross section in the longitudinal direction of the vehicle bumper reinforcement 10.

The front wall portion 11 is formed in a plate shape extending in the vehicle width direction and facing the vehicle compartment. The central portion in the vehicle height direction of the front surface of the front wall portion 11, the groove portion G ₁₁ extending in the vehicle width direction is formed. The upper wall portion 12 is formed in a plate shape that extends in the vehicle width direction and extends rearward (vehicle compartment side) from the upper end portion of the front wall portion 11. The rear end portion of the upper wall portion 12 is located slightly above the front end portion of the upper wall portion 12. The lower wall portion 13 extends rearward (vehicle compartment side) from the lower end portion of the front wall portion 11. The rear end portion of the lower wall portion 13 is located slightly below the front end portion of the lower wall portion 13. The upper rear wall portion 14 and the lower rear wall portion 15 are formed in a plate shape extending in the vehicle width direction and facing the passenger compartment. That is, the upper rear wall portion 14 and the lower rear wall portion 15 are substantially parallel to the front wall portion 11. The upper rear wall portion 14 extends downward from the rear end of the upper wall portion 12. The lower rear wall portion 15 extends upward from the rear end of the lower wall portion 13. The lower end surface of the upper rear wall portion 14 and the upper end surface of the lower rear wall portion 15 are opposed to each other. That is, the vehicle bumper reinforcement 10 is opened rearward. The front end portions of the side members SL and SR are inserted into the vehicle bumper reinforcement 10. Then, the side members SL and SR and the vehicle bumper reinforcement 10 are fastened with the front surfaces of the side members SL and SR in contact with the rear surface of the front wall portion 11.

The wall thickness of the front wall portion 11, the upper rear wall portion 14, and the lower rear wall portion 15 is substantially the same, and the wall thickness of the upper wall portion 12 and the lower wall portion 13 is the same as that of the front wall portion 11 and the upper rear wall portion 14. And approximately half of the lower rear wall 15. However, the intermediate portion of the front wall portion 11 in the vehicle height direction has a lower thickness than the other portions of the front wall portion 11 and has a lower rigidity than the other portions of the front wall portion _11. and the low-rigidity area Q ₁₁ is formed. For example, the thickness of the low rigidity portion _{P 11, Q 11,} of the front wall portion 11, is substantially half the thickness of the portion except for the low-rigidity portion _{P 11, Q 11.} The low rigidity portions P ₁₁ and Q ₁₁ are extended in the vehicle width direction. That is, the low rigidity portions P ₁₁ and Q ₁₁ are formed from the right end to the left end of the front wall portion 11. Low-rigidity portion _{P 11} is positioned between the upper wall portion 12 and the groove _{G 11.} Further, the low-rigidity portion _{Q 11} is positioned between the lower wall portion 13 and the groove _{G 11.} The width of the low-rigidity portion _{P 11, Q 11} (the dimensions of the vehicle height direction) is equal to the thickness of the low rigidity portion _{P 11, Q 11.} The rear surface of the portion except for the groove G ₁₁ of the front wall portion 11 is positioned in the same plane. In other words, only the groove G ₁₁ of the front wall portion 11 protrudes rearward, the portion excluding the groove G ₁₁ not formed stepped. In addition, the low-rigidity part is not formed in the front wall part 21 of the conventional bumper reinforcement 20 for vehicles (refer FIG. 8). That is, the thickness of each part of the front wall portion 21 is substantially the same.

  The vehicle bumper reinforcement 10 has various through holes (not shown) (for example, holes into which fastening members (rivets, bolts, etc.) for fastening the vehicle bumper reinforcement 10 to the side members SL, SR are inserted). Is provided.

  The vehicle bumper reinforcement 10 is formed as follows. First, a metal material (for example, an aluminum alloy material) is extruded to form a linear intermediate formed body. The extrusion direction of the metal material corresponds to the vehicle width direction. The shape of the cross section perpendicular to the longitudinal direction of the intermediate molded body is the same as the shape of the cross section shown in FIG. Next, the various through holes are formed in the wall portion of the intermediate molded body. Next, the intermediate molded body is bent into a bow shape. Thus, the bumper reinforcement 10 for vehicles is formed.

As described above, the configuration of the vehicle bumper reinforcement 10 is substantially the same as the configuration of the conventional vehicle bumper reinforcement 20 shown in FIG. However, while the thickness of each part of the front wall portion 21 of the conventional vehicle bumper reinforcement 20 is substantially the same, a part of the front wall portion 11 of the vehicle bumper reinforcement 10 of the present embodiment (low The rigid portions P ₁₁ and Q ₁₁ ) are formed thinner than the other portions. Therefore, the vehicle bumper reinforcement 10 is lighter than the vehicle bumper reinforcement 20.

When an impact load is applied to the front surface of the substantially central portion in the longitudinal direction of the vehicle bumper reinforcement 10, the vehicle bumper reinforcement 10 bends as shown in FIG. 3A. In this state, the stress σ along the longitudinal direction of the vehicle bumper reinforcement 10 acts on the upper wall portion 12 and the lower wall portion 13. By the action of the stress sigma of the vehicle stress sigma _a is a front-rear direction component (see FIG. 3B), the portion where an impact load is bent to act (hereinafter, bending deformation portion) low rigidity formed in the front wall 11 of the Starting from the parts P ₁₁ and Q ₁₁ , as shown in FIG. 4, the upper wall part 12 and the lower wall part 13 in the bent deformation part are deformed so as to open. Thereafter, the front wall portion 11, the upper wall portion 12, and the lower wall portion 13 in the bent deformation portion are formed into a single plate shape, and the upper rear wall portion 14 and the lower side are overlapped with the single plate-shaped portion. The rear wall portion 15 is in a state substantially parallel to one plate-like portion.

In this way, the bending deformation portion is deformed into a plate shape in the process of deformation of the vehicle bumper reinforcement 10 (that is, the bending deformation portion is deformed so that the dimension of the bending deformation portion in the vehicle front-rear direction becomes small). Therefore, the vehicle bumper reinforcement 10 can be bent more greatly than the conventional vehicle bumper reinforcement 20 without breaking. That is, it is possible to suppress the vehicle bumper reinforcement 10 from being broken immediately after the collision. Since a part of the front wall part 11 (low-rigidity parts P ₁₁ and Q ₁₁ ) is formed thinner than the other parts, the rigidity of the front wall part 11 of the vehicle bumper reinforcement 10 is the vehicle bumper reinforcement. It is lower than the rigidity of the front wall portion 21 of the ment 20. Therefore, as shown in FIG. 6A, the impact load (characteristic shown by the solid line in the figure) received by the vehicle bumper reinforcement 10 is the characteristic shown by the broken line in the conventional vehicle bumper reinforcement 20. ) Is smaller. However, the vehicle bumper reinforcement 10 bends larger than the vehicle bumper reinforcement 20 without breaking. Therefore, as shown in FIG. 6B, the shock absorption amount of the vehicular bumper reinforcement 10 is equivalent to the conventional vehicular bumper reinforcement 20. That is, the bumper reinforcement 10 for a vehicle is lighter than the conventional one, but has a shock absorbing performance equivalent to the conventional one.

  Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

For example, like the vehicle bumper reinforcement 10A shown in FIG. 7, the dimension in the vehicle height direction of the low rigidity portions P ₁₁ and Q ₁₁ may be set larger than that in the above embodiment (FIG. 2). Moreover, in the said embodiment, although the bumper reinforcement 10 for vehicles is curving in the shape of a bow, the bumper reinforcement 10 for vehicles may be formed in linear form. Moreover, although the said embodiment is an example which applied this invention to the bumper reinforcement for vehicles attached to the front end (front of a compartment) of the vehicle V, this invention is the rear end (rear of a compartment) of the vehicle V. It can also be applied to bumper reinforcements for vehicles that are attached to the vehicle.

DESCRIPTION OF SYMBOLS 10,10A ... Bumper reinforcement for vehicles, 11 ... Front wall part, 12 ... Upper wall part, 13 ... Lower wall part, 14 ... Upper rear wall part, 15 ... Lower Side rear wall part, P ₁₁ , Q ₁₁ ... Low rigidity part

Claims (5)

A bumper reinforcement for a vehicle arranged in front of or behind the passenger compartment,
A plate-like first wall portion extending in the vehicle width direction and arranged to face the vehicle compartment;
A second wall portion and a third wall portion respectively extending in the vehicle width direction, each of a plate-like second wall portion and a third wall portion respectively extending from the upper end portion and the lower end portion of the first wall portion to the vehicle compartment side. The wall,
With
The vehicle bumper, wherein a rigidity of a predetermined portion extending in a vehicle width direction at an intermediate portion in the vehicle height direction of the first wall portion is set lower than rigidity of other portions of the first wall portion. Reinforcement. The bumper reinforcement for a vehicle according to claim 1,
A bumper reinforcement for a vehicle, wherein a thickness of the predetermined portion is smaller than a thickness of other portions of the first wall portion. The bumper reinforcement for a vehicle according to claim 2,
A vehicle-side surface of the predetermined portion and a vehicle-side surface of a portion of the first wall portion that is continuous with an upper end and a lower end of the predetermined portion are located in the same plane. Bumper reinforcement. In the bumper reinforcement for vehicles according to any one of claims 1 to 3,
A bumper reinforcement for a vehicle that is open toward the passenger compartment. In the vehicle bumper reinforcement according to any one of claims 1 to 4,
The bumper reinforcement for a vehicle, wherein the first wall portion has a vertically symmetrical shape with a center portion in a vehicle height direction as a center.

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