Vehicle bumper device

Abstract

To provide a vehicle bumper device capable of following deformation of a crash box.SOLUTION: A vehicle bumper device comprises: a bumper reinforcement lower 13 including at least a front surface 131, an upper surface 132 and a lower surface 133, and extending integrally in a vehicle lateral direction; a box-shaped crash box lower 14 arranged behind the bumper reinforcement lower; and a plate-like member 20 which is provided on the bumper reinforcement lower and extends vehicle-rearward of a rear end of the bumper reinforcement lower so as to cover the crash box lower and which is separated from the bumper reinforcement lower.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a vehicle bumper device.

Background Art

[0002] As a vehicle bumper device, there are known ones having a bumper reinforcement, a crash box, and a fastening nut. The bumper reinforcement has a plate portion that constitutes an outer surface, and the crash box is disposed at a position closer to the cabin than the plate portion and has a cylindrical portion fixed to the plate portion with its axial direction extending in the vehicle longitudinal direction (Patent Document 1). In this type of vehicle bumper device, when a load is applied to the bumper reinforcement due to a collision of the vehicle, the crash box collapses, and thereby the collision energy is absorbed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional vehicle bumper device, the crash box collapses and expands in diameter due to a collision of the vehicle. However, since the bumper reinforcement is an integral structure extending in the left-right direction, there is a possibility that the bumper reinforcement may not deform following the expansion deformation of the crash box.

[0005] The problem to be solved by the present invention is to provide a vehicle bumper device that can follow the deformation of the crash box.

Means for Solving the Problems

[0006] The present invention relates to a vehicle bumper device comprising at least a bumper reinforcement and a crash box, wherein the bumper reinforcement is separate from the crash box. The structure is U-shaped in cross-sectional view along the vehicle's longitudinal direction, and includes a front surface facing the front of the bumper reinforcement, an upper surface facing the upper surface of the crash box, and a lower surface facing the lower surface of the crash box. The above problem is solved by providing a plate-shaped member on at least one of the upper or lower surfaces of the bumper reinforcement so as to cover the crash box. [Effects of the Invention]

[0007] According to the present invention, when the crash box deforms due to a vehicle collision, the plate-shaped member deforms in accordance with that deformation. [Brief explanation of the drawing]

[0008] [Figure 1] This is an exploded perspective view showing the front portion of an automobile to which one embodiment of the vehicle bumper device according to the present invention is applied. [Figure 2] This is an exploded perspective view showing one embodiment of a vehicle bumper device according to the present invention. [Figure 3] Figure 2 is a perspective view showing the main parts. [Figure 4] This is a cross-sectional view along the line IV-IV in Figure 3. [Figure 5] This is a cross-sectional view showing the deformation state in the event of a frontal collision for an embodiment and comparative example of a vehicle bumper device according to the present invention. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Figure 1 is an exploded perspective view showing the front portion of an automobile to which one embodiment of the vehicle bumper device according to the present invention is applied, Figure 2 is an exploded perspective view showing the bumper reinforcement lower 13 in Figure 1, Figure 3 is a perspective view showing the main part of the bumper reinforcement lower 13 in Figure 2, and Figure 4 is a cross-sectional view along the line IV-IV in Figure 3. The bumper device 1 of this embodiment, as shown in Figure 1, comprises a bumper reinforcement upper 11, two crash box uppers 12, 12, a bumper reinforcement lower 13, two crash box lowers 14, 14, an energy absorber upper 15, an energy absorber lower 16, and a bumper fascia 17, and is mounted on the front end of the vehicle body B of the automobile.

[0010] The vehicle body B to which the bumper device 1 of this embodiment is attached comprises a pair of left and right front side members B1 extending in the longitudinal direction of the vehicle body B, and a front suspension member B2 that supports the front suspension device, in order to constitute its frame.

[0011] The bumper reinforcement upper 11 of this embodiment is made of a highly rigid metal material such as steel or aluminum, and is constructed by bending a plate material so that its cross-section is U-shaped, H-shaped, or closed. Alternatively, two members with a U-shaped cross-section may be joined together to form a bumper reinforcement upper 11 with a closed cross-section. The bumper reinforcement upper 11 of this embodiment extends integrally from the left end to the right end of the vehicle body B, and a crash box upper 12 is fixed to each of its left and right ends by welding or the like. The bumper reinforcement upper 11 is then fixed to the vehicle body B by fixing the two crash box uppers 12, 12 to the front end of the front side member B1. The method of fixing the crash box upper 12 to the front side member B1 is not particularly limited, and bolts or the like can be used.

[0012] The crash box upper 12 of this embodiment is made of a highly rigid metal material such as steel or aluminum, and is formed in a rectangular box or cylindrical shape in cross-section. At least one end of the front-rear ends of the vehicle body B may be open, or both may be closed. Furthermore, the crash box upper 12 of this embodiment has a weak point formed on its side or the ridge of the side, consisting of a notch or bead, so that it collapses in the front-rear direction of the vehicle body B during a frontal collision.

[0013] The bumper reinforcement lower 13 of this embodiment, like the bumper reinforcement upper 11, is made of a highly rigid metal material such as steel or aluminum, and is constructed by bending a plate material so that its cross-section is U-shaped, H-shaped, or closed. Alternatively, two members with a U-shaped cross-section may be joined together to form a bumper reinforcement lower 13 with a closed cross-section. As shown in Figure 4, the bumper reinforcement lower 13 of this embodiment has a closed cross-section and has a front surface 131, an upper surface 132, a lower surface 133, and a rear surface 134.

[0014] In this embodiment, the bumper reinforcement lower 13 extends integrally from the left end to the right end of the vehicle body B, and a crash box lower 14 is fixed to each of its left and right ends by welding or the like. The bumper reinforcement lower 13 is then fixed to the vehicle body B by fixing the two crash box lowers 14, 14 to the front end of the front suspension member B2. The method of fixing the crash box lower 14 to the front suspension member B2 is not particularly limited, and bolts or the like can be used.

[0015] The crash box lower 14 of this embodiment, like the crash box upper 12, is made of a highly rigid metal material such as steel or aluminum, and is formed in a rectangular box or cylindrical shape in cross-section, and as shown in Figures 3 and 4, has an upper surface 141, a lower surface 142, and two side surfaces 143. At least one end of the front-rear end of the vehicle body B may be open, or both may be closed. Furthermore, the crash box upper 12 of this embodiment has a weak portion 144 formed on the side surface or the ridge of the side surface, consisting of a notch or recess, so that it collapses in the front-rear direction of the vehicle body B during a frontal collision.

[0016] The energy absorber upper 15 and energy absorber lower 16 are impact absorbing members for light collisions that can effectively compress and deform in response to collision loads of objects such as pedestrians, and can be made of resin materials such as foamed resin or metal materials such as aluminum. In this embodiment, the energy absorber upper 15 is fixed to the bumper reinforcement upper 11 so as to cover the front surface of the bumper reinforcement upper 11, and the energy absorber lower 16 is fixed to the bumper reinforcement lower 13 so as to cover the front surface of the bumper reinforcement lower 13. In the bumper device of the present invention, these energy absorber upper 15 and energy absorber lower 16 are not essential components, and may be omitted as needed.

[0017] A bumper fascia 17 is fixed to the vehicle body B in front of the energy absorber upper 15 and energy absorber lower 16. The bumper fascia 17 is a design component that hides the bumper reinforcement upper 11, bumper reinforcement lower 13, energy absorber upper 15, and energy absorber lower 16, which constitute the bumper device 1, so that they are not exposed on the front of the vehicle body B. The bumper fascia 17 in this embodiment is not particularly limited, but can be made of a resin material with excellent strength, flexibility, and paintability, such as polypropylene.

[0018] Particularly, as shown in FIG. 2, the bumper device 1 of the present embodiment includes a plate-like member 20 formed as a separate member from the bumper reinforcement lower 13, and this plate-like member 20 is fixed to the bumper reinforcement lower 13. The plate-like member 20 of the present embodiment is made of a material having a breaking strength equal to or higher than the breaking strength of the material of the crash box lower 14, for example, a high-rigidity metal material such as a steel material or an aluminum material. As shown in FIGS. 3 and 4, the plate-like member 20 of the present embodiment has a shape in which a plate-like material is bent into a U-shape in a cross-sectional view along the vehicle front-rear direction, and includes an upper surface 201 facing the upper surface 141 of the crash box lower 14, a lower surface 202 also facing the lower surface 142 of the crash box lower 14, and a front surface 203 facing the front surface 131 of the bumper reinforcement lower 13.

[0019] As shown in FIG. 4, the plate-like member 20 of the present embodiment is fixed to the front surface 131 of the bumper reinforcement lower 13 by welding or the like, and extends rearward of the vehicle from the rear end of the bumper reinforcement lower 13 so that the upper surface 201 covers the upper surface 141 of the crash box lower 14 and the lower surface 202 covers the lower surface 142 of the crash box lower 14.

[0020] As shown in FIGS. 3 and 4, the plate-like member 20 of the present embodiment has a bead 204 extending in the vehicle left-right direction and protruding rearward of the vehicle on its front surface 203. Also, as shown in FIGS. 3 and 4, the plate-like member 20 of the present embodiment has a hole 205 extending in the vehicle left-right direction on its front surface 203.

[0021] In the illustrated embodiment, the case where the plate-like member 20 is provided at the joint portion between the bumper reinforcement lower 13 and the crash box lower 14 is shown. Instead of or in addition to this, a plate-like member 20 having the same configuration may be provided at the joint portion between the bumper reinforcement upper 11 and the crash box upper 12.

[0022] Next, the operation will be described. Figure 5 is a cross-sectional view showing the deformation state in the event of a frontal collision for an embodiment and a comparative example of the bumper device 1 of this embodiment. The embodiment shown at the bottom of the figure is a bumper device 1 equipped with the plate-shaped member 20 according to this embodiment shown in Figures 2 to 4, while the comparative example shown at the top of the figure is the same structure as the embodiment but with the plate-shaped member 20 omitted. A full-wrap frontal collision test was conducted under predetermined conditions using vehicles relating to the embodiment and comparative example, which include a bumper device 1 with such configurations. In Figure 5, the left barrier BR and the cross-sectional line shown by the thin line indicate the state before the collision, and the right barrier BR and the cross-sectional line shown by the thick line indicate the state after the collision. In an actual full-wrap frontal collision test, the vehicle moves forward from right to left in Figure 5 and collides with a barrier whose position is fixed, but for the sake of explanation, in Figure 5, the barrier BR is assumed to be moving from left to right.

[0023] In the bumper device 1 of the comparative example shown in the upper diagram of Figure 5, when the vehicle collides with the barrier BR, the impact force from the barrier BR is applied to the bumper reinforcement lower 13, pushing the bumper reinforcement lower 13 toward the rear of the vehicle. Since the crash box lower 14 has a weak point 144 that is vulnerable in the longitudinal direction of the vehicle, the impact force toward the rear of the vehicle applied to the bumper reinforcement lower 13 is transmitted to the crash box lower 14, and the crash box lower 14 is crushed in the longitudinal direction of the vehicle, starting from the weak point 144. At this time, as shown in the upper diagram of Figure 5, a sharp edge ED toward the barrier BR may be formed on the crushed and enlarged crash box lower 14. It is undesirable for such a sharp edge ED to come into contact with or approach the barrier BR.

[0024] In contrast, in the bumper device 1 according to the embodiment shown in the lower diagram of Figure 5, when the vehicle collides with the barrier BR, the impact force from the barrier BR is applied to the bumper reinforcement lower 13, similar to the comparative example described above, pushing the bumper reinforcement lower 13 toward the rear of the vehicle. Since the crash box lower 14 has a weak point 144 that is vulnerable in the longitudinal direction of the vehicle, the impact force toward the rear of the vehicle applied to the bumper reinforcement lower 13 is transmitted to the crash box lower 14, and the crash box lower 14 is crushed in the longitudinal direction of the vehicle, starting from the weak point 144. At this time, as shown in the lower diagram of Figure 5, a sharp edge ED toward the barrier BR may be formed on the crash box lower 14, which has expanded in diameter due to the crushing.

[0025] However, in the bumper device 1 according to the embodiment, even if a sharp edge ED toward the barrier BR is formed on the crush box lower 14, which has expanded in diameter due to crushing, the upper surface 201 and lower surface 202 of the plate-shaped member 20 extend toward the rear of the vehicle beyond the rear end of the bumper reinforcement lower 13, as shown in the lower part of Figure 5, so as to cover the upper surface 141 and lower surface 142 of the crush box lower 14, respectively. As a result, the sharp edge ED toward the barrier BR formed on the expanded crush box lower 14 comes into contact with the upper surface 201 and lower surface 202 of the plate-shaped member 20, as shown in the lower part of Figure 5. Consequently, it is possible to suppress the sharp edge ED from contacting or approaching the barrier BR.

[0026] As described above, the bumper device 1 of this embodiment includes a bumper reinforcement lower 13 having at least a front surface 131, an upper surface 132, and a lower surface 133 and extending integrally in the left-right direction of the vehicle, a box-shaped crash box lower 14 positioned behind the bumper reinforcement lower 13, and a separate plate-like member 20 provided on the bumper reinforcement lower 13 and extending further rearward from the rear end of the bumper reinforcement lower 13 so as to cover the crash box lower 14. Therefore, when the crash box lower 14 deforms due to a vehicle collision, the plate-like member 20 deforms in accordance with the deformation. As a result, it is possible to suppress the deformed crash box lower 14 from contacting or approaching the barrier BR.

[0027] Furthermore, according to the bumper device 1 of this embodiment, the plate-shaped member 20 has a U-shape in a cross-sectional view along the vehicle's longitudinal direction, and includes a front surface 203 facing the front surface 131 of the bumper reinforce lower 13, an upper surface 201 facing the upper surface 141 of the crash box lower 14, and a lower surface 202 facing the lower surface 142 of the crash box lower 14. Therefore, it can be constructed from a single member, resulting in good assembly workability and a reduction in the number of parts. It can also follow the deformation of the upper surface 141 and the lower surface 142 of the crash box lower 14. In addition, deformation of the side surface 143 of the crash box lower 14 toward the barrier BR can be shielded by the bumper reinforce lower 13.

[0028] Furthermore, according to the bumper device 1 of this embodiment, since the front surface 203 of the plate-shaped member 20 has a bead 204 that extends in the left-right direction of the vehicle, the upper surface 201 and the lower surface 202 are more easily deformed in the direction of opening. Therefore, it can follow the deformation of the crash box lower 14 even more effectively.

[0029] Furthermore, according to the bumper device 1 of this embodiment, the breaking strength of the plate-shaped member 20 is greater than or equal to the breaking strength of the material of the crush box lower 14, so even if the sharp edge ED of the deformed crush box lower 14 comes into contact with it, the breaking of the plate-shaped member 20 can be suppressed. This further suppresses the deformed crush box lower 14 from coming into contact with or approaching the barrier BR. Also, even if the crush box lower 14 breaks, the plate-shaped member 20 will not break and can cover and protect the crush box lower 14.

[0030] Furthermore, according to the bumper device 1 of this embodiment, the bumper reinforcement lower 13 has a front surface 131, an upper surface 132, a lower surface 133, and a rear surface 134, and has a closed cross-sectional shape when viewed in cross-sectional view along the longitudinal direction of the vehicle. Therefore, it has high rigidity and is resistant to deformation, and can appropriately transmit the impact force of the vehicle to the crash box lower 14.

[0031] Furthermore, according to the bumper device 1 of this embodiment, the bumper reinforcement includes a bumper reinforcement upper 11 and a bumper reinforcement lower 13, and the plate-shaped member 20 is provided at least on the bumper reinforcement lower 13, so that it can appropriately respond to collisions to the underside of the vehicle. In the bumper device 1 of the above-described embodiment, the plate-shaped member 20 is provided on the bumper reinforcement lower 13, but the bumper device of the present invention is not limited to this, and the plate-shaped member 20 may also be provided on the bumper reinforcement upper 11. [Explanation of Symbols]

[0032] 1... Bumper device 11…Bumper Reinforce Upper 12... Crashbox Upper 13…Bumper Reinforce Lower 131...Front 132…Top surface 133…Bottom surface 134…Rear side 14... Crashbox Roar 141...Top surface 142…Bottom surface 143... Side view 144…Vulnerable parts 15…Energy absorber upper 16…Energy absorber lower 17... Vampire Fetish 20…Plate-shaped member 201...Top surface 202…Bottom surface 203...Front 204...bead 205...hole

Claims

1. A bumper reinforcement having at least a front, top, and bottom surface, and extending integrally in the left-right direction of the vehicle, The aforementioned bumper reinforcement includes a box-shaped crash box positioned at the rear of the vehicle, The bumper reinforcement includes a separate plate-shaped member that is provided on the bumper reinforcement and extends further rearward from the rear end of the bumper reinforcement so as to cover the crash box, The plate-shaped member is In a cross-sectional view along the front-to-rear direction of the vehicle, it has a U-shape. A vehicle bumper device comprising a front surface facing the front of the bumper reinforcement, a top surface facing the upper surface of the crash box, and a bottom surface facing the lower surface of the crash box.

2. The vehicle bumper device according to claim 1, wherein the front surface of the plate-like member has a bead extending in the left-right direction of the vehicle.

3. The vehicle bumper device according to claim 1 or 2, wherein the breaking strength of the material of the plate-shaped member is equal to or greater than the breaking strength of the material of the crash box.

4. The bumper reinforcement has a front surface, an upper surface, a lower surface, and a rear surface, and has a closed cross-sectional shape when viewed in cross-sectional view along the longitudinal direction of the vehicle, as described in claim 1 or 2.

5. The aforementioned bumper reinforcement includes a bumper reinforcement upper and a bumper reinforcement lower. The vehicle bumper device according to claim 1 or 2, wherein the plate-shaped member is provided at least on the lower bumper reinforcement.

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