Bumper beam of vehicle

Abstract

To provide a bumper beam of a vehicle which can reduce displacement magnitude due to buckling even when biased transmittance of stress is performed at a light collision.SOLUTION: A bumper beam 8 comprises: a front panel 20 which extends in a vehicle width direction; a rear panel 25 which extends in the vehicle width direction and faces the front panel 20 in a cross direction of a vehicle body 2; an upper panel 26u and a lower panel 26l which respectively extend from an upper edge part and a lower edge part of the rear panel 25 to a front side of the vehicle body 2 to respectively connect with an upper edge part and a lower edge part of the front panel 20; and a plurality of first beads 28u and a plurality of second beads 28l which are arranged in the middle of the upper panel 26u and the lower panel 26l in the vehicle width direction to extend from the front panel 20 side to the rear panel side 25. Extension ends of the plurality of first beads 28u and the plurality of second beads 28l are configured at positions apart from a ridge line L1 and a ridge line L2.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a bumper beam of a vehicle that extends in the vehicle width direction. [Background technology]

[0002] Conventionally, vehicles such as automobiles have a bumper at the front of the vehicle body to absorb frontal collision loads. Such a bumper has a bumper beam extending in the vehicle width direction and a pair of left and right crash boxes.

[0003] Generally, bumper beams are provided with beads that can control the buckling of the bumper beam. For example, Patent Document 1 discloses a technology in which multiple parallel beads extending from the front end to the rear end of the bumper beam are formed on panels that make up the upper and lower surfaces of the bumper beam (reinforcement body). For example, if beads are provided at two locations on the left and right of the bumper beam, the bumper beam will buckle at two locations on the left and right, starting from each bead, during a vehicle collision. By setting these buckling positions at symmetrical positions on the left and right of the bumper beam, the bumper beam deforms while suppressing the amount of movement toward the rear of the vehicle body during a minor collision, and efficiently absorbs the collision load. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-205732 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if a collision load (stress) is unevenly transmitted to the vicinity of one of the multiple beads on the bumper beam due to a pole collision or other incident, the bumper beam may buckle significantly in only one location. In such a case, the buckling shape of the bumper beam differs significantly between the left and right sides, making it difficult to suppress the amount of displacement caused by the buckling of the bumper beam. As a result, the buckled portion of the bumper beam may be displaced significantly toward the rear of the vehicle, potentially damaging on-board components.

[0006] An object of the present invention is to provide a bumper beam for a vehicle that can reduce the amount of displacement due to buckling even when stress is unevenly transmitted during a minor collision. [Means for solving the problem]

[0007] A vehicle bumper beam according to one embodiment of the present invention comprises a first panel extending in the vehicle width direction and forming an input surface for a collision load; a second panel extending in the vehicle width direction and facing the first panel in the fore-and-aft direction of the vehicle body; a pair of third panels extending from the upper and lower edges of the second panel in the fore-and-aft direction of the vehicle body, respectively, and connecting to the upper and lower edges of the first panel, respectively; and beads provided in multiple positions in the middle of the vehicle width direction on at least one of the pair of third panels, extending from the first panel side to the second panel side, with the extended ends of the multiple beads set at a position away from the ridge between the third panel and the second panel, on which the multiple beads are provided. [Effects of the Invention]

[0008] According to the vehicle bumper beam of the present invention, the amount of displacement due to buckling can be reduced even when stress is unevenly transmitted during a minor collision. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a front body frame of a vehicle. [Figure 2] A plan view showing the front body frame of a vehicle [Figure 3]A perspective view showing a bumper beam [Figure 4] Exploded perspective view showing the bumper beam [Figure 5] VV cross section of Figure 2 [Figure 6] A plan view showing the front body frame of a vehicle during a minor collision. [Figure 7] An explanatory diagram showing the stress distribution in the bumper beam during a minor collision [Figure 8] FIG. 10 is a plan view showing the front body frame of a vehicle in a minor collision according to a comparative example. [Figure 9] FIG. 10 is an explanatory diagram showing the stress distribution of a bumper beam during a minor collision in a comparative example. [Figure 10] FIG. 10 is a perspective view showing a bumper beam according to a first modified example. [Figure 11] FIG. 10 is an explanatory diagram showing the stress distribution of the bumper beam during a minor collision according to the first modified example. [Figure 12] FIG. 10 is a perspective view showing a bumper beam according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings, in which: Figure 1 is a perspective view showing a front body frame of a vehicle according to an embodiment of the present invention;

[0011] As shown in FIG. 1, a vehicle body 2 that forms the front part of a vehicle 1 is constructed by assembling panel-shaped members that are press-formed from steel plates and joining them together by spot welding or the like.

[0012] The vehicle body 2 has a pair of left and right front side frames 5 , a pair of left and right upper side frames 6 , a radiator support 7 , and a bumper beam 8 .

[0013] Each front side frame 5 extends in the longitudinal direction of the vehicle body 2. Furthermore, the base end side of each front side frame 5 is curved downward to be connected to left and right side sills (not shown).

[0014] Each upper side frame 6 extends in the front-to-rear direction of the vehicle body 2 above each front side frame 5. Furthermore, the base end side of each front side frame 5 is connected to the front edge of a front pillar (not shown).

[0015] The radiator support 7 has a pair of left and right radiator support sides 10 , an upper radiator support 11 , and a lower radiator support 12 .

[0016] The upper end portions of the side radiator supports 10 are joined to the left and right end portions of the upper radiator support 11, respectively. The lower end portions of the side radiator supports 10 are joined to the left and right end portions of the lower radiator support 12, respectively.

[0017] Further, plate-shaped frame mounting portions 15 that protrude outward in the vehicle width direction are provided on the radiator support side 10. The rear surfaces of the frame mounting portions 15 are connected to the front ends of the respective front side frames 5 by welding or the like.

[0018] Furthermore, the left and right ends of the upper radiator support 11 are connected to the front ends of the upper side frames 6 by welding or the like.

[0019] As a result, the radiator support 7 is supported by the front side frames 5 and the upper side frames 6.

[0020] As shown in FIG. 2, a radiator 17 and an air conditioning condenser 18 are attached inside the radiator support 7.

[0021] As shown in FIGS. 2 to 5, the bumper beam 8 has a front panel 20 as a first panel, and a beam body 21.

[0022] The front panel 20 is made of a long sheet metal member having a generally rectangular shape when viewed from the front. The front panel 20 is arranged to extend in the vehicle width direction (left-right direction) of the vehicle body 2. As a result, the front panel 20 forms the front wall portion of the bumper beam 8. The front wall surface of the front panel 20 forms an input surface for inputting a collision load to the bumper beam 8 in the event of a frontal collision of the vehicle 1.

[0023] The beam main body 21 has a rear panel 25 as a second panel, an upper panel 26u and a lower panel 26l as third panels, and a pair of flanges 27u, 27l. In this embodiment, the rear panel 25, the upper panel 26u, the lower panel 26l, and the pair of flanges 27u, 27l are integrally formed by pressing a sheet metal member. As a result, the cross section of the beam main body 21 has a substantially hat-like shape (see FIG. 5).

[0024] The rear panel 25 has a generally rectangular shape when viewed from the front. The rear panel 25 is disposed so as to extend along the vehicle width direction, facing the front panel 20 at the rear (front-rear direction) of the vehicle body 2.

[0025] The upper panel 26u and the lower panel 26l extend forward (in the front-rear direction) of the vehicle body 2 from the front edge and rear edge of the rear panel 25, respectively.

[0026] The flanges 27u, 27l extend upward and downward from the front edges of the upper panel 26u and the lower panel 26l, respectively. Each flange 27u, 27l has a shape that allows it to abut against the upper and lower edges of the rear surface of the front panel 20. Each flange 27u, 27l is joined to the front panel 20 by spot welding or the like. As a result, each flange 27u, 27l connects the extending ends of the upper panel 26u and the lower panel 26l to the upper and lower edges of the front panel 20.

[0027] In the bumper beam 8 having such a basic configuration, the upper panel 26u and the lower panel 26l each have a plurality of beads midway in the vehicle width direction. In this embodiment, the upper panel 26u has two first beads 28u as beads. Also, the lower panel 26l has two second beads 28l as beads. These first beads 28u and second beads 28l form starting points for buckling the bumper beam 8 when a collision load is input to the bumper beam 8.

[0028] The two first beads 28u are provided, for example, at positions symmetrical in the vehicle width direction (positions symmetrical in the left-right direction) with respect to the center of the upper panel 26u in the vehicle width direction.

[0029] Each of the first beads 28u is formed by a convex bead that protrudes upward from the outer surface of the upper panel 26u. That is, each of the first beads 28u is formed by a convex bead that protrudes outward from the bumper beam 8. It is also possible to form each of the first beads 28u by a concave bead that recesses downward from the outer surface of the upper panel 26u.

[0030] Each first bead 28u extends from the front panel 20 side to the rear panel 25 side. In this case, the position of the extending end of each first bead 28u is set at a position away from the ridge line L1 between the upper panel 26u and the rear panel 25. In other words, there is a predetermined gap between the extending end of each first bead 28u and the ridge line L1.

[0031] The two second beads 28l are provided at positions symmetrical in the vehicle width direction, for example, with respect to the center of the lower panel 26l in the vehicle width direction. Furthermore, the two second beads 28l are provided at positions facing the two first beads 28u, respectively, in the vehicle width direction.

[0032] Each second bead 28l is formed by a convex bead that protrudes downward from the outer surface of the lower panel 26l. That is, each second bead 28l is formed by a convex bead that protrudes outward from the bumper beam 8. It is also possible to form each second bead 28l by a concave bead that recesses upward from the outer surface of the lower panel 26l.

[0033] Each second bead 28l extends from the front panel 20 side toward the rear panel 25 side. In this case, the position of the extending end of each second bead 28l is set at a position away from the ridge line L2 between the lower panel 26l and the rear panel 25. In other words, there is a predetermined gap between the extending end of each second bead 28l and the ridge line L2.

[0034] 2, the pitch of the welding points 30 joining the front panel 20 to the flanges 27u, 27l is preferably set to be different in the area where the first bead 28u and the second bead 28l are provided than in the other areas. Specifically, the pitch of the welding points 30 in the area where the first bead 28u and the second bead 28l are provided is preferably set to be shorter than the pitch of the welding points 30 in the other areas.

[0035] The bumper beam 8 configured in this manner is attached to the vehicle body 2 via a pair of left and right crash boxes 35 .

[0036] That is, the tip end of each crash box 35 is joined to the beam main body 21 via a bracket 36. In this case, the joining position of each crash box 35 to the beam main body 21 is set outward in the vehicle width direction from the area where the first bead 28u and the second bead 28l are provided.

[0037] The base end of each crash box 35 is joined to the front surface of each frame mounting portion 15 via a flange 37 .

[0038] As a result, the bumper beam 8 is attached to the vehicle body 2 with a predetermined distance between it and the condenser 18. The bumper beam 8, together with the crash boxes 35, constitutes the framework of the front bumper.

[0039] The bumper beam 8 configured in this manner buckles while absorbing the collision load during a frontal collision of the vehicle 1. Such buckling of the bumper beam 8 occurs starting from each of the first beads 28u and each of the second beads 28l.

[0040] Here, the pitch of the welding points 30 in the region where the first beads 28u and the second beads 28l are provided is set shorter than the pitch of the welding points 30 in other regions, so that the collision load input to the bumper beam 8 is efficiently transmitted to the first beads 28u and the second beads 28l.

[0041] On the other hand, the extending ends (rear ends) of the first beads 28u and the second beads 28l are set at positions away from the ridge lines L1 and L2. As a result, even when the first beads 28u and the second beads 28l are provided on the upper panel 26u and the lower panel 26l, the rigidity of the rear portion of the bumper beam 8 is ensured to a predetermined level by the ridge lines L1 and L2. By ensuring rigidity in this manner, stress input to the first beads 28u and the second beads 28l is dispersed at the rear portion of the bumper beam 8.

[0042] 6 and 7, even if a collision load is biased toward one end of the bumper beam 8 in the vehicle width direction (for example, toward the right side), the bumper beam 8 will buckle approximately evenly at two locations on the left and right, starting from each of the first beads 28u and each of the second beads 28l. This makes it possible to suppress the amount of displacement caused by the buckling of the bumper beam 8, and to suppress damage to the condenser 18, radiator 17, etc., caused by the buckled bumper beam 8.

[0043] As a comparative example, Figures 8 and 9 show the buckling behavior of a bumper beam 8' in a frontal collision in which each of the first beads 28u' and each of the second beads 28l' extend to the ridge lines L1 and L2. In a bumper beam 8' configured in this manner, most of the stress input to the first beads 28u' and the second beads 28l' is transmitted to the ridge lines L1 and L2 without being dispersed. Therefore, when a collision load is applied unevenly to a position near one end of the bumper beam 8' in the vehicle width direction, the buckling shape of the bumper beam 8' differs significantly between the left and right sides. As a result, even in a minor vehicle collision, the amount of displacement due to buckling of the bumper beam 8' increases, increasing the likelihood of damage to the condenser 18, radiator 17, and other components caused by the buckled bumper beam 8.

[0044] According to this embodiment, the bumper beam 8 includes a front panel 20 extending in the vehicle width direction, a rear panel 25 extending in the vehicle width direction and facing the front panel 20 in the fore-and-aft direction of the vehicle body 2, an upper panel 26u and a lower panel 26l extending forward of the vehicle body 2 from the upper and lower edges of the rear panel 25 and connecting to the upper and lower edges of the front panel 20, respectively, and a plurality of first beads 28u and a plurality of second beads 28l provided midway in the vehicle width direction on the upper panel 26u and the lower panel 26l, respectively, extending from the front panel 20 side to the rear panel 25 side. The extending ends of the plurality of first beads 28u and the plurality of second beads 28l are set at positions away from the ridge line L1 between the upper panel 26u and the rear panel 25 and the ridge line L2 between the lower panel 26l and the rear panel 25. As a result, even if stress is unevenly transmitted during a minor collision, the amount of displacement caused by buckling of the bumper beam 8 can be reduced.

[0045] 10, it is also possible to provide three or more (for example, four) first beads 28u (and second beads 28l) at positions symmetrical in the vehicle width direction with respect to the center of the bumper beam 8. By configuring in this way, it is possible to buckle the bumper beam 8 at more points, for example, as shown in FIG. 11, and it is possible to more effectively reduce the amount of displacement of the bumper beam 8 due to buckling.

[0046] 12, sub-beads 29 may be provided on the front panel 20 at positions corresponding to the first beads 28u and the second beads 28l. This configuration allows the bumper beam 8 to buckle properly during a collision, even when the rearward extension of the first beads 28u and the second beads 28l is reduced. By reducing the rearward extension of the first beads 28u and the second beads 28l, the extension ends of the first beads 28u and the second beads 28l can be spaced sufficiently apart from the ridge lines L1 and L2. Therefore, the buckling of the bumper beam 8 due to the beads and the distribution of stress can be achieved at a higher level.

[0047] The invention described in the above embodiments is not limited to those embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. For example, in the above embodiments, a configuration in which a plurality of first beads 28u and a plurality of second beads 28l are provided on the upper panel 26u and the lower panel 26l, respectively, has been described. However, a configuration in which a plurality of beads are provided on only at least one of the upper panel 26u and the lower panel 26l is also possible. Furthermore, in the above embodiments, an example in which the present invention is applied to the bumper beam 8 of a front bumper has been described, but the present invention can also be applied to the bumper beam of a rear bumper.

[0048] Furthermore, the above-mentioned embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of the disclosed constituent elements. For example, if the stated problem can be solved and the stated effect can be obtained even if some constituent elements are deleted from all the constituent elements shown in the above-mentioned embodiments, the configuration from which these constituent elements are deleted can be extracted as an invention. [Explanation of symbols]

[0049] 1 … Vehicle 2... Body 5...Front side frame 6 ... Upper side frame 7... Radiator support 8... Bumper beam 10... Radiator support side 11... Radiator support upper 12... Radiator support lower 15...Frame mounting part 17... Radiator 18... Capacitor 20 … Front panel 21...Beam body 25 … Rear panel 26u ... Upper panel 26l ... Lower panel 27u, 27l ... flange 28u … 1st bead 28l ... second bead 29... Subbed 30...welding point 35... Crash box 36... Bracket 37... flange L1, L2 ... ridge line

Claims

1. a first panel extending in a vehicle width direction and forming an input surface for a collision load; a second panel extending in the vehicle width direction and facing the first panel in the front-rear direction of the vehicle body; a pair of third panels extending in the front-rear direction of the vehicle body from upper and lower edges of the second panel and connected to upper and lower edge portions of the first panel, respectively; a plurality of beads provided in the middle of at least one of the pair of third panels in the vehicle width direction, the beads extending from the first panel side to the second panel side, A bumper beam for a vehicle, characterized in that the extended ends of the plurality of beads are set at a position away from the ridge line between the third panel and the second panel on which the plurality of beads are provided.

2. a plurality of welding points for joining the first panel and the pair of third panels by spot welding, 2. The bumper beam of claim 1, wherein the pitch of the plurality of weld points in the region where the bead is provided is shorter than the pitch of the plurality of weld points in other regions.

3. 2. The vehicle bumper beam according to claim 1, wherein the first panel has sub-beads at positions corresponding to the plurality of beads.

4. 2. The bumper beam of a vehicle according to claim 1, wherein a joint position with a crash box is set outside in the vehicle width direction of an area where the plurality of beads are provided.

5. 2. The bumper beam of a vehicle according to claim 1, wherein the second panel and the pair of third panels are integrally formed by pressing a sheet metal member.

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