Vehicle

Abstract

This vehicle comprises: a pair of rear side members extending along the vehicle front-rear direction on both sides in the vehicle width direction; a rear bumper beam provided rearward of the rear ends of the pair of rear side members, the rear bumper beam extending along the vehicle width direction so as to at least partially overlap the pair of rear side members in the vehicle height direction; a rear suspension cross member provided forward of the rear ends of the pair of rear side members, the rear suspension cross member being fixed to each of the pair of rear side members below the pair of rear side members; a rear motor attached to the rear suspension cross member so as to drive the rear wheels of the vehicle; and a first cross member fixed to each of the pair of rear side members at positions between the rear suspension cross member and the rear bumper beam in the vehicle front-rear direction.

Description

Vehicle

[0001] The present disclosure relates to a vehicle.

[0002] Patent Document 1 discloses a vehicle rear structure in which a battery pack is suspended and fixed to a rear side member. The rear side member has a strength reducing portion on a vehicle rear side of a suspending portion that suspends and fixes a vehicle rear end side of the battery pack, and the strength reducing portion bends and deforms the rear side member when the rear side member receives a collision load from the vehicle rear side.

[0003] Japanese Patent Application Laid-Open No. 2019-156028

[0004] Incidentally, when a rear motor is attached to a rear suspension cross member so as to drive rear wheels of a vehicle, it is necessary to fix the rear suspension cross member more toward the vehicle rear side than before, and it is not possible to provide a bend-deformable region in the rear side member.

[0005] In view of the above circumstances, at least one embodiment of the present invention aims to provide a vehicle that can absorb collision energy behind a rear suspension cross member when the vehicle receives a collision load from the vehicle rear side.

[0006] A vehicle according to at least one embodiment of the present invention includes: a pair of rear side members each extending along a vehicle front-rear direction on both sides in a vehicle width direction; a rear bumper beam provided rearward of rear ends of the pair of rear side members, the rear bumper beam extending along the vehicle width direction such that at least a portion of the rear bumper beam overlaps the pair of rear side members in a vehicle height direction; a rear suspension cross member provided forward of the rear ends of the pair of rear side members, the rear suspension cross member being respectively fixed to the pair of rear side members below the pair of rear side members; a rear motor attached to the rear suspension cross member so as to drive rear wheels of the vehicle; and a first cross member respectively fixed to each of the pair of rear side members at a position between the rear suspension cross member and the rear bumper beam in the vehicle front-rear direction.

[0007] According to the above configuration, when a vehicle receives a collision load from the rear, the collision load is transmitted from the rear side member on the collision side through the first cross member to the rear side member on the non-collision side, so that the collision energy is absorbed by the rear side member on the collision side and the rear side member on the non-collision side. As a result, when a vehicle receives a collision load from the rear, the collision energy can be absorbed behind the rear suspension cross member.

[0008] According to at least one embodiment of the present invention, when a vehicle is subjected to a collision load from the rear of the vehicle, collision energy can be absorbed behind the rear suspension cross member.

[0009] This is a schematic perspective view showing the rear structure of a vehicle according to an embodiment. This is a bottom view of the rear structure of the vehicle shown in Figure 1. This is a cross-sectional view of the rear structure of the vehicle shown in Figure 2, taken along line III-III. This is a schematic perspective view showing the frame shown in Figure 1. This is a bottom view of the frame shown in Figure 4.

[0010] Hereinafter, several embodiments of the present invention will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. For example, expressions describing relative or absolute arrangements such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" should not only strictly represent such arrangements, but also represent states of relative displacement with tolerances, or angles or distances that allow the same function to be obtained. Furthermore, expressions describing shapes such as square or cylindrical should not only represent geometrically precise square or cylindrical shapes, but also shapes including concave and concave parts, chamfered parts, etc., to the extent that the same effect can be obtained. On the other hand, expressions such as "equipped," "possess," "features," "includes," or "has" a single component are not exclusive expressions that exclude the existence of other components.

[0011] Figure 1 is a schematic perspective view showing the rear structure of vehicle 1 according to an embodiment. Figure 2 is a bottom view of the rear structure of vehicle 1 shown in Figure 1, and Figure 3 is a cross-sectional view taken along line III-III of the rear structure of vehicle 1 shown in Figure 2. Figure 4 is a schematic perspective view showing the frame 2 shown in Figure 1. Figure 5 is a bottom view of the frame 2 shown in Figure 4.

[0012] As shown in Figures 1 to 3, the vehicle 1 according to this embodiment includes a pair of rear side members 11 and 13, a rear bumper beam 15, a rear suspension cross member 17, a rear motor 19, and a cross member (first cross member) 21.

[0013] The pair of rear side members 11 and 13 extend along the vehicle's longitudinal direction on both sides in the vehicle width direction. As shown in Figure 3, the pair of rear side members 11 and 13 are formed to be at a substantially constant height in the vehicle height direction and are slightly inclined so as to gradually decrease downward in the vehicle height direction toward the front of the vehicle in the vehicle longitudinal direction.

[0014] The rear bumper beam 15 is a rear bumper beam provided behind the rear ends of the pair of rear side members 11 and 13, and extends along the vehicle width direction such that at least a portion of it overlaps with the pair of rear side members 11 and 13 in the vehicle height direction. In this embodiment, the length of the rear bumper beam 15 in the vehicle height direction is greater than the length of the pair of rear side members 11 and 13 in the vehicle height direction, and the rear bumper beam 15 overlaps with the entire pair of rear side members 11 and 13 in the vehicle height direction.

[0015] Crash boxes 23 and 25 are provided between each of the pair of rear side members 11 and 13 and the rear bumper beam 15. The crash boxes 23 and 25 are the parts that are crushed first when the vehicle 1 is hit from behind. The crash boxes 23 and 25 are box-shaped and are longer in the front-rear direction than in the width direction and height direction of the vehicle, and are provided so as to overlap each of the pair of side members 11 and 13 in the height direction of the vehicle.

[0016] The rear suspension cross member 17 is a rear suspension cross member provided in front of the rear ends of the pair of rear side members 11 and 13, and is fixed to the pair of rear side members 11 and 13 below them.

[0017] The rear motor 19 is mounted on the rear suspension cross member 17 to drive the rear wheels of the vehicle.

[0018] The first cross member 21 is fixed to each of the pair of rear side members 11 and 13 at a position between the rear suspension cross member 17 and the rear bumper beam 15 in the longitudinal direction of the vehicle. In this embodiment, the first cross member 21 is provided at the rear end of the rear side members 11 and 13, but it does not have to be at the rear end of the rear side members 11 and 13 as long as it is between the rear suspension cross member 17 and the rear bumper beam 15 in the longitudinal direction of the vehicle.

[0019] The first cross member 21 is positioned to overlap with a pair of rear side members 11 and 13 in the vehicle height direction. The first cross member 21 includes a bottom plate portion and a front plate portion, which form an L-shape when viewed from the rear side member 11 to the rear side member 13. The bottom plate portion has a rear edge flange extending downward from its rear edge, and the front plate portion has a front edge flange extending forward from its upper edge. Furthermore, flanges 27, 27 extending forward from the front plate portion are formed at both ends of the first cross member 21, and the first cross member 21 is fixed to the rear side members 11 and 13 by joining these flanges 27, 27 to the inner sides of the rear side members 11 and 13, respectively.

[0020] As shown in Figures 3 to 5, the vehicle 1 according to this embodiment is equipped with a cross member (second cross member) 31 fixed to each of a pair of rear side members 11 and 13 at a position that overlaps with the rear end of the rear suspension cross member 17 in the longitudinal direction of the vehicle. The bending stiffness of the second cross member 31 is higher than that of the first cross member 21, but is not limited to this. The bending stiffness is an index that indicates the bending deformation of the beam members (first cross member 21 and second cross member 31), and is expressed as the product EI of the second moment of area I, which is determined by the cross-sectional shape and size of the beam member, and the Young's modulus E of the beam member.

[0021] The rear suspension cross member 17 is fixed to the second cross member 31.

[0022] The second cross member 31 is positioned to overlap with the pair of rear side members 11 and 13 in the vehicle height direction. The second cross member 31 is arch-shaped and is formed so that its height in the vehicle height direction decreases from each end toward the center in the vehicle width direction. The height in the vehicle height direction of the center of the second cross member 31 in the vehicle width direction is approximately the same as the height in the vehicle height direction of the rear side members 11 (13), and the height in the vehicle height direction of each end of the second cross member 31 is higher than the height in the vehicle height direction of the rear side members 11 (13). Both ends of the second cross member 31 are joined to the inner side surface and the lower surface of the pair of rear side members 11 and 13, respectively.

[0023] The second cross member 31 is groove-shaped with an open top surface, and a front edge flange extending forward in the vehicle's longitudinal direction and a rear edge flange extending backward are formed on both side edges of the opening. Furthermore, flanges 33, 35, and 37 are formed at both ends of the second cross member 31, respectively, to be joined to the inner side surface, the lower surface, and the outer side surface of the rear side members 11 and 13. The second cross member 31 is fixed to the rear side members 11 and 13 by joining these flanges 33, 35, and 37 to the inner side surface, lower surface, and outer surface of the rear side members 11 and 13, respectively.

[0024] According to the embodiment of vehicle 1, when vehicle 1 is subjected to an offset collision from the rear and receives a collision load from the rear, the collision load is transmitted from the rear side member 11 (13) on the collision side through the first cross member 21 to the rear side member 13 (11) on the non-collision side, so that the collision energy is absorbed by the rear side member 11 (13) on the collision side and the rear side member 13 (11) on the non-collision side. As a result, when vehicle 1 receives a collision load from the rear, the collision energy can be absorbed behind the rear suspension cross member 17.

[0025] Furthermore, since the second cross member 31 is fixed to a pair of rear side members 11 and 13 at a position that overlaps with the rear end of the rear suspension cross member 17 in the longitudinal direction of the vehicle, the rear motor 19 attached to the rear suspension cross member 17 can be protected even if the vehicle 1 is hit from the rear.

[0026] Furthermore, since the first cross member 21 is positioned to overlap with the pair of rear side members 11 and 13 in the vehicle height direction, when vehicle 1 is hit by an offset collision from the rear and receives a collision load from the rear, the collision load is efficiently transmitted from the rear side member 11 (13) on the collision side through the first cross member 21 to the rear side member 13 (11) on the non-collision side.

[0027] Furthermore, since the second cross member 31 is positioned to overlap with the pair of rear side members 11 and 13 in the vehicle height direction, when vehicle 1 is hit by an offset collision from the rear and receives a collision load from the rear, the collision load is efficiently transmitted from the rear side member 11 (13) on the collision side through the second cross member 31 to the rear side member 13 (11) on the non-collision side.

[0028] Furthermore, since the bending rigidity of the second cross member 31 is higher than that of the first cross member 21, even if the vehicle 1 is hit from the rear and the first cross member 21 bends, the second cross member 31 can withstand the impact load.

[0029] The present invention is not limited to the embodiments described above, and includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate.

[0030] 1. Vehicle 2. Frame 11, 13. Rear side members 15. Rear bumper beam 17. Rear suspension cross member 19. Rear motor 21. Cross member (first cross member) 23, 25. Crash box 27. Flange 31. Cross member (second cross member) 33, 35, 37. Flange

Claims

1. A vehicle comprising: a pair of rear side members extending along the vehicle's longitudinal direction on both sides in the vehicle width direction; a rear bumper beam provided behind the rear ends of the pair of rear side members, extending along the vehicle width direction such that at least a portion of it overlaps with the pair of rear side members in the vehicle height direction; a rear suspension cross member provided in front of the rear ends of the pair of rear side members, each fixed to the pair of rear side members below the pair of rear side members; a rear motor attached to the rear suspension cross member to drive the rear wheels of the vehicle; and a first cross member fixed to each of the pair of rear side members at a position between the rear suspension cross member and the rear bumper beam in the vehicle's longitudinal direction.

2. The vehicle according to claim 1, further comprising a second cross member fixed to each of the pair of rear side members at a position overlapping with the rear end of the rear suspension cross member in the longitudinal direction of the vehicle.

3. The vehicle according to claim 1 or 2, wherein the first cross member is provided in a position that overlaps with the pair of rear side members in the vehicle height direction.

4. The vehicle according to claim 2, wherein the second cross member is provided in a position that overlaps with the pair of rear side members in the vehicle height direction.

5. The vehicle according to claim 2, wherein the bending rigidity of the second cross member is higher than that of the first cross member.

6. The vehicle according to claim 2, wherein the rear suspension cross member is fixed to the second cross member.

7. The vehicle according to claim 1 or 2, further comprising a pair of crash boxes provided between each of the pair of rear side members and the rear bumper beam.

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