Vehicle rear structure

Abstract

The electric motor at the rear of the vehicle suppresses vibrations transmitted into the vehicle's interior. [Solution] The rear structure of the vehicle has a left side member 20, a right side member 30, a first cross member 40, and a second cross member 45. The rear floor panel 10, surrounded by the left side member 20, the right side member 30, the first cross member 40, and the second cross member 45, is provided with openings 12a and 12b. The center member 50 extends in the front-rear direction of the vehicle, straddling the openings 12a and 12b, and is joined to the first cross member 40 and the second cross member 45. An electric motor 2 is positioned in the opening 12a between the left side member 20 and the center member 50, and a lead-acid battery is positioned in the opening 12b between the right side member 30 and the center member 50.

Description

Technical Field

[0001] The present invention relates to a vehicle rear structure.

Background Art

[0002] An electric vehicle has a battery pack disposed below a floor panel that constitutes a floor portion of the vehicle, as disclosed in, for example, Patent Document 1. In order to extend the cruising range of the electric vehicle, the battery pack is required to have a larger capacity. As a result, the battery pack tends to become larger. As the battery pack becomes larger, the proportion of the space below the floor portion occupied by the battery pack increases.

[0003] In this example, a drive electric motor is disposed on the vehicle front side of the battery pack. For example, in a vehicle in which a power compartment is provided at the front of the vehicle, the vehicle compartment and the power compartment are partitioned by a dash panel or the like. Further, the electric motor is supported by a highly rigid motor frame or the like, and vibration of the electric motor is suppressed from being transmitted to the vehicle compartment.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a vehicle with a specification in which the space on the front side of the vehicle compartment is narrow, an electric motor may be disposed on the rear side of the battery pack. Further, there is known a vehicle in which a passenger compartment and a cargo compartment are integrally configured, such as a commercial vehicle or the like. In such a vehicle, when an electric motor is disposed at the rear of the vehicle, the electric motor is disposed, for example, below a floor panel that constitutes a floor portion of the cargo compartment.

[0006] Since electric motors are devices with a certain weight, they are mounted to vehicle frame members such as the side members and cross members at the rear of the vehicle via support brackets. However, in vehicles where the passenger compartment and the cargo compartment are integrally formed, vibrations from the electric motor, which is located below the floor panel, may be transmitted to the passenger compartment.

[0007] Therefore, in the structure of the above example, there was room for improvement in suppressing vibration transmission into the vehicle cabin via the floor in vehicles where the electric motor is located below the floor at the rear of the vehicle.

[0008] The present invention was made to solve the above problems, and its objective is to provide a rear vehicle structure that can suppress vibrations transmitted into the vehicle cabin by driving an electric motor located at the rear of the vehicle. [Means for solving the problem]

[0009] The vehicle rear structure according to the present invention for achieving the above objective comprises a floor panel disposed at the rear of the vehicle, a first side member and a second side member disposed in pairs on both sides of the floor panel in the vehicle width direction and extending in the vehicle longitudinal direction, a first cross member extending in the vehicle width direction so as to connect the first side member and the second side member, and a second cross member disposed on the vehicle rear side of the first cross member and extending in the vehicle width direction so as to connect the first side member and the second side member, wherein the rear floor panel enclosed by the first side member, the second side member, the first cross member, and the second cross member has an opening, and has a center member extending in the vehicle longitudinal direction so as to straddle the opening and joined to the first cross member and the second cross member, a lead battery disposed in the opening between the first side member and the center member, and an electric motor disposed in the opening between the second side member and the center member. [Effects of the Invention]

[0010] According to the present invention, vibrations transmitted into the vehicle cabin can be suppressed by driving an electric motor located at the rear of the vehicle. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic perspective view of one embodiment of the vehicle rear structure according to the present invention, as seen from the underside of the vehicle. [Figure 2] Figure 1 is a schematic perspective view of the rear floor panel. [Figure 3] Figure 1 is a magnified view of the battery tray and its surroundings, virtually showing the main body of the center member. [Figure 4] Figure 1 is a magnified view of the battery tray and its surroundings, virtually showing the rear extension member and towing hook bracket. [Figure 5] This is a schematic end view taken along the line AA in Figure 4. [Figure 6] Figure 1 is a perspective view of the battery tray and other components as seen from the outside of the vehicle, with the extension members omitted. [Figure 7] Figure 1 is a perspective view of the rear structure as seen from above the vehicle. [Figure 8] Figure 7 is a schematic perspective view showing the rear floor panel omitted. [Modes for carrying out the invention]

[0012] Hereinafter, an embodiment of the vehicle rear structure according to the present invention will be described with reference to the drawings (Figures 1 to 8). In the figures, the direction of arrow Fr indicates the front in the longitudinal direction of the vehicle. In the description of the embodiment, "front (front end) and rear (rear end)" correspond to the front and rear of the vehicle in the longitudinal direction. Arrows R and L indicate the right and left sides as seen from the perspective of an occupant looking forward of the vehicle. Arrow U indicates the upward direction in the vertical direction of the vehicle.

[0013] As shown in Figure 1, the rear structure of the vehicle in this embodiment includes a rear floor panel 10 (floor panel) located at the rear of the vehicle, and a right side member 30 (first side member) and a left side member 20 (second side member) arranged in pairs on both sides of the rear floor panel 10 in the vehicle width direction and extending in the vehicle front-rear direction. Furthermore, the rear structure includes a first cross member 40 extending in the vehicle width direction so as to connect the left and right side members 20 and 30, and a second cross member 45 located on the rear side of the vehicle of the first cross member 40 and extending in the vehicle width direction so as to connect the left and right side members 20 and 30.

[0014] Furthermore, in this embodiment, the rear structure of the rear floor panel 10, which is surrounded by a left side member 20, a right side member 30, a first cross member 40, and a second cross member 45, is provided with a left opening 12a and a right opening 12b (Figure 2). In addition, a flange is provided on the outer side of the rear floor panel 10 in the vehicle width direction, which protrudes upward from the vehicle and extends in the vehicle longitudinal direction. Furthermore, the rear structure of this embodiment has a center member 50 that extends in the vehicle longitudinal direction so as to straddle the openings 12a and 12b and is joined to the first cross member 40 and the second cross member 45. As shown in Figures 1 and 7, an electric motor 2 for driving is arranged in the left opening 12a between the left side member 20 and the center member 50, and as shown in Figures 1 and 7, a lead battery 1 is arranged in the right opening 12b between the right side member 30 and the center member 50. The lead battery 1 is fixed to a battery tray 60. As shown in Figures 3 and 4, the battery tray 60 is positioned between the center member 50 and the right side member 30 and is joined to the center member 50 and the second cross member 45. The rear structure of the vehicle will be described in detail below.

[0015] First, the rear floor panel 10 will be described. As shown in FIGS. 1 and 2, the rear floor panel 10 is a panel disposed at the rear of the vehicle. The left side member 20 and the right side member 30 are joined to the outer side portions in the vehicle width direction on the lower surface of the rear floor panel 10. Further, the first cross member 40 is joined to the front portion of the rear floor panel 10, and the second cross member 45 is joined to the rear portion of the rear floor panel 10. Also, as shown in FIG. 2, the rear floor panel 10 is provided with the openings 12a and 12b as described above. At the intermediate portion in the vehicle width direction in the openings 12a and 12b, a partition portion 13 extending in the vehicle front-rear direction so as to span the openings 12a and 12b in the front-rear direction is provided, which constitutes the left opening 12a and the right opening 12b. The shape of the partition portion 13 will be described later.

[0016] As shown in FIG. 2, a concave portion 11 recessed downward is provided at the intermediate portion in the vehicle width direction at the rear portion of the rear floor panel 10 of the present embodiment. The concave portion 11 has a bottom surface portion 11a, a left inclined wall portion 11b, and a right inclined wall portion 11c. The bottom surface portion 11a is disposed below the lower surface located at the outer side portion in the vehicle width direction of the rear floor panel 10 and is a portion extending in the vehicle width direction.

[0017] The left inclined wall portion 11b inclines downward as it goes inward in the vehicle width direction from a predetermined position on the lower surface located at the left outer side portion in the vehicle width direction of the rear floor panel 10 and is connected to the left side portion of the bottom surface portion 11a. Here, the predetermined position corresponds to the position of the front portion of the left end of the left opening 12a of the rear floor panel 10 in the vehicle width direction. The right inclined wall portion 11c inclines downward as it goes inward in the vehicle width direction from a predetermined position on the lower surface located at the right outer side portion in the vehicle width direction of the rear floor panel 10 and is connected to the right side portion of the bottom surface portion 11a. Here, the predetermined position corresponds to the position of the front portion of the right end of the right opening 12b of the rear floor panel 10 in the vehicle width direction. The second cross member 45 is disposed along the concave portion 11.

[0018] As shown in FIG. 2, the partition portion 13 connects the front portion of the bottom surface portion 11a of the concave portion 11 and the front edge portions of the openings 12a and 12b, and is provided so as to partition the openings 12a and 12b left and right. In the present embodiment, a right-side opening 12b is formed on the right side of the partition portion 13, and a left-side opening 12a is formed on the left side. The partition portion 13 has a straight portion 13a and an inclined portion 13b. The straight portion 13a is a portion that extends rearward of the vehicle from the intermediate portion in the vehicle width direction at the front portion of the bottom surface portion 11a of the concave portion 11. The inclined portion 13b is a portion that extends obliquely upward toward the vehicle front from the front end of the straight portion 13a and is connected to the front edges of the openings 12a and 12b. In the present embodiment, as shown in FIG. 7, the center member 50 is disposed along the partition portion 13 of the rear floor panel 10.

[0019] Next, the left and right side members 20 and 30 will be described. Each of the left and right side members 20 and 30 is a member that extends in the vehicle front-rear direction, is a highly rigid member formed of a metal material, and constitutes the frame of the vehicle body. As shown in FIG. 1, the left and right side members 20 and 30 are arranged so as to be paired on both outer sides in the vehicle width direction at the rear portion of the vehicle.

[0020] The left side member 20 is joined to the left outer side portion in the vehicle width direction on the lower surface of the rear floor panel 10, as shown in FIGS. 1 and 8. The left side member 20 has a lower surface portion 21 that extends in the vehicle width direction, an outer wall portion 22 that extends upward from the outer end of the lower surface portion 21 and extends in the vehicle front-rear direction, and an inner wall portion 23 that extends upward from the inner end of the lower surface portion 21 and extends in the vehicle front-rear direction (FIG. 8). Further, the upper portion of the outer wall portion 22 is joined to a flange provided at the left outer end of the rear floor panel 10 by spot welding. As shown in FIG. 8, an inner flange 24 that protrudes inward in the vehicle width direction and extends in the vehicle front-rear direction is provided at the upper end of the inner wall portion 23, and the inner flange 24 is joined to the lower surface of the rear floor panel 10 by spot welding.

[0021] The right side member 30 is joined to the right outer portion in the vehicle width direction on the underside of the rear floor panel 10. Similar to the left side member 20, the right side member 30 has a lower portion 31, an outer wall portion 32, an inner wall portion 33, and an inner flange 34. The upper part of the outer wall portion 32 is joined by spot welding to a flange provided at the right outer end of the rear floor panel 10, and the inner flange 34 is joined by spot welding to the underside of the rear floor panel 10.

[0022] The area near the joint between the first cross member 40 and the left and right side members 20 and 30 has high rigidity. For this reason, for example, heavy objects such as the rear suspension structure are attached to the lower surfaces 21 and 31 of the left and right side members 20 and 30 near the joint.

[0023] As shown in Figures 1 and 8, the first cross member 40 extends in the vehicle width direction, connecting the left and right side members 20 and 30. The first cross member 40 is joined to the front part of the lower surface of the rear floor panel 10, and the outer part of the first cross member 40 in the vehicle width direction is joined to the left and right side members 20 and 30. In this embodiment, the first cross member 40 has a central member 41 that extends in the vehicle width direction and outer members 42 that are arranged on both sides of the central member 41 in the vehicle width direction, and these are integrally configured.

[0024] The central member 41 is positioned at the front of the rear floor panel 10 and extends in the vehicle width direction. The central member 41 has a front wall portion 41a, a rear wall portion, and a lower surface portion 41c. The front wall portion 41a faces the front of the vehicle, protrudes downward from the lower surface of the rear floor panel 10, and extends in the vehicle width direction. The rear wall portion is a wall portion positioned at a distance from the front wall portion 41a on the rear side of the vehicle, and extends in the vehicle width direction. The lower surface portion 41c connects the lower end of the front wall portion 41a and the lower end of the rear wall portion and extends in the vehicle width direction.

[0025] As shown in Figure 6, a front flange 41b projecting forward is provided at the upper end of the front wall portion 41a, and the front flange 41b is joined to the front part of the lower surface of the rear floor panel 10 by spot welding. Similar to the front wall portion 41a, a rear flange projecting backward is provided at the upper end of the rear wall portion, and the rear flange is joined to the front side of the openings 12a and 12b of the rear floor panel 10. The rear flange is preferably positioned with a gap in front of the front edge of the openings 12a and 12b. In this embodiment, a closed cross-sectional structure is formed by the central member 41 and the rear floor panel 10, ensuring rigidity.

[0026] As shown in Figures 1 and 6, the outer members 42 are positioned on both sides of the central member 41 in the vehicle width direction and are joined to the outer portions of the central member 41 in the vehicle width direction. In this example, the outer members 42, like the central member 41, have a front wall portion 42a, a rear wall portion, and a lower surface portion 42c.

[0027] As shown in Figure 6, the front wall portion 42a of the outer member 42 is configured similarly to the front wall portion 41a of the central member 41, and the inner portion of the front wall portion 42a of the outer member 42 in the vehicle width direction is joined to the outer portion of the front wall portion 41a of the central member 41 in the vehicle width direction. A front flange 42b is provided at the upper end of the front wall portion 42a, and the front flange 42b is joined to the lower surface of the rear floor panel 10. Alternatively, the front flange 42b of the outer member 42 may be joined to the front flange 41b of the central member 41. Furthermore, a vertical flange is provided on the outer portion of the front wall portion 42a in the vehicle width direction, and the vertical flange is joined to the inner walls of the left and right side members 20 and 30 by spot welding. The rear wall portion of the outer member 42 is configured similarly to the rear wall portion of the central member 41. The rear wall portion is joined to each member in the same way as the front wall portion 42a.

[0028] The lower surface portion 42c of the outer member 42 connects the lower end of the front wall portion 42a and the lower end of the rear wall portion and extends in the vehicle width direction. In this example, the lower surface portion 42c extends inclined downward from the outer side portion 41c of the central member 41 in the vehicle width direction toward the outer side, and connects to the lower surfaces of the left and right side members 20 and 30. The inner side portion 42c of the lower surface portion 42c of the outer member 42 in the vehicle width direction is joined to the outer side portion 41c of the central member 41 in the vehicle width direction. In addition, a lower flange 42d that protrudes outward in the vehicle width direction is provided on the outer side portion 42c of the outer member 42, and this lower flange 42d is joined to the lower surfaces 21 and 31 of the left and right side members 20 and 30 by spot welding.

[0029] As shown in Figures 1 and 6, the second cross member 45 is joined to the rear of the rear floor panel 10 by spot welding. The front of the second cross member 45 is provided with a front wall portion 45a facing the front of the vehicle, and is formed to correspond to the concave portion 11. A front flange 45f is provided at the upper end of the front wall portion 45a, and the front flange 45f is joined to the concave portion 11 located at the rear of the rear floor panel 10. The lower surface portion 45b extending rearward from the lower end of the front wall portion 45a is formed to correspond to the concave portion 11. A flange 45c projecting downward is provided at the rear end of the lower surface portion 45b of the second cross member 45. The flange is formed to correspond to the concave portion 11. For example, an end panel (not shown) may be joined to the flange 45c by spot welding.

[0030] Next, the center member 50 will be described. As shown in Figures 1, 3, and 8, the center member 50 of this embodiment extends in the longitudinal direction of the vehicle so as to straddle the openings 12a and 12b of the rear floor panel 10 and is joined to the first cross member 40 and the second cross member 45.

[0031] The center member 50 is a member that extends along the longitudinal direction of the vehicle as a whole. The center member 50, like the left and right side members 20, 30, etc., is made of a metal material and is a highly rigid member that constitutes the vehicle body frame. As shown in Figures 1, 3, and 4, the center member 50 of this embodiment has a member body 51, a front extension member 52 joined to the front of the member body 51, a rear extension member 53 joined to the rear of the member body 51, and an inner reinforcement 55 disposed inside the member body 51.

[0032] The inner reinforcement 55 is a member that covers a portion of the partition 13 of the rear floor panel from below, and is made of metal. As shown in Figures 5 and 8, the inner reinforcement 55 is formed to correspond to the straight portion 13a and the inclined portion 13b of the partition 13. The inner reinforcement 55 has a U-shaped cross-section that opens upwards towards the vehicle. The inner wall portion 55a of the inner reinforcement 55 is joined to the inner wall portion 51e of the member body 51. The outer wall portion 55b of the inner reinforcement 55 is preferably joined to the inner wall portion 62a of the battery tray 60 via the outer wall portion 51d of the member body 51. The lower surface portion 55c of the inner reinforcement 55 is positioned above the lower surface portion 51c of the member body 51 with a gap between them.

[0033] The member body 51 is a component positioned to cover the inner reinforcement 55 from below, and, like the inner reinforcement 55, has a straight section 51a and an inclined section 51b corresponding to the straight section 13a and inclined section 13b of the partition section 13. The straight section 51a is a portion that extends linearly from the front side of the second cross member 45, and the rear part of the straight section 51a is joined to the rear extension member 53, etc. The inclined section 51b is a portion that slopes upward from the front of the straight section 51a as it extends forward, and the straight section 51a and the inclined section 51b are integrally formed. The front part of the inclined section 51b is joined to the front extension member 52 by spot welding.

[0034] As shown in Figure 5, the member body 51 has a U-shaped cross-section that opens upwards towards the vehicle, similar to the inner reinforcement 55. The inner wall portion 51e of the member body 51 is joined to the inner wall portion 55a of the inner reinforcement 55 by spot welding, and the outer wall portion 51d of the member body 51 is joined to the outer wall portion 55b of the inner reinforcement 55. Furthermore, the outer wall portion 51d of the member body 51 is joined to the inner wall portion 55a of the battery tray 60 by spot welding. In this example, the outer wall portion 55b of the inner reinforcement 55, the outer wall portion 51d of the member body 51, and the inner wall portion 62a of the battery tray 60 are joined in a triple-layered state.

[0035] As shown in Figures 3 and 4, the front extension member 52 is a member that extends in the longitudinal direction of the vehicle so as to connect the front part of the inclined portion 51b of the member body 51 and the central member 41 of the first cross member 40, and is made of a metal material. The rear part of the lower surface of the front extension member 52 preferably covers the lower surface of the inclined portion 51b of the member body 51 from below and is joined to the front part of the lower surface of the inclined portion 51b of the member body 51 by spot welding.

[0036] The front portion of the lower surface portion 52a of the front extension member 52 is joined to the lower surface portion 41c of the central member 41 of the first cross member 40 by spot welding. Furthermore, flanges 52d are provided at the lower ends of the inner wall portion 52b and the outer wall portion 52c of the front extension member 52, and these flanges 52d are joined to the lower surface of the rear floor panel 10. Additionally, vertical flanges (not shown) are provided at the front ends of the inner wall portion 52b and the outer wall portion 52c, and these vertical flanges may be joined to the rear wall portion of the central member 41 of the first cross member 40.

[0037] As shown in Figures 1, 3, and 4, the rear extension member 53 connects the rear of the straight portion 51a of the member body 51 to the second cross member 45 and is further joined to the rear of the bottom portion 62b of the battery tray 60, and is made of metal. The rear of the lower portion 52a of the front extension member 52 preferably covers the lower surface of the inclined portion 51b of the member body 51 from below and is joined to the front of the lower surface of the inclined portion 51b of the member body 51 by spot welding.

[0038] The rear extension member 53 has a lower surface portion 53a, a side wall portion 53b, a vertical wall portion 53c, and an upper surface portion 53d. The lower surface portion 53a is a plate-shaped portion that extends in the longitudinal direction and the vehicle width direction. The rear part of the lower surface portion 53a is joined to the lower surface portion 45b of the second cross member 45, and the front part of the lower surface portion 45b is joined to the lower surface portion 51c of the straight portion 51a of the member body 51 by spot welding, and is also joined to the bottom surface portion 62b of the battery tray 60.

[0039] Furthermore, as shown in Figures 3 and 4, the side wall portion 53b is a wall portion extending upward from the front of the inner portion in the vehicle width direction of the lower surface portion 53a, and is joined to the straight portion 51a of the member body 51. The vertical wall portion 53c is a wall portion projecting inward in the vehicle width direction from the rear end of the side wall portion 53b, and is joined to the front wall portion 45a of the second cross member 45. The upper surface portion 53d is a surface portion connected to the upper end of the vertical wall portion 53c and the upper end of the side wall portion 53b, and is preferably joined to the front flange 45f of the second cross member 45 and the rear floor panel 10. By providing the center member 50, it is possible to improve the rigidity around the openings 12a and 12b of the rear floor panel 10.

[0040] Next, the battery tray 60 for securing the lead battery 1 will be described. As shown in Figure 1, the battery tray 60 is located in the right-side opening 12b between the center member 50 and the right-side member 30, as described above, and is a box-shaped structure attached to the center member 50, the second cross member 45, and the rear floor panel 10. The battery tray 60 in this embodiment has a first member 61 and a second member 62, and the first member 61 and the second member 62 constitute a box-shaped structure.

[0041] As shown in Figures 4 and 6, the first member 61 is a component that makes up the front wall portion 61a and the outer wall portion 61b of the battery tray 60. The front wall portion 61a of the first member 61 is a wall portion that extends downward from near the front edge of the right-side opening 12b. An upper flange 61e that protrudes forward is provided at the upper end of the front wall portion of the first member 61 and is joined to the front edge of the right-side opening 12b by spot welding. In addition, a lower flange 61d that protrudes rearward is provided at the lower end of the front wall portion 61a and is joined to the front of the bottom surface portion 62b of the second member 62 by spot welding.

[0042] The rear portion of the outer wall 61b of the first member 61 is preferably joined to the outer portion in the vehicle width direction of the front wall 45a of the second cross member 45. Also, as shown in Figure 6, an outer flange 61c is provided at the upper end of the outer wall 61b, projecting outward in the vehicle width direction and extending in the vehicle longitudinal direction. The outer flange 61c is joined to the lower surface of the rear floor panel 10.

[0043] As shown in Figures 3 and 4, the second member 62 is a component that constitutes the inner wall portion 62a and the bottom portion 62b of the battery tray 60. The inner wall portion 62a of the second member 62 is a wall portion located on the outside in the vehicle width direction of the center member 50, and extends rearward from the inner end of the front wall portion 61a. The outer wall portion 51d of the member body 51 of the center member 50 is joined to the inner wall portion 62a of the second member 62 by spot welding. Alternatively, the outer wall portion 55b of the inner reinforcement 55, the outer wall portion 51d of the member body 51, and the inner wall portion 62a of the battery tray 60 may be joined by spot welding in a three-layer stacked state.

[0044] The bottom portion 62b is the part that extends outward in the vehicle width direction from the lower end of the inner wall portion 62a, and is the part on which the lead battery 1 is mounted. The lower flange 61d of the front wall portion 61a of the first member 61 is joined to the front of the bottom portion 62b by spot welding. The towing hook bracket 65 is joined to the rear of the bottom portion 62b. The towing hook bracket 65 will be described later. As shown in Figure 4, the bottom portion 62b is provided with a through hole 62g. Also, as shown in Figure 6, the outer part of the bottom portion 62b in the vehicle width direction is provided with an outer flange 62d that protrudes downward. The outer flange 62d and the outer wall portion 61c of the first member 61 are joined to the rear floor panel 10.

[0045] Furthermore, in this embodiment, as shown in Figures 1 and 5, there is a widthwise reinforcement 68 that extends in the vehicle width direction to connect the battery tray 60 and the right side member 30. The widthwise reinforcement 68 has a lower surface portion 68d, a front wall portion 68a, and a rear wall portion, and is a highly rigid member formed of a metal material. The lower surface portion 68d of the widthwise reinforcement 68 is inclined upward as it extends outward in the vehicle width direction from the bottom surface portion 62b of the battery tray 60. An outer flange 68f is provided on the outer side of the lower surface portion 68d in the vehicle width direction, and the outer flange 68f is joined to the lower surface portion 31 of the right side member 30 by spot welding. In addition, an inner flange 68e is provided on the inner side of the lower surface portion 68d in the vehicle width direction, and the inner flange 68e is joined to the outer side in the vehicle width direction at the front of the bottom surface portion 62b of the battery tray 60 by spot welding.

[0046] The front wall portion 68a of the widthwise reinforcement 68 extends upward from the front end of the lower surface portion 68d. A front flange 68b projecting forward is provided at the upper end of the front wall portion 68a and is joined to the rear floor panel 10. An outer flange 68c projecting forward is provided on the outer side of the front wall portion 68a in the vehicle width direction and is joined to the inner wall portion 33 of the right side member 30. Furthermore, a vertical flange may be provided on the inner side of the front wall portion 68a in the vehicle width direction, which is joined to the outer wall portion 61b of the battery tray 60.

[0047] The rear wall section, like the front wall section 68a, is joined to the lower surface of the rear floor panel 10, the right side member 30, and the battery tray 60. By providing the widthwise reinforcement 68, the rigidity of the outer wall section 61b of the battery tray 60 is improved. In addition, the rigidity of the rear floor panel 10 near the outer edge of the right-side opening 12b is also improved.

[0048] In this embodiment, the electric motor 2 is positioned in the left-side opening 12a between the left side member 20 and the center member 50, and the lead-acid battery 1 is positioned in the right-side opening 12b between the right side member 30 and the center member 50. That is, the electric motor 2 is positioned in the left-side opening 12a, which is located to the left of the partition 13 and the center member 50. The electric motor 2 may be supported by, for example, three battery mounts. In this example, a reinforcing bracket 27 may be joined to the left-side corner formed by the second cross member 45 and the left side member 20, and the left-side mount bracket may be positioned on the reinforcing bracket 27. In addition, the central mount bracket may be positioned at the front corner formed by the front extension member 52 of the center member 50 and the first cross member 40. Furthermore, the right-side mount bracket may be positioned on the rear extension member 53 or on the straight portion 51a of the member body 51 of the center member 50. The electric motor 2 may be positioned inside the left-side opening 12a via these mount brackets.

[0049] Furthermore, as shown in Figures 5 and 7, the lead-acid battery 1 is located inside a battery tray 60 which is joined to the center member 50 and the second cross member 45. The lead-acid battery 1 is roughly rectangular in shape and has a predetermined weight. The lower part of the lead-acid battery 1 may be fixed to the bottom surface 62b with fastening members such as bolts.

[0050] In this embodiment, in a vehicle where the electric motor 2 is located at the rear of the vehicle, by positioning the heavy lead-acid battery 1 adjacent to the electric motor 2, the rigidity of the surrounding structure of the electric motor 2 is improved, making it possible to reduce vibrations (e.g., noise) generated by the electric motor 2. This suppresses vibrations transmitted into the vehicle cabin due to the operation of the electric motor 2.

[0051] Furthermore, in this embodiment, since the outer portion of the battery tray 60 in the vehicle width direction is joined to the side of the center member 50, the rigidity of the inner wall portion 62a of the battery tray 60 is improved. Since this inner wall portion 62a is the portion facing the electric motor 2, the improved rigidity of the inner wall portion 62a enhances the effect of suppressing vibrations around the electric motor 2.

[0052] Furthermore, in this embodiment, the rear end of the center member 50, i.e., the rear extension member 53, is joined to the second cross member 45 and the battery tray 60. This improves the rigidity of the area where they are joined, thereby enhancing the vibration suppression effect around the electric motor 2.

[0053] Furthermore, in this embodiment, a towing hook bracket 65 to which a towing hook 66 is attached is joined to the bottom surface 62b of the battery tray 60, as described above. The towing hook bracket 65 has a plate-shaped joining surface 65a extending in the vehicle's longitudinal direction, and a bulging portion 65d provided in the middle of the joining surface 65a in the vehicle's width direction, which bulges outwards from the vehicle. The bulging portion 65d extends in the vehicle's longitudinal direction. The towing hook 66 is joined to the side of the bulging portion 65d by arc welding or the like. The joining surface 65a located around the bulging portion 65d is joined to the bottom surface 62b of the battery tray 60 by spot welding. In this example, the bulging portion 65d is positioned to cover the through hole 62g provided in the bottom surface 62b.

[0054] Furthermore, since the towing hook bracket 65 is joined to the bottom surface 62b of the battery tray 60, the strength and rigidity of the bottom surface 62b are improved. The improved rigidity of the bottom surface 62b enhances the effect of suppressing vibrations around the electric motor 2. In addition, when towing heavy objects such as other vehicles, the load acting on the towing hook 66 can be effectively distributed to the vehicle frame via the towing hook bracket 65.

[0055] Furthermore, in this embodiment, as described above, the towing hook bracket 65 is joined to the bottom surface 62b and outer wall 61b (bottom surface and side surface) of the battery tray 60 and to the second cross member 45. This improves the rigidity of the parts to which they are joined, thereby enhancing the vibration suppression effect around the electric motor 2.

[0056] Furthermore, in this embodiment, there is a widthwise reinforcement 68 joined to the battery tray 60 and the right side member 30 (first side member). By providing the widthwise reinforcement 68, the rigidity of the outer wall portion 61b of the battery tray 60 is improved, and the rigidity of the rear floor panel 10 near the outer edge of the right side opening 12b is also improved. This enhances the effect of suppressing vibrations around the electric motor 2.

[0057] Furthermore, in this embodiment, as shown in Figures 7 and 8, the third cross member 29 is positioned on the rear side of the vehicle relative to the first cross member 40 and extends in the vehicle width direction to connect the left and right side members 20 and 30. Also, the third cross member 29 and the front extension member 52 of the center member 50 (the front end of the center member 50) are positioned overlapping in a plan view. In this example, the third cross member 29 is joined to the upper surface of the rear floor panel 10, to the portion located on the front side of the openings 12a and 12b. The third cross member 29 is a highly rigid member formed from a metal material and constitutes the vehicle frame, similar to the center member 50, etc. By providing the third cross member 29, it is possible to increase the rigidity near the front edges of the openings 12a and 12b. This makes it possible to enhance the vibration suppression effect around the electric motor 2. It is also possible to reinforce the first cross member 40 to which the motor mount is attached.

[0058] The description of this embodiment is illustrative for explaining the present invention and does not limit the invention as described in the claims. Furthermore, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications are possible within the technical scope described in the claims.

[0059] For example, in this embodiment, the electric motor 2 is located on the left side and the lead-acid battery 1 is located on the right side, but this is not limited to this configuration. For example, the electric motor 2 may be located on the right side and the lead-acid battery 1 on the left side.

[0060] Furthermore, since the electric motor 2 is located inside the left-side opening 12a, the upper part of the electric motor 2 is positioned above the rear floor panel 10. For this reason, a cover (not shown) may be provided to cover the electric motor 2 from above. Alternatively, a luggage board (not shown) or the like may be placed above the electric motor 2. [Explanation of Symbols]

[0061] 1 Lead-acid battery 2 Electric motor 10. Rear floor panel (floor panel) 11 Concave portion 11a Bottom part 11b Left inclined wall 11c Right inclined wall 12a Left side opening 12b Right side opening 13 Partition section 13a Straight section 13b Slope 20 Left side member (second side member) 21 Bottom part 22 Exterior wall 23 Inner wall section 24 Inner flange 27 Reinforcement bracket 29. Third Crossmember 30 Right side member (1st side member) 31 Bottom part 32 Exterior wall 33 Inner wall section 34 Inner flange 40. First Crossmember 41 Central Members 41a Front wall 41b Front flange 41c Bottom part 42 Outer members 42a Front wall 42b Front flange 42c Bottom part 45. Second Crossmember 45a Front wall 45b Bottom part 45c flange 50 Center Members 51 Member body 51a Straight section 51b Slope 51c Bottom part 51d Exterior wall 51e Inner wall 52 Front extension member 52a Bottom part 52b Inner wall 52c Exterior wall 52d flange 53 Rear extension member 53a Bottom part 53b Side wall part 53c Vertical wall section 53d Top part 55 Inner Reinforcement 55a Inner wall 55b External wall 55c Bottom part 60 Battery Tray 61 First Member 61a Front wall 61b Exterior wall 61c outer flange 61d Lower flange 61e Upper flange 62 Second Member 62a Inner wall 62b Bottom part 62d Outer flange 65 Towing Hook Bracket 65a Joint surface part 65d bulge 66 Towing Hooks 68. Width-direction reinforcement 68a Front wall 68b Front flange 68c outer flange 68d Bottom part 68e Inner flange 68f Outer flange

Claims

1. The floor panel located at the rear of the vehicle, The floor panel is arranged in pairs on both sides in the vehicle width direction, and the first side member and the second side member extend in the vehicle longitudinal direction, A first cross member extending in the vehicle width direction so as to connect the first side member and the second side member, A second cross member is positioned on the rear side of the vehicle of the first cross member and extends in the vehicle width direction so as to connect the first side member and the second side member, In a vehicle rear structure having, The rear floor panel, which is surrounded by the first side member, the second side member, the first cross member, and the second cross member, is provided with an opening. It has a center member that extends in the vehicle longitudinal direction so as to straddle the opening and is joined to the first cross member and the second cross member, A lead-acid battery is placed in the opening between the first side member and the center member. A vehicle rear structure characterized in that an electric motor is arranged in the opening between the second side member and the center member.

2. A battery tray on which the lead-acid battery can be placed is positioned in the opening located between the first side member and the center member. The rear vehicle structure according to claim 1, characterized in that the inner portion of the battery tray in the vehicle width direction is joined to the side portion of the center member.

3. The rear end of the center member is joined to the second cross member and the battery tray, as described in claim 1 or 2.

4. The vehicle rear structure according to claim 2, characterized in that a towing hook bracket to which a towing hook is attached is joined to the lower surface of the battery tray.

5. The vehicle rear structure according to claim 4, characterized in that the towing hook bracket is joined to the lower surface and side surface of the battery tray and to the second cross member.

6. The vehicle rear structure according to claim 2, characterized in that it has a widthwise reinforcement joined to the battery tray and the first side member.

7. The first cross member is positioned on the rear side of the vehicle and has a third cross member that extends in the vehicle width direction so as to connect the first side member and the second side member. The vehicle rear structure according to claim 1, characterized in that the third cross member and the front end of the center member are arranged to overlap in a plan view.

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