Electric vehicle undercarriage

Abstract

To effectively protect electrical components by placing them in the limited space below the floor. [Solution] The lower structure of the electric vehicle has a battery pack located in front of the electric motor and below the floor, and a vehicle frame located on both sides of the battery pack 10. A space R is provided between the front of the battery pack and the floor, and subframes 51 and 52 suspended from the vehicle frames on both sides are arranged in space R. Electrical components 60 are attached to the parts of the subframes 51 and 52 that face space R.

Description

Technical Field

[0001] The present invention relates to the understructure of an electric vehicle.

Background Art

[0002] An electric vehicle has a battery pack disposed on the lower side of a floor panel that constitutes a floor portion of the vehicle, as disclosed in, for example, Patent Document 1. Also, in this example, a drive electric motor is disposed on the front side of the vehicle of the battery pack.

[0003] The battery pack is required to have a larger capacity in order to extend the cruising range of the electric vehicle. As a result, the battery pack tends to be enlarged. As the battery pack is enlarged, the proportion of the space on the lower side of the floor portion occupied by the battery pack increases. Also, an electric vehicle having a battery pack and an electric motor etc. needs to mount a plurality of electrical components. Therefore, for example, on the lower side of the floor portion, it is necessary to secure a space for disposing the battery pack and to secure a space for disposing the electrical components.

[0004] The vehicle in the above example has a so-called cab-over structure in which front seats (driver's seat and passenger seat) are disposed on the upper side of the electric motor. In this example, a space portion is provided between the battery pack and the electric motor in the vehicle front-rear direction to secure a space for disposing a plurality of electrical components. Note that the front seats are disposed on the upper side of the space portion where the electrical components are disposed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the structure of the example above, it may become difficult to position electrical components when installing a battery pack with large dimensions in the front-to-rear direction of the vehicle. Also, in the structure of the example above, the lower side of the electrical components is open, so when the vehicle is in motion, the electrical components may be damaged by, for example, muddy water adhering to them or small stones hitting them.

[0007] Furthermore, in vehicles with a design where the space in front of the passenger compartment is narrow, the electric motor may be placed behind the battery pack. In such electric vehicles, the battery pack needs to be placed further forward. As a result, it may be difficult to provide space for electrical components. Therefore, in the structure of the example above, there was room for improvement in order to secure space for electrical components to be placed below the floor while suppressing damage to those electrical components.

[0008] The present invention was made to solve the above problems, and its objective is to provide an understructure for an electric vehicle that can arrange electrical components in a limited space below the floor of the electric vehicle and effectively protect said electrical components. [Means for solving the problem]

[0009] To achieve the above objective, the electric vehicle substructure according to the present invention comprises a battery pack disposed below the floor portion of the vehicle, an electric motor disposed on the rear side of the battery pack, and a vehicle frame member disposed on both outer sides in the vehicle width direction of the battery pack below the floor portion, with each of the vehicle frame members on both sides in the vehicle width direction extending in the vehicle longitudinal direction. The electric vehicle substructure has a subframe that extends in the vehicle width direction and is suspended from the vehicle frame members on both sides in the vehicle width direction, a space is provided between the front of the battery pack and the floor portion, the subframe is disposed above the vehicle in front of the battery pack, and electrical components are attached to the portion of the subframe facing the space. [Effects of the Invention]

[0010] According to the present invention, electrical components can be placed in the limited space below the floor of an electric vehicle and these electrical components can be effectively protected. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view of the lower structure of the electric vehicle according to the present invention, as seen from above the floor portion of the electric vehicle. [Figure 2] Figure 1 is an enlarged perspective view of the battery pack and other components as seen from the underside of the vehicle. [Figure 3] Figure 2 is a schematic perspective view showing the battery side suspension bracket removed. [Figure 4] Figure 1 is a bottom view of the undercarriage of the electric vehicle, as seen from below. [Figure 5] This is a plan view of the subframe and space shown in Figure 1, seen from above. [Figure 6] This is a schematic end view taken along the line AA in Figure 1. [Figure 7] This is a schematic end view taken along the arrow BB in Figure 4. [Figure 8] Figure 5 is a perspective view of the subframe and subframe brackets, etc., as seen from the underside of the vehicle. [Figure 9] Figure 5 is a perspective view of the subframe and other components as seen from inside the vehicle. [Figure 10] Figure 5 is a schematic end view taken along the CC arrow. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the understructure of the electric vehicle according to the present invention will be described with reference to the drawings (Figures 1 to 10). In the figures, the direction of arrow Fr indicates the front in the longitudinal direction of the vehicle. In the description of the embodiments, "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 when an occupant looks forward of the vehicle. Arrow U indicates the upward direction in the vertical direction of the vehicle.

[0013] As shown in Figures 1 and 2, the understructure of the electric vehicle in this embodiment includes a battery pack 10, a vehicle body frame, subframes 41 and 46, and battery mount members 30A and 30B. In this embodiment, a space R is provided between the front of the battery pack 10 and the floor in the vertical direction of the vehicle. Subframes 41 and 46, which extend in the vehicle width direction and are suspended from the vehicle body frames on both sides in the vehicle width direction, are arranged in space R. Electrical components 60 are attached to the portion of the subframe facing space R. The members constituting the understructure of this embodiment will be described below.

[0014] As shown in Figures 1 to 4 and Figure 6, the battery pack 10 is located on the front side of the vehicle, below the floor of the vehicle, and on the front side of the electric motor 61 located at the rear of the vehicle. In this example, the battery pack 10 is a so-called heavy object located below the floor panel 17 that constitutes the floor of the vehicle. A detailed explanation of the structure of the battery pack 10 will be omitted, but the external shape of the battery pack 10 is approximately a rectangular parallelepiped, and it has a top surface 11, left and right side walls 12, a bottom surface 13, a front wall 14, and a rear wall 15 (Figures 3 and 4). The battery pack 10 is suspended from a vehicle body component such as a side member 20 via, for example, battery mount members 30A, 30B, a battery side suspension bracket 35, and a battery front suspension bracket 39. The configuration to which the battery pack 10 is attached will be explained later.

[0015] As shown in FIG. 6, the electric vehicle of this embodiment has a so-called cab-over structure in which the front seat 63 is disposed above the electric motor 61. Similar to this vehicle, a space R is provided below the cushion portion 63a of the front seat 63. In the electric vehicle of this embodiment, the space R is provided above the upper surface portion 11 of the battery pack 10 and below the floor portion, and electrical components 60 are arranged in the space R. The arrangement of the electrical components 60 will be described later.

[0016] In this embodiment, the electric motor 61 driven by the battery pack 10 is arranged at the rear of the vehicle. In this example, the drive motor 61 may be arranged behind the battery pack 10, for example, below the upper floor panel 18. That is, the electric vehicle of this embodiment is a so-called rear-wheel drive type in which the rear wheels are driven by the electric motor 61 at the rear of the vehicle. In addition, a cushion portion of a rear seat (not shown) may be installed on the upper floor panel 18.

[0017] The vehicle body frame of this embodiment is a member that is arranged outside the battery pack 10 in the vehicle width direction below the floor portion and extends in the vehicle front-rear direction. The vehicle body frame is a member with high rigidity formed of a metal material. The vehicle body frame of this embodiment is a side member 20.

[0018] The side member 20 is a member with high rigidity that constitutes the vehicle body skeleton and is formed of a metal material. As shown in FIG. 3, the side members 20 are arranged in a pair on both outer sides in the vehicle width direction at the lower part of the vehicle and extend in the vehicle front-rear direction. In this example, the side members 20 are arranged along the side wall portions 12 of the battery pack 10 with a space therebetween outside the vehicle width direction of the left and right side wall portions 12 of the battery pack 10. In the vehicle front-rear direction, the front portion of the side member 20 is arranged on the front side of the vehicle with respect to the front wall portion 14 of the battery pack 10, and the rear portion of the side member 20 is arranged on the rear side of the vehicle with respect to the rear wall portion 15 of the battery pack 10.

[0019] Furthermore, the side member 20 located on the front side of the battery pack 10, specifically the front portion of the side member 20, extends inward in the vehicle width direction as it approaches the front of the vehicle. Subframe brackets 41 and 46 are attached to the front portion of the side member 10, as shown in Figure 5. The subframe brackets 41 and 46 will be described later.

[0020] Furthermore, a side brace 25 is joined to the front of the side member 20, as shown in Figure 4. The side brace 25, like the side member 20, is a highly rigid member that constitutes the vehicle body frame and is made of metal. The upper part of the side brace 25 on the inner side in the vehicle width direction is joined to the lower part of the front of the side member 20, and the outer part of the side brace 25 in the vehicle width direction is joined to, for example, the side inner panel 26 that constitutes the side of the vehicle body. In addition, a battery front suspension bracket 39 is attached to the lower part of the side brace 25. The battery front suspension bracket 39 will be described later.

[0021] As shown in Figure 7, the front portion of the side member 20 has a U-shaped cross-section that opens upwards on the vehicle. Specifically, the side member 20 has an inner wall portion 21, an outer wall portion 22, and a bottom portion 23, the bottom portion 23 having a substantially rectangular horizontal surface extending in the vehicle's longitudinal direction. The inner wall portion 21 protrudes upward from the inner end of the bottom portion 23 in the vehicle width direction and extends in the vehicle's longitudinal direction. An inner flange portion 21a protruding inward in the vehicle width direction is provided at the upper end of the inner wall portion 21. The outer wall portion 22 protrudes upward from the outer end of the bottom portion 23 in the vehicle width direction and extends in the vehicle's longitudinal direction. An outer flange portion 22a protruding outward in the vehicle width direction is provided at the upper end of the outer wall portion 22. The inner flange portion 21a and the outer flange portion 22a are joined to the cover member 24, for example, by spot welding. The protruding portion 24a of the lid member 24 is joined to the first subframe bracket 41, which will be described later, via the inner flange portion 21a (Figure 9).

[0022] Next, the battery mount members 30A and 30B will be described. As shown in Figures 2 and 3, in this embodiment, two battery mount members (front battery mount member 30A and rear battery mount member 30B) are arranged along the bottom surface 23 of the side member 20, spaced apart from each other in the vehicle's longitudinal direction. The front battery mount member 30A and the rear battery mount member 30B are made of metal and have high rigidity. The front battery mount member 30A and the rear battery mount member 30B extend along the side wall 12 of the battery pack 10 in the vehicle's longitudinal direction and are joined to the lower part of the side member 20 by spot welding. A side body outer panel 28 is arranged on the outer side in the vehicle width direction of the side member 20, the front battery mount member 30A, and the rear battery mount member 30B.

[0023] The front battery mount member 30A is positioned below the side member 20. Similarly, the rear battery mount member 30B is positioned below the side member 20. By joining the front battery mount member 30A and the rear battery mount member 30B to the lower part of the side member 20, it is possible to construct a structure with high rigidity.

[0024] Furthermore, by arranging the side member 20 and the battery mount members 30A and 30B vertically, the side member 20 and the battery mount members 30A and 30B have a predetermined vertical length (height) and act as a protective wall extending in the front-rear direction of the vehicle, protecting the outside of the battery pack 10 in the vehicle width direction.

[0025] Here, the structures of the battery mount members 30A and 30B will be described. In this embodiment, the structure of the front battery mount member 30A will be described in detail as an example. As shown in Figure 7, the front battery mount member 30A has an inner wall portion 31, an outer wall portion 32, and a bottom surface portion 33, and, like the side member 20, has a U-shaped cross-section.

[0026] The upper part of the inner wall portion 31 of the front battery mount member 30A is joined to the inner wall portion 21 of the side member 20 by spot welding. Similarly, the upper part of the outer wall portion 32 of the front battery mount member 30A is joined to the outer wall portion 22 of the side member 20 by spot welding. As a result, the front battery mount member 30A and the bottom portion 23 of the side member 20 form a closed cross-sectional structure in cross-section. This improves rigidity and allows the battery pack 10 to be suspended stably.

[0027] As shown in Figure 2, closing portions 34 are provided at the front and rear ends of the front battery mount member 30A. The closing portion 34 is plate-shaped and is joined to the inner wall portion 31, the outer wall portion 32, and the bottom surface portion 33 of the battery mount member 30. Furthermore, a flange is provided at the upper end of the closing portion 34, and this flange is joined to the bottom surface portion 23 of the side member 20. As a result, a closed space is formed inside the rear battery mount member 30B, and a closed cross-sectional structure is formed in the flat cross-section of the front battery mount member 30A, making it possible to ensure high rigidity for the front battery mount member 30A.

[0028] In this embodiment, the cross-sectional structure of the front battery mount member 30A has been described in detail as described above, but the cross-sectional structure of the rear battery mount member 30B is configured in the same way as the front battery mount member 30A.

[0029] Here, we will describe the configuration in which the battery pack 10 is suspended from the vehicle body. The side wall portion 12 of the battery pack 10 is suspended from the vehicle body, such as the side member 20, via the battery mount members 30A, 30B and the battery side suspension bracket 35. The front wall portion 14 of the battery pack 10 is suspended from the side brace 25 via the battery front suspension bracket 39.

[0030] The battery side suspension bracket 35 is suspended from the bottom surface 33 of the battery mount members 30A and 30B via a connecting member 38a and is positioned below the bottom surface 33 of the battery mount members 30A and 30B. In this example, as shown in Figure 4, the battery side suspension bracket 35 extends along the side wall 12 of the battery pack 10 in the longitudinal direction of the vehicle.

[0031] The front end of the battery side suspension bracket 35 is positioned slightly rearward from the front end of the front battery mount member 30A. Alternatively, the front ends of the battery side suspension bracket 35 and the front end of the front battery mount member 30A may be aligned in the vehicle's longitudinal direction. Similarly, the rear end of the battery side suspension bracket 35 is positioned slightly forward from the rear end of the rear battery mount member 30B. Alternatively, the rear ends of the battery side suspension bracket 35 and the rear end of the rear battery mount member 30B may be aligned in the vehicle's longitudinal direction.

[0032] As shown in Figures 2 to 4, the battery side suspension bracket 35 of this embodiment is a substantially rectangular parallelepiped member extending in the longitudinal direction of the vehicle, with a notch provided in a part of its side, and is arranged along the side wall portion 12 of the battery pack 10. As shown in Figure 7, the battery side suspension bracket 35 has an upper member 36 and a lower member 37.

[0033] As shown in Figure 7, the upper member 36 has an upper surface portion 36a, an inner wall portion 36b, and an outer flange portion 36c. The upper surface portion 36a is positioned below the lower surface of the bottom surface portion 33 of the battery mount member 30, with a gap between them. The outer flange portion 36c is the portion that protrudes upward from the outer end of the upper surface portion 36a in the vehicle width direction and extends in the vehicle's longitudinal direction. The inner wall portion 36b is a wall portion that extends downward from the inner end of the upper surface portion 36a in the vehicle width direction, and is positioned below the side wall portion 12 of the battery pack 10, with a gap between it and the side wall portion 12 in the vehicle width direction.

[0034] As shown in Figure 7, the lower member 37 has a bottom surface portion 37a, an outer wall portion 37b, and an inner flange portion 37c. The bottom surface portion 37a is positioned below the upper surface portion 36a of the upper member 36, with a gap between them. The outer wall portion 37b is a wall portion that extends upward from the outer end of the bottom surface portion 37a in the vehicle width direction. Furthermore, in the vehicle width direction, the outer wall portion 37b is positioned slightly inward in the vehicle width direction from the outer wall portion 32 of the battery mount member 30 and below the bottom surface portion 33 of the battery mount member 30.

[0035] Furthermore, the upper part of the outer wall portion 37b of the lower member 37 protrudes above the upper surface portion 36a and is joined to the outer flange portion 36c by spot welding. The inner flange portion 37c is the part that protrudes downward from the inner end in the vehicle width direction of the bottom surface portion 37a and extends in the vehicle's longitudinal direction. The lower part of the inner wall portion 36b of the upper member 36 is joined to the inner flange portion 37c by spot welding.

[0036] Furthermore, as shown in Figure 7, the battery side suspension bracket 35 is provided with a plurality of outer connecting portions 35a and a plurality of inner connecting portions 35b. The plurality of outer connecting portions 35a are located outside the center of the battery side suspension bracket 35 in the vehicle width direction and are spaced apart from each other along the longitudinal direction (vehicle front-rear direction) of the battery side suspension bracket 35. The outer connecting portions 35a are connected to the bottom surface portion 33 of the battery mount member 30 via connecting members 38a.

[0037] Multiple inner connecting portions 35b are arranged inward from the vehicle width center of the battery side suspension bracket 35, along the longitudinal direction (vehicle front-rear direction) of the battery side suspension bracket 35, and spaced apart from each other. The inner connecting portions 35b are preferably arranged inside the outer connecting portions 35a. The inner connecting portions 35b are the parts that connect to the protruding portion 12a that protrudes outward in the vehicle width direction from the side wall portion 12 of the battery pack 10, and the protruding portion 12a and the inner connecting portion 35b are connected by a connecting member 38b.

[0038] As described above, the battery pack 10 is suspended from the battery side suspension bracket 35 via a connecting member 38b, and the battery side suspension bracket 35 is connected to the battery mount member 30 via a connecting member 38a.

[0039] Next, the battery front suspension bracket 39 will be described. As shown in Figure 5, the battery front suspension bracket 39 has a main body portion 39a and a battery connection portion 39b. The main body portion 39a is a metal member that extends downward from the lower surface of the side brace 25 to the lower surface of the vehicle. The main body portion 39a of the battery front suspension bracket 39 is suspended from the lower surface of the side brace 25 via a connecting member (not shown). The connection between the side brace 25 and the battery front suspension bracket 39 is the same as the connection between the side member 20 and the battery side suspension bracket 35.

[0040] The battery connection portion 39b is located on the inner side of the main body portion 39a in the vehicle width direction and is a roughly rectangular parallelepiped-shaped portion that extends in the vehicle's longitudinal direction. As shown in Figure 4, a front projection portion 14a that protrudes forward from the front wall portion 14 of the battery pack 10 is connected to the battery connection portion 39b. As a result, the front wall portion 14 of the battery pack 10 is suspended from the vehicle body via the battery front suspension bracket 39.

[0041] Next, the subframe will be described. As shown in Figure 5, the subframe of this embodiment has a first subframe 51 and a second subframe 52. The first subframe 51 and the second subframe 52 are metal members that extend in the vehicle width direction and have, for example, a substantially rectangular cross-sectional shape that extends in the vehicle longitudinal direction. In this embodiment, the first subframe 51 is positioned at a distance from the second subframe 52 on the vehicle front side.

[0042] As shown in Figure 5, the first subframe 51 is suspended from the side member 20 via the first subframe bracket 41, and the second subframe 52 is suspended from the side member 20 via the second subframe bracket 46. The first subframe 51 and the second subframe 52 are arranged in the space R as described above, and electrical components 60 are attached to the upper surfaces of the first subframe 51 and the second subframe 52, as shown in Figure 6.

[0043] In this embodiment, the electric vehicle is rear-wheel drive, and therefore the electric motor 61 is located below the floor of the cargo area at the rear of the vehicle. As a result, it is difficult to place the battery pack 10 in the area where the electric motor 61 is located, so the battery pack 10 is placed towards the front of the vehicle. In this embodiment, a space R is provided above the front of the upper surface 11 of the battery pack 10, and the electrical components 60 are attached to this space R via the first subframe 51 and the second subframe 52. This makes it possible to prevent mud and water from getting on the electrical components 60 and to prevent them from being hit by flying stones while the vehicle is in motion. As a result, failure of the electrical components 60 can be prevented.

[0044] Furthermore, by housing the electrical components 60 in the space R using the first subframe 51 and the second subframe 52, it is possible to prevent contact between the upper surface 11 of the battery pack 10 and the electrical components 60. As a result, it is possible to reduce the occurrence of failures of the battery pack 10 and the electrical components 60.

[0045] In this example, two rear stays 53 are arranged on the second subframe 52, spaced apart from each other in the vehicle width direction. The rear stays 53 are joined to the second subframe 52 and extend from the second subframe 52 toward the rear of the vehicle. In this example, the rear end of the rear stay 53 is a free end. It is also preferable to arrange an intermediate stay 55 so as to connect the first subframe 51 and the second subframe 52. The intermediate stay 55 extends in the vehicle longitudinal direction, with the front part of the intermediate stay 55 joined to the first subframe 51 and the rear part of the intermediate stay 55 joined to the second subframe 52. By providing the rear stay 53 and the intermediate stay 55, the mounting state of the electrical components 60 can be made more stable. As a result, the battery pack 10 and the electrical components 60 can maintain a stable state with space between them.

[0046] In this embodiment, the front battery mount member 30A is attached to the side member 20, and the battery pack 10 has a protruding portion 12 (suspension portion) that is suspended from the front battery mount member 30A.

[0047] This allows the battery pack 10 to be positioned on the lower side of the vehicle relative to the side member 20. As a result, it becomes possible to secure the volume of the space R. Consequently, larger electrical components 60 can be placed in the space R.

[0048] Furthermore, in this embodiment, the first subframe 51 and the second subframe 52 are suspended from the inner wall portion 21 of the side member 20. Also, in a view in the vehicle width direction, at least a portion of the first subframe 51 and at least a portion of the second subframe 52 are arranged to overlap the side member 20. For example, as shown in Figure 10, the second subframe 52 is arranged below the side member 20, side by side in the vehicle width direction, and is joined to the inner wall surface 21 of the side member 20. Moreover, in this embodiment, the lower ends of the first subframe 51 and the second subframe 52 are positioned above the lower end of the side member 20.

[0049] Since the first subframe 51 and the second subframe 52, which support the electrical components 60, are positioned between the side members 20 on both sides in the vehicle width direction, when an impact load such as a side collision acts on the side of the vehicle body, the side members 20 can absorb the impact load, and the impact load acting on the first subframe 51 and the second subframe 52 can be suppressed. Therefore, deformation of the first subframe 51 and the second subframe 52 due to impact loads can be suppressed, making it possible to reduce damage to the electrical components 60 and the battery pack 10.

[0050] In this embodiment, the first subframe 51 and the second subframe 52 extend linearly in the vehicle width direction, but this is not limited to this configuration. For example, the intermediate portion of the first subframe 51, etc., in the vehicle width direction may be curved so as to be convex upwards towards the vehicle. In this case, even if a load is applied to the first subframe 51, etc., from the outside in the vehicle width direction, the intermediate portion of the first subframe 51, etc., will deform upwards, thereby suppressing contact between the battery pack 10 and the first subframe 51, etc. As a result, the battery pack 10 can be effectively protected against impact loads.

[0051] Furthermore, in this embodiment, as shown in Figure 10, a gap G is formed between the first subframe 51 and the second subframe 52 and the side member 20 in the vehicle width direction, and the first subframe 51 and the second subframe 52 are suspended from the side member 20 in a state that allows them to slide in the vehicle width direction.

[0052] In this embodiment, as shown in Figure 5, the first subframe 51 is suspended from the inner wall portion 21 of the side member 20 via the first subframe bracket 41. Therefore, the outer end of the first subframe 51 in the vehicle width direction is positioned with respect to the inner wall portion 21 while maintaining a gap G. Similarly, the second subframe is suspended from the inner wall portion 21 of the side member 20 via the second subframe bracket 46. Therefore, the outer end of the second subframe in the vehicle width direction is positioned with respect to the inner wall portion 21 while maintaining a gap G.

[0053] In the above configuration, even if the side member 20 deforms toward the interior of the vehicle due to an impact load from the outside in the vehicle width direction, the gap G prevents the impact load from being directly transmitted to the first subframe 51 and the second subframe 52. Furthermore, since the first subframe 51 and the second subframe 52 are slidable, they can slide in the vehicle width direction by the length of the gap G in the vehicle width direction, thereby absorbing the impact load.

[0054] In this embodiment, one of the brackets 41, 46 and the subframes 51, 52 is provided with elongated holes 51c, 52c extending in the vehicle width direction, and the other is provided with a shaft portion 45 that penetrates the elongated holes 51c, 52c, and the subframes 51, 52 and the brackets 41, 46 are connected in such a way that the shaft portion 45 can move within the elongated holes 51c, 52c.

[0055] In this embodiment, as shown in Figures 5 and 9, the first subframe 51 and the second subframe 52 are provided with elongated holes 51c and 52c, and the first subframe bracket 41 and the second subframe bracket 46 are provided with shaft portions 45. The elongated hole 51c is formed in the upper surface portion 51a of the first subframe 51 and penetrates in the vertical direction of the vehicle. In addition, a notch 51d is provided at the outer end in the vehicle width direction of the lower surface portion 51b corresponding to the elongated hole 51c. By providing the notch 51d, a working space is secured for attaching the first subframe 51 to the first subframe bracket 41. The elongated hole 52c of the second subframe 52 is provided in the upper surface portion and the lower surface portion 52a of the second subframe 52, similar to the elongated hole 51c of the first subframe 51.

[0056] For example, the first subframe bracket 41, positioned on the right side in the vehicle width direction, has a substantially rectangular lower surface portion 42, a front wall portion 43, and a rear wall portion 44, as shown in Figures 5, 8, and 9. The lower surface portion 42 faces downwards towards the vehicle and has, for example, a circular through-hole formed therein. The front wall portion 43 extends upwards towards the vehicle from the front end of the lower surface portion 42. The rear wall portion 44 extends upwards towards the vehicle from the rear end of the lower surface portion 42.

[0057] A lower flange 42a is provided on the outer side in the vehicle width direction of the lower surface portion 42, projecting downwards from the vehicle. The lower flange 42a is joined to the inner wall portion 21 of the side member 20 by spot welding. A front outer flange 43a is provided on the outer side in the vehicle width direction of the front wall portion 43, projecting forward from the vehicle, and a front upper flange 43b is provided at the upper end of the front wall portion 43, projecting forward from the vehicle. The front outer flange 43a is joined to the inner wall portion 21 of the side member 20, and the front upper flange 43b is joined to the inner flange portion 21a of the side member 20.

[0058] An outer rear flange 44a is provided on the outer side of the rear wall portion 44 in the vehicle width direction, projecting toward the rear of the vehicle, and an upper rear flange 44b is provided at the upper end of the rear wall portion 44, projecting toward the rear of the vehicle. The outer rear flange 44a is joined to the inner wall portion 21 of the side member 20, and the upper rear flange 44b is joined to the inner flange portion 21a of the side member 20.

[0059] The upper surface of the first subframe 51 is suspended, for example, in contact with the lower surface 42 of the first subframe bracket 41. A connecting member 45 (shaft portion) is preferably fixed to the first subframe bracket 41. For example, a substantially cylindrical connecting member 45 extending in the vertical direction of the vehicle is preferably fixed to the lower surface 42 of the first subframe bracket 41, with the connecting member 45 passing through a through hole 42b provided in the first subframe bracket 41.

[0060] As shown in Figures 5 and 9, it is preferable that a larger diameter portion 42a bulging radially outward is provided at the lower part of the through portion 45b of the connecting member 45. The through portion 45b of the connecting member 45 passes through the elongated hole 51c of the first subframe 51, and the larger diameter portion 45a is positioned below the upper surface portion 51a of the first subframe 51. For example, the connecting member 45 is a bolt, with the bolt head positioned on the lower surface portion 42 and a nut (larger diameter portion 45a) positioned on the lower side of the upper surface portion 51a, thereby suspending the first subframe 51 from the first subframe bracket 41. Here, the first subframe 51 is suspended in a state that allows parallel movement relative to the first subframe bracket 41 along the longitudinal direction (vehicle width direction) of the elongated hole 51c.

[0061] By configuring it as described above, even if the side member 20 receives an impact load from the outside in the vehicle width direction and deforms inward, the first subframe 51 can move in parallel by the length of the elongated hole 51c in the vehicle width direction, thereby suppressing the direct transmission of the impact load.

[0062] The second subframe 52 and the second subframe bracket 46 have the same structure as the first subframe 51 and the second subframe bracket 46, and the same effects can be obtained. The second subframe bracket 46 in this embodiment has a lower surface portion 47, a front wall portion 48, and a rear wall portion 49. A through hole is provided in the lower surface portion 47. The through hole is arranged to communicate with an elongated hole 52c provided in the upper surface portion 52a of the second subframe 52, and a connecting member 45 is placed through the through hole and the elongated hole 52c, and the second subframe 52 is fixed to the second subframe bracket 46.

[0063] The front wall portion 48 extends upward from the front end of the lower surface portion 47. In this example, the inner end of the front wall portion 48 in the vehicle width direction is inclined outward in the vehicle width direction as it extends upward from the vehicle. The outer end of the front wall portion 48 in the vehicle width direction is provided with a front flange 48a that protrudes forward from the vehicle. The front flange 48a is joined to the inner wall portion 21 of the side member 20 by spot welding. The rear wall portion 49 extends upward from the rear end of the lower surface portion 47, and similar to the front wall portion 48, the inner end of the rear wall portion 49 in the vehicle width direction is inclined outward in the vehicle width direction as it extends upward from the vehicle. The outer end of the rear wall portion 49 in the vehicle width direction is provided with a rear flange 49a that protrudes rearward from the vehicle, and the rear flange 49a is joined to the inner wall portion 21 of the side member 20 by spot welding.

[0064] Since the direct transmission of impact loads to the first subframe 51 and the second subframe 52 is suppressed, deformation of the first subframe 51 and the second subframe 52 is suppressed. As a result, the electrical components 60 and the battery pack 10 can be effectively protected from impact loads.

[0065] 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.

[0066] For example, in this embodiment, the first subframe 51 and the second subframe 52 are provided with elongated holes 51c, and the first subframe bracket 41 and the second subframe bracket 46 are provided with shaft portions, but this is not limited to this. For example, the first subframe bracket 41 and the second subframe bracket 46 may be provided with elongated holes, and the first subframe 51 and the second subframe 52 may be provided with shaft portions.

[0067] Alternatively, the first subframe 51 and the second subframe 52 may be positioned above the positions in this embodiment, and the electrical components 60 may be attached to the lower parts of the first subframe 51 and the second subframe 52.

[0068] Furthermore, although the vehicle body frame is described as a side member 20 in this embodiment, it is not limited to this. For example, the vehicle body frame may be a side sill. [Explanation of Symbols]

[0069] 10 Battery Packs 11 Top part 12 Side wall section 12a Protrusion 13 Bottom part 14 Front wall 14a Front protrusion 15 Rear wall 17 Floor Panel 18 Upper floor panel 20 Side Members 21 Inner wall section 21a Inner flange portion 22 Exterior wall 22a Outer flange portion 23 Bottom part 24 Lid member 25 Side braces 26 Side Inner Panel 28 Side Body Outer Panel 30A Front Battery Mount Member 30B Rear battery mount member 31 Inner wall section 32 Exterior wall 33 Bottom part 34 Closing part 35 Battery side suspension bracket 36 Upper member 36a Top part 36b Inner wall 36c Outer flange section 37 Lower part 37a Bottom part 37b Exterior wall 37c Inner flange section 39 Battery front suspension bracket 39a Main body 39b Battery connection 41. First subframe bracket 42 Bottom part 42a Lower flange 42b Through hole 43 Front wall 43a Front outer flange 43b Front upper flange 44 Rear wall 44a Rear outer flange 44b Rear upper flange 45 Connecting member 45a Large diameter section 45b Penetration 46. ​​Second subframe bracket 47 Bottom part 47a Lower flange 48 Front wall 48a Front flange 49 Rear wall 49a Rear flange 51 First Subframe 51a Top part 51b Bottom part 51c long hole 51d Notch 52 Second Subframe 52a Top part 52b Bottom part 52c long hole 52d Notch 53 Rear stay 55 Intermediate stay 60 Electrical Components 61 Electric motor 63 Front Seats 63 Cushion part R space part G gap

Claims

1. The electric motor is located at the rear of the vehicle, and the battery pack is located on the front side of the vehicle, below the floor of the vehicle. An electric vehicle understructure having a vehicle frame that is positioned below the floor portion, on both outer sides in the vehicle width direction of the battery pack, and extending in the vehicle's longitudinal direction, In the vertical direction of the vehicle, a space is provided between the front of the battery pack and the floor portion. In the aforementioned space, a subframe is arranged that extends in the vehicle width direction and is suspended from the vehicle body frame on both sides in the vehicle width direction. The lower structure of an electric vehicle is characterized in that electrical components are attached to the portion of the subframe that faces the space.

2. A battery mount member for suspending the battery pack is attached to the vehicle frame. The lower structure of the electric vehicle according to claim 1, characterized in that the battery pack has a suspension portion that is suspended from the battery mount member.

3. The subframe is suspended from the inner side of the vehicle body frame in the vehicle width direction, and is positioned such that at least a portion of the subframe overlaps the vehicle body frame when viewed in the vehicle width direction. The lower end of the subframe is positioned above the lower end of the vehicle body frame, characterized in that the lower structure of the electric vehicle according to claim 1 or claim 2.

4. In the vehicle width direction, a gap is formed between the subframe and the vehicle body frame. The lower structure of an electric vehicle according to claim 3, characterized in that the subframe is suspended from the vehicle body frame in a manner that allows it to slide in the vehicle width direction.

5. The subframe is suspended from the vehicle body frame via brackets, An elongated hole extending in the vehicle width direction is provided in one of the mounting bracket and the subframe, and a shaft portion passing through the elongated hole is provided in the other. The lower structure of an electric vehicle according to claim 3, characterized in that the shaft portion is connected to the bracket in such a way that it can move within the elongated hole in the vehicle width direction.

Images