Vehicle body structure

Abstract

A vehicle body structure is capable of efficiently mounting peripheral members of a lower portion of a vehicle body to the vehicle body and also capable of obtaining high mounting rigidity. The vehicle body structure (A) is provided with a battery protection frame (33) having a hollow cross section. A partition wall portion (33e) is provided inside the battery protection frame (33). A plurality of closed cross section portions (D1 to D4) are formed by the wall portions (33a to 33d) and the partition wall portion (33e) on the battery protection frame (33). Different peripheral members (34, 35, 40) are respectively mounted on the plurality of closed cross section portions (D1 to D4).

Description

Technical Field

[0001] This disclosure relates to, for example, the body structure of an electric vehicle. Background Technology

[0002] For example, Patent Document 1 discloses a vehicle in which a battery is mounted below a floor panel. In Patent Document 1, the vehicle includes an annular bottom frame of the vehicle body formed along the outer periphery of the floor panel, and an annular battery mounting frame fixed to the bottom frame of the vehicle body. The battery is disposed inside the battery mounting frame. An upper mounting wall and a lower mounting wall are provided on the battery mounting frame in the form of outwardly protruding flanges. These upper and lower mounting walls are disposed on the lower surface of the bottom frame of the vehicle body and fastened with bolts.

[0003] Existing technical documents Patent documents Patent Document 1: International Publication No. 2020 / 105283 Summary of the Invention

[0004] The technical problem that the invention aims to solve However, the lower part of the vehicle body houses components that form the suspension system. In addition, electric vehicles contain numerous peripheral components, such as battery-related components. If these were to be installed separately on the vehicle body, dedicated brackets would be required, leading to problems with space efficiency and manufacturing efficiency. In particular, increasing the mounting rigidity of these peripheral components necessitates larger brackets, further deteriorating space efficiency, and the increased number of brackets further worsens manufacturing efficiency.

[0005] This application is made in view of the above circumstances, and its purpose is to enable the peripheral components of the lower part of the vehicle body to be efficiently installed on the vehicle body and to achieve high installation rigidity.

[0006] Technical solutions to solve technical problems To achieve the aforementioned objectives, the premise of the first aspect of this disclosure may be a vehicle body structure, specifically an electric vehicle body structure, wherein the electric vehicle has a drive motor and a battery supplying power to the drive motor is disposed below the floor panel. The vehicle body structure has a hollow battery protection frame, which is fixed to the vehicle body to protect the battery. Inside the battery protection frame, there are partitions that divide the internal space of the battery protection frame. On the battery protection frame, multiple closed cross-sections are formed by the wall portion constituting the outer surface of the battery protection frame and the partitions, and different peripheral components are respectively installed on each of the multiple closed cross-sections.

[0007] Based on this configuration, the battery protection frame fixed to the vehicle body has multiple closed cross-sections, thus creating a highly rigid and lightweight battery protection frame. Since these multiple closed cross-sections are located at different parts of the battery protection frame, it is possible to install, for example, the cover and base plate of the battery cell on different closed cross-sections. Furthermore, it is possible to install suspension brackets for connecting suspension devices on closed cross-sections different from those on the cover and base plate where the battery cell is mounted. Therefore, even without providing dedicated brackets for each peripheral component, the high rigidity of the battery protection frame can improve the mounting rigidity of peripheral components, and also improves space efficiency and manufacturing efficiency.

[0008] In the second aspect of this disclosure, in one of the plurality of closed cross-sections, a plurality of mounting portions for the peripheral components are provided.

[0009] According to this configuration, peripheral components to be installed on the closed section can be installed through multiple mounting parts, thus further improving the mounting rigidity of the peripheral components.

[0010] The battery protection frame of the third embodiment of this disclosure may also have a first closed section, a second closed section, and a third closed section. A vehicle body component that forms part of the vehicle body can be mounted on the first closed section, and a peripheral component that forms part of a component supporting the suspension system can be mounted on the second closed section. Furthermore, a peripheral component that forms part of a battery cell containing the battery can be mounted on the third closed section.

[0011] According to this configuration, the battery protection frame can be fixed to the vehicle body by installing a vehicle body component on the first closed section. Furthermore, by installing peripheral components that constitute part of the component supporting the suspension device and peripheral components that constitute part of the battery cell onto a common battery protection frame, the space efficiency under the floor panel can be improved, thereby increasing the battery capacity.

[0012] In the fourth embodiment of this disclosure, the battery protection frame may further extend in the vehicle width direction and be disposed below the vehicle body component. The first closed section portion may be formed on the upper part of the battery protection frame.

[0013] That is, the upper part of the battery protection bracket is close to the vehicle body component. Since this part that is close to the vehicle body component can be fixed to the vehicle body component, the battery protection bracket can be firmly fixed to the vehicle body component.

[0014] The battery protection frame of the fifth embodiment of this disclosure can also extend in the vehicle width direction behind the battery. The first closed section portion can be formed on the rear vehicle side of the battery protection frame, and the third closed section portion can be formed on the front vehicle side of the battery protection frame.

[0015] According to this configuration, the third closed section is close to the battery cell. By installing peripheral components that constitute part of the battery cell in the third closed section that is close to the battery cell, the layout is improved and the space efficiency is further improved.

[0016] The partition portion of the sixth embodiment of this disclosure may further include a first partition portion extending in the vehicle's longitudinal and width directions, and a second partition portion extending in the vertical and width directions. The first partition portion and the second partition portion can be integrated in an intersecting state, thereby further improving the rigidity of the battery protection frame.

[0017] Invention Effects As explained above, different peripheral components can be installed in the multiple closed sections formed on the hollow cross-section battery protection frame, thus enabling the efficient installation of multiple peripheral components onto the vehicle body and achieving high installation rigidity. Attached Figure Description

[0018] Figure 1 This is a side view of an electric vehicle with the implementation method omitted.

[0019] Figure 2 This is a side view showing the electric vehicle divided into a lower structure and an upper structure.

[0020] Figure 3 This is a top view of the lower structure.

[0021] Figure 4 It is a bottom view of the rear part of the vehicle body structure.

[0022] Figure 5 This is a three-dimensional view of the rear part of the lower structure as seen from above.

[0023] Figure 6 This is a side view of the rear part of the lower structure.

[0024] Figure 7 This is a bottom view of the rear part of the upper structure.

[0025] Figure 8 It is a cross-sectional view obtained by cutting the rear and left sides of the vehicle body structure longitudinally.

[0026] Figure 9It is an enlarged cross-sectional view obtained by longitudinally cutting off the rear and left sides of the vehicle body structure.

[0027] Figure 10 It is a three-dimensional cross-section obtained by cutting the rear and left sides of the vehicle body structure longitudinally.

[0028] Symbol Explanation 1. Electric vehicles 10 Battery casing 21 Rear suspension system 33 Rear battery holder (battery protection holder) 33a Upper wall portion 33b Anterior wall portion 33c Rear wall portion 33d Lower wall 33e, Part 1 33f Second partition 34 Base plate (peripheral components) 35. Cover (peripheral components) 40 Arm Support Bracket (Peripheral Components) 42, 43 Arm connection (suspension connection) 95 Rear side crossbeam (vehicle body component) BY battery unit D1~D4 Closed section 1~4 Detailed Implementation

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the following description of preferred embodiments is merely illustrative and is not intended to limit the invention, its applicability, or its uses.

[0030] Figure 1 This is a left-side view of an electric vehicle (electric car) 1 having a body structure A according to an embodiment of the present invention. The electric vehicle 1 is as follows... Figure 2 The diagram shows a lower structure 2 and an upper structure 3. In Figure 1 In the image, the front bumper, rear bumper, and front and rear wheels are omitted and represented by dashed lines, with each part indicated schematically. Figure 2 In addition to Figure 1 In addition to the parts omitted, the doors, hood, front fenders, windows, front and rear lights, interior parts, etc. are also omitted, and each part is indicated schematically.

[0031] In addition, in the description of this embodiment, the front side of the vehicle is referred to as "front", the rear side of the vehicle as "rear", the right side of the vehicle as "right", and the left side of the vehicle as "left". The left and right direction of the vehicle refers to the width direction of the vehicle.

[0032] like Figure 1 As shown, electric vehicle 1 is a passenger car. Electric vehicle 1 can be, for example, any type such as a van, hatchback, or single-box, and its shape is not particularly limited. Figure 2 As shown, an interior space (passenger compartment space), i.e., compartment R1, is formed on the electric vehicle 1. For example... Figure 1 As shown, a front seat (seat) S1 is provided at the front of the passenger compartment R1, and a rear seat S2 is provided behind the front seat S1. A trunk R2 is provided behind the rear seat S2 as needed. The passenger compartment R1 and the trunk R2 are located in the upper structure 3. Alternatively, the passenger compartment R1 can contain only the front seat S1, or a third row of seats (not shown) can be provided behind the rear seat S2.

[0033] On the other hand, the front part of the electric vehicle 1, that is, the space forward of the passenger compartment R1 (front space), can be, for example, configured as the power compartment R3. That is, as Figure 3 As shown, the vehicle body structure A is provided in an electric vehicle 1 which includes a front drive motor M1 mounted at the front of the vehicle and a rear drive motor M2 mounted at the rear of the vehicle, a battery B that supplies power to the drive motors M1 and M2, and a battery case 10 that houses the battery B. The battery case 10 is disposed below the floor panel 70, which will be described later.

[0034] The front drive motor M1 is a motor that generates the driving force to drive the left and right front wheels FT. The front powertrain PT1 consists solely of this front drive motor M1, or either the front drive motor M1 combined with a reducer, transmission, etc. Furthermore, Figure 2 and Figure 3 The rear-side driving motor M2 shown in the image generates the drive motor RT for the left and right rear wheels. Figure 1 The motor that drives the vehicle (shown in the diagram) consists only of the rear travel motor M2, or the rear travel motor M2 and the reducer, gearbox, etc., constitute the rear powertrain PT2.

[0035] In this embodiment, the rear-side drive motor M2 generates a higher maximum output (maximum torque) than the front-side drive motor M1, and the rear-side drive motor M2 is larger than the front-side drive motor M1. Consequently, the rear-side powertrain PT2 is larger than the front-side powertrain PT1. Alternatively, the rear-side drive motor M2 may generate a lower maximum output than the front-side drive motor M1, or the rear-side drive motor M2 may generate the same maximum output as the front-side drive motor M1. Furthermore, it is possible to have only the front-side powertrain PT1 or only the rear-side powertrain PT2. Additionally, for example, in the case of a large vehicle, a front-side drive motor M1 and a rear-side drive motor M2 that are larger than those in a small vehicle are used.

[0036] like Figure 2 As shown, the lower structure 2 includes a battery housing 10, a pair of left and right front side frames 11 and 12 extending forward in front of the battery housing 10, and a pair of left and right rear side frames 13 and 14 extending rearward behind the battery housing 10. The left and right rear side frames 13 and 14 extend in the longitudinal direction at the rear of the vehicle. Symbol 11 indicates the left front side frame, and symbol 12 indicates the right front side frame. Similarly, symbol 13 indicates the left rear frame, and symbol 14 indicates the right rear frame. Figure 2 The cover 35 of the battery case 10 was removed (described later).

[0037] In typical electric vehicles, the battery casing is often separated from the vehicle body and detachably installed under the floor. However, in this embodiment, not only the battery casing 10 can be detached from the upper structure 13, but the left and right front side frames 11 and 12 and the left and right rear frames 13 and 14 are integrated into the battery casing 10. The left and right front side frames 11 and 12 and the left and right rear frames 13 and 14 can also be detached from the upper structure 3 together with the battery casing 10.

[0038] Specifically, the electric vehicle 1 of this embodiment is configured to be divisible into a lower structure 2 having a battery casing 10 and an upper structure 3 forming a passenger compartment R1 and a trunk R2. The ability to be divisible means that the lower structure 2 is integrated with the upper structure 3 using bolts, nuts, screws, and other fastening components without welding or bonding. Therefore, after the electric vehicle 1 is handed over to the user, the lower structure 2 can be separated from the upper structure 3 as needed for maintenance or repair, resulting in good maintainability. Furthermore, the fastening components used in the following description also include bolts, nuts, screws, etc.

[0039] Here, as a vehicle body structure, the ladder frame type is well known. In a ladder frame type body structure, it can be divided into a ladder frame and a cabin. However, since the ladder frame extends continuously in the longitudinal direction, it mainly bears the collision load in frontal and rear-end collisions. In side collisions, the ladder frame only auxiliaryly bears the collision load, while the cabin mainly bears the collision load. Thus, in a ladder frame type body structure, the components that bear the collision load in frontal and rear-end collisions are usually distinguished from those that bear the collision load in side collisions.

[0040] In the case of the electric vehicle 1 of this embodiment, although the lower structure 2, which has left and right front side frames 11, 12 and left and right rear frames 13, 14, can be separated from the upper structure 3, in both frontal and rearward collisions and side collisions, the lower structure 2 and the upper structure 3 bear the collision load, thereby distributing and absorbing the collision load to the two structures 2 and 3. This technical concept is quite different from the conventional ladder frame type vehicle body structure. The structure of the lower structure 2 and the upper structure 3 will be described in detail below.

[0041] (Lower structure) First, the lower structure 2 will be described. In addition to the battery housing 10, front side frames 11 and 12, and left and right rear frames 13 and 14, the lower structure 2 also includes front and rear powertrains PT1 and PT2, front wheels FT, rear wheels RT, a front suspension device 20, and a rear suspension device 21. The form of the front suspension device 20 and the rear suspension device 21 is not particularly limited.

[0042] The battery cell BY consists of the battery casing 10 and the battery B housed inside the battery casing 10. In addition, the battery cell BY may also include, for example, a battery cooling device.

[0043] The battery casing 10 is a large casing formed below the floor panel 70 of the upper structure 3, extending from near the left end to near the right end of the floor panel 70, and from near the front end to near the rear end of the floor panel 70. By providing the battery casing 10 over such a large area below the floor panel 70, a high-capacity battery B can be mounted on the electric vehicle 1. The battery B can be, for example, a lithium-ion battery, a solid-state battery, or other rechargeable batteries. Furthermore, the battery B can be either a single battery cell or a battery pack containing multiple battery cells. In this embodiment, the battery B is composed of battery packs, and multiple battery packs are mounted in a configuration arranged in both the front-rear and left-right directions.

[0044] Battery housing 10 includes a left battery holder 30, a right battery holder 31, a front battery holder 32, a rear battery holder 33, a bottom plate 34, and a cover 35 that covers battery B from above (shown in...). Figure 5 Additionally. Figure 2 and Figure 3 The middle part indicates that the cover 35 has been removed.

[0045] The left battery holder 30, right battery holder 31, front battery holder 32, and rear battery holder 33 are made of, for example, extruded aluminum alloy parts, but can also be made of aluminum alloy sheet or stamped steel sheet. The base plate 34 can also be made of extruded parts. In the following description, "extruded parts" refers to extruded aluminum alloy parts, and "stamped parts" refers to stamped aluminum alloy sheet or stamped steel sheet. Furthermore, each component can also be made of, for example, castings.

[0046] The cross-sectional shape of the left battery rack 30, right battery rack 31, front battery rack 32, and rear battery rack 33 in the direction orthogonal to the length direction is all rectangular. In addition, the left battery rack 30, right battery rack 31, front battery rack 32, and rear battery rack 33 are all arranged at the same height and extend approximately horizontally.

[0047] The left battery rack 30 and the right battery rack 31 are outer battery racks extending in the front-rear direction from the outer side of the battery B in the vehicle width direction. The left battery rack 30 is located on the left side of the battery housing 10 and extends in the front-rear direction along the left side beam 74. The left battery rack 30 is mounted to the left side beam 74 by fastening members or the like. The right battery rack 31 is located on the right side of the battery housing 10 and extends in the front-rear direction along the right side beam 75. The right battery rack 31 is mounted to the right side beam 75 by fastening members or the like. The left battery rack 30 and the right battery rack 31 are battery protection racks that protect the battery B.

[0048] Furthermore, the front battery holder 32 is located at the front of the battery casing 10 and extends in the left-right direction. Additionally, the rear battery holder 33 extends in the left-right direction at the rear of the battery casing 10, behind the battery B. The front battery holder 32 and the rear battery holder 33 serve as battery protection holders for the battery B.

[0049] The left end of the front battery holder 32 is connected to the front end of the left battery holder 30, and the right end of the front battery holder 32 is connected to the front end of the right battery holder 31. The left end of the rear battery holder 33 is connected to the rear end of the left battery holder 30, and the right end of the rear battery holder 33 is connected to the rear end of the right battery holder 31. Therefore, the left battery holder 30, the right battery holder 31, the front battery holder 32, and the rear battery holder 33 are components that constitute a frame-shaped frame that surrounds all batteries B when viewed from above.

[0050] The left and right ends of the front battery holder 32 and the left and right ends of the rear battery holder 33 are respectively mounted to the left and right side beams 74 and 75 via fastening components. Furthermore, the left and right ends of the rear battery holder 33 are connected to the left battery holder 30 and the right battery holder 31, and are thus mounted to the left and right side beams 74 and 75 via the left and right battery holders 30 and 31. Alternatively, the left and right ends of the rear battery holder 33 can be directly mounted to the left and right side beams 74 and 75.

[0051] Figure 4 The base plate 34 shown extends generally horizontally and is fixed to the lower surfaces of the left battery holder 30, right battery holder 31, front battery holder 32, and rear battery holder 33. Furthermore, Figure 5 and Figure 6 The cover 35 shown is fixed to the upper surfaces of the left battery holder 30, the right battery holder 31, the front battery holder 32, and the rear battery holder 33. That is, the cover 35 is mounted on the battery holders 30-33. The rear battery holder 33 protrudes further rearward than the rear of the cover 35.

[0052] When installing the cover 35 onto the battery racks 30-33, fastening components, adhesive bonding, welding, or other methods can be used. Thus, the left battery rack 30, right battery rack 31, front battery rack 32, rear battery rack 33, base plate 34, and cover 35 form a battery housing space S (shown in...) for housing the battery B. Figure 2 ).

[0053] The size of the battery storage space S can be changed according to the capacity of the battery B. The size of the battery storage space S can be easily changed by altering the lengths of the left battery rack 30, right battery rack 31, front battery rack 32, and rear battery rack 33, as well as the shape of the base plate 34. For example, in a small car with a short wheelbase and narrow track, the battery storage space S is reduced accordingly by shortening the left battery rack 30, right battery rack 31, front battery rack 32, and rear battery rack 33, and correspondingly reducing the shape of the base plate 34 and cover 35. On the other hand, in a large car, the battery storage space S is increased accordingly by lengthening the left battery rack 30, right battery rack 31, front battery rack 32, and rear battery rack 33, and correspondingly increasing the shape of the base plate 34 and cover 35. When the left battery rack 30, right battery rack 31, front battery rack 32, and rear battery rack 33 are constructed from extruded parts, their lengths can be easily changed. In addition, the base plate 34 can also be made of extruded material, which allows for easy changes in shape.

[0054] The upper part of the battery housing space S can be closed either by the aforementioned cover 35 or by the floor panel 70 of the upper structure 3. In addition to housing the battery B, the battery housing space S can also be equipped with a cooling device for cooling the battery B, a heating device for heating the battery B, etc. (temperature control devices). Furthermore, the power from the battery B is supplied to the driving motors M1 and M2 via a control device not shown. Moreover, the battery B can be charged via a charging socket not shown, a contactless charger, etc.

[0055] like Figure 2 As shown, inside the battery casing 10 constituting the battery unit BY, there are first to third casing inner parts (unit inner parts) 25A, 25B, and 25C as strength members extending in the left-right direction. The first to third casing inner parts 25A, 25B, and 25C all have the same height, approximately the same as the height of the left-side battery holder 30, etc. The casing inner parts 25A, 25B, and 25C can be formed by extrusion or stamping. In this embodiment, although there are three casing inner parts 25A, 25B, and 25C, the number of casing inner parts 25A, 25B, and 25C can be increased or decreased depending on the front-rear dimensions of the battery casing 10. The first to third casing inner parts 25A, 25B, and 25C are the second constituent parts.

[0056] The first to third housing inner components 25A, 25B, and 25C are arranged spaced apart from each other in the front-to-back direction, with the first housing inner component 25A at the front and the third housing inner component 25C at the back. The lower part of each housing inner component 25A, 25B, and 25C is fixed to the upper surface of the base plate 34. In addition, the left end of each housing inner component 25A, 25B, and 25C is fixed to the inner surface (right side) of the left battery rack 30, and the right end of each housing inner component 25A, 25B, and 25C is fixed to the inner surface (left side) of the right battery rack 31. That is, the housing inner components 25A, 25B, and 25C are components that connect the left battery rack 30 and the right battery rack 31.

[0057] Inside the battery casing 10, a front central member (unit inner member) 26 and first to third rear central members (unit inner members) 27 to 29 are provided as strength members extending in the front-rear direction. The front central member 26 and the first to third rear central members 27 to 29 are arranged at approximately the same height and are located at the center in the left-right direction of the battery casing 10. The lower ends of the front central member 26 and the first to third rear central members 27 to 29 are mounted on the upper surface of the base plate 34. The front central member 26 and the first to third rear central members 27 to 29 are first structural members. The front central member 26 and the first to third rear central members 27 to 29 intersect with the first to third inner members 25A, 25B, and 25C.

[0058] The front central member 26 is disposed between the front battery holder 32 and the first inner housing member 25A. The front end of the front central member 26 is fixed to the center portion of the front battery holder 32 in the left-right direction, and the rear end of the front central member 26 is fixed to the center portion of the first inner housing member 25A in the left-right direction. Therefore, the front battery holder 32 is a member that extends in such a way that the front ends of the left battery holder 30 and the right battery holder 31 are connected to the front end of the front central member 26.

[0059] A first rear central member 27 is disposed between a first inner shell member 25A and a second inner shell member 25B. The front end of the first rear central member 27 is fixed to the center portion of the first inner shell member 25A in the left-right direction, and the rear end of the first rear central member 27 is fixed to the center portion of the second inner shell member 25B in the left-right direction. Furthermore, a second rear central member 28 is disposed between a second inner shell member 25B and a third inner shell member 25C. The front end of the second rear central member 28 is fixed to the center portion of the second inner shell member 25B in the left-right direction, and the rear end of the second rear central member 28 is fixed to the center portion of the third inner shell member 25C in the left-right direction. Furthermore, a third rear central member 29 is disposed between a third inner shell member 25C and a rear battery holder 33. The front end of the third rear central member 29 is fixed to the center portion of the third inner shell member 25C in the left-right direction, and the rear end of the third rear central member 29 is fixed to the center portion of the rear battery holder 33 in the left-right direction. Therefore, the first to third inner shell components 25A, 25B, 25C, the front central component 26, and the first to third rear central components 27 to 29 are arranged in a grid pattern inside the battery casing 10 and connected to each other, thus further improving the reinforcing effect of the battery casing 10.

[0060] When conceiving a hypothetical straight line extending in the front-to-back direction when viewed from above, the front central member 26 and the first to third rear central members 27 to 29 are positioned in the left-to-right direction on this hypothetical straight line. That is, the first to third rear central members 27 to 29 are arranged on the hypothetical extension line of the front central member 26 facing rearward. Alternatively, the front central member 26 and the first to third rear central members 27 to 29 may also be composed of a single, continuous member in the front-to-back direction.

[0061] like Figure 5 and Figure 6 As shown in the diagram, the lower structure 2 includes a rear battery rack 33, left and right rear frames 13 and 14, and an arm support bracket 40, which constitute part of the vehicle body structure A. The left and right rear frames 13 and 14 can be constructed, for example, by extrusion or stamping. In this embodiment, since the left and right rear frames 13 and 14 are constructed by extrusion, the cross-sectional shape in the direction orthogonal to the front and rear directions is approximately equal from the front end to the rear end.

[0062] The left and right rear frames 13 and 14 are mounted on the rear battery rack 33, which forms the rear of the battery case 10, via the arm support bracket 40. That is, the arm support bracket 40 extends along the rear battery rack 33 in the left and right direction, and the front of the left and right rear frames 13 and 14 is fixed to the arm support bracket 40, which is connected to the rear battery rack 33.

[0063] Specifically, the arm support bracket 40 is constructed from a single piece of metal and extends in the left-right direction; therefore, it can also be referred to as a crossbeam. The front of the left and right rear frames 13 and 14 are fixed to the arm support bracket 40 using welding, bonding, or fastening components. The metal constituting the arm support bracket 40 is not particularly limited; for example, aluminum can be used. In this case, the arm support bracket 40 can be made of die-cast aluminum.

[0064] Although the left and right rear brackets 13 and 14 are mounted to the rear battery rack 33 via the arm support bracket 40, the front parts of the left and right rear brackets 13 and 14 can touch the rear surface of the rear battery rack 33. Therefore, the left and right rear brackets 13 and 14 extend rearward from the rear battery rack 33. Alternatively, the front parts of the left and right rear brackets 13 and 14 may be separated from the rear surface of the rear battery rack 33 to a certain extent. In this case, overall, it can also be said that the left and right rear brackets 13 and 14 extend rearward from the rear battery rack 33.

[0065] The front part of the left rear shelf 13 is positioned to correspond to the portion of the rear battery holder 33 that is slightly to the left of the center in the left-right direction. Similarly, the front part of the right rear shelf 14 is positioned to correspond to the portion of the rear battery holder 33 that is slightly to the right of the center in the left-right direction. Thus, the spacing between the left and right rear shelves 13 and 14 is a predetermined spacing. The spacing between the left and right rear shelves 13 and 14 is set to be narrower than the spacing between the left battery holder 30 and the right battery holder 31 of the battery case 10. Furthermore, the left and right rear shelves 13 and 14 are approximately the same height.

[0066] like Figures 8-10As shown, the rear battery holder 33 has a hollow cross-section orthogonal to the length direction, forming a space inside. Specifically, the rear battery holder 33 has an upper wall portion 33a extending in the left-right direction, a front wall portion 33b extending downward from the front edge of the upper wall portion 33a and extending in the left-right direction, a rear wall portion 33c extending downward from the rear edge of the upper wall portion 33a and extending in the left-right direction, and a lower wall portion 33d extending from the lower edge of the front wall portion 33b to the lower edge of the rear wall portion 33c and extending in the left-right direction. Therefore, the cross-section of the rear battery holder 33 is rectangular, but the cross-sectional shape of the rear battery holder 33 is not limited to a rectangle and can also be a complex polygonal shape. The upper wall portion 33a and the lower wall portion 33d are set to have the same dimensions in the front-rear direction, but are not limited to this; one may be shorter than the other. Furthermore, the front wall portion 33b and the rear wall portion 33c are set to have the same dimensions in the vertical direction, but are not limited to this; one may be shorter than the other.

[0067] Inside the rear battery holder 33, between the upper wall portion 33a and the lower wall portion 33d, a first partition portion 33e is provided to vertically divide the interior space of the rear battery holder 33. The first partition portion 33e extends from the middle of the vertical direction of the front wall portion 33b to the middle of the vertical direction of the rear wall portion 33c in both the front-rear and left-right directions. The first partition portion 33e is substantially parallel to the upper wall portion 33a, and also substantially parallel to the lower wall portion 33d. In this embodiment, the first partition portion 33e is horizontal, but it can also be tilted.

[0068] Inside the rear battery holder 33, between the front wall portion 33b and the rear wall portion 33c, a second partition portion 33f is provided to divide the interior space of the rear battery holder 33 front to back. That is, in this embodiment, the partition portion includes a first partition portion 33e and a second partition portion 33f. Although not shown, it is also possible to have only the first partition portion 33e or only the second partition portion 33f. Furthermore, although not shown, a third partition portion and a fourth partition portion, etc., may also be provided.

[0069] The second partition wall portion 33f is substantially orthogonal to the first partition wall portion 33e, and is integrated in such a state that the middle portion of the second partition wall portion 33f in the vertical direction intersects the middle portion of the first partition wall portion 33e in the front-back direction. The second partition wall portion 33f extends vertically from the middle portion of the upper wall portion 33a to the middle portion of the lower wall portion 33d, and also extends horizontally. The second partition wall portion 33f is substantially parallel to the front wall portion 33b, and also substantially parallel to the rear wall portion 33c. In this embodiment, the second partition wall portion 33f is vertical, but it can also be inclined.

[0070] The outer surface of the rear battery holder 33 is composed of an upper wall portion 33a, a front wall portion 33b, a rear wall portion 33c, and a lower wall portion 33d. Furthermore, as... Figure 9 and Figure 10 As shown, on the rear battery holder 33, four closed section portions are formed by the upper wall portion 33a, the front wall portion 33b, the rear wall portion 33c, the lower wall portion 33d, the first partition wall portion 33e, and the second partition wall portion 33f: namely, the first closed section portion D1, the second closed section portion D2, the third closed section portion D3, and the fourth closed section portion D4. The first closed section portion D1 is formed on the upper and rear portions of the rear battery holder 33. The second closed section portion D2 is formed on the lower and rear portions of the rear battery holder 33. The third closed section portion D3 is formed on the upper and front portions of the rear battery holder 33. The fourth closed section portion D4 is formed on the lower and front portions of the rear battery holder 33. The third closed section D3 and the fourth closed section D4 are formed on the side near the rear battery rack 33, while the first closed section D1 and the second closed section D2 are formed on the side away from the rear battery rack 33, i.e., near the rear suspension assembly 21. Details will be explained later. Different peripheral components are installed on the first to fourth closed section D1 to D4. Peripheral components refer to components disposed around the rear battery rack 33, such as components that form part of the members supporting the rear suspension assembly 21 and components that form part of the battery cell BY.

[0071] More specifically, the first closed section portion D1 is composed of the portion of the upper wall portion 33a that is rearward of the second partition wall portion 33f, the portion of the rear wall portion 33c that is upperward of the first partition wall portion 33e, the portion of the second partition wall portion 33f that is upperward of the first partition wall portion 33e, and the portion of the first partition wall portion 33e that is rearward of the second partition wall portion 33f. The rectangular closed section portion formed by these wall portions is called the first closed section portion D1.

[0072] The second closed section portion D2 is composed of the portion of the lower wall portion 33d that is rearward compared to the second partition wall portion 33f, the portion of the rear wall portion 33c that is lower than the first partition wall portion 33e, the portion of the second partition wall portion 33f that is lower than the first partition wall portion 33e, and the portion of the first partition wall portion 33e that is rearward compared to the second partition wall portion 33f. The rectangular closed section portion formed by these wall portions is called the second closed section portion D2. In the first closed section portion D1 and the second closed section portion D2, the portion of the first partition wall portion 33e that is rearward compared to the second partition wall portion 33f is a common wall portion.

[0073] The third closed section portion D3 is composed of the portion of the upper wall portion 33a that is forward of the second partition wall portion 33f, the portion of the front wall portion 33b that is upward of the first partition wall portion 33e, the portion of the second partition wall portion 33f that is upward of the first partition wall portion 33e, and the portion of the first partition wall portion 33e that is forward of the second partition wall portion 33f. The rectangular closed section portion formed by these wall portions is called the third closed section portion D3. In the first closed section portion D1 and the third closed section portion D3, the portion of the second partition wall portion 33f that is upward of the first partition wall portion 33e is a common wall portion.

[0074] The fourth closed section portion D4 is composed of the portion of the lower wall portion 33d that is forward of the second partition wall portion 33f, the portion of the front wall portion 33b that is downward of the first partition wall portion 33e, the portion of the second partition wall portion 33f that is downward of the first partition wall portion 33e, and the portion of the first partition wall portion 33e that is forward of the second partition wall portion 33f. The rectangular closed section portion formed by these wall portions is called the fourth closed section portion D4. In the second closed section portion D2 and the fourth closed section portion D4, the portion of the second partition wall portion 33f that is downward of the first partition wall portion 33e is a common wall portion. Furthermore, in the third closed section portion D3 and the fourth closed section portion D4, the portion of the first partition wall portion 33e that is forward of the second partition wall portion 33f is a common wall portion.

[0075] like Figure 9 As shown, the arm support bracket 40 includes a longitudinal plate portion 40a extending along the rear wall portion 33c of the rear battery rack 33 in both the vehicle width and vertical directions, and a lower plate portion 40b extending forward from the lower edge of the longitudinal plate portion 40a along the lower wall portion 33d of the rear battery rack 33 and also extending in the vehicle width direction. The longitudinal plate portion 40a and the lower plate portion 40b are respectively fixed to the rear wall portion 33c and the lower wall portion 33d of the rear battery rack 33 by a plurality of fastening members described later. By fixing the longitudinal plate portion 40a and the lower plate portion 40b of the arm support bracket 40 to the rear wall portion 33c and the lower wall portion 33d of the rear battery rack 33 in this way, the mounting rigidity of the arm support bracket 40 relative to the rear battery rack 33 can be improved.

[0076] like Figure 4 and Figure 5As shown, the arm support bracket 40 includes a left outer rib 40c located on the left side of the left rear frame 13, a left inner rib 40d located on the right side of the left rear frame 13, a right outer rib 40e located on the right side of the right rear frame 14, and a right inner rib 40f located on the left side of the right rear frame 14. The left outer rib 40c and the left inner rib 40d suppress the left-right tilting of the left rear frame 13, and the right outer rib 40e and the right inner rib 40f suppress the right-right tilting of the right rear frame 14. Furthermore, since the ribs 40c, 40d, 40e, and 40f are configured to extend in the left-right directions of the left and right rear frames 13 and 14, for example, when an impact load acts on the rear frames 13 and 14 from the rear, the ribs 40c, 40d, 40e, and 40f can be used to disperse the impact load over a wide range in the left-right direction.

[0077] The arm support bracket 40 is provided with a connecting part 41 that connects the rear ends of the left outer rib 40c and the left inner rib 40d with the rear ends of the right outer rib 40e and the right inner rib 40f. The connecting part 41 extends in the left-right direction, and the middle parts of the left and right rear frames 13 and 14 in the front-rear direction are connected to each other through the connecting part 41. That is, when viewed from above, the left and right rear frames 13 and 14, the rear battery bracket 33 and the connecting part 41 form a rectangular closed section.

[0078] On the outer sides of the arm support bracket 40 in the vehicle width direction, namely the left and right sides, there are a pair of left and right arm connecting parts (suspension connecting parts) 42 and 43, respectively. The front parts of the left and right suspension arms 21A are rotatably connected to the left and right arm connecting parts 42 and 43 in the vertical direction. The left and right arm connecting parts 42 and 43 extend to a position higher than the connecting part 41, and the upper parts of the left and right arm connecting parts 42 and 43 are detachably mounted to the upper structure 3. In addition, the arm support bracket 40 is also a component that constitutes part of the rear suspension device 21, and is a peripheral component disposed around the rear battery rack 33.

[0079] Rear suspension crossbeams 44 extending in the left-right direction are provided at the rear of the left and right rear frames 13 and 14. The rear parts of the left and right rear frames 13 and 14 are connected to each other by the rear suspension crossbeams 44. On the outer side of the rear suspension crossbeams 44 in the vehicle width direction, i.e., the left and right sides, there are left and right arm connecting parts 44a and 44b respectively. The rear parts of the left and right suspension arms 21A are rotatably connected to the left and right arm connecting parts 44a and 44b in the vertical direction. The left and right arm connecting parts 44a and 44b extend upward, and the upper parts of the left and right arm connecting parts 44a and 44b are detachably mounted to the upper structure 3. Furthermore, in a top view, the left and right rear frames 13 and 14, the connecting parts 41, and the rear suspension crossbeams 44 form a rectangular closed section.

[0080] A subframe 46 is provided at the rear of the lower structure 2. The subframe 46 includes a left member 46a which is positioned behind the left rear frame 13 and extends in the front-rear direction, a right member 46b which is positioned behind the right rear frame 14 and extends in the front-rear direction, and a rear member 46c which connects the rear ends of the left member 46a and the right member 46b to each other.

[0081] The front parts of the left side member 46a and the right side member 46b of the subframe 46 are fixed to the rear suspension crossbeam 44. That is, the subframe 46 is connected to the left and right rear frames 13 and 14 via the rear suspension crossbeam 44. Figure 6 As shown, in the connected state, the left and right rear frames 13 and 14 are located lower than the subframe 46.

[0082] (Upper structure) First, let's explain the upper structure 3. For example... Figure 2 As shown, the upper structure 3 includes a floor panel 70, a front bulkhead (partition section) 71, and a pair of side beams 74 and 75 on the left and right sides. Symbol 74 indicates the left side beam, and symbol 75 indicates the right side beam.

[0083] The floor panel 70 forms the floor of the carriage R1 and is constructed of steel plates extending in both the longitudinal and lateral directions. The space above the floor panel 70 forms the carriage R1. A roof 80 is provided on the upper part of the carriage R1. Furthermore, a front opening 3a and a rear opening 3b are formed on the left and right sides of the upper structure 3, respectively. Figure 1 As shown, the front opening 3a and the rear opening 3b are opened and closed freely by the front door 81 and the rear door 82, respectively. In addition, although not shown, a front door and a rear door are also provided freely on the right side of the upper structure 3.

[0084] The left and right side beams 74 and 75 are configured to extend in the front-rear direction from the left and right ends of the floor panel 70, respectively. The left end of the floor panel 70 is connected to the middle of the left side beam 74 in the vertical direction, and the right end of the floor panel 70 is connected to the middle of the right side beam 75 in the vertical direction. The upper portions of the left and right side beams 74 and 75 protrude upward from the connection points of the floor panel 70, and the lower portions of the left and right side beams 74 and 75 protrude downward from the connection points of the floor panel 70. Since the battery housing 10 is disposed below the floor panel 70, the battery housing 10 is positioned between the left and right side beams 74 and 75, and the lower portions of the left and right side beams 74 and 75 overlap with the battery housing 10 when the vehicle is viewed from the side.

[0085] The front bulkhead 71 extends in both the width and vertical directions and serves as a component for separating the passenger compartment R1 and the engine compartment R3. The lower end of the front bulkhead 71 is connected to the front end of the floor panel 70.

[0086] Figure 7 This is a bottom view of the rear part of the upper structure 3, as shown. Figure 7 As shown, the floor panel 70 of the upper structure 3 has a rear panel portion 70A that forms the ground of the trunk R2. Left and right rear wheel covers 72 and 73 are respectively provided on the left and right sides of the rear panel portion 70A.

[0087] The upper structure 3 has a pair of left and right rear side frames 90, 91 extending in the front-rear direction at the rear of the vehicle. The left rear side frame 90 is formed to extend along the left end of the rear panel portion 70A at a position inside the vehicle width direction of the left rear wheel arch 72. At the rear of the left rear side frame 90, a left collapsible box 90a is provided, protruding rearward beyond the rear of the rear panel portion 70A.

[0088] The right rear side bracket 91 is formed to extend along the right end of the rear panel portion 70A at a position inside the right rear wheel arch 73 in the vehicle width direction. A right-side crumple zone 91a is provided at the rear of the right rear side bracket 91, protruding rearward beyond the rear of the rear panel portion 70A. Bumper reinforcement members 92 extending in the left-right direction are mounted at the rear of the left and right crumple zones 90a and 91a, respectively. The front portions of the left and right rear side brackets 90 and 91 are formed to bend or tilt downwards.

[0089] In addition, such as Figure 4 and Figure 8 As shown, the rear battery rack 33 of the battery housing 10 extends in the vehicle width direction at a position slightly forward of the left and right rear side racks 90 and 91. More specifically, since the battery housing 10 is located below the floor panel 70, the rear battery rack 33 is positioned slightly lower than the front of the left and right rear side racks 90 and 91.

[0090] The front portion of the left rear side bracket 90 is separated from the rear portion of the left side beam 74 by a predetermined distance in the rearward and inward direction in the vehicle width direction, and the front portion of the left rear side bracket 90 is not connected to the rear portion of the left side beam 74. Similarly, the front portion of the right rear side bracket 91 is separated from the rear portion of the right side beam 75 by a predetermined distance in the rearward and inward direction in the vehicle width direction, and the front portion of the right rear side bracket 91 is not connected to the rear portion of the right side beam 75. That is, assuming that the left rear side bracket 90 is connected to the left side beam 74, the front portion of the left rear side bracket 90 is extended forward to connect to the rear portion of the left side beam 74. In this way, the front portion of the left rear side bracket 90 protrudes inward in the vehicle width direction than the left rear wheel arch 72. Similarly, the front portion of the right rear side bracket 91 protrudes inward in the vehicle width direction than the right rear wheel arch 73. If the left and right rear side frames 90 and 91 protrude inward in the vehicle width direction, the left and right dimensions of the rear side of the battery case 10 must be shortened, thus reducing the amount of battery B installed.

[0091] In this embodiment, by making the left and right rear side frames 90, 91 and the left and right side beams 74, 75 non-connected, a space is formed that allows the battery case 10 to extend rearward. This allows the battery case 10 to be extended rearward to near the left and right rear wheel arches 72, 73, and ensures that the left and right dimensions of the rear side of the battery case 10 are long enough, thus increasing the capacity of the battery B.

[0092] For example, Figure 7 As shown, assuming a dotted straight line L1 extending forward from the center of the front part of the left rear side frame 90 in the left-right direction, and assuming a dotted straight line L2 extending forward from the center of the front part of the right rear side frame 91 in the left-right direction, the battery case 10 (represented by a dotted line) is positioned from a region to the left of the dotted straight line L1 to a region to the right of the dotted straight line L2. By providing such a large battery case 10, the battery B can be mounted all the way to the outer side in the vehicle width direction beyond the dotted straight lines L1 and L2, further increasing the amount of battery B that can be mounted.

[0093] Furthermore, when viewed from the side, the battery case 10 extends to a position further rearward than the rear of the left and right side beams 74 and 75. Therefore, the rear battery rack 33 is located further rearward than the rear of the left and right side beams 74 and 75, thus allowing the battery B to be mounted to a position further rearward than the rear of the left and right side beams 74 and 75.

[0094] Furthermore, if the left and right rear side frames 90, 91 and the left and right side beams 74, 75 are respectively set to be non-connected, there is a possibility that there is no direct load transfer path from the left and right rear side frames 90, 91 to the left and right side beams 74, 75 when the impact load is applied from the rear, but in this embodiment, even if there is no such load transfer path, the battery case 10 can be used to absorb the impact load from the rear.

[0095] That is, such as Figures 8-10 As shown, the left and right rear side frames 90 and 91 are connected to the rear battery rack 33 via arm support brackets 40. Specifically, the upper structure 3 has a vehicle body component, namely a rear side beam 95, which is part of the vehicle body. The rear side beam 95 is configured such that the front parts of the left and right rear side frames 90 and 91 abut against the rear side beam 95 from the rear, and the rear side beam 95 extends in the vehicle width direction. The rear side beam 95 has a front plate portion 95a that is continuous from the vicinity of the front part of the left wheel arch 72 to the vicinity of the front part of the right wheel arch 73 and extends in the vertical and horizontal directions, a rear plate portion 95b that is separated from the front plate portion 95a and extends in the vertical and horizontal directions, and a lower plate portion 95c that extends from the lower end of the front plate portion 95a to the lower end of the rear plate portion 95b. The vertical dimension of the rear panel 95b is set to be longer than that of the front panel 95a, and the upper end of the rear panel 95b is located above the upper end of the front panel 95a. Furthermore, the tilt angle of the front panel 95a and the rear panel 95b is set such that the distance between the front panel 95a and the rear panel 95b in the front-rear direction becomes wider towards the top.

[0096] The upper ends of the front panel 95a and the rear panel 95b are joined to the lower surface of the floor panel 70, forming a closed section with the front panel 95a, the rear panel 95b, the lower panel 95c, and the floor panel 70. This improves the rigidity of the floor panel 70.

[0097] The front parts of the left and right rear side frames 90 and 91 abut against the rear plate portion 95b of the rear crossbeam 95 from the rear, and are joined to the rear plate portion 95b and the lower plate portion 95c. Since the vertical dimension of the rear plate portion 95b is longer than that of the front plate portion 95a, the joint area of ​​the left and right rear side frames 90 and 91 relative to the rear crossbeam 95 can be ensured to be large.

[0098] like Figure 8 As shown, the rear battery holder 33 is disposed below the rear crossbeam 95, and is formed such that the lower plate portion 95c of the rear crossbeam 95 extends along the outer surface (upper surface) of the upper wall portion 33a of the rear battery holder 33. The rear crossbeam 95 and the rear battery holder 33 are fastened to each other in the vertical direction, thereby allowing the rear battery holder 33 to be detachably mounted on the rear crossbeam 95.

[0099] Specifically, such as Figure 9 As shown, the first closed section D1 of the rear battery holder 33 is adjacent to the lower part of the rear crossbeam 95, and the rear crossbeam 95 is installed on the first closed section D1 of the rear battery holder 33. As a prerequisite, the lower surface of a cylindrical nut N1 extending in the vertical direction is fixed to the upper surface of the lower plate portion 95c of the rear crossbeam 95. Since the nut N1 is disposed inside the rear crossbeam 95, the internal space of the rear crossbeam 95 can be effectively utilized.

[0100] like Figure 10 As shown, multiple nuts N1 are spaced apart in the left-right direction. Inside the rear crossbeam 95, multiple reinforcing plates 95d are provided corresponding to the number of nuts N1. Each reinforcing plate 95d has a through hole 95e through which the upper part of the nut N1 passes. With the upper part of the nut N1 passing through the through hole 95e, the outer peripheral surface of the nut N1 is welded to the periphery of the through hole 95e, thus improving the fixing strength of the nut N1. The front portion of the reinforcing plate 95d is formed along the inner surface of the front plate portion 95a and is welded to the front plate portion 95a. The rear portion of the reinforcing plate 95d is formed along the inner surface of the rear plate portion 95b and is welded to the rear plate portion 95b. Therefore, the front plate portion 95a and the rear plate portion 95b are connected by the reinforcing plate 95d.

[0101] A through hole 33g is formed on the first partition wall 33e of the rear battery holder 33 for inserting a bolt B1 from below. The number of through holes 33g is the same as the number of nuts N1, and they are formed at intervals equal to the intervals between the nuts N1. Nuts N1 are positioned directly above the through holes 33g. The bolt B1, inserted into the through hole 33g, passes through the upper wall 33a of the rear battery holder 33 and through the lower plate 95c, and is screwed onto the nut N1 from below. Although not shown, a through hole for inserting a bolt B1 is formed on the upper wall 33a of the rear battery holder 33, and also on the lower plate 95c of the rear crossbeam 95.

[0102] A hole 33h is formed in the lower wall portion 33d of the rear battery holder 33. This hole 33h is a hole through which the bolt B1 passes, opening into the outer surface (lower surface) of the lower wall portion 33d of the rear battery holder 33, and is formed to connect with the internal space of the rear battery holder 33. The shape of the hole 33h is circular, but not limited to this. Furthermore, the diameter of the hole 33h is set to be larger than the maximum outer diameter of the head of the bolt B1, so that the bolt B1 can be easily inserted.

[0103] The holes 33h are also provided in the same number as the nuts N1, and are formed at the same intervals as the nuts N1. With the shafts of each bolt B1 facing upwards, the bolts B1 are inserted from the holes 33h into the space inside the rear battery holder 33 and screwed into each nut N1, thereby enabling the rear crossbeam 95 to be fastened to the rear battery holder 33 at multiple points.

[0104] The head of bolt B1 enters the interior of the rear battery holder 33, abutting against the periphery of the through hole 33g on the first partition 33e from below. Thus, the head of bolt B1 exerts a fixing force on the periphery of the through hole 33g on the first partition 33e from below and upward, thereby securing the rear battery holder 33 to the rear crossbeam 95 from within the rear battery holder 33. In other words, bolt B1 is inserted into the space inside the rear battery holder 33 from the hole 33h, and the rear battery holder 33 is secured to a fixing member on the rear crossbeam 95, which is different from the arm support bracket 40, from within the rear battery holder 33. Furthermore, although not shown, the fixing member is not limited to bolts; for example, it could be a screw, rivet, or other fastening member.

[0105] The lower plate portion 40b of the arm support bracket 40 is formed to extend along the outer surface (outer surface of the lower wall portion 33d) of the rear battery holder 33 where the hole 33h is formed. Therefore, the lower plate portion 40b can cover the hole 33h from below. In this embodiment, the lower plate portion 40b is a cover portion that covers the hole 33h from the outside of the rear battery holder 33. The lower plate portion 40b extends to a position further forward than the front of the hole 33h, thus completely covering the hole 33h.

[0106] (Installation structure of the arm support bracket) Next, the mounting structure of the arm support bracket 40 and the rear battery rack 33 will be described. For example... Figure 9 As shown, the second closed section D2 of the lower wall portion 33d of the rear battery rack 33 is adjacent to the upper part of the lower plate portion 40b of the arm support bracket 40, and the lower plate portion 40b of the arm support bracket 40 is mounted on the second closed section D2 of the rear battery rack 33. As a prerequisite, multiple nuts N2 are fixed at intervals in the vehicle width direction on the inner surface (upper surface) of the rear portion of the lower wall portion 33d of the rear battery rack 33. The axes of the nuts N2 extend in the vertical direction and are parallel to the axis of the nuts N1. The rear portion of the lower wall portion 33d is part of the second closed section D2.

[0107] On the outer surface (lower surface) of the lower wall portion 33d of the rear battery holder 33, a lower plate portion 40b of the arm support bracket 40 is disposed. Multiple bolts B2, which are screwed into the lower wall portion 33d of the rear battery holder 33 and the lower plate portion 40b of the arm support bracket 40, pass through from below and are screwed into the nut N2. By screwing each bolt B2 into each nut N2, the arm support bracket 40 and the rear battery holder 33 can be fastened at multiple points.

[0108] Furthermore, the first closed section D1 and the second closed section D2 of the rear battery rack 33 are adjacent to the rear of the longitudinal plate portion 40a of the arm support bracket 40, and the longitudinal plate portion 40a of the arm support bracket 40 is mounted on the first closed section D1 and the second closed section D2 of the rear battery rack 33. As a prerequisite, a plurality of nuts N3 are fixed on the inner surface (front surface) of the rear wall portion 33c of the rear battery rack 33. The axis of the nut N3 extends in the front-rear direction and is orthogonal to the axis of the nuts N1 and N2 when viewed from the side. The plurality of nuts N3 are spaced apart from each other in the vehicle width direction, and are also respectively provided on the upper part (the part forming the first closed section D1) and the lower part (the part forming the second closed section D2) of the rear wall portion 33c of the rear battery rack 33. On the outer surface (rear surface) of the rear wall portion 33c of the rear battery rack 33, a longitudinal plate portion 40a of the arm support bracket 40 is disposed. Multiple bolts B3, which are screwed into the rear wall portion 33c of the rear battery rack 33 and the longitudinal plate portion 40a of the arm support bracket 40, pass through and are screwed into the nut N3. The bolts B3, which pass through the rear wall portion 33c of the rear battery rack 33 and the longitudinal plate portion 40a of the arm support bracket 40 from below, are screwed into the nut N3 from the rear. By screwing each bolt B3 into each nut N3, the arm support bracket 40 and the rear battery rack 33 can be fastened at multiple points.

[0109] Therefore, when focusing on the first closed section D1 of the rear battery rack 33, the rear crossbeam 95 and the longitudinal plate 40a of the arm support bracket 40 are installed at the first closed section D1. The rear crossbeam 95 is mounted to multiple parts of the first closed section D1 by bolts B1, and the longitudinal plate 40a is mounted to multiple parts of the first closed section D1 by nuts N3 on the upper side.

[0110] Furthermore, the longitudinal plate portion 40a of the arm support bracket 40 is also installed on the second closed section portion D2 of the rear battery rack 33. The longitudinal plate portion 40a is formed by the lower nut N3 for the multiple mounting portions of the second closed section portion D2.

[0111] (The mounting structure of the battery cell cover and base plate) The cover 35 and base plate 34 of the battery unit BY are peripheral components disposed around the rear battery rack 33. For example... Figure 9 As shown, the third closed section D3 of the rear battery holder 33 is adjacent to the lower part of the rear portion of the cover 35 of the battery cell BY, and the rear portion of the cover 35 is installed on the third closed section D3 of the rear battery holder 33. The rear portion of the cover 35 overlaps the upper surface of the third closed section D3 and is installed on the upper surface of the third closed section D3 by welding or bonding. Alternatively, although not shown, the rear portion of the cover 35 can also be installed on the third closed section D3 by fastening members.

[0112] Furthermore, the fourth closed section D4 of the rear battery rack 33 is adjacent to the upper rear of the base plate 34 of the battery cell BY, and the rear of the base plate 34 is mounted on the fourth closed section D4 of the rear battery rack 33. As a prerequisite, multiple nuts N4 are fixed at intervals in the vehicle width direction on the inner surface (upper surface) of the front portion of the lower wall portion 33d of the rear battery rack 33. The axis of the nuts N4 extends in the vertical direction and is parallel to the axis of the nuts N1. The front portion of the lower wall portion 33d is part of the fourth closed section D4.

[0113] A base plate 34 is disposed on the outer surface (lower surface) of the lower wall portion 33d of the rear battery rack 33. Multiple bolts B4, which are screwed into the lower wall portion 33d and the base plate 34 from below, pass through the rear battery rack 33 and N4. By screwing each bolt B4 into each nut N4, the base plate 34 can be fastened to the rear battery rack 33 at multiple points.

[0114] (Effects of the implementation method) As explained above, according to this embodiment, the first partition portion 33e and the second partition portion 33f are provided on the rear battery rack 33 fixed to the vehicle body to form the first to fourth closed section portions D1 to D4, thus resulting in a highly rigid and lightweight rear battery rack 33. The first to fourth closed section portions D1 to D4 are located at different positions on the rear battery rack 33, and the third closed section portion D3 and the fourth closed section portion D4 can be close to the battery cell BY. Therefore, the cover 35 of the battery cell BY can be installed on the third closed section portion D3, and the base plate 34 can be installed on the fourth closed section portion D4. In addition, the first closed section portion D1 and the second closed section portion D2 can be close to the rear suspension device 21, so the arm support bracket 40 can be installed on the first closed section portion D1 and the second closed section portion D2. Thus, even without providing dedicated brackets for each peripheral component, the high rigidity of the rear battery rack 33 can improve the mounting rigidity of the peripheral components and improve space efficiency.

[0115] The foregoing embodiments are merely examples in all respects and should not be interpreted in a limiting way. Furthermore, variations and modifications within the scope of equivalents of the claims are all within the scope of this invention.

[0116] In this embodiment, four closed cross-sections are formed on the rear battery holder 33, but it is not limited to this; two, three, or five or more closed cross-sections can also be formed. In this case, different peripheral components can be installed on each closed cross-section. Furthermore, the size of the closed cross-sections can be arbitrarily set; multiple closed cross-sections can all be different sizes, some can be the same, or all can be the same. In addition, the peripheral components can also be crossbeams, various frames, electrical components, etc.

[0117] Industrial availability As explained above, the vehicle body structure disclosed herein can be installed, for example, in an electric vehicle.

Claims

1. A vehicle body structure for an electric vehicle, the electric vehicle having a drive motor and a battery supplying power to the drive motor disposed below the floor panel, the vehicle body structure being characterized in that... A battery protection frame with a hollow cross-section is fixed to the vehicle body to protect the battery. The battery protection bracket extends in the width direction at the rear of the vehicle and is positioned below the rear side crossbeam that forms part of the vehicle body. Inside the battery protection holder, there is a partition that divides the internal space of the battery protection holder. The partition includes a first partition extending in the vehicle's longitudinal and width directions, and a second partition extending in the vertical and width directions, wherein the first partition and the second partition are integrated in an intersecting manner. On the battery protection frame, a first closed section, a second closed section, a third closed section, and a fourth closed section are formed by the wall portion constituting the outer surface of the battery protection frame, the first partition wall portion, and the second partition wall portion. The first closed section is formed on the rear vehicle side of the upper portion of the battery protection frame. The second closed section is formed on the lower part of the battery protection frame on the rear part of the vehicle. The third closed section is formed on the upper part of the battery protection frame on the front part of the vehicle. The fourth closed section is formed on the lower part of the battery protection frame on the front part of the vehicle. The peripheral component includes the rear crossbeam and the longitudinal plate portion of the arm support bracket, which forms part of the component supporting the suspension device located on the rear side of the vehicle, relative to the battery protection frame. The longitudinal plate portion of the arm support bracket is also installed in the second closed section as a peripheral component. A cover for housing the battery is installed on the upper surface of the third closed section as a peripheral component. The bottom plate of the battery case is installed on the lower surface of the fourth closed section as a peripheral component.

2. The vehicle body structure according to claim 1, characterized in that, In at least one of the first closed section portion, the second closed section portion, the third closed section portion, and the fourth closed section portion, the mounting portion of the peripheral component is provided with a plurality of such portions.

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