Body structure

Abstract

A vehicle body structure effectively improves the rigidity of the higher portion of the floor panel by utilizing a battery box disposed below the floor panel. The floor panel (70) includes a first floor portion (70b) and a second floor portion (70c) located above the first floor portion (70b). A connecting member (160) is provided in the vehicle body structure. The connecting member extends from the battery box (10) to the second floor portion (70c) to connect the battery box (10) and the second floor portion (70c).

Description

Technical Field

[0001] The invention relates to a body structure of an electric vehicle. Background Art

[0002] For example, in the case of an automobile equipped with a traction motor, a battery unit for supplying electric power to the traction motor is mounted, and the capacity of the battery unit is increased in order to extend the cruising distance of the traction motor.

[0003] The battery unit of the electric vehicle disclosed in Patent Document 1 is mounted in a wide area under the floor. A pair of left and right front longitudinal beams extending in the front-to-back direction of the vehicle and a bottom beam extending in the front-to-back direction of the vehicle below the front longitudinal beams are provided at the front portion of the vehicle body. In addition, the battery unit under the floor has a box body. A pair of left and right front extensions extending toward the front of the vehicle are formed on the front wall of the box body, and the rear end of the bottom beam is connected to the front end of each front extension. In addition, a pair of left and right rear extensions extending toward the rear of the vehicle are integrally formed on the rear wall of the box body. The box body is fixed to the floor bottom reinforcement, and the front extension and the rear extension are fixed to the front longitudinal beam and the rear longitudinal beam, respectively.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-158688

[0007] However, a floor panel of a car may have a lower portion and a higher portion. For example, there is a floor panel in which a portion corresponding to the feet of a rear seat passenger is lowered and a portion for the rear seat passenger to sit is raised.

[0008] Although the floor panel is a relatively large component of the vehicle body, it is a plate-shaped component, so how to improve the rigidity of the floor panel itself becomes a problem. This is because if the rigidity of the floor panel is low, the rigidity of the vehicle body will be reduced.

[0009] In order to improve the rigidity of the vehicle body, generally speaking, it is only necessary to install reinforcement members on various parts. However, the reinforcement members used to improve the rigidity of the vehicle body are large and heavy, so it is difficult to say that they can effectively improve the rigidity of the vehicle body.

[0010] Regarding this point, Patent Document 1 fixes the battery unit housing to a floor underbody reinforcement. However, because the floor underbody reinforcement extends horizontally in the front-to-rear direction below the floor panel, if there is a high portion of the floor panel, this high portion cannot be fixed to the housing. In other words, while the floor underbody reinforcement and the housing body may improve the rigidity of the lower portion of the floor panel, the higher portion, which is separated upward from the floor underbody reinforcement and the housing body, can hardly expect any reinforcement from these two elements. Summary of the Invention

[0011] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to effectively improve the rigidity of the higher portion of the floor panel by utilizing a battery box provided below the floor panel.

[0012] To achieve the above-mentioned object, in a first aspect of the present disclosure, the vehicle body structure of the electric vehicle can be based on the following premise: the electric vehicle is provided with a driving motor, and a battery box containing a battery for supplying power to the driving motor is arranged below a floor panel. The floor panel has a first floor portion and a second floor portion located above the first floor portion. The vehicle body structure is provided with a connecting member connecting the battery box and the second floor portion, a first cross member extending in the vehicle width direction is mounted on the lower surface of the second floor portion, the battery box has a second cross member extending in the vehicle width direction above a rear end member constituting the rear portion of the battery box, the upper portion of the connecting member is fixed to the first cross member, and the lower portion of the connecting member is fixed to the second cross member, the battery box and the second floor portion are connected by the connecting member via the first cross member, and the first cross member and the second cross member are arranged so as to face each other in the vertical direction.

[0013] This structure provides a floor panel with a first floor section (relatively low) and a second floor section (relatively high). The second floor section is connected to the battery box via a connecting member. The battery box, housing the heavy batteries, is therefore highly robust. This eliminates the need for heavier reinforcement members and utilizes the high-strength battery box to reinforce the second floor section, effectively increasing its rigidity.

[0014] According to this configuration, the portion whose strength is increased by the first cross member can be connected by the connecting member, and thus the rigidity of the second floor portion can be further increased.

[0015] According to this configuration, the battery box, whose strength is enhanced by the second cross member, can be connected by the connecting member, and thus the rigidity of the second floor portion can be further enhanced.

[0016] According to this configuration, the first horizontal beam and the second horizontal beam are close to each other, so that the vertical dimension of the connecting member can be shortened, and the reinforcing effect can be further enhanced.

[0017] In the second aspect of the present disclosure, a pair of left and right wheelhouse portions are connected to both ends of the second floor portion in the vehicle width direction, and both ends of the first cross member are connected to the left and right wheelhouse portions, respectively.

[0018] According to this structure, for example, the load input to the wheel house portion during driving can be distributed to the battery box via the first cross member, the second floor portion, and the connecting member, thereby further improving the vehicle body rigidity.

[0019] In the third aspect of the present disclosure, a floor-side cross member extending in the vehicle width direction just above the first cross member is attached to the upper surface of the second floor portion.

[0020] According to this configuration, the highly rigid portion of the second floor portion can be connected by the connecting member, thereby further enhancing the reinforcing effect.

[0021] Effects of the Invention

[0022] As described above, the battery box and the relatively high second floor portion are connected by the connecting member, and thus the rigidity of the second floor portion can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a side view of the electric vehicle according to the embodiment of the present invention.

[0024] Figure 2 This is a side view showing a state where the electric vehicle is divided into a lower structure and an upper structure.

[0025] Figure 3 This is a three-dimensional view of the lower structure viewed from above.

[0026] Figure 4 This is a top view of the lower structure.

[0027] Figure 5 It is a lower structure with a small battery box. Figure 4 Picture.

[0028] Figure 6 This is a left side view of the lower structure when the height of the front center beam is increased.

[0029] Figure 7 It is a cross-sectional view of the central portion in the left-right direction of the electric vehicle.

[0030] Figure 8 This is a cross-sectional view of an electric vehicle viewed from the front.

[0031] Figure 9 This is a cross-sectional view of an electric vehicle viewed from the rear.

[0032] Figure 10 This is a perspective view showing a section passing through the front seat portion of the electric vehicle as viewed from the front.

[0033] Figure 11 This is a diagram schematically showing a floor panel, a front seat, a front seat occupant, and a battery unit.

[0034] Figure 12 It will Figure 10 A magnified view of part C in FIG. 1 and viewed from the front.

[0035] Figure 13 It is a perspective view showing a cross section of the rear portion of the electric vehicle as viewed from below.

[0036] Figure 14 It is a diagram schematically showing a floor panel and a battery unit according to a modified example.

[0037] Explanation of symbols

[0038] 1. Electric Vehicles

[0039] 10 Battery Box

[0040] 11 Front frame part

[0041] 20 Left side beam

[0042] 21 Right side beam

[0043] 22 Front end beam

[0044] 22a protrusion

[0045] 25A, 25B, 25C First to third battery side cross members

[0046] 26 Front center beam (front reinforcement beam)

[0047] 27-29 First to third rear center beams (rear reinforcement beams)

[0048] 30 External connection (one side connection)

[0049] 31 Inner connection (other connection)

[0050] 53, 54 left connection

[0051] 55, 56 right side connection

[0052] 70 Floor

[0053] 70a Front floor

[0054] 70b Rear floor portion (first floor portion)

[0055] 70c Upper curved portion (second floor portion)

[0056] 72 front side frame

[0057] 73 lower side beam

[0058] 100 Seat fixing part

[0059] 110A, 110B, 110C First to third floor side cross members

[0060] 120 Side load transfer component (inner reinforcement)

[0061] 123 Inner upper longitudinal wall portion (first longitudinal wall portion)

[0062] 124 inner lower vertical wall portion (second vertical wall portion)

[0063] 150 hinge column

[0064] 151 Floor reinforcement (first front-to-rear load transfer component)

[0065] 152 Lower load transmission member (second front-to-back load transmission member)

[0066] 153 beam

[0067] 160 connecting parts

[0068] 170 rear wheel housing

[0069] 171 rear cross member (first cross member)

[0070] 180 Box side beam (second beam)

[0071] A Body structure

[0072] B Battery

[0073] M driving motor DETAILED DESCRIPTION

[0074] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applicable objects, or its uses.

[0075] Figure 1 FIG. 1 is a left side view of an electric vehicle 1 having a vehicle body structure A according to an embodiment of the present invention. Figure 2As shown in FIG. 1 , the electric vehicle 1 includes a lower structure 2 and an upper structure 3 , and the lower structure 2 and the upper structure 3 constitute a vehicle body structure A. Figure 2 shows a state where the doors, hood, front fenders, window glass, bumpers, front and rear lighting devices, etc. are removed. In the description of this embodiment, the front side of the vehicle is simply referred to as "front," the rear side of the vehicle is simply referred to as "rear," the right side of the vehicle is simply referred to as "right," and the left side of the vehicle is simply referred to as "left." The left-right direction of a vehicle is the vehicle width direction.

[0076] like Figure 1 As shown, the electric vehicle 1 is a passenger car. Figure 2 As shown, a front seat S1 is provided at the front of a passenger compartment R1, which serves as a passenger compartment. A rear seat S2 is provided behind the front seat S1 within the compartment R1. A luggage compartment R2 is provided behind the rear seat S2 as needed. The compartment R1 and the luggage compartment R2 are provided in an upper structure 3. Alternatively, only the front seat S1 may be provided within the compartment R1, or a third row of seats (not shown) may be provided behind the rear seat S2.

[0077] On the other hand, the space in front of the vehicle cabin R1, which is the front part of the electric vehicle 1, can be used as, for example, a power room R3. Specifically, the vehicle body structure A includes: a driving motor M, which generates power for driving the drive wheels; and a battery box 10, which houses a battery B (only in the case of a vehicle) that supplies power to the driving motor M. Figure 4 (shown in FIG). The power transmission system PT is composed of only the electric motor M for driving, or the electric motor M for driving and a speed reducer or a transmission. Figure 1 and Figure 2 , the case where the powertrain PT is only provided in the power chamber R3 is shown, but the powertrain PT can also be provided in the lower space R4 of the luggage compartment R2 (the powertrain in the rear is not shown). When the powertrain PT is only provided in the power chamber R3, only the front wheels F are driven. When the powertrain PT is provided in the lower space R4, only the rear wheels R are driven. In this case, the power chamber R3 can be used as a luggage compartment space, etc. In addition, when the powertrain PT is provided in both the power chamber R3 and the lower space R4, it becomes a four-wheel drive vehicle. The battery box 10 is arranged below the floor panel 70 described later.

[0078] like Figure 3 and Figure 4 As shown in FIG. 1 , the lower structure 2 includes a battery box 10, a front frame member 11 extending forward in front of the battery box 10, and a rear frame member 12 extending rearward in rear of the battery box 10. Figure 3 The left front wheel F, rear wheel R, suspension arm, etc. are omitted.

[0079] In the case of a general electric vehicle, the battery box is often separated from the vehicle body and can be loaded and unloaded under the floor. However, in this embodiment, not only is the battery box 10 integrated, but the front frame component 11 and the rear frame component 12 are also integrated with the battery box 10, and the front frame component 11 and the rear frame component 12 can also be loaded and unloaded relative to the upper structure 3 together with the battery box 10.

[0080] Specifically, the electric vehicle 1 of this embodiment is configured to be separable vertically into a lower structure 2 containing a battery box 10 and an upper structure 3 forming the vehicle interior R1 and luggage compartment R2. Separability refers to the integration of the lower structure 2 and the upper structure 3 using fasteners such as bolts, nuts, or screws, rather than welding or bonding. This allows the lower structure 2 to be separated from the upper structure 3 as needed for maintenance or repair after the electric vehicle 1 is delivered to the user, improving maintainability.

[0081] A ladder-frame type vehicle body structure is known. While a ladder-frame type vehicle body structure can be divided vertically into the ladder frame and the cab, the ladder frame extends continuously in the front-to-back direction. Therefore, the ladder frame primarily bears the impact load in frontal and rear-end collisions. In side collisions, the ladder frame only plays a secondary role in bearing the impact load, while the cab bears the primary impact load. Thus, in a ladder-frame type vehicle body structure, the components that bear the impact load in frontal, rear-end, and side collisions are typically separate.

[0082] In contrast, in the electric vehicle 1 of this embodiment, although the lower structure 2 and upper structure 3, which have frame members 11 and 12, are separable, the collision load is borne by both the lower structure 2 and the upper structure 3 in both frontal, rear, and side collisions. This allows the collision load to be distributed and absorbed between the two structures 2 and 3. This technical concept differs significantly from conventional ladder-frame vehicle body structures. The structures and functional effects of the lower structure 2 and the upper structure 3 will be described below in order.

[0083] (Lower structure)

[0084] First, the lower structure 2 will be described. Figure 3 as well as Figure 4As shown, the lower structure 2 includes a battery box 10, a front frame member 11, and a rear frame member 12, as well as a powertrain PT, front wheels F, rear wheels R, a front suspension 13, and a rear suspension 14. The types of the front suspension 13 and the rear suspension 14 are not particularly limited.

[0085] The battery box 10 is a large box formed below the floor panel 70, which is described later, and extends from the vicinity of the left end to the vicinity of the right end of the floor panel 70 and from the vicinity of the front end to the vicinity of the rear end of the floor panel 70. In this way, the battery box 10 is installed in a wide area below the floor panel 70, so that Figure 4 As shown, a large-capacity battery B can be installed in electric vehicle 1. Battery B can be, for example, a lithium-ion battery, an all-solid-state battery, or other secondary battery. Battery B can also be a so-called battery cell or a battery pack containing multiple battery cells.

[0086] The battery box 10 includes a left side square beam 20, a right side square beam 21, a front end beam 22, a rear end beam 23 and a bottom plate 24. The left side square beam 20, the right side square beam 21, the front end beam 22 and the rear end beam 23 are made of, for example, an extruded material made of an aluminum alloy. Alternatively, they may be made of a stamped material made of an aluminum alloy plate or a steel plate. The bottom plate 24 may also be made of an extruded material. In the following description, when referred to as an "extruded material", it is an extruded material made of an aluminum alloy. Additionally, when referred to as a "stamped material", it is a stamped material made of an aluminum alloy plate or a steel plate. In addition, each component may also be made of, for example, a casting.

[0087] The left side beam 20, the right side beam 21, the front end beam 22, and the rear end beam 23 all have rectangular cross-sections in a direction perpendicular to the longitudinal direction. Furthermore, the left side beam 20, the right side beam 21, the front end beam 22, and the rear end beam 23 are all arranged at the same height and extend substantially horizontally.

[0088] The left side beam 20 is provided at the left end of the battery box 10 and extends in the front-to-back direction. The right side beam 21 is provided at the right end of the battery box 10 and extends in the front-to-back direction. In addition, the front end beam 22 is provided at the front end of the battery box 10 and extends in the left-right direction. The left end of the front end beam 22 is connected to the front end of the left side beam 20, and the right end of the front end beam 22 is connected to the front end of the right side beam 21. The rear end beam 23 is provided at the rear end of the battery box 10 and extends in the left-to-right direction. The left end of the rear end beam 23 is connected to the rear end of the left side beam 20, and the right end of the rear end member 23 is connected to the rear end of the right side beam 21. The bottom plate 24 extends approximately horizontally and is fixed to the lower surfaces of the left side beam 20, the right side beam 21, the front end beam 22 and the rear end beam 23. Therefore, a battery accommodation space S ( Figure 3 shown).

[0089] The size of the battery storage space S can be changed according to the capacity of the battery B installed. The size of the battery storage space S can be easily changed by changing the length of the left side beam 20, the right side beam 21, the front end beam 22, and the rear end beam 23, and the shape of the bottom plate 24. For example, in the case of a small car with a short wheelbase and a narrow tread, the left side beam 20, the right side beam 21, the front end beam 22, and the rear end beam 23 can be shortened, and the shape of the bottom plate 24 can be reduced accordingly. In this way, the battery storage space S can be reduced in accordance with the small car (see Figure 5 On the other hand, in the case of a large vehicle, the left side beam 20, right side beam 21, front end beam 22, and rear end beam 23 are lengthened, and the shape of the floor plate 24 is correspondingly enlarged. This increases the battery storage space S in proportion to the large vehicle. If the left side beam 20, right side beam 21, front end beam 22, and rear end beam 23 are formed of extruded material, their lengths can be easily changed. Furthermore, the floor plate 24 can also be formed of extruded material, making its shape easily changeable.

[0090] The upper portion of the battery storage space S can be closed with a cover (not shown) or with a floor panel 70 (described later). In addition to the battery B, the battery storage space S may also be provided with a cooling device for cooling the battery B, a heating device for heating the battery B, or the like (temperature control device). Furthermore, power from the battery B is supplied to the driving motor M via a control device (not shown). Furthermore, the battery B can be charged via a charging socket (not shown).

[0091] like Figure 3As shown, inside the battery box 10, first to third battery side cross beams 25A, 25B, and 25C are provided as reinforcing members extending in the left-right direction. The heights of the first to third battery side cross beams 25A, 25B, and 25C are all the same and are approximately the same as the height of the left side square beam 20 and the like. The battery side cross beams 25A, 25B, and 25C can be made of extruded material or stamped material. In this embodiment, three battery side cross beams 25A, 25B, and 25C are provided, but the number of battery side cross beams 25A, 25B, and 25C can be increased or decreased according to the front-to-back dimensions of the battery box 10.

[0092] The first to third battery-side cross-members 25A, 25B, and 25C are spaced apart from each other in the front-to-back direction, with the first battery-side cross-member 25A positioned at the front and the third battery-side cross-member 25C positioned at the rear. The lower portion of each battery-side cross-member 25A, 25B, and 25C is fixed to the upper surface of the floor panel 24. Furthermore, the left end of each battery-side cross-member 25A, 25B, and 25C is fixed to the inner surface (right side) of the left side beam 20, and the right end of each battery-side cross-member 25A, 25B, and 25C is fixed to the inner surface (left side) of the right side beam 21. In other words, the battery-side cross-members 25A, 25B, and 25C connect the left side beam 20 and the right side beam 21.

[0093] above Figure 5 The example of the lower structure 2 including a small battery box 10 is shown. The size of the small battery box 10 in the front-back direction is set to be smaller than that of the lower structure 2. Figure 4 The battery box 10 shown is short in the front-to-back direction. Figure 5 In the example shown, the third battery-side cross member 25C is omitted because the dimension in the front-rear direction is shortened. On the contrary, although not shown, a fourth battery-side cross member may be provided.

[0094] Inside the battery box 10, a front center beam (front reinforcement beam) 26 and first to third rear center beams (rear reinforcement beams) 27 to 29 are provided as reinforcement members extending in the front-to-back direction. The front center beam 26 and the first to third rear center beams 27 to 29 are arranged at approximately the same height and positioned in the left-right center of the battery box 10. The lower ends of the front center beam 26 and the first to third rear center beams 27 to 29 are attached to the upper surface of the floor panel 24.

[0095] The front center beam 26 is positioned between the front end beam 22 and the first battery-side cross beam 25A. The front end of the front center beam 26 is fixed to the left-right center of the front end beam 22, and the rear end of the front center beam 26 is fixed to the left-right center of the first battery-side cross beam 25A. Therefore, the front end beam 22 is an extended member that connects the front ends of the left and right side beams 20 and 21 to the front end of the front center beam 26.

[0096] The first rear center beam 27 is positioned between the first battery-side cross beam 25A and the second battery-side cross beam 25B. Its front end is fixed to the left-right center of the first battery-side cross beam 25A, and its rear end is fixed to the left-right center of the second battery-side cross beam 25B. Furthermore, the second rear center beam 28 is positioned between the second battery-side cross beam 25B and the third battery-side cross beam 25C. Its front end is fixed to the left-right center of the second battery-side cross beam 25B, and its rear end is fixed to the left-right center of the third battery-side cross beam 25C. Furthermore, the third rear center beam 29 is positioned between the third battery-side cross beam 25C and the rear end beam 23. Its front end is fixed to the left-right center of the third battery-side cross beam 25C, and its rear end is fixed to the left-right center of the rear end beam 23. Therefore, the first to third battery-side cross members 25A, 25B, 25C, the front center member 26, and the first to third rear center members 27 to 29 are arranged in a lattice pattern inside the battery box 10 and connected to each other, thereby further enhancing the reinforcement effect of the battery box 10.

[0097] When the front center beam 26 and the first to third rear center beams 27 to 29 are positioned in the left-right direction, assuming an imaginary straight line extending in the front-to-back direction when viewed from above, they are arranged on this imaginary straight line. In other words, the first to third rear center beams 27 to 29 are positioned on an imaginary rearward extension of the front center beam 26. Alternatively, the front center beam 26 and the first to third rear center beams 27 to 29 may be formed from a single member that is continuous in the front-to-back direction.

[0098] Figure 6 This means that the height of the front center beam 26 is greater than that of the first to third rear center beams 27 to 29 ( Figure 6) is a diagram showing an example of an increased height. As will be described in detail later, in the floor panel 70 of the upper structure 3, the front floor portion 70a is located above the rear floor portion 70b. A front center beam 26 is provided below the front floor portion 70a, and further, first to third rear center beams 27 to 29 are provided below the rear floor portion 70b. The upper end portion of the front center beam 26 is formed so as to be located above the rear floor portion 70b. In other words, the upper end portions of the first to third rear center beams 27 to 29 are located below the upper end portion of the front center beam 26 to correspond to the relatively low position of the rear floor portion 70b. In this case, the first battery side cross beam 25A can be provided below the front floor portion 70a. In this case, the upper end portion of the first battery side cross beam 25A can be formed so as to be located above the second and third battery side cross beams 25B and 25C.

[0099] like Figure 3 and Figure 4 As shown, a pair of left and right front frame members 11 are provided, extending substantially horizontally and linearly below the left and right front side frames 72 (described later). Each front frame member 11 can be formed from, for example, an extruded material or a stamped material. In this embodiment, each front frame member 11 is formed from an extruded material, so the cross-sectional shape perpendicular to the front-to-back direction is substantially uniform from the front end to the rear end.

[0100] The left front frame member 11 is connected to a portion of the front end beam 22 that constitutes the front portion of the battery box 10, to the left of the left-right center. This connection portion is located to the right of the left side beam 20 of the battery box 10. Furthermore, the right front frame member 11 is connected to a portion of the front end beam 22 that is to the right of the left-right center. This connection portion is located to the left of the right side beam 21 of the battery box 10. This allows the left and right front frame members 11 to be spaced at a predetermined distance, allowing the lower portion of the powertrain PT to be positioned between the left and right front frame members 11. The distance between the left and right front frame members 11 is set to be narrower than the distance between the left and right side beams 20, 21 of the battery box 10.

[0101] The left and right front frame members 11 are arranged at substantially the same height. In addition, the left and right front frame members 11 and the front center beam 26, the left side beam 20, and the right side beam 21 of the battery box 10 are arranged at substantially the same height.

[0102] The battery box 10 side (rear side) of each front frame member 11 is connected to the battery box 10 at multiple locations separated from each other in the left-right direction. Specifically, the rear end of the right front frame member 11 is connected to the front end beam 22. Furthermore, a location separated forward from the rear end of the front frame member 11 is connected to the front end beam 22 via an outer connecting portion (one connecting portion) 30 and an inner connecting portion (the other connecting portion) 31. This allows the collision load input to the front frame member 11 during a head-on collision to be distributed and transmitted to multiple locations in the battery box 10.

[0103] The outer connecting portion 30 and the inner connecting portion 31 are formed from highly rigid components, such as extruded or stamped materials, and are cylindrical, plate-shaped, or columnar. When viewed from above, the width of the outer connecting portion 30 and the inner connecting portion 31 is set to be wider than the width of the front frame member 11, thereby further improving the dispersion of the collision load. Furthermore, the width of the outer connecting portion 30 and the inner connecting portion 31 can be the same as or narrower than the width of the front frame member 11.

[0104] The right outer connecting portion 30 is positioned to the right (outward in the vehicle width direction) of the right front frame member 11 and at approximately the same height as the front frame member 11. It is inclined relative to the front-to-back direction when viewed from above, with the position becoming more rightward as it approaches the rear end. The front end of the right outer connecting portion 30 is connected to a portion of the front frame member 11 between the front-to-back center and the rear end (the midway portion in the front-to-back direction). The outer connecting portion 30 extends from the portion connected to the front frame member 11 toward the right and rear, i.e., toward a rocker 73 (described later) of the upper structure 3. Furthermore, the rear end of the right outer connecting portion 30 is connected to a portion of the front end beam 22 that is spaced rightward from the rear end of the front frame member 11. The connection structures between the outer connecting portion 30 and the front frame member 11 and the front end beam 22 may use fasteners such as bolts and nuts, or may use welding, adhesive bonding, or the like.

[0105] The right inner connecting portion 31 is provided at a position to the left (inward in the vehicle width direction) of the right front frame member 11 at approximately the same height as the front frame member 11 and is inclined relative to the front-to-back direction in a plan view such that the closer it is to the rear end, the more leftward it is. The front end of the right inner connecting portion 31 is connected to a portion (midway in the front-to-back direction) between the front-to-back center and the rear end of the front frame member 11. The right inner connecting portion 31 extends from the connection portion with the front frame member 11 toward the left and rear, i.e., the left-to-right center of the battery box 10. Furthermore, the rear end of the inner connecting portion 31 is connected to a portion of the front end beam 22 that is separated to the left from the rear end of the front frame member 11. The connection structure of the inner connecting portion 31 to the front frame member 11 and the connection structure of the inner connecting portion 31 to the front end beam 22 can be the same as the connection structure of the outer connecting portion 30.

[0106] In this embodiment, the right front frame member 11 is connected to the front end beam 22 at three locations separated from each other in the left-right direction. However, the present invention is not limited to this. One of the outer connecting portion 30 and the inner connecting portion 31 may be omitted and connected at two locations. Alternatively, the rear end of the front frame member 11 may not be connected to the front end beam 22 but may be connected to the front end beam 22 only via the outer connecting portion 30 and the inner connecting portion 31.

[0107] The left front frame member 11 can also be connected to the front end beam 22 in the same manner as the right front frame member 11. The connection structure of the left front frame member 11 can be bilaterally symmetrical with respect to the connection structure of the right front frame member 11.

[0108] like Figure 3 As shown, an intermediate connecting beam 49, a front connecting beam 50, and a rear connecting beam 51 are provided at intervals in the front-to-back direction at a position forward of the battery box 10 on the lower structure 2. The front connecting beam 50 extends in the vehicle width direction from the front of the left front frame member 11 to the front of the right front frame member 11, connecting the left and right front frame members 11. The rear connecting beam 51 extends in the vehicle width direction from the rear of the left front frame member 11 to the rear of the right front frame member 11, connecting the left and right front frame members 11. The front connecting beam 50 and the rear connecting beam 51 are made of, for example, extruded material or stamped material. By connecting the left and right front frame members 11 using the front connecting beam 50 and the rear connecting beam 51, a frame structure is formed that has a frame shape when viewed from above.

[0109] Furthermore, an intermediate connecting beam 49 is provided between the front connecting beam 50 and the rear connecting beam 51. The intermediate connecting beam 49 extends in the vehicle width direction from the front portion of the left front frame member 11 to the front portion of the right front frame member 11, and connects the left front frame member 11 to the right front frame member 11. The intermediate connecting beam 49 may be provided as needed and may be omitted.

[0110] The front connecting beam 50 is arranged to extend from the upper surface of the left front frame member 11 to the upper surface of the right front frame member 11, and protrudes upward from the upper surfaces of both front frame members 11. Meanwhile, the rear connecting beam 51 is arranged between the left and right front frame members 11. The left end of the rear connecting beam 51 is connected to the side surface of the left front frame member 11, and the right end of the rear connecting beam 51 is connected to the side surface of the right front frame member 11. The front connecting beam 50 and the rear connecting beam 51 can be fixed to the front frame member 11 by fastening members, welding, adhesive bonding, etc.

[0111] The longitudinal dimensions of the front connecting beam 50 and the rear connecting beam 51 are set to be longer than the lateral dimension of the front frame member 11. This can improve the connection strength of the two connecting beams 50 and 51 to the front frame member 11.

[0112] like Figure 4 As shown, the powertrain PT is positioned rearward of the front connecting beam 50. Specifically, in a plan view, the powertrain PT is positioned between the front connecting beam 50 and the rear connecting beam 51. Drive shafts 52 are provided on the left and right sides of the lower structure 2 to transmit the output of the powertrain PT to the left and right front wheels F, respectively.

[0113] The left and right suspension arms 13a forming part of the front suspension system 13 are swingably supported by the left and right front frame members 11 via brackets 13b. The brackets 13b are provided at the connection between the left and right front frame members 11 and the rear connecting member 51.

[0114] In the lower structure 2, two left-side connecting parts 53 and 54 for connecting the front frame part 11 on the left side and the front side frame 72 (described later) on the left side are provided at intervals in the front-to-back direction, and two right-side connecting parts 55 and 56 for connecting the front frame part 11 on the right side and the front side frame 72 (described later) on the right side are provided at intervals in the front-to-back direction. The left-side connecting parts 53 and 54 and the right-side connecting parts 55 and 56 can be composed of a plate, a tubular part, a columnar part, etc. extending in the up-down direction. In this embodiment, the left-side connecting parts 53 and 54 and the right-side connecting parts 55 and 56 are composed of a stamped material, but can also be composed of an extruded material, etc. In addition, the number of the left-side connecting parts 53 and 54 is not limited to 2, and more than 3 can also be provided at intervals in the front-to-back direction. The same is true for the right-side connecting parts 55 and 56.

[0115] The front left connecting portion 53 is provided at the connection location of the front connecting beam 50 with the left front frame member 11. Specifically, the front portion of the left front frame member 11 and the left end portion of the front connecting beam 50 are arranged so as to overlap in the vertical direction. Since the left end portion of the front connecting beam 50 is connected to the front portion of the left front frame member 11, the connection location is formed by the left end portion of the front connecting beam 50. The lower end portion of the front left connecting portion 53 is attached to the left end portion of the front connecting beam 50.

[0116] Furthermore, the front right connecting portion 55 is provided at the connection location of the front connecting beam 50 with the right front frame member 11. Specifically, the front portion of the right front frame member 11 and the right end portion of the front connecting beam 50 are arranged so as to overlap in the vertical direction. Since the right end portion of the front connecting beam 50 is connected to the front portion of the right front frame member 11, the right end portion of the front connecting beam 50 forms the connection location. The lower end portion of the front right connecting portion 55 is attached to the right end portion of the front connecting beam 50.

[0117] The rear left connecting portion 54 is provided at the connection portion of the left front frame member 11 to the intermediate connecting beam 49. The lower end of the rear left connecting portion 54 is attached to the left front frame member 11 and is positioned rearward relative to the left drive shaft 52. Furthermore, the rear right connecting portion 56 is provided at the connection portion of the right front frame member 11 to the intermediate connecting beam 49. The lower end of the rear right connecting portion 56 is attached to the right front frame member 11 and is positioned rearward relative to the right drive shaft 52. This allows for greater spacing between the front and rear left connecting portions 53 and 54, as well as greater spacing between the front and rear right connecting portions 55 and 56.

[0118] The right front frame member 11 and Figure 8The front side frame 72 on the right side shown is arranged on the left side (inward in the vehicle width direction), and the front frame member 11 on the left side is arranged on the left side. Figure 2 The left front side frame 72 is arranged on the right side (inward in the vehicle width direction) as shown. Therefore, the distance between the left and right front side frames 72 is wider than the distance between the left and right front frame members 11. A powertrain PT including a driving motor M is mounted between the left and right front side frames 72.

[0119] like Figure 3 As shown, the right-side connecting portions 55 and 56 are formed so as to be positioned more to the right (outer in the vehicle width direction) as they go up. This is because the right-side front side frame 72 is positioned above the right-side front frame member 11 and to the right of the front frame member 11. The left-side connecting portions 53 and 54 are similarly formed so as to be positioned more to the left (outer in the vehicle width direction) as they go up.

[0120] Similar to the front frame member 11, a pair of left and right rear frame members 12 are provided, extending substantially horizontally and linearly toward the rear. Each rear frame member 12 can be formed of, for example, an extruded material or a stamped material. In this embodiment, each rear frame member 12 is formed of an extruded material.

[0121] The left rear frame member 12 is connected to a portion of the rear end beam 23 constituting the rear portion of the battery box 10, to the left of the left-right center. This connection portion is located to the right of the left side beam 20 of the battery box 10. Furthermore, the right rear frame member 12 is connected to a portion of the rear end beam 23 to the right of the left-right center. This connection portion is located to the left of the right side beam 21 of the battery box 10. The connection structure between the rear frame member 12 and the rear end beam 23 can be similar to the connection structure between the front frame member 11 and the front end beam 22 described above.

[0122] In addition, Figure 5 In the illustrated embodiment, the front ends of the left and right rear frame members 12 are connected to the rear end beam 23, and the middle portion of the rear frame member 12 in the front-to-rear direction is connected to the rear end beam 23 via a connecting member 60. As a result, the battery box 10 side of the rear frame member 12 is connected to the battery box 10 at multiple locations separated from each other in the left-right direction.

[0123] Left and right suspension arms 14 a constituting a part of the rear suspension system 14 are swingably supported by the left and right rear frame members 12 via brackets 14 b , respectively.

[0124] (Upper structure)

[0125] Next, the upper structure 3 will be described. Figures 7 to 10As shown, the upper structure 3 includes a floor panel 70, a dash panel 71, a pair of left and right front side frames 72, and a pair of left and right rocker rails 73. Figures 7 to 10 , shows the state after the doors, engine hood, front fenders, window glass, bumper, front and rear lighting devices, part of the seats, interior materials, etc. are removed.

[0126] The floor panel 70 constitutes the floor surface of the vehicle compartment R1 and is made of a steel plate or the like extending in the front-rear direction and also in the left-right direction. The space above the floor panel 70 becomes the vehicle compartment R1. A roof 80 is provided above the vehicle compartment R1. Figure 2 As shown in FIG, a front opening 3a and a rear opening 3b are formed on the left side of the upper structure 3. Figure 1 As shown, the front opening 3a and the rear opening 3b are openable and closable by a front door 81 and a rear door 82, respectively. Although not shown, a front door and a rear door are also provided on the right side of the upper structure 3 so as to be openable and closable.

[0127] The dash panel 71 is a member for separating the vehicle compartment R1 and the power compartment R3 in the front-rear direction. The dash panel 71 is made of, for example, a steel plate, and extends in the left-right direction and also in the up-down direction. Figures 7 to 9 As shown, front wheel housings 85 for accommodating the left and right front wheels F are provided on the left and right sides of the front portion of the upper structure 3 (in FIG. Figures 7 to 9 Only the right front wheel housing portion is shown). The left end portion of the front panel 71 and the left front wheel housing portion 85 ( Figure 2 In addition, the right end of the front panel 71 is connected to the right front wheel cover 85 ( Figures 7 to 9 as shown) connection.

[0128] like Figure 11 As shown schematically, the floor panel 70 includes a front floor portion 70a and a rear floor portion 70b. Figure 10 As shown, the floor panel 70 further includes an upturned portion 70c at its rear portion. The front floor portion 70a, rear floor portion 70b, and upturned portion 70c may be integrally formed from a single plate material or may be formed from separate plates. When formed from separate plates, a single floor panel 70 may be formed by joining multiple plates.

[0129] like Figure 11 As shown, the front floor portion 70a constitutes the front portion of the floor panel 70 and is inclined or curved so as to be positioned upward as it moves forward. The front end of the front floor portion 70a is connected to the lower end of the dash panel 71. Therefore, the floor panel 70 is provided so as to extend rearward from the lower end of the dash panel 71.

[0130] The rear floor portion 70b extends rearward from the rear end of the front floor portion 70a, forming the middle portion of the floor panel 70 in the front-to-back direction. The front portion of the battery box 10 of the lower structure 2 is located directly below the front floor portion 70a, while the rear portion of the battery box 10 is located directly below the rear floor portion 70b. Therefore, the battery box 10 is formed so that it extends from below the front floor portion 70a to below the rear floor portion 70b, allowing the batteries B to be mounted in the majority of the area under the floor panel 70.

[0131] The front-to-back middle portion of the floor panel 70 is lower than the front floor portion 70a. Specifically, the front floor portion 70a is located forward of the rear floor portion 70b and above it. Attached to the front side of the rear floor portion 70b is at least a portion of a seat fixing portion 100 for securing the front seat S1. The seat fixing portion 100 is comprised of, for example, a bracket. It suffices to attach at least the rear portion of the seat fixing portion 100 to the rear floor portion 70b, or the entire seat fixing portion 100 may be attached to the rear floor portion 70b. Attaching at least the rear portion of the seat fixing portion 100 to the rear floor portion 70b allows the front seat S1 to be positioned lower, thereby lowering the hip point of the front seat occupant P. This creates more headroom for the front seat occupant P and improves vehicle comfort. Furthermore, a lowered hip point lowers the front seat occupant P's seated position, thereby lowering the vehicle's center of gravity when the occupant is seated. In this embodiment, since the entire seat fixing portion 100 is mounted on the rear floor portion 70 b , the front seat S1 can be laid out even lower.

[0132] When the driver, serving as a front seat occupant P, sits in the front seat S1, the front seat occupant P's heel P1 rests on the front floor portion 70a. Because the front floor portion 70a, where the heel P1 rests, is positioned higher than the rear floor portion 70b, the heel P1 is positioned higher than in a typical vehicle (one with the front and rear floors at the same height). This arrangement allows the front seat occupant P to position their thighs P2 and calves P3 widely apart. Figure 11 Symbol 101 represents the center line of the thigh P2, and symbol 102 represents the center line of the calf P3. The height difference between the front floor portion 70a and the rear floor portion 70b is set so that the angle formed by the center line 101 and the center line 102 (the opening angle α between the thigh P2 and the calf P3) is in the range of 125° to 150°.

[0133] By setting this height difference, the angle formed between the lower leg P3 and the front floor portion 70a (the angle β formed between the centerline 101 and the front floor portion 70a) is reduced. Consequently, the vertical component of the force input to the heel P1 during pedal operation is reduced, thereby improving the operability of the brake pedal 103. Specifically, when the front seat occupant P steps on the brake pedal 103, the heel P1 applies a downward force F to the front floor portion 70a. This force F is decomposed into a vertical force and a horizontal force, respectively, force F1 and force F2. As described above, the reduced angle β reduces the vertical component of the force F1 input from the heel P1. This allows for quick and accurate operation, such as switching from the brake pedal 103 to the accelerator pedal (not shown), or vice versa, resulting in improved pedal operability.

[0134] In addition, the rear seat passenger's feet may be placed on the rear floor portion 70b. Since the rear floor portion 70b is lower than the front floor portion 70a, the space under the rear seat passenger's feet is increased, and the rear seat passenger's loading performance is improved.

[0135] like Figures 7 to 9 As shown, the upper curved portion 70c constitutes the rear portion of the floor panel 70 and is connected to the rear end of the rear floor portion 70b. The upper curved portion 70c is located above the rear floor portion 70b, and a vertical plate portion 70d extending in the vertical direction is formed between the upper curved portion 70c and the rear floor portion 70b. The height of the upper curved portion 70c is set to be higher than the height of the front floor portion 70a. The rear seat S2 ( Figure 2 Below the upper curved portion 70c, a battery B may be provided, and a control device for the electric vehicle 1 may also be provided (not shown).

[0136] A floor cross member 110 is attached to the floor panel 70, extending in the left-right direction along the floor panel 70. The floor cross member 110 is welded, for example, to the upper surface of the rear floor portion 70b of the floor panel 70. The shape of the floor cross member 110 is not particularly limited; in this embodiment, it bulges upward and opens downward, forming a substantially uniform cross-sectional shape at both left and right ends. By attaching the floor cross member 110 to the rear floor portion 70b, the floor cross member 110 and the rear floor portion 70b form a closed cross-section. The left end of the floor cross member 110 is located near the inner surface of the left rocker 73 in the vehicle width direction, while the right end of the floor cross member 110 is located near the inner surface of the right rocker 73 in the vehicle width direction. Alternatively, the floor cross member 110 may be attached to the lower surface of the rear floor portion 70b.

[0137] like Figures 7 to 9 As shown, the left and right front side frames 72 are arranged at the front part of the vehicle body and are high-strength components extending in the front-rear direction. Figures 7 to 9 In FIG, only the front side frame 72 on the right side is shown. Figure 2 , the left front side frame 72 is shown. That is, the left and right front side frames 72 are positioned forward of the floor panel 70 and positioned upward of the floor panel 70. Specifically, the left and right front side frames 72 are arranged so as to extend forward from the left and right sides of the lower portion of the front panel 71, respectively.

[0138] The left and right front side frames 72 are bilaterally symmetrical and can be formed, for example, by joining a plurality of stamped materials or by extruding a material. The cross-section of each front side frame 72 in a direction perpendicular to the front-to-back direction is set to be larger than the cross-section of the front frame member 11 of the lower structure 2 in the same direction. As a result, each front side frame 72 becomes a member thicker and stronger than the front frame member 11.

[0139] The front ends of the left and right front side frames 72 each have a crush box 72a that compresses and deforms during a head-on collision to absorb the collision energy. The crush box 72a is a cylindrical metal component that extends in the front-to-back direction. A front bumper reinforcement 86 that extends in the left-to-right direction is fixed to the front ends of the left and right crush boxes 72a.

[0140] like Figure 8 As shown, the upper portion of the right connecting portion 55 located in front of the lower structure 2 is connected to the right crush box 72a. In addition, the left connecting portion 53 ( Figure 2 The upper portion of the left connecting portion 53 (shown) is connected to the left crush box 72a. Since the crush box 72a is located at the front end of the front side frame 72, by connecting the upper portion of the left connecting portion 53 to the crush box 72a, the connection point of the left connecting portion 53 can be set to a position close to the front end of the vehicle body. As a result, the distance between the left connecting portions 53 and 54 in the front-to-back direction can be increased, so the effect of connecting the front frame member 11 to the front side frame 72 via the left connecting portions 53 and 54 is further significant. The same applies to the right connecting portions 55 and 56. The connection structure of the left connecting portions 53 and 54 and the right connecting portions 55 and 56 to the front side frame 72 uses fastening members such as bolts and nuts. In addition, the front left connecting portion 53 and the right connecting portion 55 can also be connected to a position of the front side frame 72 that is farther back than the crush box 72a.

[0141] In addition, if Figure 5 As shown, the lower portion of the rear right connecting portion 56 is connected to the front frame member 11 at a position behind the drive shaft 52. Figure 8As shown, the upper portion of the rear right connecting portion 56 is connected to a portion of the front side frame 72 that is further rearward than the front-back center. This further increases the front-back distance between the right connecting portions 55 and 56. The same applies to the left connecting portions 53 and 54.

[0142] The left and right side rails 73 are respectively provided at the left and right ends of the floor panel 70 so as to extend in the front-rear direction. Figure 12 As shown, the left end of the floor panel 70 is connected to the middle portion of the left rocker 73 in the vertical direction. The upper portion of the rocker 73 protrudes upward from the connection point with the floor panel 70, and the lower portion of the rocker 73 protrudes downward from the connection point with the floor panel 70. Because the battery box 10 is located below the floor panel 70, the lower portion of the rocker 73 and the battery box 10 overlap when viewed from the side of the vehicle. Similarly, the right rocker 73 is connected to the right end of the floor panel 70.

[0143] The left and right side rails 73 are of bilaterally symmetrical structure. Figure 12 The detailed structure of the left side sill 73 will be described. The left side sill 73 includes an inner member 90 and an outer member 91, both made of stamped material. The inner member 90 forms the interior inner portion of the side sill 73, bulging outward from the interior and extending in the front-to-back direction. The outer member 91 forms the exterior outer portion of the side sill 73, bulging outward from the exterior and extending in the front-to-back direction. The upper portions of the inner member 90 and the outer member 91 are joined together, and the lower portions of the inner member 90 and the outer member 91 are joined together, thereby forming the side sill 73 with a hollow interior.

[0144] A first recess 73a is formed in the lower portion of the vehicle width inner side of the lower side member 73, extending in the front-to-rear direction and recessed outward in the vehicle width direction. The first recess 73a is open downward and inward in the vehicle width direction. The vehicle width outer side of the battery box 10 of the lower structure 2 is formed so as to fit into the first recess 73a. Specifically, the left side member 20 of the battery box 10 enters the first recess 73a from below. This ensures that the battery box 10 has a longer dimension in the vehicle width direction and reduces the amount of downward protrusion of the battery box 10.

[0145] A hollow side load transfer member 120 is provided inside the rocker 73. This member extends in the front-to-rear direction and is used to transfer loads from the outside to the inside in the vehicle width direction. The loads transferred by the side load transfer member 120 are not those assumed during normal driving, but rather extremely large loads that can cause deformation of the side components of the electric vehicle 1, such as during a side collision, such as when an obstacle collides with the electric vehicle 1 from the side.

[0146] The side load transmission member 120 can be formed of, for example, an extruded material and extends continuously from the front end to the rear end of the rocker 73. The side load transmission member 120 is secured to the rocker 73 at an appropriate location. The structure for securing the side load transmission member 120 to the rocker 73 is not particularly limited; for example, a structure using fastening members such as bolts, nuts, or rivets can be used.

[0147] The side load transfer member 120 has high rigidity, enabling it to transfer the load during a side collision inward in the vehicle width direction. Therefore, it is resistant not only to compression but also to bending and torsional forces. During normal driving, it also functions as a reinforcement member that strengthens the rocker 73 and contributes to improving vehicle body rigidity. Since the side load transfer member 120 is located inside the rocker 73 to reinforce it, it can be called an inner reinforcement.

[0148] The side load transmission member 120 includes an upper wall portion 121, an outer wall portion 122, an inner upper vertical wall portion 123, an inner lower vertical wall portion 124, an intermediate wall portion 125, and a lower wall portion 126. The upper wall portion 121 extends in the vehicle width direction and is positioned near the upper end inside the rocker 73. The outer wall portion 122 extends downward from the vehicle width outer end of the upper wall portion 121 and is positioned near the vehicle width outer end inside the rocker 73. The upper end of the outer wall portion 122 is positioned above the upper end of the floor-side cross member 110. The lower end of the outer wall portion 122 is positioned below the upper end of the second battery-side cross member 25B disposed inside the battery box 10. Although not shown, the positional relationship between the first battery-side cross member 25A and the third battery-side cross member 25C and the side load transmission member 120 is substantially the same.

[0149] The inner upper vertical wall portion 123 extends downward from the inner end portion of the upper wall portion 121 in the vehicle width direction and is disposed within the rocker 73 near the inner end portion in the vehicle width direction. The upper end portion of the inner upper vertical wall portion 123 is located above the upper end portion of the floor-side cross member 110. The lower end portion of the inner upper vertical wall portion 123 is located below the rear floor portion 70b and above the upper end portion of the second battery-side cross member 25B.

[0150] The middle wall portion 125 extends outward in the vehicle width direction from the lower end of the inner upper vertical wall portion 123. The outer end of the middle wall portion 125 in the vehicle width direction is located inward of the center of the upper wall portion 121 in the vehicle width direction. The inner lower vertical wall portion 124 extends downward from the inner end of the middle wall portion 125 in the vehicle width direction. The lower end of the inner lower vertical wall portion 124 is located below the upper end of the second battery-side cross member 25B. The vertical dimension of the inner lower vertical wall portion 124 is set to be shorter than the vertical dimension of the inner upper vertical wall portion 123.

[0151] The side load transmission member 120 has a second recess 120a formed on the lower portion of the vehicle interior inner side of the vehicle compartment, formed by the inner lower vertical wall portion 124 and the intermediate wall portion 125, which is recessed outward in the vehicle width direction so as to correspond to the first recess 73a of the rocker 73. The portion of the rocker 73 where the first recess 73a is formed fits into the second recess 120a of the side load transmission member 120.

[0152] The lower wall portion 126 extends from the lower end portion of the inner lower vertical wall portion 124 to the lower end portion of the outer side wall portion 122. The dimension of the lower wall portion 126 in the vehicle width direction is set to be longer than the dimension of the intermediate wall portion 125 in the vehicle width direction.

[0153] When viewed from the side of the vehicle, the upper portion of the side load transmission member 120 overlaps with the floor-side cross member 110, while the lower portion of the side load transmission member 120 overlaps with the second battery-side cross member 25B. Specifically, the side load transmission member 120 includes an inner upper vertical wall portion (first vertical wall portion) 123 that overlaps with the floor-side cross member 110 and extends in the vertical direction when viewed from the side of the vehicle, and an inner lower vertical wall portion (second vertical wall portion) 124 that overlaps with the battery box 10 and extends in the vertical direction when viewed from the side of the vehicle. Alternatively, the lower portion of the inner upper vertical wall portion 123 may overlap with the upper portion of the battery box 10.

[0154] First to fourth ribs 131 to 134 are integrally formed within the side load transmission member 120. The first rib 131 extends in the vehicle width direction at a location separated upward from the intermediate wall portion 125. The vehicle width inner end of the first rib 131 is connected to the vertical middle portion of the inner upper longitudinal wall portion 123. The first rib 131 is inclined so as to be positioned upward as it moves outward in the vehicle width direction.

[0155] The second rib 132 extends in the vehicle width direction at a location spaced downward from the first rib 131. The vehicle width inner end of the second rib 132 is connected to the upper end of the inner lower vertical wall portion 124. The vehicle width outer end of the second rib 132 is connected to the vertically intermediate portion of the outer side wall portion 122. The first rib 131 and the second rib 132 may extend generally horizontally, or may be inclined so as to be positioned upward as they move inward in the vehicle width direction, or may be inclined so as to be positioned upward as they move outward in the vehicle width direction.

[0156] The third rib 133 extends upward from the upper end of the inner lower vertical wall portion 124. The upper end of the third rib 133 is connected to the middle portion of the upper wall portion 121 in the vehicle width direction. The third rib 133 is inclined so that it is positioned more outward in the vehicle width direction as it moves upward. The outer end of the first rib 131 in the vehicle width direction is connected to the middle portion of the third rib 133 in the vertical direction.

[0157] The fourth rib 134 extends in the vehicle width direction at a location separated upward from the second rib 132. The vehicle width inner end of the fourth rib 134 is connected to the vertical middle portion of the third rib 133. The vehicle width outer end of the fourth rib 134 is connected to the vertical middle portion of the outer side wall portion 122. The vehicle width inner end of the fourth rib 134 is connected to the vehicle width outer end of the first rib 131 via the third rib 133, forming a single rib continuous in the vehicle width direction. The number and shape of the ribs formed within the side load transfer component 120 are not limited to those described above, and the number of ribs may be three or fewer, or five or more.

[0158] The battery box 10 is fixed to the lower side member 73 and directly fixed to the side load transmission member 120. A plurality of metal cylindrical members 140 extending in the vertical direction are fixed to the left side member 20 of the battery box 10. The front-to-back spacing of the cylindrical members 140 can be set to, for example, several tens of centimeters. Figure 2 As shown in FIG, a plurality of cylindrical members 140 are arranged at intervals in the front-rear direction. Bolts 141 are inserted into each cylindrical member 140 from below.

[0159] Meanwhile, an opening is formed in the inner surface of the rocker 73, corresponding to the first recess 73a, to allow the shaft of the bolt 141 to pass through. Similarly, an opening is formed in the intermediate wall 125 of the side load transmission component 120 to allow the shaft of the bolt 141 to pass through, and the two openings are aligned. Nuts 142 are housed within the side load transmission component 120. Nuts 142 are secured to the upper surface of the intermediate wall 125 of the side load transmission component 120. The number and position of the openings and nuts 142 correspond to the number and position of the tubular component 140.

[0160] Therefore, by inserting each bolt 141 into the cylindrical member 140 so that it passes through the opening of the rocker 73 and the opening of the side load transmission member 120, and then screwing it in by screwing it into the nut 142, multiple locations on the left side of the battery box 10 can be fixed to the side load transmission member 120 and the rocker 73. The right side of the battery box 10 can also be fixed in the same manner.

[0161] While this embodiment describes the side load transmission member 120 as an integrally molded component, the present invention is not limited thereto. The side load transmission member 120 may also be constructed by combining multiple components. Although not shown, the side load transmission member 120 may also have a two-part structure, where the vehicle widthwise inner and outer portions are molded separately and then integrated. Alternatively, the side load transmission member 120 may have a three-part structure.

[0162] like Figure 7 As shown in FIG. 1 and FIG. 2 , the upper structure 3 includes a pair of left and right hinge pillars 150. The right hinge pillar 150 extends upward from the front end of the right side sill 73. Figure 2 As shown, the left hinge pillar 150 extends upward from the front end of the left side rail 73. The left and right front doors 81 ( Figure 1 shown).

[0163] In addition, if Figure 10 As shown in FIG. 1 , the upper structure 3 further includes a pair of left and right center pillars 157. The right center pillar 157 extends upward from the middle portion of the right side sill 73 in the front-rear direction. Figure 2 As shown, the left center pillar 157 extends upward from the middle portion of the left side rail 73 in the front-rear direction. The left and right rear doors 82 ( Figure 1 shown).

[0164] like Figure 9 As shown, the upper structure 3 has a pair of left and right floor reinforcements (first front-to-back load transfer components) 151. The floor reinforcements 151 extend in the front-to-back direction along the upper surface of the front floor portion 70a. The front end of the floor reinforcement 151 on the right side is connected to the rear end of the front side frame 72 on the right side. The rear end of the floor reinforcement 151 on the right side is connected to the front end of the lower side beam 73 on the right side. Therefore, the front side frame 72 and the lower side beam 73 are connected through the floor reinforcement 151. Therefore, if the collision load during a head-on collision, for example, is input to the front side frame 72, the collision load is transferred to the lower side beam 73 via the floor reinforcement 151.

[0165] The floor reinforcement 151 bulges upward and opens downward, and the bulging shape continues from the front end to the rear end. By attaching the floor reinforcement 151 to the upper surface of the front floor portion 70a, the floor reinforcement 151 and the front floor portion 70a form a closed cross section.

[0166] Because the lower side sill 73 is located outboard of the front side frame 72 in the vehicle width direction, the floor reinforcement 151 curves and extends in a manner such that it is located outboard in the vehicle width direction as it moves toward the rear side when viewed from above. The curved shape of the floor reinforcement 151 corresponds to the shape of the lower end of the front wheel housing 85. In other words, the floor reinforcement 151 extends along the lower end of the front wheel housing 85 and is connected to and integrated with the front wheel housing 85. In addition, the left floor reinforcement (not shown) is symmetrical with the right floor reinforcement.

[0167] The floor reinforcement 151 is mounted on the upper surface of the front floor portion 70a. On the other hand, the outer connecting portion 30 ( Figure 3 As shown in FIG. 1 , the floor reinforcement 151 is positioned below the front floor portion 70a, and thus the floor reinforcement 151 and the outer connecting portion 30 are separated from each other in the vertical direction. Similarly, the floor reinforcement 151 and the inner connecting portion 31 are also separated from each other in the vertical direction.

[0168] Furthermore, when viewed from above, the portion of the right floor reinforcement 151 on the side of the rocker 73 (the rear end of the floor reinforcement 151) overlaps the portion of the right outer connector 30 on the side of the battery compartment 10 (the rear end of the outer connector 30). The rear end of the floor reinforcement 151 is connected to the rocker 73 and is therefore positioned adjacent to the rocker 73. On the other hand, the outer connector 30 is connected to the battery compartment 10 and is therefore separate from the rocker 73. However, the fact that the rear end of the outer connector 30 overlaps the rear end of the floor reinforcement 151 when viewed from above allows the rear end of the outer connector 30 to be closer to the rocker 73. This ensures that frontal collision loads are reliably directed toward the rocker 73 via the outer connector 30. The same applies to the left side.

[0169] The rear end of the right floor reinforcement 151 and the base end (lower end) of the right hinge pillar 150 are positioned at the same position in the front-rear direction. That is, the area near the base end of the hinge pillar 150 in the rocker 73 is particularly rigid. By connecting the rear end of the floor reinforcement 151 to this particularly rigid area, the rocker 73 can effectively absorb collision loads.

[0170] like Figure 7As shown, the upper structure 3 includes a pair of left and right lower load transfer members (second front-to-back load transfer members) 152. The lower load transfer members 152 are arranged above the front frame member 11 of the lower structure 2, and the front frame member 11 and the lower load transfer members 152 are separated from each other in the vertical direction. In addition, the lower load transfer members 152 extend in the front-to-back direction along the lower surface of the front floor portion 70a. Figure 11 As shown schematically, the front end of the right lower load transfer member 152 is connected to the rear end of the right front side frame 72. Furthermore, the lower load transfer member 152 extends toward the front of the battery compartment 10. Therefore, when a frontal collision load, for example, is input rearwardly to the front side frame 72, the load is transferred to the front of the battery compartment 10 via the lower load transfer member 152. The left lower load transfer member 152 is symmetrical with the right lower load transfer member.

[0171] The lower load transmission member 152 bulges downward and opens upward, with the bulging shape continuing from the front end to the rear end. By attaching the lower load transmission member 152 to the lower surface of the front floor portion 70a, the lower load transmission member 152 and the front floor portion 70a form a closed cross-section.

[0172] The rear portion of the right lower load transmission member 152 is positioned to the right of the front center beam 26 in the battery box 10 and to the left of the right side beam 21. Furthermore, the rear portion of the left lower load transmission member 152 is positioned to the left of the front center beam 26 in the battery box 10 and to the right of the left side beam 20.

[0173] like Figures 7 to 9 As shown, a cross member 153 is provided on the lower surface of the front floor portion 70a. This cross member 153 extends in the left-right direction and connects the rear portion of the left lower load transfer member 152 with the rear portion of the right lower load transfer member 152. The cross member 153 bulges downward and opens upward, forming a substantially uniform cross-sectional shape at both left and right ends. By attaching the cross member 153 to the lower surface of the front floor portion 70a, the cross member 153 and the front floor portion 70a form a closed cross-sectional shape. The provision of the cross member 153 prevents the rear portion of the left and right lower load transfer members 152 from displacing in the left-right direction when the lower load transfer members 152 are subjected to the impact load of a head-on collision.

[0174] like Figure 11 As shown, the front end beam 22 constituting the front portion of the battery box 10 is disposed directly below the cross member 153. The front end beam 22 is fastened to the cross member 153 by bolts and nuts (not shown). The fastening structure of the front end beam 22 can be the same as the fastening structure of the left side beam 20 to the lower side beam 73.

[0175] A protrusion 22a that protrudes upward is provided at the front of the battery box 10. Specifically, the protrusion 22a is provided at a portion of the front end beam 22 that is rearward of the cross beam 153. The protrusion 22a is located rearward of the rear portion of the lower load transfer component 152. In addition, the protrusion 22a is formed so that its upper end is located above the lower surface of the cross beam 153 and above the lower surface of the rear portion of the lower load transfer component 152. As a result, when viewed from the front-to-back direction, the cross beam 153 and the lower load transfer component 152 overlap with the protrusion 22a. The protrusion 22a is the portion to which the collision load is transferred from the lower load transfer component 152 when the lower load transfer component 152 moves backward due to the collision load during a head-on collision.

[0176] The protrusion 22a extends continuously in the left-right direction. In other words, during a head-on collision, the rear portion of the lower load transmission member 152 could potentially shift slightly in the left-right direction. However, because the protrusion 22a is continuous in the left-right direction, even if the rear portion of the lower load transmission member 152 shifts in the left-right direction, the collision load is reliably transmitted to the protrusion 22a. Furthermore, the protrusion 22a is not limited to a continuous left-right structure; it can be formed discontinuously and at least partially overlap the rear portion of the lower load transmission member 152 when viewed from the front-back direction.

[0177] The protrusion 22a can be integrally formed with the front end beam 22 or comprised of a separate component. If the front end beam 22 is made of an extruded material, the protrusion 22a can be easily integrally formed. The protrusion 22a can be fixed to, for example, the base plate 24, the left side beam 20, the right side beam 21, or the like. The protrusion 22a can have any desired shape, such as a plate (rib), a rod, or a cylinder. By forming the protrusion 22a in a rib-like shape and integrally with the front end beam 22, a reinforcement effect can be achieved for the front end beam 22.

[0178] The rear portion of the lower load transmission member 152 and the protrusion 22a are arranged with a predetermined distance in the front-to-rear direction. This predetermined distance prevents the lower load transmission member 152 from contacting the protrusion 22a during normal driving, thereby preventing interference noise and the like. On the other hand, if the lower load transmission member 152 moves rearward during a head-on collision, the rear portion of the lower load transmission member 152 contacts the protrusion 22a, reliably transmitting the collision load to the protrusion 22a. Specifically, the predetermined distance is set so that the lower load transmission member 152 and the protrusion 22a do not contact each other during normal driving, but do contact each other during a head-on collision. For example, the predetermined distance can be set to a distance of several millimeters to several centimeters. Alternatively, the rear portion of the lower load transmission member 152 and the protrusion 22a may be in contact. Furthermore, the rear portion of the lower load transmission member 152 and the protrusion 22a may be fastened together using a fastening member.

[0179] In addition, Figure 6 In the illustrated embodiment, the front center beam 26 within the battery box 10 is positioned below the front floor portion 70a and is taller than the first to third rear center beams 27 to 29. Consequently, the vertical dimension of the front center beam 26 is increased, and the large-cross-section front center beam 26 is positioned at the front of the battery box 10. This prevents deformation of the battery box 10 when the front of the battery box 10 bears a collision load transmitted from the lower load transmission member 152.

[0180] (Connection structure between the rear of the battery box and the upper structure)

[0181] like Figure 13 As shown, the rear portion of the battery box 10 and the upper structure 3 are connected by a connecting member 160. Before explaining the connection structure, the structure of the rear side of the upper structure 3 will be described. The rear wheel housing 170 for accommodating the left and right rear wheels R is provided on the left and right sides of the rear portion of the upper structure 3 (at Figures 7 to 9 Only the right rear wheelhouse portion is shown in the figure. The luggage compartment floor portion 70e, which constitutes the floor surface of the luggage compartment R2, extends rearward from the rear of the upper curved portion 70c and is located above the rear floor portion 70b. The rear floor portion 70b is regarded as the first floor portion, and the upper curved portion 70c and the luggage compartment floor portion 70e are regarded as the relatively higher second floor portion. The left end of the luggage compartment floor portion 70e is aligned with the left rear wheelhouse portion 170 ( Figure 2 In addition, the right end portion of the luggage compartment floor portion 70e is connected to the right rear wheel cover portion 170 ( Figures 7 to 9 (as shown) connections.

[0182] like Figures 7 to 9As shown, a rear cross member (first cross member) 171 extending in the left-right direction is attached to the lower surface of the upper curved portion 70c. The rear cross member 171 bulges downward and opens upward, with this bulging shape continuing from the left end to the right end. By attaching the rear cross member 171 to the lower surface of the upper curved portion 70c, the rear cross member 171 and the upper curved portion 70c form a closed cross section.

[0183] A rear floor cross member 172 is attached to the upper surface of the upper curved portion 70c, extending horizontally directly above the rear cross member 171. The rear floor cross member 172 bulges upward and opens downward, with this bulging shape continuing from the left end to the right end. By attaching the rear floor cross member 172 to the upper surface of the upper curved portion 70c, the rear floor cross member 172 and the upper curved portion 70c form a closed cross section. When viewed from above, the rear floor cross member 172 overlaps the rear cross member 171.

[0184] In addition, the right end portion of the rear floor side cross member 172 is connected to the right rear wheel housing portion 170, and the left end portion of the rear floor side cross member 172 is connected to the left rear wheel housing portion 170. In addition, the lower end portion of a side reinforcement 173 extending upward along the right rear wheel housing portion 170 is connected to the right end portion of the rear floor side cross member 172. In addition, the lower end portion of a side reinforcement (not shown) extending upward along the left rear wheel housing portion 170 is connected to the left end portion of the rear floor side cross member 172. Moreover, the upper portion of the right side reinforcement 173 and the upper portion of the left side reinforcement are connected by a connecting member 174 ( Figure 8 and Figure 9 That is, the rear floor side cross member 172, the left and right side reinforcements 173, and the connecting member 174 form an annular structure. The annular structure can also be formed by a reinforcement member (not shown) provided on the roof 80 side.

[0185] On the other hand, Figure 13 As shown, the battery box 10 has a box side crossbeam (second crossbeam) 180 (at Figures 2 to 6 (omitted). The box-side cross member 180 extends in the left-right direction and is attached to the rear end member 23 that constitutes the rear portion of the battery box 10. The box-side cross member 180 is located above the rear end member 23. The box-side cross member 180 and the rear cross member 171 are arranged so as to face each other in the vertical direction.

[0186] like Figure 13As shown, the connecting member 160 is used to connect the rear end beam 23 of the battery box 10 and the upper curved portion 70c. This allows the battery box 10 to reinforce the upper curved portion 70c, thereby increasing its rigidity. By increasing the rigidity of the upper curved portion 70c, the overall rigidity of the floor panel 70 is also increased. In this embodiment, the connecting member 160 is formed of a plate extending in the left-right and up-down directions, but is not limited to this. It may also be a beam with a closed cross-section extending in the up-down direction or at an angle, an axial member, a cylindrical member, or the like. Furthermore, multiple connecting members 160 may be provided.

[0187] The upper portion of the connecting member 160 is fixed to the lower portion of the rear cross member 171. Thus, the battery box 10 and the upper curved portion 70c are connected by the connecting member 160 via the rear cross member 171. That is, the upper portion of the connecting member 160 can be fixed to the portion whose rigidity is increased by providing the rear cross member 171, thereby increasing the fixing strength of the connecting member 160 to the upper curved portion 70c. The fixing structure of the upper portion of the connecting member 160 can use a detachable fastening structure using fastening members such as bolts and nuts (not shown). Alternatively, the upper portion of the connecting member 160 can be directly connected to the upper curved portion 70c.

[0188] Furthermore, the lower portion of the connecting member 160 is fixed to the case-side cross member 180, which constitutes a portion of the battery case 10. This allows the lower portion of the connecting member 160 to be fixed to a portion of the battery case 10 with increased rigidity, thereby increasing the strength with which the connecting member 160 is fixed to the battery case 10. Furthermore, the lower portion of the connecting member 160 can be detachably fixed to the battery case 10 using the aforementioned fastening member. The connecting member 160 can be provided as a component of either the upper structural body 3 or the lower structural body 2.

[0189] (Positional Relationship between the Beams of the Upper and Lower Structures)

[0190] Figure 14 This schematic diagram illustrates the positional relationship between the cross members of the upper structure 3 and the lower structure 2, according to a modified embodiment. First, second, and third floor-side cross members 110A, 110B, and 110C extending in the vehicle width direction are attached to the upper surface of the floor panel 70 of the upper structure 3. Furthermore, a cross member 153 is attached to the lower surface of the floor panel 70. Cross member 153 is a floor-side cross member because it is attached to the floor panel 70.

[0191] The first floor side cross member 110A is the above-mentioned cross member 110, and is arranged to be separated from the cross member 153 to the rear. The second floor side cross member 110B is arranged to be separated from the first floor side cross member 110A to the rear. The third floor side cross member 110C is arranged to be separated from the second floor side cross member 110B to the rear. On the other hand, the battery box 10 of the lower structure 2 is provided with the above-mentioned first to third battery side cross members 25A, 25B, 25C. When viewed from the side, the cross member 153, the first to third floor side cross members 110A, 110B, 110C and the first to third battery side cross members 25A, 25B, 25C are in contact with the lower side member 73 ( Figure 10 etc.) overlap.

[0192] When viewed from the side of the vehicle, the cross member 153 and the first to third floor-side cross members 110A, 110B, and 110C are offset from the first to third battery-side cross members 25A, 25B, and 25C in the vehicle front-to-rear direction. Specifically, the cross member 153, the first battery-side cross member 25A, the first floor-side cross member 110A, the second battery-side cross member 25B, the second floor-side cross member 110B, the third battery-side cross member 25C, and the third floor-side cross member 110C are arranged in this order from the vehicle front toward the rear. The cross member 153, the first to third floor-side cross members 110A, 110B, and 110C are alternately arranged with the first to third battery-side cross members 25A, 25B, and 25C in the front-to-rear direction.

[0193] For example, when focusing on the first floor-side cross member 110A and the second floor-side cross member 110B, the second battery-side cross member 25B is located forward of the first floor-side cross member 110A and rearward of the second floor-side cross member 110B. On the other hand, when focusing on the first battery-side cross member 25A and the second battery-side cross member 25B, the first floor-side cross member 110A is located rearward of the first battery-side cross member 25A and forward of the second battery-side cross member 25B. This positional relationship is referred to as "misalignment in the vehicle front-rear direction."

[0194] In addition, "offset in the vehicle front-rear direction" may also include other forms. For example, it may include a form in which the front-rear center of the first floor side cross member 110A and the front-rear center of the second battery side cross member 25B are offset in the front-rear direction. In this case, Figure 14 The embodiment shown in the figure also includes an embodiment in which the rear portion of the first floor-side cross member 110A and the front portion of the second battery-side cross member 25B are in an overlapping positional relationship in a plan view.

[0195] Furthermore, for example, a configuration in which the front portion of the first floor side cross member 110A is located forward of the front portion of the second battery side cross member 25B, and a configuration in which the rear portion of the second battery side cross member 25B is located rearward of the rear portion of the first floor side cross member 110A are also included in “offset in the vehicle front-rear direction.”

[0196] In the event of a side collision, the collision load can be absorbed by cross member 153, along with the first to third floor-side cross members 110A, 110B, 110C, and the first to third battery-side cross members 25A, 25B, 25C. Since cross member 153, along with the first to third floor-side cross members 110A, 110B, 110C, and the first to third battery-side cross members 25A, 25B, 25C are offset in the vehicle front-to-rear direction as described above, even if the obstacle is a thin object such as a pole, the collision load of the obstacle can be transferred to any one of cross member 153, the first to third floor-side cross members 110A, 110B, 110C, and the first to third battery-side cross members 25A, 25B, 25C.

[0197] When viewed from the side of the vehicle, only the hinge pillar 150 (at Figure 14 In the area where the first to third floor-side cross members 110A, 110B, and 110C do not overlap (indicated by phantom lines in the figure), the first to third battery-side cross members 25A, 25B, and 25C are offset in the front-to-back direction. Specifically, the first to third floor-side cross members 110A, 110B, and 110C, located rearward of the hinge pillar 150, and the first to third battery-side cross members 25A, 25B, and 25C are offset in the front-to-back direction. This means that the area where the hinge pillar 150 is located has a higher resistance to side collision loads. Therefore, even if the floor-side cross members and the battery-side cross members are not offset in the front-to-back direction, the collision load can still be absorbed by the hinge pillar 150.

[0198] Similarly, when viewed from the side of the vehicle, only the first and third floor-side cross members 110A, 110C and the first to third battery-side cross members 25A, 25B, 25C located in the region not overlapping with the center pillar 157 may be offset in the front-rear direction.

[0199] (Effects of head-on collision)

[0200] Next, a description will be given of a head-on collision of the electric vehicle 1 constructed as described above. The collision load during a head-on collision is input to the left and right front side frames 72 via the front bumper reinforcement 86. Furthermore, the collision load during a head-on collision is also input to the left and right front frame members 11.

[0201] The front frame member 11 is connected to the left front side frame 72 by the left connecting portions 53 and 54 at multiple locations separated in the front-to-back direction. Therefore, the left front frame member 11, which is subjected to the collision load, is stable and less likely to tilt in the left-right and vertical directions. The same applies to the right front frame member 11. As a result, the collision load is linearly transmitted to the front of the battery box 10 through the left and right front frame members 11.

[0202] At this time, the front frame member 11 is connected to the battery box 10 at multiple locations separated from each other in the left-right direction via the outer connecting portions 30 and the inner connecting portions 31. Therefore, collision loads applied to the front frame member 11 are applied to multiple, separated locations in the battery box 10. The battery box 10 includes a front center beam 26 and left and right side beams 20, 21 extending in the front-to-back direction. Therefore, collision loads applied to multiple, separated locations in the left-to-right direction are distributed and transmitted to the front center beam 26, left and right side beams 20, 21. This allows the battery box 10 to actively absorb collision loads, thereby increasing the amount of collision load absorbed by the lower structure 2. This, in turn, optimizes the strength of the front side frames 72 and the components near the rear ends of the front side frames 72, thereby reducing the overall vehicle weight.

[0203] Furthermore, collision loads applied to the front side sills 72 are transmitted to the rocker 73 via the floor reinforcement 151. Furthermore, because the outer connecting portion 30 extends toward the rocker 73, collision loads applied to the front frame member 11 are also directed toward the rocker 73 via the outer connecting portion 30. At this point, because the floor reinforcement 151 and the outer connecting portion 30 are separated in the vertical direction, the collision loads transmitted from the front side sills 72 to the rocker 73 follow different paths than the collision loads transmitted from the front frame member 11 toward the rocker 73. Consequently, the collision loads are transmitted to the rocker 73 through multiple paths. The rocker 73 is a particularly rigid member of the vehicle body, so the rocker 73 can absorb the collision loads.

[0204] Furthermore, the collision load input to the front side frame 72 is transmitted from the rear portion of the front side frame 72 to the battery box 10 via both the floor reinforcement 151 and the lower load transmission member 152. This also creates a path for the collision load to be transmitted to the battery box 10 via the lower load transmission member 152, allowing the collision load to be distributed and absorbed by both the rocker 73 and the battery box 10. Furthermore, because the floor reinforcement 151 and the lower load transmission member 152 extend along the floor panel 70, a portion of the collision load input to the floor reinforcement 151 and the lower load transmission member 152 is also transmitted to the floor panel 70, thereby also being absorbed by the floor panel 70.

[0205] In addition, in the case of a frontal offset collision, a large collision load will be input to either the left or right side, but this embodiment is also effective in this case. In addition, in the case of a rear-end collision, the rear frame member 12 is provided, so the same effect can be achieved.

[0206] (Effects of side collision)

[0207] Next, a description will be given of a side collision involving the electric vehicle 1 configured as described above. During a side collision, the impact load is input from the outside in the vehicle width direction to the inside of the rocker 73. Because the rocker 73 is internally provided with a side load transfer member 120, the impact load is input from the outside in the vehicle width direction to the inside of the rocker 73. In this case, the inner upper longitudinal wall portion 123 of the side load transfer member 120 overlaps with the floor-side cross members 110 and 153, and the inner lower longitudinal wall portion 124 overlaps with the battery box 10. This distributes the impact load across the floor-side cross members 110 and 153 and the battery box 10. Because the floor-side cross members 110 and 153 extend in the vehicle width direction when attached to the floor panel 70, they have a high resistance to side loads. This absorbs a portion of the impact load, reducing the impact load input to the battery box 10 and protecting the battery B. Furthermore, since the battery box 10 is provided with the first to third battery-side cross members 25A, 25B, and 25C, the front end member 22 , and the rear end member 23 , the collision load can also be absorbed by the battery box 10 .

[0208] In addition, when an obstacle such as a pole collides with the vehicle from the side, Figure 14The cross member 153, along with the first to third floor-side cross members 110A, 110B, and 110C, and the first to third battery-side cross members 25A, 25B, and 25C, are offset in the vehicle's longitudinal direction. This allows collision loads to be transferred to any of the cross members. Furthermore, a thin bar could collide between the first floor-side cross member 110A and the second battery-side cross member 25B. In this case, after the high-strength side load transfer member 120 receives the collision load from the bar, the collision load can be distributed and absorbed between at least the first floor-side cross member 110A and the second battery-side cross member 25B.

[0209] Furthermore, when the obstacle is a large-diameter pole or a car, the collision load is input to both the first to third floor-side cross members 110A, 110B, 110C and the first to third battery-side cross members 25A, 25B, 25C. Therefore, the collision load is distributed and transmitted to the floor panel 70 and the battery box 10.

[0210] The above embodiments are merely illustrative in all respects and should not be construed as limiting. Moreover, all modifications and variations within the scope of equivalents to the scope of the claimed invention are within the scope of the present invention.

[0211] Industrial applicability

[0212] As described above, the vehicle body structure according to the present invention is suitable for an electric vehicle equipped with a traction motor and a battery.

Claims

1. A vehicle body structure for an electric vehicle, wherein the electric vehicle includes a driving motor, and a battery box containing a battery for supplying power to the driving motor is disposed below a floor panel, wherein: The floor panel includes a first floor portion and a second floor portion located above the first floor portion. The vehicle body structure is provided with a connecting member connecting the battery box and the second floor portion. A first cross member extending in the vehicle width direction is mounted on the lower surface of the second floor portion. The battery box has a second cross member extending in the vehicle width direction above a rear end member constituting a rear portion of the battery box. The upper portion of the connecting member is fixed to the first beam, The lower portion of the connecting member is fixed to the second crossbeam, The battery box and the second floor portion are connected by the connecting member via the first cross member. The first beam and the second beam are arranged to face each other in the up-down direction.

2. The vehicle body structure according to claim 1, wherein: A pair of left and right wheel housings are connected to both ends of the second floor portion in the vehicle width direction. Both ends of the first cross member are connected to the left and right wheel house portions, respectively.

3. The vehicle body structure according to claim 1 or 2, characterized in that: A floor side cross member extending in the vehicle width direction directly above the first cross member is attached to the upper surface of the second floor portion.

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