Body structure

Abstract

To efficiently enhance the rigidity of a high part of a floor panel by utilizing a battery case provided below the floor panel.SOLUTION: A floor panel 70 has a first floor portion 70b, and a second floor portion 70c located higher than the first floor portion 70b. A vehicle body structure is provided with a connecting member 160 extending from a battery case 10 to the second floor portion 70c and connecting the battery case 10 and the second floor portion 70c.SELECTED DRAWING: Figure 13

Description

[Technical Field]

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

[0002] For example, in the case of a vehicle equipped with a traction motor, a battery unit is installed to supply power to the traction motor, and this battery unit has a large capacity to extend the driving range of the traction motor.

[0003] The battery unit of the electric vehicle disclosed in Patent Document 1 is mounted over a wide area under the floor. The front of the vehicle body is provided with a pair of left and right front side members extending in the longitudinal direction of the vehicle, and an under-member extending in the longitudinal direction of the vehicle below the front side members. The battery unit under the floor also includes a case main body. A pair of left and right front extensions extending toward the front of the vehicle are formed on the front wall of the case main body, and the front ends of the front extensions are connected to the rear ends of the under-members. A pair of left and right rear extensions extending toward the rear of the vehicle are integrally formed on the rear wall of the case main body. The case main body is fixed to a floor under-reinforcement, and the front and rear extensions are fixed to the front side members and rear side members, respectively. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-158688 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, automobile floor panels may have low and high portions. For example, there are floor panels in which the portion corresponding to the feet of rear seat passengers is low and the portion where the rear seat passengers sit is high.

[0006] Although the floor panel is one of the largest components that make up the vehicle body, it is plate-shaped, and so improving the rigidity of the floor panel itself is an issue, as a lack of floor panel rigidity leads to a decrease in the rigidity of the vehicle body.

[0007] Generally, the rigidity of a vehicle body can be improved by attaching reinforcing members to various parts. However, since reinforcing members for improving the rigidity of a vehicle body are large and heavy, it is difficult to say that such members can efficiently improve the rigidity of a vehicle body.

[0008] In this regard, Patent Document 1 stipulates that the case body of the battery unit is fixed to the floor under-reinforcement, but because the floor under-reinforcement is a member that extends horizontally in the fore-and-aft direction under the floor panel, if the floor panel has a high portion, that high portion cannot be fixed to the case body. In other words, while the floor under-reinforcement and the case body may be able to improve the rigidity of the low portion of the floor panel, the high portion is separated upward from the floor under-reinforcement and the case body, and little reinforcing effect can be expected from the floor under-reinforcement and the case body.

[0009] The present invention was made in consideration of these points, and its purpose is to efficiently improve the rigidity of the higher parts of the floor panel by utilizing a battery case located below the floor panel. [Means for solving the problem]

[0010] To achieve the above object, a first aspect of the present disclosure can be based on a vehicle body structure for an electric vehicle that includes a traction motor and a battery case that houses a battery that supplies power to the traction motor and is disposed below a floor panel. The floor panel has a first floor section and a second floor section that is positioned above the first floor section. A connecting member is provided to connect the battery case and the second floor section.

[0011] According to this configuration, the floor panel is provided with a first floor section, which is a relatively low section, and a second floor section, which is a relatively high section. The second floor section is then connected to the battery case by a connecting member. This battery case is configured to be highly strong because it houses a heavy battery. Therefore, the second floor section is reinforced using the high-strength battery case without providing a heavy reinforcing member, thereby efficiently improving the rigidity of the second floor section.

[0012] In a second aspect of the present disclosure, a first cross member extending in the vehicle width direction is attached to the underside of the second floor portion, the upper part of the connecting member is fixed to the first cross member, and the battery case and the second floor portion are connected by the connecting member via the first cross member.

[0013] With this configuration, the portions whose strength has been increased by the first cross member can be connected by the connecting member, thereby further improving the rigidity of the second floor portion.

[0014] In a third aspect of the present disclosure, the battery case has a second cross member extending in the vehicle width direction, and a lower portion of the connecting member is fixed to the second cross member.

[0015] According to this configuration, the battery case, whose strength has been increased by the second cross member, can be connected by the connecting member, thereby further improving the rigidity of the second floor portion.

[0016] According to a fourth aspect of the present disclosure, the first cross member and the second cross member are disposed to face each other in the up-down direction.

[0017] According to this configuration, the first cross member and the second cross member are closer to each other, so that the vertical dimension of the connecting member can be shortened, further improving the reinforcing effect.

[0018] In a fifth aspect of the present disclosure, a pair of left and right wheel house sections are connected to both end sections of the second floor section in a vehicle width direction, The vehicle further includes a floor-side cross member extending in the left-right direction, the left end of the floor-side cross member being connected to the left wheel house portion, and the right end of the floor-side cross member being connected to the right wheel house portion. are.

[0019] With this configuration, for example, the load input to the wheelhouse section during driving can be distributed to the battery case via the first cross member, the second floor section, and the connecting member, thereby further improving the rigidity of the vehicle body.

[0020] In a sixth aspect of the present disclosure, The floor side cross member is Directly above the first cross member On the upper surface of the second floor portion It is installed.

[0021] With this configuration, the highly rigid portions of the second floor section can be connected by the connecting member, further improving the reinforcing effect. [Effects of the Invention]

[0022] As described above, the battery case and the relatively high second floor section are connected by the connecting member, so the rigidity of the second floor section can be improved efficiently. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a side view of an electric vehicle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side view showing the electric vehicle divided into a lower structure and an upper structure. [Figure 3]FIG. 2 is a perspective view of the lower structure seen from above. [Figure 4] FIG. [Figure 5] FIG. 5 is a view equivalent to FIG. 4 of a lower structure equipped with a small battery case. [Figure 6] FIG. 10 is a left side view of the lower structure when the height of the front central member is increased. [Figure 7] FIG. 2 is a cross-sectional view of the electric vehicle at the center in the left-right direction. [Figure 8] FIG. 1 is a cross-sectional view of an electric vehicle as seen from the front. [Figure 9] FIG. 1 is a cross-sectional view of an electric vehicle seen from the rear. [Figure 10] FIG. 1 is a front perspective view showing a cross section passing through the front seat portion of an electric vehicle. [Figure 11] FIG. 2 is a diagram schematically showing a floor panel, a front seat, a front seat occupant, and a battery unit. [Figure 12] 11 is an enlarged view of part C in FIG. 10 as seen from the front. [Figure 13] FIG. 2 is a perspective view from below showing a cross section of the rear part of the electric vehicle. [Figure 14] 10A and 10B are diagrams schematically showing a floor panel and a battery unit according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

[0025] FIG. 1 is a left side view of an electric vehicle 1 equipped with a vehicle body structure A according to an embodiment of the present invention. As shown in FIG. 2, this electric vehicle 1 is equipped with a lower structure 2 and an upper structure 3, and the lower structure 2 and the upper structure 3 constitute the vehicle body structure A. FIG. 2 shows a state in which the doors, bonnet hood, front fenders, windshields, bumpers, front and rear lighting devices, etc. have been removed. In the description of this embodiment, the front side of the vehicle will be simply referred to as the "front", the rear side of the vehicle will be simply referred to as the "rear", the right side of the vehicle will be simply referred to as the "right", and the left side of the vehicle will be simply referred to as the "left". The left-right direction of the vehicle is the vehicle width direction.

[0026] As shown in FIG. 1, the electric vehicle 1 is a passenger vehicle. As shown in FIG. 2, a front seat S1 is provided at the front of a passenger compartment R1, which is a living space for passengers, and a rear seat S2 is provided behind the front seat S1 in the passenger compartment R1. A luggage compartment R2 is provided behind the rear seat S2 as needed. The passenger compartment R1 and the luggage compartment R2 are provided in an upper structure 3. Note that the passenger compartment R may be provided with only the front seat S1, or may also have a third row of seats (not shown) behind the rear seat S2.

[0027] Meanwhile, the space in front of the passenger compartment R1, which is the front portion of the electric vehicle 1, can be, for example, a power compartment R3. That is, the vehicle body structure A includes a traction motor M that generates power to drive the drive wheels and a battery case 10 that houses a battery B (shown only in FIG. 4) that supplies power to the traction motor M. A powertrain PT is configured by the traction motor M alone, or the traction motor M together with a reducer, a transmission, and the like. While FIGS. 1 and 2 show a case in which the powertrain PT is provided only in the power compartment R3, the powertrain PT may also be provided in the lower space R4 of the luggage compartment R2 (a rear powertrain is not shown). When the powertrain PT is provided only in the power compartment 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 compartment R3 can be used as a luggage compartment, etc. Furthermore, when the powertrain PT is provided in both the power compartment R3 and the lower space R4, the vehicle becomes a four-wheel drive vehicle. The battery case 10 is disposed below a floor panel 70, which will be described later.

[0028] 3 and 4, the lower structure 2 includes a battery case 10, a front frame member 11 extending forward in front of the battery case 10, and a rear frame member 12 extending rearward behind the battery case 10. In FIG. 3, the left front wheel F, rear wheel R, suspension arm, etc. are omitted.

[0029] In the case of a typical electric vehicle, the battery case is often separate from the vehicle body and is detachably attached under the floor, but in this embodiment, not only is the battery case 10 formed as an integral part of the battery case 10, but the front frame member 11 and rear frame member 12 are also integrated into the battery case 10, and the front frame member 11 and rear frame member 12 are also detachably attached to the upper structure 3 together with the battery case 10.

[0030] Specifically, the electric vehicle 1 of this embodiment is configured to be separable into a lower structure 2 having a battery case 10 and an upper structure 3 that forms the passenger compartment R1 and luggage compartment R2. Being separable into upper and lower structures means that the lower structure 2 is integrated with the upper structure 3 using fastening members such as bolts, nuts, and screws, without using welding, adhesives, or the like. This allows the lower structure 2 to be separated from the upper structure 3 as needed when performing maintenance or repairs on the electric vehicle 1 after it has been delivered to the user, improving maintainability.

[0031] Here, a ladder frame type vehicle body structure is known as an automobile body structure. In the case of a ladder frame type vehicle body structure, the ladder frame can be separated into an upper and lower portion and a cabin. However, since the ladder frame extends continuously in the fore-and-aft direction, it mainly bears the collision load in the event of a frontal collision and a rearward collision. In the event of a side collision, the ladder frame only auxiliarily bears the collision load, and it is the cabin that mainly bears the collision load. In this way, in a ladder frame type vehicle body structure, the components that bear the collision load in the event of a frontal collision and a rearward collision and in the event of a side collision are usually separated.

[0032] In contrast, in the case of the electric vehicle 1 of this embodiment, the lower structure 2 and upper structure 3 having frame members 11, 12 are separable, but in the event of a frontal collision, a rear collision, and a side collision, the collision load is received by the lower structure 2 and the upper structure 3, and the collision load can be distributed and absorbed by both structures 2, 3, which is a significant difference in technical concept from a conventional ladder frame type vehicle body structure. Below, the structures and effects of the lower structure 2 and upper structure 3 will be explained in order.

[0033] (undercarriage) First, we will explain the lower structure 2. As shown in Figures 3 and 4, in addition to the battery case 10, front frame 11, and rear frame 12, the lower structure 2 also includes a power train PT, front wheels F, rear wheels R, a front suspension device 13, and a rear suspension device 14. There is no particular restriction on the type of the front suspension device 13 and the rear suspension device 14.

[0034] The battery case 10 is a large case formed below a floor panel 70 (described later), extending from near the left end to near the right end of the floor panel 70 and from near the front end to near the rear end of the floor panel 70. By providing the battery case 10 over a wide area below the floor panel 70 in this manner, it becomes possible to mount a large-capacity battery B in the electric vehicle 1, as shown in FIG. 4. The battery B may be, for example, a lithium-ion battery, an all-solid-state battery, or another secondary battery. The battery B may also be a so-called battery cell, or a battery pack containing multiple battery cells.

[0035] The battery case 10 includes a left side member 20, a right side member 21, a front end member 22, a rear end member 23, and a bottom plate 24. The left side member 20, the right side member 21, the front end member 22, and the rear end member 23 are made of, for example, an aluminum alloy extrusion, but may also be made of an aluminum alloy plate or a press-formed steel plate. The bottom plate 24 may also be made of an extrusion. In the following description, "extrusion" refers to an aluminum alloy extrusion, and "press-formed material" refers to an aluminum alloy plate or a press-formed steel plate. Each member may also be made of, for example, a casting.

[0036] The cross-sectional shapes of the left side member 20, the right side member 21, the front end member 22, and the rear end member 23 in a direction perpendicular to the longitudinal direction are all rectangular. Furthermore, the left side member 20, the right side member 21, the front end member 22, and the rear end member 23 are all disposed at the same height and extend substantially horizontally.

[0037] The left side member 20 is provided at the left end of the battery case 1 and extends in the front-rear direction. The right side member 21 is provided at the right end of the battery case 1 and extends in the front-rear direction. The front end member 22 is provided at the front end of the battery case 1 and extends in the left-right direction. The left end of the front end member 22 is connected to the front end of the left side member 20, and the right end of the front end member 22 is connected to the front end of the right side member 21. The rear end member 23 is provided at the rear end of the battery case 1 and extends in the left-right direction. The left end of the rear end member 23 is connected to the rear end of the left side member 20, and the right end of the rear end member 23 is connected to the rear end of the right side member 21. The bottom plate 24 extends approximately horizontally and is fixed to the lower surfaces of the left side member 20, right side member 21, front end member 22, and rear end member 23. Therefore, the left side member 20, the right side member 21, the front end member 22, the rear end member 23 and the bottom plate 24 define a battery accommodating space S (shown in FIG. 3) for accommodating the battery B.

[0038] The size of the battery accommodating space S can be changed depending on the capacity of the battery B to be installed. The size of the battery accommodating space S can be easily changed by changing the lengths of the left side member 20, the right side member 21, the front end member 22, and the rear end member 23 and the shape of the bottom plate 24. For example, in the case of a compact vehicle with a short wheelbase and a narrow tread, the left side member 20, the right side member 21, the front end member 22, and the rear end member 23 can be shortened and the shape of the bottom plate 24 can be reduced accordingly, thereby reducing the battery accommodating space S for a compact vehicle (see FIG. 5). On the other hand, in the case of a large vehicle, the left side member 20, the right side member 21, the front end member 22, and the rear end member 23 can be lengthened and the shape of the bottom plate 24 can be increased accordingly, thereby increasing the battery accommodating space S for a large vehicle. If the left side member 20, the right side member 21, the front end member 22, and the rear end member 23 are made of extruded material, the lengths can be easily changed. Furthermore, the bottom plate 24 can also be made of extruded material, which makes it easy to change the shape.

[0039] The top of the battery storage space S may be closed by a lid (not shown) or by 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 (temperature control device), etc. Furthermore, the power of 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).

[0040] As shown in Fig. 3, first to third battery-side cross members 25A, 25B, and 25C are provided inside the battery case 10 as reinforcing members extending in the left-right direction. The first to third battery-side cross members 25A, 25B, and 25C all have the same height, which is approximately the same as the height of the left side member 20 and the like. The battery-side cross members 25A, 25B, and 25C may be made of an extruded material or a press-formed material. In this embodiment, three battery-side cross members 25A, 25B, and 25C are provided, but the number of battery-side cross members 25A, 25B, and 25C can be increased or decreased depending on the dimension of the battery case 10 in the front-rear direction.

[0041] The first to third battery-side cross members 25A, 25B, and 25C are spaced apart from one another in the front-to-rear direction, with the first battery-side cross member 25A positioned at the forefront and the third battery-side cross member 25C positioned at the rearmost. The lower portions of each battery-side cross member 25A, 25B, and 25C are fixed to the upper surface of the bottom plate 24. The left ends of each battery-side cross member 25A, 25B, and 25C are fixed to the inner surface (right side surface) of the left side member 20, and the right ends of each battery-side cross member 25A, 25B, and 25C are fixed to the inner surface (left side surface) of the right side member 21. In other words, the battery-side cross members 25A, 25B, and 25C are members that connect the left side member 20 and the right side member 21.

[0042] Figure 5 above shows an example of a lower structure 2 equipped with a small battery case 10 that is set to be shorter in the front-to-rear direction than the battery case 10 shown in Figure 4, but in the example shown in Figure 5, the third battery-side cross member 25C is omitted due to the shorter front-to-rear direction dimension. Conversely, although not shown, a fourth battery-side cross member can also be provided.

[0043] A front central member (front reinforcing member) 26 and first to third rear central members (rear reinforcing members) 27 to 29 are provided inside the battery case 10 as reinforcing members extending in the front-rear direction. The front central member 26 and the first to third rear central members 27 to 29 are disposed at approximately the same height and are provided in the center of the battery case 10 in the left-right direction. The lower ends of the front central member 26 and the first to third rear central members 27 to 29 are attached to the upper surface of the bottom plate 24.

[0044] The front central member 26 is disposed between the front end member 22 and the first battery-side cross member 25A, with the front end of the front central member 26 fixed to the left-right center of the front end member 22 and the rear end of the front central member 26 fixed to the left-right center of the first battery-side cross member 25A. Therefore, the front end member 22 is a member that extends to connect the front ends of the left side member 20 and the right side member 21 to the front end of the front central member 26.

[0045] The first rear central member 27 is disposed between the first battery-side cross member 25A and the second battery-side cross member 25B, with the front end of the first rear central member 27 fixed to the left-right center of the first battery-side cross member 25A and the rear end of the first rear central member 27 fixed to the left-right center of the second battery-side cross member 25B. The second rear central member 28 is disposed between the second battery-side cross member 25B and the third battery-side cross member 25C, with the front end of the second rear central member 28 fixed to the left-right center of the second battery-side cross member 25B and the rear end of the second rear central member 28 fixed to the left-right center of the third battery-side cross member 25C. Furthermore, the third rear central member 29 is disposed between the third battery-side cross member 25C and the rear end member 23, with the front end of the third rear central member 29 fixed to the left-right center of the third battery-side cross member 25C and the rear end of the third rear central member 29 fixed to the left-right center of the rear end member 23. Therefore, the first to third battery-side cross members 25A, 25B, 25C, the front central member 26, and the first to third rear central members 27-29 are arranged in a lattice pattern inside the battery case 10 and connected to one another, further enhancing the reinforcing effect of the battery case 10.

[0046] When an imaginary straight line extending in the front-to-rear direction is imagined in a plan view, the front central member 26 and the first to third rear central members 27-29 are positioned in the left-to-right direction so as to be disposed on that imaginary straight line. In other words, the first to third rear central members 27-29 are provided so as to be positioned on an imaginary extension line to the rear of the front central member 26. The front central member 26 and the first to third rear central members 27-29 may be configured as a single member that is continuous in the front-to-rear direction.

[0047] FIG. 6 is a diagram showing an example in which the height of the front central member 26 is made higher than the height of the first to third rear central members 27 to 29 (not shown in FIG. 6). As will be described in detail later, the floor panel 70 of the upper structure 3 has a front floor portion 70a located higher than a rear floor portion 70b. The front central member 26 is provided below the front floor portion 70a, and the first to third rear central members 27 to 29 are provided below the rear floor portion 70b. The upper end of the front central member 26 is formed to be located higher than the rear floor portion 70b. In other words, the upper ends of the first to third rear central members 27 to 29 are located lower than the upper end of the front central member 26 to correspond to the relatively low height of the rear floor portion 70b. In this case, the first battery side cross member 25A may be provided below the front floor portion 70a, in which case the upper end of the first battery side cross member 25A can be formed so as to be positioned higher than the second and third battery side cross members 25B and 25C.

[0048] 3 and 4, a pair of left and right front frame members 11 are provided, and extend substantially horizontally in a straight line below left and right front side frames 72, which will be described later. Each front frame member 11 can be made of, for example, an extruded material or a press-formed material. In this embodiment, since each front frame member 11 is made of an extruded material, the cross-sectional shape in the direction perpendicular to the front-to-rear direction is substantially uniform from the front end to the rear end.

[0049] The left front frame member 11 is connected to a portion of the front end member 22 that constitutes the front part of the battery case 10 that is shifted to the left of the center in the left-right direction, and this connection portion is located to the right of the left side member 20 of the battery case 10. The right front frame member 11 is connected to a portion of the front end member 22 that is shifted to the right of the center in the left-right direction, and this connection portion is located to the left of the right side member 21 of the battery case 10. This provides a predetermined distance between the left and right front frame members 11, making it possible to position the lower part of the powertrain PT between the left and right front frame members 11. The distance between the left and right front frame members 11 is set narrower than the distance between the left side member 20 and right side member 21 of the battery case 10.

[0050] The left and right front frame members 11 are approximately the same height. The left and right front frame members 11, the front central member 26 of the battery case 10, the left side member 20, and the right side member 21 are also disposed at approximately the same height.

[0051] The battery case 10 side (rear side) of each front frame member 11 is connected to the battery case 10 at multiple locations spaced apart 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 member 22, and a location further forward than the rear end of the front frame member 11 is connected to the front end member 22 by an outer connection portion (one side connection portion) 30 and an inner connection portion (the other side connection portion) 31. This allows the collision load input to the front frame member 11 during a frontal collision to be distributed and transmitted to multiple locations on the battery case 10.

[0052] The outer connection portion 30 and the inner connection portion 31 are made of highly rigid members, such as extruded or press-formed members, and have a cylindrical, plate-like, or columnar shape. In a plan view, the widths of the outer connection portion 30 and the inner connection portion 31 are set wider than the width of the front frame member 11, which further enhances the effect of dispersing the collision load. The widths of the outer connection portion 30 and the inner connection portion 31 may be the same as the width of the front frame member 11, or may be narrower than the width of the front frame member 11.

[0053] The right outer connection portion 30 is provided to the right of the right front frame member 11 (outer in the vehicle width direction) at approximately the same height as the front frame member 11, and is inclined relative to the fore-and-aft direction in a plan view so that the closer it is to the rear end, the more rightward it is positioned. The front end of the right outer connection portion 30 is connected to a portion of the front frame member 11 between the fore-and-aft center and the rear end (midway in the fore-and-aft direction). The outer connection portion 30 extends from the connection portion with the front frame member 11 to the right and rear, that is, toward a side sill 73 (described later) of the upper structure 3. The rear end of the right outer connection portion 30 is connected to a portion of the front end member 22 that is spaced to the right from the rear end of the front frame member 11. The connection structure between the outer connection portion 30 and the front frame member 11 and the connection structure between the outer connection portion 30 and the front end member 22 may be a connection structure using fastening members such as bolts and nuts, or a connection structure using welding, adhesive, or the like.

[0054] The right inner connection portion 31 is provided to the left of the right front frame member 11 (inner in the vehicle width direction) at approximately the same height as the front frame member 11, and is inclined relative to the front-to-rear direction in a plan view so that it is positioned more leftward as it approaches the rear end. The front end of the right inner connection portion 31 is connected to a portion of the front frame member 11 between the front-to-rear center and the rear end (midway in the front-to-rear direction). The right inner connection portion 31 extends leftward and rearward from the connection portion with the front frame member 11, that is, toward the left-to-right center of the battery case 10. The rear end of the inner connection portion 31 is connected to a portion of the front end member 22 that is spaced leftward from the rear end of the front frame member 11. The connection structure between the inner connection portion 31 and the front frame member 11 and the connection structure between the inner connection portion 31 and the front end member 22 can be similar to the connection structure of the outer connection portion 30.

[0055] In this embodiment, the right front frame member 11 is connected to the front end member 22 at three locations spaced apart in the left-right direction, but this is not limited to this. One of the outer connection portion 30 and the inner connection portion 31 may be omitted and the front frame member 11 may be connected at two locations, or the rear end of the front frame member 11 may be connected to the front end member 22 only by the outer connection portion 30 and the inner connection portion 31, without being connected to the front end member 22.

[0056] The left front frame member 11 can also be connected to the front end member 22 in the same manner as the right front frame member 11. The connection structure of the left front frame member 11 can be a symmetrical structure to that of the right front frame member 11.

[0057] As shown in FIG. 3 , an intermediate connecting member 49, a front connecting member 50, and a rear connecting member 51 are provided in front of the battery case 10 of the lower structure 2, spaced apart in the front-to-rear direction. The front connecting member 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 front frame member 11 and the right front frame member 11. The rear connecting member 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 front frame member 11 and the right front frame member 11. The front connecting member 50 and the rear connecting member 51 are made of, for example, an extruded material or a press-molded material. Connecting the left and right front frame members 11 with the front connecting member 50 and the rear connecting member 51 forms a frame structure that is frame-shaped in plan view.

[0058] The intermediate connecting member 49 is provided between the front connecting member 50 and the rear connecting member 51, and 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, connecting the left front frame member 11 and the right front frame member 11. The intermediate connecting member 49 may be provided as needed, or may be omitted.

[0059] The front connecting member 50 extends from the upper surface of the left front frame member 11 to the upper surface of the right front frame member 11, and is disposed so as to protrude above the upper surfaces of both front frame members 11. Meanwhile, the rear connecting member 51 is disposed between the left and right front frame members 11, with the left end of the rear connecting member 51 connected to the side surface of the left front frame member 11 and the right end of the rear connecting member 51 connected to the side surface of the right front frame member 11. The front connecting member 50 and the rear connecting member 51 may be fixed to the front frame members 11 with fastening members, or by welding, adhesive, etc.

[0060] The longitudinal dimensions of the front connecting member 50 and the rear connecting member 51 are set to be longer than the lateral dimension of the front frame member 11. This increases the strength with which the front frame member 11 is connected by both connecting members 50, 51.

[0061] As shown in Fig. 4, the powertrain PT is disposed rearward of the front connecting member 50. Specifically, in a plan view, the powertrain PT is disposed between the front connecting member 50 and the rear connecting member 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.

[0062] Furthermore, left and right suspension arms 13a that constitute part of the front suspension device 13 are supported via brackets 13b on the left and right front frame members 11 so as to be able to swing freely. The brackets 13b are provided at the connection portions between the left and right front frame members 11 and the rear connecting member 51.

[0063] The lower structure 2 is provided with two left-side connecting portions 53, 54 spaced apart from each other in the front-rear direction, which connect the left front frame member 11 to the left front side frame 72 (described later), and two right-side connecting portions 55, 56 spaced apart from each other in the front-rear direction, which connect the right front frame member 11 to the right front side frame 72 (described later). The left-side connecting portions 53, 54 and the right-side connecting portions 55, 56 can be formed of a plate material, a tubular member, a columnar member, or the like that extends in the vertical direction. In this embodiment, the left-side connecting portions 53, 54 and the right-side connecting portions 55, 56 are formed of press-formed material, but they may also be formed of extruded material, or the like. Furthermore, the number of left-side connecting portions 53, 54 is not limited to two, and three or more may be provided spaced apart from each other in the front-rear direction. The same applies to the right-side connecting portions 55, 56.

[0064] The front left-side coupling part 53 is provided at the connection part of the front connecting member 50 with the left front frame member 11. Specifically, the front part of the left front frame member 11 and the left end part of the front connecting member 50 are arranged to overlap in the vertical direction, and the left end part of the front connecting member 50 is connected to the front part of the left front frame member 11, so that the connection part is formed by the left end part of the front connecting member 50. The lower end part of the front left-side coupling part 53 is attached to the left end part of this front connecting member 50.

[0065] Furthermore, the front right-side coupling part 55 is provided at the connection part of the front connecting member 50 with the right front frame member 11. Specifically, the front part of the right front frame member 11 and the right end part of the front connecting member 50 are arranged to overlap in the vertical direction, and the right end part of the front connecting member 50 is connected to the front part of the right front frame member 11, so that the connection part is formed by the right end part of the front connecting member 50. The lower end part of the front right-side coupling part 55 is attached to the right end part of this front connecting member 50.

[0066] The rear left-side coupling part 54 is provided at a connection portion between the left front frame member 11 and the intermediate coupling member 49. The lower end portion of the rear left-side coupling part 54 is attached to the left front frame member 11 and is located rearward of the left drive shaft 52. The rear right-side coupling part 56 is provided at a connection portion between the right front frame member 11 and the intermediate coupling member 49. The lower end portion of the rear right-side coupling part 56 is attached to the right front frame member 11 and is located rearward of the right drive shaft 52. This makes it possible to widen the distance between the front and rear left-side coupling parts 53, 54 and the distance between the front and rear right-side coupling parts 55, 56.

[0067] The right front frame member 11 is disposed to the left (inner in the vehicle width direction) of the right front side frame 72 shown in Fig. 8, and the left front frame member 11 is disposed to the right (inner in the vehicle width direction) of the left front side frame 72 shown in Fig. 2. This makes the distance between the left and right front side frames 72 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.

[0068] 3, the right-side connecting portions 55, 56 are formed so that they are positioned further to the right (outside in the vehicle width direction) as they go up. This is because the right front side frame 72 is positioned above the right front frame member 11 and to the right of the front frame member 11. Similarly, the left-side connecting portions 53, 54 are formed so that they are positioned further to the left (outside in the vehicle width direction) as they go up.

[0069] Similar to the front frame members 11, a pair of left and right rear frame members 12 are provided, and extend rearward in a substantially horizontal straight line. Each rear frame member 12 can be made of, for example, an extruded material or a press-formed material. In this embodiment, each rear frame member 12 is made of an extruded material.

[0070] The left rear frame member 12 is connected to a portion of the rear end member 23 that constitutes the rear of the battery case 10 that is shifted to the left of the center in the left-right direction, and this connection portion is located to the right of the left side member 20 of the battery case 10. The right rear frame member 12 is connected to a portion of the rear end member 23 that is shifted to the right of the center in the left-right direction, and this connection portion is located to the left of the right side member 21 of the battery case 10. The connection structure of the rear frame member 12 to the rear end member 23 can be the same as the connection structure of the front frame member 11 to the front end member 22 described above.

[0071] 5, the front ends of the left and right rear frame members 12 are connected to the rear end members 23, and the middle portion of the rear frame members 12 in the front-to-rear direction is connected to the rear end members 23 by the connecting members 60. As a result, the rear frame members 12 on the battery case 10 side are connected to the battery case 10 at multiple locations spaced apart from each other in the left-to-right direction.

[0072] Left and right suspension arms 14a constituting part of the rear suspension device 14 are supported by the left and right rear frame members 12 via brackets 14b so as to be able to swing freely.

[0073] (superstructure) Next, the upper structure 3 will be described. As shown in Figures 7 to 10, 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 side sills 73. Figures 7 to 10 show a state in which the doors, hood, front fenders, windshield, bumpers, front and rear lighting devices, some seats, interior materials, etc. have been removed.

[0074] The floor panel 70 forms the floor surface of the vehicle compartment R1 and is made of steel plates or the like that extend in the front-to-rear and left-to-right directions. The space above the floor panel 70 forms the vehicle compartment R1. A roof 80 is provided above the vehicle compartment R1. As shown in FIG. 2, a front opening 3a and a rear opening 3b are formed on the left side of the upper structure 3. As shown in FIG. 1, the front opening 3a and the rear opening 3b can be opened and closed 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 in an openable and closable manner.

[0075] Dash panel 71 is a member that separates the passenger compartment R1 and the power compartment R3 in the front-rear direction. This dash panel 71 is made of, for example, a steel plate and extends in the left-right direction as well as the up-down direction. As shown in FIGS. 7 to 9, front wheel house sections 85 (only the right one is shown in FIGS. 7 to 9) for accommodating left and right front wheels F are provided on both the left and right sides of the front part of the upper structure 3. The left end of dash panel 71 is connected to the left front wheel house section 85 (shown in FIG. 2), and the right end of dash panel 71 is connected to the right front wheel house section 85 (shown in FIGS. 7 to 9).

[0076] As shown schematically in Figure 11, the floor panel 70 includes a front floor portion 70a and a rear floor portion 70b. Furthermore, as shown in Figure 10, the floor panel 70 also includes a kick-up portion 70c at its rear. The front floor portion 70a, the rear floor portion 70b, and the kick-up portion 70c may be integrally formed from a single plate material, or may be formed from different plate materials. If formed from different plate materials, a single floor panel 70 can be constructed by joining multiple plate materials.

[0077] 11, the front floor portion 70a forms the front portion of the floor panel 70 and is inclined or curved so that it is positioned higher as it moves toward the front. 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.

[0078] The rear floor section 70b is formed to extend rearward from the rear end of the front floor section 70a and constitutes the middle section of the floor panel 70 in the front-to-rear direction. The front section of the battery case 10 of the lower structure 2 is located directly below the front floor section 70a, and the rear section of the battery case 10 is located directly below the rear floor section 70b. Therefore, the battery case 10 is formed to extend from below the front floor section 70a to below the rear floor section 70b, which allows the battery B to be mounted in most of the space below the floor panel 70.

[0079] A longitudinally intermediate portion of the floor panel 70 is lower than the front floor portion 70a. In other words, the front floor portion 70a is provided in front of the rear floor portion 70b and is positioned higher than the rear floor portion 70b. At least a portion of a seat fixing portion 100 for fixing the front seat S1 is attached to a front portion of the rear floor portion 70b. The seat fixing portion 100 is configured, for example, with a bracket. It is sufficient that at least the rear portion of the seat fixing portion 100 is attached to the rear floor portion 70b, and the entire seat fixing portion 100 may be attached to the rear floor portion 70b. By attaching at least the rear portion of the seat fixing portion 100 to the rear floor portion 70b, the front seat S1 can be laid out lower, thereby lowering the hip point of the front seat occupant P. As a result, the front seat occupant P has more headroom and is more comfortable. Furthermore, lowering the hip point means that the seating position of the front seat occupant P is lowered, which lowers the height of the center of gravity of the vehicle when in the riding position. In this embodiment, the entire seat fixing part 100 is attached to the rear floor part 70b, so the front seat S1 can be laid out even lower.

[0080] When a driver serving as a front seat occupant P sits in the front seat S1, the heel P1 of the front seat occupant P is placed on the front floor portion 70a. Because the front floor portion 70a on which the heel P1 is placed is positioned higher than the rear floor portion 70b, the heel P1 is placed in a higher position compared to the operating posture of a typical automobile (an automobile in which the front and rear floor portions are the same height). With this layout, the front seat occupant P's upper leg P2 and lower leg P3 are placed in a posture with a wide gap between them. In FIG. 11, reference numeral 101 indicates the center line of the upper leg P2, and reference numeral 102 indicates the center line of the lower leg P3. The difference in height between the front floor portion 70a and the rear floor portion 70b is set so that the angle between the center line 101 and the center line 102 (the angle α between the upper leg P2 and the lower leg P3) is in the range of 125° to 150°.

[0081] By setting the height difference in this manner, the angle between the lower leg P3 and the front floor portion 70a (the angle β between the center line 101 and the front floor portion 70a) is reduced, thereby reducing the vertical component of force input to the heel P1 during pedal operation and improving operability of the brake pedal 103. Specifically, when the front seat occupant P depresses the brake pedal 103, the heel P1 applies a diagonally downward force F to the front floor portion 70a. This force F can be divided into a vertical force and a horizontal force, resulting in forces F1 and F2. As described above, the smaller angle β reduces the vertical component of force F1 input from the heel P1. This allows, for example, a change of foot from the brake pedal 103 to an accelerator pedal (not shown) or vice versa to be performed quickly and accurately, resulting in improved pedal operability.

[0082] In addition, rear seat passengers may place their feet on the rear floor portion 70b. Since the rear floor portion 70b is lower than the front floor portion 70a, the leg space of the rear seat passengers is increased, improving the comfort of the rear seat passengers.

[0083] As shown in FIGS. 7 to 9, the kick-up 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 kick-up portion 70c is located higher than the rear floor portion 70b, and a vertically extending vertical plate portion 70d is formed between the kick-up portion 70c and the rear floor portion 70b. The height of the kick-up portion 70c is set higher than that of the front floor portion 70a. A rear seat S2 (shown in FIG. 2) is attached to the upper surface of the kick-up portion 70c. A battery B or a control device (not shown) for the electric vehicle 1 may be disposed below the kick-up portion 70c.

[0084] A floor-side cross member 110 is attached to the floor panel 70, extending in the left-right direction along the floor panel 70. The floor-side cross member 110 is, for example, welded to the upper surface of the rear floor portion 70b of the floor panel 70. The shape of the floor-side cross member 110 is not particularly limited, but in this embodiment, it bulges upward and opens downward, with both left and right ends having a substantially uniform cross-sectional shape. By attaching the floor-side cross member 110 to the rear floor portion 70b, a closed cross section is formed by the floor-side cross member 110 and the rear floor portion 70b. The left end of the floor-side cross member 110 is located near the inner surface of the left side sill 73 in the vehicle width direction, and the right end of the floor-side cross member 110 is located near the inner surface of the right side sill 73 in the vehicle width direction. The floor-side cross member 110 may also be attached to the underside of the rear floor portion 70b.

[0085] As shown in Figures 7 to 9, the left and right front side frames 72 are disposed at the front of the vehicle body and are high-strength members extending in the front-to-rear direction. Figures 7 to 9 show only the right front side frame 72, and Figure 2 shows the left front side frame 72. In other words, the left and right front side frames 72 are positioned forward of the floor panel 70 and above the floor panel 70, and more specifically, they are disposed so as to extend forward from both the left and right sides of the lower part of the dash panel 71.

[0086] The left and right front side frames 72 have a symmetrical structure and can be formed, for example, by joining multiple press-formed materials together or by extrusion. The cross section of each front side frame 72 in a direction perpendicular to the front-to-rear 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. This makes each front side frame 72 a thicker, stronger member than the front frame member 11.

[0087] The front ends of the left and right front side frames 72 each have a crush can 72a that compresses and deforms to absorb collision energy during a frontal collision. The crush can 72a is a cylindrical metal member that extends in the front-to-rear 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 cans 72a.

[0088] As shown in FIG. 8, the upper part of the right-side coupling part 55, which is located in front of the lower structure 2, is connected to the right crash can 72a. The upper part of the left-side coupling part 53 (shown in FIG. 2), which is located in front of the lower structure 2, is connected to the left crash can 72a. Because the crash can 72a is located at the front end of the front side frame 72, connecting the upper part of the left-side coupling part 53 to the crash can 72a allows the coupling position of the left-side coupling part 53 to be located closer to the front end of the vehicle body. This allows the distance between the left-side coupling parts 53, 54 in the front-to-rear direction to be increased, further enhancing the effect of connecting the front frame member 11 to the front side frame 72 by the left-side coupling parts 53, 54. The same applies to the right-side coupling parts 55, 56. The left-side coupling parts 53, 54 and the right-side coupling parts 55, 56 are connected to the front side frame 72 using fastening members such as bolts and nuts. The front left connecting portion 53 and the front right connecting portion 55 may be connected to the front side frame 72 at a position behind the crash can 72a.

[0089] 5, the lower part of the rear right coupling part 56 is connected to the front frame member 11 behind the drive shaft 52, and as shown in FIG. 8, the upper part of the rear right coupling part 56 is connected to a part of the front side frame 72 that is rearward of the center in the fore-and-aft direction. This makes it possible to further increase the distance between the right coupling parts 55, 56 in the fore-and-aft direction. The same applies to the left coupling parts 53, 54.

[0090] The left and right side sills 73 are disposed so as to extend in the front-to-rear direction at both left and right ends of the floor panel 70. As shown in FIG. 12 , the left end of the floor panel 70 is connected to the vertical middle portion of the left side sill 73, with the upper portion of the side sill 73 protruding upward from the connection portion with the floor panel 70 and the lower portion of the side sill 73 protruding downward from the connection portion with the floor panel 70. The battery case 10 is disposed below the floor panel 70, so that the lower portion of the side sill 73 and the battery case 10 overlap in a side view of the vehicle. The right side sill 73 is similarly connected to the right end of the floor panel 70.

[0091] The left and right side sills 73 have a symmetrical structure. The detailed structure of the left side sill 73 will be described below with reference to FIG. 12. The left side sill 73 includes an inner member 90 and an outer member 91 made of press-formed material. The inner member 90 is a member that constitutes the cabin interior portion of the side sill 73, and is formed to bulge toward the cabin interior and elongate in the front-to-rear direction. The outer member 91 is a member that constitutes the cabin exterior portion of the side sill 73, and is formed to bulge toward the cabin exterior and elongate in the front-to-rear 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 hollow side sill 73.

[0092] A first recess 73a, which is recessed outward in the vehicle width direction and extends in the front-to-rear direction, is formed in a lower portion of the inner side of the side sill 73 in the vehicle width direction. The first recess 73a is open downward and inward in the vehicle width direction. The outer side of the battery case 10 of the lower structure 2 in the vehicle width direction is formed to fit into the first recess 73a. Specifically, the left side member 20 of the battery case 10 is configured to enter the first recess 73a from below the first recess 73a. This ensures a long dimension of the battery case 10 in the vehicle width direction and reduces the amount of downward protrusion of the battery case 10.

[0093] Inside the side sill 73, a hollow lateral load transfer member 120 is provided, which extends in the front-rear direction and transfers a load from the outside to the inside in the vehicle width direction to the inside in the vehicle width direction. The lateral load transfer member 120 transfers loads that are not intended for normal driving, but are extremely large loads that cause deformation of the members on the sides of the electric vehicle 1, such as in a side collision in which an obstacle hits the electric vehicle 1 from the side.

[0094] The lateral load transfer member 120 can be made of, for example, an extruded material, and is continuous from the front end to the rear end of the side sill 73. The lateral load transfer member 120 is fixed at appropriate locations to the side sill 73. The structure for fixing the lateral load transfer member 120 to the side sill 73 is not particularly limited, but examples include a structure using fastening members such as bolts and nuts, rivets, etc.

[0095] The lateral load transmission member 120 has high rigidity so that it can transmit the load in the side collision to the inside in the vehicle width direction, and is therefore resistant not only to compressive force but also to bending force and torsional force, and functions as a reinforcing member that reinforces the side sill 73 during normal driving and contributes to improving the rigidity of the vehicle body. Such a lateral load transmission member 120 can be called an inner reinforcement because it is a member that reinforces the side sill 73 inside the side sill 73.

[0096] The side load transmission member 120 has 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 disposed inside the side sill 73 near its upper end. The outer wall portion 122 extends downward from the outer end of the upper wall portion 121 in the vehicle width direction and is disposed inside the side sill 73 near its outer end in the vehicle width direction. The upper end of the outer wall portion 122 is located above the upper end of the floor-side cross member 110. The lower end of the outer wall portion 122 is located below the upper end of the second battery-side cross member 25B provided inside the battery case 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 also substantially the same.

[0097] The inner upper vertical wall portion 123 extends downward from the inner end portion in the vehicle width direction of the upper wall portion 121 and is disposed near the inner end portion in the vehicle width direction inside the side sill 73. The upper end portion of the inner upper vertical wall portion 123 is located higher than 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 lower than the rear floor portion 70b and higher than the upper end portion of the second battery-side cross member 25B.

[0098] 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 closer to the inside than 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 lower than the upper end of the second battery-side cross member 25B. The vertical dimension of the inner lower vertical wall portion 124 is set shorter than the vertical dimension of the inner upper vertical wall portion 123.

[0099] The inner lower vertical wall portion 124 and the intermediate wall portion 125 form a second recess 120a that is recessed outward in the vehicle width direction at the lower portion of the lateral load transmission member 120 on the interior side of the vehicle so as to correspond to the first recess 73a of the side sill 73. The portion of the side sill 73 where the first recess 73a is formed is adapted to fit into the second recess 120a of the lateral load transmission member 120.

[0100] The lower wall portion 126 extends from the lower end of the inner lower vertical wall portion 124 to the lower end of the outer 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.

[0101] In a side view of the vehicle, an upper portion of the side load transmission member 120 overlaps with the floor-side cross member 110, and a lower portion of the side load transmission member 120 overlaps with the second battery-side cross member 25B. That is, the side load transmission member 120 has an inner upper vertical wall portion (first vertical wall portion) 123 that overlaps with the floor-side cross member 110 in a side view of the vehicle and extends in the vertical direction, and an inner lower vertical wall portion (second vertical wall portion) 124 that overlaps with the battery case 10 in a side view of the vehicle and extends in the vertical direction. Note that the lower portion of the inner upper vertical wall portion 123 may overlap with the upper portion of the battery case 10.

[0102] First to fourth ribs 131 to 134 are integrally formed inside the side load transmission member 120. The first rib 131 extends in the vehicle width direction at a location spaced upward from the intermediate wall portion 125, and the inner end portion of the first rib 131 in the vehicle width direction is connected to the vertical intermediate portion of the inner upper vertical wall portion 123. The first rib 131 is inclined so that it is positioned higher as it moves outward in the vehicle width direction.

[0103] The second rib 132 extends in the vehicle width direction at a location spaced downward from the first rib 131, and the inner end of the second rib 132 in the vehicle width direction is connected to the upper end of the inner lower vertical wall portion 124. The outer end of the second rib 132 in the vehicle width direction is connected to the middle portion in the up-down direction of the outer wall portion 122. The first rib 131 and the second rib 132 may extend substantially horizontally, or may be inclined so as to be positioned higher as they move inward in the vehicle width direction, or may be inclined so as to be positioned higher as they move outward in the vehicle width direction.

[0104] 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 a middle portion of the upper wall portion 121 in the vehicle width direction. The third rib 133 is inclined so that it is positioned further outward in the vehicle width direction as it goes 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 up-down direction.

[0105] The fourth rib 134 extends in the vehicle width direction at a location spaced upward from the second rib 132. An inner end of the fourth rib 134 in the vehicle width direction is connected to a vertically intermediate portion of the third rib 133. An outer end of the fourth rib 134 in the vehicle width direction is connected to a vertically intermediate portion of the outer wall portion 122. An inner end of the fourth rib 134 in the vehicle width direction and an outer end of the first rib 131 in the vehicle width direction are connected via the third rib 133, and the first rib 131 and the fourth rib 134 form a single rib that is continuous in the vehicle width direction. The number and shape of the ribs formed inside the side load transmission member 120 are not limited to those described above, and the number of ribs may be three or less, or five or more.

[0106] The battery case 10 is fixed to the side sill 73 and is also directly fixed to the side load transmission member 120. A plurality of metallic tubular members 140 extending in the vertical direction are fixed to the left side member 20 of the battery case 10. The spacing between the tubular members 140 in the front-to-rear direction can be set to, for example, about several tens of centimeters. As shown in FIG. 2, the plurality of tubular members 140 are arranged at intervals from one another in the front-to-rear direction. A bolt 141 is inserted into each tubular member 140 from below.

[0107] Meanwhile, an opening is provided in a portion of the side sill 73 corresponding to the inner surface of the first recess 73a so that the shank of the bolt 141 can be inserted therethrough. Similarly, an opening is also provided in the intermediate wall portion 125 of the side load transfer member 120 so that the shank of the bolt 141 can be inserted therethrough, and both openings are aligned. A nut 142 is housed inside the side load transfer member 120. The nut 142 is fixed to the upper surface of the intermediate wall portion 125 of the side load transfer member 120. The number and positions of the openings and nuts 142 correspond to the number and positions of the tubular members 140.

[0108] Therefore, by inserting each bolt 141 into the cylindrical member 140, passing it through the openings in the side sill 73 and the openings in the side load transmission member 120, and screwing it onto the nut 142 and tightening it, it is possible to fix multiple locations on the left side of the battery case 10 to the side load transmission member 120 and the side sill 73. The right side of the battery case 10 can also be fixed in a similar manner.

[0109] In the present embodiment, the case where the side load transfer member 120 is integrally molded has been described, but the present invention is not limited to this, and the side load transfer member 120 may be configured by combining a plurality of members. Although not shown, for example, the side load transfer member 120 may have a two-piece structure in which an inner portion and an outer portion in the vehicle width direction are molded separately and then integrated. Alternatively, the side load transfer member 120 may have a three-piece structure.

[0110] As shown in Figure 7 etc., the upper structure 3 is equipped with 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. Furthermore, as shown in Figure 2, the left hinge pillar 150 extends upward from the front end of the left side sill 73. Left and right front doors 81 (shown in Figure 1) are attached to the left and right hinge pillars 150, respectively.

[0111] As shown in Fig. 10, the upper structure 3 also 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-to-rear direction. As shown in Fig. 2, the left center pillar 157 extends upward from the middle portion of the left side sill 73 in the front-to-rear direction. Left and right rear doors 82 (shown in Fig. 1) are attached to the left and right center pillars 157, respectively.

[0112] As shown in FIG. 9 , the upper structure 3 is equipped with a pair of left and right floor reinforcements (first longitudinal load transmission members) 151. The floor reinforcements 151 extend in the longitudinal direction along the upper surface of the front floor portion 70a. The front end of the right floor reinforcement 151 is connected to the rear end of the right front side frame 72. The rear end of the right floor reinforcement 151 is connected to the front end of the right side sill 73. Therefore, since the front side frame 72 and the side sill 73 are connected by the floor reinforcement 151, when a collision load is input to the front side frame 72 during a frontal collision, for example, the collision load is transmitted to the side sill 73 via the floor reinforcement 151.

[0113] The floor reinforcement 151 bulges upward and opens downward, and this 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, a closed cross section is formed by the floor reinforcement 151 and the front floor portion 70a.

[0114] Because the side sills 73 are positioned more outboard in the vehicle width direction than the front side frames 72, the floor reinforcement 151 extends while curving in a plan view so that it is positioned more outboard in the vehicle width direction as it moves toward the rear. The curved shape of this floor reinforcement 151 corresponds to the shape of the lower end of the front wheel house section 85. In other words, the floor reinforcement 151 extends along the lower end of the front wheel house section 85 and is connected to and integrated with the front wheel house section 85. The left floor reinforcement (not shown) has a bilaterally symmetrical structure to the right one.

[0115] While the floor reinforcement 151 is attached to the upper surface of the front floor portion 70a, the outer connection portion 30 (shown in FIG. 3, etc.) of the lower structure 2 is located below the front floor portion 70a, so the floor reinforcement 151 and the outer connection portion 30 are spaced apart from each other in the vertical direction. Similarly, the floor reinforcement 151 and the inner connection portion 31 are also spaced apart from each other in the vertical direction.

[0116] Furthermore, in a plan view, the portion of the right floor reinforcement 151 facing the side sill 73 (the rear end of the floor reinforcement 151) and the portion of the right outer connection portion 30 facing the battery case 10 (the rear end of the outer connection portion 30) overlap each other. The rear end of the floor reinforcement 151 is connected to the side sill 73, and is therefore disposed adjacent to the side sill 73. On the other hand, the outer connection portion 30 is connected to the battery case 10, and is therefore spaced apart from the side sill 73. However, the fact that the rear end of the outer connection portion 30 overlaps the rear end of the floor reinforcement 151 in a plan view means that the rear end of the outer connection portion 30 can be brought closer to the side sill 73. Therefore, a frontal collision load can be reliably applied toward the side sill 73 via the outer connection portion 30. The same is true for the left side.

[0117] The rear end of the right floor reinforcement 151 and the base end (lower end) of the right hinge pillar 150 are located at the same position in the front-to-rear direction. That is, the portion of the side sill 73 near the base end of the hinge pillar 150 is particularly rigid, and by connecting the rear end of the floor reinforcement 151 to this particularly rigid portion, the collision load can be efficiently absorbed by the side sill 73.

[0118] As shown in FIG. 7, the upper structure 3 is equipped with a pair of left and right lower load transmission members (second front-rear load transmission members) 152. The lower load transmission members 152 are disposed above the front frame members 11 of the lower structure 2, and the front frame members 11 and the lower load transmission members 152 are spaced apart from each other in the up-down direction. The lower load transmission members 152 extend in the front-rear direction along the underside of the front floor portion 70a. As shown schematically in FIG. 11, the front end of the right lower load transmission member 152 is connected to the rear end of the right front side frame 72. The lower load transmission members 152 extend toward the front of the battery case 10. Therefore, when a collision load is applied rearward to the front side frame 72 during a frontal collision, for example, the collision load is transmitted to the front of the battery case 10 via the lower load transmission members 152. The left lower load transmission member 152 is bilaterally symmetrical to the right lower load transmission member 152.

[0119] The lower load transmission member 152 bulges downward and opens upward, and this bulging shape continues from the front end to the rear end. By attaching the lower load transmission member 152 to the underside of the front floor portion 70a, a closed cross section is formed by the lower load transmission member 152 and the front floor portion 70a.

[0120] The rear portion of the right lower load transmission member 152 is positioned to the right of the front central member 26 and to the left of the right side member 21 inside the battery case 10. In addition, the rear portion of the left lower load transmission member 152 is positioned to the left of the front central member 26 and to the right of the left side member 20 inside the battery case 10.

[0121] As shown in Figures 7 to 9, a cross member 153 is disposed on the underside of the front floor section 70a, extending in the left-right direction and connecting the rear portions of the left and right lower load transmission members 152. The cross member 153 bulges downward and opens upward, with a substantially uniform cross-sectional shape across both left and right ends. By attaching the cross member 153 to the underside of the front floor section 70a, a closed cross section is formed by the cross member 153 and the front floor section 70a. By disposing the cross member 153, it is possible to prevent the rear portions of the lower load transmission members 152 from being displaced in the left-right direction when the left and right lower load transmission members 152 receive a collision load during a frontal collision.

[0122] As shown in Figure 11, the front end member 22 that constitutes the front part of the battery case 10 is disposed directly below the cross member 153. The front end member 22 is fastened to the cross member 153 with bolts and nuts (not shown). The fastening structure of the front end member 22 can be the same as the fastening structure of the left side member 20 to the side sill 73.

[0123] A protrusion 22a that protrudes upward is provided at the front of the battery case 10. Specifically, the protrusion 22a is provided at a location on the front end member 22 rearward of the cross member 153. This protrusion 22a is located rearward of the rear of the lower load transmission member 152. The protrusion 22a is formed such that its upper end is located higher than the lower surface of the cross member 153 and higher than the lower surface of the rear portion of the lower load transmission member 152. As a result, the cross member 153 and the lower load transmission member 152 overlap with the protrusion 22a in a front-to-rear direction view. The protrusion 22a is a portion to which a collision load is transmitted from the lower load transmission member 152 when the lower load transmission member 152 is moved backward by the collision load during a frontal collision.

[0124] The protrusion 22a extends continuously in the left-right direction. That is, during a frontal collision, it is conceivable that the rear portion of the lower load transmission member 152 will be displaced slightly in the left-right direction, but because the protrusion 22a is continuous in the left-right direction, the collision load will be reliably input to the protrusion 22a even if the rear portion of the lower load transmission member 152 is displaced in the left-right direction. Note that the protrusion 22a is not limited to being continuous in the left-right direction, and may be formed discontinuously so long as at least a portion of it overlaps with the rear portion of the lower load transmission member 152 when viewed in the front-rear direction.

[0125] The protruding portion 22a may be integrally molded with the front end member 22, or may be formed as a separate member. When the front end member 22 is an extruded material, the protruding portion 22a can be easily integrally molded. The protruding portion 22a may be fixed to, for example, the bottom plate 24, or may be fixed to the left side member 20, the right side member 21, or the like. The protruding portion 22a may have any shape, such as a plate shape (rib shape), a rod shape, or a cylinder shape. By integrally molding the protruding portion 22a in a rib shape with the front end member 22, a reinforcing effect for the front end member 22 can also be obtained.

[0126] The rear portion of the lower load transmission member 152 and the protruding portion 22a are disposed with a predetermined distance in the front-to-rear direction. By providing the predetermined distance, the lower load transmission member 152 and the protruding portion 22a do not come into contact with each other during normal driving, thereby avoiding the generation of interference noise and the like. On the other hand, when the lower load transmission member 152 moves rearward during a frontal collision, the rear portion of the lower load transmission member 152 comes into contact with the protruding portion 22a, ensuring that the collision load is reliably input to the protruding portion 22a. In other words, the predetermined distance is a distance set so that the lower load transmission member 152 and the protruding portion 22a do not come into contact with each other during normal driving, but the rear portion of the lower load transmission member 152 comes into contact with the protruding portion 22a during a frontal collision, and can be, for example, several millimeters to several centimeters. The rear portion of the lower load transmission member 152 and the protruding portion 22a may be in contact with each other. Alternatively, the rear portion of the lower load transmission member 152 and the protruding portion 22a may be joined by a fastening member.

[0127] 6, the front central member 26 inside the battery case 10 is provided below the front floor portion 70a and is taller than the first to third rear central members 27 to 29. Therefore, the vertical dimension of the front central member 26 is longer, and the front central member 26 with a large cross section is located at the front of the battery case 10. This suppresses deformation of the battery case 10 when a collision load transmitted from the lower load transmission member 152 is received at the front of the battery case 10.

[0128] (Connection structure between rear of battery case and upper structure) As shown in FIG. 13, the rear of the battery case 10 and the upper structure 3 are connected by a connecting member 160. Before describing this connecting structure, the structure of the rear side of the upper structure 3 will be described. Rear wheel housing sections 170 (only the right one is shown in FIGS. 7 to 9) for accommodating the left and right rear wheels R are provided on both the left and right sides of the rear of the upper structure 3. The luggage compartment floor section 70e, which constitutes the floor surface of the luggage compartment R2 in the floor panel 70, extends rearward from the rear of the kick-up section 70c and is located higher than the rear floor section 70b. The rear floor section 70b is defined as a first floor section, and the kick-up section 70c and luggage compartment floor section 70e are defined as a relatively higher second floor section. The left end of the luggage compartment floor section 70e is connected to the bottom of the left rear wheel housing section 170 (shown in FIG. 2), and the right end of the luggage compartment floor section 70e is connected to the right rear wheel housing section 170 (shown in FIGS. 7 to 9).

[0129] As shown in Figures 7 to 9, a rear cross member (first cross member) 171 extending in the left-right direction is attached to the underside of kick-up portion 70c. Rear cross member 171 bulges downward and is open upward, with this bulging shape continuing from the left end to the right end. By attaching rear cross member 171 to the underside of kick-up portion 70c, a closed cross section is formed by rear cross member 171 and kick-up portion 70c.

[0130] A rear floor-side cross member 172 extending in the left-right direction directly above the rear cross member 171 is attached to the upper surface of the kick-up portion 70c. The rear floor-side 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-side cross member 172 to the upper surface of the kick-up portion 70c, a closed cross section is formed by the rear floor-side cross member 172 and the kick-up portion 70c. In a plan view, the rear floor-side cross member 172 and the rear cross member 171 overlap.

[0131] The right end of the rear floor-side cross member 172 is connected to the right rear wheel house section 170, and the left end of the rear floor-side cross member 172 is connected to the left rear wheel house section 170. The right end of the rear floor-side cross member 172 is connected to the lower end of a side reinforcement 173 extending upward along the right rear wheel house section 170. The left end of the rear floor-side cross member 172 is connected to the lower end of a side reinforcement (not shown) extending upward along the left rear wheel house section 170. The upper part of the right side reinforcement 173 and the upper part of the left side reinforcement are connected by a connecting member 174 (shown in FIGS. 8 and 9) extending in the left-right direction. In other words, a ring-shaped structure is formed by the rear floor-side cross member 172, the left and right side reinforcements 173, and the connecting member 174. The ring-shaped structure may be formed by using a reinforcement (not shown) provided up to the roof 80 side.

[0132] On the other hand, as shown in Figure 13, the battery case 10 has a case-side cross member (second cross member) 180 (omitted in Figures 2 to 6). The case-side cross member 180 extends in the left-right direction and is attached to the rear end member 23 that forms the rear of the battery case 10. The case-side cross member 180 is located above the rear end member 23. The case-side cross member 180 and the rear cross member 171 are arranged to face each other in the up-down direction.

[0133] As shown in FIG. 13 , the connecting member 160 is a member for connecting the rear end member 23 of the battery case 10 and the kick-up portion 70c. This reinforces the kick-up portion 70c by utilizing the battery case 10, thereby improving the rigidity of the kick-up portion 70c. The improved rigidity of the kick-up portion 70c also improves the rigidity of the entire floor panel 70. In this embodiment, the connecting member 160 is made of a plate material extending in the left-right and up-down directions, but is not limited thereto and may be a member with a closed cross section that extends in the up-down direction or obliquely, a shaft-shaped member, a cylindrical member, or the like. Furthermore, a plurality of connecting members 160 may be provided.

[0134] The upper part of the connecting member 160 is fixed to the lower part of the rear cross member 171. As a result, the battery case 10 and the kick-up portion 70c are connected by the connecting member 160 via the rear cross member 171. In other words, the upper part of the connecting member 160 can be fixed to a portion whose rigidity has been improved by providing the rear cross member 171, thereby increasing the fixing strength of the connecting member 160 to the kick-up portion 70c. The fixing structure for the upper part of the connecting member 160 can be a detachable fastening structure using fastening members such as bolts and nuts (not shown). The upper part of the connecting member 160 may also be directly connected to the kick-up portion 70c.

[0135] Furthermore, the lower part of the connecting member 160 is fixed to a case-side cross member 180 that constitutes part of the battery case 10. This allows the lower part of the connecting member 160 to be fixed to a part of the battery case 10 with improved rigidity, thereby increasing the fixing strength of the connecting member 160 to the battery case 10. Note that the lower part of the connecting member 160 may be detachably fixed to the battery case 10 by the fastening member. The connecting member 160 may be a component of the upper structure 3 side or a component of the lower structure 2 side.

[0136] (Positional relationship between the upper structure and the lower structure cross member) 14 is a schematic diagram showing the positional relationship between the cross members of the upper structure 3 and the lower structure 2 according to a modified embodiment. First to third floor-side cross members 110A, 110B, 110C extending in the vehicle width direction are attached to the upper surface of the floor panel 70 of the upper structure 3, and a cross member 153 is attached to the underside of the floor panel 70. The cross member 153 is attached to the floor panel 70 and is therefore a floor-side cross member.

[0137] The first floor-side cross member 110A is the above-mentioned cross member 110, and is disposed rearward and away from the cross member 153. The second floor-side cross member 110B is disposed rearward and away from the first floor-side cross member 110A. The third floor-side cross member 110C is disposed rearward and away from the second floor-side cross member 110B. Meanwhile, the battery case 10 of the lower structure 2 is provided with the above-mentioned first to third battery-side cross members 25A, 25B, and 25C. In a side view, the cross member 153, 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 overlap with the side sill 73 (shown in FIG. 10, etc.).

[0138] In a side view of the vehicle, cross member 153 and first to third floor-side cross members 110A, 110B, 110C are offset from first to third battery-side cross members 25A, 25B, 25C in the front-to-rear direction of the vehicle. That is, from the front to the rear of the vehicle, cross member 153, first battery-side cross member 25A, first floor-side cross member 110A, second battery-side cross member 25B, second floor-side cross member 110B, third battery-side cross member 25C, and third floor-side cross member 110C are positioned in this order, and cross member 153, first to third floor-side cross members 110A, 110B, 110C and first to third battery-side cross members 25A, 25B, 25C are arranged alternately in the front-to-rear direction.

[0139] For example, when looking at the first floor-side cross member 110A and the second floor-side cross member 110B, the second battery-side cross member 25B is positioned in front of the first floor-side cross member 110A and behind the second floor-side cross member 110B. On the other hand, when looking at the first battery-side cross member 25A and the second battery-side cross member 25B, the first floor-side cross member 110A is positioned behind the first battery-side cross member 25A and in front of the second battery-side cross member 25B. This positional relationship is referred to as being "displaced in the fore-and-aft direction of the vehicle."

[0140] Furthermore, "offset in the vehicle fore-and-aft direction" may include other configurations. For example, it may include a configuration in which the fore-and-aft center of the first floor-side cross member 110A and the fore-and-aft center of the second battery-side cross member 25B are offset in the fore-and-aft direction. This includes the configuration shown in FIG. 14, but also includes a configuration in which, for example, 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 a positional relationship that overlaps in a plan view.

[0141] In addition, for example, a configuration in which the front of the first floor side cross member 110A is positioned in front of the front of the second battery side cross member 25B, and a configuration in which the rear of the second battery side cross member 25B is positioned behind the rear of the first floor side cross member 110A are also included in the term ``displaced in the fore-and-aft direction of the vehicle.''

[0142] In the event of a side collision, the collision load can be received by cross member 153 and first to third floor-side cross members 110A, 110B, 110C and first to third battery-side cross members 25A, 25B, 25C. Because cross member 153 and first to third floor-side cross members 110A, 110B, 110C and first to third battery-side cross members 25A, 25B, 25C are offset in the fore-and-aft direction of the vehicle as described above, even if the obstacle is a thin object such as a pole, the collision load of the obstacle can be input to any of floor-side cross members 153, 110A, 110B, 110C and battery-side cross members 25A, 25B, 25C.

[0143] In a side view of the vehicle, only the floor-side cross-members 110A, 110B, 110C and the battery-side cross-members 25A, 25B, 25C in the area that does not overlap with the hinge pillar 150 (shown by an imaginary line in Figure 14) are shifted in the fore-and-aft direction. In other words, the floor-side cross-members 110A, 110B, 110C and the battery-side cross-members 25A, 25B, 25C that are located rearward of the hinge pillar 150 are shifted in the fore-and-aft direction. In other words, because the area where the hinge pillar 150 is located has high strength against a collision load from the side, the collision load can be borne by the hinge pillar 150 even if the floor-side cross-member and the battery-side cross-member are not shifted in the fore-and-aft direction.

[0144] Similarly, only floor-side cross-members 110A, 110C and battery-side cross-members 25A, 25B, 25C in an area that does not overlap with center pillar 157 in a side view of the vehicle may be shifted in the front-rear direction.

[0145] (Effective in the event of a frontal collision) Next, a case where the electric vehicle 1 configured as described above is involved in a frontal collision will be described. The collision load during a frontal collision is input to the left and right front side frames 72 via the front bumper reinforcement 86. The collision load during a frontal collision is also input to the left and right front frame members 11.

[0146] With regard to the front frame member 11, multiple portions of the front frame member 11 that are spaced apart in the fore-and-aft direction are connected to the left front side frame 72 by the left connectors 53, 54, respectively, so that the left front frame member 11 that receives a collision load is stabilized and is less likely to tilt left / right or up / down. The same is true for the right front frame member 11. As a result, the collision load is transmitted linearly to the front of the battery case 10 by the left and right front frame members 11.

[0147] At this time, because the front frame member 11 is connected to the battery case 10 by the outer connecting portions 30 and the inner connecting portions 31 at multiple locations that are spaced apart in the left-right direction, the collision load input to the front frame member 11 is input to multiple locations in the battery case 10 that are spaced apart in the left-right direction. Because the battery case 10 includes a front central member 26, left side member 20, and right side member 21 that extend in the fore-and-aft direction, the collision load input to the multiple locations that are spaced apart in the left-and-right direction is distributed and transmitted to the front central member 26, left side member 20, and right side member 21. This makes it possible to actively utilize the battery case 10 to absorb the collision load, thereby increasing the amount of collision load absorption by the lower structure 2. This in turn makes it possible to optimize the strength of the front side frames 72 and the strength of members near the rear ends of the front side frames 72, thereby achieving a reduction in the weight of the entire vehicle.

[0148] Furthermore, the collision load input to the front side frame 72 is transmitted to the side sill 73 via the floor reinforcement 151. Furthermore, because the outer connection portion 30 extends toward the side sill 73, the collision load input to the front frame member 11 can also be applied toward the side sill 73 via the outer connection portion 30. In this case, because the floor reinforcement 151 and the outer connection portion 30 are spaced apart in the vertical direction, the route of the collision load transmitted from the front side frame 72 to the side sill 73 is different from the route of the collision load acting from the front frame member 11 toward the side sill 73. Therefore, the collision load is transmitted to the side sill 73 via multiple routes. The side sill 73 is a particularly rigid member among the members that make up the vehicle body, and therefore the collision load can be absorbed by the side sill 73.

[0149] Furthermore, the collision load input to the front side frame 72 is transmitted from the rear of the front side frame 72 to the battery case 10 via both the floor reinforcement 151 and the lower load transmission member 152. This also forms a route for the collision load to be transmitted to the battery case 10 via the lower load transmission member 152, so the collision load is dispersed and absorbed by both the side sill 73 and the battery case 10. Furthermore, because the floor reinforcement 151 and the lower load transmission member 152 are aligned 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 and is also absorbed by the floor panel 70.

[0150] In the case of an offset frontal collision, a large collision load is input to either the left or right side, and this embodiment is also effective in this case. In the case of a rear collision, the same effect can be achieved because the rear frame member 12 is provided.

[0151] (Effective in the event of a side collision) Next, a side collision of the electric vehicle 1 configured as described above will be described. During a side collision, the collision load is input to the side sill 73 from the outside toward the inside in the vehicle width direction. Because the side load transfer member 120 is provided inside the side sill 73, the collision load is input to the side load transfer member 120 from the outside toward the inside in the vehicle width direction. At this time, the inner upper vertical wall portion 123 of the side load transfer member 120 overlaps with the floor-side cross members 110 and 153, and the inner lower vertical wall portion 124 overlaps with the battery case 10, so the collision load is distributed and transmitted to the floor-side cross members 110 and 153 and the battery case 10. Because the floor-side cross members 110 and 153 extend in the vehicle width direction while attached to the floor panel 70, they have a high resistance to lateral loads, which absorbs part of the collision load and reduces the collision load input to the battery case 10, thereby protecting the battery B. Furthermore, since the battery case 10 is provided with the first to third battery-side cross members 25A, 25B, 25C, the front end member 22, and the rear end member 23, the battery case 10 can also absorb the collision load.

[0152] Furthermore, when an obstacle such as a pole collides with the vehicle from the side, as shown in FIG. 14, the cross member 153 and the first to third floor-side cross members 110A, 110B, and 110C are misaligned in the fore-and-aft direction of the vehicle from the first to third battery-side cross members 25A, 25B, and 25C, allowing the collision load to be input to one of the cross members. It is also possible that a thin pole may collide between the first floor-side cross member 110A and the second battery-side cross member 25B. In this case, the high-strength side load transmission member 120 receives the pole's collision load, and then the collision load can be distributed and absorbed by at least the first floor-side cross member 110A and the second battery-side cross member 25B.

[0153] Furthermore, if the obstacle is a large diameter pole or a car, the collision load will be input to both the floor side cross members 110A, 110B, 110C and the battery side cross members 25A, 25B, 25C, and the collision load will be distributed and transmitted to the floor panel 70 and the battery case 10.

[0154] The above-described embodiments are merely examples in all respects and should not be construed as limiting. Furthermore, all modifications and variations within the scope of the claims are within the scope of the present invention. [Industrial Applicability]

[0155] 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. [Explanation of symbols]

[0156] 1. Electric vehicles 10 Battery case 11 Front frame member 20 Left side member 21 Right-hand member 22 Front end member 22a Protrusion 25A, 25B, 25C 1st to 3rd battery side cross members 26 Front center member (front reinforcing member) 27-29 1st to 3rd rear center members (rear reinforcement members) 30 Outer connection part (one-side connection part) 31 Inner connection part (other connection part) 53, 54 Left side connection part 55, 56 Right side connection part 70 Floor Panel 70a Front floor 70b Rear floor section (first floor section) 70c kick-up section (second floor section) 72 Front side frame 73 Side sill 100 Seat fixing part 110A, 110B, 110C 1st to 3rd floor cross members 120 Lateral load transfer member (inner reinforcement) 123 Inner upper vertical wall section (first vertical wall section) 124 Inner lower vertical wall (second vertical wall) 150 Hinge pillar 151 Floor reinforcement (first longitudinal load transmission member) 152 Lower load transmission member (second longitudinal load transmission member) 153 Cross member 160 Connecting member 170 Rear wheel house 171 Rear cross member (first cross member) 180 Case side cross member (second cross member) A. Body structure B Battery M Traction motor

Claims

1. A body structure of an electric vehicle having a driving motor and a battery case accommodating a battery that supplies power to the driving motor, the body structure comprising: The floor panel has a first floor portion and a second floor portion located rearward and above the first floor portion, the battery case is located below the first floor portion and the second floor portion, a connecting member is provided that vertically connects the battery case and the second floor portion at a position that is a certain distance rearward from the front end of the second floor portion, a first cross member extending in the vehicle width direction is attached to the underside of the second floor portion; the battery case has a second cross member extending in the vehicle width direction above a rear end member that forms a rear portion of the battery case, an upper portion of the connecting member is fixed to a lower surface of the first cross member; a lower portion of the connecting member fixed to an upper surface of the second cross member; A vehicle body structure in which the first cross member and the second cross member are arranged to face each other in the vertical direction.

2. The vehicle body structure according to claim 1, A pair of left and right wheel house sections are connected to both ends of the second floor section in the vehicle width direction, Further provided is a rear floor side cross member extending in the left-right direction, a left end portion of the rear floor-side cross member connected to the left wheel house portion; A vehicle body structure in which the right end of the rear floor side cross member is connected to the right wheel house portion.

3. The vehicle body structure according to claim 2, A vehicle body structure in which the rear floor side cross member is attached to the upper surface of the second floor portion directly above the first cross member.

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