Body structure

Abstract

A vehicle body structure is provided, which optimizes the strength of each component constituting the vehicle body and realizes the overall lightness of the vehicle by dispersively transferring the collision load during a frontal collision to the vehicle body and a battery box. The vehicle body structure comprises: a front panel (71); a pair of left and right front side frames (72); a pair of left and right lower side beams (73); a first front-to-back direction load transfer component (151), which extends from the vehicle rear portion of the front side frame (72) along the upper surface of the floor panel (70) to the lower side beam (73); and a second front-to-back direction load transfer component (152), which extends from the vehicle rear portion of the front side frame (72) along the lower surface of the floor panel (70) toward the vehicle front portion of the battery box (10).

Description

Technical Field

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

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

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

[0004] In Patent Document 1, the bottom beam is configured to be more easily deformed than the front extension portion, so that when a vehicle collides head-on with an obstacle or the like, the bottom beam is first deformed to absorb the collision load. The collision load that cannot be completely absorbed by the deformation of the bottom beam is absorbed by the deformation of the front extension portion of the box body. That is, in Patent Document 1, the bottom beam and the front extension portion of the box body are actively deformed as impact absorbing components during a head-on collision, thereby absorbing the collision load in two stages and suppressing the deformation of the box body.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-158688

[0008] As described above, in Patent Document 1, a bottom member deformed by a relatively small load and a front extension deformed by a relatively large load are combined in the vehicle longitudinal direction, so that the collision load is not transmitted to the box body and deformation of the box body is suppressed.

[0009] However, there is a demand for further improvement in collision safety in automobiles. In particular, when a large collision load is input to the vehicle body, it is necessary to suppress the deformation of the cab caused by the collision load. In electric vehicles, it is also necessary to protect the large-capacity battery cells carried. On the other hand, there is also a strong demand for lightweight vehicle bodies. Therefore, how to strike a balance between further improvement in collision safety and lightweight vehicle bodies has become a problem.

[0010] In this regard, in the case of Patent Document 1, the bottom beam and the front extension are deformed at the lower part of the vehicle body so as to absorb the collision load. Therefore, if a larger collision load is input, the strength of the front longitudinal beam located above the bottom beam must be increased, so there is a concern that the vehicle body weight will increase. In addition, if the strength of the front longitudinal beam is increased, a concentrated load will be locally input to the vehicle body from the rear end of the front longitudinal beam, so it is also necessary to strengthen this part, which may lead to a further increase in the vehicle body weight. Summary of the invention

[0011] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to optimize the strength of each member constituting the vehicle body and achieve weight reduction of the entire vehicle by distributing the collision load during a frontal collision to the vehicle body and the battery box.

[0012] In order to achieve the above-mentioned object, in a first aspect of the present disclosure, the following vehicle body structure of an electric vehicle can be assumed: the electric vehicle is provided with a driving motor, and a battery box containing a battery for supplying power to the driving motor is arranged below a floor panel. The vehicle body structure includes: a dash panel that divides a vehicle compartment and a space in front of the vehicle compartment in the vehicle front-rear direction, and the lower end of the dash panel is connected to the vehicle front end of the floor panel; a pair of left and right front side frames that extend from both sides of the dash panel in the vehicle width direction toward the vehicle front; a pair of left and right lower side beams that are arranged at both ends of the floor panel in the vehicle width direction to extend in the vehicle front-rear direction; a first front-rear direction load transmission component that extends from the vehicle rear portion of the left and right front side frames along the upper surface of the floor panel to the left and right lower side beams; and a second front-rear direction load transmission component that extends from the vehicle rear portion of the left and right front side frames along the lower surface of the floor panel toward the vehicle front portion of the battery box.

[0013] According to this structure, when the collision load during a head-on collision is input to the front side frame, it is transmitted from the rear of the vehicle of the front side frame to the lower side beam via the first front-rear direction load transmission component, and is also transmitted to the battery box via the second front-rear direction load transmission component. Thus, a path for the collision load transmitted to the lower side beam via the first front-rear direction load transmission component and a path for the collision load transmitted to the battery box via the second front-rear direction load transmission component are formed, so that the collision load is dispersedly absorbed by both the lower side beam and the battery box. In addition, since the first front-rear direction load transmission component and the second front-rear direction load transmission component are along the floor panel, a part of the collision load input to the first front-rear direction load transmission component and the second front-rear direction load transmission component is also transmitted to the floor panel, and is also absorbed by the floor panel.

[0014] In a second aspect of the present disclosure, a frame member is provided, the frame member extending from the battery box below the front side frame toward the front of the vehicle.

[0015] According to this structure, the collision load during the frontal collision is also input to the frame member. The collision load input to the frame member is transmitted to the battery box and absorbed.

[0016] In the third aspect of the present disclosure, the second front-rear direction load transmission member is disposed above the frame member.

[0017] According to this structure, since the frame member and the second front-rear direction load transmission member are arranged in a vertically aligned state, the collision load transmitted from the frame member and the collision load transmitted from the second front-rear direction load transmission member can be dispersed to the lower side and the upper side of the battery box.

[0018] In a fourth aspect of the present disclosure, a cross member is provided on the lower surface of the floor panel, the cross member extending in the vehicle width direction and connecting the vehicle rear portion of the second front-rear direction load transmission component on the left side and the vehicle rear portion of the second front-rear direction load transmission component on the right side.

[0019] According to this structure, the second front-to-back load transfer component on the left side and the second front-to-back load transfer component on the right side are connected by the cross beam, thereby suppressing the displacement of the rear portions of the two second front-to-back load transfer components when the collision load is input. As a result, the collision load can be transferred from the two second front-to-back load transfer components to the battery box.

[0020] In the fifth aspect of the present disclosure, a central beam extending in the front-rear direction of the vehicle is arranged at the center of the battery box in the vehicle width direction, and the rear portion of the vehicle of the second front-rear direction load transfer component on the left side is positioned on the left side of the vehicle body compared to the central beam, and the rear portion of the vehicle of the second front-rear direction load transfer component on the right side is positioned on the right side of the vehicle body compared to the central beam.

[0021] According to this configuration, the center beam can absorb both the collision load transmitted from the left second front-rear direction load transmission member to the battery box and the collision load transmitted from the right second front-rear direction load transmission member to the battery box.

[0022] In a sixth aspect of the present disclosure, a protrusion protruding upward is provided at the vehicle front portion of the battery box, and the vehicle rear portion of the second front-rear load transmission member and the protrusion overlap each other when viewed in the vehicle front-rear direction.

[0023] According to this structure, the collision load is reliably transmitted from the second front-rear direction load transmission member to the battery box via the protruding portion.

[0024] In the seventh aspect of the present disclosure, the protrusion extends continuously in the vehicle width direction, so even if the vehicle rear portion of the second front-rear load transfer component is slightly displaced in the vehicle width direction during a frontal collision, the collision load is reliably input to the protrusion.

[0025] In an eighth aspect of the present disclosure, the vehicle rear portion of the second front-rear direction load transmission member and the protruding portion are arranged at a predetermined interval in the vehicle front-rear direction.

[0026] According to this structure, during normal driving, the second front-to-back load transmission component does not contact the protruding portion of the battery box, thereby avoiding the generation of interference sound and the like. On the other hand, if the second front-to-back load transmission component moves rearward during a head-on collision, the rear portion of the second front-to-back load transmission component contacts the protruding portion, so that the collision load is reliably input to the protruding portion. In other words, the above-mentioned predetermined interval refers to the following interval: the interval is set so that the second front-to-back load transmission component does not contact the protruding portion during normal driving, and the rear portion of the second front-to-back load transmission component contacts the protruding portion during a head-on collision.

[0027] Effects of the Invention

[0028] As described above, the first front-to-back load transfer component and the second front-to-back load transfer component are provided, wherein the first front-to-back load transfer component extends from the rear of the front side frame along the upper surface of the floor panel to the lower side beam, and the second front-to-back load transfer component extends from the rear of the front side frame along the lower surface of the floor panel toward the front of the battery box, so that the collision load during a frontal collision can be dispersedly transferred to the vehicle body and the battery box. Thus, the strength of each component constituting the vehicle body can be optimized to achieve overall lightweighting of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a side view of the electric vehicle according to the embodiment of the present invention.

[0030] Figure 2 This is a side view showing a state where the electric vehicle is divided into a lower structure and an upper structure.

[0031] Figure 3 This is a three-dimensional view of the lower structure viewed from above.

[0032] Figure 4 This is a top view of the lower structure.

[0033] Figure 5 It is equivalent to a lower structure with a small battery box. Figure 4 .

[0034] Figure 6 This is a left side view of the lower structure when the height of the front center beam is increased.

[0035] Figure 7 It is a cross-sectional view of the central part in the left-right direction of the electric vehicle.

[0036] Figure 8 This is a cross-sectional view of an electric vehicle as viewed from the front.

[0037] Fig. 9 This is a cross-sectional view of an electric vehicle as viewed from the rear.

[0038] Fig.10 This is a perspective view showing a section passing through the front seat portion of the electric vehicle as seen from the front.

[0039] Fig.11 The figure schematically shows a floor panel, a front seat, a front seat occupant, and a battery unit.

[0040] Fig.12 Yes Fig.10 The C part in the figure is enlarged and viewed from the front.

[0041] Fig.13 This is a perspective view showing a cross section of the rear portion of the electric vehicle as seen from below.

[0042] Fig.14 It is a diagram schematically showing a floor panel and a battery unit according to a modified example.

[0043] Explanation of symbols

[0044] 1. Electric Vehicles

[0045] 10 Battery Box

[0046] 11 Front frame part

[0047] 20 Left side beam

[0048] 21 Right side beam

[0049] 22 Front end beam

[0050] 22a Protrusion

[0051] 25A, 25B, 25C First to third battery side crossbeams

[0052] 26 Front center beam (front reinforcement beam)

[0053] 27~29 1st to 3rd rear center beams (rear reinforcement beams)

[0054] 30 Outer connection (one side connection)

[0055] 31 Inner connection part (other connection part)

[0056] 53, 54 Left side connection

[0057] 55, 56 Right side connection

[0058] 70 Floor

[0059] 70a Front floor section

[0060] 70b Rear floor portion (first floor portion)

[0061] 70c Upper curved portion (second floor portion)

[0062] 72 front side frame

[0063] 73 Lower side beam

[0064] 100 Seat fixing part

[0065] 110A, 110B, 110C First to third floor side beams

[0066] 120 Side load transfer component (internal reinforcement)

[0067] 123 Inner upper longitudinal wall portion (first longitudinal wall portion)

[0068] 124 Inner lower vertical wall portion (second vertical wall portion)

[0069] 150 hinge column

[0070] 151 Floor reinforcement (first front-rear direction load transfer component)

[0071] 152 lower load transmission member (second front-rear direction load transmission member)

[0072] 153 Beam

[0073] 160 Connecting parts

[0074] 170 Rear wheel housing

[0075] 171 Rear crossbeam (first crossbeam)

[0076] 180 Box side beam (second beam)

[0077] A Body structure

[0078] B Battery

[0079] M Travel motor DETAILED DESCRIPTION

[0080] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In addition, the following description of the preferred embodiments is essentially just illustrative, and is not intended to limit the present invention, its applicable objects, or the use of the present invention.

[0081] Figure 1 FIG. 1 is a left side view of an electric vehicle 1 having a vehicle body structure A according to an embodiment of the present invention. Figure 2 As shown in FIG. 1 , the electric vehicle 1 includes a lower structure 2 and an upper structure 3, and the lower structure 2 and the upper structure 3 constitute a vehicle body structure A. Figure 2 , the vehicle door, engine hood, front fender, window glass, bumper, front and rear lighting devices, etc. are removed. In the description of this embodiment, the front side of the vehicle is referred to as "front", the rear side of the vehicle is referred to as "rear", the right side of the vehicle is referred to as "right", and the left side of the vehicle is referred to as "left". The left-right direction of the vehicle is the vehicle width direction.

[0082] like Figure 1 As shown, the electric vehicle 1 is a passenger vehicle. Figure 2 As shown, a front seat S1 is provided at the front side of a vehicle cabin R1 serving as a passenger carrying space, and a rear seat S2 is provided behind the front seat S1 in the vehicle cabin R1. A luggage compartment R2 is provided behind the rear seat S2 as required. The vehicle cabin R1 and the luggage compartment R2 are provided in an upper structure 3. In addition, only the front seat S1 may be provided in the vehicle cabin R1, or a third row of seats (not shown) may be provided behind the rear seat S2.

[0083] On the other hand, the space in front of the vehicle cabin R1, which is the front part of the electric vehicle 1, can be used as, for example, a power room R3. That is, the vehicle body structure A includes: a driving motor M, which generates power for driving the driving wheels; and a battery box 10, which houses a battery B (only when the battery box 10 is used) that supplies power to the driving motor M. Figure 4 ). The power transmission system PT is composed of only the driving motor M, or the driving motor M and a speed reducer or a transmission. Figure 1 and Figure 2In the figure, the case where the powertrain PT is only provided in the power room R3 is shown, but the powertrain PT can also be provided in the lower space R4 of the luggage compartment R2 (the powertrain of the rear is not shown). In the case where the powertrain PT is only provided in the power room R3, only the front wheels F are driven. In the case where the powertrain PT is provided in the lower space R4, only the rear wheels R are driven. In this case, the power room R3 can be used as a luggage compartment space, etc. In addition, in the case where the powertrain PT is provided in both the power room R3 and the lower space R4, it becomes a four-wheel drive vehicle. The battery box 10 is arranged below the floor panel 70 described later.

[0084] like Figure 3 and Figure 4 As shown in FIG. 1 , the lower structure 2 includes a battery box 10, a front frame member 11 extending forward in front of the battery box 10, and a rear frame member 12 extending rearward in rear of the battery box 10. Figure 3 The left front wheel F, rear wheel R, suspension arm, etc. are omitted.

[0085] In the case of a general electric vehicle, the battery box is mostly separated from the vehicle body and can be loaded and unloaded under the floor. However, in this embodiment, not only the battery box 10 is integrated, but the front frame part 11 and the rear frame part 12 are also integrated with the battery box 10, and the front frame part 11 and the rear frame part 12 can also be loaded and unloaded relative to the upper structure 3 together with the battery box 10.

[0086] Specifically, the electric vehicle 1 of the present embodiment is configured to be divisible into a lower structure 2 having a battery box 10 and an upper structure 3 forming a vehicle room R1 and a luggage compartment R2. The term "divisible into upper and lower parts" means that the lower structure 2 and the upper structure 3 are integrated by fastening members such as bolts, nuts or screws without welding or bonding. Thus, when the electric vehicle 1 is delivered to the user for maintenance or repair, the lower structure 2 can be separated from the upper structure 3 as needed, thereby improving maintainability.

[0087] Here, as a vehicle body structure, a ladder frame type vehicle body structure is known. In the case of a ladder frame type vehicle body structure, although it can be divided into a ladder frame and a cab in the upper and lower parts, since the ladder frame extends continuously in the front-to-back direction, the ladder frame mainly bears the collision load in the case of a frontal collision and a rear collision. In the case of a side collision, the ladder frame only bears the collision load auxiliaryly, and the cab mainly bears the collision load. In this way, in a ladder frame type vehicle body structure, usually, the parts that bear the collision load in the case of a frontal collision, a rear collision, and a side collision are separated.

[0088] In contrast, in the case of the electric vehicle 1 of the present embodiment, although the lower structure 2 and the upper structure 3 having the frame members 11 and 12 are separable, in both cases of a frontal collision, a rear collision, and a side collision, the collision load is borne by the lower structure 2 and the upper structure 3, and the collision load can be dispersed and absorbed by the two structures 2 and 3. In this respect, the technical concept is greatly different from the conventional ladder frame type vehicle body structure. The structures and effects of the lower structure 2 and the upper structure 3 are described in order below.

[0089] (Lower structure)

[0090] First, the lower structure 2 will be described. Figure 3 as well as Figure 4 As shown, the lower structure 2 includes a battery box 10, a front frame member 11, and a rear frame member 12, as well as a powertrain PT, front wheels F, rear wheels R, a front suspension device 13, and a rear suspension device 14. The form of the front suspension device 13 and the rear suspension device 14 is not particularly limited.

[0091] The battery box 10 is a large box body formed below the floor panel 70 to be described later, extending from the vicinity of the left end to the vicinity of the right end of the floor panel 70 and from the vicinity of the front end to the vicinity of the rear end of the floor panel 70. In this way, the battery box 10 is disposed in a wide range under the floor panel 70, so that Figure 4 As shown, a large-capacity battery B can be mounted on the electric vehicle 1. The battery B can be, for example, a lithium-ion battery, an all-solid-state battery, or other secondary batteries. In addition, the battery B can be a so-called battery cell or a battery pack containing a plurality of battery cells.

[0092] The battery box 10 includes a left side square beam 20, a right side square beam 21, a front end beam 22, a rear end beam 23 and a bottom plate 24. The left side square beam 20, the right side square beam 21, the front end beam 22 and the rear end beam 23 are made of, for example, an extruded material made of an aluminum alloy, or may be made of a stamped material made of an aluminum alloy plate or a steel plate. The bottom plate 24 may also be made of an extruded material. In the following description, the term "extruded material" refers to an extruded material made of an aluminum alloy, and the term "stamped material" refers to a stamped material made of an aluminum alloy plate or a steel plate. In addition, each component may be made of, for example, a casting.

[0093] The cross-sectional shapes of the left side beam 20, the right side beam 21, the front end beam 22 and the rear end beam 23 in the direction perpendicular to the longitudinal direction are all rectangular. In addition, the left side beam 20, the right side beam 21, the front end beam 22 and the rear end beam 23 are all arranged at the same height and extend substantially horizontally.

[0094] The left side square beam 20 is provided at the left end of the battery box 10 and extends in the front-to-back direction. The right side square beam 21 is provided at the right end of the battery box 10 and extends in the front-to-back direction. In addition, the front end beam 22 is provided at the front end of the battery box 10 and extends in the left-right direction. The left end of the front end beam 22 is connected to the front end of the left side square beam 20, and the right end of the front end beam 22 is connected to the front end of the right side square beam 21. The rear end beam 23 is provided at the rear end of the battery box 10 and extends in the left-to-right direction. The left end of the rear end beam 23 is connected to the rear end of the left side square beam 20, and the right end of the rear end member 23 is connected to the rear end of the right side square beam 21. The bottom plate 24 extends approximately horizontally and is fixed to the lower surfaces of the left side square beam 20, the right side square beam 21, the front end beam 22, and the rear end beam 23. Therefore, a battery accommodation space S ( Figure 3 shown).

[0095] The size of the battery storage space S can be changed according to the capacity of the battery B installed. The size of the battery storage space S can be easily changed by changing the length of the left side beam 20, the right side beam 21, the front end beam 22 and the rear end beam 23 and the shape of the bottom plate 24. For example, in the case of a small car with a short wheelbase and a narrow tread, the left side beam 20, the right side beam 21, the front end beam 22 and the rear end beam 23 are shortened, and the shape of the bottom plate 24 is reduced accordingly, so that the battery storage space S becomes smaller in accordance with the small car (see Figure 5 ). On the other hand, in the case of a large vehicle, the left side beam 20, the right side beam 21, the front end beam 22 and the rear end beam 23 are lengthened, and the shape of the bottom plate 24 is enlarged accordingly, so that the battery storage space S becomes larger according to the large vehicle. When the left side beam 20, the right side beam 21, the front end beam 22 and the rear end beam 23 are made of extruded material, the length can be easily changed. In addition, the bottom plate 24 can also be made of extruded material, thereby making it easy to change the shape.

[0096] The upper part of the battery storage space S may be closed with a cover body not shown in the figure, or may be closed with a floor panel 70 described later. In addition to the battery B, a cooling device for cooling the battery B, a heating device for heating the battery B, etc. (temperature regulating device) may be provided in the battery storage space S. In addition, the power of the battery B is supplied to the driving motor M via a control device not shown in the figure. Moreover, the battery B can also be charged via a charging socket not shown in the figure.

[0097] like Figure 3As shown, inside the battery box 10, the first to third battery side beams 25A, 25B, and 25C are provided as reinforcing members extending in the left-right direction. The heights of the first to third battery side beams 25A, 25B, and 25C are all the same, and are substantially the same as the height of the left side square beam 20, etc. The battery side beams 25A, 25B, and 25C can be made of extruded materials or stamped materials. In this embodiment, three battery side beams 25A, 25B, and 25C are provided, but the number of battery side beams 25A, 25B, and 25C can be increased or decreased according to the dimensions of the battery box 10 in the front-to-back direction.

[0098] The first to third battery side cross beams 25A, 25B, and 25C are arranged at intervals from each other in the front-to-back direction, with the first battery side cross beam 25A being positioned at the front and the third battery side cross beam 25C being positioned at the rear. The lower portion of each battery side cross beam 25A, 25B, and 25C is fixed to the upper surface of the bottom plate 24. In addition, the left end portion of each battery side cross beam 25A, 25B, and 25C is fixed to the inner surface (right side) of the left side square beam 20, and the right end portion of each battery side cross beam 25A, 25B, and 25C is fixed to the inner surface (left side) of the right side beam 21. In other words, the battery side cross beams 25A, 25B, and 25C are components that connect the left side square beam 20 and the right side square beam 21.

[0099] Above Figure 5 The example of the lower structure 2 having a small battery box 10 is shown. The size of the small battery box 10 in the front-rear direction is set to be smaller than that of the lower structure 2. Figure 4 The battery box 10 shown in the figure is short in the front-to-back direction, but Figure 5 In the example shown, the third battery side cross member 25C is omitted because the dimension in the front-rear direction is shortened. On the contrary, although not shown, a fourth battery side cross member may be provided.

[0100] Inside the battery box 10, as reinforcing members extending in the front-rear direction, a front center beam (front reinforcing beam) 26 and first to third rear center beams (rear reinforcing beams) 27 to 29 are provided. The front center beam 26 and the first to third rear center beams 27 to 29 are arranged at substantially the same height and are provided in the left-right center of the battery box 10. The lower ends of the front center beam 26 and the first to third rear center beams 27 to 29 are attached to the upper surface of the bottom plate 24.

[0101] The front center beam 26 is disposed between the front end beam 22 and the first battery side cross beam 25A, the front end of the front center beam 26 is fixed to the left-right center of the front end beam 22, and the rear end of the front center beam 26 is fixed to the left-right center of the first battery side cross beam 25A. Therefore, the front end beam 22 is a member extending in a manner that connects the front ends of the left side beam 20 and the right side beam 21 to the front end of the front center beam 26.

[0102] The first rear center beam 27 is disposed between the first battery side cross beam 25A and the second battery side cross beam 25B, the front end of the first rear center beam 27 is fixed to the left-right center of the first battery side cross beam 25A, and the rear end of the first rear center beam 27 is fixed to the left-right center of the second battery side cross beam 25B. In addition, the second rear center beam 28 is disposed between the second battery side cross beam 25B and the third battery side cross beam 25C, the front end of the second rear center beam 28 is fixed to the left-right center of the second battery side cross beam 25B, and the rear end of the second rear center beam 28 is fixed to the left-right center of the third battery side cross beam 25C. In addition, the third rear center beam 29 is disposed between the third battery side cross beam 25C and the rear end beam 23, the front end of the third rear center beam 29 is fixed to the left-right center of the third battery side cross beam 25C, and the rear end of the third rear center beam 29 is fixed to the left-right center of the rear end beam 23. Therefore, the first to third battery side cross members 25A, 25B, 25C, the front center member 26, and the first to third rear center members 27 to 29 are arranged in a lattice pattern inside the battery box 10 and connected to each other, so that the reinforcement effect of the battery box 10 is further improved.

[0103] When an imaginary straight line extending in the front-rear direction is assumed in a plan view, the front center beam 26 and the first to third rear center beams 27 to 29 are set in their respective left-right directions so as to be arranged on the imaginary straight line. In other words, the first to third rear center beams 27 to 29 are provided so as to be located on an imaginary extension line of the front center beam 26 in the rear direction. In addition, the front center beam 26 and the first to third rear center beams 27 to 29 may be formed of one member continuous in the front-rear direction.

[0104] Figure 6 This means that the height of the front center beam 26 is greater than that of the first to third rear center beams 27 to 29 ( Figure 670a is located above the rear floor portion 70b. The front center beam 26 is provided below the front floor portion 70a, and the first to third rear center beams 27 to 29 are provided below the rear floor portion 70b. The upper end of the front center beam 26 is formed to be located above the rear floor portion 70b. In other words, the upper end of the first to third rear center beams 27 to 29 is located below the upper end of the front center beam 26 to correspond to the relatively low rear floor portion 70b. At this time, the first battery side cross beam 25A can be provided below the front floor portion 70a, in which case the upper end of the first battery side cross beam 25A can be formed to be located above the second and third battery side cross beams 25B and 25C.

[0105] like Figure 3 and Figure 4 As shown, a pair of left and right front frame members 11 are provided, and extend substantially horizontally and linearly below left and right front side frames 72 described later. Each front frame member 11 can be made of, for example, an extruded material, a stamped material, etc. In the present embodiment, each front frame member 11 is made of an extruded material, so that the cross-sectional shape in the direction perpendicular to the front-rear direction is substantially the same from the front end to the rear end.

[0106] The left front frame member 11 is connected to a portion of the front end beam 22 constituting the front portion of the battery box 10, which is located to the left of the center in the left-right direction, and this connection portion is located to the right of the left side beam 20 of the battery box 10. In addition, the right front frame member 11 is connected to a portion of the front end beam 22, which is located to the right of the center in the left-right direction, and this connection portion is located to the left of the right side beam 21 of the battery box 10. Thus, the interval between the left and right front frame members 11 becomes a predetermined interval, and the lower part of the powertrain PT can be arranged between the left and right front frame members 11. The interval between the left and right front frame members 11 is set to be narrower than the interval between the left side beam 20 and the right side beam 21 of the battery box 10.

[0107] The left and right front frame members 11 have substantially the same height. In addition, the left and right front frame members 11 and the front center beam 26, the left side beam 20, and the right side beam 21 of the battery box 10 are disposed at substantially the same height.

[0108] The battery box 10 side (rear side) of each front frame member 11 is connected to the battery box 10 at a plurality of locations separated from each other in the left-right direction. Specifically, the rear end of the right front frame member 11 is connected to the front end beam 22, and a location separated forward from the rear end of the front frame member 11 is connected to the front end beam 22 via an outer connection portion (one connection portion) 30 and an inner connection portion (the other connection portion) 31. Thus, the collision load input to the front frame member 11 during a frontal collision can be distributed and transmitted to a plurality of locations of the battery box 10.

[0109] The outer connecting portion 30 and the inner connecting portion 31 are made of a high-rigidity member, and the high-rigidity member is made of, for example, an extruded material or a stamped material, and the outer connecting portion 30 and the inner connecting portion 31 are cylindrical, plate-shaped, or columnar. When viewed from above, the width of the outer connecting portion 30 and the inner connecting portion 31 is set to be wider than the width of the front frame member 11, thereby further improving the dispersion effect of the collision load. In addition, the width of the outer connecting portion 30 and the inner connecting 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.

[0110] The right outer connecting portion 30 is provided at a position closer to the right side (outer side in the vehicle width direction) than the right front frame member 11 at substantially the same height as the front frame member 11, and is inclined relative to the front-rear direction in a manner that the closer to the rear end, the more right side. The front end of the right outer connecting portion 30 is connected to a portion (midway portion in the front-rear direction) between the center and the rear end of the front frame member 11 in the front-rear direction. The outer connecting portion 30 extends from the connecting portion with the front frame member 11 toward the right and rear side, that is, the side of the lower side beam 73 (described later) provided in the upper structure 3. Moreover, the rear end of the right outer connecting portion 30 is connected to a portion of the front end beam 22 that is separated from the rear end of the front frame member 11 in the right direction. The connecting structure of the outer connecting portion 30 and the front frame member 11 and the connecting structure of the outer connecting portion 30 and the front end beam 22 may be a connecting structure using fastening members such as bolts and nuts, or a connecting structure using welding, bonding, etc.

[0111] The inner connecting portion 31 on the right side is provided at a position closer to the left side (inner side in the vehicle width direction) than the front frame member 11 on the right side at a height substantially the same as that of the front frame member 11, and is inclined relative to the front-rear direction in a manner that the closer to the rear end, the more to the left. The front end of the inner connecting portion 31 on the right side is connected to a portion (midway portion in the front-rear direction) between the center in the front-rear direction and the rear end of the front frame member 11. The inner connecting portion 31 on the right side extends from the connection portion with the front frame member 11 toward the left and rear, i.e., the center in the left-right direction of the battery box 10. Moreover, the rear end of the inner connecting portion 31 is connected to a portion of the front end beam 22 that is separated from the rear end of the front frame member 11 in the left direction. The connection structure of the inner connecting portion 31 and the front frame member 11, and the connection structure of the inner connecting portion 31 and the front end beam 22 can be set to be the same as the connection structure of the outer connecting portion 30.

[0112] In this embodiment, the right front frame member 11 is connected to the front end beam 22 at three locations separated from each other in the left-right direction, but the present invention is not limited to this. One of the outer connecting portion 30 and the inner connecting portion 31 may be omitted and connected at two locations. Alternatively, the rear end of the front frame member 11 may not be connected to the front end beam 22, but may be connected to the front end beam 22 only through the outer connecting portion 30 and the inner connecting portion 31.

[0113] The left front frame member 11 can also be connected to the front end beam 22 similarly to the right front frame member 11. The connection structure of the left front frame member 11 can be bilaterally symmetrical with respect to the connection structure of the right front frame member 11.

[0114] like Figure 3 As shown, at a position forward of the battery box 10 of the lower structure 2, an intermediate connecting beam 49, a front connecting beam 50, and a rear connecting beam 51 are provided at intervals in the front-to-rear direction. The front connecting beam 50 is a member that extends from the front of the left front frame member 11 to the front of the right front frame member 11 in the vehicle width direction, and connects the left front frame member 11 with the right front frame member 11. In addition, the rear connecting beam 51 is a member that extends from the rear of the left front frame member 11 to the rear of the right front frame member 11 in the vehicle width direction, and connects the left front frame member 11 with the right front frame member 11. The front connecting beam 50 and the rear connecting beam 51 are made of, for example, an extruded material, a stamped material, or the like. By connecting the left and right front frame members 11 with the front connecting beam 50 and the rear connecting beam 51, a frame structure that is frame-shaped when viewed from above is formed.

[0115] In addition, the middle connecting beam 49 is provided between the front connecting beam 50 and the rear connecting beam 51. The middle connecting beam 49 is a member that extends from the front portion of the left front frame member 11 to the front portion of the right front frame member 11 in the vehicle width direction and connects the left front frame member 11 and the right front frame member 11. The middle connecting beam 49 may be provided as required or may be omitted.

[0116] The front connecting beam 50 is arranged to extend from the upper surface of the left front frame member 11 to the upper surface of the right front frame member 11, and protrude upward from the upper surfaces of the two front frame members 11. On the other hand, the rear connecting beam 51 is arranged between the left and right front frame members 11, and the left end of the rear connecting beam 51 is connected to the side surface of the left front frame member 11, and the right end of the rear connecting beam 51 is connected to the side surface of the right front frame member 11. The front connecting beam 50 and the rear connecting beam 51 may be fixed to the front frame member 11 by a fastening member, or may be fixed to the front frame member 11 by welding, bonding, etc.

[0117] The front and rear connection beams 50 and 51 are set to have a longitudinal dimension longer than the lateral dimension of the front frame member 11. This can improve the connection strength of the two connection beams 50 and 51 to the front frame member 11.

[0118] like Figure 4 As shown, the powertrain PT is arranged rearward of the front connecting beam 50. Specifically, in a plan view, the powertrain PT is arranged between the front connecting beam 50 and the rear connecting beam 51. The lower structure 2 is provided with drive shafts 52 on the left and right sides for transmitting the output of the powertrain PT to the left and right front wheels F, respectively.

[0119] The left and right suspension arms 13a constituting part of the front suspension device 13 are swingably supported by the left and right front frame members 11 via brackets 13b. The brackets 13b are provided at the connection portions between the left and right front frame members 11 and the rear connecting beam 51.

[0120] In the lower structure 2, two left-side connecting parts 53, 54 are provided at intervals in the front-to-back direction to connect the front frame part 11 on the left side with the front side frame 72 (described later) on the left side, and two right-side connecting parts 55, 56 are provided at intervals in the front-to-back direction to connect the front frame part 11 on the right side with the front side frame 72 (described later) on the right side. The left-side connecting parts 53, 54 and the right-side connecting parts 55, 56 can be composed of a plate, a tubular part, a columnar part, etc. extending in the up-down direction. In this embodiment, the left-side connecting parts 53, 54 and the right-side connecting parts 55, 56 are composed of stamping materials, but can also be composed of extruded materials, etc. In addition, the number of the left-side connecting parts 53, 54 is not limited to 2, and more than 3 can also be provided at intervals in the front-to-back direction. The same is true for the right-side connecting parts 55, 56.

[0121] The front left connecting portion 53 is provided at a connection portion of the front connecting beam 50 with the left front frame member 11. Specifically, the front portion of the left front frame member 11 and the left end portion of the front connecting beam 50 are arranged to overlap in the vertical direction, and the left end portion of the front connecting beam 50 is connected to the front portion of the left front frame member 11, so that the connection portion is formed by the left end portion of the front connecting beam 50. The lower end portion of the front left connecting portion 53 is attached to the left end portion of the front connecting beam 50.

[0122] In addition, the front right connecting portion 55 is provided at the connection portion of the front connecting beam 50 with the right front frame member 11. Specifically, the front portion of the right front frame member 11 and the right end portion of the front connecting beam 50 are arranged to overlap in the vertical direction, and the right end portion of the front connecting beam 50 is connected to the front portion of the right front frame member 11, so that the connection portion is formed by the right end portion of the front connecting beam 50. The lower end portion of the front right connecting portion 55 is attached to the right end portion of the front connecting beam 50.

[0123] The rear left-side connecting portion 54 is provided at a connection portion of the left front frame member 11 with the intermediate connecting beam 49. The lower end portion of the rear left-side connecting portion 54 is attached to the left front frame member 11 and is arranged at the rear side compared to the left drive shaft 52. In addition, the rear right-side connecting portion 56 is provided at a connection portion of the right front frame member 11 with the intermediate connecting beam 49. The lower end portion of the rear right-side connecting portion 56 is attached to the right front frame member 11 and is arranged at the rear side compared to the right drive shaft 52. Thus, the intervals between the front and rear left-side connecting portions 53 and 54 and the intervals between the front and rear right-side connecting portions 55 and 56 can be widened.

[0124] The right front frame member 11 and Figure 8The front side frame 72 on the right side shown in the figure is arranged on the left side (inward in the vehicle width direction), and the front frame member 11 on the left side is arranged on the left side. Figure 2 The left front side frame 72 is arranged on the right side (inward in the vehicle width direction) as shown. Therefore, the distance between the left and right front side frames 72 is wider than the distance between the left and right front frame members 11. A powertrain PT including a travel motor M is mounted between the left and right front side frames 72.

[0125] like Figure 3 As shown, the right side connecting parts 55 and 56 are formed so as to be located more to the right (outer side in the vehicle width direction) as they go up. This is because the right side front side frame 72 is located above the right front frame member 11 and is located to the right of the front frame member 11. The left side connecting parts 53 and 54 are similarly formed so as to be located more to the left (outer side in the vehicle width direction) as they go up.

[0126] The rear frame members 12 are provided in a pair of left and right parts similar to the front frame members 11, and extend substantially horizontally and linearly toward the rear. Each rear frame member 12 can be made of, for example, an extruded material, a stamped material, etc. In this embodiment, each rear frame member 12 is made of an extruded material.

[0127] The left rear frame member 12 is connected to a portion of the rear end beam 23 constituting the rear portion of the battery box 10, which is located to the left of the center in the left-right direction, and this connection portion is located to the right of the left side beam 20 of the battery box 10. In addition, the right rear frame member 12 is connected to a portion of the rear end beam 23, which is located to the right of the center in the left-right direction, and this connection portion is located to the left of the right side beam 21 of the battery box 10. The connection structure of the rear frame member 12 to the rear end beam 23 can be the same as the connection structure of the front frame member 11 to the front end beam 22 described above.

[0128] In addition, Figure 5 In the illustrated embodiment, the front ends of the left and right rear frame members 12 are connected to the rear end beam 23, and the middle portion of the rear frame member 12 in the front-rear direction is connected to the rear end beam 23 by a connecting member 60. Thus, the battery box 10 side of the rear frame member 12 is connected to the battery box 10 at a plurality of locations separated from each other in the left-right direction.

[0129] Left and right suspension arms 14 a constituting a part of the rear suspension device 14 are swingably supported by the left and right rear frame members 12 via brackets 14 b , respectively.

[0130] (Upper structure)

[0131] Next, the upper structure 3 will be described. Figure 7 to Figure 10As shown in FIG. 1 , 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 rails 73. Figure 7 to Figure 10 , the state after the doors, engine hood, front fender, window glass, bumper, front and rear lighting devices, part of the seats, interior materials, etc. are removed is shown.

[0132] The floor panel 70 constitutes the floor surface of the vehicle compartment R1 and is formed of a steel plate or the like extending in the front-rear direction and also in the left-right direction. The space above the floor panel 70 becomes the vehicle compartment R1. A roof 80 is provided above the vehicle compartment R1. Figure 2 As shown in FIG. 1 , a front opening 3a and a rear opening 3b are formed on the left side of the upper structure 3. Figure 1 As shown, the front opening 3a and the rear opening 3b are openable and closable by a front door 81 and a rear door 82, respectively. Although not shown, a front door and a rear door are also provided on the right side of the upper structure 3 so as to be openable and closable.

[0133] The dash panel 71 is a member for separating the vehicle room R1 and the power room R3 in the front-rear direction. The dash panel 71 is made of, for example, a steel plate, and extends in the left-right direction and also in the up-down direction. Figure 7 to Figure 9 As shown, front wheel covers 85 (in the left and right sides) for accommodating the left and right front wheels F are respectively provided on the left and right sides of the front portion of the upper structure 3. Figure 7 to Figure 9 Only the right front wheel housing portion is shown). The left end portion of the front panel 71 and the left front wheel housing portion 85 ( Figure 2 In addition, the right end of the front panel 71 is connected to the right front wheel cover 85 ( Figure 7 to Figure 9 as shown) connection.

[0134] like Fig.11 As shown schematically, the floor panel 70 includes a front floor portion 70a and a rear floor portion 70b. Fig.10 As shown, the floor panel 70 further includes an upwardly curved portion 70c at its rear portion. The front floor portion 70a, the rear floor portion 70b, and the upwardly curved portion 70c may be integrally formed from a single plate, or may be formed from mutually different plates. In the case of being formed from different plates, a single floor panel 70 may be formed by joining a plurality of plates.

[0135] like Fig.11 As shown, the front floor portion 70a constitutes the front side portion of the floor panel 70, and is inclined or curved so as to be located upward as it goes to the front side. 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.

[0136] The rear floor portion 70b is formed to extend rearward from the rear end of the front floor portion 70a, and constitutes the middle portion of the floor panel 70 in the front-rear direction. The front portion of the battery box 10 of the lower structure 2 is located directly below the front floor portion 70a, and the rear portion of the battery box 10 is located directly below the rear floor portion 70b. Therefore, the battery box 10 is formed to extend from below the front floor portion 70a to below the rear floor portion 70b, thereby enabling the battery B to be mounted in the majority of the area under the floor panel 70.

[0137] The middle part of the floor panel 70 in the front-to-back direction is lower than the front floor part 70a. That is, the front floor part 70a is provided in front of the rear floor part 70b and is located above the rear floor part 70b. At least a part of the seat fixing part 100 for fixing the front seat S1 is mounted on the front side part of the rear floor part 70b. The seat fixing part 100 is composed of, for example, a bracket. It is sufficient that at least the rear part of the seat fixing part 100 is mounted on the rear floor part 70b, or the entire seat fixing part 100 may be mounted on the rear floor part 70b. By mounting at least the rear part of the seat fixing part 100 on the rear floor part 70b, the front seat S1 can be arranged lower, so that the hip point of the front seat passenger P can be lowered, and as a result, a margin is created above the head of the front seat passenger P, and the loading performance is improved. In addition, the lowering of the hip point means that the sitting position of the front seat passenger P is lowered, thereby lowering the center of gravity height of the vehicle in the riding state. In this embodiment, since the entire seat fixing portion 100 is mounted on the rear floor portion 70 b , the front seat S1 can be laid out even lower.

[0138] When the driver, who is the front seat passenger P, sits on the front seat S1, the heel P1 of the front seat passenger P is placed on the front floor portion 70a. Since the front floor portion 70a where the heel P1 is located is positioned higher than the rear floor portion 70b, the heel P1 is placed at a position higher than the operating posture of a general automobile (an automobile with the front floor portion and the rear floor portion at the same height). With such a layout, the thigh P2 and the calf P3 of the front seat passenger P are in a posture with their thighs P2 and calves P3 widely spread. Fig.11 Symbol 101 represents the center line of the thigh P2, and symbol 102 represents the center line of the calf P3. The height difference between the front floor portion 70a and the rear floor portion 70b is set so that the angle formed by the center line 101 and the center line 102 (the opening angle α between the thigh P2 and the calf P3) is in the range of 125° to 150°.

[0139] By setting the height difference in this way, the angle formed by the calf P3 and the front floor portion 70a (the angle β formed by the center line 101 and the front floor portion 70a) becomes smaller, so the vertical component force input to the heel P1 when operating the pedal becomes smaller, and the operability of the brake pedal 103 is improved. Specifically, when the front seat occupant P steps on the brake pedal 103, the heel P1 acts on the front floor portion 70a with a force F that is diagonally downward. If the force F is decomposed into a force in the vertical direction and a force in the horizontal direction, they are force F1 and force F2, respectively. As described above, the angle β becomes smaller, so the vertical component force F1 input from the heel P1 becomes smaller. As a result, it is possible to quickly and accurately perform a step-shifting operation, such as from the brake pedal 103 to the accelerator pedal (not shown), or a step-shifting operation in the opposite direction, and as a result, the operability of the pedal is improved.

[0140] In addition, the rear seat passengers' feet may be placed on the rear floor portion 70b. Since the rear floor portion 70b is lower than the front floor portion 70a, the space under the rear seat passengers' feet is increased, and the rear seat passengers' loading performance is improved.

[0141] like Figure 7 to Figure 9 As shown, the upper curved portion 70c constitutes the rear side portion of the floor panel 70 and is connected to the rear end of the rear floor portion 70b. The upper curved portion 70c is located above the rear floor portion 70b, and a longitudinal plate portion 70d extending in the vertical direction is formed between the upper curved portion 70c and the rear floor portion 70b. The height of the upper curved portion 70c is set to be higher than the height of the front floor portion 70a. A rear seat S2 ( Figure 2 A battery B may be disposed below the upper curved portion 70c, and a control device of the electric vehicle 1 may also be disposed (not shown).

[0142] A floor side cross member 110 extending in the left-right direction along the floor panel 70 is mounted on the floor panel 70. The floor side cross member 110 is welded, for example, to the upper surface of the rear floor portion 70b of the floor panel 70. The shape of the floor side cross member 110 is not particularly limited. In the present embodiment, the floor side cross member 110 is bulged upward and opened downward, and has a substantially identical cross-sectional shape at both ends in the left-right direction. By mounting the floor side cross member 110 on 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 rocker 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 rocker 73 in the vehicle width direction. In addition, the floor side cross member 110 may also be mounted on the lower surface of the rear floor portion 70b.

[0143] like Figure 7 to Figure 9 As shown, the left and right front side frames 72 are arranged at the front part of the vehicle body and are high-strength components extending in the front-rear direction. Figure 7 to Figure 9 In FIG. 7 , only the front side frame 72 on the right side is shown. Figure 2 That is, the left and right front side frames 72 are positioned forward and upward compared to the floor panel 70, and specifically, the left and right front side frames 72 are arranged to extend forward from the left and right sides of the lower part of the front panel 71, respectively.

[0144] The left and right front side frames 72 are bilaterally symmetrical structures, and can be formed by joining a plurality of stamping materials, or by extruding materials. The cross section of each front side frame 72 in a direction perpendicular to the front-back direction is set to be larger than the cross section of the front frame member 11 of the lower structure 2 in the same direction. Thus, each front side frame 72 becomes a member thicker and stronger than the front frame member 11.

[0145] The front ends of the left and right front side frames 72 respectively have a crush box 72a that is compressed and deformed to absorb the collision energy during a head-on collision. The crush box 72a is a cylindrical metal component extending in the front-to-back direction. A front bumper reinforcement 86 extending in the left-right direction is fixed to the front ends of the left and right crush boxes 72a.

[0146] like Figure 8 As shown, the upper portion of the right connecting portion 55 located in front of the lower structure 2 is connected to the right collapse box 72a. In addition, the left connecting portion 53 ( Figure 2 The upper portion of the left connecting portion 53 is connected to the crush box 72a on the left side. Since the crush box 72a is located at the front end of the front side frame 72, by connecting the upper portion of the left connecting portion 53 to the crush box 72a, the connecting position of the left connecting portion 53 can be set at a position close to the front end of the vehicle body. As a result, the interval between the left connecting portions 53 and 54 in the front-to-back direction can be expanded, so the effect of connecting the front frame member 11 to the front side frame 72 through the left connecting portions 53 and 54 is further significant. The same is true for the right connecting portions 55 and 56. The connection structure in which the left connecting portions 53 and 54 and the right connecting portions 55 and 56 are connected to the front side frame 72 is a structure using fastening components such as bolts and nuts. In addition, the front left connecting portion 53 and the right connecting portion 55 can also be connected to a position of the front side frame 72 that is rearward of the crush box 72a.

[0147] In addition, if Figure 5 As shown, the lower portion of the rear right connecting portion 56 is connected to the front frame member 11 at a position rearward of the drive shaft 52. Figure 8As shown, the upper portion of the rear right connecting portion 56 is connected to a portion of the front side frame 72 that is further rearward than the front-rear center. This can further increase the distance between the right connecting portions 55 and 56 in the front-rear direction. The same is true for the left connecting portions 53 and 54.

[0148] The left and right side rails 73 are respectively disposed at the left and right ends of the floor panel 70 so as to extend in the front-rear direction. Fig.12 As shown, the left end of the floor panel 70 is connected to the middle part of the left side rail 73 in the vertical direction, and the upper part of the side rail 73 protrudes upward from the connection part of the floor panel 70, and the lower part of the side rail 73 protrudes downward from the connection part of the floor panel 70. Since the battery box 10 is arranged below the floor panel 70, the lower part of the side rail 73 and the battery box 10 are arranged in an overlapping manner when viewed from the side of the vehicle. In addition, the right side rail 73 is also connected to the right end of the floor panel 70.

[0149] The left and right side rails 73 are of a bilaterally symmetrical structure. Fig.12 The detailed structure of the left side rail 73 is described. The left side rail 73 includes an inner member 90 and an outer member 91 made of stamped material. The inner member 90 is a member that constitutes the inner part of the vehicle interior of the side rail 73, bulges toward the inner part of the vehicle interior, and is formed long in the front-rear direction. The outer member 91 is a member that constitutes the outer part of the vehicle exterior of the side rail 73, bulges toward the outer part of the vehicle exterior, and is formed long in the front-rear direction. The upper parts of the inner member 90 and the outer member 91 are joined to each other, and the lower parts of the inner member 90 and the outer member 91 are joined to each other, thereby forming the side rail 73 with a hollow interior.

[0150] A first recess 73a is formed at the lower portion of the lower side beam 73 on the inner side in the vehicle width direction, extending in the front-rear direction, and is recessed toward the outer side in the vehicle width direction. The first recess 73a is open toward the lower side and the inner side in the vehicle width direction. The outer side in the vehicle width direction of the battery box 10 of the lower structure 2 is formed to be embedded in the first recess 73a. Specifically, the left side beam 20 of the battery box 10 enters the first recess 73a from below. As a result, the dimension of the battery box 10 in the vehicle width direction can be ensured to be longer, and the amount of the battery box 10 protruding downward can be reduced.

[0151] A hollow side load transfer member 120 is provided inside the lower side sill 73. The side load transfer member 120 extends in the front-rear direction and is used to transfer the load from the outside to the inside in the vehicle width direction. The side load transfer member 120 transfers a load not assumed during normal driving but a load extremely large to the extent that the side parts of the electric vehicle 1 are deformed, such as in a side collision when an obstacle hits the electric vehicle 1 from the side.

[0152] The side load transmission member 120 can be made of, for example, an extruded material, and is continuous from the front end to the rear end of the rocker 73. The side load transmission member 120 is fixed to the rocker 73 at an appropriate position. The fixing structure of the side load transmission member 120 to the rocker 73 is not particularly limited, and for example, a structure using fastening members such as bolts and nuts, rivets, etc. can be cited.

[0153] The side load transmission member 120 has high rigidity so as to be able to transmit the load in the case of a side collision to the inside in the vehicle width direction. Therefore, it is not only resistant to compression force, but also resistant to bending force and torsion force. During normal driving, it also functions as a reinforcing member that reinforces the rocker 73 and helps to improve the rigidity of the vehicle body. Such a side load transmission member 120 is a member that reinforces the rocker 73 inside the rocker 73, and therefore can be called an inner reinforcement.

[0154] The side load transmission member 120 includes an upper wall portion 121, an outer wall portion 122, an inner upper longitudinal wall portion 123, an inner lower longitudinal 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 in the vicinity of the upper end portion inside the rocker 73. The outer wall portion 122 extends downward from the outer end portion in the vehicle width direction of the upper wall portion 121 and is disposed in the vicinity of the outer end portion in the vehicle width direction inside the rocker 73. The upper end portion of the outer wall portion 122 is located above the upper end portion of the floor side cross member 110. The lower end portion of the outer wall portion 122 is located below the upper end portion of the second battery side cross member 25B provided inside the battery box 10. Although not shown in the figure, 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.

[0155] The inner upper longitudinal 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 rocker 73. The upper end portion of the inner upper longitudinal wall portion 123 is located above the upper end portion of the floor side cross member 110. The lower end portion of the inner upper longitudinal wall portion 123 is located below the rear floor portion 70b and above the upper end portion of the second battery side cross member 25B.

[0156] The middle wall portion 125 extends outward in the vehicle width direction from the lower end of the inner upper longitudinal wall portion 123. The outer end of the middle wall portion 125 in the vehicle width direction is located inward of the center of the upper wall portion 121 in the vehicle width direction. The inner lower longitudinal 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 longitudinal wall portion 124 is located below the upper end of the second battery side cross member 25B. The dimension of the inner lower longitudinal wall portion 124 in the vertical direction is set shorter than the dimension of the inner upper longitudinal wall portion 123 in the vertical direction.

[0157] The lower portion of the side load transmission member 120 on the inner side of the vehicle interior is formed with a second recess 120a that is recessed outward in the vehicle width direction in a manner corresponding to the first recess 73a of the rocker 73 by the inner lower longitudinal wall portion 124 and the intermediate wall portion 125. The portion of the rocker 73 where the first recess 73a is formed is fitted into the second recess 120a of the side load transmission member 120.

[0158] The lower wall portion 126 extends from the lower end portion of the inner lower vertical wall portion 124 to the lower end portion of the outer side wall portion 122. The dimension of the lower wall portion 126 in the vehicle width direction is set to be longer than the dimension of the intermediate wall portion 125 in the vehicle width direction.

[0159] When viewed from the side of the vehicle, the upper portion of the side load transmission member 120 overlaps with the floor side cross member 110, and the 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 includes an inner upper vertical wall portion (first vertical wall portion) 123 that overlaps with the floor side cross member 110 and extends in the vertical direction when viewed from the side of the vehicle, and an inner lower vertical wall portion (second vertical wall portion) 124 that overlaps with the battery box 10 and extends in the vertical direction when viewed from the side of the vehicle. In addition, the lower portion of the inner upper vertical wall portion 123 may overlap with the upper portion of the battery box 10.

[0160] The 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 position separated upward from the middle wall portion 125, and the inner end portion of the first rib 131 in the vehicle width direction is connected to the middle portion in the vertical direction of the inner upper longitudinal wall portion 123. The first rib 131 is inclined so as to be located upward as it goes outward in the vehicle width direction.

[0161] The second rib 132 extends in the vehicle width direction at a portion separated 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 longitudinal wall portion 124. The outer end of the second rib 132 in the vehicle width direction is connected to the middle portion of the outer side wall portion 122 in the vertical direction. The first rib 131 and the second rib 132 may extend substantially horizontally, or may be inclined so as to be located upward as they go inward in the vehicle width direction, or may be inclined so as to be located upward as they go outward in the vehicle width direction.

[0162] The third rib 133 extends upward from the upper end of the inner lower longitudinal wall portion 124. The upper end of the third rib 133 is connected to the middle portion in the vehicle width direction of the upper wall portion 121. The third rib 133 is inclined so as to be located more 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 in the up-down direction of the third rib 133.

[0163] The fourth rib 134 extends in the vehicle width direction at a position separated upward from the second rib 132. The inner end of the fourth rib 134 in the vehicle width direction is connected to the middle portion of the third rib 133 in the vertical direction. The outer end of the fourth rib 134 in the vehicle width direction is connected to the middle portion of the outer side wall portion 122 in the vertical direction. The inner end of the fourth rib 134 in the vehicle width direction is connected to the outer end of the first rib 131 in the vehicle width direction via the third rib 133, and the first rib 131 and the fourth rib 134 constitute a single rib continuous in the vehicle width direction. The number and shape of the ribs formed inside the side load transfer component 120 are not limited to the above-mentioned number and shape, and the number of ribs may be 3 or less, or 5 or more.

[0164] The battery box 10 is fixed to the lower side beam 73 and directly fixed to the side load transmission component 120. A plurality of metal cylindrical components 140 extending in the vertical direction are fixed to the left side beam 20 of the battery box 10. The intervals in the front-to-back direction of the cylindrical components 140 can be set to, for example, about tens of centimeters. Figure 2 As shown in FIG. 1 , the plurality of tubular members 140 are arranged at intervals from each other in the front-rear direction. A bolt 141 is inserted into each tubular member 140 from below.

[0165] On the other hand, the portion of the inner surface of the lower side member 73 corresponding to the first recessed portion 73a is opened in such a manner that the shaft of the bolt 141 can be inserted therethrough. Similarly, the intermediate wall portion 125 of the side load transmission component 120 is also opened in such a manner that the shaft of the bolt 141 can be inserted therethrough, and the two openings are consistent with each other. Nuts 142 are accommodated inside the side load transmission component 120. The nuts 142 are fixed to the upper surface of the intermediate wall portion 125 of the side load transmission component 120. The number and positions of the openings and nuts 142 correspond to the number and positions of the tubular component 140.

[0166] Therefore, by inserting each bolt 141 into the cylindrical member 140 so as to pass through the opening of the lower side rail 73 and the opening of the side load transmission member 120 and screwing it in a manner of being screwed with the nut 142, multiple locations on the left side of the battery box 10 can be fixed to the side load transmission member 120 and the lower side rail 73. The right side of the battery box 10 can also be fixed in the same manner.

[0167] In the present embodiment, the side load transmission member 120 is described as an integrally formed member, but the invention is not limited thereto, and the side load transmission member 120 may be formed by combining a plurality of members. Although not shown in the figure, the side load transmission member 120 may be a two-part structure in which the inner and outer parts in the vehicle width direction are formed separately and then integrated. In addition, the side load transmission member 120 may be a three-part structure.

[0168] like Figure 7 As shown in FIG. 1 and FIG. 2 , the upper structure 3 includes a pair of left and right hinge pillars 150. The right hinge pillar 150 extends upward from the front end of the right side rail 73. Figure 2 As shown, the left hinge pillar 150 extends upward from the front end of the left lower side beam 73. The left and right front doors 81 ( Figure 1 shown).

[0169] In addition, if Fig.10 As shown in FIG. 1 , the upper structure 3 further includes a pair of left and right center pillars 157. The right center pillar 157 extends upward from the middle portion of the right side rail 73 in the front-rear direction. Figure 2 As shown, the left center pillar 157 extends upward from the middle portion of the left lower side beam 73 in the front-rear direction. The left and right rear doors 82 ( Figure 1 shown).

[0170] like Fig. 9 As shown, the upper structure 3 has a pair of left and right floor reinforcements (first front-to-back direction load transfer components) 151. The floor reinforcement 151 extends in the front-to-back direction along the upper surface of the front floor portion 70a. The front end of the floor reinforcement 151 on the right side is connected to the rear end of the front side frame 72 on the right side. The rear end of the floor reinforcement 151 on the right side is connected to the front end of the lower side beam 73 on the right side. Therefore, the front side frame 72 and the lower side beam 73 are connected through the floor reinforcement 151. Therefore, if the collision load during a head-on collision is input to the front side frame 72, the collision load is transmitted to the lower side beam 73 via the floor reinforcement 151.

[0171] The floor reinforcement 151 bulges upward and opens downward, and the bulging shape continues from the front end to the rear end. By attaching the floor reinforcement 151 to the upper surface of the front floor portion 70a, a closed cross section is formed by the floor reinforcement 151 and the front floor portion 70a.

[0172] Since the lower side beam 73 is located on the outer side in the vehicle width direction compared with the front side frame 72, the floor reinforcement 151 is bent and extended in a manner that the further it goes to the rear side, the further it is located on the outer side in the vehicle width direction when viewed from above. The curved shape of the floor reinforcement 151 corresponds to the shape of the lower end of the front wheel cover 85. In other words, the floor reinforcement 151 extends along the lower end of the front wheel cover 85 and is connected to the front wheel cover 85 to form an integrated structure. In addition, the left floor reinforcement (not shown) is a structure that is symmetrical with the right floor reinforcement.

[0173] The floor reinforcement 151 is mounted on the upper surface of the front floor portion 70a. On the other hand, the outer connecting portion 30 ( Figure 3 As shown in FIG. 1 and FIG. 2 , the floor reinforcement 151 and the outer connecting portion 30 are located below the front floor portion 70a, so the floor reinforcement 151 and the outer connecting portion 30 are separated from each other in the vertical direction. Similarly, the floor reinforcement 151 and the inner connecting portion 31 are also separated from each other in the vertical direction.

[0174] In addition, when viewed from above, the portion of the right floor reinforcement 151 on the side of the rocker 73 (the rear end of the floor reinforcement 151) overlaps with the portion of the right outer connecting portion 30 on the side of the battery box 10 (the rear end of the outer connecting portion 30). The rear end of the floor reinforcement 151 is a portion connected to the rocker 73, so the rear end is arranged adjacent to the rocker 73. On the other hand, the outer connecting portion 30 is a component connected to the battery box 10, so the outer connecting portion 30 is separated from the rocker 73. However, when viewed from above, the rear end of the outer connecting portion 30 overlaps with the rear end of the floor reinforcement 151, which allows the rear end of the outer connecting portion 30 to be close to the rocker 73. Therefore, the collision load from the front can be reliably applied to the side of the rocker 73 via the outer connecting portion 30. The same is true for the left side.

[0175] The rear end of the right floor reinforcement 151 and the base end (lower end) of the right hinge pillar 150 are arranged at the same position in the front-rear direction. That is, the vicinity of the base end of the hinge pillar 150 in the rocker 73 is a particularly high rigidity portion, and by connecting the rear end of the floor reinforcement 151 to this particularly high rigidity portion, the rocker 73 can efficiently absorb the collision load.

[0176] like Figure 7As shown, the upper structure 3 includes a pair of left and right lower load transfer members (second front-to-back load transfer members) 152. The lower load transfer member 152 is disposed above the front frame member 11 of the lower structure 2, and the front frame member 11 and the lower load transfer member 152 are separated from each other in the vertical direction. In addition, the lower load transfer member 152 extends in the front-to-back direction along the lower surface of the front floor portion 70a. Fig.11 As shown schematically, the front end of the right lower load transfer member 152 is connected to the rear end of the right front side frame 72. Moreover, the lower load transfer member 152 extends toward the front of the battery box 10. Therefore, when the collision load of a frontal collision is input to the front side frame 72 toward the rear, the collision load is transmitted to the front of the battery box 10 via the lower load transfer member 152. The left lower load transfer member 152 is symmetrical with the right lower load transfer member.

[0177] The lower load transmission member 152 bulges downward and opens upward, and the bulging shape continues from the front end to the rear end. The lower load transmission member 152 is attached to the lower surface of the front floor portion 70a, so that the lower load transmission member 152 and the front floor portion 70a form a closed cross section.

[0178] The rear portion of the right lower load transfer member 152 is positioned to the right of the front center beam 26 in the battery box 10 and to the left of the right side beam 21. In addition, the rear portion of the left lower load transfer member 152 is positioned to the left of the front center beam 26 in the battery box 10 and to the right of the left side beam 20.

[0179] like Figure 7 to Figure 9 As shown in FIG. 1 , a cross beam 153 is provided on the lower surface of the front floor portion 70a. The cross beam 153 extends in the left-right direction and connects the rear portion of the lower load transfer member 152 on the left side and the rear portion of the lower load transfer member 152 on the right side. The cross beam 153 bulges downward and opens upward, and forms a substantially identical cross-sectional shape across both ends in the left-right direction. By attaching the cross beam 153 to the lower surface of the front floor portion 70a, a closed cross section is formed by the cross beam 153 and the front floor portion 70a. By providing the cross beam 153, it is possible to suppress the following situation: when the left and right lower load transfer members 152 receive the collision load during a head-on collision, the rear portion of the lower load transfer member 152 is displaced in the left-right direction.

[0180] like Fig.11 As shown, the front end beam 22 constituting the front part of the battery box 10 is arranged directly below the cross beam 153. The front end beam 22 is fastened to the cross beam 153 by bolts and nuts not shown. The fastening structure of the front end beam 22 can be the same as the fastening structure of the left side beam 20 fastened to the lower side beam 73.

[0181] A protrusion 22a protruding upward is provided at the front of the battery box 10. Specifically, the protrusion 22a is provided at a portion of the front end beam 22 that is rearward of the cross beam 153. The protrusion 22a is located rearward compared to the rear portion of the lower load transfer component 152. In addition, the protrusion 22a is formed so that its upper end portion is located above the lower surface of the cross beam 153 and is located above the lower surface of the rear portion of the lower load transfer component 152. Thus, when viewed from the front-to-back direction, the cross beam 153 and the lower load transfer component 152 overlap with the protrusion 22a. The protrusion 22a is a portion to which the collision load is transferred from the lower load transfer component 152 when the lower load transfer component 152 moves backward due to the collision load during a head-on collision.

[0182] The protrusion 22a extends continuously in the left-right direction. That is, in the event of a head-on collision, the rear portion of the lower load transfer member 152 may be slightly displaced in the left-right direction. However, since the protrusion 22a is continuous in the left-right direction, even if the rear portion of the lower load transfer member 152 is displaced in the left-right direction, the collision load is reliably input to the protrusion 22a. In addition, the protrusion 22a is not limited to a structure that is continuous in the left-right direction, and it is sufficient as long as it is formed discontinuously and at least a part overlaps with the rear portion of the lower load transfer member 152 when viewed from the front-rear direction.

[0183] The protrusion 22a may be formed integrally with the front end beam 22, or may be formed of a different member. When the front end beam 22 is an extruded material, the protrusion 22a can be easily formed integrally. The protrusion 22a may be fixed to, for example, the bottom plate 24, or may be fixed to the left side beam 20, the right side beam 21, etc. The protrusion 22a may be in any shape, such as a plate (rib), a rod, or a cylinder. By making the protrusion 22a rib-shaped and forming it integrally with the front end beam 22, a reinforcement effect on the front end beam 22 can also be obtained.

[0184] The rear portion of the lower load transmission member 152 and the protrusion 22a are arranged at a predetermined interval in the front-to-back direction. By separating the predetermined interval, the lower load transmission member 152 and the protrusion 22a do not contact each other during normal driving, so that the generation of interference sound and the like can be avoided. On the other hand, if the lower load transmission member 152 moves backward during a frontal collision, the rear portion of the lower load transmission member 152 contacts the protrusion 22a, so that the collision load is reliably input to the protrusion 22a. That is, the predetermined interval is an interval set so that the lower load transmission member 152 and the protrusion 22a do not contact each other during normal driving, and the rear portion of the lower load transmission member 152 contacts the protrusion 22a during a frontal collision, and can be set to, for example, several millimeters to several centimeters. In addition, the rear portion of the lower load transmission member 152 may be in contact with the protrusion 22a. In addition, the rear portion of the lower load transmission member 152 and the protrusion 22a may be connected by a fastening member.

[0185] In addition, Figure 6 In the embodiment shown, the front center beam 26 in the battery box 10 is provided below the front floor portion 70a and is higher than the heights of the first to third rear center beams 27 to 29. Therefore, the dimension of the front center beam 26 in the vertical direction becomes longer, and thus the front center beam 26 with a large cross section is located at the front of the battery box 10. Thus, the deformation of the battery box 10 is suppressed when the front of the battery box 10 receives the collision load transmitted from the lower load transmission member 152.

[0186] (Connection structure between the rear of the battery box and the upper structure)

[0187] like Fig.13 As shown in FIG. 1 , the rear portion of the battery box 10 and the upper structure 3 are connected by a connecting member 160. Before describing the connecting structure, the structure of the rear side of the upper structure 3 is described. The rear wheel housings 170 (in FIG. 1 ) for accommodating the left and right rear wheels R are provided on the left and right sides of the rear portion of the upper structure 3. Figure 7 to Figure 9 Only the right rear wheel housing portion is shown in the figure). The luggage compartment floor portion 70e constituting the floor surface of the luggage compartment R2 in the floor panel 70 extends rearward from the rear of the upper curved portion 70c and is located above the rear floor portion 70b. The rear floor portion 70b is regarded as the first floor portion, and the upper curved portion 70c and the luggage compartment floor portion 70e are regarded as the relatively high second floor portion. The left end of the luggage compartment floor portion 70e is connected to the left rear wheel housing portion 170 ( Figure 2 In addition, the right end of the luggage compartment floor portion 70e is connected to the right rear wheel cover portion 170 ( Figure 7 to Figure 9 as shown) connection.

[0188] like Figure 7 to Figure 9As shown, a rear cross beam (first cross beam) 171 extending in the left-right direction is installed on the lower surface of the upper curved portion 70c. The rear cross beam 171 bulges downward and opens upward, and the bulging shape continues from the left end to the right end. By installing the rear cross beam 171 on the lower surface of the upper curved portion 70c, a closed cross section is formed by the rear cross beam 171 and the upper curved portion 70c.

[0189] A rear floor side cross member 172 extending in the left-right direction just above the rear cross member 171 is mounted on the upper surface of the upper curved portion 70c. The rear floor side cross member 172 bulges upward and opens downward, and the bulging shape continues from the left end to the right end. By mounting the rear floor side cross member 172 on the upper surface of the upper curved portion 70c, a closed cross section is formed by the rear floor side cross member 172 and the upper curved portion 70c. When viewed from above, the rear floor side cross member 172 overlaps with the rear cross member 171.

[0190] In addition, the right end of the rear floor side cross member 172 is connected to the right rear wheel housing portion 170, and the left end of the rear floor side cross member 172 is connected to the left rear wheel housing portion 170. In addition, the lower end of a side reinforcement 173 extending upward along the right rear wheel housing portion 170 is connected to the right end of the rear floor side cross member 172. In addition, the lower end of a side reinforcement (not shown) extending upward along the left rear wheel housing portion 170 is connected to the left end of the rear floor side cross member 172. Furthermore, the upper portion of the right side reinforcement 173 and the upper portion of the left side reinforcement are connected by a connecting member 174 ( Figure 8 and Fig. 9 That is, the rear floor side cross member 172, the left and right side reinforcement members 173 and the connection member 174 form an annular structure. The annular structure can also be formed by a reinforcement member (not shown) provided on the roof 80 side.

[0191] On the other hand, Fig.13 As shown, the battery box 10 has a box side cross beam (second cross beam) 180 (in Figure 2 to Figure 6 The box-side cross beam 180 extends in the left-right direction and is attached to the rear end beam 23 constituting the rear portion of the battery box 10. The box-side cross beam 180 is located above the rear end beam 23. The box-side cross beam 180 and the rear cross beam 171 are arranged to face each other in the up-down direction.

[0192] like Fig.13As shown, the connecting component 160 is a component for connecting the rear end beam 23 of the battery box 10 and the upper curved portion 70c. Thus, the upper curved portion 70c is reinforced by the battery box 10, thereby improving the rigidity of the upper curved portion 70c. By improving the rigidity of the upper curved portion 70c, the rigidity of the floor panel 70 as a whole is also improved. In this embodiment, the connecting component 160 is composed of a plate extending in the left-right direction and the up-down direction, but is not limited to this, and may also be a closed cross-sectional beam extending in the up-down direction or obliquely, an axial component, a cylindrical component, etc. In addition, a plurality of connecting components 160 may also be provided.

[0193] The upper portion of the connecting member 160 is fixed to the lower portion of the rear cross beam 171. Thus, the battery box 10 and the upper curved portion 70c are connected by the connecting member 160 via the rear cross beam 171. That is, the upper portion of the connecting member 160 can be fixed to the portion whose rigidity is improved by providing the rear cross beam 171, so that the fixing strength of the connecting member 160 to the upper curved portion 70c can be improved. The fixing structure of the upper portion of the connecting member 160 can use a detachable fastening structure using fastening members such as bolts and nuts (not shown). In addition, the upper portion of the connecting member 160 can also be directly connected to the upper curved portion 70c.

[0194] In addition, the lower portion of the connecting member 160 is fixed to the box-side cross member 180 constituting a part of the battery box 10. As a result, the lower portion of the connecting member 160 can be fixed to the portion of the battery box 10 where the rigidity is improved, so that the fixing strength of the connecting member 160 to the battery box 10 can be improved. In addition, the lower portion of the connecting member 160 can also be fixed to the battery box 10 in a detachable manner using the above-mentioned fastening member. The connecting member 160 can be set as a component of the upper structural body 3 side, and can also be set as a component of the lower structural body 2 side.

[0195] (Positional Relationship between the Beams of the Upper Structure and the Lower Structure)

[0196] Fig.14 The modified example of the embodiment is a schematic diagram showing the positional relationship between the cross beams of the upper structure 3 and the lower structure 2. First to third floor side cross beams 110A, 110B, 110C extending in the vehicle width direction are mounted on the upper surface of the floor panel 70 of the upper structure 3, and a cross beam 153 is mounted on the lower surface of the floor panel 70. The cross beam 153 is a floor side cross beam because it is mounted on the floor panel 70.

[0197] The first floor side cross beam 110A is the above-mentioned cross beam 110, and is disposed to be separated from the cross beam 153 to the rear. The second floor side cross beam 110B is disposed to be separated from the first floor side cross beam 110A to the rear. The third floor side cross beam 110C is disposed to be separated from the second floor side cross beam 110B to the rear. On the other hand, the above-mentioned first to third battery side cross beams 25A, 25B, 25C are provided in the battery box 10 of the lower structure 2. When viewed from the side, the cross beam 153, the first to third floor side cross beams 110A, 110B, 110C, and the first to third battery side cross beams 25A, 25B, 25C are in contact with the lower side beam 73 ( Fig.10 etc.) overlap.

[0198] When viewed from the side of the vehicle, the cross member 153 and the first to third floor side cross members 110A, 110B, 110C are staggered with the first to third battery side cross members 25A, 25B, 25C in the front-rear direction of the vehicle. That is, the cross member 153, the first battery side cross member 25A, the first floor side cross member 110A, the second battery side cross member 25B, the second floor side cross member 110B, the third battery side cross member 25C, and the third floor side cross member 110C are arranged in order from the front side to the rear side of the vehicle, and the cross member 153, the first to third floor side cross members 110A, 110B, 110C and the first to third battery side cross members 25A, 25B, 25C are alternately arranged in the front-rear direction.

[0199] For example, when focusing on the first floor side cross member 110A and the second floor side cross member 110B, the second battery side cross member 25B is located in front of the first floor side cross member 110A and in the rear of the second floor side cross member 110B. On the other hand, when focusing on the first battery side cross member 25A and the second battery side cross member 25B, the first floor side cross member 110A is located in the rear of the first battery side cross member 25A and in the front of the second battery side cross member 25B. Such a positional relationship is referred to as "misalignment in the vehicle front-rear direction".

[0200] In addition, "displaced in the front-to-back direction of the vehicle" may include other forms. For example, it may include a form in which the center of the first floor side cross member 110A in the front-to-back direction and the center of the second battery side cross member 25B in the front-to-back direction are offset in the front-to-back direction. In this case, Fig.14 The embodiment shown in the figure also includes an embodiment 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 an overlapping positional relationship in a plan view.

[0201] For example, a situation in which the front portion of the first floor side cross member 110A is located forward of the front portion of the second battery side cross member 25B and a situation in which the rear portion of the second battery side cross member 25B is located rearward of the rear portion of the first floor side cross member 110A are also included in “shifted in the vehicle front-rear direction”.

[0202] In the event of a side collision, the collision load can be borne by the cross member 153, the first to third floor side cross members 110A, 110B, 110C, and the first to third battery side cross members 25A, 25B, 25C. Since the cross member 153, the first to third floor side cross members 110A, 110B, 110C, and the first to third battery side cross members 25A, 25B, 25C are offset in the vehicle front-rear direction as described above, even if the obstacle is a thin object such as a pole, the collision load of the obstacle can be input to any one of the cross member 153, the first to third floor side cross members 110A, 110B, 110C, and the first to third battery side cross members 25A, 25B, 25C.

[0203] When viewed from the side of the vehicle, only the hinge pillar 150 (at Fig.14 The first to third floor side cross beams 110A, 110B, 110C and the first to third battery side cross beams 25A, 25B, 25C in the non-overlapping area (indicated by imaginary lines in FIG. 1 ) are offset in the front-to-back direction. That is, the first to third floor side cross beams 110A, 110B, 110C and the first to third battery side cross beams 25A, 25B, 25C located at the rear side compared to the hinge pillar 150 are offset in the front-to-back direction. That is, the position where the hinge pillar 150 is located has a higher strength against the collision load from the side, so even if the floor side cross beam and the battery side cross beam are not offset in the front-to-back direction, the collision load can be borne by the hinge pillar 150.

[0204] Similarly, when viewed from the side of the vehicle, only the first and third floor side cross members 110A and 110C and the first to third battery side cross members 25A, 25B and 25C located in the region not overlapping with the center pillar 157 may be offset in the front-rear direction.

[0205] (Effects of head-on collision)

[0206] Next, a case where a frontal collision occurs in the electric vehicle 1 configured as described above is described. The collision load in the frontal collision is input to the left and right front side frames 72 via the front bumper reinforcement 86. In addition, the collision load in the frontal collision is also input to the left and right front frame members 11.

[0207] As for the front frame member 11, since the multiple parts of the front frame member 11 separated in the front-back direction are connected to the left front side frame 72 through the left connecting parts 53 and 54, the left front frame member 11 to which the collision load is input is stable and is difficult to tilt in the left-right direction and the up-down direction. The same is true for the right front frame member 11. As a result, the collision load is linearly transmitted to the front of the battery box 10 through the left and right front frame members 11.

[0208] At this time, the front frame member 11 is connected to the battery box 10 at multiple locations separated from each other in the left-right direction by the outer connecting portion 30 and the inner connecting portion 31, so the collision load input to the front frame member 11 is input to multiple locations separated from each other in the left-right direction in the battery box 10. The battery box 10 includes a front center beam 26 and a left side beam 20 and a right side beam 21 extending in the front-rear direction, so the collision load input to multiple locations separated from each other in the left-right direction is distributedly transmitted to the front center beam 26 and the left side beam 20 and the right side beam 21. As a result, the battery box 10 can be actively used to absorb the collision load, so the amount of collision load absorbed in the lower structure 2 can be increased, and accordingly, the strength of the front side frame 72 and the strength of the components near the rear end of the front side frame 72 can be optimized to achieve overall vehicle weight reduction.

[0209] In addition, the collision load input to the front side frame 72 is transmitted to the rocker 73 via the floor reinforcement 151. In addition, since the outer connecting portion 30 extends toward the rocker 73 side, the collision load input to the front frame member 11 can also act on the rocker 73 side via the outer connecting portion 30. At this time, since the floor reinforcement 151 and the outer connecting portion 30 are separated in the up-down direction, the path of the collision load transmitted from the front side frame 72 to the rocker 73 and the path of the collision load acting from the front frame member 11 toward the rocker 73 side become different paths, so the collision load is transmitted to the rocker 73 through multiple paths. The rocker 73 is a member with particularly high rigidity among the members constituting the vehicle body, so the collision load can be absorbed by the rocker 73.

[0210] In addition, the collision load input to the front side frame 72 is transmitted from the rear of the front side frame 72 to the battery box 10 via both the floor reinforcement 151 and the lower load transmission member 152. Thus, a path for the collision load transmitted to the battery box 10 via the lower load transmission member 152 is also formed, so that the collision load is dispersedly absorbed by both the lower side beam 73 and the battery box 10. In addition, since the floor reinforcement 151 and the lower load transmission member 152 are along the floor panel 70, part 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.

[0211] In addition, in the case of a frontal offset collision, a large collision load is input to either the left or right side, but in this case, the present embodiment is also effective. In addition, in the case of a rear-end collision, the rear frame member 12 is provided, so the same effect can be achieved.

[0212] (Effects of side collision)

[0213] Next, a case where the electric vehicle 1 constructed as described above is subjected to a side collision will be described. The collision load during a side collision is input to the lower side member 73 from the outer side in the vehicle width direction to the inner side. A side load transfer member 120 is provided inside the lower side member 73, so the collision load is input to the side load transfer member 120 from the outer side in the vehicle width direction to the inner side. At this time, since the inner upper longitudinal wall portion 123 of the side load transfer member 120 overlaps with the floor side cross beams 110 and 153, and the inner lower longitudinal wall portion 124 overlaps with the battery box 10, the collision load is distributedly transmitted to the floor side cross beams 110 and 153 and the battery box 10. The floor side cross beams 110 and 153 extend in the vehicle width direction when mounted on the floor panel 70, so they have a large resistance to the load from the side, thereby absorbing part of the collision load and reducing the collision load input to the battery box 10, and the battery B is protected. Furthermore, since the battery box 10 is provided with the first to third battery-side cross members 25A, 25B, and 25C, the front end member 22 , and the rear end member 23 , the collision load can also be absorbed by the battery box 10 .

[0214] In addition, when an obstacle such as a pole collides from the side of the vehicle, Fig.14The cross member 153 and the first to third floor side cross members 110A, 110B, 110C are staggered from the first to third battery side cross members 25A, 25B, 25C in the vehicle front-rear direction, so that the collision load can be input to any cross member. In addition, it is conceivable that a thin rod collides between the first floor side cross member 110A and the second battery side cross member 25B. In this case, after the high-strength side load transmission member 120 receives the collision load of the rod, the collision load can be dispersed to at least the first floor side cross member 110A and the second battery side cross member 25B and absorbed.

[0215] Moreover, when the obstacle is a large-diameter pole or car, the collision load is input to both the first to third floor side cross beams 110A, 110B, 110C and the first to third battery side cross beams 25A, 25B, 25C, so the collision load is distributed and transmitted to the floor panel 70 and the battery box 10.

[0216] The above-described embodiments are merely illustrative in all aspects and should not be interpreted as limiting. Moreover, all modifications and changes within the scope of equivalents to the scope of the claimed invention are within the scope of the present invention.

[0217] Industrial Applicability

[0218] As described above, the vehicle body structure according to the present invention is suitable for an electric vehicle equipped with a running motor and a battery.

Claims

1. A vehicle body structure, which is a vehicle body structure of an electric vehicle, wherein the electric vehicle has a running motor, and a battery box containing a battery for supplying electric power to the running motor is arranged below a floor panel, wherein the vehicle body structure is characterized by comprising: a dash panel that partitions a vehicle compartment and a space in front of the vehicle compartment in a vehicle front-rear direction, and a lower end portion of the dash panel is connected to a vehicle front end portion of the floor panel; A pair of left and right front side frames, the pair of left and right front side frames respectively extending from both sides of the front panel in the vehicle width direction toward the front of the vehicle; A pair of left and right side rails, the pair of left and right side rails are arranged at both ends of the floor panel in the vehicle width direction and extend in the front-rear direction of the vehicle; a first front-rear direction load transmission member extending from the vehicle rear portion of the left and right front side frames along the upper surface of the floor panel to the left and right lower side rails; as well as a second front-to-rear direction load transmission member extending from the vehicle rear portion of the left and right front side frames along the lower surface of the floor panel toward the vehicle front portion of the battery box, A protrusion protruding upward is provided at the front part of the vehicle of the battery box. The vehicle rear portion of the second front-rear direction load transmission member and the protruding portion overlap each other when viewed in the vehicle front-rear direction.

2. The vehicle body structure according to claim 1, characterized in that: A frame member is provided, the frame member extending from the battery box to the front of the vehicle below the front side frame.

3. The vehicle body structure according to claim 2, characterized in that: The second front-rear direction load transmission member is disposed above the frame member.

4. The vehicle body structure according to any one of claims 1 to 3, characterized in that: A cross member is disposed on a lower surface of the floor panel. The cross member extends in the vehicle width direction and connects a vehicle rear portion of the left second front-rear direction load transmission member and a vehicle rear portion of the right second front-rear direction load transmission member.

5. The vehicle body structure according to any one of claims 1 to 3, characterized in that: A central beam extending in the front-rear direction of the vehicle is provided at the center of the battery box in the vehicle width direction. The vehicle rear portion of the second front-rear direction load transmission member on the left side is positioned on the left side of the vehicle body relative to the center beam. The vehicle rear portion of the right second front-rear direction load transmission member is positioned on the vehicle body right side relative to the center beam.

6. The vehicle body structure according to claim 4, characterized in that: A central beam extending in the front-rear direction of the vehicle is provided at the center of the battery box in the vehicle width direction. The vehicle rear portion of the second front-rear direction load transmission member on the left side is positioned on the left side of the vehicle body relative to the center beam. The vehicle rear portion of the right second front-rear direction load transmission member is positioned on the vehicle body right side relative to the center beam.

7. The vehicle body structure according to claim 1, characterized in that: The protruding portion extends continuously in the vehicle width direction.

8. The vehicle body structure according to claim 1 or 7, characterized in that: The vehicle rear portion of the second front-rear direction load transmission member and the protruding portion are arranged at a predetermined interval in the vehicle front-rear direction.

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