Front body structure

Abstract

To reduce a length of a pole entering an electric vehicle at the time of a pole collision.SOLUTION: A vehicle body front structure A of an electric vehicle includes: a front battery frame 32 extending in a vehicle width direction; a pair of left and right side frames 11, 12 which extends forward from the front battery frame 32; a cross member 19 which is provided spanning the left and right side frames 11, 12; and reinforcement members 19A, 19B which extend from the cross member 19 to the vehicle rear toward the front battery frame 32.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure relates to, for example, a front body structure of an electric vehicle.

Background Art

[0002] For example, in the front part of the vehicle body of an automobile disclosed in Patent Document 1, a pair of left and right front side frames extending in the vehicle front-rear direction are provided, and a front sub-frame is provided below these front side frames and behind the engine room. Left pipe frames and right pipe frames are provided at the left front end and the right front end of the front sub-frame, respectively, so as to extend forward of the vehicle. The left pipe frame and the right pipe frame are inclined with respect to the center line extending in the vehicle front-rear direction so as to be located on the outer side in the vehicle width direction as they go forward.

[0003] In Patent Document 1, it is said that since the left pipe frame and the right pipe frame are inclined so as to be located on the outer side in the vehicle width direction as they go forward, the impact load can be favorably absorbed in the case of an offset collision in which an impact load is input from the obliquely front side of the vehicle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in addition to offset collisions as disclosed in Patent Document 1, for example, it is also necessary to ensure safety in a pole collision where a vehicle collides with a vertically extending pole from the front. In this regard, in a conventional vehicle equipped with an engine, many auxiliary component parts such as intake and exhaust system parts were arranged together with the engine in the engine room at the front of the vehicle body. Therefore, when a large local impact load such as a pole collision was input, the auxiliary component parts also absorbed the impact load by being deformed.

[0006] However, in an electric vehicle without an engine, in many cases, a driving motor smaller than the engine is mounted in the space corresponding to the conventional engine room. Also, since fewer auxiliary component parts are required than an engine, there was a concern that the amount of intrusion of the pole during a pole collision would increase.

[0007] The present disclosure is in view of such a point, and an object thereof is to reduce the amount of intrusion of a pole during a pole collision in an electric vehicle.

Means for Solving the Problems

[0008] To achieve the above object, in a first aspect of the present disclosure, on the premise of a vehicle body front structure of an electric vehicle in which a battery case accommodating a driving motor and a battery for supplying power to the driving motor is disposed below a floor panel. The vehicle body front structure includes a front battery frame provided at the front of the battery case and extending in the vehicle width direction, a pair of left and right side frames extending from the front battery frame toward the front of the vehicle, a portion of the left side frame away from the front battery frame toward the front of the vehicle, and a portion of the right side frame away from the front battery frame toward the front of the vehicle. It includes a cross member installed between them, and a reinforcing member extending rearward of the vehicle from the cross member toward the front battery frame.

[0009] According to this configuration, in the case of assuming a pole collision, the entering pole may apply a backward impact load to the cross member. The cross member subjected to the backward impact load tends to bend backward, but since there is a reinforcing member extending toward the front side battery frame located behind the cross member, the cross member is supported from behind by the reinforcing member. As a result, the impact load can be transmitted to the front side battery frame as well, so that the deformation of the cross member is suppressed, and thus the entering amount of the pole is reduced.

[0010] In the second aspect of the present disclosure, the left and right side frames extend so as to be located more outward in the vehicle width direction as they go forward. According to this configuration, for example, in the case of assuming a left offset collision in which an impact load is input from the left obliquely forward, since the left side frame extends so as to correspond to the input direction of the impact load, the impact load from the left obliquely forward is input so as to generally follow the axial direction of the left side frame, and the impact load is absorbed by the left side frame. In addition, since the impact load input to the left side frame is transmitted to the front side battery frame, it is also absorbed by the front side battery frame. The same applies to the right offset collision.

[0011] In the third aspect of the present disclosure, a frame bracket that connects the rear portions of the left and right side frames to the front side battery frame may be provided. In this case, the rear portion of the reinforcing member can be brought into contact with the frame bracket.

[0012] According to this configuration, since the rear portion of the reinforcing member can be supported from behind by the frame bracket, the effect of suppressing the deformation of the cross member subjected to the backward impact load can be enhanced.

[0013] The reinforcing member according to the fourth aspect of the present disclosure may include a left reinforcing member and a right reinforcing member that are provided at intervals from each other in the vehicle width direction. The left reinforcing member and the right reinforcing member can be provided so as to be located more outward in the vehicle width direction as they go backward.

[0014] According to this configuration, since the cross member subjected to a rearward impact load can be firmly supported by the left and right reinforcing members, the effect of suppressing the deformation of the cross member subjected to a rearward impact load can be further enhanced.

[0015] In a fifth aspect of the present disclosure, a suspension arm constituting a front suspension device may be configured to be swingably supported on the outer side in the vehicle width direction of the frame bracket.

[0016] According to this configuration, since the portion for supporting the suspension arm is also provided on the frame bracket, the rigidity of the frame bracket as a whole can be increased.

[0017] The front portion of the traveling motor according to the sixth aspect of the present disclosure can be positioned behind the front portion of the cross member in the vehicle rearward direction.

[0018] According to this configuration, the pole that enters during a collision hits the cross member before hitting the traveling motor. Thereby, the effect of suppressing the entry of the pole by the cross member and the reinforcing member is sufficiently exhibited.

[0019] The cross member according to the seventh aspect of the present disclosure may be formed such that the middle portion in the vehicle width direction is positioned below the lower surface of the side frame. Further, the reinforcing member may extend from the middle portion in the vehicle width direction of the cross member through the lower side of the side frame toward the front battery frame.

[0020] According to this configuration, since the reinforcing member and the side frame are laid out so as to be aligned in the height direction, it becomes easy to achieve both arranging the side frame so as to be positioned more outward in the vehicle width direction as going forward and arranging the reinforcing member so as to extend toward the front battery frame.

Effect of the Invention

[0021] As described above, since the reinforcing member extends from the cross member installed on the left and right side frames toward the front battery frame, even in an electric vehicle, the intrusion amount of the pole during a pole collision can be reduced.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses.

[0024] FIG. 1 is a left side view of an electric vehicle (electric car) 1 equipped with a front body structure A according to an embodiment of the present invention. As shown in FIG. 2, this electric vehicle 1 includes a lower structure body 2 and an upper structure body 3. In FIG. 1, the front bumper, rear bumper, front and rear wheels, etc. are omitted, and they are shown by phantom lines, and each part is schematically shown. In FIG. 2, in addition to the parts omitted in FIG. 1, the door, bonnet hood, front fender, windshield, front and rear lighting devices, interior materials, etc. are omitted, and each part is schematically shown.

[0025] In the description of this embodiment, the front side of the vehicle is simply referred to as "front", the rear side of the vehicle is simply referred to as "rear", the right side of the vehicle is simply referred to as "right", and the left side of the vehicle is simply referred to as "left". The left and right directions of the vehicle are the vehicle width direction.

[0026] As shown in FIG. 1, the electric vehicle 1 is a passenger car. The electric vehicle 1 may be of any type such as a sedan type, hatchback type, one-box type, etc., and its shape is not particularly limited. As shown in FIG. 2, a passenger compartment R1 serving as a living space for passengers is formed in the electric vehicle 1. As shown in FIG. 1, a front seat S1 is provided on the front side in the passenger compartment R1, and a rear seat S2 is provided behind the front seat S1 in the passenger compartment R1. A luggage compartment R2 is provided behind the rear seat S2 as needed. The passenger compartment R1 and the luggage compartment R2 are provided in the upper structure body 3. Note that only the front seat S1 may be provided in the passenger compartment R1, or a third-row seat (not shown) may be provided behind the rear seat S2.

[0027] On the other hand, the space in front of the passenger compartment R1, which is the front part of the electric vehicle 1, can be, for example, a power compartment R3. That is, the front body structure A is provided in the electric vehicle 1 including a front-side traveling motor M1 and a rear-side traveling motor M2, a battery B that supplies electric power to the traveling motors M1 and M2, and a battery case 10 in which the battery B is housed. The battery case 10 is disposed below a floor panel 70 described later.

[0028] The front traveling motor M1 generates a driving force for driving the left and right front wheels FT. The front power train PT1 is constituted by only this front traveling motor M1, or by the front traveling motor M1 and a speed reducer, a transmission, or the like. Further, the rear traveling motor M2 generates a driving force for driving the left and right rear wheels RT. The rear power train PT2 is constituted by only this rear traveling motor M2, or by the rear traveling motor M2 and a speed reducer, a transmission, or the like.

[0029] In this embodiment, the rear traveling motor M2 is configured to generate a higher maximum output (maximum torque) than the front traveling motor M1, and the rear traveling motor M2 is larger in size than the front traveling motor M1. Accordingly, the rear power train PT2 becomes larger than the front power train PT1. Note that the rear traveling motor M2 may generate a lower maximum output than the front traveling motor M1, or the rear traveling motor M2 and the front traveling motor M1 may generate the same maximum output. Further, only the front power train PT1 may be provided, or only the rear power train PT2 may be provided.

[0030] As shown in FIG. 2, the lower structure 2 includes a battery case 10, a pair of left and right front side frames 11 and 12 extending forward in front of the battery case 10, and a pair of left and right rear frames 13 and 14 extending rearward behind the battery case 10. Reference numeral 11 indicates the left front side frame, and reference numeral 12 indicates the right front side frame. Further, reference numeral 13 indicates the left rear frame, and reference numeral 14 indicates the right rear frame.

[0031] In the case of a general electric vehicle, the battery case is often made detachable under the floor as a separate body from the vehicle body. However, in this embodiment, not only the battery case 10, but also the left and right front side frames 11, 12 and the left and right rear frames 13, 14 are integrated with the battery case 10, and the front side frames 11, 12 and the rear frames 13, 14 are also detachable from the upper structure 3 together with the battery case 10.

[0032] Specifically, the electric vehicle 1 of this embodiment is configured to be vertically divisible into a lower structure 2 having a battery case 10 and an upper structure 3 forming a passenger compartment R1 and a cargo compartment R2. Being vertically divisible means integrating the lower structure 2 with the upper structure 3 using fastening members such as bolts, nuts, and screws without using welding, adhesion, etc. Thereby, when performing maintenance or repair after the electric vehicle 1 is delivered to the user, the lower structure 2 can be separated from the upper structure 3 as necessary, so that the maintainability is improved. Note that the fastening members used in the following description also include bolts, nuts, screws, etc.

[0033] Here, as an automobile body structure, a ladder frame type body structure is known. In the case of a ladder frame type body structure, it is vertically divisible into a ladder frame and a cabin. However, since the ladder frame extends continuously in the front-rear direction, it mainly receives the collision load during a frontal collision and a rear collision. During a side collision, the ladder frame only receives the collision load assistantly, and the cabin mainly receives the collision load. Thus, in a ladder frame type body structure, it is normal that the members receiving the collision load are separated between during a frontal collision and a rear collision and during a side collision.

[0034] In contrast, in the case of the electric vehicle 1 of the present embodiment, the lower structure 2 having the front side frames 11 and 12 and the rear frames 13 and 14 and the upper structure 3 are separable. However, in both the case of a frontal collision and a rear collision and the case of a side collision, by receiving the collision load by the lower structure 2 and the upper structure 3, the collision load can be dispersed and absorbed by the two structures 2 and 3, and the technical concept is greatly different from that of the conventional ladder frame type vehicle body structure. Hereinafter, the structures of the lower structure 2 and the upper structure 3 will be described in detail.

[0035] (Upper structure) First, the upper structure 3 will be described. As shown in FIG. 2, the upper structure 3 includes a floor panel 70, a dash panel 71, a pair of left and right front main frames 72 and 73, and a pair of left and right side sills 74 and 75. Reference numeral 72 indicates the left front main frame, and reference numeral 73 indicates the right front main frame. Reference numeral 74 indicates the left side sill, and reference numeral 75 indicates the right side sill.

[0036] The floor panel 70 constitutes the floor surface of the passenger compartment R1 and is made of a steel plate or the like that extends in the front-rear direction and also in the left-right direction. The space above the floor panel 70 is the passenger compartment R1. A roof 80 is provided above the passenger compartment R1. In addition, front openings 3a and rear openings 3b are formed on both left and right sides of the upper structure 3, respectively. As shown in FIG. 1, the front openings 3a and the rear openings 3b can be opened and closed by the front door 81 and the rear door 82, respectively. Although not shown, a front door and a rear door are also disposed on the right side of the upper structure 3 so as to be openable and closable.

[0037] The dash panel 71 is a member for partitioning the passenger compartment R1 and the power compartment R3 in the front-rear direction. This dash panel 71 is made of, for example, a steel plate or the like, and extends in the left-right direction and also in the up-down direction. On both the left and right sides of the front part of the upper structure 3, left and right front wheel house parts 85 and 86 for accommodating the left and right front wheels FT are provided respectively. The left end of the dash panel 71 is connected to the left front wheel house part 85, and the right end of the dash panel 71 is connected to the right front wheel house part 86.

[0038] The left and right front main frames 72 and 73 are disposed at the front part of the vehicle body and are high-strength members extending in the front-rear direction. That is, the left and right front main frames 72 and 73 are positioned in front of the floor panel 70 and also above the floor panel 70, and specifically are disposed so as to extend forward from both the left and right sides at the lower part of the dash panel 71.

[0039] The left and right front main frames 72 and 73 have a symmetric structure and can be configured, for example, by joining a plurality of press-formed materials or by using an extruded material. The cross-section of each of the front main frames 72 and 73 in the direction orthogonal to the front-rear direction is set larger than the cross-section of the front side frames 11 and 12 of the lower structure 2 in the same direction. Thereby, each of the front main frames 72 and 73 becomes a thicker and higher-strength member compared to the front side frames 11 and 12.

[0040] The front end parts of the left and right front main frames 72 each have crush cans 72a and 73a that compress and deform during a frontal collision to absorb collision energy. The crush cans 72a and 73a are cylindrical members extending in the front-rear direction. The crush cans 72a and 73a compress and deform at a stage before the front main frames 72 and 73 deform due to an impact load from the front, and absorb the impact load. A front bumper reinforcement 87 extending in the left-right direction is fixed to the front end parts of the left and right crush cans 72a and 73a.

[0041] The left and right side sills 74 and 75 are respectively arranged at both left and right ends of the floor panel 70 so as to extend in the front-rear direction. The left end of the floor panel 70 is connected to the middle part in the vertical direction of the left side sill 74, and the right end of the floor panel 70 is connected to the middle part in the vertical direction of the right side sill 75. The upper parts of the side sills 74 and 75 protrude upward from the connection part of the floor panel 70, and the lower parts of the side sills 74 and 75 protrude downward from the connection part of the floor panel 70. Since the battery case 10 is arranged below the floor panel 70, in a side view of the vehicle, the lower parts of the side sills 74 and 75 and the battery case 10 are arranged so as to overlap. The battery case 10 is fixed to the side sills 74 and 75.

[0042] (Lower structure) Next, the lower structure 2 will be described. The lower structure 2 includes, in addition to the battery case 10, the front side frames 11 and 12, and the rear frames 13 and 14, the front and rear power trains PT1 and PT2, the front wheels FT, the rear wheels RT, the front suspension device 20, and the rear suspension device 21, etc. The types of the front suspension device 20 and the rear suspension device 21 are not particularly limited.

[0043] The battery case 10 is a large case formed so as to extend 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 below the floor panel 70 of the upper structure 3. In this way, by providing the battery case 10 in a wide range of the lower region of the floor panel 70, it becomes possible to mount a large-capacity battery B on the electric vehicle 1. The battery B may be, for example, a lithium-ion battery, an all-solid-state battery, or other secondary batteries. Also, the battery B may be a so-called battery cell or a battery pack containing a plurality of battery cells. In the present embodiment, the battery B is constituted by a battery pack, and a plurality of battery packs are mounted in a state of being arranged in the front-rear direction and the left-right direction.

[0044] The battery case 10 includes a left battery frame 30, a right battery frame 31, a front battery frame 32, a rear battery frame 33, a bottom plate 34, and a lid 35 (shown in FIG. 3). FIG. 2 shows the state where the lid 35 is removed.

[0045] The left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33 are made of, for example, extruded materials made of aluminum alloy, but may also be made of aluminum alloy plates or press-formed materials made of steel plates. The bottom plate 34 can also be made of an extruded material. In the following description, the "extruded material" refers to an extruded material made of aluminum alloy, and the "press-formed material" refers to an aluminum alloy plate or a press-formed material made of a steel plate. Also, each member may be made of, for example, a casting.

[0046] The cross-sectional shapes in the direction orthogonal to the longitudinal direction of each of the left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33 are all rectangular. Also, the left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33 are all arranged at the same height and extend substantially horizontally.

[0047] The left battery frame 30 is provided on the left side of the battery case 10 and extends in the front-rear direction. The right battery frame 31 is provided on the right side of the battery case 10 and extends in the front-rear direction. Also, the front battery frame 32 is provided at the front of the battery case 10 and extends in the left-right direction. The rear battery frame 33 is provided at the rear of the battery case 10 and extends in the left-right direction.

[0048] The left end of the front battery frame 32 is connected to the front end of the left battery frame 30, and the right end of the front battery frame 32 is connected to the front end of the right battery frame 31. The left end of the rear battery frame 33 is connected to the rear end of the left battery frame 30, and the right end of the rear battery frame 33 is connected to the rear end of the right battery frame 31. Therefore, the left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33 form a frame shape that surrounds all the batteries B in plan view.

[0049] The bottom plate 34 extends substantially horizontally and is fixed to the lower surfaces of the left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33. Also, the lid 35 is fixed to the lower surfaces of the left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33. Thus, a battery accommodation space S (shown in FIG. 2) for accommodating the battery B is partitioned and formed by the left battery frame 30, the right battery frame 31, the front battery frame 32, the rear battery frame 33, the bottom plate 34, and the lid 35.

[0050] The size of the battery accommodation space S can be changed according to the capacity of the mounted battery B. The size of the battery accommodation space S can be easily changed by changing the lengths of the left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33 and the shape of the bottom plate 34. For example, when the wheelbase is short and the tread is narrow in a small car, the left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33 are shortened, and accordingly, the shapes of the bottom plate 34 and the lid 35 are made smaller, so that the battery accommodation space S becomes smaller according to the small car. On the other hand, in the case of a large car, the left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33 are lengthened, and accordingly, the shapes of the bottom plate 34 and the lid 35 are made larger, so that the battery accommodation space S becomes larger according to the large car. When the left battery frame 30, the right battery frame 31, the front battery frame 32, and the rear battery frame 33 are made of extruded materials, the length can be easily changed. Also, the bottom plate 34 can be made of an extruded material, whereby the shape can be easily changed.

[0051] The upper part of the battery accommodation space S may be closed by the lid 35 or may be closed by the floor panel 70 of the upper structure 3. In addition to the battery B, a cooling device for cooling the battery B, a heating device for heating the battery B, etc. (temperature control device) can also be provided in the battery accommodation space S. Further, the power of the battery B is supplied to the driving motors M1 and M2 via a control device (not shown). Furthermore, the battery B can be charged via a charging socket, a non-contact charger, etc. (not shown).

[0052] As shown in Fig. 2, inside the battery case 10, first to third in-case members 25A, 25B, and 25C are provided as strength members extending in the left-right direction. The heights of the first to third in-case members 25A, 25B, and 25C are all the same and are substantially the same as the height of the left battery frame 30 or the like. The in-case members 25A, 25B, and 25C may be formed of an extruded material or a press-formed material. In this embodiment, three in-case members 25A, 25B, and 25C are provided, but the number of in-case members 25A, 25B, and 25C can be increased or decreased according to the front-rear dimension of the battery case 10.

[0053] The first to third in-case members 25A, 25B, and 25C are arranged at intervals in the front-rear direction, with the first in-case member 25A positioned at the frontmost and the third in-case member 25C positioned at the rearmost. The lower portions of the in-case members 25A, 25B, and 25C are fixed to the upper surface of the bottom plate 34. Also, the left end portions of the in-case members 25A, 25B, and 25C are fixed to the inner surface (right side surface) of the left battery frame 30, and the right end portions of the in-case members 25A, 25B, and 25C are fixed to the inner surface (left side surface) of the right battery frame 31. That is, the in-case members 25A, 25B, and 25C are members that connect the left battery frame 30 and the right battery frame 31.

[0054] Inside the battery case 10, a front central member 26 and first to third rear central members (rear reinforcing members) 27 to 29 are provided as strength members extending in the front-rear direction. The front central member 26 and the first to third rear central members 27 to 29 are arranged at substantially the same height and are provided at the center in the left-right direction of the battery case 10. The lower end portions of the front central member 26 and the first to third rear central members 27 to 29 are attached to the upper surface of the bottom plate 34.

[0055] The front central member 26 is disposed between the front battery frame 32 and the first in-case member 25A. The front end portion of the front central member 26 is fixed to the central portion in the left-right direction of the front battery frame 32, and the rear end portion of the front central member 26 is fixed to the central portion in the left-right direction of the first in-case member 25A. Therefore, the front battery frame 32 is a member that extends so as to connect the front end portions of the left battery frame 30 and the right battery frame 31 and the front end portion of the front central member 26.

[0056] The first rear central member 27 is disposed between the first in-case member 25A and the second in-case member 25B. The front end portion of the first rear central member 27 is fixed to the central portion in the left-right direction of the first in-case member 25A, and the rear end portion of the first rear central member 27 is fixed to the central portion in the left-right direction of the second in-case member 25B. Also, the second rear central member 28 is disposed between the second in-case member 25B and the third in-case member 25C. The front end portion of the second rear central member 28 is fixed to the central portion in the left-right direction of the second in-case member 25B, and the rear end portion of the second rear central member 28 is fixed to the central portion in the left-right direction of the third in-case member 25C. Also, the third rear central member 29 is disposed between the third in-case member 25C and the rear battery frame 33. The front end portion of the third rear central member 29 is fixed to the central portion in the left-right direction of the third in-case member 25C, and the rear end portion of the third rear central member 29 is fixed to the central portion in the left-right direction of the rear battery frame 33. Therefore, the first to third in-case members 25A, 25B, 25C, the front central member 26, and the first to third rear central members 27 to 29 are arranged in a lattice pattern inside the battery case 10 and are connected to each other, so that the reinforcing effect of the battery case 10 is further enhanced.

[0057] When assuming a virtual straight line extending in the front-rear direction in a plan view, the front central member 26 and the first to third rear central members 27 to 29 are each set in their left-right positions so as to be arranged on the virtual straight line. That is, the first to third rear central members 27 to 29 are provided so as to be positioned on the virtual extension line of the front central member 26 rearward. Incidentally, the front central member 26 and the first to third rear central members 27 to 29 may be constituted by a single member continuous in the front-rear direction.

[0058] As shown in FIGS. 4 to 6 and the like, the vehicle body front structure A includes a pair of left and right front side frames 11, 12, a frame bracket 40, a first cross member 15, a pair of left and right impact absorbing members 16, 17, and a second cross member 19. In the present embodiment, in addition to the above members, a front member 18, reinforcing members 19A, 19B, etc. are also provided. The members constituting the vehicle body front structure A are not limited to the members described above, and may include other members, devices, apparatuses, etc. Further, among the members described above, members that do not become essential components of the present invention may be omitted.

[0059] The front side frames 11, 12 extend linearly substantially horizontally below the left and right front main frames 72, 73 of the upper structure 3. The front side frames 11, 12 can be constituted by, for example, extruded materials or press-formed materials. In this embodiment, since the front side frames 11, 12 are constituted by extruded materials, the cross-sectional shape in the direction orthogonal to the front-rear direction is substantially equal from the front end portion to the rear end portion.

[0060] The left and right front side frames 11 and 12 are attached to the front battery frame 32 that constitutes the front part of the battery case 10 via frame brackets 40. That is, the rear parts of the left and right front side frames 11 and 12 are connected to the front battery frame 32 by the frame brackets 40. This frame bracket 40 is an integrally formed metal product and extends in the left-right direction along the front surface of the front battery frame 32. The rear parts of the left and right front side frames 11 and 12 are fixed to the frame bracket 40. The metal constituting the frame bracket 40 is not particularly limited, and for example, aluminum etc. can be mentioned. In this case, the frame bracket 40 can be made of aluminum die-casting.

[0061] The left and right front side frames 11 and 12 are attached to the front battery frame 32 via the frame brackets 40, but the rear parts of the front side frames 11 and 12 are abutted against the front surface of the front battery frame 32. Therefore, the front side frames 11 and 12 extend forward from the front battery frame 32. Incidentally, the rear parts of the front side frames 11 and 12 may be slightly separated forward from the front surface of the front battery frame 32. Even in this case, when viewed as a whole, it can be said that the front side frames 11 and 12 extend forward from the front battery frame 32.

[0062] The rear part of the left front side frame 11 is arranged to correspond to a position closer to the left than the center in the left-right direction of the front battery frame 32. Also, the rear part of the right front side frame 12 is arranged to correspond to a position closer to the right than the center in the left-right direction of the front battery frame 32. Thereby, the interval between the left and right front side frames 11 and 12 becomes a predetermined interval. The interval between the rear parts of the front side frames 11 and 12 is set to be narrower than the interval between the left battery frame 30 and the right battery frame 31 of the battery case 10.

[0063] The heights of the left and right front side frames 11 and 12 are substantially the same. Also, the left and right front side frames 11 and 12, the front center member 26 of the battery case 10, the left battery frame 30, and the right battery frame 31 are arranged at substantially the same height.

[0064] The left and right front side frames 11 and 12 extend so as to be positioned more outward in the vehicle width direction as they go forward. That is, the left front side frame 11 is inclined with respect to a virtual straight line extending in the longitudinal direction of the vehicle in plan view so as to be positioned more to the left as it goes forward. Also, the right front side frame 12 is inclined with respect to a virtual straight line extending in the longitudinal direction of the vehicle in plan view so as to be positioned more to the right as it goes forward. As a result, the interval (the distance apart in the vehicle width direction) between the left and right front side frames 11 and 12 becomes wider as it goes forward, and a space C is formed between the left and right front side frames 11 and 12 in which all or part of various parts, devices, apparatuses, etc. can be arranged. And the space C has a shape that expands in the vehicle width direction as it goes forward.

[0065] The inclination angle of the left front side frame 11 with respect to the virtual straight line is equal to the inclination angle of the right front side frame 11 with respect to the virtual straight line. The front part of the left front side frame 11 is arranged more inward in the vehicle width direction than the left battery frame 30 of the battery case 10. Also, the front part of the right front side frame 12 is arranged more inward in the vehicle width direction than the right battery frame 31 of the battery case 10.

[0066] Also, as shown in FIG. 1, the front parts of the left and right front side frames 11 and 12 and the front parts of the left and right front main frames 72 of the upper structure 3 are set to have substantially the same position in the longitudinal direction.

[0067] As shown in FIG. 7, the frame bracket 40 includes a vertical plate portion 40a that extends in the vehicle width direction and the vertical direction along the front surface of the front battery frame 32, and a lower plate portion 40b that extends rearward along the lower surface of the front battery frame 32 from the lower edge portion of the vertical plate portion 40a and also extends in the vehicle width direction. The vertical plate portion 40a and the lower plate portion 40b are fixed to the front battery frame 32 by fastening members or the like. In this way, by fixing the vertical plate portion 40a and the lower plate portion 40b of the frame bracket 40 to the front surface and the lower surface of the front battery frame 32 respectively, the mounting rigidity of the frame bracket 40 with respect to the front battery frame 32 can be enhanced.

[0068] In the vertical plate portion 40a of the frame bracket 40, a left insertion hole 40c into which the rear portion of the left front side frame 11 is inserted and a right insertion hole 40d into which the rear portion of the right front side frame 12 is inserted are formed at intervals in the vehicle width direction. The rear portion of the left front side frame 11 is fixed to the frame bracket 40 by, for example, an adhesive or a fastening member in a state of being inserted into the left insertion hole 40c.

[0069] As shown in FIG. 5, the frame bracket 40 includes a left upper plate portion 40e that extends in the front-rear direction so as to cover the upper surface of the left front side frame 11, and a right upper plate portion 40f that extends in the front-rear direction so as to cover the upper surface of the right front side frame 12. The left upper plate portion 40e and the upper surface of the left front side frame 11 are adhered by, for example, an adhesive, and the right upper plate portion 40f and the upper surface of the right front side frame 12 are adhered in the same manner. Thereby, the left and right front side frames 11, 12 can be firmly fixed to the frame bracket 40.

[0070] The frame bracket 40 has a left support portion 41 and a right support portion 42, and the left support portion 41 and the right support portion 42 are integrally formed with a vertical plate portion 40a and a lower plate portion 40b. The left support portion 41 is disposed on the outer side (left side) in the vehicle width direction of the left front side frame 11 and is a portion that supports the front side frame 11 from the outer side in the vehicle width direction. Specifically, the left support portion 41 protrudes forward from the left side portion of the left insertion hole 40c in the vertical plate portion 40a and extends along the left side surface of the left front side frame 11. The front portion of the left support portion 41 reaches the vicinity of the center portion in the front-rear direction of the left front side frame 11. Therefore, a wide range of the left support portion 41 can be supported by the left support portion 41. It is also possible to adhere the left front side frame 11 to the left support portion 41.

[0071] Also, the right support portion 42 is disposed on the outer side (right side) in the vehicle width direction of the right front side frame 12 and is a portion that supports the front side frame 12 from the outer side in the vehicle width direction. Specifically, the right support portion 42 protrudes forward from the right side portion of the right insertion hole 40d in the vertical plate portion 40a and extends along the right side surface of the right front side frame 12. The front portion of the right support portion 42 reaches the vicinity of the center portion in the front-rear direction of the right front side frame 12. Therefore, a wide range of the right support portion 42 can be supported by the right support portion 42. It is also possible to adhere the right front side frame 12 to the right support portion 42.

[0072] On the outer side in the vehicle width direction of the frame bracket 40, the left and right suspension arms 20A that constitute the front suspension device 20 are supported so as to be swingable in the vertical direction. That is, on the left side portion of the frame bracket 40 that is more to the left than the left support portion 41, a left arm mounting portion 43 is provided so as to protrude to the left. The proximal end portion of the left suspension arm 20A is rotatably attached to the left arm mounting portion 43 about an axis extending in the front-rear direction. Further, on the right side portion of the frame bracket 40 that is more to the right than the right support portion 42, a right arm mounting portion 44 is provided so as to protrude to the right. The proximal end portion of the right suspension arm 20A is rotatably attached to the right arm mounting portion 44 about an axis extending in the front-rear direction.

[0073] The first cross member 15 is a member installed between a portion of the left front side frame 11 that is away from the front side battery frame 32 in the front and a portion of the right front side frame 12 that is away from the front side battery frame 32 in the front, and extends linearly in the vehicle width direction. The first cross member 15 can also be composed of an extruded material, a press material, or the like. In this embodiment, the left side portion of the first cross member 15 is fixed to the front portion of the left front side frame 11, and the right side portion of the first cross member 15 is fixed to the front portion of the right front side frame 12. Therefore, the front portions of the left and right front side frames 11 and 12 are connected by the first cross member 15.

[0074] Also, the first cross member 15 and the front side battery frame 32 are substantially parallel. Thereby, in plan view, a rectangular shape (a trapezoidal shape in this example) is formed by the first cross member 15, the left and right front side frames 11 and 12, and the front side battery frame 32, and a closed cross section is formed when looking at the horizontal cross section.

[0075] The left side of the first cross member 15 protrudes outward in the vehicle width direction from the front portion of the left front side frame 11. Also, the right side of the first cross member 15 protrudes outward in the vehicle width direction from the front portion of the right front side frame 12.

[0076] The second cross member 19 corresponding to the cross member of the present invention is disposed between the first cross member 15 and the front battery frame 32, and is a member erected on the left front side frame 11 and the right front side frame 12, and extends linearly in the vehicle width direction. The second cross member 19 can also be formed of an extruded material, a pressed material, or the like. The dimension of the second cross member 19 in the vehicle width direction is shorter than the dimension of the first cross member 15 in the vehicle width direction.

[0077] As also shown in FIG. 7, the left end portion of the second cross member 19 is fixed to the right side surface of the left front side frame 11 by adhesion, welding, fastening members, or the like. The right end portion of the second cross member 19 is similarly fixed to the left side surface of the right front side frame 12. As a result, the intermediate portions in the front-rear direction of the left and right front side frames 11 and 12 are connected to each other.

[0078] The front traveling motor M1 is located above the second cross member 19. The front portion of the front traveling motor M1 is positioned rearward of the vehicle with respect to the front portion of the second cross member 19.

[0079] The shape of the second cross member 19 is not particularly limited, but in the present embodiment, it includes an intermediate portion 19a that constitutes the intermediate portion in the vehicle width direction, a left side portion 19b that constitutes the left side, and a right side portion 19c that constitutes the right side. The intermediate portion 19a is formed so as to be located below the lower surfaces of the front side frames 11 and 12. The left end portion of the left side portion 19b is fixed to the right side surface of the left front side frame 11, and the right end portion of the right side portion 19c is fixed to the left side surface of the right front side frame 12. The left side portion 19b and the right side portion 19c are inclined so as to be located lower as they go inward in the vehicle width direction. The right end portion of the left side portion 19b and the left end portion of the right side portion 19c are continuous with the left end portion and the right end portion of the intermediate portion 19a, respectively. The second cross member 19 can be obtained, for example, by bending a single cylindrical member.

[0080] Further, the second cross member 19 is substantially parallel to the front battery frame 32. As a result, in a plan view, a rectangular shape (a trapezoidal shape in this example) is formed by the second cross member 19, the left and right front side frames 11, 12, and the front battery frame 32, and a closed cross section is configured when looking at a horizontal cross section. Also, in a plan view, a rectangular shape is formed by the second cross member 19, the left and right front side frames 11, 12, and the first cross member 15.

[0081] As shown in FIG. 5, in the present embodiment, it includes a left reinforcing member 19A and a right reinforcing member 19B that are provided at intervals in the vehicle width direction. The left reinforcing member 19A and the right reinforcing member 19B extend from the middle portion in the vehicle width direction of the second cross member 19 through the lower sides of the front side frames 11, 12 toward the front battery frame 32.

[0082] That is, the left reinforcing member 19A extends rearward from a portion of the second cross member 19 that is closer to the left than the center in the vehicle width direction toward the front battery frame 32. Also, the right reinforcing member 19B extends rearward from a portion of the second cross member 19 that is closer to the right than the center in the vehicle width direction toward the front battery frame 32.

[0083] Further, the left reinforcing member 19A and the right reinforcing member 19B are provided so as to be located on the outer side in the vehicle width direction as they go rearward, and the rear portions of the left reinforcing member 19A and the right reinforcing member 19B are in contact with the frame bracket 40. Specifically, on the left side portion of the frame bracket 40, a left fixing plate portion 46 that protrudes downward and extends in the front-rear direction is formed. This left fixing plate portion 46 is located near the boundary portion between the left support portion 41 and the left arm mounting portion 43 and extends below the lower surface of the left arm mounting portion 43. The left end portion of the left reinforcing member 19A is fixed to the right side surface of this left fixing plate portion 46 by adhesion, welding, or the like. The extending direction of the left reinforcing member 19A and the extending direction of the left fixing plate portion 46 intersect each other, and a wide adhesion or welding range of the left end portion of the left reinforcing member 19A to the left fixing plate portion 46 is ensured.

[0084] Similarly, on the right side portion of the frame bracket 40, a right fixing plate portion 47 that protrudes downward and extends in the front-rear direction is formed. This right fixing plate portion 47 is located near the boundary portion between the right support portion 42 and the right arm attachment portion 44, and extends below the lower surface of the right arm attachment portion 44. The right end portion of the right reinforcing member 19B is fixed to the left side surface of this right fixing plate portion 47 by adhesion, welding, or the like.

[0085] The left shock absorbing member 16 is provided in front of the left front side frame 11 and is composed of a tubular member extending forward. Also, the right shock absorbing member 17 is provided in front of the right front side frame 12 and is composed of a tubular member extending forward. The shock absorbing members 16 and 17, similar to the crash cans 72a and 73a of the upper structure 3, are compressed and deformed at a stage before the front side frames 11 and 12 are deformed by an impact load from the front, and absorb the impact load. As shown in FIG. 1, the rear portions of the left and right shock absorbing members 16 and 17 and the rear portions of the crash cans 72a and 73a of the upper structure 3 are set to have substantially the same position in the front-rear direction.

[0086] The rear portion of the left shock absorbing member 16 is fixed to the front portion of the left front side frame 11. The extending direction of the left shock absorbing member 16 is along the longitudinal direction of the left front side frame 11, and the axis of the shock absorbing member 16 is positioned on the extension line in front of the left front side frame 11. Also, the rear portion of the right shock absorbing member 17 is fixed to the front portion of the right front side frame 12. The extending direction of the right shock absorbing member 17 is along the longitudinal direction of the right front side frame 12, and the axis of the shock absorbing member 17 is positioned on the extension line in front of the right front side frame 12.

[0087] As shown in FIGS. 3 and 4 and the like, the front member 18 is a member installed on the left and right shock absorbing members 16 and 17. A portion of the front member 18 on the left side of the center in the vehicle width direction is fixed to the front portion of the left shock absorbing member 16, and a portion of the front member 18 on the right side of the center in the vehicle width direction is fixed to the front portion of the right shock absorbing member 17. Thus, the left and right shock absorbing members 16 and 17 are connected by the front member 18. As shown in FIG. 1, the front member 18 and the front bumper reinforcement 87 of the upper structure 3 are set to have substantially the same position in the front-rear direction, and the front member 18 is positioned directly below the front bumper reinforcement 87.

[0088] (Modification) FIG. 8 shows a modification of the embodiment. In this modification, the second cross member 19 extends linearly in the vehicle width direction. The left end portion of the second cross member 19 is fixed to the right side surface of the left front side frame 11 by adhesion, welding, fastening members, etc., and the right end portion of the second cross member 19 is similarly fixed to the left side surface of the right front side frame 12.

[0089] The left reinforcing member 19A and the right reinforcing member 19B extend toward the front side battery frame 32. The front portions of the left reinforcing member 19A and the right reinforcing member 19B are fixed to the rear surface of the second cross member 19. The rear portion of the left reinforcing member 19A is fixed to the right side surface of the left front side frame 11. The rear portion of the right reinforcing member 19B is fixed to the left side surface of the right front side frame 12. That is, in this modification, the left reinforcing member 19A and the right reinforcing member 19B are arranged at the same height as the front side frames 11 and 12.

[0090] (Advantages of the Embodiment) Next, the collision of the electric vehicle 1 configured as described above will be explained. First, assume a pole collision in which the electric vehicle 1 collides with a vertically extending pole (not shown) from the front. At the time of the pole collision, the impact load is input to the left and right crash cans 72a, 73a and the left and right front main frames 72, 73 via the front bumper reinforcement 87 of the upper structure 3. At this time, the front bumper reinforcement 87 bends and deforms so that the center portion in the vehicle width direction is located at the rearmost position, allowing the pole to enter. Further, the impact load is input to the left and right shock absorbing members 16, 17 and the left and right front side frames 11, 12 via the front member 18 of the lower structure 2, and the front member 18 bends and deforms, allowing the pole to enter.

[0091] The entering pole may bend the first cross member 15, causing the pole to enter deeper. The pole that has entered deeper applies a backward impact load to the second cross member 19. The second cross member 19, which has a backward impact load acting on it, tries to bend backward. At this time, since the reinforcing members 19A and 19B are provided behind the second cross member 19 and extend toward the front battery frame 32, the second cross member 19 is supported from behind by the reinforcing members 19A and 19B. As a result, the impact load is transmitted to and absorbed by the front battery frame 32, so that the deformation of the second cross member 19 is suppressed, and thus the penetration amount of the pole is reduced.

[0092] Since the rear portions of the reinforcing members 19A and 19B can be supported from behind by the frame brackets 40, the effect of suppressing the deformation of the second cross member 19, on which a backward impact load acts, can be further enhanced.

[0093] In addition, since the front portion of the front traveling motor M1 is positioned behind the front portion of the second cross member 19 in the vehicle rear direction, the entering pole hits the second cross member 19 before hitting the front traveling motor M1 at the time of collision. Thereby, the effect of suppressing the entry of the pole by the second cross member 19 and the reinforcing members 19A and 19B is sufficiently exerted.

[0094] Next, assume a left offset collision where an impact load is input, for example, from the front left diagonally. In this case, the impact load from the front left diagonally is input to and absorbed by the left crash can 72a and the left front main frame 72 via the front bumper reinforcement 87 of the upper structure 3. Also, the impact load from the front left diagonally is input to the left shock absorbing member 16 and the left front side frame 11 via the front member 18 of the lower structure 2.

[0095] At this time, the left front side frame 11 is positioned more to the left as it goes forward and extends so as to correspond to the input direction of the impact load. Therefore, the impact load from the front left diagonally is input so as to generally follow the axial direction of the left front side frame 11. As a result, the impact load is absorbed by the left front side frame 11. In addition, the impact load input to the left front side frame 11 is transmitted to the front battery frame 32 that constitutes the battery case 10, and thus is also absorbed by the front battery frame 32. In particular, since the front center member 26 and the first to third rear center members 27 to 29 are arranged behind the front battery frame 32 and are supported from the rear, the impact load can also be transmitted to and absorbed by the front center member 26 and the first to third rear center members 27 to 29. Furthermore, the impact load input to the front battery frame 32 can also be transmitted to and absorbed by the left battery frame 30 and the right battery frame 31. In this way, the impact load can be absorbed not only by the upper structure 3 but also by the lower structure 2, and in the lower structure 2, the impact load can be dispersed to each part of the high-strength battery case 10. Note that the same applies to the right offset collision.

[0096] The above-described embodiments are merely illustrative in every respect and should not be construed in a limiting sense. Furthermore, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

Industrial Applicability

[0097] As described above, the front body structure according to the present disclosure can be provided, for example, in an electric vehicle.

Explanation of Signs

[0098] 1 Electric vehicle 10 Battery case 11, 12 Front side frames 19 Second cross member 19A Left reinforcing member 19B Right reinforcing member 20 Front suspension device 32 Front battery frame 40 Frame bracket 41 Left support portion 42 Right support portion 70 Floor panel A Front body structure B Battery M1 Driving motor

Claims

1. In a front body structure of an electric vehicle equipped with a traveling motor and having a battery case that houses a battery for supplying power to the traveling motor disposed below a floor panel, a front battery frame provided at the front of the battery case and extending in the vehicle width direction, a pair of left and right side frames extending forward from the front battery frame, a cross member installed between a portion of the left side frame that is away from the front battery frame in the vehicle forward direction and a portion of the right side frame that is away from the front battery frame in the vehicle forward direction, a reinforcing member extending rearward from the cross member toward the front battery frame, and a frame bracket connecting the rear portions of the left and right side frames to the front battery frame, wherein the rear portion of the reinforcing member abuts against the frame bracket, and a suspension arm constituting a front suspension device is swingably supported on the outside in the vehicle width direction of the frame bracket. A front body structure.

2. In the front body structure according to Claim 1, the left and right side frames extend such that they are positioned more outward in the vehicle width direction as they go forward. A front body structure.

3. In the front body structure according to Claim 1 or 2, the reinforcing member includes a left reinforcing member and a right reinforcing member provided at intervals from each other in the vehicle width direction, and the left reinforcing member and the right reinforcing member are provided such that they are positioned more outward in the vehicle width direction as they go rearward. A front body structure.

4. In the front body structure according to any one of Claims 1 to 3, the front portion of the traveling motor is positioned rearward of the front portion of the cross member. A front body structure.

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