JP5614544B2 - Body structure of electric vehicle - Google Patents

Description

  The present invention relates to a vehicle body structure of an electric vehicle, and more particularly to a mounting structure for a trailing arm constituting a rear suspension.

  For example, some electric vehicles such as an electric vehicle and a hybrid vehicle have a battery unit including a plurality of drive batteries for supplying electric power to a traveling motor attached below the floor. Since the battery unit is relatively heavy, the mounting position of the battery unit affects the steering stability of the electric vehicle. For example, when the battery unit is mounted on the rear side of the electric vehicle, the electric vehicle is likely to be oversteered.

  By the way, various vehicles such as an electric vehicle include a trailing arm type suspension having a pair of trailing arms. The leading end side of the trailing arm is connected to a vehicle body frame such as a side member via a trailing arm bracket. And in order to improve the steering stability of an electric vehicle, it is preferable that the connection part of a side member and a trailing arm has high rigidity. Therefore, generally, the leading end side of the trailing arm is connected to a trailing arm bracket (joint bracket) fixed to the side member by welding or the like (see, for example, Patent Document 1).

JP 2007-137322 A

  In such a configuration, the rigidity of the connecting portion between the trailing arm and the side member can be increased. That is, since the mounting position of the trailing arm with respect to the trailing arm bracket is close to the side member, the rigidity of this portion is relatively high. Thereby, although it is possible to improve the steering stability according to the mounting position of the battery unit, it cannot be said that it is sufficient, and further improvement of the steering stability is desired.

  For example, the influence on the steering stability of the battery unit mounting position as described above can be suppressed to some extent by the arrangement of the trailing arm. Specifically, the steering stability of the electric vehicle can be improved by placing the trailing arm close to the horizontal.

  However, when the arrangement of the trailing arm is changed in this way, the rigidity of the connecting portion between the trailing arm and the side member is lowered, and the steering stability may not be sufficiently improved.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle body structure for an electric vehicle capable of improving steering stability by using a trailing arm as a desired arrangement.

According to a first aspect of the present invention, a battery unit including a driving battery is fixed to a vehicle body frame including a pair of side members extending in the front-rear direction of the vehicle, and one end of a trailing arm can swing. The side member has a protruding portion that protrudes downward from the lower surface of the side member, and the battery unit is provided on an inner surface of the protruding portion that faces inward in the vehicle width direction. And one end of the trailing arm is detachably connected to a bottom surface of the protruding portion and below the fixing portion between the battery unit and the protruding portion. It is in the vehicle body structure.
According to a second aspect of the present invention, the battery unit is fixed to an inner side surface of the projecting portion facing inward in the vehicle width direction through a battery bracket to reinforce the projecting portion, and is a bottom surface of the projecting portion. One end of the trailing arm is detachably connected to a position below the battery bracket. The vehicle body structure for an electric vehicle according to the first aspect is characterized in that:

In the first or second aspect, the protrusion is provided, so that the attachment position on the leading end side of the trailing arm is a relatively low position. Therefore, the trailing arm can be arranged in a state close to the horizontal. In addition, a relatively large load is input to the protruding portion in the left-right direction (lateral direction) of the electric vehicle, but the battery unit is fixed to the side surface (lateral end surface) of the protruding portion, and the rigidity of the protruding portion is compared. Therefore, the projecting portion is not greatly deformed.

According to a third aspect of the present invention, there is provided a vehicle body structure for an electric vehicle according to the first or second aspect, wherein the protruding portion and one end of the trailing arm are connected by a connecting member.

In the third aspect, it is possible to finely adjust the attachment position on the leading end side of the trailing arm.

A fourth aspect of the present invention, the protrusions and the side member from the first, characterized in that it is constituted by the reinforcing member which is welded integrally fixed to the lower surface of the side member separately 3 The vehicle body structure of the electric vehicle according to any one of the aspects.

In the fourth aspect, the projecting portion is formed of a reinforcing member that is separate from the side member, so that the trailing arm is arranged in a substantially horizontal state without significantly changing the structure of the side member. can do.

  As described above, in the present invention, the trailing arm can be arranged in a substantially horizontal state, and the rigidity of the protruding portion is enhanced by the battery unit. Therefore, it is possible to improve the handling stability or riding comfort of the electric vehicle.

It is a figure showing a schematic structure of an electric vehicle concerning one embodiment. It is a top view which shows the attachment state of the battery unit which concerns on one Embodiment. It is a figure showing a schematic structure of a rear suspension concerning one embodiment. It is a side view which shows the attachment state of the trailing arm which concerns on one Embodiment. It is sectional drawing which shows the connection part of the trailing arm which concerns on one Embodiment, and a vehicle body frame.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, for example, an electric vehicle 10 that is an electric vehicle includes a vehicle body frame 20 that forms a skeleton below a vehicle body 11 and a battery unit 30 fixed to the vehicle body frame 20 under a floor (vehicle compartment). In preparation.

  The body frame 20 includes a pair of side members 21 extending in the front-rear direction of the electric vehicle 10 and a plurality of (three in the present embodiment) extending in the left-right direction (vehicle width direction) of the electric vehicle 10. The cross member 22 is provided. Each cross member 22 is fixed to a predetermined position of the side member 21 by welding.

  As shown in FIGS. 1 and 2, the battery unit 30 is detachably fixed to the vehicle body frame 20 having such a configuration from below. Since the structure of the battery unit 30 is a known one, it will be briefly described here.

  The battery unit 30 includes a battery case 31. The battery case 31 houses a plurality of driving batteries for supplying electric power to a traveling motor (not shown) mounted on the electric vehicle 10. The battery case 31 includes, for example, a tray member 32 positioned on the lower side and a cover member 33 positioned on the upper side.

  The cover member 33 is made of, for example, an integrally molded product of synthetic resin reinforced with fibers. On the other hand, the tray member 32 is, for example, a molded product in which a reinforcing metal plate is inserted into an integrally molded synthetic resin. ) Girder member 34 (34A, 34B, 34C, 34D). A pair of left and right front support members 35 (35A, 35B) are provided at the front end of the tray member 32. In addition, the plurality of beam members 34 and the front support member 35 may be provided independently of each other, but are continuous on the lower surface side of the tray member 32 in the present embodiment. Thereby, the battery unit 30 has relatively high rigidity.

  The battery unit 30 is fixed to the vehicle body frame 20 by the girder member 34 and the front support member 35. That is, each girder member 34 of the battery unit 30 is fixed to the side member 21 of the vehicle body frame 20, and the front support member 35 is fixed to the cross member 22.

  Here, among the girder members 34A to 34D, the girder members 34A to 34C on the front side of the vehicle are fixed to the bottom surface side of the side member 21, but the girder member 34D located at the rearmost side will be described in detail later. Further, the side member 21 is fixed to the inner side surface of the projecting portion 40 that projects from the bottom surface side.

  Incidentally, the front wheel 50 (see FIG. 1) of the electric vehicle 10 is supported on the vehicle body 11 by a front suspension (not shown). The rear wheel 51 is supported on the vehicle body 11 by a trailing rear suspension 60 as shown in FIG. The rear suspension 60 is provided with a suspension spring 62, a shock absorber 63, a lateral rod 64, and the like between the vehicle body 11 and the rear axle 61. The lateral rod 64 has one end connected to the vehicle body and the other end connected to the rear axle 61.

  The pair of trailing arms 65 (65A, 65B) extending in the front-rear direction of the vehicle 10 is also connected at the front end (one end side) to the vehicle body side and at the rear end (the other end side) to the rear axle 61. ing. Hereinafter, the structure of the connecting portion 100 (see FIG. 2) between the trailing arm 65 and the vehicle body frame 20 will be described. As shown in FIGS. 4 and 5, a protruding portion 40 that protrudes downward is provided at a predetermined position corresponding to the connecting portion 100 of the side member 21. The trailing arms 65 </ b> A and 65 </ b> B are connected to the bottom surface side of the protruding portion 40 via a connecting member (fitting member) 45 so as to be rotatable in the vertical direction. In this embodiment, the protrusion part 40 is comprised by welding the bulkhead 41 which is a reinforcement member inside. That is, the bulkhead 41 which is a separate body from the side member 21 is integrally fixed by welding or the like. Although the structure of this bulkhead 41 is not specifically limited, For example, it has the 1st member 42 which comprises the inner wall side of the protrusion part 40, and the 2nd member 43 which comprises the outer wall side.

  As described above, the girder member 34 </ b> D of the battery unit is fixed to the inner surface of the protruding portion 40. That is, the girder member 34 </ b> D is fixed to the first member 42 constituting the bulkhead 41 via the battery bracket 70. Although the structure of the battery bracket 70 is not particularly limited, in the present embodiment, the battery bracket 70 includes a contact member 71 that contacts the beam member 34D and a covering member 72 that is provided so as to cover the contact member 71.

  The fitting member 45 is detachably fixed to the bottom surface side of the bulkhead 41 that constitutes the protruding portion 40 by a fastening member 46 such as a bolt. The outfitting member 45 is open downward and defines an insertion groove 47 into which each trailing arm 65 is inserted. The leading end side of each trailing arm 65 is supported in the insertion groove 47 of the mounting member 45 so as to be vertically rotatable by a bolt or the like.

  As described above, the leading end side of each trailing arm 65 is connected to the side member 21 constituting the vehicle body frame 20 via the fitting member 45 functioning as a trailing arm bracket and the bulkhead 41. Thereby, compared with the case where the trailing arm 65 is attached to the side member 21 itself, the attachment position to the vehicle body frame 20 on the front end side of the trailing arm 65 can be lowered. Therefore, the trailing arm 65 can be arranged in a state close to horizontal, and the steering stability of the electric vehicle 10 is improved. For example, if the battery unit 30 is arranged behind the electric vehicle 10, the electric vehicle 10 tends to be oversteered, but the trailing arms 65A and 65B are arranged substantially horizontally, so that the electric vehicle 10 The tendency of oversteering is suppressed and steering stability is improved.

  Further, when the electric vehicle 10 travels on a curve, the trailing arm 65 may be swung in the substantially left-right direction of the electric vehicle 10 by a centrifugal force acting on the vehicle body 11 (indicated by an arrow in FIG. 3). ). At that time, a large lateral load is also input to the protrusion 40 protruding downward from the bottom surface of the side member 21. Even in such a case, the girder member 34D of the battery unit 30 is fixed to the side surface of the bulkhead 41 constituting the protrusion 40, and the rigidity of the protrusion 40 in the lateral direction is significantly increased. The deformation of 40 is greatly suppressed. Therefore, the handling stability and riding comfort of the vehicle 10 can be improved.

  Furthermore, in the configuration of the present embodiment, since the outfitting member 45 is detachably attached to the bulkhead 41, the arrangement of the trailing arm 65 can be adjusted. Thereby, the arrangement of the trailing arm 65 can be adjusted according to the state of the vehicle 10, and the riding comfort of the vehicle 10 can always be maintained satisfactorily. Further, such a mounting structure of the trailing arm 65 can be adopted for a plurality of vehicle types, and the arrangement of the trailing arm 65 can be changed according to the vehicle type. Therefore, the manufacturing cost can be reduced.

  In the above-described embodiment, the protruding portion 40 is configured by the bulkhead 41 that is a separate body from the side member 21. Of course, the protruding portion 40 may be formed integrally with the side member 21. Good. In the above-described embodiment, the rearmost girder member 34D is fixed to the protruding portion 40. Of course, other girder members 34A to 34C may be fixed.

  As mentioned above, although one Embodiment of this invention was described, Of course, this invention is not limited to such Embodiment. The present invention can be modified as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Electric vehicle 11 Car body 20 Body frame 21 Side member 22 Cross member 30 Battery unit 31 Battery case 32 Tray member 33 Cover member 34 Girder member 35 Front side support member 40 Protruding part 41 Bulkhead 42 1st member 43 2nd member 45 Connecting member (fitting member)
46 Fastening member 47 Insertion groove 50 Front wheel 51 Rear wheel 60 Rear suspension 61 Rear axle 62 Suspension spring 63 Lateral rod 64 Shock absorber 65 Trailing arm 70 Battery bracket 71 Contact member 72 Cover member 100 Connecting portion

Claims (4)

A vehicle body structure for an electric vehicle in which a battery unit including a driving battery is fixed to a vehicle body frame including a pair of side members extending in the front-rear direction of the vehicle, and one end of a trailing arm is swingably connected. Because
The side member has a protruding portion that protrudes downward from the lower surface of the side member,
The battery unit is fixed to an inner side surface of the protruding portion facing inward in the vehicle width direction, and the trailing is provided at a bottom surface of the protruding portion and below the fixing portion between the battery unit and the protruding portion. A vehicle body structure for an electric vehicle, wherein one end of an arm is detachably connected.   The battery unit is fixed to the inner side surface of the projecting portion facing inward in the vehicle width direction via a battery bracket to reinforce the projecting portion, and the bottom surface of the projecting portion is positioned below the battery bracket. One end of the trailing arm is detachably connected
The vehicle body structure of an electric vehicle according to claim 1. Body structure for an electric vehicle according to claim 1 or 2 and one end of said projecting portion and the trailing arm, characterized in that it is connected by a connecting member. The protrusion according to any one of claims 1-3 and the side member, characterized in that it is constituted by the reinforcing member which is welded integrally fixed to the lower surface of the side member separately Body structure of an electric vehicle.

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