Vehicle battery pack mounting structure

Abstract

This invention provides a vehicle battery pack fixing structure that can improve vehicle body rigidity and handling stability by increasing the rigidity of the connection point between the battery pack and the rear side member. [Solution] The vehicle battery pack fixing structure 1 includes a vehicle body side bracket 12 fixed to a rear side member 4, and a battery side bracket 13 installed between the battery pack 3 and the vehicle body side bracket 12. The vehicle body side bracket 12 is fixed to the rear side member 4 adjacent to an arm support portion 7 that pivotably supports the trailing arm 61. The battery side bracket 13 is integrally formed with a vertical wall portion 13A fixed to the battery pack 3 side, a vehicle body side wall portion 13B extending outward in the vehicle width direction from the upper end portion of the vertical wall portion 13A and fixed to the vehicle body side bracket 12, and an arm support side wall portion 13C extending outward in the vehicle width direction from the lower end portion of the vertical wall portion 13A and fixed to the arm support portion 7.

Description

Technical Field

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[0001] The present invention relates to a fixing structure for a vehicle battery pack.

Background Art

[0002] Generally, a large battery pack for driving an electric vehicle is disposed below the floor panel of an electric vehicle such as an electric car. As an example of a structure for fixing this driving battery pack to the vehicle body side, a structure in which a rear end side portion of the battery pack is fixed to a vehicle body structural member such as a rear side member disposed at the rear of the electric vehicle via a bracket is known. For example, Patent Document 1 below discloses a structure in which a bracket located at the most rearward side of a plurality of brackets provided on both sides in the vehicle width direction of a driving battery pack is fixed to a rear side member via another bracket connected to the upper portion of the bracket.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in conventional fixing structures such as the one disclosed in Patent Document 1, the brackets connecting the battery pack and the rear side member are made up of a combination of plate-shaped members, which sometimes resulted in insufficient rigidity. Specifically, large and heavy drive battery packs are subjected to very large inertial forces in the longitudinal and lateral directions of the vehicle due to acceleration, deceleration, and turning during vehicle operation. These inertial forces act on the connection points between the battery pack and the rear side member, requiring high rigidity at these connection points. Furthermore, the trailing arms of the rear suspension system mounted on electric vehicles are fixed to the rear side member, and if deformation occurs at the connection points between the rear side member and the battery pack, reducing the rigidity of the vehicle body, it could negatively affect the handling stability of the electric vehicle, indicating room for improvement.

[0005] This invention was made in view of the above-mentioned points, and aims to provide a vehicle battery pack fixing structure that can improve vehicle body rigidity and handling stability by increasing the rigidity of the connection point between the battery pack and the rear side member. [Means for solving the problem]

[0006] To achieve the above objective, one aspect of the present invention provides a vehicle battery pack fixing structure for fixing a drive battery pack mounted below the floor panel of an electric vehicle to a rear side member located on the widthwise side of the rear of the electric vehicle and extending in the longitudinal direction of the vehicle. This vehicle battery pack fixing structure includes a vehicle body side bracket fixed to the rear side member, and a battery side bracket installed between a fixing portion provided on the rear end portion of the battery pack and the vehicle body side bracket. The vehicle body side bracket is fixed to the rear side member adjacent to an arm support portion that pivotably supports the trailing arm of a rear suspension device mounted on the electric vehicle and is fixed to the rear side member. The battery-side bracket has a vertical wall portion that extends in the vertical direction of the vehicle and is fixed to the fixing portion of the battery pack; a vehicle-side lateral wall portion that extends outward in the vehicle width direction from one end portion of the vertical wall portion in the vertical direction of the vehicle and is fixed to the vehicle-side bracket; and an arm-support side lateral wall portion that extends outward in the vehicle width direction from the other end portion of the vertical wall portion in the vertical direction of the vehicle and is fixed to the arm support portion, wherein the vertical wall portion, the vehicle-side lateral wall portion, and the arm-support side lateral wall portion are integrally formed. [Effects of the Invention]

[0007] According to one aspect of the present invention, a vehicle battery pack fixing structure can be used to improve vehicle body rigidity and handling stability by increasing the rigidity of the connection point between the battery pack and the rear side member. [Brief explanation of the drawing]

[0008] [Figure 1] This is a bottom view of the rear right side of an electric vehicle to which a vehicle battery pack fixing structure according to one embodiment of the present invention is applied, viewed from below the vehicle. [Figure 2] Figure 1 shows the rear suspension system removed, and this is a perspective view taken from the lower rear of the vehicle, with the area around the connection point between the battery pack and the rear side member magnified. [Figure 3] This is a cross-sectional rear view along line AA in Figure 2. [Figure 4] Figure 2 is a cross-sectional side view along line BB. [Figure 5] Figure 2 is a perspective view of the vehicle from the lower rear, obliquely, with the battery pack, extension member, battery-side bracket, and arm support-side bracket removed. [Figure 6] Figure 5 is a bottom view of the vehicle as seen from below. [Figure 7] This is a perspective view of the battery-side bracket, seen from the lower, rearward side of the vehicle. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Figure 1 is a bottom view of the rear right side of an electric vehicle EV to which a vehicle battery pack fixing structure 1 according to one embodiment of the present invention is applied, viewed from below the vehicle. Figure 2 is a perspective view taken from diagonally behind and below the vehicle, with the rear suspension device 6 removed from Figure 1, and the area around the connection point between the battery pack 3 and the rear side member 4 magnified. In the figures described below, the direction of arrow F indicates the front in the longitudinal direction of the vehicle, the direction of arrow U indicates the up in the vertical direction of the vehicle, and the directions of arrows R and L indicate the right and left when viewed from inside the vehicle towards the front.

[0010] In Figures 1 and 2, the vehicle battery pack fixing structure 1 of this embodiment is applied to a structure for fixing a drive battery pack 3, which is mounted below the floor panel 2 in an electric vehicle (EV), to a pair of left and right rear side members 4, which are located on both sides in the vehicle width direction at the rear underside of the EV. The left and right rear side members 4 extend generally in the longitudinal direction of the vehicle.

[0011] The floor panel 2 is a panel member whose rear portions on both sides in the vehicle width direction are joined to the left and right rear side members 4. The upper surface of the floor panel 2 forms the floor surface of the passenger compartment. Below the floor panel 2 of the vehicle, the battery pack 3 and the rear suspension system 6 are located.

[0012] Furthermore, the fixing structure of the battery pack 3 to the right rear side member 4 and the fixing structure of the battery pack 3 to the left rear side member 4 are symmetrical. For this reason, in the following explanation, the fixing structure of the battery pack 3 to the right rear side member 4 will be described in detail with reference to the drawings, while the fixing structure of the battery pack 3 to the left rear side member 4 will not be shown or described.

[0013] The battery pack 3 is a power supply device configured to supply power to a drive unit (not shown) including a drive motor mounted on an electric vehicle (EV). The battery pack 3 includes, for example, a main body 31, a fixing part 32, and an input / output port part 33.

[0014] The main body 31 has a number of batteries (battery modules) housed in a case. The main body 31 is formed in a box shape that extends in the vehicle's longitudinal and width directions and has the required width (height) in the vehicle's vertical direction. In this embodiment, a step is provided in the rear end portion 31A of the main body 31, where the side portion in the vehicle width direction is located slightly forward of the middle portion in the vehicle width direction.

[0015] The fixing portion 32 is a part for fixing the main body portion 31 to the vehicle body, and is fixed to the main body portion 31 by welding or the like, or is formed integrally with the main body portion 31. The fixing portion 32 extends toward the rear of the vehicle from the rear surface of the side portion in the vehicle width direction of the rear end portion 31A of the main body portion 31, and has a substantially rectangular cross-sectional shape. The extension length of the fixing portion 32 is about the same as or slightly longer than the step in the rear end portion of the main body portion 31. An extension member 11, which is a component of the vehicle battery pack fixing structure 1, is attached to the tip (rear end) portion of the fixing portion 32.

[0016] The input / output port section 33 is electrically connected to a number of batteries housed within the main body section 31. The input / output port section 33 is provided at a position slightly to the right in the vehicle width direction intermediate portion of the rear end side portion 31A of the main body section 31. A power supply junction box (not shown) or the like is attached to the input / output port section 33 from the rear side of the vehicle.

[0017] The rear side member 4 is disposed on the outer side in the vehicle width direction at the lower side of the rear part of the electric vehicle EV and extends in the vehicle longitudinal direction. The rear side member 4 is a member having a substantially hat-shaped cross-sectional shape that is open upward in the vehicle. At the upper part of the rear side member 4, the side portions in the vehicle width direction of the floor panel 2 are joined, and a closed cross-sectional structure is formed by the rear side member 4 and the floor panel 2.

[0018] On the outer side in the vehicle width direction at the front part of the rear side member 4, a side sill 51 extending in the vehicle longitudinal direction is overlapped and joined. The side sill 51 is disposed on the front side of the rear side member 4 and extends continuously rearward from a floor side member 52 (FIG. 2) extending in the vehicle longitudinal direction. Reinforcement members 53 are joined to the upper side and the inner side in the vehicle width direction at the overlapping portion of the rear side member 4, the side sill 51, and the floor side member 52. Further, at the inner side in the vehicle width direction of the reinforcement member 53, the end portion of a cross member 54 extending in the vehicle width direction is joined (FIGS. 1 and 2). The floor panel 2, the rear side member 4, the side sill 51, the floor side member 52, and the cross member 54 are each highly rigid members that constitute a part of the vehicle body structure member (vehicle body skeleton) and are formed of a metal material.

[0019] The rear side member 4 has an inclined portion 41 at the middle part in the front-rear direction. The inclined portion 41 extends obliquely upward and toward the center in the vehicle width direction as it goes toward the rear of the vehicle. According to the inclination in the vertical direction of the inclined portion 41, a step is formed between the floor surface on the front side and the floor surface on the rear side of the floor panel 2 joined to the upper part of the rear side member 4. Thereby, a space for arranging the rear suspension device 6 or the like is secured below the rear floor surface.

[0020] On the inclined portion 41 of the rear side member 4, a body side bracket 12 which is a component of the vehicle battery pack fixing structure 1 and an arm support portion 7 which swingably supports the trailing arm 61 (FIG. 1) of the rear suspension device 6 are fixed adjacent to each other. In the vehicle battery pack fixing structure 1, the body side bracket 12 is connected to the extension member 11 via the battery side bracket 13. Further, the extension member 11 is connected to the arm support portion 7 via the battery side bracket 13 and the arm support side bracket 14.

[0021] The rear suspension device 6 is a torsion beam type suspension device to which a rear tire (not shown) is attached. The rear suspension device 6 includes a pair of left and right trailing arms 61, a torsion beam 62, and the like. In FIG. 1, the right trailing arm 61 and the torsion beam 62 are shown, and the illustration of the left trailing arm 61 is omitted.

[0022] The trailing arm 61 is a metal member that extends generally in the longitudinal direction of the vehicle. When viewed from below the vehicle, the trailing arm 61 has a shape in which the middle section in the longitudinal direction is curved toward the center in the vehicle width direction relative to the front and rear sections. At the front end of the trailing arm 61, a cylindrical metal vehicle body-side connecting portion 63 is provided, which extends in a direction inclined by a required angle θ with respect to the vehicle width direction. A cylindrical rubber bushing is fitted inside the vehicle body-side connecting portion 63. A pin 64 supported by the arm support portion 7 is inserted into this bushing. As a result, the trailing arm 61 is connected to the vehicle body (rear side member 4) so ​​that it can swing vertically with the pin 64 as the pivot point. In other words, in this embodiment, the central axis of the pin 64 is the arm support axis a (dotted line in Figure 1).

[0023] The torsion beam 62 is a metal member that extends linearly in the vehicle width direction and applies torsional reaction force to each of the left and right rear tires. Both ends of the torsion beam 62 in the vehicle width direction are joined to the intermediate portions in the front-rear direction of the inner parts in the vehicle width direction of the left and right trailing arms 61. A spring support portion 65 that supports the lower end of a coil spring (not shown) is joined to the rear side of the joint portion with the torsion beam 62 on the inner part of the trailing arm 61 in the vehicle width direction. The upper end of the coil spring is connected to a vehicle body structural member.

[0024] Here, the vehicle battery pack fixing structure 1 (extension member 11, vehicle body side bracket 12, battery side bracket 13, and arm support side bracket 14) and the arm support portion 7 of this embodiment will be described in detail with reference to Figures 3 to 7.

[0025] Figure 3 is a cross-sectional rear view along line AA in Figure 2, and Figure 4 is a cross-sectional side view along line BB in Figure 2. Figure 5 is a perspective view of the vehicle from the lower rear with the battery pack 3, extension member 11, battery-side bracket 13, and arm support-side bracket 14 removed, and Figure 6 is a bottom view of the vehicle from below with the same configuration as in Figure 5. Furthermore, Figure 7 is a perspective view of the battery-side bracket 13 from the lower rear of the vehicle.

[0026] First, the extension member 11, the vehicle body side bracket 12, and the battery side bracket 13 of the vehicle battery pack fixing structure 1 will be described in detail. As shown in Figures 1 to 4, the extension member 11 is attached to the fixing portion 32 of the battery pack 3 and is formed in a block shape that extends from the rear end of the fixing portion 32 toward the rear of the vehicle. The extension member 11 in this embodiment has a rectangular prism shape that extends in the front-rear direction of the vehicle and is a solid, block-shaped metal member surrounded by six surfaces: front, rear, top, bottom, right, and left. By making the extension member 11 block-shaped, the rigidity of the extension member 11 is increased. However, the extension member 11 is not limited to a block shape and may be a plate-shaped metal member processed into the required shape.

[0027] The extension member 11 has two through holes 11A that extend from the front to the rear, spaced apart in the vertical direction (Figures 2 to 4). The fixing part 32 of the battery pack 3 has screw holes 32A (dotted lines in Figure 4) that correspond to each of the through holes 11A of the extension member 11. The extension member 11 is fixed to the battery pack 3 by inserting bolts or the like through each of the through holes 11A of the extension member 11 and tightening them into the screw holes 32A of the fixing part 32.

[0028] The right side of the extension member 11 is a flat outer surface 11B facing outward in the vehicle width direction in the fixing structure of the battery pack 3 to the right rear side member 4 as shown in the figure (Figure 1). The battery-side bracket 13 is joined to this outer surface 11B of the extension member 11. Two screw holes 11C for fixing the battery-side bracket 13 are formed on the outer surface 11B of the extension member 11, spaced apart in the vertical direction (dotted lines in Figures 3 and 4).

[0029] The vehicle body bracket 12 is a sheet metal processed member having a protruding portion 12A that projects toward the center in the vehicle width direction from the inclined portion 41 of the rear side member 4, and flange portions 12B that are fixed to the lower surface portion 41A and the side portion 41B toward the center in the vehicle width direction of the inclined portion 41 of the rear side member 4, respectively. (Figures 3 to 6).

[0030] The protruding portion 12A has a flat lower surface 12A1 facing downwards on the vehicle, a front surface 12A2 and a rear surface 12A3 extending upwards on the vehicle from the front and rear ends of the lower surface 12A1, and a side surface 12A4 extending upwards on the vehicle from the central end of the lower surface 12A1 in the vehicle width direction, connecting the front surface 12A2 and the rear surface 12A3 (Figures 5 and 6). The lower surface 12A1 of the protruding portion 12A extends with its outer end in the vehicle width direction inclined along the inclined portion 41 of the rear side member 4, and is formed in a substantially trapezoidal shape when viewed from below the vehicle. A screw receiving portion 12A5 for fixing the battery side bracket 13 is provided in the approximately central part of the lower surface 12A1 of the protruding portion 12A.

[0031] The flange portion 12B consists of an outer flange 12B1 that protrudes outward in the vehicle width direction from near the center of the outer end in the vehicle width direction of the lower surface 12A1 of the protruding portion 12A, a front flange 12B2 that protrudes toward the front of the vehicle from the outer end in the vehicle width direction of the front surface 12A2 of the protruding portion 12A, and a rear flange 12B3 that protrudes toward the rear of the vehicle from the outer end in the vehicle width direction of the rear surface 12A3 of the protruding portion 12A (Figures 5 and 6). A step is formed at the boundary between the lower surface 12A1 of the protruding portion 12A and the outer flange 12B1, so that the lower surface of the outer flange 12B1 is located slightly lower than the lower surface 12A1 of the protruding portion 12A. The outer flange 12B1 is fixed to the lower surface portion 41A of the inclined portion 41 of the rear side member 4 by welding or the like. Furthermore, the front flange 12B2 and the rear flange 12B3 are fixed to the side portion 41B on the vehicle width direction center side of the inclined portion 41 of the rear side member 4 by welding or the like.

[0032] As described above, the vehicle-side bracket 12 fixed to the inclined portion 41 of the rear side member 4 forms a tower-shaped structure that protrudes from the rear side member 4 toward the center in the vehicle width direction. The battery-side bracket 13 is installed between the lower surface 12A1 of this vehicle-side bracket 12 and the outer surface 11B of the extension member 11 attached to the fixing portion 32 of the battery pack 3, as described above, thereby fixing the battery pack 3 to the vehicle-side rear side member 4.

[0033] As shown in Figure 7, the battery-side bracket 13 is a metal member formed in a roughly U-shape, open to the outside in the vehicle width direction when viewed from the front-rear direction of the vehicle. The battery-side bracket 13 has a vertical wall portion 13A extending in the vehicle's vertical direction, a vehicle-side lateral wall portion 13B extending outward in the vehicle width direction from one end (upper end) of the vertical wall portion 13A in the vehicle's vertical direction, and an arm-support side lateral wall portion 13C extending outward in the vehicle width direction from the other end (lower end) of the vertical wall portion 13A in the vehicle's vertical direction. The vertical wall portion 13A, the vehicle-side lateral wall portion 13B, and the arm-support side lateral wall portion 13C of the battery-side bracket 13 are integrally formed.

[0034] The front and rear edges of the vertical wall portion 13A of the battery-side bracket 13 are bent outward in the vehicle width direction, the front and rear edges of the vehicle-side lateral wall portion 13B are bent downward towards the vehicle, and the front and rear edges of the arm-support side lateral wall portion 13C are bent upward towards the vehicle. In other words, the front and rear edges of the battery-side bracket 13 have flanges that protrude inward in a roughly U-shape. These flanges increase the rigidity of the battery-side bracket 13.

[0035] Specifically, the vertical wall portion 13A located on the vehicle width side of the battery-side bracket 13 has a roughly rectangular shape that is elongated in the front-to-back direction when viewed from the vehicle width side (Figures 4 and 7). The front-to-back width Wa of the vertical wall portion 13A is wider than the front-to-back width of the extension member 11 (Figure 4). Two through holes 13A1 that penetrate in the vehicle width direction are formed in the vertical wall portion 13A, spaced apart in the vertical direction (Figure 7). The battery-side bracket 13 is fixed to the extension member 11 by inserting bolts or the like through each through hole 13A1 of the vertical wall portion 13A and tightening them into the screw holes 11C on the outer surface 11B of the extension member 11.

[0036] The vehicle-side side wall portion 13B, located on the upper side of the vehicle of the battery-side bracket 13, has a front edge that extends outward in the vehicle width direction from the central end in the vehicle width direction, and a rear edge that extends inclined towards the rear of the vehicle as it moves outward in the vehicle width direction from the central end in the vehicle width direction (Figure 7). The vehicle-side side wall portion 13B has a roughly trapezoidal shape when viewed from above the vehicle. The front-rear width Wb of the vehicle-side side wall portion 13B in the vehicle width direction is slightly wider than the front-rear width Wa of the vertical wall portion 13A (Wb > Wa). The vehicle-side side wall portion 13B has one through hole 13B1 that penetrates in the vertical direction of the vehicle. The battery-side bracket 13 is fixed to the vehicle-side bracket 12 by inserting a bolt or the like through the through hole 13B1 of the vehicle-side side wall portion 13B and tightening it to the screw receiving portion 12A5 on the lower surface 12A1 of the vehicle-side bracket 12.

[0037] The arm support side wall portion 13C, located on the underside of the vehicle of the battery-side bracket 13, has a front edge that extends straight outward in the vehicle width direction from the central end in the vehicle width direction, and then curves towards the rear of the vehicle as it extends outward in the vehicle width direction (Figure 7). The rear edge portion of the arm support side wall portion 13C also extends inclined towards the rear of the vehicle as it extends outward in the vehicle width direction from the central end in the vehicle width direction. When viewed from below the vehicle, the width Wc of the outer portion in the vehicle width direction of the arm support side wall portion 13C is wider than the width Wa of the central portion in the vehicle width direction, i.e., the width Wa of the vertical wall portion 13A (Wc > Wa).

[0038] Two through-holes 13C1, extending through the vehicle in the vertical direction, are formed in the outer portion of the arm support side wall 13C in the vehicle width direction, with a gap of approximately the front-rear direction between them. In addition, an opening 13C2, extending through the vehicle in the vertical direction, is provided in the middle portion of the arm support side wall 13C in the vehicle width direction. Furthermore, a bead-shaped portion 13C3 is formed between the two through-holes 13C1 in the outer portion of the arm support side wall 13C in the vehicle width direction, projecting downwards towards the vehicle and extending approximately in the vehicle width direction. The bead-shaped portion 13C3 is formed to coincide with the extension of the arm support axis a in the arm support portion 7 (Figure 1).

[0039] Next, the arm support section 7 and the arm support side bracket 14 will be described in detail. As described above, the arm support portion 7 pivotably supports the trailing arm 61 of the rear suspension device 6. In this embodiment, the arm support portion 7, as shown in Figures 1 to 6, includes an outer bracket 71, an inner bracket 72, and a reinforcing bracket 73.

[0040] The outer bracket 71 of the arm support portion 7 has a roughly U-shape that opens towards the center in the vehicle width direction when viewed from below the vehicle and extends in the vertical direction of the vehicle. The inner bracket 72 has a roughly U-shape that opens outward in the vehicle width direction when viewed from below the vehicle and extends in the vertical direction of the vehicle. The center end of the outer bracket 71 in the vehicle width direction and the outer end of the inner bracket 72 in the vehicle width direction are joined to each other, and when viewed from below the vehicle, the outer bracket 71 and the inner bracket 72 form a cylindrical shape.

[0041] The outer bracket 71 and the inner bracket 72 are arranged in a roughly U-shaped space with a cross-section that is open to the lower part of the vehicle, formed between the outer side surface 41C in the vehicle width direction of the inclined portion 41 of the rear side member 4 and the inner side surface in the vehicle width direction of the rear of the side sill 51 (Figures 1 to 3). Inside the outer bracket 71 and the inner bracket 72, a space is formed that can accommodate the vehicle body side connecting portion 63 provided at the front end of the trailing arm 61.

[0042] The side wall portion 71A of the outer bracket 71, located on the outer side in the vehicle width direction, is joined to the inner surface of the side sill 51 (Figures 2 and 3). A bearing portion 71B is provided at the joint between the side wall portion 71A of the outer bracket 71 and the side sill 51 to support the outer end of the pin 64 (support shaft) of the trailing arm 61 (Figure 3). The upper end of the outer bracket 71 is joined to a stepped portion formed on the outer side surface portion 41C in the vehicle width direction of the inclined portion 41 of the rear side member 4.

[0043] The upper portion of the side wall 72A located on the vehicle width-direction center side of the inner bracket 72 is joined to the lower portion of the outer side surface 41C in the vehicle width direction of the inclined portion 41 of the rear side member 4 (Figure 3). The lower portion of the side wall 72A of the inner bracket 72 is joined to the outer surface in the vehicle width direction of the reinforcing bracket 73. A bearing portion 72B is provided at the joint between the side wall 72A of the inner bracket 72 and the reinforcing bracket 73 to support the inner end of the pin 64 (support shaft) of the trailing arm 61.

[0044] The reinforcing bracket 73 has a side wall portion 73A that extends generally in the front-rear direction along the side wall portion 72A of the inner bracket 72, and a front wall portion 73B that extends outward in the vehicle width direction from the front end portion of the side wall portion 73A (Figures 5 and 6). The side wall portion 73A is recessed outward in the vehicle width direction around the portion corresponding to the bearing portion 72B of the inner bracket 72. A lateral flange portion 73C is formed at the upper end portion of the side wall portion 73A, which is bent toward the center in the vehicle width direction and extends along the lower surface portion 41A of the inclined portion 41 of the rear side member 4. Furthermore, an upper flange portion 73D is formed at the rear portion of the lateral flange portion 73C, which protrudes toward the upper side of the vehicle. The lateral flange portion 73C is fixed to multiple locations on the lower surface portion 41A of the rear side member 4 by welding or the like, and the upper flange portion 73D is fixed to the side portion 41B on the center side in the vehicle width direction of the rear side member 4 by welding or the like.

[0045] The front wall portion 73B of the reinforcing bracket 73 has a front flange portion 73E formed at its tip (outer end in the vehicle width direction) that bends toward the front of the vehicle and extends along the inner surface of the side sill 51. The front flange portion 73E is fixed to multiple locations on the inner surface of the side sill 51 by welding or the like. The rigidity of the entire arm support portion 7 is increased by joining the inner bracket 72 to the reinforcing bracket 73 which is fixed to the lower surface portion 41A of the rear side member 4 and the inner surface of the side sill 51 in this way. The arm support side bracket 14 is joined to the inner surface in the vehicle width direction of the side wall portion 73A of the reinforcing bracket 73 (Figures 2 to 4).

[0046] The arm support bracket 14 has a lower wall portion 14A that protrudes toward the center in the vehicle width direction from the lower inner surface of the side wall portion 73A of the reinforcing bracket 73 of the arm support portion 7, and a side wall portion 14B that extends toward the upper side of the vehicle from the outer edge in the vehicle width direction of the lower wall portion 14A, and is formed in a substantially L shape when viewed from the rear of the vehicle (Figures 3 and 4). The front and rear edges of the lower wall portion 14A are bent toward the upper side of the vehicle, and the front and rear edges of the side wall portion 14B are bent toward the center in the vehicle width direction. In other words, the arm support bracket 14 has a shape in which a substantially U-shaped cross section is continuous along a substantially L shape. The lower wall portion 14A is provided with two screw receiving portions (not shown) that are spaced roughly apart in the front-rear direction for fixing the arm support side wall portion 13C of the battery side bracket 13. The battery-side bracket 13 is fixed to the arm-support-side bracket 14 by inserting bolts or the like through each through-hole 13C1 of the arm-support-side side wall portion 13C and tightening them to the screw-receiving portion of the arm-support-side bracket 14. The outer surface of the side wall portion 14B of the arm-support-side bracket 14 is fixed to the lower part of the inner surface of the side wall portion 73A of the reinforcing bracket 73 of the arm support portion 7 by welding or the like.

[0047] The vehicle battery pack fixing structure 1 of this embodiment (extension member 11, vehicle body side bracket 12, battery side bracket 13, and arm support side bracket 14) is fixed to the inclined portion 41 of the rear side member 4 adjacent to the arm support portion 7 which has high rigidity as described above.

[0048] Specifically, as shown by the dashed line in Figure 1, the extension member 11, the vehicle body side bracket 12, the battery side bracket 13, and the arm support side bracket 14 are arranged within a band-shaped region A1 formed by shifting the outer width of the arm support portion 7 in the vehicle's longitudinal direction parallel to the vehicle's width direction, when viewed from below the vehicle. In the example in Figure 1, the outer width of the arm support portion 7 in the vehicle's longitudinal direction is the width from the front end of the reinforcing bracket 73 to the rear end of the outer bracket 71.

[0049] In addition, in this embodiment, the extension member 11, the vehicle body side bracket 12, the battery side bracket 13, and the arm support side bracket 14 are arranged within a band-shaped region A2 formed by shifting the outer width of the arm support portion 7 in a direction perpendicular to the arm support axis a (central axis of the pin 64) in the direction of the arm support axis a, when viewed from below the vehicle. In the example of Figure 1, the outer width of the arm support portion 7 in a direction perpendicular to the arm support axis a is the width from the front end to the rear end of the reinforcing bracket 73. In particular, when viewed from below the vehicle, it is preferable that the bead-shaped portion 13C3 and opening 13C2 of the arm support side wall portion 13C of the battery side bracket 13, and the through hole 13B1 of the vehicle body side wall portion 13B are positioned at a location that coincides with the extension line of the arm support axis a.

[0050] Next, the effects and advantages of the vehicle battery pack fixing structure 1 of this embodiment will be described in detail. In the vehicle battery pack fixing structure 1 of this embodiment described above, the vehicle body bracket 12 is fixed to the rear side member 4 adjacent to the arm support portion 7 that pivotably supports the trailing arm 61 of the rear suspension device 6. The vertical wall portion 13A and the vehicle body side wall portion 13B of the battery side bracket 13 are installed between the fixing portion 32 of the battery pack 3 and the vehicle body bracket 12 via an extension member 11 extending from the fixing portion 32, and the vertical wall portion 13A and the arm support side wall portion 13C of the battery side bracket 13 are installed between the extension member 11 and the arm support portion 7 via an arm support side bracket 14 joined to the arm support portion 7, thereby fixing the battery pack 3 to the rear side member 4.

[0051] In this vehicle battery pack fixing structure 1, the area around the fixing point of the arm support portion 7 on the rear side member 4 has relatively high rigidity. Therefore, by fixing the vehicle body bracket 12 to the rear side member 4 adjacent to the arm support portion 7, the rigidity of the vehicle body bracket 12 is increased. In addition, the extension member 11 is provided on the fixing portion 32 of the battery pack 3, making it easier to adjust the positional relationship between the fixing portion 32, the vehicle body bracket 12, and the arm support portion 7. This makes it easy to accommodate cases where one of several types of battery packs with different external dimensions is envisioned for installation in electric vehicles (EVs). Furthermore, the extension member 11 provided on the fixing portion 32 of the battery pack 3 is connected to the two highly rigid members (vehicle body bracket 12 and arm support portion 7) fixed to the rear side member 4 by the battery side bracket 13 and the arm support side bracket 14, respectively, so that the connection point between the rear side member 4 and the battery pack 3 has high rigidity. The battery-side bracket 13 forming the connection point has a roughly U-shaped form in which the vertical wall portion 13A, the vehicle body-side horizontal wall portion 13B, and the arm support-side horizontal wall portion 13C are integrally formed, and the rigidity of the battery-side bracket 13 itself is also increased. As a result, deformation of the connection point between the rear side member 4 and the battery pack 3 is suppressed, making it possible to improve vehicle body rigidity and handling stability.

[0052] Furthermore, in the vehicle battery pack fixing structure 1 of this embodiment, when viewed from below the vehicle, the width Wc of the outer portion in the vehicle width direction of the arm support side wall portion 13C of the battery side bracket 13 is wider than the width Wa of the central portion in the vehicle width direction. With such a battery side bracket 13, the load acting on the arm support side side wall portion 13C of the battery side bracket 13 via the arm support portion 7 and the arm support side bracket 14 from the rear suspension device 6 when the vehicle is running is prevented from concentrating at the joint between the arm support side side wall portion 13C and the arm support side bracket 14, thereby suppressing deformation of the battery side bracket 13. As a result, the connection point between the rear side member 4 and the battery pack 3 becomes less prone to deformation, making it possible to further improve vehicle body rigidity and handling stability.

[0053] Furthermore, in the vehicle battery pack fixing structure 1 of this embodiment, the vehicle body side bracket 12 has a protruding portion 12A that protrudes from the rear side member 4 toward the center in the vehicle width direction, and a flange portion 12B that is fixed to the lower surface portion 41A and the side portion 41B toward the center in the vehicle width direction of the rear side member 4, respectively. The vehicle body side wall portion 13B of the battery side bracket 13 is joined to the flat lower surface 12A1 of the protruding portion 12A of the vehicle body side bracket 12 that faces downwards towards the vehicle. With such a structure, the rigidity of the vehicle body side bracket 12 against forces in the vehicle width direction acting on the vehicle body side bracket 12 due to turning during vehicle driving can be increased. As a result, the connection point between the rear side member 4 and the battery pack 3 becomes less prone to deformation, making it possible to further improve vehicle body rigidity and handling stability.

[0054] In addition, in the vehicle battery pack fixing structure 1 of this embodiment, the vehicle body side bracket 12, the battery side bracket 13, the extension member 11, and the arm support side bracket 14 are arranged in a strip-shaped region A1 formed by shifting the outer width of the arm support portion 7 in the vehicle longitudinal direction parallel to the vehicle width direction when viewed from below the vehicle, and are also arranged in a strip-shaped region A2 formed by shifting the outer width of the arm support portion 7 in the direction perpendicular to the arm support axis a parallel to the arm support axis a direction. With this arrangement, the loss (transmission loss) that occurs when the force in the vehicle width direction input to the rear side member 4 via the trailing arm 61 and the arm support portion 7 due to turning during vehicle driving is transmitted to the connection point between the rear side member 4 and the battery pack 3 is reduced, so that the force can be distributed efficiently. As a result, the strength and rigidity of the connection point between the rear side member 4 and the battery pack 3 are improved and deformation can be effectively suppressed, so that the vehicle body rigidity and handling stability can be further improved.

[0055] Furthermore, in the vehicle battery pack fixing structure 1 of this embodiment, the battery-side bracket 13 has a bead-shaped portion 13C3 formed on the outer portion in the vehicle width direction of the arm support side wall portion 13C, and the bead-shaped portion 13C3 is formed to overlap with the extension line of the arm support axis a when viewed from below the vehicle. With such a battery-side bracket 13, the strength and rigidity of the joint between the arm support side bracket 14 and the battery-side bracket 13 can be further improved with respect to the direction of force input from the arm support portion 7 to the battery-side bracket 13 via the arm support side bracket 14.

[0056] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications and changes are possible based on the technical concept of the present invention.

[0057] For example, in the embodiment described above, an example was described in which the battery-side bracket 13 is fixed to the fixing portion 32 of the battery pack 3 via the extension member 11 and also fixed to the arm support portion 7 via the arm support-side bracket 14. However, the extension member 11 and / or the arm support-side bracket 14 can be omitted depending on the relative positional relationship between the rear side member 4 and the battery pack 3.

[0058] Furthermore, in the embodiment described above, an example was explained in which the width Wc of the outer portion in the vehicle width direction of the arm support side wall portion 13C of the battery side bracket 13 is wider than the width Wa of the central portion in the vehicle width direction. However, the shape of the arm support side side wall portion 13C is not limited to the above example, and may be a shape that extends from the arm support side to the battery side with a certain width. The shape of the arm support side side wall portion 13C can be appropriately designed according to the positional relationship between the extension member 11 (or the fixing portion 32 of the battery pack 3) and the arm support side bracket 14 (or the arm support portion 7).

[0059] Furthermore, in the embodiment described above, an example was shown in which the vehicle body-side bracket 12 forms a tower-shaped structure that protrudes from the rear side member 4 toward the center in the vehicle width direction. However, the shape of the vehicle body-side bracket 12 is not limited to the above example, and it can be any shape that can connect the rear side member 4 and the extension member 11 (or the fixing part 32 of the battery pack 3) via the battery-side bracket 13.

[0060] In addition, although the above-described embodiment shows an example in which the vehicle body bracket 12 and the arm support portion 7 are fixed to the inclined portion 41 of the rear side member 4, it is also possible to fix the vehicle body bracket 12 and the arm support portion 7 to a part of the rear side member 4 other than the inclined portion 41. [Explanation of symbols]

[0061] 1… Vehicle battery pack fixing structure 11…Extension member 11A...Through hole 11B…External surface 11C... screw hole 12…Body-side bracket 12A…Protrusion 12A1…Bottom surface 12A2…Front 12A3…Rear side 12A4…Side 12B...Flange section 12B1…Outer flange 12B2…Front flange 12B3…Rear flange 13…Battery side bracket 13A…Vertical wall part 13A1, 13B1, 13C1...Through hole 13B... Side wall section of the vehicle body 13C... Side wall section on the arm support side 13C2…Aperture 13C3...Bead shape section 14…Arm support bracket 14A…Lower wall part 14B…Side wall part 2…Floor panel 3…Battery pack 31...Main body 31A…Rear end side part 32…Fixed part 32A... Screw hole 33…Input / Output Port Section 4…Rear side member 41…Slope part 41A…Bottom part 41B... Side section on the center side in the vehicle width direction 41C...Outer side section in the vehicle width direction 51... Side sill 52... Floor side member 53…Reinforcement member 54…Crossmember 6…Rear suspension system 61... Trailing arm 62... Torsion beam 63...Body-side coupling section 64... pins 65... Spring support part 7... Arm support section 71…Outer bracket 71A…Side wall part 71B...Bearing section 72…Inner bracket 72A…Side wall part 72B...Bearing section 73…Reinforcement bracket 73A…Side wall part 73B…Front wall part 73C... Side flange section 73D... Upper flange section 73E... Front flange section a...arm support shaft A1... A strip-shaped area in the vehicle width direction A2...Strip-shaped region in the direction of the arm support axis EV…Electric Vehicle Wa, Wb, Wc... Width of the battery-side bracket

Claims

1. A vehicle battery pack fixing structure for fixing a drive battery pack mounted below the floor panel of an electric vehicle to a rear side member that is located on the side in the width direction of the rear of the electric vehicle and extends in the longitudinal direction of the vehicle, A vehicle body bracket fixed to the aforementioned rear side member, The battery-side bracket is installed between the fixing portion provided on the rear end portion of the battery pack and the vehicle body-side bracket, The vehicle body bracket is fixed to the rear side member adjacent to the arm support portion fixed to the rear side member, and swingably supports the trailing arm of the rear suspension device mounted on the electric vehicle. The aforementioned battery-side bracket is A vertical wall portion extending in the vertical direction of the vehicle and fixed to the fixing portion of the battery pack, A vehicle-side lateral wall portion extends outward in the vehicle width direction from one end portion in the vehicle vertical direction of the aforementioned vertical wall portion and is fixed to the vehicle-side bracket, The vertical wall portion has an arm support side lateral wall portion that extends outward in the vehicle width direction from the other end portion in the vehicle vertical direction and is fixed to the arm support portion, A vehicle battery pack fixing structure characterized in that the vertical wall portion, the vehicle body side side wall portion, and the arm support side side wall portion are integrally formed.

2. An extension member extending from the fixing portion of the battery pack toward the rear of the vehicle, The present invention further includes an arm support bracket that is joined to the arm support portion and protrudes toward the center in the vehicle width direction, The vehicle battery pack fixing structure according to claim 1, characterized in that the battery-side bracket has its vertical wall portion fixed to the fixing portion of the battery pack via the extension member, and its arm-support side horizontal wall portion fixed to the arm support portion via the arm-support side bracket.

3. The vehicle battery pack fixing structure according to claim 1, characterized in that the side wall portion of the arm support side of the battery-side bracket has a width that is wider on the outer side in the vehicle width direction than on the central side in the vehicle width direction when viewed from below the vehicle.

4. The aforementioned vehicle body side bracket is A protruding portion that extends from the rear side member toward the center in the vehicle width direction, The rear side member has flange portions that are fixed to the lower surface and the side surface on the center side in the vehicle width direction, respectively. The vehicle battery pack fixing structure according to claim 1, characterized in that the vehicle body side wall portion of the battery side bracket is joined to the flat lower surface of the protruding portion facing downward on the vehicle.

5. The vehicle battery pack fixing structure according to claim 1, characterized in that the vehicle body side bracket and the battery side bracket are arranged in a strip-shaped region formed by moving the outer width of the arm support portion in the vehicle's longitudinal direction parallel to the vehicle's width direction when viewed from below the vehicle.

6. The vehicle battery pack fixing structure according to claim 1, characterized in that the vehicle body side bracket and the battery side bracket are arranged in a strip-shaped region formed by moving the outer width of the arm support portion in a direction perpendicular to the arm support axis in parallel with the arm support axis direction when viewed from below the vehicle.

7. The battery-side bracket has a bead-shaped portion formed on the outer side portion in the vehicle width direction of the arm support side wall, The vehicle battery pack fixing structure according to claim 6, characterized in that the bead-shaped portion is formed to overlap with the extension line of the arm support shaft when viewed from below the vehicle.

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