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 fixes the drive battery pack 3 mounted on an electric vehicle (EV) to the rear side member 4. This fixing structure includes a vehicle body side bracket 12 fixed to the rear side member 4, and a battery side bracket 13 installed between the fixing portion 32 of 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 of the rear suspension device 6, and a reinforcing bracket 14 is installed between the fixing portion 32 of the battery pack 3 and the arm support portion 7.

Description

Technical Field

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

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 via a bracket to a vehicle body structural member such as a rear side member disposed at the rear of the electric vehicle is known. For example, Patent Document 1 below discloses a structure in which a bracket located at the most rearward side in the vehicle width direction of a plurality of brackets provided on both sides 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, and a reinforcing bracket is installed between the fixing portion and the arm support portion of the battery pack. [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, reinforcing 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, taken from the lower right side of the vehicle. [Figure 8] This is a bottom view of the reinforcing bracket, seen from below 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 driving motor mounted on an electric vehicle EV. The battery pack 3 includes, for example, a main body portion 31, a fixing portion 32, and an input / output port portion 33.

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

[0015] The fixing portion 32 is a portion for fixing the main body portion 31 to the vehicle body side, and is fixed to the main body portion 31 by welding or the like, or is integrally formed with the main body portion 31. The fixing portion 32 extends rearward of the vehicle from the rear surface of the side portion in the vehicle width direction of the rear end side 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 approximately the same as the step of the rear end side portion of the main body portion 31 or slightly longer than the step. 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 portion 33 is electrically connected to a number of batteries housed in the main body portion 31. The input / output port portion 33 is provided at a position slightly to the right of the middle portion in the vehicle width direction of the rear end side portion 31A of the main body portion 31. A power supply junction box (not shown) or the like is attached to the input / output port portion 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 rear portion of the electric vehicle EV and extends in the vehicle front-rear direction. The rear side member 4 is a member having a substantially hat-shaped cross-sectional shape that is open upward of the vehicle. The side portion in the vehicle width direction of the floor panel 2 is joined to the upper portion of the rear side member 4, 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 arranged on the front side of the rear side member 4 and continuously extends rearward from a floor side member 52 (FIG. 2) extending in the vehicle longitudinal direction. At the upper side and the inner side in the vehicle width direction of the overlapping part of the rear side member 4, the side sill 51, and the floor side member 52, a reinforcing member 53 is joined. Further, at the inner side in the vehicle width direction of the reinforcing member 53, an 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 a highly rigid member constituting a part of a 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 front floor surface and the rear floor surface on the floor panel 2 joined to the upper part of the rear side member 4, in front of the inclined portion 41. Thereby, a space for arranging the rear suspension device 6 and the like is secured below the rear floor surface.

[0020] On the inclined portion 41 of the rear side member 4, a vehicle 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 a 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 vehicle body side bracket 12 is connected to an extension member 11 via a battery side bracket 13. Further, the extension member 11 is connected to the arm support portion 7 via a reinforcing bracket 14 and an arm support side bracket 15.

[0021] The rear suspension system 6 is a torsion beam type suspension system to which the rear tires (not shown) are attached. The rear suspension system 6 includes a pair of left and right trailing arms 61 and a torsion beam 62, etc. Note that Figure 1 shows the right trailing arm 61 and torsion beam 62, and the left trailing arm 61 is not shown.

[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, reinforcing bracket 14, and arm support side bracket 15) and the arm support portion 7 of this embodiment will be described in detail with reference to Figures 3 to 8.

[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, reinforcing bracket 14, and arm support-side bracket 15 removed, and Figure 6 is a bottom view of the vehicle from below, showing the state in Figure 5. Furthermore, Figure 7 is a perspective view of the battery-side bracket 13 from the lower right, and Figure 8 is a bottom view of the reinforcing bracket 14 from below, showing the state in Figure 5.

[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). In addition, two screw holes 11D for fixing the reinforcing bracket 14 are formed on the lower surface of the extension member 11, spaced apart in the vehicle's front-rear 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 into an L-shape when viewed from the front-rear direction of the vehicle. The battery-side bracket 13 has a vertical wall portion 13A that extends in the vertical direction of the vehicle, and a horizontal wall portion 13B that extends outward in the vehicle width direction from the upper end portion of the vertical wall portion 13A. The battery-side bracket 13 has a predetermined width in the vehicle front-rear direction, with the front and rear ends of the vertical wall portion 13A bent outward in the vehicle width direction, and the front and rear ends of the horizontal wall portion 13B bent downward towards the vehicle. In other words, the battery-side bracket 13 has a shape in which a substantially U-shaped cross section is continuous along the L-shape.

[0034] The vertical wall portion 13A of the battery-side bracket 13 has two through holes 13C that penetrate in the vehicle width direction and are spaced apart in the vertical direction. The battery-side bracket 13 is fixed to the extension member 11 by inserting bolts or the like through each through hole 13C of the vertical wall portion 13A of the battery-side bracket 13 and tightening them into the screw holes 11C of the outer surface 11B of the extension member 11.

[0035] The battery-side bracket 13 has a through-hole 13D formed in the center of its side wall portion 13B, which extends through the vehicle in the vertical direction. The battery-side bracket 13 is fixed to the vehicle-side bracket 12 by inserting a bolt or the like through the through-hole 13D in the side wall portion 13B of the battery-side bracket 13 and tightening it to the screw receiving portion 12A5 on the lower surface 12A1 of the vehicle-side bracket 12.

[0036] Next, the arm support section 7, as well as the arm support side bracket 15 and the reinforcing 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 an inner reinforcing bracket 73.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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 inner reinforcing bracket 73. A bearing portion 72B is provided at the joint between the side wall 72A of the inner bracket 72 and the inner reinforcing bracket 73 to support the inner end of the pin 64 (support shaft) of the trailing arm 61.

[0041] The inner 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.

[0042] The front wall portion 73B of the inner 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 inner 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 15 is joined to the inner surface in the vehicle width direction of the side wall portion 73A of the inner reinforcing bracket 73 (Figures 2 to 4).

[0043] The arm support bracket 15 has a lower wall portion 15A that protrudes toward the center in the vehicle width direction from the lower inner surface of the side wall portion 73A of the inner reinforcing bracket 73 of the arm support portion 7, and a side wall portion 15B that extends toward the upper side of the vehicle from the outer edge of the lower wall portion 15A in the vehicle width direction, 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 15A are bent toward the upper side of the vehicle, and the front and rear edges of the side wall portion 15B are bent toward the center in the vehicle width direction. In other words, the arm support bracket 15 has a shape in which a substantially U-shaped cross section is continuous along a substantially L shape. Two screw receiving portions (not shown) for fixing the reinforcing bracket 14 are provided on the lower wall portion 15A, spaced roughly apart in the front-rear direction. The outer surface of the side wall portion 15B is fixed by welding or the like to the lower inner surface of the side wall portion 73A of the inner reinforcing bracket 73 of the arm support portion 7.

[0044] The reinforcing bracket 14 is a metal member that extends generally in the vehicle width direction from the lower surface of the lower wall portion 15A of the arm support bracket 15 toward the lower surface of the extension member 11 (Figures 1 to 4). In this embodiment, the height of the lower surface of the lower wall portion 15A of the arm support bracket 15 is roughly the same as the height of the lower surface of the extension member 11, and the extension member 11 is located further forward of the vehicle than the arm support bracket 15. Corresponding to this positional relationship between the extension member 11 and the arm support bracket 15, the reinforcing bracket 14 extends while curving toward the front of the vehicle as it moves from the arm support side (outer side in the vehicle width direction) toward the battery side (center side in the vehicle width direction).

[0045] Specifically, as shown in Figure 8, the reinforcing bracket 14 in this embodiment is divided into a side portion 14A located on the arm support side (outer side in the vehicle width direction), a side portion 14B located on the battery side (center side in the vehicle width direction), and an intermediate portion 14C connecting the respective side portions 14A and 14B in the extension direction of the reinforcing bracket 14 (direction along the dashed line Lo in Figure 8).

[0046] The side portion 14A on the arm support side extends in a direction inclined forward by an angle θ (the inclination angle of the arm support axis a of the trailing arm 61) with respect to the vehicle width direction. The side portion 14A on the arm support side has a width Wa in a direction perpendicular to its extension direction (along the dashed line La in Figure 8). Two arm support mounting portions 14D are provided on the side portion 14A on the arm support side, spaced apart in this perpendicular direction. Each arm support mounting portion 14D is a hole that penetrates vertically, and the reinforcing bracket 14 is attached to the arm support bracket 15 by inserting a bolt or the like through each and tightening it to the screw receiving portion of the lower wall portion 15A of the arm support bracket 15. At this time, the mounting pitch Pa of the side portion 14A on the arm support side corresponds to the distance between each arm support mounting portion 14D.

[0047] The battery-side portion 14B extends in the vehicle width direction and has a width Wb in a direction perpendicular to its extension direction (along the dashed line Lb in Figure 8). Two battery-side mounting portions 14E are provided on the battery-side portion 14B, spaced apart in this perpendicular direction. Each battery-side mounting portion 14E is a hole that penetrates vertically, and the reinforcing bracket 14 is attached to the extension member 11 by inserting a bolt or the like through each and tightening it into the screw hole 11D on the lower surface of the extension member 11. At this time, the mounting pitch Pb of the battery-side portion 14B corresponds to the distance between each battery-side mounting portion 14E.

[0048] The intermediate section 14C extends in a curved manner such that the inclined extension direction of the arm support side section 14A gradually approaches the extension direction (vehicle width direction) of the battery side section 14B. The width of the intermediate section 14C in the direction perpendicular to the curved extension direction gradually narrows from Wa to Wb as it moves from the arm support side towards the battery side. An elongated oval opening 14F, which is long in the vehicle width direction, is formed in the intermediate section 14C. When viewed from below the vehicle, the intermediate section 14C is positioned to overlap the fixing position between the vehicle body side bracket 12 and the battery side bracket 13 (Figures 1 and 2). In other words, when the reinforcing bracket 14 is viewed from below the vehicle, the intermediate section 14C of the reinforcing bracket 14 is positioned so that the fastening point between the through hole 13D of the battery side bracket 13 and the screw receiving portion 12A5 of the vehicle body side bracket 12 is visible through the opening 14F of the intermediate section 14C.

[0049] A slight vertical step 14G is provided near the boundary between the arm-supporting side portion 14A and the intermediate portion 14C of the reinforcing bracket 14 (Figures 2-4 and 8). This step 14G adjusts the height difference between the lower surface of the lower wall portion 15A of the arm-supporting bracket 15 and the lower surface of the extension member 11. In addition, the front and rear edges of the reinforcing bracket 14 are bent toward the underside of the vehicle, respectively. In other words, the reinforcing bracket 14 has a shape in which a roughly U-shaped cross-section is continuous along the extension direction.

[0050] The shape of the reinforcing bracket 14, which has the arm support side portion 14A, the battery side portion 14B, and the intermediate portion 14C as described above, is designed such that the width Wa of the arm support side portion 14A is wider than the width Wb of the battery side portion 14B (Wa > Wb). In addition, the arrangement of each arm support side mounting portion 14D and each battery side mounting portion 14E in the reinforcing bracket 14 is designed such that the mounting pitch Pa of the arm support side portion 14A is longer than the mounting pitch Pb of the battery side portion 14B (Pa > Pb).

[0051] The vehicle battery pack fixing structure 1 of this embodiment (extension member 11, vehicle body side bracket 12, battery side bracket 13, reinforcing bracket 14, and arm support side bracket 15) 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.

[0052] 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, the reinforcing bracket 14, and the arm support side bracket 15 are arranged within a band-shaped region A1 formed by translating 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 inner reinforcing bracket 73 to the rear end of the outer bracket 71.

[0053] In addition, in this embodiment, the extension member 11, the vehicle body side bracket 12, the battery side bracket 13, the reinforcing bracket 14, and the arm support side bracket 15 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 inner reinforcing bracket 73. In particular, it is preferable that the fixing points of the vehicle body side bracket 12 and the battery side bracket 13 (the screw receiving portion 12A5 of the vehicle body side bracket 12 and the through hole 13D of the battery side bracket 13), as well as the intermediate portion 14C of the reinforcing bracket 14, are positioned at locations that coincide with the extension line of the arm support axis a when viewed from below the vehicle.

[0054] 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. A battery-side bracket 13 is 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 a reinforcing bracket 14 is installed between the extension member 11 and the arm support portion 7 via an arm support-side bracket 15 joined to the arm support portion 7, thereby fixing the battery pack 3 to the rear side member 4.

[0055] In this vehicle battery pack fixing structure 1, the area around the fixing portion 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, since the extension member 11 is provided on the fixing portion 32 of the battery pack 3, it becomes 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 to be installed in electric vehicles (EVs). Furthermore, the extension member 11 provided on the fixing portion 32 of the battery pack 3 is connected to two highly rigid members (vehicle body side bracket 12 and arm support portion 7) fixed to the rear side member 4 by the battery side bracket 13, the reinforcing bracket 14, and the arm support side bracket 15, respectively. As a result, the connection point between the rear side member 4 and the battery pack 3 becomes highly rigid, and deformation is suppressed, thereby improving vehicle body rigidity and handling stability.

[0056] Furthermore, in the vehicle battery pack fixing structure 1 of this embodiment, the reinforcing bracket 14 extends from the arm support side bracket 15 joined to the arm support portion 7 toward the extension member 11 provided on the fixing portion 32 of the battery pack 3. Multiple arm support side mounting portions 14D are provided on the arm support side portion 14A in the direction of extension, and multiple battery side mounting portions 14E are provided on the battery side portion 14B. When viewed from below the vehicle, the width Wa of the arm support side portion 14A of the reinforcing bracket 14 is wider than the width Wb of the battery side portion 14B, and the mounting pitch Pa of the arm support side portion 14A is longer than the mounting pitch Pb of the battery side portion 14B.

[0057] With such a reinforcing bracket 14, the load acting on the reinforcing bracket 14 from the rear suspension device 6 via the arm support portion 7 and the arm support side bracket 15 during vehicle operation is prevented from concentrating on each arm support side mounting portion 14D provided on the side portion 14A of the arm support side, thereby suppressing deformation of the reinforcing bracket 14. 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 the rigidity of the vehicle body and handling stability.

[0058] Furthermore, in the vehicle battery pack fixing structure 1 of this embodiment, the intermediate portion 14C of the reinforcing bracket 14 is positioned to overlap the fixing position between the vehicle body side bracket 12 and the battery side bracket 13 when viewed from below the vehicle. With this arrangement, the fixing position between the arm support side portion 14A of the reinforcing bracket 14 and the arm support side bracket 15, the fixing position between the battery side portion 14B of the reinforcing bracket 14 and the extension member 11, and the fixing position between the vehicle body side bracket 12 and the battery side bracket 13 form a triangle that is distributed in the vertical and vehicle width directions. As a result, the force acting on the connection point between the rear side member 4 and the battery pack 3 is less likely to concentrate at a specific point. This makes it possible to further suppress deformation of the connection point and to further improve vehicle body rigidity and handling stability.

[0059] In addition, 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 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 even less susceptible to deformation, making it possible to further improve vehicle body rigidity and handling stability.

[0060] Furthermore, in the vehicle battery pack fixing structure 1 of this embodiment, the extension member 11, the vehicle body side bracket 12, the battery side bracket 13, the reinforcing bracket 14, and the arm support side bracket 15 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 that is 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.

[0061] 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.

[0062] For example, in the embodiment described above, the battery-side bracket 13 is fixed to the fixing portion 32 of the battery pack 3 via the extension member 11, and the reinforcing bracket 14 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 15. However, the extension member 11 and / or the arm support-side bracket 15 can be omitted depending on the relative positional relationship between the rear side member 4 and the battery pack 3.

[0063] Furthermore, in the above-described embodiment, an example was explained in which the width Wa of the side portion 14A on the arm support side of the reinforcing bracket 14 is wider than the width Wb of the side portion 14B on the battery side, and the mounting pitch Pa on the side portion 14A on the arm support side is longer than the mounting pitch Pb on the side portion 14B on the battery side. However, the shape of the reinforcing bracket 14 is not limited to the above example, and may be a strip-shaped plate extending from the arm support side to the battery side with a certain width. The shape and mounting pitch of the reinforcing bracket 14 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 15 (or the arm support portion 7).

[0064] Furthermore, in the embodiment described above, an example was shown in which the vehicle body-side bracket 12 forms a tower-shaped structure protruding from the rear side member 4 toward the center in the vehicle width direction, and the battery-side bracket 13 is formed in an L-shape. However, the shapes of the vehicle body-side bracket 12 and the battery-side bracket 13 are not limited to the above example, and 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).

[0065] 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]

[0066] 1… Vehicle battery pack fixing structure 11…Extension member 11A...Through hole 11B…External surface 11C, 11D… screw holes 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 13B…Side wall part 13C,13D…Through hole 14…Reinforcement bracket 14A... Side of the arm support 14B...Battery side 14C…middle part 14D... Mounting part on the arm support side 14E...Battery side mounting part 14F…Opening 14G... step 15…Arm support bracket 15A…Lower wall part 15B…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…Inner 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 Pa, Pb... Mounting pitch of reinforcing brackets Wa, Wb…Width of the reinforcing 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. A vehicle battery pack fixing structure characterized in that a reinforcing bracket is installed between the fixing portion and the arm support portion of the battery pack.

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 battery-side bracket is fixed to the fixing portion of the battery pack via the extension member. The vehicle battery pack fixing structure according to claim 1, characterized in that the reinforcing bracket is fixed to the fixing portion of the battery pack via the extension member and also fixed to the arm support portion via the arm support side bracket.

3. The reinforcing bracket extends from the arm support portion (7) toward the fixing portion (32) of the battery pack (3), and a plurality of arm support side mounting portions are provided on the arm support side in the extension direction at intervals in an orthogonal direction perpendicular to the extension direction, and a plurality of battery side mounting portions are provided on the battery side in the extension direction at intervals in the orthogonal direction, and in a view from below the vehicle, the width in the orthogonal direction on the arm support side is wider than the width in the orthogonal direction on the battery side, and the mounting pitch on the arm support side is longer than the mounting pitch on the battery side, characterized in that the vehicle battery pack fixing structure according to claim 1.

4. The vehicle battery pack fixing structure according to claim 1, characterized in that, when viewed from below the vehicle, the intermediate portion in the extension direction of the reinforcing bracket is positioned to overlap the fixing position between the vehicle body side bracket and the battery side bracket.

5. 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 battery-side bracket is joined to the flat lower surface of the protruding portion facing downwards on the vehicle.

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

7. The vehicle battery pack fixing structure according to claim 1, characterized in that the vehicle body side bracket, the battery side bracket, and the reinforcing 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.

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