JP6965812B2 - Battery pack - Google Patents

Description

The present invention relates to a battery pack mounted under the floor of a vehicle, and particularly to a protective structure in a side collision.

Among vehicles equipped with an electric motor as a prime mover for driving a vehicle, there is known a vehicle in which a battery pack containing a battery for supplying electric power to the electric motor is mounted under the floor. The following Patent Document 1 shows a battery (battery 10) mounted under the floor of a vehicle. The battery (10) is arranged in a space partitioned by frames (16, 17, 18, 19, 20) and members (5, 6, 7, 8, 9) arranged in a grid pattern. By surrounding the battery (10) with a frame or the like, the battery (10) is protected in the event of a side collision. The member names and codes in parentheses are the codes used in Patent Document 1 below, and are not related to the member names and codes used in the description of the embodiments of the present application.

Japanese Unexamined Patent Publication No. 6-219336

The grid-shaped frames and members may increase the weight, and the space for mounting the battery may be narrowed.

An object of the present invention is to provide a battery pack having a protective structure having a simple and lightweight structure.

The battery pack mounted under the floor of the vehicle according to the present invention is fixed to a battery pack case for accommodating a battery stack, a pair of fixed bases extending in the front-rear direction on the left and right sides of the bottom of the battery pack case, and a fixed base. A pair of stack support brackets that support the left and right sides of the battery stack, a support beam that extends horizontally below the battery pack case and is coupled to the vehicle floor skeleton structure at both ends, and the battery pack case. A pair of L-shaped outer brackets joined to the upper surface of the support beam on the outer side in the left-right direction and joined to the outer surface of the side wall of the battery pack case, and the inner surface of the side wall of the battery pack case to which the outer bracket is joined. It has a pair of L-shaped inner brackets that are joined to face the outer bracket and are joined to the fixed base.

By joining the outer bracket and the inner bracket facing each other via the side wall of the battery pack case, the collision load input to the support beam at the time of a side collision is efficiently transmitted to the battery pack, and the battery pack is moved to the opposite side of the collision. be able to.

It is a perspective view which looked at the lower body structure of a vehicle from below, and is the figure which shows the state which the battery pack is separated from the floor. It is an external view of a battery pack. It is a figure which shows the inside of the battery pack with the case cover removed. It is a figure which shows the structure inside the battery pack, especially the bottom surface with the case cover and the battery stack removed. It is a figure which shows the battery stack alone. It is a figure which shows the fixed base on the left side by itself. It is a figure which shows the structure of the end of the support beam and the battery pack around it in the state which was seen from the outside in the width direction of a vehicle. It is a figure which shows the structure of the end of the support beam and the battery pack around it in the state which was seen from the inside in the width direction of a vehicle. It is a figure which shows the outer bracket by itself. It is a figure which shows the inner bracket by itself. It is sectional drawing which shows the structure of the battery pack at the end of a support beam and around it.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a lower body structure 10 of a vehicle. In the figure, the direction of the arrow FR indicates the front of the vehicle, the direction of the arrow UP indicates the upper side of the vehicle, and the direction of the arrow LH indicates the left side of the vehicle. In the following description, unless otherwise specified, the terms indicating the direction and direction such as front-back, left-right, up-down, etc. indicate the direction with respect to the vehicle.

Under the floor 12 of the lower body structure 10, a battery pack 14 for storing electric power to be supplied to a vehicle driving motor is mounted. In FIG. 1, the lower body structure 10 is shown with the battery pack 14 separated from the floor 12. The battery pack 14 includes a pack body 16 containing a battery and a grid-like support frame 18 arranged on the lower surface of the pack body 16. The pack body 16 has a thick vertical dimension in a portion corresponding to the lower part of the rear seat of the vehicle and a thin portion in the front portion thereof. The support frame 18 has a plurality of support beams 20 extending in the left-right direction, and the end portion of the support beam 20 projects laterally from the pack body 16. At this projecting portion, the support beam 22 is suspended from the floor 12. It is supported down. Further, the support frame 18 is suspended and supported on the floor 12 by the suspension bracket 24 on the rear end surface 18a.

A pair of underlay insertions 26 and 28 extending in the front-rear direction are provided at the left and right edge portions under the floor 12. Further, a cross member 30 extending to the left and right is provided so as to connect the underlay insertions 26 and 28. The hanging bolts 22 are fastened to the underlay insertions 26 and 28, and the hanging bracket 24 is connected to the cross member 30, so that the battery pack 14 is mounted under the floor 12.

The underlay insertions 26, 28 and the cross member 30 are floor skeleton structural materials that are responsible for the strength and rigidity of the floor 12. The floor skeleton structural material also includes rockers provided on the left and right edge edges of the floor 12, and the battery pack 14 may be suspended and supported from other floor skeleton structural materials such as rockers.

2 to 4 are views showing the battery pack 14, FIG. 2 is an external view, and FIGS. 3 and 4 are views showing the inside. The battery pack 14 has a battery pack case 34 that houses the battery stack 32. The battery pack case 34 has a case cover 36 located on the upper side and a case tray 38 located on the lower side. The case cover 36 and the case tray 38 are made of, for example, steel plates. By joining the flanges provided around the case cover 36 and the case tray 38 with bolts and nuts, for example, the case cover 36 and the case tray 38 are integrated, and the battery pack case defines a sealed internal space. 34 is formed.

The grid-shaped support frame 18 is arranged below the battery pack case 34 and is joined to the case tray 38 by a method such as welding. The support beam 20, which is a member extending laterally of the support frame 18, projects from the side of the battery pack case 34, and a hanging bolt 22 is arranged at the extending end portion.

FIG. 3 is a diagram showing a state in which the case cover 36 is removed, and shows the battery stack 32 housed in the battery pack case 34. The battery stack 32 has a rectangular parallelepiped shape or a sideways prismatic shape, and a plurality of battery stacks 32 extend in the left-right direction and are housed in the battery pack case 34. The battery pack 14 has 11 battery stacks 32, and the battery stacks 32 are stacked in two stages at the rear of the battery pack 14. One battery stack 32 is shown in FIG. The battery stack 32 is configured by stacking a plurality of battery cells 40 in the longitudinal direction of the battery stack 32. Stack support brackets 42 for fixing the battery stack 32 to the battery pack case 34 are coupled to the left and right side surfaces of the battery stack 32. The stack support bracket 42 can be made of steel plate and has a substantially L-shape.

FIG. 4 is a view in which the case cover 36 and the battery stack 32 are removed so that the bottom surface of the case tray 38 can be seen. A pair of fixed bases 44, 46 extending in the front-rear direction are arranged on the left and right edge portions of the bottom surface of the case tray 38. FIG. 6 shows a fixed base 44 located on the left side. The fixed base 46 on the right side has a symmetrical shape with the fixed base 44 on the left side. The fixed bases 44 and 46 can be made of steel plate and are joined to the bottom surface of the case tray 38 by a method such as welding. The stack support bracket 42 is joined to the upper surfaces of the fixed bases 44 and 46 by a method such as welding. The stack support bracket 42 is connected to the battery stack 32 by bolts or the like on the surface corresponding to the L-shaped vertical image, and is joined to the fixed bases 44 and 46 on the surface corresponding to the L-shaped horizontal image.

7 and 8 are views showing the left end of the support beam 20 and the pack body 16 around it, showing the case cover 36 removed and the case tray 38 translucent. The right end of the support beam 20 is symmetrical with the left end.

An outer bracket 48 is arranged on the upper surface of the support beam 20 located outside the case tray 38 in the left-right direction. The outer bracket 48 is shown alone in FIG. The outer bracket 48 has a substantially L-shape, and is joined to the outer surface of the side wall 38a of the case tray 38 at a portion 48a corresponding to the L-shaped vertical image (hereinafter, referred to as a vertical image portion 48a), and is L-shaped. It is joined to the upper surface of the support beam 20 at the portion 48b corresponding to the horizontal image (hereinafter, referred to as the horizontal image portion 48b). The outer bracket 48 can be made of steel plate and can be joined to the case tray 38 and the support beam 20 by a method such as welding.

The cross-sectional shapes of the support beam 20 and the outer bracket 48 are hat-shaped, joined at the edges on both sides of the hat-shaped, and spaced in the central portion. A circular tube-shaped spacer 50 extending upward from the support beam 20 so as to penetrate the hole 48c formed in the top surface of the outer bracket 48 is arranged. The hanging bolt 22 penetrates the internal space of the circular tube-shaped spacer 50. The spacer 50 determines the height of the support beam 20 and the vertical mounting position of the battery pack 14 when the hanging bolts 22 are fastened to the underlay insertions 26 and 28.

An inner bracket 54 is arranged above the support beam 20 and inside the case tray 38. The inner bracket 54 is shown alone in FIG. The inner bracket 54 has a substantially L-shape, and in a portion 54a corresponding to the L-shaped vertical image (hereinafter, referred to as a vertical image portion 54a), the inner surface of the side wall 38a of the case tray 38, particularly the outer bracket. It is joined to the portion where the vertical image portion 48a of the above is joined. Further, the inner bracket 54 is joined to the case tray 38 and the fixed base 44 at the portion 54b corresponding to the L-shaped horizontal image (hereinafter, referred to as the horizontal image portion 54b).

11A and 11B are views showing a cross section orthogonal to the right end of the support beam 20 and its surroundings in the front-rear direction, where FIG. 11A shows a state before a side collision and FIG. 11B shows a deformed state after a collision. .. The case cover 36 is omitted. The vertical image portion 48a of the outer bracket and the vertical image portion 54a of the inner bracket face each other with the side wall 38a of the case tray 38 interposed therebetween, and are joined to the outer surface and the inner surface, respectively.

At the time of a side collision, the vehicle body, for example, the rockers 56 arranged on the left and right sides of the floor, project outward from the support beam 20, so that the collision load F is first received from the collision object 58 and is displaced inward. Along with this displacement, the collision load is transmitted through the suspension bolt 22 and the spacer 50 to bend and deform the support beam 20. The above-mentioned structure in which the L-shaped outer bracket 48 and the inner bracket 54 are arranged so as to face each other is a structure that resists the above-mentioned bending deformation, suppresses bending of the support beam 20, and supports the collision load F by the support beam 20. Acts as a force to move. As a result, the battery stack 32 can be released to the side opposite to the collision object 58 that has entered. Further, the inner bracket 54 is connected to the stack support bracket 42 via the fixed base 44, and the force acting on the inner bracket 54 is transmitted through the stack support bracket 42 to the battery stack 32 to release the battery stack 32. Acts like. As a result, it is possible to secure a distance from the vehicle body structure that is deformed and approaches the battery stack 32, and it is possible to suppress damage to the battery stack 32.

In the above-described embodiment, the outer bracket 48 and the inner bracket 54 are arranged to face each other in one support beam 20, but this structure may be adopted in a plurality of support beams 20.

10 Lower body structure, 12 floors, 14 battery pack, 16 pack body, 18 support frame, 18a rear end face (of support frame), 20 support beam, 22 hanging bolts, 24 hanging brackets, 26, 28 underlaying hosement , 30 cross member, 32 battery stack, 34 battery pack case, 36 case cover, 38 case tray, 38a side wall (of case tray), 40 battery cell, 42 stack support bracket, 44,46 fixed base, 48 outer bracket, 48a Vertical image part (of outer bracket), 50 spacer, 54 inner bracket, 54a Vertical image part (of inner bracket), 56 rocker, 58 Collision object.

Claims (1)

A battery pack mounted under the floor of the vehicle
A battery pack case that houses the battery stack and
A pair of fixed bases extending in the front-rear direction from the left and right of the bottom of the battery pack case,
A pair of stack support brackets that are fixed to the fixed base and support the left and right sides of the battery stack, respectively.
A support beam that extends horizontally below the battery pack case and is coupled to the floor skeleton structural material of the vehicle at both ends.
A pair of L-shaped outer brackets joined to the upper surface of the support beam on the lateral side of the battery pack case and joined to the outer surface of the side wall of the battery pack case.
A pair of L-shaped inner brackets joined to the inner surface of the side wall of the battery pack case to which the outer brackets are joined so as to face the outer brackets and joined to the fixed base.
Battery pack with.

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