Receiving structure for battery cell stack

Abstract

The invention provides a storage structure for a battery cell laminate, which can reduce the load of each part along with the size change of the battery cell laminate. A storage structure for a battery cell stack is provided with: a battery cell stack having a plurality of battery cells stacked in a stacking direction; a lower case accommodating the battery cell stack; a pair of brackets fixed to both sides of the battery cell stack in the stacking direction, respectively; and a pair of holder engagement parts disposed on both sides in the stacking direction with respect to the pair of holders, respectively, and fixed to the lower case. The pair of holder engagement parts is provided with a pair of holder engagement part-side contact surfaces which are set so as to face each other in the stacking direction and which have an interval in the stacking direction that widens toward the side opposite the lower case, and which are in contact with the pair of holders, each of the holder engagement parts being in contact with the pair of holder engagement part-side contact surfaces.

Description

Technical Field

[0001] This invention relates to a housing structure for a battery cell stack. Background Technology

[0002] Patent Document 1 discloses a battery storage module mounted in a vehicle. In this battery storage module, a pair of constraint straps extending along the side of a battery pack are connected to a pair of end plates. The constraint straps have a flat surface, a first bend extending from both ends of the flat surface in the short side direction and in a direction close to each other, and a wide second bend. The first bends are connected to an intermediate plate disposed near the center of the battery pack in the stacking direction. In this structure, the constraint straps are fixed to the intermediate plate near the center in the stacking direction, thus increasing rigidity in the cross direction of the stacking direction. Therefore, by using thin-walled and lightweight constraint straps, multiple stacked batteries can be reliably constrained, and deformation of the constraint straps can be suppressed.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-122572 Summary of the Invention

[0004] However, it is believed that in battery cell stacks, such as battery packs, dimensional changes occur due to variations in the charging rate of each battery cell constituting the stack. Therefore, it is desirable to obtain a battery cell stack housing structure that can reduce the load on each part accompanying the dimensional changes of the battery cell stack.

[0005] In view of the above facts, the present invention aims to obtain a housing structure for a battery cell stack that can reduce the load on each part that is accompanied by dimensional changes in the battery cell stack.

[0006] The battery cell stack housing structure of the first embodiment includes: a battery cell stack having a plurality of battery cells stacked along a stacking direction; a housing for housing the battery cell stack; a pair of brackets respectively fixed to both sides of the battery cell stack in the stacking direction; and a pair of bracket engaging portions respectively disposed on both sides of the pair of brackets in the stacking direction and fixed to the housing. The pair of bracket engaging portions has a pair of bracket engaging portion side contact surfaces, which are configured to face each other in the stacking direction and the spacing in the stacking direction widens as it faces the side opposite to the housing. The pair of brackets respectively contact the brackets. When the dimension of the battery cell stack changes in the stacking direction, the pair of brackets slides against the pair of bracket engaging portion side contact surfaces, and the battery cell stack can be displaced toward the housing side or the side opposite to the housing.

[0007] In the battery cell stack housing structure of the first embodiment, a pair of brackets are respectively fixed to both sides of the battery cell stack in the stacking direction. Furthermore, a pair of bracket engaging portions are fixed to the housing, and these engaging portions are respectively disposed on both sides of the stacking direction relative to the pair of brackets fixed to the battery cell stack. Moreover, when the pair of brackets fixed to the battery cell stack are in contact with the pair of bracket engaging portion side contact surfaces of the pair of bracket engaging portions, the pair of brackets engage with the pair of bracket engaging portions. Furthermore, when the dimensions of the battery cell stack in the stacking direction change, the pair of brackets fixed to the battery cell stack slides against the pair of bracket engaging portion side contact surfaces of the pair of bracket engaging portions, and the battery cell stack shifts towards the housing side or the side opposite to the housing. Here, the spacing in the stacking direction of the pair of bracket engaging portion side contact surfaces is set to widen towards the side opposite to the housing. In this structure, the engaging position of the pair of bracket engaging portions of the pair of brackets can be changed according to the dimensional changes of the battery cell stack in the stacking direction. Therefore, the load on each part accompanying the dimensional changes of the battery cell stack can be reduced.

[0008] In the second embodiment of the battery cell stack housing structure, in the first embodiment of the battery cell stack housing structure, a pair of brackets have a pair of bracket-side contact surfaces, the pair of bracket-side contact surfaces are configured to contact the pair of bracket engagement-side contact surfaces respectively, and the spacing in the stacking direction widens as it faces the side opposite to the housing.

[0009] In the second embodiment of the battery cell stack housing structure, when a pair of brackets are engaged with a pair of bracket engaging portions, the bracket-side contact surfaces of the pair of brackets contact with the bracket engaging portion-side contact surfaces of the pair of bracket engaging portions. Here, the spacing in the stacking direction of the pair of bracket-side contact surfaces of the pair of brackets is set to widen towards the side opposite to the housing. In this way, by aligning the spacing in the stacking direction of the pair of bracket-side contact surfaces of the pair of brackets with the spacing in the stacking direction of the bracket engaging portion-side contact surfaces of the pair of bracket engaging portions, smooth sliding between the two is possible.

[0010] Invention Effects

[0011] The battery cell stack housing structure of the present invention has the excellent effect of reducing the load on each part that is accompanied by changes in the size of the battery cell stack. Attached Figure Description

[0012] Figure 1 This is a schematic side view of the battery module, etc., according to the first embodiment.

[0013] Figure 2 Is with Figure 1 The corresponding side view indicates relative to Figure 1The state shown is the expanded state of the battery cell stack.

[0014] Figure 3 This is a three-dimensional view of the front support and the front support engagement part, viewed from the left diagonal rear side.

[0015] Figure 4 This is a three-dimensional view of the front support and the front support engagement part, viewed from the right diagonal front side.

[0016] Figure 5 This is a schematic side view of the battery module, etc., according to the second embodiment. Detailed Implementation

[0017] use Figures 1-4 The following describes a battery module 10, which incorporates the battery cell stack-accommodating structure according to the first embodiment of the present invention. In the figures, arrow FR indicates the front side of the vehicle, arrow UP indicates the upper side of the vehicle, arrow LH indicates the left side in the vehicle width direction (left-right direction), and arrow RH indicates the right side in the vehicle width direction (left-right direction). Furthermore, in the following description, unless otherwise specified, "front-back," "up-down," and "left-right" directions refer to "front-back" in the vehicle's front-back direction, "up-down" in the vehicle's up-down direction, and "left-right" in the vehicle's left-right direction.

[0018] like Figure 1 and Figure 2 As shown, the battery module 10 of this embodiment includes: a battery cell stack 14 having a plurality of battery cells 12; a lower housing 16 serving as a housing for accommodating the battery cell stack 14, etc.; and a pair of brackets 18 and a pair of bracket engaging portions 20 supporting the battery cell stack 14 on both sides in the front-rear direction relative to the battery cell stack 14.

[0019] The battery cell 12 is, for example, an all-solid-state battery formed in a rectangular block shape. A plurality of battery cells 12 are configured into a battery cell stack 14 by means of junction lines defined in a stacked state along a front-back direction that is the stacking direction.

[0020] The lower housing 16 is disposed on the lower side relative to the battery cell stack 14. A receiving recess 16A is formed in the lower housing 16, recessed downwards. The lower portion of the battery cell stack 14 is disposed within this receiving recess 16A.

[0021] like Figure 1 , Figure 3 and Figure 4As shown, a pair of brackets 18 are fixed to both sides of the battery cell stack 14 in the front-rear direction. Furthermore, the pair of brackets 18 are symmetrical in the front-rear direction. Therefore, in the following description, the structure of the front bracket 18 will sometimes be described, while the description of the structure of the rear bracket 18 will be omitted. Also, the corresponding parts of the rear bracket 18 will be marked with the same symbols as the corresponding parts of the front bracket 18.

[0022] The bracket 18 is formed as a triangular prism with its left and right sides forming right-angled triangles. The rear of the bracket 18 is formed as a planar surface extending in both vertical and horizontal directions, serving as a fixing surface 18A to the front side of the battery cell stack 14. Furthermore, the upper surface of the bracket 18 is formed as a planar surface extending in both front-rear and horizontal directions. Moreover, the front surface of the bracket 18 is formed as a planar surface extending in both vertical and horizontal directions, and forms a bracket-side contact surface 18B that slopes from the upper side towards the lower side and then towards the rear. And, as... Figure 1 As shown, when viewed from the side of the vehicle, the distance A1 in the front-rear direction between the contact surfaces 18B of the pair of brackets 18 gradually widens towards the side opposite to the lower housing 16, i.e., the upper side. Figure 3 and Figure 4 As shown, a threaded hole 18C is formed on the bracket 18, extending from the upper surface side of the bracket 18 to the bracket side contact surface 18B side in the vertical direction.

[0023] A limiting bolt 22 is screwed into the bracket 18. The limiting bolt 22 has a bolt head 22A that engages with a tool and a bolt shaft portion 22B that protrudes downward from the bolt head 22A. A thread peak is formed on the outer periphery of the portion of the bolt shaft portion 22B on the side of the bolt head 22A. The bolt shaft portion 22B of the limiting bolt 22 is screwed into a threaded hole 18C formed in the bracket 18 from above, thereby fixing the limiting bolt 22 to the bracket 18. Furthermore, with the limiting bolt 22 fixed to the bracket 18, the lower portion 22C of the bolt shaft portion 22B protrudes downward from the bracket-side contact surface 18B of the bracket 18. In this embodiment, the outer periphery of the lower portion 22C of the bolt shaft portion 22B is not formed with a thread peak. That is, the outer periphery of the lower portion 22C of the bolt shaft portion 22B is cylindrical.

[0024] like Figure 1 , Figure 3 and Figure 4As shown, a pair of bracket engaging portions 20 are fixed to the lower housing 16 on both sides of the receiving recess 16A in the front-rear direction. Furthermore, the pair of bracket engaging portions 20 are symmetrically configured in the front-rear direction. Therefore, in the following description, the structure of the front bracket engaging portion 20 will sometimes be described, while the description of the structure of the rear bracket engaging portion 20 will be omitted. Also, the portions of the rear bracket engaging portion 20 corresponding to those of the front bracket engaging portion 20 will be marked with the same symbols as the corresponding portions of the front bracket engaging portion 20.

[0025] The bracket engaging portion 20 is formed as a triangular prism with its left and right sides forming right-angled triangles. The lower surface of the bracket engaging portion 20 is formed as a planar shape extending in both the front-rear and left-right directions, serving as a fixing surface 20A fixed to the upper surface of the lower housing 16. Furthermore, the front surface of the bracket engaging portion 20 is formed as a planar shape extending in both the vertical and horizontal directions. Moreover, the rear surface of the bracket engaging portion 20 is formed as a planar shape extending in both the vertical and horizontal directions, and serves as a bracket engaging portion side contact surface 20B that slopes from the upper side towards the lower side and then towards the rear. Furthermore, as... Figure 1 As shown, when viewed from the side of the vehicle, the distance A2 in the front-rear direction between the contact surfaces 20B of the pair of bracket engaging parts 20 gradually widens towards the side opposite to the lower housing 16, i.e., the upper side. Figure 3 As shown, in the bracket engaging portion 20, a concave limiting groove 20C with the bracket engaging portion side contact surface 20B open is formed along the front-back direction.

[0026] like Figure 1 , Figure 3 and Figure 4 As shown, a pair of brackets 18 fixed to the battery cell stack 14 engage with a pair of bracket engaging portions 20 fixed to the lower housing 16 from the top side. Furthermore, when the pair of brackets 18 are engaged with the pair of bracket engaging portions 20, the pair of bracket-side contact surfaces 18B of the pair of brackets 18 contact the pair of bracket engaging portion-side contact surfaces 20B of the pair of bracket engaging portions 20. Thus, the battery cell stack 14 is supported from the bottom, front, and rear sides by the pair of brackets 18 and the pair of bracket engaging portions 20. Moreover, when the pair of brackets 18 are engaged with the pair of bracket engaging portions 20, the lower portion 22C of the bolt shaft portion 22B of the limiting bolt 22 fixed to the pair of brackets 18 is inserted into the limiting groove 20C formed in the pair of bracket engaging portions 20. Therefore, the displacement of the pair of brackets 18 relative to the pair of bracket engaging portions 20 in the left-right direction is restricted. Alternatively, multiple limiting bolts 22 can be fixed to the bracket 18, and multiple limiting grooves 20C can be formed in the bracket engaging portion 20, so that the multiple limiting bolts 22 fixed to the bracket 18 can be inserted into the multiple limiting grooves 20C formed in the bracket engaging portion 20 respectively.

[0027] like Figure 1 and Figure 2 As shown, in the embodiment described above, when the battery cell stack 14 expands in the front-rear direction, the pair of support side contact surfaces 18B of the pair of supports 18 fixed to the battery cell stack 14 slide against the pair of support engagement side contact surfaces 20B of the pair of support engagement parts 20, and the battery cell stack 14 is displaced to the side opposite to the lower housing 16, i.e., the upper side.

[0028] In contrast, by reducing SOC, when the battery cell stack 14 shrinks in the front-rear direction, the pair of bracket side contact surfaces 18B of the pair of brackets 18 fixed to the battery cell stack 14 slide against the pair of bracket engagement side contact surfaces 20B of the pair of bracket engagement parts 20, and the battery cell stack 14 is displaced to the lower housing 16 side, i.e., the lower side.

[0029] In this embodiment, the distance A2 in the front-rear direction between the contact surfaces 20B of the pair of bracket engaging portions is set to widen towards the upward side. In this structure, the engaging position of the pair of bracket engaging portions 20 of the pair of brackets 18 can be changed according to the dimensional changes of the battery cell stack 14 in the front-rear direction. This reduces the load on various parts (brackets 18, bracket engaging portions 20, and lower housing 16, etc.) that accompany the dimensional changes of the battery cell stack 14.

[0030] Furthermore, in this embodiment, the front-to-back distance A1 between the pair of bracket-side contact surfaces 18B of the pair of brackets 18 is set to be wider towards the upward side. In this way, by aligning the front-to-back distance A1 between the pair of bracket-side contact surfaces 18B of the pair of brackets 18 with the front-to-back distance A2 between the pair of bracket-engaging side contact surfaces 20B of the pair of bracket engaging portions 20, the two can slide smoothly.

[0031] Furthermore, in this embodiment, an example of contact between the planar support-side contact surface 18B and the planar support engagement-side contact surface 20B has been described, but the present invention is not limited thereto. For example, as Figure 5 As shown, a structure can also be adopted in which the bracket side contact surface 18B, which is bent into a convex shape toward the bracket engagement portion 20, contacts the planar bracket engagement portion side contact surface 20B.

[0032] The present invention has been described above as an embodiment of the invention, but the invention is not limited to the above description. Of course, various modifications can be made without departing from the spirit of the invention.

[0033] Symbol Explanation

[0034] 12-Battery unit, 14-Battery unit stack, 16-Lower housing (shell), 18-Bracket, 18B-Bracket side contact surface, 20-Bracket engaging part, 20B-Bracket engaging part side contact surface.

Claims

1. A housing structure for a battery cell stack, characterized in that, have: A battery cell stack having multiple battery cells stacked along a stacking direction; A housing that accommodates the battery cell stack; A pair of brackets, respectively fixed on both sides of the stacking direction in the battery cell stack; and A pair of bracket engaging portions are respectively disposed on both sides of the pair of brackets in the stacking direction and fixed to the housing. Each pair of bracket engaging portions has a pair of bracket engaging portion side contact surfaces, which are configured to face each other in the stacking direction and the spacing in the stacking direction widens as it faces the side opposite to the housing, and each pair of brackets contacts these surfaces. When the dimensions of the battery cell stack change in the stacking direction, the pair of brackets slide against the contact surfaces of the bracket engagement portions, and the battery cell stack can be displaced toward the housing side or the side opposite to the housing.

2. The housing structure of the battery cell stack according to claim 1, characterized in that, Each pair of brackets has a pair of bracket-side contact surfaces, which are configured to contact the engagement side contact surfaces of the pair of brackets respectively, and the spacing in the stacking direction widens as it faces the side opposite to the housing.

Images