Fixing structure of a battery stack

Abstract

The present application aims to suppress an increase in the mass of a battery while fixing a battery stack to a battery pack case. A fixing structure of a battery stack according to the present application includes a battery pack case for housing a battery stack in which a plurality of battery cells are stacked in a stacking direction, and a column member. The column member is connected to a fixing resin frame and a bottom surface of the battery pack case, the fixing resin frame being one of a plurality of resin frames arranged between adjacent battery cells.

Description

Technical Field

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

[0002] Patent Document 1 describes a battery pack housing that accommodates a battery stack containing multiple batteries. The two ends of the battery pack housing are configured to abut against the two ends of the battery stack and press the two ends of the battery stack toward the center in the stacking direction.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-129474 Summary of the Invention

[0004] In Patent Document 1, the battery stack is held within the battery pack housing by pressing it down from both ends. That is, the friction generated between the inner end face of the battery pack housing and the two end faces of the battery stack suppresses the vertical displacement of the battery stack, which is orthogonal to the stacking direction. However, when the battery stack structure is held in place solely by friction, vertical displacement cannot be suppressed, and the battery stack may pop out upwards.

[0005] To prevent the battery stack from popping out, gap-filling materials such as battery shock absorbers and supports are placed between the upper casing of the battery pack and the battery stack. The battery stack is pressed downwards from the upper casing side by bolts fastening the upper casing to the battery pack casing. However, in this case, it can be assumed that the axial force of the bolts decreases due to the reaction force of the battery shock absorbers, etc. Furthermore, the overall mass of the battery increases due to the placement of gap-filling materials.

[0006] The present invention was made in view of the above-mentioned problems, and provides a technology that can suppress the increase in battery mass while more reliably fixing the battery stack.

[0007] One aspect of the present invention is a fixing structure for a battery stack. This fixing structure includes: a battery pack housing for accommodating a battery stack formed by stacking multiple battery cells along a stacking direction; and a column member. The column member is connected to a fixing resin frame and the bottom surface of the battery pack housing, the fixing resin frame being one of a plurality of resin frames located between adjacent battery cells.

[0008] Invention Effects

[0009] According to the battery stack fixing structure of the present invention, the resin frame for fixing the battery stack is connected to the bottom surface of the battery pack housing via a column member. Thus, the battery stack is fixed to the bottom surface of the battery pack housing, thereby preventing the battery stack from popping out. Furthermore, the additional component for fixing is only a small column member, thus enabling a lightweight battery pack. Attached Figure Description

[0010] Figure 1 This is a perspective view showing the structure of the battery pack according to an embodiment of the present invention.

[0011] Figure 2 This is a cross-sectional view of the battery pack according to an embodiment of the present invention, cut along the stacking direction and the vertical direction.

[0012] Figure 3 It is an enlarged representation Figure 2 A diagram of the structure near the pillar component of the battery pack.

[0013] Figure 4 This is a cross-sectional view of the battery pack according to the embodiments of the present invention, cut with a plane perpendicular to the vertical direction.

[0014] Figure 5 This is a schematic diagram illustrating the structure of the cooling mechanism of the battery pack according to an embodiment of the present invention.

[0015] Figure 6 This is a cross-sectional view of the space below the battery stack of the battery pack according to the embodiments of the present invention, cut with a plane perpendicular to the vertical direction. Detailed Implementation

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in the drawings, identical or corresponding parts are labeled with the same symbols, and their descriptions are simplified or omitted.

[0017] Implementation method.

[0018] Figure 1 This is a perspective view showing the structure of the battery pack 1 according to an embodiment of the present invention. The battery pack 1 according to this embodiment is, for example, an on-board battery pack for use in vehicles such as hybrid vehicles, plug-in hybrid vehicles, or electric vehicles.

[0019] Figure 1 In the diagram, the battery pack 1 contains only the battery stack 10 and the battery pack housing 22, indicating the state in which the battery stack 10 has been removed from the battery pack housing 22. The battery pack 1 comprises a battery stack 10 consisting of multiple battery cells stacked along a stacking direction. The battery stack 10 is housed in the battery pack housing 22 in a compressed and constrained state.

[0020] exist Figure 1 In the example, two receiving spaces 22a corresponding to the battery stacks 10 are formed in the battery pack housing 22 to accommodate two battery stacks 10. However, the number of battery stacks 10 accommodated in one battery pack 1 is not limited, but is appropriately set according to the required output, etc.

[0021] Figure 2This is a cross-sectional view of the battery pack 1 along the stacking direction and the vertical direction. In this embodiment, the vertical direction is the direction perpendicular to the bottom surface of the battery pack housing 22. Figure 2 The top and bottom of the paper are aligned.

[0022] like Figure 2 As shown, in battery pack 1, battery stack 10 is disposed within the space formed by battery pack housing 22 and upper housing 21 disposed on the upper side of battery pack housing 22. A bracket 23 is installed on the outside of battery pack housing 22.

[0023] like Figure 2 As shown, the battery stack 10 includes multiple battery cells 11 stacked along the stacking direction. Each battery cell 11 includes a positive electrode, a separator, a negative electrode, etc. Resin frames 12 are disposed between adjacent battery cells 11 in the battery stack 10. The number of battery cells 11 stacked in one battery stack 10 is not limited.

[0024] The fixing structure of the battery stack 10 according to this embodiment includes a battery pack housing 22 and a column member 30. With the battery stack 10 housed, the battery pack housing 22 presses the battery stack 10 towards the center from both end faces in the stacking direction. The battery stack 10 is held in place by the frictional force between the two end faces in the stacking direction of the battery stack 10 and the inner wall surfaces of the battery pack housing 22 at both end faces in the stacking direction.

[0025] Figure 3 It is an enlarged representation Figure 2 The diagram shows the area near column component 30. Furthermore, Figure 4 It is a cross-sectional view of the battery pack 1 cut with a plane perpendicular to the vertical direction, and shown in the state of the perspective column member 30. (As shown) Figure 3 As shown, the lower surface of the pillar member 30 is bonded and fixed to the bottom surface of the inner wall side of the battery pack housing 22, and the upper surface is bonded and fixed to one of the fixing resin frames 12a in the resin frame 12 of the battery stack 10. However, the fixing method of the pillar member 30 is not limited. The pillar member 30 can be bonded, for example, by an adhesive. Furthermore, the width of the pillar member 30 in the stacking direction is smaller than the width of the lower surface of the resin frame 12 in the stacking direction.

[0026] like Figure 4 As shown, the resin frame 12 of the fixing post member 30, i.e., the fixing resin frame 12a, is a resin frame 12 located between two adjacent battery cells 11 at a position closest to the center of the stacking direction of the battery stack 10. Furthermore, the post member 30 is positioned at the center of its width direction, perpendicular to the stacking direction of the fixing resin frame 12a. That is, as... Figure 4As shown, the column member 30 is connected to a position near the center of the lower surface of the battery stack 10, and to a position near the center of the portion of the bottom surface of the battery pack housing 22 opposite to the lower surface of the battery stack 10.

[0027] By bonding and fixing the battery pack housing 22 and the fixing resin frame 12a with the column component 30, the central part of the battery stack 10, which is more likely to exert a large force in the ejection direction, can be fixed with a force in the opposite direction to the ejection direction, thereby stably fixing the battery stack 10 inside the battery pack housing 22.

[0028] Figure 5 This is a schematic diagram showing the structure of the cooling mechanism of the battery pack, and it is a cross-sectional view along the stacking direction and vertical direction of the battery pack 1. For example... Figure 5 As shown, a space 22b is formed between the lower surface of the battery stack 10 and the bottom surface of the battery pack housing 22. Furthermore, a blower 40 is disposed outside one end face of the battery pack 1 in the stacking direction. The blower 40 causes cooling air to flow in the space 22b at the bottom of the battery stack 10. That is, the cooling air supplied from the blower 40 flows from one end face to the other end face in the stacking direction through the space 22b, and passes along the bottom surface of the battery pack housing 22 through the lower part of the battery stack 10, thereby cooling the battery stack 10.

[0029] Figure 6 This is a cross-sectional view showing the lower space 22b of the battery stack 10 cut using a plane perpendicular to the vertical direction. (Example) Figure 6 As shown, the column member 30 has a streamlined cross-sectional shape designed to reduce the resistance of the bottom of the battery stack 10 to the flow of cooling air. Therefore, the column member 30 can secure the battery stack 10 to the battery pack housing 22 without significantly obstructing the flow of cooling air.

[0030] As explained above, according to the fixing structure of the battery stack 10 in this embodiment, by adding the column member 30 and fixing the lower surface of the battery stack 10 near the center to the battery pack housing 22, the vertical movement of the battery stack 10 can be effectively reduced, and the ejection of the battery stack 10 can be suppressed. Furthermore, since ejection can be suppressed by the column member 30 alone, the components used to fix the battery pack 1 are lightweight, thus achieving a lightweight and miniaturized battery pack 1.

[0031] In this embodiment, the case where the column member 30 is bonded to the lower surface of the battery stack 10 on its upper surface and to the bottom surface of the battery pack housing 22 on its lower surface is described. However, the structure of the column member 30 is not limited to this. For example, the column member 30 may be integrally formed with the battery pack housing 22. In this case, the column member 30 is formed to protrude upward near the center of the receiving space 22a that receives the battery stack 10. Then, when the battery stack 10 is received in the battery pack housing 22, the upper surface of the column member 30 is bonded and fixed to the fixing resin frame 12a near the center of the battery stack 10.

[0032] Furthermore, the column member 30 can be a component integrally formed on the center of the lower surface of the fixing resin frame 12a of the battery stack 10. In this case, when the battery stack 10 is housed in the battery pack housing 22, the lower surface of the column member 30 is bonded and fixed to the bottom surface of the battery pack housing 22.

[0033] Even when the column component 30 is integrally molded with the battery pack housing 22 or the fixing resin frame 12a, such as Figure 6 As shown, the column component 30 also preferably has a streamlined cross-sectional shape designed to reduce resistance to cooling airflow in a cross-section in a direction parallel to the bottom surface of the battery pack housing 22.

[0034] Furthermore, in the battery stack fixing structure of this embodiment, the case where one column member 30 is fixed at a location near the center of the lower surface of the battery stack 10 has been described. However, the number of column members 30 is not limited to this, and multiple column members 30 may be provided to fix multiple parts of the resin frame of the battery stack 10.

[0035] Symbol Explanation

[0036] 1-Battery pack, 10-Battery stack, 11-Battery unit, 12-Resin frame, 12a-Fixing resin frame, 21-Upper housing, 22-Battery pack housing, 22a-Accommodation space, 22b-Space, 23-Bracket, 30-Column component, 40-Blower.

Claims

1. A fixing structure for a battery stack, characterized in that, have: A battery pack housing for accommodating a battery stack consisting of multiple battery cells stacked along a stacking direction; and Column components, The column component is connected to the bottom surface of the fixing resin frame and the battery pack housing. The fixing resin frame is one of a plurality of resin frames located between adjacent battery cells.

2. The fixing structure of the battery stack according to claim 1, characterized in that, The width of the column component in the stacking direction is smaller than the width of the fixing resin frame.

3. The fixing structure of the battery stack according to claim 1 or 2, characterized in that, The cross-sectional shape of the column component in the direction parallel to the bottom surface is designed to be streamlined to reduce resistance to wind flowing along the stacking direction.

4. The fixing structure of the battery stack according to claim 1 or 2, characterized in that, The column component is integrally formed with the battery pack housing or the fixing resin frame.

5. The fixing structure of the battery stack according to claim 1 or 2, characterized in that, The fixing resin frame is a resin frame located between adjacent battery cells that are centrally located in the stacking direction among the plurality of battery cells.

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