Battery case

Abstract

The utility model relates to a battery shell, which is used for accommodating a battery unit laminated body formed by laminating a plurality of battery units, and is provided with a pressing component for pressing the battery unit laminated body; a load support member separated from the battery cell stack; and a connection member that connects the pressing member and the load support member. The pressing member is disposed so as to face the battery cell stack. The load support member is disposed so as to face the battery cell stack in the same direction as the pressing member, and is disposed at a position farther from the battery cell stack than the pressing member. According to this structure, a load applied from above the vehicle is easily input to the load support member, and the load support member deforms toward the battery cell. However, since the load support member does not come into contact with the battery cells, it is possible to suppress the transmission of load to the battery cell stack. As a result, the risk of damage to the battery with respect to a load applied from above the vehicle can be suppressed.

Description

Technical Field

[0001] The utility model relates to a battery casing for accommodating a battery unit stack. Background Art

[0002] Patent document 1 discloses a technology for a vehicle-mounted structure of a battery pack having a plurality of battery cells. The battery pack disposed on the vehicle floor comprises a battery cell, a battery pack housing, and a buffer member, wherein the plurality of battery cells are arranged in the battery pack housing. By fixing the battery pack housing to the floor, the buffer member is arranged to be clamped between the battery cell and the floor or between the battery cell and the battery pack housing. Thus, the tolerance of the battery cell can be absorbed, so that the plurality of battery cells can be reliably fixed with a simple structure while ensuring high reliability.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-123227 Utility Model Content

[0004] In the above-mentioned conventional structure, when a load is applied from above the vehicle, the load is easily transmitted to the battery via the battery case or the buffer member. The load is easily transmitted to the battery, that is, the battery is easily damaged, which may shorten the battery life.

[0005] An object of the present invention is to provide a technology that suppresses the risk of battery damage and contributes to extending the life of a vehicle-mounted battery in response to the above-mentioned problem.

[0006] The first embodiment of the utility model relates to a battery case for accommodating a battery cell stack formed by stacking a plurality of battery cells. The battery case comprises: a pressing member for pressing the battery cell stack; a load-bearing member separated from the battery cell stack; and a connecting member for connecting the pressing member to the load-bearing member. The pressing member is arranged opposite to the battery cell stack. The load-bearing member is arranged opposite to the battery cell stack in the same direction as the pressing member, and is arranged at a position farther from the battery cell stack than the pressing member.

[0007] A second aspect of the present invention is the first aspect, wherein the load supporting member and the pressing member are arranged so that an image of the load supporting member projected onto the battery cell stack and an image of the pressing member projected onto the battery cell stack do not overlap each other.

[0008] A third aspect of the present invention is the first aspect, wherein the rigidity of the connecting member is lower than the rigidity of the load supporting member.

[0009] The fourth mode of the utility model is that, based on the first mode, the connecting member connects the first connecting part and the second connecting part, the first connecting part is a part of the side of the load-bearing member opposite to the battery cell stack, and the second connecting part is a part of the side of the pressing member opposite to the battery cell stack.

[0010] A fifth aspect of the present invention is any one of the first to fourth aspects, further comprising a buffer member disposed between the battery cell stack and the pressing member.

[0011] According to the first embodiment, since the load-bearing member is arranged at a position farther from the pressing member, the load is easily input to the load-bearing member. The load-bearing member receiving the load is deformed toward the battery cell stack, but since the load-bearing member and the battery cell stack are separated, the two do not contact each other, and the load transfer from the load-bearing member to the battery cell stack can be suppressed.

[0012] According to the second embodiment, the load-bearing member and the pressing member are arranged so as not to overlap (the detailed embodiment will be described later). Thus, when the load-bearing member that bears the load is deformed toward the battery cell stack, the load-bearing member and the pressing member are not easily in contact with each other. Therefore, the load transfer to the battery cell stack via the pressing member can be suppressed.

[0013] According to the third embodiment, the connecting member has lower rigidity than the load-bearing member. As a result, the low-rigidity connecting member deforms and absorbs energy by receiving the load transmitted from the load-bearing member. As a result, the load is not easily transmitted to the pressing member, and the load transmission to the battery cell stack via the pressing member can also be suppressed. In addition, if the connecting member can be implemented using a low-rigidity member, its cross-sectional area can be smaller than other parts, or the amount of reinforcing material used can be reduced, thereby contributing to cost reduction and weight reduction.

[0014] According to the fourth embodiment, the connecting member "connects the load-bearing member and the pressing member on the lower surface" (the detailed embodiment will be described later). As a result, the room for deformation of the load-bearing member can be increased. That is, by connecting the lower surface, the gap between the load-bearing member and the pressing member can be reduced by an amount corresponding to the thickness of the load-bearing member, compared with the case where the lower surface connection is not performed, and as a result, the thickness of the battery pack can be reduced.

[0015] According to the fifth aspect, a buffer member is interposed between the pressing member and the battery cell stack. This improves the degree of fixation between the battery cell stack and the pressing member and ensures a space between the pressing member and the battery cell stack required for lower surface connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a vehicle equipped with a battery pack according to the embodiment.

[0017] Figure 2A and Figure 2B It is a cross-sectional view showing the structure of a battery pack according to an embodiment.

[0018] Figure 3 It is a perspective view showing the structure of a battery case according to the embodiment.

[0019] Figure 4 This is a cross-sectional view of a battery pack for explaining the operation and effects.

[0020] Figure 5A and Figure 5B It is a schematic diagram used to explain the action and effect.

[0021] Fig. 6A and Figure 6B It is a plan view showing a modification of the battery case according to the embodiment. DETAILED DESCRIPTION

[0022] The embodiments of the present invention will be described with reference to the accompanying drawings.

[0023] First, the main structure of the battery case will be described.

[0024] Figure 1 1 is a schematic diagram of a vehicle 1 equipped with a battery pack 10 according to the embodiment. Generally, the battery pack 10 is mounted under the floor of the vehicle 1. The battery pack 10 is used as a power source for electric vehicles such as BEV, PEV, and HEV.

[0025] here, Figure 1 The FR direction indicated by the middle arrow indicates the direction in which the vehicle 1 is moving forward, the UP direction indicates the upward direction of the vehicle 1, and the LH direction indicates the left direction as viewed by the passengers in the vehicle 1, that is, the direction toward the front of the paper. Figure 2A The arrows shown below have the same meaning.

[0026] Figure 2A and Figure 2B 1 is a cross-sectional view showing the structure of the battery pack 10 according to the embodiment. Figure 2A The configuration of the battery pack 10 will be described.

[0027] The battery pack 10 includes a battery cell stack 20 formed by stacking a plurality of battery cells and a battery case 30 for accommodating the battery cell stack 20. The battery cell is a secondary battery capable of charge and discharge, such as a lithium-ion secondary battery. The stacking direction of the battery cell stack 20 is along the LH direction, and the shape of the battery cell stack 20 is shown as a substantially rectangular parallelepiped. The battery case 30 includes an outer shell 31, a load supporting member 32, a pressing member 33, and a connecting member 34 as described below.

[0028] The outer shell 31 is configured to cover the battery cell stack 20. The outer shell 31 is not configured to entirely cover the battery cell stack 20, but is configured to cover the battery cell stack 20. Figure 2A and Figure 2B As shown, it is a partially open shape.

[0029] The load supporting member 32 is a member extending in a cantilever beam shape from the end of the outer shell 31. The load supporting member 32 is separated from the battery cell stack 20.

[0030] The pressing member 33 is a member for fixing the battery cell stack 20 to the outer shell 31 so that the battery cell stack 20 does not move due to driving vibration, etc. For example, the pressing member 33 is arranged above the battery cell stack 20 and presses the battery cell stack 20 toward the bottom of the outer shell 31.

[0031] In addition, if Figure 2A and Figure 2B As shown, a buffer member 40 may be interposed between the pressing member 33 and the battery cell stack 20. In addition, a buffer member 40 may be provided on the side opposite to the side where the pressing member 33 is provided, that is, between the outer shell 31 and the battery cell stack 20. The buffer member 40 is preferably made of an elastic body such as rubber or sponge to improve the fixation between the battery cell stack 20 and the battery case 30.

[0032] Typically, the housing portion 31 , the load supporting member 32 , and the pressing member 33 are composed of metal plates made of an alloy or the like.

[0033] Here, the positional relationship between the load supporting member 32 and the pressing member 33 is described. First, the load supporting member 32 and the pressing member 33 are arranged so as to face the battery cell stack 20 in the same direction. Second, the load supporting member 32 is arranged at a position farther from the battery cell stack 20 than the pressing member 33.

[0034] Furthermore, the load supporting member 32 and the pressing member 33 are preferably arranged so that their images when projected onto the battery cell stack 20 do not overlap each other, and the reason for this will be described later. Hereinafter, such an arrangement relationship is referred to as "arranged without overlapping".

[0035] The connection member 34 connects the load supporting member 32 and the pressing member 33. The connection member 34 is preferably less rigid than the load supporting member 32.

[0036] In addition, a preferred form of the connecting member 34 is to connect the first connecting portion 32a of the load-bearing member 32 and the second connecting portion 33a of the pressing member 33. Here, the first connecting portion 32a refers to a portion of the load-bearing member 32 on the side opposite to the battery cell stack 20. In addition, the second connecting portion 33a refers to a portion of the surface of the pressing member 33 on the side opposite to the battery cell stack 20. Such a connecting method is hereinafter referred to as "lower surface connection". As an example of the lower surface connection, a method in which a thin metal plate patch is used as the connecting member 34 and connected by welding at the first connecting portion 32a and the second connecting portion 33a can be cited.

[0037] The material constituting the connecting member 34 is not limited to the metal plate patch of the thin plate illustrated above, but may also be a resin member, a leather member, a sponge, etc. In addition, as another example, Figure 2B As shown in FIG. 1 , the connecting member 34 is shaped so as to bend in the direction toward the battery cell stack 20 .

[0038] Here, in order to achieve the bottom surface connection, a space is required between the second connection portion 33a and the battery cell stack 20. In order to ensure this space, Figure 2A and Figure 2B As shown, a buffer member 40 smaller than the pressing member 33 may be used. Alternatively, instead of using the buffer member 40, the pressing member 33 may have a stepped cross-sectional shape to ensure space.

[0039] Figure 3 3 is a perspective view showing the structure of the battery case 30 involved in the embodiment. As can be seen from the above content, the battery case 30 includes an outer shell 31, a load supporting member 32, a pressing member 33, and a connecting member 34 connecting the load supporting member 32 and the pressing member 33. By accommodating the battery cell stack 20 inside the battery case 30, the battery cell stack 20 is isolated from the outside.

[0040] The structure in the prior art (e.g., Patent Document 1) is that there is no member equivalent to the load supporting member 32 in the present invention, and the load from the UP direction is easily transmitted to the battery unit via the battery case or the buffer member. The load is easily transmitted to the battery, that is, the battery is easily damaged, which may shorten the battery life.

[0041] Figure 4The cross-sectional view of the battery pack 10 is used to illustrate the function and effect of the present invention. The present invention solves the above-mentioned problems by the following functions. In the present invention, the load-bearing member 32 is arranged at a position farther from the battery cell stack 20 than the pressing member 33, so that the load is easily input to the load-bearing member. The load-bearing member 32 that bears the load is deformed toward the battery cell stack 20, but since the load-bearing member 32 is separated from the battery cell stack 20, the two do not contact each other, and the load transfer from the load-bearing member 32 to the battery cell stack 20 can be suppressed.

[0042] Here, when the load supporting member 32 and the pressing member 33 are arranged so as not to overlap, when the load supporting member 32 receiving the load is deformed toward the battery cell stack 20, the load supporting member 32 and the pressing member 33 are not easily in contact with each other. Thus, the load transmission to the battery cell stack 20 via the pressing member 33 can be suppressed. Therefore, it is more preferable that the load supporting member 32 and the pressing member 33 are arranged so as not to overlap each other.

[0043] Here, when the connecting member 34 has lower rigidity than the load supporting member 32, the connecting member 34 with lower rigidity receives the load transmitted from the load supporting member 32 and deforms to absorb energy. As a result, the load is not easily transmitted to the pressing member 33, and the load transmission to the battery cell stack 20 via the pressing member 33 can also be suppressed. Therefore, it is more preferable that the connecting member 34 has lower rigidity. In addition, if the connecting member 34 can be implemented by a low-rigidity member, its cross-sectional area can be smaller than other parts, or the amount of reinforcing material used can be reduced, thereby contributing to cost reduction and weight reduction.

[0044] use Figure 5A and Figure 5B The effect when the connecting member 34 connects the load supporting member 32 and the pressing member 33 through the lower surface connection is described. Here, the distance between the load supporting member 32 and the pressing member 33 in the UP direction is set to Δ, and the thickness of the load supporting member 32 is set to t. In addition, for the load supporting member 32 and the connecting member 34 in the figure, the portion drawn with a dotted line represents the state before receiving a load (before deformation), and the portion drawn with a solid line represents the state after receiving a load and deforming.

[0045] First, through Figure 5A Consider the case where the connecting member 34 is not connected to the lower surface. In this case, when the load acts on the load supporting member 32 and the load supporting member 32 is deformed in the direction of the battery cell stack 20, at the time of deformation Δ, the connecting member 34 is clamped by the load supporting member 32 and the pressing member 33 and contacts the two, thereby generating resistance. The generation of resistance means that the load is transmitted to the pressing member 33, which means that the load is easily transmitted to the battery cell stack 20.

[0046] On the other hand, through Figure 5B Consider the case of the lower surface connection. Even when the load-bearing member 32 is deformed by Δ, the connecting member 34 will not be clamped by the load-bearing member 32 and the pressing member 33, and will not generate resistance accompanying it. In this case, further deformation occurs, and when the deformation reaches Δ+t, the upper end of the load-bearing member 32 is aligned with the upper end of the pressing member 33. At this time, when the load surface acts widely and in a distributed manner, the load begins to act directly on the pressing member 33, so the load can act on the pressing member 33 at the moment of deformation Δ+t. That is, under the premise of not transferring the load to the pressing member 33, it can be said that the deformation Δ+t is the maximum value that can be deformed.

[0047] That is, when the lower surface is connected, the deformation margin is large and the maximum deformation can be Δ+t. In contrast, when the lower surface is not connected, the maximum deformation can only be Δ. This means that when the lower surface is connected, the deformation margin can be increased by the thickness t of the load supporting member 32 compared to when the lower surface is not connected. Furthermore, in other words, when achieving the same allowable deformation, the distance Δ can be reduced by the thickness t of the load supporting member 32 by connecting the lower surface, which helps to reduce the thickness of the battery pack 10.

[0048] When the buffer member 40 is interposed between the pressing member 33 and the battery cell stack 20 , not only can the fixation between the battery cell stack 20 and the battery case 30 be improved, but also a space between the second connecting portion 33 a required for the lower surface connection and the battery cell stack 20 can be ensured.

[0049] According to the above-mentioned effects, the present invention can suppress the risk of damage to the battery cell stack 20, thereby contributing to extending the life of the vehicle-mounted battery.

[0050] exist Figure 3 The figure shows an example in which a pressing member 33 is arranged in the center of the battery case 30, and a connecting member 34 and a load supporting member 32 are arranged in a manner surrounding the pressing member 33, but other methods are also possible as long as the effect of the utility model can be exerted. The following shows several modified examples that can exert the effect of the utility model.

[0051] A first modification example will be described. Fig. 6A This is a top view of the first modified example of the battery case 30 according to the embodiment when viewed from the UP direction. Fig. 6AIn the example shown, the pressing member 33 is separated into two parts, and the connecting member 34 and the load supporting member 32 are arranged around each part. In other words, the load supporting member 32 is in the shape of a Japanese character, and the load supporting member 32 and the connecting member 34 are arranged in shapes corresponding to the two openings thereof. In this way, the pressing member 33 can be separated into a plurality of parts, and the effect of the utility model can also be exerted in this case.

[0052] A second modification example will be described. Figure 6B This is a plan view of the second modified example of the battery case 30 according to the embodiment when viewed from the UP direction. Figure 6B In the example shown, the pressing member 33 is not completely surrounded by the connecting member 34 and the load supporting member 32, and its end extends to the end of the battery case 30. From another point of view, the load supporting member 32 is separated into two parts, and the load supporting member 32 and the connecting member 34 having a shape corresponding to the free part are arranged. In this way, the load supporting member 32 can be separated into a plurality of parts, and the effect of the utility model can also be exerted in this case.

Claims

1. A battery case for accommodating a battery cell stack formed by stacking a plurality of battery cells, characterized in that: have: A pressing member pressing the battery cell stack; a load bearing member separated from the battery cell stack; and a connecting member connecting the pressing member and the load supporting member, The pressing member is arranged to face the battery cell stack. The load supporting member is disposed so as to face the battery cell stack in the same direction as the pressing member, and is disposed at a position farther from the battery cell stack than the pressing member.

2. The battery housing according to claim 1, characterized in that: The load supporting member and the pressing member are arranged so that an image of the load supporting member projected onto the battery cell stack and an image of the pressing member projected onto the battery cell stack do not overlap each other.

3. The battery housing according to claim 1, characterized in that: The rigidity of the connecting member is lower than the rigidity of the load supporting member.

4. The battery housing according to claim 1, characterized in that: The connecting member connects a first connecting portion which is a portion of the load supporting member on a side opposite to the battery cell stack and a second connecting portion which is a portion of the pressing member on a side opposite to the battery cell stack.

5. The battery case according to any one of claims 1 to 4, characterized in that: A buffer member is further provided between the battery cell stack and the pressing member.

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