Battery case

Abstract

To evenly cool a plurality of cell stacks accommodated in a battery case.SOLUTION: A battery case for accommodating a plurality of cell stacks therein includes: a case body including a plurality of refrigerant passages configured to flow a refrigerant to the respective fuel cell stacks; and a refrigerant branch section configured to distribute the refrigerant to the refrigerant passages. The refrigerant branch section is removably attached to the case body.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a battery case for housing a multiple battery stack. [Background technology]

[0002] Patent Document 1 discloses a battery cooling device that simultaneously cools multiple battery stacks. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-089865 Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have recognized for the first time the following problem regarding cooling of multiple battery stacks housed in a battery case. That is, the flow rate of the refrigerant distributed to the multiple passages through which the refrigerant flows for cooling the multiple battery stacks varies depending on the relative positions of the cooling device and the battery case. In order to improve the output and extend the life of the batteries, it is desirable to uniformly cool each battery stack during operation. However, when the flow rate of the refrigerant distributed to each refrigerant passage differs as described above, it is difficult to say that each battery stack is uniformly cooled. Such a state is not optimal for improving the output and extending the life of the batteries.

[0005] One object of the present disclosure is to provide a technique that can solve the problem of uneven cooling of multiple battery stacks. [Means for solving the problem]

[0006] One aspect of the present disclosure relates to a battery case for housing a multiple battery stack. The battery case is a case body including a plurality of refrigerant passages configured to allow a refrigerant to flow through each of the plurality of battery stacks; and a refrigerant branch configured to distribute the refrigerant to the plurality of refrigerant passages. The refrigerant branching portion is detachable from the case body. Effect of the Invention

[0007] According to one aspect of the present disclosure, the refrigerant branching portion is formed to be detachable from the case body. The shape of the refrigerant branching portion can be optimized according to the positional relationship between the cooling device and the battery case. In other words, the shape of the refrigerant branching portion can be designed to cool the multiple battery stacks as uniformly as possible. This contributes to improving the output and extending the life of the battery.

[0008] Furthermore, the fact that the refrigerant branching section can be manufactured independently of the case body means that the same shape of the case body can be used in a variety of situations regardless of the relative positions of the cooling device and the battery case, which contributes to reducing parts costs compared to when the refrigerant branching section is integrated with the case body. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic diagram illustrating an example of a battery pack. [Diagram 2] FIG. 1 is a schematic diagram illustrating a problem and a method for solving the problem. [Diagram 3] FIG. 2 is a schematic diagram illustrating an example of a battery case according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0011] 1.Main configuration 1 is a schematic diagram showing an example of a battery pack 1. The battery pack 1 is used as a power source for electric vehicles such as BEVs, PEVs, HEVs, etc. The battery pack 1 includes a battery case 11 and a cooling device 12.

[0012] The battery case 11 includes a case body 111 and a refrigerant branching section 112 .

[0013] A plurality of battery stacks 113 are housed (arranged) in the case body 111. Each battery stack 113 is configured by accumulating a large number of battery cells. The battery cells are rechargeable secondary batteries, for example, lithium ion secondary batteries.

[0014] The case body 111 includes a plurality of branch refrigerant passages 1111. A refrigerant 2 for cooling the plurality of battery stacks 113 flows through each of the plurality of branch refrigerant passages 1111. That is, the plurality of branch refrigerant passages 1111 are provided for each of the plurality of battery stacks 113. The refrigerant 2 is, for example, air.

[0015] The refrigerant branching portion 112 is a structure for distributing the refrigerant 2 flowing from the cooling equipment 12 (described later) to a plurality of branch refrigerant passages 1111 .

[0016] 1 includes a cooling device 121 and a main refrigerant passage 122. The refrigerant 2 generated in the cooling device 121 passes through the main refrigerant passage 122 and flows into the branch refrigerant passages 1111 in the battery case 11. When the refrigerant 2 flows into the branch refrigerant passages 1111, the refrigerant 2 hits the refrigerant branch section 112, and the refrigerant 2 is distributed from the main refrigerant passage 122 to each branch refrigerant passage 1111, changing direction.

[0017] 2. Challenges The inventors of the present application were the first to recognize the following problem with the battery case 11 with the cooling equipment 12 as described above. That is, the flow rate of the refrigerant 2 distributed to the multiple branch refrigerant passages 1111 varies depending on the positional relationship between the cooling device 121 and the battery case 11.

[0018] To improve the output and life of the batteries, it is desirable to uniformly cool the multiple battery stacks 113. However, when there is a difference in the flow rate of the refrigerant 2 distributed to the multiple branch refrigerant passages 1111 as described above, it is difficult to say that the multiple battery stacks 113 are uniformly cooled.

[0019] 2A shows a state in which the cooling of the multiple battery stacks 113 is uneven. In the case of FIG. 2A, the battery stack 113-1 is located in the direction in which the refrigerant 2 generated by the cooling device 121 flows straight. Therefore, the flow rate of the refrigerant 2-1A flowing toward the battery stack 113-1 is greater than the flow rate of the refrigerant 2-2A flowing toward the battery stack 113-2. As a result, the battery stack 113-1 is cooled more strongly than the battery stack 113-2.

[0020] One way to address the issue of uneven cooling of the battery stack as described above is to change the shape of the coolant branching portion 112.

[0021] 2B, for example, tip 112a of refrigerant branching section 112 is shaped to be biased toward battery stack 113-1, which has a larger amount of refrigerant flowing in than in (A). In this case, the amount of refrigerant 2-1B flowing into battery stack 113-1 is less than the amount of refrigerant 2-1A in (A). On the other hand, the amount of refrigerant 2-2B flowing into battery stack 113-2 is more than the amount of refrigerant 2-2A in (A). In other words, by adopting a structure such as (B), the amount of refrigerant flowing into battery stacks 113-1 and 113-2 becomes closer to being uniform than in the state of (A).

[0022] However, since there are many possible positional relationships between the cooling device 121 and the battery case 11 depending on the installation situation, it is necessary to install a new battery case 11 each time with a refrigerant branching section 112 with a shape suitable for each situation. This increases the parts cost, and the effect of the above measure is limited.

[0023] 3.Characteristics and Effects of Battery Cases The upper part of the document mentions two problems: uneven cooling of the multiple battery stacks 113, and increased parts costs due to the installation of a new battery case 11 according to the positional relationship between the cooling device 121 and the battery case 11. In order to solve these problems, the present embodiment proposes a structure in which the refrigerant branching section 112 is detachable from the case body 111.

[0024] 3A shows an example of a battery case 11 according to an embodiment of the present disclosure. The refrigerant branching part 112 is not formed integrally with the case body 111. Instead, the refrigerant branching part 112 is formed to be detachable from the case body 111. The shape of the refrigerant branching part 112 is designed so that the multiple battery stacks 113 can be cooled as uniformly as possible. In other words, the shape of the refrigerant branching part 112 is optimized according to the positional relationship between the cooling device 121 and the battery case 11. The shape of the surface of the refrigerant branching part 112 that comes into contact with the refrigerant 2 may be an arc shape or a rectangle shape.

[0025] In the present embodiment as well, it is possible to use the refrigerant branching section 112 having an optimal shape, and therefore it is possible to uniformly cool the multiple battery stacks 113. This contributes to improving the output and extending the life of the battery.

[0026] Furthermore, the fact that refrigerant branching section 112 can be manufactured independently of case body 111 means that case body 111 of the same shape can be applied to various situations regardless of the positional relationship between cooling device 121 and battery case 11. Therefore, compared to the case where refrigerant branching section 112 is integrated with case body 111, this contributes to reducing parts costs.

[0027] 4. Configuration Example 3B and 3C show examples of joining the case body 111 and the refrigerant branching portion 112. In FIG.

[0028] Here, case body 111 and refrigerant branching part 112 form a labyrinth structure by joining contact surface 1112B on the case body 111 side and contact surface 1121B on the refrigerant branching part side in a stepped manner. This labyrinth structure can prevent foreign matter such as sand and dust from entering battery case 11. Case body 111 and refrigerant branching part 112 are integrated by bolts 3 that penetrate refrigerant branching part 112. Here, case body 111 and refrigerant branching part 112 may be fastened by a bolt extending from the case body 111 side and a nut on the refrigerant branching part 112 side with a through hole.

[0029] As another embodiment of the case body 111 and the refrigerant branching part 112, as shown in (C) of FIG. 3, there is a structure in which the refrigerant branching part 112 is slid and fitted to the case body 111. For example, a groove 1112C is provided in the case body 111. Meanwhile, a convex part 1121C having a shape corresponding to the groove 1112C of the case body 111 is provided in the refrigerant branching part 112. Then, the convex part 1121C of the refrigerant branching part 112 is inserted into the groove 1112C of the case body 111 and slid. As a result, the case body 111 and the refrigerant branching part 112 are joined together to form a labyrinth structure. The labyrinth structure can prevent foreign matter such as sand and dust from entering the battery case 11. [Explanation of symbols]

[0030] 1: battery pack, 2: refrigerant, 11: battery case, 12: cooling equipment, 111: case body, 112: refrigerant branching section, 113: battery stack, 121: cooling device, 122: main refrigerant passage, 1111: branch refrigerant passage

Claims

[Claim 1] A battery case for housing a plurality of battery stacks, a case body including a plurality of refrigerant passages configured to allow a refrigerant to flow through each of the plurality of battery stacks; a refrigerant branching section configured to distribute the refrigerant to the plurality of refrigerant passages; The refrigerant branching portion is detachable from the case body. Battery case.

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