Battery pack

Abstract

To provide a technique for suppressing contact between an upper case and parts inside a pack in a battery pack.SOLUTION: The battery pack includes a plurality of batteries, a case having a case body that partitions a compartment that accommodates the plurality of batteries and a flange portion that extends outward from the top of the case body, and a seal member that seals the flange portion. The case has a lower case that has a lower case body with a concave shape that constitutes the case body and a lower flange that constitutes the flange portion and an upper case that covers an opening and has an upper case body that constitutes the case body and an upper flange that constitutes the flange portion. The lower flange and upper flange each have an end portion where the seal member is arranged and an opposing unit that connects the end portion and the case body and extends outward from the top portion. The end portion is slanted with respect to the opposing unit.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a battery pack. [Background technology]

[0002] Conventionally, there is known a battery pack to be mounted on a vehicle, etc. For example, Patent Document 1 discloses a battery pack having a secondary battery accommodated in the battery pack, an upper flange provided on an upper case, a lower flange provided on a lower case, and a seal member disposed between the upper flange and the lower flange. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-165836 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a battery pack, when the pressure inside the battery pack increases due to, for example, a large amount of gas containing hydrogen being generated from the secondary battery, the upper case may deform by bulging upward due to the pressure inside the battery pack. In this case, a part of the upper case main body constituting the housing chamber that houses the battery pack is displaced inward. This may cause interference between the upper case and internal components arranged inside the battery pack. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to a first aspect of the present disclosure, there is provided a battery pack comprising: a case body defining a chamber for accommodating a plurality of batteries, the case body having a flange portion extending outward from an upper portion of the case body; and a seal member for sealing the flange portion, the case comprising a lower case having an opening formed at an upper end portion, the lower case having a concave lower case body constituting the case body and a lower flange constituting the flange portion, and an upper case covering the opening, the upper case body constituting the case body, and an upper flange constituting the flange portion, the lower flange and the upper flange each having an end portion where the seal member is disposed, and an opposing portion connecting the end portion and the case body, the opposing portion extending outward from the upper portion, the end portion being inclined with respect to the opposing portion. According to this embodiment, since the flange portion has an opposing portion that projects outward from the case body, even if the pressure inside the battery pack increases and the upper case deforms so as to bulge upward, the upper case body can be prevented from deforming inwardly of the storage chamber, thereby reducing the possibility of interference between the upper case and internal components of the pack. (2) In the above embodiment, a boundary portion may be provided between the end portion and the opposing portion, and the end portion may be bent at the boundary portion so as to be inclined with respect to the opposing portion. According to this embodiment, when the pressure inside the battery pack increases and the upper case deforms to bulge upward, the upper case deforms upward starting from the boundary portion, thereby reducing the possibility of interference between the upper case and internal components of the battery pack. (3) In the above embodiment, the end portion may extend from the opposing portion toward a side where a bottom portion of the lower case body is located, and may be inclined with respect to the opposing portion. According to this embodiment, the end portion is located lower than the opposing portion, i.e., closer to the bottom of the lower case body, thereby making it possible to prevent the case height from becoming large. (4) In the above embodiment, the end portion may be bent at a right angle to the facing portion, and thus may be inclined with respect to the facing portion. According to this embodiment, by bending the end portion at a right angle to the opposing portion, it is possible to prevent the dimension of the case in a direction perpendicular to the height direction from increasing. The present disclosure can be realized in various forms, and in addition to the forms described above, the present disclosure can be realized in the form of a manufacturing method of a battery pack, etc. [Brief description of the drawings]

[0007] [Figure 1] A view of the battery pack from above. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the battery pack taken along line II-II. [Diagram 3] 11 is an explanatory diagram showing deformation of an upper case when the internal pressure of a conventional battery pack increases. [Figure 4] 5 is an explanatory diagram showing deformation of an upper case when the internal pressure increases in the first embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. First embodiment: FIG. 1 is a view of the battery pack 1 as seen from above. The battery pack 1 includes a case 9, a plurality of modules 3 arranged in the case 9, and a bus bar 5 that electrically connects the plurality of modules 3. The case 9 includes a case body 90 that defines a storage chamber 8 that stores the plurality of modules 3. Each of the plurality of modules 3 includes a plurality of secondary batteries 4. The secondary batteries 4 are, for example, lithium ion batteries. The bus bar 5 is a component within the pack and is also a high-voltage component. The battery pack 1 further includes a pressure release valve 7 formed in the case body 90. The secondary batteries 4 are not limited to lithium ion batteries, and may be other batteries such as nickel-metal hydride batteries. The pressure release valve 7 is provided at an arbitrary position of an upper case body 210 of the case body 90 described later.

[0009] Fig. 2 is a schematic diagram showing a cross section of the battery pack 1 taken along line II-II in Fig. 1. In addition to a case body 90, the case 9 has a flange portion 30 that protrudes outward from an upper portion of the case body 90. The case 9 has a lower case 100 and an upper case 200. The lower case 100 and the upper case 200 are made of metal.

[0010] The lower case 100 has an opening formed at its upper end. The lower case 100 has a concave-shaped lower case main body 110 constituting the case main body 90, and a lower flange 120 constituting the flange portion 30. The lower flange 120 protrudes outward from the lower case main body 110. In this embodiment, the module 3 is fixed to the lower case main body 110 using a bracket and adhesive (not shown).

[0011] Upper case 200 has a shape that covers the opening of lower case 100. Upper case 200 has an upper case main body 210 that constitutes case main body 90, and an upper flange 220 that constitutes flange portion 30. Upper flange 220 protrudes outward from upper case main body 210 and faces lower flange 120.

[0012] The battery pack 1 further includes a seal member 10 that seals the flange portion 30. The seal member 10 seals between the lower case 100 and the upper case 200, and hermetically seals the battery pack 1. More specifically, the seal member 10 seals between the lower flange 120 and the upper flange 220. The seal member 10 is, for example, a gasket. Note that the seal member 10 is not limited to a gasket, and may be an adhesive or the like.

[0013] The flange portion 30 includes an end portion 22 where the seal member 10 is disposed, an opposing portion 24 that connects the end portion 22 and the case body 90 and protrudes outward from an upper portion of the case body 90, and a boundary portion 26 that is a boundary between the end portion 22 and the opposing portion 24. The boundary portion 26 is a region where the flange portion 30 is bent.

[0014] The lower flange 120 includes a lower flange end portion 122 constituting the end portion 22, a lower flange opposing portion 124 constituting the opposing portion 24, and a lower flange boundary portion 126 constituting the boundary portion 26.

[0015] The upper flange 220 includes an upper flange end portion 222 constituting the end portion 22 , an upper flange opposing portion 224 constituting the opposing portion 24 , and an upper flange boundary portion 226 constituting the boundary portion 26 .

[0016] The lower flange end portion 122 and the upper flange end portion 222 are parallel to each other. The lower flange opposing portion 124 and the upper flange opposing portion 224 are also parallel to each other.

[0017] In this embodiment, the facing portion 24 extends in a direction perpendicular to the direction in which the bottom of the lower case body 110 and the upper case body 210 face each other, i.e., the up-down direction of the battery pack 1. The perpendicular direction is the horizontal direction when the battery pack 1 is placed on a horizontal surface. The end portion 22 extends from the facing portion 24 so as to approach the side where the bottom of the lower case body 110 is located. Furthermore, the flange portion 30 is bent at a right angle at the boundary portion 26, and the end portion 22 is inclined at a right angle to the facing portion 24. Here, the "right angle" corresponds to a range of 90±10°.

[0018] In this embodiment, the bus bar 5 is located between a side surface of the case body 90 (specifically, a side surface of the lower case body 110) and the module 3. In this embodiment, in the height direction of the battery pack 1, a part of the bus bar 5 is at a height position overlapping with an upper part of the module 3. Moreover, the bus bar 5 is disposed at a predetermined distance from the bottom of the lower case body 110.

[0019] 3 is an explanatory diagram showing deformation of an upper case 200t when the internal pressure of a conventional battery pack 1t increases. A conventional flange portion 30t in the battery pack 1t is not located at the top of a case body 90t, but is located in the middle of the case body 90t.

[0020] The flange portion 30t is composed of an end portion 22t and an opposing portion 24t, and does not include the boundary portion 26. The lower flange 120t includes a lower flange end portion 122t constituting the end portion 22t, and a lower flange opposing portion 124t constituting the opposing portion 24t. The upper flange 220t includes an upper flange end portion 222t constituting the end portion 22t, and an upper flange opposing portion 224t constituting the opposing portion 24t. The upper case main body 210t includes a top portion 211t and a side portion 212t. The other configurations are the same as those in FIG. 2.

[0021] In FIG. 3, for example, when the secondary battery 4 constituting the module 3 is short-circuited, a large amount of gas containing hydrogen may be generated in the battery pack 1t in a short time. In that case, even if the battery pack 1t is equipped with a pressure release valve 7, hydrogen gas or the like may accumulate in the battery pack 1t, exceeding the release capacity of the pressure release valve 7. In FIG. 3, since the gas containing hydrogen is lighter than air, it accumulates in the upper space S1 in the accommodation chamber 8t. As a result, when the internal pressure of the battery pack 1t exceeds a specified value, the top part 211t of the upper case main body 210t is deformed upward. Meanwhile, the side part 212t of the upper case main body 210t is deformed in a direction approaching the bus bar 5 under the influence of the deformation of the top part 211t. As a result, the upper case 200t and the bus bar 5 may interfere with each other, causing a short circuit.

[0022] Fig. 4 is an explanatory diagram showing deformation of upper case 200 when internal pressure rises in this embodiment. A part of case body 90 and flange portion 30 in Fig. 4 are configured similarly to those in Fig. 2. Note that the bending point of upper flange boundary portion 226 constituting boundary portion 26 is referred to as bending point a.

[0023] In FIG. 4, for example, when the secondary battery 4 constituting the module 3 is short-circuited, a large amount of gas containing hydrogen is generated in the battery pack 1 in a short time. As a result, hydrogen gas and the like exceeding the release capacity of the pressure release valve 7 are accumulated in the upper space S2 of the storage chamber 8. When the internal pressure of the battery pack 1 exceeds a specified value due to the generation of gas, the upper case body 210 is deformed upward. At this time, the upper case 200 is deformed upward from a bending point a of the upper flange boundary portion 226 constituting the boundary portion 26 of the upper flange 220 located on the outer side of the upper case body 210. This makes it possible to suppress the upper case body 210 from deforming inwardly of the storage chamber 8, thereby reducing the possibility of interference between the upper case 200 and the bus bar 5. Therefore, a short circuit between the upper case 200 and the bus bar 5 can be suppressed.

[0024] As described above, in the battery pack 1 of this embodiment, as shown in Fig. 2, the flange portion 30 has the facing portion 24 that protrudes outward from the upper portion of the case body 90. Therefore, even if the pressure inside the battery pack 1 increases and the upper case 200 deforms so as to bulge upward, the upper case body 210 can be prevented from deforming inwardly of the storage chamber 8. This reduces the possibility of interference between the upper case 200 and the bus bar 5. Therefore, a short circuit between the upper case 200 and the bus bar 5 can be prevented.

[0025] In addition, in the battery pack 1 of this embodiment, the flange portion 30 is bent at a right angle at the boundary portion 26, so that the opposing portion 24 and the end portion 22 are inclined at a right angle. This makes it possible to prevent the height of the case 9 from increasing. Furthermore, it is possible to prevent the distance from the case main body 90 to the end portion 22, that is, the dimension in the direction perpendicular to the case main body 90, from increasing. Therefore, it is possible to design a more compact battery pack 1.

[0026] B. Other embodiments: (B1) In the above-described first embodiment, the battery pack 1 is provided with a pressure release valve 7. In contrast, the battery pack 1 does not necessarily have to be provided with a pressure release valve 7.

[0027] (B2) In the above-described first embodiment, the in-pack component is the bus bar 5. However, the in-pack component does not have to be the bus bar 5.

[0028] (B3) In the first embodiment described above, the flange portion 30 is bent at a right angle at the boundary portion 26, and the opposing portion 24 and the end portion 22 are inclined at a right angle. In contrast, the flange portion 30 does not have to be bent at a right angle at the boundary portion 26, and the opposing portion 24 and the end portion 22 do not have to be inclined at a right angle.

[0029] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features of the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention can be appropriately replaced or combined to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0030] 1,1t...battery pack, 3...module, 4...secondary battery, 5...bus bar, 7...pressure release valve, 8...accommodation chamber, 9...case, 10...sealing member, 22,22t...end, 24,24t...facing portion, 26...boundary portion, 30,30t...flange portion, 90,90t...case body, 100...lower case, 110...lower case body, 120,120t...lower flange, 122,122t...lower Flange end, 124, 124t...lower flange facing portion, 126...lower flange boundary portion, 200, 200t...upper case, 210, 210t...upper case main body, 211t...top portion, 212t...side portion, 220, 220t...upper flange, 222, 222t...upper flange end, 224, 224t...upper flange facing portion, 226...upper flange boundary portion

Claims

1. A battery pack comprising: A number of batteries; a case having a case body defining a chamber for accommodating the plurality of batteries and a flange portion extending outward from an upper portion of the case body; a seal member that seals the flange portion, The case is a lower case having an opening at an upper end, the lower case having a concave-shaped lower case body constituting the case body and a lower flange constituting the flange portion; an upper case covering the opening, the upper case having an upper case main body constituting the case main body and an upper flange constituting the flange portion; The lower flange and the upper flange each include an end portion at which the seal member is disposed; a facing portion that connects the end portion and the case body and that protrudes outward from the upper portion, The end portion is inclined relative to the opposing portion.

2. 2. The battery pack according to claim 1, a boundary portion between the end portion and the opposing portion; The battery pack is bent at the boundary portion, so that the end portion is inclined relative to the opposing portion.

3. 2. The battery pack according to claim 1, The end portion extends from the opposing portion toward a side where a bottom portion of the lower case body is located, and is inclined with respect to the opposing portion.

4. The battery pack according to any one of claims 1 to 3, The end portion is bent at a right angle to the opposing portion and is inclined with respect to the opposing portion.

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