Battery pack

Abstract

To provide a battery pack with improved sealing performance against water hammer caused by high-pressure cleaning, etc.SOLUTION: A battery pack includes a battery pack including a plurality of battery cells arranged in a first direction, a case including an internal space for accommodating the battery pack and a wall surface defining at least a portion of the internal space, and a sealing component that penetrates the wall surface to reach the internal space, the wall surface includes a recess that is recessed toward the internal space when viewed from the outside of the case, a through hole that reaches the internal space is formed at the bottom of the recess, and the sealing component seals the through hole.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present technology relates to battery packs. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2019-220592 (Patent Document 1) discloses a structure of a ventilation unit that can prevent water and the like from entering into a case of an electrical component such as a battery pack for an automobile. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-220592 Summary of the Invention [Problem to be solved by the invention]

[0004] It is required that the sealing performance of O-rings and the like is not destroyed even when subjected to water hammer from high-pressure cleaning, etc. From this perspective, conventional sealing structures are not necessarily sufficient.

[0005] An object of the present technology is to provide a battery pack with improved sealing performance against water hammer caused by high-pressure cleaning or the like. [Means for solving the problem]

[0006] The present technology provides the following battery pack.

[0007] [1] A battery pack comprising: a battery pack including a plurality of battery cells arranged in a first direction; a case including an internal space for accommodating the battery pack and a wall surface defining at least a portion of the internal space; and a sealing component that penetrates the wall surface and reaches the internal space, wherein the wall surface has a recess that is recessed toward the internal space when viewed from the outside of the case, and a through hole that reaches the internal space is formed at the bottom of the recess, and the sealing component seals the through hole. [2] The battery pack according to [1], wherein the wall surface is made of a plate-shaped member.

[0008] [3] The battery pack according to [1] or [2], wherein the sealing part includes a pressure regulating valve that opens when the internal pressure of the internal space exceeds a predetermined value.

[0009] [4] The battery pack according to [3], further comprising an electrical component unit housed in the case, wherein the pressure regulating valve is located on the opposite side of the electrical component unit with respect to the assembled battery.

[0010] [5] The battery pack according to any one of [1] to [3], further comprising an electrical component unit housed in the case, wherein the sealing component includes a connector electrically connected to the electrical component unit.

[0011] [6] The battery pack according to any one of [1] to [5], wherein the sealing component is inserted into the through hole along a second direction perpendicular to the first direction.

[0012] [7] The battery pack according to any one of [1] to [6], wherein the recessed portion has a diameter that decreases from the outside of the case toward the internal space. [Effects of the Invention]

[0013] According to the present technology, it is possible to provide a battery pack with improved sealing properties against water hammer caused by high-pressure washing or the like. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a diagram showing the configuration of a battery pack. [Figure 2] FIG. [Figure 3] FIG. 2 is a perspective view showing a battery cell. [Figure 4] FIG. 2 is a perspective view of the case of the battery pack. [Figure 5] FIG. 2 is a side view of the case of the battery pack. [Figure 6] FIG. 3 is a cross-sectional view showing the structure around the pressure regulating valve. [Figure 7] 1 is a diagram showing an example (part 1) of the arrangement of a battery pack and a pressure regulating valve in a vehicle. [Figure 8] FIG. 10 is a diagram showing an example (part 2) of the arrangement of a battery pack and a pressure regulating valve in a vehicle. [Figure 9] FIG. 2 is a perspective view showing the periphery of an electrical component unit in the battery pack. [Figure 10] 10 is a diagram showing the electrical component unit shown in FIG. 9 as viewed from the Y-axis direction. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0016] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0017] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0018] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0019] In this specification, "battery" is not limited to lithium-ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries.

[0020] In this specification, "battery cells" are not necessarily limited to prismatic ones, but may also include cells of other shapes, such as cylindrical, pouch, and blade types. Furthermore, "battery cells" can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). However, the use of "battery cells" is not limited to in-vehicle use.

[0021] 1 is a diagram showing the configuration of a battery pack according to the present embodiment. As shown in Fig. 1, the battery pack 1 includes a battery pack 10, a case 20, a pressure regulating valve 30, a connector 40, and an electrical component unit 50.

[0022] The battery pack 10 includes multiple battery cells stacked in the Y-axis direction. The case 20 includes an internal space 21 that houses the battery pack 10 and the electrical component unit 50, as well as a wall surface 22, a floor surface 23, and a lid surface 24 that define the internal space 21.

[0023] Wall surface 22 of case 20 has recessed portion 22A recessed toward internal space 21 when viewed from the outside of case 20. Floor surface 23 includes first floor surface portion 23A extending in the XY plane direction and second floor surface portion 23B intersecting obliquely with the XY plane direction.

[0024] The pressure regulating valve 30 penetrates the wall surface 22 of the case 20 along the X-axis direction and reaches the internal space 21 of the case 20. The pressure regulating valve 30 opens when the internal pressure of the internal space 21 of the case 20 exceeds a predetermined value. This prevents the internal pressure of the internal space 21 from rising excessively.

[0025] 1, the pressure regulating valve 30 is located on the opposite side of the battery pack 10 from the electrical component unit 50. The connector 40 is electrically connected to the electrical components included in the electrical component unit 50.

[0026] By providing the pressure regulating valve 30 on the opposite side of the connector 40 and the electrical component unit 50, it is possible to prevent gas from being discharged from the pressure regulating valve 30 toward workers during maintenance work on the electrical component unit 50.

[0027] However, the shape of the case 20 and the arrangement of the battery pack 10, pressure regulating valve 30, connector 40, and electrical component unit 50 in the case 20 are not limited to those illustrated in Fig. 1. Furthermore, the stacking direction of the battery cells in the battery pack 10 is not limited to the Y-axis direction.

[0028] Fig. 2 is a perspective view of the battery pack 10. The battery pack 10 shown in Fig. 2 includes battery cells 100 and insulating members 200 (inter-cell separators). The battery cells 100 and the insulating members 200 are arranged alternately along the Y-axis direction (first direction).

[0029] The battery cells 100 are rectangular battery cells, and a plurality of battery cells 100 are provided along the Y-axis direction. The plurality of battery cells 100 are electrically connected to one another via bus bars (not shown).

[0030] The insulating member 200 is provided between the multiple battery cells 100. The insulating member 200 prevents unintended electrical conduction between adjacent battery cells 100. The insulating member 200 ensures electrical insulation between adjacent battery cells 100.

[0031] 1 is formed by housing the battery assembly 10 in a case 20. The battery pack 1 may have a cell-to-pack structure in which a stack of battery cells 100 and insulating members 200 is directly supported by the wall surface 22 of the case 20, or may have a cell-module-pack structure in which a battery module including a plurality of battery cells 100 and insulating members 200 is housed in the case 20.

[0032] 3 is a perspective view showing the battery cell 100. As shown in Fig. 3, the battery cell 100 has a rectangular shape. The battery cell 100 has an electrode terminal 110, a battery case 120, and a gas release valve 130.

[0033] The electrode terminal 110 is formed on the battery case 120. The electrode terminal 110 has a positive electrode terminal 111 and a negative electrode terminal 112 that are aligned along an X-axis direction (second direction) that is perpendicular to a Y-axis direction (first direction). The positive electrode terminal 111 and the negative electrode terminal 112 are spaced apart from each other in the X-axis direction.

[0034] The battery case 120 has a rectangular parallelepiped shape and forms the exterior of the battery cell 100. The battery case 120 includes a case body 120A that houses an electrode assembly and an electrolyte (not shown), and a sealing plate 120B that seals the opening of the case body 120A. The sealing plate 120B is joined to the case body 120A by welding.

[0035] The battery case 120 has an upper surface 121, a lower surface 122, a first side surface 123, a second side surface 124, and two third side surfaces 125.

[0036] The upper surface 121 is a plane perpendicular to the Z-axis direction (third direction) that is perpendicular to the Y-axis direction and the X-axis direction. The electrode terminals 110 are disposed on the upper surface 121. The lower surface 122 faces the upper surface 121 along the Z-axis direction.

[0037] Each of the first side surface 123 and the second side surface 124 is a plane perpendicular to the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has the largest area among the multiple side surfaces of the battery case 120. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction, with the X-axis direction being the longitudinal direction and the Z-axis direction being the lateral direction.

[0038] The multiple battery cells 100 are stacked such that the first side surfaces 123 and the second side surfaces 124 of the battery cells 100 adjacent to each other in the Y-axis direction face each other. As a result, the positive electrode terminals 111 and the negative electrode terminals 112 are arranged alternately in the Y-axis direction in which the multiple battery cells 100 are stacked.

[0039] The gas release valve 130 is provided on the top surface 121. When the temperature of the battery cell 100 rises (thermal runaway) and the internal pressure of the battery case 120 exceeds a predetermined value due to gas generated inside the battery case 120, the gas release valve 130 releases the gas to the outside of the battery case 120.

[0040] FIG. 4 is a perspective view of the case 20 of the battery pack 1, and FIG.

[0041] As shown in Figures 4 and 5, recess 22A provided in wall surface 22 tapers in a truncated cone shape from the outside of case 20 toward internal space 21. Recess 22A is provided near a corner of case 20. Because the rigidity of case 20 is high near the corner of case 20, deformation of case 20 around pressure regulating valve 30 is suppressed even when the pressure in internal space 21 increases. As a result, it becomes easier to control pressure regulating valve 30 to operate accurately at the desired pressure.

[0042] 5, for example, the "vicinity of the corner" refers to a region between the center of case 20 in the Y-axis direction (case center) and the end of case 20 in the Y-axis direction (case end), where the center of recess 22A is closer to the case end than to the case center. In the example of FIG. 5, the center of recess 22A is located in a position away from the center of case 20 in the Z-axis direction (a position shifted downward in FIG. 5).

[0043] However, the shapes and positions of the recess 22A and the pressure adjustment valve 30 are not limited to those exemplified in Fig. 5. For example, the recess 22A and the pressure adjustment valve 30 may be provided on the wall surface 22 extending in the XZ plane direction.

[0044] Fig. 6 is a cross-sectional view showing the structure around the pressure regulating valve 30. As shown in Fig. 6, the wall surface 22 of the case 20 is made of a plate-shaped member. A recess 22A is formed by drawing the plate-shaped member. A through-hole 22B is formed at the bottom of the recess 22A, reaching the internal space 21. The recess 22A has a depth D.

[0045] The pressure regulating valve 30 includes a plug 31 and a seal member 32. The plug 31 includes a main body portion 31A and an insertion portion 31B. The insertion portion 31B of the plug 31 is inserted into the through-hole 22B. The seal member 32 seals the gap between the insertion portion 31B of the plug 31 and the through-hole 22B of the case 20.

[0046] 5, the height H1 of the main body 31A of the plug 31 is greater than the depth D of the recess 22A (H1>D), and therefore the plug 31 protrudes from the outer surface of the case 20 by the difference H2 (H1-D). This difference H2 is, for example, approximately 0.5 mm.

[0047] In this way, by making the plug 31 protrude slightly beyond the outer surface of the case 20 adjacent to the recess 22A, space can be secured for providing a jig for pushing the plug 31 into the through hole 22B, thereby enabling the pressure regulating valve 30 to be installed easily and reliably.

[0048] 6, by providing a through-hole 22B at the bottom of recess 22A and inserting plug 31 to provide pressure regulating valve 30, it is possible to shield at least a portion of the periphery of pressure regulating valve 30, thereby preventing damage to the sealing properties of pressure regulating valve 30 due to water hammer during high-pressure washing. As a result, water is prevented from entering internal space 21 of case 20 through through-hole 22B.

[0049] Furthermore, by making the recess 22A narrower in diameter toward the internal space 21, a slope can be formed on the lower side of the battery pack 1 (lower side in Figure 6) that causes water to flow to the outside of the case 20, thereby more effectively preventing water from entering the internal space 21.

[0050] Furthermore, by forming recess 22A, the rigidity of the plate-like member that constitutes case 20 is increased around recess 22A. As a result, as described above, it is easy to control pressure regulating valve 30 to operate accurately at the desired pressure. Also, it is easy to prevent unintended removal of pressure regulating valve 30 when pressure regulating valve 30 opens.

[0051] 7 and 8 are diagrams showing examples of the arrangement of the battery pack 1 and the pressure regulating valve 30 in a vehicle.

[0052] 7, the battery pack 1 is entirely covered by vehicle components when attached to the bottom of the vehicle 1000. In this case, the impact of water hammer when the vehicle 1000 is high-pressure washed is relatively small.

[0053] 8, when the battery pack 1 is attached to the bottom of the vehicle 1000, the bottom of the battery pack 1 protrudes from the bottom of the vehicle 1000. In this case, the impact of water hammer during high-pressure washing of the vehicle 1000, etc., becomes greater. In this case, by attaching the pressure regulating valve 30 to the top of the battery pack 1, the pressure regulating valve 30 is covered by vehicle components, and water can be prevented from entering the case 20 through the through-hole 22B for attaching the pressure regulating valve 30.

[0054] In this way, the mounting position of the pressure regulating valve 30 in the case 20 can be changed depending on the mounting position and mounting direction of the battery pack 1 in the vehicle 1000, etc.

[0055] Fig. 9 is a perspective view showing the periphery of the electrical component unit, and Fig. 10 is a view showing the electrical component unit shown in Fig. 9 as viewed from the Y-axis direction.

[0056] 9 and 10, a connector 40 is provided on the wall surface 22 of the case 20. The connector 40 constitutes a power supply port for the battery cells 100 and electrical component unit 50 housed inside the case 20.

[0057] The housing 51 of the electrical component unit 50 houses electronic components including a main relay 52, a shunt resistor 53, a cement resistor 54, a bus bar 55, and a current sensor 56. The housing 51 may also house other electronic components not shown in FIGS. 9 and 10, such as a fuse and a precharge relay.

[0058] The electronic components housed in housing 51 include first electronic components (such as main relay 52 and current sensor 56) that are relatively tall in the Z-axis direction, and second electronic components (such as shunt resistor 53, cement resistor 54, and bus bar 55) that are relatively short in the Z-axis direction. By arranging the second electronic components, which are shorter in height, closer to wall surface 22 than the first electronic components, which are taller, it is possible to effectively utilize internal space 21 of case 20 located on second floor surface portion 23B.

[0059] The various examples in this embodiment do not limit the scope of the present technology beyond the scope of the claims. For example, in this embodiment, the structure of the pressure adjustment valve 30 provided in the recess 22A has been described, but a similar structure may also be applied to the installation portion of the connector 40.

[0060] The pressure regulating valve 30 and the connector 40 may be adjacent to each other and positioned to block water hammer from each other. Furthermore, a shielding structure such as a rib (which may be integral with the case 20 or a separate part) may be provided around the recess 22A of the case 20 to block at least part of the water hammer.

[0061] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0062] 1 battery pack, 10 assembled battery, 20 case, 21 internal space, 22 wall surface, 22A recess, 22B through hole, 23 floor surface, 23A first floor surface portion, 23B second floor surface portion, 24 lid surface, 30 pressure regulating valve, 31 plug, 31A main body portion, 31B fitting portion, 32 sealing member, 40 connector, 50 electrical component unit, 51 housing, 52 main relay, 53 shunt resistor, 54 cement resistor, 55 bus bar, 56 current sensor, 100 battery cell, 110 electrode terminal, 111 positive terminal, 112 negative terminal, 120 battery case, 120A case body, 120B sealing plate, 121 upper surface, 122 lower surface, 123 first side surface, 124 second side surface, 125 Third side, 130 gas exhaust valve, 200 insulating member, 1000 vehicle.

Claims

1. a battery pack including a plurality of battery cells arranged in a first direction; a case including an internal space for accommodating the battery pack and a wall surface that defines at least a portion of the internal space; a sealing component that penetrates the wall surface and reaches the internal space, the wall surface has a recess that is recessed toward the internal space when viewed from the outside of the case, a through-hole reaching the internal space is formed in a bottom of the recess, and the sealing component seals the through-hole; the wall surface is made of a plate-like member, and the depth of the recess is greater than the thickness of the plate-like member; the sealing component includes a pressure regulating valve that opens when the internal pressure of the internal space exceeds a predetermined value, the pressure regulating valve includes a main body portion that contacts a bottom portion of the recessed portion, an insertion portion that is inserted into the through hole and protrudes toward the internal space, and a seal member that seals a gap between the insertion portion and the through hole, The through-hole and the sealing member are shielded from the outside of the case by the main body and the plate-like member.

2. A battery pack as described in claim 1, wherein a rib protruding from the wall surface to the outside of the case is provided around the recess.

3. further comprising an electrical component unit housed in the case, 3. The battery pack according to claim 1, wherein the pressure regulating valve is located on an opposite side of the assembled battery from the electrical component unit.

4. further comprising an electrical component unit housed in the case, 3. The battery pack according to claim 1, wherein the sealing part includes a connector electrically connected to the electrical component unit.

5. 3. The battery pack according to claim 1, wherein the sealing component is inserted into the through hole along a second direction perpendicular to the first direction.

6. 3. The battery pack according to claim 1, wherein the recess has a diameter that decreases from the outside of the case toward the internal space.

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