Battery pack

Abstract

A battery pack (10) has: an accommodation body (200); a battery module (100) fixed to an inner surface (217) (first surface) of a lower case (210) of the accommodation body (200); an upper bracket (320) fixed to an upper case (220) on the opposite side of the first surface (inner surface (217) of a lower plate (212)) of the accommodation body (200) and accommodating an electronic component (312); and a lower bracket (310) supporting the opposite side of the upper bracket (320) from the upper case (220), the rigidity of the lower bracket (310) being lower than the rigidity of the upper case (220) of the accommodation body (200).

Description

Technical Field

[0001] This invention relates to a battery pack. Background Technology

[0002] In recent years, a battery pack for various applications, such as automobiles, has been developed. The battery pack includes: multiple battery modules; a housing that houses the modules; and a disconnect switch for disconnecting the circuit that electrically connects the battery modules to each other. The disconnect switch is generally referred to, for example, sometimes as a service disconnect switch (SD / SW) or a service plug.

[0003] Patent document 1 describes an example of a battery pack. It proposes a technique in which a control component is fixed to a fixed beam, preventing deformation of the control component when the individual battery cells expand.

[0004] Patent document 2 discloses a technique for fixing a Manual Service Disconnect (MSD) (for manually disconnecting a maintenance plug in a high-voltage system) to a top cover via an MSD support plate. This technique increases the contact area between the MSD and the top cover, reducing concentrated stress between them and thus preventing cracks in the top cover caused by such concentrated stress.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2020 / 259139

[0008] Patent Document 2: Specification of Chinese Patent No. 107887536 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] Furthermore, when the battery pack is subjected to vibration, the casing may sometimes experience strain. Under such strain, there is a possibility that water may accumulate inside the casing.

[0011] One example of the object of the present invention is to suppress strain in the battery pack casing. Other objects of the invention will become apparent from the description herein.

[0012] Technical means to solve the problem

[0013] An embodiment of the present invention is described below.

[0014] 1. A battery pack, comprising:

[0015] Frame;

[0016] The battery module is fixed to the first side of the frame;

[0017] The component is fixed to a second side of the frame opposite to the first side and houses electronic components; and

[0018] A supporting member supports the side of the part opposite to the second surface.

[0019] The rigidity of the supporting member is lower than the rigidity of the second surface of the frame.

[0020] 2. The battery pack according to 1, wherein the rigidity of the component is higher than the rigidity of the second surface of the frame.

[0021] 3. The battery pack according to 1 or 2, wherein the rigidity of the component is higher than the rigidity of the support member.

[0022] 4. The battery pack according to 1 or 2, wherein a plurality of said battery modules are provided, and at least one of said battery modules is located below the support member.

[0023] 5. The battery pack according to 1 or 2, wherein the frame comprises: a first portion having the first surface and a second portion having the second surface.

[0024] 6. The battery pack according to 1 or 2, wherein the frame has ribs disposed on the inner surface of the first side.

[0025] The support member is fixed to the rib.

[0026] 7. The battery pack according to 1 or 2, wherein the rigidity of the support member is less than the rigidity of the first surface.

[0027] 8. The battery pack according to 6, wherein the rib is provided as part of a receiving portion for receiving the battery module.

[0028] The support member is provided as a cover for the receiving part.

[0029] The effects of the invention

[0030] According to the embodiments of the present invention, strain in the battery pack casing can be suppressed. Attached Figure Description

[0031] [ Figure 1 [ ] is a perspective view of the battery pack according to the embodiment.

[0032] [ Figure 2 [This is a plan view of the battery pack in the embodiment with the upper casing removed.]

[0033] [ Figure 3 ] is from Figure 2 A plan view showing the state of the lower and upper supports after they have been removed.

[0034] [ Figure 4 ] is to Figure 2 The diagram shows the AA section together with the floor panel.

[0035] [ Figure 5 It is focused on Figure 4 The diagram shows a simplified representation of the connection structure between the lower and upper supports. Detailed Implementation

[0036] Hereinafter, embodiments of the present invention will be described using the accompanying drawings. In all the drawings, the same reference numerals are used to denote the same components, and descriptions are omitted where appropriate.

[0037] Figure 1 This is a perspective view of the battery pack 10 according to the embodiment. Figure 2 This is a plan view of the battery pack 10 in the embodiment with the upper housing 220 removed. Figure 3 From Figure 2 A plan view showing the state of the lower bracket 310 and the upper bracket 320 after they have been removed. Figure 4 It is Figure 2 The AA section is shown in the figure together with the floor panel 50.

[0038] In one implementation, the battery pack 10 is, for example, mounted in a vehicle. Specifically, as... Figure 4 As shown, the battery pack 10 is mounted between the front and rear wheels of the vehicle and below the floor panel 50. Unless otherwise specified, the following description assumes that the battery pack 10 is mounted below the floor panel 50. However, the battery pack 10 can also be used for purposes other than automobiles.

[0039] In the figures, for illustration, the X, Y, and Z directions are shown. The X direction indicates the front-to-back direction of the battery pack 10. The Y direction is orthogonal to the X direction. The Z direction indicates the left-to-right direction of the battery pack 10. The Z direction is orthogonal to both the X and Y directions. The Z direction indicates the up-and-down direction of the battery pack 10. Arrows pointing to the X, Y, and Z directions indicate the front, left, and up directions of the battery pack 10, respectively. Figure 2 and Figure 3 In the diagram, a white circle with a black dot in the Z-direction indicates an arrow pointing in the Z-direction extending from the depths of the paper towards the foreground. Figure 4In the diagram, a white circle with a black dot in the Y direction indicates an arrow pointing in the Y direction extending from the depth of the paper toward the foreground. However, the relationship between the X, Y, and Z directions and the front-back, left-right, and up-down directions of the battery pack 10 is not limited to this example.

[0040] In this embodiment, the forward / backward, left / right, and up / down directions of the battery pack 10 are determined by the vehicle on which the battery pack 10 is mounted. The X, Y, and Z directions indicate the forward / backward, left / right, and up / down directions of the vehicle, respectively. Arrows pointing to the X, Y, and Z directions indicate the forward, left, and up directions of the vehicle, respectively. However, the relationship between the forward / backward, left / right, and up / down directions of the battery pack 10 and the forward / backward, left / right, and up / down directions of the vehicle is not limited to this example.

[0041] From here on, as needed, the direction perpendicular to the Z direction will be referred to as the horizontal direction.

[0042] The battery pack 10 includes: four battery modules 100, a housing 200, a lower bracket 310, an upper bracket 320, a disconnect switch 410, and a vent valve 420. The four battery modules 100 include a pair of battery modules 100 arranged on the left side in the X direction and a pair of battery modules 100 arranged on the right side in the X direction. The disconnect switch 410 is generally referred to, for example, sometimes as a service disconnect switch or service plug. The housing 200 has a lower housing 210 and an upper housing 220. The lower housing 210 is generally referred to, for example, sometimes as a tray or main body. The lower housing 210 includes a lower plate 212 and a side frame 214. The upper housing 220 is generally referred to, for example, sometimes as a cover or lid.

[0043] Each battery module 100 has multiple battery cells stacked in a horizontal direction. For example, in each battery module 100, multiple groups of battery cells, each comprising multiple battery cells connected in parallel, are connected in series. Alternatively, multiple individual battery cells may be connected in series.

[0044] A pair of terminals 110 are provided at the front of the side frame 214. The pair of terminals 110 are arranged approximately parallel in the Y direction. The front end of each terminal 110 protrudes forward from the front surface of the side frame 214. In the circuit, four battery modules 100 are connected in series between the pair of terminals 110.

[0045] The number and configuration of battery modules 100 are not limited to the examples of the embodiments. For example, the number of battery modules 100 may be only 2, only 3, or more than 5. That is, the battery pack 10 may include multiple battery modules 100.

[0046] The lower housing 210 and the upper housing 220 are connected to each other via a sealing material 230. The lower housing 210, the upper housing 220, and the sealing material 230 form a receiving space 250. The receiving space 250 houses four battery modules 100, a disconnect switch 410, a lower bracket 310, and an upper bracket 320.

[0047] The lower plate 212 defines the bottom of the receiving space 250. The side frame 214 defines the side portion of the receiving space 250. Specifically, viewed from the Z direction, the side frame 214 is provided along the outermost periphery of the lower plate 212. The upper shell 220 defines the top of the receiving space 250.

[0048] The sealing material 230 is, for example, an elastic material such as rubber. Viewed from the Z direction, the sealing material 230 is provided throughout the entire circumference of the side frame 214. Thus, viewed from the Z direction, the sealing material 230 surrounds the receiving space 250. Therefore, the receiving space 250 can be sealed relative to the external space of the receiving body 200 by means of the sealing material 230.

[0049] The lower support 310 and the upper support 320 are stacked in two layers relative to the receiving space 250.

[0050] Specifically, the lower end of the lower bracket 310 is fixed to the lower plate 212 by fasteners such as bolts (not shown). Figure 4 In the example shown, a rib (module defining rib 216) is provided on the inner surface of the lower plate 212 to define an area for housing the battery module 100. In other words, the lower housing 210 covers at least a portion of the battery module 100. The lower end of the lower bracket 310 is fixed to the module defining rib 216. In other words, the lower bracket 310 functions as a cover for the housing space 250.

[0051] The lower end of the upper bracket 320 is fixed to the upper surface of the lower bracket 310 by fasteners such as bolts (not shown). The upper bracket 320 protrudes upward from the upper surface of the lower bracket 310.

[0052] The disconnect switch 410 has the function of cutting off the circuit that electrically connects the battery modules 100 to each other. A portion of the battery modules 100 are electrically connected to each other via the disconnect switch 410. In some embodiments, the circuit that connects the battery modules 100 to each other is sometimes a high-voltage circuit. Therefore, under specified conditions such as maintenance work on the battery pack 10 or emergency shutdown of the battery pack 10, it is necessary to cut off the circuit that connects the battery modules 100 to each other to ensure the safety of the operator of the battery pack 10. In some embodiments, by activating the disconnect switch 410, the circuit that connects the battery modules 100 to each other can be cut off.

[0053] The disconnect switch 410 is located at the upper front end of the upper bracket 320. Therefore, the disconnect switch 410 can be partially positioned at a higher level. In this embodiment, the disconnect switch 410 faces forward and slightly upward. Figure 1 As shown, the front surface of the disconnect switch 410 protrudes from the upper housing 220. Therefore, the operator of the battery pack 10 can open the cover 52 provided on the floor panel 50 and operate the disconnect switch 410 from the front of the battery pack 10.

[0054] Air inside and outside the containment space 250 can pass through the vent valve 420. Specifically, the vent valve 420 has a venting membrane for uniformizing the pressure difference between the inside and outside of the containment space 250. Therefore, when the pressure outside the containment space 250 is higher than the pressure inside the containment space 250, the vent valve 420 allows air from outside the containment space 250 to enter the containment space 250. Conversely, when the pressure inside the containment space 250 is higher than the pressure outside the containment space 250, the vent valve 420 discharges air from inside the containment space 250 to the outside. Furthermore, the vent valve 420 can block foreign objects such as water and dust. Therefore, it can prevent foreign objects such as water and dust from entering the containment space 250 from the outside.

[0055] A vent valve 420 is located at the upper rear end of the upper bracket 320. Therefore, the vent valve 420 can be partially positioned at a higher location. In this embodiment, the disconnect switch 410 and the vent valve 420 are arranged on opposite sides of the upper bracket 320 in the X direction. Thus, the vent valve 420 is positioned on the side of the upper bracket 320 opposite to the side facing the cover plate 52. Therefore, water flowing in from the front of the floor panel 50 can be prevented from directly spraying onto the vent valve 420.

[0056] At least one electronic component 312 is disposed on the lower bracket 310. Figure 2 In the example shown, viewed from above, the two electronic components 312 are positioned on either side of the upper bracket 320 in the Y direction. However, the number and arrangement of the lower brackets 310 are not limited to this. Figure 2 The example shown illustrates this. Each electronic component 312 controls multiple battery modules 100. In this embodiment, the electronic component 312 is a Battery Management System (BMS). For example, the electronic component 312 manages and controls the charging and discharging of the multiple battery modules 100.

[0057] In this embodiment, each electronic component 312 is disposed on a lower bracket 310, which is different from the upper bracket 320 on which the disconnect switch 410 and the vent valve 420 are disposed. Viewed from above, the area of ​​the lower bracket 310 is larger than the area of ​​the upper bracket 320. Each electronic component 312 is disposed on a portion of the lower bracket 310 that does not overlap with the upper bracket 320 in the Z direction. Therefore, the mounting efficiency of components around the disconnect switch 410 can be improved.

[0058] Reference Figure 5 The rigidity of the lower support 310 and the upper support 320 is explained. Figure 5 It is focused on Figure 4 The diagram shows a simplified representation of the connection structure between the lower support 310 and the upper support 320.

[0059] Here, it is envisioned that inside the housing 200, multiple components are overlapped and fixed between the lower and upper surfaces of the housing 200. That is, as described above, inside the housing 200, the lower support 310 and the upper support 320 overlap and are fixed, with the lower support 310 fixed to the lower housing 210 (more specifically, the lower plate 212) and the upper support 320 fixed to the upper housing 220. The lower support 310 and the upper support 320 are integrally fixed by a fixing member. Below the lower support 310 (on the lower housing 210 side), at least one of the multiple battery modules 100 is located below the lower support 310.

[0060] Generally, tolerances are set for the lower bracket 310 and the upper bracket 320. The dimensional tolerances of the lower bracket 310 and the upper bracket 320 selected when manufacturing the battery pack 10 will accumulate. For example, suppose that the lower bracket 310 and the upper bracket 320 are respectively the conditions of the maximum allowable positive tolerance size (hereinafter, condition 1) and the conditions of the minimum negative tolerance size (hereinafter, condition 2).

[0061] When the structures of the lower support 310 and upper support 320 under condition 1 (positive tolerance) are fixed inside the housing 200, they are compressed by an amount corresponding to the positive tolerance. In other words, there is a latent strain inside that exerts a force pushing the housing 200 outward. When vibration or the like acts on the battery pack 10 with this strain, this strain becomes apparent, causing the portion of the housing 200 where the lower support 310 and upper support 320 are fixed to bulge, and another portion to dent as a result. Similarly, when the structures of the lower support 310 and upper support 320 under condition 2 (negative tolerance) are fixed inside the housing 200, they are stretched outward by an amount corresponding to the negative tolerance. In other words, there is a latent strain inside that exerts a force pulling the housing 200 inward. When vibration or other forces act on the battery pack 10, which exhibits this strain, the strain becomes apparent. In the housing 200, the portion where the lower support 310 and the upper support 320 are fixed will indent inward, and as a result, another portion will bulge out. Consequently, water easily accumulates in the recessed areas within the housing 200, making it prone to rusting.

[0062] Therefore, in this embodiment, the rigidity of the lower support 310 and the upper support 320 is set differently to prevent strain from occurring in the housing 200.

[0063] As described above, the upper bracket 320 is fixed to the upper housing 220 of the housing 200 on the side opposite to the inner surface 217 of the lower plate 212, and houses electronic components 312 (disconnect switch 410 or BMS). The lower bracket 310 supports the side of the upper bracket 320 opposite to the upper housing 220 (second side). More specifically, the lower bracket 310 is a box-shaped structure with a bottomed top surface 310a and an open bottom surface. A peripheral surface 310b extends downward from the outer edge of the top surface 310a, and a flange surface 310c extends horizontally outward from the lower edge of the peripheral surface 310b.

[0064] The flange surface 310c of the lower bracket 310 is fixed to the module defining rib 216 provided on the lower plate 212. The fixing method is not particularly limited; for example, bolt fixing, screw fixing, fixing by adhesive, or a combination of these methods can be used. Furthermore, the module defining rib 216 is provided as part of the receiving portion (receiving space 250) of the battery module 100. The upper bracket 320 functions as a cover for the receiving portion (receiving space 250).

[0065] The upper bracket 320 internally houses high-voltage components and is fixed between the lower bracket 310 and the upper housing 220. Specifically, the lower end 321 of the upper bracket 320 is fixed to the top surface 310a of the lower bracket 310. The fixing method is not particularly limited and can be bolt fixing, screw fixing, fixing by adhesive, or a combination of these.

[0066] The upper part of the upper bracket 320 is fixed to the upper housing 220. More specifically, the upper bracket 320 and the disconnect switch 410 are exposed on the surface such that a portion of the upper part of the upper bracket 320 protrudes from the opening 229 of the upper housing 220. The upper part 322 of the upper bracket 320 is fixed at or near the periphery of the opening 229 of the upper housing 220. The fixing method is not particularly limited and can be bolt fixing, screw fixing, fixing by adhesive, or a combination of these.

[0067] The upper support 320 has higher rigidity than the upper housing 220. Conversely, the lower support 310 has lower rigidity than the upper housing 220 of the housing 200. Furthermore, the upper support 320 has higher rigidity than the lower support 310. Additionally, the lower support 310 has lower rigidity than the lower housing 210.

[0068] Here, "high rigidity" means less prone to deformation. Conversely, "low rigidity" means easier to deform. Therefore, the statement that the upper support 320 has higher rigidity than the upper shell 220 means that the upper support 320 is more easily deformed and prone to bending compared to the upper shell 220. Similarly, the statement that the lower support 310 has lower rigidity than the upper shell 220 of the housing 200 means that the lower support 310 is more easily deformed and prone to bending compared to the upper shell 220.

[0069] By setting the rigidity of the upper support 320, lower support 310, lower housing 210, and upper housing 220 in this way, the lower support 310 can absorb the strain caused by the vibration acting on the battery pack 10. For example, deformation or vibration in the Z direction is mainly absorbed by deflection of the top surface 310a or flange surface 310c (and the boundary with the peripheral surface 10b) of the lower support 310. In addition, deformation or vibration in the horizontal direction is mainly absorbed by deflection of the peripheral surface 310b (the boundary with the top surface 310a or flange surface 310c).

[0070] Therefore, strain in the housing 200 (especially the upper housing 220) can be suppressed, which, for example, prevents the accumulation of moisture or foreign matter at the strain points. Furthermore, although the upper support 320 houses high-voltage components, it does not experience strain and therefore will not affect these components. Additionally, while the lower support 310 functions as a cover for the housing space 250 of the battery module 100, it does not directly fix the battery module 100 itself; therefore, its deformation has virtually no real negative impact on the battery module 100.

[0071] The features of this embodiment can be summarized as follows.

[0072] 1. A battery pack 10, comprising:

[0073] Containment Container 200 (Frame);

[0074] The battery module 100 is fixed to the inner surface 217 (first surface) of the lower housing 210 (more specifically the lower plate 212) of the housing 200.

[0075] The component (upper bracket 320) is fixed to the second side (upper housing 220) of the housing 200, opposite to the first side (inner surface 217 of the lower plate 212), and houses the electronic component 312 (disconnect switch 410 or BMS); and

[0076] The supporting member (lower bracket 310) supports the side of the upper bracket 320 opposite to the upper shell 220 (second side).

[0077] The rigidity of the support member (lower bracket 310) is lower than the rigidity of the upper shell 220 (second side) of the housing 200.

[0078] 2. According to the battery pack 10 of 1, the rigidity of the component (upper bracket 320) is higher than the rigidity of the second surface (upper housing 220) of the housing 200 (frame).

[0079] 3. The battery pack according to 1 or 2, wherein the rigidity of the component (upper bracket 320) is higher than the rigidity of the support member (lower bracket 310).

[0080] 4. The battery pack 10 according to 1 or 2, wherein a plurality of battery modules 100 are provided, and at least one of the battery modules 100 is located below the support member (lower bracket 310).

[0081] 5. The battery pack 10 according to claim 1, wherein the housing 200 comprises: a first portion (lower housing 210) having the first surface (inner surface 217 of the lower plate 212) and a second portion (upper housing 220) having the second surface.

[0082] 6. The battery pack 10 according to 1, wherein the housing 200 has ribs (module delineation ribs 216) provided on the inner surface 217 of the first surface (lower housing 210).

[0083] The support member (lower bracket 310) is fixed to the rib (module delineation rib 216).

[0084] 7. The battery pack 10 according to 1 or 2, wherein the rigidity of the support member (lower bracket 310) is less than the rigidity of the first surface (lower housing 210).

[0085] 8. According to the battery pack 10 described in 6, wherein the rib (module defining rib 216) is provided as part of a receiving portion (receiving space 250) for receiving the battery module.

[0086] The support member (lower bracket 310) is provided as a cover for the receiving part (receiving space 250).

[0087] The embodiments of the present invention have been described above with reference to the accompanying drawings, but these are examples of the present invention, and various other structures may also be used.

[0088] This application claims priority based on Japanese Patent Application No. 2024-035589, filed on March 8, 2024, the entire contents of which are incorporated herein by reference.

[0089] Explanation of icon numbers

[0090] 10: Battery Pack

[0091] 50: Floor panel

[0092] 52: Cover plate

[0093] 100: Battery Module

[0094] 110: Terminal

[0095] 200: Containment Entity

[0096] 210: Lower shell

[0097] 212: Lower board

[0098] 214: Side frame

[0099] 216: Module Delineation Rib

[0100] 220: Upper shell

[0101] 230: Sealing material

[0102] 250: Containment Space (Containment Department)

[0103] 310: Lower support

[0104] 310a: Top surface

[0105] 310b: Peripheral

[0106] 310c: Flange surface

[0107] 312: Electronic Components

[0108] 320: Upper bracket

[0109] 410: Disconnect switch

[0110] 420: Vent valve

Claims

1. A battery pack, comprising: Frame; The battery module is fixed to the first side of the frame; The component is fixed to a second side of the frame opposite to the first side and houses electronic components; and A supporting member supports the side of the part opposite to the second surface. The rigidity of the supporting member is lower than the rigidity of the second surface of the frame.

2. The battery pack according to claim 1, wherein the rigidity of the component is higher than the rigidity of the second surface of the frame.

3. The battery pack according to claim 1 or 2, wherein the rigidity of the component is higher than the rigidity of the support member.

4. The battery pack according to claim 1 or 2, wherein a plurality of the battery modules are provided, and at least one of the battery modules is located below the support member.

5. The battery pack according to claim 1 or 2, wherein the frame comprises: A first portion having the first face and a second portion having the second face.

6. The battery pack according to claim 1 or 2, wherein the frame has ribs disposed on the inner surface of the first side. The support member is fixed to the rib.

7. The battery pack according to claim 1 or 2, wherein the rigidity of the support member is less than the rigidity of the first surface.

8. The battery pack of claim 6, wherein the rib is provided as part of a receiving portion for receiving the battery module. The support member is provided as a cover for the receiving part.

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