Battery pack

Abstract

To provide a battery pack capable of suppressing an occurrence of distortion in a case.SOLUTION: A battery pack 10 includes: a housing body 200; a battery module 100 fixed to an inner surface 217 (first surface) of a lower case 210 of the housing body 200; an upper bracket 320 fixed to the upper case 220 on a side opposite to the first surface (an inner surface 217 of a lower plate 212) of the housing body 200 and accommodating an electronic component 312; and a lower bracket 310 supporting a side of the upper bracket 320 opposite to the upper case 220. The rigidity of the lower bracket 310 is lower than the rigidity of the upper case 220 of the housing body 200.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] In recent years, battery packs have been developed for use in a variety of applications, including automobiles. A battery pack includes multiple battery modules, a housing that houses the multiple modules, and a disconnect switch for interrupting a circuit that electrically connects the battery modules. The disconnect switch is generally also referred to as a service disconnect switch (SD / SW) or a service plug, for example.

[0003] Patent Document 1 describes an example of a battery pack, which proposes a technology in which a control member is fixed to a fixed beam, making the control member less likely to deform when the battery cell expands.

[0004] Patent Document 2 proposes a technology in which an MSD (a service plug for manually shutting off a high-voltage system) is fixed to the top cover through an MSD support plate. This technology increases the contact area between the MSD and the top cover, reducing the concentrated stress between the MSD and the top cover and preventing cracks in the top cover due to the concentrated stress. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 259139 [Patent Document 2] Chinese Patent No. 107887536 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the battery pack is subjected to vibration, the case may become distorted, which may cause water to accumulate inside the case.

[0007] One example of an object of the present invention is to suppress distortion of a battery pack case. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]

[0008] One aspect of the present invention is as follows. 1. Housing and a battery module fixed to a first surface of the housing; a component fixed to a second surface of the housing opposite to the first surface and accommodating electronic components; a support member that supports a side of the component opposite to the second surface; and The rigidity of the support member is lower than the rigidity of the second surface of the housing. Battery pack. 2. The battery pack according to claim 1, wherein the rigidity of the support member is lower than the rigidity of the second surface of the housing. 3. The battery pack according to 1. or 2., wherein the rigidity of the component is higher than the rigidity of the support member. 4. A battery pack according to 1. or 2., wherein a plurality of the battery modules are provided, and at least one of the plurality of battery modules is located below the support member. 5. A battery pack according to 1. or 2., wherein the housing has a first portion having the first surface and a second portion having the second surface. 6. The housing has a rib provided on the inner surface of the first surface, 3. The battery pack according to 1. or 2., wherein the support member is fixed to the rib. 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. 8. The rib is provided as a part of the housing portion that houses the battery module, 6. The battery pack according to 6., wherein the support member is provided as a lid for the storage section. [Effects of the Invention]

[0009] According to the above aspect of the present invention, it is possible to prevent distortion from occurring in the case of the battery pack. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a battery pack according to an embodiment. [Figure 2] FIG. 2 is a plan view of the battery pack according to the embodiment with the upper case removed. [Figure 3] 3 is a plan view showing a state in which a lower bracket and an upper bracket are removed from FIG. 2. FIG. [Figure 4] 3 is a cross-sectional view taken along the line AA in FIG. 2 together with a floor panel. [Figure 5] FIG. 5 is a simplified view focusing on the connection structure between the lower bracket and the upper bracket shown in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, similar components are designated by similar reference numerals, and the description thereof will be omitted as appropriate.

[0012] Fig. 1 is a perspective view of a battery pack 10 according to an embodiment. Fig. 2 is a plan view of the battery pack 10 according to an embodiment with an upper case 220 removed. Fig. 3 is a plan view of the battery pack 10 according to an embodiment with a lower bracket 310 and an upper bracket 320 removed. Fig. 4 is a cross-sectional view taken along line AA in Fig. 2 together with a floor panel 50.

[0013] In the embodiment, the battery pack 10 is mounted, for example, in an automobile. Specifically, as shown in Fig. 4, the battery pack 10 is mounted below a floor panel 50 between the front and rear wheels of the automobile. Unless otherwise specified, the following description will be given assuming that the battery pack 10 is mounted below the floor panel 50. However, the battery pack 10 can also be used in applications other than automobiles.

[0014] For the purpose of explanation, the X, Y, and Z directions are shown in each figure. The X direction indicates the front-to-rear direction of the battery pack 10. The Y direction is perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery pack 10. The Z direction is perpendicular to both the X and Y directions. The Z direction indicates the up-to-down direction of the battery pack 10. The arrows pointing to the X direction, the Y direction, and the Z direction indicate the front, left, and up directions of the battery pack 10, respectively. In Figures 2 and 3, the white circle with a black dot indicating the Z direction indicates that the arrow pointing to the Z direction extends from the back of the page to the front. In Figure 4, the white circle with a black dot indicating the Y direction indicates that the arrow pointing to the Y direction extends from the back of the page to the front. However, the relationship between the X direction, Y direction, and Z direction and the front-to-rear direction, left-to-right direction, and up-to-down direction of the battery pack 10 is not limited to this example.

[0015] In the embodiment, the front-rear direction, left-right direction, and up-down direction of the battery pack 10 are determined by the vehicle in which the battery pack 10 is mounted. The X direction, Y direction, and Z direction respectively indicate the front-rear direction, left-right direction, and up-down direction of the vehicle. The arrow pointing to the X direction, the arrow pointing to the Y direction, and the arrow pointing to the Z direction respectively indicate the front, left, and up directions of the vehicle. However, the relationship between the front-rear direction, left-right direction, and up-down direction of the battery pack 10 and the front-rear direction, left-right, and up-down directions of the vehicle is not limited to this example.

[0016] Hereinafter, the direction perpendicular to the Z direction will be referred to as the horizontal direction, as necessary.

[0017] 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 breather 420. The four battery modules 100 include a pair of battery modules 100 on the left side aligned in the X direction and a pair of battery modules 100 on the right side aligned in the X direction. The disconnect switch 410 may also be generally referred to as a service disconnect switch or a service plug, for example. The housing 200 includes a lower case 210 and an upper case 220. The lower case 210 may also be generally referred to as a tray or a main body, for example. The lower case 210 includes a lower plate 212 and a side frame 214. The upper case 220 may also be generally referred to as a cover or a lid, for example.

[0018] Each battery module 100 has a plurality of battery cells stacked in the horizontal direction. For example, each battery module 100 has a plurality of battery cell groups connected in series, each group including a plurality of battery cells connected in parallel. Alternatively, each battery module 100 may have a plurality of single battery cells connected in series.

[0019] A pair of terminals 110 is provided in front of the side frame 214. The pair of terminals 110 are arranged substantially parallel to each other in the Y direction. The front end of each terminal 110 protrudes forward from the front surface of the side frame 214. In the electrical path, the four battery modules 100 are connected in series between the pair of terminals 110.

[0020] The number and arrangement of the battery modules 100 are not limited to the examples described in the embodiment. For example, the number of battery modules 100 may be only two, only three, or five or more. That is, the battery pack 10 may include a plurality of battery modules 100.

[0021] The lower case 210 and the upper case 220 are attached to each other via a sealant 230. The lower case 210, the upper case 220, and the sealant 230 form an accommodating space 250. The accommodating space 250 accommodates four battery modules 100, a disconnect switch 410, a lower bracket 310, and an upper bracket 320.

[0022] The lower plate 212 defines the bottom of the storage space 250. The side frames 214 define the sides of the storage space 250. Specifically, when viewed from the Z direction, the side frames 214 are provided along the outermost periphery of the lower plate 212. The upper case 220 defines the top of the storage space 250.

[0023] The sealing material 230 is an elastic material such as rubber. When viewed from the Z direction, the sealing material 230 is provided around the entire periphery of the side frame 214. As a result, when viewed from the Z direction, the sealing material 230 surrounds the storage space 250. Therefore, the sealing material 230 can seal the storage space 250 from the space outside the storage body 200.

[0024] The lower bracket 310 and the upper bracket 320 are stacked in two stages relative to the accommodation space 250 . Specifically, the lower end of the lower bracket 310 is fixed to the lower plate 212 by fasteners such as bolts (not shown). In the example shown in Fig. 4, a rib (module defining rib 216) that defines the area for accommodating the battery modules 100 is provided on the inner surface of the lower plate 212. In other words, the lower case 210 covers at least some of the battery modules 100. The lower end of the lower bracket 310 is fixed to this module defining rib 216. In other words, the lower bracket 310 functions as a lid for the accommodation space 250. The lower end of the upper bracket 320 is fixed to the upper surface of the lower bracket 310 by a fastener such as a bolt (not shown). The upper bracket 320 protrudes upward from the upper surface of the lower bracket 310.

[0025] The disconnect switch 410 has a function of interrupting the circuit electrically connecting the battery modules 100 to each other. Some of the battery modules 100 are electrically connected to each other via the disconnect switch 410. In the embodiment, the circuit electrically connecting the battery modules 100 to each other may be a high-voltage circuit. Therefore, under certain conditions, such as maintenance work on the battery pack 10 or emergency shutdown of the battery pack 10, it is necessary to interrupt the circuit electrically connecting the battery modules 100 to each other to ensure the safety of workers working on the battery pack 10. In the embodiment, the circuit connecting the battery modules 100 to each other can be interrupted by operating the disconnect switch 410.

[0026] The disconnect switch 410 is provided at the front upper end of the upper bracket 320. Therefore, the disconnect switch 410 can be located at a locally high position. In this embodiment, the disconnect switch 410 faces diagonally upward and forward. As shown in FIG. 1 , the front surface of the disconnect switch 410 is exposed from the upper case 220. Therefore, a worker working on the battery pack 10 can open a lid 52 provided on the floor panel 50 and operate the disconnect switch 410 from the front of the battery pack 10.

[0027] The breather 420 allows air inside the accommodation space 250 and air outside the accommodation space 250 to pass through. Specifically, the breather 420 has an air permeable membrane for equalizing the difference between the pressure inside the accommodation space 250 and the pressure outside the accommodation space 250. Therefore, when the pressure outside the accommodation space 250 is higher than the pressure inside the accommodation space 250, the breather 420 allows air outside the accommodation space 250 to enter the accommodation space 250. On the other hand, when the pressure inside the accommodation space 250 is higher than the pressure outside the accommodation space 250, the breather 420 discharges the air inside the accommodation space 250 to the outside of the accommodation space 250. The breather 420 is also capable of blocking foreign matter such as water and dust. Therefore, it is possible to prevent foreign matter such as water and dust from entering the accommodation space 250 from the space outside the accommodation space 250 toward the space inside the accommodation space 250.

[0028] The breather 420 is provided at the rear upper end of the upper bracket 320. Therefore, the breather 420 can be located at a locally higher position. In the embodiment, the disconnect switch 410 and the breather 420 are located on opposite sides of the upper bracket 320 in the X direction. As a result, the breather 420 is located on the opposite side of the upper bracket 320 from the side facing the lid 52. This prevents water flowing in from the front of the floor panel 50 from being sprayed directly onto the breather 420.

[0029] At least one electronic component 312 is provided on the lower bracket 310. In the example shown in FIG. 2, two electronic components 312 are arranged on both sides of the upper bracket 320 in the Y direction when viewed from above. However, the number and arrangement of the lower brackets 310 are not limited to the example shown in FIG. 2. Each electronic component 312 controls multiple battery modules 100. In the embodiment, the electronic component 312 is a BMS (Battery Management System). For example, the electronic component 312 manages and controls the charging and discharging of the multiple battery modules 100.

[0030] In the embodiment, each electronic component 312 is provided on a lower bracket 310 that is different from the upper bracket 320 on which the disconnect switch 410 and the breather 420 are provided. When 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 provided on a portion of the lower bracket 310 that does not overlap with the upper bracket 320 in the Z direction. This improves the mounting efficiency of components around the disconnect switch 410.

[0031] The rigidity of lower bracket 310 and upper bracket 320 will be described with reference to Fig. 5. Fig. 5 is a simplified view focusing on the connection structure between lower bracket 310 and upper bracket 320 shown in Fig. 4.

[0032] Here, it is assumed that multiple components are arranged and fixed between the bottom and top surfaces of the housing 200, stacked inside the housing 200. That is, as described above, the lower bracket 310 and the upper bracket 320 are stacked and fixed inside the housing 200, with the lower bracket 310 fixed to the lower case 210 (more specifically, the lower plate 212), and the upper bracket 320 fixed to the upper case 220. The lower bracket 310 and the upper bracket 320 are fixed together by a fixing means. At least one battery module 100 out of the multiple battery modules 100 is located below the lower bracket 310 (on the lower case 210 side).

[0033] 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 are cumulative. For example, there are two possible conditions (hereinafter, condition 1) in which the lower bracket 310 and the upper bracket 320 each have dimensions with the maximum allowable positive tolerance, and there is also a condition (hereinafter, condition 2) in which the lower bracket 310 and the upper bracket 320 each have dimensions with the minimum allowable negative tolerance.

[0034] When the structure of lower bracket 310 and upper bracket 320 under condition 1 (positive tolerance) is fixed inside housing 200, it is pressed down by the positive tolerance. In other words, there is an inherent distortion that potentially has a force that pushes housing 200 outward. When a battery pack 10 having such distortion is subjected to vibration or the like, the distortion becomes apparent, causing the portion of housing 200 where lower bracket 310 and upper bracket 320 are fixed to bulge, which in turn causes a dent in another portion. Similarly, when the structure of lower bracket 310 and upper bracket 320 under condition 2 (negative tolerance) is fixed inside housing 200, it is pulled outward by the negative tolerance. In other words, there is an inherent distortion that potentially has a force that pulls housing 200 inward. When a battery pack 10 with such distortion is subjected to vibration or the like, the distortion becomes apparent, causing housing 200 to dent inward at the portion where lower bracket 310 and upper bracket 320 are fixed, which in turn causes other portions to bulge. As a result, the dent in housing 200 becomes prone to water accumulation and rust.

[0035] Therefore, in this embodiment, a difference in rigidity is provided between the lower bracket 310 and the upper bracket 320 to prevent distortion of the housing body 200.

[0036] As described above, the upper bracket 320 is fixed to the upper case 220 on the side opposite to the inner surface 217 of the lower plate 212 of the rack 200, and accommodates the electronic component 312 (disconnect switch 410 and BMS). The lower bracket 310 supports the side of the upper bracket 320 opposite to the upper case 220 (second surface). More specifically, the lower bracket 310 has a box-like shape with a top surface 310a, which is the upper surface, having a bottom and an open bottom. A peripheral surface 310b extends downward from the outer edge of the top surface 310a, and a flange surface 310c is provided that extends horizontally outward from the lower edge of the peripheral surface 310b.

[0037] The flange surface 310c of the lower bracket 310 is fixed to a module-defining rib 216 provided on the lower plate 212. The fixing method is not particularly limited, but may be, for example, bolt fixing, screw fixing, fixing with an adhesive, or a combination of these. The module-defining rib 216 is provided as part of the accommodation section (accommodation space 250) that accommodates the battery module 100. The upper bracket 320 functions as a lid for the accommodation section (accommodation space 250).

[0038] Upper bracket 320 houses high-voltage components inside, and is fixed between lower bracket 310 and upper case 220. Specifically, lower end 322 of upper bracket 320 is fixed to top surface 310a of lower bracket 310. The fixing method is not particularly limited, but bolt fixing, screw fixing, adhesive fixing, or a combination thereof can be used.

[0039] An upper portion of upper bracket 320 is fixed to upper case 220. More specifically, a portion of the upper portion of upper bracket 320 protrudes from opening 229 of upper case 220, with upper bracket 320 and disconnect switch 410 exposed on the surface. An upper portion 321 of upper bracket 320 is fixed to the periphery of opening 229 of upper case 220 or in the vicinity thereof. The fixing method is not particularly limited, but bolt fixing, screw fixing, fixing with an adhesive, or a combination thereof can be used.

[0040] The rigidity of the upper bracket 320 is higher than that of the upper case 220. Moreover, the rigidity of the lower bracket 310 is lower than that of the upper case 220 of the rack 200. Furthermore, the rigidity of the upper bracket 320 is higher than that of the lower bracket 310. Furthermore, the rigidity of the lower bracket 310 is lower than the rigidity of the lower case 210.

[0041] Here, high rigidity means that it is difficult to deform. Similarly, low rigidity means that it is easy to deform. Therefore, when the rigidity of the upper bracket 320 is higher than that of the upper case 220, this means that the upper bracket 320 is more easily deformed and prone to bending than the upper case 220. Similarly, when the rigidity of the lower bracket 310 is lower than that of the upper case 220 of the housing 200, this means that the lower bracket 310 is more easily deformed and prone to bending than the upper case 220. When the rigidity of the upper bracket 320 is higher than that of the lower bracket 310, this means that the lower bracket 310 is more easily deformed and prone to bending than the upper bracket 320. When the rigidity of the lower bracket 310 is lower than that of the lower case 210, this means that the lower bracket 310 is more easily deformed and prone to bending than the lower case 210.

[0042] By setting the rigidity of upper bracket 320, lower bracket 310, lower case 210, and upper case 220 in this manner, lower bracket 310 can absorb vibrations acting on battery pack 10 and also absorb distortions caused by the vibrations. For example, deformation and vibrations in the Z direction are absorbed mainly by bending of top surface 310a and flange surface 310c of lower bracket 310 (and the boundary with peripheral surface 310b). Furthermore, deformation and vibrations in the horizontal direction are absorbed mainly by bending of peripheral surface 310b (the boundary with top surface 310a and flange surface 310c).

[0043] Therefore, distortion of the housing 200 (particularly the upper case 220) can be suppressed, and as a result, for example, the accumulation of moisture or foreign matter due to distortion can be suppressed. Furthermore, although the upper bracket 320 houses high-voltage components, the high-voltage components are not affected because no distortion occurs in the upper bracket 320. Furthermore, although the lower bracket 310 itself functions as a lid for the housing space 250 that houses the battery module 100, it does not directly fix the battery module 100 itself, and therefore its deformation has almost no practical adverse effect on the battery module 100.

[0044] The features of this embodiment can be briefly summarized as follows. 1. A housing 200 (housing), a battery module 100 fixed to an inner surface 217 (first surface) of a lower case 210 (more specifically, a lower plate 212) of the housing 200; a component (upper bracket 320) that is fixed to a second surface (upper case 220) on the opposite side (opposite side) of the first surface (inner surface 217 of the lower plate 212) of the housing 200 and that houses an electronic component 312 (disconnect switch 410 or BMS); a support member (lower bracket 310) that supports the side of the upper bracket 320 opposite to the upper case 220 (second surface); and The rigidity of the support member (lower bracket 310) is lower than the rigidity of the upper case 220 (second surface) of the housing 200. Battery pack 10. 2. The battery pack 10 according to 1., wherein the rigidity of the support member (lower bracket 310) is lower than the rigidity of the second surface (upper case 220) of the housing 200. 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). 4. A battery pack 10 as described in 1. or 2., wherein a plurality of the battery modules 100 are provided, and at least one of the plurality of battery modules 100 is positioned below the support member (lower bracket 310). 5. The battery pack 10 described in 1., wherein the housing 200 has a first part (lower case 210) having the first surface (inner surface 217 of the lower plate 212) and a second part (upper case 220) having the second surface. 6. The housing 200 has a rib (module defining rib 216) provided on the inner surface 217 of the first surface (lower case 210), 1. The battery pack 10 according to claim 1, wherein the support member (lower bracket 310) is fixed to the rib (module-defining rib 216). 7. The battery pack 10 according to 1 or 2, wherein the rigidity of the support member (lower bracket 310) is lower than the rigidity of the first surface (lower case 210). 8. The rib (module defining rib 216) is provided as part of the accommodation portion (accommodation space 250) that accommodates the battery module, 6. The battery pack 10 according to 6., wherein the support member (lower bracket 310) is provided as a lid for the accommodation portion (accommodation space 250).

[0045] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted. [Explanation of symbols]

[0046] 10 Battery pack 50 floor panel 52 Lid 100 battery modules Terminal 110 200 units 210 Lower Case 212 Lower Plate 214 Side Frame 216 Module defining rib 220 Upper Case 230 Sealing material 250 Storage space (storage section) 310 Lower bracket 310a Top 310b circumferential surface 310c flange surface 312 Electronic Components 320 upper bracket 410 Disconnect Switch 420 Breather

Claims

1. Housing and a battery module fixed to a first surface of the housing; a component fixed to a second surface of the housing opposite to the first surface and accommodating electronic components; a support member that supports a side of the component opposite to the second surface; and The rigidity of the support member is lower than the rigidity of the second surface of the housing. Battery pack.

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 housing.

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

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

5. 3. The battery pack according to claim 1, wherein the housing has a first portion having the first surface and a second portion having the second surface.

6. the housing has a rib provided on an inner surface of the first surface, The battery pack according to claim 1 , wherein the support member is fixed to the rib.

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

8. the rib is provided as a part of a housing portion that houses the battery module, The battery pack according to claim 6 , wherein the support member is provided as a lid for the housing portion.

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