Battery pack

Abstract

To provide a technique capable of suppressing water from contacting a high voltage connection portion of a battery pack.SOLUTION: A battery pack includes: a tray having a bottom wall; a cell module disposed on the tray and having at least one battery cell; a high voltage connection portion provided on the bottom surface of the cell module and electrically connected to the at least one battery cell; a high voltage bus bar connected to the high voltage connection portion; and a water absorbing sheet disposed between the bottom wall of the tray and the bottom surface of the cell module. A first opening portion is defined in the water absorbing sheet at a position opposite the high voltage connection portion.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a battery pack. [Background technology]

[0002] Patent document 1 discloses a battery pack including a tray having a bottom wall, a cell module arranged on the tray and having at least one battery cell, and a water-absorbent sheet arranged between the bottom wall of the tray and the bottom surface of the cell module. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-65419 A Summary of the Invention [Problem to be solved by the invention]

[0004] In some battery packs, a high-voltage connection part electrically connected to at least one battery cell is provided on the bottom surface of a cell module. In a battery pack configured in this way, a water-absorbent sheet is also arranged at a position facing the high-voltage connection part, that is, the water-absorbent sheet is in contact with the high-voltage connection part. In this case, water absorbed by the water-absorbent sheet comes into contact with the high-voltage connection part.

[0005] This specification provides a technique that can prevent water from coming into contact with a high-voltage connection part of a battery pack. [Means for solving the problem]

[0006] In a first aspect of the present technology, a battery pack includes a tray having a bottom wall, a cell module arranged on the tray and having at least one battery cell, a high-voltage connection part provided on a bottom surface of the cell module and electrically connected to the at least one battery cell, a high-voltage bus bar connected to the high-voltage connection part, and a water-absorbent sheet arranged between the bottom wall of the tray and the bottom surface of the cell module. A first opening part is defined in the water-absorbent sheet at a position facing the high-voltage connection part. In this specification, "high voltage" means an operating voltage exceeding 60V DC or an operating voltage exceeding 30V AC (effective value).

[0007] According to the above-mentioned configuration, the water absorbent sheet is not disposed at a position facing the high-voltage connection part. In other words, the water absorbent sheet is not in contact with the high-voltage connection part. This makes it possible to prevent the water absorbed by the water absorbent sheet from coming into contact with the high-voltage connection part.

[0008] According to a second aspect of the present technology, in the above-mentioned first aspect, the first opening may surround the high-voltage connection portion via a gap.

[0009] According to the above configuration, compared to a configuration in which the first opening surrounds the high-voltage connection portion without a gap, the possibility that water absorbed by the water absorbent sheet will come into contact with the high-voltage connection portion can be reduced.

[0010] In a third aspect of the present technology, in the first or second aspect, the tray may include an engagement member protruding upward from the bottom wall, and the water absorbent sheet may have a second opening defined therein for engaging with the engagement member.

[0011] According to the above configuration, it is possible to prevent the position of the first opening of the water absorbent sheet from shifting relative to the high-voltage connection portion, and it is possible to further prevent water absorbed by the water absorbent sheet from coming into contact with the high-voltage connection portion.

[0012] In a fourth aspect of the present technology, in any one of the first to third aspects, the tray may further include a positioning rib that protrudes upward from the bottom wall and is disposed around a portion of the high-voltage connection portion. The positioning rib may be inserted into the first opening of the water-absorbent sheet.

[0013] According to the above configuration, the positioning rib of the tray can be used to align the first opening of the water absorbent sheet with the high-voltage connection portion. Also, the position of the first opening of the water absorbent sheet can be prevented from shifting from the high-voltage connection portion. Therefore, it is possible to further prevent the water absorbed by the water absorbent sheet from coming into contact with the high-voltage connection portion.

[0014] According to a fifth aspect of the present technology, in any one of the first to fourth aspects, the water-absorbent sheet may be a nonwoven fabric.

[0015] According to the above-mentioned configuration, the water on the water absorption tray can be absorbed thoroughly. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a plan view showing a schematic diagram of a battery pack 2 according to the embodiment; [Diagram 2] FIG. 2 is a perspective view showing a tray 10 according to the embodiment; [Diagram 3] FIG. 3 is a cross-sectional view showing a schematic cross section taken along dashed line III-III in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] (Example) A battery pack 2 according to the embodiment will be described with reference to the drawings. The battery pack 2 according to the embodiment is used in, for example, an electric vehicle, and supplies power to a traction motor that drives the wheels. The electric vehicle referred to here is not particularly limited, but includes battery-powered electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and fuel cell electric vehicles. The battery pack 2 is disposed under the floor of the electric vehicle.

[0018] 1, the battery pack 2 includes a tray 10, a battery cell case 12, and an electric unit case 14. The battery cell case 12 is disposed on the tray 10. The electric unit case 14 is connected to the center of the battery cell case 12 in the left-right direction. The electric unit case 14 extends forward from the battery cell case 12.

[0019] As shown in Fig. 2, the tray 10 includes a bottom wall 20, a right wall 22, a left wall 24, a rear wall 26, and a front wall 28. A right side cutout 26a recessed downward is formed at the right end of the rear wall 26, and a left side cutout 26b recessed downward is formed at the left end of the rear wall 26. The right side cutout 26a and the left side cutout 26b are openings through which fastening members for fastening a bracket for connecting the body of an electric vehicle to the battery cell case 12 (see Fig. 1) to the battery cell case 12 can pass.

[0020] The tray 10 further includes an engagement claw portion 30 protruding upward from the bottom wall 20, and a rib 32 protruding upward from the bottom wall 20. The engagement claw portion 30 is provided on the left part of the bottom wall 20 near the center in the front-rear direction. The rib 32 is provided on the right part of the bottom wall 20 rearward of the center in the front-rear direction. The rib 32 includes a first rib 32a extending in the front-rear direction, and a second rib 32b extending rightward from the rear end of the first rib 32a.

[0021] A water-absorbent sheet 40 made of nonwoven fabric is provided on the bottom wall 20. In a modified example, the water-absorbent sheet 40 may be a woven fabric, a sponge, or the like. The water-absorbent sheet 40 is a sheet for absorbing water that has entered the tray 10, and is also a sheet for absorbing electrolyte that has leaked from the battery cell case 12 (see FIG. 1). The water-absorbent sheet 40 covers substantially the entire surface of the bottom wall 20.

[0022] The water absorbent sheet 40 has a first opening 42 and a second opening 44. The first opening 42 is provided at a position corresponding to the rib 32 of the tray 10. The rib 32 is inserted into the first opening 42. When the rib 32 is inserted into the first opening 42, the left surface of the first rib 32a and the rear surface of the second rib 32b come into contact with the water absorbent sheet 40. As shown in FIG. 3, the height of the rib 32 is the same as the height of the water absorbent sheet 40. In addition, in a modified example, the height of the rib 32 may be lower than the height of the water absorbent sheet 40. That is, the upper end of the rib 32 may be located lower than the upper end of the water absorbent sheet 40. As shown in FIG. 2, the second opening 44 is provided at a position corresponding to the engaging claw portion 30 of the tray 10. The first opening 42 engages with the engaging claw portion 30. By engaging the first opening 42 with the engaging claw portion 30, the positional deviation of the water absorbent sheet 40 with respect to the tray 10 is suppressed.

[0023] 3, the battery cell case 12 is placed on the bottom wall 20 of the tray 10 via the water-absorbent sheet 40. In other words, the water-absorbent sheet 40 is sandwiched between the tray 10 and the battery cell case 12.

[0024] The battery cell case 12 houses a cell module 52 having a plurality of battery cells 50. In this embodiment, the battery cells 50 are NiMH battery cells having a rectangular parallelepiped shape. The battery cells may also be lithium ion battery cells or the like. The plurality of battery cells 50 are stacked in the vertical direction.

[0025] A high-voltage connection portion 54 protruding downward is provided on the bottom surface of the cell module 52. The high-voltage connection portion 54 is electrically connected to the plurality of battery cells 50. When the battery cell case 12 is placed on the bottom wall 20 of the tray 10, the high-voltage connection portion 54 is disposed within the first opening 42 of the water-absorbent sheet 40. The lower end of the high-voltage connection portion 54 is located between the upper end and the lower end of the water-absorbent sheet 40. The high-voltage connection portion 54 does not contact the bottom wall 20 of the tray 10. The high-voltage connection portion 54 is surrounded by the first opening 42 of the water-absorbent sheet 40 via a gap S in the front-rear and left-right directions. That is, the high-voltage connection portion 54 does not contact the water-absorbent sheet 40. The rear end of the high-voltage connection portion 54 is located forward of the front end of the second rib 32b of the bottom wall 20. The left end of the high-voltage connection portion 54 is located to the right of the right end of the first rib 32a of the bottom wall 20. That is, the high voltage connection portion 54 does not contact the first rib 32a and the second rib 32b.

[0026] One end 56a of a high-voltage bus bar 56 is electrically connected to the high-voltage connection portion 54. A high-voltage wire harness (not shown) is electrically connected to the other end 56b of the high-voltage bus bar 56. The high-voltage wire harness is electrically connected to a power control unit (PCU), a driving motor, etc. via the electric unit case 14.

[0027] As described above, the battery pack 2 includes the tray 10 having the bottom wall 20, the cell module 52 arranged on the tray 10 and having a plurality of battery cells 50, the high-voltage connection portion 54 provided on the bottom surface of the cell module 52 and electrically connected to the plurality of battery cells 50, the high-voltage bus bar 56 connected to the high-voltage connection portion 54, and the water-absorbent sheet 40 arranged between the bottom wall 20 of the tray 10 and the bottom surface of the cell module 52. A first opening 42 is defined in the water-absorbent sheet 40 at a position facing the high-voltage connection portion 54.

[0028] In the battery pack 2 of this embodiment, for example, as shown by the arrow F in FIG. 3, water may infiltrate onto the tray 10 through the right notch 26a and the left notch 26b of the rear wall 26 of the tray 10. When water infiltrates onto the tray 10, the water that has infiltrated onto the tray 10 is absorbed by the water-absorbing sheet 40 arranged on the bottom wall 20 of the tray 10. If a water-absorbing sheet is also arranged at a position facing the high-voltage connection portion 54, the water absorbed by the water-absorbing sheet will come into contact with the high-voltage connection portion 54. According to the above configuration, the water-absorbing sheet 40 is not arranged at a position facing the high-voltage connection portion 54. That is, the water-absorbing sheet 40 is not in contact with the high-voltage connection portion 54. This makes it possible to prevent the water absorbed by the water-absorbing sheet 40 from coming into contact with the high-voltage connection portion 54.

[0029] Further, the first opening 42 of the tray 10 surrounds the high-voltage connection portion 54 with the gap S therebetween.

[0030] According to the above configuration, compared to a configuration in which the first opening 42 surrounds the high-voltage connection portion 54 without the gap S, the possibility that water absorbed by the water-absorbent sheet 40 will come into contact with the high-voltage connection portion 54 can be reduced.

[0031] The tray 10 may also include an engaging claw 30 (an example of an "engaging member") protruding upward from the bottom wall 20. The water absorbent sheet 40 has a second opening 44 defined therein for engaging with the engaging claw 30.

[0032] According to the above configuration, it is possible to prevent the position of the first opening 42 of the water-absorbent sheet 40 from shifting relative to the high-voltage connection portion 54, and it is possible to further prevent the water absorbed by the water-absorbent sheet 40 from coming into contact with the high-voltage connection portion 54.

[0033] The tray 10 also includes a rib 32 (an example of a "positioning rib") that protrudes upward from the bottom wall 20 and is disposed behind and to the left of the high-voltage connection portion 54 (an example of a "part of the periphery") The rib 32 is inserted into the first opening 42 of the water-absorbent sheet 40.

[0034] According to the above-mentioned configuration, the ribs 32 of the tray 10 can be used to align the first opening 42 of the water absorbent sheet 40 with the high-voltage connection portion 54. Also, it is possible to prevent the first opening 42 of the water absorbent sheet 40 from being misaligned with the high-voltage connection portion 54. Therefore, it is possible to further prevent the water absorbed by the water absorbent sheet 40 from coming into contact with the high-voltage connection portion 54.

[0035] The water absorbent sheet 40 is made of nonwoven fabric.

[0036] According to the above-mentioned configuration, the water on the tray 10 can be absorbed firmly.

[0037] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples exemplified above.

[0038] (First Modification) The tray 10 does not have to have the engaging claw portion 30. In this modification, the water absorbent sheet 40 does not have to have the second opening 44.

[0039] (Second Modification) The rib 32 of the tray 10 may surround the periphery of the high-voltage connection portion 54 .

[0040] (Third Modification) The tray 10 does not have to have the ribs 32.

[0041] In addition, the technical elements described in this specification or the drawings have technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technologies illustrated in this specification or the drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0042] 2: battery pack, 10: tray, 12: battery cell case, 14: electrical unit case, 20: bottom wall, 22: right wall, 24: left wall, 26: rear wall, 26a: right side notch, 26b: left side notch, 28: front wall, 30: engagement claw, 32: rib, 32a: first rib, 32b: second rib, 40: water absorbent sheet, 42: first opening, 44: second opening, 50: battery cell, 52: cell module, 54: high voltage connection, 56: high voltage bus bar, 56a: one end, 56b: other end

Claims

1. a tray having a bottom wall; A cell module having at least one battery cell disposed on the tray; a high-voltage connection portion provided on a bottom surface of the cell module and electrically connected to the at least one battery cell; a high voltage bus bar connected to the high voltage connection; a water-absorbent sheet disposed between the bottom wall of the tray and the bottom surface of the cell module; Equipped with A first opening is defined in the water absorbent sheet at a position facing the high voltage connection portion. Battery pack.

2. The battery pack according to claim 1 , wherein the first opening surrounds the high-voltage connection portion via a gap.

3. The tray includes an engagement member that protrudes upward from the bottom wall, The battery pack according to claim 1 , wherein the water absorbent sheet is defined with a second opening adapted to engage with the engaging member.

4. the tray includes a locating rib projecting upwardly from the bottom wall and positioned partially around the periphery of the high voltage connection; The battery pack according to claim 1 , wherein the positioning rib is inserted into the first opening of the water absorbent sheet.

5. The battery pack according to claim 1 , wherein the water-absorbent sheet is a nonwoven fabric.

Images