Battery pack

Abstract

To provide a battery pack that can be filled with a filling member for restricting the lateral displacement of a power storage device up to a position higher than the position of a joint portion between a lower case and an upper case.SOLUTION: A battery pack that includes a lower case and an upper case and accommodates a power storage device therein has a joint portion for joining the lower case and the upper case to each other, the lower case and the upper case facing each other in a first direction. The joint portion is located so as to overlap with the power storage device as viewed in a second direction perpendicular to the first direction, and the lower case has a partition wall arranged to surround the periphery of the power storage device. The partition wall protrudes toward the upper case side in the first direction beyond the joint portion, and a filling member is filled between the partition wall and the power storage device up to the upper case side in the first direction beyond the joint portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a battery module that includes a lateral restriction portion that restricts horizontal displacement of the battery cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-081820 Summary of the Invention [Problem to be solved by the invention]

[0004] In a battery pack having a lower case and an upper case and housing a power storage device, if the lateral regulating portion is formed by solidifying a liquid filling material in order to position the lateral regulating portion without any gaps between the power storage device and the lower case, the filling material can only be filled up to the position of the joint between the lower case and the upper case.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a battery pack that can be filled with a filling member that restricts lateral displacement of the storage device up to a position higher than the joint between the lower case and the upper case. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the battery pack of the present invention is a battery pack comprising a lower case and an upper case and accommodating an electric storage device, wherein the lower case and the upper case face each other in a first direction, the lower case has a joint that joins with the upper case, and the joint is positioned so as to overlap with the electric storage device when viewed from a second direction perpendicular to the first direction, the lower case has a partition wall that protrudes toward the upper case in the first direction beyond the joint wall, and a filling material is filled between the partition wall and the electric storage device up to the upper case side in the first direction beyond the joint wall.

[0007] As a result, the partition wall that protrudes toward the upper case beyond the joint between the lower case and the upper case is higher than the joint surface, allowing the filling material to be filled up to a position higher than the joint position between the lower case and the upper case.

[0008] In addition, in the above, the partition wall may protrude toward the upper case in the first direction further than the storage device, and the filling member may be filled between the partition wall and the storage device up to the upper case side in the first direction further than the storage device.

[0009] With this, the partition wall that protrudes further toward the upper case than the power storage device is higher than the power storage device, so that the filler can be filled into the upper case in the first direction further than the power storage device.

[0010] In the above configuration, the lower case may have a bottom surface portion and a side surface portion, and the partition wall may be formed from the side surface portion toward the upper case in the first direction.

[0011] As a result, by forming the partition wall on the side edge of the lower case, the volumetric efficiency of the battery pack can be improved compared to when the partition wall is formed on the bottom surface of the lower case.

[0012] In addition, in the above, the partition has a first partition portion and a second partition portion, the second partition portion is arranged extending from the bottom surface portion side in the first direction of the side surface portion further than the first partition portion, a liquid reservoir portion is arranged between the second partition portion and the side surface portion, and the liquid reservoir portion may be equipped with a water ingress detection device.

[0013] As a result, if water seeps into the battery pack from outside through the joint, the water will pass between the first partition and the lower case and collect in the reservoir provided between the second partition and the side of the lower case, allowing the water to be detected by the water intrusion detection device. Also, by collecting the water in the reservoir, water intrusion can be detected early even if only a water intrusion detection device is provided in a part of the battery pack.

[0014] In the above configuration, the partition wall may have an elastic member on a surface facing the upper case.

[0015] By providing an elastic member between the partition and the upper case, inertial force is transmitted to the partition, causing the partition to deform, and the elastic member functions as a buffer member when the partition collides with the upper case, thereby preventing the generation of abnormal noise and damage to the partition. [Effects of the Invention]

[0016] The battery pack of the present invention has an advantage in that the partition wall that protrudes toward the upper case is higher than the joint between the lower case and the upper case, thereby providing a battery pack in which a filling member that restricts lateral displacement of the storage device can be filled up to a position higher than the joint between the lower case and the upper case. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a partial cross-sectional view showing a schematic configuration of a battery pack according to a first embodiment. [Figure 2]FIG. 2 is a partial cross-sectional view showing a schematic configuration of a battery pack according to the second embodiment. [Figure 3] FIG. 3 is a top view of the battery pack according to the third embodiment with the upper cover removed. [Figure 4] FIG. 4 is a cross-sectional view of the battery pack shown in FIG. 3 taken along the line BB. [Figure 5] FIG. 5 is a diagram showing a case where an elastic member is provided on the upper end surface of the partition wall. DETAILED DESCRIPTION OF THE INVENTION

[0018] (Embodiment 1) A battery pack according to a first embodiment of the present invention will be described below, although the present invention is not limited to this embodiment.

[0019] FIG. 1 is a partial cross-sectional view showing a schematic configuration of a battery pack 1 according to the first embodiment.

[0020] The battery pack 1 in the first embodiment is mounted on an electric vehicle and serves as, for example, a power supply source that supplies power to a motor that is a drive source of the electric vehicle. The battery pack 1 according to the first embodiment includes a case 3 that is composed of an upper case 31 and a lower case 32. The case 3 houses a battery stack 2 that is a power storage device.

[0021] The battery stack 2 is a stacked body formed by alternately stacking a plurality of battery modules 21a, 21b, 21c, and 21d and a plurality of current-carrying members 22a, 22b, and 22c between a lower current collecting member 23a and an upper current collecting member 23b in a height direction (vertical direction), which is a first direction of the battery pack 1. In the battery pack 1 according to the first embodiment, the height direction is the same as the stacking direction of the plurality of battery modules 21a, 21b, 21c, and 21d.

[0022] The upper case 31 and the lower case 32 face each other in the height direction. The upper case 31 and the lower case 32 have flange-shaped upper joint portion 310 and lower joint portion 320 on their respective peripheries for joining them to each other. In the case 3, the upper joint portion 310 and the lower joint portion 320 are joined to form the case joint portion 300. The lower joint portion 320 is positioned so as to overlap with the battery stack 2 when viewed from the vehicle width direction, which is a second direction perpendicular to the height direction.

[0023] The lower case 32 is provided with a plate-shaped partition wall 4 extending upward in the height direction from a bottom surface portion 321 of the lower case 32 at a predetermined distance from the battery stack 2 so as to surround the periphery of the battery stack 2. An upper end surface 400 of the partition wall 4 protrudes toward the upper case 31 in the height direction beyond the lower-side joint portion 320. In the battery pack 1 according to the first embodiment, the height of the upper end surface (vertex) 400 of the partition wall 4 is configured to be higher than the height of the upper end surface (vertex) 200 of the battery stack 2 by a distance d in the height direction. In the battery pack 1 according to the first embodiment, the upper surface of the upper current collecting member 23b forms the upper end surface 200 of the battery stack 2.

[0024] The space between the partition wall 4 and the battery stack 2 is filled with a filler 5 that can fill the space between the partition wall 4 and the battery stack 2 without any gaps. The filler 5 also fills the space from the lower joint 320 up to the upper case 31 side in the height direction. An upper end surface 500 of the filler 5 is located at approximately the same height as an upper end surface 200 of the battery stack 2 in the height direction. The filler 5 functions as a displacement restriction portion that restricts lateral displacement of the battery stack 2. For example, the filler 5 can be made of a material that is initially liquid and hardens over time.

[0025] Because the filling member 5 is held by the battery stack 2 and the partition wall 4, it can be filled without closing the lid member, improving the flexibility of the filling work. Furthermore, because the filling member 5 can be visually inspected during the filling work, it is possible to improve the efficiency of detecting abnormalities such as abnormal filling, thereby improving quality.

[0026] Furthermore, compared to the prior art where no partition wall 4 is provided and the filling member 5 is filled before closing the lid member, the dead space can be reduced, making it possible to improve the freedom of vehicle height adjustment and battery capacity.

[0027] Furthermore, in the battery pack 1 according to embodiment 1, the upper end surface 400 of the partition 4 protrudes further toward the upper case 31 than the lower-side joint 320, so that even if water seeps in through the case joint 300, the partition 4 can prevent the water from seeping into the battery stack 2.

[0028] (Embodiment 2) A battery pack according to a second embodiment of the present invention will be described below. Note that in this embodiment, the same configuration as in the first embodiment will not be described as appropriate.

[0029] FIG. 2 is a partial cross-sectional view showing a schematic configuration of a battery pack 1 according to a second embodiment.

[0030] In the battery pack 1 according to the second embodiment, as shown in Fig. 2, the partition wall 4 is provided from the side surface portion 322 of the lower case 32 toward the upper case 31 in the height direction. The partition wall 4, which is arranged to surround the periphery of the battery stack 2, is tapered upward (vertically upward) in the height direction and inward (toward the interior of the vehicle) in the vehicle width direction. In other words, the partition wall 4 is provided on the side surface portion 322 of the lower case 32 so as to be inclined inward in the vehicle width direction with respect to the height direction. Note that the partition wall 4 is not limited to being inclined continuously inward in the vehicle width direction, and may be inclined intermittently.

[0031] In the battery pack 1 of embodiment 2, the partition wall 4 is provided on the side surface portion 322 of the lower case 32. This makes it possible to expand the physical dimensions of the battery stack 2, such as the width, compared to when the partition wall 4 is provided on the bottom surface portion 321 of the lower case 32, thereby enabling the battery capacity of the battery stack 2 to be improved.

[0032] In addition, in the battery pack 1 of embodiment 2, the partition wall 4 is provided on the side portion 322 of the lower case 32, so it can be made shorter than when the partition wall 4 is provided on the bottom portion 321 of the lower case 32, and the partition wall 4 can be made lighter.

[0033] (Embodiment 3) A battery pack according to a third embodiment of the present invention will be described below. Note that in this embodiment, the same configuration as in the second embodiment will not be described as appropriate.

[0034] Fig. 3 is a top view of the battery pack 1 according to embodiment 3 with the upper case 31 removed. Fig. 4 is a cross-sectional view taken along line BB of the battery pack 1 shown in Fig. 3. The cross-sectional view taken along line AA of the battery pack 1 shown in Fig. 3 is the same as Fig. 2.

[0035] The partition wall 4 is composed of a first partition wall portion, which is the portion of the partition wall 4 shown in Fig. 2, and a second partition wall portion, which is the portion of the partition wall 4 shown in Fig. 4. The second partition wall portion is provided to extend further from the bottom surface portion 321 side of the side surface portion 322 of the lower case 32 in the height direction than the first partition wall portion. As shown in Figs. 3 and 4, a liquid reservoir portion 6 is provided between the second partition wall portion of the partition wall 4 and the side surface portion 322 of the lower case 32.

[0036] In other words, in the battery pack 1 according to the third embodiment, as shown in Fig. 3, a portion of the partition 4 (the second partition) is recessed inward (inside the battery pack 1) in the vehicle width direction relative to the other portion (the first partition), to provide the liquid reservoir 6. As shown in Fig. 4, the liquid reservoir 6 is a groove that is deeper than the other portion (the first partition) where the liquid reservoir 6 is not provided, as shown in Fig. 2. The liquid reservoir 6 is provided with a water ingress detection device 7 for detecting the occurrence of water ingress into the case 3 through the case joint 300. The water ingress detection device 7 detects water ingress, for example, by detecting water that has ingressed into the case 3 through the case joint 300 and accumulated in the liquid reservoir 6.

[0037] In the battery pack 1 according to the third embodiment, the partition wall 4 in the other portion (first partition wall portion) where the liquid reservoir 6 as shown in FIG. 2 is not provided, together with the upper case 31 and the lower case 32, forms a flow path (gutter) for flowing water toward the liquid reservoir 6. As a result, water that has entered the case 3 from the case joint portion 300 can be easily collected in the liquid reservoir 6 by the flow path, and water ingress can be detected early by the water ingress detection device 7. Furthermore, by collecting water that has entered the case 3 in the liquid reservoir 6, water ingress can be detected early even by simply providing the liquid reservoir 6 at one location in the circumferential direction of the battery stack 2 and providing the water ingress detection device 7.

[0038] FIG. 5 is a diagram showing a case where an elastic member 8 is provided on the upper end surface 400 of the partition wall 4. In FIG.

[0039] 5, in the battery pack 1 according to the third embodiment, an elastic member 8 made of, for example, rubber may be provided on an upper end surface 400, which is the surface of the partition wall 4 that is located on the upper case 31 side in the height direction. This allows the elastic member 8 to function as a buffer member and suppress the generation of abnormal noise and damage to the partition wall 4 when, for example, an inertial force is transmitted to the partition wall 4 during vehicle travel, causing the partition wall 4 to deform and collide with the upper case 31. [Explanation of symbols]

[0040] 1 battery pack 2 Battery stack 3 Cases 4 Bulkhead 5 Filler material 6 Liquid reservoir 7. Water ingress detection device 8 Elastic member 21a, 21b, 21c, 21d Battery modules 22a, 22b, 22c Current-carrying members 23a Lower current collecting member 23b Upper current collecting member 31 Upper Case 32 Lower case 200,400,500 Top surface 300 Case joint 310 Upper joint 320 Lower side joint 321 Bottom part 322 Side part

Claims

1. A battery pack including a lower case and an upper case, the battery pack housing an electricity storage device, the lower case and the upper case face each other in a first direction, a joint portion that joins the lower case and the upper case, the joint is positioned so as to overlap the power storage device when viewed from a second direction perpendicular to the first direction, the lower case has a partition wall arranged to surround the power storage device, the partition wall protrudes toward the upper case in the first direction beyond the joint portion, a filling member is filled between the partition wall and the power storage device up to a portion toward the upper case side in the first direction beyond the joint portion.

2. the partition wall protrudes toward the upper case in the first direction further than the power storage device, 2 . The battery pack according to claim 1 , wherein the filling member is filled between the partition wall and the power storage device up to a position closer to the upper case than the power storage device in the first direction.

3. The lower case has a bottom portion and a side portion, 3. The battery pack according to claim 2, wherein the partition wall is formed from the side surface portion toward the upper case in the first direction.

4. The partition wall has a first partition wall portion and a second partition wall portion, the second partition wall portion is provided to extend from the bottom surface portion side of the side surface portion in the first direction further than the first partition wall portion, a liquid reservoir is provided between the second partition and the side surface, The battery pack according to claim 3, further comprising a water ingress detection device in the liquid reservoir.

5. The battery pack according to claim 4 , wherein the partition wall has an elastic member on a surface located on the upper case side.

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