Battery pack

Abstract

The present invention relates to a battery pack which is provided with a lower case and an upper case and accommodates an electricity storage device, the lower case and the upper case facing each other in a first direction, the battery pack having a joining portion that joins the lower case and the upper case, the joining portion being located at a position overlapping the electricity storage device when viewed from a second direction orthogonal to the first direction, and the joining portion being located at a position overlapping the electricity storage device when viewed from the second direction orthogonal to the first direction. The lower case has a partition wall disposed so as to surround the electricity storage device, the partition wall protrudes toward the upper case side from the joint portion in the first direction, and the filling member is filled between the partition wall and the electricity storage device until the filling member is closer to the upper case side from the joint portion in the first direction.

Description

Technical Field

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

[0002] Japanese Patent Application Laid-Open No. 2018-081820 discloses a battery module including a lateral restriction portion for suppressing horizontal displacement of a single battery cell. Summary of the invention

[0003] In a battery pack having a lower shell and an upper shell and accommodating a storage device, when the side restriction portions are formed by solidifying a liquid filling member in order to arrange the side restriction portions without a gap between the storage device and the lower shell, the filling member can only be filled to the position of the joint between the lower shell and the upper shell.

[0004] The present invention has been made in view of the above problems, and an object thereof is to provide a battery pack capable of filling a filling member for restricting lateral displacement of an electric storage device to a position higher than a joint between a lower case and an upper case.

[0005] In order to solve the above-mentioned problems and achieve the purpose, the battery pack according to the present invention is a battery pack including a lower case and an upper case and accommodating an electric storage device, characterized in that:

[0006] The lower shell and the upper shell are opposite to each other in a first direction,

[0007] The lower housing has a joint portion engaged with the upper housing,

[0008] The joining portion is located at a position overlapping with the power storage device when viewed from a second direction orthogonal to the first direction.

[0009] The lower housing has a partition wall.

[0010] The partition wall protrudes toward the upper housing side from the joint portion in the first direction.

[0011] A filling member is filled between the partition wall and the power storage device to a position closer to the upper case than the joining portion in the first direction.

[0012] Thus, the partition wall protruding toward the upper case from the joint portion between the lower case and the upper case is higher than the joint surface, so that the filling member can be filled to a position higher than the joint portion between the lower case and the upper case.

[0013] In addition, in the above, it can be,

[0014] The partition wall protrudes toward the upper case side from the power storage device in the first direction.

[0015] The filling member is filled between the partition wall and the power storage device to a position closer to the upper case than the power storage device in the first direction.

[0016] Thus, the partition wall protruding toward the upper case side from the power storage device is higher than the power storage device, and thus the filling member can be filled to a position closer to the upper case than the power storage device in the first direction.

[0017] In addition, in the above, it can be,

[0018] The lower housing has a bottom surface portion and a side surface portion.

[0019] The partition wall is formed from the side surface portion toward the upper case along the first direction.

[0020] Thus, since the partition wall is formed on the side edge portion of the lower case, the volume efficiency of the battery pack can be improved compared to a case in which the partition wall is formed on the bottom surface portion of the lower case.

[0021] In addition, in the above, it can be,

[0022] The partition wall has a first partition wall portion and a second partition wall portion,

[0023] The second partition wall portion is provided to extend from the bottom surface side of the side surface portion in the first direction further than the first partition wall portion.

[0024] A liquid accumulation portion is provided between the second partition wall portion and the side surface portion,

[0025] The liquid accumulation portion is provided with a water submersion detection device.

[0026] Thus, when water enters the battery pack from the outside through the joint, water that enters the liquid accumulation portion provided between the second partition wall portion and the side portion of the lower case through the gap between the first partition wall portion and the lower case is accumulated, and the water intrusion detection device can detect the water intrusion. In addition, by collecting the intruded water in the liquid accumulation portion, even if the water intrusion detection device is only partially provided, the water intrusion can be detected at an early stage.

[0027] In addition, in the above, it can be,

[0028] The partition wall includes an elastic member on a surface located on the upper case side.

[0029] Thus, by providing the elastic member between the partition wall and the upper case, when the inertial force is transmitted to the partition wall and the partition wall is deformed and collides with the upper case, the elastic member functions as a buffer member, thereby suppressing the generation of abnormal sound and damage to the partition wall.

[0030] The battery pack according to the present invention has the effect of providing a battery pack capable of filling a filling member that restricts lateral displacement of the power storage device to a position higher than the position of the joint between the lower shell and the upper shell by making the partition wall protruding toward the upper shell side higher than the joint between the lower shell and the upper shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0032] Figure 1 is a partial cross-sectional view showing a schematic structure of a battery pack according to Embodiment 1;

[0033] Figure 2 is a partial cross-sectional view showing a schematic structure of a battery pack according to Embodiment 2;

[0034] Figure 3 is a top view of the battery pack according to Embodiment 3 with the upper cover removed;

[0035] Figure 4 yes Figure 3 A BB cross-sectional view of the battery pack shown; and

[0036] Figure 5 This is a diagram showing a case where an elastic member is provided on the upper end surface of the partition wall. DETAILED DESCRIPTION

[0037] Implementation Method 1

[0038] Hereinafter, a first embodiment of a battery pack according to the present invention will be described. However, the present invention is not limited to this embodiment.

[0039] Figure 1 This is a partial cross-sectional view showing a schematic structure of a battery pack 1 according to the first embodiment.

[0040] In the first embodiment, the battery pack 1 is mounted on an electric vehicle, and is, for example, a power supply source for supplying power to a motor as a driving source of the electric vehicle. The battery pack 1 according to the first embodiment includes a housing 3 composed of an upper housing 31 and a lower housing 32. A battery stack 2 as a power storage device is accommodated in the housing 3.

[0041] The battery stack 2 is a stacked body formed by alternately stacking a plurality of battery assemblies 21a, 21b, 21c, 21d and a plurality of current-carrying members 22a, 22b, 22c in the vertical direction (vertical direction) as the first direction of the battery pack 1, between the lower current collecting member 23a and the upper current collecting member 23b. In the battery pack 1 according to the first embodiment, the vertical direction is the same direction as the stacking direction of the plurality of battery assemblies 21a, 21b, 21c, 21d.

[0042] The upper shell 31 and the lower shell 32 are opposite to each other in the height direction. The upper shell 31 and the lower shell 32 have flange-shaped upper joints 310 and lower joints 320 for joining each other at their respective peripheries. In the shell 3, the upper joint 310 and the lower joint 320 are joined to form a shell joint 300. The lower joint 320 is located at a position overlapping with the battery stack 2 when viewed from the vehicle width direction as a second direction orthogonal to the height direction.

[0043] In the lower shell 32, a plate-shaped partition wall 4 extending upward from the bottom surface portion 321 of the lower shell 32 along the height direction is provided at a predetermined interval from the battery stack 2 in a manner surrounding the battery stack 2. The upper end surface 400 of the partition wall 4 protrudes toward the upper shell 31 side in the height direction more than the lower side joint portion 320. In addition, in the battery pack 1 involved in the first embodiment, it is configured so that in the height direction, the height of the upper end surface (vertex) 400 of the partition wall 4 is higher than the height of the upper end surface (vertex) 200 of the battery stack 2 by a distance d. In addition, in the battery pack 1 involved in the first embodiment, the upper surface of the upper current collecting member 23b forms the upper end surface 200 of the battery stack 2.

[0044] Between the partition wall 4 and the battery stack 2, a filling member 5 is filled that can fill the partition wall 4 and the battery stack 2 without a gap. In addition, the filling member 5 is filled until it is closer to the upper shell 31 side than the lower joint 320 in the height direction. The upper end face 500 of the filling member 5 is located at approximately the same height as the upper end face 200 of the battery stack 2 in the height direction. The filling member 5 functions as a displacement limiting portion that limits the lateral displacement of the battery stack 2. As the filling member 5, for example, a material that is initially liquid and solidifies over time can be used.

[0045] The filling member 5 is held by the battery stack 2 and the partition 4, so the filling member 5 can be filled even without closing the cover member, which can improve the freedom of the filling operation. In addition, during the filling operation, the filling member 5 can be visually observed, so the efficiency of finding abnormalities such as filling abnormalities is improved, which can achieve quality improvement.

[0046] Furthermore, compared with the case where the partition wall 4 is not provided and the filling member 5 is filled before the lid member is closed as in the prior art, the dead space can be reduced, and the degree of freedom in adjusting the vehicle height and the improvement of the battery capacity can be achieved.

[0047] In the battery pack 1 according to the first embodiment, the upper end surface 400 of the partition wall 4 protrudes toward the upper case 31 from the lower joint portion 320 . Therefore, even if water enters from the case joint portion 300 , the partition wall 4 can prevent water from entering the battery stack 2 .

[0048] Implementation Method 2

[0049] Hereinafter, a second embodiment of the battery pack according to the present invention will be described. In this embodiment, description of the same configuration as that of the first embodiment will be appropriately omitted.

[0050] Figure 2 This is a partial cross-sectional view showing a schematic structure of a battery pack 1 according to the second embodiment.

[0051] In the battery pack 1 according to the second embodiment, Figure 2 As shown, the partition wall 4 is provided from the side surface portion 322 of the lower shell 32 toward the upper shell 31 side along the height direction. In addition, the partition wall 4 arranged in a manner surrounding the battery stack 2 is provided in a shape that narrows toward the upper side (vertically upward) in the height direction and toward the inner side (inside 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 shell 32 so as to be inclined toward the inner side in the vehicle width direction relative to the height direction. In addition, the partition wall 4 is not limited to being configured to be continuously inclined toward the inner side in the vehicle width direction, and may also be configured to be intermittently inclined.

[0052] In the battery pack 1 involved in embodiment 2, the partition wall 4 is provided on the side surface portion 322 of the lower shell 32. Therefore, compared with the case where the partition wall 4 is provided on the bottom surface portion 321 of the lower shell 32, the volume of the battery stack 2 can be expanded, thereby increasing the battery capacity of the battery stack 2.

[0053] In the battery pack 1 according to the second embodiment, since the partition wall 4 is provided on the side surface portion 322 of the lower case 32 , the partition wall 4 can be shorter than when the partition wall 4 is provided on the bottom surface portion 321 of the lower case 32 , and the partition wall 4 can be made lighter.

[0054] Implementation 3

[0055] Hereinafter, a third embodiment of the battery pack according to the present invention will be described. In this embodiment, description of the same configuration as that of the second embodiment will be appropriately omitted.

[0056] Figure 3It is a plan view of the battery pack 1 according to the third embodiment with the upper case 31 removed. Figure 4 yes Figure 3 The BB cross-sectional view of the battery pack 1 is shown. Figure 3 The AA cross-sectional view of the battery pack 1 shown in FIG. Figure 2 It's the same.

[0057] Next door 4 Figure 2 The portion of the partition wall 4 shown is the first partition wall portion and Figure 4 The second partition wall portion is formed by the portion of the partition wall 4 shown in the figure. The second partition wall portion is extended from the bottom surface portion 321 side of the side surface portion 322 of the lower shell 32 in the height direction compared to the first partition wall portion. Figure 3 as well as Figure 4 As shown, the liquid storage 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 .

[0058] In other words, in the battery pack 1 according to the third embodiment, Figure 3 As shown in FIG. 1 , a portion of the partition wall 4 (the second partition wall portion) is recessed toward the inside (the inside of the battery pack 1) in the vehicle width direction compared to the other portion (the first partition wall portion). Figure 4 As shown, the liquid accumulation part 6 is Figure 2 The other part (first partition part) where the liquid accumulation part 6 is not provided is deep groove-shaped. The liquid accumulation part 6 is provided with a water intrusion detection device 7 for detecting water intrusion from the shell joint part 300 into the shell 3. The water intrusion detection device 7 detects water intrusion by detecting water intruding from the shell joint part 300 into the shell 3 and accumulating in the liquid accumulation part 6, for example.

[0059] In the battery pack 1 according to the third embodiment, Figure 2 The partition wall 4 at the other portion (first partition wall portion) where the liquid accumulation portion 6 is not provided as shown forms a flow path (water conduit) for causing water to flow toward the liquid accumulation portion 6 through the upper shell 31 and the lower shell 32. As a result, water that has penetrated into the shell 3 from the shell joint portion 300 can be easily collected in the liquid accumulation portion 6 through the flow path, and water intrusion can be detected early by the water intrusion detection device 7. In addition, by collecting the water intruded into the shell 3 in the liquid accumulation portion 6, even if the liquid accumulation portion 6 is provided at only one portion in the circumferential direction of the battery stack 2 and the water intrusion detection device 7 is provided, water intrusion can be detected early.

[0060] Figure 5 This is a diagram showing a state where the elastic member 8 is provided on the upper end surface 400 of the partition wall 4 .

[0061] In the battery pack 1 according to the third embodiment, for example, Figure 5As shown, the surface located at the upper shell 31 side in the height direction of the partition wall 4, i.e., the upper end surface 400, may be provided with, for example, an elastic member 8 made of rubber or the like. Thus, for example, when the inertial force is transmitted to the partition wall 4 during vehicle travel and the partition wall 4 is deformed and collides with the upper shell 31, the elastic member 8 functions as a buffer member, and the generation of abnormal sound and damage to the partition wall 4 can be suppressed.

Claims

1. A battery pack comprising a lower case and an upper case and accommodating a power storage device, characterized in that: The lower shell and the upper shell are opposite to each other in a first direction, having a joint portion for joining the lower shell to the upper shell, The joining portion is located at a position overlapping with the power storage device when viewed from a second direction orthogonal to the first direction. The lower case has a partition wall arranged so as to surround the power storage device. The partition wall protrudes toward the upper housing side from the joint portion in the first direction. A filling member is filled between the partition wall and the power storage device to a position closer to the upper case than the joining portion in the first direction.

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

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

4. The battery pack according to claim 3, characterized in that: 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 side of the side surface portion in the first direction further than the first partition wall portion. A liquid accumulation portion is provided between the second partition wall portion and the side surface portion, The liquid storage portion is provided with a water submersion detection device.

5. The battery pack according to claim 4, characterized in that: The partition wall includes an elastic member on a surface located on the upper case side.

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