Battery pack

Abstract

To provide a battery pack that can improve the vibration resistance and heat dissipation of the battery module. [Solution] The battery pack of the present invention comprises a battery case consisting of an upper case and a lower case, and a battery module housed in the battery case and having a plurality of battery cells stacked on top of each other, the battery pack further comprising: a first fastening member for fastening the top plate portion of the upper case to the battery module, a second fastening member for fastening the bottom plate portion of the lower case to the battery module, and a heat conductive member provided between the battery module and the top plate portion, in contact with the upper surface of the battery module and the inner surface of the top plate portion.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a battery module in which a plurality of battery cells are arranged side by side in one direction and a pair of end plates are arranged at both ends in the one direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the battery module disclosed in Patent Document 1, there is room for improvement in vibration resistance and heat dissipation.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a battery pack capable of improving the vibration resistance and heat dissipation of a battery module.

Means for Solving the Problems

[0006] [[ID=4'6]]In order to solve the above-described problems and achieve the object, a battery pack according to the present invention includes a battery case including an upper case and a lower case, and a battery module accommodated in the battery case in which a plurality of battery cells are stacked, and a plurality of first fastening members that fasten the top plate portion of the upper case and the battery module, and a plurality of second fastening members that fasten the bottom plate portion of the lower case and the battery module, and a heat conduction member provided in contact with the upper surface of the battery module and the inner surface of the top plate portion between the battery module and the top plate portion.

[0007] As a result, in the battery pack according to the present invention, the vibration resistance and heat dissipation of the battery module can be improved by fastening and fixing the battery module to the upper case with a first fastening member, in addition to the case in which the battery module is fastened and fixed to the lower case only with a second fastening member.

[0008] Furthermore, in the above configuration, two ribs extending in the longitudinal direction of the battery module are provided on the inner surface of the top plate portion, spaced apart in the width direction perpendicular to the longitudinal direction, and the heat conductive member may be placed between the two ribs in the width direction.

[0009] This makes it possible to suppress the displacement of the heat conduction member in the width direction of the battery module due to vibration.

[0010] Furthermore, in the above, the battery module may include a pair of end plates that sandwich the plurality of battery cells from the stacking direction, the end plates and the upper case may be fastened together by the first fastening member, and the end plates and the lower case may be fastened together by the second fastening member.

[0011] This makes it easy to secure fastening points for the battery module to the upper case and lower case using the first fastening member and the second fastening member.

[0012] Furthermore, in the above, the end plate is divided into an upper end plate and a lower end plate in the height direction of the battery module, the upper end plate and the upper case are fastened together by the first fastening member, the lower end plate and the lower case are fastened together by the second fastening member, and the upper end plate and the lower end plate may be connected by an elastic member.

[0013] This makes it possible to fasten the lower end plate to the lower case from the inside of the case using a second fastening member, and to fasten the upper end plate to the upper case from the inside of the case using a first fastening member, with the upper case removed from the lower case. [Effects of the Invention]

[0014] The battery pack according to the present invention has the effect of improving the vibration resistance and heat dissipation of the battery module. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a cross-sectional view showing the schematic configuration of the battery pack according to the embodiment, as viewed from the side. [Figure 2] Figure 2 is a cross-sectional view of the battery pack according to Embodiment 1. [Figure 3] Figure 3 is a cross-sectional view of the battery pack according to Embodiment 2. [Figure 4] Figure 4 is a cross-sectional view of the battery pack according to Embodiment 3. [Modes for carrying out the invention]

[0016] (Embodiment 1) Embodiment 1 of the battery pack according to the present invention will be described below. However, the present invention is not limited to this embodiment.

[0017] Figure 1 is a cross-sectional view showing the schematic configuration of a battery pack 1 according to an embodiment, viewed from the side. The battery pack 1 according to this embodiment is configured by housing a battery module 100 in a battery case 2 consisting of an upper case 21 and a lower case 22. Figure 2 is a cross-sectional view of the battery pack 1 according to Embodiment 1.

[0018] The battery module 100 has a plurality of battery cells 10, a pair of end plates 3, and an intermediate plate 6. Each battery cell 10 is a rechargeable secondary battery such as, for example, a lithium-ion battery. The battery cells 10 are generally formed in a rectangular parallelepiped shape. The pair of end plates 3 are generally flat plate-like members. The pair of end plates 3 face each other with the plurality of battery cells 10 interposed therebetween. The pair of end plates 3 are connected to each other via a band member (not shown) that extends in the longitudinal direction of the battery module 100, which is the stacking direction of the plurality of battery cells 10. Thereby, the battery module 100 is constrained by the pair of end plates 3 and a constraining member such as the band member. The intermediate plate 6 is provided so as to divide the plurality of battery cells 10 in the longitudinal direction of the battery module 100.

[0019] In addition, in the present embodiment, the longitudinal direction of the battery module 100 is also simply referred to as the "longitudinal direction". Also, in the present embodiment, the width direction orthogonal to the longitudinal direction of the battery module 100 is also simply referred to as the "width direction". Further, in the present embodiment, the height direction orthogonal to the longitudinal direction and the width direction of the battery module 100 is also simply referred to as the "height direction". Moreover, in the present embodiment, the longitudinal direction of the battery module 100 and the longitudinal direction of the battery pack 1 are the same direction, the width direction of the battery module 100 and the width direction of the battery pack 1 are the same direction, and the height direction of the battery module 100 and the height direction of the battery pack 1 are the same direction.

[0020] The upper case 21 of the battery case 2 has a top plate portion 210, side plate portions 215, and flange portions 216, and has a box-shaped form that opens upward. The upper case 21 is made of a metal material such as iron or aluminum. The top plate portion 210 of the upper case 21 is formed, for example, in a flat shape and is positioned above the battery module 100. As shown in Figures 1 and 2, a heat conductive member 51 is positioned between the top plate portion 210 of the upper case 21 and the battery module 100 in the height direction, in contact with the inner surface 212 of the top plate portion 210 and the upper surface 101 of the battery module 100. Note that the heat conductive member 51 only needs to be positioned between at least a number of battery cells 10 and the top plate portion 210 of the upper case 21, in contact with the upper surface of each battery cell 10 and the inner surface 212 of the top plate portion 210. The side plate portion 215 of the upper case 21 extends downward from the periphery of the top plate portion 210 and surrounds the battery module 100. The flange portion 216 of the upper case 21 has a shape that protrudes outward from the lower end of the side plate portion 215.

[0021] The lower case 22 of the battery case 2 has a bottom plate portion 220, a side plate portion 225, and a flange portion 226, and has a box-shaped form that opens upward. The lower case 22 is made of a metal material such as iron or aluminum. The bottom plate portion 220 is located below the battery module 100. As shown in Figures 1 and 2, a heat conductive member 52 is placed between the bottom plate portion 220 of the lower case 22 and the battery module 100 in the height direction, in contact with the inner surface 222 of the bottom plate portion 220 and the lower surface 102 of the battery module 100. Note that the heat conductive member 52 only needs to be placed between at least a number of battery cells 10 and the bottom plate portion 220 of the lower case 22, in contact with the lower surface of each battery cell 10 and the inner surface 222 of the bottom plate portion 220. The side plate portion 225 of the lower case 22 rises from the periphery of the bottom plate portion 220 and surrounds the periphery of the battery module 100. The flange portion 226 of the lower case 22 has a shape that protrudes outward from the upper end of the side plate portion 225 and is fastened to the flange portion 216 of the upper case 21 by fastening members such as bolts (not shown).

[0022] As shown in FIG. 2, at the upper part of the end plate 3 and at both ends in the width direction, a pair of upper flanges 311A and 311B protruding in the width direction are provided. Also, at the lower part of the end plate 3 and at both ends in the width direction, a pair of lower flanges 321A and 321B protruding in the width direction are provided.

[0023] Through holes 3210A and 3210B penetrating in the height direction are provided in the lower flanges 321A and 321B of the end plate 3. Also, lower bosses 221A and 221B on which the lower flanges 321A and 321B of the end plate 3 are placed are provided on the bottom plate portion 220 of the lower case 22. Female screw portions 2210A and 2210B are provided in the lower bosses 221A and 221B so as to communicate with the through holes 3210A and 3210B of the lower flanges 321A and 321B. Then, bolts 42A and 42B, which are second fastening members, are inserted and passed through the through holes 3210A and 3210B of the lower flanges 321A and 321B from above in the height direction, and the bolts 42A and 42B are screwed into the female screw portions 2210A and 2210B of the lower bosses 221A and 221B. Thereby, the lower flanges 321A and 321B of the end plate 3 and the lower bosses 221A and 221B of the lower case 22 are fastened by the bolts 42A and 42B, and the end plate 3 is fixed to the lower case 22.

[0024] The upper flanges 311A ​​and 311B of the end plate 3 are provided with female threaded portions 3110A and 3110B. The top plate portion 210 of the upper case 21 is provided with upper bosses 211A and 211B at positions corresponding to the upper flanges 311A ​​and 311B of the end plate 3. The upper bosses 211A and 211B are provided with through holes 2110A and 2110B that communicate with the female threaded portions 3110A and 3110B of the upper flanges 311A ​​and 311B. The bolts 41A and 41B, which are the first fastening members, are inserted through the through holes 2110A and 2110B of the upper case 21 from the top side (outside the upper case 21) in the height direction and screwed into the female threaded portions 3110A and 3110B of the upper flanges 311A ​​and 311B. As a result, the upper flanges 311A ​​and 311B of the end plate 3 and the upper bosses 211A and 211B of the upper case 21 are fastened together by bolts 41A and 41B, and the end plate 3 is fixed to the upper case 21.

[0025] As a result, in the battery pack 1 according to Embodiment 1, the rigidity can be increased by fastening the battery module 100 to the upper case 21 with bolts 41A and 41B, compared to the case where the battery module 100 is fastened and fixed only to the lower case 22 with bolts 42A and 42B, and vibrations in the height direction (vertical direction) and width direction (lateral direction) of the battery module 100 can be suppressed.

[0026] Furthermore, if the top plate portion 210 of the upper case 21 is significantly displaced due to vibration, there is a risk that contact between the top plate portion 210 of the upper case 21 and the heat conductive member 51 may become difficult. In contrast, by fastening and fixing the top plate portion 210 of the upper case 21 and the end plate 3 with bolts 41A and 41B, it is possible to suppress significant displacement of the top plate portion 210 of the upper case 21 due to vibration. As a result, in the battery pack 1 according to Embodiment 1, good contact between the upper case 21 and the heat conductive member 51 can be maintained.

[0027] Furthermore, in the battery pack 1 according to Embodiment 1, the end plate 3 and the upper case 21 are fastened together with bolts 41A and 41B, and the end plate 3 and the lower case 22 are fastened together with bolts 42A and 42B. As a result, in the battery pack 1 according to Embodiment 1, it is possible to easily secure fastening points for the battery module 100 to the upper case 21 and the lower case 22 using bolts 41A, 41B, 42A, and 42B.

[0028] Furthermore, in the battery pack 1 according to Embodiment 1, a heat dissipation path for releasing heat from the battery module 100 is formed not only on the lower case 22 side via bolts 42A and 42B, but also on the upper case 21 side via bolts 41A and 41B, thereby increasing the amount of heat dissipated. As a result, for example, when any of the battery cells 10 of the battery module 100 overheat, the amount of heat dissipated from the overheated battery cell 10 to the battery case 2 via the end plate 3 and the multiple bolts 41A, 41B, 42A, and 42B can be increased to release the heat and suppress the chain reaction of overheating to other battery cells 10.

[0029] Furthermore, the number of bolts used to fasten the top plate portion 210 of the upper case 21 to the end plate 3 is not limited to two. Similarly, the number of bolts used to fasten the bottom plate portion 220 of the lower case 22 to the end plate 3 is not limited to two. In addition, in the battery pack 1 according to Embodiment 1, the intermediate plate 6, as well as the pair of end plates 3, may be fastened and secured to the top plate portion 210 of the upper case 21 and the bottom plate portion 220 of the lower case 22 with fastening members such as bolts.

[0030] (Embodiment 2) Embodiment 2 of the battery pack according to the present invention will be described below. In this embodiment, explanations similar to those in Embodiment 1 will be omitted as appropriate.

[0031] Figure 3 is a cross-sectional view of the battery pack 1 according to Embodiment 2. In the battery pack 1 according to Embodiment 2, as shown in Figure 3, compared to the battery pack 1 according to Embodiment 1, two ribs 213A and 213B are provided on the inner surface 212 of the top plate portion 210 of the upper case 21, extending in the longitudinal direction of the battery module 100 (upper case 21). The heat conductive member 51 provided between the upper surface 101 of the battery module 100 and the top plate portion 210 of the upper case 21 is positioned between the two ribs 213A and 213B in the width direction of the battery module 100.

[0032] As a result, the space in which the heat conduction member 51 is positioned can be defined by the top plate portion 210 of the upper case 21, the top surface 101 of the battery module 100, and the two ribs 213A and 213B. Therefore, displacement of the heat conduction member 51 due to vibration, especially displacement of the heat conduction member 51 in the width direction of the battery module 100, can be suppressed compared to the case without the two ribs 213A and 213B.

[0033] In the battery pack 1 according to Embodiment 2, two ribs extending in the longitudinal direction of the battery module 100 (lower case 22) may be provided on the inner surface 222 of the bottom plate portion 220 of the lower case 22, spaced apart in the width direction, and the heat conductive member 52 may be placed between the two ribs. This allows the space in which the heat conductive member 52 is placed to be defined by the bottom plate portion 220 of the lower case 22, the lower surface of the battery module 100, and the two ribs. Therefore, displacement of the heat conductive member 52 due to vibration, particularly displacement of the heat conductive member 52 in the width direction of the battery module 100, can be suppressed compared to the case where there are no two ribs on the bottom plate portion 220 of the lower case 22.

[0034] (Embodiment 3) Embodiment 3 of the battery pack according to the present invention will be described below. In this embodiment, explanations similar to those in Embodiment 1 will be omitted as appropriate.

[0035] Figure 4 is a cross-sectional view of the battery pack 1 according to Embodiment 3. In the battery pack 1 according to Embodiment 3, the end plate 3 is divided into an upper end plate 31 and a lower end plate 32 in the height direction of the battery module 100. The lower surface 312 of the upper end plate 31 and the upper surface 322 of the lower end plate 32 are connected by a plurality of springs 7, which are a plurality of elastic members.

[0036] As shown in Figure 4, the upper end plate 31 is provided with a pair of upper flanges 311A ​​and 311B that protrude in the width direction at both ends of the upper part in the width direction. The lower end plate 32 is provided with a pair of lower flanges 321A and 321B that protrude in the width direction at both ends of the lower part in the width direction.

[0037] The upper flanges 311A ​​and 311B of the upper end plate 31 are provided with through holes 3111A and 3111B that penetrate through in the height direction. The top plate portion 210 of the upper case 21 is provided with upper bosses 211A and 211B on which the upper flanges 311A ​​and 311B of the upper end plate 31 are mounted. The upper bosses 211A and 211B are provided with female threaded portions 2111A and 2111B that communicate with the through holes 3111A and 3111B of the upper flanges 311A ​​and 311B. Bolts 41A and 41B are then inserted from below in the height direction through the through holes 3111A and 3111B of the upper flanges 311A ​​and 311B, and the bolts 41A and 41B are screwed into the female threaded portions 2111A and 2111B of the upper bosses 211A and 211B. As a result, the upper flanges 311A ​​and 311B of the upper end plate 31 and the upper bosses 211A and 211B of the upper case 21 are fastened together by bolts 41A and 41B, and the upper end plate 31 is fixed to the upper case 21.

[0038] The lower flanges 321A and 321B of the lower end plate 32 are provided with through holes 3211A and 3211B that penetrate through in the height direction. The bottom plate portion 220 of the lower case 22 is provided with lower bosses 221A and 221B on which the lower flanges 321A and 321B of the lower end plate 32 are mounted. The lower bosses 221A and 221B are provided with female threaded portions 2211A and 2211B that communicate with the through holes 3211A and 3211B of the lower flanges 321A and 321B. Bolts 42A and 42B are then inserted through the through holes 3211A and 3211B of the lower flanges 321A and 321B from above in the height direction, and the bolts 42A and 42B are screwed into the female threaded portions 2211A and 2211B of the lower bosses 221A and 221B. As a result, the lower flanges 321A and 321B of the lower end plate 32 and the lower bosses 221A and 221B of the lower case 22 are fastened together by bolts 42A and 42B, and the lower end plate 32 is fixed to the lower case 22.

[0039] In the battery pack 1 according to Embodiment 3, with the upper case 21 removed from the lower case 22 (with the battery case 2 open), for example, the bottom plate portion 220 of the lower case 22 and the lower end plate 32 are fastened together from the inside of the case with bolts 42A and 42B. Then, the springs 7 of the end plate 3 are extended, and the top plate portion 210 of the upper case 21 and the upper end plate 31 are fastened together from the inside of the case with bolts 41A and 41B. Note that the order of fastening the bottom plate portion 220 of the lower case 22 and the lower end plate 32 with bolts 42A and 42B, and fastening the top plate portion 210 of the upper case 21 and the upper end plate 31 from the inside of the case with bolts 41A and 41B may be reversed.

[0040] Thus, in the battery pack 1 according to Embodiment 3, the work of fastening the upper end plate 31 and the upper case 21 from the inside of the case with bolts 41A and 41B, and the work of fastening the lower end plate 32 and the lower case 22 from the inside of the case with bolts 42A and 42B can be performed. [Explanation of symbols]

[0041] 1 Battery pack 2 Battery Case 3 End Plates 6 Intermediate plate 7 Springs 10 battery cells 21 Upper Case 22 Lower Cases 31 Upper end plate 32 Lower end plate 41A, 41B, 42A, 42B bolts 51, 52 Heat conductive material 100 Battery Modules 101 Top surface 102 Bottom surface 210 Top panel 212,222 Inner 213A, 213B Ribs 215,225 Side plate part 216,226 Flange section 220 Bottom plate part 211A, 211B Upper boss 221A, 221B Lower boss 311A, 311B Upper flange 312 Bottom surface 321A, 321B Lower flange 322 Top

Claims

1. A battery case consisting of an upper case and a lower case, Housed in the aforementioned battery case is a battery module in which multiple battery cells are stacked, A battery pack equipped with, A first fastening member that fastens the top plate portion of the upper case and the battery module, A second fastening member fastens the bottom plate portion of the lower case and the battery module, Between the battery module and the top plate, a heat conductive member is provided in contact with the upper surface of the battery module and the inner surface of the top plate, A battery pack characterized by having the following features.

2. Two ribs extending in the longitudinal direction of the battery module are provided on the inner surface of the top plate portion, spaced apart in the width direction perpendicular to the longitudinal direction. The battery pack according to claim 1, characterized in that the heat conductive member is arranged between the two ribs in the width direction.

3. The aforementioned battery module includes a pair of end plates that sandwich multiple battery cells from the stacking direction, The end plate and the upper case are fastened together by the first fastening member. The battery pack according to claim 1 or 2, characterized in that the end plate and the lower case are fastened together by the second fastening member.

4. The end plate is divided into an upper end plate and a lower end plate in the height direction of the battery module. The upper end plate and the upper case are fastened together by the first fastening member. The lower end plate and the lower case are fastened together by the second fastening member. The battery pack according to claim 3, characterized in that the upper end plate and the lower end plate are connected by an elastic member.

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