Battery pack

Abstract

To prevent, in a battery pack including a buffer member placed between a protection plate and a connecting portion, a cooling module from being damaged when an impact force is applied to the protection plate.SOLUTION: A battery pack includes: a plurality of battery stacks provided so as to be placed at intervals in an arrangement direction; a battery outer case in which the battery stacks are stacked; a cooler placed on a bottom face of the battery outer case; and a buffer member 13. The cooler includes a plurality of cooling modules provided so as to be placed at intervals in the arrangement direction; and a connecting portion 47 configured to connect adjacent cooling modules in the arrangement direction to each other. In each of the cooling modules, a refrigerant passage through which refrigerant flows is formed. The buffer member 13 is placed between the connecting portion 47 and a protection plate placed below the cooler at an interval. A vulnerable portion 16, 17 is formed in a part of the connecting portion 47, the part having the buffer member 13 placed.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] 2. Description of the Related Art Various battery packs including a battery device and a cooler for cooling the battery device have been proposed.

[0003] For example, the battery pack described in JP 2020-82983 A is arranged on the underside of a vehicle floor panel, and includes a battery case and a cooler arranged on the underside of the battery case. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-82983 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the battery device as described above, a plurality of battery stacks may be arranged at intervals within the battery case.

[0006] In view of this, the inventors of the present application have considered providing a cooling module for each battery stack in the cooler as well, and providing a connection portion for connecting the cooling modules with each other.

[0007] On the other hand, if a battery pack is placed on the underside of the floor panel, foreign objects thrown by the vehicle while in motion may apply impact force to the battery pack. Therefore, the inventors of the present application have studied a battery pack in which a protective plate is placed below the bottom surface of the battery case and a buffer member is placed between the protective plate and the connection portion.

[0008] In the battery pack described above, when an impact force is applied to the protective plate, the impact force is applied to the connection portion through the protective plate and the buffer member. As a result, the inventors have found that the impact force applied to the connection portion is transmitted to the cooling module, causing damage to the cooling module.

[0009] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a battery pack that includes a protective plate and a cushioning member arranged between a connection portion, in which damage to a cooling module is suppressed when an impact force is applied to the protective plate. [Means for solving the problem]

[0010] The battery pack of the present disclosure comprises a plurality of battery stacks arranged at intervals in an arrangement direction, a battery case accommodating the plurality of battery stacks, a cooler arranged on the bottom surface of the battery case, and a cushioning member, wherein the cooler includes a plurality of cooling modules arranged at intervals in the arrangement direction and a connection portion connecting adjacent cooling modules in the arrangement direction, a refrigerant passage through which a refrigerant flows is formed within the cooling module, the cushioning member is arranged between the connection portion and a protective plate arranged below the cooler, and a weak portion is formed in the portion of the connection portion where the cushioning member is arranged.

[0011] The weak portion is a scribe line. The weak portion is located closer to the contact portion between the joint portion and the buffer member than the joint portion between the cooling module and the connection portion. Effect of the Invention

[0012] According to the present disclosure, in a battery pack including a cooler including a cooling module and a connection portion, a protective plate arranged below the cooler, and a cushioning member arranged between the protective plate and the connection portion, it is possible to prevent damage to the cooling module when an impact force is applied to the protective plate. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing a vehicle 1 on which a battery pack 10 is mounted. [Diagram 2] FIG. 2 is an exploded perspective view showing the battery pack 10. [Diagram 3] FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] 2 is a cross-sectional view showing the upper end portion of a cushioning member 13 and the surrounding structure. [Figure 6] 1 is a plan view showing the cushioning member 13, the connection portion 47, and the scribe lines 16 and 17. FIG. [Figure 7] 10 is a cross-sectional view of a protective plate 14 when an impact force is applied thereto. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] A battery pack according to the present embodiment will be described with reference to Figures 1 to 7. Among the configurations shown in Figures 1 to 7, the same or substantially the same configurations are denoted by the same reference numerals and duplicated description will be omitted.

[0015] 1 is a schematic diagram showing a vehicle 1 equipped with a battery pack 10. The vehicle 1 includes a floor panel 2. The floor panel 2 is a metal plate-like member that forms the bottom surface of the vehicle 1.

[0016] The battery pack 10 is disposed on the lower surface of the floor panel 2. The battery pack 10 includes a battery device 11, a cooler 12, and a cushioning member 13.

[0017] The battery device 11 is disposed on the underside of the floor panel 2. The cooler 12 is disposed on the underside of the battery device 11. The protective plate 14 is disposed below the battery device 11 with a gap therebetween. The buffer member 13 is disposed between the protective plate 14 and the battery device 11 with a gap therebetween.

[0018] FIG. 2 is an exploded perspective view showing the battery pack 10. As shown in FIG.

[0019] The battery device 11 includes a plurality of battery stacks 20 and a battery case 21 that houses the plurality of battery stacks 20.

[0020] The battery stack 20 is formed long in the vehicle width direction W. The battery stack 20 includes a plurality of battery cells 23 arranged in the vehicle width direction W. The battery stacks 20 are arranged at intervals in the front-rear direction (arrangement direction) L.

[0021] The battery case 21 includes an upper case 24 and a lower case 25. The upper case 24 is provided so as to cover the multiple battery stacks 20 from above. The lower case 25 is provided so as to cover the multiple battery stacks 20 from below. The upper case 24 and the lower case 25 are formed of a metal such as an aluminum alloy.

[0022] The lower case 25 includes a bottom plate 26 and a peripheral wall 27. The peripheral wall 27 is formed on the outer periphery of the bottom plate 26 and is formed so as to rise upward from the outer periphery of the bottom plate 26.

[0023] The battery pack 10 includes an inner thermally conductive layer 30 disposed on an upper surface of the base plate 26 and an outer thermally conductive layer 31 disposed on a lower surface of the base plate 26 .

[0024] The inner thermally conductive layer 30 includes a plurality of thermally conductive portions 33, and each thermally conductive portion 33 is disposed between the battery stack 20 and the bottom plate 26. Each thermally conductive portion 33 is formed elongated in the vehicle width direction W.

[0025] The inner thermally conductive layer 30 is formed of, for example, a urethane-based resin. The inner thermally conductive layer 30 may be formed of an adhesive containing a silicone-based resin, an acrylic-based resin, an epoxy resin, or the like.

[0026] The inner thermally conductive layer 30 is a member that transfers heat from each battery stack 20 to the cooler 12. The inner thermally conductive layer 30 also functions as an adhesive that fixes each battery stack 20 to the bottom plate 26.

[0027] The outer thermally conductive layer 31 is disposed between the bottom plate 26 and the cooler 12. The outer thermally conductive layer 31 includes an outer frame portion 40 formed in an annular shape and a plurality of thermally conductive portions 41.

[0028] Each thermally conductive portion 41 is located below the battery stack 20. Each thermally conductive portion 41 is formed long in the vehicle width direction W. Both ends of each thermally conductive portion 41 are connected to the outer frame portion 40.

[0029] The outer thermally conductive layer 31 is formed of, for example, a urethane resin. The outer thermally conductive layer 31 may be formed of an adhesive containing a ricon-based resin, an acrylic resin, or an epoxy resin. The outer thermally conductive layer 31 also functions as an adhesive for bonding the cooler 12 and the bottom plate 26 together.

[0030] The outer thermally conductive layer 31 transfers heat from the battery stack 20 transferred through the inner thermally conductive layer 30 and the bottom plate 26 to the cooler 12 .

[0031] 3 is a perspective view showing the cooler 12. The cooler 12 includes a cooling unit 44, a holding frame 46, a supply pipe 48, a discharge pipe 49, and a reinforcing portion 50.

[0032] The holding frame 46 is formed in an annular shape and includes a front beam 51, a rear beam 52, a side beam 53, and a side beam 54.

[0033] The front beam 51 is provided at the front end and is formed so as to extend in the vehicle width direction W. The rear beam 52 is provided at the rear end and is formed so as to extend in the vehicle width direction W.

[0034] The side beam 53 is provided on the left side of the vehicle and is formed to extend in the front-rear direction L. The side beam 54 is provided on the right side of the vehicle and is formed to extend in the front-rear direction L.

[0035] The supply pipe 48 and the discharge pipe 49 are provided on the front beam 51. The coolant C is supplied from the supply pipe 48. The supplied coolant C is supplied to each cooling unit 44. The coolant C that has flowed through the cooling unit 44 is discharged to the outside from the discharge pipe 49.

[0036] A plurality of cooling units 44 are provided. In the example shown in Fig. 3, four cooling units 44 are provided. The cooling unit 44 includes a plurality of cooling modules 45 and a plurality of connection parts 47. In the example shown in Fig. 3, the cooling unit 44 includes two cooling modules 45. A cooling passage through which the refrigerant C flows is formed in each cooling module 45.

[0037] The cooling unit 44 is formed to extend in the vehicle width direction W. On the left side of the vehicle, one end of the cooling unit 44 is supported by a side beam 53, and the other end of the cooling unit 44 is supported by a side beam 54.

[0038] The cooling modules 45 are arranged at intervals in the front-rear direction L. The connection parts 47 are provided to connect adjacent cooling modules 45. Each connection part 47 is formed to extend in the front-rear direction L. The multiple connection parts 47 are arranged at intervals in the vehicle width direction W. The buffer member 13 is arranged on the underside of the connection part 47.

[0039] The reinforcing portions 50 are provided so as to connect the cooling units 44 adjacent to each other in the front-rear direction L. The number of the connecting portions 47 arranged in the vehicle width direction W is greater than the number of the reinforcing portions 50 arranged in the vehicle width direction W.

[0040] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

[0041] 4, the cooling modules 45A, 45B include cooling plates 60A, 60B and cooling plates 61A, 61B. The cooling plates 61A, 61B are formed with a plurality of grooves extending in the vehicle width direction W. The cooling plates 61A, 61B are welded to the cooling plate 60A, 60B, or the like, to form a plurality of refrigerant passages 62 between the cooling plate 60 and the cooling plates 61A, 61B.

[0042] An outer thermally conductive layer 31 is formed on the upper surfaces of the cooling plates 60A, 60B, and the bottom plate 26 of the lower case 25 is disposed on the upper surface of the outer thermally conductive layer 31. An inner thermally conductive layer 30 is formed on the upper surface of the bottom plate 26. Although not shown in Fig. 4, the battery stack 20 is disposed on the upper surface of the inner thermally conductive layer 30.

[0043] The heat of the battery stack 20 passes through the inner thermally conductive layer 30, the bottom plate 26, and the outer thermally conductive layer 31 in this order, and is dissipated to the cooler 12.

[0044] The connection portion 47 is formed to connect the cooling plate 61A and the cooling plate 61B. The connection portion 47 is formed integrally with the cooling plate 61A and the cooling plate 61B.

[0045] The protective plate 14 is located below the cooler 12. The protective plate 14 is fixed to the lower case 25 by a fixing member (not shown). The buffer member 13 is disposed between the protective plate 14 and the connection portion 47.

[0046] Fig. 5 is a cross-sectional view showing the upper end portion of cushioning member 13 and the surrounding structure. In Fig. 5, scribe lines 16 and 17 are formed on lower surface 43 of connecting portion 47. Fig. 6 is a plan view showing cushioning member 13, connecting portion 47, and scribe lines 16 and 17.

[0047] 5 and 6, the marking lines 16, 17 extend in the vehicle width direction W.

[0048] The scribing lines 16 and 17 are formed in a portion of the connection part 47 where the buffer member 13 is disposed. Here, the portion of the connection part 47 where the buffer member 13 is disposed is not limited to the portion where the upper end of the buffer member 13 contacts the lower surface of the connection part 47, but includes the portion located therearound. Therefore, in the example shown in Fig. 5 and Fig. 6, the scribing lines 16, 17 are formed in a position away from the upper end of the buffer member 13 in the front-rear direction L.

[0049] In other words, in the direction in which the connecting portion 47 extends, the contact portion between the connecting portion 47 and the buffer member 13 is located between the scribe line 16 and the scribe line 17 .

[0050] The scribe line 16 is located closer to the center of the connection part 47 in the front-rear direction L than the connection part of the cooling plate 61A and the connection part 47. The contact part of the cushioning member 13 and the connection part 47 is located at the center in the front-rear direction L. Similarly, the scribe line 17 is located closer to the center of the connection part 47 in the front-rear direction L than the connection part of the cooling plate 61B and the connection part 47.

[0051] The assembly process of the battery pack 10 includes a process of placing the cushioning member 13 at a predetermined position on the underside of the connection portion 47. In this placement process, the scribe lines 16, 17 can be used as markers, making it easy to confirm the attachment position of the cushioning member 13 and facilitating quality checks.

[0052] In the battery pack 10 configured as above, while the vehicle 1 is traveling, a foreign object on the road may be thrown off by the tires or the like and collide with the protective plate 14. Also, the vehicle 1 may run over an object that has fallen on the road or may interfere with the road surface. In such a case, an impact force is applied upward to the protective plate 14.

[0053] FIG. 7 is a cross-sectional view of the protective plate 14 when an impact force is applied to the protective plate 14. As shown in FIG.

[0054] The protective plate 14 is deformed by the impact force so as to bulge upward. As the protective plate 14 is deformed so as to bulge upward, the buffer member 13 is deformed so as to contract and presses the connection portion 47 upward.

[0055] Here, scribe lines 16, 17 are formed on the lower surface 43 of the connection portion 47. Therefore, when a load is applied upward from the buffer member 13, the buffer member 13 curves with the scribe lines 16, 17 as starting points.

[0056] In other words, even if an impact force is applied to connection portion 47 at the contact portion between buffer member 13 and connection portion 47, the transmission of load to the connection portion between cooling plate 61A and connection portion 47 and the connection portion between cooling plate 61B and connection portion 47 can be prevented.

[0057] This makes it possible to suppress the load from being transmitted to the cooler 12, and thus makes it possible to suppress damage to the cooler 12.

[0058] For example, when an impact force is applied to the cooler 12, the cooling plates 61A, 61B and the cooling plate 60 are separated, causing problems such as the refrigerant C leaking to the outside. In the present embodiment, it is possible to prevent such problems from occurring.

[0059] In this manner, in this embodiment, the scribe lines 16, 17 function as "weakened parts". On the other hand, various configurations can be adopted as the weak parts. For example, the scribe lines 16, 17 can be made thin-walled or corroded.

[0060] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the scope of the claims, and it is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. [Explanation of symbols]

[0061] 1 vehicle, 2 floor panel, 10 battery pack, 11 battery device, 12 cooler, 13 cushioning material, 14 protective plate, 16, 17 wire, 20 battery stack, 21 battery case, 23 battery cell, 24 upper case, 25 lower case, 26 bottom plate, 27 peripheral wall, 30 inner thermally conductive layer, 31 outer thermally conductive layer, 33, 41 thermally conductive portion, 40 outer frame portion, 43 underside, 44 cooling unit, 45, 45A, 45B cooling module, 46 retaining frame, 47 connection portion, 48 supply pipe, 49 discharge pipe, 50 reinforcement portion, 51 front beam, 52 rear beam, 53, 54 side beam, 60, 60A, 60B, 61A, 61B cooling plate, 62 refrigerant passage, C refrigerant, L front-rear direction, W vehicle width direction.

Claims

1. A plurality of battery stacks arranged at intervals in an arrangement direction; a battery case that houses the plurality of battery stacks; A cooler disposed on a bottom surface of the battery case; A cushioning member; Equipped with the cooler includes a plurality of cooling modules arranged at intervals in the arrangement direction and a connection portion connecting the cooling modules adjacent to each other in the arrangement direction, A coolant passage through which a coolant flows is formed in the cooling module, the buffer member is disposed between the connection portion and a protective plate disposed below the cooler, A weak portion is formed in the connection portion at a portion where the buffer member is disposed.

2. The battery pack according to claim 1 , wherein the weakened portion is a scribe line.

3. 3. The battery pack according to claim 1, wherein the fragile portion is located closer to a contact portion between the connecting portion and the buffer member than a joint portion between the cooling module and the connecting portion.

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