Battery cooling device

Abstract

This battery cooling device is provided with: a battery case having a housing part for housing a battery module; an introduction port into which the cooling liquid supplied from the pump is introduced, the introduction port being provided in the center of the battery case in the first direction and on one end side in the second direction; a discharge port for discharging the cooling liquid introduced into the introduction port above each of the plurality of battery cells; and a communication path that communicates the introduction port and the discharge port. The communication path has a branch flow path including a first branch flow path that communicates with the introduction port and branches toward one end side in the first direction, and a second branch flow path that communicates with the introduction port and branches toward the other end side in the first direction.

Description

TECHNICAL FIELD

[0001] The present application relates to a battery cooling device that cools a battery. BACKGROUND

[0002] A battery is configured to have a plurality of battery assemblies formed by arranging a plurality of battery cells. Such a battery generates heat by outputting and charging electric power. The use of the battery in this state of heat generation is a cause of a decrease in performance of the battery. In addition, when the temperature of the battery reaches a prescribed temperature or more, there is a possibility of causing thermal runaway. Therefore, a technology of cooling a battery has been studied (for example, Patent Literature 1).

[0003] Patent Literature 1 describes a secondary battery cooling mechanism that can cool a plurality of secondary batteries individually. The secondary battery cooled by the secondary battery cooling mechanism is provided with a safety valve that opens a valve when reaching a prescribed temperature on an upper surface of each housing, and a spray nozzle that can spray cooling water is disposed opposite the safety valve. It is configured that when the temperature in the housing reaches a prescribed temperature, the safety valve operates, cooling water flows into the inside of the secondary battery, and the inside of the secondary battery is cooled.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2018-133134.

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In the secondary battery cooling structure described in Patent Literature 1, a plurality of spray nozzles (nozzles) are provided branching from one pipe. Therefore, the supply amount of cooling water is reduced on the downstream side compared to the upstream side, and the pressure of the cooling water on the downstream side also decreases compared to the upstream side. Therefore, the supply amount of cooling water is less on the downstream side than on the upstream side, and uneven cooling occurs on the upstream side and the downstream side, and there is a possibility that the battery assemblies that constitute the battery cannot be cooled uniformly. SUMMARY

[0009] Therefore, a battery cooling device that can uniformly cool battery assemblies is needed.

[0010] MEANS OF SOLVING THE PROBLEMS

[0011] The battery cooling device according to the present application is characterized by cooling a battery having a battery assembly in which a plurality of battery cells are arranged along a first direction, the battery cooling device including: a battery case having a housing portion that houses the battery assembly; an inlet port provided at a central portion in the first direction in the battery case and at one end side in a second direction orthogonal to the first direction, into which cooling liquid supplied from a pump is introduced; an outlet port that discharges the cooling liquid introduced into the inlet port above each of the plurality of battery cells; and a communication passage that communicates the inlet port and the outlet port, the communication passage having a branch flow path including a first branch flow path that communicates with the inlet port and branches toward one end side in the first direction, and a second branch flow path that communicates with the inlet port and branches toward the other end side in the first direction.

[0012] If such a configuration is employed, by causing the cooling liquid introduced into the inlet port to branch and flow through the branch flow path, it is possible to reduce fluctuations in the length (flow path length) of the communication passage that communicates the inlet port and the outlet port provided above each of the plurality of battery cells. Therefore, since it is possible to reduce fluctuations in the amount of cooling liquid discharged toward each of the plurality of battery cells, it is possible to uniformly cool the battery assembly. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 FIG. 1 is a view showing the configuration of a battery cooling device according to a first embodiment.

[0014] Figure 2 FIG. 3 is a view showing a communication passage and an outlet port according to the first embodiment.

[0015] Figure 3 FIG. 6 is a view showing a communication passage and an outlet port according to a second embodiment.

[0016] Figure 4 FIG. 9 is a view showing a communication passage and an outlet port according to a third embodiment.

[0017] Figure 5 FIG. 12 is a view showing a flow control mechanism. DETAILED DESCRIPTION

[0018] (First Embodiment)

[0019] The battery cooling device according to the present application is configured to cool a battery (also referred to as "battery pack") that has a battery assembly composed of a plurality of battery cells. A battery cell is a smallest unit of a battery, and a plurality of battery cells are connected in series to constitute one battery assembly. Further, in the present embodiment, a plurality of battery modules are connected in series, and the series-connected battery modules are connected in parallel to constitute one battery. The battery cooling device cools the battery by cooling each of the battery modules. Hereinafter, the battery cooling device 1 of the present embodiment will be described.

[0020] Figure 1 is a diagram schematically showing the structure of the battery cooling device 1. Figure 2 is a plan view of the battery cooling device 1. As shown in Figure 1 , the battery cooling device 1 has a battery case 10, an inlet port 20, an outlet port 30, and a communication passage 40.

[0021] The battery case 10 has a plurality of housing portions 11 separated by plate-like assembly- interposing plates 12. In Figure 1 , the battery case 10 is separated by three assembly-interposing plates 12, and four housing portions 11 are formed. Each of the plurality of battery assemblies 2 is housed in the housing portions 11. Thus, one battery assembly 2 is housed in one housing portion 11.

[0022] Here, in the plan view of the battery cooling device 1, the direction in which the assembly-interposing plates 12 extend is set as a first direction X, and the direction in which the three assembly-interposing plates 12 are aligned orthogonal to the first direction X is set as a second direction Y. In addition, the direction orthogonal to both the first direction X and the second direction Y is set as a third direction Z.

[0023] As shown in Figure 2 , the plurality of battery cells 3 are arranged along the first direction X. The battery assemblies 2 are arranged along the second direction Y. Thus, the battery case 10 is provided with a plurality of battery assemblies 2 in which the plurality of battery cells 3 are respectively arranged along the first direction X, and the plurality of battery assemblies 2 are arranged along the second direction Y. In the present embodiment, six battery cells 3 are arranged along the first direction X in one battery assembly 2, and four battery assemblies 2 are arranged along the second direction Y.

[0024] The inlet port 20 is provided at the central portion in the first direction X and at one end side in the second direction Y in the battery case 10. The central portion in the first direction X in the battery case 10 refers to the portion in the battery case 10 that is central between one end side and the other end side in the first direction X. Here, if a face of the battery case 10 at one end side in the first direction X is set as a first side face 10A, and a face of the battery case 10 at the other end side in the first direction X is set as a second side face 10B, the portion in the battery case 10 that is central between one end side and the other end side in the first direction X corresponds to the portion that is central between the first side face 10A and the second side face 10B.

[0025] Furthermore, the end side in the second direction Y refers to the end of the battery box 10 along the second direction Y. Here, if the surface of the battery box 10 along the second direction Y is designated as the third side surface 10C, and the surface of the battery box 10 along the other side in the second direction Y is designated as the fourth side surface 10D, then the end of the battery box 10 along the second direction Y corresponds to the third side surface 10C.

[0026] Therefore, as Figure 2 As shown, the inlet 20 is the central part of the first side 10A and the second side 10B in the battery box 10, and is located on the third side 10C in the battery box 10.

[0027] Additionally, the coolant supplied from pump P is introduced into inlet 20. For example... Figure 1 As shown, pump P and battery box 10 are separately installed, with pump P's outlet PO connected to inlet 20. Additionally, pump P's suction inlet PI is connected to battery box 10's outlet 21. Pump P is driven by an electric motor (not shown). Thus, coolant circulates between pump P and battery box 10. Alternatively, a cooling device for cooling the coolant can be installed between outlet 21 and pump P's suction inlet PI, through which pump P draws coolant from outlet 21. Here, the coolant is a long-life coolant (LLC) such as cooling water, paraffin-based insulating oil, etc.

[0028] The outlet 30 discharges the coolant introduced into the inlet 20 above each of the plurality of battery cells 3. The coolant introduced into the inlet 20, as described above, is coolant from the pump P. "Above each of the plurality of battery cells 3" refers to the area above each of the plurality of battery cells 3 arranged in a matrix within the battery case 10 along the third direction Z. Therefore, the outlet 30 discharges the coolant from the pump P introduced into the inlet 20 from above each of the plurality of battery cells 3 arranged in a matrix within the battery case 10 along the third direction Z.

[0029] Here, the outlet 30 can be equipped with a nozzle that discharges the incoming coolant toward each of the plurality of battery cells 3. This allows coolant to be directly blown onto each of the plurality of battery cells 3. Therefore, the coolant blown onto each of the plurality of battery cells 3 easily dissipates heat from the battery cells 3, improving the cooling effect. The outlet 30 can also be configured to allow the coolant to contain air bubbles, or it can be configured to disperse the cooling system like a shower head.

[0030] The inlet port 20 and the outlet port 30 are communicated by a communication passage 40. In the present embodiment, the entire passage that communicates the inlet port 20 and the outlet port 30 is referred to as the communication passage 40. Thus, the coolant introduced into the inlet port 20 circulates in the communication passage 40 to reach the outlet port 30, and is discharged from the outlet port 30.

[0031] In the present embodiment, the communication passage 40 has a branch passage 50, a connection passage 60, and a return passage 70. In the present embodiment, the branch passage 50 includes a first branch passage 51 and a second branch passage 52. The first branch passage 51 is communicated with the inlet port 20, and corresponds to a passage branched toward one end side in the first direction X. As shown in FIG. 1, in the present embodiment, the inlet port 20 is provided to project in the second direction Y inside the battery case 10. The first branch passage 51 is provided to branch from the top end portion in the second direction Y in the inlet port 20 toward the first side surface 10A side of the battery case 10. The second branch passage 52 is communicated with the inlet port 20, and corresponds to a passage branched toward the other end side in the first direction X. Thus, the second branch passage 52 is provided to branch from the top end portion in the second direction Y in the inlet port 20 toward the second side surface 10B side of the battery case 10. Figure 2

[0032] The connection passage 60 includes a first connection passage 61 and a second connection passage 62. The first connection passage 61 is communicated with the first branch passage 51, and corresponds to a passage projecting toward the other end side in the second direction Y. That is, the first connection passage 61 projects in the second direction Y on the one end side in the first direction X. In the present embodiment, the first connection passage 61 is provided to project from the one end side in the first direction X in the first branch passage 51 toward the other end side in the second direction Y. Thus, the first connection passage 61 projects from the first side surface 10A side in the first branch passage 51 along the first side surface 10A of the battery case 10. The second connection passage 62 is communicated with the second branch passage 52, and corresponds to a passage projecting toward the other end side in the second direction Y. That is, the second connection passage 62 projects in the second direction Y on the other end side in the first direction X. In the present embodiment, the second connection passage 62 is provided to project from the other end side in the first direction X in the second branch passage 52 toward the other end side in the second direction Y. Thus, the second connection passage 62 projects from the second side surface 10B side in the second branch passage 52 along the second side surface 10B of the battery case 10.

[0033] ​The return flow path 70 includes a first return flow path 71 and a second return flow path 72. The first return flow path 71 extends from the first connecting flow path 61 toward the second connecting flow path 62. That is, it communicates with the first branch flow path 51, and is equivalent to a flow path that turns back from one end to the other end in the first direction X. In this embodiment, the first return flow path 71 is connected to the first branch flow path 51 via the first connecting flow path 61. Therefore, the first return flow path 71 is connected to the first branch flow path 51 via the first connecting flow path 61 and extends from the first connecting flow path 61 toward the second side surface 10B. The second return flow path 72 extends from the second connecting flow path 62 toward the first connecting flow path 61. That is, it communicates with the second branch flow path 52, and is equivalent to a flow path that turns back from the other end to one end in the first direction X. In this embodiment, the second return flow path 72 is connected to the second branch flow path 52 via the second connecting flow path 62. Therefore, the second return flow path 72 is connected to the second branch flow path 52 via the second connecting flow path 62, and extends from the second connecting flow path 62 toward the first side 10A.

[0034] like Figure 2 As shown, the first return flow path 71 and the second return flow path 72 at least partially overlap each other in the second direction Y (i.e., when viewed along the second direction). Therefore, a second return flow path 72 can be positioned between two adjacent first return flow paths 71, and a first return flow path 71 can be positioned between two adjacent second return flow paths 72. Thus, the space between the two first return flow paths 71 and the space between the two second return flow paths 72 can be effectively utilized to form a flow path.

[0035] In addition, such as Figure 2 As shown, the first return flow path 71 extends along the first direction X to the front of the second connecting flow path 62, and the second return flow path 72 extends along the first direction X to the front of the first connecting flow path 61. Thus, for example, coolant can be discharged from the outlet 30 on the side of the first return flow path 71 near the first branch flow path 51 and from the outlet 30 on the side of the second return flow path 72 away from the second branch flow path 52. Coolant can also be discharged from the outlet 30 on the side of the first return flow path 71 away from the first branch flow path 51 and from the outlet 30 on the side of the second return flow path 72 near the second branch flow path 52. Furthermore, coolant can be discharged from the outlet 30 in the middle section of the first return flow path 71 and from the outlet 30 in the middle section of the second return flow path 72. Therefore, since the amount of discharged coolant can be averaged out, the battery assembly 2 can be cooled more evenly.

[0036] The return flow paths 70 are provided so that both the first return flow path 71 and the second return flow path 72 are located above one battery assembly 2. As described above, the first return flow path 71 is provided from the first branch flow path 51 toward the second side 10B side along the first direction X. In addition, the second return flow path 72 is provided from the second branch flow path 52 toward the first side 10A side along the first direction X. The first return flow path 71 and the second return flow path 72 are provided so that distances from the branch flow path 50 along the second direction Y are different from each other. Thus, as shown in FIG. 6, the first return flow path 71 and the second return flow path 72 are arranged in parallel to each other above one battery assembly 2. Figure 2

[0037] In each of the first return flow path 71 and the second return flow path 72, an outlet 30 is provided so as to discharge the coolant toward the lower side at a position overlapping the battery cell 3 when viewed from above. Here, the amount of the coolant flowing in the first return flow path 71 decreases as it approaches the second side 10B from the first connecting flow path 61. On the other hand, the amount of the coolant flowing in the second return flow path 72 decreases as it approaches the first side 10A from the second connecting flow path 62.

[0038] Thus, in the battery cell 3 close to the first side 10A, the amount of the coolant discharged from the first return flow path 71 is large, and the amount of the coolant discharged from the second return flow path 72 is small. On the other hand, in the battery cell 3 close to the first side 10A, the amount of the coolant discharged from the first return flow path 71 is small, and the amount of the coolant discharged from the second return flow path 72 is large. In addition, in the battery cell 3 in the central region of the first direction X, the amounts of the coolant discharged from the first return flow path 71 and the second return flow path 72 are moderate. Thus, for each of the battery cells 3 provided in one battery assembly 2, the sum of the amount of the coolant discharged from the first return flow path 71 and the amount of the coolant discharged from the second return flow path 72 can be the same degree as each other. Thus, it is possible to uniformly cool the plurality of battery cells 3 arranged along the first direction X.

[0039] The above-described inlet 20, outlet 30, and communication path 40 are formed in the upper plate 13 provided on the upper side of the battery case 10. A lower plate 14 is provided on the lower side of the battery case 10, and the coolant introduced into the battery case 10 is discharged from the outlet 21 via the discharge portion 110 and the discharge communication path 111 formed in the lower plate 14. Further, the discharge communication path 111 can also be configured to have a return flow path as with the above-described communication path 40.

[0040] (Second Embodiment)

[0041] ​Next, a second embodiment of the battery cooling device 1 will be described. In the first embodiment described above, coolant is discharged from both the first return flow path 71 and the second return flow path 72 relative to each battery cell 3. However, in the second embodiment, coolant is discharged from only one of the first return flow path 71 and the second return flow path 72 relative to each battery cell 3, which differs from the first embodiment. The battery box 10, the inlet 20, the branch flow path 50, and the connecting flow path 60 are the same as in the first embodiment, so their descriptions are omitted. The following description will focus on the differences from the first embodiment.

[0042] Figure 3 This is a top view showing the battery cooling device 1 according to this embodiment. In this embodiment, similar to the first embodiment, the return flow path 70 also includes a first return flow path 71 and a second return flow path 72. (As shown...) Figure 3 As shown, the first return flow path 71 is connected to the first branch flow path 51, which is equivalent to a flow path that turns back from one end of the first direction X to the central region of the first direction X. In this embodiment, similar to the first embodiment, the first return flow path 71 is connected to the first branch flow path 51 via the first connecting flow path 61. The central region of the first direction X refers to the region along the center of the first direction X between the first side surface 10A and the second side surface 10B. Therefore, the first return flow path 71 is connected to the first branch flow path 51 via the first connecting flow path 61, and is provided extending from the first connecting flow path 61 to the region along the center of the first direction X between the first side surface 10A and the second side surface 10B. The second return flow path 72 is connected to the second branch flow path 52, which is equivalent to a flow path that turns back from the other end of the first direction X to the central region of the first direction X. In this embodiment, the second return flow path 72 is connected to the second branch flow path 52 via the second connecting flow path 62. Therefore, the second return flow path 72 is connected to the second branch flow path 52 via the second connecting flow path 62, and extends from the second connecting flow path 62 to the central area along the first direction X between the first side surface 10A and the second side surface 10B. The first return flow path 71 and the second return flow path 72 are arranged above the battery assembly 2 in a state where they are not connected to each other.

[0043] The return flow path 70 is configured such that both the first return flow path 71 and the second return flow path 72 are located above a battery assembly 2. The first return flow path 71 extends from the first branch flow path 51 along the first direction X to the central region along the first direction X between the first side surface 10A and the second side surface 10B. The second return flow path 72 extends from the second branch flow path 52 along the first direction X to the central region along the first direction X between the first side surface 10A and the second side surface 10B. The first return flow path 71 and the second return flow path 72 are configured to be equidistant from the branch flow path 50 along the second direction Y. Therefore, as...Figure 3 As shown, the first return flow path 71 and the second return flow path 72 are provided so that the tip ends thereof face each other in a region in the center in the first direction X between the first side surface 10A and the second side surface 10B. Thereby, above one battery cell 3, the return flow path 70 is provided so that only one of the first return flow path 71 and the second return flow path 72 exists.

[0044] In the present embodiment, in each of the first return flow path 71 and the second return flow path 72, two discharge ports 30 are provided so as to discharge the coolant toward the lower side in a position overlapping one battery cell 3, as viewed from above. The amount of the coolant flowing in the first return flow path 71 is less the farther from the first connecting flow path 61, and the amount of the coolant flowing in the second return flow path 72 is less the farther from the second connecting flow path 62.

[0045] However, in the present embodiment, by making the length of the return flow path 70 from the connecting flow path 60 shorter than the length in the first direction X between the first side surface 10A and the second side surface 10B (by being about half), the difference in the amount of the coolant discharged to the battery cell 3 on the side closer to the connecting flow path 60 in the return flow path 70 and the amount of the coolant discharged to the battery cell 3 on the side closer to the central region in the return flow path 70 is reduced. Thereby, it is possible to uniformly cool the plurality of battery cells 3 arranged in the first direction X.

[0046] (Third Embodiment)

[0047] Next, the third embodiment of the battery cooling device 1 will be described. In the first and second embodiments described above, the flow path in the second direction Y in the communication path 40 is two, the first connecting flow path 61 and the second connecting flow path 62, but in the third embodiment, the flow path in the second direction Y is provided outside of these two flow paths, which is different from the first and second embodiments described above. The battery case 10, the guide inlet 20, the branch flow path 50, and the connecting flow path 60 are the same as in the first embodiment, and thus the description thereof will be omitted, and the following description will mainly center on the differences from the first embodiment.

[0048] Figure 4 A plan view of the battery cooling device 1 of the present embodiment is shown. The communication path 40 of the present embodiment has the branch flow path 50, the connecting flow path 60, the return flow path 70, the auxiliary flow path 80, and the branch flow path 90. As described above, the branch flow path 50 and the connecting flow path 60 are the same as in the first embodiment.

[0049] The auxiliary flow path 80 branches from a middle portion of the branch flow path 50. The middle portion of the branch flow path 50 corresponds to a portion of the branch flow path 50 between a portion that communicates with the introduction port 20 and a portion that communicates with the connection flow path 60. Thus, the auxiliary flow path 80 is provided to branch from the portion of the branch flow path 50 between the portion that communicates with the introduction port 20 and the portion that communicates with the connection flow path 60.

[0050] In the present embodiment, the branch flow path 50 also includes a first branch flow path 51 and a second branch flow path 52, and the connection flow path 60 also includes a first connection flow path 61 and a second connection flow path 62. In addition, in the present embodiment, the auxiliary flow path 80 includes a first auxiliary flow path 81 and a second auxiliary flow path 82. The first auxiliary flow path 81 branches from a middle portion of the first branch flow path 51 toward the other end side in the second direction Y. That is, the first auxiliary flow path 81 is provided to extend from the portion of the first branch flow path 51 between the portion that communicates with the introduction port 20 and the portion that communicates with the first connection flow path 61 toward the fourth side surface 10D side. In addition, the second auxiliary flow path 82 branches from a middle portion of the second branch flow path 52 toward the other end side in the second direction Y. That is, the second auxiliary flow path 82 is provided to extend from the portion of the second branch flow path 52 between the portion that communicates with the introduction port 20 and the portion that communicates with the second connection flow path 62 toward the fourth side surface 10D side.

[0051] The return flow path 70 returns from the branch flow path 50. In the present embodiment, as in the above-described first embodiment, the return flow path 70 is configured to return from the branch flow path 50 via the connection flow path 60. The return flow path 70 includes a first return flow path 71 and a second return flow path 72. The first return flow path 71 communicates with the first branch flow path 51 and corresponds to a flow path that returns from the one end side in the first direction X to the first auxiliary flow path 81. In the present embodiment, as in the first embodiment, the first return flow path 71 communicates with the first branch flow path 51 via the first connection flow path 61. Returning from the one end side in the first direction X to the first auxiliary flow path 81 means returning from the first side surface 10A side to the front of the first auxiliary flow path 81. That is, the first return flow path 71 is provided in a state of not being connected to the first auxiliary flow path 81. Thus, the first return flow path 71 communicates with the first branch flow path 51 via the first connection flow path 61 and is provided so as to extend from the first connection flow path 61 to the front of the first auxiliary flow path 81 in the first direction X.

[0052] The second return flow path 72 is connected to the second branch flow path 52, which is equivalent to a flow path that turns back from the other end of the first direction X to the second auxiliary flow path 82. In this embodiment, similar to the second embodiment, the second return flow path 72 is connected to the second branch flow path 52 via the second connecting flow path 62. Turning back from the other end of the first direction X to the second auxiliary flow path 82 means turning back from the second side 10B side to the front of the second auxiliary flow path 82. That is, the second return flow path 72 is set in a state where it is not connected to the second auxiliary flow path 82. Therefore, the second return flow path 72 is connected to the second branch flow path 52 via the second connecting flow path 62, and is set to extend from the second connecting flow path 62 along the first direction X to the front of the second auxiliary flow path 82.

[0053] Branch path 90 extends from auxiliary path 80 along the first direction X. Branch path 90 includes a first branch path 91 and a second branch path 92. For example... Figure 4 As shown, the first branch flow path 91 is connected to the first auxiliary flow path 81, and is equivalent to a flow path extending from the first auxiliary flow path 81 along the first direction X to the central region of the first direction X. The central region of the first direction X refers to the region between the first side 10A and the second side 10B along the center of the first direction X. Therefore, the first branch flow path 91 is connected to the first branch flow path 51 via the first auxiliary flow path 81, and is arranged to extend from the first auxiliary flow path 81 to the central region of the first direction X between the first side 10A and the second side 10B. The second branch flow path 92 is connected to the second auxiliary flow path 82, and is equivalent to a flow path extending from the second auxiliary flow path 82 along the first direction X to the central region of the first direction X. Therefore, the second branch flow path 92 is connected to the second branch flow path 52 via the second auxiliary flow path 82, and is arranged to extend from the second auxiliary flow path 82 to the central region of the first direction X between the first side 10A and the second side 10B. The first branch flow path 91 and the second branch flow path 92 are arranged above the battery assembly 2 in a state where they are not connected to each other.

[0054] The configuration is such that any one of the first return flow path 71, the second return flow path 72, the first branch flow path 91, and the second branch flow path 92 is located above the respective battery cell 3 of the battery assembly 2. Figure 4In this example, the first return flow path 71 is positioned above the battery cell 3 closest to the first side 10A, along the first direction X from the first branch flow path 51. Similarly, the second return flow path 72 is positioned above the battery cell 3 closest to the second side 10B, along the first direction X from the second branch flow path 52. Furthermore, the first branch flow path 91 is positioned above the second and third battery cells 3 starting from the first side 10A, along the first direction X from the first auxiliary flow path 81. Also, the second branch flow path 92 is positioned above the second and third battery cells 3 starting from the second side 10B, along the first direction X from the second auxiliary flow path 82.

[0055] In this embodiment, each of the first return flow path 71, the second return flow path 72, the first branch flow path 91, and the second branch flow path 92, when viewed from above, has two outlets 30 at a position overlapping with one battery cell 3, in order to discharge coolant downwards. Since the lengths of the first return flow path 71, the second return flow path 72, the first branch flow path 91, and the second branch flow path 92 along the first direction X can be made approximately equal, the plurality of battery cells 3 arranged along the first direction X can be cooled uniformly.

[0056] (Fourth Implementation)

[0057] Next, a fourth embodiment of the battery cooling device 1 will be described. In the first, second, and third embodiments described above, the flow path cross-sectional area of ​​the connecting path 40 was uniform. The connecting path 40 in this embodiment differs from the embodiments in that the flow path cross-sectional area is not uniform. Other structures are the same as in the first embodiment, so descriptions are omitted. The following description will focus on the differences from the first embodiment.

[0058] In this embodiment, the battery cooling device 1 includes a flow control mechanism 100. The shorter the distance from the pump P to the turnaround portion 70S, which is the starting point of the turnaround flow path 70, the more the flow control mechanism 100 increases the pressure loss of the coolant flowing in the turnaround flow path 70. Figure 5 This refers to pump P, return flow path 70, and return section 70S. In this embodiment, pump P is connected to inlet 20, through which coolant is introduced into battery cooling device 1. The coolant introduced from inlet 20 flows through return flow path 70 via branch flow path 50 and connecting flow path 60. The return section 70S, which is the starting point of return flow path 70, corresponds to the connection portion between return flow path 70 and connecting flow path 60.

[0059] In the present embodiment, the link flow path 60 on the first side surface 10A side that communicates with the first branch flow path 51 is provided with four return flow paths 70 along the second direction Y. Hereinafter, the four return flow paths 70 will be provided in order from the side closer to the guide inlet 20 as return flow path 70B, return flow path 70D, return flow path 70F, and return flow path 70H. Also, the link flow path 60 on the second side surface 10B side that communicates with the second branch flow path 52 is provided with four return flow paths 70 along the second direction Y. Hereinafter, the four return flow paths 70 will be provided in order from the side closer to the guide inlet 20 as return flow path 70A, return flow path 70C, return flow path 70E, and return flow path 70G.

[0060] Therefore, among the distances from the pump P to the return sites 70S of the return flow path 70A, return flow path 70B, return flow path 70C, return flow path 70D, return flow path 70E, return flow path 70F, return flow path 70G, and return flow path 70H, the distance to the return site 70S of the return flow path 70A is the shortest, and gradually becomes longer in order of the return flow path 70A, return flow path 70B, return flow path 70C, return flow path 70D, return flow path 70E, return flow path 70F, return flow path 70G, and return flow path 70H.

[0061] Therefore, in the present embodiment, the battery cooling device 1 is configured so that the pressure loss of the coolant flowing through the return flow path 70A is the largest, and gradually becomes smaller in order of the return flow path 70B, return flow path 70C, return flow path 70D, return flow path 70E, return flow path 70F, return flow path 70G, and return flow path 70H.

[0062] In the present embodiment, as the flow control mechanism 100, the return flow path 70A is configured so that the flow path cross-sectional area is the smallest, and gradually becomes larger in order of the return flow path 70B, return flow path 70C, return flow path 70D, return flow path 70E, return flow path 70F, return flow path 70G, and return flow path 70H.

[0063] Thus, in the link flow path 60, the farther away from the guide inlet 20, the smaller the flow rate of the coolant, but the closer to the guide inlet 20, the smaller the flow path cross-sectional area of the return flow path 70, so the amount of coolant discharged from the discharge outlet 30 is reduced, and the farther away from the guide inlet 20, the larger the flow path cross-sectional area of the return flow path 70, so the amount of coolant discharged from the discharge outlet 30 can be increased. Therefore, the coolant discharged from the respective discharge outlets 30 of the return flow path 70A, return flow path 70B, return flow path 70C, return flow path 70D, return flow path 70E, return flow path 70F, return flow path 70G, and return flow path 70H becomes the same degree, and the difference in cooling effect on each battery assembly 2 can be reduced.

[0064] (Other embodiments)

[0065] In the above embodiment, the case where the battery case 10 has four accommodation portions 11 is described as an example, but the accommodation portions 11 can be two or three. In addition, it can be five or more.

[0066] In the above embodiment, it is described that the battery cooling device 1 is provided with the flow control mechanism 100 that increases the pressure loss of the coolant flowing in the return flow path 70 as the distance from the pump P to the return site 70S that is the start point of the return flow path 70 is shorter. However, the battery cooling device 1 can also be configured without the flow control mechanism 100.

[0067] In the above embodiment, it is described that the flow control mechanism 100 is configured such that the shorter the distance from the pump P to the return site 70S of the return flow path 70, the smaller the flow path cross-sectional area of the return flow path 70, and the longer the distance from the pump P to the return site 70S of the return flow path 70, the larger the flow path cross-sectional area of the return flow path 70. For example, the flow control mechanism 100 can also be configured such that the shorter the distance from the pump P to the return site 70S of the return flow path 70, the longer the length of the return flow path 70, and the longer the distance from the pump P to the return site 70S of the return flow path 70, the shorter the flow path cross-sectional area of the return flow path 70. In addition, the flow control mechanism 100 can also be configured to increase the pressure loss by both the reduction of the flow path cross-sectional area and the extension of the length of the return flow path 70.

[0068] In the above embodiment, it is described that the battery has a plurality of battery assemblies 2, and the battery case 10 accommodates the plurality of battery assemblies 2. However, the battery can also be configured to have a single battery assembly 2. In this case, the battery case 10 accommodates the single battery assembly 2. Even in this case, the battery assembly 2 can be uniformly cooled.

[0069] (Summary of the above embodiment)

[0070] Hereinafter, a summary of the above-described battery cooling device 1 will be described.

[0071] (1) The battery cooling device 1 is a battery cooling device 1 that cools a battery having a battery assembly 2 in which a plurality of battery cells 3 are arranged along a first direction X, and includes: a battery case 10 having a housing portion 11 that houses the battery assembly 2; a guide inlet 20 provided at a central portion in the first direction X of the battery case 10 and at one end side in a second direction Y orthogonal to the first direction X, into which cooling liquid supplied from a pump P is guided; a discharge outlet 30 that discharges the cooling liquid guided into the guide inlet 20 above each of the plurality of battery cells 3; and a communication passage 40 that communicates the guide inlet 20 and the discharge outlet 30, the communication passage 40 having a branch flow path 50 including a first branch flow path 51 that communicates with the guide inlet 20 and branches toward one end side in the first direction X, and a second branch flow path 52 that communicates with the guide inlet 20 and branches toward the other end side in the first direction X.

[0072] According to the present structure, by causing the cooling liquid guided into the guide inlet 20 to flow through the branch flow path 50, fluctuations in the length (flow path length) of the communication passage 40 that communicates the guide inlet 20 and the discharge outlet 30 provided above each of the plurality of battery cells 3 can be reduced. Therefore, fluctuations in the amount of cooling liquid discharged toward each of the plurality of battery cells 3 can be reduced, and thus the battery assembly 2 can be uniformly cooled.

[0073] (2) In the battery cooling device 1 described in (1), it is preferable that the communication passage 40 have: a link flow path 60 including a first link flow path 61 that communicates with the first branch flow path 51 and extends along the second direction Y on one end side in the first direction X, and a second link flow path 62 that communicates with the second branch flow path 52 and extends along the second direction Y on the other end side in the first direction X; and a return flow path 70 including a first return flow path 71 that extends from the first link flow path 61 toward the second link flow path 62 side, and a second return flow path 72 that extends from the second link flow path 62 toward the first link flow path 61 side.

[0074] According to the present structure, the cooling liquid flows from the guide inlet 20, via the link flow path 60 that extends along the second direction Y from the branch flow path 50 that extends along the first direction X, and further through the return flow path 70 that extends from one link flow path 60 toward the other link flow path 60 side. Thus, a flow path is formed in which the cooling liquid flows along both the first direction X and the second direction Y of the battery assembly 2, and thus the battery assembly 2 can be further uniformly cooled.

[0075] (3) In the battery cooling device 1 described in (2), it is preferable that the first return flow path 71 and the second return flow path 72 at least partially overlap each other in the second direction.

[0076] According to the present structure, the interval of the return flow paths 70 adjacent to each other can be reduced, for example, by providing the second return flow path 72 between two first return flow paths 71 adjacent to each other and / or providing the first return flow path 71 between two second return flow paths 72 adjacent to each other. Thus, since the coolant can be further uniformly discharged toward the plurality of battery cells 3, the battery assembly 2 can be uniformly cooled. In addition, the space between the two first return flow paths 71 and the space between the two second return flow paths 72 can be effectively utilized to form the flow paths.

[0077] (4) In the battery cooling device 1 described in (3), it is preferable that the first return flow path 71 extends to the front of the second connecting flow path 62 along the first direction, and the second return flow path 72 extends to the front of the first connecting flow path 61 along the first direction.

[0078] According to the present structure, the amount of cooling flowing in the first return flow path 71 is more as it is closer to the first branch flow path 51 and less as it is farther from the first branch flow path 51. In addition, the amount of cooling flowing in the second return flow path 72 is more as it is closer to the second branch flow path 52 and less as it is farther from the second branch flow path 52. Thus, for example, on the side of the first return flow path 71 closer to the first branch flow path 51, the coolant can be discharged from the discharge port 30 on the side of the first return flow path 71 closer to the first branch flow path 51 and the discharge port 30 on the side of the second return flow path 72 farther from the second branch flow path 52, on the side of the first return flow path 71 farther from the first branch flow path 51, the coolant can be discharged from the discharge port 30 on the side of the first return flow path 71 farther from the first branch flow path 51 and the discharge port 30 on the side of the second return flow path 72 closer to the second branch flow path 52, and on the middle of the first return flow path 71, the coolant can be discharged from the discharge port 30 on the middle of the first return flow path 71 and the discharge port 30 on the middle of the second return flow path 72. Thus, since the amount of discharged coolant can be averaged, the battery assembly 2 can be further uniformly cooled.

[0079] (5) In the battery cooling device 1 described in (2), it is preferable that the first return flow path 71 returns from the first connecting flow path 61 to the central region of the first direction X, the second return flow path 72 returns from the second connecting flow path 62 to the central region, and the return flow path 70 is provided so that both the first return flow path 71 and the second return flow path 72 are located above one battery assembly 2.

[0080] According to the present structure, it is possible to shorten the respective lengths of the first return flow path 71 and the second return flow path 72. Therefore, it is possible to reduce fluctuations in the amounts of the coolant discharged from the plurality of discharge ports 30 provided in the first return flow path 71, and it is possible to reduce fluctuations in the amounts of the coolant discharged from the plurality of discharge ports 30 provided in the second return flow path 72. Thus, it is possible to further uniformly cool the battery assembly 2.

[0081] (6) In the battery cooling device 1 described in (2), it is preferable that the communication path 40 further have: an auxiliary flow path 80 branched from a middle portion of the branch flow path 50, a return flow path 70 that returns from the branch flow path 50, and a branch flow path 90 that extends from the auxiliary flow path 80, the auxiliary flow path 80 including a first auxiliary flow path 81 that branches from a middle portion of the first branch flow path 51 toward the other end side in the second direction Y and a second auxiliary flow path 82 that branches from a middle portion of the second branch flow path 52 toward the other end side in the second direction Y, the first return flow path 71 returning from the first connecting flow path 61 to the first auxiliary flow path 81 side, the second return flow path 72 returning from the second connecting flow path 62 to the second auxiliary flow path 82 side, and the branch flow path 90 including a first branch flow path 91 that communicates with the first auxiliary flow path 81 and extends from the first auxiliary flow path 81 to a central region in the first direction X along the first direction X and a second branch flow path 92 that communicates with the second auxiliary flow path 82 and extends from the second auxiliary flow path 82 to the central region along the first direction X.

[0082] According to the present structure, it is possible to reduce fluctuations in the lengths from the guide inlet 20 to the discharge ports 30 provided above each of the plurality of battery cells 3. Therefore, since it is possible to make the amounts of the coolant discharged with respect to each of the plurality of battery cells 3 uniform, it is possible to further uniformly cool the battery assembly 2.

[0083] (7) In the battery cooling device 1 described in (2) to (6), it is preferable that a flow control mechanism 100 that increases a pressure loss of the coolant flowing through the return flow path 70 be provided the shorter the distance from the pump P to the return position that is the start point of the return flow path 70.

[0084] According to the present structure, it is possible to further reduce fluctuations in the amounts of the coolant discharged from the discharge ports 30 regardless of the distances from the guide inlet 20 to the discharge ports 30. Therefore, it is possible to further uniformly cool the battery assembly 2.

[0085] (8) In the battery cooling device 1 described in (1), it is preferable that the battery have a plurality of battery assemblies 2, the plurality of battery assemblies 2 be arranged along the second direction Y, and the battery case 10 house the plurality of battery assemblies 2.

[0086] According to the present structure, the plurality of battery assemblies 2 can be uniformly cooled.

[0087] Industrial applicability

[0088] The present application can be used for a battery cooling device that cools a battery.

[0089] Symbol explanation

[0090] 1: battery cooling device, 2: battery assembly, 3: battery cell, 10: battery case, 11: housing portion, 20: inlet, 30: outlet, 40: communication passage, 50: branch flow path, 51: first branch flow path, 52: second branch flow path, 60: connection flow path, 61: first connection flow path, 62: second connection flow path, 70: return flow path, 70S: return portion, 71: first return flow path, 72: second return flow path, 80: auxiliary flow path, 81: first auxiliary flow path, 82: second auxiliary flow path, 90: branch flow path, 91: first branch flow path, 92: second branch flow path, 100: flow control mechanism, P: pump, X: first direction, Y: second direction.

Claims

1. A battery cooling device that cools a battery having a battery assembly in which a plurality of battery cells are arranged along a first direction, wherein Possessing: a battery box having a housing portion that houses the battery assembly; a guide inlet provided at a central portion in the first direction in the battery box and at one end side in a second direction orthogonal to the first direction, into which cooling liquid supplied from a pump is guided; a discharge outlet that discharges the cooling liquid guided into the guide inlet above each of the plurality of battery cells; and a communication path that communicates the guide inlet and the discharge outlet, the communication path has a branch flow path including a first branch flow path that communicates with the guide inlet and branches toward one end side in the first direction, and a second branch flow path that communicates with the guide inlet and branches toward the other end side in the first direction.

2. The battery cooling device according to claim 1, wherein the communication path has: a link flow path including a first link flow path that communicates with the first branch flow path and extends in the second direction at the one end side in the first direction, and a second link flow path that communicates with the second branch flow path and extends in the second direction at the other end side in the first direction; and a return flow path including a first return flow path that extends from the first link flow path toward the second link flow path side, and a second return flow path that extends from the second link flow path toward the first link flow path side.

3. The battery cooling device according to claim 2, wherein at least a portion of the first return flow path and the second return flow path overlap each other in the second direction.

4. The battery cooling device according to claim 3, wherein the first return flow path extends in the first direction to the front of the second link flow path, the second return flow path extends in the first direction to the front of the first link flow path.

5. The battery cooling device according to claim 2, wherein the first return flow path returns from the first link flow path to a central region in the first direction, and the second return flow path returns from the second link flow path to the central region, the return flow path is provided so that both the first return flow path and the second return flow path are located above one of the battery assemblies.

6. The battery cooling device according to claim 2, wherein the communication path further has: an auxiliary flow path that branches from a midway portion of the branch flow path, a return flow path that returns from the branch flow path, and a branch flow path that extends from the auxiliary flow path, the auxiliary flow path includes a first auxiliary flow path that branches from the midway portion of the first branch flow path toward the other end side in the second direction, and a second auxiliary flow path that branches from the midway portion of the second branch flow path toward the other end side in the second direction, the first return flow path returns from the first link flow path to the first auxiliary flow path side, and the second return flow path returns from the second link flow path to the second auxiliary flow path side, ​ The branch flow path includes a first branch flow path that communicates with the first auxiliary flow path and extends from the first auxiliary flow path to a central region in the first direction, and a second branch flow path that communicates with the second auxiliary flow path and extends from the second auxiliary flow path to the central region in the first direction.

7. The battery cooling device according to any one of claims 2 to 6, wherein A flow control mechanism is further provided, and the shorter the distance from the pump to a turnaround site that is a starting point of the turnaround flow path, the greater the flow control mechanism increases the pressure loss of the coolant flowing through the turnaround flow path.

8. The battery cooling device according to claim 1, wherein The battery has a plurality of the battery assemblies, and the plurality of the battery assemblies are arranged in the second direction, The battery case houses the plurality of the battery assemblies.

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