Battery case

Abstract

To provide a battery case that can supply and discharge a cooling medium with a simple structure, thereby being able to cool a battery module.SOLUTION: A battery case 10 that accommodates a battery module 15 includes a bottom member 16 on which the battery module 15 is placed, a side peripheral part 40 that is bonded to the bottom member 16 and surrounds an outer periphery of the battery module 15, and a lid member that is bonded to the side peripheral part 40 and covers an upper part of the battery module 15. The side peripheral part 40 includes a plurality of wall members bonded to each other (left side wall member 11, right side wall member 12, front side wall member 14, rear side wall member 13). At least one of the wall members has a closed cross-sectional shape having a cavity part extending in a longitudinal direction. The cavity part has a wall member side cooling medium flow channel that circulates the cooling medium. On the wall member having the wall member side cooling medium flow channel, a cooling medium support port 18 into the wall member side cooling medium flow channel and a cooling medium discharge port 17 from the wall member side cooling medium flow channel are provided toward the outside of the battery case 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery case used to house a battery module. [Background technology]

[0002] In recent years, the development of electrically powered vehicles such as electric vehicles and hybrid vehicles has progressed. In battery systems installed in such vehicles, a large number of batteries are generally housed in a battery case constructed of a predetermined frame or the like. Not only in vehicles, but also in structures that use batteries that are charged and discharged with a large current, the temperature of the batteries rises during charging and discharging, and therefore a cooling mechanism is generally required to cool the batteries.

[0003] For example, Patent Document 1 proposes a cooling device for cooling, for example, a battery pack. The cooling device described in Patent Document 1 has a device body formed by extrusion into a rectangular parallelepiped shape with multiple through-holes in the extrusion direction. The multiple through-holes form multiple inlet-side flow paths and multiple outlet-side flow paths through which a coolant flows. One end and the other end of the device body in the longitudinal direction are formed with communication sections that connect the multiple flow paths to each other. In addition, flat sections are provided at both ends of the device body in the longitudinal direction by crushing at least one of the upper wall and the lower wall, and the openings of the through-holes are blocked. Furthermore, an inlet pipe communicating with the multiple inlet-side flow paths and an outlet pipe communicating with the multiple outlet-side flow paths are attached to the center of the device body.

[0004] In the cooling device configured as described above, the coolant flows from the inlet pipe into the inlet space of the device body, passes through the inlet flow path, reaches the connecting portion, then passes through the outlet flow path, passes through the outlet space, and flows out of the outlet pipe. In this way, the coolant cools the battery pack placed on the top surface of the device body while flowing through the inlet and outlet flow paths of the device body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-169112 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the cooling device described in Patent Document 1 requires inlet and outlet pipes to be attached between multiple batteries in the center of the device body formed by extrusion, making the structure complex. Also, since space is required between the batteries to attach the inlet and outlet pipes, it is difficult to design a battery pack. Furthermore, it is unclear how the coolant that flows out of the outlet pipe is cooled and then flows back in through the inlet pipe. If the coolant were cooled inside the battery case that houses the assembled battery, it would be difficult to cool the coolant efficiently because the battery case is sealed. Furthermore, if the coolant were to be discharged outside the battery case, a hose or other device would be required to connect the cooling device to the outside of the battery case, making the structure inside the battery case complicated.

[0007] The present invention has been made in view of the above-mentioned problems, and has an object to provide a battery case that can cool a battery module with a simple structure. [Means for solving the problem]

[0008] The above object of the present invention is achieved by the following configuration (1) relating to the battery case.

[0009] (1) A battery case for accommodating a battery module, a bottom member on which the battery module is placed; a side periphery joined to the bottom member and surrounding the sides of the battery module; a cover member joined to the side periphery and covering an upper portion of the battery module, The side periphery is made up of a plurality of wall members joined together, At least one of the plurality of wall members has a closed cross-sectional shape having a cavity portion extending in a longitudinal direction, the cavity portion has a wall member-side refrigerant flow path through which a refrigerant flows, a wall member having a wall member-side refrigerant flow path, the wall member having the wall member-side refrigerant flow path, and a refrigerant discharge port for the wall member-side refrigerant flow path facing outward from the battery case.

[0010] Furthermore, preferred embodiments of the present invention relating to the battery case relate to the following (2) to (9).

[0011] (2) The battery case according to (1), wherein at least one of the coolant supply port and the coolant discharge port is provided in at least one open end of the wall member having the cavity.

[0012] (3) At least one of the hollow portions has a plurality of partitions divided along the longitudinal direction, Among the plurality of partitions, At least one first partition has the wall member-side refrigerant flow path, The battery case according to (1) or (2), wherein a harness connected to the battery module is disposed in at least one second compartment.

[0013] (4) At least one of the hollow portions is divided along the longitudinal direction and has a total of three or more partitions, Among the three or more partitions, At least one first partition section has the wall member-side refrigerant flow path, a harness connected to the battery module is disposed in at least one second compartment; The battery case according to (1) or (2), wherein at least one third compartment has an air discharge path for discharging air from inside the battery case.

[0014] (5) Among the plurality of wall members, a pair of opposing wall members each have a closed cross-sectional shape having the cavity portion extending in the longitudinal direction, and each of the cavity portions in the pair of wall members has the wall member-side refrigerant flow path, The battery case according to any one of (1) to (4), wherein one of the pair of wall members is provided with a supply port for the coolant, and the other is provided with a discharge port for the coolant.

[0015] (6) The bottom member has a bottom member-side refrigerant flow path through which the refrigerant flows, The battery case according to (5), wherein the wall member-side refrigerant flow paths of the pair of wall members are connected via the bottom member-side refrigerant flow path.

[0016] (7) The cavity has a plurality of partitions divided along the longitudinal direction, The battery case according to (6), wherein a first partition, which is the closest to the bottom member among the plurality of partitions, has the wall member-side refrigerant flow path.

[0017] (8) The bottom member is A flat plate-like member; a flow path member having a flat portion and a recessed portion, the planar portion is joined to the flat plate-like member, The battery case according to (6) or (7), wherein the bottom member-side refrigerant flow path is formed between the recess and the flat plate-like member.

[0018] (9) The flat plate-like member is The battery case according to (8), characterized in that it is directly joined to the side periphery.

[0019] The above object of the present invention is achieved by the following configuration (10) relating to a method for manufacturing a battery case.

[0020] (10) A method for manufacturing a battery case that houses a battery module, comprising: a step of joining a bottom member including a flat plate-shaped member and a flow path member to one open end surface of a side periphery that surrounds the side of the battery module and is formed by a plurality of wall members; placing the battery module in a space defined by the bottom member and the side periphery; and joining a lid member to the other open end surface of the side periphery, the plurality of wall members include a first flow path wall member that forms a first flow path and a second flow path wall member that forms a second flow path, and the first flow path wall member and the second flow path wall member each have a closed cross-sectional shape having a cavity portion extending in a longitudinal direction, the first flow path wall member has a refrigerant discharge port that discharges the refrigerant from the first flow path to the outside of the battery case, and has a first wall member side communication hole on a surface to which the bottom member is joined, the second flow path wall member has a refrigerant supply port that supplies a refrigerant from the outside of the battery case to the second flow path, and has a second wall member-side communication hole on a surface to which the bottom member is joined, the flat plate-like member has a first bottom member-side communicating hole and a second bottom member-side communicating hole at positions that align with the first wall member-side communicating hole and the second wall member-side communicating hole when the bottom member is joined to the first flow path wall member and the second flow path wall member, respectively; the flow path member has a flat portion and a recessed portion, The step of joining the bottom member includes: a connecting step of joining the first wall member-side communicating hole of the first flow path wall member and the first bottom member-side communicating hole of the flat plate-like member so as to communicate with each other, and also joining the second wall member-side communicating hole of the second flow path wall member and the second bottom member-side communicating hole of the flat plate-like member so as to communicate with each other; and a step of overlapping the flow path member and the flat plate-like member so that the planar portion and the flat plate-like member are in contact with each other, and joining the planar portion and the flat plate-like member so as to surround the recessed portion, thereby forming a bottom member-side refrigerant flow path between the recessed portion and the flat plate-like member, wherein the refrigerant supply port and the refrigerant discharge port are connected to each other via the first flow path, the bottom member-side refrigerant flow path, and the second flow path. [Effects of the Invention]

[0021] According to the present invention, the battery case has a wall member with a closed cross-sectional shape having a hollow portion extending in the longitudinal direction, and this wall member is provided with a refrigerant supply port and a discharge port facing outward from the battery case, so that a battery case can be provided that can supply and discharge refrigerant with a simple structure and thereby cool the battery module. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view showing a battery case according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the back side of the battery case in FIG. [Figure 3] FIG. 3 is an enlarged side view of a part of FIG. [Figure 4] FIG. 4 is a partially cutaway view illustrating the inside of a wall member of the battery case in FIG. [Figure 5A] FIG. 5A is a perspective view showing the manufacturing method of the battery case according to this embodiment in the order of steps. [Figure 5B] FIG. 5B is a diagram showing the manufacturing method of the battery case according to this embodiment in the order of steps, and is a perspective view showing the step subsequent to that of FIG. 5A. [Figure 5C] FIG. 5C is a diagram showing the manufacturing method of the battery case according to this embodiment in the order of steps, and is a perspective view showing the step following that of FIG. 5B. [Figure 5D] FIG. 5D is a diagram showing the manufacturing method of the battery case according to this embodiment in the order of steps, and is a perspective view showing the step following that of FIG. 5C. [Figure 5E] FIG. 5E is a diagram showing the manufacturing method of the battery case according to this embodiment in the order of steps, and is a perspective view showing the step following that of FIG. 5D. [Figure 6A] FIG. 6A is a cross-sectional view showing a method for manufacturing the bottom member in the order of steps. [Figure 6B] FIG. 6B is a diagram showing the manufacturing method of the bottom member in the order of steps, and is a cross-sectional view showing the step subsequent to the step in FIG. 6A. [Figure 7] FIG. 7 is a partially cutaway view showing an enlarged area A of FIG. 5E. [Figure 8] FIG. 8 is a partially cutaway view showing an enlarged area B of FIG. 5E. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of a battery case according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and can be implemented with any modifications within the scope of the gist of the present invention.

[0024] <Battery case> Fig. 1 is a perspective view showing a battery case according to an embodiment of the present invention. Fig. 2 is a perspective view showing the back side of the battery case in Fig. 1. Fig. 3 is an enlarged side view of a portion of Fig. 1. Fig. 4 is a partially cutaway view illustrating the inside of a wall member of the battery case in Fig. 1. The battery case according to an embodiment of the present invention will be described with reference to Figs. 1 to 4.

[0025] The battery case 10 according to this embodiment houses a battery module 15 and is placed, for example, inside a vehicle (not shown). The battery case 10 has a rectangular bottom member 16, a side periphery 40 joined to the bottom member 16 by welding or the like and surrounding the sides of the battery module 15, and a lid member 30 joined to the side periphery 40 by welding or the like and covering the top of the battery module 15. In this embodiment, the bottom member 16, the side periphery 40, and the lid member 30 are all made of aluminum or an aluminum alloy.

[0026] The side peripheral portion 40 is configured to have a rectangular shape in a plan view, and is made up of a pair of left and right wall members 11 and 12 arranged parallel to and facing each other in the left-right direction, and a pair of front and rear wall members 14 and 13 arranged parallel to and facing each other in the front-rear direction. Specifically, both end faces of the front wall member 14 are joined by welding or the like to the front of the opposing surfaces of the left and right wall members 11 and 12. Similarly, both end faces of the rear wall member 13 are joined by welding or the like to the rear of the opposing surfaces of the left and right wall members 11 and 12.

[0027] In this specification, the front-rear direction of the battery case 10 refers to the direction of travel of the vehicle when the battery case is installed in the vehicle and the opposite direction, and the left-right direction of the battery case 10 refers to the left-right direction of the vehicle when the battery case is installed in the vehicle. However, the battery case 10 according to this embodiment is not limited to being installed inside a vehicle. Therefore, the present invention is not limited to the following embodiment, and the left side wall member 11 and the right side wall member 12, the front side wall member 14 and the rear side wall member 13, and the front-rear direction and the left-right direction may be interchanged.

[0028] The left side wall member 11, the right side wall member 12, the front side wall member 14, and the rear side wall member 13 are all formed from extruded material. The left side wall member 11 has a closed cross-sectional shape with a cavity extending in the longitudinal direction, which is divided into three compartments along the longitudinal direction, namely, a first left side compartment 11a, a second left side compartment 11b, and a third left side compartment 11c, which are formed in that order from the bottom member 16 side. The right side wall member 12 also has a closed cross-sectional shape with a cavity extending in the longitudinal direction, which is divided into three compartments along the longitudinal direction, namely, a first right side compartment 12a, a second right side compartment 12b, and a third right side compartment 12c, which are formed in that order from the bottom member 16 side.

[0029] The left side wall member 11 and the right side wall member 12 will now be described in more detail with reference to FIGS. A refrigerant flow path (left-wall-member-side refrigerant flow path 41) for cooling the battery modules 15 housed in the battery case 10 is formed in the left-side first compartment 11a of the left-side wall member 11. The rear end of the left-side first compartment 11a is closed by a water blocking wall 37, and a water blocking wall 35 having a refrigerant outlet 17 is formed at the front end. In addition, a hole (not shown) is formed near the water blocking wall 37 of the left-side wall member 11 on the surface that comes into contact with the bottom member 16, which will be described later.

[0030] A harness 22 is disposed in the second left compartment 11b of the left wall member 11. Specifically, a harness hole 31 is formed in the surface of the second left compartment 11b that faces the inside of the battery case 10. A rubber grommet 39 is attached to the harness hole 31 to fill the gap between the harness 22 that passes through the harness hole 31 and the harness hole 31. One terminal of the harness 22 is connected to the battery module 15, and the other terminal passes through the hole in the rubber grommet 39 and the inside of the second left compartment 11b, is taken out of the battery case 10, and is connected to a motor (not shown) or the like.

[0031] An air exhaust path for exhausting air from inside the battery case 10 is formed in the left-side third compartment 11c of the left side wall member 11. Specifically, an air exhaust hole 29 is formed in the surface of the left-side third compartment 11c that faces the inside of the battery case 10. A check valve 23 is attached to the air exhaust hole 29 to exhaust air from inside the battery case 10 and to prevent water from entering the battery case 10 from the outside.

[0032] Meanwhile, in the right-side first compartment 12a of the right-side wall member 12, similar to the left-side first compartment 11a, a flow path (right-wall member-side refrigerant flow path) for cooling the battery modules 15 housed in the battery case 10 is formed. The rear end of the right-side first compartment 12a is closed by a water blocking wall (not shown), and the front end is formed with a water blocking wall 36 having a refrigerant supply port 18. In addition, near the water blocking wall 36 of the left-side wall member 11, a hole (not shown) is formed in the surface that comes into contact with the bottom member 16 (described later).

[0033] In this embodiment, the right second compartment 12b and the right third compartment 12c of the right side wall member 12 are empty and remain hollow, but if necessary, space for arranging other harnesses, air exhaust passages, etc. can be provided.

[0034] Next, the base member 16 will be described in more detail with reference to FIG. The bottom member 16 is formed by stacking a flat plate member 24 and a flow path member 25. The rectangular flat plate member 24 is disposed on the upper side, i.e., the side on which the battery module 15 is placed, and the rectangular flow path member 25 is disposed on the lower side, i.e., the back side of the battery module 15.

[0035] The flow path member 25 has a flat portion 25a that contacts the flat plate-shaped member 24 when placed on the flat plate-shaped member 24, and a recessed portion 25b that is recessed in a direction away from the flat plate-shaped member 24. The recessed portion 25b has a serpentine shape that extends from the vicinity of one corner of the flow path member 25 to the vicinity of the opposing corner, and is formed so as to be surrounded by the flat portion 25a. The flat portion 25a and the flat plate-shaped member 24 are joined together, and a joint portion 26 is formed around the periphery of the recessed portion 25b, thereby forming a bottom member-side refrigerant flow path 38 between the recessed portion 25b in the flow path member 25 and the flat plate-shaped member 24.

[0036] Holes (not shown) (first bottom member-side communication hole 24b and second bottom member-side communication hole 24a shown in FIG. 5A ) are provided in the flat plate member 24 near one end and the other end of the bottom member-side refrigerant flow path 38. One of the holes (second bottom member-side communication hole 24a) provided in the flat plate member 24 is connected to a hole provided in the first right-side partition 12a of the right side wall member 12 via a blind nut 32. The other hole (first bottom member-side communication hole 24b) provided in the flat plate member 24 is connected to a hole provided in the first left-side partition 11a of the left side wall member 11 via a blind nut 33. As a result, the right-wall member-side refrigerant flow path (not shown) formed by the first right-side partition 12a, the bottom member-side refrigerant flow path 38, and the left-wall member-side refrigerant flow path 41 formed by the first left-side partition 11a are connected in this order.

[0037] The rectangular lid member 30 is joined by welding or the like to the side periphery 40 so as to cover the upper surface of the opening of the side periphery 40, which is made up of the left side wall member 11, the right side wall member 12, the rear side wall member 13, and the front side wall member 14. This gives the battery case 10 a watertight structure that prevents liquid from entering from the outside.

[0038] 1, a circulation device 19 and a radiator 20 are disposed in front of the battery case 10. The circulation device 19 stores a refrigerant and incorporates a pump for circulating the refrigerant inside the battery case 10. The radiator 20 incorporates a heat exchanger that dissipates heat from the refrigerant sent therein, and a fan 21 is attached in front of the radiator 20.

[0039] The circulation device 19 is connected to a refrigerant outlet 17 attached to the front end of the left first compartment 11a and a refrigerant supply port 18 attached to the front end of the right first compartment 12a via hoses 27 and 28. The circulation device 19 and the radiator 20 are connected via hoses 47 and 48.

[0040] The flow of refrigerant in the battery case 10 according to this embodiment will be described below. First, the refrigerant cooled by the radiator 20 is filled into the right-side first compartment 12a through the refrigerant supply port 18 via the circulation device 19. Next, the refrigerant in the right-side first compartment 12a flows through the bottom member-side refrigerant flow path 38 while cooling the battery module 15, and reaches the left-side first compartment 11a via the blind nut 33. After that, the refrigerant, which has become hot by flowing through the right-side first compartment 12a, the bottom member-side refrigerant flow path 38, and the left-side first compartment 11a, is discharged to the outside of the battery case 10 through the refrigerant discharge port 17. The discharged refrigerant then passes through the circulation device 19, is cooled in the radiator 20, and is again supplied to the inside of the battery case 10 through the refrigerant supply port 18.

[0041] In the battery case 10 configured in this manner, the wall members (left side wall member 11 and right side wall member 12) with a closed cross-section and a cavity extending in the longitudinal direction are used as a refrigerant flow path. A refrigerant outlet 17 and a refrigerant supply port 18 are provided facing outward from the battery case 10, and the refrigerant cooled outside the battery case 10 is circulated inside the wall members to cool the battery modules 15. Therefore, unlike conventional cooling devices, there is no need to install inlet and outlet pipes between the batteries, and the battery modules can be cooled with an extremely simple structure. Furthermore, because the refrigerant outlet 17 and the refrigerant supply port 18 are provided at the open ends of the wall members, they can be easily formed.

[0042] In the present invention, the cavity of the wall member may or may not be divided. As long as a refrigerant flow path is formed in this cavity, the battery case 10 can be designed with a simple structure. When the cavity is divided into multiple compartments, space for arranging the harness can be secured in addition to the refrigerant flow path, which allows for an even simpler structure without the harness becoming complicated and intertwined. When the cavity is divided into three or more compartments in total, the refrigerant flow path can be formed in the first compartment, the harness can be arranged in the second compartment, and an air exhaust path for exhausting air expanded inside the battery case 10 can be formed in the third compartment. Therefore, the mechanisms required for the battery case 10 can be housed within the wall member, further simplifying the structure.

[0043] The refrigerant flow path, harness, and air discharge path are preferably arranged in partitions provided in a pair of opposing wall members (left side wall member 11 and right side wall member 12), and their arrangement positions are not particularly limited. For example, as shown in the above embodiment, the refrigerant flow path, harness, and air discharge path may be provided in one of the left side wall members 11, and the other, right side wall member 12, may be provided with only the refrigerant flow path. Alternatively, each of the pair of opposing wall members may be divided into two partitions, and the refrigerant flow path and harness may be provided in one of the left side wall members 11, and the refrigerant flow path and air discharge path may be provided in the other, right side wall member 12, and any combination of arrangements may be used.

[0044] Furthermore, in the battery case 10 according to this embodiment, a bottom member-side refrigerant flow path 38 is formed in the bottom member 16, and a left wall member-side refrigerant flow path 41 formed by the left first partition 11a and a right wall member-side refrigerant flow path (not shown) formed by the right first partition 12a are connected via the bottom member-side refrigerant flow path 38. Therefore, the refrigerant cooled by the radiator 20 is supplied from the refrigerant supply port 18, flows through the left wall member 11, the bottom member 16, and the right wall member 12, is discharged from the refrigerant discharge port 17, and returns to the radiator 20, repeating this cycle. As a result, the battery modules 15 can be efficiently cooled from the wall and bottom sides.

[0045] As described above, when the bottom member-side refrigerant flow path 38 is formed, the refrigerant flow paths of the left and right wall members 11, 12 are preferably disposed in the left first compartment 11a and the right first compartment 12a, which are located closest to the bottom member 16. With this configuration, the refrigerant flow path in the left wall member 11 and the refrigerant flow path in the right wall member 12 can be directly connected to the bottom member-side refrigerant flow path 38, thereby reducing the number of members required for connection.

[0046] In the present invention, it is not necessary to provide a refrigerant flow path in the bottom member, and a refrigerant flow path connecting the right side wall member 12 and the left side wall member 11 may be provided at a position different from the bottom member. Furthermore, when the battery module 15 is cooled only by the wall member-side refrigerant flow path, for example, a refrigerant supply port and a refrigerant discharge port may be provided in each of the two compartments in the right side wall member 12, so that the refrigerant circulates only in the right side wall member 12. Specifically, the refrigerant may be supplied to one compartment from the front of the battery case 10, moved to the adjacent compartment at the rear of the battery case 10, and discharged from the front of the battery case 10.

[0047] In this embodiment, usable refrigerants include water, air, and liquids specifically designed for cooling, but it is preferable to use water because it is easy to handle, low cost, and can efficiently cool the battery module 15. In this embodiment, the left-side first compartment 11a and the right-side first compartment 12a are used as the left-wall member-side refrigerant flow path 41 and the right-wall member-side refrigerant flow path, respectively, but pipes for circulating the refrigerant in the left-side first compartment 11a and the right-side first compartment 12a may be provided.

[0048] In a cooling device such as that described in Patent Document 1, in which refrigerant flows through multiple inlet-side channels and then joins at a communication section and flows into multiple outlet-side channels, the refrigerant may stagnate in an area at the communication section, resulting in an inconsistent flow rate through the multiple channels. This may result in poor cooling efficiency. On the other hand, in the present embodiment, in which the refrigerant flows through a single refrigerant channel from a single refrigerant supply port 18 to a single refrigerant discharge port 17, refrigerant stagnation in a specific area can be prevented, improving cooling efficiency. Furthermore, as shown in the present embodiment, when the battery case 10 has a bottom-side refrigerant channel 38 and this bottom-side refrigerant channel 38 is formed in a serpentine shape, the bottom surface of the battery module 15 can be efficiently cooled without using multiple channels.

[0049] <Battery case manufacturing method> Next, a method for manufacturing a battery case 10 according to this embodiment will be described in detail with reference to the drawings. FIGS. 5A to 5E are perspective views showing the manufacturing method for a battery case according to this embodiment in the order of steps. FIG. 5E is a partially cutaway view to illustrate the interior of the left side wall member 11. FIGS. 6A and 6B are cross-sectional views showing the manufacturing method for the bottom member in the order of steps. FIG. 7 is a partially cutaway view showing an enlarged view of region A in FIG. 5E, and FIG. 8 is a partially cutaway view showing an enlarged view of region B in FIG. 5E. In FIGS. 5A to 5E, 6A, 6B, 7, and 8, the same components as those in the battery case 10 shown in FIGS. 1 to 4 are designated by the same reference numerals, and detailed description thereof will be omitted or simplified.

[0050] (1. Preparation process of bottom member, wall member and lid member) As shown in Fig. 5A, multiple wall members made of extruded aluminum or aluminum alloy, flat plate-like members 24 and flow path members 25 constituting the bottom member, and a cover member (not shown) are prepared. The multiple wall members include a left side wall member (first flow path wall member) 11, a right side wall member (second flow path wall member) 12, a front side wall member 14, and a rear side wall member 13. A surface of the left side wall member 11 that faces the inside of the battery case is provided with multiple air discharge holes 29 communicating with the left third compartment 11c, and a harness hole 31 communicating with the left second compartment 11b. Furthermore, a first wall member-side communication hole and a second wall member-side communication hole (not shown) are formed in the surfaces of the left side wall member 11 and the right side wall member 12 to which the bottom member (described later) is joined, respectively, to establish communication with the bottom member-side refrigerant flow path. The first wall member side communication hole and the second wall member side communication hole are respectively connected to the left side first partition portion (first flow path) 11a of the left side wall member 11 and the right side first partition portion (second flow path) 12a of the right side wall member 12.

[0051] A first bottom member-side communication hole 24b and a second bottom member-side communication hole 24a are formed in the flat plate member 24 at positions aligned with the first wall member-side communication hole of the left side wall member 11 and the second wall member-side communication hole of the right side wall member 12. A recess 25b for forming a bottom member-side refrigerant flow path is formed in the flow path member 25.

[0052] (2. Side circumference forming process) 5B, the left side wall member 11, the right side wall member 12, the front side wall member 14, and the rear side wall member 13 are joined together to form the side periphery 40. The flat plate-shaped member 24 is also arranged on one open end face of the side periphery 40 so that the first wall member-side communication hole and the first bottom member-side communication hole 24b are aligned, and the second wall member-side communication hole and the second bottom member-side communication hole 24a are aligned.

[0053] (3. Step of connecting the wall member-side communication hole and the bottom member-side communication hole) Figure 5C is a view in which the upside-down direction of Figure 5B is reversed. As shown in Figure 5C, a slotted blind nut 33 is inserted into the position where the first wall member-side communication hole and the first bottom member-side communication hole 24b communicate and then crimped to join the left side wall member 11 and the flat plate-like member 24. Similarly, a slotted blind nut 32 is inserted into the position where the second wall member-side communication hole and the second bottom member-side communication hole 24a communicate and then crimped to join the right side wall member 12 and the flat plate-like member 24.

[0054] (4. Step of forming the refrigerant flow path on the bottom member side) 6A and 6B, flow path member 25 is placed on flat plate-shaped member 24 so that flat portion 25a of flow path member 25 contacts flat plate-shaped member 24, and flat portion 25a and flat plate-shaped member 24 are joined to surround recessed portion 25b, forming joint 26. As a result, bottom member-side refrigerant flow path 38 is formed between recessed portion 25b and flat plate-shaped member 24. Note that the method for joining flat portion 25a and flat plate-shaped member 24 is not particularly limited, and brazing, adhesive, arc welding, laser welding, friction stir welding (FSW), etc. can be used.

[0055] (5. Wall member side refrigerant flow path forming process) 5E, 7, and 8, a water blocking wall 37 is joined by welding or the like to the rear end of the left-side first compartment 11a of the left side wall member 11, and a water blocking wall 35 having a refrigerant outlet 17 is joined by welding or the like to the front end. A water blocking wall (not shown) is also joined to the rear end of the right-side first compartment 12a of the right side wall member 12, and a water blocking wall 36 having a refrigerant supply port 18 is joined to the front end. This completes a flow path for refrigerant between the refrigerant supply port 18 and the refrigerant outlet port 17. The blind nut 33 is attached at a position that connects the bottom member-side refrigerant flow path 38 with the left-side first compartment 11a. The gap between its head 33a and the flat plate-like member 24 and the outer peripheral surface of its shaft 33b are covered with rubber. The blind nut 32 has a similar configuration. This prevents refrigerant from leaking between the flat plate-like member 24 and the left side wall member 11 or the right side wall member 12. Additionally, a rubber grommet 39 is fitted into the harness hole 31, and check valves 23 are fitted into the plurality of air discharge holes 29.

[0056] (6. Battery module accommodation process) 1, the battery module 15 is placed in the space defined by the bottom member 16 and the side periphery 40, and the harness 22 connected to the battery module 15 is passed through the rubber grommet 39 and taken out from the rear end of the second left compartment. In addition, the cover member is joined to the top of the left side wall member 11, the right side wall member 12, the front side wall member 14, and the rear side wall member 13 by welding or the like.

[0057] The battery case 10 according to the present embodiment manufactured as described above has wall members formed from an extruded material, so that a refrigerant flow path can be easily secured. In a conventional manufacturing method for forming a refrigerant flow path on the bottom side of a battery case, a plate member with a flow path formed by stacking two plate members is prepared, and the plate member with a flow path is then attached to the bottom surface of a box-shaped case having a bottom. On the other hand, according to the above manufacturing method, the left side wall member 11, right side wall member 12, front side wall member 14, and rear side wall member 13 that constitute the side peripheral portion 40 are directly joined to the flat plate member 24 that constitutes the bottom member-side refrigerant flow path 38, and then the flow path member 25 is joined to the flat plate member 24. This allows for a reduction in the number of plate members that form the bottom side of the battery case, thereby reducing weight and improving cooling efficiency from the bottom side.Furthermore, compared to conventional methods, the bottom member-side refrigerant flow path can be formed more easily and at lower cost.

[0058] The method for manufacturing a battery case according to this embodiment does not involve joining flat plate-shaped member 24 and flow path member 25 in advance to form a bottom member having bottom-member-side refrigerant flow path 38, and then joining this bottom member to side periphery 40. Specifically, after a step of joining left side wall member 11 having a first flow path and right side wall member 12 having a second flow path to flat plate-shaped member 24 while ensuring the flow paths (communication step), a step of joining flat plate-shaped member 24 to flow path member 25 (bottom-member-side refrigerant flow path formation step) is performed. This reduces the number of plate materials and reduces weight, as described above.

[0059] Therefore, as long as the communicating step and the wall member-side refrigerant flow path forming step are performed as described above, the order of the other steps is not particularly limited. For example, the timing for joining the left side wall member 11, the right side wall member 12, the front side wall member 14, and the rear side wall member 13 to each other can be freely set. As shown in the above embodiment, the side peripheral portion 40 may be formed in advance by joining the left side wall member 11 and the right side wall member 12 to the flat plate-like member 24. Furthermore, the left side wall member 11, the right side wall member 12, the front side wall member 14, and the rear side wall member 13 to each other may be joined to each other at any timing after the left side wall member 11 and the right side wall member 12 are joined to the flat plate-like member 24.

[0060] Similarly, there are no particular limitations on the timing for forming the water blocking wall, the refrigerant outlet 17, the refrigerant supply port 18, etc. in the left side wall member 11 and the right side wall member 12, and the timing may be arbitrary. [Explanation of symbols]

[0061] 10 Battery case 11 Left side wall member 11a First compartment on the left side 11b Second compartment on the left side 11c Third compartment on the left 12 Right side wall member 12a 1st section on the right side 12b Second section on the right side 12c Third section on the right side 15 Battery Module 16 Bottom member 17 Refrigerant outlet 18 Refrigerant supply port 22 Harness 24 Flat plate member 25 Flow path components 25a Flat part 25b recess 30 Lid member 38 Bottom member side refrigerant flow path 40 Side circumference 41 left wall member side refrigerant flow path

Claims

1. A battery case that houses a battery module, a bottom member on which the battery module is placed; a side periphery joined to the bottom member and surrounding a side of the battery module; a cover member joined to the side periphery and covering an upper portion of the battery module, The side periphery is made up of a plurality of wall members joined together, At least one of the plurality of wall members has a closed cross-sectional shape having a cavity portion extending in a longitudinal direction, the cavity portion has a wall member-side refrigerant flow path through which a refrigerant flows, the wall member having the wall member-side refrigerant flow path is provided with a refrigerant supply port to the wall member-side refrigerant flow path and a refrigerant discharge port from the wall member-side refrigerant flow path facing outward from the battery case, At least one of the cavities has a plurality of partitions divided along the longitudinal direction, Among the plurality of partitions, At least one first partition section has the wall member-side refrigerant flow path, A battery case, wherein a harness connected to the battery module is disposed in at least one second compartment.

2. A battery case that houses a battery module, a bottom member on which the battery module is placed; a side periphery joined to the bottom member and surrounding a side of the battery module; a cover member joined to the side periphery and covering an upper portion of the battery module, The side periphery is made up of a plurality of wall members joined together, At least one of the plurality of wall members has a closed cross-sectional shape having a cavity portion extending in a longitudinal direction, the cavity portion has a wall member-side refrigerant flow path through which a refrigerant flows, the wall member having the wall member-side refrigerant flow path is provided with a refrigerant supply port to the wall member-side refrigerant flow path and a refrigerant discharge port from the wall member-side refrigerant flow path facing outward from the battery case, At least one of the cavities is divided along the longitudinal direction and has a total of three or more partitions; Among the three or more partitions, At least one first partition section has the wall member-side refrigerant flow path, a harness connected to the battery module is disposed in at least one second compartment; A battery case, wherein at least one third compartment has an air discharge path for discharging air from within the battery case.

3. 3. The battery case according to claim 1, wherein at least one of the coolant supply port and the coolant discharge port is provided in at least one open end of the wall member having the cavity.

4. a pair of opposing wall members among the plurality of wall members each have a closed cross-sectional shape having the cavity portion extending in a longitudinal direction, and each of the cavity portions in the pair of wall members has the wall member-side refrigerant flow path; The battery case according to claim 1 or 2, wherein one of the pair of wall members is provided with a supply port for the coolant, and the other is provided with a discharge port for the coolant.

5. the bottom member has a bottom member-side refrigerant flow path through which the refrigerant flows, The battery case according to claim 4 , wherein the wall member-side refrigerant flow paths of the pair of wall members are connected to each other via the bottom member-side refrigerant flow path.

6. The cavity has a plurality of compartments divided along the longitudinal direction, The battery case according to claim 5 , wherein a first partition, which is located closest to the bottom member, of the plurality of partitions has the wall member-side refrigerant flow path.

7. The bottom member is A flat plate-like member; a flow path member having a flat portion and a recessed portion, the planar portion is joined to the flat plate-like member, The battery case according to claim 5 , wherein the bottom member-side refrigerant flow path is formed between the recess and the flat plate-like member.

8. The flat plate-like member is The battery case according to claim 7 , wherein the battery case is directly joined to the side periphery.

9. A method for manufacturing a battery case that houses a battery module, comprising: a step of joining a bottom member including a flat plate-shaped member and a flow path member to one open end surface of a side periphery that surrounds the side of the battery module and is formed by a plurality of wall members; placing the battery module in a space defined by the bottom member and the side periphery; and joining a lid member to the other open end surface of the side periphery, the plurality of wall members include a first flow path wall member that forms a first flow path and a second flow path wall member that forms a second flow path, and the first flow path wall member and the second flow path wall member each have a closed cross-sectional shape having a cavity portion extending in a longitudinal direction, the cavity portion has a wall member-side refrigerant flow path through which a refrigerant flows, At least one of the cavities has a plurality of partitions divided along the longitudinal direction, Among the plurality of partitions, At least one first partition section has the wall member-side refrigerant flow path, a harness connected to the battery module is disposed in at least one second compartment; the first flow path wall member has a refrigerant discharge port that discharges the refrigerant from the first flow path to the outside of the battery case, and has a first wall member side communication hole on a surface to which the bottom member is joined, the second flow path wall member has a refrigerant supply port that supplies a refrigerant from the outside of the battery case to the second flow path, and has a second wall member-side communication hole on a surface to which the bottom member is joined, the flat plate-like member has a first bottom member-side communication hole and a second bottom member-side communication hole at positions that align with the first wall member-side communication hole and the second wall member-side communication hole when the bottom member is joined to the first flow path wall member and the second flow path wall member, respectively; the flow path member has a flat portion and a recessed portion, The step of joining the bottom member includes: a connecting step of joining the first wall member-side communication hole of the first flow path wall member and the first bottom member-side communication hole of the flat plate-like member so as to communicate with each other, and joining the second wall member-side communication hole of the second flow path wall member and the second bottom member-side communication hole of the flat plate-like member so as to communicate with each other; and a step of overlapping the flow path member and the flat plate-like member so that the planar portion and the flat plate-like member are in contact with each other, and joining the planar portion and the flat plate-like member so as to surround the recessed portion, thereby forming a bottom member-side refrigerant flow path between the recessed portion and the flat plate-like member, wherein the refrigerant supply port and the refrigerant discharge port are connected via the first flow path, the bottom member-side refrigerant flow path, and the second flow path.

10. A method for manufacturing a battery case that houses a battery module, comprising: a step of joining a bottom member including a flat plate-shaped member and a flow path member to one open end surface of a side periphery that surrounds the side of the battery module and is formed by a plurality of wall members; placing the battery module in a space defined by the bottom member and the side periphery; and joining a lid member to the other open end surface of the side periphery, the plurality of wall members include a first flow path wall member that forms a first flow path and a second flow path wall member that forms a second flow path, and the first flow path wall member and the second flow path wall member each have a closed cross-sectional shape having a cavity portion extending in a longitudinal direction, the cavity portion has a wall member-side refrigerant flow path through which a refrigerant flows, At least one of the cavities is divided along the longitudinal direction and has a total of three or more partitions; Among the three or more partitions, At least one first partition section has the wall member-side refrigerant flow path, a harness connected to the battery module is disposed in at least one second compartment; at least one third compartment has an air discharge path for discharging air from within the battery case; the first flow path wall member has a refrigerant discharge port that discharges the refrigerant from the first flow path to the outside of the battery case, and has a first wall member side communication hole on a surface to which the bottom member is joined, the second flow path wall member has a refrigerant supply port that supplies a refrigerant from the outside of the battery case to the second flow path, and has a second wall member-side communication hole on a surface to which the bottom member is joined, the flat plate-like member has a first bottom member-side communication hole and a second bottom member-side communication hole at positions that align with the first wall member-side communication hole and the second wall member-side communication hole when the bottom member is joined to the first flow path wall member and the second flow path wall member, respectively; the flow path member has a flat portion and a recessed portion, The step of joining the bottom member includes: a connecting step of joining the first wall member-side communication hole of the first flow path wall member and the first bottom member-side communication hole of the flat plate-like member so as to communicate with each other, and joining the second wall member-side communication hole of the second flow path wall member and the second bottom member-side communication hole of the flat plate-like member so as to communicate with each other; and a step of overlapping the flow path member and the flat plate-like member so that the planar portion and the flat plate-like member are in contact with each other, and joining the planar portion and the flat plate-like member so as to surround the recessed portion, thereby forming a bottom member-side refrigerant flow path between the recessed portion and the flat plate-like member, wherein the refrigerant supply port and the refrigerant discharge port are connected via the first flow path, the bottom member-side refrigerant flow path, and the second flow path.

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