Battery pack case

Abstract

To obtain a battery pack case capable of holding a battery cell in a stable state, securing a flow path for cooling air for the battery cell, and further suppressing an increase in weight.SOLUTION: In a battery pack case 10, a flow path forming portion 24 made of resin is provided integrally with a battery cell housing portion 16 and a battery cell housing portion 18 made of metal, and a part of the flow path forming portion 24 is disposed on the other side of a battery cell 14 in the second direction, and the flow path forming portion 24 constitutes parts of a cooling air flow path section 30 and a cooling air flow path section 33 through which cooling air for the battery cell 14 flows.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 below discloses an invention related to a pack case. In this pack case, the restoring force of a battery stack formed by stacking multiple battery cells is supported by side walls having a sandwich panel structure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-129474 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, since the battery cells generate heat during charging and discharging, it is preferable that the pack case be provided with a flow path for cooling air to cool the battery cells.

[0005] However, in the above-mentioned prior art, since no flow path for cooling air to cool the battery cells is provided, there is room for improvement in terms of cooling the battery cells. In this regard, by making the pack case into a casting, the shape of the pack case can be designed to ensure a flow path for cooling air, but this configuration increases the weight of the pack case.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a battery pack case that can hold battery cells in a stable state, ensure a flow path for cooling air for the battery cells, and suppress weight increase. [Means for solving the problem]

[0007] The battery pack case of the present invention described in claim 1 has a metal battery cell accommodating section in which a plurality of battery cells stacked in a first direction can be accommodated from one side in a second direction perpendicular to the first direction while being compressed in the first direction, and which is capable of supporting the restoring force of the battery cells, and a flow path forming section made of resin that is formed integrally with the battery cell accommodating section, is positioned on the other side of the battery cells in the second direction, and constitutes part of a cooling air flow path section through which cooling air for the battery cells flows.

[0008] According to the present invention as set forth in claim 1, a metal battery cell housing section is provided, and a plurality of battery cells stacked in a first direction are housed in the battery cell housing section from one side in a second direction perpendicular to the first direction in a state where the battery cells are compressed in the first direction. The restoring force of the battery cells is supported by the battery cell housing section.

[0009] Since the battery cells generate heat during charging and discharging, it is preferable to provide a flow path for cooling air to cool the battery cells. However, if the battery cell accommodating section is made of metal and all of the cooling air flow paths are provided in the battery cell accommodating section, the structure of the battery cell accommodating section becomes complicated, and it is necessary to construct the battery cell accommodating section as a casting. However, such a structure is considered to increase the weight of the battery pack case.

[0010] Here, in the present invention, a flow path forming portion made of resin is provided integrally with the battery cell storage portion, and this flow path forming portion is positioned on the other side of the battery cell in the second direction and forms part of the cooling air flow path portion through which cooling air for the battery cell flows.

[0011] Therefore, in the present invention, by forming the parts of the cooling air flow path section that have complex shapes using a flow path forming section made of resin, it is possible to prevent the configuration of the battery cell storage section from becoming complicated while ensuring a flow path for the cooling air that cools the battery cells.

[0012] The battery pack case of the present invention as described in claim 2 is the invention as described in claim 1, wherein the battery cell accommodating portion is configured to include a first part including a pair of first side wall portions extending in the first direction and capable of supporting the battery cell in a third direction perpendicular to the first direction and the second direction, and a support wall portion supporting the battery cell from the other side of the second direction, and a pair of second parts including a second side wall portion capable of supporting the battery cell in the first direction, and a pair of third side wall portions that are continuous with the second side wall portions on one and the other sides of the second side wall portions in the third direction and are joined to the first side wall portions.

[0013] According to the present invention described in claim 2, the battery cell storage section includes a first side wall portion extending in a first direction and capable of supporting the battery cell in a third direction, a support wall portion supporting the battery cell from the other side in the second direction, and a second side wall portion capable of supporting the battery cell in the first direction.

[0014] Incidentally, in a battery cell housing portion configured as described above, the restoring force of the battery cells acts mainly on the second side wall portion, so it is preferable to ensure that the second side wall portion has sufficient tensile strength and rigidity against the restoring force.

[0015] On the other hand, since the restoring force of the battery cell does not directly act on the first side wall portion and the support wall portion, actively ensuring the tensile strength and rigidity against the restoring force in the first side wall portion and the support wall portion would cause excessive quality.

[0016] However, for example, in cases where the battery cell housing section is made up of a casting including a first side wall section, a support wall section, and a second side wall section, it becomes difficult to ensure the tensile strength and rigidity of only the second side wall section.

[0017] Here, in the present invention, the battery cell housing portion is configured to include a first component and a pair of second components. The first component is configured to include a pair of first side walls and a support wall.

[0018] On the other hand, the second component is configured to include a second side wall portion and a pair of third side wall portions that are provided contiguous with the second side wall portion on one side and the other side in the third direction of the second side wall portion and are joined to the first side wall portion. Therefore, by configuring only the second component from a material with high tensile strength or a material with a large plate thickness, it is possible to ensure tensile strength and rigidity against the restoring force of the battery cells in the battery cell housing portion.

[0019] A battery pack case according to the present invention as described in claim 3 is the invention as described in claim 2, wherein a main flow path portion which constitutes part of the cooling air flow path portion, extends in the first direction, and is capable of supplying the cooling air to the battery cell is provided integrally with the support wall portion on the other side in the second direction, and the flow path forming portion includes an end component portion which is provided integrally with a portion of the first component on one side in the first direction and the second component on the one side in the first direction and constitutes an end of the cooling air flow path portion, and an air blower portion which is provided integrally with a portion of the first component on the other side in the first direction and the second component on the other side in the first direction and is connectable to a blower portion capable of supplying the cooling air to the cooling air flow path portion.

[0020] According to the present invention as set forth in claim 3, a main flow path portion constituting a part of the cooling air flow path portion is provided integrally with the support wall portion on the other side in the second direction of the support wall portion of the first component, and the main flow path portion extends in the first direction. Therefore, the cooling air flows in the first direction through the main flow path portion, and the cooling air is supplied from the main flow path portion to the battery cells.

[0021] Incidentally, since the battery cell housing portion is made of metal, it is preferable to simplify the shapes of the first and second parts that make up the battery cell housing portion in order to form these parts by press working or the like.

[0022] On the other hand, the cooling air flow path needs to have a portion that configures the end of the cooling air flow path and a portion that connects to the air blower that supplies cooling air to the cooling air flow path. However, if these are provided in the first component and the second component, the shapes of these components become complicated, making it difficult to form these components by press working.

[0023] Here, in the present invention, the resin flow path forming portion includes an end portion constituting an end portion of the cooling air flow path portion, and an air outlet portion connectable to the air blower portion. The end portion is provided integrally with a portion of the first component on one side in the first direction and a second component on the one side in the first direction. Meanwhile, the air outlet portion is provided integrally with a portion of the first component on the other side in the first direction and a second component on the other side in the first direction.

[0024] For this reason, in the present invention, the parts of the cooling air flow path that are likely to have a complex configuration can be constructed with a flow path forming portion made of resin, and as a result, the shapes of the first and second parts can be simplified to shapes that can be molded by press processing, etc.

[0025] The battery pack case of the present invention as described in claim 4 is the invention as described in claim 2 or claim 3, wherein the battery cell accommodating sections are arranged in a row in the third direction, and further include a first connecting member made of metal that connects the second side wall portions on one side in the first direction, and a second connecting member made of metal that connects the second side wall portions on the other side in the first direction.

[0026] According to the present invention as set forth in claim 4, a plurality of battery cell accommodation sections are arranged in a row in the third direction, and the volume capable of accommodating battery cells can be expanded. Also, in the battery cell accommodation sections arranged in a row in the third direction, the second side wall sections on one side in the first direction are connected to each other by a first metal connecting member, and the second side wall sections on the other side in the first direction are connected to each other by a second metal connecting member. Therefore, in the present invention, the second side wall section on one side in the first direction can be reinforced by the first connecting member, and the second side wall section on the other side in the first direction can be reinforced by the second connecting member.

[0027] A battery pack case according to the present invention as described in claim 5 is the invention as described in claim 4, wherein the second side wall portion, the first connecting member and the second connecting member each have a bead portion extending in the third direction and protruding on the side opposite the battery cell.

[0028] According to the present invention as set forth in claim 5, the second side wall portion of the second component, the first connecting member, and the second connecting member are provided with bead portions that extend in the third direction and protrude to the side opposite the battery cell. Therefore, in the present invention, it is possible to ensure rigidity against the restoring force of the battery cell in each of the second side wall portion, the first connecting member, and the second connecting member. Effect of the Invention

[0029] As described above, the battery pack case of the present invention as set forth in claim 1 has the excellent effect of holding the battery cells in a stable state, while ensuring a flow path for cooling air for the battery cells, and further suppressing weight increase.

[0030] The battery pack case according to the present invention as set forth in claim 2 has the excellent effect of being able to prevent excessive quality while ensuring the tensile strength and rigidity against the restoring force of the battery cells.

[0031] The battery pack case according to the present invention as set forth in claim 3 has the excellent effect of improving production efficiency.

[0032] The battery pack case according to the present invention as set forth in claim 4 has the excellent effect of contributing to ensuring power capacity and providing reinforcement against the restoring force of the battery cells.

[0033] The battery pack case according to the present invention as set forth in claim 5 has the excellent effect of increasing the rigidity against the restoring force of the battery cells. [Brief description of the drawings]

[0034] [Figure 1] FIG. 2 is a plan view illustrating a schematic configuration of a battery pack case according to the embodiment. [Diagram 2] 2 is a side view (view taken in the direction of arrow 2 in FIG. 1) that illustrates a schematic configuration of a battery pack case according to the present embodiment. [Diagram 3] 2 is an exploded perspective view showing the configuration of a metal portion that constitutes the battery pack case according to the embodiment; FIG. [Figure 4] 4 is a plan view showing the configuration of a metal portion that constitutes the battery pack case according to the embodiment. FIG. [Diagram 5] 5 is a cross-sectional view (cross-sectional view showing a state cut along line 5-5 in FIG. 4) that shows a schematic configuration of a metal portion that constitutes the battery pack case according to the present embodiment. FIG. [Figure 6] 6 is a rear view (view taken in the direction of the arrow 6 in FIG. 4) that illustrates a schematic configuration of a metal portion that constitutes the battery pack case according to the present embodiment. FIG. [Figure 7] 7 is a partial cross-sectional view (cross-sectional view taken along line 7-7 in FIG. 1) showing a schematic configuration of a battery pack case according to the present embodiment. [Figure 8] 8 is a partial cross-sectional view (cross-sectional view showing a state cut along line 8-8 in FIG. 1) that shows a schematic configuration of a battery pack case according to the present embodiment. [Figure 9] 4 is a plan view showing a schematic configuration of a resin portion that constitutes the battery pack case according to the embodiment; FIG. [Figure 10] 1 is a rear view (view taken in the direction of the arrow 10 in FIG. 1) showing the configuration of the battery pack case according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] An example of an embodiment of a battery pack case according to the present invention will be described below with reference to Figures 1 to 10. A "battery pack case 10" according to this embodiment forms the outer shell of a battery pack 12 mounted on a vehicle (not shown), such as a hybrid car, a plug-in hybrid car, or an electric car, and holds a plurality of "battery cells 14", as described below.

[0036] In each figure, the arrow FR indicates the front side of the battery pack 12 in the front-rear direction, the arrow UP indicates the upper side of the battery pack 12 in the height direction, and the arrow LH indicates the left side of the battery pack 12 in the left-right direction.

[0037] In addition, unless otherwise specified below, the front side of the battery pack 12 in the fore-and-aft direction will be referred to as one side in the first direction, the upper side of the battery pack 12 in the height direction will be referred to as one side in the second direction, and the left side of the battery pack 12 in the left-right direction will be referred to as one side in the third direction.

[0038] 1, the battery pack case 10 is configured to be line symmetrical with respect to a center line CL extending in the first direction when viewed from the second direction. This battery pack case 10 includes a metal "battery cell accommodating section 16," a "battery cell accommodating section 18," a "connecting member 20" as a first connecting member, a "connecting member 22" as a second connecting member, and a resin "flow path forming section 24."

[0039] As shown in FIGS. 3 to 5, the battery cell housing portion 16 is configured to include a "main body portion 26" as a first part, and a pair of "end portions 28" as second parts.

[0040] In more detail, main body 26 is formed by pressing a steel plate having a tensile strength of 270 MPa and a thickness of 0.6 mm, for example, and is configured to include bottom wall 26A, a "side wall 26B" as the first side wall, and a "side wall 26C" as the first side wall. Bottom wall 26A extends in the first direction, and one side and the other side in the third direction are configured as a "support wall 26A1" whose thickness direction is the second direction, and support wall 26A1 supports battery cell 14 from the other side in the second direction.

[0041] Meanwhile, a "main flow path section 26A2" is provided integrally with the support wall section 26A1 in a central portion in the third direction of the lower wall section 26A, and constitutes part of a "cooling air flow path section 30" for supplying cooling air to the battery cells 14. This main flow path section 26A2 is disposed on the other side in the second direction of the support wall section 26A1, and has a rectangular shape extending in the first direction when viewed from the second direction, and is U-shaped with one side in the second direction open when viewed from the first direction.

[0042] The main flow path portion 26A2 is not provided at the end portion on one side of the first direction and the end portion on the other side of the first direction of the support wall portion 26A1, and the central portions of the peripheral portion on one side of the first direction and the peripheral portion on the other side of the first direction of the lower wall portion 26A are recessed in a rectangular shape toward the central portion of the lower wall portion 26A when viewed from the second direction.

[0043] The side wall portion 26B is in the form of a plate extending from the peripheral edge portion on one side in the third direction of the lower wall portion 26A to one side in the second direction, with the third direction being the plate thickness direction, and a flange portion 26D extends from the peripheral edge portion on one side in the second direction of the side wall portion 26B to one side in the third direction.

[0044] Meanwhile, the side wall portion 26C is generally in the form of a plate extending from the peripheral edge of the bottom wall portion 26A on the other side in the third direction to one side in the second direction, with the third direction being the plate thickness direction. A bulging portion 26C1 is provided on one side of the side wall portion 26C in the second direction, bulging to the other side in the third direction, except for an end portion on one side in the first direction and an end portion on the other side in the first direction. The side wall portions 26B and 26C support the battery cell 14 in the third direction.

[0045] The end portions 28 are disposed at one end portion in the first direction and the other end portion in the first direction of the main body portion 26. As an example, the end portions 28 are formed by pressing a steel plate having a tensile strength of 980 [MPa] and a thickness of 1.6 [mm], and include a "main wall portion 28A" as a second side wall portion, and a pair of "side wall portions 28B" as third side wall portions.

[0046] The main wall portion 28A has a rectangular plate shape extending in the third direction, with the plate thickness direction being the first direction, and has a "bead portion 28C" provided in its central portion in the second direction, as shown in Figures 7 and 8. This bead portion 28C extends in the third direction and protrudes from the main wall portion 28A on the side opposite the central portion of the lower wall portion 26A, i.e., the side opposite the battery cell 14, and has an arc-shaped cross section when viewed from the third direction. The main wall portion 28A supports the battery cell 14 in the first direction on the surface opposite the bead portion 28C.

[0047] On the other hand, the side wall portion 28B is in the form of a plate extending from each of the peripheral edge portions on one side in the third direction of the main wall portion 28A and the peripheral edge portions on the other side in the third direction to the central portion side of the lower wall portion 26A with the plate thickness direction being the third direction. In other words, the end portion 28 is in a U-shape with the central portion side of the lower wall portion 26A being open when viewed from the second direction.

[0048] In addition, side wall portion 28B has a trapezoidal shape that narrows toward the center of lower wall portion 26A when viewed from the third direction, and is joined to one of side wall portion 26B and side wall portion 26C via a joint made by spot welding or the like (not shown) while being abutted from the center side in the third direction of lower wall portion 26A.

[0049] On the other hand, the battery cell accommodating section 18 is composed of a "main body portion 32" as a first part and a pair of "end portions 34" as second parts, and is arranged adjacent to the battery cell accommodating section 16 on one side of the battery cell accommodating section 16 in the third direction.

[0050] Specifically, the main body 32 is formed, for example, by pressing a steel plate having a tensile strength of 270 MPa and a thickness of 0.6 mm. The main body 32 includes a bottom wall 32A having a similar configuration to the bottom wall 26A, a "side wall 32B" serving as a first side wall having a similar configuration to the side wall 26B, and a "side wall 32C" serving as a first side wall having a similar configuration to the side wall 26C.

[0051] The lower wall portion 32A is configured to include a "support wall portion 32A1" that supports the battery cell 14 from the other side in the second direction, and a "main flow path portion 32A2" that forms part of a "cooling air flow path portion 33" for supplying cooling air to the battery cell 14.

[0052] In this embodiment, the side wall portion 32B constitutes a portion on the other side in the third direction of the main body portion 32, and the side wall portion 32C constitutes a portion on one side in the third direction of the main body portion 32. A flange portion 32D extends in the other side in the third direction from a peripheral edge portion on one side in the second direction of the side wall portion 32B.

[0053] On the other hand, the side wall portion 32C constitutes one side of the main body portion 32 in the third direction, and is adjacent to the side wall portion 26C, and is joined to the bulging portion 26C1 through a joint portion (not shown) such as spot welding with the bulging portion 32C1 abutting against the bulging portion 26C1. Note that in Figures 4 and 5, the bulging portion 26C1 and the bulging portion 32C1 are shown separated from each other so that the configurations of the bulging portion 26C1 and the bulging portion 32C1 can be easily understood.

[0054] The end portions 34 are disposed at the end portion on one side in the first direction of the main body portion 32 and the end portion on the other side in the first direction. As an example, the end portions 34 are formed by pressing a steel plate having a tensile strength of 980 [MPa] and a thickness of 1.6 [mm]. The end portions 34 include a "main wall portion 34A" as the second side wall portion and a pair of "side wall portions 34B" as the third side wall portions, and have the same configuration as the end portions 28.

[0055] The main wall portion 34A has a configuration similar to that of the main wall portion 28A, and is provided with a “bead portion 34C.” The main wall portion 34A supports the battery cell 14 in the first direction on the surface opposite the bead portion 34C.

[0056] On the other hand, the side wall portion 34B has a similar configuration to the side wall portion 28B, and extends from each of the peripheral edge portion on one side in the third direction of the main wall portion 34A and the peripheral edge portion on the other side in the third direction to the center side of the lower wall portion 26A with the plate thickness direction being the third direction. The side wall portion 34B is joined to one of the side wall portion 32B and the side wall portion 32C via a joint portion made by spot welding or the like (not shown) in a state in which the side wall portion 34B is in contact with the center side of the lower wall portion 32A in the third direction.

[0057] As an example, the connecting member 20 is formed by pressing a steel plate having a tensile strength of 780 MPa and a thickness of 2.0 mm, and is arranged on one side in the first direction of the battery cell accommodating section 16 and the battery cell accommodating section 18, as shown in Figures 3 and 8.

[0058] Specifically, the connecting member 20 includes a main wall portion 20A, an upper flange portion 20B, a lower flange portion 20C, and an extending wall portion 22E. The main wall portion 20A is a rectangular plate extending in the third direction with the plate thickness direction being the first direction, and is joined to a main wall portion 28A of an end portion 28 on one side in the first direction and a main wall portion 34A of an end portion 34 on one side in the first direction via joints formed by spot welding or the like (not shown). In other words, the connecting member 20 connects the main wall portion 28A and the main wall portion 34A in the third direction on one side in the first direction.

[0059] Furthermore, a "bead portion 20D" is provided in the center of the main wall portion 20A in the second direction. This bead portion 20D extends in the third direction and protrudes from the main wall portion 20A on the side opposite the battery cell accommodation portion 16 and the battery cell accommodation portion 18, i.e., the side opposite the battery cell 14, and has an arc-shaped cross section when viewed from the third direction. Furthermore, the bead portion 20D is disposed at a position that overlaps with the bead portion 28C of the battery cell accommodation portion 16 and the bead portion 34C of the battery cell accommodation portion 18 when viewed from the first direction, and is spaced apart from these in the first direction.

[0060] The upper flange portion 20B extends from a peripheral edge portion on one side in the second direction of the main wall portion 20A toward one side in the first direction, and has a plate shape extending in a third direction with its plate thickness direction defined as the second direction.

[0061] On the other hand, the lower flange portion 20C extends from a peripheral portion of the main wall portion 20A on the other side of the second direction to one side in the first direction, and has a plate shape extending in a third direction with the plate thickness direction being the second direction. Also, an extending wall portion 20E extending from a peripheral portion of the lower flange portion 20C on one side in the first direction to the other side in the second direction is provided at each of an end portion on one side in the third direction and an end portion on the other side in the third direction of the lower flange portion 20C.

[0062] The connecting member 20 is connected to an electronic device unit (not shown) that includes a plurality of electronic devices, and power is supplied from the battery cell 14 to the electronic device unit.

[0063] On the other hand, the connecting member 22 is formed, for example, by pressing a steel plate having a tensile strength of 780 MPa and a thickness of 2.0 mm, and is arranged on the other side in the first direction of the battery cell accommodating section 16 and the battery cell accommodating section 18, as shown in Figures 3, 6, and 7.

[0064] In detail, the connecting member 22 includes a main wall portion 22A, an upper flange portion 22B, and a lower flange portion 22C. The main wall portion 22A is a rectangular plate extending in the third direction with the plate thickness direction being the first direction, and is joined to the main wall portion 28A of the end portion 28 on the other side in the first direction and the main wall portion 34A of the end portion 34 on the other side in the first direction via joints formed by spot welding or the like (not shown). In other words, the connecting member 22 connects the main wall portion 28A and the main wall portion 34A in the third direction on the other side in the first direction.

[0065] Furthermore, a "bead portion 22D" is provided in the center of the main wall portion 22A in the second direction. This bead portion 22D extends in the third direction and protrudes from the main wall portion 22A on the side opposite the battery cell accommodation portion 16 and the battery cell accommodation portion 18, i.e., the side opposite the battery cell 14, and has an arc-shaped cross section when viewed from the third direction. Furthermore, the bead portion 22D is disposed at a position that overlaps with the bead portion 28C of the battery cell accommodation portion 16 and the bead portion 34C of the battery cell accommodation portion 18 when viewed from the first direction, and is spaced apart from these in the first direction.

[0066] The upper flange portion 22B is a plate-like member extending from a peripheral portion on one side in the second direction of the main wall portion 22A to the other side in the first direction, and extending in a third direction with the plate thickness direction being the second direction. On the other hand, the lower flange portion 22C is a plate-like member extending from a peripheral portion on the other side in the second direction of the main wall portion 22A to the other side in the first direction, and extending in a third direction with the plate thickness direction being the second direction.

[0067] Next, the configuration of the flow path forming section 24 will be described with reference to Figures 1, 2, and 7 to 10. This flow path forming section 24 is provided integrally with the above-mentioned battery cell housing sections 16, 18, connecting members 20, and connecting members 22 by injection molding a specific resin. In other words, the battery pack case 10 is a composite molded product made of a metal member and a resin member.

[0068] In detail, the flow path forming portion 24 is configured to include an "end portion forming portion 36" which forms a portion on one side in the first direction and which forms the ends of the cooling air flow path portion 30 and the cooling air flow path portion 33, and an "air outlet portion 38" which forms a portion on the other side in the first direction.

[0069] The end portion 36 is composed of a lower portion 36A that constitutes the other side in the second direction, a front portion 36B that constitutes one side in the first direction, and a pair of side portions 36C and a front partition portion 36D that constitute the outer portion in the third direction of the battery pack case 10.

[0070] The cross section of the main part of the lower constituent part 36A as viewed from the first direction is hat-shaped with one side in the second direction being open, and covers the parts of the main body part 26 and the main body part 32 on one side in the first direction from the other side in the second direction. Specifically, the lower constituent part 36A covers recessed parts at the ends on one side in the first direction of the lower wall part 26A of the main body part 26 and the lower wall part 32A of the main body part 32, and connects the main body part 26, the main body part 32, the end part 28, and the end part 34 on the other side in the second direction.

[0071] The lower constituent portion 36A has a front wall portion 36A1, which is located on the other side in the second direction of the main wall portion 28A of the end portion 28 and the main wall portion 34A of the end portion 34, and extends in the third direction. In other words, the lower constituent portion 36A can be considered to be a portion of the end portion constituent portion 36 that constitutes a part of the cooling air flow path portion 30 and the cooling air flow path portion 33.

[0072] The front constituent portion 36B covers the main wall portion 28A of the end portion 28, the main wall portion 34A of the end portion 34, and the connecting member 20. A part of the front constituent portion 36B is inserted between the bead portion 20D and the bead portion 28C and the bead portion 34C, thereby forming a sandwich structure stacked in the first direction at one side of the battery pack case 10 in the first direction.

[0073] The side constituent portion 36C is provided contiguous with the front constituent portion 36B and extends to the other side in the first direction, covering the outer side wall portion 28B and the side wall portion 34B of the battery pack case 10 in the third direction.

[0074] The front partition portion 36D extends from the front constituent portion 36B to the other side in the first direction, and covers the portions of the side wall portion 26C and the side wall portion 32C on one side in the first direction.

[0075] On the other hand, the air outlet portion 38 is composed of a lower component 38A that constitutes the part on the other side in the second direction, a rear component 38B that constitutes the part on the other side in the first direction, a pair of side components 38C that constitute the outer part in the third direction of the battery pack case 10, a rear partition portion 38D, and an opening 38E.

[0076] The cross section of the lower component 38A viewed from the first direction is hat-shaped with one side in the second direction being open, and covers the portions of the main body 26 and the main body 32 on the other side in the first direction from the other side in the second direction. Specifically, the lower component 38A covers recessed portions at the ends on the other side in the first direction of the lower wall 26A of the main body 26 and the lower wall 32A of the main body 32, and connects the main body 26, the main body 32, the end portion 28, and the end portion 34 on the other side in the second direction.

[0077] Rear constituent portion 38B covers main wall portion 28A of end portion 28, main wall portion 34A of end portion 34, and connecting member 22. Also, a portion of rear constituent portion 38B is inserted between bead portion 22D and bead portion 28C and bead portion 34C, thereby forming a sandwich structure stacked in the first direction in the portion of battery pack case 10 on the other side in the first direction.

[0078] The side constituent portion 38C is provided contiguous with the rear constituent portion 38B and extends to one side in the first direction, covering the outer side wall portion 28B and the side wall portion 34B of the battery pack case 10 in the third direction.

[0079] The rear partition portion 38D extends from the rear constituent portion 38B to the other side in the first direction, and covers the portions of the side wall portion 26C and the side wall portion 32C on the other side in the first direction.

[0080] The opening 38E is provided on the other side in the second direction of the rear constituent portion 38B when viewed from the first direction. This opening 38E includes an upper wall portion 38E1 constituting an upper portion in the second direction, a lower wall portion 38E2 constituting a portion on the other side in the second direction, and a pair of outer wall portions 38E3 connecting the upper wall portion 38E1 and the lower wall portion 38E2 in the second direction on the outside in the third direction of the battery pack case 10.

[0081] Specifically, the upper wall portion 38E1 extends from a peripheral portion on the other side in the second direction of the rear constituent portion 38B to one side in the first direction with the plate thickness direction being the second direction, and also extends in the third direction. On the other hand, the lower wall portion 38E2 extends from a peripheral portion on the other side in the first direction of the bottom of the lower constituent portion 38A to the other side in the first direction and the other side in the second direction, and also extends in the third direction.

[0082] The third direction central portion of the upper wall portion 38E1 and the third direction central portion of the lower wall portion 38E2 are connected in the second direction by a branch portion 38E4. More specifically, the branch portion 38E4 has an outer circumferential shape that is wider from the other side in the first direction to the one side in the first direction when viewed from the second direction, and the opening 38E is branched by the branch portion 38E4 into a first inlet portion 38E5 on the other side in the third direction and a second inlet portion 38E6 on the one side in the third direction. The first inlet portion 38E5 constitutes a part of the cooling air flow path portion 30, and the second inlet portion 38E6 constitutes a part of the cooling air flow path portion 33.

[0083] In addition, a "blower 40" serving as an air sending section is connected to the opening 38E, and when the blower 40 is driven, cooling air blown out from the blower 40 is supplied to the cooling air flow path section 30 and the cooling air flow path section 33.

[0084] In the battery cell housing section 16 and the battery cell housing section 18 of the battery pack case 10 configured as described above, a plurality of battery cells 14 are stacked in the first direction and housed in a compressed state from one side in the second direction. End plates 42 are arranged on each of the one side in the first direction and the other side in the first direction of the stacked battery cells 14.

[0085] In the battery cell housing section 16, the cooling air flow path section 30 is open on the other side in the second direction of the battery cells 14, and in the battery cell housing section 18, the cooling air flow path section 33 is open on the other side in the second direction of the battery cells 14. Cooling air from the blower 40 is supplied to the battery cells 14 via the cooling air flow path section 30 and the cooling air flow path section 33.

[0086] (Actions and Effects of the Present Embodiment) Next, the operation and effects of this embodiment will be described.

[0087] 1, the battery pack case 10 includes metal battery cell housing sections 16 and 18, which house a plurality of battery cells 14 stacked in a first direction from one side in the second direction while being compressed in the first direction. The restoring force of the battery cells 14 is supported by the battery cell housing sections 16 and 18.

[0088] Incidentally, since the battery cells 14 generate heat during charging and discharging, it is preferable that the battery pack case 10 has a flow path for cooling air to cool the battery cells 14. However, if the battery cell housing section 16 and the battery cell housing section 18 are made of metal and all of the cooling air flow paths are provided in these sections, the configuration becomes complicated and it becomes necessary to construct these sections as castings. However, with such a configuration, it is considered that the weight of the battery pack case 10 will increase.

[0089] Here, in this embodiment, a flow path forming portion 24 made of resin is provided integrally with the battery cell accommodating portion 16 and the battery cell accommodating portion 18, and a portion of this flow path forming portion 24 is positioned on the other side of the second direction of the battery cell 14, and forms part of the cooling air flow path portion 30 and the cooling air flow path portion 33 through which the cooling air for the battery cell 14 flows.

[0090] Therefore, in this embodiment, by forming the parts of the cooling air flow path section 30 and the cooling air flow path section 33 that have complex shapes using a flow path forming section 24 made of resin, it is possible to ensure a flow path for the cooling air that cools the battery cells 14 while preventing the configuration of the battery cell accommodating section 16 and the battery cell accommodating section 18 from becoming complicated.

[0091] Therefore, the battery pack case 10 according to this embodiment can stably hold the battery cells 14, ensure a flow path for cooling air for the battery cells 14, and further suppress an increase in weight.

[0092] In addition, in this embodiment, as shown in Figures 3 and 4, the battery cell storage section 16 includes side wall portions 26B and 26C that extend in the first direction and are capable of supporting the battery cell 14 in the third direction, a support wall portion 26A1 that supports the battery cell 14 from the other side in the second direction, and a main wall portion 28A that is capable of supporting the battery cell 14 in the first direction.

[0093] In addition, the battery cell storage section 18 includes side wall portions 32B and 32C that extend in the first direction and are capable of supporting the battery cell 14 in the third direction, a support wall portion 32A1 that supports the battery cell 14 from the other side in the second direction, and a main wall portion 34A that is capable of supporting the battery cell 14 in the first direction.

[0094] Incidentally, in the battery cell storage section 16 and the battery cell storage section 18 configured as described above, the restoring force of the battery cells 14 acts mainly on the main wall portion 28A and the main wall portion 34A, so it is preferable to ensure tensile strength and rigidity against the restoring force of these battery cells 14.

[0095] On the other hand, since the restoring force of the battery cell 14 does not directly act on side wall portion 26B, side wall portion 26C, side wall portion 32B, side wall portion 32C, support wall portion 26A1, and support wall portion 32A1, actively ensuring the tensile strength and rigidity of these portions against the restoring force of the battery cell 14 would cause excessive quality.

[0096] However, for example, if the battery cell accommodating section 16 is composed of a casting including side wall portions 26B, 26C, support wall portion 26A1, and main wall portion 28A, it is difficult to ensure the tensile strength and rigidity of only the main wall portion 28A. Similarly, if the battery cell accommodating section 18 is composed of a casting including side wall portions 32B, 32C, support wall portion 32A1, and main wall portion 34A, it is difficult to ensure the tensile strength and rigidity of only the main wall portion 34A.

[0097] Here, in this embodiment, the battery cell housing portion 16 is configured to include a main body portion 26 and a pair of end portions 28. The main body portion 26 is configured to include a side wall portion 26B, a side wall portion 26C, and a support wall portion 26A1.

[0098] On the other hand, the end portion 28 is configured to include a main wall portion 28A and a pair of side wall portions 28B that are provided continuously with the main wall portion 28A on one and the other sides in the third direction of the main wall portion 28A and are joined to the side wall portion 26B or the side wall portion 26C.

[0099] The battery cell housing portion 18 is configured to include a main body portion 32 and a pair of end portions 34. The main body portion 32 is configured to include a side wall portion 32B, a side wall portion 32C, and a support wall portion 32A1.

[0100] On the other hand, the end portion 34 is configured to include a main wall portion 34A and a pair of side wall portions 34B that are continuous with the main wall portion 34A on one and the other sides in the third direction of the main wall portion 34A and are joined to the side wall portion 32B or the side wall portion 32C.

[0101] Therefore, by constructing end portions 28 and 34 from a material with high tensile strength or a material with a thick plate thickness, it is possible to ensure the tensile strength and rigidity against the restoring force of the battery cells 14 in the battery cell storage portion 16 and the battery cell storage portion 18.

[0102] Therefore, in this embodiment, the tensile strength and rigidity of the battery pack case 10 against the restoring force of the battery cells 14 can be ensured, while preventing the battery pack case 10 from becoming of excessive quality.

[0103] In addition, in this embodiment, as shown in Figures 1 and 5, a main flow path portion 26A2 that constitutes a part of the cooling air flow path portion 30 is provided integrally with the support wall portion 26A1 on the other side of the second direction of the support wall portion 26A1 of the main body portion 26, and the main flow path portion 26A2 extends in the first direction.

[0104] Furthermore, a main flow path portion 32A2 that constitutes part of the cooling air flow path portion 33 is provided integrally with the support wall portion 32A1 on the other side in the second direction of the support wall portion 32A1 of the main body portion 32, and the main flow path portion 32A2 extends in the first direction. For this reason, cooling air flows in the first direction through the main flow path portion 26A2 and the main flow path portion 32A2, and the cooling air is supplied to the battery cells 14 from the main flow path portion 26A2 and the main flow path portion 32A2.

[0105] Incidentally, since the battery cell accommodation section 16 is made of metal, in order to form the main body section 26 and end sections 28 that constitute the battery cell accommodation section 16 by press working or the like, it is preferable to be able to simplify the shapes of these components. The same is true for the battery cell accommodation section 18.

[0106] On the other hand, it is necessary to provide the cooling air flow path section 30 with a portion that constitutes the end of the cooling air flow path section 30 and a portion that connects to the blower 40 that supplies cooling air to the cooling air flow path section 30. Similarly, it is necessary to provide the cooling air flow path section 33 with a portion that constitutes the end of the cooling air flow path section 33 and a portion that connects to the blower 40. However, if these are provided in the main body section 26, the main body section 32, the end section 28, and the end section 34, the shapes of these components become complicated, making it difficult to form these components by press working.

[0107] 9 and 10, in this embodiment, the resin flow path forming portion 24 is configured to include an end portion configuration portion 36 that configures the end portions of the cooling air flow path portions 30 and 33, and an air outlet portion 38 that can be connected to a blower 40. The end portion configuration portion 36 is provided integrally with the portions of the main body portion 26 and the main body portion 32 on one side in the first direction, and the end portions 28 and 34 on one side in the first direction.

[0108] On the other hand, the air outlet portion 38 is provided integrally with the portions of the main body portion 26 and the main body portion 32 on the other side in the first direction, and with the end portions 28 and 34 on the other side in the first direction.

[0109] For this reason, in this embodiment, in the cooling air flow path section 30 and the cooling air flow path section 33, the parts that are likely to have a complex configuration can be configured with the flow path forming section 24 made of resin, and as a result, the shapes of the main body section 26, the main body section 32, the end section 28 and the end section 34 can be simplified into shapes that can be molded by press processing or the like.

[0110] Therefore, in this embodiment, the manufacturing efficiency of the battery pack case 10 can be improved.

[0111] 4, in this embodiment, the battery cell accommodation sections 16 and 18 are arranged in series in the third direction, which increases the volume capable of accommodating the battery cells 14. In the battery cell accommodation sections 16 and 18 arranged in series in the third direction, the main wall section 28A and the main wall section 34A on one side in the first direction are connected by a metallic connecting member 20, and the main wall section 28A and the main wall section 34A on the other side in the first direction are connected by a metallic connecting member 22.

[0112] For this reason, in this embodiment, the main wall portion 28A and the main wall portion 34A on one side in the first direction can be reinforced by the connecting member 20, and the main wall portion 28A and the main wall portion 34A on the other side in the first direction can be reinforced by the connecting member 22. Therefore, this embodiment can contribute to ensuring the power capacity of the battery pack 12, and can also provide reinforcement against the restoring force of the battery cells 14 of the battery pack case 10.

[0113] Additionally, in this embodiment, a bead portion 28C is provided on the main wall portion 28A of the end portion 28, a bead portion 34C is provided on the main wall portion 34A of the end portion 34, a bead portion 20D is provided on the connecting member 20, and a bead portion 22D is provided on the connecting member 22. The bead portions 20D, 22D, 28C, and 34C extend in the third direction and protrude to the side opposite the battery cell 14. For this reason, in this embodiment, the rigidity against the restoring force of the battery cell 14 can be ensured in each of the main wall portion 28A, the main wall portion 34A, the connecting member 20, and the connecting member 22. Therefore, in this embodiment, the rigidity of the battery pack case 10 against the restoring force of the battery cell can be increased.

[0114] <Supplementary explanation of the above embodiment> (1) In the embodiment described above, the battery pack case 10 includes a plurality of battery cell housing sections, but the number of battery cell housing sections can be increased or decreased depending on the specifications of the vehicle in which the battery pack case 10 is mounted. Note that the configurations of the connecting members 20 and 22 may also be changed as appropriate depending on the number of battery cell housing sections.

[0115] (2) In the above-described embodiment, part of the cooling air flow path portion is formed by the battery cell housing portion, but the cooling air flow path portion may be formed entirely of resin depending on the specifications of the battery cells to be housed in the battery pack case 10. For example, the battery cell housing portion may be formed of a frame-shaped metal member when viewed from the second direction, and the battery cell support portion and the cooling air flow path portion may all be provided in the flow path forming portion made of resin. [Explanation of symbols]

[0116] 10 Battery pack case 14 Battery Cells 16 Battery cell housing 18 Battery cell housing 20 Connecting member (first connecting member) 20D bead part 22 Connecting member (second connecting member) 22D Bead section 24 Flow path forming section 26 Main body (first part) 26A1 Support wall section 26A2 Main flow section 26B Side wall part (first side wall part) 26C Side wall part (first side wall part) 28 End part (second part) 28A Main wall (second side wall) 28B Side wall part (3rd side wall part) 28C Bead section 30 Cooling air passage section 32 Main body (first part) 32A1 Support wall section 32A2 Main flow section 32B Side wall part (first side wall part) 32C Side wall part (first side wall part) 33 Cooling air flow path section 34 End part (second part) 34A Main wall (second side wall) 34B Side wall part (3rd side wall part) 34C Bead section 36 End component 38 Air outlet 40 Blower (air blowing section)

Claims

1. a battery cell receiving section made of metal in which a plurality of battery cells stacked in a first direction can be received from one side in a second direction perpendicular to the first direction in a state where the battery cells are compressed in the first direction, and which can support a restoring force of the battery cells; a flow path forming portion made of resin that is provided integrally with the battery cell housing portion, that is disposed on the other side of the battery cell in the second direction, and that constitutes a part of a cooling air flow path portion through which cooling air for the battery cell flows; A battery pack case having a

2. The battery cell housing portion includes: a first component including a pair of first side wall portions extending in the first direction and capable of supporting the battery cell in a third direction perpendicular to the first direction and the second direction, and a support wall portion supporting the battery cell from the other side in the second direction; a pair of second components including a second side wall portion capable of supporting the battery cell in the first direction, and a pair of third side wall portions provided contiguous with the second side wall portion on one side and the other side in the third direction of the second side wall portion and joined to the first side wall portion; The invention is configured to include The battery pack case according to claim 1 .

3. a main flow path portion that constitutes a part of the cooling air flow path portion, extends in the first direction, and is capable of supplying the cooling air to the battery cell, the main flow path portion being integrally provided with the support wall portion on the other side in the second direction, The flow passage forming portion includes an end portion that is integral with a portion of the first component on one side in the first direction and the second component on the one side in the first direction and that constitutes an end portion of the cooling air flow passage portion, and an air outlet portion that is integral with a portion of the first component on the other side in the first direction and the second component on the other side in the first direction and that can be connected to an air blower that can supply the cooling air to the cooling air flow passage portion. The battery pack case according to claim 2 .

4. The battery cell housing portions are arranged in a row in the third direction, a first connecting member made of metal that connects the second side wall portions on one side in the first direction to each other; and a second connecting member made of metal that connects the second side wall portions on the other side in the first direction to each other. The battery pack case according to claim 2 or 3.

5. the second side wall portion, the first connecting member, and the second connecting member each have a bead portion extending in the third direction and protruding to a side opposite the battery cell; The battery pack case according to claim 4 .

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