Method for manufacturing an electrical storage device

Abstract

Provided is a method for manufacturing an electrical storage device that can suppress variation in the thickness of a heat-conducting agent located in the gap between a lower case and an electrical storage module. The method for manufacturing an electrical storage device includes the steps of: applying a heat-conducting agent to the upper surface of a bottom wall of a lower case; and pressing an electrical storage module against the heat-conducting agent applied to the upper surface, wherein the overlapping region of the bottom wall that overlaps the electrical storage module includes a deformation portion that deforms downward when protruding upward and being pressed downward, and the heat-conducting agent located between the electrical storage module and the upper surface is set to a prescribed thickness by the deformation portion deforming downward in the step of pressing the electrical storage module.

Description

Technical Field

[0001] This invention relates to a method for manufacturing an energy storage device. Background Technology

[0002] As a conventional energy storage device, Japanese Patent Application Publication No. 2024-092300 (Patent Document 1) discloses a structure in which multiple energy storage modules are fixed to the lower shell of a housing containing the multiple energy storage modules using adhesive material.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2024-092300 Summary of the Invention

[0004] When multiple energy storage modules are fixed to the bottom wall of the lower housing using a thermally conductive agent, the modules are pressed from above onto the thermally conductive agent coated on the upper surface of the bottom wall. If the bottom wall of the lower housing is flat, the bottom of the lower housing may sometimes sink downwards due to the pressure from the multiple energy storage modules. In this case, the distance between the lower surface of the energy storage modules and the bottom wall widens, and the thickness of the thermally conductive agent becomes greater than the designed target value. Furthermore, there are concerns that due to design deviations in the lower housing and energy storage modules, the thickness of the thermally conductive agent in the gap between the lower housing and the energy storage modules may become wider.

[0005] The present invention was made in view of the problems described above, and the object of the present invention is to provide a method for manufacturing an energy storage device capable of suppressing the thickness deviation of the thermally conductive agent located in the gap between the lower housing and the energy storage module.

[0006] A method for manufacturing an energy storage device according to the present invention includes: a step of coating a thermally conductive agent on the upper surface of a bottom wall of a lower housing; and a step of pressing an energy storage module onto the thermally conductive agent coated on the upper surface. The overlapping area in the bottom wall that overlaps with the energy storage module includes a deformable portion that deforms downward when protruding upward and being pressed downward. In the step of pressing the energy storage module, the downward deformation of the deformable portion establishes a predetermined thickness of the thermally conductive agent located between the energy storage module and the upper surface.

[0007] Typically, as the thermally conductive agent is crushed by the energy storage module and its thickness decreases, the load applied to the bottom wall of the lower casing increases, leading to greater deformation of the bottom wall. If the deformation of the bottom wall increases, it becomes difficult to further reduce the thickness of the thermally conductive agent.

[0008] As described above, by having a deformable portion that protrudes upwards from the overlapping area that overlaps with the energy storage module, the deformation of the bottom wall increases when the deformable portion is deformed downwards during the pressing process of the energy storage module. Therefore, when the deformable portion is deformed, the thickness of the thermal conductive agent becomes less likely to become thinner, maintaining a predetermined thickness. As a result, deviations in the thickness of the thermal conductive agent located in the gap between the lower housing and the energy storage module can be suppressed.

[0009] In the manufacturing method of the energy storage device based on the present invention described above, the energy storage module may include a plurality of energy storage battery cells arranged in an arrangement direction. The bottom wall may include two ends located at both ends in a direction parallel to the arrangement direction, and a central portion located between the two ends. The deformable portion may have a shape that faces upward from the two ends towards the central portion before the step of pressing the energy storage module is performed.

[0010] According to the above structure, the thermal conductive agent can be expanded from the central part to its surroundings, thus more effectively suppressing the thickness deviation of the thermal conductive agent located in the gap between the lower housing and the energy storage module.

[0011] In the manufacturing method of the energy storage device based on the present invention, the deformed portion can be substantially flat during the process of pressing the energy storage module.

[0012] According to the above structure, the deformed state of the deformation part is roughly flat, which can more effectively suppress the deviation of the thickness of the thermal conductive agent located in the gap between the lower shell and the energy storage module.

[0013] Invention Effects

[0014] According to the present invention, a method for manufacturing an energy storage device is provided that can suppress the thickness deviation of the thermally conductive agent located in the gap between the lower housing and the energy storage module. Attached Figure Description

[0015] Figure 1 This is an exploded perspective view of the energy storage device involved in the implementation method.

[0016] Figure 2 This is a cross-sectional view of the energy storage device involved in the embodiment.

[0017] Figure 3 This is a flowchart illustrating the manufacturing process of the energy storage device involved in the implementation method.

[0018] Figure 4 It means in Figure 3 The diagram shows the process of pressing the battery module in the manufacturing process.

[0019] Figure 5 It means in Figure 3The diagram shows the state after the step of pressing the battery module in the manufacturing process. Detailed Implementation

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in the embodiments shown below, the same or common parts are labeled with the same symbols as in the drawings, and their descriptions will not be repeated.

[0021] Figure 1 This is an exploded perspective view of the energy storage device involved in the implementation method. Figure 2 This is a cross-sectional view of the energy storage device involved in the embodiment, along... Figure 1 The sectional view shown is cut along line II-II. Additionally, in Figure 2 For simplicity, the protective panel 50, described later, is omitted from the illustration and only shown in the diagram. (Reference) Figure 1 and Figure 2 The energy storage device 1 involved in the implementation method will be described.

[0022] The energy storage device 1 involved in the embodiment is mounted on a hybrid vehicle that can travel using the power of at least one of a motor and an engine, or an electric vehicle that travels using driving force obtained from electrical energy.

[0023] like Figure 1 and Figure 2 As shown, the energy storage device 1 involved in the embodiment includes multiple energy storage modules 10, a housing 20, a cooler 30, an outer heat-conducting layer 40, a protective panel 50, a thermally conductive agent 60, and a pressing component 80 (see reference). Figure 2 ).

[0024] Multiple energy storage modules 10 each include multiple energy storage battery cells 12 arranged in an arrangement direction (DR1 direction). When the energy storage device 1 is mounted on a vehicle, the DR1 direction is, for example, approximately parallel to the left-right direction of the vehicle. The multiple energy storage battery cells 12 are connected by a pair of end plates 16 (see reference). Figure 2 The end plates 16 are clamped in the DR1 direction. A pair of end plates 16 are made of a metal material such as aluminum. Spacers (not shown) are arranged between adjacent battery cells 12.

[0025] Multiple energy storage modules 10 are arranged in an intersecting direction DR2 (more specifically, a direction orthogonal to the aforementioned arrangement direction) that intersects the aforementioned DR1 direction. In the aforementioned mounting state, the aforementioned DR2 direction is, for example, substantially parallel to the vehicle's longitudinal direction.

[0026] Multiple energy storage modules 10 are fixed to the bottom wall 22 of the housing 20 by thermal conductive agent 60.

[0027] The housing 20 internally houses multiple energy storage modules 10. The housing 20 includes a lower housing 21 and an upper housing 26.

[0028] The lower housing 21 has a generally box-shaped form with an opening facing upwards. The lower housing 21 is thermally conductive, for example, made of metal. The lower housing 21 has a bottom wall 22, a peripheral wall portion 23, a flange portion 24, and a partition wall 211.

[0029] The bottom wall 22 is located below the plurality of energy storage modules 10. The bottom wall 22 has an upper surface 22a facing the side of the energy storage module 10 and a lower surface 22b facing the side opposite to the side where the energy storage module 10 is located.

[0030] The peripheral wall portion 23 is provided in such a way that it rises from the periphery of the bottom wall 22. The flange portion 24 is provided in such a way that it extends outward from the upper end of the peripheral wall portion 23.

[0031] Multiple partition walls 211 are provided. The partition walls 211 are arranged at predetermined intervals in the DR2 direction. The partition walls 211 separate areas where energy storage modules 10 are arranged at predetermined intervals. In this embodiment, the partition walls 211 separate areas where two energy storage modules 10 are arranged, but this is not a limitation; the position of the partition walls 211 can be appropriately set. Both ends of the partition walls 211 in the DR1 direction can be connected to the peripheral wall portion 23. The partition walls 211 can reinforce the peripheral wall portion 23.

[0032] The upper housing 26 has a generally box-shaped opening facing downwards. The upper housing 26 is made of metal, for example.

[0033] The upper housing 26 has a top portion 27, a peripheral wall portion 28, and a flange portion 29. The top portion 27 forms the upper wall of the housing 20. The peripheral wall portion 28 extends downward from the periphery of the top portion 27. The flange portion 29 extends outward from the lower end of the peripheral wall portion 28.

[0034] Flange 24 and flange 29 are fastened together by multiple fastening components (not shown) while overlapping each other in the vertical direction, thereby housing multiple energy storage modules 10 inside the upper housing 26 and lower housing 21.

[0035] The cooler 30 is a device for cooling multiple energy storage modules 10. The cooler 30 is disposed on the outside of the housing 20. Specifically, the cooler 30 is disposed below the bottom wall 22 of the lower housing 21. An outer heat-conducting layer 40 is disposed between the cooler 30 and the lower surface 22b. The cooler 30 is disposed on the outside of the lower housing 21 in thermal contact with the lower surface 22b.

[0036] The cooler 30 is made of a metal material such as aluminum. The cooler 30 includes multiple main cooling sections 31 and a holding section 32. A refrigerant flow path 31a for cooling the energy storage module 10 is provided inside the multiple main cooling sections 31 and the holding section 32 (see reference). Figure 2 In the main cooling section 31, such as... Figure 2 As indicated by the middle arrow, the refrigerant flows in a direction parallel to the aforementioned arrangement.

[0037] The cooler 30 has a refrigerant inlet 33 and a refrigerant outlet 34. Refrigerant is introduced from the outside into the refrigerant flow path through the refrigerant inlet 33. Refrigerant is discharged from the refrigerant flow path through the refrigerant outlet 34.

[0038] Multiple main cooling units 31 are arranged in a direction parallel to the DR2 direction. Multiple main cooling units 31 extend along the DR1 direction. Multiple main cooling units 31 are respectively disposed at positions opposite to the energy storage module 10 through the bottom wall 22.

[0039] The retaining portion 32 holds a plurality of main cooling portions 31. The retaining portion 32 is provided at least in a manner that holds both ends of the main cooling portions 31 in the DR1 direction. The retaining portion 32 includes, for example, a pair of extensions extending along the DR2 direction at both ends of the main cooling portions 31. Alternatively, the retaining portion 32 may be provided in a frame shape to surround the plurality of main cooling portions 31.

[0040] The outer heat-conducting layer 40 is made of heat-conducting material and is disposed between the bottom wall 22 of the lower housing 21 and the cooler 30. The outer heat-conducting layer 40 has multiple central heat-conducting sections 41 and annular heat-conducting sections 42.

[0041] Multiple central heat-conducting sections 41 are disposed between each main cooling section 31 and the bottom wall 22 of the lower housing 21. The central heat-conducting section 41 has a shape that extends along the DR1 direction.

[0042] The annular heat-conducting part 42 has a shape that surrounds each central heat-conducting part 41. The annular heat-conducting part 42 is disposed between the holding part 32 and the receiving box 20. As a result, water is prevented from entering the space inside the annular heat-conducting part 42.

[0043] The outer thermally conductive layer 40 also functions as an adhesive layer, bonding and fixing the cooler 30 to the bottom wall 22. The outer thermally conductive layer 40 is composed of an adhesive containing silicone resin, acrylic resin, urethane resin, or epoxy resin.

[0044] The protective panel 50 is configured to cover the cooler 30 from below. The protective panel 50 protects the cooler 30 and prevents the cooler 30 from being submerged in water. The protective panel 50 is made of metal.

[0045] A thermally conductive agent 60 is disposed between each energy storage module 10 and the bottom wall 22 (more specifically, the upper surface 22a). The thermally conductive agent 60 also functions as an adhesive layer, bonding and fixing each energy storage module 10 to the bottom wall 22.

[0046] The thermal conductive agent 60 can be, for example, an adhesive containing silicone resin, acrylic resin, urethane resin or epoxy resin.

[0047] The pressing member 80 is a component that presses the energy storage module 10 toward the bottom wall 22. With the energy storage module 10 pressed toward the bottom wall 22 to allow the thermal conductive agent 60 to spread, the pressing member 80 installs the energy storage module 10 into the housing 20. The pressing member 80 has a first pressing part 81 and a second pressing part 82.

[0048] The first pressing part 81 presses one end of the energy storage module 10 in the DR1 direction toward the bottom wall 22. The first pressing part 81 has a bracket 811 and a fastening member 812.

[0049] One end of the bracket 811 is fixed to the flange 24, and the other end of the bracket 811 is fixed to the energy storage module 10. The bracket 811 has a roughly L-shaped design.

[0050] The bracket 811 has a first portion extending along the DR1 direction and a second portion extending along the DR2 direction. The front end of the first portion is fixed to the flange 24. The second portion extends upward from the base end of the first portion located on the side of the energy storage module 10. The second portion is fixed to the end plate 16 located on one side in the DR1 direction by a fastening member 812. The bracket 811 is made of metal.

[0051] The second pressing part 82 presses the other end of the energy storage module 10 in the DR1 direction toward the bottom wall 22. The second pressing part 82 has a bracket 821 and a fastening member 822.

[0052] One end of the bracket 821 is fixed to the flange 24, and the other end of the bracket 821 is fixed to the energy storage module 10. The bracket 821 has a roughly L-shaped design.

[0053] The bracket 821 has a first portion extending along the DR1 direction and a second portion extending along the DR2 direction. The front end of the first portion is fixed to the flange 24. The second portion extends upward from the base end of the first portion located on the side of the energy storage module 10. The second portion is fixed to the end plate 16 located on the other side in the DR1 direction by a fastening member 822. The bracket 821 is made of metal.

[0054] By pressing the energy storage module 10 toward the bottom wall 22 with the first pressing part 81 and the second pressing part 82, the heat-conducting agent 60 disposed between the energy storage module 10 and the bottom wall 22 can be expanded.

[0055] Figure 3 This is a flowchart illustrating the manufacturing process of the energy storage device involved in the implementation method. Figure 4 It means in Figure 3 The diagram shows the process of pressing the battery module in the manufacturing process. Figure 5 It means in Figure 3 The diagram shows the state of the battery module after the pressing step in the manufacturing process. (Reference) Figures 3 to 5 The manufacturing method of the energy storage device 1 according to the embodiment will be described.

[0056] like Figure 3 As shown, the manufacturing method of the energy storage device 1 includes a process of coating a thermally conductive agent (S10) and a process of pressing the energy storage module (S20).

[0057] During the implementation process (S10), as the energy storage module 10, a section with at least an overlapping area R1 (see reference) is prepared. Figure 4 The deformed part 25 (reference) Figure 4 The overlapping region R1 deforms downwards when it protrudes upwards and is pressed downwards. The overlapping region R1 is the area in the bottom wall 22 that overlaps with each energy storage module 10.

[0058] The bottom wall 22 of the energy storage module 10 includes two ends located at both ends in a direction parallel to the DR1 direction, and a central portion located between the two ends. The deformable portion 25, in its state before the pressing of the energy storage module (S20), has, for example, a shape that faces upwards from the two ends of the bottom wall 22 towards the central portion of the bottom wall 22. In a cross-section perpendicular to the DR1 direction, the deformable portion 25 may have a shape formed by the sides of a triangle excluding the base, a shape formed by the sides of a trapezoid excluding the base, or a dome-shaped shape.

[0059] In process (S10), a thermally conductive agent 60 is applied to the upper surface 22a of the bottom wall 22. The thermally conductive agent 60 is applied in strips to each overlapping region R1. For example, the thermally conductive agent 60 is applied along the DR2 direction.

[0060] Next, as Figure 4 As shown, the energy storage module 10 is pressed onto the thermally conductive agent 60 coated on the upper surface 22a of the bottom wall 22. Specifically, with the brackets 811 and 821 fixed to both ends of the energy storage module 10, as... Figure 4 As indicated by the middle arrow AR1, the energy storage module 10 is moved from above the thermal conductive agent 60 downwards. Additionally, the front ends of the brackets 811 and 821 overlap with the flange portion 24 of the lower housing 21 in the vertical direction.

[0061] By pressing the energy storage module 10 onto the thermally conductive agent 60, the pressing pressure is also transmitted through the thermally conductive agent 60 to the bottom wall 22 of the lower housing 21. Thus, as... Figure 4 As shown by the dashed line, the deformable portion 25 deforms downwards. In this case, the deformable portion 25 is preferably substantially flat. That is, the deformable portion 25 is preferably parallel to the DR1 direction.

[0062] like Figure 5 As shown, in the state after process (S10), as described above, through deformation by the deformation section 25, the thickness of the heat-conducting agent 60 located between the energy storage module 10 and the upper surface 22a of the bottom wall 22 becomes a predetermined thickness. Furthermore, the predetermined thickness refers to a value approximately equal to the design target value.

[0063] Furthermore, in the state described above, the front end of the bracket 811 faces the flange 24, and by fixing the front end and the flange, the heat-conducting agent 60 can be maintained at a specified thickness.

[0064] Typically, the thermally conductive agent is thinned by being crushed by the energy storage module. As the thermally conductive agent becomes thinner, the load applied to the bottom wall of the lower casing increases, and the deformation of the bottom wall becomes larger. If the deformation of the bottom wall becomes large, it becomes difficult to further thin the thermally conductive agent.

[0065] In this embodiment, as described above, by having a deformable portion 25 that protrudes upwards from the overlapping area R1 that overlaps with the energy storage module 10, during the step (S20) of pressing the energy storage module 10, the deformation of the bottom wall 22 increases when the deformable portion 25 is deformed downwards. Therefore, when the deformable portion 25 is deformed, the thickness of the thermal conductive agent 60 becomes less likely to become thinner, maintaining a predetermined thickness. As a result, deviations in the thickness of the thermal conductive agent 60 located in the gap between the lower housing 21 and the energy storage module 10 can be suppressed.

[0066] Furthermore, as described above, since the deformable portion 25 has a shape that faces upwards from both ends of the bottom wall 22 in the DR1 direction toward the central portion in its state before deformation, the thermally conductive agent 60 can expand from the central portion to its surroundings in the above-described process (S20). As a result, the thickness deviation of the thermally conductive agent 60 located in the gap between the lower housing 21 and the energy storage module 10 can be more effectively suppressed.

[0067] Furthermore, since the deformable portion 25 is approximately flat in the deformed state, the thickness deviation of the thermal conductive agent 60 located in the gap between the lower housing 21 and the energy storage module 10 can be more effectively suppressed.

[0068] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the invention is defined by the appended claims, including all equivalents and modifications within the scope of the claims.

[0069] Symbol Explanation

[0070] 1-Energy storage device, 10-Energy storage module, 12-Energy storage battery unit, 16-End plate, 20-Housing box, 21-Lower shell, 22-Bottom wall, 22a-Upper surface, 22b-Lower surface, 23-Peripheral wall, 24-Flange, 25-Deformation part, 26-Upper shell, 27-Top, 28-Peripheral wall, 29-Flange, 30-Cooler, 31-Main cooling part, 31a-Refrigerant flow path, 32-Retaining part 33-Refrigerant inlet, 34-Refrigerant outlet, 40-Outer heat-conducting layer, 41-Central heat-conducting part, 42-Annular heat-conducting part, 50-Protective panel, 60-Heat-conducting agent, 80-Pressing component, 81-First pressing part, 82-Second pressing part, 211-Separation wall, 811, 821-Bracket, 812, 822-Fastening component, DR1-Arrangement direction, DR2-Crossing direction, R1-Overlapping area.

Claims

1. A method for manufacturing an energy storage device, characterized in that, The process includes the following steps: The process of applying a thermally conductive agent to the upper surface of the bottom wall of the lower housing; and The process of pressing the energy storage module onto the thermally conductive agent coated on the upper surface, wherein... The overlapping area in the bottom wall that overlaps with the energy storage module includes a deformable portion, which deforms downward when it protrudes upward and is pressed downward. In the process of pressing the energy storage module, the heat-conducting agent located between the energy storage module and the upper surface is set to a specified thickness by deforming the deformable part downward.

2. The method for manufacturing the energy storage device according to claim 1, characterized in that, The energy storage module includes multiple energy storage battery cells arranged in an array direction. The bottom wall includes two ends located at both ends in a direction parallel to the arrangement direction, and a central portion located between the two ends. Before the process of pressing the energy storage module is performed, the deformable part has a shape that faces upwards from the two end sides toward the central part side.

3. The method for manufacturing the energy storage device according to claim 1 or 2, characterized in that, During the process of pressing the energy storage module, the deformed portion becomes substantially flat.

Images