Energy storage device

Abstract

This method suppresses the deterioration of part positioning accuracy while keeping production costs down. [Solution] The energy storage device comprises an energy storage module 14, a lower case 12 housing the energy storage module 14, and a positioning member 30 provided in the gap between the side surface of the energy storage module 14 and the inner wall of the lower case 12, which abuts against the side surface and the inner wall respectively, and restricts the relative movement of the energy storage module 14 within the lower case 12. The positioning member 30 is made of a thermally conductive material that can deform according to the gap.

Description

Technical Field

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[0001] The present disclosure relates to a power storage device.

Background Art

[0002] For example, Japanese Patent No. 4858660 (Patent Document 1) describes an assembly structure of a secondary battery having positioning pins.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the distance between components is narrow or the components are likely to move before fastening, in order to avoid contact between the components after fastening and the generation of abnormal noise caused by the contact, the components may be assembled using positioning pins or a positioning structure may be set. However, when using positioning pins in the production process, processes such as the process of attaching, removing, and reusing the positioning pins are required, so the production cost may increase when fully automating, or the production cost may increase by setting a positioning structure that only aims at positioning.

[0005] The present disclosure has been made to solve the above-described problems, and an object thereof is to provide a power storage device that suppresses deterioration of the positional accuracy of components while suppressing an increase in production cost.

Means for Solving the Problems

[0006] An energy storage device according to one aspect of the present disclosure comprises an energy storage module, a housing for housing the energy storage module, and a positioning member provided in the gap between the side surface of the energy storage module and the inner wall of the housing, which abuts against the side surface and the inner wall respectively and restricts the relative movement of the energy storage module within the housing. The positioning member is made of a thermally conductive material that can deform according to the gap.

[0007] This method allows for the positioning of the energy storage module within the enclosure without the need for positioning pins. Furthermore, since the heat from the energy storage module can be dissipated to the enclosure via the positioning member, the positioning member can be given the function of improving cooling performance in addition to its positioning function. As a result, it is possible to suppress the deterioration of the positional accuracy of the components while keeping production costs down.

[0008] In this embodiment, the positioning member is provided to clamp the energy storage module in a predetermined direction, thereby restricting relative movement in that predetermined direction.

[0009] In this way, the relative movement of the energy storage modules can be restricted, while the heat from the energy storage modules can be dissipated to the housing via the positioning member.

[0010] Furthermore, in this embodiment, the side surface of the energy storage module and the contact surface of the positioning member with the energy storage module are each provided with interlocking protrusions and recesses.

[0011] This allows the energy storage module and the positioning member to be assembled as a single unit into the housing, thereby improving ease of assembly.

[0012] Furthermore, in this embodiment, the housing includes an upper cover and a lower case. The positioning member is configured such that its upper end abuts against the upper cover.

[0013] In this way, the heat from the energy storage module can be dissipated to the housing via the positioning member, not only against the inner wall of the lower case but also against the upper cover.

[0014] Furthermore, in this embodiment, the positioning member further includes a protrusion that contacts the upper surface of the energy storage module.

[0015] In this way, the relative upward movement of the energy storage module can also be restricted by the protruding portion of the positioning member, thereby suppressing the generation of abnormal noises and other issues. [Effects of the Invention]

[0016] According to this disclosure, it is possible to provide an energy storage device that suppresses the deterioration of component positioning accuracy while suppressing increases in production costs. [Brief explanation of the drawing]

[0017] [Figure 1] This figure shows an example of the configuration of the energy storage device according to this embodiment. [Figure 2] This is a cross-sectional view illustrating an example of the positioning of an energy storage module. [Figure 3] This is a cross-sectional view showing an example of the configuration of the energy storage device according to this embodiment. [Figure 4] This is a cross-sectional view showing an example of the configuration of a modified energy storage device. [Figure 5] This is a cross-sectional view showing another example of the configuration of a modified energy storage device. [Modes for carrying out the invention]

[0018] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0019] FIG. 1 is a diagram showing an example of the configuration of the power storage device 10 according to the present embodiment. FIG. 1 shows a view of the power storage device 10 as viewed from above. The power storage device 10 is mounted on an electric vehicle that runs using an electric motor, such as a hybrid vehicle or an electric vehicle, as a drive source. The power storage device 10 has, for example, a rectangular shape and is mounted on the vehicle such that the longitudinal direction of the power storage device 10 coincides with the width direction or the longitudinal direction of the vehicle. The power storage device 10 supplies power to the electric motor of the vehicle or is charged by receiving regenerative power from the electric motor.

[0020] As shown in FIG. 1, the power storage device 10 includes a power storage module 14, a lower case 12, and positioning members 30, 32, 34, 36.

[0021] The power storage module 14 is configured, for example, by arranging a plurality of battery cells in a predetermined direction and connecting them in series. Note that the power storage module 14 may be configured by connecting a plurality of battery cell groups in which two or more battery cells are connected in parallel in series.

[0022] The battery cell is, for example, a secondary battery such as a nickel-hydrogen battery or a lithium-ion battery. The battery cell may have a liquid electrolyte or a solid electrolyte. Further, the battery cell may have a rectangular shape or a cylindrical shape. Further, the power storage device 10 may be configured using one or more capacitors that can be charged and discharged instead of the battery cells.

[0023] The energy storage module 14 is housed within the lower case 12. The enclosure is composed of the lower case 12 and an upper cover (not shown), which will be described later. The energy storage module 14 is installed through an opening that opens upwards in the lower case 12 and is positioned on the bottom surface of the lower case 12. Bolt holes 16 are formed in the energy storage module 14 in the vertical direction (front-to-back direction in Figure 1). The bolt holes 16 may be provided, for example, on the end plate of the energy storage module 14. The energy storage module 14 is fixed to the bottom surface of the lower case 12 by passing bolts through the bolt holes 16 and fastening them to nuts fixed to the bottom surface of the lower case 12. Bolt holes 16 are provided in multiple locations on the energy storage module 14. In Figure 1, an example is shown in which six bolt holes 16, 18, 20, 22, 24, and 26 are formed in the energy storage module 14, and nuts are fixed to the corresponding six locations on the lower case 12. There can be multiple fixing points, and it is not limited to six. The upper cover is provided to close the opening of the lower case 12 to which the energy storage module 14 is fixed.

[0024] In this case, if the distance between the lower case 12 and the energy storage module 14 is narrow, the positional accuracy between the parts may deteriorate, causing the parts to come into contact with each other when vibrations occur in the vehicle, resulting in abnormal noise. Furthermore, if a thermal conductive material made of a silicone-based adhesive or the like is provided between the lower case 12 and the energy storage module 14, positional misalignment may occur between the energy storage module 14 and the lower case 12 between the time the energy storage module 14 is mounted on the lower case 12 and the time it is fastened to the lower case 12. To suppress such deterioration of positional accuracy and misalignment, for example, it is conceivable to assemble the energy storage module 14 to the lower case 12 using positioning pins.

[0025] The following describes an example of positioning the energy storage module 14 relative to the lower case 12 using positioning pins. Figure 2 is a cross-sectional view illustrating an example of positioning the energy storage module 14. Figure 2 shows a cross-section corresponding to the plane AA in Figure 1.

[0026] As shown in Figure 2, a heat conductive material 50 is provided between the bottom surface of the lower case 12 and the energy storage module 14. A cooler 60 is also provided below the lower case 12. The cooler 60 is configured, for example, by circulating a refrigerant, and is configured to exchange heat with the energy storage module 14 via the lower case 12 and the heat conductive material 50.

[0027] The nut 46 is fixed to the base member 13 by welding or the like. The base member 13 is fixed to the bottom surface of the lower case 12 by welding or the like. A positioning pin 48 is attached to the nut 46. The shape of the base member 13 is not limited to the shape shown in Figure 2, as long as the nut 46 can be fastened with a bolt inserted from above when the base member 13 is fixed to the bottom surface of the lower case 12. The nut 46 may also be directly fixed to the lower case 12 by welding or the like.

[0028] The positioning pins 48 may be attached to nuts at positions corresponding to each bolt hole 16, 18, 20, 22, 24, 26, or they may be attached to nuts at at least two positions. After that, the heat conductive material 50 is provided on the bottom surface of the lower case 12. The energy storage module 14 is then attached to the lower case 12 so that the positioning pins 48 are inserted into the bolt holes 16 of the energy storage module 14. After that, the positioning pins 48 are removed and bolts are passed through the bolt holes 16, 18, 20, 22, 24, 26. The energy storage module 14 is fixed to the lower case 12 by fastening the bolts to nuts 46.

[0029] However, using the positioning pins 48 in the production process of the energy storage device 10 may increase production costs when fully automating the process because it requires processes such as installation, removal, and reuse of the positioning pins 48. Alternatively, it is possible to set up a positioning structure in the lower case 12 or energy storage module 14 instead of the positioning pins 48, but setting up a positioning structure solely for the purpose of positioning may also increase production costs.

[0030] Therefore, in this embodiment, a positioning member is provided in the gap between the side surface of the energy storage module 14 and the inner wall of the lower case 12 included in the housing, and contacts each of the side surface of the energy storage module 14 and the inner wall of the lower case 12 to restrict the relative movement of the energy storage module 14 within the housing. The positioning member is made of a thermally conductive material that can deform according to the gap between the side surface of the energy storage module 14 and the inner wall of the housing.

[0031] This method allows for the positioning of the energy storage module 14 within the housing without the need for positioning pins. Furthermore, since the heat from the energy storage module 14 can be dissipated to the housing via the positioning member, the positioning member can be given the function of improving cooling performance in addition to its positioning function. As a result, it is possible to suppress the deterioration of the positional accuracy of the components while keeping production costs down.

[0032] Figure 3 is a cross-sectional view showing an example of the configuration of the energy storage device 10 according to this embodiment. Figure 3 shows a cross-sectional view from plane AA of Figure 1. As shown in Figure 3, the energy storage device 10 according to this embodiment is configured to include the positioning members 30, 32, 34, and 36 shown in Figure 1.

[0033] As shown in Figure 3, the positioning member 30 is provided in the gap between the side surface of the energy storage module 14 and the inner wall of the lower case 12 contained within the housing. The positioning member 30 is formed to fill this gap and abuts against both the side surface of the energy storage module 14 and the inner wall of the lower case 12. The positioning member 30, along with the opposing positioning member 32, restricts the relative movement of the energy storage module 14 within the lower case 12. In this embodiment, the positioning member 30 corresponds to the "first member," and the positioning member 32 corresponds to the "second member." The positioning member 30 is made of a thermally conductive material that can deform according to the gap between the side surface and the inner wall. The material constituting the positioning member 30 may be, for example, a resin material or an elastic material such as rubber. Furthermore, as shown in Figure 1, the positioning member 30 is formed continuously along the side surface of the energy storage module 14 for a predetermined length.

[0034] A thermal conductive material 50 is provided between the energy storage module 14 and the lower case 12. The thermal conductive material 50 is applied, for example, before the energy storage module 14 is attached to the lower case 12. The thermal conductive material 50 is made of, for example, a highly thermally conductive silicone-based adhesive. A cooler 60 is provided below the lower case 12. Heat generated in the energy storage module 14 is exchanged with the energy storage module 14 via the lower case 12 and the thermal conductive material 50. This cools the energy storage module 14.

[0035] Positioning members 32, 34, and 36 are configured in the same way as positioning member 30. Therefore, the energy storage module 14 is positioned so as to be sandwiched in a predetermined first direction (horizontal direction in Figure 1) by positioning members 30 and 32. In other words, positioning members 30 and 32 restrict the relative movement of the energy storage module 14 with respect to the lower case 12 in the first direction. Similarly, the energy storage module 14 is positioned so as to be sandwiched in a predetermined second direction (vertical direction in Figure 1) by positioning members 34 and 36. In other words, positioning members 34 and 36 restrict the relative movement of the energy storage module 14 with respect to the lower case 12 in the second direction.

[0036] Furthermore, as shown in Figure 3, the side surface of the energy storage module 14 and the contact surface of the positioning member 30 with the energy storage module 14 are each provided with fitting recesses and protrusions. More specifically, as shown in Figure 3, a projection 15 is formed on the side surface of the energy storage module 14, projecting toward the inner wall of the lower case 12. Also, a recess 31 is formed on the contact surface of the positioning member 30 with the energy storage module 14, into which the projection 15 can be fitted. The projection 15 on the side surface of the energy storage module 14 is fitted into the recess 31 of the positioning member, allowing the energy storage module 14 and the positioning member 30 to move together as a single unit. Positioning members 32, 34, and 36 are attached to the energy storage module 14 in a similar manner, allowing them to move together as a single unit. The positioning members 30, 32, 34, and 36 are attached to the energy storage module 14 and then housed in the lower case 12. With this configuration, the relative movement of the energy storage module 14 to the lower case 12 is restricted by the positioning members 30, 32, 34, and 36. In this state, bolts 44 are inserted into bolt holes 16, 18, 20, 22, 24, and 26, and fastened with nuts 46, thereby fixing the energy storage module 14 to the lower case 12.

[0037] The operation of the energy storage device 10 having the above configuration will now be explained. The recesses of the positioning members 30, 32, 34, and 36 are fitted into the protruding parts on the sides of the energy storage module 14. As a result, the energy storage module 14 and the positioning members 30, 32, 34, and 36 can move as a single unit. A thermal conductive material 50 is applied to the bottom surface of the lower case 12 in advance. When the energy storage module 14 and the positioning members 30, 32, 34, and 36 are installed through the opening of the lower case 12, the positioning members 30, 32, 34, and 36 come into contact with the side of the energy storage module 14 and the inner wall of the lower case 12, respectively, and the relative movement of the energy storage module 14 with respect to the lower case 12 is restricted. As a result, displacement of the position of the energy storage module 14 after assembly to the lower case 12 is suppressed. In this state, bolts 44 are inserted into bolt holes 16, 18, 20, 22, 24, and 26, and fastened to the corresponding nuts 46, thereby fixing the energy storage module 14 to the lower case 12.

[0038] This configuration eliminates the need for jigs such as positioning pins, thus eliminating the steps of attaching the positioning pins to the nuts 46 and removing the positioning pins from the nuts 46, thereby simplifying the production process.

[0039] Furthermore, for example, heat generated in the energy storage module 14 by exchanging power with the electric motor that drives the vehicle is transferred to the lower case 12 via the heat conductive material 50, and also via the positioning members 30, 32, 34, and 36. The heat transferred to the lower case 12 is dissipated by the cooler 60, thereby cooling the energy storage module 14. In this way, the positioning members 30, 32, 34, and 36 assist in the heat dissipation of the energy storage module 14, thereby improving battery performance.

[0040] As described above, the energy storage device 10 according to this embodiment allows for the positioning of the energy storage module 14 within the lower case 12 included in the housing without the use of positioning pins. Furthermore, since the heat from the energy storage module 14 can be dissipated to the housing via the positioning members 30, 32, 34, and 36, the positioning members 30, 32, 34, and 36 can be given not only a positioning function but also a function to improve cooling performance. By providing the positioning members 30, 32, 34, and 36 with multiple functions in this way, the increase in production costs can be suppressed. Therefore, it is possible to provide an energy storage device that suppresses the deterioration of the positional accuracy of the parts while suppressing the increase in production costs.

[0041] Furthermore, since the positioning members 30, 32, 34, and 36 abut against the side of the energy storage module 14 and the inner wall of the lower case 12, it is possible to suppress noise generation caused by repeated contact and separation of the parts due to vibrations that occur during vehicle operation.

[0042] Since positioning pins are not required, the processes of attaching, removing, and reusing positioning pins are eliminated, thus suppressing increases in production costs.

[0043] Furthermore, since relative movement of the energy storage module 14 within the housing including the lower case is suppressed, even in the event of a collision while the vehicle is in operation, for example, the positioning members 30, 32, 34, and 36 can mitigate the impact and reduce the inertia generated in the energy storage module 14.

[0044] The following describes variations. In the above-described embodiment, the positioning members 30, 32, 34, and 36 were described as being in contact with the lower case 12 as an example, but the configuration is not limited to this. The positioning members 30, 32, 34, and 36 may be configured to be in contact with the upper cover in addition to the lower case 12. Furthermore, a heat conductive material may be provided between the lower part of the positioning members 30, 32, 34, and 36 and the lower case 12.

[0045] Figure 4 is a cross-sectional view showing an example of the configuration of a modified energy storage device 10. Figure 4 shows a diagram corresponding to the cross-section of the energy storage device 10 by plane AA in Figure 1. The energy storage device 10 shown in Figure 4 differs from the energy storage device 10 shown in Figure 3 in that an upper cover 70 is shown, a positioning member 38 is included instead of the positioning member 30, and a heat conductive material 52 is provided in addition to the heat conductive material 50 provided in the lower case 12. The other configurations are the same as those of the energy storage device 10 shown in Figure 3, except as described below, so a detailed explanation will not be repeated.

[0046] As shown in Figure 4, the positioning member 38 differs from the positioning member 30 in that it protrudes above the upper surface of the energy storage module 14 and has a shape that reaches a position where it contacts the upper cover 70. The upper surface of the positioning member 38 is formed to follow the shape of the upper cover 70 over its entire surface. Furthermore, a thermal conductive material 52 is provided below the positioning member 38 between it and the lower case 12. The thermal conductive material 52 is made of a silicone-based adhesive, similar to the thermal conductive material 50.

[0047] Furthermore, the shape of the other positioning members corresponding to positioning members 32, 34, and 36 above the upper surface of the energy storage module 14 is the same as that of positioning member 38, with the entire upper surface in contact with the upper cover 70. Therefore, a detailed explanation will not be repeated. In addition, a heat conductive material similar to the heat conductive material 52 is provided below the other positioning members corresponding to positioning members 32, 34, and 36.

[0048] With this configuration, the energy storage module 14, which has four positioning members including a positioning member 38, is housed in the lower case 12. When the upper cover 70 is attached to close the opening at the top of the lower case 12, the entire upper surfaces of the four positioning members come into contact with the upper cover 70. Furthermore, the lower parts of all four positioning members come into contact with the heat conductive material, including the heat conductive material 52 applied to the lower case 12. As a result, the heat generated in the energy storage module 14 is transferred from the four positioning members to the upper cover 70 and the heat conductive material 52. This increases the heat transfer paths and further improves the cooling performance of the energy storage module 14.

[0049] The positioning member 38 may also be configured to further restrict the relative vertical movement of the energy storage module 14.

[0050] Figure 5 is a cross-sectional view showing another example of the configuration of the modified energy storage device 10. Figure 5 shows a diagram corresponding to the cross-section of the energy storage device 10 by plane AA in Figure 1. The energy storage device 10 shown in Figure 5 differs from the energy storage device 10 shown in Figure 4 in that it includes a positioning member 40 instead of a positioning member 38. The other configurations are the same as those of the energy storage device 10 shown in Figure 4, except as described below, so a detailed explanation will not be repeated.

[0051] As shown in Figure 5, the positioning member 40, compared to the positioning member 38, is provided with a projection 42 that contacts the upper surface of the energy storage module 14 from above. The projection 42 is provided so as to protrude perpendicularly (to the left in the plane of the paper in Figure 5) from the contact surface of the positioning member 40 with the energy storage module 14. The projection 42 may be formed continuously along the upper edge of the energy storage module 14, or multiple projections of predetermined lengths may be provided at predetermined intervals. Furthermore, the projection 42 may be formed to a position that contacts the lower surface of the upper cover 70, as shown by the dashed line in Figure 5. Note that the shape of the other positioning members corresponding to positioning members 32, 34, and 36 above the upper surface of the energy storage module 14 is the same as that of positioning member 40. Therefore, a detailed explanation of them will not be repeated.

[0052] In this way, the four positioning members can restrict the relative movement of the energy storage module 14 with respect to the housing (upper cover 70 and lower case 12) not only in the horizontal direction but also in the vertical direction.

[0053] Furthermore, in the above-described embodiment, the case in which the energy storage module 14 has a rectangular parallelepiped shape was explained as an example, but it is not particularly limited to a rectangular parallelepiped shape. In particular, it is not particularly limited to a solid in which opposing end faces are parallel, and the end faces forming the energy storage module 14 are not particularly limited to flat surfaces, but may be curved surfaces.

[0054] Furthermore, in the above-described embodiment, a configuration in which a protrusion 15 is provided on the energy storage module 14 and a recess 31 is provided on the positioning member 30 was explained as an example. However, it is also possible to provide a recess on the energy storage module 14 and a protrusion that can fit into the recess on the positioning member 30.

[0055] Furthermore, in the above-described embodiment, the positioning member was described as being formed continuously along the side surface of each energy storage module 14 as one example, but it may also be provided at multiple locations (for example, two locations) along the side surface, separated by a predetermined distance.

[0056] Furthermore, in the above-described embodiment, the positioning member was described as being formed from, for example, resin or rubber, but it may also be formed by attaching an insulating member to a metal such as aluminum.

[0057] Furthermore, in the above-described embodiment, the positioning members 30, 32, 34, and 36 were described as being in contact with the lower case 12 and the energy storage module 14 respectively, but a thermal conductive material may be applied to at least one of the spaces between the positioning members 30, 32, 34, and 36 and the lower case 12, or to at least one of the spaces between the positioning members 30, 32, 34, and 36 and the energy storage module 14.

[0058] Furthermore, in the above-described embodiment, a configuration in which the side surface of the energy storage module 14 and the contact surface of the positioning member 30 with the energy storage module 14 are each provided with fitting recesses and protrusions, was described as an example. However, the side surface of the energy storage module 14 may be provided with a plurality of protrusions, and the contact surface of the positioning member 30 with the energy storage module 14 may be provided with a plurality of recesses that can be fitted with the plurality of protrusions. Alternatively, the side surface of the energy storage module 14 may be provided with protrusions and recesses, and the contact surface of the positioning member 30 with the energy storage module 14 may be provided with recesses that can be fitted with the protrusions of the energy storage module 14 and protrusions that can be fitted with the recesses of the energy storage module 14.

[0059] Furthermore, the above-mentioned modifications may be implemented by combining all or part of them as appropriate. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0060] 10 Energy storage device, 12 Lower case, 13 Base member, 14 Energy storage module, 15, 42 Protrusions, 16, 18, 20, 22, 24, 26 Bolt holes, 30, 32, 34, 36, 38, 40 Positioning members, 31 Recess, 44 Bolt, 46 Nut, 48 Positioning pin, 50, 52 Thermal conductive material, 60 Cooler, 70 Upper cover.

Claims

1. Energy storage module and A housing for the aforementioned energy storage module, The system includes a positioning member provided in the gap between the side surface of the energy storage module and the inner wall of the housing, which abuts against the side surface and the inner wall, and which restricts the relative movement of the energy storage module within the housing, The positioning member is made of a thermally conductive material that can deform according to the gap, in this energy storage device.

2. The energy storage device according to claim 1, wherein the positioning member is provided to clamp the energy storage module in a predetermined direction and includes a first member and a second member that restrict the relative movement in the predetermined direction.

3. The energy storage device according to claim 1, wherein the side surface of the energy storage module and the contact surface of the positioning member with the energy storage module are each provided with a fitting recess or protrusion.

4. The aforementioned housing includes an upper cover and a lower case, The energy storage device according to claim 1, wherein the positioning member is configured such that the upper end of the positioning member abuts against the upper cover.

5. The energy storage device according to claim 4, wherein the positioning member further includes a protrusion that abuts against the upper surface of the energy storage module.

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