Energy storage device

Abstract

The present invention provides an energy storage device that can reduce the stress placed on the electronic equipment that monitors the energy storage module. [Solution] The energy storage device comprises a first energy storage module and a second energy storage module, a case housing the first and second energy storage modules, a cross member 20, a mounting member 30 fixed to the cross member 20, and an electronic device 41. The height of the mounting member 30 is greater than the height of the electronic device 41. The electronic device 41 includes a first end 411 fixed to the mounting member 30 and a second end 412 fixed to the cross member 20 in a second direction. The mounting member 30 includes a column portion 31 and an outer end 35 provided adjacent to the column portion so as to be located closer to the first end portion than the column portion 31 in a second direction, to which the first end portion 411 is fixed. The height of the outer end 35 is less than the height of the column portion 31, and a weak portion is provided at the boundary between the outer end 35 and the column portion 31.

Description

Technical Field

[0001] This disclosure relates to a power storage device.

Background Art

[0002] As a conventional power storage device, Japanese Patent No. 6003838 (Patent Document 1) discloses a configuration in which, in a battery module having a plurality of juxtaposed single cells and a restraint for integrating the plurality of single cells, at least one of a battery monitoring ECU for monitoring the state of the plurality of single cells and a switching element unit including a switching element controlled by the battery monitoring ECU is thermally joined to the restraint.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration disclosed in Patent Document 1, when a single cell generates heat and the battery module thermally expands, stress acts on the restraint. In this case, stress is applied to the substrate of the battery monitoring ECU or the substrate of the switching element joined to the restraint. Similarly, when the battery module contracts, stress is also applied to the substrate of the battery monitoring ECU or the substrate of the switching element joined to the restraint. For this reason, there is concern that the battery monitoring ECU or the switching element may not operate normally.

[0005] This disclosure has been made in view of the above problems, and an object of this disclosure is to provide a power storage device capable of reducing stress applied to an electronic device for monitoring a power storage module.

Means for Solving the Problems

[0006] The energy storage device according to this disclosure comprises a first energy storage module and a second energy storage module arranged side by side in a first direction perpendicular to the vertical direction; a case housing the first energy storage module and the second energy storage module; a cross member positioned between the first energy storage module and the second energy storage module within the case and extending in a second direction perpendicular to the vertical direction and the first direction; a mounting member fixed to the upper surface of the cross member; and electronic equipment for monitoring the first energy storage module or the second energy storage module. In the vertical direction, the height of the mounting member is greater than the height of the electronic equipment. The electronic equipment is positioned adjacent to the mounting member in the second direction and includes a first end located on the side of the mounting member in the second direction and a second end located on the opposite side from the side where the mounting member is located in the second direction. The first end is fixed to the mounting member. The second end is fixed to the cross member.

[0007] According to the above configuration, since the electronic equipment is placed on a cross member positioned between the first and second energy storage modules, it is possible to suppress the transmission of stress caused by the expansion or contraction of the first and second energy storage modules to the electronic equipment.

[0008] Furthermore, if stress is applied from the upper side of the case, it can be transmitted to the bottom wall of the case via the mounting member and cross member, which are taller than the electronic equipment. On the other hand, if stress is applied from the lower side of the case, it can be transmitted to the upper wall of the case via the cross member and mounting member. Therefore, even when stress is applied to the case in the vertical direction, the transmission of stress to the electronic equipment can be suppressed.

[0009] Furthermore, since the first end of the electronic device is fixed to the mounting member and the second end of the electronic device is fixed to the cross member, the input acceleration to the electronic device can be suppressed in response to vibration input during vehicle operation.

[0010] In the energy storage device according to the above disclosure, the mounting member may include a column portion located on the first end side of the electronic device in the second direction and having a greater height in the vertical direction than the electronic device, and an outer end portion provided adjacent to the column portion so as to be located on the first end side of the column portion in the second direction and to which the first end portion is fixed. In the vertical direction, the height of the outer end portion may be lower than the height of the column portion. A weak portion may be provided at the boundary between the outer end portion and the column portion.

[0011] According to the above configuration, when stress is applied to the case in the vertical direction, the transmission of stress acting on the column to the outer end can be suppressed by the fracture of the weak point.

[0012] In the energy storage device according to the above disclosure, the mounting member may have a first lower surface portion that constitutes the lower surface of the column portion and a second lower surface portion that constitutes the lower surface of the outer end portion. The first lower surface portion may be provided with an insertion portion that is inserted into the cross member. The outer end portion may be provided with a fixed portion that is fixed to a fastening member provided on the cross member on the first end side and lower side. The first lower surface portion is in contact with the upper surface of the cross member, and the second lower surface portion is provided so as to be separated upward from the upper surface of the cross member.

[0013] According to the above configuration, the second lower surface is positioned spaced apart from the upper surface of the cross member between the fastened portion and the insertion portion, thereby allowing the weak portion to be easily fractured. This prevents the transmission of stress acting on the column portion to the outer end when stress is applied to the case in the vertical direction. [Effects of the Invention]

[0014] According to this disclosure, it is possible to provide an energy storage device that can reduce the stress placed on the electronic equipment that monitors the energy storage module. [Brief explanation of the drawing]

[0015] [Figure 1] It is a diagram showing an exploded perspective view of the power storage device according to the embodiment. [Figure 2] It is a perspective view schematically showing the configuration of the power storage device according to the embodiment. [Figure 3] It is a schematic perspective view showing the fixing structure of an electronic device in the power storage device according to the embodiment. [Figure 4] It is a cross-sectional view taken along the line IV-IV shown in FIG. 3. [Figure 5] It is a diagram showing a state in which the mounting member according to the embodiment is broken.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments shown below, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0017] FIG. 1 is a diagram showing an exploded perspective view of the power storage device according to the embodiment. FIG. 2 is a perspective view schematically showing the configuration of the power storage device according to the embodiment. The power storage device 1 according to the embodiment will be described with reference to FIGS. 1 and 2.

[0018] As shown in FIGS. 1 and 2, the power storage device 1 includes a plurality of power storage modules 10, a plurality of cross members 20, a plurality of mounting members 30, a plurality of electronic devices 41 and 42, and a case 200.

[0019] The plurality of power storage modules 10 are arranged side by side at intervals in a first direction (DR1 direction) orthogonal to the vertical direction. The plurality of power storage modules 10 include, for example, four power storage modules 10, and include a first power storage module 10A, a second power storage module 10B, a third power storage module 10C, and a fourth power storage module 10D. These first power storage module 10A, second power storage module 10B, third power storage module 10C, and fourth power storage module 10D are arranged in order in the first direction.

[0020] Note that the number of the power storage modules 10 is not limited to four, and two or more are acceptable. Also, in the mounted state where the power storage device 1 is mounted on a vehicle, the first direction is parallel to, for example, the longitudinal direction of the vehicle.

[0021] Each power storage module 10 may include a plurality of power storage stacks 100. In the present embodiment, each power storage module 10 includes two power storage stacks 100. Note that the number of the power storage stacks 100 included in the power storage module 10 is not limited to two, and may be a single number or three or more. The plurality of power storage stacks 100 are arranged side by side in the first direction.

[0022] Each power storage stack 100 has a first unit stack 101, a second unit stack 102, and an intermediate plate 103.

[0023] Each of the first unit stack 101 and the second unit stack 102 includes a plurality of power storage cells 110 arranged in the vertical direction and a second direction (DR2 direction) orthogonal to the first direction. The power storage cell 110 is, for example, a secondary battery such as a nickel-hydrogen battery or a lithium-ion battery. The power storage cell 110 has, for example, a rectangular shape. The power storage cell 110 may use a liquid electrolyte or a solid electrolyte.

[0024] The first unit stack 101 is arranged on one side in the second direction. The first unit stack 101 may include an end plate. The end plate is arranged outside the power storage cell 110 arranged most outside on one side in the second direction.

[0025] The second unit stack 102 is arranged on the other side in the second direction. In the present embodiment, the number of the power storage cells 110 included in the second unit stack 102 is the same as the number of the power storage cells 110 included in the first unit stack 101, but may be different. The second unit stack 102 may include an end plate arranged outside the power storage cell 110 on the other side in the second direction.

[0026] The intermediate plate 103 is positioned between the first unit stack 101 and the second unit stack 102. The intermediate plate 103 is located in the center of the energy storage stack 100 in the second direction. The intermediate plate 103 is made of synthetic resin or the like.

[0027] The case 200 houses multiple energy storage modules 10, multiple cross members 20, multiple mounting members 30, and multiple electronic devices 41, 42. The case 200 has a lower case 210 and an upper case 220. Note that the upper case 220 is omitted in Figure 2 for convenience.

[0028] The lower case 210 has a roughly box-shaped form that opens upwards. The lower case 210 is made of metal, synthetic resin, or the like. The lower case 210 has a bottom wall 212, a lower side peripheral wall portion 214, and a lower side flange 216.

[0029] The bottom wall 212 is located below the multiple energy storage modules 10. Below the bottom wall 212, a cooler (not shown) may be provided to cool the energy storage stack 100 via the bottom wall 212. In this case, a heat conductive member may be provided between the cooler and the bottom wall 212, or between each energy storage stack 100 and the bottom wall 212. As the heat conductive member, for example, an adhesive containing a silicone resin, acrylic resin, or epoxy resin, and grease can be used.

[0030] The lower peripheral wall portion 214 rises from the periphery of the bottom wall 212 and surrounds the lower part of the multiple energy storage modules 10. The lower flange 216 has a shape that protrudes outward from the upper end of the lower peripheral wall portion 214.

[0031] The upper case 220 has a roughly box-like shape that opens downwards. The upper case 220, together with the lower case 210, houses a plurality of energy storage modules 10. The upper case 220 is made of metal or synthetic resin, etc. The upper case 220 has a top wall 222, an upper side peripheral wall portion 224, and an upper side flange 226.

[0032] The top wall 222 is positioned above the multiple energy storage stacks 100. The top wall 222 faces the bottom wall 212 in the vertical direction. The top wall 222 may be formed in a flat plate shape. A gap is formed between the top wall 222 and each energy storage module 10.

[0033] The upper peripheral wall portion 224 extends downward from the periphery of the top wall 222 and surrounds the upper periphery of multiple energy storage modules 10. The upper peripheral wall portion 224, together with the lower peripheral wall portion 214, constitutes the peripheral wall of the case 200. The lower peripheral wall portion 214 and the upper peripheral wall portion 224 connect the periphery of the bottom wall 212 and the periphery of the top wall 222, and surround the periphery of multiple energy storage stacks 100.

[0034] The upper flange 226 has a shape that protrudes outward from the lower end of the upper peripheral wall portion 224. The upper flange 226 is fixed to the lower flange 216 by bolts or the like.

[0035] Each of the multiple cross members 20 is positioned in the gaps between adjacent energy storage modules 10 in the first direction. Specifically, a cross member 20 is positioned in the gap between the first energy storage module 10A and the second energy storage module 10B, the gap between the second energy storage module 10B and the third energy storage module 10C, and the gap between the third energy storage module 10C and the fourth energy storage module 10D.

[0036] The cross member 20 is fixed to the bottom wall 212. The bottom wall 212 extends along a second direction. Both ends of the cross member 20 may be connected to the lower side peripheral wall portion 214. The cross section of the cross member 20 perpendicular to the second direction is formed in a shape that is convex upward. Specifically, the cross member 20 includes, for example, an upper wall portion that constitutes the upper surface 20a, and a pair of vertical wall portions that extend downward from both sides of the upper wall portion in the first direction. A space may be provided between the upper wall portion and the bottom wall 212. The upper surface 20a is formed to be substantially flat.

[0037] The mounting member 30 is fixed to the upper surface 20a (see Figure 3) of the cross member 20. The mounting member 30 has a first column portion 31, a second column portion 32, a connecting portion 33, a first outer end portion 35, and a second outer end portion 36.

[0038] The first column portion 31 and the second column portion 32 are located on the cross member 20, separated in a second direction. The first column portion 31 is located on one side of the second column portion 32 in the second direction. The upper ends of the first column portion 31 and the upper ends of the second column portion 32 may be in contact with the top wall 222 or may be spaced apart from the top wall 222.

[0039] The heights of the first column section 31 and the second column section 32 in the vertical direction are greater than the heights of the connecting section 33, the first outer end section 35, and the second outer end section 36. Also, the heights of the first column section 31 and the second column section 32 in the vertical direction are greater than the heights of the electronic equipment 41 and 42. As a result, the first column section 31 and the second column section 32 transmit the load applied downward to the top wall 222 to the cross member 20. Similarly, the first column section 31 and the second column section 32 transmit the load applied upward to the bottom wall 212 from the cross member 20 to the top wall 222.

[0040] The connecting portion 33 connects the first column portion 31 and the second column portion 32. The connecting portion 33 extends along the second direction.

[0041] The first outer end portion 35 constitutes the end portion of the mounting member 30 on one side in the second direction. The first outer end portion 35 is positioned in the second direction toward the first end portion 411 of the electronic device 41 than the first column portion 31. As will be described later, the first end portion 411 of the electronic device 41 is fixed to the first outer end portion 35.

[0042] The first outer end portion 35 is provided adjacent to the first column portion 31. A first weak point 37 is provided at the boundary between the first outer end portion 35 and the first column portion 31.

[0043] The second outer end portion 36 constitutes the end portion of the mounting member 30 on the other side in the second direction. The second outer end portion 36 is positioned on the side of the first end portion 421 of the electronic device 42 that is closer to the second column portion 32 in the second direction. As will be described later, the first end portion 421 of the electronic device 42 is fixed to the second outer end portion 36.

[0044] The second outer end portion 36 is provided adjacent to the second column portion 32. A second weak portion 38 is provided at the boundary between the second outer end portion 36 and the second column portion 32.

[0045] The electronic device 41 is located on one side of the mounting member 30 in the second direction. The electronic device 41 is positioned adjacent to the mounting member 30 in the second direction. The electronic device 41 is positioned on the mounting member 30.

[0046] The electronic device 41 has a first end 411 and a second end 412 in the second direction. The first end 411 is located on the side of the mounting member 30 in the second direction. The second end 412 is located on the side opposite to the side where the mounting member 30 is located in the second direction.

[0047] The electronic device 41 is a monitoring unit that monitors the energy storage modules 10. The electronic device 41 monitors at least one of the adjacent energy storage modules 10. Specifically, for example, the electronic device 41 located between the first energy storage module 10A and the second energy storage module 10B monitors at least one of them.

[0048] The electronic device 42 is located on one side of the mounting member 30 in the second direction. The electronic device 42 is positioned adjacent to the mounting member 30 in the second direction. The electronic device 42 is positioned on the mounting member 30.

[0049] The electronic device 42 has a first end 421 and a second end 422 in the second direction. The first end 421 is located on the side of the mounting member 30 in the second direction. The second end 422 is located on the side opposite to the side where the mounting member 30 is located in the second direction.

[0050] Electronic device 42 is a monitoring unit that monitors a different energy storage module 10 from electronic device 41. For example, if electronic device 42 is located between the first energy storage module 10A and the second energy storage module 10B, then electronic device 42 will monitor the second energy storage module 10B when electronic device 41 is monitoring the first energy storage module 10A.

[0051] Figure 3 is a schematic perspective view showing the fixing structure of the electronic equipment in the energy storage device according to the embodiment. The fixing structure of the electronic equipment 41 will be described with reference to Figure 3.

[0052] As shown in Figure 3, the first end 411 of the electronic device 41 is fixed to the mounting member 30, and the second end 412 of the electronic device 41 is fixed to the cross member 20.

[0053] Specifically, the first end 411 of the electronic device 41 is fixed to the first outer end 35 by an inner connecting member 51. The inner connecting member 51 has a shape that extends from the first end 411 toward the mounting member 30. The end of the inner connecting member 51 located on the mounting member 30 side is fixed to a bolt 71 that protrudes from the upper surface of the first outer end 35. The end of the inner connecting member 51 located on the electronic device 41 side is fixed toward the first end 411 side.

[0054] The second end 412 of the electronic device 41 is fixed to the upper surface 20a of the cross member 20 by an outer connecting member 52 on one side in the second direction from the second end 412. The outer connecting member 52 has a shape that extends from the second end 412 toward one side in the second direction. The end of the outer connecting member 52 located on the electronic device 41 side is fixed to the second end 412 side. The end of the outer connecting member 52 located on one side in the second direction is fixed to a bolt 72 that protrudes upward from the upper surface 20a of the cross member 20.

[0055] The electronic device 42 is fixed in the same way as the electronic device 41. Specifically, the first end 421 of the electronic device 42 is fixed to the second outer end 36 of the mounting member 30 by an inner connecting member (not shown). The second end 422 of the electronic device 42 is fixed to the upper surface 20a of the cross member 20 on the other side in the second direction from the second end 422 by an outer connecting member (not shown).

[0056] As described above, since the electronic devices 41 and 42 are installed on a cross member 20 positioned between adjacent energy storage modules 10, it is possible to suppress the transmission of stress caused by expansion or contraction of the energy storage modules 10 to the electronic devices 41 and 42.

[0057] Furthermore, when stress is applied to the case 200 in the vertical direction, since the height of the electronic devices 41 and 42 is set lower than the height of the mounting member 30, stress can be transmitted from the top wall 222 to the bottom wall 212, or from the bottom wall 212 to the top wall 222, via the cross member 20 and the mounting member 30. This suppresses the transmission of stress to the electronic devices 41 and 42.

[0058] Furthermore, as described above, in each of the electronic devices 41 and 42, one end of the electronic device 41 or 42 is fixed to the mounting member 30, and the other end is fixed to the cross member 20, thereby suppressing the input acceleration to the electronic devices 41 and 42 in response to vibration input during vehicle operation.

[0059] In addition, even in situations where it is difficult to fix the ends (first ends) of the electronic devices 41 and 42 located on the mounting member 30 side to the cross member 20, the electronic devices 41 and 42 can be stably fixed by fixing the first ends to the mounting member 30.

[0060] Furthermore, the first outer end portion 35 is provided with a fixed portion 351 on the side of the first end portion 411 (one side in the first direction) and on the lower side. The fixed portion 351 is fixed to a bolt 73, which is a fastening member provided on the cross member 20.

[0061] Similarly, the second outer end 36 is provided with a fixing portion on the side of the first end 421 (the other side in the first direction) and on the lower side. The flying boat portion is fixed to bolts, which are fastening members, provided on the cross member 20.

[0062] Figure 4 is a cross-sectional view along the line IV-IV shown in Figure 3. As shown in Figure 4, the mounting member 30 has a first lower surface portion 31b that constitutes the lower surface of the first column portion 31 and a second lower surface portion 35b that constitutes the lower surface of the first outer end portion 35. The first lower surface portion 31b is provided with an insertion portion 31c that protrudes downward. The insertion portion 31c is inserted into the upper surface 20a of the cross member 20. On the second column portion 32 side, an insertion portion is also provided on the lower surface of the second column portion 32, and this insertion portion is inserted into the upper surface 20a. The first lower surface portion 31b is in contact with the upper surface 20a.

[0063] The second lower surface portion 35b is provided so as to move upward away from the upper surface 20a of the cross member 20. Specifically, the second lower surface portion 35b is inclined upward as it moves away from the first column portion 31 in the second direction. The lower surface 351a of the fixed portion 351 is substantially parallel to the upper surface 20a. Similarly, on the second outer end portion 36 side, the lower surface portion (third lower surface portion) of the second outer end portion 36 is inclined upward as it moves away from the second column portion 32.

[0064] The second lower surface portion 35b and the third lower surface portion may be provided so as to create a step between them and the first lower surface portion 31b. In this case, the second lower surface portion 35b and the third lower surface portion may be provided substantially parallel to the upper surface 20a.

[0065] Figure 5 shows the fracture of the mounting member according to the embodiment. As described above, a first weak point 37 is provided at the boundary between the first column portion 31 and the first outer end portion 35. The first weak point 37 is formed by a notch, such as a cutout or notch.

[0066] As shown in Figure 5, the first weak point 37 is provided to break when a predetermined load is applied to the mounting member 30. When a large stress is applied to the case 200 due to a vehicle collision or the like, and the mounting member 30 absorbs the stress, the first weak point 37 breaks, preventing the stress from being transmitted from the mounting member 30 to the electronic equipment 41. Similarly, the second weak point 38 breaks, preventing the stress from being transmitted from the mounting member 30 to the electronic equipment 42. As a result, damage to the electronic equipment 41 and 42 can be suppressed.

[0067] Furthermore, as described above, since the second lower portion 35b and the third lower portion are provided so as to be separated upward from the upper surface 20a, the first weak portion 37 and the second weak portion 38 can be easily fractured when stress is applied to the mounting member 30.

[0068] (Other variations) In the above description, the first ends of the electronic devices 41 and 42 were explained as examples of being indirectly fixed to the mounting member 30 via an internal connecting member. However, the internal connecting member may be omitted, and the first ends may be directly fixed to the mounting member 30.

[0069] In the above description, the case in which the second ends of the electronic devices 41 and 42 are fixed to the cross member 20 via an external connecting member was illustrated as an example, but the external connecting member may be omitted, and the second ends may be directly fixed to the cross member 20.

[0070] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and all modifications are within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0071] 1 Energy storage device, 10 Energy storage module, 10A First energy storage module, 10B Second energy storage module, 10C Third energy storage module, 10D Fourth energy storage module, 20 Cross member, 20a Top surface, 30 Mounting member, 31 First column section, 31b First bottom surface section, 31c Insertion section, 32 Second column section, 33 Connecting section, 35 First outer end section, 35b Second bottom surface section, 36 Second outer end section, 37 First vulnerable section, 38 Second vulnerable section, 41,42 Electronic equipment, 51 Inner connecting member, 52 Outer connecting member, 71,72,73 Bolts, 100 Energy storage stack, 101 First unit stack, 102 Second unit stack, 103 Intermediate plate, 110 Energy storage cell, 200 Case, 210 Lower case, 212 Bottom wall, 212a Raised section, 214 Lower side peripheral wall portion, 216 Lower side flange, 220 Upper case, 222 Top wall, 224 Upper side peripheral wall portion, 226 Upper side flange, 351 Fixed portion, 351a Bottom surface, 411, 421 First end portion, 412, 422 Second end portion.

Claims

1. A first energy storage module and a second energy storage module are arranged side by side in a first direction perpendicular to the vertical direction, A case housing the first energy storage module and the second energy storage module, Displaced within the case between the first energy storage module and the second energy storage module, a cross member extending in a second direction perpendicular to the vertical direction and the first direction, A mounting member fixed to the upper surface of the cross member, The system comprises electronic equipment for monitoring the first energy storage module or the second energy storage module, In the vertical direction, the height of the mounting member is greater than the height of the electronic device. The electronic device is arranged adjacent to the mounting member in the second direction and includes a first end located on the side of the mounting member in the second direction and a second end located on the opposite side from the side where the mounting member is located in the second direction. The first end is fixed to the mounting member, The second end is fixed to the cross member, The mounting member includes a column portion located on the first end side of the electronic device in the second direction and having a greater vertical height than the electronic device, and an outer end portion provided adjacent to the column portion so as to be located on the first end side of the column portion in the second direction and to which the first end is fixed. In the aforementioned vertical direction, the height of the outer end is lower than the height of the column portion. A power storage device in which a weak portion is provided at the boundary between the outer end and the column portion.

2. The mounting member has a first lower surface portion that constitutes the lower surface of the column portion and a second lower surface portion that constitutes the lower surface of the outer end portion. The first lower portion is provided with an insertion portion that is inserted into the cross member, The outer end is provided with a fixed portion which is fixed to a fastening member provided on the cross member on the first end side and lower side. The first lower portion is in contact with the upper surface of the cross member, The energy storage device according to claim 1, wherein the second lower portion is provided so as to be separated upward from the upper surface of the cross member.

Images