Power storage device

Abstract

A power storage device comprises: a first power storage module and a second power storage module; a housing that accommodates the first and second power storage modules; a crossbar; a mounting element attached to the upper surface of the crossbar; and an electronic device. The height of the mounting element in the vertical direction is greater than the height of the electronic device. The electronic device is positioned adjacent to the mounting element in the horizontal direction and comprises a first end section located on the side of the mounting element in the horizontal direction and a second end section located on the side opposite the mounting element in the horizontal direction. The first end section is attached to the mounting element. The second end section is attached to the crossbar.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a power storage device.2. Description of the Prior ArtAs a conventional power storage device, Japanese Patent JP 6 003 838 B discloses a battery module having a plurality of unit cells arranged side by side and a holder that integrates the plurality of unit cells. The battery module has a configuration in which at least one of the following elements is thermally connected to the bracket: a battery monitoring electronic control unit (ECU) that monitors the state of the plurality of unit cells; or a switching element unit including a switching element controlled by the battery monitoring ECU.SUMMARY OF THE INVENTIONHowever, in the configuration disclosed in JP 6 003 838 B, when a unit cell generates heat and the battery module thermally expands, a (mechanical) stress acts on the bracket. In this case, the voltage acts on the substrate of the battery monitoring ECU or the substrate of the switching element connected to the holder. When the battery module contracts, a (mechanical) stress also acts on the substrate of the battery monitoring ECU or on the substrate of the switching element connected to the holder. This may result in the battery monitoring ECU or the switching element not functioning properly.The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a power storage device capable of alleviating the (mechanical) stress applied to an electronic device that monitors a power storage module.A power storage device according to the present invention includes: a first power storage module and a second power storage module that are arranged side by side in a first direction orthogonal to a height direction and an up-down direction, respectively; a housing that accommodates the first power storage module and the second power storage module; a cross bar that is disposed between the first power storage module and the second power storage module in the housing and extends in the height direction and a second direction perpendicular to the first direction; a fixing member that is fixed to an upper surface of the cross bar; and an electronic device that monitors the first power storage module or the second power storage module. The height of the fixing member in the height direction is greater than the height of the electronic device. The electronic device is disposed adjacent to the fastener in the second direction, and includes a first end portion disposed on the side of the fastener in the second direction and a second end portion disposed on the side opposite to the side on which the fastener is disposed in the second direction. The first end portion is fixed to the fixing member. The second end portion is fixed to the cross strut.According to the above configuration, the electronic device is installed on the cross member disposed between the first power storage module and the second power storage module. Therefore, the transmission of a (mechanical) stress caused by the expansion or contraction of the first power storage module and the second power storage module to the electronic device can be reduced.When the stress is introduced from the top of the housing, the stress can be transmitted to the lower wall portion of the housing through the cross member and the fixing member having a height larger than that of the electronic device. On the other hand, the stress when applied from the lower side of the housing can be transmitted to the upper wall portion of the housing through the cross member and the fastening member. Therefore, even when the housing is strained in the up-down direction, the transmission of the stress to the electronic device can be reduced.In addition, since the first end portion of the electronic device is fixed to the fixing member and the second end portion of the electronic device is fixed to the cross member, the input acceleration to the electronic device in response to vibration influences during vehicle travel can be reduced.In the power storage device of the present invention, the fixing member may include: a pillar portion disposed on the first end portion side of the electronic device in the second direction, the height of the pillar portion in the height direction being greater than that of the electronic device; and an outer end portion disposed adjacent to the pillar portion so as to be disposed closer to the first end portion side than the pillar portion in the second direction, the first end portion being fixed to the outer end portion. The height of the outer end portion may be lower than the height of the pillar portion in the height direction. A fragile portion may be disposed at the boundary portion between the outer end portion and the pillar portion.According to the above configuration, when the stress in the height direction is introduced into the housing, the transmission of the stress acting on the pillar portion to the outer end portion can be reduced by the fragile portion being broken.In the power storage device of the present invention, the fixing member may include a first lower surface portion forming a lower surface of the pillar portion and a second lower surface portion forming a lower surface of the outer end portion. The first lower surface portion may be provided with an insertion portion that is insertable into the cross member. The outer end portion may be provided with a fixed portion fixed to a fixing member disposed on the cross member on the first end portion side and on a 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 disposed to be spaced upward from the upper surface of the cross member.According to the above configuration, the second lower surface portion is spaced apart from the upper surface of the cross member between the fixed portion and the insertion portion, whereby the fragile portion can be easily broken. Therefore, when the stress in the height direction is applied to the housing, the transmission of the stress acting on the pillar portion to the outer end portion can be reduced.According to the present invention, it is possible to provide a power storage device capable of reducing the load applied to an electronic device that monitors a power storage module.BRIEF DESCRIPTION OF THE DRAWINGSThe features and advantages, and technical and economic significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like reference numerals designate like elements, and wherein: FIG. 1 is an exploded perspective view of a power storage device of an embodiment; FIG. 2 is a perspective view schematically showing the configuration of the power storage device of the embodiment; FIG. 3 is a schematic perspective view showing a mounting structure of an electronic device in the power storage device of the embodiment; FIG. 4 is a cross-sectional view taken along line IV--IV shown in FIG. 3; and FIG. 5 is a view showing a broken state of a fastener of the embodiment.DETAILED DESCRIPTION OF EMBODIMENTSHereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiment, identical or common parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.FIG. 1 is an exploded perspective view of a power storage device of the embodiment. FIG. 2 is a perspective view schematically showing the configuration of the power storage device of the embodiment. A power storage device 1 of the embodiment will be described with reference to FIGS. 1 and 2.As illustrated 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 fasteners 30, a plurality of electronic devices 41, 42, and a housing 200.The plurality of power storage modules 10 are arranged side by side at intervals in a first direction (direction DR 1) orthogonal to the height direction, up-down direction, or up-down direction. The plurality of power storage modules 10 includes, for example, four power storage modules 10, and includes 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. The first power storage module 10A, the second power storage module 10B, the third power storage module 10C, and the fourth power storage module 10D are arranged side by side in the first direction.Note that the number of the power storage modules 10 is not limited to four, and only needs to be two or more. In a mounted state in which the power storage device 1 is mounted on a vehicle, the first direction is, for example, parallel to the front-rear direction of the vehicle.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 power storage stacks 100 included in the power storage module 10 is not limited to two, and may be either one or three or more. The plurality of power storage stacks 100 are arranged side by side in the first direction.Each power storage stack 100 includes a first unit stack 101, a second unit stack 102, and an intermediate plate 103.Each of the first unit stack 101 and the second unit stack 102 includes a plurality of power storage cells 110 arranged in a second direction (direction DR 2) orthogonal to the height direction and the first direction. The power storage cell 110 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The power storage cell 110 has, for example, a square shape. The power storage cell 110 may use a liquid electrolyte or a solid electrolyte.The first unit stack 101 is disposed on one side in the second direction. The first unit stack 101 may include an end plate. The end plate is disposed outside the power storage cell 110 disposed on a side outermost in the second direction.The second unit stack 102 is disposed on the other side in the second direction. In the present embodiment, the number of power storage cells 110 included in the second unit stack 102 is the same as the number of 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 disposed outside the power storage cell 110 on the other side in the second direction.The intermediate plate 103 is disposed between the first unit stack 101 and the second unit stack 102. The intermediate plate 103 is disposed at the center of the power storage stack 100 in the second direction. The intermediate plate 103 is made of synthetic resin or the like.The housing 200 houses the plurality of power storage modules 10, the plurality of cross members 20, the plurality of fasteners 30, and the plurality of electronic devices 41, 42. In FIG. 2, the upper case 220 is omitted for simplicity.The lower case 210 is substantially in the form of a box that opens upward. The lower case 210 is made of metal, synthetic resin, or the like. The lower housing 210 includes a bottom wall 212, a lower peripheral wall portion 214, and a lower flange 216.The bottom wall 212 is disposed below the plurality of power storage modules 10. Below the bottom wall 212, a cooler (not shown) may be provided for cooling the power storage stack 100 by the bottom wall 212. In this case, a thermal conductive element may be provided between the radiator and the bottom wall 212, or a thermal conductive element may be provided between each power storage stack 100 and the bottom wall 212. As the heat conducting member, for example, an adhesive containing a silicone resin, an acrylic resin, an epoxy resin, or the like and grease can be used.The lower peripheral wall portion 214 rises from the peripheral edge of the bottom wall 212 and surrounds the lower portions of the plurality of power storage modules 10.The upper case 220 is substantially in the form of a box that opens downward. The upper case 220 houses the plurality of power storage modules 10 together with the lower case 210. the upper case 220 is made of metal, synthetic resin, or the like. The upper housing 220 includes an upper wall 222, an upper peripheral wall portion 224, and an upper flange 226.The top wall 222 is disposed above the plurality of power storage stacks 100. The upper wall 222 faces the lower wall 212 in the height direction. The top wall 222 may be formed in a flat plate shape. Between the top wall 222 and each power storage module 10, a gap is formed.The upper peripheral wall portion 224 extends downward from the peripheral edge portion of the upper wall 222 and surrounds the upper portions of the plurality of power storage modules 10. The lower peripheral wall portion 214 and the upper peripheral wall portion 224 connect the peripheral edge portion of the lower wall 212 to the peripheral edge portion of the upper wall 222 and surround the periphery of the plurality of power storage stacks 100.The upper flange 226 has a shape protruding outward from the lower end portion of the upper peripheral wall portion 224. The upper flange 226 is fixed to the lower flange 216 with bolts or the like.The plurality of cross members 20 are arranged side by side in the first direction in the respective gaps between the power storage modules 10. Specifically, the cross member 20 is disposed in the gap between the first power storage module 10A and the second power storage module 10B. The cross member 20 is disposed in the gap between the second power storage module 10B and the third power storage module 10C. The cross member 20 is disposed in the gap between the third power storage module 10C and the fourth power storage module 10D.The cross strut 20 is attached to the bottom wall 212. The bottom wall 212 extends in the second direction. Both ends of the cross member 20 may be connected to the lower peripheral wall portion 214. The cross section of the cross member 20 orthogonal to the second direction is formed in an upwardly convex shape. Specifically, for example, the cross member 20 includes an upper wall portion forming an upper surface 20 aand a pair of vertical wall portions extending 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 lower wall 212. The upper surface 20a is formed substantially flat.The fastening member 30 is fastened to the upper surface 20 a(see FIG. 3 ) of the cross member 20. The fastening element 30 comprises 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.The first pillar portion 31 and the second pillar portion 32 are spaced apart on the cross member 20 in the second direction. The first pillar portion 31 is disposed closer to a side in the second direction than the second pillar portion 32.The heights of the first pillar portion 31 and the second pillar portion 32 in the height direction are greater than the respective heights of the connection portion 33, the first outer end portion 35, and the second outer end portion 36. The heights of the first pillar portion 31 and the second pillar portion 32 in the height direction are greater than the heights of the electronic devices 41, 42. As a result, the first pillar portion 31 and the second pillar portion 32 transmit a load inputted downward to the upper wall 222 to the cross member 20.The connecting portion 33 connects the first pillar portion 31 and the second pillar portion 32.The first outer end portion 35 forms the end portion of the fastening member 30 on a side in the second direction. The first outer end portion 35 is disposed to be closer to a first end portion 411 of the electronic device 41 than the first pillar portion 31 in the second direction. As described later, the first end portion 411 of the electronic device 41 is fixed to the first outer end portion 35.The first outer end portion 35 is disposed adjacent to the first pillar portion 31. A first fragile portion 37 is disposed at the boundary portion between the first outer end portion 35 and the first pillar portion 31.The second outer end portion 36 forms the end portion of the fastening member 30 on the other side in the second direction. The second outer end portion 36 is disposed to be closer to a first end portion 421 of the electronic device 42 than the second pillar 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.The second outer end portion 36 is disposed adjacent to the second pillar portion 32. A second fragile portion 38 is disposed at the boundary portion between the second outer end portion 36 and the second pillar portion 32.The electronic device 41 is disposed closer to one side in the second direction than the fixing member 30. the electronic device 41 is disposed next to the fixing member 30 in the second direction. The electronic device 41 is disposed on the fixing member 30.The electronic device 41 includes the first end portion 411 and a second end portion 412 in a second direction. The first end portion 411 is disposed on the side of the fastening member 30 in the second direction. The second end portion 412 is disposed on the side opposite to the side on which the fastening member 30 is disposed in the second direction.The electronic device 41 is a monitoring unit that monitors the power storage module 10. The electronic device 41 monitors at least one of the power storage modules 10 arranged side by side. More specifically, the electronic device 41 arranged between, for example, the first power storage module 10A and the second power storage module 10B monitors at least one of these power storage modules.The electronic device 42 is disposed closer to one side in the second direction than the fixing member 30. the electronic device 42 is disposed next to the fixing member 30 in the second direction. The electronic device 42 is disposed on the fastening member 30.The electronic device 42 includes the first end portion 421 and a second end portion 422 in the second direction. The first end portion 421 is disposed on the side of the fixing member 30 in the second direction. The second end portion 422 is disposed on the side opposite to the side on which the fastening member 30 is disposed in the second direction.The electronic device 42 is a monitoring unit that monitors a power storage module 10 other than the electronic device 41. For example, the electronic device 42 disposed between the first power storage module 10A and the second power storage module 10B monitors the second power storage module 10B when the electronic device 41 monitors the first power storage module 10A.FIG. 3 is a schematic perspective view showing the mounting structure of the electronic device in the power storage device of the embodiment. The mounting structure of the electronic device 41 will be described with reference to FIG. 3.As illustrated in FIG. 3, the first end portion 411 of the electronic device 41 is fixed to the fixing member 30, and the second end portion 412 of the electronic device 41 is fixed to the cross member 20.Specifically, the first end portion 411 of the electronic device 41 is fixed to the first outer end portion 35 by an inner connection member 51. The inner connecting member 51 has a shape extending from the first end portion 411 toward the fastening member 30. The end portion of the inner link member 51 located on the side of the fastening member 30 is fastened to a bolt 71 that protrudes from the upper surface of the first outer end portion 35. The end portion of the inner connection member 51 located on the electronic device 41 side is fixed to the first end portion 411.The second end portion 412 of the electronic device 41 is fixed to the upper surface 20 aof the cross member 20 by an outer link member 52 disposed closer to a side in the second direction than the second end portion 412. The outer link member 52 has a shape extending from the second end portion 412 to one side in the second direction. The end portion of the outer connection member 52 located on the electronic device 41 side is fixed to the second end portion 412. The end portion of the outer link member 52 located on one side in the second direction is fastened to a bolt 72 that protrudes upward from the upper surface 20 aof the cross member 20.The electronic device 42 is fixed in the same manner as the electronic device 41. Specifically, the first end portion 421 of the electronic device 42 is fixed to the second outer end portion 36 of the fixing member 30 by an inner connection member (not shown). The second end portion 422 of the electronic device 42 is fixed to the upper surface 20 aof the cross member 20 by an outer connecting member (not illustrated) disposed closer to the other side in the second direction than the second end portion 422.As described above, the electronic devices 41, 42 are installed on the cross member 20 that is juxtaposed between the power storage modules 10. Therefore, when the power storage module 10 expands or contracts, the transmission of the stress caused by the expansion or contraction to the electronic devices 41, 42 can be reduced.The electronic devices 41, 42 have a height lower than the height of the fixing member 30, and therefore, when the housing 200 is loaded in the height direction, the load by the cross member 20 and the fixing member 30 can be transmitted from the upper wall 222 to the lower wall 212 or from the lower wall 212 to the upper wall 222. This can reduce the transmission of the load to the electronic devices 41, 42.In addition, as described above, in each of the electronic devices 41, 42, one end portion of both ends of each of the electronic devices 41, 42 is fixed to the fixing member 30, and the other end portion is fixed to the cross member 20. This can reduce the applied acceleration to the electronic devices 41, 42 in response to vibration influences during vehicle travel.Moreover, even in a situation where it is difficult to fix the end portion (first end portion) of each of the electronic devices 41, 42 disposed on the fixing member 30 side to the cross member 20, the electronic devices 41, 42 can be stably fixed by fixing the first end portion to the fixing member 30.Note that the first outer end portion 35 is provided with a fixed portion 351 on the first end portion 411 side (a side in the first direction) and on the lower side. The fixed portion 351 is fastened to a bolt 73 as a fastening member provided on the cross member 20.Similarly, the second outer end portion 36 is provided with a fixed portion on the first end portion 421 side (the other side in the first direction) and on the lower side. The fixed portion is fastened to a bolt or a screw as a fastening element, which is / is provided on the cross strut 20.FIG. 4 is a cross-sectional view taken along line IV-IV illustrated in FIG. 3. As illustrated in FIG. 4, the fastening member 30 includes a first lower surface portion 31 bforming the lower surface of the first pillar portion 31 and a second lower surface portion 35 bforming the lower surface of the first outer end portion 35. The first lower surface portion 31 bis provided with a downwardly protruding insertion portion 31 c. The insertion portion 31 cis inserted into the upper surface 20 aof the cross member 20. On the side of the second pillar portion 32, an insertion portion is also provided on the lower surface of the second pillar portion 32 and is inserted into the upper surface 20 a. The first lower surface portion 31 bis in contact with the upper surface 20 a.The second lower surface portion 35 bis disposed so as to be spaced upward from the upper surface 20 aof the cross member 20. Specifically, the second lower surface portion 35 bis inclined upward in the second direction as the distance from the first pillar portion 31 increases. The lower surface 351 aof the fixed portion 351 is substantially parallel to the upper surface 20 a. 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 also inclined upward with increasing distance from the second pillar portion 32.It is to be noted that the second lower surface portion 35 band the third lower surface portion may be provided so as to form a step between each of these portions and the first lower surface portion 31 b. In this case, the second lower surface portion 35 band the third lower surface portion may be disposed substantially parallel to the upper surface 20 a.FIG. 5 is a view showing a broken state of a fastener of the embodiment. As described above, the first fragile portion 37 is provided at the boundary portion between the first pillar portion 31 and the first outer end portion 35. For example, a notch, a cut-out, or the like forms the first fragile portion 37.As illustrated in FIG. 5, the first fragile portion 37 is provided such that the first fragile portion 37 can be broken when a predetermined load is applied to the fastening member 30. When a large stress is applied to the housing 200 and the fastener 30 receives the stress due to a vehicle collision or the like, the stress can be prevented from being transmitted from the fastener 30 side to the electronic device 41 by breaking the first fragile portion 37. Similarly, by breaking the second fragile portion 38, the load can be prevented from being transmitted from the side of the fastening member 30 to the electronic device 42. As a result, the electronic devices 41, 42 can be prevented from being damaged.In addition, since the second lower surface portion 35 band the third lower surface portion are provided so as to be spaced upward from the upper surface 20 a, the first fragile portion 37 and the second fragile portion 38 can be easily broken when a load is applied to the fastening member 30.Other VariationsIn the above description, the case where the first end portion of each of the electronic devices 41, 42 is indirectly fixed to the fixing member 30 through the inner connection member has been illustrated. However, the inner connecting member may be omitted, and the first end portion may be directly fixed to the fixing member 30.In the above description, the case where the second end portion of each of the electronic devices 41, 42 is fixed to the cross member 20 by the outer connecting member has been illustrated. However, the outer connecting member may be omitted, and the second end portion may be directly fixed to the cross member 20.As described above, the embodiment disclosed herein is exemplary in all respects and is not limiting. The scope of the present invention is indicated by the claims and includes all modifications within the meaning and scope corresponding to the claims.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedJP 6 003 838 B [0002, 0003]

Claims

A power storage device, comprising: a first power storage module and a second power storage module arranged side by side in a first direction orthogonal to a height direction; a housing accommodating the first power storage module and the second power storage module; a cross member arranged between the first power storage module and the second power storage module in the housing and extending in the height direction and a second direction perpendicular to the first direction; a fixing member fixed to an upper surface of the cross member; and an electronic device monitoring the first power storage module or the second power storage module, wherein: a height of the fixing member in the height direction is greater than a height of the electronic device; and the electronic device is disposed adjacent to the fastener in the second direction and includes a first end portion disposed on a side of the fastener in the second direction and a second end portion disposed on a side opposite to the side on which the fastener is disposed in the second direction; wherein the first end portion is fixed to the fastener; and the second end portion is fixed to the cross member.The power storage device according to claim 1, wherein: the fixing member comprises a pillar portion disposed on a side of the first end portion of the electronic device in the second direction, a height of the pillar portion in the height direction is greater than that of the electronic device, and an outer end portion disposed adjacent to the pillar portion so as to be disposed closer to the side of the first end portion than the pillar portion in the second direction, the first end portion being fixed to the outer end portion; a height of the outer end portion is less than the height of the pillar portion in the height direction; and a fragile portion is disposed at a boundary portion between the outer end portion and the pillar portion.The power storage device according to claim 2, wherein: the fixing member comprises a first lower surface portion forming a lower surface of the pillar portion and a second lower surface portion forming a lower surface of the outer end portion; the first lower surface portion is provided with an insertion portion insertable into the cross member; the outer end portion is provided with a fixed portion fixed to a fixing member disposed on the cross member on the side of the first end portion and on a 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 disposed so as to be spaced upward from the upper surface of the cross member.

Images