Energy storage device

Abstract

The present invention provides an energy storage device that can suppress deformation of the energy storage stack when an external force is applied from below to above. [Solution] The energy storage device comprises a lower case including a bottom wall portion 23, a first energy storage module 11A and a second energy storage module 11B arranged on the inner surface side of the bottom wall portion 23 at a distance from each other in the front-rear direction, and a cover member 50 that covers the bottom wall portion 23 from below. The bottom wall portion 23 includes a first projection portion 26 that protrudes downward, the first energy storage module 11A has a rear side corner portion 11b, the second energy storage module 11B has a front side corner portion 11a, the first projection portion 26 has a front side base portion 26a and a rear side base portion 26b, the front side base portion 26a is located in a position that overlaps with the rear side corner portion 11b in the vertical direction, and the rear side base portion 26b is located in a position that overlaps with the front side corner portion 11a in the vertical direction.

Description

Technical Field

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

Background Art

[0002] As a conventional power storage device, Japanese Patent Application Laid-Open No. 2023-046671 (Patent Document 1) discloses a structure in which a power storage stack disposed in a lower case is cooled using a cooler disposed below the lower case. The lower case is provided with a protruding portion that protrudes downward, and a protection panel for protecting the cooler is fixed to the protruding portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration of Patent Document 1, a recess is formed in a portion of the bottom of the lower case where the protruding portion is attached. Therefore, when an impact is input to the protection panel from below to above due to road surface interference or the like, there is a concern that the bottom will deform so as to bend upward starting from the end of the recess in the bottom. In such a case, there is a concern that the bent upward bottom will interfere with the lower surface of the power storage stack (power storage module) in the lower case, causing the power storage stack to deform.

[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 suppressing deformation of a power storage module when an external force directed from the lower side to the upper side is applied.

Means for Solving the Problems

[0006] The energy storage device according to this disclosure comprises a lower case including a bottom wall portion having an inner surface and an outer surface aligned in the vertical direction, a first energy storage module and a second energy storage module fixed to the inner surface at a distance from each other in the front-rear direction perpendicular to the vertical direction, and a cover member that covers the bottom wall portion from below, with a gap formed between the cover member and the bottom wall portion. The bottom wall portion includes a first projection that protrudes downward. The first projection portion is located between the first energy storage module and the second energy storage module when viewed from above. The first energy storage module has a rear corner portion located at the lower part of its rear. The second energy storage module has a front corner portion located at the lower part of its front. The first projection portion has a front root portion located on the front side and a rear root portion located on the rear side. The front root portion is located in a position that overlaps the rear corner portion in the vertical direction. The rear root portion is located in a position that overlaps the front corner portion in the vertical direction.

[0007] According to the above configuration, when an upward external force is applied to the cover member due to road surface interference or the like, the cover member abuts against the first protrusion, thereby suppressing deformation of the cover member. The first protrusion is pressed upward by the cover member, but because the rigidity is high at the front and rear root portions, the bottom wall portion deforms with the front and rear root portions as fulcrums. At this time, the front root portion contacts the rear corner portion of the first energy storage module, and the rear root portion contacts the front corner portion of the second energy storage module. The load transmitted to the rear corner portion of the first energy storage module and the front corner portion of the second energy storage module by this deformation is transmitted to the vertical walls of the first and second energy storage modules. This suppresses large deformation of the bottom surfaces of the first and second energy storage modules. Furthermore, because the vertical walls have high strength, they can absorb high loads. As a result, deformation of the energy storage module can be suppressed when an external force is applied from below to above.

[0008] In the energy storage device based on the above disclosure, the cover member may include a second projection that faces the first projection in the vertical direction and protrudes upward.

[0009] With the above configuration, the second protrusion makes it easier for the cover member to abut against the first protrusion. As a result, when an upward external force is applied to the cover member due to road surface interference or the like, the load transmitted to the rear corner of the first energy storage module and the front corner of the second energy storage module is more easily transmitted to the vertical walls of the first and second energy storage modules.

[0010] The energy storage device according to the above disclosure may further include a cooler disposed between the bottom wall portion and the cover member for cooling the first energy storage module and the second energy storage module. The first protrusion may protrude downward from the cooler.

[0011] With the above configuration, the cooler can be protected by the cover member. Furthermore, since the first protrusion protrudes below the cooler, it is possible to prevent the cover member from hitting the cooler when an upward external force is applied to the cover member due to road surface interference or the like.

[0012] The energy storage device according to the above disclosure may further include a first cross member and a second cross member arranged on the inner surface side at a distance from each other in the front-rear direction, and a first reinforcing member and a second reinforcing member arranged on the outer surface side at a distance from each other in the front-rear direction. The first cross member and the first reinforcing member may be arranged in the vertical direction with the bottom wall in between. The second cross member and the second reinforcing member may be arranged in the vertical direction with the bottom wall in between. The first energy storage module and the second energy storage module may be arranged between the first cross member and the second cross member. The cover member may be fixed to the first reinforcing member and the second reinforcing member.

[0013] With the above configuration, the uniformity of the bottom wall can be increased by the first cross member 29 and the first bottom reinforcing member, as well as the second cross member and the second bottom reinforcing member, which are arranged vertically on either side of the bottom. Furthermore, because the cover member is fixed to the first bottom reinforcing member and the second bottom reinforcing member, when an upward external force is applied to the cover member due to road surface interference or the like, the cover member can be deformed to bend upward between the first bottom reinforcing member and the second bottom reinforcing member, using the first bottom reinforcing member and the second bottom reinforcing member as fulcrums. This makes it easier to apply the cover member to the first protrusion, and as described above, the load is more easily transmitted to the vertical wall surfaces of the first and second energy storage modules. [Effects of the Invention]

[0014] According to this disclosure, it is possible to provide an energy storage device that can suppress deformation of the energy storage stack when an external force is applied from below to above. [Brief explanation of the drawing]

[0015] [Figure 1] This is an exploded perspective view of the energy storage device according to the embodiment. [Figure 2] This is a perspective view of the lower case to which the cooler according to the embodiment is fixed, as seen from the bottom side. [Figure 3] Figure 2 is a schematic cross-sectional view of the energy storage device at a position along line III-III shown. [Figure 4] Figure 3 is a schematic cross-sectional view along the line IV-IV shown. [Figure 5] This is a plan view showing the positional relationship between a bracket for fixing electrical equipment, a cooler, and a first protrusion in an energy storage device according to an embodiment. [Figure 6] This is a cross-sectional view illustrating the deformation behavior of an energy storage device according to an embodiment when an external force is applied upward on the lower side of the electrical equipment. [Figure 7] Figure 2 is a schematic cross-sectional view of the energy storage device located along the line VII-VII shown. [Figure 8]It is a view showing an enlarged area surrounded by line VIII shown in FIG. 7. [Figure 9] In the energy storage device according to the embodiment, it is a cross-sectional view for explaining the deformation behavior when an external force is applied upward below the energy storage module.

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 an exploded perspective view of an energy storage device according to an embodiment. Referring to FIG. 1, the energy storage device 1 according to the present embodiment will be described.

[0018] The energy storage device 1 is mounted on, for example, a vehicle such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a battery electric vehicle (BEV). The energy storage device 1 is mounted, for example, below the floor panel of the vehicle. Note that the ceiling portion of the upper member 21 described later of the energy storage device 1 may function as a floor panel.

[0019] As shown in FIG. 1, the energy storage device 1 includes an energy storage unit 10, a housing case 20, a plurality of reinforcing members 25, a plurality of cross members 29, a cooler 30, a heat conduction member 40, a cover member 50, an inner heat conduction layer 60, and an electric device 80.

[0020] The energy storage unit 10 includes a plurality of energy storage modules 11. The plurality of energy storage modules 11 are arranged in a first direction (DR1 direction) orthogonal to the vertical direction. The first direction is parallel to, for example, the front-rear direction of the vehicle when the energy storage device 1 is mounted on the vehicle.

[0021] Each of the multiple energy storage modules 11 includes multiple energy storage cells 12 arranged in the vertical direction and in a second direction (DR2 direction) perpendicular to the first direction. In the above-described mounting configuration, the second direction is parallel to the width direction of the vehicle.

[0022] The energy storage cell 12 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The energy storage cell 12 has, for example, a prismatic shape. The energy storage cell 12 may use a liquid electrolyte or a solid electrolyte. Alternatively, the energy storage cell 12 may be a unit capacitor configured to store energy.

[0023] The housing case 20 houses the energy storage unit 10 and the electrical equipment 80. The housing case 20 includes an upper member 21 and a lower case 22.

[0024] The upper member 21 has a substantially box-like shape that is open downwards. The upper member 21 may be made of a metal material. Alternatively, for weight reduction, the upper member 21 may be made of a resin material. Furthermore, if the height of the peripheral wall portion of the lower case 22 is higher than that of the energy storage unit 10, the upper member 21 may have a plate-like shape.

[0025] The lower case 22 has a substantially box-like shape that is open upwards. The lower case 22 is made of a metal material. Preferably, the lower case 22 has good thermal conductivity.

[0026] The lower case 22 has a bottom wall 23. Multiple energy storage modules 11 are arranged in the bottom wall 23 with an inner heat conduction layer 60 interposed between them. The bottom wall 23 has an inner surface 23a and an outer surface 23b that are aligned vertically. The inner surface 23a faces upward and towards the multiple energy storage modules 11. The outer surface 23b faces downward and away from the side where the multiple energy storage modules 11 are located.

[0027] Multiple cross members 29 are arranged within the lower case 22 at intervals in the first direction (front-to-back direction). The multiple cross members 29 are positioned on the inner surface 23a side. The multiple cross members 29 extend along the second direction. The multiple cross members 29 demarcate the area where the electrical equipment 80 and the energy storage module 11 are arranged. For example, two energy storage modules 11 are arranged between two adjacent cross members 29 in the front-to-back direction.

[0028] The two energy storage modules 11, positioned between two adjacent cross members 29, are fixed to the cross members 29 or the bottom wall 23 by fixing members (not shown) located at both ends in the arrangement direction of the energy storage cells 12.

[0029] The inner thermal conductive layer 60 is positioned between each energy storage module 11 and the inner surface 23a. The inner thermal conductive layer 60 also functions as an adhesive layer, bonding and fixing each energy storage module 11 to the bottom wall 23. Each energy storage module 11 is in thermal contact with the inner surface 23a by the inner thermal conductive layer 60.

[0030] The inner heat conductive layer 60 is made of a resin material having thermal conductivity. For example, the inner heat conductive layer 60 can be an adhesive containing a silicone resin, acrylic resin, urethane resin, or epoxy resin.

[0031] The cooler 30 is a device for cooling multiple energy storage modules 11. Inside the cooler 30, there is a refrigerant flow path through which the refrigerant flows. This refrigerant flow path is connected to a refrigerant inlet 61 and a refrigerant outlet 62. The refrigerant introduced into the refrigerant flow path from the refrigerant inlet 61 cools the multiple energy storage modules 11 and is then discharged from the refrigerant outlet 62.

[0032] The cooler 30 is located below the bottom wall 23 of the lower case 22. The cooler 30 is made of a metal material such as aluminum. The detailed structure of the cooler 30 will be described later with reference to Figure 2.

[0033] The heat conduction member 40 is positioned between the outer surface 23b of the bottom wall portion 23 and the cooler 30. Multiple energy storage modules 11 are cooled by the cooler 30 via the heat conduction member 40, the bottom wall portion 23, and the inner heat conduction layer 60. The heat conduction member 40 also functions as an adhesive layer that bonds the bottom wall portion 23 and the cooler 30. As the heat conduction member 40, an adhesive containing, for example, a silicone resin, acrylic resin, urethane resin, or epoxy resin can be used.

[0034] Multiple reinforcing members 25 are fixed to the outer surface 23b of the bottom wall portion 23. The multiple reinforcing members 25 are arranged in a first direction. The multiple reinforcing members 25 are positioned so as not to interfere with the cooler 30.

[0035] The cover member 50 covers the bottom wall portion 23 from below, with a gap formed between it and the bottom wall portion 23. Specifically, the cover member 50 covers the cooler 30, which is located below the bottom wall portion 23, from below. The cover member 50 protects the cooler 30. The cover member 50 is fixed to a plurality of reinforcing members 25. The cover member 50 is made of a metal material.

[0036] The electrical equipment 80 is arranged in the first direction alongside the energy storage unit 10. The electrical equipment 80 is located on one side of the energy storage unit 10 in the first direction. The electrical equipment 80 includes, for example, a junction box. The electrical equipment 80 may also include an electronic control unit. As will be described later, the electrical equipment 80 is fixed to the bottom wall 23 using a bracket 90 (see Figure 3).

[0037] Figure 2 is a perspective view of the lower case to which the cooler according to the embodiment is fixed, viewed from the bottom side. The detailed structure of the cooler 30 and the shape of the bottom wall portion 23 will be described with reference to Figure 2.

[0038] The cooler 30 includes a pair of holding parts 31, a plurality of cooling parts 32, and a front part 33. The refrigerant flow path is routed inside the pair of holding parts 31, the plurality of cooling parts 32, and the front part 33.

[0039] The pair of retaining parts 31 extend along a first direction. The pair of retaining parts 31 are arranged apart from each other in a second direction. The pair of retaining parts 31 hold a plurality of cooling parts 32.

[0040] Multiple cooling units 32 are arranged in a one-to-one correspondence with multiple energy storage modules 11. The number of cooling units 32 is provided according to the number of energy storage modules 11. Each of the multiple cooling units 32 is provided to connect a pair of holding units 31 in a second direction. The multiple cooling units 32 are arranged side by side with spacing between them in a first direction.

[0041] The multiple cooling units 32 include multiple cooling units 32A, multiple cooling units 32B, and cooling unit 32C. Cooling unit 32C is located on one side in the first direction of the multiple cooling units 32A and 32B. Cooling unit 32C is positioned between the cooling unit 32A located on the furthest side in the first direction of the multiple cooling units 32A and the front unit 33.

[0042] Multiple cooling units 32A and 32B are arranged alternately in the first direction. In this embodiment, when viewed from above, one pair of cooling units 32A and 32B are arranged between adjacent cross members 29 in the first direction.

[0043] In the pair of cooling units 32A and 32B, cooling unit 32A cools the energy storage module 11 located on one side in the first direction of the two energy storage modules 11 located between adjacent cross members 29 in the first direction. Cooling unit 32B cools the energy storage module 11 located on the other side in the first direction of the two energy storage modules 11 located between adjacent cross members 29 in the first direction.

[0044] The cooler 30 is provided with a plurality of openings 37h. The plurality of openings 37h are provided between two adjacent cooling sections 32A and 32B, between the cooling section 32A and cooling section 32C located on the far side in the first direction, and between the front section 33 and cooling section 32C. The openings 37h extend in a second direction.

[0045] Reinforcement members 25 and first protrusions 26 are positioned inside the multiple openings 37h. Specifically, a reinforcement member 25 is positioned inside each opening 37h located below the multiple cross members 29. A first protrusion 26 is positioned inside each opening 37h that does not overlap with the multiple cross members 29.

[0046] The bottom wall portion 23 of the lower case 22 has a plurality of first protrusions 26, 26C that project downward. The first protrusions 26, 26C are formed by recesses provided in the bottom wall portion 23. The amount of protrusion of the first protrusions 26, 26C is less than the height of the reinforcing member 25 in the vertical direction, but they protrude downward more than the cooling portions 32A, 32B, 32C.

[0047] The cooling section 32C is provided with, for example, two holes 38h. The two holes 38h are arranged side by side in a second direction. The first protrusion 26C is located inside the two holes 38h.

[0048] Figure 3 is a schematic cross-sectional view of the energy storage device along the line III-III shown in Figure 1. For convenience, the upper member 21 is omitted in Figure 3. Figure 4 is a schematic cross-sectional view along the line IV-IV shown in Figure 3. Figure 5 is a plan view showing the positional relationship between the bracket for fixing the electrical equipment, the cooler, and the first protrusion in the energy storage device according to the embodiment. The configuration around the electrical equipment 80 will be described with reference to Figures 3 to 5.

[0049] As shown in Figure 3, the cooling unit 32C is positioned below the electrical equipment 80. The first protrusion 26C is positioned so as to overlap with the electrical equipment 80 in the vertical direction. The first protrusion 26C is inserted into the hole 38h of the cooling unit 32C and protrudes downward from the cooling unit 32C.

[0050] The cover member 50 has a second projection 52C that faces the first projection 26C in the vertical direction and protrudes upward. The second projection 52C is spaced apart from the first projection 26C. The cover member 50 is fastened and fixed to a plurality of reinforcing members 25, for example, by fastening members 70.

[0051] The multiple reinforcing members 25 include a first reinforcing member 25A1 and a second reinforcing member 25A2. The first reinforcing member 25A1 and the second reinforcing member 25A2 are arranged side by side in a first direction. The first reinforcing member 25A1 is located on the furthest side of the multiple reinforcing members 25 in the first direction. The second reinforcing member 25A2 is adjacent to the first reinforcing member 25A1 in the first direction. In the first direction, the first protrusion 26C and the second protrusion 52C described above are arranged between the first reinforcing member 25A1 and the second reinforcing member 25A2.

[0052] The cover member 50 includes a first fixing portion P11 fixed to the first reinforcing member 25A1 and a second fixing portion P12 fixed to the second reinforcing member 25A2. The first fixing portion P11 is located below the front end portion 81 (the end portion located on one side in the first direction) of the electrical equipment 80. The second fixing portion P12 is located below the rear end portion 82 (the end portion located on the other side in the first direction) of the electrical equipment 80, or behind and below the said rear end portion 82.

[0053] The front end portion 81 is fixed to the bracket 90 at a first fixed position P1, and the rear end portion 82 is fixed to the bracket 90 at a second fixed position P2. The first fixed portion P11 is located below the first fixed position P1. The second fixed portion P12 is located below the second fixed position P2, or behind and below the second fixed position P2.

[0054] Each reinforcing member 25 has a bottom plate portion 251, a pair of side wall portions 252, and a pair of flange portions 253. A cover member 50 is fastened and fixed to the bottom plate portion 251.

[0055] A pair of side walls 252 are connected to both ends of the base plate 251 in a first direction. The pair of side walls 252 are positioned opposite each other in the first direction. The pair of side walls 252 are inclined to move away from each other in the first direction as they extend upward. The pair of side walls 252 extend along a second direction.

[0056] The pair of flange portions 253 are connected to the upper ends of the pair of side wall portions 252. The pair of flange portions 253 are substantially parallel to the first direction.

[0057] The cross member 29 has an upper wall portion 291, a pair of side wall portions 292, and a pair of flange portions 293. The pair of side wall portions 292 are connected to both ends of the upper wall portion 291 in a first direction. The pair of side wall portions 292 are arranged facing each other in the first direction. The pair of side wall portions 292 extend along a second direction.

[0058] The pair of flange portions 293 are connected to the lower ends of the pair of side wall portions 292. The pair of flange portions 293 are substantially parallel to the first direction.

[0059] The pair of flange portions 253 and 293 described above are arranged vertically with the bottom wall portion 23 in between them. These pair of flange portions 253 and 293 and the bottom wall portion 23 are fixed to each other by welding or the like.

[0060] As shown in Figures 3 to 5, the electrical equipment 80 is fixed to the inner surface 23a of the bottom wall portion 23 by a bracket 90. In this embodiment, the electrical equipment 80 is fixed to the bottom wall portion 23 by two brackets 90.

[0061] The two brackets 90 are spaced apart in a second direction. Each bracket 90 extends along a first direction. Each bracket 90 has a ceiling portion 91, a pair of side wall portions 92, and a pair of flange portions 93.

[0062] The pair of side wall sections 92 are connected to both ends of the ceiling section 91 in the second direction. The pair of side wall sections 92 are arranged facing each other in the second direction. The pair of side wall sections 92 extend along the first direction.

[0063] The pair of flange portions 93 are connected to the lower ends of the pair of side wall portions 92. The pair of flange portions 93 are substantially parallel to the first direction.

[0064] One end of the pair of flange portions 93, located on one side in the first direction, is fixed to the other by welding or the like, sandwiching the flange portion 253 and bottom wall portion 23 of the reinforcing member 25 located on the far right side in the first direction.

[0065] The other end of the pair of flange portions 93, located on the other side in the first direction, is fixed by welding or the like to the flange portion 293 of the cross member 29 located on the far right side in the first direction.

[0066] The electrical equipment 80 is fixed to each bracket 90 at a first fixed position P1 and a second fixed position P2 that are spaced apart in the first direction. Between the first fixed position P1 and the second fixed position P2, the electrical equipment 80 has a portion that is spaced apart from the bracket 90.

[0067] Specifically, the electrical equipment 80 has a recess 80b that is recessed upward, and a gap is formed between the recess 80b and the ceiling portion 91 of the bracket 90. That is, the recess 80b is spaced upward from the ceiling portion 91. The recess 80b extends in a planar manner and, when viewed from a first direction, is formed across the two brackets 90. The recess 80b is located between the front end portion 81 and the rear end portion 82 of the electrical equipment 80.

[0068] A heat conductive member 65 is positioned between at least a portion of the bottom surface of the electrical equipment 80 and the inner surface 23a of the bottom wall portion 23 of the lower case 22. This allows the electrical equipment 80 and the cooler 30 to come into thermal contact via the bottom wall portion 23 and the heat conductive member 65, thereby cooling the electrical equipment 80.

[0069] In the second direction, both ends of the electrical equipment 80 are located outside the bracket 90 described above, and the heat conductive member 65 is positioned between these ends and the bottom wall 23. As the heat conductive member 65, for example, an adhesive containing silicone resin, acrylic resin, urethane resin, or epoxy resin can be used.

[0070] Figure 6 is a cross-sectional view illustrating the deformation behavior of an energy storage device according to an embodiment when an external force is applied upward on the lower side of the electrical equipment.

[0071] As shown in Figure 6, when an upward external force is applied to the cover member 50 due to road surface interference or the like, the second protrusion 52C abuts against the first protrusion 26C, thereby suppressing deformation of the cover member 50. At this time, since the first protrusion 26C protrudes below the lower surface of the cooler 30, the cover member 50 is prevented from hitting the cooler 30, and thus the external force applied to the cooler 30 is suppressed.

[0072] Specifically, because the cover member 50 is fixed to the first reinforcing member 25A1 and the second reinforcing member 25A2 by the first fixing part P11 and the second fixing part P12, when an upward external force is applied to the cover member 50, the cover member 50 deforms such that the intermediate part between the first fixing part P11 and the second fixing part P12 in the first direction bends upward, as shown by the dashed line DL1.

[0073] In this case, the first protrusion 26C and the second protrusion 52C are positioned between the first fixing portion P11 and the second fixing portion P12 in the first direction, thereby effectively suppressing the deformation of the cover member 50 that bends upward as described above.

[0074] Furthermore, since the first fixing part P11 is located below the front end portion 81 of the electrical equipment 80, and the second fixing part P12 is located below or behind and below the rear end portion 82 of the electrical equipment 80, the upward bending deformation described above can be induced between the first fixing part P11 and the second fixing part P12 as described above.

[0075] In addition, two brackets 90 are positioned in the upper part of the bottom wall 23, from the first reinforcing member 25A1 to the second reinforcing member 25A2. As a result, the rigidity of this part is increased, and even when the first protrusion 26C is pressed upward, it is possible to suppress the upward bending deformation of this part of the bottom wall 23, as shown by the dashed line DL2. Furthermore, even if this part does bend, as described above, the recess 80b of the electrical equipment 80 is spaced apart from the bracket 90 between the first fixed position P1 and the second fixed position P2, which prevents the deformed bottom wall 23 from hitting the electrical equipment 80 and prevents impact from being input to the electrical equipment 80.

[0076] In addition, since the first protrusion 26C is inserted through the hole 38h provided in the cooling section 32C, the first protrusion 26C can be installed efficiently.

[0077] Figure 7 is a schematic cross-sectional view of the energy storage device at a position along the line VII-VII shown in Figure 2. For convenience, the upper member 21 is omitted in Figure 7. The structure surrounding the energy storage module 11 will now be described with reference to Figure 7.

[0078] As shown in Figure 7, the multiple energy storage modules 11 include multiple sets of first energy storage modules 11A and second energy storage modules 11B on the rear side (the other side in the first direction) of the electrical equipment 80. Note that there only needs to be one or more sets of first energy storage modules 11A and second energy storage modules 11B. The first energy storage modules 11A and second energy storage modules 11B are adjacent to each other in the first direction. The first energy storage modules 11A and second energy storage modules 11B are spaced apart in the first direction.

[0079] The first energy storage module 11A is located on one side in the first direction relative to the second energy storage module 11B. The second energy storage module 11B is located on the other side in the first direction relative to the first energy storage module 11A.

[0080] The multiple cross members 29 include a first cross member 29A1 and a second cross member 29A2, which are spaced apart in the first direction. The first cross member 29A1 and the second cross member 29A2 are positioned on the inner surface 23a side of the bottom wall portion 23. The structure of the first cross member 29A1 and the second cross member 29A2 is the same as the structure of the cross member 29 described above. A first energy storage module 11A and a second energy storage module 11B are positioned between the first cross member 29A1 and the second cross member 29A2.

[0081] The first protrusion 26 described above is positioned between the first energy storage module 11A and the second energy storage module 11B when viewed from above. The first protrusion 26 is inserted into the opening 37h of the cooler 30.

[0082] The cover member 50 has a second projection 52 that faces the first projection 26 in the vertical direction and projects upward. The second projection 52 is spaced apart from the first projection 26. The cover member 50 is fixed to a plurality of reinforcing members 25, including a first bottom reinforcing member 25B1 and a second bottom reinforcing member 25B2, as will be described later.

[0083] Multiple reinforcing members 25 reinforce the bottom wall portion 23. The first bottom reinforcing member 25B1 and the second bottom reinforcing member 25B2 are arranged on the outer surface 23b of the bottom wall portion 23 at intervals in the first direction. The structure of the first bottom reinforcing member 25B1 and the second bottom reinforcing member 25B2 is the same as that of the first reinforcing member 25A1 and the second reinforcing member 25A2 described above.

[0084] The first cross member 29A1 and the first bottom reinforcing member 25B1 described above are arranged vertically with the bottom wall portion 23 in between. That is, the first bottom reinforcing member 25B1 is positioned below the first cross member 29A1.

[0085] The second cross member 29A2 and the second bottom reinforcing member 25B2 described above are arranged vertically, sandwiching the bottom wall portion 23. That is, the second bottom reinforcing member 25B2 is positioned below the second cross member 29A2.

[0086] The cooler 30 is positioned between the bottom wall 23 of the lower case 22 and the cover member 50. The cooling unit 32A described above cools the first energy storage module 11A, and the cooling unit 32B cools the second energy storage module 11B.

[0087] Figure 8 is a magnified view of the region enclosed by line VIII in Figure 7. As shown in Figure 8, the first energy storage module 11A has a rear corner portion 11b located at the bottom of the rear end (the end located on the other side in the first direction). The second energy storage module 11B has a front corner portion 11a located at the bottom of the front end (the end located on one side in the first direction).

[0088] The first projection 26 has a base plate portion 261 and a pair of side wall portions 262. The pair of side wall portions 262 are connected to both ends of the base plate portion 261 in a first direction. The pair of side wall portions 262 are arranged facing each other in the first direction. The pair of side wall portions 262 are inclined to move away from each other in the first direction as they extend upward. The pair of side wall portions 262 extend along a second direction.

[0089] The upper ends of each of the pair of side wall portions 262 form the base portions of the first projection 26. The first projection 26 has a front base portion 26a (a one-side base portion located on one side in the first direction) and a rear base portion 26b (a other-side base portion located on the other side in the first direction).

[0090] The front root portion 26a is positioned to overlap with the rear corner portion 11b in the vertical direction. The rear root portion 26b is positioned to overlap with the front corner portion 11a in the vertical direction.

[0091] Figure 9 is a cross-sectional view illustrating the deformation behavior of the energy storage device according to the embodiment when an external force is applied upward to the lower side of the energy storage module.

[0092] As shown in Figure 9, when an upward external force is applied to the cover member 50 due to road surface interference or the like, the cover member 50 abuts against the first protrusion 26, thereby suppressing deformation of the cover member 50.

[0093] The first protrusion 26 is pressed upward by the cover member 50, but because the rigidity is high at the front root portion 26a and the rear root portion 26b, the bottom wall portion 23 deforms with the front root portion 26a and the rear root portion 26b as fulcrums. At this time, as described above, the front root portion 26a is located in a position that overlaps the rear corner portion 11b in the vertical direction, and the rear root portion 26b is located in a position that overlaps the front corner portion 11a in the vertical direction. Therefore, the front root portion 26a contacts the rear corner portion 11b of the first energy storage module 11A, and the rear root portion 26b contacts the front corner portion 11a of the second energy storage module 11B.

[0094] Here, the load transmitted to the rear corner 11b of the first energy storage module 11A is transmitted to the vertical wall surface (more specifically the rear surface) of the first energy storage module 11A, as shown by arrow AR5. Similarly, the load transmitted to the front corner 11a of the second energy storage module 11B is transmitted to the vertical wall surface (more specifically the front surface) of the second energy storage module 11B, as shown by arrow AR6. This prevents the bottom surfaces of the first and second energy storage modules 11A and 11B from deforming significantly. Furthermore, because the vertical wall surface has high strength, it can absorb high loads.

[0095] The cover member 50 is provided with a second projection 52 that protrudes toward the first projection 26, which makes it easier for the cover member 50 to abut against the first projection 26. This effectively induces the deformation behavior described above.

[0096] Furthermore, because the first protrusion 26 protrudes downward from the cooler 30, the cover member 50 can be prevented from hitting the cooler 30. This prevents damage to the cooler 30.

[0097] In addition, the first cross member 29A1 and the first bottom reinforcing member 25B1 are arranged vertically on either side of the bottom wall 23, and the second cross member 29A2 and the second bottom reinforcing member 25B2 are also arranged vertically on either side of the bottom wall 23, thereby increasing the rigidity of the lower case 22. Furthermore, because the cover member 50 is fixed to the first bottom reinforcing member 25B1 and the second bottom reinforcing member 25B2, the cover member 50 can be deformed to bend upward between the first bottom reinforcing member 25B1 and the second bottom reinforcing member 25B2, with the first bottom reinforcing member 25B1 and the second bottom reinforcing member 25B2 acting as fulcrums. In this case, the first protrusion 26 and the second protrusion 52 are positioned between the first bottom reinforcing member 25B1 and the second bottom reinforcing member 25B2 in the first direction, thereby effectively suppressing the deformation of the cover member 50 as it bends upward as described above.

[0098] Furthermore, the first cross member 29A1 and the second cross member 29A2 have a convex shape that protrudes upward, and the first protrusion 26 located between the first cross member 29A1 and the second cross member 29A2 has a convex shape that protrudes downward. Therefore, by utilizing the second moment of area of ​​the first cross member 29A1, the second cross member 29A2, and the first protrusion 26, deformation due to reaction forces of the inner heat conduction layer 60 located between the first cross member 29A1 and the first protrusion 26, and the inner heat conduction layer 60 located between the second cross member 29A2 and the first protrusion 26, can be suppressed in the first direction.

[0099] In the above description, the example given is that the front base portion 26a and the rear base portion 26b overlap the rear corner portion 11b of the first energy storage module 11A and the front corner portion 11a of the second energy storage module 11B in the vertical direction, but the example is not limited to this.

[0100] Even if the first protrusion 26 is pressed upward and the front base portion 26a and the rear base portion 26b come into contact with the lower surface of the energy storage module, the front base portion 26a and the rear base portion 26b may be positioned offset in the first direction from the rear corner portion 11b of the first energy storage module 11A and the front corner portion 11a of the second energy storage module 11B, as long as the lower surface of the energy storage module is not damaged and the force transmitted to the vertical wall surface of the energy storage module is greater than the force transmitted to the lower surface of the energy storage module.

[0101] 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]

[0102] 1 Energy storage device, 10 Energy storage unit, 11 Energy storage module, 11A First energy storage module, 11B Second energy storage module, 11a Front side corner, 11b Rear side corner, 12 Energy storage cell, 20 Housing case, 21 Upper member, 22 Lower case, 23 Bottom wall, 23a Inner surface, 23b Outer surface, 25 Reinforcement member, 25A1 First reinforcement member, 25A2 Second reinforcement member, 25B1 First bottom reinforcement member, 25B2 Second bottom reinforcement member, 26, 26C First protrusion, 26a Front base, 26b Rear base, 29 Cross member, 29A1 First cross member, 29A2 Second cross member, 30 Cooler, 31 Holding part, 32, 32A, 32B, 32C Cooling part, 33 Front part, 37h Opening, 38h Hole, 40 Heat conduction member, 50 Cover member, 52, 52C Second protrusion, 60 Inner heat conduction layer, 61 Refrigerant introduction section, 62 Refrigerant discharge section, 65 Heat conduction member, 70 Fastening member, 80 Electrical equipment, 80b Recess, 81 Front end, 82 Rear end, 90 Bracket, 91 Ceiling section, 92 Side wall section, 93 Flange section, 251 Bottom plate section, 252 Side wall section, 253 Flange section, 261 Bottom plate section, 262 Side wall section, 291 Top wall section, 292 Side wall section, 293 Flange section, P1 First fixing position, P2 Second fixing position, P11 First fixing section, P12 Second fixing section.

Claims

1. A lower case including a bottom wall portion having an inner surface and an outer surface arranged in the vertical direction, A first energy storage module and a second energy storage module are fixed to the inner surface at intervals in the front-to-back direction perpendicular to the vertical direction, A cover member that covers the bottom wall from below, with a gap formed between it and the bottom wall, The bottom wall portion includes a first projection that protrudes downward, The first protrusion is located between the first energy storage module and the second energy storage module when viewed from above. The first energy storage module has a rear side corner located at the lower rear, The second energy storage module has a front side corner located at the lower part of the front, The first projection has a front base portion located on the front side and a rear base portion located on the rear side. The aforementioned front root portion is located in a position that overlaps with the aforementioned rear corner portion in the vertical direction. The rear base portion is located in a position that overlaps with the front corner portion in the vertical direction, and is used as an energy storage device.

2. The energy storage device according to claim 1, wherein the cover member includes a second projection that faces the first projection in the vertical direction and protrudes upward.

3. The system further includes a cooler positioned between the bottom wall and the cover member, which cools the first energy storage module and the second energy storage module. The energy storage device according to claim 2, wherein the first protrusion protrudes downward from the cooler.

4. The first cross member and the second cross member are arranged on the inner surface side with a gap between them in the front-rear direction, The device further comprises a first bottom reinforcing member and a second bottom reinforcing member, which are positioned on the outer surface side at intervals in the front-rear direction and reinforce the bottom wall portion. The first cross member and the first bottom reinforcing member are arranged in the vertical direction, sandwiching the bottom wall portion. The second cross member and the second bottom reinforcing member are arranged in the vertical direction, sandwiching the bottom wall portion. The first energy storage module and the second energy storage module are arranged between the first cross member and the second cross member. The energy storage device according to any one of claims 1 to 3, wherein the cover member is fixed to the first bottom reinforcing member and the second bottom reinforcing member.

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