power storage device

Abstract

The present application provides a power storage device, which has a lower housing having a bottom portion provided with a protruding portion protruding downward, and a cooler disposed below the bottom portion, the cooler including a cooling portion having an end portion facing the protruding portion in a first direction orthogonal to an up-down direction, the cooling portion having an upper plate portion and a lower plate portion stacked in the up-down direction, the upper plate portion and the lower plate portion being joined at a joint surface each has at the end portion side, the lower plate portion having a protruding portion protruding toward the protruding portion at the end portion side more than the upper plate portion.

Description

Technical Field

[0001] This disclosure relates to an energy storage device mounted on a vehicle. Background Technology

[0002] As a conventional energy storage device, Japanese Patent Application Publication No. 2020-053148 discloses a structure in which an energy storage stack and a cooler are arranged inside a housing. The cooler is formed by stacking a first metal plate (upper plate) and a second metal plate (lower plate) in the vertical direction and joining them together by means of brazing or the like.

[0003] An energy storage device with a structure where the cooler is located outside the housing was discussed. In such a case, the cooler of a vehicle equipped with this energy storage device is susceptible to water exposure during rainy weather or when driving on puddles. In such situations, without any intervention, liquids such as water can adhere to the ends of the joined upper and lower plates, and rust may develop near the joint where the liquid adheres. In this case, the refrigerant flowing within the cooler may sometimes leak from the rusted areas. Summary of the Invention

[0004] This disclosure provides an energy storage device that, in a structure in which a cooler having a cooling section that joins an upper plate and a lower plate is disposed outside a lower housing, can suppress liquid adhering to the vicinity of the joint between the upper plate and the lower plate.

[0005] The energy storage device based on this disclosure includes: a lower housing having a bottom, the bottom having a downwardly projecting protrusion; and a cooler disposed below the bottom. The cooler includes a cooling section having an end portion facing the protrusion in a first direction orthogonal to the vertical direction. The cooling section has an upper plate portion and a lower plate portion stacked along the vertical direction. The upper plate portion and the lower plate portion are joined at their respective mating surfaces at the end portions. The lower plate portion has a protrusion at the end portion that extends towards the protrusion beyond the upper plate portion.

[0006] According to the above structure, when external liquid touches the protrusion on the lower side of the lower housing, the protrusion can repel the liquid that is about to move upwards back downwards. This prevents liquid from adhering to the vicinity of the joint between the upper and lower plates, and inhibits rusting near the joint between the upper and lower plates.

[0007] In the energy storage device based on the present disclosure, the upper plate portion may have an edge portion and an inclined portion. The edge portion is provided with the mating surface, and the inclined portion is connected to the edge portion from the opposite side of the side where the protrusion is located, and faces upward as it tends to the opposite direction of the side where the protrusion is located.

[0008] According to the above structure, when condensation occurs in the cooling section, the condensation can flow towards the protrusion through the inclined section. Therefore, the condensation can be retained at the front end of the protrusion.

[0009] In the energy storage device based on the present disclosure, the cooling section may have a first end and a second end in a second direction orthogonal to the vertical direction and the first direction. In this case, the protruding portion may be respectively provided on the first end side and the second end side.

[0010] According to the above structure, the adhesion of liquid to the vicinity of the joint between the upper plate and the lower plate can be suppressed on both the first end side and the second end side in the second direction. Especially when mounted on a vehicle with the second direction parallel to the width direction of the vehicle, liquid from the outside at both ends in the second direction can easily bounce back through the protrusion due to vehicle vibration. Therefore, the installation position of the protrusion can be defined, the installation area of ​​the protrusion can be reduced, and the adhesion of water to the vicinity of the joint between the upper plate and the lower plate can be effectively suppressed.

[0011] Based on the above, the energy storage device disclosed herein may include a plate that covers the protrusion and the cooler from below.

[0012] According to the above structure, by covering the cooler with a plate, it is possible to prevent the cooler from directly encountering liquid from the outside, and to prevent liquid from the outside from adhering to the vicinity of the joint between the upper plate and the lower plate.

[0013] According to this disclosure, an energy storage device can be provided in which a cooler having a cooling section that joins the upper plate and the lower plate is disposed outside the lower housing, and liquid can be prevented from adhering to the vicinity of the joint between the upper plate and the lower plate. Attached Figure Description

[0014] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein similar reference numerals denote similar elements, wherein:

[0015] Figure 1 This is an exploded perspective view of the energy storage device according to the embodiment.

[0016] Figure 2 This is a top view of the cooler in the embodiment.

[0017] Figure 3 This is a perspective view of the lower housing of the cooler with the embodiment fixed, viewed from the bottom side.

[0018] Figure 4 It is along Figure 3 The cross-sectional view shown along line IV-IV.

[0019] Figure 5 This diagram illustrates the situation where liquid is bounced back through the extension of the cooler in the embodiment.

[0020] Figure 6 This is a diagram illustrating the flow of condensed water in the cooler of the embodiment. Detailed Implementation

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that in the embodiments shown below, the same or common parts are labeled with the same reference numerals in the drawings, and their descriptions are omitted.

[0022] Figure 1 This is an exploded perspective view of the energy storage device according to the embodiment. (Refer to...) Figure 1 The energy storage device 1 of the embodiment is described below.

[0023] The energy storage device 1 of the embodiment is mounted on a hybrid vehicle capable of driving using the power of at least one of an electric motor and an engine, or an electric vehicle capable of driving using driving force obtained through electrical energy. The energy storage device 1 is mounted, for example, under the floor of the vehicle.

[0024] like Figure 1 As shown, the energy storage device 1 includes multiple energy storage stacks 10, a housing 20, a cooler 30, a heat-conducting component 40, a shared panel 50, and an inner heat-conducting layer 60.

[0025] Multiple energy storage stacks 10 are arranged side by side along a first direction (DR1 direction) orthogonal to the vertical direction. When the energy storage device 1 is mounted on a vehicle, this first direction is parallel to the vehicle's longitudinal direction.

[0026] Each of the multiple energy storage stacks 10 includes multiple energy storage cells 11 arranged along a second direction (DR2 direction) orthogonal to the vertical direction and the first direction. In the above-described mounting configuration, the second direction is parallel to the width direction of the vehicle.

[0027] The energy storage cell 11 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The energy storage cell 11 may have a square shape. The energy storage cell 11 can be constructed using a liquid electrolyte or a solid electrolyte. Furthermore, the energy storage cell 11 can also be a unit capacitor capable of storing electricity.

[0028] The housing 20 houses multiple battery packs 10. The housing 20 includes an upper housing 21 and a lower housing 22.

[0029] The upper housing 21 has a generally box-shaped form that opens downwards. The upper housing 21 can be made of metal. Moreover, for the purpose of weight reduction, the upper housing 21 can also be made of resin.

[0030] The lower housing 22 has a generally box-shaped form that opens upwards. The lower housing 22 is made of a metallic material. The lower housing 22 preferably has good thermal conductivity.

[0031] The lower housing 22 has a bottom 23. A plurality of battery stacks 10 are mounted on the bottom 23. The bottom 23 has an inner surface 23a and an outer surface 23b facing each other. The inner surface 23a faces the side of the plurality of battery stacks 10. The outer surface 23b faces the opposite side of the side where the plurality of battery stacks 10 are located.

[0032] The bottom 23 has a plurality of protrusions 25 projecting downward. The plurality of protrusions 25 are arranged side by side with gaps along a first direction. The plurality of protrusions 25 enter the gaps between adjacent cooling sections 32 (described later) at predetermined positions. The plurality of protrusions 25 extend along a second direction.

[0033] An inner thermally conductive layer 60 is disposed between each battery stack 10 and the inner surface 23a. The inner thermally conductive layer 60 also functions as an adhesive layer, bonding and fixing each battery stack 10 to the bottom 23. Each battery stack 10 is in thermal contact with the inner surface 23a through the inner thermally conductive layer 60.

[0034] The inner heat-conducting layer 60 is made of a resin component with thermal conductivity. For example, an adhesive containing silicone resin, acrylic resin, polyurethane resin or epoxy resin can be used as the inner heat-conducting layer 60.

[0035] The cooler 30 is a device for cooling the multiple battery stacks 10. Inside the cooler 30 is a refrigerant flow path for refrigerant to flow through. This refrigerant flow path is connected to the refrigerant inlet 61 and the refrigerant outlet 62. The refrigerant introduced from the refrigerant inlet 61 into the refrigerant flow path cools the multiple battery stacks 10 and is then discharged from the refrigerant outlet 62.

[0036] The cooler 30 is located below the bottom 23 of the lower housing 22. The cooler 30 is made of a metal material such as aluminum. For detailed information on the structure of the cooler 30, please refer to [link / reference needed]. Figure 2 and Figure 3 To be described later.

[0037] A heat-conducting component 40 is disposed between the outer surface 23b of the bottom 23 and the cooler 30. The multiple battery stacks 10 are cooled by the cooler 30 via this heat-conducting component 40, the bottom 23, and the inner heat-conducting layer 60. The heat-conducting component 40 also functions as an adhesive layer that bonds the bottom 23 to the cooler 30. For example, an adhesive containing silicone resin, acrylic resin, polyurethane resin, or epoxy resin can be used as the heat-conducting component 40.

[0038] The common plate 50 is configured to cover the aforementioned protrusions 25 and the cooler 30 from below. The common plate 50 protects the cooler 30 and prevents it from coming into contact with water. The common plate 50 is made of metal.

[0039] Figure 2 This is a top view of the cooler in the embodiment. Figure 3 This is a perspective view of the lower casing of the cooler with the embodiment fixed, viewed from the bottom side. It should be noted that... Figure 3 For simplicity, the shared board material 50 is omitted. (See reference...) Figure 2 and Figure 3 The detailed structure of the cooler 30 in the embodiment is explained.

[0040] The cooler 30 includes a pair of retaining parts 31, a plurality of cooling parts 32, and a front part 33. The aforementioned refrigerant flow path is arranged inside the pair of retaining parts 31, the plurality of cooling parts 32, and the front part 33.

[0041] A pair of retaining portions 31 extend along a first direction. The pair of retaining portions 31 are separately arranged along a second direction. The pair of retaining portions 31 hold a plurality of cooling portions 32.

[0042] Multiple cooling sections 32 are arranged at positions corresponding one-to-one with the multiple battery stacks 10. The number of cooling sections 32 corresponds to the number of battery stacks 10. Each of the multiple cooling sections 32 is arranged such that a pair of retaining sections 31 are connected along a second direction. The multiple cooling sections 32 are arranged side by side with gaps along a first direction.

[0043] The plurality of cooling sections 32 include cooling sections 32A and 32B having ends 37 and 38 facing the aforementioned protrusion 25. Cooling section 32A is disposed on one side of the first direction relative to the protrusion 25. Cooling section 32B is disposed on the other side of the first direction relative to the protrusion 25. That is, the protrusion 25 is disposed between cooling section 32A and cooling section 32B. Cooling section 32A and cooling section 32B have extensions 39.

[0044] Cooling sections 32A and 32B have a first end 32a and a second end 32b in a second direction. An extension 39 is provided on the side of the first end 32a and the side of the second end 32b.

[0045] The front portion 33 protrudes from one end of the pair of retaining portions 31 toward one side in a first direction. The front portion 33 has a generally C-shaped form. The aforementioned refrigerant inlet portion 61 and refrigerant outlet portion 62 are provided in the front portion 33.

[0046] Figure 4 It is along Figure 3 The cross-sectional view shown along line IV-IV. Figure 4 For simplicity, the diagram is shown below. Figure 3 Shared board material 50 (not shown).

[0047] like Figure 4 As shown, the protrusion 25 has a base plate portion 251, a pair of side wall portions 252, and a pair of flange portions 253. The base plate portion 251 forms the bottom of the protrusion 25. A hole portion 25h is provided in the base plate portion 251. It should be noted that the common plate 50 is fixed by inserting a fastening member 70 such as a bolt into the hole portion 25h.

[0048] A pair of sidewall portions 252 are connected to both ends of the base plate portion 251 in a first direction. The pair of sidewall portions 252 are arranged facing each other along the first direction. The pair of sidewall portions 252 are inclined such that they separate from each other along the first direction as they face upward. The pair of sidewall portions 252 extend along a second direction.

[0049] A pair of flange portions 253 are connected to the ends of a pair of sidewall portions 252, which are located on the opposite side of the base plate portion 251. The pair of flange portions 253 are connected to the upper ends of the pair of sidewall portions 252. The pair of flange portions 253 are arranged substantially parallel to each other along a first direction. The pair of flange portions 253 are fixed to the outer surface 23b by welding or the like.

[0050] The end 37 of the cooling section 32A faces the side wall portion 252 of the pair of side wall portions 252 located on one side in the first direction. The end 38 of the cooling section 32B faces the side wall portion 252 of the pair of side wall portions 252 located on the other side in the first direction.

[0051] The cooling section 32 includes an upper plate 35 and a lower plate 36. The upper plate 35 and the lower plate 36 are stacked in the vertical direction. The upper plate 35 and the lower plate 36 are joined at their respective mating surfaces on the end sides 37 and 38. The upper plate 35 and the lower plate 36 are joined, for example, by brazing.

[0052] The upper plate portion 35 has a plate-shaped portion 351, an inclined portion 352, and an edge portion 353. The plate-shaped portion 351 is formed to be generally flat. A heat-conducting member 40 is formed on the plate-shaped portion 351. The edge portion 353 forms the end of the upper plate portion 35 located on the other side of the first direction. The edge portion 353 is formed to be generally flat. The edge portion 353 is generally parallel to the first direction. The aforementioned mating surface is formed on the edge portion 353.

[0053] The inclined portion 352 connects the plate-shaped portion 351 to the edge portion 353. The inclined portion 352 is connected to the end of the edge portion 353 located on the opposite side of the side where the protrusion 25 is located. The inclined portion 352 is inclined upward in the opposite direction to the side where the protrusion 25 is located. A mating surface may be formed on the portion of the lower surface of the inclined portion 352 located on the side of the edge portion 353.

[0054] The lower plate portion 36 has a plate-shaped portion 361, an inclined portion 362, an edge portion 363, and a protruding portion 39. The plate-shaped portion 361 is provided in a concave-convex shape. Thus, when the plate-shaped portion 351 and the plate-shaped portion 361 overlap in the vertical direction, a gap is formed between the upper plate portion 35 and the lower plate portion 36, and a refrigerant flow path P is formed through this gap.

[0055] Edge portion 363 is located at a position corresponding to edge portion 353 and coincides with edge portion 353. Edge portion 363 is formed to be generally flat. Edge portion 363 is generally parallel to the first direction. The aforementioned mating surface is formed on edge portion 363.

[0056] An inclined portion 362 connects the plate-shaped portion 361 to the edge portion 363. The inclined portion 362 is connected to the end of the edge portion 363 located on the opposite side of the protrusion 25. The inclined portion 362 is inclined upwards in the opposite direction to the side where the protrusion 25 is located. The inclined portion 362 is provided along the aforementioned inclined portion 352. A mating surface can be formed on the upper surface of the inclined portion 362.

[0057] The protrusion 39 is provided on the end 37, 38 side such that it extends beyond the upper plate 35 toward the protrusion 25. The protrusion 39 is connected to the front end side of the edge portion 363. The protrusion 39 is provided from the edge portion 363 toward the protrusion 25. The protrusion 39 is substantially parallel to the second direction.

[0058] The front end of the protrusion 39 faces the side wall portion 252 in the first direction. The protrusion 39 is provided such that its front end side overlaps with the flange portion 253 in the vertical direction.

[0059] Reference Figure 5 This describes the situation where the liquid is bounced back through the extension of the cooler in the embodiment. Figure 5 Is with Figure 4 A cross-sectional view of the energy storage device at the corresponding location. (Refer to...) Figure 5 This explains the function of the protruding part 39.

[0060] like Figure 5As shown, when a liquid such as water is immersed between the common plate 50 and the cooler 30, due to vehicle movement, the liquid, as indicated by arrow AR1, touches the side wall portion 252 of the protrusion 25 and bounces back, thus potentially moving upwards. In such cases, by providing the protrusion 39 as described above, the upward-moving liquid can be bounced back downwards. This prevents liquid from adhering to the vicinity of the joint where the upper plate portion 35 and the lower plate portion 36 meet at the aforementioned mating surface. As a result, corrosion of the upper plate portion 35 and the lower plate portion 36 can be suppressed near the joint, and refrigerant leakage from the corroded areas can be prevented.

[0061] Furthermore, as described above, the protrusion 39 is provided on the first end 32a side and the second end 32b side. The first end 32a and the second end 32b are located on both sides of the vehicle's width direction. When the vehicle vibrates, especially on both sides of the vehicle's width direction, liquid is prone to move as shown by arrow AR1. Therefore, by providing the protrusion 39 on the first end 32a side and the second end 32b side, the installation area of ​​the protrusion 39 can be reduced, and liquid can be effectively prevented from adhering to the vicinity of the aforementioned joint.

[0062] Reference Figure 6 This illustrates the flow of condensed water in the cooler of the embodiment. Figure 6 Is with Figure 4 A cross-sectional view of the energy storage device at the corresponding location.

[0063] like Figure 6 As shown, when condensation occurs around the cooling section 32, as indicated by arrow AR2, the condensation can flow through the inclined section 352 toward the protrusion 39. This allows the condensation to remain on the front end side of the protrusion 39, which separates from the joint.

[0064] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the invention is set forth in the claims and includes all modifications within the meaning and scope of the claims.

Claims

1. An electric power storage device, characterized by comprising: Comprise: a lower case having a bottom portion provided with a protrusion projecting downward; and a cooler disposed below the bottom portion, the cooler including a cooling portion having an end portion facing the protrusion in a first direction orthogonal to an up-down direction, the cooling portion having an upper plate portion and a lower plate portion stacked in the up-down direction, the upper plate portion and the lower plate portion being joined at a joint surface each has at the end portion side, the lower plate portion having a protruding portion projecting toward the protrusion more than the upper plate portion at the end portion side.

2. The power storage device according to claim 1, wherein the upper plate portion has an edge portion provided with the joint surface and a slope portion connected to the edge portion from a side opposite to the side where the protrusion is present, and inclining upward as it tends in a direction opposite to the side where the protrusion is present.

3. The power storage device according to claim 1 or 2, wherein the cooling portion has a first end portion and a second end portion in a second direction orthogonal to the up-down direction and the first direction, the protruding portions are respectively provided at the first end portion side and the second end portion side of the cooling portion.

4. The power storage device according to any one of claims 1 to 3, further comprising a plate member covering the protrusion and the cooler from a lower side. ​

Images