Power storage device

Abstract

To prevent impact force from a lower part from being transmitted to a battery part 110.SOLUTION: A power storage device 11 is provided under a floor of a vehicle, and includes a battery part 110, and fixing members (a lower case 13 and an upper case 12) for fixing the battery part 110 under the floor of the vehicle. The fixing member includes a bottom plate 134 capable of heat conduction with the lower surface of the battery part 110. The bottom plate 134 has a plurality of thin plate-shaped heat dissipation fins 135 capable of conducting heat to the bottom plate 134 on the back surface of the surface on the battery unit 110 side. The cross-sectional area of the root portion of the heat dissipation fins 135A to 135C on the bottom plate 134 side may be smaller than the cross-sectional area of other portions different from the root portion. The extending direction from the root portion to the tip portion of the heat dissipation fins 135, 135A to 135D may form an angle of less than 90 degrees with respect to the bottom plate 134.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device, and more particularly to an electricity storage device provided under the floor of a vehicle. [Background technology]

[0002] Conventionally, there has been a device that includes a fuel cell and a mounting frame for fixing the fuel cell in a predetermined position under a vehicle floor panel (see, for example, Patent Document 1). In the device of Patent Document 1, the fuel cell and the mounting frame are in thermal contact with each other, and heat from the fuel cell is transferred to the mounting frame. The mounting frame is attached to the vehicle floor panel so that one main surface faces the exterior of the fuel cell vehicle body. This allows the heat transferred from the fuel cell to the mounting frame to be dissipated into the outside air from one main surface of the mounting frame. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-210176 Summary of the Invention [Problem to be solved by the invention]

[0004] The device of Patent Document 1 has a problem in that if an obstacle on the road surface comes into contact with the mounting frame, the impact force on the mounting frame is transmitted to the fuel cell.

[0005] This disclosure has been made to solve the above-mentioned problems, and its purpose is to provide an electricity storage device in which impact force from below is less likely to be transmitted to the battery unit. [Means for solving the problem]

[0006] The power storage device according to this disclosure is an power storage device provided under the floor of a vehicle, and includes a battery unit and a fixing member that fixes the battery unit to the underfloor of the vehicle. The fixing member includes a bottom plate that is thermally conductive with the underside of the battery unit. The bottom plate has a plurality of thin heat dissipation fins that are thermally conductive with the bottom plate on the back side of the surface facing the battery unit. The cross-sectional area of ​​the base portion of the heat dissipation fin on the bottom plate side is smaller than the cross-sectional area of ​​other portions different from the base portion.

[0007] With this configuration, the base of the heat dissipation fin has a smaller cross-sectional area than the other portions below the base. Therefore, when an impact from below is transmitted to the heat dissipation fin, the heat dissipation fin is likely to break from the base. If the heat dissipation fin breaks, the impact force is not transmitted to the battery unit. As a result, it is possible to provide an energy storage device in which the impact force from below is less likely to be transmitted to the battery unit.

[0008] The direction in which the heat dissipating fins extend from their bases to their tips may form an angle of less than 90 degrees with respect to the bottom plate.

[0009] With this configuration, the impact force transmitted vertically upward to the heat dissipation fins acts obliquely on the bottom plate. This separates the impact force into a force transmitted perpendicular to the bottom plate and a force acting on the heat dissipation fins in a direction parallel to the bottom plate. As a result, the force transmitted to the battery section via the bottom plate can be weakened.

[0010] According to another aspect of the present disclosure, an electric storage device is provided under the floor of a vehicle, and includes a battery unit and a fixing member that fixes the battery unit to the underfloor of the vehicle. The fixing member includes a bottom plate that is thermally conductive with the underside of the battery unit. The bottom plate has a plurality of thin heat dissipation fins that are thermally conductive with the bottom plate on the back side of the surface facing the battery unit. The heat dissipation fins extend from their bases on the bottom plate side to their tips at an angle of less than 90 degrees with respect to the bottom plate.

[0011] With this configuration, an impact force transmitted vertically upward to the heat dissipation fins acts obliquely on the bottom plate. Therefore, the impact force is divided into a force transmitted perpendicular to the bottom plate and a force acting on the heat dissipation fins in a direction parallel to the bottom plate, thereby weakening the force transmitted to the battery unit via the bottom plate. As a result, it is possible to provide an energy storage device in which impact forces from below are less likely to be transmitted to the battery unit.

[0012] The fixing member may further include a road surface side plate provided below the bottom plate and the heat dissipation fins, and a ventilation port that can introduce air from the outside into the space between the bottom plate and the road surface side plate where the heat dissipation fins are located by dynamic pressure generated by the vehicle moving.

[0013] With this configuration, the heat dissipation fins can be efficiently cooled, and as a result, the battery section, which is thermally conductive with the heat dissipation fins via the bottom plate, can be efficiently cooled.

[0014] The ventilation opening may be provided with a ventilation member having a ventilation opening with a larger opening area than the ventilation opening.

[0015] With this configuration, air can be introduced more efficiently from the outside through the ventilation opening, thereby allowing the heat dissipation fins and the battery section to be cooled more efficiently. [Effects of the Invention]

[0016] According to this disclosure, it is possible to provide an electricity storage device in which impact force from below is unlikely to be transmitted to the battery unit. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a side view that schematically illustrates a vehicle that includes an electricity storage device according to an embodiment of the present disclosure. [Figure 2] 1 is a perspective view schematically showing an electricity storage device and a vehicle frame according to an embodiment of the present invention; [Figure 3] 1 is a cross-sectional view showing an outline of how the electricity storage device of this embodiment is attached to a vehicle. [Figure 4] FIG. 2 is an enlarged view showing the vicinity of a heat dissipation fin of the electricity storage device according to this embodiment. [Figure 5] 10A and 10B are diagrams illustrating the air flow in a ventilation passage provided with heat dissipation fins according to this embodiment and a modified example of an electric storage device. [Figure 6] FIG. 10 is a perspective view schematically showing a modified example of an electricity storage device. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments and modifications according to the present disclosure will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. Note that the embodiments and modifications described below may be selectively combined as appropriate.

[0019] 1 to 8, a power storage device 11 according to a first embodiment and a vehicle 10 including the power storage device 11 will be described. FIG. 1 is a side view that schematically shows a vehicle 10 that includes a power storage device 11 according to an embodiment of the present disclosure. FIG. 2 is a perspective view that schematically shows the power storage device 11 and a vehicle frame 101 of this embodiment. FIG. 3 is a cross-sectional view that shows an outline of the attachment of the power storage device 11 of this embodiment to the vehicle 10. FIG. 4 is an enlarged view that shows the vicinity of a heat dissipation fin of the power storage device 11 of this embodiment. FIG. 5 is a diagram that shows the flow of air in a ventilation passage that is provided with the heat dissipation fin of this embodiment, and a power storage device 11A of a modified example. FIG. 6 is a perspective view that schematically shows the power storage device 11A of the modified example.

[0020] 1 to 6, the forward direction, rearward direction, upward direction, downward direction, rightward direction, and leftward direction respectively refer to the forward, backward, upward, downward, rightward, and leftward directions of the vehicle 10. The axes of the forward, backward, upward, downward, and leftward directions are perpendicular to one another.

[0021] Vehicle 10 is an electrically powered vehicle. The electrically powered vehicle may be an electric vehicle (BEV: Battery Electric Vehicle), a plug-in hybrid electric vehicle (PHEV: Plug-in Hybrid Electric Vehicle), a hybrid vehicle (HEV: Hybrid Electric Vehicle), or a fuel cell electric vehicle (FCEV: Fuel Cell Electric Vehicle).

[0022] As shown in Fig. 1, a vehicle 10 includes a vehicle frame 101 and an electricity storage device 11. The electricity storage device 11 is a device that can charge and discharge electric power for driving the vehicle 10. The electricity storage device 11 is disposed below a floor panel 4 of the vehicle 10. However, the present invention is not limited to this, and the electricity storage device 11 may be mounted on the bottom of the body of the vehicle 10 and form part of the floor of the vehicle interior.

[0023] As shown in FIG. 2 , the vehicle frame 101 includes a left roof rail 30, a right roof rail 31, a left side sill 32, a right side sill 33, a left first pillar 34, a left second pillar 35, a left third pillar 36, a right first pillar 37, a right second pillar 38, and a right third pillar 39.

[0024] The left roof rail 30 and the right roof rail 31 are disposed above the vehicle frame 101. The left roof rail 30 and the right roof rail 31 are disposed at a distance from each other in the left-right direction of the vehicle 10. The left roof rail 30 and the right roof rail 31 are disposed so as to extend in the front-rear direction of the vehicle 10.

[0025] The left side sill 32 and the right side sill 33 are disposed at the bottom of the vehicle frame 101. The left side sill 32 and the right side sill 33 are disposed at a distance from each other in the left-right direction of the vehicle 10. The left side sill 32 and the right side sill 33 are disposed so as to extend in the front-rear direction of the vehicle 10.

[0026] The left first pillar 34, the left second pillar 35, and the left third pillar 36 are disposed on the left side surface of the vehicle frame 101. The left first pillar 34 is disposed so as to connect the front end of the left side sill 32 and the front end of the left roof rail 30. The left second pillar 35 is disposed so as to connect the center portion of the left side sill 32 and the center portion of the left roof rail 30. The left third pillar 36 is disposed so as to connect the rear end of the left side sill 32 and the rear portion of the left roof rail 30. In other words, the left second pillar 35 is disposed rearward from and spaced apart from the left first pillar 34, and the left third pillar 36 is disposed rearward from and spaced apart from the left second pillar 35.

[0027] The right first pillar 37, the right second pillar 38, and the right third pillar 39 are disposed on the right side surface of the vehicle frame 101. The right first pillar 37 is provided to connect the front end of the right side sill 33 to the front end of the right roof rail 31. The right second pillar 38 is provided to connect the center of the right side sill 33 to the center of the right roof rail 31. The right third pillar 39 is provided to connect the rear end of the right side sill 33 to the rear portion of the right roof rail 31. In other words, the right second pillar 38 is disposed rearward from and spaced apart from the right first pillar 37, and the right third pillar 39 is disposed rearward from and spaced apart from the right second pillar 38. A floor panel 4 is provided between the left side sill 32 and the right side sill 33.

[0028] Fig. 3 shows a cross section taken along line AA in Fig. 1. As shown in Fig. 3, the vehicle frame 101 further includes a left side member 41 and a right side member 42. The left side member 41 and the right side member 42 are disposed inside the left side sill 32 and the right side sill 33, spaced apart in the left-right direction. The left side member 41 and the right side member 42 are disposed to extend in the front-rear direction of the vehicle 10.

[0029] The power storage device 11 is disposed between the left side member 41 and the right side member 42. Gaps are provided between the power storage device 11 and the left side member 41 and the right side member 42 in the left-right direction. This makes it possible to suppress input of an impact to the power storage device 11 even in the event of a side collision of the vehicle 10.

[0030] Fixed portions are provided on both side surfaces of the power storage device 11 in the width direction of the vehicle 10. The fixed portions are fixed to the left side member 41 and the right side member 42 by fastening members 8.

[0031] The power storage device 11 includes an upper case 12, a lower case 13, and a battery unit 110. The battery unit 110 includes at least one storage cell, which is a secondary battery. The storage cell may be a lithium-ion battery, an all-solid-state battery, or a nickel-metal hydride battery, or may be another type of secondary battery. The battery unit 110 may be configured to include, for example, one or more storage modules each including one or more storage cells, or may be configured with one or more storage cells, or may be a battery pack equipped with a cover that houses the one or more storage modules or one or more storage cells.

[0032] The upper case 12 and the lower case 13 are made of steel (for example, steel plate). The upper case 12 and the lower case 13 may be made of other materials, such as resin. The upper case 12 and the lower case 13 are joined at their flanges (for example, fastened at the flanges with bolts and nuts) to form an integrated case. A space is formed inside the case of the electricity storage device 11. The upper case 12 is located above the lower case 13. The electricity storage device 11 is attached to the vehicle 10 so that its thickness direction coincides with the up-down direction of the vehicle 10. The longitudinal direction and lateral direction of the electricity storage device 11, which are perpendicular to the thickness direction, coincide with the front-rear direction and left-right direction of the vehicle 10, respectively. The longitudinal direction and lateral direction of the electricity storage device 11 are several times longer than the thickness direction.

[0033] Fig. 4 shows an enlarged view of part B in Fig. 3. Fig. 5 shows a cross section taken along line CC in Fig. 3. As shown in Figs. 3 to 5, the lower case 13 is provided with a road surface interference countermeasure structure 133. The road surface interference countermeasure structure 133 includes a bottom plate 134, a plurality of heat dissipation fins 135, and a road surface side plate 136.

[0034] The bottom plate 134 is in contact with the lower surface of the battery module 110 and is capable of thermal conduction with the battery module 110. The bottom plate 134 and the battery module 110 are fixed together by some method (for example, adhesive or screw joint).

[0035] Each heat dissipation fin 135 is a thin plate with its longitudinal direction aligned with the front-to-rear direction of the vehicle 10, is provided on the back surface of the bottom plate 134 on the side facing the battery module 110, and is capable of thermal conduction with the bottom plate 134. The heat dissipation fins 135 may be formed integrally with the bottom plate 134, or may be fixed to the bottom plate 134 by some method (for example, adhesive, welding, or melt-adhesion). As shown in FIG. 4(A), the extension direction of the heat dissipation fins 135 from their bases to their tips forms an angle of less than 90 degrees with respect to the bottom plate 134.

[0036] In this embodiment, a gap is provided between the road surface side plate 136 and the heat dissipation fins 135, but this gap may not be provided. A ventilation passage 132 is formed between the road surface side plate 136 and the bottom plate 134. A ventilation opening 131 is provided at one end of the ventilation passage 132 on the front side of the vehicle 10. The ventilation opening 131 can introduce air from the outside into the ventilation passage 132 by dynamic pressure generated by the vehicle 10 traveling. The heat dissipation fins 135 are provided so that the longitudinal direction of the heat dissipation fins 135 is approximately parallel to the direction of air flow in the ventilation passage 132. As a result, the air introduced from the ventilation opening 131 flows through the ventilation passage 132 and efficiently removes heat from the heat dissipation fins 135.

[0037] As shown in FIG. 5, a wind guide member 150 having a wind guide opening 151 with a larger opening area than that of the wind guide opening 131 may be provided at the wind guide opening 131 of the modified power storage device 11A.

[0038] [Variations] (1) In the above-described embodiment, as shown in FIG. 4(A), the cross-sectional area of ​​the base portion of the heat dissipation fin 135 on the bottom plate 134 side is the same as the cross-sectional area of ​​the other portion different from the base portion. The cross-sectional area is the area of ​​a cross section perpendicular to the extension direction of the heat dissipation fin 135. However, this is not limited thereto, and as shown in FIGS. 4(B) to 4(D), the heat dissipation fins 135A to 135C of the road surface interference countermeasure structures 133A to 133CPU may have notches 137A to 137C, respectively. In other words, the cross-sectional area of ​​the base portion of the heat dissipation fins 135A to 135C on the bottom plate 134 side may be smaller than the cross-sectional area of ​​the other portion different from the base portion.

[0039] (2) In the above-described embodiment, as shown in Fig. 4(A), the surface of the tip of the heat dissipation fin 135 of the road surface interference countermeasure structure 133 is parallel to the road surface side plate 136. However, this is not limited to this, and as shown in Fig. 4(E), the surface of the tip of the heat dissipation fin 135D of the road surface interference countermeasure structure 133D may not be parallel to the road surface side plate 136. Furthermore, the surface of the tip of the heat dissipation fin 135D may be perpendicular to the main plane of the wide area of ​​the thin plate.

[0040] (3) In the above-described embodiment, as shown in Figures 3 and 5, the power storage device 11 is provided with the upper case 12. However, this is not limited thereto, and if the battery unit 110 is provided with a cover, the upper case 12 may not be provided. In this case, the lower case 13 functions as a fixing tray for the battery unit 110.

[0041] (4) The above-described embodiment can be understood as a disclosure of power storage device 11, 11A, the structure of power storage device 11, 11A, or vehicle 10 equipped with power storage device 11, 11A.

[0042] [summary] (1) As shown in Figures 1 to 3 and 5, the power storage device 11, 11A is provided under the floor of the vehicle 10 and includes a battery unit 110 and fixing members (for example, a lower case 13, an upper case 12, and a fixing tray) that fix the battery unit 110 to the underfloor of the vehicle 10. The fixing members include a bottom plate 134 that is thermally conductive with the underside of the battery unit 110. The bottom plate 134 has, on the back side of the surface facing the battery unit 110, a plurality of thin heat dissipation fins 135 that are thermally conductive with the bottom plate 134.

[0043] (1-1) As shown in FIGS. 4(B) to 4(D), the cross-sectional area of ​​the base portion of the heat dissipation fins 135A to 135C on the bottom plate 134 side may be smaller than the cross-sectional area of ​​other portions different from the base portion.

[0044] As a result, the cross-sectional area of ​​the base portions of the heat dissipation fins 135A-135C is smaller than that of the other portions below the base portions. Therefore, when an impact from below is transmitted to the heat dissipation fins 135A-135C, the heat dissipation fins 135A-135C are likely to break from the base portions. If the heat dissipation fins 135A-135C break, the energy absorbed by the breakage prevents the impact force from being transmitted to the battery module 110. As a result, it is possible to make it difficult for the impact force from below to be transmitted to the battery module 110.

[0045] (1-2) As shown in FIGS. 3 and 4, the direction of extension of the heat dissipation fins 135, 135A to 135D from their bases to their tips may form an angle of less than 90 degrees with respect to the bottom plate .

[0046] As a result, an impact force transmitted vertically upward to the heat dissipation fins 135, 135A to 135D acts obliquely on the bottom plate 134. Therefore, the impact force is divided into a force transmitted perpendicular to the bottom plate 134 and a force acting on the heat dissipation fins 135, 135A to 135D in a direction parallel to the bottom plate 134, thereby weakening the force transmitted to the battery module 110 via the bottom plate 134. As a result, it is possible to make it difficult for an impact force from below to be transmitted to the battery module 110.

[0047] Furthermore, compared to when the extension direction of the heat dissipation fins 135, 135A to 135D is at 90 degrees relative to the bottom plate 134, the vertical height of the vehicle 10 of the road surface interference prevention structures 133, 133A to 133D can be reduced while maintaining similar heat dissipation performance.

[0048] Furthermore, if the extension direction of the heat dissipation fins 135, 135A-135D is at an angle of 90 degrees relative to the bottom plate 134, when an impact force is applied to the road surface side plate 136, the heat dissipation fins 135, 135A-135D will be stretched between the bottom plate 134 and the road surface side plate 136, and the road surface interference countermeasure structures 133, 133A-133D will not be usable as energy absorption (hereinafter referred to as "EA") structures. By making the extension direction of the heat dissipation fins 135, 135A-135D form an angle of less than 90 degrees relative to the bottom plate 134, the road surface interference countermeasure structures 133, 133A-133D can be effectively used as EA structures while still exhibiting a heat dissipation effect.

[0049] (2) As shown in Figures 3 and 5, the fixing member may further include a road surface side plate 136 provided below the bottom plate 134 and the heat dissipation fins 135, and a ventilation opening 131 that can introduce air from the outside into the ventilation passage 132 where the heat dissipation fins 135 are located between the bottom plate 134 and the road surface side plate 136 by dynamic pressure generated by the vehicle 10 moving.

[0050] This allows the heat dissipation fins 135 to be efficiently cooled. As a result, the battery module 110, which is thermally conductive with the heat dissipation fins 135, can be efficiently cooled via the bottom plate 134. Note that compared to when the heat dissipation fins 135 are not present, when the heat dissipation fins 135 are present, the cooling effect due to natural heat dissipation is high even when there is no dynamic pressure generated by the vehicle 10 traveling.

[0051] (3) As shown in FIGS. 5 and 6, the ventilation opening 131 may be provided with a ventilation member 150 having a ventilation opening 151 with a larger opening area than the ventilation opening 131.

[0052] This allows air to be introduced more efficiently from the outside through the ventilation opening 131. As a result, the heat dissipation fins and the battery section can be cooled more efficiently.

[0053] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0054] 4 floor panel, 8 fastening member, 10 vehicle, 11, 11A power storage device, 12 upper case, 13 lower case, 30 left roof rail, 31 right roof rail, 32 left side sill, 33 right side sill, 34 left first pillar, 35 left second pillar, 36 left third pillar, 37 right first pillar, 38 right second pillar, 39 right third pillar, 41 left side member, 42 right side member, 101 vehicle frame, 110 battery section, 131 ventilation opening, 132 ventilation path, 133, 133A to 133D road surface interference prevention structure, 134 bottom plate, 135, 135A to 135D heat dissipation fins, 136 road surface side plate, 150 air guide member, 151 air guide opening.

Claims

1. An electricity storage device provided under the floor of a vehicle, A battery section; a fixing member that fixes the battery unit to an underfloor of the vehicle, the fixing member includes a bottom plate that is thermally conductive with a lower surface of the battery portion, the bottom plate has a plurality of thin plate-shaped heat dissipation fins on a back surface of the surface on the side of the battery section, the heat dissipation fins being capable of thermal conduction with the bottom plate; The cross-sectional area of ​​the base portion of the heat dissipation fin on the bottom plate side is smaller than the cross-sectional area of ​​other portions different from the base portion.

2. The power storage device according to claim 1 , wherein the direction in which the heat dissipation fins extend from the base portion to the tip portion forms an angle of less than 90 degrees with respect to the bottom plate.

3. An electricity storage device provided under the floor of a vehicle, A battery section; a fixing member that fixes the battery unit to an underfloor of the vehicle, the fixing member includes a bottom plate that is thermally conductive with a lower surface of the battery portion, the bottom plate has a plurality of thin plate-shaped heat dissipation fins on a back surface of the surface on the side of the battery section, the heat dissipation fins being capable of thermal conduction with the bottom plate; The heat dissipation fins extend from their bases on the bottom plate side to their tips at an angle of less than 90 degrees relative to the bottom plate.

4. The fixing member is a road surface side plate provided under the bottom plate and the heat dissipation fins; 4. The energy storage device according to claim 1, further comprising a ventilation port in a space between the bottom plate and the road surface side plate where the heat dissipation fins are present, through which air can be introduced from the outside by dynamic pressure generated by the vehicle traveling.

5. The power storage device according to claim 4 , wherein the ventilation opening is provided with a wind guide member having a wind guide opening with an opening area larger than that of the ventilation opening.

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