Battery pack

Abstract

The utility model provides a battery pack which can restrain dew from being generated on a cooling surface under the condition that the number of battery modules accommodated in a shell is reduced from the maximum number. A battery pack is provided with: a battery module having a plurality of battery cells arranged side by side in a first direction and stacked; a case capable of accommodating the plurality of battery modules in a second direction orthogonal to the first direction; and a plurality of cooling surfaces for cooling the battery modules, the plurality of cooling surfaces being provided at positions facing the battery modules so as to correspond to the maximum number of battery modules housed in the case, the number of battery modules housed in the case being less than the maximum number, the case having a heat insulating material inside the case, and the heat insulating material being provided between the battery modules housed in the case and the battery modules. And a heat insulating material filled in a gap formed by reducing the number of the accommodated battery modules, the heat insulating material being pressed against the cooling surface.

Description

Technical Field

[0001] This utility model relates to a battery pack. Background Art

[0002] In Patent Document 1, a battery pack is disclosed in which a cooling surface of a temperature control plate through which cooling water flows contacts a lower surface of a battery module to cool the battery module.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-053273

[0004] In the battery pack disclosed in Patent Document 1, when the number of battery modules housed in a housing decreases from the maximum number, since an air layer exists around the cooling surface in a portion where there is no battery module, air inside the housing may come into contact with the cooling surface and condensation may occur. Summary of the Utility Model

[0005] This utility model is achieved in view of the above problems, and its object is to provide a battery pack that can suppress condensation on the cooling surface when the number of battery modules housed in a housing decreases from the maximum number.

[0006] To solve the above problems, the battery pack according to this utility model includes: battery modules having a plurality of battery cells arranged and stacked in a first direction; a housing capable of arranging and housing a plurality of battery modules in a second direction orthogonal to the first direction; and a plurality of cooling surfaces provided at positions opposite to the respective battery modules corresponding to the maximum number of battery modules that can be housed in the housing, for cooling the respective battery modules. When the number of battery modules housed in the housing is less than the maximum number, a heat insulating material is provided inside the housing, and the heat insulating material fills a gap formed by reducing the housed battery modules, and the heat insulating material is pressed against the cooling surface.

[0007] Thereby, when the number of battery modules housed in the housing decreases from the maximum number, an air layer can be excluded between the cooling surface and the heat insulating material, so that it is possible to suppress air inside the housing from coming into contact with the cooling surface and being cooled, and condensation occurring on the cooling surface.

[0008] In addition, in the above battery pack, the housing may also be composed of a lower housing and an upper housing, and includes: a pair of restraining end plates that sandwich the heat insulating material from the first direction; a pair of restraining side plates that sandwich the heat insulating material from the second direction; and a restraining band that is disposed on a surface of the heat insulating material on the side opposite to the cooling surface side in a third direction orthogonal to the first direction and the second direction, and extends along the first direction. The pair of restraining side plates and the restraining band are fixed to the pair of restraining end plates, and in a state where the heat insulating material is pressed against the cooling surface, the pair of restraining end plates are fixed to the lower housing.

[0009] Thus, the heat insulating material can be constrained and pressed against the cooling surface.

[0010] In addition, in the above battery pack, it is also possible to correspond to the maximum number of battery modules that can be accommodated in the housing respectively, and a plurality of coolers are provided at positions opposite to each battery module across the housing, and the inner surface of the part of the housing where the cooler is located forms a cooling surface.

[0011] Thus, condensation on the cooling surface formed on the housing can be suppressed.

[0012] The battery pack according to the present utility model has the following effects: when the number of battery modules accommodated in the housing decreases from the maximum number, the air layer can be excluded from between the cooling surface and the heat insulating material, so that it is possible to suppress the air in the housing from contacting the cooling surface and being cooled, thereby preventing condensation from occurring on the cooling surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram showing a schematic structure when observing the inside of the battery pack according to the embodiment from above.

[0014] Figure 2 It is a cross-sectional view showing a schematic structure when observing the battery pack according to the embodiment from the side.

[0015] Figure 3 It is a perspective view showing a heat insulating structure formed by constraining the packing material according to the embodiment with a constraining member.

[0016] Figure 4 It is an enlarged cross-sectional view showing the packing material and its vicinity in the battery pack according to the embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] Hereinafter, an embodiment of the battery pack according to the present utility model will be described. In addition, the present utility model is not limited by this embodiment.

[0018] Figure 1 It is a diagram showing a schematic structure when observing the inside of the battery pack 1 according to the embodiment from above. Figure 2 It is a cross-sectional view showing a schematic structure when observing the battery pack 1 according to the embodiment from the side.

[0019] The battery pack 1 according to the embodiment is configured by accommodating a plurality of battery modules 2, a packing material 3, device components 4, etc. in a housing 5. The housing 5 is composed of a lower housing 51 and an upper housing 52, and can accommodate a plurality of battery modules 2. In addition, Figure 1 The illustration of the upper housing 52 is omitted.

[0020] In the battery pack 1 according to this embodiment, up to four battery modules 2 can be accommodated in the housing 5, but the number of accommodated battery modules 2 is reduced from the maximum number to three battery modules 2 accommodated in the housing 5. The battery module 2 has a plurality of battery cells arranged and stacked in a manner arranged in the stacking direction Y (first direction) indicated by the arrow Y in Figure 1 Each battery cell is formed in a rectangular parallelepiped shape, such as a lithium-ion battery. The plurality of battery modules 2 are arranged in a manner arranged in the arrangement direction X (second direction) indicated by the arrow X in Figure 1 and are accommodated in the housing 5. The arrangement direction X is a direction orthogonal to the stacking direction Y and Figure 2 the vertical direction Z (third direction) of the battery pack 1 indicated by the arrow Z in

[0021] The gap filler 3 is a heat insulating material made of a foamed resin or the like, and is filled in the gap formed by reducing the battery module 2 in the housing 5. As the above-mentioned foamed resin, for example, foamed polypropylene, foamed styrene, etc. can be cited. The shape and size of the gap filler 3 are substantially the same as the shape and size of the battery module 2.

[0022] The device component 4 is, for example, a monitoring unit that monitors the voltage or temperature of each battery module 2.

[0023] The lower housing 51 has a shape that opens upward, and has a bottom surface portion 511, a side surface portion 512, and a flange portion 513. The lower housing 51 is made of a metal material such as iron or aluminum, for example. The bottom surface portion 511 is disposed below the plurality of battery modules 2, the gap filler 3, and the device component 4. A plurality of coolers 6 are located below the bottom surface portion 511 of the lower housing 51, respectively corresponding to the maximum number of battery modules 2 that can be accommodated in the housing 5, and are disposed at positions opposite to each battery module 2 via the bottom surface portion 511 to cool each battery module 2. In the battery pack 1 according to this embodiment, four coolers 6 are provided below the bottom surface corresponding to the maximum number of four battery modules 2 that can be accommodated in the housing 5. Therefore, as Figure 1 and Figure 2 shown, when the number of battery modules 2 that can be accommodated in the housing 5 is reduced to three battery modules 2 and one gap filler 3 is accommodated in the housing 5, one cooler 6 is also provided below the gap filler 3 through the bottom surface portion 511.

[0024] The side surface portion 512 of the lower housing 51 rises from the periphery of the bottom surface portion 511 and surrounds the plurality of battery modules 2, the gap filler 3, and the device component 4. The flange portion 513 of the lower housing 51 has a shape that protrudes outward from the upper end of the side surface portion 512.

[0025] The upper housing 52 has a shape that opens downward, and has a top surface portion 521, a side surface portion 522, and a flange portion 523. The upper housing 52 is made of a metal material such as iron or aluminum, for example. The upper housing 52, together with the lower housing 51, houses a plurality of battery modules 2, a filler material 3, and device components 4, etc. The top surface portion 521 is formed in a flat plate shape, for example, and is disposed above the plurality of battery modules 2, the filler material 3, and the device components 4. A gap is formed between the top surface portion 521 and the plurality of battery modules 2, the filler material 3, and the device components 4.

[0026] The side surface portion 522 of the upper housing 52 extends downward from the periphery of the top surface portion 521 and surrounds the periphery of the plurality of battery modules 2, the filler material 3, and the device components 4. The flange portion 523 of the upper housing 52 has a shape that projects outward from the lower end of the side surface portion 522. The flange portion 523 of the upper housing 52 is fixed to the flange portion 513 of the lower housing 51 by fastening members such as bolts.

[0027] Figure 3 It is a perspective view showing a heat insulating structure formed by constraining the filler material 3 according to the embodiment with a constraining member.

[0028] The filler material 3 housed in the battery pack 1 according to the embodiment is constrained by constraining members such as a pair of constraining end plates 31, 32, a pair of constraining side plates 33, 34, and a constraining band 35 to form a heat insulating structure. The pair of constraining end plates 31, 32, the pair of constraining side plates 33, 34, and the constraining band 35 are made of a metal material such as iron, for example.

[0029] The pair of constraining end plates 31, 32 sandwich the filler material 3 in the Figure 3 in the stacking direction Y. The pair of constraining side plates 33, 34 extend along the stacking direction Y respectively, and sandwich the filler material 3 in the Figure 3 in the arrangement direction X. The two end portions of the pair of constraining side plates 33, 34 are fixed to the pair of constraining end plates 31, 32 by fastening members such as rivets or bolts. The constraining band 35 is disposed in the vertical direction Z with respect to the filler material 3 on the surface of the filler material 3 opposite to the cooling surface 8 (refer to Figure 4 ), that is, the upper surface 3a (refer to Figure 4 ). The constraining band 35 extends along the stacking direction Y and clamps the pair of constraining end plates 31, 32 in the direction in which the pair of constraining end plates 31, 32 approach each other. The two end portions of the constraining band 35 are fixed to the pair of constraining end plates 31, 32 by rivets or bolts.

[0030] A pair of constraint end plates 31, 32 also function as a restricting member for restricting the position of the interstice material 3 in the stacking direction Y. In addition, a pair of constraint side plates 33, 34 also function as a restricting member for restricting the position of the interstice material 3 in the arrangement direction X. In addition, a pair of constraint side plates 33, 34 and a constraint band 35 also function as a restricting member for restricting the position of the interstice material 3 in the up-down direction Z.

[0031] Figure 4 FIG. is an enlarged cross-sectional view showing the interstice material 3 and its vicinity in the battery pack 1 according to the embodiment.

[0032] As Figure 4 shown, the cross-sections of a pair of constraint side plates 33, 34 are formed in a substantially C-shape, having side plate portions 331, 341 and upper flange portions 332, 342 and lower flange portions 333, 343 that stand upright inward from the upper and lower ends of the side plate portions 331, 341. The side plate portions 331, 341 face the side surfaces 3c, 3d of the interstice material 3 in the arrangement direction X. The upper flange portions 332, 342 face the upper surface 3a of the interstice material 3 from the upper side in the up-down direction Z. The lower flange portions 333, 343 face the lower surface 3b of the interstice material 3 from the lower side in the up-down direction Z. The interstice material 3 is sandwiched between the upper flange portions 332, 342 and the lower flange portions 333, 343 of a pair of constraint side plates 33, 34.

[0033] In the battery pack 1 according to the embodiment, as Figure 4 shown, a cooling surface 8 is formed on the inner surface of a portion of the bottom surface portion 511 of the lower housing 51 where the cooler 6 is located below, for cooling the battery module 2 through heat exchange with a cooling medium flowing in the internal flow path of the cooler 6. And, in the battery pack 1 according to the embodiment, in a state where the lower surface 3b of the interstice material 3 is pressed against the cooling surface 8 in the bottom surface portion of the lower housing 51, a pair of constraint side plates 33, 34 are fixed to the bottom surface portion 511 of the lower housing 51 by a plurality of bolts 38 via fastening brackets 36, 37. In addition, the fastening brackets 36, 37 are made of a metal material such as iron, for example.

[0034] In the battery pack 1 according to the embodiment, by pressing the interstice material 3 against the cooling surface 8 in the bottom surface portion 511 of the lower housing 51, an air layer can be excluded between the cooling surface 8 and the interstice material 3. Thus, in the battery pack 1 according to the embodiment, it is possible to suppress the case where air in the housing 5 contacts the cooling surface 8 and is cooled, resulting in condensation on the cooling surface 8. In particular, in the battery pack 1 according to the embodiment, it is possible to suppress the case where air containing a large amount of moisture and heated by the battery module 2 generating heat in the housing 5 contacts the cooling surface 8 and is cooled, resulting in condensation on the cooling surface 8.

[0035] In addition, in the battery pack 1 according to the embodiment, a cooler 6 is provided at a position opposite to the battery module 2 via the bottom surface portion 511 of the lower case 51, and the inner surface of the portion of the cooler 6 located below is used as a cooling surface 8 for cooling the battery module 2, but it is not limited thereto. That is, in the battery pack 1 according to the embodiment, the cooler 6 may also be provided between the bottom surface portion 511 of the lower case 51 and the battery module 2, and the surface of the cooler 6 in contact with the battery module 2 is used as the cooling surface 8.

Claims

1. A battery pack comprising: A battery module having a plurality of battery cells arranged and stacked in a first direction; A housing capable of arranging and accommodating a plurality of the battery modules in a second direction orthogonal to the first direction; and A plurality of cooling surfaces are respectively arranged at positions opposite to the battery modules corresponding to the maximum number of the battery modules that can be accommodated in the housing, and are used to cool the battery modules. The battery pack is characterized in that the number of the battery modules accommodated in the housing is less than the maximum number. The housing has a heat insulating material therein, and the heat insulating material is filled in a gap formed by reducing the number of battery modules housed therein. The heat insulating material is pressed and arranged on the cooling surface.

2. The battery pack according to claim 1, characterized in that: The housing is composed of a lower housing and an upper housing, and has: a pair of restraining end plates, sandwiching the thermal insulation material from the first direction; a pair of restraining side plates, sandwiching the thermal insulation material from the second direction; as well as a restraining band arranged on a surface of the heat insulating material opposite to the cooling surface side in a third direction orthogonal to the first direction and the second direction, and extending along the first direction, The pair of restraining side plates and the restraining belt are fixed to the pair of restraining end plates, The pair of restraining end plates are fixed to the lower case in a state where the heat insulating material is pressed against the cooling surface.

3. The battery pack according to claim 1 or 2, characterized in that: A plurality of coolers are provided at positions opposite to the battery modules across the housing, corresponding to the maximum number of battery modules that can be accommodated in the housing, and an inner surface of a portion of the housing where the coolers are located forms the cooling surface.

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