Battery pack

Abstract

To provide a battery pack capable of suppressing the generation of dew condensation onto a cooling surface in the case where the number of battery modules housed in a case is reduced from the maximum number.SOLUTION: A battery pack in which the number of battery modules housed in a case is reduced from the maximum number comprises: a battery module in which a plurality of battery cells are arrayed in a first direction, and laminated; a case which can house the plurality of battery modules such that the plurality of battery modules are arrayed in a second direction orthogonal to the first direction; and a plurality of cooling surfaces that correspond to the maximum number of the respective battery modules, which can be housed in the case, are provided to a position facing the respective battery modules, and cool the respective battery modules, and comprises a heat insulation material that is filled in a gap formed by reducing the number of battery modules to be housed in the case. The heat insulation material is provided so as to be depressed to the cooling surface.SELECTED DRAWING: Figure 4

Description

Technical Field

[0006]

[0001] The present invention relates to a battery pack.

Background Art

[0002] Patent Document 1 discloses a battery pack in which a cooling surface of a temperature control plate through which cooling water flows is brought into contact with a lower surface of a battery module to cool the battery module.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the battery pack disclosed in Patent Document 1, when the number of battery modules accommodated in the case is reduced from the maximum number, an air layer exists around the cooling surface at a location where there is no battery module, so there is a risk that the air in the case comes into contact with the cooling surface and condensation occurs.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a battery pack capable of suppressing the occurrence of condensation on a cooling surface when the number of battery modules accommodated in a case is reduced from the maximum number.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the battery pack according to the present invention comprises: a battery module in which a plurality of battery cells are arranged in a line in a first direction and stacked; a case capable of accommodating a plurality of the battery modules arranged in a second direction perpendicular to the first direction; and a plurality of cooling surfaces provided at positions opposite each battery module, corresponding to the maximum number of battery modules that can be accommodated in the case, for cooling each battery module, wherein the number of battery modules accommodated in the case is reduced to the maximum number, and the case is provided with a heat insulating material that is packed into the gaps formed by the reduction in the number of battery modules to be accommodated, and the heat insulating material is provided pressed against the cooling surfaces.

[0007] This allows the air layer between the cooling surface and the insulation material to be eliminated when the number of battery modules housed in the case is reduced from the maximum number. As a result, the air inside the case comes into contact with the cooling surface and cools it, suppressing the formation of condensation on the cooling surface.

[0008] Furthermore, in the above, the case is composed of a lower case and an upper case, and includes a pair of restraining end plates that clamp onto the heat insulating material from a first direction, a pair of restraining side plates that clamp onto the heat insulating material from a second direction, and a restraining band that is positioned on the side of the heat insulating material opposite to the cooling surface side in a third direction perpendicular to the first and second directions and extends in the first direction, wherein the pair of restraining side plates and the restraining band are fixed to the pair of restraining end plates, and the pair of restraining end plates may be fixed to the lower case while the heat insulating material is pressed against the cooling surface.

[0009] This allows the insulation material to be restrained and pressed against the cooling surface.

[0010] Furthermore, in the above, a plurality of coolers may be provided at positions facing each battery module via the case, corresponding to the maximum number of battery modules that can be housed in the case, and the inner surface of the portion of the case where the coolers are located may form the cooling surface.

[0011] This prevents condensation from forming on the cooling surface of the case. [Effects of the Invention]

[0012] The battery pack according to the present invention has the effect of eliminating the air layer between the cooling surface and the heat insulating material when the number of battery modules housed in the case is reduced from the maximum number, thereby preventing condensation from forming on the cooling surface as the air inside the case comes into contact with and cools the cooling surface. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a diagram showing the schematic configuration of the battery pack according to the embodiment, viewed from above. [Figure 2] Figure 2 is a cross-sectional view showing the schematic configuration of the battery pack according to the embodiment, as viewed from the side. [Figure 3] Figure 3 is a perspective view showing a thermal insulation structure constructed by restraining a gap-filling material with a restraining member according to the embodiment. [Figure 4] Figure 4 is an enlarged cross-sectional view showing the gap-filling material and its vicinity in a battery pack according to the embodiment. [Modes for carrying out the invention]

[0014] The following describes an embodiment of the battery pack according to the present invention. However, the present invention is not limited to this embodiment.

[0015] Figure 1 is a diagram showing the schematic configuration of the battery pack 1 according to the embodiment, viewed from above. Figure 2 is a cross-sectional view showing the schematic configuration of the battery pack 1 according to the embodiment, viewed from the side.

[0016] The battery pack 1 according to this embodiment is constructed by housing a plurality of battery modules 2, gap-filling material 3, and equipment components 4, etc., within a case 5. The case 5 is composed of a lower case 51 and an upper case 52, and is capable of housing a plurality of battery modules 2. Note that the upper case 52 is not shown in Figure 1.

[0017] In the battery pack 1 according to this embodiment, a maximum of four battery modules 2 can be housed in the case 5, but the number of battery modules 2 housed is reduced from the maximum number to three battery modules 2 housed in the case 5. The battery module 2 has a plurality of battery cells stacked and arranged in the stacking direction Y (first direction) indicated by arrow Y in Figure 1. Each battery cell is formed in a rectangular parallelepiped, and for example, a lithium-ion battery is used. The plurality of battery modules 2 are arranged in the arrangement direction X (second direction) indicated by arrow X in Figure 1, which is perpendicular to the stacking direction Y and the vertical direction Z (third direction) of the battery pack 1 indicated by arrow Z in Figure 2, and housed in the case 5. The battery module 2 is restrained by a pair of end plates, a pair of side plates, and known restraining members such as restraining bands so as to hold the plurality of battery cells together.

[0018] The gap-filling material 3 is an insulating material made of foamed resin or the like that is used to fill the gaps created by reducing the number of battery modules 2 within the case 5. Examples of the foamed resin include expanded polypropylene and expanded styrene. The shape and size of the gap-filling material 3 are approximately the same as the shape and size of the battery modules 2.

[0019] Equipment component 4 is, for example, a monitoring unit that monitors the voltage, temperature, etc., of each battery module 2.

[0020] The lower case 51 has an upwardly opening shape and has a bottom surface portion 511, a side surface portion 512, and a flange portion 513. The lower case 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 filler material 3, and the device components 4. Below the bottom surface portion 511 of the lower case 51, a plurality of coolers 6 for cooling each of the battery modules 2 are provided at positions facing the battery modules 2 through the bottom surface portion 511, corresponding to the maximum number of battery modules 2 that can be accommodated in the case 5. In the battery pack 1 according to the embodiment, four coolers 6 are provided below the bottom surface portion corresponding to each of the four battery modules 2 that can be accommodated in the case 5. Therefore, as shown in FIGS. 1 and 2, when the number of battery modules 2 accommodated in the case 5 is reduced and three battery modules 2 and one filler material 3 are accommodated in the case 5, one cooler 6 is also provided below the filler material 3 through the bottom surface portion 511.

[0021] The side surface portion 512 of the lower case 51 rises from the periphery of the bottom surface portion 511 and surrounds the peripheries of the plurality of battery modules 2, the filler material 3, and the device components 4. The flange portion 513 of the lower case 51 has a shape that projects outward from the upper end of the side surface portion 512.

[0022] The upper case 52 has a downwardly opening shape and has a top surface portion 521, a side surface portion 522, and a flange portion 523. The upper case 52 is made of a metal material such as iron or aluminum, for example. The upper case 52, together with the lower case 51, accommodates the plurality of battery modules 2, the filler material 3, the device components 4, and the like. 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.

[0023] The side portion 522 of the upper case 52 extends downward from the periphery of the top portion 521 and surrounds the multiple battery modules 2, gap-filling material 3, and equipment components 4. The flange portion 523 of the upper case 52 has a shape that protrudes outward from the lower end of the side portion 522. The flange portion 523 of the upper case 52 is fixed to the flange portion 513 of the lower case 51 by fastening members such as bolts.

[0024] Figure 3 is a perspective view showing a thermal insulation structure constructed by restraining the gap-filling material 3 according to the embodiment with a restraining member.

[0025] The gap-filling material 3 housed in the battery pack 1 according to this embodiment is restrained by restraining members such as a pair of restraining end plates 31, 32, a pair of restraining side plates 33, 34, and a restraining band 35 to form a heat insulating structure. The pair of restraining end plates 31, 32, the pair of restraining side plates 33, 34, and the restraining band 35 are made of a metal material such as iron.

[0026] A pair of restraining end plates 31 and 32 sandwich the gap-filling material 3 from the stacking direction Y in Figure 3. A pair of restraining side plates 33 and 34 each extend along the stacking direction Y and sandwich the gap-filling material 3 from the arrangement direction X in Figure 3. The ends of the pair of restraining side plates 33 and 34 are fixed to the pair of restraining end plates 31 and 32 by fastening members such as rivets and bolts. The restraining band 35 is positioned on the upper surface 3a (see Figure 4), which is the side of the gap-filling material 3 opposite to the cooling surface 8 (see Figure 4) described later, in the vertical direction Z relative to the gap-filling material 3. The restraining band 35 extends along the stacking direction Y and sandwiches the pair of restraining end plates 31 and 32 in a direction that brings them closer together. The ends of the restraining band 35 are fixed to the pair of restraining end plates 31 and 32 by rivets and bolts.

[0027] The pair of restraining end plates 31 and 32 also function as regulating members that restrict the position of the gap-filling material 3 in the stacking direction Y. Furthermore, the pair of restraining side plates 33 and 34 also function as regulating members that restrict the position of the gap-filling material 3 in the arrangement direction X. Additionally, the pair of restraining side plates 33 and 34 and the restraining band 35 also function as regulating members that restrict the position of the gap-filling material 3 in the vertical direction Z.

[0028] Figure 4 is an enlarged cross-sectional view showing the gap-filling material 3 and its vicinity in the battery pack 1 according to the embodiment.

[0029] As shown in Figure 4, the pair of restraining side plates 33 and 34 are formed in a roughly U-shaped (C-shaped) cross-section and have side plate portions 331 and 341, and upper flange portions 332 and 342 and lower flange portions 333 and 343 that rise inward from the upper and lower ends of the side plate portions 331 and 341. The side plate portions 331 and 341 face the sides 3c and 3d of the gap-filling material 3 from the alignment direction X. The upper flange portions 332 and 342 face the upper surface 3a of the gap-filling material 3 from above in the vertical direction Z. The lower flange portions 333 and 343 face the lower surface 3b of the gap-filling material 3 from below in the vertical direction Z. The gap-filling material 3 is sandwiched between the upper flange portions 332 and 342 and the lower flange portions 333 and 343 of the pair of restraining side plates 33 and 34.

[0030] In the battery pack 1 according to this embodiment, as shown in Figure 4, the inner surface of the bottom portion 511 of the lower case 51 where the cooler 6 is located below forms a cooling surface 8 for cooling the battery module 2 by heat exchange with the cooling medium flowing through the internal flow path of the cooler 6. In the battery pack 1 according to this embodiment, with the lower surface 3b of the gap-filling material 3 pressed against the cooling surface 8 on the bottom portion of the lower case 51, a pair of restraining side plates 33 and 34 are fixed to the bottom portion 511 of the lower case 51 by a plurality of bolts 38 via fastening brackets 36 and 37. The fastening brackets 36 and 37 are made of a metal material such as iron.

[0031] In the battery pack 1 according to this embodiment, the gap-filling material 3 is pressed against the cooling surface 8 on the bottom surface 511 of the lower case 51, thereby eliminating the air layer between the cooling surface 8 and the gap-filling material 3. As a result, in the battery pack 1 according to this embodiment, it is possible to suppress the occurrence of condensation on the cooling surface 8 by preventing the air inside the case 5 from coming into contact with and being cooled by the cooling surface 8. In particular, in the battery pack 1 according to this embodiment, it is possible to suppress the occurrence of condensation on the cooling surface 8 by preventing the air, which has been heated by the battery module 2 that generates heat inside the case 5 and is able to contain a large amount of moisture from coming into contact with and being cooled by the cooling surface 8.

[0032] In the battery pack 1 according to this embodiment, a cooler 6 is provided at a position opposite the battery module 2 via the bottom surface 511 of the lower case 51, and the inner surface of the portion of the bottom surface 511 where the cooler 6 is located downwards is used as a cooling surface 8 for cooling the battery module 2, but the embodiment is not limited to this. That is, in the battery pack 1 according to Embodiment 3, a cooler 6 may be provided between the bottom surface 511 of the lower case 51 and the battery module 2, and the surface of the cooler 6 that contacts the battery module 2 may be used as the cooling surface 8. [Explanation of symbols]

[0033] 1 Battery pack 2 Battery Modules 3. Gap-filling material 3a Top side 3b Bottom side 4. Equipment parts 5 cases 6 Cooler 31,32 Restraining end plate 33,34 Restraint side plates 35 Restraint band 36,37 Fastening brackets 38 volts 51 Lower Case 52 Upper Case 331,341 Side plate part 332,342 Upper flange section 333,343 Lower flange section 511 Bottom part 512 Side part 513 Flange section 521 Top section 522 Side part 523 Flange section

Claims

1. A battery module in which multiple battery cells are arranged in a line in the first direction and stacked, A case capable of arranging and housing a plurality of the battery modules in a second direction perpendicular to the first direction, Multiple cooling surfaces are provided in positions opposite to each battery module, corresponding to the maximum number of battery modules that can be housed in the case, for cooling each battery module. Equipped with, A battery pack having a reduced number of battery modules housed in the case compared to the maximum number, The case is equipped with insulating material to fill the gaps created by reducing the number of battery modules to be housed within it. A battery pack characterized in that the heat insulating material is pressed against the cooling surface.

2. The aforementioned case consists of a lower case and an upper case. A pair of restraining end plates that clamp the aforementioned insulation material from the first direction, A pair of restraining side plates that sandwich the aforementioned thermal insulation material from the second direction, A restraining band extending in the first direction is positioned on the surface of the insulating material opposite to the cooling surface side in a third direction perpendicular to the first and second directions, It has, The pair of restraint side plates and the restraint band are fixed to the pair of restraint end plates. The battery pack according to claim 1, characterized in that the pair of restraining end plates are fixed to the lower case while the insulating material is pressed against the cooling surface.

3. Multiple coolers are provided at positions facing each battery module via the case, corresponding to the maximum number of battery modules that can be housed in the case. The battery pack according to claim 1 or 2, characterized in that the inner surface of the portion of the case in which the cooler is located forms the cooling surface.

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