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]

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

[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 the lower surface of the battery module to cool the battery module. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-053273 A Summary of the Invention [Problem 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 in areas where there are no battery modules, and there is a risk that the air inside the case will come into contact with the cooling surface and cause condensation.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a battery pack that can suppress the occurrence of condensation on cooling surfaces when the number of battery modules housed in a case is reduced from the maximum number. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the battery pack of the present invention comprises a battery module in which a plurality of battery cells are arranged in a first direction and stacked, a case capable of accommodating an array of a plurality of the battery modules in a second direction perpendicular to the first direction, and a plurality of cooling surfaces for cooling each battery module, each of which corresponds to the maximum number of the battery modules that can be accommodated in the case and is provided in a position facing each battery module, and which are arranged to cool each battery module, and which reduce the number of the battery modules accommodated in the case below the maximum number, and which further comprises an insulating material that is filled in the gaps formed by reducing the number of the battery modules accommodated in the case, and which is arranged by pressing the insulating material against the cooling surfaces.

[0007] As a result, when the number of battery modules housed in the case is reduced from the maximum number, the air layer can be eliminated from between the cooling surface and the insulation material, so that the air inside the case comes into contact with the cooling surface and is cooled, thereby preventing condensation from forming on the cooling surface.

[0008] In addition, in the above, the case may be composed of a lower case and an upper case, and have a pair of constraining end plates that sandwich the insulation from the first direction, a pair of constraining side plates that sandwich the insulation from the second direction, and a constraining band that is arranged on the surface of the insulation opposite the cooling surface side in a third direction perpendicular to the first and second directions and extends in the first direction, and the pair of constraining side plates and the constraining band are fixed to the pair of constraining end plates, and the pair of constraining end plates are fixed to the lower case with the insulation pressed against the cooling surface.

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

[0010] In the above, a plurality of coolers may be provided in positions facing each battery module via the case, corresponding respectively to the maximum number of battery modules that can be accommodated 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 makes it possible to prevent condensation from occurring on the cooling surface formed on the case. Effect of the Invention

[0012] The battery pack of the present invention has the advantage that when the number of battery modules contained in the case is reduced from the maximum number, the air layer can be eliminated from between the cooling surface and the insulation material, so that the air inside the case comes into contact with the cooling surface and is cooled, thereby suppressing the formation of condensation on the cooling surface. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of the inside of a battery pack according to an embodiment when viewed from above. [Diagram 2] FIG. 2 is a cross-sectional view showing a schematic configuration of the battery pack according to the embodiment when viewed from the side. [Diagram 3] FIG. 3 is a perspective view showing a thermal insulation structure formed by restraining a filling material according to the embodiment with a restraining member. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing the filler and its vicinity in the battery pack according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a battery pack according to the present invention will be described below, however, the present invention is not limited to the embodiment.

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

[0016] A battery pack 1 according to the embodiment is configured by housing a plurality of battery modules 2, a gap filler 3, and device components 4 in a case 5. The case 5 is configured by 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 FIG. 1.

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

[0018] The gap filler 3 is a heat insulating material made of foamed resin or the like that is filled into the gaps formed by reducing the number of battery modules 2 inside the case 5. Examples of the foamed resin include foamed polypropylene and foamed styrene. The shape and size of the gap filler 3 are approximately the same as those of the battery modules 2.

[0019] The device part 4 is, for example, a monitoring unit that monitors the voltage, temperature, and the like of each battery module 2.

[0020] The lower case 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 case 51 is made of a metal material such as iron or aluminum. The bottom surface portion 511 is disposed below the plurality of battery modules 2, the gap filler 3, and the device components 4. Below the bottom surface portion 511 of the lower case 51, a plurality of coolers 6 are disposed in positions facing the battery modules 2 via the bottom surface portion 511, corresponding to the maximum number of battery modules 2 that can be accommodated in the case 5, and for cooling each battery module 2, and are provided. In the battery pack 1 according to the embodiment, four coolers 6 are provided below the bottom surface portion, corresponding to the maximum number of four battery modules 2 that can be accommodated in the case 5. Therefore, as shown in FIG. 1 and FIG. 2, when the number of battery modules 2 accommodated in the case 5 is reduced and three battery modules 2 and one gap filler 3 are accommodated in the case 5, one cooler 6 is also provided below the gap filler 3 via the bottom surface portion 511.

[0021] The side surface portion 512 of the lower case 51 stands up from the peripheral edge of the bottom surface portion 511 and surrounds the plurality of battery modules 2, the gap fillers 3, and the device components 4. The flange portion 513 of the lower case 51 has a shape that protrudes outward from the upper end of the side surface portion 512.

[0022] The upper case 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 case 52 is made of a metal material such as iron or aluminum. The upper case 52, together with the lower case 51, houses the plurality of battery modules 2, the gap filler 3, the device components 4, and the like. The top surface portion 521 is formed, for example, in a flat plate shape, and is disposed above the plurality of battery modules 2, the gap filler 3, and the device components 4. Gaps are formed between the top surface portion 521 and the plurality of battery modules 2, the gap filler 3, and the device components 4.

[0023] The side surface portion 522 of the upper case 52 extends downward from the peripheral edge of the top surface portion 521 and surrounds the plurality of battery modules 2, the gap filler 3, and the device components 4. The flange portion 523 of the upper case 52 has a shape that protrudes outward from the lower end of the side surface 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] FIG. 3 is a perspective view showing a thermal insulation structure formed by restraining the filling material 3 according to the embodiment with a restraining member.

[0025] The gap filler 3 housed in the battery pack 1 according to the 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] The pair of restraining end plates 31, 32 sandwich the gap filler 3 from the stacking direction Y in FIG. 3. The pair of restraining side plates 33, 34 each extend along the stacking direction Y and sandwich the gap filler 3 from the arrangement direction X in FIG. 3. The pair of restraining side plates 33, 34 are fixed at both ends to the pair of restraining end plates 31, 32 by fastening members such as rivets and bolts. The restraining band 35 is disposed on the upper surface 3a (see FIG. 4), which is the surface opposite to the cooling surface 8 (see FIG. 4) side of the gap filler 3 in the vertical direction Z. The restraining band 35 extends along the stacking direction Y and sandwiches the pair of restraining end plates 31, 32 in the direction in which the pair of restraining end plates 31, 32 approach each other. The restraining band 35 is fixed at both ends to the pair of restraining end plates 31, 32 by rivets, bolts, etc.

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

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

[0029] As shown in FIG. 4, the pair of restraining side plates 33, 34 are formed with a substantially C-shaped cross section, and have side plate portions 331, 341, and upper flange portions 332, 342 and lower flange portions 333, 343 that stand 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 gap filling material 3 from the arrangement direction X. The upper flange portions 332, 342 face the upper surface 3a of the gap filling material 3 from above in the vertical direction Z. The lower flange portions 333, 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, 342 and the lower flange portions 333, 343 of the pair of restraining side plates 33, 34.

[0030] 4, in the battery pack 1 according to the embodiment, the inner surface of a portion of the bottom surface 511 of the lower case 51 below which the cooler 6 is located forms a cooling surface 8 for cooling the battery modules 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 the embodiment, the pair of restraining side plates 33, 34 are fixed to the bottom surface 511 of the lower case 51 by a plurality of bolts 38 via fastening brackets 36, 37 with the lower surface 3b of the filler 3 pressed against the cooling surface 8 at the bottom surface of the lower case 51. The fastening brackets 36, 37 are made of a metal material such as iron.

[0031] In the battery pack 1 according to the embodiment, the gap filling material 3 is provided by being pressed against the cooling surface 8 on the bottom surface portion 511 of the lower case 51, so that an air layer can be removed from between the cooling surface 8 and the gap filling material 3. This makes it possible to prevent the air in the case 5 from coming into contact with the cooling surface 8 and being cooled, and thus preventing condensation from forming on the cooling surface 8, in the battery pack 1 according to the embodiment. In particular, in the battery pack 1 according to the embodiment, it is possible to prevent the air that has been warmed by the battery modules 2 that generate heat in the case 5 and that can contain a large amount of moisture from coming into contact with the cooling surface 8 and being cooled, and thus preventing condensation from forming on the cooling surface 8.

[0032] In the battery pack 1 according to the embodiment, the cooler 6 is provided at a position facing the battery module 2 with the bottom surface 511 of the lower case 51 therebetween, and the inner surface of the portion of the bottom surface 511 below which the cooler 6 is located is used as the cooling surface 8 for cooling the battery module 2, but this is not limited to this. That is, in the battery pack 1 according to the third embodiment, the 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 comes into contact with the battery module 2 may be used as the cooling surface 8. [Explanation of symbols]

[0033] 1 Battery pack 2 Battery Module 3 Gap filling material 3a Top side 3b Bottom side 4. Equipment parts 5 Cases 6 Cooler 31,32 Captive end plate 33,34 Captive side plate 35 Restraint Band 36,37 Fastening bracket 38 Volts 51 Lower case 52 Upper Case 331,341 Side plate part 332,342 Upper flange 333,343 Lower flange 511 Bottom part 512 Side part 513 Flange part 521 Top section 522 Side part 523 Flange part

Claims

1. a battery module in which a plurality of battery cells are stacked and arranged side by side in a first direction; a case capable of accommodating a plurality of the battery modules arranged in a second direction perpendicular to the first direction; a plurality of cooling surfaces provided in positions facing the maximum number of battery modules that can be accommodated in the case, the cooling surfaces being for cooling each of the battery modules; Equipped with A battery pack in which the number of the battery modules housed in the case is reduced from the maximum number, a heat insulating material is provided in the case and is filled in a gap formed by reducing the number of the battery modules accommodated therein; The battery pack according to claim 1, wherein the heat insulating material is pressed against the cooling surface.

2. The case is composed of a lower case and an upper case, A pair of restraining end plates that sandwich the thermal insulation material from the first direction; A pair of restraining side plates that sandwich the heat insulating material from the second direction; a restraint band disposed on a surface of the heat insulating material opposite to the cooling surface side in a third direction perpendicular to the first direction and the second direction, the restraint band extending in the first direction; having the pair of restraining side plates and the restraining bands are secured to the pair of restraining end plates; The battery pack according to claim 1 , wherein the pair of restraining end plates are fixed to the lower case with the heat insulating material pressed against the cooling surface.

3. a plurality of coolers are provided in positions facing the battery modules across the case, the coolers corresponding to the maximum number of battery modules that can be accommodated in the case; 3. The battery pack according to claim 1, wherein an inner surface of the portion of the case where the cooler is located forms the cooling surface.

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