JP2017037772A - Battery pack - Google Patents

Abstract

A battery pack with improved heat dissipation is provided. A battery pack 1A according to an embodiment includes a battery module 10 having a plurality of battery cells 20 arranged in parallel, a heat dissipation plate 80 having a mounting surface 80a on which the battery module is mounted, and a battery module. 10 and a case 54 that accommodates the heat sink 80. The case 54 has an attachment wall 70 to which the heat sink 80 is attached. The heat radiating plate 80 is attached to the mounting wall 70 by fixing the side opposite to the mounting surface 80 a of the heat radiating plate 80 to the mounting wall 70. In the mounting wall 70, a window portion 74 is formed in a region facing the heat radiating plate 80, and a part of the heat radiating plate 80 is exposed from the window portion 74. [Selection] Figure 5

Description

  The present invention relates to a battery pack.

  Conventionally, as in Patent Document 1, a battery pack in which a plurality of battery modules are housed in a case is known. Each battery module has a plurality of battery cells arranged in parallel. Usually, a heat transfer plate is attached to each battery cell as in Patent Document 1. In the battery pack of Patent Document 1, each battery module is fixed to the case such that a part of the heat transfer plate is in contact with the wall of the case.

JP 2014-146461 A

  When the battery module is fixed to the wall of the casing as in Patent Document 1, the heat generated in the battery module is radiated to the outside of the casing through the wall of the casing. As described above, even in the technique of Patent Document 1, heat generated in the battery module is radiated to the outside of the case. However, in this technical field, further improvement in heat dissipation is required.

  An object of this invention is to provide the battery pack with which the heat dissipation was improved.

  A battery pack according to one aspect of the present invention includes a plurality of battery modules each having a plurality of battery cells arranged side by side, a heat sink having a mounting surface on which the plurality of battery modules are mounted, a plurality of battery modules, A case for housing the heat sink. The case has an attachment wall to which the heat sink is attached. The heat sink is attached to the mounting wall by fixing the side opposite to the mounting surface of the heat sink to the mounting wall. In the mounting wall, a window portion is formed in a region facing the heat radiating plate, and a part of the heat radiating plate is exposed from the window portion.

  In the battery pack having the above configuration, a plurality of battery modules are mounted on the mounting surface of the heat sink. And the opposite side to the mounting surface in a heat sink is being fixed to the attachment wall. Therefore, the heat generated in the battery module is released to the outside through the heat sink and the mounting wall. Further, a window portion is formed on the mounting wall, and a part of the heat radiating plate is exposed from the window portion. Thereby, the heat generated in the battery module is directly released to the outside of the case through the portion of the heat radiating plate exposed from the window. Therefore, in the battery pack having the above configuration, heat dissipation is improved.

  In one embodiment, the heat radiating plate includes a plate-like main body having the mounting surface, and an exposed portion provided in a region corresponding to the window on the surface of the main body opposite to the mounting surface. And the edge part on the opposite side to the main-body part of the exposed part may protrude outside the case from the window part.

  In this case, since the end portion of the exposed portion provided in the main body portion protrudes from the window portion, the heat dissipation is further improved.

  In one embodiment, the heat radiating plate is fastened to the mounting wall by bolts inserted from the outer surface side of the mounting wall, and in the thickness direction of the heat radiating plate, the end portion and the mounting wall located outside the case in the exposed portion The maximum length between the outer surfaces of the bolts may be equal to or greater than the length of the bolt head of the bolt.

  In the battery pack having this configuration, the bolt head can be prevented from protruding from the exposed portion in the thickness direction of the heat sink.

  In one embodiment, the exposed part may have a plurality of convex parts arranged discretely. In this case, since the surface area of the exposed portion can be increased, the heat dissipation is easily improved.

  In one embodiment, the window part may have a plurality of windows corresponding to the plurality of convex parts. In the battery pack having this configuration, the plurality of protrusions protrude outward from the corresponding windows. Therefore, the heat sink and the case can be aligned by matching each of the plurality of convex portions with the corresponding window. Therefore, assembly of the battery pack is easy.

  In one embodiment, the mounting wall is a side wall erected on the bottom wall of the case, and the bottom wall is formed with a through hole penetrating the bottom wall in the thickness direction of the bottom wall. May be provided between the position of the mounting surface and the mounting wall when the heat sink is projected onto the bottom wall in the thickness direction of the bottom wall.

  In the said structure, since the window part is formed in the side wall which is an attachment wall, water may permeate into a case from a window part. Even if water permeates in this way, in the above configuration in which the through hole is formed in the bottom wall, the water can be discharged from the through hole formed in the bottom wall. Further, since the through hole is formed between the position of the mounting surface on the heat sink and the mounting wall in the thickness direction of the side wall, the water that has entered from the side wall is disposed in the case in the battery module. Can be prevented.

  In the form in which the through hole is formed in the bottom wall, the heat radiating plate may be in contact with the bottom wall. Thereby, even if water permeates from the window portion, the water can be further prevented from reaching the area where the battery module is disposed in the case.

  In one embodiment, each of the plurality of battery modules has a heat transfer member thermally connected to the battery cell, and the plurality of battery modules are fixed so that the heat transfer member is in thermal contact with the heat sink. May be.

  Thereby, the heat generated in the plurality of battery modules is transmitted to the heat dissipation plate via the heat transfer member. Therefore, the heat of each battery module can be reliably radiated.

  According to the present invention, a battery pack with improved heat dissipation can be provided.

FIG. 1 is a perspective view of a battery module included in a battery pack according to an embodiment. FIG. 2 is an exploded perspective view showing a schematic configuration of a battery cell unit included in the battery module shown in FIG. FIG. 3 is a perspective view of a battery pack according to an embodiment including the battery module shown in FIG. FIG. 4 is a schematic diagram of a cross-sectional configuration taken along line IV-IV in FIG. FIG. 5 is an exploded perspective view showing a schematic configuration of the battery pack shown in FIG. 3. FIG. 6 is a schematic diagram of a cross-sectional configuration taken along line VI-VI in FIG. FIG. 7 is a plan view of the case main body of the battery pack shown in FIG. 3 as viewed from the opening side of the case main body. FIG. 8 is a perspective view of a battery pack according to another embodiment. FIG. 9 is a schematic diagram of a cross-sectional configuration along the line IX-IX in FIG. FIG. 10 is a perspective view illustrating a schematic configuration of a subassembly included in the battery pack illustrated in FIG. 8. FIG. 11 is a perspective view showing a modification of the battery pack shown in FIG. 12 is a perspective view illustrating a schematic configuration of a subassembly included in the battery pack illustrated in FIG. 11. FIG. 13 is a perspective view of a modification of the case body included in the battery pack shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In the description, words indicating directions such as “up” and “down” are convenient words based on the state shown in the drawings. The dimensional ratios in the drawings do not necessarily match those described.

(First embodiment)
FIG. 1 is a perspective view illustrating a schematic configuration of a battery module 10 included in a battery pack according to an embodiment. As shown in FIG. 1, the battery module 10 includes a plurality of battery cell units 12. The plurality of battery cell units 12 are arranged in parallel in a predetermined direction. The plurality of battery cell units 12 are electrically connected in series or in parallel by a conductive member 14 such as a bus bar. In the example shown in FIG. 1, the plurality of battery cell units 12 are electrically connected in series.

  The plurality of battery cell units 12 arranged side by side are sandwiched and restrained by a pair of restraining members 16 and 16. An example of the restraining member 16 is an end plate. The restraining member 16 is made of a material having high rigidity such as iron. The plurality of battery cell units 12 are sequentially inserted with bolts 18a to 18d through one restraining member 16, the plurality of battery cell units 12 and the other restraining member 16, and nuts are inserted into the bolts 18a to 18d protruding from the other restraining member 16. Are fixed by screwing.

  The battery cell unit 12 will be described with reference to FIG. FIG. 2 is an exploded perspective view showing a schematic configuration of the battery cell unit 12. As shown in FIG. 2, the battery cell unit 12 includes a battery cell 20, a folder 22, and a heat transfer plate 24.

  The battery cell 20 is a storage battery such as a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. However, the battery cell 20 is not limited to a secondary battery, and may be, for example, an electric double layer capacitor. The battery cell 20 has a square shape, for example, as shown in FIG. The battery cell 20 is configured, for example, by housing an electrode assembly 28 formed by laminating a negative electrode, a separator, and a positive electrode in a case 26 filled with an electrolytic solution. Examples of the electrolytic solution include an organic solvent-based or non-aqueous electrolytic solution.

  The case 26 has a bottom surface 26a having a square shape (for example, a rectangle or a square as shown in FIG. 2), side surfaces 26b, 26c, 26d, 26e erected from the bottom surface 26a, and opposite to the bottom surface 26a. And an upper surface 26f located on the side. In the case 26, the side surface 26b and the side surface 26c face each other, and the side surfaces 26d and 26e face each other. In the case 26, for example, the opening of the bottomed cylindrical case body including the bottom surface 26a and the side surfaces 26b, 26c, 26d, and 26e erected from the bottom surface 26a is closed with a lid that forms the upper surface 26f. Is formed.

  The negative electrode and the positive electrode of the electrode assembly 28 accommodated in the case 26 are electrically connected to a pair of electrode terminals 30, 30 fixed in an insulated state to the case 26. Therefore, one of the pair of electrode terminals 30 and 30 functions as a negative electrode terminal, and the other functions as a positive electrode terminal. One end of each of the pair of electrode terminals 30, 30 protrudes from the upper surface 26 f to the outside of the case 26.

  For convenience of the following description, the normal direction of the bottom surface 26a is referred to as the z-axis direction, the normal direction of the side surface 26b erected from the bottom surface 26a is referred to as the x-axis direction, and is orthogonal to the x-axis and z-axis directions. The direction to do is sometimes referred to as the y-axis direction.

  The folder 22 is a member that holds the battery cell 20, and holds the battery cell 20 so that the side surface 26b and the side surface 26c of the case 26 are exposed. An example of the material of the folder 22 is resin. The folder 22 includes a frame body 32, a partition portion 34, a pair of terminal accommodating portions 36 and 36, a pair of bolt guide portions 38 and 38, and a pair of bolt guide portions 40 and 40.

  The frame body 32 includes a bottom plate 42 and a pair of side plates 44 and 44. The bottom plate 42 is a plate-like member having a rectangular shape in plan view (the shape seen from the thickness direction of the bottom plate 42) on which the battery cell 20 is placed, and the battery cell 20 is held in the folder 22, It faces the bottom surface 26a of the case 26. The pair of side plates 44, 44 are erected from a pair of edge portions of the bottom plate 42. In the example of FIG. 2, a pair of side plates 44, 44 are erected from both edges in the longitudinal direction on a rectangular bottom plate 42. The pair of side plates 44, 44 face the side surface 26 d and the side surface 26 e of the case 26 in a state where the battery cell 20 is held in the folder 22. In such a configuration, the battery cell 20 is held by the folder 22 by being placed on the bottom plate 42 between the pair of side plates 44, 44.

  The partition portion 34 is a plate-like member that is provided in an intermediate portion between the pair of side plates 44 and 44 in the thickness direction of the bottom plate 42 and connects the pair of side plates 44 and 44. The partition portion 34 is provided on one side of the pair of edge portions that extend in the width direction of the side plate 44 (the x-axis direction in FIG. 2). For example, the distance from the upper surface of the bottom plate 42 (the inner surface of the folder 22) to the upper end of the partition 34 can be substantially equal to the height of the case 26 of the battery cell 20 (the distance from the bottom surface 26a to the upper surface 26f). . The length of the partition portion 34 in the plate thickness direction is shorter than the height of the case 26.

  In this configuration, an opening is formed between the partition portion 34 and the bottom plate 42 on the side of the folder 22 where the partition portion 34 is provided. Therefore, the side surface 26 b of the case 26 is exposed in a state where the battery cell 20 is held in the folder 22. Since the side opposite to the partition portion 34 of the folder 22 is open, the side surface 26 c of the case 26 is also exposed while the battery cell 20 is held in the folder 22.

  A pair of terminal accommodating parts 36 and 36 accommodate a pair of electrode terminals 30 and 30 which the battery cell 20 has, respectively. Each of the pair of terminal accommodating portions 36, 36 is provided corresponding to the pair of side plates 44, 44, and has a first peripheral wall 46 and a second peripheral wall 48 that are orthogonal to each other. The first peripheral wall 46 is provided at the upper end of the partition portion 34. One end of the first peripheral wall 46 is connected to the corresponding side plate 44. The second peripheral wall 48 is connected to the other end of the first peripheral wall 46 and faces the corresponding side plate 44. Therefore, more specifically, the first peripheral wall 46 and the second peripheral wall 48 form a space (accommodation space) in which the electrode terminal 30 is accommodated by the first peripheral wall 46, the second peripheral wall 48 and the side plate 44. Has been.

  The pair of bolt guide portions 38, 38 is provided adjacent to the pair of terminal accommodating portions 36, 36, respectively. Each bolt guide part 38,38 is a cylindrical part, and it extends in the normal line direction (x-axis direction in FIG. 2) of the side surface 26b. The pair of bolt guide portions 38, 38 are formed with guide holes 38a through which the bolts 18a, 18b to be guided respectively are inserted.

  The pair of bolt guide portions 40, 40 are cylindrical portions provided on the outer surface of the bottom plate 42 of the folder 22. In one embodiment, the pair of bolt guide portions 40, 40 is provided in the vicinity of the edge portion of the bottom plate 42 where the pair of side plates 44, 44 are provided. Each bolt guide part 40 is a cylindrical part like the bolt guide part 38 and extends in the same direction as the bolt guide part 38. The pair of bolt guide portions 40, 40 are formed with bolt holes 40a through which the bolts 18c, 18d to be guided respectively are inserted.

  The heat transfer plate 24 is a heat transfer member for radiating heat from the battery cells 20. The heat transfer plate 24 is, for example, a metal plate, and an example of the material of the heat transfer plate 24 is aluminum. The heat transfer plate 24 includes a plate-like heat absorbing portion 50 and a plate-like heat radiating portion 52.

  The heat absorption part 50 is a part facing the side surface 26 b of the case 26 in the heat transfer plate 24. The heat radiating portion 52 is a portion facing the side surface 26 d of the case 26 in the heat transfer plate 24. The heat dissipating part 52 is provided at one edge of the heat absorbing part 50 and is substantially orthogonal to the heat absorbing part 50. Therefore, the heat transfer plate 24 has an L shape when viewed from the upper side in FIG.

  The heat transfer plate 24 is disposed with respect to the battery cell 20 so that the heat radiating portion 52 faces the side surface 26d across the side plate 44 on the side surface 26d side of the case 26. The heat transfer plate 24 is thermally connected to the battery cell 20 by joining the heat absorbing portion 50 and the side surface 26b of the case 26. What is necessary is just to join the heat absorption part 50 and the side surface 26b as long as they are thermally connected. For example, they can be connected via a double-sided adhesive tape.

  As described above, each battery cell unit 12 has a battery cell 20. Therefore, in the battery module 10 in which the plurality of battery cell units 12 are arranged in parallel, the plurality of battery cells 20 are also arranged in parallel.

  In the battery module 10, the plurality of battery cells 20 (or battery cell units 12) are arranged side by side in the normal direction (the x-axis direction in FIG. 2) of the side surface 26 b of the case 26. Therefore, between the adjacent battery cells 20, the heat absorbing portion 50 of the heat transfer plate 24 is disposed. The heat radiating portion 52 of the heat transfer plate 24 is erected on one edge of the heat absorbing portion 50, and faces the side surface 26d with the side plate 44 positioned on the side surface 26d side. Therefore, the heat radiation part 52 is exposed in the battery module 10.

  Next, an embodiment of a battery pack including the battery module 10 shown in FIG. 1 will be described.

  FIG. 3 is a perspective view of the battery pack according to the embodiment. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is an exploded perspective view of the battery pack shown in FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 3 to 5, the battery module 10 is schematically illustrated.

  As shown in FIGS. 3 to 5, the battery pack 1 </ b> A includes a case 54 and two subassemblies 56 and 56. When the two subassemblies 56 and 56 are described separately, they may be referred to as a subassembly 56A and a subassembly 56B.

  The case 54 is a box-like body that houses the subassembly 56. The case 54 includes a case main body 58 and a case lid 60. An example of the material of the case 54 is iron. The case body 58 has a bottomed cylindrical shape, and the side opposite to the bottom wall 62 of the case body 58 is open. A case lid 60 is fixed to the open end surface of the case body 58. The fixing method of the case lid 60 is not particularly limited, but is fastened with bolts 64 as shown in FIGS. In this case, as shown in FIG. 5, the case main body 58 is formed with a screw hole 66 into which the bolt 64 is screwed, and the case lid 60 is formed with an insertion hole 68 through which the bolt 64 is inserted.

  As shown in FIGS. 3 to 5, the case main body 58 includes a bottom wall 62, a pair of side walls (mounting walls) 70 and 70, and a pair of side walls 72 and 72. The plan view shape of the bottom wall 62 is a quadrangle (rectangle or square). The pair of side walls 70, 70 are erected from a pair of opposing edges of the four edges of the bottom wall 62. Therefore, the side wall 70 and the side wall 70 face each other. The pair of side walls 72, 72 are erected from the remaining pair of opposing edges of the four edges of the bottom wall 62. Therefore, the side wall 72 and the side wall 72 face each other. The angle formed between the bottom wall 62 and the side walls 70 and 72 is substantially 90 °, for example.

  As shown in FIGS. 4 and 5, the sub-assembly 56 is fixed to each of the pair of side walls 70, 70, and the side wall 70 has a window portion 74 for exposing a part of the sub-assembly 56. Is formed. The window portion 74 is an opening, and the shape of the window portion 74 in plan view (the shape seen from the thickness direction of the side wall 70) is not particularly limited, but may be a rectangular shape such as a rectangle or a square as shown in FIG. Alternatively, it may be circular. The subassembly 56 is fastened by a bolt 76 that is inserted from the outer surface 70 a side of the side wall 70. Therefore, a bolt insertion hole 78 is formed in the side wall 70. The bolt insertion hole 78 is formed around the window portion 74, for example.

  For convenience of explanation, as shown in FIGS. 3 to 5, the normal direction of the upper surface of the bottom wall 62 (the surface inside the case 54 in the bottom wall 62) is defined as the Z-axis direction and is orthogonal to the Z-axis direction. Two directions are referred to as an X-axis direction and a Y-axis direction. The X-axis direction and the Y-axis direction are orthogonal to each other.

  As shown in FIGS. 4 and 5, the subassembly 56 includes a plurality of battery modules 10 and a heat sink 80. The plurality of battery modules 10 are fixed to a mounting surface 80 a that is one surface of the heat dissipation plate 80.

  As illustrated in FIG. 6, each battery module 10 is fixed to the heat radiating plate 80 so that the heat radiating portion 52 of the heat transfer plate 24 is in contact with the mounting surface 80 a of the heat radiating plate 80. In one embodiment, each battery module 10 is fixed to the heat sink 80 by a pair of fixing brackets 82. Although the fixing bracket 82 and the restraining member 16 are described as separate members, the fixing bracket 82 and the restraining member 16 may be a single member formed integrally.

  As shown in FIGS. 4 and 5, the heat dissipation plate 80 is a plate-like member, and is also a mounting plate on which the battery module 10 is mounted. Although the heat sink 80 will not be specifically limited if it is comprised from the material which has heat conductivity, For example, they are iron and aluminum. A screw hole 84 to be screwed with the bolt 76 is formed in a surface (hereinafter referred to as “back surface”) 80 b opposite to the mounting surface 80 a on which the battery module 10 is mounted in the heat radiating plate 80. The heat radiating plate 80 is fixed by bolts 76 with the back surface 80 b in contact with the side wall 70. Specifically, the heat radiating plate 80 is fixed to the side wall 70 by the bolt 76 being screwed into the screw hole 84 after the bolt 76 is inserted into the bolt insertion hole 78 from the outside of the side wall 70.

  The length of the heat sink 80 in the X-axis direction (in the illustration of FIG. 5, the heat sink 80 longitudinal direction) is not particularly limited as long as the heat sink 80 can be accommodated in the case body 58. Therefore, the length of the heat sink 80 in the X-axis direction may be shorter than or the same as the length between the pair of side walls 72, 72. In one embodiment, the length of the heat sink 80 in the X-axis direction may be longer than the length between the pair of side walls 72, 72. In this case, a concave portion that extends in the Z-axis direction and guides the heat sink 80 can be formed on the inner surface of the side wall 72. If such a recess is formed in the side wall 72, the heat sink 80 can be easily aligned, and the battery pack 1A can be easily assembled.

  The length of the heat sink 80 in the Z-axis direction (the thickness direction of the bottom wall 62) is the distance between the bottom wall 62 and the case lid 60, that is, the upper surface of the bottom wall 62 and the lower surface of the case lid 60 in FIG. It is sufficient if it is equal to or less than the distance between. When the length of the heat radiating plate 80 in the Z-axis direction is shorter than the distance between the bottom wall 62 and the case lid 60, for example, as shown in FIG. 4, the heat radiating plate 80 is disposed so as to contact the bottom wall 62. Alternatively, a gap may be provided between the radiator plate 80 and the bottom wall 62. When the heat radiating plate 80 is disposed so as to contact the bottom wall 62, for example, of the four bolts 76 shown in FIG. 3 and FIG. 80 may be fixed to the side wall 70.

  As shown in FIG. 4, in the form in which the heat sink 80 and the bottom wall 62 are in contact, the subassembly 56 is housed in the case 54 in a more stable state. Therefore, for example, when the battery pack 1A is used as a battery such as an automobile or a forklift, the battery pack 1A is hardly affected by vibrations of the automobile or the forklift. Similarly, as shown in FIGS. 3 and 5, the heat sink 80 is fastened to the side wall 70 with bolts 76 on the bottom wall 62 side in addition to the case lid 60 side, thereby stabilizing the subassembly 56. Is further improved.

  A heat sink 80 included in at least one of the two subassemblies 56 may be mounted with a junction box 86 that houses electrical components such as relays and connectors. In the first embodiment, as shown in FIG. 5, the junction box 86 is mounted on the subassembly 56B.

  In the battery pack 1A, each battery cell 20 and the junction box 86 included in the plurality of battery modules 10 are appropriately electrically connected by a wiring member such as a harness. The plurality of battery modules 10 are electrically connected in series, for example. Illustration of wiring members such as a harness (or cable) is omitted in the drawings.

  In one embodiment, the bottom wall 62 of the case body 58 may be formed with a through hole 88 for draining water as shown in FIG. FIG. 7 is a plan view of the case body 58 as seen from the opening side. The through hole 88 is formed in the bottom wall 62 in the vicinity of the edge where the side wall 70 is provided.

  Specifically, the through hole 88 is formed from the projection position (or corresponding position) of the mounting surface 80a when the heat radiating plate 80 is projected onto the bottom wall 62 in a state where the heat radiating plate 80 is accommodated in the case 54. What is necessary is just to be formed between the side walls 70 to which 80 is attached. Therefore, the through hole 88 is formed in a region extending at the width of the heat radiating plate 80 along the edge at the edge of the bottom wall 62 where the side wall 70 is erected. Projecting the heat sink 80 onto the bottom wall 62 means projecting the heat sink 80 in the Z-axis direction. Or the through-hole 88 should just be formed in the projection area | region 90 which is an area | region which projected the heat sink 80 on the bottom wall 62, as shown in FIG. In FIG. 7, the projection area 90 is indicated by a two-dot chain line.

  As described above, the through hole 88 only needs to be formed from the side wall 70 to the projection position of the mounting surface 80a in the Y-axis direction (thickness direction of the side wall 70). On the other hand, there is no particular limitation in the X-axis direction (the direction along the edge of the bottom wall 62 on which the side wall 70 is erected). For example, in the region A corresponding to the formation region of the window 74 in the X-axis direction. It may be formed. Region A corresponds to a projection region on the bottom wall 62 of the portion of the heat sink 80 that faces the window 74. In FIG. 7, the area A is hatched to illustrate the area A.

  It is sufficient that at least one through hole 88 is formed on the edge side of the bottom wall 62 where the side wall 70 is erected. When a plurality of through holes 88 are provided in the projection region 90, for example, as shown in FIG. 7, the plurality of through holes 88 can be discretely arranged along the extending direction of the projection region 90. 4, which is a cross-sectional view taken along the line IV-IV in FIG. 3, shows a cross-sectional view of the battery pack 1 </ b> A having a through hole 88. The number of the through holes 88 may be determined in consideration of, for example, the strength of the case 54 and the drainage function.

  The battery pack 1A shown in FIGS. 3 to 5 can be manufactured as follows, for example. Here, a mode in which the junction box 86 is mounted on the subassembly 56B will be described.

  First, the plurality of battery modules 10 are fixed to the heat dissipation plate 80, respectively, and the subassembly 56 is manufactured. At this time, the junction box 86 is also mounted on the subassembly 56B. Next, the plurality of battery modules 10 mounted on the subassembly 56 and the electrical components in the junction box 86 are electrically connected by a wiring member such as a harness (or cable). Thereafter, the subassembly 56 is fastened with bolts 76 from the outside of the side wall 70 in a state where the back surface 80b of the heat radiating plate 80 is in contact with the inner surface of the side wall 70, whereby the subassembly 56 is accommodated in the case body 58. . Subsequently, the battery pack 1 </ b> A is obtained by fixing the case lid 60 to the case main body 58 with the bolts 64.

  The configuration of the battery pack 1 </ b> A includes a sub-assembly 56 configured by mounting a plurality of battery modules 10 on a heat sink 80. Therefore, as described above, the battery pack 1 </ b> A can be manufactured by assembling and wiring the subassembly 56 in advance and then fixing the subassembly 56 to the case 54. Therefore, for example, the battery pack 1A can be easily assembled (manufactured) as compared to the case where the plurality of battery modules 10 are individually fixed to the case 54 and wired.

  In the battery pack 1 </ b> A, the heat radiating plate 80 is fixed to the side wall 70 so that the back surface 80 b is in contact with the side wall 70. Therefore, the heat generated in the battery module 10 (specifically, the battery cell 20) is transmitted to the side wall 70 via the heat radiating plate 80 and is released to the outside from the side wall 70.

  Furthermore, since the window part 74 is formed in the side wall 70, in the battery pack 1A, a part of the heat sink 80, more specifically, a part of the back surface 80b is exposed. Therefore, the heat dissipation of the battery pack 1A is improved. This point will be described in detail in comparison with the case where the window portion 74 is not formed on the side wall 70.

  As described above, the battery pack 1A can be easily assembled by mounting the plurality of battery modules 10 on the heat dissipation plate 80 in advance and manufacturing the subassembly 56. However, even if the heat radiating plate 80 is fastened to the side wall 70 with the bolt 76, a gap (air layer) may be generated between the heat radiating plate 80 and the side wall 70. When the gap is generated in this way, if the window portion 74 is not formed on the side wall 70, there is a possibility that heat conduction from the heat radiating plate 80 to the side wall 70 may be hindered by the gap.

  On the other hand, if the window part 74 is formed in the side wall 70, even if the clearance gap has arisen between the back surface 80b of the heat sink 80 and the side wall 70, exposure of the back surface 80b exposed from the window part 74 is exposed. The battery module 10 can be efficiently dissipated through the region. As a result, the heat dissipation of the battery pack 1A is improved.

  Next, as shown in FIG. 7, in the embodiment in which the drain hole 88 is provided in the bottom wall 62 of the case 54, even if water enters from the window 74, the water can be drained. It is. This point will be specifically described.

  Normally, when the battery pack 1A is used as a battery such as an automobile or a forklift, the bottom wall 62 is disposed on the lower side in the vertical direction. Therefore, the water that has entered from the window 74 moves to the bottom wall 62 side. Therefore, in the form in which the through hole 88 is formed in the bottom wall 62, the water that has entered through the window portion 74 can be discharged from the case 54 through the through hole 88.

  The through hole 88 is formed between the projection position of the mounting surface 80a when the heat radiating plate 80 is projected onto the bottom wall 62 and the side wall 70 to which the heat radiating plate 80 is attached (or within the projection region 90). Yes. In other words, the through hole 88 is formed from the inner surface of the side wall 70 to the region of the thickness of the heat sink 80. Therefore, the water that has entered the case 54 via the window 74 is drained from the through-hole 88 before reaching the area where the battery module 10 or the like is disposed. Thereby, it is difficult for water to reach an area where electrical parts such as the battery module 10 are arranged.

  Further, if the through hole 88 is formed in the region A shown in FIG. 7, the water that has entered through the window portion 74 can be drained efficiently, so that the electrical components such as the battery module 10 can be further improved. Water is difficult to reach the area where it is located. As described above, in the form in which the heat radiating plate 80 is in contact with the bottom wall 62, the water that has entered from the window portion 74 further reaches the region where the electrical components such as the battery module 10 are disposed. hard.

(Second Embodiment)
FIG. 8 is a perspective view of the battery pack according to the second embodiment. FIG. 9 is a sectional view taken along line IX-IX in FIG. FIG. 10 is a perspective view of a subassembly included in the battery pack shown in FIG. The configuration of the battery pack 1B shown in FIGS. 8 and 9 is mainly different from the configuration of the battery pack 1A in that a subassembly 92 is provided instead of the subassembly 56. The battery pack 1B will be described focusing on this difference. Also in the description of the second embodiment and the modifications 1 and 2 described later, the X-axis direction, the Y-axis direction, and the Z-axis direction used in the description of the battery pack 1A may be used.

  The battery pack 1B includes a case 54 and two subassemblies 92, like the battery pack 1A. Since the configuration of the case 54 is the same as that of the first embodiment, description thereof is omitted.

  As shown in FIGS. 9 and 10, the subassembly 92 includes a plurality of battery modules 10 and a heat sink 94. 9 and 10, the battery module 10 is schematically shown. The subassembly 92 has the same configuration as that of the subassembly 56 except that a heat sink 94 is provided instead of the heat sink 80. The heat radiating plate 94 has a main body (base part) 96 and an exposed part 98.

  The main body 96 is a plate-like member having a mounting surface 96a on which the plurality of battery modules 10 are mounted. An exposed portion 98 is provided on a surface (hereinafter referred to as a back surface) 96 b opposite to the mounting surface 96 a of the main body portion 96. The main body portion 96 and the exposed portion 98 may be integrally formed. A screw hole 84 (see FIG. 10) into which the bolt 76 is screwed is formed around the exposed portion 98 on the back surface 96 b of the main body portion 96. The size of the main body 96 and the arrangement state in the case 54 can be the same as those of the heat sink 80 described in the first embodiment.

  The exposed portion 98 is provided on the back surface 96b of the main body portion 96 in a region facing the window portion 74, which is an opening portion, as in the first embodiment. In one embodiment, the exposed portion 98 has a plate shape as shown in FIG. The shape and size of the exposed portion 98 when viewed from the thickness direction of the heat sink 94 are substantially the same as the shape and size of the window portion 74. The thickness of the exposed portion 98 (the length in the thickness direction of the side wall 70 or the heat sink 94) is longer than the thickness of the side wall 70. Therefore, as shown in FIGS. 8 and 9, the end portion 98 a of the exposed portion 98 protrudes from the window portion 74 to the outside of the case 54 when the subassembly 92 is accommodated in the case 54. In other words, the end 98a protrudes outward from the outer surface 70a of the side wall 70, and is located outside the outer surface 70a.

  As shown in FIG. 8, the maximum length between the end portion 98a of the exposed portion 98 and the outer surface 70a of the side wall 70 of the case 54 is D, and the length of the bolt head (head) 76a of the bolt 76 is When d, D is not less than d. In one embodiment, D is the same as d. The length of the bolt head 76a is the maximum length of the bolt head 76a in the axial direction of the bolt 76, and means the thickness of the bolt head 76a.

  The battery pack 1B includes a subassembly 92 as in the battery pack 1A. A part of the heat radiating plate 94 included in the subassembly 92, more specifically, the exposed portion 98 protrudes from the window portion 74 formed on the side wall 70. Therefore, the battery pack 1B has at least the same functions and effects as the battery pack 1A. That is, the battery pack 1B is easy to assemble similarly to the battery pack 1A. Furthermore, the heat dissipation of the battery pack 1B is improved similarly to the battery pack 1A.

  In the battery pack 1 </ b> B, as shown in FIG. 9, the bolt head 76 a is prevented from protruding from the end portion 98 a of the exposed portion 98. Therefore, for example, the thickness of the heat sink 94 (the total thickness of the main body 96 and the exposed portion 98) at the portion where the exposed portion 98 is provided is equal to the thickness of the heat sink 80 in the first embodiment. If the thickness is the same, the length of the battery pack 1B in the Y-axis direction (the length of the heat dissipation plate 94 in the thickness direction) can be reduced. Therefore, the battery pack 1B can be downsized.

  In the battery pack 1 </ b> B, since the exposed portion 98 protrudes outward from the window portion 74, the exposed surface area of the heat sink 94 is increased. As a result, the heat dissipation is further improved in the battery pack 1B. As described above, the shape and size of the exposed portion 98 are substantially the same as the shape and size of the window portion 74. Therefore, the subassembly 92 can be positioned with respect to the side wall 70 by causing the exposed portion 98 to protrude from the window portion 74. As a result, the assembly of the battery pack 1B becomes easier.

  Also in the battery pack 1 </ b> B shown in FIG. 8, a through hole 88 may be formed in the bottom wall 62 of the case 54. In this case, the battery pack 1 </ b> A has the same function and effect as when the through hole 88 is formed in the bottom wall 62. That is, even if water enters the case 54 from the window 74, the water is discharged from the through hole 88. As a result, it is possible to prevent water from entering a region where electric parts such as the battery module 10 are provided.

  In the form in which the through hole 88 is formed in the bottom wall 62, the through hole 88 is attached to the heat sink 94 from the projection position of the mounting surface 96a when the heat sink 94 is projected onto the bottom wall 62 instead of the heat sink 80. What is necessary is just to be formed between the side wall 70 made. In the battery pack 1 </ b> B in which the through hole 88 is formed in the bottom wall 62, the projection area 90 described using FIG. 7 corresponds to the projection area of the heat sink 94. However, since the main body 96 is disposed in the case 54 of the heat sink 94, the projection region 90 specifically corresponds to the projection region of the main body 96.

(Modification 1)
FIG. 11 is a view showing a modification of the battery pack shown in FIG. 12 is a perspective view of a subassembly included in the battery pack shown in FIG. The battery pack 1C shown in FIG. 11 has the same configuration as that of the battery pack 1B except that the subassembly 100 shown in FIG. 12 is used instead of the subassembly 92. Therefore, the subassembly 100 will be described and description of other components will be omitted.

  The subassembly 100 includes a plurality of battery modules 10 and a heat sink 102. In FIG. 12, the battery module 10 is schematically shown. The heat radiating plate 102 is mainly different from the structure of the heat radiating plate 94 in that an exposed portion 106 having a plurality of convex portions 104 is formed on the back surface 96 b of the main body portion 96 instead of the exposed portion 98.

  The plurality of convex portions 104 extend in one direction (the Z-axis direction in FIGS. 11 and 12), and each convex portion 104 has, for example, a fin shape. The plurality of convex portions 104 are discretely arranged in a direction orthogonal to the extending direction of the convex portions 104. In this case, as shown in FIG. 11, in the battery pack 1 </ b> C, the plurality of convex portions 104 protrude from the window portion 74. Therefore, since the surface area exposed to the outside air in the heat radiating plate 102 increases, the heat dissipation can be further improved.

  In the exposed portion 106, when the maximum length between the end portion located outside the case 54 and the outer surface 70 a of the side wall 70 of the case 54 is D as in the first embodiment, the maximum length D is As in the case of the battery pack 1B, the length of the bolt head (head) 76a of the bolt 76 may be d or more. In this case, as in the case of the exposed portion 98, the bolt head 76a is prevented from protruding from the end portion 104a of the convex portion 104 in the battery pack 1C. Therefore, as in the case of the battery pack 1B, the size of the battery pack 1C can be reduced.

  Since the exposed portion 106 has a plurality of convex portions 104, the maximum length (D) is the distance between the end portion 104a located outside the case 54 of each of the plurality of convex portions 104 and the outer surface 70a. Corresponds to the maximum length. In the form shown in FIGS. 11 and 12, since the shape and size of each convex portion 104 are the same, the maximum length D corresponds to the distance between the end portion 104a and the outer surface 70a.

  Also in the first modification, a through hole 88 may be formed in the bottom wall 62 of the case 54. In this case, the battery pack 1 </ b> A shown in FIGS. 3 to 5 has the same function and effect as the embodiment in which the through hole 88 is formed in the bottom wall 62.

  In the modification 1, in the form in which the through-hole 88 is formed in the bottom wall 62, the through-hole 88 is formed on the side wall 70 to which the heat sink 102 is attached from the projection position of the mounting surface 96a, as in the case of the battery pack 1B. It is only necessary to be formed in between. In this embodiment, the projection area 90 described with reference to FIG. 7 corresponds to the heat dissipation plate 102, more specifically, the projection area of the main body 96.

(Modification 2)
In the form in which a plurality of convex portions 104 are formed on the back surface 96b of the main body 96, like the heat sink 102 shown in FIG. 12, a case main body 108 as shown in FIG. It may be adopted. The case body 108 is different from the structure of the case body 58 in that a window 110 is formed on the side wall 70 instead of the window 74.

  The window part 110 has a plurality of windows 112 corresponding to the plurality of convex parts 104. In other words, the window portion 110 corresponds to a single window portion illustrated in FIG. 5 divided into a plurality of regions (small windows or opening regions). Each window 112 is a hole through which the corresponding convex portion 104 passes. It extends in the same direction as the extending direction of the convex portion 104 (Z-axis direction in FIG. 13). Therefore, the plurality of windows 112 are discretely arranged in a direction orthogonal to the extending direction of the windows 112. The length in the extending direction of the window 112 and the length (width) in the direction orthogonal to the extending direction are substantially the same as the corresponding length of the convex portion 104.

  In the battery pack 1 </ b> C, in a battery pack using the case body 108 instead of the case body 58 (hereinafter also referred to as “battery pack of modification 2”), the corresponding protrusions 104 from the windows 112 are formed on the case body 108. Projects outward.

  The configuration of the battery pack of Modification 2 is that, except that a plurality of windows 110 are formed on the side wall 70 instead of the windows 74 (specifically, a plurality of windows 112 are formed) This is substantially the same as the battery pack 1C of the first modification. Therefore, the battery pack of Modification 2 has at least the same operational effects as the battery pack 1C.

  Since the plurality of windows 112 included in the case main body 108 and the plurality of convex portions 104 correspond to each other, the battery pack using the case main body 108 can easily align the subassembly 92. Therefore, the assembly of the battery pack is easier.

  Also in the second modification, a through hole 88 may be formed in the bottom wall 62 of the case main body 108. In this case, the battery pack of Modification 2 has the same operational effects as the battery pack 1A shown in FIGS. In the form in which the through hole 88 is formed in the bottom wall 62, the region A described using FIG. 7 may be a region corresponding to the window portion 110 instead of the window portion 74.

  As mentioned above, although various embodiment of this invention was described, this invention is not limited to the said embodiment and experiment example, A various change is possible in the range which does not deviate from the meaning of invention.

  For example, in the battery packs 1 </ b> A and 1 </ b> B, the form in which one window portion 74 is formed on one side wall 70 is exemplified. However, for example, a plurality of window portions 74 are formed on one side wall 70. Also good. In this case, the side wall 70 and the heat sinks 80 and 94 can be fastened by the bolts 76 even in the region between the two adjacent window portions 74. As a result, the stability of the subassemblies 56 and 92 in the battery packs 1A and 1B is improved. Although the battery packs 1A and 1B have been described here, the same applies to the first and second modifications of the battery pack 1B.

  In the first modification described with reference to FIGS. 11 and 12, the plurality of convex portions 104 are arranged at substantially constant intervals, but the intervals between adjacent convex portions 104 may be different. As described in the first modification, in the form in which the exposed portion has a plurality of convex portions, the shape of the convex portions is not limited to that extending in one direction like the convex portions 104. For example, the convex portion may have a shape obtained by dividing the plate-like exposed portion 98 shown in FIG. 10 in the X-axis direction and the Z-axis direction in FIG.

  Such an arrangement configuration of the plurality of protrusions (for example, the number of protrusions, the interval between adjacent protrusions, and the size of the protrusions) can be designed from the viewpoint of improving the heat dissipation by the heat sink. More specifically, the arrangement configuration of the plurality of convex portions can be designed from the viewpoint of improving the heat dissipation of the battery module that becomes a high temperature when the battery pack is used (particularly, the heat dissipation near the center of the battery module). For example, the number of convex portions in the vicinity of the central portion of the heat sink may be larger than that of other portions in the plan view shape of the heat sink (the shape seen from the thickness direction of the heat sink). Similarly, you may make the convex part in the center part vicinity of a heat sink larger than the convex part of another part. As an example, as shown in FIG. 12, when the convex portion extends in one direction, the width of the convex portion in the vicinity of the central portion of the heat sink (the length in the direction perpendicular to the extending direction of the convex portion). ) May be longer than the width of the convex portions of other portions. Alternatively, since the temperature in the vicinity of the central portion of the battery module tends to be high, more convex portions may be provided in the region corresponding to the vicinity of the central portion of the battery module mounted on the heat sink, or the convex portion in that region. The size (for example, the width of the protrusion) may be made larger. Furthermore, as shown in FIG. 12, in the embodiment in which the battery modules are provided in a two-stage configuration in the Z-axis direction shown in FIG. 12 (the normal direction of the bottom wall 62 shown in FIG. 9), Corresponding to the above, the convex portion may be provided in a two-stage configuration in the Z-axis direction. Furthermore, you may provide a some convex part in the area | region corresponding to each of the some battery module mounted in the heat sink.

  In the description of the battery pack 1B, as shown in FIG. 10, the exposed portion 98 having the flat end portion 98a is exemplified. However, the end portion 98a may not be flat. For example, in the exposed portion, the thickness of the portion corresponding to the battery module may be thicker than other portions. Thereby, since heat absorption (heat capacity) improves, heat dissipation improves. In the second embodiment, D, which is the maximum length between the end portion 98 a of the exposed portion 98 and the outer surface 70 a of the side wall 70 of the case 54, is the length of the bolt head 76 a of the bolt 76 d. The case where it is the above was illustrated and demonstrated. However, D may be less than d. For example, as described above, in the exposed part, D may be less than d in the form in which the part corresponding to the battery module is thicker than the other part. In the first and second modifications, D may be less than d.

  If the heat radiating plate on which the battery module is mounted is attached to a wall (attachment wall) in the case, the attachment method is not limited to the fastening with bolts as illustrated.

  As an embodiment, as shown in FIG. 7, a form in which a through hole is provided in the bottom wall of a case (more specifically, a case main body) is illustrated. However, the through hole may not be formed in the bottom wall. However, as described above, by providing the through hole in the bottom wall, even if water enters from the window portion, the water that has entered can be discharged from the through hole. Further, in the various embodiments so far, the mode in which the seal member (for example, the O-ring) is not disposed between the heat radiating plate and the window portion is illustrated, but the seal member is provided between the window portion and the heat radiating plate. May be. In the form in which the seal member is provided, the bottom wall may not have a through hole. However, by providing the through hole in the bottom wall, water can enter the battery module in the case. This can be further prevented.

  Although an example of a battery pack having two subassemblies has been described, the number of subassemblies may be one, or may be three or more as long as it can be accommodated in a case. Furthermore, in the case of housing a plurality of battery modules and heat sinks, the cross-sectional shape perpendicular to the normal direction of the bottom wall (Z-axis direction in FIG. 1) is not limited to a quadrangle (for example, a rectangle or a square). Hexagon may be used.

  The present invention has been described by exemplifying a battery pack having a plurality of battery modules. However, the battery pack according to the present invention only needs to include at least one battery module. That is, it is sufficient that one battery module is mounted on the heat dissipation plate provided in the battery pack.

  Further, when the battery module is mounted on the heat sink, a TIM (Thermal Interface Material) as a heat transfer sheet may be disposed between the battery module and the heat sink. That is, a TIM may be interposed between a portion of the heat transfer member included in the battery module that faces the heat dissipation plate (heat dissipation portion 52 in the example of FIG. 6) and the heat dissipation plate.

  1A, 1B, 1C ... battery pack, 24 ... heat transfer plate, 54 ... case, 62 ... bottom wall, 70 ... side wall (mounting wall), 70a ... outer surface, 74 ... window, 76 ... bolt, 76a ... bolt head, DESCRIPTION OF SYMBOLS 80 ... Heat sink, 80a ... Mounting surface, 88 ... Through-hole, 90 ... Projection area, 94 ... Heat sink, 96 ... Main part, 96a ... Mounting surface, 98 ... Exposed part, 98a ... End part (end part of exposed part) , 102 ... heat sink, 104 ... convex part, 104 a ... end part (end part of exposed part), 106 ... exposed part, 110 ... window part, 112 ... window.

Claims (8)

Battery modules each having a plurality of battery cells arranged in parallel;
A heat sink having a mounting surface on which the battery module is mounted;
A case for housing the battery module and the heat sink;
With
The case has an attachment wall to which the heat sink is attached,
The heat sink is attached to the mounting wall by fixing the side opposite to the mounting surface of the heat sink to the mounting wall.
In the mounting wall, a window portion is formed in a region facing the heat sink,
A part of the heat sink is exposed from the window portion,
Battery pack. The heat sink is
A plate-like main body having the mounting surface;
In the surface opposite to the mounting surface in the main body, an exposed portion provided in a region corresponding to the window portion;
Have
The end of the exposed portion opposite to the main body protrudes from the window to the outside of the case.
The battery pack according to claim 1. The heat sink is fastened to the mounting wall by a bolt inserted from the outer surface side of the mounting wall,
In the thickness direction of the heat radiating plate, the maximum length between the end portion of the exposed portion located outside the case and the outer surface of the mounting wall is equal to or greater than the length of the bolt head of the bolt.
The battery pack according to claim 2. The exposed portion has a plurality of convex portions arranged discretely,
The battery pack according to claim 2 or 3. The window portion has a plurality of windows corresponding to the plurality of convex portions,
The battery pack according to claim 4. The mounting wall is a side wall erected on the bottom wall of the case;
In the bottom wall, a through-hole penetrating the bottom wall in the thickness direction of the bottom wall is formed,
The through-hole is provided between the mounting surface and the mounting wall when the heat sink is projected onto the bottom wall in the thickness direction of the bottom wall.
The battery pack according to any one of claims 1 to 5. The radiator plate is in contact with the bottom wall;
The battery pack according to claim 6. The battery module has a heat transfer member thermally connected to the battery cell,
The battery module is fixed so that the heat transfer member is in thermal contact with the mounting surface of the radiator plate.
The battery pack according to any one of claims 1 to 6.

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