Battery packs and electrical equipment

Abstract

Provided are a battery pack and an electrical device with improved cooling properties of battery cells. A bottom case 3 has a plurality of outer fins 13 on the bottom surface thereof. The bottom case 3 has contact portions 15 on an inner surface section on the side opposite from the plurality of outer fins 13. The contact portions 15 have an arc-like curved surface shape which is curved along the outer surface of first battery cells 4 not covered by a separator 6, and the contact portions make direct surface contact with the outer surface of the first battery cells 4 to support the outer surface. Each of the outer fins 13 is a planar portion perpendicular to the left-right direction, and extends downward from the rear surface of the contact portion 15. The plurality of outer fins 13 are arranged side by side in the left-right direction.

Description

[Technical field]

[0001] The present invention relates to a battery pack and an electric device. [Background technology]

[0002] There is known a battery pack that contains a plurality of battery cells and is configured to be detachable from the main body of an electrical device. The following Patent Document 1 discloses a battery pack that has an air layer between the bottom of the case and the battery cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-170635 A Summary of the Invention [Problem to be solved by the invention]

[0004] Battery cells generate heat during discharging. It is desirable to suppress the temperature rise of the battery cells in order to prevent deterioration of the battery cells and to prevent unexpected shutdowns due to temperature protection functions.

[0005] An object of the present invention is to provide a battery pack and an electrical device with improved cooling performance for battery cells. [Means for solving the problem]

[0006] One aspect of the present invention is a battery pack. A plurality of battery cells; A separator supporting the plurality of battery cells; a case that houses the plurality of battery cells and the separator; A battery pack comprising: the separator is configured to cover upper portions of the plurality of battery cells and expose lower portions of the plurality of battery cells; A plurality of outer fins are formed on a portion of the outer surface of the case.R, An inner surface portion having a shape that follows the shape of the side surfaces of the multiple battery cells is formed on the inner surface opposite the part of the case on which the multiple outer fins are formed, facing the exposed portions of the multiple battery cells.

[0007] Another aspect of the present invention is a battery pack including a plurality of battery cells, a separator supporting the plurality of battery cells, and a case housing the plurality of battery cells and the separator, the separator is configured to cover upper portions of the plurality of battery cells and expose lower portions of the plurality of battery cells, and the case has an inner surface that is in surface contact with side surfaces of the plurality of battery cells exposed from the separator.

[0008] Another aspect of the present invention is a battery pack comprising a plurality of battery cells including a first battery cell and a second battery cell, a separator supporting the plurality of battery cells, and a case housing the plurality of battery cells and the separator, the separator being configured to cover upper portions of the plurality of battery cells and expose lower portions of the plurality of battery cells, and the case comprising: an inner surface having a plurality of inner fins facing the second battery cell and extending in a direction intersecting a length direction of the second battery cell or extending parallel to the length direction, an inner surface portion facing the first battery cell and parallel to the length direction of the first battery cell, an outer surface portion located opposite the plurality of inner fins, and a plurality of outer fins located opposite the inner surface portion.

[0009] Another aspect of the present invention is an electric device comprising: the battery pack; and an electric device body having a battery pack mounting portion to which the battery pack can be attached.

[0010] The "electrical equipment" of the present invention may be expressed as a "working machine" or an "electric tool", and such expressions are also valid as aspects of the present invention. Effect of the Invention

[0011] According to the present invention, it is possible to provide a battery pack and an electric device with improved cooling performance for a battery cell. [Brief description of the drawings]

[0012] [Figure 1] 1 is a left side view of an electric device 1 according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the battery pack 10 of FIG. [Diagram 3] Cross-sectional view taken along line III-III in FIG. 2 . [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] 1A is a bottom perspective view of the battery pack 10 with the upper case 2 and the lower case 3 separated, and FIG. [Figure 7] FIG. [Figure 8] 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7 . [Figure 9] FIG. 11 is a plan view of a lower case 3A of a battery pack according to a second embodiment of the present invention. [Figure 10] FIG. [Figure 11] FIG. [Figure 12] FIG. 11 is a plan view of a lower case 3B of a battery pack according to embodiment 3 of the present invention. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] FIG. 11 is a plan view of a lower case 3C of a battery pack according to embodiment 4 of the present invention. [Figure 16] XVI-XVI cross-sectional view of Figure 15. [Figure 17] Bottom view of lower case 3C. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the following, the same or equivalent components, members, etc. shown in each drawing are given the same reference numerals, and duplicated explanations are omitted as appropriate. The embodiments are illustrative and do not limit the invention. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0014] 1 to 8 relate to an electric device 1 and a battery pack 10 according to a first embodiment of the present invention. Fig. 1 defines mutually orthogonal front-rear and up-down directions of the electric device 1. Also, a direction perpendicular to the front-rear and up-down directions is defined as a left-right direction.

[0015] The electric device 1 is an impact driver. The electric device 1 has a battery pack 10 and an electric device main body 30. The electric device main body 30 has a housing 39. The housing 39 includes a body portion 39a, a handle portion 39b, and a battery pack attachment portion 39c.

[0016] The body 39a is a cylindrical part whose central axis is parallel to the front-rear direction. The body 39a houses a motor, a rotary impact mechanism, etc. (not shown). The motor is an example of a drive part that is driven by the power of the battery pack 10. The handle 39b extends downward from the middle part of the body 39a. The electrical device main body 30 has a trigger switch 42 as a main switch at the upper end of the handle 39b. The trigger switch 42 is operated by a user to instruct the motor to start and stop.

[0017] The battery pack attachment section 39c is provided at the lower end of the handle section 39b. The battery pack 10 can be detachably attached to the battery pack attachment section 39c by sliding it from the front. The battery pack 10 has a display section 11 and an operation section 12 on its upper front surface. The battery pack 10 has a terminal section 18 on its top surface for electrical connection with the electrical device main body section 30.

[0018] The battery pack 10 has an upper case 2 and a lower case 3 made of, for example, a resin molded body. The upper case 2 and the lower case 3 are combined and integrated with each other by screwing or the like to form a case. Water drainage holes 9 are opened in each of the four corners of the lower surface of the lower case 3. The battery pack 10 has a plurality of battery cells, including two first battery cells 4 and three second battery cells 5. The first battery cells 4 and the second battery cells 5 are battery cells of the same type, shape, and size, but are supported by the lower case 3 in different ways, as described below.

[0019] As shown in Figs. 3 and 6, the first battery cell 4 and the second battery cell 5 are cylindrical and are aligned in a row in the front-rear direction with their length parallel to the left-right direction. The battery pack 10 has a separator 6 that supports the first battery cell 4 and the second battery cell 5. The separator 6 is, for example, a resin molded body, and is configured to cover a portion of the upper half (upper portion) of each of the first battery cell 4 and the second battery cell 5 and expose a lower portion of each of the first battery cell 4 and the second battery cell 5. The separator 6 supports a substrate 7 above itself. A terminal portion 18 is provided on the substrate 7. The first battery cell 4, the second battery cell 5, the separator 6, and the substrate 7 are housed in a case formed by combining an upper case 2 and a lower case 3.

[0020] The lower case 3 has a plurality of outer fins 13 and a plurality of outer connecting portions 14 on its lower surface which constitutes the outer surface. The lower case 3 has a contact portion 15 (inner surface portion) on the inner surface portion opposite the plurality of outer fins 13 and the plurality of outer connecting portions 14. The contact portion 15 has an arc-shaped curved surface shape (cylindrical inner surface shape) that curves along the outer surface (side surface) of the first battery cell 4 that is not covered by the separator 6 (exposed portion), and comes into direct surface contact with the outer surface of the first battery cell 4 to support the outer surface. The contact portion 15 is formed over the entire left-right direction of the inner surface portion of the lower case 3 facing upward.

[0021] Each outer fin 13 is a planar portion (rib) that extends in the front-rear direction perpendicular to the left-right direction, and extends downward from the back surface of the contact portion 15. The front-rear direction is an example of a direction that intersects with the length direction of the first battery cell 4 and the second battery cell 5. The multiple outer fins 13 are lined up in the left-right direction. Each outer connecting portion 14 is provided on the back surface of the contact portion 15 and extends in the left-right direction to connect the multiple outer fins 13. The tips (lower ends) of the multiple outer fins 13 and multiple outer connecting portions 14 are generally at the same height as the bottom surface of the lower case 3, and when the battery pack 10 is placed on a flat surface such as a floor surface, the multiple outer fins 13 and the multiple outer connecting portions 14 are generally in contact with the flat surface.

[0022] The lower case 3 has a plurality of inner fins 16 and a plurality of inner connecting portions 17 on its inner surface facing upward. The outer surface of the lower case 3 opposite the plurality of inner fins 16 and the plurality of inner connecting portions 17 forms a flat portion 8. The flat portion 8 includes a material indicating portion 8a that is slightly recessed compared to other portions, a nameplate affixing surface 8b, and a manufacturing lot engraved portion 8c. When the battery pack 10 is placed on a flat surface such as a floor surface, the entire portion of the flat portion 8 other than the material indicating portion 8a, the nameplate affixing surface 8b, and the manufacturing lot engraved portion 8c is in surface contact with the flat surface.

[0023] Each inner fin 16 is a planar portion (rib) that extends in the front-rear direction perpendicular to the left-right direction and extends upward from the back surface of the flat surface portion 8. The multiple inner fins 16 are lined up in the left-right direction. The multiple inner fins 16 are lined up across the entire left-right area of ​​the inner surface portion of the lower case 3 facing upward. The tips (upper ends) of the multiple inner fins 16 form an arc-shaped curved shape (cylindrical inner surface shape) that curves along the outer surface (side surface) of the second battery cell 5 that is not covered by the separator 6 (exposed portion), and are in direct surface contact with the outer surface of the second battery cell 5 to support the outer surface. Each inner connecting portion 17 is provided on the back surface of the flat surface portion 8 and extends in the left-right direction to connect the multiple inner fins 16.

[0024] According to this embodiment, the following effects can be obtained.

[0025] (1) Since multiple outer fins 13 are formed on the outer surface (lower surface) of the lower case 3, the surface area of ​​the lower case 3 that comes into contact with the outside air is increased, improving the cooling performance of the first battery cell 4 and the second battery cell 5. Alternatively, if the battery cell 5 is configured to be in direct contact with the multiple inner fins 16, heat from the battery cell 5 is more easily transferred to the multiple inner fins 16, making it easier to dissipate heat from the battery cell 5 to the outside via the multiple inner fins 16, improving the cooling performance of the second battery cell 5.

[0026] (2) A contact portion 15 is formed on the inner surface (surface facing upward) of the lower case 3, and an exposed portion of the first battery cell 4 that is not covered by the separator 6 is in direct contact with the contact portion 15. This makes it easier for heat from the first battery cell 4 to be transferred to the contact portion 15, and makes it easier for the heat from the first battery cell 4 to be dissipated to the outside via the contact portion 15, thereby improving the cooling performance of the first battery cell 4. Here, because the contact between the exposed portion of the first battery cell 4 and the contact portion 15 is surface-to-surface contact, heat can be efficiently transferred from the first battery cell 4 to the contact portion 15, and the cooling performance of the first battery cell 4 can be effectively improved.

[0027] (3) The lower case 3 has a shape having multiple outer fins 13 on the back surface of the contact portion 15, which reduces the risk of molding defects (sink marks). In other words, if the back surface of the contact portion 15 were to be flat like the flat portion 8, the lower case 3 would be thick at the peaks of the contact portion 15, making it more likely that molding defects would occur in which the bottom surface of the lower case 3 would be inadvertently dented. In contrast, in this embodiment, by providing multiple outer fins 13 on the back surface of the contact portion 15, the lower case 3 is designed to have no thick portions, thereby reducing the risk of molding defects (sink marks).

[0028] (4) A plurality of inner fins 16 whose tips follow the outer surface of the second battery cell 5 are formed on the inner surface (surface facing upward) of the lower case 3, and the exposed portion of the second battery cell 5 that is not covered by the separator 6 is in direct contact with the plurality of inner fins 16. This makes it easier for heat from the second battery cell 5 to be transferred to the plurality of inner fins 16, and makes it easier for the heat from the second battery cell 5 to be dissipated to the outside via the plurality of inner fins 16, thereby improving the cooling performance of the second battery cell 5. Here, because the contact between the exposed portion of the second battery cell 5 and the tips of the plurality of inner fins 16 is surface contact, heat can be efficiently transferred from the second battery cell 5 to the plurality of inner fins 16, and the cooling performance of the second battery cell 5 can be effectively improved.

[0029] (5) The portion of the outer surface (lower surface) of the lower case 3 opposite the multiple inner fins 16 is a flat portion 8, so that the flat portion 8 can be used to indicate the material, attach a nameplate, stamp the production lot, etc., thereby improving convenience.

[0030] (6) The lower case 3 has a shape having multiple inner fins 16 on the back surface of the flat portion 8, which reduces the risk of molding defects (sink marks). In other words, if the back surface of the flat portion 8 is curved like the contact portion 15, the lower case 3 will be thick at the peaks of the curved surface, making it more likely that molding defects will occur in which the bottom surface of the lower case 3 is inadvertently dented. In contrast, in this embodiment, by providing multiple inner fins 16 on the back surface of the flat portion 8, the lower case 3 is designed to have no thick portions, which reduces the risk of molding defects (sink marks).

[0031] (7) Since the outer connectors 14 connect the outer fins 13 together, the structure is strengthened and the durability is increased. Similarly, since the inner connectors 17 connect the inner fins 16 together, the structure is strengthened and the durability is increased.

[0032] (8) The lower case 3 has a flat portion 8, a plurality of outer fins 13, a plurality of outer connecting portions 14, a contact portion 15, a plurality of inner fins 16, and a plurality of inner connecting portions 17 as a single molded body. Therefore, compared to a configuration in which components such as heat dissipation fins are added separately from the lower case 3, it is possible to suppress an increase in the number of components and reduce costs. In addition, since the lower case 3 and the outer fins 13 are integrally configured, it is possible to suppress a decrease in the strength of the lower case 3 compared to a case in which the lower case 3 and the outer fins 13 are configured from separate members. In addition, since the lower case 3 and the inner fins 16 are integrally configured, it is possible to suppress a decrease in the strength of the lower case 3 compared to a case in which the lower case 3 and the inner fins 16 are configured from separate members.

[0033] (9) The improved cooling of the first battery cell 4 and the second battery cell 5 makes it possible to suppress deterioration of the first battery cell 4 and the second battery cell 5 due to heat generation during discharging and to suppress unexpected shutdown of the electrical device 1 due to the temperature protection function, thereby improving convenience. In addition, since heat generation during charging can also be suppressed, there is no need to provide ventilation holes in the case to allow cooling air to pass through during charging, and waterproofing can also be improved.

[0034] 9 to 11 relate to a second embodiment of the present invention. In this embodiment, the lower case 3 of the battery pack 10 of the first embodiment is replaced with a lower case 3A. In this embodiment, the supporting manners of the first battery cell 4 and the second battery cell 5 are the same.

[0035] The lower case 3A has a plurality of outer fins 13A on its lower surface which constitutes the outer surface. The lower case 3A has a contact portion 15A on the inner surface portion opposite the plurality of outer fins 13A. The contact portion 15A has an arc-shaped curved surface shape (cylindrical inner surface shape) that curves along the outer surfaces (exposed portions) of the first battery cell 4 and the second battery cell 5 that are not covered by the separator 6, and comes into direct surface contact with the outer surfaces of the first battery cell 4 and the second battery cell 5 to support the outer surfaces.

[0036] Each outer fin 13A is a planar portion (rib) perpendicular to the left-right direction and extends downward from the rear surface of the contact portion 15A. The outer fins 13A are aligned in the left-right direction. The tips (lower ends) of the outer fins 13A are generally at the same height as the bottom surface of the lower case 3, and when placed on a flat surface such as a floor, the outer fins 13A are generally in contact with the flat surface.

[0037] The formation area of ​​the multiple outer fins 13A and contact portions 15A is a part including the center (the center in the length direction of the first battery cell 4 and the second battery cell 5) of the inner surface portion facing upward of the lower case 3A in the left-right direction (the length direction of the first battery cell 4 and the second battery cell 5). The lower surface portion of the lower case 3A forms a flat plate portion 19 except for the contact portions 15A (both left-right ends).

[0038] According to this embodiment, the multiple outer fins 13A and contact portions 15A function similarly to the multiple outer fins 13 and contact portions 15 of embodiment 1, improving the cooling performance of the first battery cell 4 and the second battery cell 5. In addition, the risk of molding defects (sink marks) in the lower case 3A can be reduced.

[0039] In this embodiment, although the formation area of ​​the multiple outer fins 13A and the contact portion 15A is limited to a part of the left-right direction of the lower case 3A, the central portion in the length direction where the first battery cell 4 and the second battery cell 5 generate relatively more heat is in surface contact with the contact portion 15A, so that the cooling of the first battery cell 4 and the second battery cell 5 can be effectively ensured. Furthermore, by limiting the formation area of ​​the multiple outer fins 13A and the contact portion 15A to a part of the left-right direction, a configuration is formed having a flat plate portion 19, and the underside of the flat plate portion 19 can be used to indicate the material, attach a nameplate, stamp the production lot, etc. In this regard, a configuration may be adopted in which the flat plate portion 19 is eliminated and the formation area of ​​the multiple outer fins 13A and the contact portion 15A is expanded to the entire left-right direction of the lower case 3A, giving priority to improving the cooling of the first battery cell 4 and the second battery cell 5.

[0040] 12 to 14 relate to a third embodiment of the present invention. In this embodiment, the lower case 3 of the battery pack 10 in the first embodiment is replaced with a lower case 3B. In this embodiment, the supporting manners of the first battery cell 4 and the second battery cell 5 are the same.

[0041] The lower case 3B has a plurality of inner fins 16A and a plurality of inner connecting portions 17A on its inner surface facing upward. The entire lower surface of the lower case 3B is a flat surface 8A. The flat surface 8A includes a material indicating portion 8d that is slightly recessed compared to other portions, a nameplate affixing surface 8e, and a manufacturing lot engraved portion 8f. When the product is placed on a flat surface such as a floor, the entire flat surface 8A except for the material indicating portion 8d, the nameplate affixing surface 8e, and the manufacturing lot engraved portion 8f is in surface contact with the flat surface.

[0042] Each inner fin 16A is a planar portion (rib) perpendicular to the left-right direction and extends upward from the back surface of the flat portion 8A. The multiple inner fins 16A are lined up in the left-right direction. The tips (upper ends) of the multiple inner fins 16A form an arc-shaped curved shape (cylindrical inner surface shape) that curves along the outer surfaces (exposed portions) of the first battery cell 4 and the second battery cell 5 that are not covered by the separator 6, and support the outer surfaces by making direct surface contact with them. Each inner connecting portion 17A is provided on the back surface of the flat portion 8A and extends in the left-right direction to connect the multiple inner fins 16A.

[0043] The formation area of ​​the multiple inner fins 16A and multiple inner connectors 17A is a part including the center (the center in the longitudinal direction of the first battery cell 4 and the second battery cell 5) of the inner surface facing upward of the lower case 3B in the left-right direction (the longitudinal direction of the first battery cell 4 and the second battery cell 5). The lower surface of the lower case 3B forms a flat plate portion 19 (both left-right ends) excluding the formation area of ​​the multiple inner fins 16A and multiple inner connectors 17A.

[0044] According to this embodiment, the multiple inner fins 16A function in the same way as the multiple inner fins 16 of embodiment 1, and can improve the cooling of the first battery cell 4 and the second battery cell 5. It also reduces the risk of molding defects (sink marks) in the lower case 3B. Furthermore, because the entire lower surface of the lower case 3B is a flat portion 8A, it is convenient for material indication, affixing a nameplate, stamping the production lot, etc.

[0045] In this embodiment, although the formation area of ​​the multiple inner fins 16A and the multiple inner connectors 17A is limited to a portion of the left-right direction of the lower case 3B, the central portion in the longitudinal direction where the first battery cell 4 and the second battery cell 5 generate relatively more heat is in surface contact with the tips of the multiple inner fins 16A, thereby effectively ensuring the cooling of the first battery cell 4 and the second battery cell 5. In this regard, the formation area of ​​the multiple inner fins 16A and the multiple inner connectors 17A may be expanded to the entire left-right direction of the lower case 3B to further improve the cooling of the first battery cell 4 and the second battery cell 5.

[0046] 15 to 17 relate to a fourth embodiment of the present invention. In this embodiment, the lower case 3 of the battery pack 10 of the first embodiment is replaced with a lower case 3C.

[0047] The lower case 3C has a plurality of outer fins 23 on its lower surface constituting its outer surface. The lower case 3C has a contact portion 15 on its inner surface portion opposite the plurality of outer fins 23.

[0048] Each outer fin 23 is a planar portion (rib) that extends perpendicular to the front-to-rear direction and in the left-to-right direction (the length direction of the battery cell), and extends downward from the back surface of the contact portion 15. The multiple outer fins 23 are lined up in the front-to-rear direction. The tips (lower ends) of the multiple outer fins 23 are generally at the same height as the bottom surface of the lower case 3C, and when placed on a flat surface such as a floor, the entire outer fins 23 are in contact with the flat surface.

[0049] The lower case 3C has, on its inner surface facing upward, a plurality of inner fins 26 and a plurality of partition ribs 27. The outer surface portion of the lower case 3C opposite the plurality of inner fins 26 and the plurality of partition ribs 27 is a flat portion 8.

[0050] Each inner fin 26 and each partition rib 27 is a planar portion (rib) that extends perpendicular to the front-rear direction and in the left-right direction (length direction of the battery cell), and extends upward from the back surface of the flat portion 8. The inner fins 26 and the partition ribs 27 are aligned in the front-rear direction. The tips (upper ends) of the inner fins 26 form an arc-shaped curved shape (cylindrical inner surface shape) that curves along the outer surface (exposed portion) of the second battery cell 5 that is not covered by the separator 6, and directly contact the outer surface of the second battery cell 5 to support the outer surface. Each partition rib 27 separates adjacent second battery cells 5. The partition ribs 27 may also directly contact the exposed portion of the second battery cell 5, like the inner fins 26.

[0051] According to the present embodiment, the multiple outer fins 23 and contact portions 15 function similarly to the multiple outer fins 13 and contact portions 15 of embodiment 1, and the multiple inner fins 26 function similarly to the multiple inner fins 16 of embodiment 1, thereby improving the cooling performance of the first battery cell 4 and the second battery cell 5. In addition, the risk of molding defects (sink marks) in the lower case 3C can be reduced.

[0052] In this embodiment, a plurality of outer connecting portions may be provided that extend in the front-rear direction and connect the plurality of outer fins 23. Also, a plurality of inner connecting portions may be provided that extend in the front-rear direction and connect the plurality of inner fins 26. Also, the formation area of ​​the plurality of outer fins 23 and / or the plurality of inner fins 26 may be limited to a portion of the lower case 3C in the left-right direction, preferably a portion that includes the center portions of the first battery cell 4 and the second battery cell 5 in the length direction.

[0053] The outer fins 23 and / or inner fins 26 may be divided into a plurality of parts in the extension direction in the left-right direction (the length direction of the battery cell). That is, the outer fins 23 and / or inner fins 26 may be a plurality of short fins extending in the left-right direction lined up in the left-right direction.

[0054] The plurality of outer fins 23 may be substituted for the plurality of outer fins 13 of the first embodiment. Alternatively, the plurality of inner fins 26 may be substituted for the plurality of inner fins 16 of the first embodiment.

[0055] Although the present invention has been described above using the embodiment as an example, it will be understood by those skilled in the art that various modifications are possible to the components and processes of the embodiment within the scope of the claims. Modifications will be mentioned below.

[0056] The combination of lengths and extension directions of the multiple outer fins and multiple inner fins may be arbitrary. For example, one of the multiple outer fins and multiple inner fins may extend in the left-right direction (the length direction of the battery cells), and the other may extend in the front-rear direction (the arrangement direction of the battery cells). In addition, one or both of the multiple outer fins and multiple inner fins may be divided into multiple parts in the extension direction.

[0057] The number of battery cells, etc., given as specific numerical values ​​in the embodiment do not limit the scope of the invention in any way and can be changed as desired to meet the required specifications. The electrical device of the present invention may be any type that operates on power from a battery pack, and may be a power tool or work machine other than an impact driver, or may be an electrical device other than a power tool or work machine. [Explanation of symbols]

[0058] 1...electrical device, 2...upper case, 3, 3A, 3B, 3C...lower case, 4...first battery cell, 5...second battery cell, 6...separator, 7...circuit board, 8...flat portion, 8a...material display portion, 8b...nameplate affixing surface, 8c...manufacturing lot stamping portion, 8d...material display portion, 8e...nameplate affixing surface, 8f...manufacturing lot stamping portion, 9...drain hole, 10...battery pack, 11...display portion, 12...operation portion (remaining battery level display switch), 13 , 13A...outer fin, 14...outer connecting portion, 15, 15A...contact portion, 16, 16A...inner fin, 17, 17A...inner connecting portion, 18...terminal portion, 19...flat plate portion, 23...outer fin, 26...inner fin, 27...partition rib, 30...electrical device main body portion, 39...housing, 39a...body portion, 39b...handle portion, 39c...battery pack attachment portion, 42...trigger switch (main switch).

Claims

1. A plurality of battery cells; A separator supporting the plurality of battery cells; a case that houses the plurality of battery cells and the separator; A battery pack comprising: the separator is configured to cover upper portions of the plurality of battery cells and expose lower portions of the plurality of battery cells; A plurality of external fins are formed on a portion of the outer surface of the case, an inner surface portion having a shape conforming to a shape of a side surface of the plurality of battery cells is formed on an inner surface opposite to the part of the case on which the plurality of outer fins are formed, the inner surface portion being opposed to the exposed parts of the plurality of battery cells; A battery pack characterized by:

2. 2. The battery pack according to claim 1, the plurality of battery cells includes a first battery cell, a contact portion that contacts a side surface of the first battery cell along the side surface of the first battery cell is formed on the inner surface portion; A battery pack characterized by:

3. 3. The battery pack according to claim 2, the plurality of battery cells includes a second battery cell different from the first battery cell; a plurality of inner fins, the tips of which extend along the side surfaces of the second battery cells, are formed on an inner surface of the case opposite to the outer surface on which the plurality of outer fins are not formed; the plurality of inner fins support an exposed portion of the second battery cell that is not covered by the separator; A battery pack characterized by:

4. 4. The battery pack according to claim 3, At least one of the plurality of outer fins and the plurality of inner fins is configured to extend in a direction intersecting a length direction of the battery cell. A battery pack characterized by:

5. 4. The battery pack according to claim 3, At least one of the plurality of outer fins and the plurality of inner fins is configured to extend in a length direction of the battery cell. A battery pack characterized by:

6. 6. The battery pack according to claim 1, the outer fins are formed in a range including central portions of the battery cells in a longitudinal direction of the battery cells, A battery pack characterized by:

7. A plurality of battery cells; A separator supporting the plurality of battery cells; a case that houses the plurality of battery cells and the separator; A battery pack comprising: the separator is configured to cover upper portions of the plurality of battery cells and expose lower portions of the plurality of battery cells; the case has an inner surface portion that is in surface contact with side surfaces of the plurality of battery cells exposed from the separator; A battery pack characterized by:

8. 8. The battery pack according to claim 7, the plurality of battery cells includes a first battery cell and a second battery cell; a contact portion that is in surface contact with a side surface of the first battery cell along a side surface of the first battery cell is formed on the inner surface portion; a plurality of inner fins are formed on the inner surface of the case, the tips of the inner fins being aligned along the side surface of the second battery cell; the inner fins support exposed portions of the battery cells that are not covered by the separators. A battery pack characterized by:

9. a plurality of battery cells including a first battery cell and a second battery cell; A separator supporting the plurality of battery cells; a case that houses the plurality of battery cells and the separator; A battery pack comprising: the separator is configured to cover upper portions of the plurality of battery cells and expose lower portions of the plurality of battery cells; The case is an inner surface having a plurality of inner fins facing the second battery cell and extending in a direction intersecting a length direction of the second battery cell or extending parallel to the length direction, and an inner surface portion facing the first battery cell and parallel to the length direction of the first battery cell; an exterior surface having an exterior surface portion opposite the plurality of internal fins and a plurality of external fins opposite the interior surface portion; Equipped with A battery pack characterized by:

10. 10. The battery pack according to claim 9, a contact portion that is in surface contact with a side surface of the first battery cell along a side surface of the first battery cell is formed on the inner surface portion; a tip of each of the inner fins is shaped to fit along a side surface of the second battery cell and supports exposed portions of the plurality of battery cells that are not covered by the separator; A battery pack characterized by:

11. 10. The battery pack according to claim 9, The plurality of outer fins are configured to extend in a direction intersecting a length direction of the first battery cell or parallel to the length direction. A battery pack characterized by:

12. The battery pack according to any one of claims 8 to 11, the inner fin is formed in a range in a longitudinal direction of the plurality of battery cells that includes central portions of the plurality of battery cells in the longitudinal direction, A battery pack characterized by:

13. The battery pack according to any one of claims 3 to 5 and 8 to 11, A portion of the outer surface of the case opposite to the plurality of inner fins is a flat surface. A battery pack characterized by:

14. The battery pack according to any one of claims 3 to 5 and 8 to 11, Each of the plurality of battery cells is cylindrical in shape; The tips of the inner fins are formed in an arc shape so as to follow the cylindrical shape. A battery pack characterized by:

15. A battery pack according to any one of claims 1 to 5 and 7 to 11; an electrical device body having a battery pack mounting portion into which the battery pack can be mounted; 1. An electrical device comprising:

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