Battery pack

Abstract

To provide a technology capable of suppressing contact of water that has entered an outer case of a battery pack with a substrate.SOLUTION: A battery pack includes an outer case, a cell case housed in the outer case, and a substrate housed in the outer case and held in the outer case, the outer case has an upper surface provided with a terminal opening for exposing a terminal, a bottom surface, a side surface extending upward from the bottom surface, a hook arranged on the side surface, and a first opening arranged on the side surface, and the substrate is provided at a position facing the side surface, the substrate is provided below the hook, and the first opening is provided below the substrate.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a battery pack. [Background technology]

[0002] A battery pack is disclosed in Patent Document 1. The battery pack in Patent Document 1 includes an outer case, a cell case housed in the outer case, and a substrate housed in the outer case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-203703 A Summary of the Invention [Problem to be solved by the invention]

[0004] Water may seep into the outer case through gaps in the outer case. If water accumulates inside the battery pack and comes into contact with the circuit board, the battery pack may no longer function properly. For this reason, it is necessary to prevent water from coming into contact with the circuit board even if it does get into the outer case.

[0005] This specification relates to a method for preventing water from entering the outer case of a battery pack. Electrical components inside the outer case The present invention provides a technology that can suppress contact with. [Means for solving the problem]

[0006] The battery pack disclosed in this specification comprises an outer case, a hook, and a substrate housed in and held by the outer case, the outer case having a top surface having a terminal opening for exposing terminals, a bottom surface, a side surface extending upward from the bottom surface, and a first opening disposed on the side surface, the hook being disposed on the side surface of the outer case, the substrate being disposed at a position opposite the side surface, the substrate being disposed below the hook, and the first opening being disposed below the substrate.

[0007] In the battery pack, water that has entered the outer case is drained through a first opening provided below the board. Therefore, even if water enters the outer case, the water does not accumulate near the board. Therefore, it is possible to prevent the water that has entered the outer case from coming into contact with the board.

[0008] Another battery pack disclosed in this specification comprises an outer case, a battery cell, a cell case housed in the outer case and housing the battery cell, and a substrate housed in the outer case, the outer case having a top surface with a terminal opening for exposing terminals, a bottom surface, and a side surface extending upward from the bottom surface, the substrate is provided between the cell case and the side surface and is arranged along a direction perpendicular to the bottom surface, and the outer case has an opening on a surface opposite the lower surface of the substrate.

[0009] In the battery pack described above, water that has entered the outer case is drained through an opening facing the underside of the board. Therefore, even if water enters the outer case, it does not accumulate near the board. Therefore, it is possible to prevent water that has entered the outer case from coming into contact with the board.

[0010] Another battery pack disclosed in this specification comprises an outer case and a substrate held by the outer case, the outer case having a top surface provided with a terminal opening for exposing terminals, a bottom surface, and a side surface extending upward from the bottom surface, the substrate being disposed in a position opposite the side surface, and the side surface having an opening.

[0011] In the battery pack described above, water that has entered the outer case is drained through the opening. Therefore, even if water enters the outer case, the water does not accumulate near the circuit board. Therefore, it is possible to prevent the water that has entered the outer case from coming into contact with the circuit board. [Brief description of the drawings]

[0012] [Figure 1A] 1 is a perspective view of a battery pack 2 of a first embodiment as viewed from above on the front right. [Figure 1B] 1 is a perspective view of a battery pack 2 of a first embodiment as viewed from below on the front right. [Figure 1C] 1 is a perspective view of a battery pack 2 of a first embodiment as viewed from above and behind on the right. [Diagram 2] FIG. 2 is a bottom view of the battery pack 2 of the first embodiment as viewed from below. [Diagram 3] FIG. 2 is a right side view of the battery pack 2 of the first embodiment as viewed from the right. [Figure 4A] FIG. 2 is a bottom view of the upper case 14 of the first embodiment as viewed from below. [Figure 4B] 1 is a perspective view of an upper case 14 of the first embodiment as viewed from below on the front left. [Figure 4C] 2 is a cross-sectional view of the slide rail 20 of the upper case 14 of the first embodiment as viewed from the rear. FIG. [Diagram 5] FIG. 4B is an enlarged view of a portion V shown by the dashed line in FIG. 4A. [Figure 6] FIG. 2 is a top view of the lower case 15 of the first embodiment as viewed from above. [Figure 7] 7 is an enlarged perspective view of a portion VII shown by a broken line in FIG. 6, as viewed from above on the right rear side. [Figure 8]FIG. 2 is a perspective view of a lower case 15 of the first embodiment as viewed from above, rear, and left. [Figure 9A] 1 is a perspective view of a battery module 10 according to a first embodiment, as viewed from above on the front right. [Figure 9B] 1 is a perspective view of a battery module 10 according to a first embodiment, as viewed from above and behind the left. [Figure 10] FIG. 9B is a cross-sectional view taken along line XX in FIG. 9A. [Figure 11A] 2 is a perspective view of the cell case 80 of the first embodiment, seen from above on the front right. FIG. [Figure 11B] 1 is a perspective view of a right cell case 85 of the first embodiment as viewed from above and behind on the left. FIG. [Figure 11C] FIG. 2 is a top view of the cell case 80 of the first embodiment. [Figure 12A] FIG. 2 is a top view of the battery module 10 and the lower case 15 in a fixed state in the first embodiment. [Figure 12B] FIG. 2 is a top view of the battery pack 2 of the first embodiment. [Figure 13A] FIG. 12B is an enlarged view of a portion XIII enclosed by a dashed line in FIG. 12A. [Figure 13B] FIG. 13B is a cross-sectional view taken along line XIIIB-XIIIB in FIG. 13A. [Figure 14] 2 is a top cross-sectional view of a battery pack 2 according to the present embodiment. FIG. [Figure 15] 15 is an enlarged view of a portion XV of FIG. 14 surrounded by a dashed line. [Figure 16] 2 is a top cross-sectional view of a battery pack 2 according to the present embodiment. FIG. [Figure 17] FIG. 17 is an enlarged view of a portion XVII of FIG. 16 surrounded by a dashed line. [Figure 18] 1 is a cross-sectional view of a battery pack 2 according to a first embodiment, as viewed from the right. [Figure 19] 1 is a cross-sectional view of a battery pack 2 according to a first embodiment, as viewed from the right. [Figure 20] 1 is a cross-sectional view of a battery pack 2 according to a first embodiment, as viewed from behind. [Figure 21] FIG. 12C is a cross-sectional view taken along line XXI-XXI in FIGS. 12A and 12B. [Figure 22] 1 is a cross-sectional view of a battery pack 2 according to a first embodiment attached to a charger 300, as viewed from the left. [Diagram 23] 1 is a cross-sectional view of a battery pack 2 according to a first embodiment attached to a charger 300, as viewed from the left. [Figure 24A] 1 is a perspective view of a battery pack 2 according to a first embodiment attached to a power tool 200, as viewed from the upper right front. [Figure 24B] 1 is a cross-sectional view of a battery pack 2 according to a first embodiment attached to a power tool 200, as viewed from behind. [Figure 25A] 1 is a perspective view of a battery pack 2 according to a first embodiment attached to a charger 300, as viewed from the lower left rear. FIG. [Figure 25B] 1 is a perspective view of the charger 300 as viewed from below and rear on the left side. [Figure 26] 13 is a perspective view of a battery pack 602 according to a second embodiment, as viewed from below on the front right. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The battery pack disclosed in this specification comprises an outer case, a hook, and a substrate housed in and held by the outer case, the outer case having a top surface having a terminal opening for exposing terminals, a bottom surface, a side surface extending upward from the bottom surface, and a first opening disposed on the side surface, the hook being disposed on the side surface of the outer case, the substrate being disposed at a position opposite the side surface, the substrate being disposed below the hook, and the first opening being disposed below the substrate.

[0014] In one or more embodiments, the side surface may include a sloped portion that slopes relative to the bottom surface, and the first opening may be located in the sloped portion.

[0015] According to the above configuration, water that has entered the outer case from the hooks or the like can be drained through the first opening of the inclined portion. This can further prevent water that has entered the outer case from contacting the board. In addition, the inclined portion can guide water that has not been drained through the first opening to the bottom surface.

[0016] In one or more embodiments, the battery pack may further include a battery cell and a cell case housed in the outer case and housing the battery cell. The battery cell may be disposed parallel to a bottom surface of the outer case. The first opening may be located above a lower end of the battery cell.

[0017] Water that has entered the outer case is likely to accumulate on the bottom surface of the outer case. For this reason, it is desirable to place the board as high up as possible. According to the above configuration, the first opening is provided above the lower end of the battery cell, and the board is provided above the first opening. For this reason, the board can be placed higher up compared to a case in which the first opening is provided below the lower end of the battery cell. This makes it possible to further prevent water that has entered the outer case from coming into contact with the board.

[0018] In one or more embodiments, a second opening may be provided on the top surface of the outer case, and air may be in communication with the first opening and the second opening.

[0019] According to the above configuration, for example, when the battery pack is attached to a charger, the first opening can function as an air intake or exhaust hole.

[0020] In one or more embodiments, the side surface may be provided with a plurality of protrusions protruding toward the substrate. The plurality of protrusions may divide a space between the substrate and the outer case into two or more spaces, and the outer case may be provided with first openings corresponding to the two or more spaces, respectively.

[0021] If there is a space in the two or more spaces that does not have a corresponding first opening, water will accumulate in that space. In this case, the water accumulated in that space may come into contact with the substrate. According to the above configuration, water is drained from each of the two or more spaces separated by the multiple protrusions. Therefore, it is possible to prevent water from coming into contact with the substrate.

[0022] Another battery pack disclosed in this specification comprises an outer case, a battery cell, a cell case housed in the outer case and housing the battery cell, and a substrate housed in the outer case, the outer case having a top surface with a terminal opening for exposing terminals, a bottom surface, and a side surface extending upward from the bottom surface, the substrate is provided between the cell case and the side surface and is arranged along a direction perpendicular to the bottom surface, and the outer case has an opening on a surface opposite the lower surface of the substrate.

[0023] In one or more embodiments, the surface of the outer case facing the lower surface of the substrate may be an inclined surface that is inclined with respect to the bottom surface.

[0024] According to the above-mentioned configuration, water that has entered the outer case and reached the inclined surface is guided along the inclined surface to the bottom surface, thereby making it possible to prevent water from accumulating near the board.

[0025] Another battery pack disclosed in this specification comprises an outer case and a substrate held by the outer case, the outer case having a top surface provided with a terminal opening for exposing terminals, a bottom surface, and a side surface extending upward from the bottom surface, the substrate being disposed in a position opposite the side surface, and the side surface having an opening.

[0026] In one or more embodiments, the substrate may be a substrate carrying LEDs, a substrate carrying switches, or a substrate carrying LEDs and switches.

[0027] Generally, it is difficult to waterproof a board on which an LED or a switch is provided. Therefore, it is necessary to prevent water from coming into contact with the board. With the above configuration, even if a board that is difficult to waterproof is mounted, it is possible to prevent water from coming into contact with the board.

[0028] In one or more embodiments, the side surface may be provided with a plurality of protrusions that protrude toward the substrate. The plurality of protrusions may divide the space between the substrate and the outer case into two or more spaces, and the outer case may be provided with openings corresponding to each of the two or more spaces.

[0029] If there is a space without a corresponding opening among the two or more spaces, water will accumulate in that space. In this case, the water accumulated in that space may come into contact with the substrate. According to the above configuration, water is drained from each of the two or more spaces separated by the multiple protrusions, so that water can be prevented from coming into contact with the substrate.

[0030] In one or more embodiments, the side surface may include a sloped portion that slopes relative to the bottom surface, and the opening may be located in the sloped portion of the side surface.

[0031] According to the above-mentioned configuration, water that has flowed down the side surface can be drained through the opening in the inclined portion. Therefore, it is possible to further prevent water that has entered the outer case from contacting the board. In addition, the inclined portion can guide water that has not been drained through the opening to the bottom surface.

[0032] (First Example) The battery pack 2 of the embodiment will be described below with reference to the drawings. As shown in FIG. 24A, the battery pack 2 can be detachably attached to the power tool 200. Although FIG. 24A illustrates an example in which the power tool 200 is an electric screwdriver, the power tool 200 may be, for example, an electric drill, an electric grinder, an electric circular saw, an electric chain saw, an electric reciprocating saw, an electric lawn mower, an electric brush cutter, an electric blower, or the like. When attached to the power tool 200, the battery pack 2 supplies power to the power tool 200. Also, as shown in FIG. 25, the battery pack 2 can be detachably attached to the charger 300. When attached to the charger 300, the battery pack 2 is supplied with power from the charger 300. In the following description, with respect to the battery pack 2, when attached to the power tool 200 or the charger 300, the direction in which the power tool 200 or the charger 300 is located as viewed from the battery pack 2 is referred to as the upper side, and the opposite direction is referred to as the lower side. In addition, the direction in which the battery pack 2 is slid when attached to the power tool 200 or the charger 300 is referred to as the rearward direction, and the direction in which the battery pack 2 is slid when removed from the power tool 200 or the charger 300 is referred to as the forward direction. That is, in the following description, the front-rear direction corresponds to the sliding direction in which the battery pack 2 is slid relative to the power tool 200 or the charger 300.

[0033] As shown in Fig. 1 to Fig. 13B, the battery pack 2 includes a battery module 10 (see Fig. 9) and an outer case 12 (see Fig. 1) that houses the battery module 10. The outer case 12 is formed into a generally rectangular parallelepiped shape as a whole, and is divided into an upper case 14 and a lower case 15. As shown in Fig. 2, the upper case 14 and the lower case 15 are fixed to each other by four screws 18.

[0034] (Configuration of upper case 14) As shown in FIG. 1A, the upper case 14 is formed with a slide rail 20, a terminal receiving portion 22, a hook 24, and an air hole 26.

[0035] The slide rail 20 extends along the front-rear direction and is disposed at the left and right ends of the upper part of the upper case 14. As shown in FIG. 1A, the slide rail 20 includes a base 20a, an upward extension 20b, a first right extension 20c, and a second right extension 20d. As shown in FIG. 4C, the upward extension 20b extends upward from the left end of the base 20a. The first right extension 20c extends rightward from the upward extension 20b. The lower end of the first right extension 20c is located above the upper end of the base 20a. The right end of the first right extension 20c is located leftward from the right end of the base 20a. The second right extension 20d extends rightward from the upward extension 20b. The right end of the second right extension 20d coincides with the position of the right end of the first right extension 20c in the left-right direction. As shown in FIG. 1A, the second right extension 20d is connected to the base 20a. The first right extension 20c and the second right extension 20d are provided with a plurality of recesses 20e arranged in the front-rear direction. When the battery pack 2 is attached to or detached from the power tool 200 or the charger 300, the slide rail 20 slidably engages with the slide rail (not shown) of the power tool 200 or the slide rail 302 of the charger 300 (see FIG. 25B). Specifically, the slide rail (not shown) of the power tool 200 or the slide rail 302 of the charger 300 slides between the base 20a and the first right extension 20c.

[0036] The terminal receiving portion 22 has four terminal openings 22a to 22d provided on the front upper surface 14b1 of the upper case 14. The terminal openings 22a to 22d are arranged between the left and right slide rails 20, and receive the terminals 208a, 208b, 210a, and 210c (see FIG. 24B) of the power tool 200 and the terminals (not shown) of the charger 300 when the battery pack 2 is attached to the power tool 200 and the charger 300. The terminal openings 22a to 22d are provided in the order of the terminal opening 22a, the terminal opening 22b, the terminal opening 22c, and the terminal opening 22d from the right slide rail 20 to the left slide rail 20. As shown in FIGS. 1C, 12B, and 24B, the battery side recesses 23a to 23d are provided so as to surround the terminal openings 22a to 22d. The terminal openings 22a-22d and the battery-side recesses 23a-23d have a U-shape when viewed from above the battery pack 2. The battery-side recesses 23a-23d are provided slightly below the front upper surface 14b1 of the outer case 12. In other words, the front upper surface 14b1 and the battery-side recesses 23a-23d have a stepped shape.

[0037] The hook 24 is disposed at the front upper portion of the upper case 14. The hook 24 is a resin member and includes an operating portion 24a and a protruding portion 24b. The operating portion 24a is provided on the front surface 14a of the upper case 14. The hook 24 is held by the upper case 14 so as to be movable in the up and down direction. The hook 24 is biased upward by a compression spring (not shown), and moves downward when the operating portion 24a or the protruding portion 24b is pressed downward. When the battery pack 2 is attached to the power tool 200 or the charger 300, the protruding portion 24b engages with the housing (not shown) of the power tool 200 or the housing 304 of the charger 300 (see FIG. 25B) to fix the battery pack 2 to the power tool 200 or the charger 300. When the battery pack 2 is removed from the power tool 200 or the charger 300, the user presses the operating portion 24a downward, causing the protruding portion 24b to move downward. In this state, the battery pack 2 can be slid to remove it from the power tool 200 or the charger 300. The operation unit 24a has a shape that is recessed inward. Therefore, when a user places a finger on the operation unit 24a and presses the operation unit 24a downward, the user can press the operation unit 24a down without the finger slipping.

[0038] The ventilation hole 26 is provided behind the slide rail 20. The ventilation hole 26 is provided at the rear of the rear upper surface 14b2 of the outer case 12. The rear upper surface 14b2 is located below the front upper surface 14b1 and above the base 20a of the slide rail 20. A battery-side recess 27 is provided at a part of the right side, a part of the left side, and at the front of the ventilation hole 26. The battery-side recess 27 is provided slightly below the rear upper surface 14b2. That is, the rear upper surface 14b2 and the battery-side recess 27 have a stepped shape. The charger 300 is provided with a charger-side protrusion 306 (see FIG. 25B) having a shape corresponding to the battery-side recess 27. Therefore, when the battery pack 2 is attached to the charger 300, the charger-side protrusion 306 is inserted into the battery-side recess 27.

[0039] As shown in FIG. 4A, the upper case 14 is provided with four screw holes 28 and five first protrusions 30a to 30e. The four screw holes 28 are fitted with screws 18 (see FIG. 2). As shown in FIG. 4B, the first protrusions 30a to 30e protrude downward (i.e., toward the cell case 80) from the upper surface of the upper case 14. As shown in FIG. 4C, the first protrusion 30d is provided below the slide rail 20 (specifically, the base 20a), that is, on the inside of the upper case 14. The first protrusions 30a to 30c and 30e are also provided below the slide rail 20. As shown in FIG. 5, the first protrusion 30 is composed of a thick portion 32a and a thin portion 32b. The thickness of the thick portion 32a in the left-right direction is greater than the thickness of the thin portion 32b in the left-right direction. In the first protrusion 30, thick portions 32a and thin portions 32b are alternately formed. As shown in Fig. 4A, the first protrusions 30a-30d are composed of four thick portions 32a and three thin portions 32b. The first protrusion 30e is composed of three thick portions 32a and two thin portions 32b. As shown in Fig. 5, the length L1 in the front-rear direction of the first protrusions 30a-30d is longer than the length L2 in the front-rear direction of the first protrusion 30e.

[0040] As shown in FIG. 4A, upper case 14 is provided with six second protrusions 34a to 34f for aligning upper case 14 and lower case 15. As shown in FIG.

[0041] (Configuration of the lower case 15) As shown in FIG. 1B and FIG. 8, the lower case 15 is composed of a front surface 15a, a right side surface 15b, a rear surface 15c, a left side surface 15d, and a bottom surface 15e. The front surface 15a is composed of a first upward extending surface 17a extending perpendicularly to the bottom surface 15e, an inclined surface 17b inclined relative to the bottom surface 15e, and a second upward extending surface 17c extending perpendicularly to the bottom surface 15e. As shown in FIG. 13B, the inclined surface 17b is inclined so that the rear side is inclined downward. As shown in FIG. 1A, the lower case 15 is provided with an air vent 40 and a display unit 42. The display unit 42 is provided on the front surface 15a of the lower case 15. The display unit 42 is provided with a remaining charge display unit 42a that displays the remaining charge of the battery pack 2 to the user, and a button 42b that switches the display of the remaining charge on and off. 1B, vent holes 58a to 58d are provided on inclined surface 17b of lower case 15. A hook portion 19 is provided on bottom surface 15e of lower case 15. Hook portion 19 is used when removing battery pack 2 from power tool 200 or charger 300. Specifically, the user hooks hook portion 19 with the index finger or middle finger and presses operating portion 24a (see FIG. 1A) downward with the thumb.

[0042] As shown in FIG. 3, the ventilation hole 40 is provided in the lower part of the right side surface 15b of the lower case 15. The ventilation hole 40 is composed of ten holes 40a to 40j. The ten holes 40a to 40j are arranged in two rows, one above the other. Of the five holes 40a to 40e provided in the lower row, the length in the front-rear direction of the rearmost hole 40a and the frontmost hole 40e is shorter than the length in the front-rear direction of the holes 40b to 44d. Also, of the five holes 40f to 44j provided in the upper row, the length in the front-rear direction of the rearmost hole 40f and the frontmost hole 40j is shorter than the length in the front-rear direction of the holes 40g to 44i. Also, as shown in FIG. 8, a ventilation hole 41 similar to the ventilation hole 40 is provided in the lower part of the left side surface 15d of the lower case 15. The ventilation hole 41 is composed of ten holes 41a to 41j.

[0043] As shown in FIG. 6, the lower case 15 is provided with four screw holes 46, five front ribs 48, 50, 52, 54, 56, four vent holes 58a-58d, eight side ribs 60a-60h, four screw holes 62, and six second recesses 64a-64f. The four screw holes 46 are provided at positions corresponding to the four screw holes 28 (see FIG. 4A) of the upper case 14. The four screw holes 62 are screw holes for fixing the lower case 15 and the battery module 10. The second recesses 64a-64f are provided at positions corresponding to the second protrusions 34a-34f (see FIG. 4A) of the upper case 14. The bottom surface 15e of the lower case 15 is composed of a flat portion 16a, a protruding portion 16b, a recessed portion 16c, and a step portion 16d. The protruding portion 16b protrudes upward from the flat portion 16a. As shown in FIG. 18, the protruding portion 16b has a shape that conforms to the lower surface of the cell case 80 described later. As shown in FIG. 6, the recessed portion 16c is provided at the four corners 15f of the bottom surface 15e of the lower case 15. As shown in FIG. 19, the step portion 16d connects the flat portion 16a and the recessed portion 16c. The step portion 16d descends downward from the inside to the outside of the lower case 15. The thickness t1 of the lower case 15 at the flat portion 16a is the same as the thickness t1 of the lower case 15 at the recessed portion 16c.

[0044] As shown in FIG. 7, the front ribs 48, 50, 52, 54, 56 are provided on the inclined surface 17b. The front ribs 48, 50, 52, 54, 56 extend upward from the inclined surface 17b and extend rearward from the front surface 15a of the lower case 15. The rear end of the front rib 48 is approximately aligned with the rear end of the inclined surface 17b, and the upper end of the front rib 48 is approximately aligned with the uppermost end of the inclined surface 17b. The upper surface of the front rib 48 is a flat surface. The rear end of the front rib 50 is approximately aligned with the rear end of the inclined surface 17b, and the upper end of the front rib 50 is located above the upper end of the remaining amount display section 42a. In addition, a groove 50a is provided in the front rib 50. An LED board 84 (see FIG. 13A), which will be described later, passes through the groove 50a. The rear ends of the front ribs 52, 54 are located forward of the rear end of the inclined surface 17b. In addition, the upper ends of the front ribs 52, 54 are located higher than the upper end of the remaining amount display portion 42a. The front rib 56 is composed of a light-shielding wall portion 56a and a flat portion 56b. The light-shielding wall portion 56a has a structure similar to that of the front ribs 52, 54. The flat portion 56b has a structure similar to that of the front rib 48.

[0045] The space above the inclined surface 17b is divided into four spaces S1 to S4 by the front ribs 48, 50, and 56. Specifically, the first space S1 is defined by the front rib 48, the second space S2 is defined by the front ribs 48 and 50, the third space S3 is defined by the front ribs 50 and 56, and the fourth space S4 is defined by the front rib 56. Air vents 58a to 58d are provided in each of the spaces S1 to S4. The air vents 58a to 58d penetrate the lower case 15 in the vertical direction. Therefore, of the water that has entered the outer case 12, the water that flows into the spaces S1 to S4 is drained through the air vents 58a to 58d.

[0046] As shown in FIG. 6, the side ribs 60a to 60d extend leftward from the right side surface 15b of the lower case 15. As shown in FIG. 8, the lower ends of the side ribs 60a to 60d extend upward from the bottom surface 15e of the lower case 15. The upper ends of the side ribs 60a to 60d are located slightly lower than the upper end of the lower case 15. The side ribs 60a to 60d are provided between adjacent holes 40 in the front-rear direction. Specifically, the side rib 60a is provided between the holes 40a, 40f and the holes 40b, 40g, the side rib 60b is provided between the holes 40b, 40g and the holes 40c, 40h, the side rib 60c is provided between the holes 40c, 40h and the holes 40d, 40i, and the side rib 60d is provided between the holes 40d, 40i and the holes 40e, 40j. The side ribs 60e to 60h have the same structure as the side ribs 60e to 60h, except that they extend rightward from the left side surface 15d of the lower case 15.

[0047] (Configuration of battery module 10) As shown in FIG. 9A, the battery module 10 includes a cell case 80, a control board 82, and an LED board 84. The cell case 80 is made of an insulating material, for example, a resin material. As shown in FIG. 11A, the cell case 80 is divided into a right cell case 85 and a left cell case 86. A vent hole 81a is provided in a front part 80a of the cell case 80, and a vent hole 81b is provided in a rear part 80b of the cell case 80. A thick part 80c is provided at each of the four corners of the lower part of the cell case 80. As shown in FIG. 19, a thickness t11 of the thick part 80c is thicker than a thickness t12 of a cell holding part 87 described later. As shown in FIG. 11A, the upper surface 80d of the cell case 80 has a shape corresponding to the side surface in the longitudinal direction of a battery cell 90 (see FIG. 10) described later. A recessed part 80g is provided between two adjacent battery cells 90 on the upper surface 80d of the cell case 80. The upper surface 80d of the cell case 80 is provided with four screw bosses 83 used for connecting the control board 82 and the cell case 80. As shown in FIG. 9B, the upper portion of the left side surface 80f of the cell case 80 is provided with protrusions 116a to 116c that protrude upward from the upper surface 80d of the cell case 80. As shown in FIG. 11C, the protrusions 116a to 116c are arranged so as to straddle two adjacent battery cells 90. The protrusions 116a to 116c are provided with first recesses 110a to 110c. The first recesses 110a to 110c are provided at positions corresponding to the first protrusions 30a to 30c (see FIG. 4A) of the upper case 14, respectively. As shown in FIG. 9A, the upper portion of the right side surface 80e of the cell case 80 is provided with protrusions 116d and 116e that protrude upward from the upper surface 80d of the cell case 80. As shown in Fig. 11C, the protrusions 116d, 116e are disposed so as to straddle two adjacent battery cells 90. The protrusions 116d, 116e are provided with first recesses 110d, 110e. The first recesses 110d, 110e are provided at positions corresponding to the first protrusions 30d, 30e (see Fig. 4A) of the upper case 14, respectively. As shown in Fig. 11C, the protrusions 116a-116e and the first recesses 110a-110e are provided outside the control board 82 when the battery module 10 is viewed from above.The first recesses 110a to 110e are provided between two lead plates 92, which will be described later. As shown in Fig. 9A, the protrusion 116d and the first recess 110d are provided between the lead plates 92c and 92d, and the protrusion 116e and the first recess 110e are provided between the lead plates 92d and 92e. As shown in Fig. 9B, the protrusion 116a and the first recess 110a are provided between the lead plates 92j and 92k, the protrusion 116b and the first recess 110b are provided between the lead plates 92i and 92j, and the protrusion 116c and the first recess 110c are provided between the lead plates 92h and 92i.

[0048] As shown in FIG. 11B, the right cell case 85 is provided with ten cell holding parts 87a to 87j. The ten cell holding parts 87a to 87j are arranged in two rows, one above the other. As shown in FIG. 18, which is a cross-sectional view of the battery pack 2 at the center position in the left-right direction, the cell holding parts 87a to 87c have a center holding part 89a that holds the center side of a battery cell 90, which will be described later. Also, as shown in FIG. 19, which is a cross-sectional view of the battery pack 2 at a position where a recessed part 16c is provided on the right rear side of the lower case 15, the cell holding parts 87a to 87c have an end face side holding part 89b that holds the right end face side in the longitudinal direction of the battery cell 90. Although not shown, the cell holding parts 87d and 87e also have a center side holding part and an end face side holding part. 11B, connecting portions 88 for connecting the right cell case 85 and the left cell case 86 are provided between the cell holding portions 87a, 87b, 87f, and 87g and between the cell holding portions 87d, 87e, 87i, and 87j. Although not shown, the left cell case 86 is provided with ten cell holding portions corresponding to the ten cell holding portions 87a to 87j of the right cell case 85 and two connecting portions corresponding to the two connecting portions 88 of the right cell case 85.

[0049] As shown in FIG. 10, ten battery cells 90a to 90j are arranged in two upper and lower stages in the cell case 80. The battery cells 90 are cylindrical secondary battery cells, such as lithium-ion battery cells, with a positive electrode formed at one end and a negative electrode formed at the other end. In this embodiment, the battery cells 90 are 18650-type lithium-ion battery cells, and have a rated voltage of 3.6 [V]. The battery cells 90 are arranged such that the positive and negative electrodes of the vertically adjacent battery cells 90 are in the opposite directions. Among the battery cells 90a to 90e in the lower stage, the rearmost battery cell 90a is arranged such that the right end surface side is the negative electrode and the left end surface side is the positive electrode. The battery cells 90b to 90e are arranged such that the right end surface side is the positive electrode and the left end surface side is the negative electrode. Among the upper battery cells 90f-90j, the rearmost battery cell 90f is arranged so that the right end surface side is the positive electrode and the left end surface side is the negative electrode. The battery cells 90g-90j are arranged so that the right end surface side is the negative electrode and the left end surface side is the positive electrode. The metal part 91 (see FIG. 20, for example) constituting the positive electrode of each battery cell 90 and the metal part constituting the negative electrode are connected to the end surface of the battery cell 90. One end of the battery cell 90 is connected to the metal lead plates 92a-92f provided on the right side surface 80e of the cell case 80 via the metal part (see FIG. 9A), and the other end of the battery cell 90 is connected to the metal lead plates 92g-92k provided on the left side surface 80f of the cell case 80 via the metal part (see FIG. 9B). As shown in FIG. 20, the metal part 91 constituting the positive electrode of the battery cell 90 is provided with a waterproof ring 95. 9A and 9B, the thick circle on the surface of the lead-plate 92 indicates that a waterproof ring 95 is to be disposed inside it. Therefore, the positive electrode of the battery cell 90 is connected to the thick circle on the surface of the lead-plate 92.

[0050] As shown in FIG. 9A, the lead plates 92a to 92f are arranged at intervals from one another. Therefore, the lead plates 92a to 92f are insulated from one another. The lead plate 92a is connected only to the positive electrode of the battery cell 90f. The lead plate 92f is connected only to the negative electrode of the battery cell 90j. The lead plate 92b connects two battery cells 90a and 90b adjacent to each other in the front-rear direction. The lead plates 92c to 92e connect two battery cells 90 adjacent to each other in the diagonal direction. Specifically, the lead plate 92c is connected to the negative electrode of the battery cell 90g and the positive electrode of the battery cell 90c. The lead plate 92d is connected to the negative electrode of the battery cell 90h and the positive electrode of the battery cell 90d. The lead plate 92e is connected to the negative electrode of the battery cell 90i and the positive electrode of the battery cell 90e.

[0051] As shown in FIG. 9B, the lead plates 92g-92k are arranged at intervals from each other. Therefore, the lead plates 92g-92k are insulated from each other. The lead plates 92g-92k connect the battery cells 90 adjacent to each other in the vertical direction. Specifically, the lead plate 92g connects the negative electrode of the battery cell 90e to the positive electrode of the battery cell 90j. The lead plate 92h connects the negative electrode of the battery cell 90d to the positive electrode of the battery cell 90i. The lead plate 92i connects the negative electrode of the battery cell 90c to the positive electrode of the battery cell 90h. The lead plate 92j connects the negative electrode of the battery cell 90b to the positive electrode of the battery cell 90g. The lead plate 92k connects the positive electrode of the battery cell 90a to the negative electrode of the battery cell 90f. With the above configuration, the ten battery cells 90 are electrically connected in series. Therefore, the rated voltage of the battery pack 2 is 36 V. Although not shown, insulating sheets are attached to the right side surface 80e and the left side surface 80f of the cell case 80.

[0052] According to the above configuration, the lead plates 92a, 92f connected to the control board 82 can be connected to the upper battery cells 90f, 90j via a power line (not shown). A larger current flows through the lead plates 92a, 92f connected to the control board 82 than through the other lead plates. For this reason, it is desirable that the width of the lead plates 92a, 92f is large. According to the above configuration, the width of the lead plates 92a, 92f can be sufficiently secured. Also, if at least one of the lead plates 92a, 92f connected to the control board 82 is connected to a lower battery cell, it is necessary to wire a power line from the lower part of the cell case 60. At the lower part of the cell case 60, the clearance between the cell case 60 and the right side surface of the outer case 12 is small, making it difficult to wire a power line. According to the above configuration, since both lead plates 92a, 92f connected to the control board 82 are connected to the upper battery cells 90f, 90j, it is possible to easily wire the power supply lines connecting the lead plates 92a, 92f to the control board 82. Furthermore, compared to the case where at least one of the lead plates 92a, 92f is connected to the lower battery cell 90, the length of the current lines connecting the lead plates 92a, 92f to the control board 82 can be shortened, so that the resistance of the power supply lines connecting the lead plates 92a, 92f to the control board 82 can be reduced.

[0053] 10, in a state in which the cell case 80 holds ten battery cells 90a-90j, the upper battery cells 90f-90j and the lower battery cells 90a-90e are arranged with a gap therebetween in the vertical direction. In addition, clearances are provided between the battery cells 90a, 90b, 90f, 90g and the rear connecting parts 88, and between the battery cells 90d, 90e, 90i, 90j and the front connecting parts 88. For this reason, air that flows into the cell case 80 from the ventilation hole 81a or the ventilation hole 81b of the cell case 80 can pass between the upper battery cells 90f-90j and the lower battery cells 90a-90e, between the battery cells 90a, 90b, 90f, 90g and the rear connecting parts 88, and between the battery cells 90d, 90e, 90i, 90j and the front connecting parts 88.

[0054] 9A, the control board 82 is disposed above the cell case 80. The control board 82 is disposed along a plane perpendicular to the up-down direction. The control board 82 is fixed to the cell case 80 via a fastener 100.

[0055] A plurality of terminals 102 are provided on the upper surface of the control board 82. The plurality of terminals 102 include a battery-side negative terminal 104a used for discharging or charging when the battery pack 2 is attached to the power tool 200 or the charger 300, a battery-side positive terminal 104b used for discharging or charging, and a plurality of battery-side signal terminals 106a to 106d used for transmitting and receiving signals. The battery-side negative terminal 104a and the battery-side positive terminal 104b are provided outside the battery-side signal terminals 106a to 106d in the left-right direction. The battery-side negative terminal 104a is provided on the right side of the control board 82, and the battery-side positive terminal 104b is provided on the left side of the control board 82. The battery-side signal terminals 106a and 106b are provided side by side in the front and rear. The battery-side signal terminals 106c and 106d are provided side by side in the front and rear. As shown in FIG. 12B, the battery side negative terminal 104a is positioned at a position corresponding to the terminal opening 22a of the upper case 14, the battery side signal terminals 106a, 106b are positioned at a position corresponding to the terminal opening 22b, the battery side signal terminals 106c, 106d are positioned at a position corresponding to the terminal opening 22c, and the battery side positive terminal 104b is positioned at a position corresponding to the terminal opening 22d.

[0056] 9A and 9B, the cell case 80 is provided with four fixing portions 112. Each fixing portion 112 is provided at a position corresponding to a screw hole 62 of the lower case 15. As shown in FIG. 12A, the lower case 15 and the battery module 10 are fixed to each other with four screws 114.

[0057] As shown in FIG. 9A, the LED board 84 is connected to the control board 82 via a signal line 120. The LED board 84 includes four LEDs 84a and a switch 84b. As shown in FIG. 13A, in a state in which the battery module 10 and the lower case 15 are fixed, the LED board 84 is disposed near the rear surface of the display unit 42 of the lower case 15. Specifically, the LEDs 84a are disposed on the rear surface of the remaining capacity display unit 42a, and the switch 84b is disposed on the rear surface of the button 42b. That is, the LED board 84 faces the front surface 14a on the inside of the lower case 15. The LED board 84 is inserted into the groove 50a of the front rib 50 of the lower case 15 and placed on the front ribs 48 and 56. Therefore, the LED board 84 is held by the lower case 15. The front surface of the LED board 84 is in contact with the rear ends of the front ribs 52 and 54 and the light-shielding wall portion 56a of the front rib 56. Moreover, the LED substrate 84 has ventilation holes 58a to 58d on the surface opposite to the lower surface 84c.

[0058] Below, with reference to Figures 14 to 17, we will explain the engagement clearance C1 between the first protrusion portion 30 of the upper case 14 and the first recess portion 110 of the battery module 10, and the engagement clearance C2 between the second protrusion portion 34 of the upper case 14 and the second recess portion 64 of the lower case 15.

[0059] As shown in Fig. 14, the first protrusions 30a-30e of the upper case 14 are respectively received in the first recesses 110a-110e of the battery module 10. As shown in Fig. 15, an engagement clearance C1 is provided between the first protrusion 30d and the first recess 110d.

[0060] As shown in FIG. 16, the second protrusions 34a to 34f of the upper case 14 are received in the second recesses 64a to 64f of the lower case 15, respectively. As shown in FIG. 17, an engagement clearance C2 is provided between the second protrusions 34e and the second recesses 64e. The engagement clearance C2 is used for positioning the upper case 14 and the lower case 15. The engagement clearance C1 in FIG. 14 is used for suppressing misalignment between the upper case 14 and the cell case 80. The engagement clearance C1 may be set to suppress misalignment between the upper case 14 and the cell case 80 and prevent contact between the upper case 14 and the control board 82. For this reason, the engagement clearance C1 is larger than the engagement clearance C2. As shown in FIG. 16, a labyrinth structure is formed by the second protrusions 34a to 34f and the second recesses 64a to 64f. This prevents water from entering the outer case 12 .

[0061] Next, case clearances C11 to C13 between the lower surface of the cell case 80 of the battery module 10 and the lower case 15 will be described with reference to Fig. 18 and Fig. 19. As described above, Fig. 18 shows a cross-sectional view of the battery pack 2 at the center position in the left-right direction, and Fig. 19 shows a cross-sectional view of the battery pack 2 at a position where the recessed portion 16c is provided on the right rear side of the lower case 15.

[0062] 18, the lower surface of the cell case 80 is not in contact with the bottom surface 15e of the lower case 15. Specifically, a case clearance C11 is provided between the central holding portion 89a of the cell holding portions 87a to 87c and the protruding portion 16b protruding upward (i.e., inward) from the bottom surface 15e of the lower case 15. In addition, a case clearance C12 is provided between the central holding portion 89a and the flat portion 16a. The case clearance C12 is larger than the case clearance C11.

[0063] 19, a case clearance C13 is provided between the end face side holding portion 89b corresponding to the battery cell 90a arranged closest to the corner portion 15f of the lower case 15 and the recessed portion 16c. A step portion 16d is provided between the surface of the bottom surface 15e of the lower case 15 facing the side surface 93a of the battery cell 90a and the surface facing the side surface 93b of the battery cell 90b. Note that no step portion 16d is provided between the surface of the bottom surface 15e of the lower case 15 facing the side surface 93b of the battery cell 90b and the surface facing the side surface 93c of the battery cell 90c. For this reason, the case clearance C13 is larger than the case clearance C12.

[0064] Next, the positional relationship between the battery cell 90c located in the center of the lower row among the multiple battery cells 90, and the holes 40c, 40h provided to the right of the battery cell 90c will be described with reference to Figure 20. Note that the lead plate 92i has been omitted from Figure 20 for ease of understanding.

[0065] As shown in Fig. 20, holes 40c, 40h are provided on the right side surface 15b at positions facing the longitudinal end face of the battery cell 90c. However, no holes are provided on the right side surface 15b at positions facing the longitudinal end face of the battery cell 90h located above the battery cell 90c. Parts of the holes 40c, 40h face the longitudinal end face of the battery cell 90h.

[0066] The metal portion 91 constituting the positive electrode of the battery cell 90c is provided on the right end face of the battery cell 90c. The lower ends 43h of the upper hole 40h and the lower ends 43c of the lower hole 40c are provided below the upper end 94a of the battery cell 90c and the longitudinal axis A1 of the battery cell 90c. The lower ends 43c of the lower hole 40c are provided below the lower ends 91a of the metal portion 91 and the lower ends 94b of the battery cell 90c.

[0067] Next, referring to FIG. 21, the air flow in the battery pack 2 will be described. For example, assume that the battery pack 2 is attached to the power tool 200, the power tool 200 is used by a user, and the battery pack 2 is removed from the power tool 200. In this case, the battery pack 2 is at a high temperature. In such a situation, the vents 40 and 41 provided in the lower part of the lower case 15 shown in FIG. 1A, FIG. 3, and FIG. 8 function as air intake holes through which air is introduced from the outside to the inside of the battery pack 2. Specifically, the air around the battery pack 2 is heated, and the air around the battery pack 2 flows into the battery pack 2 through the vents 40 and 41. The air introduced into the battery pack 2 from the vent 40 flows into the space between the multiple battery cells 90 and the lower case 15. As described above, the side ribs 60a to 60d are provided between the holes 40a to 40j. 20, the air introduced from the holes 40c and 40h flows into the space between the battery cells 90c and 90h and the right side surface 15b of the lower case 15. Similarly, the air introduced from the holes 40a and 40f flows into the space between the battery cells 90b and 90g and the right side surface 15b of the lower case 15, the air introduced from the holes 40b and 40g flows into the space between the battery cells 90b and 90g and the right side surface 15b of the lower case 15, the air introduced from the holes 40d and 40i flows into the space between the battery cells 90d and 90i and the right side surface 15b of the lower case 15, and the air introduced from the holes 40e and 40j flows into the space between the battery cells 90e and 90j and the right side surface 15b of the lower case 15. Therefore, the multiple battery cells 90 are reliably cooled. The air that flows into the space between the multiple battery cells 90 and the right side surface 15b of the lower case 15 cools the multiple battery cells 90, and then flows out of the battery pack 2 through the terminal openings 22a of the terminal receiving portion 22 of the upper case 14, etc. In this way, natural convection occurs when the battery pack 2 is at a high temperature. Note that the air introduced into the battery pack 2 from the ventilation holes 41 also flows into the space between each battery cell 90 and the left side surface 15d of the lower case 15, and is used to cool the battery cells 90.

[0068] 22 and 23, the air flow inside the battery pack 2 when the battery pack 2 is attached to the charger 300 will be described. The charger 300 is equipped with a blower fan (not shown) and is configured to draw air from the battery pack 2. In this state, the air vents 40 (see FIG. 1), 58a to 58d (see FIG. 6) of the battery pack 2 function as intake holes that introduce air from the outside to the inside of the battery pack 2, and the air vent 26 (see FIG. 1) of the battery pack 2 functions as an exhaust hole that exhausts air from the inside of the battery pack 2 to the charger 300.

[0069] As shown in Fig. 22, when the blower fan of the charger 300 is driven, air introduced into the battery pack 2 from the ventilation hole 58 (see Fig. 1B) flows into the space between the front part 80a of the cell case 80 and the front surface 15a of the lower case 15. An LED board 84 is provided between the front part 80a of the cell case 80 and the front surface 15a of the lower case 15. The air that has flowed into the space between the front part 80a of the cell case 80 and the front surface 15a of the lower case 15 flows into the cell case 80 through the gap between the front part 80a of the cell case 80 and the LED board 84 and through the ventilation hole 81a of the cell case 80. The air introduced into the cell case 80 passes between the upper battery cells 90f-90j and the lower battery cells 90a-90e, between the battery cells 90a, 90b, 90f, 90g and the rear connecting portion 88, and between the battery cells 90d, 90e, 90i, 90j and the front connecting portion 88. The air passing through the cell case 80 cools the battery cells 90. The air that has cooled the battery cells 90 is introduced into the charger 300 through the ventilation hole 81b in the rear portion 80b of the cell case 80, the ventilation hole 26 in the upper case 14, and the ventilation hole 308 of the charger 300 that corresponds to the ventilation hole 26 (see FIG. 25B). As described above, when the battery pack 2 is attached to the charger 300, the charger side protrusion 306 of the charger 300 is inserted into the battery side recess 27 around the ventilation hole 26. Therefore, compared to a case where the battery-side recess 27 is not provided around the ventilation hole 26, it is possible to reduce the amount of air drawn into the charger 300 through the gap between the battery pack 2 and the charger 300. This makes it possible to increase the amount of air flowing inside the battery pack 2. As a result, the battery cells 90 and lead plates 92 inside the battery pack 2 can be efficiently cooled.

[0070] As shown in FIG. 23, the air introduced into the battery pack 2 from the ventilation hole 40 flows into the space between the battery cells 90 (specifically, the lead plate 92) and the right side surface 15b of the lower case 15. The air that has flowed into the space between the battery cells 90 and the right side surface 15b of the lower case 15 flows forward above the side ribs 60a-60d and flows into the space between the front part 80a of the cell case 80 and the front surface 15a of the lower case 15. The air flows thereafter in the same manner as in FIG. 22. In this manner, the air introduced from the ventilation holes 58, 40 is used to cool the battery cells 90. In this embodiment, since the ventilation hole 40 is provided in the lower part of the lower case 15, the ventilation hole 40 is located at a higher position than the charger 300 when the battery pack 2 is attached to the charger 300. Since dust and the like accumulates at low heights, when the battery pack 2 is attached to the charger 300, dust and the like are not easily sucked in.

[0071] The effect of the battery-side recesses 23a to 23d of the upper case 14 of the battery pack 2 will be described with reference to Fig. 24B. Fig. 24B is a cross-sectional view of the battery-side signal terminal 106a (see Fig. 12A) of the battery pack 2 at the center position in the front-rear direction when the battery pack 2 is attached to the power tool 200. As shown in Fig. 24B, the power tool 200 includes a terminal holding portion 202, and the terminal holding portion 202 is provided with tool-side protrusions 206a to 206d that protrude downward (i.e., toward the battery pack 2). The tool-side protrusion 206a is provided with a tool-side negative terminal 208a corresponding to the battery-side negative terminal 104a, and the tool-side protrusion 206d is provided with a tool-side positive terminal 208b corresponding to the battery-side positive terminal 104b. The tool-side protrusion 206b is provided with a tool-side signal terminal 210a corresponding to the battery-side signal terminal 106a. A tool side signal terminal (not shown) corresponding to the battery side signal terminal 106b is provided in front of the tool side signal terminal 210a on the tool side protrusion 206b. A tool side signal terminal 210c corresponding to the battery side signal terminal 106c is provided on the tool side protrusion 206c. Since the battery side signal terminal 106d is a terminal that is used only when the battery pack 2 is attached to the charger 300, no tool side signal terminal corresponding to the battery side signal terminal 106d is provided in front of the tool side signal terminal 208c on the tool side protrusion 206c. When the battery pack 2 is attached to the power tool 200, the tool side protrusions 206a to 206d are inserted into the battery side recesses 23a to 23d, respectively. According to this configuration, the creepage distance between two terminals adjacent in the left-right direction among the multiple terminals of the power tool 200 can be made longer than when the tool-side protrusions 206a-206d are not provided on the terminal holding portion 202 of the power tool 200. Specifically, the creepage distance can be made longer by the height of the tool-side protrusions 206a-206d. Therefore, it is possible to prevent a short circuit between two terminals adjacent in the left-right direction among the multiple terminals of the power tool 200.

[0072] In one or more embodiments, as shown in FIG. 1 to FIG. 13B, the battery pack 2 includes an outer case 12, a hook 24, and an LED board 84 housed in and held by the outer case 12. The outer case 12 includes an upper surface 14b provided with a terminal opening 22a for exposing a terminal portion 102, a bottom surface 15e, front surfaces 14a, 15a extending upward from the bottom surface 15e, and vent holes 58a to 58d openings disposed on the front surface 15a. The hook 24 is disposed on the front surface 14a of the outer case 12. The LED board 84 is disposed at a position facing the front surface 15a. The LED board 84 is disposed below the hook 24, and the vent holes 58a to 58d are disposed below the LED board 84. According to the above configuration, water that has entered the outer case 12 is drained from the vent holes 58 to 58d disposed below the LED board 84. For this reason, even if water enters the outer case 12, the water does not accumulate near the LED board 84. Therefore, water that has entered the outer case 12 can be prevented from coming into contact with the LED board 84.

[0073] In one or more embodiments, as shown in Figs. 1B, 13A, and 13B, the front surface 15a of the outer case 12 includes an inclined surface 17b inclined with respect to the bottom surface 15e, and the ventilation holes 58a to 58d are provided on the inclined surface 17b. According to the above configuration, water that has entered the outer case 12 from the hooks 24 or the like can be drained through the ventilation holes 58a to 58d of the inclined surface 17b. Therefore, it is possible to further prevent the water that has entered the outer case 12 from contacting the LED board 84. In addition, the inclined surface 17b can guide the water that has not been drained through the ventilation holes 58a to 58d to the bottom surface 15e.

[0074] In one or more embodiments, as shown in FIGS. 9A to 11B, the battery pack 2 further includes a battery cell 90 and a cell case 80 that is housed in the outer case 12 and houses the battery cell 90. The battery cells 90a to 90e are arranged parallel to the bottom surface 15e of the outer case 12. Water that has entered the outer case 12 is likely to accumulate on the bottom surface 15e of the outer case 12. For this reason, it is desirable to arrange the LED board 84 as high as possible. According to the above configuration, the ventilation holes 58a to 58d are provided above the lower ends of the battery cells 90a to 90e, and the LED board 84 is provided above the ventilation holes 58a to 58d. For this reason, the LED board 84 can be arranged higher than when the ventilation holes 58a to 58d are provided below the lower ends of the battery cells 90a to 90e. This makes it possible to further prevent water that has entered the outer case 12 from contacting the LED board 84.

[0075] 1, the upper surface 14b of the outer case 12 is provided with ventilation holes 26, and the ventilation holes 58a-58d may communicate with the ventilation holes 26. According to the above configuration, for example, when the battery pack 2 is attached to the charger 300, the ventilation holes 58a-58d can function as air intake holes or exhaust holes.

[0076] In one or more embodiments, as shown in Figs. 12 and 13, the front surface 15a of the outer case 12 is provided with front ribs 48-56 protruding toward the LED board 84, and the space between the LED board 84 and the outer case 12 is divided into four spaces S1-S4 by the front ribs 48-56. The outer case 12 is provided with ventilation holes 58a-58d corresponding to the four spaces S1-S4, respectively. According to the above configuration, water is drained from each of the four spaces S1-S4 divided by the front ribs 48-56. Therefore, it is possible to further prevent water that has entered the outer case 12 from contacting the LED board 84.

[0077] (Correspondence) The LED board 84 is an example of a "board." The front surface 14a of the upper case 14 and the front surface 15a of the lower case 15 are an example of a "side surface." The ventilation holes 58a-58d and the ventilation hole 26 are examples of a "first opening" and a "second opening," respectively. The front ribs 48-56 are examples of a "multiple protrusions."

[0078] In one or more embodiments, as shown in FIG. 1 to FIG. 13B, the battery pack 2 includes an outer case 12, a battery cell 90, a cell case 80 that is housed in the outer case 12 and houses the battery cell 90, and an LED board 84 housed in the outer case 12. The outer case 12 includes an upper surface 14b in which a terminal opening 22a for exposing a terminal portion 102 is provided, a bottom surface 15e, and a front surface 15a extending upward from the bottom surface 15e. The LED board 84 is provided between the cell case 80 and the front surface 15a, and is disposed along a direction perpendicular to the bottom surface 15e. The outer case 12 is provided with ventilation holes 58a to 58d on a surface facing the lower surface 84c of the LED board 84. According to the above configuration, water that has entered the outer case 12 is drained from the ventilation holes 58a to 58d facing the lower surface 84c of the LED board 84. For this reason, even if water enters the outer case 12, the water does not accumulate near the LED board 84. Therefore, water that has entered the outer case 12 can be prevented from coming into contact with the LED board 84.

[0079] In one or more embodiments, as shown in Fig. 13B, the surface of the outer case 12 facing the lower surface 84c of the LED substrate 84 is the inclined surface 17b that is inclined with respect to the bottom surface 15e. According to the above configuration, water that has entered the outer case 12 and reached the inclined surface 17b is guided along the inclined surface 17b to the bottom surface 15e. This makes it possible to prevent water from accumulating near the LED substrate 84.

[0080] (Correspondence) The LED board 84 is an example of a "board." The front surface 14a of the upper case 14 and the front surface 15a of the lower case 15 are an example of a "side surface." The ventilation holes 58a to 58d are an example of an "opening."

[0081] In one or more embodiments, as shown in FIG. 1 to FIG. 13B, the battery pack 2 includes an outer case 12 and an LED board 84 held by the outer case 12. The outer case 12 includes an upper surface 14b provided with a terminal opening 22a for exposing a terminal portion 102, a bottom surface 15e, and front surfaces 14a, 15a extending upward from the bottom surface 15e. The LED board 84 is provided at a position facing the front surface 15a, and the front surface 15a is provided with ventilation holes 58a to 58d. According to the above configuration, water that has entered the outer case 12 is drained through the ventilation holes 58a to 58d. Therefore, even if water enters the outer case 12, water does not accumulate near the LED board 84. Therefore, it is possible to prevent the water that has entered the outer case 12 from contacting the LED board 84.

[0082] In one or more embodiments, as shown in Figs. 12A and 13A, the front surface 15a of the outer case 12 is provided with a plurality of front ribs 48-56 protruding toward the LED board 84, and the space between the LED board 84 and the outer case 12 is divided into four spaces S1-S4 by the plurality of front ribs 48-56. The outer case 12 is provided with ventilation holes 58a-58d corresponding to the four spaces S1-S4, respectively. According to the above configuration, water is drained from each of the four spaces S1-S4 divided by the front ribs 48-56. Therefore, it is possible to further prevent water that has entered the outer case 12 from contacting the LED board 84.

[0083] In one or more embodiments, as shown in FIG. 13B, the front surface 15a includes an inclined surface 17b inclined with respect to the bottom surface 15e. The ventilation holes 58a to 58d are provided in the inclined surface 17b of the front surface 15a. According to the above configuration, water that has flowed down the side surface of the second upward extension surface 17c of the front surface 15a can be drained through the ventilation holes 58a to 58d of the inclined surface 17b. Therefore, it is possible to further prevent water that has entered the outer case 12 from contacting the LED board 84. In addition, the inclined surface 17b can guide water that has not been drained through the ventilation holes 58a to 58d to the bottom surface 15e.

[0084] (Correspondence) The LED board 84 is an example of a "board." The air vents 58a-58d are an example of an "opening." The front surface 14a of the upper case 14 and the front surface 15a of the lower case 15 are an example of a "side surface." The front ribs 48-56 are an example of a "plurality of protrusions."

[0085] (Second Example) With reference to FIG. 26, the battery pack 602 of the second embodiment will be described. In the battery pack 602 of the second embodiment, the structure of the lower case 615 of the outer case 612 is different from the structure of the lower case 15 of the outer case 12 of the battery pack 2 of the first embodiment. In addition, in the battery pack 602 of this embodiment, the size of the battery cells (not shown) accommodated in the outer case 612 is different from the battery cells 90 accommodated in the outer case 12 of the first embodiment. Specifically, the battery cells of this embodiment are 21700 type lithium ion battery cells, and the rated voltage is 3.6 [V]. Therefore, the outer case 612 is larger in size than the outer case 12 of the first embodiment. Note that the outer case 612 accommodates ten battery cells, and the method of connecting the battery cells is the same as the battery pack of the first embodiment. Therefore, the rated voltage of the battery pack 602 of this embodiment is also 36 [V].

[0086] 26, two hooks 619a, 619b arranged side by side in the front-rear direction are provided on the bottom surface 615e of the lower case 615. With this configuration, when removing the battery pack 2 from the power tool 200 or the charger 300, the user can use one of the two hooks 619a, 619b that is suitable for the length of the user's fingers. This makes it easier to remove the battery pack 2 from the power tool 200 or the charger 300.

[0087] Further features of the battery pack disclosed herein are set forth below. (Feature 1) A battery pack that can be slidably attached to a power tool, A first terminal; A second terminal; an outer case that houses the first terminal and the second terminal, a first terminal opening provided on a top surface of the outer case at a position corresponding to the first terminal and a second terminal opening provided on a position corresponding to the second terminal; the battery pack, wherein a battery side recess is provided between the first terminal opening and the top surface, and between the second terminal opening and the top surface. (Feature 2) 2. The battery pack according to claim 1, wherein the battery-side recess has a shape corresponding to a tool-side protrusion of an electric power tool. (Feature 3) the first terminal is a discharge terminal, 3. The battery pack according to claim 1, wherein the second terminal is a signal terminal. (Feature 4) A first terminal; A second terminal; A third terminal; A fourth terminal; an outer case that accommodates the first terminal, the second terminal, the third terminal, and the fourth terminal, The outer case includes a pair of slide rails for receiving the power tool by sliding it therethrough. a first terminal opening provided on a top surface of the outer case between the pair of slide rails, the first terminal opening being located at a position corresponding to a first terminal, a second terminal opening being located at a position corresponding to a second terminal, a third terminal opening being located at a position corresponding to a third terminal, and a fourth terminal opening being located at a position corresponding to a fourth terminal; the first terminal opening, the second terminal opening, the third terminal opening, and the fourth terminal opening are arranged in the following order from one slide rail of the pair of slide rails to the other slide rail: the first terminal opening, the second terminal opening, the third terminal opening, and the fourth terminal opening; a battery side recess is provided between the first terminal opening and the top surface, between the second terminal opening and the top surface, between the third terminal opening and the top surface, and between the fourth terminal opening and the top surface. (Feature 5) 5. The battery pack according to claim 4, wherein the battery-side recess has a shape corresponding to a tool-side protrusion of the power tool. (Feature 6) the first terminal and the fourth terminal are discharge terminals, The battery pack according to feature 4 or 5, wherein the second terminal and the third terminal are signal terminals. (Feature 7) A battery pack that can be attached to an external device by sliding from the front to the rear, Equipped with an outer case, The outer case is a pair of slide rails for slidingly receiving the external device; a terminal opening provided between the pair of slide rails; a surface between the pair of slide rails and rearward of the terminal opening; Ventilation holes and a battery side recess provided between the pair of slide rails and between the surface rearward of the terminal opening and the air hole. (Feature 8) 9. The battery pack according to feature 8, wherein the battery-side recess has a shape corresponding to a device-side protrusion of the external device.

[0088] Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples exemplified above.

[0089] (First Modification) The ventilation holes 58a-58d may be provided in the first upwardly extending surface 17a of the front surface 15a. In this case, the ventilation holes 58a-58d may be parallel to the bottom surface 15e or may be inclined with respect to the bottom surface 15e.

[0090] (Second Modification) The ventilation holes 58a to 58d do not have to face the lower surface 84c of the LED board 84. In general terms, the ventilation holes 58a to 58d may be provided at positions that can prevent water that has flowed into the outer case 12 from accumulating and coming into contact with the LED board 84.

[0091] (Third Modification) The board held by the cell case 80 may be a board provided with only a switch and no LED. In another modification, the board may be provided with only an LED and no switch.

[0092] (Fourth Modification) The outer case 12 does not have to have the multiple front ribs 48-56. In this modification, there may be only one air vent. In another modification, air vents do not have to be provided corresponding to all of the spaces S1-S4. For example, air vents may be provided corresponding only to the spaces S1 and S4.

[0093] (Fifth Modification) The front surface 15a may be formed only of an upward extending surface extending upward from the bottom surface 15e. In another modification, the front surface 15a may be formed only of an inclined surface inclined with respect to the bottom surface 15e.

[0094] (Sixth Modification) The first upwardly extending surface 17a and the second upwardly extending surface 17c of the front surface 15a may be connected by a surface parallel to the bottom surface 15e.

[0095] (Seventh Modification) The lower surface 84c of the LED board 84 may face the bottom surface 15e of the lower case 15.

[0096] The technical elements described in this specification or drawings have technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0097] 2: battery pack, 10: battery module, 12: outer case, 14: upper case, 14a: front surface, 14b1: front upper surface, 14b2: rear upper surface, 15: lower case, 15a: front surface, 15b: right side surface, 15c: rear surface, 15d: left side surface, 15e: bottom surface, 15f: corner portion, 16a: flat portion, 16b: protruding portion, 16c: recessed portion, 16d: step portion, 17a: first upward extension surface, 17b: inclined surface, 17c: second upward extension surface, 18: screw, 19: hook portion, 20: slide rail, 20a: base portion, 20b: upward extension portion, 20c: first right extension portion, 20d: second right extension portion lateral extension, 20e: recess, 22: terminal receiving portion, 22a to 22d: terminal opening, 23a to 23d: battery side recess, 24: hook, 24a: operation portion, 24b: protrusion, 26: ventilation hole, 27: battery side recess, 28: screw hole, 30a to 30e: first protrusion, 32a: thick portion, 32b: thin portion, 34a to 34f: second protrusion, 40: ventilation hole, 40a to 40j: holes, 41: ventilation hole, 41a to 41j: holes, 42: display, 42a: remaining amount display, 42b: button, 43c: bottom end, 43h: bottom end, 46: screw hole, 48: front rib, 50: front rib, 50a: groove, 5 2: front rib, 54: front rib, 56: front rib, 56a: light shielding wall portion, 56b: flat portion, 58a to 58d: ventilation hole, 60a to 60h: side rib, 62: screw hole, 64a to 64f: second recessed portion, 80: cell case, 80a: front portion, 80b: rear portion, 80c: thick portion, 80d: upper surface, 80e: right side surface, 80f: left side surface, 80g: recessed portion, 81a: ventilation hole, 81b: ventilation hole, 82: control board, 83: screw boss, 84: LED board, 84a: LED, 84b: switch, 84c: lower surface, 85: right cell case, 86: left cell case, 87a to 87j: cell holding portion, 88: connecting portion, 89a: central holding portion, 89b: end surface holding portion, 90a to 90j: battery cell, 91: metal portion, 91a: lower end, 92a to 92k: lead plate, 93a to 93c: side surface, 93b: side surface, 93c: side surface, 94: waterproof ring, 94a: upper end, 94b: lower end, 100: fastener, 102: terminal, 104a: battery side negative terminal, 104b: battery side positive terminal, 106a to 106d: battery side signal terminal, 110a to 110e: first recess, 112: fixing portion, 114: screw, 116a to 116e: protruding portion, 120: signal line, 200: power tool, 202: terminal holding portion,206a to 206d: tool side protrusions, 208a: tool side negative terminal, 208b: tool side positive terminal, 210a, 210c: tool side signal terminal, 300: charger, 302: slide rail, 304: housing, 306: charger side protrusions, 308: ventilation hole, 602: battery pack, 612: outer case, 615: lower case, 615e: bottom surface, 619a, 619b: hooks,

Claims

1. An outer case, A substrate accommodated in the outer case; Hook and A display member, The outer case is an upper surface provided with a terminal opening for exposing the terminal; The bottom surface and a side surface extending upward from the bottom surface; an opening disposed on the side surface, the hook is disposed on the side surface of the outer case, The display member is disposed on the side surface, The display member is provided below the hook, The opening is provided below the display member, The opening is provided below the substrate.

2. The display device further includes an operating member disposed on the side surface for switching the display member on and off, The battery pack according to claim 1 , wherein the opening is provided below the display member and the operation member.

3. A battery pack, An outer case, A battery cell; A substrate accommodated in the outer case, The outer case is an upper surface provided with a terminal opening for exposing the terminal; The bottom surface and A side surface extending upward from the bottom surface and including a specific surface facing downward, The specific surface has an opening, The battery pack includes: Further comprising a display member disposed on the side surface, The specific surface is provided below the display member on the side surface, The opening is provided below the substrate. Battery pack.

4. The battery pack according to claim 3 , wherein the specific surface is an inclined surface that is inclined with respect to the bottom surface.

5. The display device further includes an operating member disposed on the side surface for switching the display member on and off, The battery pack according to claim 4 , wherein the specific surface is provided on the side surface below the display member and the operation member.

6. The battery pack further comprises: The hook has one operating part that can be operated in the up and down directions. The battery pack according to claim 3 , wherein the hook is provided above the board and the opening.

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