Battery pack

Abstract

Provided is a technique capable of suppressing damage to a battery cell housed in a battery cell case even when an impact is applied to a lower case. The battery pack includes: an outer case including an upper case and a lower case fixed to the upper case; a battery unit; and a battery cell case that accommodates the battery cells. A gap is provided between the lower case and the entire lower surface of the battery cell case.

Description

[0001] This application is a divisional application of the application with application number 2020 1 0863 135.6, application date August 25, 2020, and invention name “Battery Pack” Technical Field

[0002] The technology disclosed in this specification relates to a battery pack. Background Art

[0003] Patent Document 1 discloses a battery pack. The battery pack disclosed in Patent Document 1 includes: an outer case including an upper case and a lower case fixed to the upper case; a battery cell; and a battery cell case that accommodates the battery cell.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2014-203703

[0005] For example, when a user drops the battery pack, an impact is applied to the lower shell of the outer shell, which may deform the lower shell. In the case of the battery pack of Patent Document 1, there is a possibility that if the lower shell is deformed, the lower shell contacts the battery cell shell, and the battery cell shell is deformed, thereby damaging the battery cell housed in the battery cell shell. Summary of the invention

[0006] This specification provides a technology that can suppress damage to a battery cell housed in a battery cell case even when an impact is applied to a lower case.

[0007] The battery pack disclosed in this specification comprises: an outer shell having an upper shell and a lower shell fixed to the upper shell; a battery cell; and a battery cell shell that accommodates the battery cell, wherein a gap is provided between the lower shell and the entire lower surface of the battery cell shell.

[0008] In the battery pack described above, even when an impact is applied to the lower shell of the outer shell and the lower shell is deformed, the lower shell can be prevented from contacting the lower surface of the battery cell shell. Therefore, when an impact is applied to the lower shell, damage to the battery cell housed in the battery cell shell can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A This is a perspective view of the battery pack 2 according to the first embodiment as viewed from the upper right front.

[0010] Figure 1B This is a perspective view of the battery pack 2 according to the first embodiment as viewed from the lower right front.

[0011] Figure 1C This is a perspective view of the battery pack 2 according to the first embodiment as viewed from the upper right rear side.

[0012] Figure 2 This is a bottom view of the battery pack 2 according to the first embodiment as seen from below.

[0013] Figure 3 This is a right side view of the battery pack 2 according to the first embodiment as seen from the right.

[0014] Figure 4A This is a bottom view of the upper housing 14 of the first embodiment as viewed from below.

[0015] Figure 4B This is a perspective view of the upper housing 14 of the first embodiment as viewed from the lower left front.

[0016] Figure 4C This is a cross-sectional view of the slide rail 20 of the upper housing 14 according to the first embodiment as viewed from the rear.

[0017] Figure 5 yes Figure 4A An enlarged view of the dotted line V portion.

[0018] Figure 6 This is a plan view of the lower case 15 of the first embodiment as viewed from above.

[0019] Figure 7 Viewed from the upper right rear Figure 6 The enlarged stereogram is seen in the dotted line VII.

[0020] Figure 8 This is a perspective view of the lower housing 15 of the first embodiment as viewed from the upper left rear.

[0021] Fig. 9A This is a perspective view of the battery module 10 according to the first embodiment as viewed from the upper right front.

[0022] Fig. 9B This is a perspective view of the battery module 10 according to the first embodiment as viewed from the upper left rear.

[0023] Fig.10 It is along Fig. 9A Cross-sectional view of line XX.

[0024] Fig.11A This is a perspective view of the battery unit case 80 according to the first embodiment as viewed from the upper right front.

[0025] Fig. 11B This is a perspective view of the right battery unit case 85 of the first embodiment as viewed from the upper left rear.

[0026] Fig. 11C This is a plan view of the battery cell case 80 according to the first embodiment as seen from above.

[0027] Fig. 12A It is a plan view showing a state where the battery module 10 and the lower case 15 are fixed in the first embodiment.

[0028] Fig. 12B This is a plan view of the battery pack 2 according to the first embodiment as seen from the upper surface.

[0029] Fig.13A yes Fig. 12A An enlarged view of the dotted line XIII portion.

[0030] Fig. 13B It is along Fig.13A A cross-sectional view taken along line XIIIB-XIIIB.

[0031] Fig.14 It is a top cross-sectional view of the battery pack 2 according to the present embodiment.

[0032] Fig.15 yes Fig.14 An enlarged view of the dotted line XV portion.

[0033] Fig.16 It is a top cross-sectional view of the battery pack 2 according to the present embodiment.

[0034] Fig.17 yes Fig.16 An enlarged view of the dotted line XVII.

[0035] Fig.18 This is a cross-sectional view of the battery pack 2 according to the first embodiment when viewed from the right.

[0036] Fig.19 This is a cross-sectional view of the battery pack 2 according to the first embodiment when viewed from the right.

[0037] Fig. 20 This is a cross-sectional view of the battery pack 2 according to the first embodiment as viewed from the rear.

[0038] Fig.21 It is along Fig. 12A , Fig. 12B Cross-sectional view of line XXI-XXI.

[0039] Fig. 22 This is a cross-sectional view showing a state where the battery pack 2 according to the first embodiment is mounted on the charger 300 as seen from the left.

[0040] Fig.23 This is a cross-sectional view showing a state where the battery pack 2 according to the first embodiment is mounted on the charger 300 as seen from the left.

[0041] Fig.24AThis is a perspective view showing a state where the battery pack 2 according to the first embodiment is mounted on the electric power tool 200 as viewed from the upper right front.

[0042] Fig. 24B This is a cross-sectional view showing a state where the battery pack 2 according to the first embodiment is mounted on the electric power tool 200 as seen from the rear.

[0043] Fig.25A This is a perspective view showing a state where the battery pack 2 according to the first embodiment is mounted on the charger 300 as viewed from the lower left rear side.

[0044] Fig.25B This is a perspective view of charger 300 as viewed from the lower left rear side.

[0045] Fig.26 This is a perspective view of the battery pack 602 of the second embodiment as viewed from the lower right front.

[0046] Description of Reference Numerals

[0047] 2...battery pack; 10...battery module; 12...outer shell; 14...upper shell; 14a...front surface; 14b1...front upper surface; 14b2...rear upper surface; 15...lower shell; 15a...front surface; 15b...right side; 15c...rear surface; 15d...left side; 15e...bottom surface; 15f...corner; 16a...flat portion; 16b...protruding portion; 16c...recessed portion; 16d...stepped portion; 17a...first upper extension surface; 17b...inclined surface; 17c...second upper extension surface; 18...screw; 19...hook portion; 20...sliding guide rail; 20 a...base; 20b...upper extension; 20c...first right extension; 20d...second right extension; 20e...recess; 22...terminal receiving portion; 22a~22d...terminal opening; 23a~23d...battery side recess; 24...hook member; 24a...operating portion; 24b...protrusion; 26...vent; 27...battery side recess; 28...threaded hole; 30a~30e...first protrusion; 32a...thick wall portion; 32b...thin wall portion; 34a~34f...second protrusion; 40...vent; 40a~40j...hole; 41...vent; 41a~41j. ..hole; 42...display portion; 42a...remaining amount display portion; 42b...button; 43c...lower end; 43h...lower end; 46...threaded hole; 48...front rib; 50...front rib; 50a...groove portion; 52...front rib; 54...front rib; 56...front rib; 56a...light shielding wall portion; 56b...flat portion; 58a~58d...vent hole; 60a~60h...side rib; 62...threaded hole; 64a~64f...second recessed portion; 80...battery unit housing; 80a...front portion; 80b...rear portion; 80c...thick wall portion; 80d...upper surface; 80e...right side surface; 8 0f...left side; 80g...recessed portion; 81a...vent hole; 81b...vent hole; 82...control substrate; 83...threaded protrusion; 84...LED substrate; 84a...LED; 84b...switch; 84c...lower surface; 85...right battery cell housing; 86...left battery cell housing; 87a~87j...battery cell holding portion; 88...connecting portion; 89a...central side holding portion; 89b...end side holding portion; 90a~90j...battery cell; 91...metal portion; 91a...lower end; 92a~92k...pin plate; 93a~93c...side; 93b...side; 93c...side; 94...waterproof ring; 94a...upper end; 94b...lower end; 100...fastener; 102...terminal; 104a...battery side negative terminal; 104b...battery side positive terminal; 106a~106d...battery side signal terminal; 110a~110e...first recessed portion; 112...fixing portion; 114...screw; 116a~116e...protruding portion; 120...signal line; 200...power tool; 202...terminal Holding portion; 206a-206d... tool side protrusion; 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 protrusion; 308... vent; 602... battery pack; 612... housing; 615... lower housing; 615e... bottom surface; 619a, 619b... hooking portion. . DETAILED DESCRIPTION

[0048] In one or more embodiments, the battery cell housing may be threadedly fixed to the outer housing.

[0049] According to the above structure, for example, when the user drops the battery pack, the outer shell and the battery cell case can be prevented from being misaligned. Therefore, when an impact is applied to the lower shell, damage to the battery cells accommodated in the battery cell case can be further suppressed.

[0050] In one or more embodiments, the lower shell may contain three or more battery cells arranged in parallel with the bottom surface of the lower shell. The three or more battery cells may be composed of an outer battery cell closest to the corner of the lower shell and an inner battery cell disposed inside the outer battery cell. The gap between the first retaining portion holding the outer battery cell in the lower surface of the battery cell shell and the lower shell may be larger than the gap between the second retaining portion holding the inner battery cell in the lower surface of the battery cell shell and the lower shell.

[0051] In the case where the user drops the battery pack, etc., it is easy to apply an impact to the corners of the four corners of the bottom surface of the lower shell of the outer shell. That is, the corners of the four corners of the bottom surface of the lower shell are most likely to deform. The distance between the first holding portion that holds the outer battery cell and the corner with the shortest distance to the outer battery cell among the four corners of the bottom surface of the lower shell is shorter than the distance between the second holding portion that holds the inner battery cell and the corner with the shortest distance to the outer battery cell among the four corners of the bottom surface of the lower shell. Therefore, in the case where the corners of the four corners of the bottom surface of the lower shell are deformed, the bottom surface of the lower shell is relatively easy to contact with the first holding portion compared to the second holding portion. According to the above structure, even if the corners of the four corners of the bottom surface of the lower shell are deformed, it is possible to suppress the lower shell from contacting the lower surface of the battery cell shell. Therefore, in the case where an impact is applied to the lower shell, it is possible to suppress damage to the battery cell housed in the battery cell shell.

[0052] In one or more embodiments, the first holding portion may be composed of an end surface side holding portion for holding the end surface side of the outer battery cell in the long side direction and a center side holding portion for holding the center side of the outer battery cell in the long side direction. The gap between the end surface side holding portion and the lower shell may be larger than the gap between the center side holding portion and the lower shell.

[0053] The end surface side holding portion is relatively close to the four corners of the bottom surface of the lower shell body compared to the central side holding portion. According to the above structure, even if the four corners of the bottom surface of the lower shell body are deformed, it is possible to prevent the lower shell body from contacting the lower surface of the battery cell shell body. Therefore, when an impact is applied to the lower shell body, it is possible to prevent the battery cell housed in the battery cell shell body from being damaged.

[0054] In one or more embodiments, a step portion may be provided on the bottom surface of the lower housing between the side surface of the outer battery cell and the bottom surface to which the side surface of the inner battery cell faces. Alternatively, the step portion may descend downward from the inner battery cell side toward the outer battery cell side.

[0055] According to the above structure, the gap between the first holding portion and the lower shell can be made larger than the gap between the second holding portion and the lower shell. Therefore, even if the four corners of the bottom surface of the lower shell are deformed, the lower shell can be prevented from contacting the lower surface of the battery cell shell. Therefore, when an impact is applied to the lower shell, damage to the battery cell accommodated in the battery cell shell can be further suppressed.

[0056] In one or more embodiments, the thickness of the four corners of the lower portion of the battery cell case may be greater than the thickness of the battery cell case below the longitudinal axis of the battery cell.

[0057] When the lower shell is deformed, the lower shell is likely to contact the four corners of the lower part of the battery cell shell. According to the above structure, the strength of the portion of the battery cell shell where the lower shell is likely to contact can be increased. Therefore, even if the lower shell contacts the battery cell shell, damage to the battery cell housed in the battery cell shell can be suppressed.

[0058] (First embodiment)

[0059] The battery pack 2 of the embodiment will be described below with reference to the accompanying drawings. Fig.24A As shown, the battery pack 2 can be detachably mounted on the electric tool 200 . Fig.24A In the example, the electric tool 200 is an electric screwdriver, but the electric tool 200 may also 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 lawn mower, an electric blower, etc. If installed in the electric tool 200, the battery pack 2 supplies power to the electric tool 200. In addition, as shown in FIG. 25, the battery pack 2 can be detachably installed in the charger 300. If installed in the charger 300, the battery pack 2 is supplied with power from the charger 300. In addition, in the following description, with respect to the battery pack 2, the direction in which the electric tool 200 and the charger 300 are viewed from the battery pack 2 when installed in the electric tool 200 and the charger 300 is referred to as the upper direction, and the opposite direction is referred to as the lower direction. In addition, with respect to the battery pack 2, the direction in which the battery pack 2 slides when installed in the electric tool 200 and the charger 300 is referred to as the rear direction, and the direction in which the battery pack 2 slides when removed from the electric tool 200 and the charger 300 is referred to as the front direction. That is, in the following description, the front-rear direction corresponds to a sliding direction in which the battery pack 2 is slid relative to the electric power tool 200 or the charger 300 .

[0060] As shown in Figure 1~ Fig. 13B As shown, the battery pack 2 includes: a battery module 10 (see FIG. 9 ) and an outer shell 12 (see FIG. 1 ) that accommodates the battery module 10. The outer shell 12 is generally formed in a rectangular parallelepiped shape and is divided into an upper shell 14 and a lower shell 15. Figure 2 As shown, the upper housing 14 and the lower housing 15 are fixed to each other by four screws 18 .

[0061] (Structure of the upper housing 14)

[0062] like Figure 1AAs shown, the upper housing 14 is formed with a slide rail 20 , a terminal receiving portion 22 , a hook member 24 , and a vent hole 26 .

[0063] The slide rails 20 extend in the front-rear direction and are disposed at the left and right ends of the upper portion of the upper housing 14. Figure 1A As shown in FIG. 2 , the slide rail 20 includes a base portion 20a, an upper extension portion 20b, a first rightward extension portion 20c, and a second rightward extension portion 20d. Figure 4C As shown, the upper extension portion 20b extends upward from the left end of the base portion 20a. The first right extension portion 20c extends rightward from the upper extension portion 20b. The lower end of the first right extension portion 20c is located above the upper end of the base portion 20a. The right end of the first right extension portion 20c is located to the left of the right end of the base portion 20a. The second right extension portion 20d extends rightward from the upper extension portion 20b. The right end of the second right extension portion 20d is aligned with the right end of the first right extension portion 20c in the left-right direction. As shown Figure 1A As shown in FIG. 1 , 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 recessed portions 20e arranged in the front-to-back direction. When the battery pack 2 is installed or removed from the power tool 200 or the charger 300, the slide rail 20 is relatively close to the slide rail 302 of the power tool 200 (not shown) or the charger 300 (see FIG. 1 ). Fig.25B Specifically, the slide rail (not shown) of the electric tool 200 and the slide rail 302 of the charger 300 slide between the base 20a and the first right extension portion 20c.

[0064] The terminal receiving portion 22 includes four terminal openings 22a to 22d provided on the front upper surface 14b1 of the upper housing 14. The terminal openings 22a to 22d are arranged between the left and right slide rails 20, and when the battery pack 2 is installed in the power tool 200 and the charger 300, the terminals 208a, 208b, 210a, and 210c (see Fig. 24B ), the terminals of the charger 300 (not shown). The terminal openings 22a to 22d are arranged in order from the right side of the slide rail 20 to the left side of the slide rail 20, namely, the terminal opening 22a, the terminal opening 22b, the terminal opening 22c, and the terminal opening 22d. Figure 1C , Fig. 12B , Fig. 24BAs shown, the battery side recessed portions 23a to 23d are provided so as to surround the terminal opening portions 22a to 22d. When the battery pack 2 is viewed from above, the terminal opening portions 22a to 22d and the battery side recessed portions 23a to 23d have a U-shape. The battery side recessed portions 23a to 23d are provided slightly below the front upper surface 14b1 of the outer shell 12. That is, the front upper surface 14b1 and the battery side recessed portions 23a to 23d have a stepped shape.

[0065] The hook member 24 is arranged at the front upper part of the upper housing 14. The hook member 24 is a member made of resin, and includes an operating portion 24a and a protrusion 24b. The operating portion 24a is provided on the front surface 14a of the upper housing 14. The hook member 24 is held on the upper housing 14 in a manner that allows it to move in the up and down directions. The hook member 24 is urged upward by a compression spring (not shown), and when the operating portion 24a and the protrusion 24b are pressed downward, the hook member 24 moves downward. When the battery pack 2 is mounted on the electric tool 200 and the charger 300, the protrusion 24b is in contact with the housing of the electric tool 200 (not shown) and the housing 304 of the charger 300 (see FIG. 2 ). Fig.25B ) is engaged to fix the battery pack 2 on the power tool 200 or the charger 300. When removing the battery pack 2 from the power tool 200 or the charger 300, the user presses the operating portion 24a downward, so that the protrusion 24b moves downward. In this state, the battery pack 2 can be removed from the power tool 200 or the charger 300 by sliding the battery pack 2. The operating portion 24a has a shape that is recessed inward. Therefore, when the user places a finger on the operating portion 24a and presses the operating portion 24a downward, the finger can be pressed without slipping.

[0066] The vent hole 26 is provided at the rear of the sliding guide rail 20. The vent hole 26 is provided at the rear of the rear upper surface 14b2 of the outer shell 12. The rear upper surface 14b2 is located below the front upper surface 14b1 and above the base 20a of the sliding guide rail 20. A battery side recess 27 is provided in the right part, the left part and the front of the vent 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 step shape. A charger side protrusion 306 having a shape corresponding to the battery side recess 27 is provided on the charger 300 (refer to Fig.25B ). Therefore, when the battery pack 2 is mounted on the charger 300 , the charger-side protrusion 306 is inserted into the battery-side recess 27 .

[0067] like Figure 4A As shown, four threaded holes 28 and five first protrusions 30a to 30e are provided in the upper housing 14. The screws 18 (see Figure 2 ).like Figure 4B As shown in FIG. 1 , the first protrusions 30a to 30e protrude downward (ie, toward the battery cell case 80) from the upper surface of the upper case 14. Figure 4C As shown in FIG. 1 , the first protrusion 30d is provided below the slide rail 20 (specifically, the base 20a), that is, inside the upper housing 14. The first protrusions 30a to 30c and 30e are also provided below the slide rail 20. Figure 5 As shown, the first protrusion 30 is composed of a thick wall portion 32a and a thin wall portion 32b. The thickness of the thick wall portion 32a in the left-right direction is greater than the thickness of the thin wall portion 32b in the left-right direction. In the first protrusion 30, the thick wall portion 32a and the thin wall portion 32b are alternately formed. Figure 4A As shown in FIG. 1 , the first protrusions 30a to 30d are composed of four thick-walled portions 32a and three thin-walled portions 32b. The first protrusion 30e is composed of three thick-walled portions 32a and two thin-walled portions 32b. Figure 5 As shown, the length L1 of the first protrusions 30a to 30d in the front-rear direction is greater than the length L2 of the first protrusion 30e in the front-rear direction.

[0068] like Figure 4A As shown in FIG. 1 , the upper case 14 is provided with six second protrusions 34 a to 34 f for aligning the upper case 14 and the lower case 15 .

[0069] (Structure of the lower housing 15)

[0070] like Figure 1B , Figure 8 As shown in FIG. 1 , the lower housing 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 upper extension surface 17a extending perpendicularly to the bottom surface 15e, an inclined surface 17b inclined relative to the bottom surface 15e, and a second upper extension surface 17c extending perpendicularly to the bottom surface 15e. Fig. 13B As shown, the inclined surface 17b is inclined in such a way that the rear portion thereof is inclined downward. Figure 1A As shown in FIG. 1 , the lower housing 15 is provided with a vent hole 40 and a display unit 42. The display unit 42 is provided on the front surface 15a of the lower housing 15. The display unit 42 includes a remaining charge display unit 42a which indicates the remaining charge of the battery pack 2 to the user and a button 42b which switches the display of the remaining charge on / off. Figure 1BAs shown in FIG. 1 , ventilation holes 58a to 58d are provided on the inclined surface 17b of the lower housing 15. In addition, a hook portion 19 is provided on the bottom surface 15e of the lower housing 15. The hook portion 19 is used when removing the battery pack 2 from the power tool 200 or the charger 300. Specifically, the user hooks the index finger or the middle finger on the hook portion 19 and presses the operation portion 24a downward with the thumb (see FIG. 1 ). Figure 1A ).

[0071] like Figure 3 As shown, the vent hole 40 is provided at the lower part of the right side surface 15b of the lower shell 15. The vent hole 40 is composed of ten holes 40a~40j. The ten holes 40a~40j are arranged in two layers, one above the other. Among the five holes 40a~40e provided in the lower layer, the length of the hole 40a provided at the rearmost side and the hole 40e provided at the frontmost side in the front-to-back direction is smaller than the length of the holes 40b~44d in the front-to-back direction. In addition, among the five holes 40f~44j provided in the upper layer, the length of the hole 40f provided at the rearmost side and the hole 40j provided at the frontmost side in the front-to-back direction is smaller than the length of the holes 40g~44i in the front-to-back direction. In addition, as Figure 8 As shown, a vent hole 41 similar to the vent hole 40 is also provided at the lower portion of the left side surface 15d of the lower case 15. The vent hole 41 is composed of ten holes 41a to 41j.

[0072] In addition, if Figure 6 As shown, the lower shell 15 is provided with four threaded holes 46, five front ribs 48, 50, 52, 54, 56, four vent holes 58a to 58d, eight side ribs 60a to 60h, four threaded holes 62, and six second recessed portions 64a to 64f. The four threaded holes 46 are located in the upper shell 14 and the four threaded holes 28 (see Figure 4A ) are provided at positions corresponding to the four threaded holes 62 for fixing the lower housing 15 and the battery module 10. The second recessed portions 64a to 64f are provided at the positions corresponding to the second protruding strips 34a to 34f (see Figure 4A ) is set at a corresponding position. The bottom surface 15e of the lower shell 15 is composed of a flat portion 16a, a protruding portion 16b, a recessed portion 16c, and a stepped portion 16d. The protruding portion 16b protrudes upward from the flat portion 16a. Fig.18 As shown in FIG. 1 , the protrusion 16 b has a shape along the lower surface of the battery cell case 80 described later. Figure 6 As shown in FIG. 1 , the recessed portions 16c are provided at the corner portions 15f of the four corners of the bottom surface 15e of the lower housing 15. Fig.19As shown, 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 shell 15. The thickness t1 of the lower shell 15 of the flat portion 16a is the same as the thickness t1 of the lower shell 15 of the recessed portion 16c.

[0073] like Figure 7 As shown, the front ribs 48, 50, 52, 54, 56 are arranged 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 shell 15. The rear end of the front rib 48 is roughly aligned with the rear end of the inclined surface 17b, and the upper end of the front rib 48 is roughly 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 roughly 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 portion 42a. In addition, a groove portion 50a is provided on the front rib 50. The LED substrate 84 described later (refer to Fig.13A ) passes through the groove portion 50a. The rear ends of the front ribs 52 and 54 are located in front of the rear end of the inclined surface 17b. In addition, the upper ends of the front ribs 52 and 54 are located above 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 the same structure as the front ribs 52 and 54. The flat portion 56b has the same structure as the front rib 48.

[0074] 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 divided by the front rib 48, the second space S2 is divided by the front ribs 48 and 50, the third space S3 is divided by the front ribs 50 and 56, and the fourth space S4 is divided by the front rib 56. Ventilation holes 58a to 58d are provided in each of the spaces S1 to S4. The vents 58a to 58d penetrate the lower housing 15 in the up-down direction. Therefore, the water that has entered the outer housing 12 and flows into the spaces S1 to S4 is discharged from the vents 58a to 58d.

[0075] like Figure 6 As shown in FIG. 1 , the side ribs 60a to 60d extend leftward from the right side surface 15b of the lower housing 15. Figure 8As shown, 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 below 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 and 40f and the holes 40b and 40g, the side rib 60b is provided between the holes 40b and 40g and the holes 40c and 40h, the side rib 60c is provided between the holes 40c and 40h and the holes 40d and 40i, and the side rib 60d is provided between the holes 40d and 40i and the holes 40e and 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.

[0076] (Structure of Battery Module 10)

[0077] like Fig. 9A As shown in FIG. 1 , the battery module 10 includes a battery cell case 80, a control substrate 82, and an LED substrate 84. The battery cell case 80 is made of an insulating material, such as a resin material. Fig.11A As shown, the battery cell housing 80 is divided into a right battery cell housing 85 and a left battery cell housing 86. A vent hole 81a is provided at the front portion 80a of the battery cell housing 80, and a vent hole 81b is provided at the rear portion 80b of the battery cell housing 80. Thick wall portions 80c are provided at the four corners of the lower portion of the battery cell housing 80. Fig.19 As shown in FIG. 1 , the thickness t11 of the thick wall portion 80c is greater than the thickness t12 of the battery cell holding portion 87 described later. Fig.11A As shown, the upper surface 80d of the battery cell case 80 has a shape similar to that of the battery cell 90 (see Fig.10 ) has a shape corresponding to the side surface in the long side direction. A recessed portion 80g is provided on the upper surface 80d of the battery cell housing 80 and between two adjacent battery cells 90. Four threaded protrusions 83 are provided on the upper surface 80d of the battery cell housing 80 for connecting the control substrate 82 to the battery cell housing 80. Fig. 9B As shown in FIG. 1 , protrusions 116a to 116c are provided on the upper portion of the left side surface 80f of the battery cell case 80 so as to protrude upward from the upper surface 80d of the battery cell case 80. Fig. 11C As shown, the protrusions 116a to 116c are arranged across two adjacent battery cells 90. The protrusions 116a to 116c are provided with first recessed portions 110a to 110c. The first recessed portions 110a to 110c are respectively formed on the upper case 14 and adjacent to the first protrusions 30a to 30c (see Figure 4A ) corresponding position settings. Fig. 9AAs shown in FIG. 1 , protrusions 116d, 116e are provided on the upper portion of the right side surface 80e of the battery cell case 80 so as to protrude upward from the upper surface 80d of the battery cell case 80. Fig. 11C As shown, the protrusions 116d and 116e are arranged across two adjacent battery cells 90. The protrusions 116d and 116e are provided with first recessed portions 110d and 110e. The first recessed portions 110d and 110e are respectively provided at the first protrusions 30d and 30e (see Figure 4A ) corresponding position settings. Fig. 11C As shown in FIG. 1 , when the battery module 10 is viewed from above, the protrusions 116a to 116e and the first recesses 110a to 110e are provided outside the control substrate 82. The first recesses 110a to 110e are provided between two lead plates 92 described later. Fig. 9A As shown, 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. Fig. 9B As shown, 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.

[0078] like Fig. 11B As shown, ten battery cell holding portions 87a to 87j are provided on the right battery cell housing 85. The ten battery cell holding portions 87a to 87j are arranged in two layers, one above the other. Fig.18 As shown, the battery cell holding portions 87a to 87c include a center holding portion 89a for holding the center side of a battery cell 90 described later. Fig.19 As shown, the battery cell holding parts 87a to 87c have an end surface side holding part 89b that holds the right end surface side of the long side direction of the battery cell 90. Although not shown in the figure, the battery cell holding parts 87d and 87e also have a center side holding part and an end surface side holding part. Fig. 11BAs shown, between the battery cell holding parts 87a, 87b, 87f, 87g and between the battery cell holding parts 87d, 87e, 87i, 87j, a connecting part 88 for connecting the right battery cell case 85 and the left battery cell case 86 is provided. In addition, although not shown in the figure, ten battery cell holding parts corresponding to the ten battery cell holding parts 87a to 87j of the right battery cell case 85 and two connecting parts corresponding to the two connecting parts 88 of the right battery cell case 85 are provided in the left battery cell case 86.

[0079] like Fig.10 As shown, ten battery cells 90a to 90j are arranged in two layers in the upper and lower layers on the battery cell housing 80. The battery cell 90 is a cylindrical secondary battery cell, such as a lithium-ion battery cell, with a positive electrode formed at one end and a negative electrode formed at the other end. In this embodiment, the battery cell 90 is a 18650 type lithium-ion battery cell with a rated voltage of 3.6 [V]. The battery cells 90 are arranged so that the directions from the positive electrode to the negative electrode in the battery cells 90 adjacent in the vertical direction are opposite to each other. Among the battery cells 90a to 90e in the lower layer, the battery cell 90a on the rear side is arranged so that the right end surface side becomes the negative electrode and the left end surface side becomes the positive electrode. In addition, the battery cells 90b to 90e are arranged so that the right end surface side becomes the positive electrode and the left end surface side becomes the negative electrode. In addition, among the battery cells 90f to 90j in the upper layer, the battery cell 90f on the rear side is arranged so that the right end surface side becomes the positive electrode and the left end surface side becomes the negative electrode. The battery cells 90g to 90j are arranged so that the right end surface side becomes the negative electrode and the left end surface side becomes the positive electrode. The metal portion 91 (see, for example, Fig. 20 ) and the metal portion constituting the negative electrode are connected to the end face of the battery cell 90. One end of the battery cell 90 is connected to the metal pin plates 92a to 92f provided on the right side 80e of the battery cell case 80 via the metal portion (see Fig. 9A ), the other end of the battery cell 90 is connected to the metal pin plates 92g to 92k provided on the left side 80f of the battery cell housing 80 via the metal portion (refer to Fig. 9B ). In addition, if Fig. 20 As shown in FIG. 1 , a waterproof ring 95 is provided on the metal portion 91 constituting the positive electrode of the battery cell 90. Fig. 9A , Fig. 9B In FIG. 1 , the portion of the lead plate 92 marked with a thick circle indicates that a waterproof ring 95 is disposed inside the portion of the lead plate 92 marked with a thick circle. Therefore, the positive electrode of the battery cell 90 is connected to the portion of the lead plate 92 marked with a thick circle.

[0080] like Fig. 9AAs shown, a plurality of pin plates 92a to 92f are arranged at intervals from each other. Therefore, a plurality of pin plates 92a to 92f are insulated from each other. Pin plate 92a is connected only to the positive electrode of battery cell 90f. Pin plate 92f is connected only to the negative electrode of battery cell 90j. Pin plate 92b connects two battery cells 90a and 90b adjacent in the front-to-back direction. Pin plates 92c to 92e connect two battery cells 90 adjacent in the oblique direction. Specifically, pin plate 92c is connected to the negative electrode of battery cell 90g and the positive electrode of battery cell 90c. Pin plate 92d is connected to the negative electrode of battery cell 90h and the positive electrode of battery cell 90d. Pin plate 92e is connected to the negative electrode of battery cell 90i and the positive electrode of battery cell 90e.

[0081] In addition, if Fig. 9B As shown, a plurality of pin plates 92g to 92k are arranged at intervals from each other. Therefore, a plurality of pin plates 92g to 92k are insulated from each other. Pin plates 92g to 92k connect battery cells 90 adjacent in the vertical direction. Specifically, pin plate 92g connects the negative electrode of battery cell 90e to the positive electrode of battery cell 90j. In addition, pin plate 92h connects the negative electrode of battery cell 90d to the positive electrode of battery cell 90i. In addition, pin plate 92i connects the negative electrode of battery cell 90c to the positive electrode of battery cell 90h. In addition, pin plate 92j connects the negative electrode of battery cell 90b to the positive electrode of battery cell 90g. In addition, pin plate 92k connects the positive electrode of battery cell 90a to the negative electrode of battery cell 90f. According to the above structure, ten battery cells 90 are electrically connected in series. Therefore, the rated voltage of battery pack 2 is 36 [V]. Although not shown in the figure, insulating sheets are attached to the right side surface 80 e and the left side surface 80 f of the battery cell case 80 .

[0082] According to the above structure, the pin plates 92a and 92f connected to the control substrate 82 via the power line (not shown) can be connected to the battery cells 90f and 90j on the upper side. A larger current flows through the pin plates 92a and 92f connected to the control substrate 82 than in other pin plates. Therefore, it is desirable that the width of the pin plates 92a and 92f is large. According to the above structure, the width of the pin plates 92a and 92f can be fully ensured. In addition, assuming that at least one of the pin plates 92a and 92f connected to the control substrate 82 is connected to the battery cell on the lower side, it is necessary to wire the power line from the lower part of the battery cell housing 60. In the lower part of the battery cell housing 60, the gap between the battery cell housing 60 and the right side surface of the outer shell 12 is small, so it is more difficult to wire the power line. According to the above structure, both the pin plates 92a and 92f connected to the control substrate 82 are connected to the upper battery cells 90f and 90j, so it is easy to wire the power lines connecting the pin plates 92a and 92f and the control substrate 82. In addition, compared with the case where at least one of the pin plates 92a and 92f is connected to the battery cell 90 in the lower layer, the length of the current line connecting the pin plates 92a and 92f and the control substrate 82 can be shortened, so the resistance generated by the power line connecting the pin plates 92a and 92f and the control substrate 82 can be reduced.

[0083] like Fig.10 As shown, in a state where the battery cell case 80 holds ten battery cells 90a to 90j, the battery cells 90f to 90j on the upper layer and the battery cells 90a to 90e on the lower layer are arranged at intervals in the vertical direction. In addition, gaps are provided between the battery cells 90a, 90b, 90f, 90g and the connecting portion 88 on the rear side, and between the battery cells 90d, 90e, 90i, 90j and the connecting portion 88 on the front side. Therefore, air flowing into the battery cell case 80 from the vent hole 81a or the vent hole 81b of the battery cell case 80 can pass between the battery cells 90f to 90j on the upper layer and the battery cells 90a to 90e on the lower layer, between the battery cells 90a, 90b, 90f, 90g and the connecting portion 88 on the rear side, and between the battery cells 90d, 90e, 90i, 90j and the connecting portion 88 on the front side.

[0084] like Fig. 9A As shown, the control board 82 is arranged above the battery cell case 80 . The control board 82 is arranged along a plane perpendicular to the up-down direction. The control board 82 is fixed to the battery cell case 80 via a fastener 100 .

[0085] A plurality of terminals 102 are provided on the upper surface of the control substrate 82. The plurality of terminals 102 include a battery-side negative terminal 104a used for discharging or charging when the battery pack 2 is installed on the electric 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 sending and receiving signals. The battery-side negative terminal 104a and the battery-side positive terminal 104b are arranged on the outside in the left-right direction than the battery-side signal terminals 106a to 106d. The battery-side negative terminal 104a is provided on the right side of the control substrate 82, and the battery-side positive terminal 104b is provided on the left side of the control substrate 82. The battery-side signal terminals 106a and 106b are arranged front to back. The battery-side signal terminals 106c and 106d are arranged front to back. As shown in FIG. Fig. 12B As shown, the negative terminal 104a on the battery side is arranged at a position of the upper shell 14 corresponding to the terminal opening 22a, the signal terminals 106a and 106b on the battery side are arranged at positions corresponding to the terminal opening 22b, the signal terminals 106c and 106d on the battery side are arranged at positions corresponding to the terminal opening 22c, and the positive terminal 104b on the battery side is arranged at a position corresponding to the terminal opening 22d.

[0086] like Fig. 9A , Fig. 9B As shown in FIG. 1 , four fixing portions 112 are provided on the battery cell housing 80. Each fixing portion 112 is provided at a position corresponding to the threaded hole 62 of the lower housing 15. Fig. 12A As shown, the lower housing 15 and the battery module 10 are fixed to each other by four screws 114 .

[0087] like Fig. 9A As shown, the LED substrate 84 is connected to the control substrate 82 via a signal line 120. The LED substrate 84 includes a switch 84b and four LEDs 84a. Fig.13A As shown, in a state where the battery module 10 and the lower shell 15 are fixed, the LED substrate 84 is arranged near the back side of the display unit 42 of the lower shell 15. Specifically, the LED 84a is arranged on the back side of the remaining display unit 42a, and the switch 84b is arranged on the back side of the button 42b. That is, the LED substrate 84 is opposite to the front surface 14a at the inner side of the lower shell 15. In addition, the LED substrate 84 is inserted into the groove portion 50a of the front rib 50 of the lower shell 15 and placed on the front ribs 48 and 56. Therefore, the LED substrate 84 is held by the lower shell 15. In addition, the front surface of the LED substrate 84 contacts the rear ends of the front ribs 52 and 54 and the light shielding wall portion 56a of the front rib 56. In addition, ventilation holes 58a to 58d are provided on the surface of the LED substrate 84 opposite to the lower surface 84c.

[0088] Below, refer to Figure 14 to Figure 17 , an engagement gap C1 between the first protrusion 30 of the upper case 14 and the first recess 110 of the battery module 10 and an engagement gap C2 between the second protrusion 34 of the upper case 14 and the second recess 64 of the lower case 15 are described.

[0089] like Fig.14 As shown in FIG. 1 , the first protrusions 30a to 30e of the upper case 14 are respectively accommodated in the first recesses 110a to 110e of the battery module 10. Fig.15 As shown in FIG. 1 , an engagement gap C1 is provided between the first protrusion portion 30d and the first recessed portion 110d.

[0090] In addition, if Fig.16 As shown in FIG. 1 , the second protrusions 34a to 34f of the upper housing 14 are respectively accommodated in the second recesses 64a to 64f of the lower housing 15. Fig.17 As shown, an engagement gap C2 is provided between the second protrusion 34e and the second recess 64e. The engagement gap C2 is used to position the upper case 14 and the lower case 15. The engagement gap C2 is used to suppress the displacement between the upper case 14 and the battery cell case 80. Fig.14 The engagement gap C1 is set to be able to suppress the displacement between the upper shell 14 and the battery cell shell 80 and prevent the upper shell 14 from contacting the control substrate 82. Therefore, the engagement gap C1 is larger than the engagement gap C2. Fig.16 As shown in FIG. 1 , the second protrusions 34 a to 34 f and the second recesses 64 a to 64 f form a labyrinth structure, thereby preventing water from entering the outer shell 12 .

[0091] Next, refer to Fig.18 , Fig.19 , the case gaps C11 to C13 between the lower surface of the battery cell case 80 of the battery module 10 and the lower case 15 are described. As described above, Fig.18 A cross-sectional view showing the battery pack 2 at the center position in the left-right direction, Fig.19 The cross-sectional view of the battery pack 2 shows a position where the recessed portion 16 c is provided on the right rear side of the lower case 15 .

[0092] like Fig.18 As shown in FIG. 1 , the lower surface of the battery cell case 80 does not contact the bottom surface 15e of the lower case 15. Specifically, a case gap C11 is provided between the central side holding portion 89a of the battery 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 gap C12 is provided between the central side holding portion 89a and the flat portion 16a. The case gap C12 is larger than the case gap C11.

[0093] In addition, if Fig.19 As shown, a housing gap C13 is provided between the end face side retaining portion 89b corresponding to the battery cell 90a arranged at the position closest to the corner portion 15f of the lower housing 15 and the recessed portion 16c. A step portion 16d is provided between the surface of the bottom surface 15e of the lower housing 15 that faces the side surface 93a of the battery cell 90a and the surface that faces the side surface 93b of the battery cell 90b. In addition, no step portion 16d is provided between the surface of the bottom surface 15e of the lower housing 15 that faces the side surface 93b of the battery cell 90b and the surface that faces the side surface 93c of the battery cell 90c. Therefore, the housing gap C13 is larger than the housing gap C12.

[0094] Next, refer to Fig. 20 , the positional relationship between the battery cell 90c located in the center of the lower layer among the plurality of battery cells 90 and the holes 40c and 40h provided on the right side of the battery cell 90c is described. In addition, Fig. 20 In the figure, for easy understanding, the pin plate 92i is omitted.

[0095] like Fig. 20 As shown in the figure, holes 40c and 40h are provided on the right side surface 15b at a position facing the end surface of the battery cell 90c in the long-side direction. In addition, no hole is provided on the right side surface 15b at a position facing the end surface of the battery cell 90h in the long-side direction located above the battery cell 90c. Parts of the holes 40c and 40h face the end surface of the battery cell 90h in the long-side direction.

[0096] The metal part 91 constituting the positive electrode of the battery cell 90c is provided on the end face on the right side of the battery cell 90c. The lower end 43h of the upper hole 40h and the lower end 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. In addition, the lower end 43c of the lower hole 40c is provided below the lower end 91a of the metal part 91 and the lower end 94b of the battery cell 90c.

[0097] Next, refer to Fig.21 , the flow of air in the battery pack 2 is described. For example, it is assumed that the battery pack 2 is installed in the power tool 200, the power tool 200 is used by the user, and the battery pack 2 is removed from the power tool 200. In this case, the battery pack 2 becomes hot. In such a situation, Figure 1A , Figure 3 , Figure 8The vents 40 and 41 provided at the lower portion of the lower shell 15 shown in the figure function as air intake holes for introducing air 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 plurality of battery cells 90 and the lower shell 15. As described above, side ribs 60a to 60d are provided between the holes 40a to 40j. Therefore, as Fig. 20 As shown, 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 plurality of battery cells 90 are reliably cooled. The air flowing into the space between the plurality of battery cells 90 and the right side surface 15b of the lower case 15 cools the plurality of battery cells 90, and then flows out to the outside of the battery pack 2 through the terminal opening 22a of the terminal receiving portion 22 of the upper case 14, etc. In this way, natural convection is generated when the battery pack 2 is at a high temperature. In addition, the air introduced into the battery pack 2 from the vent hole 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.

[0098] Next, refer to Fig. 22 , Fig.23 , the flow of air in the battery pack 2 when the battery pack 2 is mounted on the charger 300 will be described. The charger 300 is equipped with a blower fan (not shown) and is configured to suck air from the battery pack 2. In this state, the vent holes 40 (see FIG. 1 ) and 58a to 58d (see FIG. 2 ) of the battery pack 2 are Figure 6 ) functions as an air inlet hole for introducing air from the outside to the inside of the battery pack 2, and the vent hole 26 (see Figure 1) of the battery pack 2 functions as an exhaust hole for exhausting air from the inside of the battery pack 2 to the charger 300.

[0099] like Fig. 22 As shown, when the air supply fan of the charger 300 is driven, air is blown from the vent hole 58 (see Figure 1B) The air introduced into the battery pack 2 flows into the space between the front portion 80a of the battery cell case 80 and the front surface 15a of the lower case 15. The LED substrate 84 is provided between the front portion 80a of the battery cell case 80 and the front surface 15a of the lower case 15. The air flowing into the space between the front portion 80a of the battery cell case 80 and the front surface 15a of the lower case 15 flows into the battery cell case 80 through the space between the front portion 80a of the battery cell case 80 and the LED substrate 84 and the vent hole 81a of the battery cell case 80. The air introduced into the battery cell case 80 passes between the upper battery cells 90f to 90j and the lower battery cells 90a to 90e, between the battery cells 90a, 90b, 90f, 90g and the connecting portion 88 on the rear side, and between the battery cells 90d, 90e, 90i, 90j and the connecting portion 88 on the front side. The air passing through the battery cell case 80 cools the plurality of battery cells 90. The air that has cooled the plurality of battery cells 90 is then passed through the vent holes 81 b of the rear portion 80 b of the battery cell housing 80, the vent holes 26 of the upper housing 14, and the vent holes 308 of the charger 300 corresponding to the vent holes 26 (see FIG. Fig.25B ), and introduced into the charger 300. As described above, when the battery pack 2 is mounted on the charger 300, the charger-side protrusion 306 of the charger 300 is inserted into the battery-side recess 27 around the vent hole 26. Therefore, compared with the case where the battery-side recess 27 is not provided around the vent hole 26, the amount of air sucked into the charger 300 from the gap between the battery pack 2 and the charger 300 can be reduced. As a result, the amount of air flowing in the battery pack 2 can be increased. Therefore, the battery cells 90 and the pin plates 92 in the battery pack 2 can be efficiently cooled.

[0100] In addition, if Fig.23 As shown in FIG. 1 , the air introduced into the battery pack 2 from the vent hole 40 flows into the space between the plurality of battery cells 90 (specifically, the pin plate 92) and the right side surface 15b of the lower shell 15. The air that has flowed into the space between the battery cells 90 and the right side surface 15b of the lower shell 15 flows forward over the plurality of side ribs 60a to 60d and flows into the space between the front portion 80a of the battery cell shell 80 and the front surface 15a of the lower shell 15. The subsequent air flow is similar to Fig. 22 In this way, the air introduced from the vent holes 58 and 40 is used to cool the plurality of battery cells 90. In addition, in the present embodiment, the vent hole 40 is provided at the lower portion of the lower housing 15, so when the battery pack 2 is mounted on the charger 300, the vent hole 40 is located at a position higher than the charger 300. Dust and the like remain at a low position, so when the battery pack 2 is mounted on the charger 300, dust and the like are not easily sucked in.

[0101] Reference Fig. 24B , the effect of the battery side recessed portions 23a to 23d of the upper shell 14 of the battery pack 2 will be described. Fig. 24B The battery side signal terminal 106a of the battery pack 2 when the battery pack 2 is mounted on the electric tool 200 (see Fig. 12A ) in the center position in the front-to-back direction. Fig. 24B As shown, the terminal holding portion 202 of the electric tool 200 is provided, and tool-side protrusions 206a to 206d protruding toward the lower side (i.e., the battery pack 2 side) are provided on the terminal holding portion 202. A tool-side negative terminal 208a corresponding to the battery-side negative terminal 104a is provided on the tool-side protrusion 206a, and a tool-side positive terminal 208b corresponding to the battery-side positive terminal 104b is provided on the tool-side protrusion 206d. A tool-side signal terminal 210a corresponding to the battery-side signal terminal 106a is provided on the tool-side protrusion 206b. In addition, on the tool-side protrusion 206b, 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. A tool-side signal terminal 210c corresponding to the battery-side signal terminal 106c is provided on the tool-side protrusion 206c. In addition, the battery-side signal terminal 106d is a terminal used only when the battery pack 2 is installed in the charger 300, so in the tool-side protrusion 206c, a tool-side signal terminal corresponding to the battery-side signal terminal 106d is not provided in front of the tool-side signal terminal 208c. When the battery pack 2 is installed in the electric tool 200, the tool-side protrusions 206a to 206d are respectively inserted into the battery-side recesses 23a to 23d. According to such a structure, compared with the case where the tool-side protrusions 206a to 206d are not provided on the terminal holding portion 202 of the electric tool 200, the creepage distance between two adjacent terminals in the left-right direction among the multiple terminals of the electric tool 200 can be lengthened. Specifically, the creepage distance can be lengthened by the height of the tool-side protrusions 206a to 206d. Therefore, it is possible to suppress the short circuit of two adjacent terminals in the left-right direction among the multiple terminals of the electric tool 200.

[0102] In one or more embodiments, as shown in FIGS. 1 to 13 , the battery pack 2 includes: an outer shell 12 including an upper shell 14 and a lower shell 16 fixed to the upper shell 14; a battery cell 90; and a battery cell shell 80 that accommodates the battery cell 90. Fig.18 , Fig.19As shown, case gaps C11 to C13 are provided between the lower case 16 and the entire lower surface of the battery cell case 80. According to the above structure, even when an impact is applied to the lower case 16 of the outer case 12 and the lower case 16 is deformed, it is possible to suppress the lower case 16 from contacting the lower surface of the battery cell case 80. Therefore, when an impact is applied to the lower case 16, it is possible to suppress the battery cell 90 accommodated in the battery cell case 80 from being deformed.

[0103] In one or more embodiments, Fig. 12A As shown, the battery cell case 80 is screwed to the lower case 16. According to the above structure, for example, when the user drops the battery pack 2, it is possible to suppress the occurrence of displacement between the lower case 15 and the battery cell case 80. Therefore, when an impact is applied to the lower case 15, it is possible to further suppress the battery cell 90 accommodated in the battery cell case 80 from being damaged.

[0104] In one or more embodiments, Fig.10 As shown in FIG. 1 , five battery cells 90a to 90e are arranged and housed in the lower housing 15 in parallel with the bottom surface 15e of the lower housing 15. The five battery cells 90a to 90e are composed of battery cells 90a and 90e closest to the corner 15f of the lower housing 15 and battery cells 90b to 90d disposed inside the battery cells 90a and 90e. Fig.19 As shown in FIG. 1 , the case gap C13 between the battery cell holding portion 87a holding the battery cell 90a and the lower case 16 is larger than the case gap C12 between the battery cell holding portion 87b holding the battery cell 90b and the lower case 15. According to the above structure, even if the corners 15f of the four corners of the bottom surface 15e of the lower case 15 are deformed, it is possible to suppress the lower case 15 from contacting the lower surface of the battery cell case 80. Therefore, when an impact is applied to the lower case 16, it is possible to further suppress the battery cell 90 accommodated in the battery cell case 80 from being damaged.

[0105] In one or more embodiments, Fig.18 , Fig.19As shown, the battery cell holding portion 87a holding the battery cell 90a is composed of an end surface side holding portion 89b holding the end surface side of the battery cell 90a in the long side direction and a center side holding portion 89a holding the center side of the battery cell 90a in the long side direction. The housing gap C13 between the end surface side holding portion 89b and the lower housing 15 is larger than the housing gap C12 between the center side holding portion 89a and the lower housing 15. The end surface side holding portion 89b is closer to the corners 15f of the four corners of the bottom surface 15e of the lower housing 15 than the center side holding portion 89a. According to the above structure, even if the corners 15f of the four corners of the bottom surface 15e of the lower housing 15 are deformed, it is possible to suppress the lower housing 15 from contacting the lower surface of the battery cell housing 80. Therefore, it is possible to further suppress the battery cell 90 accommodated in the battery cell housing 80 from being damaged when an impact is applied to the lower housing 16.

[0106] In one or more embodiments, Figure 6 , Fig.19 As shown, in the bottom surface 15e of the lower shell 15, a step portion 16d is provided between the bottom surface 15e to which the side surface 93a of the battery cell 90a and the side surface 93b of the battery cell 90b face. The step portion descends downward from the battery cell 90b side toward the battery cell 90a side. According to the above structure, the shell gap C13 between the battery cell holding portion 87a holding the battery cell 90a and the lower shell 16 can be made larger than the shell gap C12 between the battery cell holding portion 87b holding the battery cell 90b and the lower shell 16. Therefore, even if the corners 15f of the four corners of the bottom surface 15e of the lower shell 15 are deformed, it is possible to suppress the lower shell 15 from contacting the lower surface of the battery cell shell 80. Therefore, it is possible to further suppress the battery cell 90 accommodated in the battery cell shell 80 from being damaged when an impact is applied to the lower shell 15.

[0107] In one or more embodiments, Fig.19 As shown, the thickness t11 of the thick wall portion 80c at the four corners of the lower portion of the battery cell case 80 is greater than the thickness t12 of the battery cell case 80 below the longitudinal axis A1 of the battery cell 90. According to the above structure, the strength of the portion of the battery cell case 80 that is likely to be in contact with the lower case 16 can be increased. Therefore, even if the lower case 16 contacts the battery cell case 80, damage to the battery cell 90 accommodated in the battery cell case 80 can be suppressed.

[0108] (Corresponding relationship)

[0109] The battery cells 90a and 90e are examples of “outer battery cells”. The battery cells 90b to 90d are examples of “inner battery cells”. The battery cell holding portion 87a holding the battery cell 90a and the battery cell holding portion 87b holding the battery cell 90b are examples of “first holding portion” and “second holding portion”, respectively.

[0110] (Second embodiment)

[0111] Reference Fig.26 , the battery pack 602 of the second embodiment is described. For the battery pack 602 of the second embodiment, the structure of the lower shell 615 of the outer shell 612 is different from the structure of the lower shell 15 of the outer shell 12 of the battery pack 2 of the first embodiment. In addition, for the battery pack 602 of this embodiment, the size of the battery cell (not shown) accommodated in the outer shell 612 is different from the battery cell 90 accommodated in the outer shell 12 of the first embodiment. Specifically, the battery cell of this embodiment is a 21700 type lithium ion battery cell with a rated voltage of 3.6 [V]. Therefore, the outer shell 612 is larger than the outer shell 12 of the first embodiment. In addition, ten battery cells are accommodated in the outer shell 612, and the connection method of each battery cell is the same as that of the battery pack of the first embodiment. Therefore, the rated voltage of the battery pack 602 of this embodiment is also 36 [V].

[0112] like Fig.26 As shown, two hooks 619a and 619b arranged in the front-to-back direction are provided on the bottom surface 615e of the lower housing 615. According to such a structure, when the user removes the battery pack 2 from the electric tool 200 or the charger 300, the user can use the hook 619 of the two hooks 619a and 619b that is suitable for the length of the user's finger. Therefore, the battery pack 2 can be easily removed from the electric tool 200 or the charger 300.

[0113] Further features of the battery pack disclosed by this specification are as follows.

[0114] (Feature 1)

[0115] A battery pack is a battery pack that can be slidably mounted on an electric tool, wherein the battery pack comprises:

[0116] Terminal 1;

[0117] a second terminal; and

[0118] an outer shell, which accommodates the first terminal and the second terminal,

[0119] The upper surface of the outer shell is provided with a first terminal opening portion provided at a position corresponding to the first terminal and a second terminal opening portion provided at a position corresponding to the second terminal.

[0120] A battery-side recessed portion is provided between the first terminal opening and the upper surface and between the second terminal opening and the upper surface.

[0121] (Feature 2)

[0122] In the battery pack according to feature 1, the battery-side recess has a shape corresponding to a tool-side protrusion of the electric tool.

[0123] (Feature 3)

[0124] In the battery pack according to feature 1 or 2, the first terminal is a discharge terminal.

[0125] The second terminal is a signal terminal.

[0126] (Feature 4)

[0127] A battery pack comprising:

[0128] Terminal 1;

[0129] Terminal 2;

[0130] Terminal 3;

[0131] Terminal 4; and

[0132] an outer shell, which accommodates the first terminal, the second terminal, the third terminal and the fourth terminal,

[0133] The outer shell has a pair of slide rails for sliding and receiving the electric tool.

[0134] A first terminal opening portion provided at a position corresponding to the first terminal, a second terminal opening portion provided at a position corresponding to the second terminal, a third terminal opening portion provided at a position corresponding to the third terminal, and a fourth terminal opening portion provided at a position corresponding to the fourth terminal are provided on an upper surface between the pair of sliding guide rails of the outer shell.

[0135] The first terminal opening, the second terminal opening, the third terminal opening and the fourth terminal opening are arranged in sequence from one of the pair of sliding guides toward the other sliding guide.

[0136] Battery-side recessed portions are provided between the first terminal opening and the upper surface, between the second terminal opening and the upper surface, between the third terminal opening and the upper surface, and between the fourth terminal opening and the upper surface.

[0137] (Feature 5)

[0138] In the battery pack according to feature 4, the battery-side recess has a shape corresponding to a tool-side protrusion of the electric tool.

[0139] (Feature 6)

[0140] In the battery pack according to feature 4 or 5, the first terminal and the fourth terminal are discharge terminals.

[0141] The second terminal and the third terminal are signal terminals.

[0142] (Feature 7)

[0143] A battery pack is slidably mounted on an external device from front to rear, wherein:

[0144] With an outer shell,

[0145] The above-mentioned outer shell has:

[0146] a pair of sliding guides that slide the external device and receive it;

[0147] A terminal opening portion, which is disposed between the pair of sliding guide rails;

[0148] a surface located between the pair of slide rails and further rearward than the terminal opening;

[0149] Vents; and

[0150] The battery-side recessed portion is located between the pair of slide rails and is provided between the surface located rearward of the terminal opening and the vent hole.

[0151] (Feature 8)

[0152] In the battery pack according to feature 7, the battery-side recessed portion has a shape corresponding to a device-side protruding portion of the external device.

[0153] Although the specific examples of the present invention have been described in detail above, these are merely examples and do not limit the claims. The technology described in the claims includes various modifications and changes of the specific examples described above.

[0154] (First Modification)

[0155] Alternatively, the battery cell case 80 may be screwed to the upper case 14 .

[0156] (Second Modification)

[0157] The housing gaps C11 to C13 may be equal to each other. In addition, the housing gaps C11 and C12 may be larger than the housing gap C13.

[0158] (Third Modification)

[0159] The step portion 16 d may not be provided on the bottom surface 15 e of the lower case 15 .

[0160] (Fourth Modification)

[0161] The thick wall portions 80c may not be provided at the four corners of the lower portion of the battery cell case 80. That is, the four corners of the lower portion of the battery cell case 80 may have a shape corresponding to the outer shape of the battery cell 90 when the battery cell case 80 is viewed from the right.

[0162] The technical elements described in this specification or drawings can achieve technical effectiveness alone or in various combinations, and are not limited to the combinations recorded in the claims at the time of application. In addition, the technology exemplified in this specification or drawings can achieve multiple purposes at the same time, and achieving one of the purposes itself has technical effectiveness.

Claims

1. A battery pack, characterized in that: Having an outer shell, The outer shell has: an upper surface provided with a terminal opening for exposing the terminal; bottom surface; and a side surface extending upward from the bottom surface, The four corners of the bottom surface are provided with protrusions protruding downwards, When the battery pack placed on the placement surface is viewed from the side surface, only the protrusion is placed on the placement surface.

2. The battery pack according to claim 1, characterized in that: The four corners include a first corner and a second corner arranged in a first direction relative to the first corner, The battery pack further includes a hook portion provided on the bottom surface and at least partially provided between the first corner portion and the second corner portion.

3. The battery pack according to claim 1 or 2, characterized in that: The four corners include a first corner provided on the bottom surface and the side surface and a fourth corner provided on the bottom surface and the side surface and arranged relative to the first corner in the second direction. The inner wall of the outer shell at the first corner and the fourth corner is located below the inner wall of the outer shell between the first corner and the fourth corner.

4. The battery pack according to any one of claims 1 to 3, characterized in that: The four corners include a first corner provided on the bottom surface and the side surface and a fourth corner provided on the bottom surface and the side surface and arranged relative to the first corner in the second direction. On the side surface, between the first corner portion and the fourth corner portion, a recessed portion is provided which is recessed toward the inner side of the outer shell than the first corner portion and the fourth corner portion. The recessed portion is provided with an opening.

Images