Battery pack and electrical apparatus

Abstract

To improve the strength and wear resistance of a latch mechanism of a battery pack.SOLUTION: A metal reinforcing member (plate 70) is provided at a part of a hook component 60 which is a component constituting a latch mechanism of a battery pack and is formed by integrally molding a synthetic resin. The hook component 60 includes: a hook part 65 to be engaged with an electric apparatus body; an operation part 61 to be operated for moving the hook part 65; and a connection part 63 and a coupling part 64 for coupling the hook part 65 and the operation part 61. The second member 70 reinforcing the first member is manufactured by bending a metal plate into a predetermined shape by press working and casting it into a synthetic resin.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] In recent years, the lineup of battery packs with higher capacity and power output of battery cells, and higher output and larger electric devices such as power tools, has been increasing. Patent Document 1 describes a battery pack having a latch mechanism for preventing the battery pack from falling off the main body of the electric device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-38720 A Summary of the Invention [Problem to be solved by the invention]

[0004] As the output of products increases, the vibration transmitted to the battery pack increases, and as the battery pack becomes larger and heavier, the impact force on the battery pack when dropped, etc. increases, and there is a growing concern that the battery pack components will be damaged, so increasing the strength of the components is an issue. Hook components that engage with power tools are particularly susceptible to the above concerns, and when the engagement surface of the hook component wears out due to vibration, the battery pack can move to a position outside of its design, and the conductive parts of the product and the battery pack separate, causing malfunctions. In addition, when an impact is applied from a certain direction, the impact is concentrated on the engagement surface of the hook component, so there is a risk that the hook component cannot withstand it and may break.

[0005] The present invention has been made in view of the above-mentioned background, and has an object to provide a battery pack and an electrical device in which wear and damage to a latch mechanism is suppressed. Another object of the present invention is to provide a battery pack and an electrical device having a latch mechanism that has improved strength and wear resistance by using improved hook components without changing the structure or size of the latch mechanism. [Means for solving the problem]

[0006] Representative features of the invention disclosed in this application are as follows. According to one feature of the present invention, a battery pack includes a battery cell, a case that houses the battery cell, and a latch mechanism that is movable relative to the case and engages with an electrical device body, the latch mechanism including a hook portion that engages with the electrical device body, an operating portion that operates the hook portion, and a connecting portion that connects the hook portion and the operating portion. In the latch mechanism, the hook portion, the operating portion, and the connecting portion are made of a first member, and a second member different from the first member is provided on the hook portion and the connecting portion for reinforcing the first member. The battery pack is configured to be attached to the electrical device body by sliding in a first direction, and the hook portion has a front outer surface located on the front side in the first direction and contacting the electrical device body when the battery pack is slid in the first direction, and a rear outer surface located on the rear side in the first direction and engaging with the electrical device body to prevent the battery pack from falling off from the electrical device body when the battery pack is attached to the electrical device body. The second member, which serves as a reinforcing member, is provided on the front outer surface and the rear outer surface.

[0007] According to another feature of the present invention, the connecting portion of the latch mechanism extends from the operating portion in a direction intersecting the first direction and is configured to be able to contact the main body of the electrical device, and the second member is provided at a contact portion of the connecting portion that is able to contact the case. The first member is resin, and the second member is a member having higher strength or wear resistance than resin, such as metal. The second member is cast into the first member by insert molding. The second member may be provided partially in the hook portion and the connecting portion.

[0008] According to yet another feature of the present invention, a substrate to which battery-side terminals that are to be connected to device-side terminals of the electrical device main body are connected is provided above the battery cells of the battery pack, and the latch mechanism is located above the substrate. The hook portion and the connecting portion that are provided above the substrate and facing the substrate are mainly composed of a first member, and a second member is provided above the first member. In this manner, an electrical device is configured that includes a battery pack and an electrical device main body having a battery pack mounting portion to which the battery pack can be mounted. Effect of the Invention

[0009] According to the present invention, it is possible to provide a battery pack and an electric device in which wear and breakage of the latch mechanism is suppressed. In addition, it is possible to provide a battery pack and an electric device having a latch mechanism with improved strength and wear resistance by using an improved hook part without changing the structure or size of the latch mechanism. In addition, in order to reduce wear of the hook part as much as possible, a highly wear-resistant part such as a metal plate is interposed in the hook part of the latch mechanism and its vicinity, thereby increasing the wear and strength of the hook part. Furthermore, the interposed part with high wear resistance is effective in preventing wear of the hook engagement surface when the product is attached and preventing breakage of the hook engagement shape. If the hook part is located close to a current-carrying part such as a board and the entire hook part is made of a metal material, there is a risk that the hook part will move and approach the board part when disengaged from the main body of the electric device, causing a short circuit. However, in the present invention, a metal plate or the like is cast into a resin material, so that a short circuit will not occur even if the resin material part of the hook part comes into contact with the current-carrying part such as a board. Furthermore, in the case of a structure in which there is a distance between the claw shape where the hook part engages with the product and the operating part, it is possible to expect an increase in the strength of the arm shape between the claw shape and the operating part. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing the shape of a battery pack mounting portion 10 of an electric device body 1 to which a battery pack 20 of the present invention is mounted. [Diagram 2]2 is a partial right side view showing a state in which a battery pack 20 according to the present embodiment is attached to the electrical device body 1 of FIG. 1. FIG. [Diagram 3] FIG. 1 is a perspective view of a battery pack 20 of the present invention. [Figure 4] 2 is a perspective view of a hook component 60 of the battery pack 20 of the present invention. FIG. [Diagram 5] 5 is a horizontal cross-sectional view of the hook component 60 of FIG. 4 at the vertical center position. [Figure 6] 5 is a perspective view showing the shape of a plate 70 cast into the hook component 60 of FIG. 4. FIG. [Figure 7] 3 is a partial cross-sectional view showing an engaged state and a disengaged state between a hook part 60 of the battery pack 20 of the first embodiment and an electric device main body 1. FIG. [Figure 8] 1 is a cross-sectional view showing an engagement state between a hook component 60 according to a first embodiment of the present invention and an electric device body 1. FIG. [Figure 9] FIG. 11 is a diagram showing a second embodiment of the present invention, and is a partial cross-sectional view showing the states when the hook component 60 and the rail portion 14 on the electric device body 1A side are engaged with and disengaged from each other. [Figure 10] FIG. 13 is a diagram showing a third embodiment of the present invention, and is a partial cross-sectional view showing the states when hook part 260 and rail part 214 on electric device body 201 are engaged with and disengaged from each other. [Figure 11] 1 is a perspective view showing the shape of a hook component 160 of a conventional battery pack. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same parts are given the same reference numerals, and repeated explanations will be omitted. In addition, in this specification, the front, back, left, right, and up and down directions will be described as directions shown in the drawings.

[0012] FIG. 1 is a perspective view showing the shape of a battery pack attachment section 10 of an electric device main body 1. The electric device main body 1 is an apparatus for operating a load section that consumes electric power, such as a motor, a light source, an audio device, and a heat source, using a battery pack 20 (described later in FIG. 2 and subsequent figures) as a power source. The electric device main body 1 has a housing 2 that accommodates the load section. The electric device main body 1 of FIG. 1 is an impact driver, and is provided with a handle section that extends downward from a body section of the housing 2, and the battery pack attachment section 10 is formed below the handle section. A trigger switch 4 is provided on the handle section. An anvil (not shown) serving as an output shaft is provided on the front side of the housing 2, and a tip tool holder 5 for attaching a tip tool 6 is provided on the tip of the anvil. In this example, a Phillips screwdriver bit is attached as the tip tool 6.

[0013] Not only in power tools, but also in general electrical devices using a battery pack, a battery pack mounting section 10 is formed to correspond to the shape of the battery pack to be mounted. In the electrical device main body 1 of FIG. 1, a battery pack mounting section 10 for mounting a battery pack 20 is formed in a part of the housing 2. In the battery pack mounting section 10, rail sections 12, 14 extending in parallel in the front-rear direction are formed on the inner wall sections on both the left and right sides. The front-rear length, width (vertical length) and shape of the rail sections 12, 14 are formed to fit the mountable battery pack 20, and are configured so that an incompatible battery pack cannot be mounted. A hollow section 12d is provided in the inner section of the rail section 12 to reduce weight. Since the formation of the hollow section 12d is not essential, the hollow section 12d does not have to be provided. Although not shown in the figure, a hollow section 14d (see FIG. 7(d) described later) is also provided in the inner section of the rail section 14.

[0014] A terminal section 16 is provided between the rail sections 12, 14. The terminal section 16 is manufactured by integral molding of a non-conductive material such as synthetic resin, and a plurality of metal terminals, for example, an apparatus-side positive terminal 17, an apparatus-side negative terminal 18, and an LD terminal (abnormality signal terminal) 19, are cast into the terminal section 16. The terminal section 16 is formed with a vertical surface 16a that serves as an abutment surface in the mounting direction (front-rear direction) and a horizontal surface 16b, which is adjacent to and faces an upper surface 34 (described later in FIG. 3) when the battery pack 20 is mounted. A protrusion 10a that engages with a recessed portion 36 (described later in FIG. 3) of the battery pack 20 is formed on the front side of the horizontal surface 16b.

[0015] FIG. 2 is a part of a right side view showing a state where the battery pack 20 according to this embodiment is attached to the electric device body 1 of FIG. 1. In the example of FIG. 2, a battery pack attachment section 10 formed at the lower part of a handle section of a known impact tool is partially illustrated. The battery pack 20 can be attached to the electric device body 1 by moving the battery pack 20 from a predetermined direction to the electric device body 1 along the rail section in the attachment direction. In this specification, the state where the battery pack 20 is attached to the electric device body 1 is called an "electric device", but the electric device body 1 in a state where the battery pack 20 is removed may also be called an "electric device". When the battery pack 20 is attached to the electric device body 1 to a predetermined position in the battery pack attachment direction (in this specification, the direction of the arrow 25 is called a "first direction"), a latch mechanism operates to fix the battery pack 20 so that it does not fall off the electric device body 1. When removing the battery pack 20 from the electrical device main body 1, the operating parts 51 (see FIG. 3), 61 of the latch mechanism are pressed, and then the battery pack 20 is moved in the battery pack removal direction opposite to the battery pack installation direction 25 (in this specification, the direction of the arrow 26 is referred to as the "second direction").

[0016] FIG. 3 is a perspective view of the battery pack 20. The housing of the battery pack 20 is made of a non-conductive synthetic resin, and is formed of a lower case 21 and an upper case 30 that can be separated in the vertical direction. The upper case 30 is formed with two rail grooves 42, 46 for fitting with the rails 12, 14 (see FIG. 1) formed in the battery pack mounting portion 10 of the electrical device body 1. The rail grooves 42, 46 are formed to be parallel and continuous in the front-rear direction, and the surface connecting the upper sides of the space sandwiched between them is the upper stage surface 34. A flat lower stage surface 32 is formed on the front side of the upper case 30, and the lower stage surface 32 and the upper stage surface 34 are formed in a stepped shape, and the connection portion between them is a stepped portion 33 having a vertical surface that descends in a stepped shape from the upper stage surface. A slot group arrangement region 40 is formed from the stepped portion 33 to the upper stage surface 34, and a plurality of slots are formed therein such that they are cut out from the front to the rear. The multiple slots are cut out portions having a predetermined length in the battery pack attachment direction so as to extend rearward from the step portion 33, and each cut-out portion is provided with multiple battery side terminals (not shown) that can engage with device side terminals of the electrical device main body 1 or an external charging device (not shown).

[0017] A protruding portion 35 is formed on the rear side of the upper surface 34. The protruding portion 35 has an outer shape that protrudes upward from the upper surface 34, and the space inside the protruding portion 35 is a space for the latch components 50, 60 to slide and move. A recessed portion 36 is formed near the center of the protruding portion 35. The recessed portion 36 is a surface that is abutted against the protrusion 10a (see FIG. 1 ) of the battery pack mounting portion 10 when the battery pack 20 is mounted on the battery pack mounting portion 10, and when the protrusion on the electric device main body 1 moves relatively to a position where it abuts against the recessed portion 36, multiple terminals (device side terminals) arranged on the electric device main body 1 and multiple connection terminals arranged on the battery pack 20 come into contact with each other and are electrically connected. At the same time, the operating portions 51, 61, hook portions 55 (not visible in the figure), and hook portions 65 of the hook parts 50, 60 of the battery pack 20 pop out in the left and right directions within the recesses of the rail groove portions 42, 46 due to the action of a spring not shown, and engage with the recesses 13, 15 formed in the rail portions 12, 14 of the electrical device main body 1, thereby preventing the battery pack 20 from falling off from the electrical device main body 1.

[0018] The rail groove 42 is a portion formed so as to be recessed from the right side wall surface of the battery pack 20 toward the left-right center point, and is formed continuously from the front to the rear of the battery pack 20. Similarly, the rail groove 46 is a portion formed so as to be recessed from the upper end of the left side wall surface of the battery pack 20 toward the left in the direction perpendicular to the left side wall surface, and is formed linearly from the front to the rear of the battery pack 20. The front end of the rail grooves 42, 46 is an open end, and the rear end is a closed end connected to the front wall surface of the protruding portion 35. The rail grooves 42, 46 and the hook portions 55, 65 that fit into the recesses of the rail portion on the electric device body 1 side form the fixing portion of the latch mechanism. When the battery pack 20 is removed from the electric device body 1, the operation portions 51, 61 of the latch mechanism on both the left and right sides are pressed to release the engagement state of the hook portions 55 (not shown in the figure), 65 for latching with the recesses of the rail portion on the electric device body 1 side, and the battery pack 20 is moved in this state in the opposite direction to the mounting direction.

[0019] FIG. 4 is a perspective view of the hook component 60 of the battery pack 20 of the present invention. The hook component 60 has two main parts. One is a hook part 65 that engages with a recess 15 formed in the rail part 14 of the electric device body 1, and the other is an operation part 61 that is operated by an operator to move the hook part 65. To connect these two main parts, a connecting part 64, a front connection part 63, and a rear connection part 62 are formed. The operation part 61 is a part that an operator presses with his / her finger, and a number of small grooves 61a extending in parallel in the vertical direction are formed in the part that the operator's finger touches to prevent slipping. The outer end of the spring 39 (the left end on the hook component 60 side) is connected to the back side of the operation part 61, so that the repulsive force of the compression spring 39 urges the operation part 61 outward (leftward) from the center position of the battery pack 20 in the left-right direction. The spring 39 is arranged so that the inner end of the spring 39 abuts against a wall surface (abutment surface) 37 formed inside the upper case 30. The latch mechanism including the hook parts 50 and 60 and the spring 39 is fixed to the upper case 30 side when the upper case 30 and the lower case 21 of the battery pack are removed. The shape of the spring 39 and the wall surface 37 is arbitrary, and the shape shown in FIG. 4 is a schematic diagram for explaining the operation of the hook part 60. The hook part 60 can be moved inward (to the right in the case of the left hook part 60) by the operator's pushing, and the hook part 60 moves outward (to the left) by the repulsive force of the spring 39 when the pushing operation is released. The outward movement of the hook part 60 stops at a limit position where it abuts against a part of the wall surface of the upper case 30. Incidentally, the mechanism for guiding the sliding movement of the hook part 60 and the mechanism for determining the limit position for the leftward movement of the hook part 60 may be the same as a conventional latch mechanism, and therefore detailed explanations thereof will be omitted here.

[0020] The connecting portion 64 is a portion that holds a hook portion 65 that extends from the front connection portion 63 of the operating portion 61 to the front side (first direction side) and is configured to be able to contact the electrical device body 1. The hook portion 65 has a surface (a rear outer surface 65c described later in FIG. 5) that intersects (for example, perpendicular to) the outer surface 64a portion of the connecting portion 64. When the operating portion 61 moves in the pressing direction 49b, the hook portion 65 also moves to the right together with the movement of the operating portion 61. For comparison, the shape of a hook component 160 of a conventional battery pack will be described with reference to FIG. 11. In FIG. 11, the hook component 160 is manufactured by integral molding of a synthetic resin. As is obvious when comparing the conventional hook component 160 shown in FIG. 11 with the hook component 60 of this embodiment shown in FIG. 4, the only difference between them is whether or not a metal plate 70 is provided on the hook portion 65. The metal plate 70 is provided to reinforce the hook component 60, and is particularly provided on the surface that comes into contact with the mating member, that is, the surface that comes into contact with the recess 15 of the rail portion 14 of the electric device body 1.

[0021] The plate 70 is provided so as to extend partly to a part of the connecting portion 64 extending rearward from the hook portion 65. In this way, by interposing a highly wear-resistant part (plate 70) formed of a metal plate or the like in the hook portion 65, wear of the hook portion 65, which is a part of the hook part 60 that is easily damaged, can be minimized. The hook part 60 can be manufactured by casting the plate 70 (insert molding) during injection molding of the conventional hook part 160 made of synthetic resin. In addition, the shape of the plate 70 is not a simple flat shape, but is a shape that follows the shape of the hook part 65, so that the outer edge shape of the hook part 65 can be maintained the same as the conventional shape by the outer surface of the plate 70. Therefore, by replacing the conventional hook part 160 shown in FIG. 11 with the hook part 60 of this embodiment shown in FIG. 4, the battery pack 20 to which the present invention is applied can be easily realized.

[0022] FIG. 5 is a horizontal cross-sectional view (a cross-sectional view seen from below) of the hook part 60 in FIG. 4 at the vertical center position. In this specification, the various parts of the hook part 60 are referred to as in FIG. 5. The part indicated by the hatched portion above the two-dot chain line is referred to as the operation part 61. The operation part 61 is a part pressed by an operator, and is a part protruding outward from the inner opening of the through hole 48 (see FIG. 1) of the upper case 30. The hook part 65 is a part protruding outward from the vertical plane passing through the outer surface 64a of the connecting part 64, that is, the part indicated by the hatched line outside (left side) the one-dot chain line. The hook part 65 is a part that engages with the device to be mounted, that is, the electric device main body 1, and is a part that engages with the recess 15 formed in the rail part 14 of the electric device main body 1. The hook portion 65 and the operating portion 61 are connected by a connecting portion 64, and move to a position where it protrudes from the upper case 30 of the battery pack 20 into the rail groove portion 46 (see FIG. 3) and a position where it does not protrude as the operating portion 61 moves (here, in the left-right direction). The hook portion 65 is located on the front side (first direction side) of the hook component 60, and is formed to have a front outer surface 65a that is first in contact with the electric device body 1 when the battery pack 20 is slid in the first direction, a rear outer surface 65c that is located on the rear side of the front outer surface 65a and acts to prevent the battery pack 20 from falling off from the electric device body 1 when the battery pack 20 is attached to the electric device body 1, and a curved surface 65b between the front outer surface 65a and the rear outer surface 65c. In this specification, the front outer surface 65a and the curved surface 65b are sometimes collectively referred to as the "front outer surface" in a broad sense, and this "front outer surface" refers to the portion that pairs with the rear outer surface 65c.

[0023] The connecting portion 64 is located inside (on the right side) of the dashed line in FIG. 5. The connecting portion 64 extends in the front-rear direction of the battery pack 20, and connects the hook portion 65 and the operation portion 61 at a certain distance. The front connection portion 63 is a portion that fills the portion between the connecting portion 64 and the operation portion 61, and adjusts the left-right position of the operation portion 61 relative to the connecting portion 64, and serves as a guide surface that guides the movement of the hook portion 65. The rear connection portion 62 serves as a guide surface that guides the movement of the hook portion 65, and further serves as a wall portion that separates the space that houses the spring 39 (see FIG. 4) together with the front connection portion 63 located opposite to the front side. The rear connection portion 62 is formed with a stopper portion 62a that protrudes rearward in a rib shape. The outer surface of the stopper portion 62a and the rear portion of the outer surface 64a of the connecting portion 64 abut against the wall portion of the upper case 30, thereby limiting the movement of the hook part 60 in the direction protruding from the through hole 48 of the upper case 30 (see Figure 3).

[0024] The plate 70 is disposed in the portion shown in black in FIG. 5. In this embodiment, the plate is shaped so that the outer surface of the hook portion 65 on the outside of the claw portion matches the outer surface of the plate 70, and the plate is cast in resin. The plate 70 extends rearward from near the front end position of the hook portion 65 along the outer surface of the hook portion 65, and is disposed so as to cover more than half of the outer surface (left side surface) of the connecting portion 64. The plate 70 is provided to reinforce the synthetic resin (first member) that constitutes the hook component 60, and is composed of a second member different from the first member. Here, a metal is used as the second member, and is cast in the first member.

[0025] FIG. 6 is a perspective view showing the shape of the plate 70 provided in the hook part 60 of FIG. 4. The plate 70 is made of a metal plate having strength and high wear resistance, such as a stainless steel alloy. Here, a stainless steel plate of a predetermined thickness is cut out by pressing and bent into the shape shown in the figure. The plate 70 is formed in a vertically symmetrical shape so that it can be used commonly for the right hook part 50 and the left hook part 60. The plate 70 is formed of two main parts: a part (71a-71c, 72, 73a, 73b) that fits along the outer surface of the hook part 65, and a part (74-75) that fits along the outer surface of the connecting part 64. In FIG. 6(c), the side part of the hook part 65 is formed with a vertical plane 71a, a curved surface 71b, and a vertical plane 71c from the front side, which form the front outer surface of the hook part 65 and are arranged on the front outer surface 65a of the hook part 65 (see FIG. 5). The rear surface 72 extending in the up-down and left-right directions is formed on the rear surface of the hook portion 65, and is disposed on the rear surface 65c of the hook portion 65 (see FIG. 5). The vertical size of the rear surface 72 is formed to be substantially equal to the vertical size of the corresponding portion of the hook portion 65 (rear surface 65c). On the other hand, the vertical size of the front surface (vertical plane 71a, curved surface 71b, vertical plane 71c) is formed to be smaller than the vertical size of the corresponding portion of the hook portion 65 (front surface 65a). The vertical size of the front surface is reduced in order to increase the fixing stability of the plate 70 during casting. Therefore, if there is no problem with strength or durability, the vertical size of the front surface of the plate 70 may be formed to be equal to the vertical size of the corresponding portion of the hook portion 65.

[0026] In FIG. 6(b), the portion that is aligned with the outer surface of the connecting portion 64 is formed by the curved portion 74 and the extending flat portion 75. As can be seen from FIG. 4, the positional relationship between these portions and the hook component 50 is less than half the vertical size of the connecting portion 64. This is because the outer surface of the connecting portion 64 does not abut against the upper case 30, so there is no need to increase the wear resistance. In addition, by narrowing the vertical width, the upper and lower edges of the connecting portion 64 and the extending flat portion 75 are cast into synthetic resin, so that the plate 70 is fixed more stably. Thus, in this embodiment, the curved portion 74 and the extending flat portion 75 are provided on the plate 70 in order to stably cast the plate 70 placed on the hook portion 65 into a resin member and to make use of the strength of the plate 70. Furthermore, in order to stabilize the fixation by casting into resin, through holes 76a, 76b, 77a, and 77b are formed in the plate 70, and the synthetic resin that is the main component of the hook component 60 is filled therein.

[0027] Fig. 7 is a partial cross-sectional view showing an engaged state and a disengaged state between the hook part 60 of the battery pack 20 of the present embodiment 1 and the electric device main body 1. These cross-sectional views are horizontal cross-sections passing near the vertical center of the hook part 60 located on the left side of the battery pack 20, viewed from below. Fig. 7(a) shows the state immediately before the battery pack 20 is moved in the first direction (front side) and attached to the electric device main body 1, (b) shows the state in which the battery pack 20 has been moved in the first direction (front side) and attached to the electric device main body 1, and (c) shows the state in which the battery pack 20 has been slightly moved in the second direction (rear side) without being released from the latch.

[0028] The hook part 60 is disposed so that the operation part 61 protrudes outward from the through hole 48 formed in the upper case 30 of the battery pack 20 and the hook part 65 protrudes from the latch hole 47 of the rail groove part 46. This position of the hook part 60 is due to the force of the spring 39 (not shown). In this state, the rail groove part 46 of the battery pack 20 is moved relatively to the electric device body 1 while being aligned with the rail part 14 of the electric device body 1. Then, the outer surface (mainly the curved surface 71b) on the front side having the tip corner of the hook part 65 of the hook part 60 abuts against the inner corner part 14b of the rail part 14 of the electric device body 1. Both the curved surface 71b and the inner corner part 14b are formed obliquely with respect to the mounting direction of the battery pack 20, so that a force is applied to move the hook part 60 inward (to the right in the case of the hook part 60) by the abutment therebetween, and the hook part 65 moves more inward than in FIG. 7(a). Then, the right end face of the hook portion 65 is positioned inside the inner corner 14b of the rail portion 14, so that the interference between the hook portion 65 and the rail portion 14 in the mounting direction of the battery pack 20 is released, and the battery pack 20 can be inserted in the first movement direction up to a specified position as shown in Figure 7(b).

[0029] The position of the battery pack 20 in the mounting direction is restricted, for example, by a part of the upper case 30 abutting against the tip 14a of the rail portion 14. At this time, the front end of the hook portion 65 is located in an area that fits into the recess 15 formed in the rail portion 14, so the hook part 60 moves outward (to the left) due to the action of a spring (not shown), resulting in the state shown in FIG. 7(b). Note that the front-rear direction of the battery pack 20 (shown in FIG. 7) and the front-rear direction of the electrical device body 1 (shown in FIG. 1) are opposite to each other. In the state shown in FIG. 7, the hook portion 65 is located inside the recess 15, so that even if a force acts to move the battery pack 20 in the second direction, the rear outer surface 72 of the plate 70 provided on the hook portion 65 comes into contact with the front surface 15a of the recess 15 as shown in FIG. 7(c), so that the battery pack 20 can be prevented from falling off the electrical device body 1.

[0030] 4, the outward movement of the hook component 60 due to the biasing force of the spring 39 is limited by contact between the portion of the upper case 30 indicated by the arrow 30b and the connecting portion 64, and by contact between the portion of the upper case 30 indicated by the arrow 30c and the stopper portion 62a. On the inner surface of the hook component 60, two parallel guide ribs 38 extending from the upper wall portion of the upper case 30 are formed, and are positioned so that the guide ribs 38 can come into contact with the front connecting portion 63 and the rear connecting portion 62. In addition, a spring 39 (see FIG. 4) is disposed in a space enclosed by the two guide ribs 38, the front connecting portion 63, the rear connecting portion 62, and the operating portion 61.

[0031] 7, wearing of the hook portion 65 can be effectively prevented by casting an intermediate part (plate 70) on the surface of the hook portion 65 that serves as the engagement surface with the electric device body 1. Furthermore, in a battery pack 20 that can be attached to the electric device body 1 simply by pushing the battery pack 20 in a first direction without operating the operating unit 61, by using the hook portion 65 with the plate 70 cast therein according to this embodiment, wearing of the portion of the hook portion 65 that first comes into contact when pushed in can be prevented, and an increase in the battery pack attachment load due to deterioration of the claw-shaped surface can be suppressed, thereby realizing a battery pack 20 with a long life.

[0032] FIG. 8 is a cross-sectional view showing the engagement between the hook component 60 and the electric device body 1 according to the first embodiment of the present invention, showing a vertical cross-sectional view passing near the center in the front-rear direction of the connecting portion 64 of the hook component 60. This vertical cross-section is a surface extending in the left-right and up-down directions of the battery pack 20. Five battery cells are accommodated in the battery pack 20, and the second battery cell 92 from the front is arranged at the cross-sectional position of FIG. 8. The battery cells 92 and the like are aligned by an insulator 80 made of synthetic resin so that their longitudinal directions face the left-right direction. A circuit board 90 is fixed between the insulator 80 and the upper wall of the upper case 30. A circuit pattern is formed on the circuit board 90, and electronic elements such as a microcomputer, resistors, and capacitors (not shown) are mounted thereon, and a battery side terminal (not shown in the figure) that establishes an electrical connection by engaging with an equipment side terminal formed on the electric device body 1 is fixed thereon. Both side terminals of the series connection of multiple battery cells are connected to the circuit board 90 by connection tabs (not shown), and power is supplied to battery side terminals (+ terminal, - terminal) (not shown) via a wiring pattern (not shown) of the circuit board 90. The operating portion 61 of the hook component 60 is shaped to protrude to the left beyond the upper case 30, and the lower end positions of the hook portion 65 (not visible in the figure) and the connecting portion 64 are located at approximately the same position as the lower end position of the circuit board 90.

[0033] FIG. 8(b) is a diagram showing a state where the operating part 61 is pushed inward (toward the center of the battery case in the lateral direction) from the state shown in FIG. 8(a), and the operating part 61 is pushed inward beyond the outer edge of the upper case 30. As can be seen by comparing the positions of the connecting part 64 of the hook part 60 in FIG. 8(a) and (b), the connecting part 64 moves inward beyond the bottom of the rail groove part 46 (however, since the cross-sectional position in FIG. 8 corresponds to the position of the latch hole 47 of the rail groove part 46, there is no vertical wall forming the bottom surface of the groove). The hook part 65 (see FIG. 7), which is in a position not visible in the figure, retreats to the inside of the upper case 30 to a state where it does not protrude beyond the bottom surface of the rail groove part 46. As described above, when the operator pushes in the operating part 61 of the hook part 60, the hook part 65 (see FIG. 7) is disengaged from the electrical device main body 1.

[0034] 3 to 9, the hook part 60 located on the left side of the battery pack 20 has been described, but the hook part 50 located on the right side has the same structure except that its shape is symmetrical. As described above, according to this embodiment, the hook parts 50 and 60 of the battery pack 20 can be significantly strengthened, so that it is possible to cope with an increase in vibration transmitted to the battery pack 20 as the electric device body 1 becomes higher in output, and also to cope with a phenomenon in which the impact force on the battery pack 20 increases when the battery pack 20 is dropped, etc. as the battery pack 20 itself becomes larger and heavier. Furthermore, since the hook parts 50 and 60 can be reinforced by the metal plate 70, it is possible to significantly suppress wear and damage (breakage) of the engagement surface of the hook part 65 that engages with the electric device body 1, and it is possible to avoid the occurrence of a phenomenon in which the battery pack 20 moves to a position outside the design with respect to the electric device body 1. If the battery pack 20 moves to this undesigned position, the device side terminal of the electric device main body 1 and the connection terminal of the battery pack 20 may separate, causing malfunction, so the hook members 50, 60 of this embodiment are effective in preventing such malfunction. In the first embodiment, the hook parts 50, 60 are configured to be reinforced with the metal plate 70, but it is also possible to configure the rail parts 12, 14 on the electric device main body 1 side to be reinforced with a metal plate. An example of this will be described with reference to Fig. 9. EXAMPLES

[0035] FIG. 9 is a view showing a latch mechanism according to a second embodiment of the present invention. Here, the configuration of the battery pack 20 side is the same as that of the first embodiment, and the hook part 60 is the same part as that shown in FIGS. 4 to 7. The tip of the rail part 14 of the electric device body 1A and the vicinity of the recess 15 are reinforced by providing a metal plate 170. The plate 170 is basically made of the same material and by the same manufacturing method as the plate 70 shown in FIG. 6 except for the shape, and is formed by cutting out a metal thin plate into a predetermined shape by pressing and bending it. The plate 170 is fixed by casting it into the rail part 14 during insert molding of the synthetic resin housing 2 (see FIG. 1). The plate 170 is provided at a location that contacts the hook part 65 or a location where a strong force is applied by contact with the hook part 65. Here, the plate 170 covers the outer surface of a part of the tip part 14a of the rail part 14, the inner corner part 14b of the tip, and a part of the front surface 15a and the side surface 15b of the recess 15. The vertical size of the plate 170 may be the same as the height of the rail portion 14, or the height of the plate 170 may be smaller than the height of the rail portion 14.

[0036] The plate 170 is insert molded together with the resin constituting the rail portion 14 so as to be exposed on the outer surface of the rail portion 14 so as to abut against the plate 170 on the hook component 60 side. The shape of the plate 170 is a shape that combines, from the front side, a left-right vertical 171, an inclined surface 172, a front-rear vertical surface 173, a left-right vertical surface 174, and a front-rear vertical surface 175. The connecting portion from the left-right vertical surface 174 to the front-rear vertical surface 175 is curved along the front surface 15a to the side surface 15b of the recess 15. Note that, although FIG. 9 only describes the shape of one rail portion 14 formed on the electric device main body 1A, the shape of the other rail portion 12 is the same, and the shape of the rail portion 12 on the left side of the electric device main body 1A is symmetrical to that in FIG. 9. In the second embodiment, metal plates 70, 170 are provided on both the hook components 50, 60 and the rail portions 12, 14 at the locations where they come into contact with each other, thereby further increasing strength and improving wear resistance. EXAMPLES

[0037] FIG. 10 is a diagram showing a third embodiment of the present invention, and is a partial cross-sectional view showing the state when the hook part 260 and the rail part on the electric device body 201 side are engaged and released. The battery pack mounting part of the third embodiment has a shape different from that of the battery pack mounting part 10 of the electric device body 1, 1A of the first and second embodiments. The hook part 260 protrudes from the upper surface of the battery pack 220 toward the electric device body 201 to which the battery pack 220 is to be mounted, thereby engaging with a latch recess 215 formed on the battery pack mounting surface 214 of the electric device body 201 to restrict the movement of the battery pack 220. Here, the hook part 260 is a movable member that can slide up and down relative to the battery pack 220. FIG. 10(a) is a diagram showing a state immediately before mounting the battery pack 220, (b) is a diagram showing a state during mounting (a state in which the hook part 260 is lowered in the direction of the arrow 281), and (c) is a diagram showing a state in which mounting of the battery pack 220 to the electric device body 201 is completed (a state in which the latch mechanism is activated).

[0038] In FIG. 10(a), the latch mechanism of the battery pack 220 includes a hook part 260 that can move in the vertical direction. The hook part 260 is formed near the rear end of the upper surface of the battery pack 220, near the center in the left-right direction. Also, unlike the first and second embodiments, the number of hook parts 260 used is one. The hook part 260 is made of synthetic resin and includes an operating part 261 and a hook part 265. The operating part 261 and the hook part 265 are connected by a connecting part 264. A metal plate 270, which is a reinforcing member, is provided on the outer surface of the hook part 265 of the hook part 260. That is, a slope 271 of the plate 270 is formed on the slope on the front side of the hook part 265, and a vertical surface 27 of the plate 270 is formed on the vertical surface on the rear side. A slight horizontal surface 272 is formed between the slope 271 and the vertical surface 273 of the plate 270. Plate 270 is shaped to fit the outer surface of hook portion 265, and is manufactured by being cast in during molding of synthetic resin (first member). Plate 270 extends not only to the portion located inside latch recess 215, but also to the portion located inside battery pack 220, i.e., the portions indicated by arrows 274 and 275 in Fig. 10(b). Arrow 275 portion of plate 270 is shaped to bend at a right angle to the plane extending from arrow 273 to 274, thereby greatly increasing the strength of plate 270.

[0039] A recess 215 is formed on the electrical device body 201 side corresponding to the hook portion 265 of the hook component 260. The shape of a vertical cross section passing through the left-right center position of the recess 215 corresponds to the shape of the hook portion 265, as can be seen from Figures 10(a) and (b). The recess 215 has vertical planes 215a and 215d between the front and rear, a slope 215b extending obliquely upward from the upper end of the vertical plane 215a, and a horizontal plane 215c having a narrow width in the front-rear direction is formed between the slope 215b and the vertical plane 215d.

[0040] When battery pack 220 is moved in the first movement direction (mounting direction) from the position shown in Fig. 10(a), inclined surface 271 of plate 270 comes into contact with corner 214a of battery pack mounting surface 214. Corner 214a and inclined surface 271 are both inclined surfaces, and hook part 260 is movable downward, so that latch part moves in the direction of arrow 281 as shown in Fig. 10(b). As a result of this movement, the interference state between the upper end of hook part 265 and the lower end of corner 214a is released, and battery pack 220 can be moved further in the first direction. Normally, the impact caused when corner 214a and inclined surface 271 hit each other hard would result in a force that distorts hook part 260, but in this embodiment, the portions of plate 270 indicated by arrows 273-275 are bent at right angles, so that plate 270 can effectively receive the reaction force transmitted to the opposite side to the first direction, thereby significantly increasing the strength of hook part 260.

[0041] When the battery pack 220 is further moved in the first direction from the state of FIG. 10(b) and the hook portion 265 reaches a position below the recess 215, the hook portion 265 moves upward as indicated by the arrow 282 by the biasing force of a spring (not shown), and the hook portion 265 enters the inside of the recess 215. At this time, the portion that abuts against the inner surface of the recess 215 abuts against the plate 270, so that wear of the resin portion of the hook portion 265 can be effectively suppressed. As described above, in this embodiment, the hook portion 265, the operation portion 261, and the connecting portion 264 are made of a first member (synthetic resin), and the hook portion 265 and the connecting portion 264 are reinforced with a second member (e.g., a metal plate 270) for reinforcing the first member, so that a latch mechanism with improved strength and wear resistance can be realized.

[0042] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the present invention. For example, the shape of the hook parts 60, 260 is arbitrary, and the shapes of the claw parts (hook parts) and the connecting parts, and the shape of the reinforcing member (second member) cast therein can be freely configured. Furthermore, the type of the electric device main body is arbitrary, and any electric device main body can be combined with the battery pack 20, 220 as long as it is compatible with the battery pack 20, 220 to be installed. [Explanation of symbols]

[0043] 1, 1A Electrical device body 2 Housing 4 Trigger switch 5 Tool holder 6 Tool 10 Battery pack attachment 10a protrusion 12 rail portion 13 recess 14 rail portion 14a Tip 14b Inner corner 14c Inner tip 14d Hollow portion 15 Recess 15a Front surface (of recess) 15b (recess) side surface 15c (recess) rear surface 16 Terminal portion 16a Vertical surface 16b Horizontal surface 17 Positive terminal on device side 18 Negative terminal on device side 19 LD terminal 20 Battery pack 21 Lower case 23a~23d Screw holes 25 Battery pack installation direction (first direction) 26 Battery pack removal direction (second direction) 30 Upper case 32 Lower surface 33 Step portion 34 Upper surface 35 Raised portion 36 recess 37 wall 38 guide rib 39 spring 40 slot group arrangement area 42, 46 rail groove portion 47 latch hole 48 through hole 49b pressing direction 50 hook part 51 operating part 55 Hook portion 60 Hook part 61 Operating portion 61a Groove 62 rear connection portion 62a stopper portion 63 front connection portion 64 Connection portion 64a Outer surface 65 Hook portion 65a (the hook portion) front outer surface 65b (the hook portion) curved surface 65c (hook portion) rear outer surface 70 plate (second member) 71a Vertical plane 71b Curved surface 71c Vertical plane 72 Rear outer surface 73a Top wall 73b Bottom wall 74 Curved part 75 Extended flat part 76a, 76b, 77a, 77b Through hole 80 insulator 90 circuit board 92 battery cell 160 Hook part (first member) 170 Plate 171 Left-right vertical 172 Inclined surface 173 Front-back vertical surface 174 Left-right vertical plane 175 Front-back vertical plane 201 Electrical equipment body 214 Battery pack mounting surface 214a Corner 215 Recess 215a Vertical plane 215b Slope 215c Horizontal plane 215d Vertical plane 220 Battery pack 260 Hook parts 261 Operating section 264 Connecting section 265 Hook section 270 Plate (second component) 271 Slope 272 Horizontal surface 273 Vertical surface (upper side) 274 Vertical surface (lower side) 275 Top surface of connection part

Claims

1. A battery cell; a case that houses the battery cell; a latch mechanism movable relative to the case and adapted to engage with a main body of an electrical device; A battery pack configured to be slid and attached to the electrical device body in a first direction, the latch mechanism includes an operating portion operated by an operator, a hook portion operated by the operating portion and located forward of the operating portion in the first direction and engaging with the electrical device body, and a connecting portion having an outer surface, extending from the operating portion in the first direction to connect the hook portion and the operating portion, The hook portion is configured to extend from the connecting portion in a direction intersecting the first direction, a front outer surface that is located on a front side in the first direction and that comes into contact with the electrical device body when the battery pack is slid in the first direction; a rear outer surface located rearward of the front outer surface and adapted to engage with the electrical device body so as to prevent the battery pack from falling off the electrical device body when the battery pack is attached to the electrical device body; having the hook portion, the operation portion, and the connecting portion are formed of a first member, A second member different from the first member and reinforcing the first member is provided on the front outer surface, the rear outer surface, and the outer surface of the connecting portion. A battery pack characterized by:

2. 2. The battery pack according to claim 1, The first member is a resin, and the second member is a member having strength or abrasion resistance higher than that of the resin. A battery pack characterized by:

3. A battery pack according to claim 1 or 2, The second member is a metal plate that extends rearward from the front outer surface along the outer surface of the hook portion and is disposed so as to span the outer surface of the connecting portion. A battery pack characterized by:

4. 4. The battery pack according to claim 3, The plate is made of metal and is cast into the resin that constitutes the first member. A battery pack characterized by:

5. A battery pack as claimed in claim 3, the plate has a first portion adapted to fit along an outer surface of the hook portion and a second portion adapted to fit along the outer surface of the connecting portion, The vertical size of the first portion disposed on the front outer surface is smaller than the vertical size of the front outer surface. A battery pack characterized by:

6. A battery pack as claimed in claim 3, the plate has a first portion adapted to fit along an outer surface of the hook portion and a second portion adapted to fit along the outer surface of the connecting portion, The vertical size of the second portion disposed on the outer surface of the connecting portion is smaller than the vertical size of the outer surface. A battery pack characterized by:

7. 7. The battery pack according to claim 6, a substrate having a battery side terminal connected to an equipment side terminal of an electric device body, the battery side terminal being connected to the equipment side terminal of the electric device body, the substrate being provided above the battery cell; the connecting portion is located above the battery cell, from a side of the board to an upper portion of the board; The second portion is located above the substrate in the vertical direction. A battery pack characterized by:

8. The battery pack according to claim 1 or 2, an electrical device body having a battery pack mounting portion into which the battery pack can be mounted; An electrical device comprising:

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