JP2003209960A - Power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable power tool which is excellent in handling property, operability, and work efficiency, by achieving downsizing and weight reduction while keeping a variety of performances. <P>SOLUTION: The pistol type power tool 1 is composed of an operating part 11 comprising a brushless DC motor 10, a reduction gear mechanism 14, and an output part 15 coupled with the brushless DC motor 10 via the reduction mechanism 14; a grip comprising a switch mechanism 17 equipped with an operation switch and a power source 13; and a drive circuit 20 composed of a control circuit 22 and a power circuit 21. The grip part 12 projects from the operating part 11, the control circuit 22 and the power circuit 21 constituting the drive circuit 20 are separated and arranged within the power tool 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a power tool,
Furthermore, the present invention relates to a portable electric tool equipped with a brassless DC motor.

[0002]

2. Description of the Related Art Conventionally, a power tool such as a portable power screwdriver and a power drill has been generally used as a power tool used for cutting work such as tightening screws and bolts and drilling holes. This electric tool has the functions of adjusting the rotational speed and rotational torque of the drive motor, switching the rotational direction, and the like, and the tip tool can be replaced. BACKGROUND ART A cordless power tool using a brushless DC motor (hereinafter referred to as a DC motor) that uses a rechargeable battery as a power source is small and lightweight, easy to operate, has high performance, is low in noise, and is widely used in households.

An example of a conventional cordless power tool using a DC motor will be described below with reference to the external view of an electric driver drill 100 shown in FIG. Wiring between the components in the drill is omitted in the figure.

The cordless electric screwdriver drill 100 shown in the figure includes a DC motor 110 as a drive source, a speed reduction mechanism section 104 containing a speed reduction mechanism composed of gears for reducing the rotation speed of the DC motor 110, and a speed reduction mechanism section 104. An operating unit 101 including an output shaft 105 connected thereto, a switch mechanism 107 including an operation switch, and a gripping unit 102 having a detachable rechargeable battery 108 as a power source 103 provided on the bottom, The outer shell of the pistol-type driver drill 100 having the portion 102 protruding from the operating portion 101 is formed by a casing 109.

A flat drive circuit board 111 on which a control circuit for driving and controlling the DC motor 110 and a power circuit are mounted is arranged on the bottom side of the DC motor 110.

However, the drive circuit board 111 requires a large board area for mounting the control circuit and the power circuit on one board, and as shown in the figure, the drive circuit board 111 is provided.
Occupies a large housing space below the DC motor 110 and the speed reduction mechanism 104, and also creates a dead space 112 at the rear of the DC motor 110, which makes the operating unit 101 axially long and radially large. Drill 100
The overall size is increased, the weight is increased, the handleability is poor, the workability is deteriorated, and it is not yet sufficiently satisfactory as a portable tool.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and maintains various performances such as tightening and cutting performance using a conventional DC motor, low noise, durability and the like. It is therefore an object of the present invention to provide a portable power tool which realizes a small size and a light weight of the power tool and has good operability and workability.

[0008]

According to a first aspect of the present invention, there is provided a brushless DC motor, a speed reducing mechanism, an operating portion including an output shaft connected to the brushless DC motor and the speed reducing mechanism, and an operation switch. With a switch mechanism,
In a pistol-type electric tool, which comprises a gripping part made up of a power source and a drive circuit part composed of a control circuit and a power circuit, and the gripping part protruding from the operating part, the drive circuit part constituting the driving circuit part. The electric power tool is characterized in that the control circuit and the power circuit are divided and arranged in the electric power tool.

According to the electric power tool of the present invention, since the control circuit and the power circuit constituting the drive circuit section for controlling the drive of the brushless DC motor are divided into two, each circuit is separated from the other in the electric power tool. Can be placed in position.
Then, each of the divided boards is also made smaller, which increases the degree of freedom in selecting the layout of the circuit board by utilizing the empty space in the power tool, realizing the downsizing of the power tool, and reducing the size of the tool. The weight can be reduced.

According to a second aspect of the present invention, one of the control circuit and the power circuit is arranged at a bottom portion of the brushless DC motor, and the other is arranged at a side surface portion of the brushless DC motor. The electric tool according to item 1.

In the electric power tool of the present invention, the size of the tool can be reduced by disposing the circuit board in the space on the side surface of the brushless DC motor. In particular, by arranging the circuit board by utilizing the dead space that is generated behind the conventional brushless DC motor, it is possible to reduce the size in the output shaft direction by utilizing the dead space.

According to a third aspect of the present invention, the switch mechanism and the control circuit are integrated.
The electric power tool described in.

In the electric power tool of the present invention, the switch mechanism and the control circuit are mounted on one board, so that the space can be utilized to reduce the size of the tool while suppressing an increase in the number of parts and the number of assembly steps. it can.

The invention of claim 4 is a cordless power tool using a rechargeable battery.
The power tool according to any one of 1.

In the power tool of the present invention, since the power cord is eliminated, the handleability of the tool is further improved, the operability and workability are further improved, and the cord can be focused on the work and the safety is improved. To do. Further, the power source of the electric tool is not restricted, and the work can be performed without being restricted to the work place.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The internal structure of the embodiment of the present invention shown by the broken line will be described below based on the external view of a cordless electric driver drill 1 shown in the drawings. It should be noted that in the figure, the wiring that connects the components in the drill is omitted.

(First Embodiment) FIG. 1 shows a cordless electric screwdriver drill 1 (hereinafter referred to as drill 1) of the first embodiment.
That is).

The drill 1 shown in the drawing is connected to a DC motor 10 as a drive source, a speed reducing mechanism section 14 containing a speed reducing mechanism composed of gears for reducing the rotation speed of the DC motor 10, and a speed reducing mechanism section 14. An operating unit 11 including an output shaft 15;
A casing 19 forms a pistol-type drill 1 having a switch mechanism 17 having an operation switch 17a and a grip portion 2 provided with a power source 13, and the grip portion 12 protruding from the operating portion 11.

Rechargeable battery 18 which is the power source 13 of the drill 1.
Is removably attached to the lower portion of the grip portion 12, and the rechargeable battery 18 can be freely attached and detached by the bottom portion of the grip portion 12 and the cartridge type detaching means, and is common during power supply to the drill 1 and charging. It is equipped with electrical contacts. Further, the tip 15a of the output shaft 15 is provided with a socket for mounting a tip tool such as a bit or a drill.

The drill 1 has a drive circuit section 20 composed of a control circuit for driving and controlling the DC motor 10 and a power circuit.
The power circuit board 21 on which the power circuit is mounted is arranged on the bottom side of the DC motor 13, and the control circuit board 22 on which the control circuit is mounted is arranged in the rear portion of the DC motor 10.

As shown in the block diagram of the drill 1 of FIG. 2, the drive circuit section 20 receives the electric power from the rechargeable battery 18 according to the operation of the switch 17 to drive and control the DC motor 10, and the switch mechanism. 17 is connected to the drive circuit unit 20, and the control circuit 22 and the power circuit 21 of the drive circuit unit 20 convert the electric power supplied from the battery 18 into a signal instructing the rotation direction and speed, and send the signal to the DC motor 10. The output is sent to the speed reduction mechanism section 14 to drive the output shaft 15.

In the drill 1, the power of the battery 18 is supplied to the power circuit 21 of the drive circuit section 20 by operating the switch 17a.
And the control circuit 22 to the operating unit 11 to control the on / off of the motor 13, the number of revolutions, and the direction of rotation, and to attach a tip tool (not shown) such as a bit or a drill attached to the tip 15a of the output shaft 15. It rotates and tightens screws and bolts, cuts and works such as drilling and breaking, and has performance equivalent to that of a conventional drill having a drive circuit unit made of one substrate.

In the drill 1 having the above-mentioned structure, the power circuit board 21 is substantially housed in the DC motor 10 on the bottom side, and the control circuit board 22 is arranged in the rear part of the DC motor 10 to form the dead space of the conventional DC motor 10. The space in the rear part is utilized, the remaining space can be omitted, and the widths of the power circuit board 21 and the control circuit board 22 can be narrowed.
It becomes a miniaturized product that is shortened in the direction and also reduced in the radial direction.

Further, due to the downsizing of the drill 1, a casing front external view of the drill 1 shown in FIG. 3 and the conventional drill 100 (the tip of the drill is superposed at the same position, and the overlapping portion is shown by a thick solid line). ), The casing outer shape 19a (solid line) of the drill 1 is smaller than the casing outer shape 109a (dashed line) of the drill 100 in the axial direction and the radial direction of the drill operating portion, so that the casing becomes smaller. It is possible to reduce the weight of the drill by reducing the weight.

(Second Embodiment) FIG. 4 shows a cordless electric screwdriver drill 2 (hereinafter referred to as drill 2) of the second embodiment.
That is).

The drill 2 shown in the drawing is connected to a DC motor 30 which is a drive source, a reduction mechanism portion 34 which accommodates a reduction mechanism composed of gears for reducing the rotation speed of the DC motor 30, and a reduction mechanism portion 34. An operating unit 31 including an output shaft 35,
A switch mechanism 37 including an operation switch 37a, a switch mechanism integrated control circuit 43 in which a control circuit portion of a drive circuit portion is integrated, and a grip portion 32 including a power source 33. The pistol-type drill 2 that protrudes is formed by the casing 39.

Rechargeable battery 38 which is the power source 33 of the drill 2.
Is the same battery as in the case of the drill 1, which is detachably provided in the lower part of the grip portion 32, and has a socket for mounting a tip tool such as a bit or a drill at the tip 35a of the output shaft 35. It is provided.

The drill 2 has a drive circuit section 4 composed of a control circuit for driving and controlling the DC motor 30 and a power circuit.
Power circuit board 4 with built-in 0 and a power circuit
1 is mounted on the bottom side of the DC motor 30, and the control circuit is mounted on the switch mechanism integrated control circuit board 43 integrated with the switch mechanism 37, and is arranged in the grip portion 32 behind the switch 37a.

As shown in the block diagram of the drill 2 of FIG. 5, the drive circuit section 40 receives the electric power from the rechargeable battery 38 according to the operation of the operation switch and controls the drive of the DC motor 30. Switch mechanism 3 with
7 and the control circuit 42 of the drive circuit unit 40 are integrated and mounted on the switch mechanism integrated control circuit board 43.
2 and the power circuit 41 convert the electric power supplied from the battery 38 into a signal instructing the rotation direction and speed, and the DC motor 30
To output the output to the deceleration mechanism section 34 to drive the output shaft 35, and has the same function as in the case of the block diagram of FIG. 2 except that the board on which the circuit is mounted and the arrangement thereof are different. .

Therefore, in the drill 2, similarly to the drill 1, the power of the battery 38 is sent to the operation unit 31 through the power circuit 41 and the control circuit 42 of the drive circuit unit 40 by operating the switch 37a, and the motor 30 is turned on. The turning-off, the number of rotations, and the rotation direction are controlled, and a tip tool (not shown) such as a bit or a drill attached to the tip 35a of the output shaft 35 is rotated.

In the drill 2 having the above-mentioned structure, the power circuit board 41 is almost accommodated in the bottom portion of the DC motor 30, and the switch mechanism integrated control circuit board 43 is arranged in the grip portion 32, which is a dead space in the past. DC motor 3
0 No rear space is required, and the switch mechanism integrated control circuit board 43 is utilized by utilizing the empty space of the grip 32.
Will be able to place.

As a result, the drill 2 maintains the shape of the grip portion 32 in the conventional size, and is shortened in the direction of the output shaft 35, and the width of the power circuit board 41 is narrowed to be small in the radial direction. The drill 1 can be made smaller than the drill 1.

Due to the downsizing of the drill 2, a casing front external view of the drill 1 and the drill 2 shown in FIG. 6 and the conventional drill 100 (the tip of the drill is superposed at the same position, and the overlapping portion is shown by a thick solid line). As shown in FIG. 2), the casing outer shape 39a (dotted line) of the drill 2 is smaller than the casing outer shape 109a (dashed line) of the drill 100 by shortening the drill operation portion in the axial direction and the radial direction, and D
The space behind the C motor is saved, and the size is made smaller than that of the casing 19a (solid line) of the drill 1, and the weight reduction effect is further increased due to the size reduction of the drill.

In the power tool of the above invention, the power tool is downsized and lightweight while maintaining excellent performance such as controllability, low noise, durability, maintainability and price of the motor using the DC motor as a drive source. It is an electric power tool that is easy to handle and has excellent workability.

The electric tool of the present invention can be applied to an electric screwdriver, an electric screwdriver drill, an electric drill, an electric impact driver, an electric wrench, and the like.

Further, each of the above-mentioned electric tools is provided with a vibration generating function and a hit generating function for causing a bit or a drill of a tip tool to vibrate or hit, so that it can be used in an electric impact driver, a vibrating drill, and an electric chiseling machine. You can also

In the above embodiment, the electric tool using the detachable rechargeable battery as the power source has been described, but the rechargeable battery is provided in the main body of the electric tool as a power source, for example, the lower side of the handle. It can also be applied to battery-fixed power tools built into parts and the like.

In the above embodiment, the present invention has been described according to the pistol type electric screwdriver drill. However, the divided drive circuit used in the electric power tool of the present invention is not limited to the above electric power tool, and may be an electric drill or an electric power drill. It may be applied and used for electric tools such as canna, electric saw, cutters such as screw cutters and knife cutters, clippers for planting, and sanders and polishers. It can also be used for desktop type electric tools such as small drilling machines.

[0039]

As described above, according to the present invention,
Since the drive circuit of the brushless DC motor is divided into a control circuit and a power circuit and placed in an empty space generated in the power tool, the features of using the brushless DC motor are maintained, and the power tool is made smaller and lighter. It is possible to obtain an electric power tool that is easy to handle and has excellent operability and workability.

[Brief description of drawings]

FIG. 1 is an external view of an electric screwdriver drill according to a first embodiment.

FIG. 2 is a block diagram of a drive circuit unit according to the first embodiment.

FIG. 3 is an outline view comparing the casing shapes of the drills of the first embodiment.

FIG. 4 is an external view of an electric screwdriver drill according to a second embodiment.

FIG. 5 is a block diagram of a drive circuit unit according to a second embodiment.

FIG. 6 is an outline view comparing the casing shapes of the drills of the second embodiment.

FIG. 7 is an external view of a conventional electric screwdriver drill.

[Explanation of symbols]

1,2 ... Electric screwdriver drill 10, 30 ... Brushless DC motor 11,31 …… Operating part 12, 32 ... Grip 13, 33 ... Power supply 14,34 ...... Reduction mechanism 15, 35 ... Output shaft 17,37 ... Switch mechanism 20, 40 ...... Drive circuit 21, 41 ... Power circuit (power circuit board) 22, 42 ... Control circuit (control circuit board) 43 ... Control circuit integrated with switch mechanism

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5H019 AA07                 5H605 BB05 BB10 CC08 DD09 EC13                       EC14 EC20

Claims (4)

[Claims] 1. A brushless DC motor, a speed reduction mechanism,
The brushless DC motor and an output unit connected via the speed reduction mechanism, an operating unit, a switch mechanism including an operation switch, a grip unit including a power supply, a control circuit and a power circuit. A pistol type electric tool comprising a drive circuit section, the grip section protruding from the operating section, wherein the control circuit and the power circuit constituting the drive circuit section are divided and arranged in the electric tool. An electric tool that is characterized by 2. The electric motor according to claim 1, wherein one of the control circuit and the power circuit is disposed at a bottom portion of the brushless DC motor, and the other is disposed at a side surface portion of the brushless DC motor. tool. 3. The electric power tool according to claim 1, wherein the switch mechanism and the control circuit are integrated. 4. The power tool according to claim 1, which is a cordless power tool using a rechargeable battery.