JP2010058182A - Power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power tool which solves such a problem that it is troublesome to attach a screw and the strength of a switching element is small. <P>SOLUTION: In the power tool, the strength of a switching element is improved and the switching element, a circuit board and a cooling fin are easily mounted by making screws passing through a hole of the switching element, a hole of the cooling fin and a hole of the circuit board common. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power tool. In particular, the present invention relates to a power tool having a cooling element that has a switching element for driving a brushless motor and can cool the switching element.

  A power tool having a brushless motor requires a switching element for driving the brushless motor. Since this switching element generates heat, it is necessary to cool in order to prevent the switching element from being damaged by the generated heat. For the cooling, a cooling fin is proposed. An electric tool having a brushless motor is disclosed in Patent Document 1.

JP2007-196363

  The cooling fin needs to be adjacent to the switching element in order to cool the switching element. In addition, the switching element is mounted on the circuit board but is configured to be fixed to the power tool, and thus the strength is higher than that of the switching element is fixed to the circuit board. Further, the circuit board needs to be fixed to the electric tool.

  Therefore, a method of fixing the cooling fin to the electric tool with a first screw and fixing the circuit board to the electric tool with a second screw can be considered.

  However, depending on such a configuration, there is a problem that it takes time to install screws and the strength of the switching element is small.

  An object of the present invention is to provide an electric tool that can increase the strength of a switching element and facilitate the mounting of the switching element, a circuit board, and a cooling fin.

  The above object is, as in the present invention, a brushless motor having a rotor having a rotating shaft and a stator, a plurality of switching elements for energizing the brushless motor, and a cooling fin capable of cooling the switching elements, A circuit board on which the switching element is mounted; a speed reduction mechanism connected to the rotating shaft; a housing accommodating the brushless motor and the speed reduction mechanism; and a connection to the speed reduction mechanism for performing a predetermined operation. A power tool having a tip tool, wherein the switching element is provided with a first hole, the cooling fin is provided with a second hole, and the circuit board is provided with a third hole, The switching element, the cooling fin, and the circuit board are formed in the housing by a screw that passes through the first hole, the second hole, and the third hole. By being fixed against, it is achieved.

  According to the present invention, the strength of the switching element can be increased, and an electric tool in which the switching element, the circuit board, and the cooling fin can be easily attached can be provided.

  An embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a partial cross-sectional view of an electric driver drill 1 as an example of an electric tool showing an embodiment of the present invention. As shown in FIG. 1, the driver drill 1 has a housing 2. The housing 2 has a body 2 </ b> A that houses a brushless motor 5 and a speed reduction mechanism 6 that is connected to the brushless motor 5. Further, the housing 2 has a grip 2B extending downward from the body portion 2A. A battery connection portion 2C is provided below the grip 2B. A storage battery 3 is detachably attached to the battery connection part 2C by a battery operation part 3A. A light 10 is provided in front of the battery housing portion 2C.

  An operable trigger 4 is provided in front of the vicinity of the connecting portion between the body portion 2A and the grip 2B. When the trigger 4 is operated, power is supplied from the storage battery 3 to the brushless motor 5.

  The brushless motor 5 is connected to the speed reduction mechanism unit 6. The speed reduction mechanism unit 6 is connected to the clutch mechanism unit 7. The clutch mechanism portion 7 is connected to a tip tool holding portion 8 that can hold a tip tool (not shown) by a claw 8A.

  The speed change switch 9 can change the reduction ratio between the brushless motor 5 and the tip tool holding portion 8 by a mechanism (not shown) of the reduction mechanism.

  The rotor 201 of the brassless motor 5 is supported by the bearing 11A so as to be rotatable on the rear side with respect to the housing 2, and is supported so as to be rotatable on the front side with respect to the housing 2 by means of a soaking pad 11B.

  FIG. 2 is an enlarged partial sectional view of only the vicinity of the brushless motor 5 of FIG. The brushless motor 5 includes a stator portion 100 fixed to a housing by a structure (not shown), a rotor portion 200 that is partially rotatable inside the stator portion 100, and a circuit board portion that can energize the stator portion.

  The stator portion 100 has a protrusion whose outer diameter is not shown, and has an iron core 101 fixed to the housing 2 by the protrusion. The iron core 101 has an insulator 102 provided so as to cover the iron core 101 and insulated from the iron core 101, and a coil wound around the insulator 102. The insulator 102 has a radial portion 102A extending in a direction perpendicular to the axial direction of the rotation shaft 201 of the rotor 200, which will be described later, and a radial portion 102A extending in a direction parallel to the axial direction of the rotation shaft 201 at a rear portion thereof. And an axial portion 102B. Six screw holes 102B1, 102B2, 102B3, 102B4, 102B5, and 102B6 are provided in the axial portion 102B. In FIG. 2, two screw holes 102B2 and 102B4 are shown.

  A part of the rotor 200 is accommodated in the stator 100. The rotor 200 includes a rotating shaft 201 having the rotation center of the rotor 200, a rotor core 202 fixed to the rotating shaft 201, a permanent magnet 202 fixed to the rotor core, and a cooling fixed to the rotating shaft 201. And a fan 203. A bearing for rotatably supporting the rotor 200 on the housing is provided at the rear end of the rotating shaft 201. A pinion connected to the speed reduction mechanism unit is fixed to the rotation shaft 201 at the front end of the rotation shaft 201. Between the pinion and the cooling fan 203, a bearing that rotatably supports the rotor 200 with respect to the housing is provided on the front side.

  The circuit board unit 300 includes a circuit board 303, a cooling fin 302 that contacts the circuit board 303 via an insulator 305, and a switching element 301 that contacts the aluminum cooling fin. Six switching elements 301A, 301B, 301C, 301D, 301E, and 301F are provided. In FIG. 2, switching elements 301B and 301E are shown. The switching element 301B is connected to the circuit board 303 via the legs 301B2. As shown in FIG. 3, the switching element 301B is connected to the circuit board 303 by three legs 301B1, 301B2, and 301B3.

  In addition, a hall element 307 is provided on the front side of the circuit board, and the rotation of the rotor 200 can be monitored by outputting a signal by the rotation of the permanent magnet 203.

  As shown in FIG. 3, aluminum cooling fins 302 </ b> A having good heat conductivity are provided on the front side of the switching elements 301 </ b> A, 301 </ b> B, and 301 </ b> C and on the rear side of the circuit board 303. The cooling fin 302A is provided above, but the cooling fin 302B is similarly provided below.

  An insulator 305 is provided between the cooling fin 302A and the circuit board 303 so that energization does not occur between the substrate 303 and the cooling fin 302A. The switching element 301B is provided with a hole 301B4 above it. The cooling fin 302 is provided with three holes 302A1, 302A2, 302A3 in the vicinity of the upper side thereof. In FIG. 2, 302A2 is shown. Further, the circuit board 303 is provided with holes 303B1, 303B2, 303B3, 303B4, 303B5, and 303B6 above the rotation axis 201 and substantially concentrically. The switching element 301B, the cooling fin 302A, and the circuit board 303 are fixed to the screw hole 102B2 by screws 304B.

  The circuit board 303 has a substantially circular shape, and a through hole 303A through which the rotation shaft 201 passes is provided near the center thereof. In addition, coil connection portions 303C1, 303C2, 303C3, 303C4, 303C5, and 303C6 that are connected to the coil 103 are provided at the left and right positions in the center of the circuit board 303. A connector 306 is provided at the lower end of the circuit board 303.

  3 is a view in the direction of arrow B in FIG.

  Each of the six switching elements 301 is attached to the screw holes of the radial portion 102 of the insulator 102 through the six holes of the cooling fins 302A and 302B and the six holes of the circuit board 303 by screws. Each of the six switching elements 301 is electrically connected to the circuit board 303 with three legs.

  Thus, the strength of the switching element can be increased by fixing the switching element 301, the cooling fin 302 and the circuit board 303 to the insulator 102 fixed to the iron core 101 fixed to the housing 2 with screws. It is possible to provide a power tool that facilitates mounting of an element, a circuit board, and a cooling fin.

  Further, by providing the screw fixing portion 102B for attaching the screw to the axial direction portion 102B extending the insulator 102 in the axial direction, the screw can be fixed with a simple structure without providing the screw fixing portion other than the insulator. be able to.

  The operation of the power tool of the present invention will be described.

  When the trigger 4 is operated, electricity is supplied from the storage battery 3 to the switching element 301 and electricity is supplied to the six coils 103. Thereby, the permanent magnet 202 of the rotor 200 receives a force, and the rotor 200 rotates. By rotation of the rotor 200, outside air can be taken into the housing from the outside of the housing through a wind window (not shown), and the cooling fins 302 can be cooled by the wind. For this reason, the heat generated in the switching element 301 can be dissipated through the cooling fin, and the switching element 301 is less likely to be damaged.

  In the embodiment of the present invention, the switching element, the cooling fin, and the circuit board are fixed to the insulator fixed to the housing with screws. However, the switching element, the cooling fin, and the circuit board are fixed to the housing with screws. If it is a structure, the effect of this invention can be show | played. For example, the structure which provides a screw hole in a housing may be sufficient. For example, the structure which provides a screw hole in the inner cover fixed to a housing may be sufficient.

  In the present invention, the switching element, the cooling fin, and the circuit board are fixed to the insulator by screws, but any fixing means may be used. As an example of the fixing means, it may be clamped, fitted, or embedded. Any fixing means can provide the effects of the present invention as long as it is based on one fixing means.

  Moreover, although it was set as the structure which can be electrically fed to a brushless motor with a rechargeable battery, it is also possible to comprise this invention also with a commercial AC power supply.

  Moreover, although the electric driver drill was demonstrated to the example as an example of the electric tool of this invention, another electric tool may be sufficient. For example, an electric drill, an electric impact driver, an electric circular saw, an electric hammer drill, an electric hammer, an electric grinder, an electric jigsaw, an electric tabletop circular saw, an electric garden tool, or any other electric tool may be used.

1 is a partial sectional view of a driver drill showing an embodiment of the present invention. 1 is a partial sectional view of a brushless motor constituting one embodiment of the present invention. B direction arrow view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Driver drill, 2 Housing, 3 Storage battery, 4 Trigger, 5 Brushless motor, 6 Deceleration mechanism part, 7 Clutch mechanism part, 8 Tip tool holding part, 9 Shift switch, 10 Light, 101 Iron core, 102 Insulator, 103 Coil, 201 Rotating shaft, 202 Rotor core, 203 Permanent magnet, 204 Pinion, 301 Switching element, 302 Cooling fin, 303 Circuit board

Claims (8)

A stator having an iron core and an insulator that insulates the iron core from the coil;
A rotor having a rotating shaft and rotatable within the stator;
A switching element capable of energizing the coil;
A cooling fin capable of cooling the switching element;
A circuit board to which the switching element is connected,
The circuit board extends in a direction perpendicular to the rotation axis, and is fixed to the insulator;
The cooling fin is located on the side opposite to the stator with respect to the circuit board,
The power tool according to claim 1, wherein the switching element is located on a side opposite to the circuit board with respect to the cooling fin.   The electric power tool according to claim 1, wherein the switching element, the cooling fin, and the circuit board are fixed to the stator by one fixing means. The switching element is provided with a first hole, the cooling fin is provided with a second hole, and the circuit board is provided with a third hole,
The switching element, the cooling fin, and the circuit board are fixed to the insulator by screws that pass through the first hole, the second hole, and the third hole. The electric tool according to claim 1. A brushless motor having a rotor having a rotating shaft and a stator;
A switching element for energizing the brushless motor;
A cooling fin capable of cooling the switching element;
A circuit board on which the switching element is mounted;
A housing that houses the brushless motor;
A power tool connected to the brushless motor and performing a predetermined work,
The switching element is provided with a first hole, the cooling fin is provided with a second hole, and the circuit board is provided with a third hole,
The switching element, the cooling fin, and the circuit board can be fixed to the housing by a single screw that passes through the first hole, the second hole, and the third hole. An electric tool characterized by that. The stator has an iron core fixed to the housing, an insulator fixed to the iron core and insulated from the iron core, and a coil wound through the insulator,
The fixing means is a screw;
The power tool according to claim 4, wherein the screw is fixed to the insulator. The rotor is housed inside the stator, and the circuit board is provided with a through hole through which the rotating shaft passes,
The rotor is provided with a permanent magnet,
The circuit board is provided with a hall element capable of monitoring the rotation of the permanent magnet,
By extending the insulator in the rotation axis direction, a screw fixing portion is provided,
The power tool according to claim 5, wherein the screw is fixed to the screw fixing portion. A brushless motor having a rotor having a rotating shaft, a stator having a coil and an insulator, and
A switching element for energizing the brushless motor;
A cooling fin capable of cooling the switching element;
A circuit board on which the switching element is mounted;
A housing that houses the brushless motor;
A power tool connected to the brushless motor and performing a predetermined work,
The power tool characterized in that the switching element, the cooling fin, and the circuit board can be fixed to the housing by one fixing means. A brushless motor having a rotor having a rotating shaft, an iron core, an insulator fixed to the iron core and insulated from the iron core, and a stator wound around the insulator;
A switching element for energizing the brushless motor;
A cooling fin capable of cooling the switching element;
A circuit board on which the switching element is mounted;
A housing that houses the brushless motor;
A power tool having a tip tool connected to the motor and performing a predetermined work,
The cooling fin extends along the circuit board, the switching element extends along the board,
The electric power tool, wherein the circuit board, the cooling fin, and the switching element are provided in the housing in this order.

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