JP2010000566A - Power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power tool that prevents a switching device driving a brushless motor from being damaged. <P>SOLUTION: The power tool has: the brushless motor which comprises a stator core, an insulator for insulation installed on a stator core, a coil wound around the insulator, and a rotor inserted into the insulator; and a housing which accommodates an end tool for performing a prescribed work with the torque from the brushless motor, a substrate screwed on the insulator, and the brushless motor, wherein a switching device driving the brushless motor is disposed on one surface of the substrate, from which the thread is protruded, the amount of the thread protrusion being greater than the thickness of the switching device on the substrate, and thereby the switching device is prevented from being damaged. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a power tool having a brushless motor and having a switching element for driving the brushless motor.

  An electric tool having a brushless motor and having a switching element for driving the brushless motor is known. For example, FIG. 8 of Patent Document 1 described below discloses a technique in which an output transistor as a switching element is provided on a substrate.

JP2007-196363

  The technique disclosed in Patent Document 1 described above does not disclose a switching element that drives a brushless motor, a method for attaching the substrate, and a state of attachment.

  A switching element for driving a brushless motor in a conventional electric tool may be easily damaged by contact with surrounding members when an unexpected impact is applied to the electric tool.

  An object of this invention is to provide the electric tool which can prevent the switching element which drives a brushless motor from being damaged.

  The above object is achieved by a brushless motor having a stator core, an insulating insulator attached to the stator core, a coil wound around the insulator, and a rotor inserted into the insulator, and a rotational force of the brushless motor. A power tool having a tip tool for performing a predetermined operation, a substrate screwed to the insulator, the brushless motor, and a housing for accommodating the substrate, wherein the brushless motor is provided on one surface of the substrate. A switching element capable of driving the switching element is provided, and on one surface on which the switching element is provided, the protrusion amount of the screw from the substrate can be achieved by being larger than the thickness of the switching element on the substrate. .

  A brushless motor having an insulator, a coil wound around the insulator, and a rotor inserted into the insulator; a tip tool for performing a predetermined operation by the rotational force of the brushless motor; and the brushless motor. A power tool having a substrate on which a switching element to be driven is provided, wherein the substrate is held by a substrate holder, and the substrate holder is provided with a wall projecting from the substrate; In one surface on which the switching element is provided, the protruding amount of the wall from the substrate can be achieved by being larger than the thickness of the switching element on the substrate.

  According to the power tool of claim 1, on one surface on which the switching element is provided, the projecting amount of the screw from the substrate is larger than the thickness of the switching element on the substrate, so that the power tool is unexpectedly impacted. In some cases, the other elements come into contact with the screws protruding earlier than the switching elements, so that the switching elements can be prevented from being damaged.

  According to the fourth aspect of the present invention, since the projection amount of the wall from the substrate is larger than the thickness of the switching element on the substrate on one surface where the switching element is provided, the electric tool is unexpectedly impacted. In this case, since the other members are in contact with the wall protruding earlier than the switching element, it is possible to prevent the switching element from being damaged.

  FIG. 1 shows an embodiment of the present invention.

  In FIG. 1, a direction connecting the tip tool holding portion 7 capable of holding a tip tool (not shown) and the brushless motor 10 is defined as a front-rear direction, and a direction connecting the brushless motor 10 and the storage battery 3 is defined as a vertical direction. The tip tool holding part is provided in the front, and the brushless motor 10 is provided in the rear. The brushless motor is provided on the upper side, and the storage battery is provided on the lower side.

  FIG. 1 shows an electric impact driver 1 that is an electric tool in which a brushless motor 10 is accommodated in a housing 2. The housing 2 includes a motor housing portion 2B that houses the brushless motor 10 and a grip portion 2C. A storage battery 3 is detachably provided below the grip portion 2C so as to be connected to the housing 2. Further, a trigger 4 is provided in the vicinity where the grip 2C and the motor housing portion 2B are connected to each other in the front. A brushless motor 10, a speed reduction mechanism 5, and an impact mechanism 6 are provided inside the motor housing 2B. A part of the tip tool holding part 7 is accommodated in the motor housing, but the other part protrudes forward from the motor housing 2B.

  The brushless motor 10 includes a stator core 10A, an insulating insulator 10A1 attached to the stator core and provided with resin, a coil 10B wound around the insulator, and a rotor 10C rotatable inside the insulator 10A. . The rotor 10C is provided with a shaft 10C2 and a magnet 10C1 which are rotating shafts. The rotor 10C is rotatably held on the housing 2 by a ball bearing 10E and a ball bearing 10F fixed to the housing 2. A fan 10D is provided in a non-rotatable manner on the shaft 10C2 in front of the magnet 10C1 and rearward of the bearing 10F. The stator core 10A is fixed in the motor housing 2B by a rib (not shown).

  A pinion is provided in front of the shaft 10 </ b> C <b> 2 and the speed reduction mechanism unit 5 is connected thereto. An impact mechanism section 6 is provided in front of the speed reduction mechanism section 5, and the tip tool holding section 7 can be struck in the rotation direction.

  The insulator 10A1 of the brushless motor 10 is provided with a screw boss (not shown) so that a screw can be attached. As shown in FIG. 1, a substrate 11 is attached to an insulator 10A1.

  FIG. 2 is a view taken along the line AA in FIG.

  The substrate 11 has a hole portion 11A substantially in the middle thereof, and the shaft 10C2 passes through the hole portion 11A. As shown in the figure, the FET 13 which is a switching element is provided on the rear surface of the substrate 11. The screw 12 is inserted into the board from the rear side and is attached to the insulator 10A1. The screw head protrudes rearward from the board 11. All six FETs 13 for driving the brushless motor 10 are provided on the substrate 11.

  The operation of the first embodiment of the present invention will be described.

  When an operator attaches the storage battery 3 to the housing 2 in a charged state, grips the grip housing 2C, and operates the trigger 4, power is supplied to the FET 13 that is a switching element by a power line housed inside the grip housing 2C. Then, electric power is supplied from the FET 13 to the coil 10B. The coil 10B is excited by the electric power supplied to the FET 13, and the rotor 10C provided with the magnet 10C1 rotates. The rotation of the rotor 10 </ b> C causes the fan 10 </ b> D to rotate, and air flows into the housing 2 from a hole (not shown) behind the motor housing 2. Further, the rotation is transmitted to the speed reduction mechanism unit 5 connected to a pinion provided in front of the shaft 10C2 that is non-rotatably attached to the rotor 10C. The rotation is transmitted from the speed reduction mechanism unit 5 to the impact mechanism unit 6, and the impact is transmitted to the tip tool holding unit 7.

  An operator grips the grip housing 2C and operates the trigger 4, but the electric impact driver 1 may be dropped unexpectedly or hit an object. In such a case, the electric impact driver 1 receives an impact unexpectedly.

  Referring to FIG. 1, comparing the size of the FET 13 projecting backward from the substrate and the size of the screw 12 projecting backward from the substrate, the amount of the screw 12 projecting backward from the substrate 11 is as follows. large. As described above, since the relationship between the substrate 11, the screw 12 and the FET 13 is configured, when the housing 2 is unexpectedly impacted, the housing 2 or other members inside the housing collide with the FET 13. Even if an attempt is made, the FET 13 can be prevented from being damaged by an impact because it hits the screw 12 first.

  A second embodiment of the present invention will be described with reference to FIG.

  In FIG. 3, the FET 113 serving as a switching element is accommodated below the grip housing 2 </ b> C. Thus, since the FET 113 and the substrate 111 are provided below the grip housing 2C, the motor housing 2B does not become large. For this reason, unlike the first embodiment, electric power is supplied from the FET 113 located below the grip housing 2C to the coil 10B.

  As shown in FIG. 3, the FET 113 is provided on the upper surface of the substrate 111. The periphery of the substrate is covered with a wall 112 of the substrate holder. The wall 112 is configured to extend from the outer periphery of the substrate 111 in a direction perpendicular to the substrate. The wall 112 of the substrate holder is fixed to the housing 2 at a position not shown. In addition, an operation unit 114 that can be operated by a push-type button is connected to the substrate 111 so that an operator can appropriately operate it.

  FIG. 4 shows a BB line arrow view of FIG.

  As shown in the figure, all six FETs 13 capable of driving the brushless motor 10 are provided on the upper surface of the substrate 111. In addition, an operation unit 114 including push buttons 114A and 114B is provided in front of the substrate 111.

  As shown in FIG. 3, when the amount of protrusion of the wall 112 upward from the substrate 111 is compared with the amount of protrusion of the FET 13 upward from the substrate 111, the wall 112 protrudes upward from the substrate 111. The magnitude of the quantity is larger. For this reason, even when an impact is applied to the electric impact driver, such as when the operator is operating the electric impact driver, before the collision with the FET 113 by the housing 2 or other members, Since it collides with 112, the FET 13 can be prevented from being damaged by impact.

  In the embodiment of the present invention, the electric impact driver has been described as an example of the electric tool, but the present invention can be applied to other electric tools. For example, even if it is an electric driver drill, an electric vibration drill, an electric circular saw, an electric grinder, etc., if it has a brushless motor, it is applicable.

  Moreover, although this invention was set as the structure which protects FET with the wall of a screw and a substrate holder, the member which protrudes from another board | substrate is set as the structure which protrudes from a board | substrate rather than FET, and also as a structure which protects FET of this invention An effect can be produced.

The electric tool which shows the 1st Embodiment of this invention. AA arrow view of FIG. The electric tool which shows the 2nd Embodiment of this invention. BB line view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric impact driver, 2 Housing, 3 Storage battery, 4 Trigger, 5 Reduction mechanism part, 6 Impact mechanism part, 7 Tip tool holding part, 10 Brushless motor, 11 Board | substrate, 12 Screw, 13 Switching element (FET)

Claims (6)

A brushless motor having a stator core, an insulating insulator attached to the stator core, a coil wound around the insulator, and a rotor inserted into the insulator;
A tip tool for performing a predetermined operation by the rotational force of the brushless motor;
A substrate to be screwed to the insulator;
An electric tool having the brushless motor and a housing for accommodating the substrate,
On one surface of the substrate, a switching element capable of driving the brushless motor is provided,
1. The electric tool according to claim 1, wherein a protruding amount of the screw from the substrate is larger than a thickness of the switching element on the substrate on a surface on which the switching element is provided. The tip tool is provided in front of the brushless motor,
The substrate is provided behind the brushless motor,
The substrate has the switching element on a rear surface,
The insulator is attached to the insulator from behind,
The power tool according to claim 1, wherein a protruding amount of the screw from the board to the rear is larger than a thickness of the switching element from the board to the rear.   The power tool according to claim 1, wherein six switching elements are provided, and all of the switching elements are provided on the substrate. A brushless motor having a stator core, an insulating insulator attached to the stator core, a coil wound around the insulator, and a rotor inserted into the insulator;
A tip tool for performing a predetermined operation by the rotational force of the brushless motor;
A power tool having a substrate on which a switching element for driving the brushless motor is provided;
The substrate is held by a substrate holder;
The substrate holder is provided with a wall protruding from the substrate,
1. The electric tool according to claim 1, wherein a protruding amount of the wall from the substrate is larger than a thickness of the switching element on the substrate on a surface on which the switching element is provided. The brushless motor is housed in a motor housing;
A grip that can be gripped by an operator is provided below the motor housing,
A power supply unit is provided at the bottom of the grip,
The switching element is provided on an upper surface of the substrate;
The wall is provided to protrude upward from the substrate,
The electric power tool according to claim 4, wherein a protruding amount of the wall upward from the substrate is larger than a thickness of the switching element upward from the substrate.   6. The power tool according to claim 4, wherein six switching elements are provided, and all of the switching elements are provided on the substrate.

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