Electric working machine

Patent metadata

Field	Value
Publication number	US-2017246735-A1
Application number	US-201515505597-A
Country	US
Kind code	A1
Filing date	Aug 21, 2015
Priority date	Aug 29, 2014
Publication date	Aug 31, 2017
Grant date	—

Abstract

The present invention provides an electric working machine in which a control board can be disposed without limitations based on a length of a brushless motor in a direction along an axial line. The electric working machine comprises: a brushless motor provided with a rotor and a stator; a motor case and a motor housing in which the brushless motor is stored; a control board which is provided outside of the motor housing in a radial direction of an axial line defined at the center of the rotor, and supports the switching elements; a connection board which is provided in the motor case, and supports the sensors; a through hole provided on the motor case; a through hole provided on the motor housing; and leads and signal lines extending from inside of the motor housing to the outside of the motor housing through the holes.

First claim

1 . An electric working machine comprising:
an electric motor provided with a rotor and a stator; a tubular housing in which the electric motor is stored; a first control unit which is provided outside of the tubular housing in a radial direction of a rotation axis defined at a center of the rotor, and controls the electric motor; a second control unit which is provided in the tubular housing, and controls the electric motor; a through hole provided on the tubular housing; and an electric wire which connects the first control unit with the second control unit, and extends into the through hole.

2 . The electric working machine according to claim 1 , wherein the second control unit is attached to the stator.

3 . The electric working machine according to claim 1 , wherein the second control unit includes: a rotational position detection sensor which transmits signals indicative of a rotational position of the rotor, and a supporting board which supports the rotational position detection sensor.

4 . The electric working machine according to claim 1 , wherein the electric motor comprises coils through which currents flow so as to generate a rotating magnetic field; and the first control unit has switching elements which control the currents flowing through the coils, and a control board on which the switching elements are mounted.

5 . The electric working machine according to claim 4 , wherein the electric motor is a brushless motor, the coils being provided on the stator and the rotor being provided with permanent magnets; and when currents flow through the coils, the permanent magnets and the coils cooperate with each other so as to generate the rotating magnetic field.

6 . The electric working machine according to claim 3 , wherein a fan is attached to the rotor and induces air from outside of the tubular housing into the tubular housing, and the second control unit is disposed between the stator and the fan in a direction along the rotation axis.

7 . The electric working machine according to claim 6 , wherein the fan is provided with a magnetic member, and the rotational position detection sensor detects a magnetic force of the magnetic member and transmits signals indicative of the rotational position of the rotor.

8 . The electric working machine according to claim 6 , wherein air outside of the tubular housing is induced into the tubular housing through the through hole.

9 . The electric working machine according to claim 6 , wherein a bottom portion is provided on an end of the tubular housing in the direction along the rotation axis, and the bottom portion is provided with a ventilation hole in which air outside of the tubular housing is induced into the tubular housing through the ventilation hole.

10 . The electric working machine according to claim 1 , wherein the tubular housing has an insulating inner housing which includes the electric motor, and a conductive outer housing disposed outside of the inner housing in the radial direction;
and the through hole includes a first hole provided in the inner housing and a second hole provided in the outer housing.

11 . The electric working machine according to claim 10 , wherein the inner housing is made of resin and the outer housing is made of aluminum.

12 . The electric working machine according to claim 11 , wherein an insulating holder supports the first control unit, and is provided outside of the outer housing, between the outer housing and the first control unit in the radial direction.

13 . The electric working machine according to claim 12 , wherein the holder has a tubular portion which is provided with the first hole and the second hole, and the electric wire extends into the tubular portion.

14 . The electric working machine according to claim 6 , wherein the fan is a centrifugal fan which transports air induced into the tubular housing outward in the radial direction; and a regulating mechanism is provided to prevent the air transported from the inside outward in the radial direction by the centrifugal fan, to flow back toward the through hole.

15 . The electric working machine according to claim 11 , further comprising:
a working machine main body which supports the electric motor; an operation member which is supported by the working machine main body, and reciprocatively moves along an operation center line which intersects with the rotation axis; a power conversion mechanism which is supported by the working machine main body, and converts the rotational force of the electric motor to a reciprocating force of the operation member; a tip tool which is supported by the working machine main body, and strikes a target; and a hammering element which is supported by the working machine main body, and transmits a hammering force generated by the reciprocating movements of the operation member to the tip tool, wherein the operation center line and the rotation axis are disposed so as to intersect with each other.

16 . The electric working machine according to claim 15 , wherein the working machine main body has an end portion in the radial direction of the operation center line, and the outer housing and the inner housing protrude from the end portion outward in the radial direction of the operation center line.

Assignees

• Hitachi Koki Kk

Inventors

• Hashimoto Hideyuki
• Abe Satoshi
• Yamazaki Shingo
• Nishikawa Tomomasa
• Matsushita Akira

Classifications

• B25D2250/221

  Sensors · CPC title

• B25D11/04 Primary

  in which the tool bit or anvil is hit by an impulse member · CPC title

• B25F5/00

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title

• B25D2211/068

  Crank-actuated impulse-driving mechanisms · CPC title

• H02K5/225

  Terminal boxes or connection arrangements (specially adapted for submersible motors H02K5/132) · CPC title