Hitachi Koki Co., Ltd.

Koki Holdings Co., Ltd.

Kenichirou Yoshida

Hideyuki Tanimoto

Kazutaka Iwata

Shinji Kuragano

Katsuhiro Oomori

Yoshihiro Komuro

Hayato Yamaguchi

Tomomasa Nishikawa

Akira Onose

Takuya Konnai

Junichi Kamimura

Takuma Nonaka

Takashi Kawamata

Nobuhiro Takano

Kazuhiko Funabashi

Shinichi Sakamoto

Atsushi Nakagawa

Takao Aradachi

Shinji Watanabe

Yoshikazu Kawano

Tomoyoshi Yokota

Mizuho Nakamura

Toshiaki Koizumi

Shinji Takano

Yoshio Osada

Hiroto Inagawa

Teruo Imai

Kenji Niwa

Satsuo Sato

Kenji Fukuda

Satoshi Shimada

Youichi Kawamura

There is provided an electric power tool having a plurality of operation modes with different rotation speeds at least in a predetermined load range. The electric power tool is capable of switching between the operation modes when a predetermined condition is satisfied even during a motor is driven, and configured such that a rotation speed of the motor is changed smoothly or in a stepwise manner at the switching between the operation modes.

Electric power tool

A portable electric cutter includes a housing in which a motor is accommodated, a saw blade driven to rotate by the motor, a base coupled to the housing and having a bottom surface slidable on a surface of a material to be cut, a fan driven to rotate by the motor, a driving circuit for switching power supplied to the motor, and a control circuit for controlling the driving circuit. A circuit board on which the driving circuit, the control circuit and others are mounted is provided, motor cooling air vents are provided in the housing on a side opposite to the saw blade, and circuit board cooling air vents are provided in the housing on the side opposite to the saw blade.

Portable electric cutter

A power tool includes a motor and control means for controlling the motor. The motor is capable of being driven by power supplied from a battery pack including a battery cell. The control means is configured to continue to rotate the motor even when a motor-halt signal is inputted from the battery pack. With this structure, the power tool can be used continuously without need to halt rotation of the motor, even when receiving a halt signal, such as an overdischarge detection signal or an overcurrent detection signal.

Power tool and battery pack

An electric power tool includes a brushless motor, a control unit configured to control power supply to the brushless motor, a rotary tool configured to be rotated by the brushless motor, a rotation speed detecting unit configured to detect a rotation speed of the brushless motor, a main switch configured to transmit, to the control unit, an ON/OFF signal for switching between driving and stopping of the brushless motor, and a mode switching unit configured to transmit, to the control unit, a mode switching signal for switching between multiple modes of rotation control of the brushless motor, the control unit is configured to perform the rotation control of the brushless motor in any one of the multiple modes including at least a high-speed mode and a low-speed mode.

An electric tool includes a brushless motor having a plurality of phases, the brushless motor. The brushless motor includes a plurality of stator coils connected in parallel with each of the plurality of phases, and a plurality of crossover wires, each of the crossover wires being configured to electrically connect the plurality of stator coils for each of the plurality of phases to each other. The plurality of crossover wires for the plurality of phases are electrically connected to each other.

Electric tool

A portable electric cutter includes a housingin which a motoris accommodated, a saw blade driven to rotate by the motor, a basecoupled to the housingand having a bottom surface slidable on a surface of a material to be cut, a fandriven to rotate by the motor, a driving circuit for switching power supplied to the motor, and a control circuit for controlling the driving circuit. A circuit boardon which the driving circuit, the control circuit and others are mounted is provided, motor cooling air vents are provided in the housingon a side opposite to the saw blade, and circuit board cooling air vents are provided in the housingon the side opposite to the saw blade.

A disk motor including: a rotor; a stator; an output shaft concentrically fixed to the rotor; at least one coil disk which is provided to one of the rotor or the stator, a coil pattern which includes a plurality of radial patterns or radial pattern groups extending outwards in a radial direction from a center part of the coil disk being formed on at least one surface of the coil disk; an electric current supply portion which supplies electric current to the coil pattern; a magnetic flux generating portion which is provided to another of the rotor or the stator and faces the coil pattern; and an intermediate pattern which is formed between adjacent radial patterns or adjacent radial pattern groups on the coil disk.

Disk motor, electric working machine including disk motor and method for manufacturing disk motor

A power tool includes a housing, a brushless motor, and a cover member. The housing has an air intake hole and an air exhaust hole formed therein, the housing having an inner surface. The brushless motor has an outer surface disposed in the housing, a first endface near the air intake hole, and a second endface near the air exhaust hole. The cover member covers at least one of the first endface and the second endface for preventing dust from entering the brushless motor. The inner surface of the housing and outer surface of the brushless motor define a circulation path providing communication between the air intake hole and the air exhaust hole.

Power tool

A power tool includes a housing, an electric motor accommodated in the housing, a secondary battery that supplies electric power to the electric motor, a handle provided at the housing, a trigger switch provided at the handle for controlling electric power supply to the electric motor, a residual capacity display for displaying a residual capacity of the secondary battery, and a lock-release switch provided at the handle and configured to allow the trigger switch to be operable and to start displaying the residual capacity at the residual capacity display upon manipulation to the lock-release switch.

Power tool having display that displays residual capacity of battery

A current detection circuit () detects that a drive current of the stator coil () is exceeding a threshold value Ir. A rotation number detection circuit () detects that the number of rotations of a rotor () is lower than a threshold value Nr. A computing part () outputs a PWM signal which switches a semiconductor switching element () of the inverter circuit part (). The computing part () changes the threshold values Ir and Nr in accordance with the PWM duty of the PWM signal determined in accordance with a pressed distance of a switch trigger () and detects a locked state of the motor () on the conditions that the motor current I is exceeding the set threshold value Ir and that the number of rotations N thereof is lower than the threshold value Nr.

Electric rotating tool

The electric tool includes a base having an opening portion and a bottom face; a blade being projected downward from the bottom face of the base through the opening portion of the base, the blade being capable of cutting while sliding the bottom face of the base on an upper face of a work piece; a motor driving the blade; a housing accommodating the motor. The bottom face of the base is at least partially coated with a resin including fluorine.

According to an aspect of the present invention, there is provided a power tool including: a housing having a suction port formed thereon to introduce an cooling air from an outside of the housing; and a brushless motor that is housed in the housing and has an electric circuit, the electric circuit having a heat radiating surface, wherein the heat radiating surface is disposed in a neighborhood of the suction port.

A portable electric cutting device includes housing, a saw blade, a saw cover, a base linked to the housing, and a centrifugal fan. The saw cover has a partition wall formed with a plurality of division walls including front and rear divisional walls. The plurality of division walls have an inclined part that extends at an angle with respect to a radial direction of the rotary axis of the fan such that a radially outer part of the inclined part locates upstream from a radially inner part of the inclined part with respect to the rotary direction of the fan.

Growing community of inventors

Hitachinaka, Japan

Kenichirou Yoshida