Hitachi Koki Co., Ltd.

Koki Holdings Co., Ltd.

Koki Holdings Kabushiki Kaisha

Naoki Tadokoro

Takuya Teranishi

Toshiaki Koizumi

Takuma Saito

Takeshi Taniguchi

Katsuhiro Oomori

Kazutaka Iwata

Yoshiki Aoki

Nobuhiro Takano

Kazuhiko Funabashi

Masato Sakai

Masanori Okada

Hideki Ishida

Shinichi Kakefuda

Shingo Kosugi

Eiji Nakayama

Junichi Toukairin

Toshihiko Tachibana

Hiroyuki Hasegawa

Hideyuki Hashimoto

Yoshikazu Yokoyama

Shinichirou Satou

Yasutaka Shimizu

Yuta Noguchi

Nobuhito Hosokawa

Hiroshi Haga

Shigeru Takahashi

Ken Miyazawa

Ryosuke Nakano

Ken Inui

Akira Oono

Tomoaki Sudo

Shuji Takeda

Hajime Kikuchi

Tomoyuki Hoshi

There is provided a power tool in which impact applied to a power transmission portion can be mitigated to thereby suppress components constituting the power transmission portion from being deformed and damaged. The power tool includes a brushless motorhaving a rotation shaft portionrotatable about a rotation axis A, a housingaccommodating therein the brushless motor, a power transmission portionconfigured to receive a rotation force of the rotation shaft portionand to transmit a driving force based on the rotation force, and a driven portionconfigured to be driven by receiving the transmitted driving force. The rotation shaft portionis supported by the housingso as to be movable relative to the housingin an axial direction of the rotation axis A

Power tool

There is provided a power tool including a housing, a brushless motor, a power supply circuit, and a fan. The housing is formed with an inlet hole and an exhaust hole. The brushless motor is supported by the housing. The power supply circuit includes at least one circuit element for supplying electric power of a power source to the brushless motor. The fan is driven by rotation of the brushless motor to generate a cooling air flow that flows from the inlet hole to the exhaust hole in the housing. The housing includes a first housing including a grip portion and supporting the brushless motor. The inlet hole is formed in the first housing. The at least one circuit element is disposed inside the first housing and is cooled by the cooling air flow.

It is an object of the invention to provide a power tool capable of performing a control process for avoiding an operation of a protection function for protecting a motor against an overload, unlike the conventional power tool. The control unit detects current I flowing in the motor and determines whether current I exceeds Ior not (S). When current I exceeds I(S: Yes), the control unit starts a duty ratio adjustment mode. When current I exceeds Imax (S: Yes), the control unit accords a protection priority over the adjustment of the duty ratio and stops supplying power to the motor (S). If current I does not exceed Imax (S: No), the duty ratio is decreased (S). When current I becomes lower than I(S: Yes), the control unit increases the duty ratio (S).

Portable electric saw

An electric tool including a motor configured to be driven by a PWM control of a semiconductor switching element by using a power supply, a power transmission mechanism configured to transmit a rotation of the motor to an end tool, and a controller configured to control a rotation of the motor by a duty ratio of a PWM signal, wherein the controller is configured to set the duty ratio to a reference duty ratio less than 100% when a voltage of the power supply applied to the electric tool is within a predetermined range including a rated voltage of the electric tool, and wherein the controller is configured to drive the motor by setting the duty ratio to be higher than the reference duty ratio when the voltage of the power supply applied to the electric tool is lower than the predetermined range.

Electric tool

In the present invention, a housing having a trunk part accommodating therein a brushless motor and an output part to which a tip tool is to be connected, a handle part having one end connected to the trunk part, and an accommodation part provided at an other end of the handle part is used, and a FET serving as a switching element that supplies power to the motor is accommodated in the accommodation part from which a power supply cord is pulled out. It is possible to reduce the length of the trunk part in the front-rear direction compared to a case where the FET is disposed in the front-rear direction of the motor.

An electric tool includes a brushless motor and an output part, which is driven by the brushless motor and to which a tip tool is mounted, and a tumbler switch. The tumbler switch applies, to the control unit, a stop signal for stopping the brushless motor at a neutral position, a forward rotation signal for forward rotating the brushless motor by an operation in a first direction, and a reverse rotation signal for reversely rotating the brushless motor by an operation in a second direction.

A power tool includes a motor, an impact mechanism, an output unit, a circuit board, a housing, and a power cord. The circuit board includes a power-source circuit board configured to convert alternate current into direct current and a control circuit board. The housing includes a body section, a board accommodating section, and a handle section. The board accommodating section accommodates the circuit board. The handle section has one end portion connected to the body section and another end portion connected to the board accommodating section. The power cord extends from the board accommodating section. The power cord is positioned opposed to the handle section with respect to the board accommodating section. The control circuit board is located at a position close to the handle section in the board accommodating section. The power-source circuit board is located between the control circuit board and the power cord.

Power tool provided with circuit board

A cutter for cutting a workpiece while using a water includes a housing, an electric motor disposed in the housing, a rotation shaft, a base, and a splashboard. The rotation shaft is supported by the housing for rotatably supporting an end tool driven by the electric motor. The base supports the housing, and has a top surface and a bottom surface to be in contact with the workpiece. The end tool has a part protrudable from the bottom surface. The splashboard section is positioned on the top surface and behind the end tool in a cutting direction. The splashboard section protrudes in a direction away from the top surface and extends in a direction substantially parallel to an axial direction of the rotation shaft.

Cutter

An electric driver includes a hook portion which is constituted by a deformable hook-like portion and a connecting portion for connecting the hook-like portion to the handle. The hook-like portion is constituted by a base portion connected to the connecting portion and a bent portion continuous to the base portion, and a front end portion continuous to the bent portion and arranged at a position substantially opposed to the base portion. The front end portion and the base portion can be proximate to and remote from each other. The connecting portion holds the hook-like portion in a direction substantially the same as a direction in which the handle extends. The hook-like portion is pivotably held on a first rotating axis center extending in substantially the same direction as the handle.

Portable electric grinder

A power toolincludes a cylindrical-shaped yoke, magnetsprovided in the interior of the yoke, an armaturedisposed rotatably in the interior of the yoke, a cooling fanrotatably secured to the armature, a fan guidedisposed on the periphery of the cooling fan, and a cylindrical-shaped housingfor storing the yoketherein. The fan guideis contacted with the axial-direction one end face of the yoke, and the fan guideis engaged with the yokein the rotation direction thereof.

Power tool with yoke rotation prevention means

A power tool includes a main housing, a motor, a hammer case, an end-tool holding part, a driving-force transmitting mechanism, a light-unit mounting part, a light unit, and a cover. The motor is accommodated in the main housing and is configured to generate a driving force. The hammer case has an outer peripheral surface. The end-tool holding part is configured to hold an end tool. The driving-force transmitting mechanism is accommodated in the hammer case. The driving-force transmitting mechanism is configured to transmit the driving force to the end-tool holding part. The light-unit mounting part is formed integrally with the hammer case. The light unit is mounted to the light-unit mounting part. The cover covers the outer peripheral surface of the hammer case and accommodates the light-unit mounting part and the light unit.

Power tool equipped with light

Portable electric driver

Growing community of inventors

Ibaraki, Japan

Naoki Tadokoro