Hitachi Koki Co., Ltd.

Koki Holdings Co., Ltd.

Tetsuhiro Harada

Tomomasa Nishikawa

Yoshihiro Nakano

Hiroki Uchida

Nobuhiro Takano

Kazutaka Iwata

Hideyuki Tanimoto

Shinki Ohtsu

Chikai Yoshimizu

Hiroyuki Hanawa

Yoshihiro Komuro

Yoshiichi Komazaki

Tatsuya Ito

Takahiro Hirai

Satoru Matsuno

Norikazu Baba

Hiroki Tsunoda

Katsuaki Sukegawa

Kazuhiko Morita

Shiniki Otsu

Shinki Otsu

Yang Li

To provide a rotary impact tool capable of: suppressing a rise in temperature in a motor or switching elements and a current flowing in the motor or switching elements while suppressing a degradation in tightening performance; and improving operability. The rotary impact tool includes: a motor; an end-bit holding part driven by the motor; an impact mechanism provided on a drive transmission path from the motor to the end-bit holding part and configured to intermittently produce rotary impacts, the rotary impacts transmitting a drive force of the motor to the end-bit holding part; a switching element configured to change a voltage supplied to the motor; and a control unit controlling the switching element. The control unit is configured such that the voltage supplied to the motor begins to gradually rise within a period of time from a timing when a first rotary impact ends to a timing when a second rotary impact subsequent to the first rotary impact starts.

Rotary impact tool

A power tool includes: a motor; a fan driven by the motor and defining an axis and a radial direction; and a housing for accommodating the motor and the fan therein, the housing including: a peripheral wall formed with a ventilation hole; and a grid partly covering the ventilation hole, the ventilation hole being positioned adjacent to the fan and having a shape defined by a circumferential surface, the grid including at least one elongated portion extending in a longitudinal direction perpendicular to the radial direction, and a distance from the axis of the fan to the circumferential surface is different from a distance from the axis of the fan to one elongated portion in the radial direction of the fan.

Power tool

In order to provide a driver for reducing reaction generated to a driver main body, the driverincludes a nose portionprovided in a housingand extending in a longitudinal direction, the nose portion being configured to allow a fastener to pass therethrough, a plungerconfigured to move in an impact direction parallel to the longitudinal direction to impact the fastener through the nose portion, a weight, and a coil springconfigured to be compressed by a motorin the longitudinal direction. a release of the compression causing the plungerto move in the impact direction, while causing the weightto move in a counter-impact direction which is away from the plunger. The coil springis provided between the plungerand the weight. The coil spring has one end portion urging the plunger, and another end portion urging the weight

Driver

The sealing property obtained when a battery pack is attached to an electric power tool is improved. An electric power tool to/from which a battery pack retaining a battery cell is attachable/detachable has: a tool main body being provided with an attachment part to/from which the battery pack is attached/detached; a guide groove which is provided in the attachment part and which determines a direction of the attachment/detachment of the battery pack; a device-side terminal which is provided in the attachment part and which is connected to a battery-side terminal provided in the battery pack; and a seal member which is provided in the attachment part and which seals a connecting part between the battery-side terminal and the device-side terminal.

Electric device including sealing member between attachment part and battery pack

An electric device body in which a battery pack including a plurality of battery cells and a plurality of first terminals is detachably mounted includes: a housing; a guide mechanism; and a plurality of second terminals; and a pressed portion. The battery pack is configured to be attached to and detached from the housing along a first direction. The guide mechanism is provided at the housing and configured to define the first direction. The plurality of second terminals is configured to be connected to the plurality of first terminals upon attachment of the battery pack to the housing. The pressed portion is configured to be pressed against the battery pack in a second direction intersecting the first direction when the battery pack has been attached to the housing.

Electric device body and electric device

A power tool () and a method of producing such power tool capable of improving dust proof performance with respect to a circuit board () and a stator coil (B), and capable of securing cooling performance to the circuit board. The power tool includes a brushless motor () having a hollow stator (), a rotor () positioned in an internal space of the stator, and a motor driver circuit connected to the stator. The stator includes a coil (B) electrically connected to the motor driver circuit. The coil is coated with a coating agent (D), and the motor driver circuit is covered with an insulation cover member (D).

Power tool and method for producing the same

An oil pulse tool includes a motor, an oil pulse unit, an output shaft on which a front end tool is attached, a torque detecting sensor for detecting generation of an impact torque, and an operating portion configured to detect a time period between a first impact torque detected by the torque detecting sensor and a second impact torque detected by the torque detecting sensor. The second impact torque is smaller than the first impact torque. The operating portion carries out a notification when the time period between the first impact torque and the second impact torque is less than a predetermined evaluation value for the time period between the first impact torque and the second impact torque.

Oil pulse tool

According to an aspect of the invention, an oil pulse tool includes: a motor generating a driving force according to a driving voltage; an oil pulse unit driven by the driving force and generating a torque in a pulse-like shape when the motor passes a strike position on a shaft thereof; and an output shaft on which a front end tool is mounted, the output shaft being connected to the shaft, characterized in that the oil pulse tool further comprises driving adjusting means to control the driving voltage, the driving voltage is reduced during a given period including a timing when the torque is transmitted to the output shaft, and the reduced driving voltage is increased when the given period is finished.

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Hitachinaka, Japan

Tetsuhiro Harada