Hitachi Koki Co., Ltd.

Kenro Ishimaru

Nobuhiro Takano

Kazuhiko Funabashi

Eiji Nakayama

Yoshikazu Kawano

Chikai Yoshimizu

Kazutaka Iwata

Takao Aradachi

Yoshio Iimura

Masateru Niyada

Yuuichi Konuma

Tomomasa Nishikawa

Yoshitaka Akiba

Haruhisa Fujisawa

Kazumi Tanaka

Nobihiro Takano

Masahiro Isono

When a battery pack having an output voltage of 14.4 V that is connectable to an electric tool in a sliding manner is used as a power supply source for the electric tool that is connectable to a battery pack in an insertion manner and has a rated voltage of 12 V, the electric tool and the battery pack are connected to each other with an adaptor interposed therebetween. The adaptor has an FET that is switched at a predetermined duty of a predetermined frequency. The battery pack and the electric tool are connected or disconnected to or from each other by the switching operation, thereby dropping the output voltage of the battery pack. When the detected voltage is out of a predetermined value range, it is judged that the overcurrent or overdischarge has occurred. Then, the FET is turned off to stop the electric tool.

Adaptor, assembly of battery pack and adaptor, and electric tool with the same

According to an aspect of the present invention, there is provided a power tool including: a motor; a switching device that switches over, in response to a conduction angle thereof, an AC voltage to be applied to the motor; a rotation speed setting unit that sets a target rotation speed of the motor; a rotation speed detection unit that detects an actual rotation speed of the motor; and a controller that determines the conduction angle by comparing the actual rotation speed with the target rotation speed and that controls the switching device by use of the conduction angle based on a maximum conduction angle, the maximum conduction angle being set in accordance with the target rotation speed.

Power tool

According to an aspect of the present invention, there is provided a rotary striking tool includes: a motor; an oil pulse unit that is driven by the motor; an output shaft that is coupled to the oil pulse unit so that a tip tool can be attached to the output shaft; a first detection unit that detects a rotation angle of the motor and outputs a first output signal; a second detection unit that detects an impact generated at the oil pulse unit and outputs a second output signal; and a control unit that controls a rotation of the motor, wherein the control unit uses a portion of the second output signal based on the first output signal for control of the rotation of the motor.

Rotary striking tool

According to an aspect of the present invention, there is provided a rotary striking tool, including: a motor; an impact unit having a driving part being driven by the motor and an output part; a tip-tool side output shaft that is coupled to the output part; an impact detection unit that detects an impact generated at the impact unit; and a control unit programmed to: control the impact unit to perform a confirmation striking when the impact detected by the impact detection unit reaches a prescribed value, detect a rotation angle of the output shaft at the confirmation striking, determine whether a fastening operation is completed when the detected rotation angle is equal to or smaller than a predetermined angle, and continue the fastening operation when the detected rotation angle is larger than the predetermined angle.

When a battery pack having an output voltage of 14.4 V that is connectable to an electric tool in a sliding manner is used as a power supply source for the electric tool that is connectable to a battery pack in an insertion manner and has a rated voltage of 12 V, the electric tool and the battery pack are connected to each other with an adaptor interposed therebetween. The adaptor has an FET that is switched at a predetermined duty of a predetermined frequency. The battery pack and the electric tool are connected or disconnected to or from each other by the switching operation, thereby dropping the output voltage of the battery pack. The voltage from the battery pack is detected. When the detected voltage is out of a predetermined value range, it is judged that the overcurrent or overdischarge has occurred. Then, the FET is turned off to stop the electric tool.

A battery charging apparatus includes a switching power source supplying a current to a battery pack, an input voltage detecting unit detecting an input voltage of the switching power source, a charging current control unit that detects a charging current of the battery and controlling the charging current in accordance with a charging current set value, and a microcomputer detecting whether the current supplied to the battery to be charged is less than a predetermined value on the basis of a detection signal of the input voltage detecting unit and controls the charging current set value in accordance with the input voltage. When it is discriminated that the input voltage is less than a predetermined value on the basis of the detection signal, the microcomputer sets the charging current set value to be a value less than the predetermined value.

Battery charging apparatus

A battery charger including a charging power supply circuit connected to an input power supply and adapted to charge a battery to be charged, a charging control circuit adapted to control charging of the battery, and a constant voltage power supply adapted to drive the charging control circuit, wherein the charging control circuit stops an output of the constant voltage power supply when the battery is detached from the charger.

Battery charger

A combustion-powered, fastener-driving tool includes a cylinder and a combustion chamber disposed on top of the cylinder that accommodates a gaseous mixture of existing air in the combustion chamber and fuel injected therein. A spark plug generates a spark to combust the gaseous mixture in the combustion chamber. A trigger produces the spark in the spark plug when operated. A piston is movably supported in the cylinder and driven by combustion in the combustion chamber. A driving blade is coupled to the piston for driving a fastener. A spark controller is provided for generating a plurality of sparks in succession with the spark plug.

Growing community of inventors

Ibaraki, Japan

Kenro Ishimaru