Makita Corporation

Kenya Yanagihara

Yoshitaka Ichikawa

Motohiro Omura

Ying Yang

Yutaka Matsunaga

Yuki Kawai

A driving tool, such as a nailer, includes a compression cylinder, a compression piston, an electric motor, a control apparatus, a trigger, a trigger switch, a driver guide, and a contact-arm switch. The control apparatus prevents fasteners, such as nails, from being driven when the controller identifies a state, in which it is likely that a malfunction or mis-operation of the driving tool is occurring.

Driving tool

A driving tool, such as a nailer, includes a compression piston slidably disposed within a compression cylinder. An electric motor and a crank mechanism reciprocally drive the compression piston within the compression cylinder, and a sensor directly or indirectly detects the position of the compression piston. Prior to the start of a driving operation, a return operation is performed to move the compression piston to its bottom dead center when the sensor detects that the compression piston is located at a position other its bottom dead center.

A cordless electric power tool comprises a motor that drives a tool, a battery that supply electric power to the motor and a motor drive circuit that is disposed between the motor and the battery. The motor is a three-phase brushless motor, and the battery has a nominal voltage of 18 volts. An overall electric efficiency of the cordless electric power tool becomes at least 70 percent when a value of current passing through the motor becomes at least 35 amperes but no more than 45 amperes and the cordless electric power tool outputs power of at least 450 watts but no more than 550 watts.

Cordless electric power tool

An electric power tool according to the present invention is provided with a tool main body, an induction motor, a power supply unit, and an inverter. The power supply unit and the inverter are integrally incorporated in the tool main body together with the induction motor.

Electric power tool

An electric power tool is provided with a three-phase brushless motor that drives a tool and a motor driver that drives the three-phase brushless motor with square voltage waves. The motor driver is able to set a conduction angle to a value that is equal to or more than 130 degrees but not more than 180 degrees, and especially to change the conduction angle among at least two values that are equal to or more than 130 degrees but not more than 180 degrees. In this configuration, it may be preferable that the conduction angle is set to a larger value as a load applied to the tool becomes smaller. On the other hand, it may be also preferable that the conduction angle is set to a larger value as a load applied to the tool becomes smaller.

A motor current detection apparatus in the present invention includes: a current detection unit, a first filter, and a second filter. The detection unit detects a conduction current flowing from a battery to a brushless motor and outputs a conduction current signal corresponding to the detected conduction current. The first filter extracts a first current signal which is included in the conduction current signal outputted from the detection unit and is a signal component in a frequency band equal to or lower than a predetermined first cutoff frequency. The second filter extracts a second current signal which is included in the conduction current signal outputted from the detection unit and is a signal component in a predetermined frequency band within a frequency band equal to or lower than a predetermined second cutoff frequency higher than the first cutoff frequency and having the second cutoff frequency as a maximum value.

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Anjo, Japan

Kenya Yanagihara