Patent ID: 9073186
Filing Date: 2015-07-07
Classification: B25B,B25F

Abstract:
1. An electric power tool comprising: a motor configured to rotationally drive a rotational shaft, on which a tool element can be mounted; a current detection unit configured to detect a motor current flowing through the motor; an operating portion that is operated to input a command that is used to cause the motor to operate, the operating portion configured to be operated a varied amount proportional to a desired speed of the motor; a torque setting portion configured to set a torque in accordance with one of a plurality of predetermined torque settings; a current threshold setting unit that sets a current threshold, which is an upper limit of the motor current, based at least in part on the set torque; and a control unit that drives the motor in accordance with the varied amount of operation of the operating portion, and stops driving of the motor when the motor current detected by the current detection unit reaches the current threshold set by the current threshold setting unit, wherein the current threshold setting unit sets the current threshold, after the control unit has started driving of the motor, such that (i) the current threshold is set to a first value when a predetermined first period of time elapses after the control unit has started driving of the motor, (ii) the current threshold subsequently decreases from the first value so that the current threshold reaches to a constant value when a predetermined second period of time elapses after the control unit has started driving of the motor, and, (iii) the current threshold is maintained at a fixed value of the constant value after the current threshold is decreased to the constant value, the first value being larger than the constant value and the constant value corresponding to the set torque.