Control method and device for impact screw tightening device

摘要

In an impact screw tightening device using an electric motor as the drive source for rotation, tightening torque accuracy is improved and time required for screw tightening is reduced. A control method for an impact screw tightening device using an electric motor as the drive source for rotation, where an electric current is intermittently supplied to the motor to drive and rotate it so that torque applied to a load by the rotation of the motor is pulse-shaped on a time axis, and where, after the torque has reached target approach torque TQN which is a first set value, an electric current for each beat of the pulse of the torque is controlled so that an increment for each beat is less than that before the torque reaches the target approach torque TQN.