Patent attributes
In an impact fastening tool, erroneous detection of a strike by a hammer is prevented. The impact fastening tool includes a strike mechanism that transmits a driving force of a motor to an output shaft with an impact force generated by striking an anvil by the hammer, a fastening torque calculator that calculates a fastening torque equivalent to an actual fastening torque generated by the impact forces, a strike detector that detects occurrences of strikes by the hammer, a motor controller that stops the driving of the motor at a time when the fastening torque reaches a predetermined reference value, a current detector that detects current information in an interval of strikes, and a strike judger that judges whether the detection of a strike is real or unreal by using current information. The fastening torque calculator calculates the fastening torque by ignoring the strike judged real by the strike judger.
