A rotational speed controlling module includes an input unit, a first receiving unit, a second receiving unit, and a controlling unit. The input unit is to input a first target rotational speed value, a second target rotational speed value and a target number of turns. The first receiving unit is to receive a real-time rotational speed value from an electric screw driver with clutch. The second receiving unit is to receive a real-time number of turns. The controlling unit is to control real-time rotational speed value to decrease from the first target rotational speed value to the second target rotational speed value when the real-time number of turns reaches the target number of turns.

A rotational speed controlling module includes an input unit, a first receiving unit, a second receiving unit, and a controlling unit. The input unit is to input a first target rotational speed value, a second target rotational speed value and a target number of turns. The first receiving unit is to receive a real-time rotational speed value from an electric screw driver with clutch. The second receiving unit is to receive a real-time number of turns. The controlling unit is to control real-time rotational speed value to decrease from the first target rotational speed value to the second target rotational speed value when the real-time number of turns reaches the target number of turns.

An impact drill includes a lock pin, a biasing element, a function conversion member and an operation member. The lock pin is connected to the locking ring. The biasing element is connected to the lock pin and provides a biasing force that causes the lock pin to press against the locking ring. The function conversion member includes a stop portion configured to stop the movement of the lock pin along the first axis and a release portion configured to allow the movement of the lock pin along the first axis. The operation member is connected to the function conversion member. The operation member is configured to drive the function conversion member to rotate around the first axis to switch the stop state of the movement of the lock pin along the first axis.

An electric pulse tool is configured to deliver torque in pulses on an output shaft thereof and includes an electric motor to drive the output shaft. The electric pulse tool is configured to, for each period, provide a current pulse to the electric motor during a current-on time interval, pause a current feed to the electric motor after the current-on time interval until an end of a torque pulse, determine a width of the torque pulse, and continue pausing the current feed to the electric motor during a pause interval from the end of the torque pulse. The pause interval is determined based on the width of the torque pulse such that a wider torque pulse results in a wider pause interval and a narrower torque pulse results in a shorter pause interval.

An electric pulse tool is configured to deliver torque in pulses on an output shaft thereof and includes an electric motor to drive the output shaft. The electric pulse tool is configured to, for each period, provide a current pulse to the electric motor during a current-on time interval, pause a current feed to the electric motor after the current-on time interval until an end of a torque pulse, determine a width of the torque pulse, and continue pausing the current feed to the electric motor during a pause interval from the end of the torque pulse. The pause interval is determined based on the width of the torque pulse such that a wider torque pulse results in a wider pause interval and a narrower torque pulse results in a shorter pause interval.

A screw driving device includes: a case; a motor provided with a rotor; an output member capable of driving in rotation an element for driving an element to be screwed; a transmission connecting the rotor to the output member, the transmission including at least one additional gear train capable of being engaged/disengaged; an motor controller. The device includes an element for engaging the additional gear train, which is capable of being in at least: an engagement state in which the additional train is engaged, and a disengagement state in which the additional gear train is not engaged. A reduction ratio of the transmission between the rotor and the output member is different according to whether or not the additional gear train is engaged, the reduction ratio being greater when the additional gear train is engaged.

A screw driving device includes: a case; a motor provided with a rotor; an output member capable of driving in rotation an element for driving an element to be screwed; a transmission connecting the rotor to the output member, the transmission including at least one additional gear train capable of being engaged/disengaged; an motor controller. The device includes an element for engaging the additional gear train, which is capable of being in at least: an engagement state in which the additional train is engaged, and a disengagement state in which the additional gear train is not engaged. A reduction ratio of the transmission between the rotor and the output member is different according to whether or not the additional gear train is engaged, the reduction ratio being greater when the additional gear train is engaged.

A screwdriver is connected to an electric power supply, and rotates a mounted bit to tighten a screw. The screwdriver includes a camera, an image information recording section, a basic information registration section, a determination section, and an LED unit. The camera captures the screw to be tightened or surroundings of a threaded hole in which the screw is to be tightened. The recording section records an image captured by the camera. The registration section registers beforehand image information, which has been acquired by capturing with the camera an image of the surroundings of the threaded hole, as basic information. The determination section determines whether or not new image information, which has been newly acquired by capturing an image of the surroundings of the threaded hole with the camera, coincides with the basic information. The LED unit notifies a result of determination by the determination section.

A screwdriver is connected to an electric power supply, and rotates a mounted bit to tighten a screw. The screwdriver includes a camera, an image information recording section, a basic information registration section, a determination section, and an LED unit. The camera captures the screw to be tightened or surroundings of a threaded hole in which the screw is to be tightened. The recording section records an image captured by the camera. The registration section registers beforehand image information, which has been acquired by capturing with the camera an image of the surroundings of the threaded hole, as basic information. The determination section determines whether or not new image information, which has been newly acquired by capturing an image of the surroundings of the threaded hole with the camera, coincides with the basic information. The LED unit notifies a result of determination by the determination section.

A power tool with an impact mechanism and that is controlled based on a drive angle from impacting. The power tool includes a housing, a brushless direct current (DC) motor within the housing, an impact mechanism, and an output drive device. The brushless DC motor includes a rotor coupled to a motor shaft to produce a rotational output. The impact mechanism includes a hammer coupled to the motor shaft, and an anvil that receives impacts from the hammer and drives an output device. The power tool further includes a position sensor that senses a position of the rotor and a controller coupled to the position sensor. The controller detects an impact of the impact mechanism, calculates a drive angle of the anvil caused by the impact based on output from the position sensor, and controls the brushless DC motor based on the drive angle.