Rotary striking tool

Abstract

The invention provides a rotary striking tool. A fastening torque is controlled into a rotary striking tool with a desired torque by the constant rotation control of the motor. Before striking, the motor can rotate at a high speed and the abnormal striking is avoided. The rotary striking tool is provided with a motor, a striking mechanism, a striking detection unit, and a control unit. The striking mechanism includes a hammer that is rotated by the rotational force of the motor, an anvil to be rotated by the rotational force of the hammer, and a mounting portion for mounting the tool member onthe anvil. When a torque of more than a predetermined value is applied to the anvil base from the outside, the hammer is separated from the anvil to spin. Meanwhile, the anvil is struck in the rotating direction, and the control unit detects a strike by using the striking detection unit after the driving of the motor is started. At the same time, the PWM (pulse width modulation) control is carried out on the electrifying current flowing to the motor at a constant duty ratio. The rotation speed of the motor is controlled to be constant as a constant rotation speed if the striking detection part is used for detecting the striking.

Description

technical field [0001] The present invention relates to a rotary striking tool, which is rotated by the rotational force of a motor and exerts striking force in the direction of rotation when a torque greater than a predetermined value is applied from the outside. Background technique [0002] Conventionally, a rotary hammering tool includes a hammer that is rotated by the rotational force of a motor, and an anvil that is rotated by the rotational force of the hammer. [0003] Then, when a torque greater than a predetermined value is applied from the outside to the anvil on which the tool member is mounted, the hammer is freed from the anvil and idling, and after idling by a predetermined angle, hits the anvil in the rotational direction. [0004] Therefore, according to the rotary driving tool, when fixing the screw to the target object, the screw can be firmly fastened to the target object by hitting the anvil with the hammer. [0005] In addition, in such a rotary drivin...

AI Technical Summary

Problems solved by technology

[0012] In this case, the hammer does not hit the anvil, but goes over the anvil, and the number of blows per motor rotation decreases, resulting in abnormal blows that deteriorate the torque accuracy

In addition, when such an abnormal impact occurs, the cam of the hammer rubs against the anvil and goes over, so there is also a problem of deterioration of the above-mentioned parts.

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