Hilti Aktiengesellschaft

Matthaeus Alberding

Dario Bralla

Antonio Orvieto

Christian Woetzl

A control method includes two operating modes carried out in response to a position of a selector switch. The first operating mode provides: carrying out first impacts of the hammer onto the anvil; detecting the event of an impact of the hammer onto the anvil with an impact sensor; detecting an angular position of the anvil with an angle sensor; estimating an individual impact angle of the anvil due to the last detected impact, based on the angular position of the anvil before the last detected impact and the angular position of the anvil after the last detected impact, and comparing the individual impact angle with an individual impact setpoint angle. The first operating mode is ended when the individual impact angle drops below an individual impact setpoint angle. The second operating mode provides: detecting the angular position of the anvil with the angle sensor as the initial position; carrying out second impacts of the hammer onto the anvil; and detecting a relative rotation angle of the anvil with respect to the initial position during the second impacts. The second operating mode is ended when the relative rotation angle exceeds a standard angle.

Control method for an impact wrench

A control method for tightening a threaded connection executes, in response to actuation of a pushbutton key, a sequence with consecutive phases. In a first phase, an impact mechanism of an impact wrench exerts a predefined number of rotary impacts on the threaded connection. During the first phase, a profile of a rotational angle over time is estimated. A pattern is adapted to the profile and on the basis of the pattern a setpoint torque is determined for a second phase and a final rotational angle or a final number of impacts is determined for a third phase. During the second phase, rotary impacts are exerted until an estimated torque reaches the setpoint torque. During the third phase, rotary impacts are exerted on the threaded connection until a number of rotary impacts corresponds to the final number or a rotational angle corresponds to the final rotational angle.

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Lindau, Germany

Matthaeus Alberding