Method for controlling an intermittently operating screw tool
AssigneePaul-Heinz Wagner
InventorsPaul-Heinz Wagner, Ulf Sittig
Life of this patent
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Abstract
In the method for controlling an intermittent screw process first a torque mode (DMM) is applied in which the torque is continuously measured. Upon attainment of a pre-torque (MF) a rotation angle mode (DWM) is carried out in which the rotation angle is measured. Proceeding from the rotation angle α=0 (corresponding to the pre-torque (MF)) the rotation angle (α) is counted up during each stroke. In this connection that torque (MHE) is stored which has been reached at the end of the stroke. During the next stroke the angle (α) is continued to be counted only when the torque (MHE) at the stroke end of the previous stroke has been reached again. Upon attainment of a target angle (αz) the screw process is terminated.
Claims17
A method of automatically controlling a screw tool which carries out intermittent rotating strokes and includes a torque sensor (23) and a rotation angle sensor (33) comprising the steps of:
- carrying-out intermittent reciprocal strokes to rotate a screw tool while measuring the torque (MD) in a torque mode (DMM),
- upon attaining a predetermined pre-torque (MF) transitioning to a rotation angle mode (DWM) and thereby count-up the rotation angle (α) up to the end of the current stroke, and storing the rotation angle (αHE1) and torque (MHE1) values attained at the end of the current stroke,
- performing subsequent intermittent reciprocal strokes and during each continuing counting-up the rotation angle (α) when the torque (MD) has reached a value corresponding to the torque (MHE) at the end of the previous intermittent reciprocal stroke, and storing the rotation angle (αHE) and torque (MHE) values attained at the end of each subsequent reciprocal intermittent stroke, and
- terminating the screw process when the counted-up rotation angle has reached a target angle (αZ).
Dependencies are inferred from the claim text.