Method and device for controlling electrically actuated weft brakes for the automatic adjustment of mechanical tension of a weft thread in textile machines with mechanical insertion

摘要

A method for controlling electrically actuated weft brakes (LF) for automatically adjusting mechanical tension (T) of a weft thread (F) in textile machines with mechanical insertion, characterized in that it comprises the steps of: generating and modulating an excitation current of an actuator (MF) of an electrically actuated brake with a device which comprises a control loop (A) which is sensitive both to variations of mechanical tension (T) measured on the weft thread (F) and to an actual value (v) of a travel speed of the weft thread during insertion; the control loop (A) being adapted to recondition a reference parameter of the braking action (fren-ref), determined by the control loop on the basis of a reference tension (tens-rif) and a measured tension (tens-mis), with a multiplication factor which is represented by a decreasing function [f(v)] of the actual value (v) of the travel speed of the weft thread.