Yarn feed tension control on flat bed knitting machine

摘要

There is a thread feed (1) to supply especially hard yarns which is designed especially for knitting machines (2) with thread requirements varying considerably in time. The thread feed (1) has a motor-driven thread wheel (13) which, in the ideal case, feeds directly into the knitting machine (2) or its thread guide (7) without the intervention of thread storage devices. The thread tension is monitored via a sensor (22) which detects the measurement for a regulator (15, 16) controlling the feed through the thread wheel (13). The regulator (15, 16) is also designed so that it can process signals containing information on the future thread requirements. It is thus possible for the regulator (15, 16) act in advance of imminent drastic changes in requirements which, for example, occur periodically in flat knitting machines (2) at the fabric edges (thread guide reversing points) by providing extra thread in advance or stopping the thread feed. It is thus possible to even out peak thread tensions and excessively steep tension drops. The regulator (15, 16) can be designed in such a way that it acts as a state regulator and temporarily as a control. Other measures like disturbance variable compensation, parameter adaptation or the like are possible.