Ribbon stroke and loop control

摘要

For the regulation of the actual tension of a metal strip, between two roll stands in a rolling mill, a lifter between the roll stands acts on the strip to bring it to a nominal tension value. Actual and nominal values (Z'*,Z') are fed to the control unit (15) to determine a tension equalizing signal (ZA) with a time delayed integral portion (IA) to give a nominal speed value (ovl*) for at least one roll stand. The difference between the two signals determines a nominal speed portion for the lifter. The nominal (psi *) and actual (psi ) lifter positions are fed to the loop control (16) to determine a loop equalizing signal (SA). A time delay determines a second loop equalizing signal to give a further nominal speed value for a roll stand. The output signals are passed to the roll stand speed control and the loop lifter setting unit.