CONTROL SYSTEM OF THE ELECTRIC DRIVE OF THE LOOP HOLDER OF THE FINISHING GROUP OF THE HOT ROLLING MILL, WHICH IMPLEMENTS CONTROL AND FORCING OF THE ELECTRIC DRIVE MOMENT

Abstract

The operation of the DC electric drive of the loop holder installed on the hot rolling mill between the stands of the finishing group, which is part of the SARN with the indirect principle of metal tension control, which generates control signals based on the control of the specific tension of the strip passing between two stands, is considered. It is shown that the SARN action algorithm is based on taking into account the impact on the strip of the auxiliary mechanism – the loop holder, the frame of which must be rotated to the optimal angle. The conditions are described under which the looper is in an equilibrium state, when the moment of the electric motor balances the moment of resistance on its shaft, determined by the force arising due to the tension of the strip. It is shown that the high-speed electric drive of the looper, which is in the steady braking mode for most of the cycle time and creates a braking torque, at the moment the strip enters the interstand gap, should provide a short-term forcing of the moment for the movement of the frame, followed by a stop in the allowable zone of the angle of rotation.