Limiting Dynamic Loads in the Main Line of a Rolling Mill through an Automated Drive

Abstract

A typical dynamic mode of the plate mill stand drives is shock loading at the time of roll biting. The analysis of the Mill 5000 reversing stand drive torque and speed waveforms has shown that in this case, the drive enters the torque limit mode. On the transmission shaft, damping torsional oscillations occur which are two or more times higher than the steady rolling torque. The objectives of developing the drive control algorithms that allow reducing dynamic loads have been defined. A way to limit dynamic loads by preliminary accelerating drive before biting has been considered. The dependence of the dynamic torque amplitude on the accuracy of determining the workpiece position relative to the stand has been noted. A drive control technique has been developed, which ensures limiting dynamic loads regardless of the accuracy of tracking the workpiece movement on the roller table. The speed setting charts implemented in conventional and developed techniques have been considered. The drive torque - time curves obtained in the simulation have been represented and improving the dynamic characteristics confirmed. A comparative analysis of the dynamic performance of the Mill 5000 drive has been performed with the implementation of conventional and developed control algorithms. Recommendations have been given on implementing the technique for the plate rolling mills.