JPS54101744A - Automatic controlling method for breadth of strip in hot strip mill - Google Patents

Abstract

PURPOSE:To accurately, automatically control the breadth of strip in the roughing mill group provided with vertical rolls, by taking the temperature and the reaction force against the load of the vertical roll as the input information source, and by varying the gap of vertical rolls depending on the feedforward system. CONSTITUTION:The reaction force against the load of the upstream side vertical rolls 10 and the surface temperature of the bar FB at the same place are detected by the reaction force meter 4 and the thermometer 5, and are sent to the memory/ arithmetic unit 6. In the meantime, the clock unit 1 and the mill roll tachometer 2 of the horizontal mill 11 operate 3 the length of the bar FB at every moment since the start of rolling until the end of rolling, depending on the time counted from the start of rolling and the revolution of the roll; thus obtained length of the bar FB is sent to the memory/arithmetic unit 6. The memory/arithmetic unit 6 arithmetically processes above information so as to find out the load deviation and the temperature deviation in longitudinal direction of the bar FB, and then, forecasts the variation in the breadth. Next, the variation of the gap necessary for vertical rolls 10' in the rear stand is settled so as to eliminate this variation in the breadth; and a signal is sent to the roll gap setter 7 for adjusting the gap of vertical rolls 10'.