DEVICE FOR CONTROLLING PLATE THICKNESS OF ROLLING MILL

摘要

PURPOSE:To enable automatic correction of the gap between work rolls by presetting said gap with the load predicted in the stage of rolling then correcting automatically the gap and determining the correcting rate of the gap from the difference between the predicted load and the actual load and the mill constant in the final shift. CONSTITUTION:An arithmetic control device 21 calculates and instructs the presetting position of the gap between work rolls 1 and 2 in accordance with the load PRO predicted in the stage of rolling. The mill constant KP2 and zero point position after roll shifting with respect to the mill constant and zero point position in the presetting are respectively calculated by the device 21 and a calculator 16 for the fluctuation in the zero point when the rolls are shifted after presetting of the gap between the rolls 1 and 2. An adder 20 calculates the correcting rate of the preset gap according to the calculated results so that the gap is corrected by a hydraulic screw-down device 11. The correcting rate of the gap between the rolls 1 and 2 is determined by a multiplier 19 from the difference between the load PRO and the actual load PR by an adder 18 and the mill constant KP2 by a mill constant detector 15 when the rolls are finally shifted and the gap is corrected via the adder 20 by the device 11 in the stage of rolling.