AUTOMATIC ROLLING REDUCTION DEVICE OF HOT REVERSIBLE ROLLING MILL

摘要

PURPOSE:To promote the increase in production capacity by providing the differentiator calculating the difference in the rolling reduction set value and the present value of the rolling reduction quantity and by connecting the rolling reduction calculating device of different accuracy with switching to a differentiator. CONSTITUTION:A rolling reduction position detector 7 detects the present value of the gap (d) between rolling rolls 1, 3 and rolling reduction setter 10 outputs the set value (ds) of the set roll intervals to a memory device 8. A differentiator 11 calculates the difference between the present value of the roll intervals (d) detected by the detector 7 and the set value (ds) and inputs into the rolling reduction speed arithmetic device 13 or 14 of lower accuracy and higher accuracy via a changeover mechanism 12. The rolling reduction time is shortened with said mechanism with performing the control of rolling reduction with using the arithmetic device 13 of lower accuracy for the initial several passes. The positioning of higher accuracy is then performed with using the arithmetic device 14 of high accuracy for the several last passes. Consequently, the dimensional accuracy of a rolling material is secured and the production capacity is increased by the shortening in rolling reduction time.