| 摘要 |
PURPOSE:To improve the accuracy of sheet-thickness control by restricting the movement of at least one of work rolls to make rolling loads at respective passes unequal and controlling the rolling reductions of work rolls based on the variations, etc. of rolling loads. CONSTITUTION:A roll chock restricting part S for restricting the upward movement of a work-roll chock WC2 is installed. The rolling loads P2, P3 of the 2nd and 3rd passes are made equal to each other because the movements of the 2nd and 3rd work rolls are not restricted, but are not equal to the 1st rolling load P1. The load P1 of the 1st pass is detected by a load cell 2, and the loads P2, P3 are detected by a load cell 3. A rolling reduction device 11 is controlled so as to make the difference portion DELTAP between the measured variation portion DELTAP1 of rolling load P1 and a variation portion DELTAP1cal. calculated by an operational amplifier 9 based on a mill constant, etc., to be zero. Therefore, the sheet thickness after the 1st pass is kept at a fixed value, and the accuracy of sheet-thickness control is improved. |
