METHOD FOR CHANGING ROLL CROSS ANGLE AND ROLL BENDING FORCE IN FLYING AND DEVICE THEREFOR

PROBLEM TO BE SOLVED: To provide the changing method of roll cross angle and roll bending force in flying by which the meandering of a metallic strip is prevented in the case of changing the roll cross angle in rolling and a device which is used for execution. SOLUTION: Relating to a cross angle controller 3, the amount of changing upper cross angle and amount of changing lower cross angle are determined from the roll cross angles θA, θB and roll cross declination αA, αB of a preceding material A and succeeding material B. Relating to the cross angle controller 3, the time T required for the change is calculated from the max. rotational speed VUP. MAX of the upper work rolls 51 and the amount of changing the upper cross angle and, using the obtained time T, the rotational speed VDW of lower work rolls 52 is calculated. To a bending force controller 4, the roll bending forces FW. AO, FW. BO of the preceding material A and succeeding material B are set and, relating to the bending force controller 4, the roll bending force FW. A and roll bending force FW. B, are calculated with time from both roll bending forces FW. AO, FW. BO, the rotational speed VDW of the lower work roll 52 and the max. rotational speed VUP. MAX of the upper work roll 51.