ROLL ECCENTRICITY REMOVING DEVICE

PURPOSE:To prevent the variation in a plate thickness by estimating the eccentricity of backup rolls at the driving side and work side with its separation and by correcting respectively the backup roll chock position based on each eccentricity estimating signal. CONSTITUTION:Rolling load detecting devices 11, 12 at driving side and work side are provided and the angle of rotation detecting devices 21, 22 of the upper and lower backup roll B1, B2 are arranged as well. Moreover, the estimating waveform of the roll eccentricity at driving side and work side is respectively operated by providing a roll eccentricity estimation arithmetic unit 31. Then, a roll eccentricity control output arithmetic unit 41 compensates the variation in the rolling reduction position by finding a roll eccentricity waveform and the roll eccentricity control signal of reverse phase on the driving side and work side respectively based on the eccentric waveform found by the arithmetic unit 31 and the angle of rotation of the upper and lower backup rolls of the detecting device 21, 22. In this way the plate thickness variation based on eccentricity can be prevented completely.