ROLL-ECCENTRICITY DETECTION DEVICE AND SHEET-THICKNESS CONTROL DEVICE

PURPOSE:To improve the accuracy of sheet thickness by providing a detection device of the rotating angle and angular velocity of a backup roll and obtaining the amplitude and phase of the eccentricity of backup roll through an A/D conversion device and a Fourier transformation device. CONSTITUTION:A rolling-load detection device 3 detects a rolling load in roll- kissing test or during rolling. Rotating-angle and angular-velocity detection devices 14, 15 detect the rotating angles and angular velocities of upper and lower backup rolls B1, B2 through specific points P1, P2 respectively. The output of a rolling-load detection device 3 is sampled by an A/D conversion device 4. The converted data is inputted to a Fourier transformation device 5. Further, an arithmetic device 10 eliminates the eccentricity-information of backup roll. By this method, the variation of sheet thickness due to the eccentricities of upper and lower rolls is eliminated to improve the accuracy of sheet thickness.