CONTROL DEVICE FOR ROLLING MILL

摘要

PURPOSE:To perform efficiently roll shifting in a kiss roll state by making a position control system changeable to a low pressure control system in the stage of shifting work rolls in the axial center direction. CONSTITUTION:A signal is fed to a change-over device 15 before shift drivers 23 start driving when a shift commander 14 is operated in the stage of shifting work rolls 3, 4. A selector valve 13 is changed over by the signal from the device 15 so that the oil from a pressure regulating valve 11 side for low pressure is fed to a screw-down device 61 and that the position control is changed over to constant pressure control with low pressure. A command signal is thereafter fed from the commander 14 to the driver 23 and the rolls 3, 4 can be shifted under specified low pressure load in the kiss roll state. The command signal is also fed from the commander 14 to the device 15 and at the same time to a change-over device 22 and since a selector valve 21 is changed over to the low pressure side, the balancing force of a roll balancer 7 is decreased and the frictional resistance in the sliding part is decreased.