JPS5568111A - Controlling method for rolled shape after broadside rolling work for plate - Google Patents

Abstract

PURPOSE:To improve the yield of material, by controlling the rolled shape in the vertical rolling pass before executing the broadside rolling. CONSTITUTION:When the material discharged from the heating furnace 1 arrives at the position of the tip position detector 4, the signals are produced from the tip position detector 4 and the speed meter 6, and are inputted into the control unit 5. Hereby, the command for reducing action is charged on the screw-down device 31 at the moment excluding the time lag of response of the screw-down device from the time for passing the distance l. The reducing roll gives the reduction to the material so as to gradually reduce the gap DELTAS1 of the reducing position for a specified length DELTAL1 at the material tip; at the moment after passing the specified length DELTAL1, the reference reducing position condition is maintained, and hereafter whole of middle part is uniformly reduced at the reducing position S0. When the passing of the material's rear end is detected by the detector 4 or 7, a signal is inputted into the control unit 5, and the roll gives the reduction to the material's rear end so as to gradually increase the reduction for the specified length DELTAL2, and the reduction is finished at the moment of passing DELTAL2. After enlarging the thickness difference between the front end and rear end as above stated, the broadside rolling is carried out. Accordingly, excessively small breadth is not formed in both ends of the material.