| 摘要 |
<p>PURPOSE:To obtain a high accuracy in plate thickness throughout the whole of rolled plate by reducing the speed of motor by detecting the welding joints of plate to be rolled in an hydraulic reduction type rolling mill and by making feedback control on the basis of varied gain. CONSTITUTION:The signal from the welding joint detector 21 provided at the introduciton portion of the strip 2 is sent to the motor swivelling speed controller 22 to reduce the speed of the motor and thus the rolling processing of welding joints is made with a moderate speed. The rotaton of the motor 6 is detected by the motor swivelling speed detector 23, and the signal is put in the speed comparator 13 for comparing with the lower limiting set value. With the output signal, the correcting coefficient variable setting device 13 is changed to an appropriate value. a rolling gap value immediately before the introduction of joints is held in the memory circuit 17. When the joints are introduced, feedback with different gains is made at the arithmetic treating device 15, and after finishing the rolling of joints, the switch 15 is changed to make feeback on the basis of the original correcting coefficient and early gap set value.</p> |
