| 摘要 |
PURPOSE:To smoothly change over from tension control to suspension characteristic control by adding suspension setting circuit between the suspension characteristic control circuit and suspension setting device of speed controlling device of a tandem rolling mill, and turning the suspension setting device output signal on and off by a changeover switch. CONSTITUTION:During tension control, a speed correcting signal 16 from a tension control circuit 7 is added to a speed reference signal 10 through a changeover switch 11, and given to a Leonard device 5, and the speed of an electric motor 8 for driving the roll mill is controlled. During suspension characteristic control, a speed correcting signal from a suspension characteristic circuit 6 replaces the signal 16 through the switch 11 and control is effected in the same way as mentioned above. When slip occurs between the rolls and rolling material 4, tension control is changed to suspension characteristic control by reversing the switch 11. At this time, to prevent abrupt change of the speed correcting signal, a suspension setting controlling circuit 13 between the circuit 6 and a suspension setting device 9 makes the suspension coefficient K in the expression (DELTANM': amount of correction, IR: rolling current) a time function and changes the signal 15 with lapse of time. |
