GB1125687A - Rolling mill control system - Google Patents

Abstract

1,125,687. Electric control systems. GENERAL DYNAMICS CORP. May 18, 1967 [May 20, 1966], No. 23142/67. Heading G1N. [Also in Divisions B3 and G4] In the production of a longitudinally tapered strip in a rolling mill, the spacing between the rollers 11, 12, Fig. 1 is continually adjusted during a run by movement of wedge 18 into the gap between a backing roller 13 and a fixed wedge 19, under the control of a hydraulic ram 17. For larger adjustments of the spacing between runs a conventional screw-down arrangement 21 is provided. The ram 17 is controlled by an error signal from an amplifier 36 indicative of the difference between the actual position of the wedge 18, obtained from potentiometer 37, and the required position to produce the required spacing of rolls 11, 12. The required position of the wedge is obtained by multiplying a signal indicative of the required taper (change in thickness per unit length), from computer 22 (see Division G4), with a signal indicative of the instantaneous position of the rolls 11, 12 along the strip, obtained from a pulse tachometer 25, counter 24 and digital-to-analogue converter 23, in which the multiplication also occurs. To compensate for, e. g. changes in the roll diameters, the output from the computer 22 is fed to an adjustable potentiometer 31. To compensate for non-linearity between the position of the wedge and spacing of the rolls 11, 12, the computer 22 may be modified to take into account deflecting forces acting on the frame 10 which produce the non-linearity. In operation, when the strip has left the rollers, a force detector 38 senses the resulting reduction in force and transmits a signal to energize relay 33 connecting a clock 41 to the counter 24 which causes the wedge to be driven to the end of its stroke in preparation for the next run.