An automatic thick control method and - a system

摘要

1,083,333. Automatic thickness control. RANK ORGANISATION Ltd. March 18, 1964 [March 21, 1963], No. 11315/63. Heading G3R. An automatic thickness control system for a rolling mill comprises means 18 for measuring the thickness of a strip 11 to produce a signal when the strip thickness deviates from a desired value, which signal is amplified in an amplifier 22 and fed to a trigger mechanism 23 to control either of relays 26 or 27 so as to energize the screw down motor 16 to adjust the work rolls 13 to correct the thickness deviation of the strip. The screw down motor 16 also drives a tachogenerator 28 the output of which is integrated by an integrator 29 and then fed to the trigger mechanism 23 in opposition to the signal from the amplifier 22 so that when the two input signals to mechanism 23 are equal the screw down motor 16 is switched off. The integrator 29 is controlled by the signal from the measuring means 18 so that the integrated signal to the trigger mechanism 23 is maintained after the screw down motor 16 has been de-energized and the output from the tacho-generator 18 disappeared until the corrected strip thickness reaches the measuring means 18 whereupon the output from the integrator 29 is cancelled. In a further embodiment means are provided to prevent energization of the screw down motor in the opposite direction to an already applied correction should the output from the trigger mechanism 23 become reversed as may happen when large deviations are sensed by the means 18. In the case of short transportation lags a switch may be inserted between the tacho-generator and the integrator whereby the integration process may be prematurely ended and the switch may be under the control of a transducer responsive to the speed of the strip. Furthermore a signal giving the transportation lag may be derived by means of a slipping clutch mechanism. Alternatively the system may be controlled by measuring the strip tension and controlling the drive to the take up roll.