GB982232A - Improvements in or relating to automatic strip gauge control for a rolling mill - Google Patents

Abstract

982,232. Rolling. WESTINGHOUSE ELECTRIC CORPORATION. Sept. 20, 1963 [Sept. 21, 1962; April 29, 1963], No. 37077/63. Heading B3M. [Also in Division G3] A method of controlling the thickness of an increment of a workpiece which is reduced in a number of passes of a rolling mill comprises determining a first pass screwdown setting by predicting the roll separation force from the incoming and desired delivery thickness and incoming temperature of the increment, rolling the increment with this setting, determining the actual delivery thickness and temperature from the measured roll separation force, determining a second pass screwdown position using the actual temperature for the first pass, rolling the increment with this setting, determining from the measured roll separation force the actual delivery thickness and temperature for the second pass, and proceeding thus for each succeeding pass. The difference between the estimated and actual roll separating force, and hence the increment thickness, is assumed to be due to errors in determining the increment temperature this being difficult to measure, and thus for each succeeding pass the estimated temperature is modified, to produce a determined temperature, according to the difference between actual and estimated roll separating force for the preceding pass. When the thickness of each increment of a strip becomes less than 2 inches, the actual thickness can be directly measured by an X-ray gauge instead of being calculated. In a reversing mill, for example, a screwdown position control 28 and a roll speed control 22 are controlled by, and send feedback signals to, a computer 24. The computer is also fed signals from a roll force transducer 27, a roll speed transducer 29, strip thickness gauges 31 and 34, width gauges 33 and 35, temperature gauges 36 and 38, and from a manual input 40 and card reader 42 so that mill parameters such as roll diameters, mill spring, incoming and desired final strip thicknesses and strip composition may be used. Specification 982,231 and U.S.A. Specifications 2,303,596 and 2,332,272 are referred to.