GB1391475A - Cutting control system and method in rolling mills - Google Patents

Abstract

1391475 Controlling shearing BRITISH STEEL CORP 12 July 1973 [13 April 1972] 17114/72 Heading B3 A system for controlling the operation of cutting means 15 downstream of a rolling mill 10 for cutting a rolled elongate workpiece 13 comprises a comparator 23 for producing, from data proportional to the speed of travel of a workpiece on the upstream and downstream sides of the mill, an elongation factor, data storage means for storing the factor and a computer 30 which has access to the elongation factor and data inputs relating to one length of a further workpiece to be rolled in the mill and to the permissible lengths into which it may be cut and which produces an output signal to the cutting means to control the lengths into which the further workpiece is cut. The passage of the trailing end of a bloom 13 past a photo-cell 20 actuates a pulse generator 22 connected to a billet-measuring roll 14. The pulses generated during travel of the trailing end over a known distance between photo-cell 20 and a photo-cell 21 are fed to the comparator 23. The elongation factor produced is stored for use when a bloom of similar dimensions is to be rolled and cut and may be recalculated and corrected if necessary during the rolling of the further bloom. The length of an incoming bloom is measured before it enters the mill by, e.g. photo-cells 29 and the measurement fed to the computer which has access to a previouslyderived elongation factor and thus can calculate the rolled billet length. The computer is supplied from input 3, with information necessary to ascertain the lengths into which the billet should be cut to minimize waste and signals these lengths to a cut-to-length logic unit 32 of the shear. The operator may feed into input 31 his estimate of the cutting instructions for the unit 32 and adjust it if necessary after checking its accuracy on read-out means. A motor 35 driving the measuring roll 14 is actuated when the leading end of a billet leaves the mill 10 and a pulse generator 36 feeds data on the length of billet passing the roll to the cutter control unit 32.