Patent GB-879277-A (GB)
Title: Rolling mill control
IPC: B21B37/24
Filed: 1959-09-10
Abstract: 879,277. Rolling. SQUARE D CO. Sept. 10, 1959 [Oct. 16, 1958], No. 30884/59. Class 83 (4). A rolling mill is controlled by a device for computing the number of passes necessary to reduce the work to the required final thickness, said device comprising a number of signalresponsive devices each responsive to a particular signal relating the different number of passes, a number of signal sources each providing a signal representative of a particular condition of the work, means for receiving said signals and combining them into a single signal representing the number of passes and means for transmitting the combined signal to the signal-responsive devices to cause the relevant one of them to respond. The rolling mill comprises means 16 driving an approach table 10, Fig. 1, means 18 driving an entry table 11, means 20 driving a delivery table 12, means 22 driving vertical rolls 14, 14<SP>1</SP> having a screwdown driven by means 23 and means 26 driving horizontal rolls 15, 151 having a screwdown driven by means 27. There are also entry side guides 31, 31<SP>1</SP> above the entry table and delivery side guides 32, 32<SP>1</SP> above the delivery table, the separation of each pair of guides being adjusted by means 33 and 35, respectively, so as to keep the work 13 in the middle of the tables. The operation of the mill is controlled by a control system comprising a start and stop control 92 and a master programmer 50, Fig. 4, which is coupled by signal carriers 51-54 to position detectors PD1, PD2 and PD3 and a load detector LD1 and which is also coupled by signal carriers 62-66 with controllers 57-61 which directly control respectively, the approach drive 16, entry drive 18, delivery drive 20, vertical roll drive 22 and horizontal roll drive 26. The master programmer also controls the time of operation of the horizontal and vertical roll screw-downs through digital control units 69 and 72 and screwdown controllers 67 and 70 but the extent of the movement of the screwdowns is determined by a screwdown programme computer 75 also acting through the control units 69 and 72 and controllers 67 and 70. The digital control unit 69 is also responsive to signals from a horizontal roll shaft encoder 79 and from a horizontal calibration control 81 and the control unit 72 is also responsive to signals from a vertical roll shaft encoder 83 and from a vertical calibration control 85. Conditions of the workpiece such as thickness, temperature and metallurgy or resistance to rolling are sensed by gauge, a pyrometer and the like while the work is on the approach or entry table and translated into electrical signals in a condition signal source 86 which is interconnected with the screwdown programme computer 75. The entry side guide positioners 33 and 35 are controlled by a guide controller 87 responsive to both the condition signal source 86 and the master programmer 50. A punched card may be fed into a translator 90 forming part of the condition signal source 86. The screwdown computer 75 includes a number of passes computer, total horizontal and total vertical draft computers, horizontal rolling pattern and vertical rolling pattern computers and a draft compensation computer, all of which are described in the Specification. When the master control 92 is operated to start the mill, programmer 50 sends a signal to the approach table controller 57 to start the table and move the workpiece 13. The data translator 90 and pyrometer 91 of signal sources 86 convert the workpiece conditions to electrical signals which are fed to the side guide controller 87 and screwdown programme computer 75 which thereupon produce signals which are transmitted to the screwdown controllers 67 and 70 of screwdowns 27 and 23. Simultaneously programmer 50 signals the entry controller 58 to start the entry table and the side guide controller 87 to adjust the guides. When the leading end of the workpiece reaches the position detector PD3, the programmer 50 responds to a signal from carrier 53 to stop the approach and entry tables. When the screwdown adjustment is nearly completed the roll drives are set in motion and the entry table driven at entry speed. When the tail end of the work passes the detector PD the entry table is stopped and the delivery table driven. As the workpiece leaves the rolls, the roll drives are stopped, the screwdowns are again set in motion ready for the second pass and the operations repeated with the work moving from left to right as seen in Fig. 1. The number of passes computer receives signals relating to the temperature of the billet, its metallurgy and the differences between the original and final desired width and thickness and determines the number of passes required to reduce the billet to the desired form without overloading the mill. The master programmer 50 co-ordinates the operations of the various parts of the mill.