| 摘要 |
<p>1,127,926. Automatic control of rolling. DAVY & UNITED ENG. CO. Ltd. Dec. 15, 1965 [Dec. 22, 1964], No. 52116/64. Heading G3R. [Also in Division B3] In a rolling mill, parts of the mill other than the rolls are pre-stressed to an extent that is automatically controlled by a signal derived from independent measurements of the pre-stressing load and the total of the pre-stressing load and the rolling load, so that the roll gap is maintained constant. In Fig. 1, mill rolls 20 are journalled in chocks 17, 18 located in recesses in further chocks 14, 15 carrying back-up rolls 16. Chocks 14, 15 are located in end housings 12 and the roll gap is adjustable by screws 22. The mill stand is pre-stressed by hydraulic actuators 25 which force chocks 14,15 apart and are under the control of a valve 27. When material is being rolled, an electrical signal dependent on the total force is derived from load cells 23 associated with screws 22 and another signal dependent on the pre-stressing force is derived from a pressure transducer 29 associated with the hydraulic supply to actuators 25. The difference between these two signals, which represents the rolling force, is obtained by a circuit 31. A proportion of this rolling force signal is selected by a potentiometer 32 and added to the total force signal by a circuit 30 to produce a signal representative of the enlargement of the roll gap caused by the forces involved. This calculated gap enlargement signal is compared with a desired enlargement signal obtained by subtracting, in a circuit 41, a signal from a transducer 40, representing screw-down setting, from an adjustable reference signal produced by a unit 35. Any difference resulting from the comparison produces an output from a circuit 33 which is applied to control valve 27 so that gap enlargement is restored to the desired value. Signals from a gauge 38 detecting errors in thickness of the rolled material are integrated at 37 and modify the output of unit 35 to correct long term changes in thickness. Camber of the rolls may be automatically controlled by the signal representing rolling force to maintain a desired shape of cross-section. Alternative arrangements for pre-stressing the mill and for calculating the gap enlargement are referred to.</p> |
