GB1477314A - Rolling mill test equipment - Google Patents

Abstract

1477314 Testing rolling mill stand BRITISH STEEL CORP 6 Sept 1974 [7 Sept 1973] 42240/73 Headings G1M G1N G1S and G1W Apparatus for testing the characteristics of a rolling mill stand comprises two rigid members 8, 9 pivotally inter-connected at 14, each member being adapted to be mounted on a respective work roll mounting means at a location spaced from pivot 14, means 35 for applying a load between the rigid members, and means for measuring the load. The work rolls 4 of stand 1 have been removed in Fig. 1, and arms 9, 10 are mounted on the securing bolts (5, 6) by means of bushes (10, 11), spacers 19, 20 and nuts 21 22 Fig. 3 (not shown). The spacing of the arms 9, 10 is measured by a transducer 30, and the arms engage the back-up rolls via pads 15, 16. To apply load between the arms there is provided an hydraulic piston and cylinder assembly 35 which is seated on a rubber cushion 34 intended to simulate the stress-strain characteristics of a rolled hot billet, and the relative displacement of the piston and cylinder of the assembly is measured by transducer 38. The assembly 35 and a cushion 34 may be replaced, as shown in Fig. 4, by an hydraulic piston and cylinder unit 44 mounted on a load cell 46. Pivot 14 is connected via links 48 to the cylinder of an hydraulic piston and cylinder unit 50, the piston of which is connected to a draw rod 51 passing between the working rolls 4 of stand 2. The displacement of the piston of assembly 50 is measured by a transducer 52, and rod 51 carries a strain gauge. The end of draw rod 51 is connected to a yoke 54 which engages the rolls 4 via four pairs of rollers 57 and which is slidably mounted on a pivoted arm 55. In use, the arrangement of Fig. 4 is set up and assembly 44 actuated to apply forces to the arms 8, 9 and hence to rollers 3. The automatic gap control system of the roll stand operates to maintain the gap between rolls 3 constant and readings of the roll stand load cells and the gap transducers of the roll gap control system are checked against the readings of transducer 30 and load cell 46 respectively. From the operations of the gap control system, it is possible to deduce the stretch of the mill stand caused by the load, and the stiffness of the mill stand is calculated. The arrangement of Figure 4 is then replaced by that of Fig. 2 and the response of the gap control system is checked by applying a squarewave pressure input to assembly 35 and recording the pressure input and the outputs of transducers 30 and 38. In the next step, pressure is applied to assembly 50 and the roll stand tension measuring devices are calibrated against the strain gauge on draw bar 51. Finally the response of the roll stand tension measuring devices is checked by applying an oscillatory pressure input to the assembly, and the pressure applied or the output of transducer 52 is recorded in a U.V. recorder along with the outputs of the roll stand tension measuring devices.