GB1354971A - Method and apparatus for controlling delivery gauge in a metals rolling mill - Google Patents

Abstract

1354971 Automatic control of rolling mills GENERAL ELECTRIC CO 2 Aug 1971 [13 Aug 1970] 36132/71 Heading G3R In a multiple stand rolling mill, the exit thickness of strip from a stand is controlled by the difference between valves of exit thickness calculated (a) from the force on the rolls, the unloaded roll gap and the mill modulus of elasticity and (b) from the exit strip speed at that stand, and the exit strip speed and thickness at the final stand. In the embodiment, the force on the rolls is measured by load cells 20, 30, the strip speed by tachogenerators 21, 39 and the output thickness by an X-ray gauge. For stand II, for example, the calculations of exit thickness using "gaugemeter" and "mass flow" techniques are differenced, and fed to a summer 25 and position control 26 to adjust the screwdowns. The "mass flow" calculation may be corrected according to the proportion of the total load exerted by the stand. The differenced signal may be passed periodically to the roll gap adjuster, which may be digital or analogue.