GB1155013A - Rolling Mill - Google Patents

Abstract

1,155,013. Rolling. UNITED ENG. & FOUNDRY CO. 5 July, 1966 [5, July, 1965], No. 28443/65. Heading B3M. [Also in Division G3] A rolling mill includes screws 42 positioned between work roll chocks 17 and 18 for setting the initial roll gap, and an additional screwdown 27, acting on the upper backing roll chock 21, for adjusting the intial roll gap. Such adjustment may be made in response to the outputs from load cells 46. Each chock 17 houses a pair of screws 42 rotatable in fixed nuts 41 and bearing against load cells 46. A spring 48 beneath each load cell protects the rolls from shock loads when the trailing end of a rolled strip leaves the mill. Each screw is rotatable, through pinions 43-45, from a rod 51 and rod 55. A pair of electric motors on top of the mill housings rotate the four screws. The conventional screwdown 27, which is driven by a further pair of motors, can conveniently be replaced by an hydraulic mechanism disposed beneath the lower chock 19. The output from load cells 46, Fig. 5, is fed to an amplifier 61 where it is converted to a thickness value, and then to an amplifier 62 where the value is compared with a reference value, and any difference fed along line L to a servo valve 65 which controls the screwdown 27. The pressure urging the work rolls together is thus maintained at a value which exceeds the rolling load by a predetermined amount. Reference thicknesses T 0 or T 1 , corresponding to the no load gap and normal rolling gap, are fed together with a modified value of the load in the cells 46 to an amplifier 72 which controls the position of the screws 42. Any resulting pressure difference in the cells 46 leads to a corrective change of the roll gap by the screwdown 27. An additional thickness control system which measures the thickness of the rolled strip can be used to monitor the control system for maintaining the pressure constant.