JPS57149014A - Method for preventing steel sheet from cambering and rolling mill used therefor - Google Patents

Abstract

PURPOSE:To prevent steel sheet from cambering, by controlling a rolling load automatically so as to eliminate a fluctuation of the mutual difference between both left and right rolling loads during rolling. CONSTITUTION:Respective rolling load signals (b) and (a), from load guages 5 and 7 located at the left and right sides, are outputted to a load-difference computing-circuit 9 when steel sheet 1 is fed into between work rolls 11 and 12, and here the difference between (a) and (b) is computed to output a load-difference signal (c). Successively when a crop part 1a of the sheet 1 reaches a standard position after passing through between the work rolls 11 and 12, a position detector detects it and outputs a position-signal (d). The load-difference signal ''c'' at the time when the signal ''d'' is inputted to the circuit 13 is outputted by a standard load-difference memory-circuit 13 as a standard load- difference (e). Subtracter 14 outputs a load-difference fluctuation-signal ''g'' after computing the difference between (e) and (c). A rolling-load controlling circuit 15 prevents the fluctuation of difference between both rolling loads at the left and right sides, by outputting such a controlling signal (h), that makes (g) zero, to control both screw-down means 2 and 3 at the left and right sides through both left and right screw-down motors 16 and 17.