Rolling mills and operation thereof
AssigneeLoewy Robertson Engineering Company Limited
InventorsRobin Clarke, Douglas J. Thomas, George T. F. Kilmister, Robert R. Beal
Life of this patent
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Abstract
To operate a rolling mill to roll metal strip with a satisfactory degree of flatness, signals from tension detecting means located downstream of the mill rolls are used continuously to determine the best symmetrical parabola which fits the shape of the strip and a parameter of the parabola is used to bring about an adjustment of the bending of the mill rolls in such a sense as to change the parameter substantially to zero. Signals from the detecting means may be used in addition to control the steer of the mill and adjust the temperature of the roll assemblies along their length.
Claims11
A method of operating a rolling mill, for rolling metal strip, which includes a pair of roll assemblies, means for adjusting the gap between said roll assemblies at each of their ends, means for bending said roll assemblies, means for adjusting the temperature of said roll assemblies along their length, and means located downstream of said roll assemblies for detecting the tension of a strip being rolled at a plurality of zones defined across the width thereof, comprising the steps of:
- utilizing signals from said detecting means to substantially continuously determine the best straight line which fits the shape of said strip being rolled as represented by said signals;
- utilizing at least one parameter of said straight line to initiate differential adjustment of said roll gap in such a sense as to change said parameter substantially to a predetermined value;
- utilizing said signals from said detecting means to substantially continuously determine the best symmetrical parabola which fits the shape of said strip being rolled as represented by said signals;
- utilizing at least one parameter of said parabola to initiate the operation of said roll bending means in such a sense as to change said parameter substantially to a predetermined value;
- estimating the resulting effect of said differential adjustment and said roll bending action upon said signals from said detecting means;
- and
- subtracting said estimated effects from said signals from said detecting means so as to produce residual signals which are used to operate said temperature adjusting means in order to adjust the temperature of said roll assemblies at localized regions along their length so as to even out residual variations of said tension of said strip across its width.
A method of operating a rolling mill, for rolling metal strip, which includes a pair of roll assemblies, means for adjusting the gap between said roll assemblies at each of their ends, means for bending said roll assemblies, means for adjusting the temperature of said roll assemblies along their length, and means located downstream of said roll assemblies for detecting the tension of a strip being rolled at a plurality of zones defined across the width thereof, comprising the steps of:
- utilizing signals from said detecting means to substantially continuously determine the best straight line which fits the shape of said strip being rolled as represented by said signals;
- utilizing at least one parameter of said straight line to initiate differential adjustment of said roll gap in such a sense as to change said parameter substantially to a predetermined value;
- estimating the resulting effect of said differential adjustment upon said signals from said detecting means;
- subtracting said estimated effect from said signals from said detecting means so as to produce residual signals;
- utilizing said residual signals to substantially continuously determine the best symmetrical parabola which fits the shape of said strip being rolled as represented by said residual signals;
- utilizing at least one parameter of said parabola to initiate an adjustment of said roll bending means in such a sense as to change said parameter substantially to a predetermined value;
- estimating the resulting effect of said roll bending action upon said residual signals;
- and
- subtracting said estimated effect from said residual signals so as to produce further residual signals which are used to operate said temperature adjusting means in order to adjust the temperature of said roll assemblies at localized regions along their length so as to even out residual variations of said tension of said strip across its width.
Dependencies are inferred from the claim text.