US 4,240,147 A · Gauge control method and system for rolling mill

Abstract

The present invention provides a method and a system for controlling strip thickness in rolling mill, especially adapted in the case where material is rolled by a tandem rolling mill. According to the present invention, the change in the strip thickness from one sampling epoch to another is calculated on the basis of two sampling values, i.e. strip thickness and strip thickness deviation, at the entrance side of a mill stand; the press-down speed and the workpiece tension are determined according to such a condition as to minimize the calculated change during the sampling period; and the press-down speed and the interstand tension are regulated by the thus determined mill speed and tension when a certain portion of the strip reaches the stand bite of the next mill stand.

Claims13

Dependent claims

A system for minimizing deviations in the delivered strip thickness in a tandem rolling mill, comprising:

means for sampling one of thicknesses and thickness deviations of the strip at the entry and delivery sides of each rolling stand of the tandem mill during rolling operation with a predetermined sampling period;
a calculating unit for determining the time rate of change of the incoming thickness of the strip at each rolling stand as a function of the sampled values thereof and the sampling period;
an optimal control unit receiving the outputs of said sampling means and said calculating unit for determining an optimal value of a control parameter for mill operation effective to control the delivery thickness of the strip at each rolling stand, the optimal value satisfying a predetermined evaluating function which is a function of at lease one of the time rate of change of the incoming thickness, the delivery thickness and thickness deviation of the strip at each rolling stand, and said control parameter;
and
means for controlling the mill operation on the basis of said optimal value determined for each rolling stand.

2 more elements

A method for controlling the strip thickness out of a tandem rolling mill to a desired value, comprising the steps of:

sampling one of thicknesses and thickness deviations of the strip at the entry and delivery sides of a respective mill stand of the tandem rolling mill during rolling operation with a predetermined sampling period and generating electrical signals in accordance therewith;
determining the time rate of change of the incoming thickness of the strip at respective mill stands as a function of the generated electrical signals of the sampled values thereof and the sampling period and generating electrical signals in accordance therewith;
obtaining optimal values of control variables at respective mill stands in response to the generated electrical signals of the time rate of change of thickness of the strip and generating electrical signals in accordance therewith, the values being obtained for satisfying a predetermined evaluating function;
and
automatically controlling the tandem rolling mill in response to the generated electrical signals of the optimal values obtained so as to maintain the optimal values and minimize deviations in the delivered strip thickness.

2 more elements

Dependencies are inferred from the claim text.

Gauge control method and system for rolling mill

Life of this patent

Gauge control method and system for rolling mill

Life of this patent

Abstract

Claims13