JPH03128110A - Controller for plate width of continuous rolling mill - Google Patents

Abstract

PURPOSE:To perform the plate width control of a continuous rolling by calculating a tension correction value from the deviation of an actual plate width for an objective plate pressure, calculating an allowable maximum pressure that the shape of a steel plate is not degraded and defining the smaller part between the value that a tension corrected value is added to a tension set value and the maximum allowable tension as a tension reference. CONSTITUTION:The deviation from an objective plate width is fetched from a plate width detector 6 set up at a finishing outlet side, the correction amount of the tension is operated so that the deviation becomes smaller and added to the tension set value on rolling. A means comparing the value with the tension allowable value decided by the specific operation from the rolling conditions and giving the tension control signal corresponding to the value thereof in the case of smaller than the tension allowable value and to the tension allowable value in the case of larger than the tension allowable value, is provided. Thus, the tension of a steel plate is controlled within the range of the tension value without degrading the shape and the plate width control can be performed without degrading the shape of a product.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a strip width control device for a continuous rolling mill that controls strip width by adjusting tension in a hot strip mill finishing mill or the like. It is something.

(Prior Art) In strip width control in hot strip finishing mills, control has been carried out to prevent strip width fluctuations by keeping the tension applied to the steel plate constant. However, the width of the steel plate after rough rolling is not necessarily constant, and the temperature distribution of the steel plate in the rolling direction is also not constant, so the finished width of the exit side plate cannot be made constant just by constant tension control.

In recent years, with improvements in tension control accuracy, methods have been used to control the plate width by actively controlling the tension.

(Problems to be Solved by the Invention) However, in this method, a larger tension is applied to the steel sheet than in the case of constant tension control, which causes a problem that the shape of the finished product deteriorates.

If the shape deteriorates, it is necessary to restore the shape in a downstream process, but it is extremely difficult to restore the shape in a downstream process, leading to a decrease in yield.

The present invention was made in consideration of the conventional problems of tension control, and it calculates the tension value that does not cause shape deterioration from the rolling conditions (steel type, temperature, plate thickness, plate width, etc.), and calculates the tension value that does not cause shape deterioration. It is an object of the present invention to provide a strip width control device for a continuous rolling mill that prevents shape deterioration by controlling tension within a range.

[Structure of the invention]

(Means and effects for solving the problem) The strip width control device according to the present invention acquires the deviation from the target strip width from the strip width gauge installed on the finishing outlet side, and corrects the tension so that this deviation becomes smaller. Calculate the amount and add it to the tension setting value for rolling, compare this value with the tension tolerance determined by a predetermined calculation from the rolling conditions, and if it is smaller than the tension tolerance, add it to that value, and add it to the tension tolerance. If the tension is large, a means is provided to give a tension control signal according to the allowable tension value, thereby controlling the tension of the steel plate within a tension value range that does not cause deterioration of the product shape, and controlling the sheet width without causing deterioration of the product shape. We are making it possible to do so.

(Example) An embodiment of the invention is shown in the figure.

In the figure, 1 is the steel material to be rolled, 2A and 2B are rolling rolls, 3 is a looper for controlling the tension of the steel material 1 between the rolling rolls 2A and 2B, 4 is its drive motor, 5 is its drive power source, 6 is a plate width meter provided on the exit side of the rolling roll 2B.

That is, in order to apply tension to the steel plate 1, rolling mills 2A, 2
Rotating torque is applied to the looper 3 installed between B by an electric motor 4.

7 is a tension correction value calculator, which calculates a tension correction amount ΔT for correcting the deviation ΔW of the actual plate width from the target plate width detected by the plate width gauge 6 installed on the exit side of the rolling roll 2B. do.

Reference numeral 8 denotes a tension tolerance value calculator, which computes a tension tolerance value TA to prevent shape deterioration from given rolling conditions (steel type, temperature, plate thickness, plate width, etc.).

Reference numeral 9 is a limiter, which sets the smaller of the above-mentioned tension allowable value TA, the sum Ts + ΔT of the separately input tension set value TS and the above-mentioned tension corrector ΔT as the actual tension reference signal T*. Output.

This tension reference signal T* is input to the drive power supply 5 via the tension control calculator 10, and the looper 3 is raised and lowered via the drive motor 5 to control the tension of the steel plate 1, thereby causing deterioration of the shape of the steel plate. It becomes possible to control the width of the steel plate within a predetermined range within a certain range.

〔Effect of the invention〕

As explained above, according to the present invention, in the strip width control device of a continuous rolling mill that controls the strip width by adjusting the tension, the tension is limited to a range that does not cause deterioration of the shape of the steel sheet, resulting in deterioration of the shape of the steel sheet. It is possible to control the width of the steel plate without any problems.

[Brief explanation of the drawing]

The figure is a system diagram showing one embodiment of the present invention. steel plate rolling roll Roopa drive motor Drive power supply Plate width detector Tension correction value calculator Tension tolerance calculator restrictor Tension control calculator

Claims (1)

[Claims] In the strip width control device of a continuous rolling mill, which controls the tension of the steel strip between the rolls of the continuous rolling mill to control the width of the steel strip to the target value, the tension correction value is calculated from the deviation of the actual strip width from the target strip width. a tension correction value calculation means for calculating the maximum allowable tension to prevent deterioration of the shape of the steel plate based on the given rolling conditions; 1. A strip width control device for a continuous rolling mill, comprising a limiting means for outputting the smaller of the allowable maximum tension as a tension reference for tension control of the steel plate.