JP2015003339A - Wedge control method and device in hot strip mill finishing roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control automatically plate thickness difference between a working side and a driving side in a hot strip mill finishing roller.SOLUTION: Rolling load difference between a working side and a driving side is measured at each stand table in a hot strip mill finishing roller, immediately after a plate bit to the stand table, and the measured value is stored. Then, in following rolling, roll gap difference between the working side and the driving side is controlled so that the rolling load difference between the working side and the driving side becomes the stored value (or, an optional value applied from outside).

Description

      The present invention relates to a method and apparatus for automatically controlling a sheet wedge on a delivery side to a desired value (often zero) in a finishing mill that tandemly rolls a transfer bar.

  The present invention relates to plate wedge control in a hot strip mill finish rolling mill. The hot strip mill finish rolling mill is rolled by, for example, 5 to 7 stand rolling mills arranged in tandem (continuous). However, in the prior art, the operator manually operates the leveling of the roll gap at each stand, and the product plate on the exit side of the final stand of the finishing mill has a desired thickness difference between the working side and the drive side (this is called a wedge). (Usually there are many cases of zero).

    In the finish rolling mill, the plate wedge changes at each stand while rolling the plate. However, since there is no measuring device for the plate wedge in each stand, the operator did not know how to correct the plate wedge. For this reason, the wedge of the product plate did not reach the desired value.

    In each stand of the finishing mill, there is a problem that the plate moves in the plate width direction during rolling, so that the outlet plate wedge of each stand fluctuates.

      Patent Document 1 has a plate wedge measuring device on the exit side of the finish rolling mill, and feedback-controls the plate wedge deviation measured here to the roll gap difference of each stand. However, there is a drawback that the control accuracy of the wedge is deteriorated when it is moved in a straight line.

      There was no method and apparatus for controlling the plate wedge in cooperation with Patent Document 1 and the movement control in the plate width direction of the plate.

  JP WO2006 008808A1 2006.1.26

    The present invention automatically controls the movement in the width direction of the plate being rolled at each stand of the finish rolling mill to bring the plate wedge of the product to a desired value (usually zero). That is, the present invention is carried out in cooperation with Patent Document 1 to bring the wedge of the product plate to a desired value.

The present invention feedback-controls the rolling load difference between the working side and the driving side to the roll gap difference between the working side and the driving side at each stand of the finishing mill of the hot strip mill so as to eliminate the movement of the plate in the plate width direction. As a result, there is no change in the plate wedge.

According to the present invention, the thickness difference between the working side and the driving side of the product plate of the hot strip mill becomes a desired value, so that not only the stability of rolling is improved, but also the accuracy and flatness of equipment using this product are improved. The degree of improvement is planned.

The present invention keeps the rolling load difference between the working side and the driving side at the value at the time of biting in the finishing rolling mill of the hot strip mill, or keeps it at an arbitrary value, thereby eliminating the movement in the width direction of the plate and keeping the plate wedge constant. Therefore, an expensive wedge meter is not required for each stand.

Hereinafter, embodiments of a plate wedge control method and apparatus in a hot strip mill finish rolling mill according to the present invention will be described in detail with reference to the drawings. First of all, the present invention finds that the plate moves in the plate width direction at each stand during rolling, so that there is a difference between the rolling load on the working side and the rolling load on the driving side, which causes the plate thickness on the working side and the driving side to be different. Due to having obtained. The cause of the movement of the plate in the plate width direction is difficult to identify, but it is thought that there are differences in plate temperature on the working side and drive side, differences in mill constants, plate wedges on the stand entry side, roll wear, etc. .
The embodiment described in claim 1 of the present invention is shown in FIG. 1 is a roll gap difference (leveling) set value between the working side and the driving side before rolling. Usually this is set by the operator or by a process computer not described in the present invention. Usually, the setting value of the front material is used or the setting value is determined by a slight modification. The roll gap difference (leveling) set value between the work side and the drive side is set via the 4 work side roll gap control device for the work side and the 5 drive side roll gap control device for the drive side. When the end of the plate bites into each stand, a rolling load is generated on the working side and the driving side in the rolling mill of 6. The rolling load difference is calculated by an adder 7 and stored in a memory 9. Thereafter, the difference between the rolling load difference of 8 and the rolling load difference at the tip end of the plate stored in 9 is calculated by the adder 10, and is calculated by the 11 proportional controller and the integral controller. In addition to 2, half is subtracted by the adder 3 on the driving side and given to 4 and 5 respectively to correct the roll gap on the working side and the driving side. That is, when the roll gap on the working side is opened, the roll gap on the driving side is closed by the same amount, or the opposite operation is performed. This correction is performed, for example, every 10 (milliseconds) until the board passes through each stand. As a result, the rolling load difference between the working side and the driving side becomes equal to the rolling load difference between the working side and the driving side at the tip of the plate, so that the plate does not move in the plate width direction, and the plate wedge is constant from the tip of the plate to the tail end. Become. By applying this to the method and apparatus of [Patent Document 1], the wedge of the product plate can be set to a desired value.
Regarding claim 2, an arbitrary value (including zero) is given instead of the rolling load difference between the working side and the driving side at the front end of the plate described in claim 1. This is given at 10 in FIG. Others are the same as those of claim 1.

An economical method and apparatus since a rolling load meter and a roll gap control device which are normally installed in a hot strip mill finish rolling mill are used, and an adder and a proportional + integral control device are added thereto. Become.

These are explanatory drawings which showed the implementation method of the wedge control in a hot strip mill finish rolling mill.

DESCRIPTION OF SYMBOLS 1 Roll gap difference setting value 2, 3, 7, 10 of working side before driving and driving side Roller control device 5 on working side Roll gap controlling device 6 on driving side Rolling mill and material to be rolled 8 Working side And the rolling load difference on the drive side 9 Memory 11 Proportional + Integral control 12 Multiplier

Claims (2)

      In a hot strip mill finishing rolling mill, an apparatus for measuring the rolling load on the driving side and the working side for each stand, an apparatus for operating a roll gap difference between the driving side and the working side (referred to as roll gap leveling), a material to be rolled, , Immediately after the tip of the material to be rolled bites into each stand of the finishing mill (sheet tip), the rolling load on the driving side and the working side is measured and the rolling on the driving side and the working side is performed. The load difference is stored, and the roll gap difference between the driving side and the working side is controlled by proportional control + integral control so that the rolling load difference between the driving side and the working side coincides with the stored value in subsequent rolling. Characteristic board wedge control method and apparatus.       In a hot strip mill finishing rolling mill, an apparatus for measuring the rolling load on the driving side and the working side for each stand, an apparatus for operating a roll gap difference between the driving side and the working side (referred to as roll gap leveling), a material to be rolled, And control device, measure the rolling load on the drive side and work side of the material to be rolled, and the rolling load difference between the drive side and work side matches the value set by the operator (any value including zero) A control method and apparatus for a plate wedge, wherein the roll gap difference between the driving side and the working side is controlled by proportional control + integral control.

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