JPH08300024A - Method for controlling plate width in hot rolling - Google Patents

Abstract

PURPOSE: To contrive high speed control by feed-back-controlling an edger through the prediction of width fluctuation based on changes in the temperature and load of a metal plate immediately underneath the edger, correcting a deviation in the predicted quantity of the width fluctuation, controlling the edger through the enhanced prediction accuracy and thereby providing a width controlling function for both the edger and a horizontal rolling mill. CONSTITUTION: An arithmetic unit 5 calculates manipulated variables ΔST, ΔSP required for a edger 1, from a plate temperature inputted by a thermometer 3 and from value of roll opening degree and load inputted by the edger 1 among others, and feeds back the variables to the edger 1. In addition, an arithmetic unit 7 determines a deviation for correcting the manipulated variable required for the edger, from a difference between the manipulated variable calculated by the arithmetic unit 5 stored in a memory 6 and a change in the plate width inputted by a width meter 4, and feeds back the deviation to the edger 1. Therefore, controlling of a plate width can be carried out at high speed with the accuracy of the control also improved, enhancing quality in hot rolling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip width control method in hot rolling, and more particularly to a strip width control method using an edger and a horizontal rolling mill.

[0002]

2. Description of the Related Art As a method of controlling the strip width of a rolled material by an edger (vertical rolling mill) and a horizontal rolling mill, there is, for example, a method using an automatic strip width control device described in Japanese Patent Publication No. 60-231515. The basic principle of strip width control in this device is the temperature change value of the steel sheet upstream of the edger and the strip width variation value of the downstream side of the horizontal rolling mill, and the effect of the edger opening and temperature change on the strip width change. The influence coefficient called the edger width adjustment efficiency is obtained from the influence coefficient indicating the degree, and the opening degree of the edger is adjusted based on this edger width adjustment efficiency and the plate width fluctuation value and the temperature change value so that the plate width fluctuation becomes zero. As a result, the plate width control accuracy can be improved.

Specifically, as shown in FIG. 4, in a rolling facility having an edger 11 and a horizontal rolling mill 12, a thermometer 3 is provided upstream of the edger 11 and a width gauge 14 is provided downstream of the horizontal rolling mill 12. , The temperature change data measured by the thermometer 13 and the roll opening data of the edger 11 are stored in the memories 13M and 11M, respectively, and measured by the width gauge 14 arranged on the exit side of the horizontal rolling mill 12. Together with the plate width change data, the temperature change data corresponding to the plate width change data and the roll opening correction amount of the edger are read from the memories 13M and 11M, respectively, and input to the arithmetic unit 15. The width adjustment efficiency of the edger 11 is calculated by using the input data of the above and the coefficient of influence of the temperature change data obtained in advance from the physical constants on the plate width variation, and the width adjustment efficiency is calculated. Calculated roll angle correction amount of edger with a plate width change data and the temperature change data corresponding to efficiency, a method of controlling the edger 11 as the side plate width fluctuation out of the horizontal rolling mill 12 is zero.

[0004]

However, the above-mentioned conventional plate width control device has the following problems. The plate width deformation phenomena that must be taken into consideration when setting the roll opening of the edger include the amount of width reduction by the edger and the amount of widening of the rectangular section in the subsequent horizontal rolling mill. Further, there is a swelling deformation that occurs at the end of the plate width when the plate material passes through the edger, that is, there is a width expansion amount in which the dog bone returns in the width direction during rolling by the horizontal rolling mill. The width expansion of the dog bone is mainly influenced by the width reduction amount at the edger, the plate width, the plate thickness at the edger entrance side, etc., so that it needs to be controlled at a high speed because it changes variously. However, the dead time due to the plate material passing time from immediately below the edger to the strip width gauge on the output side of the horizontal rolling mill following the edger is usually as large as 2 to 3 seconds, and high-speed feedback control is impossible.

That is, it is necessary to combine the edger and the succeeding horizontal rolling mill as control targets into one and determine the roll opening at the edger so as to obtain the target strip thickness on the output side of the horizontal rolling mill. It is not sufficient to improve the yield, which causes a decrease in yield.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The edger and the horizontal rolling mill are each provided with a width control function, and high-speed control is realized to achieve the strip width accuracy. It is intended to propose a plate width control method that enables improvement.

[0007]

A strip width control method according to the present invention is a strip width control method in hot rolling in which a strip width of a rolled material is controlled by an edger and a horizontal rolling mill. Of the plate width fluctuation is predicted, the edger is controlled at high speed based on this predicted value, and the predicted value of the plate width fluctuation is compared with the measured value of the width gauge installed on the output side of the horizontal rolling mill to predict the deviation amount. By correcting the edger operation amount as an error, it is a method of controlling the plate width with high accuracy,
The gist is to predict the amount of edger required operation ΔS _T estimated based on the temperature change measured by a thermometer installed upstream of the edger and the amount of width variation immediately below the edger from the deviation of the edger rolling load. Based on the estimated edger required operation amount ΔS _P , the edger is feedback-controlled so that the plate width deviation amount estimated from the plate temperature change and the load change becomes zero, and the above-mentioned ΔS _T and ΔS _P are set. A corresponding strip width variation amount ΔW is obtained by a width meter disposed on the downstream side of the horizontal rolling mill, and the strip width variation amount ΔW and the above ΔS _T +
Δ The required edger operation amount based on the difference from S _P Δ
It is characterized in that S _T and ΔS _P are corrected.

[0008]

In the present invention, the edger required operation amount ΔS _T estimated based on the change of the plate temperature is an arbitrary coefficient (T) which is obtained by tracking the signal of the thermometer provided upstream of the edger to the position just below the edger. Multiplying by (constant) α (△ T ・
α) value. In addition, the required edger operation amount ΔS _{P, which} is estimated by predicting the amount of variation in width immediately below the edger from the deviation amount of the edger rolling load, is a value obtained by multiplying the rolling load ΔP _E of the edger by an arbitrary coefficient (constant). It is a value obtained by adding the opening degree ΔS _{E of the} edger. In the present invention, the edger is feedback-controlled (roll opening is corrected) based on the two required edger operation amounts ΔS _T and ΔS _P , so that the fluctuation of the plate width can be suppressed at high speed.

However, the required operation amount of the above two edgers Δ
Since S _T and ΔS _P are predicted values estimated based on the change in plate temperature and the change in load, they are not necessarily accurate values, but in the present invention, this edger required operation amount Δ
A strip width variation amount ΔW corresponding to S _T and ΔS _P is obtained by a width meter arranged on the downstream side of the horizontal rolling mill, and the strip width variation amount Δ
And W, wherein △ S _T + △ on the basis of the difference between S _P edger required operation amount △ S _T, is corrected to △ S _P, it is possible to control the strip width with high accuracy.

[0010]

【Example】

Embodiment 1 FIG. 1 is a block diagram showing an example of an apparatus configuration for carrying out the method of the present invention, 1 is an edger, 2 is a horizontal rolling mill, 3 is a thermometer, 4 is a width gauge, 5 and 7 are arithmetic units, 6 is a memory.

That is, the rolling equipment to which the present invention is applied has a structure in which an edger (vertical mill) 1 and a horizontal rolling mill 2 are arranged in this order from the upstream side to the downstream side. A thermometer 3 for measuring the temperature of the steel plate is arranged on the upstream side of the edger 1, and a width gauge 4 for measuring the plate width of the steel plate is arranged on the downstream side (outlet side) of the horizontal rolling mill 2. The thermometer 3 is connected to the arithmetic unit 5, and the width meter 4 is connected to the arithmetic unit 7, respectively. The memory 6 is
The necessary operation amount of the edger calculated by the arithmetic unit 5 is stored.

The arithmetic unit 5 uses the plate temperature input from the thermometer 3, the roll opening value and the load value input from the edger 1, etc., and the edger required operation amount ΔS _T used for correcting the roll opening of the edger 1. , ΔS _P are calculated and fed back to the edger 1. Further, the arithmetic unit 7 is
An error amount for correcting the edger required operation amount is obtained from the difference between the edger required operation amount stored in the memory 6 calculated by the arithmetic unit 5 and the plate width change value input from the width meter 4. The feedback is to the edger 1.

In the plate width control device having the above structure, the plate material is fed from the left side of the drawing into the rolling mill group including the edger 1 and the horizontal rolling mill 2. At this time, the temperature change ΔT is actually measured by the thermometer 3 arranged on the upstream side of the edger 1, and the arithmetic unit 5
Is input to Sheet is sent to the edger 1, roll angle variation of edger △ S _E and the load variation △ P _E is measured, is input to the arithmetic unit 5. In the arithmetic unit 5, and the edger required operation amount △ S _T be estimated from the temperature change △ T of the plate,
And edger required operation amount △ S _P estimated from the roll angle variation △ S _E and the load variation △ P _E of edger, edger required operation amount used in the roll opening modified edger 1 △ S ₁ is the following (1) to (3) is calculated by the formula, and at the same time fed back edger required operation amount △ S ₁ to edger 1,
The edger required operation amount ΔS ₁ is stored in the memory 6.
In edger 1 above edger required operation amount △ roll opening based on S ₁ is controlled. ΔS _T = ΔT · α (1) Formula ΔS _P = ΔP _E · β + ΔS _E (2) Formula ΔS ₁ = ΔS _T + ΔS _P (3) Formula α, β: Coefficient (constant)

Next, the measurement of the strip width change ΔW is started when the strip material reaches the width gauge 4 arranged on the exit side of the horizontal rolling mill 2. Then, the edger required operation amount ΔS ₁ corresponding to the plate width change ΔW is read from the memory 6 and input to the arithmetic unit 7, and the difference from the plate width change ΔW is obtained by the following equation (4), and is arbitrarily determined. coefficient γ and multiplying by the edger required operation amount of △ correction amount of S ₁ △ S ₂ is calculated and fed back to the correction amount △ S ₂ in edger 1, edger required operation amount △
Correct S ₁ . ΔS ₂ = (ΔW−ΔS ₁ ) · γ (4) formula

Embodiment 2 FIG. 2 shows a result of performing plate width control by applying the present invention to an actual machine.
Shown in For comparison, FIG. 3 shows the control result by the conventional plate width control device shown in FIG. The product dimensions in this example were plate thickness 3.5 mm and width 1200 mm. The coefficients α, β, and γ used in this example are 2.19 × 10 ⁻⁴ mm / ° C. and 1.16 × 10 ⁻⁴ m, respectively.
It was m / ton, 0.2 (-).

FIG. 2 shows values actually measured by the width meter 4 shown in FIG. As is clear from FIG. 2, according to the method of the present invention, the variation in the width of the tip portion before rolling was 10 mm, but it was improved to within 2 mm on the delivery side of the horizontal rolling mill, and the strip width of the steady portion was improved. The deviation is within ± 1 mm.
On the other hand, in the conventional device, as shown in FIG. 3, the amount of fluctuation of the tip portion before rolling was about 10 mm, but the control responsiveness was not high, so the plate width deviation could not be sufficiently removed. The deviation of 7 mm still remains on the output side of the horizontal rolling mill.

[0017]

As described above, since the present invention is a method for performing feedback control of the edger by predicting the width variation based on the temperature change and the load change immediately below the edger of the plate material, the plate width control can be performed at high speed. While you can
Since the edger is controlled by correcting the error of the width variation prediction amount and improving the prediction accuracy, it has the effect of significantly improving the width control accuracy, which is very effective in improving the quality and yield in hot rolling. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a device configuration for carrying out the method of the present invention.

FIG. 2 is a diagram showing a result of performing plate width control by applying the method of the present invention to an actual machine.

FIG. 3 is a diagram showing a result of plate width control by a conventional plate width control device.

FIG. 4 is a block diagram showing an example of a conventional plate width control device.

[Explanation of symbols]

 1 Edger 2 Horizontal rolling mill 3 Thermometer 4 Width meter 5 and 7 Computing device 6 Memory

Claims (1)

[Claims] 1. In a strip width control method in hot rolling in which a strip width of a rolled material is controlled by an edger and a horizontal rolling mill, it is estimated based on a temperature change measured by a thermometer provided upstream of the edger. Edger required operation amount △
Edger required operation amount ΔS estimated by predicting the width variation immediately below the edger from S _T and the deviation amount of the edger rolling load
Based on _P , the edger is feedback-controlled so that the plate width deviation amount estimated from the plate temperature change and the load change becomes zero, and the plate width variation amount ΔW corresponding to ΔS _T and ΔS _P described above. Is obtained by a width meter arranged on the downstream side of the horizontal rolling mill, and the plate width variation amount ΔW and the above ΔS _T + Δ
Based on the difference from S _P , the edger required operation amount ΔS _T ,
A strip width control method in hot rolling, characterized by correcting ΔS _P.