JPH08141616A - Automatic gage controller for rolling mill - Google Patents

Abstract

PURPOSE: To provide an automatic gage controller for rolling a rolled stock having highly accurate thickness from the headmost end of the rolled stock which is rolled with a rolling mill. CONSTITUTION: This controller is provided with an outlet-side thickness arithmetic unit 30 for calculating the correction value by the amount of thermal expansion of roll and abrasion loss of roll and also calculating thickness on the outlet side by use of the correction value, the amount of mill elongation calculated by interpolating the reference value of mill elongation amount in a mill elongation amount arithmetic unit 20 and screw-down location from a screw-down location controller 5. The correction value of the screw-down location is calculated with an arithmetic unit 40 for correction value of screw-down location so that this thickness on the outlet side is made to match the target thickness and, at the time of correcting the screw-down location of rolling rolls 3 through the screw-down location controller 5, the correction value of the amount of mill elongation is calculated with a device 50 for calculating/ correcting the amount of mill elongation and the reference value of the amount of mill elongation in the arithmetic unit 20 for the amount of mill elongation is corrected. In this way, the thickness accuracy in the tip part of the rolled stock 1 is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for automatically controlling the thickness of rolled material rolled by a rolling mill to a desired thickness.

[0002]

2. Description of the Related Art For example, a conventional method for estimating the outlet plate thickness is as follows. FIG. 7: is a schematic block diagram which shows the conventional automatic plate thickness control apparatus of a rolling mill. In this figure, 1
Is a rolled material, 2 is a vertical roll for rolling the rolled material 1,
3 is a rolling stand, 4 is a rolling load detection device, 5 is a rolling position control device, and 6 is a roll gap correction device that corrects the mill extension amount due to changes in rolling load. In addition, 7 is an exit side plate thickness detector.

The roll gap correction device 6 calculates the mill elongation change amount Δδ from the rolling load change amount ΔP using the tuning rate α and the mill constant Kc by the following equation (1), and Δδ = (α / Kc) · ΔP …………………… (1) Next, add the rolling position change amount ΔS and the mill elongation change amount Δδ, and calculate the output side plate thickness change estimated value ΔhGM by the following formula (2), and then ΔhGM = ΔS + Δδ. ……………… (2) This estimated value ΔhGM of the outlet side thickness change and the target value Δ of the outlet side thickness change
Compared with hc, the rolling position change ΔS is corrected so that they coincide with each other.

However, the amount of change in mill elongation Δδ changes under the influence of rolling load, roll rotation speed, strip width, roll crown, and the like. In particular, since the rolling load changes non-linearly, the correct amount of change in mill elongation cannot be estimated by the linear approximation by the above-mentioned equation (1), and the deviation of the strip thickness at the delivery side occurs. Therefore, for example, in Japanese Examined Patent Publication No. 6-49207, the elongation of the mill is corrected by adding a quadratic term due to the variation of the rolling load to the first term of the variation of the rolling load according to the equation (1). The error due to the linear approximation is reduced.

In recent years, the performance of strip thickness control has improved due to the introduction of hydraulic pressure reduction, the thickness gauge between stands, and the speeding up of computers, and the problem of strip thickness control has shifted from the steady part to the leading edge of the rolled material. In order to improve the thickness accuracy of the most advanced rolled material, it is important to accurately predict the appropriate rolling position from the rolling conditions, and for that purpose the mill elongation must be accurately predicted. However, the method according to Japanese Patent Publication No. 6-49207 has a problem that the approximation accuracy of the mill elongation deteriorates if the rolling load deviates from the vicinity of the standard rolling load.

Further, as a method for improving the prediction accuracy of the mill elongation, the following method is adopted. Here, as the shape control means that affects the roll crown, there are a roll bending device, a roll shift device, a crown adjusting device in a split backup roll, and the like.
Here, it is assumed that a roll bending device is included.

Now, the mill elongation amount δ is approximated by the following equation (3). δ = f (P, F, V, W) ……………… (3) where P: rolling load, F: roll bending force,
V: roll rotation speed, W: plate width. Then, the plate thickness hx detected by the delivery side plate thickness gauge and the plate thickness hGM calculated by the mill elongation amount are compared, and the error is taken in as a learning term δhlean of hGM.

HGM = S + δ + δhlean ……………… (4) δhlean = Σ {g · (hx −hGM)} ……………… (5) where g: gain, Σ; It is a sum. However, this method does not correct the error in the calculation formula (3) of the mill elongation amount δ, so it is effective when the same rolling conditions are continuous, but the strip width, rolling load, roll bending force, If the rolling conditions such as the roll rotation speed change, there is a drawback in that quick correction cannot be performed.

[0009] In Japanese Patent Laid-Open No. 5-212421, the accuracy of estimating the outgoing side plate thickness is improved by using a linear method, but since the frame of linear approximation is not shown, when the rolling conditions change significantly. , Cannot maintain accuracy.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, in which rolling load, strip width, roll rotation speed, operation amount of shape control means, etc. are changed. Even with the purpose of providing an automatic plate thickness control device for a rolling mill capable of rolling a rolled material with high plate thickness accuracy from the leading edge of the rolled material by correctly predicting the amount of mill elongation having nonlinearity. To do.

[0011]

[Means for Solving the Problems] Although there is a hysteresis in the amount of mill elongation with respect to the rolling load due to the resistance of the sliding portion, etc., this hysteresis is small and the same mill elongation is obtained under almost the same rolling conditions. Expected quantity. In addition, since the roll elongation and roll wear do not occur immediately after the rolls are replaced, the error in the mill elongation is based on the rolling state immediately after the rolls are replaced. It can be handled separately in the unit and rolled material.

In the present invention, paying attention to the above points, a plurality of mill elongation reference values are set in advance for the parameters of rolling load, strip width, operation amount of shape control means, and roll rotation speed, and the mill is set. By correcting the reference value of the elongation amount with the mill elongation amount calculated by using the difference between the detection value of the outlet plate thickness and the rolling position of the rolling position control device, the prediction accuracy of the mill elongation amount for a wide range of rolling conditions To achieve improvement.

That is, the present invention comprises a rolling load detecting device for detecting a rolling load, a delivery side plate thickness detector for detecting a delivery side plate thickness of a rolled material, a rolling load, a strip width, a roll peripheral speed and a shape control means. Calculate the mill elongation amount by pre-entering multiple reference values for the mill elongation amount using at least one factor including the rolling load as a parameter among the factors of the operation amount, and interpolating the reference value of the mill elongation amount. A mill elongation calculation device, a rolling position control device that corrects the rolling position to correct the plate thickness of the rolled material to a target value, a correction value based on the roll thermal expansion amount and the roll wear amount, and the correction value An output side plate thickness calculation device that calculates the output side plate thickness from the mill expansion amount calculated by the mill expansion amount calculation device and the detected value of the reduction position from the reduction position control device, and is calculated by the output side plate thickness calculation device. Ejection side plate thickness is eye The correction value of the rolling position is calculated so as to match the plate thickness, and the rolling position correction amount calculation device that outputs the correction value of the rolling position to the rolling position control device is provided. Correct the reference value of the mill elongation amount by using the mill elongation amount obtained from the correction value, the detection value of the outlet plate thickness from the outlet side plate thickness detector, and the detection value of the reduction position from the reduction position control device. An automatic strip thickness control device for a rolling mill, characterized in that a mill elongation calculation correction device is provided.

[0014]

According to the automatic plate thickness control device for a rolling mill of the present invention,
When the rolled material reaches the rolling mill, the correction value based on the roll thermal expansion amount and the roll wear amount is calculated as in the conventional device, and the correction value based on the roll thermal expansion amount and the roll wear amount, and the mill elongation calculation device In Eq. (3), a delivery side plate thickness calculation device that calculates the delivery side plate thickness from the mill extension amount calculated by interpolating the reference value of the mill extension amount and the reduction position of the reduction position control device is provided. The correction value of the reduction position is calculated by the reduction position correction amount calculation device so that the correction value of the reduction position is corrected, and the correction value of the mill expansion amount is calculated by the mill elongation calculation correction device when correcting the reduction position. Since the reference value of the mill elongation amount in the mill elongation amount calculation device is modified, the mill elongation amount can be calculated with high accuracy, and thereby the prediction accuracy of the delivery side plate thickness can be improved. Is.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of an automatic plate thickness control device for a rolling mill according to an embodiment of the present invention. FIG.
In the same manner as in the conventional apparatus, the rolled material 1 is rolled in the arrow F direction by the rolling roll 3 driven by the drive motor 8 controlled by the roll rotation control device 10.

The mill elongation amount calculation device 20 is a roll bending device which is a shape control means and a detected value of the rolling load from the rolling load detection device 4 and, if necessary, a detected value of the roll peripheral velocity from the roll rotation control device 10. From the roll bending force detection value from 12 and the strip width from the upper computer 100 or the strip width detection value from the strip width gauge that detects the strip width of the rolled material 1 (not shown) It is a device that interpolates values to calculate the mill elongation.

The delivery side plate thickness calculation device 30 calculates a correction value based on the roll thermal expansion amount and the roll wear amount, and the correction value, the mill extension amount calculated by the mill extension amount calculation device 20, and the rolling position control device. This is a device for calculating the outlet plate thickness from the detected value of the rolling position from 5. In addition, the rolling position correction amount calculation device 40
Calculates a correction value of the reduction position such that the output plate thickness calculated by the output side plate thickness calculation device 30 matches the target plate thickness value, and the calculated correction value of the reduction position is calculated by the reduction position control device 5
Is a device for correcting the reduction position to correct the outlet plate thickness to a target plate thickness value.

The mill elongation calculation correction device 50, which is a feature of the present invention, includes a correction value based on the roll thermal expansion amount and the roll wear amount, and a delivery side plate thickness detection value from the delivery side plate thickness detector 7.
Correction of the mill elongation amount from the detected value of the rolling load from the rolling load detection device 4, the detected value of the reduction position from the reduction position control device 5, and the calculated value of the mill elongation amount calculated by the mill elongation calculation device 20. It is an arithmetic device that calculates a value and corrects the reference value of the mill elongation amount of the mill elongation arithmetic device 20.

In the above embodiment, the roll bending device 12 is used as the shape control means and the roll bending force is used as the operation amount, but the shape control means is not limited to this, and the roll shift device or By using the crown adjusting device of the split backup roll, those operation amounts may be used as the shift amount and the crown adjusting amount, respectively. Further, these shape control means may be used alone or in combination.

The next operation will be described. The reference value of the mill elongation amount used in the mill elongation amount calculation device 20 is a parameter of one or more factors including at least the rolling load from among factors of the rolling load, the strip width, the roll peripheral speed and the operation amount of the shape control means. As a result, the amount of deformation of the housing of the rolling mill, the amount of bending of the roll, the amount of flat deformation of the roll, the amount of deformation of the rolling screw, the amount of deformation of the bearing portion, and the oil film of the bearing portion are calculated by elastic deformation calculation of a known rolling mill. The amount of thickness, the amount of change of the rocker plate and other members, the amount of deformation of the reduction cylinder, and the amount of compression deformation of the oil column may be calculated and obtained from the sum thereof, or a known rolling method or tightening method. You may ask for it by the experiment by. Furthermore, the calculated value may be corrected with the above experimental value after the calculation. However, in the method by calculation, there is an error in modeling, and in the experiment, since the cost of the experiment is high, many experiments cannot be performed, and thus there is also an error.

First, the case where the mill elongation parameter is only the rolling load will be described. In FIG. 2, n pieces of mill elongation reference values δ _i (i = i = i = i = i = _i ) with the rolling load as a parameter for calculating the mill elongation in the mill elongation calculation device 20.
1, 2, ... N) are shown as an example. This mill elongation amount contains an error. Here, P ₁ is the minimum value of the rolling load applied in the rolling mill, and P _n is the maximum value.

Therefore, when the rolling load P is input, the adjacent
Reference point A_i(P_i, Δ_i), A _{i + 1}(P_{i + 1}, Δ
_{i + 1}) Is selected and the mill elongation δcal is calculated by interpolation.
It As the interpolation method, linear approximation or polynomial of quadratic or higher
Expression approximation or spline approximation may be used. Straight line
An example of calculating the mill elongation δcal by approximation is shown below.
It is like the expression (6).

Δcal = {(δ _{i + 1} −δ _i ) / (P _{i + 1} −P _i )} · (P−P _i ) + δ _i ………… (6) Next, the outlet plate thickness The calculation device 30 uses the correction values based on the roll thermal expansion amount and the roll wear amount, the mill elongation amount δcal obtained by the mill elongation amount calculation device 20, and the reduction position S, which is the detection value from the reduction position control device 5, to determine the following. The outlet plate thickness hgm is calculated using the equation (7).

Hgm = S + δcal + S ₀ + Scmp (7) Here, the reduction position S is a detection value detected by the height of the oil column of the reduction cylinder or the moving amount of the reduction screw, and S ₀ is the replacement of the rolling roll. The correction value of the roll interval due to the change of the roll diameter, and Scmp are the correction value of the roll interval due to the roll thermal expansion amount and the roll wear amount.

The roll interval correction value S ₀ is obtained as follows. That is, the mill elongation δ at the tip of the first rolled material after replacement of the rolling rolls
Using cal, the detected value hx of the outlet plate thickness detected by the outlet plate thickness detector 7 and the rolled position S which is the detected value from the rolled position control device 5, the following formulas (8) and (9) are used. . This is because the correction values of the thermal expansion amount of the roll and the wear amount of the roll can be ignored when the leading end of the first rolled material after rolling is being rolled.

Δreal = hx−S (8) S ₀ = δreal−δcal (9) Correction value S based on roll thermal expansion Sth and roll wear Swe
cmp is calculated using the following equation (10). Scmp = Sth + Swe (10) The roll thermal expansion amount Sth is obtained, for example, by the formula (11) during rolling and by the formula (12) during non-rolling.

Sth = (Sth ₁ −Sth ₀ ) {1-exp (−t / t ₁ )} + Sth ₀ ...... (11) Sth = Sth ₂ · exp (−t / t ₂ ) ……………… (12) where Sth ₁ is the roll thermal expansion amount when the heat balance is balanced, Sth _{0 is} the roll thermal expansion amount at the start of rolling, t is the time from the start of rolling, t _{1 is the} time constant, Sth ₂ The amount of roll thermal expansion at the end of rolling, t; the time from the end of rolling, t ₂ ; the time constant.

The roll wear amount Swe is obtained, for example, by the equation (13). Swe = kwe · (P / W) · L (13) where, kwe: coefficient, P: rolling load, W: strip width, L: total rolling length rolled by the rolling roll. Is. Next, the reduction position correction amount calculation device 40 calculates the correction value of the reduction position so that the delivery side plate thickness hgm matches the target plate thickness, and outputs the correction value of the reduction position to the reduction position control device 5. The rolling position control device 5 corrects the rolling position to correct the delivery side plate thickness. As described above, since there is an error in the reference value of the mill elongation in the automatic plate thickness control device that controls the plate thickness of the rolled material, the plate thickness accuracy of the rolled material deteriorates, Plate thickness accuracy is poor.

Therefore, the present invention provides a mill elongation calculation correction device.
In 50, in order to eliminate the error of the reference value of the mill elongation amount using the rolling data, a corrected value of the mill elongation amount is calculated, and the reference value of the mill elongation amount stored in the mill elongation amount calculation device 20 is corrected. By doing so, the accuracy of the mill elongation amount is improved, and the plate thickness accuracy of the rolled material, particularly the plate thickness accuracy of the tip of the rolled material is improved.

The operation of the mill elongation calculation correction device 50 will be described. Since the amount of roll thermal expansion and the amount of roll wear at time t from the start of the rolling of the jth rolled material cannot be ignored,
In consideration of this, the true mill elongation amount δreal is the correction value Scmp calculated from the roll thermal expansion amount and the roll wear amount described above.
And the detection value h of the outlet plate thickness detected by the outlet plate thickness detector 7.
It is possible to calculate by the formula (14) using x and the rolled position S which is the detected value from the rolled position control device 5.

Δreal = hx−S−S ₀ −Scmp (14) However, S ₀ is a roll interval correction value (constant) calculated by the equation (9). Therefore, the mill elongation error Δδ is (1
It becomes the formula 5). Δδ = δreal−δcal ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………. FIG. 3 is an explanatory diagram showing an example of calculating a mill elongation error as a rolling load parameter from the relationship of FIG.

Here, the circles in the figure indicate Q ₁ as the rolling load.
The values of the mill elongation error at time t from the start of rolling when m rolling loads of up to Q _m are taken are shown. In addition, the broken line in the figure indicates the mill elongation error when the rolling load is the same. In this figure, the strip width, the roll peripheral speed, and the operation amount of the shape control means are set to be the same, so the mill elongation error is determined by the rolling load.

Mill elongation error Δδqk at rolling load Qk
Is, for example, the average value of the calculated mill elongation errors Δδ. From this, the mill elongation error Δδqk at the rolling load Qk is calculated by the correction value Scmp calculated from the amount of roll thermal expansion and the amount of roll wear at the time t from the start of rolling of the jth rolled material, and from the exit side plate thickness detector 7. Detected value h of the outlet plate thickness of
The mill elongation amount δreal obtained by substituting in the formula (14) from x and the detected value S of the reduction position from the reduction position control device 5, and the mill elongation calculated by inputting the rolling load Qk in the mill elongation calculation device 20. It can be calculated from the difference between the elongation amount Δcal, qk.

Therefore, the new mill elongation amount δcal, qk, new after correction at each rolling load Qk is expressed by the equation (16). δcal, qk, new ＝ δcal, qk ＋ Δδqk …………………… (16) Figure 4 shows the method of correcting the standard value of mill elongation by using this new mill elongation δcal, qk, new. explain.

The reference value of the uncorrected mill elongation amount shown by □ in FIG. 4 is obtained by the equation (12) and is good with respect to the corrected mill elongation amount at each rolling load shown by ●. Change the standard value of the mill elongation so that it approximates. The ∘ mark indicates the standard value of the corrected mill elongation thus obtained. The standard value of the corrected mill elongation is determined so that the evaluation function J represented by the equation (17) is minimized.

J = ΣWk · (δcal, qk, new−δAcal, qk, new) ² (17) However, δAcal, qk, new is the rolling obtained by interpolating the corrected mill elongation reference value. Mill elongation at load Q _k , W _k
Is a weighting factor. As a method of obtaining the reference value, a hill climbing method can be applied in which the reference rolling load or the reference mill elongation amount is changed by a small amount with the current reference value as the center, and the evaluation function J is sequentially moved so as to be minimized. The weighting coefficient Wk is reduced if the reliability of the calculated mill elongation error is low.
For example, if the number of data used for calculating the mill elongation error is small, the weighting factor is decreased, or if the standard deviation is large, the weighting factor is decreased. Alternatively, if the approximation accuracy of the thermal expansion amount is poor, decrease it.

Although the mill elongation amount using the rolling load as a parameter has been described above, one or more of the factors of the strip width, the roll peripheral speed and the operation amount of the shape control means may be added as a parameter. As an example thereof, an operation when a roll bending force which is an operation amount of the shape control means is added as a parameter will be described. The shape control means is not limited to this, and may be a roll shift device or a crown adjustment device for split backup rolls, and the shift amount and the crown adjustment amount may be used as the operation amounts thereof. The shape control means may be used alone or in combination.

In FIG. 5, Pi and Fj are the standard rolling load and the standard roll bending force, respectively, and δ (Pi
, Fj) is a reference mill elongation at a standard rolling load and a standard roll bending force. Here, ● mark is the corrected mill elongation data, ○ mark is the reference point before correction, □ mark is the reference point after correction, and the thin line is the mill elongation when the reference points before correction are interpolated with a plane. A plane showing the amount, and a thick line is a plane showing the amount of mill extension when the corrected reference points are interpolated by the plane.

The amount of mill elongation at an arbitrary rolling load and an arbitrary roll bending force is obtained by, for example, a method of interpolation as a plane. To obtain the mill elongation error Δδ,
For example, with the rolling load constant at an arbitrary value, the roll bending force Fk is changed in a short time to obtain a correction value Scmp calculated from the roll thermal expansion amount and the roll wear amount at the time t from the start of the rolling of the jth rolled material. , Output plate thickness detector 7
Mill extension δreal obtained by substituting the detection value hx of the outlet side plate thickness from No. 1 and the detection value S of the reduction position from the reduction position control device 5 into the equation (14), and the mill extension amount obtained by the above interpolation δ (P
i, Fk) and the difference (? real-?). In the figure, the error is positive. Further, the rolling load is changed within the range of use of the rolling mill, and the above is repeatedly obtained. The corrected mill elongation is the mill elongation error and the mill elongation δ obtained by interpolation.
Calculated as the sum of and.

The correction of the reference value is carried out in the same manner as in the case where only the rolling load is used as a parameter, and the reference rolling load, the reference roll bending force or the reference mill elongation amount is slightly changed in the vicinity of the reference value, and the evaluation function The corrected reference value is obtained by sequentially moving so as to minimize J. When the roll peripheral speed is added as a parameter to the mill elongation with the rolling load as a parameter, the roll peripheral speed is changed, and when the strip width is added as a parameter, rolled materials with different strip widths are rolled to obtain the roll bending force. May be added as a parameter in the same manner as the above case. The same applies when three parameters of rolling load, strip width and roll peripheral speed are used as parameters, or when four factors of rolling load, strip width, roll peripheral speed and operation amount of the shape control means are used as parameters.

In addition, using the strip width as a parameter, a reference value of the strip width within the rolling range of the rolling mill is set appropriately, and the mill elongation calculation device 20 and the mill elongation are set for each of the reference strip widths. By configuring the quantity calculation correction device 50, for any plate width,
Interpolation may be performed after calculating the mill elongation amount and correcting the reference value by the mill elongation amount calculation device 20 and the mill elongation amount calculation correction device 50 of the adjacent reference plate widths.

FIG. 6 shows the standard rolling load P _{0 (i)} according to the method of the present invention.
It shows the estimation accuracy of the outlet plate thickness in the vicinity of. In the case of the conventional example, when the deviation from the standard rolling load P _{0 (i)} is lost, the accuracy of estimating the outgoing side plate thickness deteriorates, whereas the apparatus of the present invention improves the accuracy of estimating the outgoing side plate thickness in a wide range. Recognize.

[0043]

As described above, according to the automatic strip thickness control system for a rolling mill of the present invention, the amount of mill elongation can be accurately obtained in a wide range of rolling conditions, so that the estimation accuracy of the delivery side strip thickness is improved. However, the plate thickness accuracy becomes good from the tip of the rolled material, which contributes to the improvement of product yield.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a method for obtaining a mill elongation amount from a reference value of the mill elongation amount using a rolling load as a parameter.

FIG. 3 is an explanatory diagram showing a method of obtaining a mill elongation amount error using a rolling load as a parameter.

FIG. 4 is an explanatory diagram showing one implementation method for correcting the mill elongation reference value using the rolling load as a parameter according to the present invention.

FIG. 5 is an explanatory diagram showing one implementation method for correcting the mill elongation reference value using the rolling load and roll bending force as parameters of the present invention.

FIG. 6 is a characteristic diagram showing an example of plate thickness accuracy according to the method of the present invention.

FIG. 7 is a schematic diagram showing a configuration of a conventional plate thickness control device.

[Explanation of symbols]

 1 Rolled material 2 Rolling stand 3 Rolling rolls 4 Rolling load detection device 5 Rolling position control device 6 Roll gap correction device 7 Output side plate thickness detector 8 Drive motor 10 Roll rotation control device 12 Roll bending device 20 Mill elongation calculation device 30 Output Side plate thickness calculation device 40 Reduction position correction amount calculation device 50 Mill elongation calculation correction device 100 High-end computer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideo Kijima, 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture Steel Research Laboratory, Kawasaki Steel Co., Ltd. (72) Sadayuki Miyoshi 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture Kawasaki Steel Works Co., Ltd. Chiba Steel Works (72) Inventor Yoshimitsu Fukui 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Works Chiba Works

Claims (1)

[Claims] 1. A rolling load detecting device for detecting a rolling load, an outgoing side plate thickness detector for detecting an outgoing side plate thickness of a rolled material, a factor of an operation amount of a rolling load, a plate width, a roll peripheral speed and a shape control means. The mill elongation amount is calculated by pre-entering multiple reference values for the mill elongation amount with one or more factors including at least the rolling load as parameters, and interpolating the mill elongation amount reference value. A calculation device, a rolling position control device that corrects the rolling position to correct the plate thickness of the rolled material to a target value, and a correction value based on the roll thermal expansion amount and the roll wear amount,
A delivery side plate thickness calculation device for calculating a delivery side plate thickness from the correction value, the mill extension amount calculated by the mill extension amount calculation device, and a detection value of a reduction position from the reduction position control device; A reduction position correction amount calculation device that calculates a correction value of the reduction position so that the delivery side plate thickness calculated by the device matches the target plate thickness, and outputs the correction value of the reduction position to the reduction position control device. Using the mill elongation amount obtained from the correction value by the roll thermal expansion amount and the roll wear amount, the detection value of the output side plate thickness from the output side plate thickness detector, and the detection value of the reduction position from the reduction position control device. An automatic strip thickness control device for a rolling mill, comprising a mill elongation calculation correction device for correcting the reference value of the mill elongation amount.