JPH0957318A - Thickness controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thickness controller by which a plate thickness deviation can be sufficiently removed even a stock to be rolled has a large deformation resistance. SOLUTION: From a distance between a thermometer 6 and a rolling mill 15 and a rolling speed, a time required from a time when the temperature of a stock S to be rolled has been detected to a time when the stock S reaches a rolling mill, is operated by a deformation resistance calculation part 21. The temperature of the stock at the time of rolling is estimated, and according to the estimated temperature and the hardness of the stock S, deformation resistance occurred when the stock is rolled, is operated. According to an operated deformation resistance and the inlet side thickness of the stock, a drawing down pattern by which a deviation occurring in an outlet side thickness should be removed, is operated by a drawing down pattern preparing part 22, the drawing down pattern is corrected by a correction part 24, and it is given to an output part 27. A rolling down position operated by a first operation part 1 has been given to the output part 27 as well. A rolling down position given from the correction part 24 of a second operation part 2, is added to the rolling down position by the output part 27, considering a time required from a time when the temperature of the stock S is detected to a time when the stock S reaches a rolling mill 15, and the obtained result is outputted to a drawing down controller 8.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thickness control device for controlling the thickness of a material to be rolled rolled by a rolling mill.

[0002]

2. Description of the Related Art In a rolling mill for producing a product sheet material by hot rolling a material sheet to be rolled such as a steel plate, a sheet thickness deviation called a skid mark is caused by a temperature deviation of the material being rolled in a heating furnace. Since it exists, in order to suppress the occurrence of strip thickness variation on the delivery side of the rolling mill, the rolling position or rolling load of the rolling mill is adjusted based on the measured value or the estimated value of the strip thickness on the delivery side of the rolling mill. A gauge meter type thickness control device for controlling the plate thickness of the rolled material to a target plate thickness is provided. However, the gauge meter type thickness control device has a problem that it is impossible to cope with a large variation in the plate thickness on the rolling mill entrance side because it is a so-called feedback control. There is also a problem that the rolling speed of the material to be rolled cannot be increased in order to prevent the plate thickness variation due to the control delay of the feedback control.

For this reason, JP-A-55-112117 and JP-A-60-15406 disclose thickness control devices for performing feedforward control in addition to the gauge meter method described above. This is to calculate the output side plate thickness deviation from the measured value of the output side plate thickness of the rolling mill, and to calculate the control amount that makes the calculated output side plate thickness deviation zero. On the other hand, the calculated value is obtained by differentiating the measured value of the inlet side plate thickness of the rolling mill, and the delay time is obtained from the rotational speed of the backup roller of the rolling mill and the distance from the measurement position of the inlet side plate thickness to the rolling mill. The control amount is corrected by integrating based on the delay time, the calculated value and the control amount.

[0004]

However, in the conventional thickness control device, the feed-forward control is performed without considering the material and temperature of the material to be rolled, so that the material to be rolled having a large deformation resistance is There is a problem that the output of the adjustment amount calculated by the thickness control device cannot sufficiently remove the strip thickness deviation on the delivery side of the rolling mill.
Further, since the error included in the measured value of the entrance side plate thickness is fed forward as it is, and there is no means for correcting it, there is a limit in improving the accuracy of the plate thickness control.

The present invention has been made in view of the above circumstances, and its object is to obtain a deformation resistance calculated based on the temperature, hardness and rolling speed of the material to be rolled, and the entrance side of the material to be rolled. By adjusting the amount of adjustment of the rolling mill that should eliminate the deviation of the delivery thickness based on the thickness, even if the material to be rolled has a large deformation resistance, the deviation of the delivery thickness of the rolling mill can be sufficient. It is to provide a thickness control device that can be removed. Another object is to compensate for the error contained in the measured value on the inlet side by using the correction value obtained based on the actual rolling results to correct the adjustment amount, and to improve the accuracy of the thickness control. To provide a high thickness control device.

[0006]

According to a first aspect of the present invention, there is provided a thickness control device, in which a thickness of an outgoing side of a material to be rolled at an outlet side of a rolling mill for hot rolling the material to be rolled, and an inlet side of the rolling mill. Based on the inlet side thickness of the material to be rolled, calculate the adjustment amount to remove the deviation between the outlet side thickness and the target thickness, adjust the rolling mill to realize the adjustment amount, and adjust the thickness of the material to be rolled. In the thickness control device for controlling the, the thermometer for detecting the temperature of the material to be rolled on the inlet side of the rolling mill, the speedometer for detecting the rolling speed of the material to be rolled, the temperature detected by the thermometer, the speedometer Rolling speed detected by, the distance between the thermometer and the rolling mill,
And, based on the hardness of the material to be rolled, the deformation resistance calculation means for calculating the deformation resistance when the material to be rolled is rolled, and the thickness at the outlet side based on the calculated deformation resistance and the thickness at the inlet side of the material to be rolled. And an adjustment amount calculation means for calculating the adjustment amount of the rolling mill so as to remove the deviation that occurs in the above.

The deformation resistance calculating means calculates the time required from the detection of the temperature of the material to be rolled to the rolling mill from the distance between the thermometer and the rolling mill and the rolling speed, and the rolling resistance is calculated. The temperature of the rolled material is estimated, and the deformation resistance when the rolled material is rolled is calculated based on the estimated temperature and the hardness of the rolled material. Based on the calculated deformation resistance and the entrance side thickness of the material to be rolled, the adjustment amount calculating means adjusts the amount of adjustment of the rolling mill such as the rolling position, the rolling load or the rolling speed in order to remove the deviation occurring in the exit side thickness. For example, it is calculated as follows.

The deviation of the entrance side thickness is obtained from the distribution of the entrance side thickness, and it is estimated that the rolling position changes in the rolling mill according to the deviation. From the estimated rolling position change and the deformation resistance, the load deviation in the rolling mill is obtained, the deviation occurring in the delivery side thickness from the load deviation and the rolling position change, and the mill constant is calculated, and the calculated delivery side thickness deviation is zero. In order to
Calculate the rolling position adjustment amount of the rolling mill.

Then, the rolling position adjustment amount calculated as described above from the rolling load and the rolling position deviation in the rolling mill during rolling and the mill constant to calculate the output side thickness deviation to zero from the mill constant, The material to be rolled is fed forward with a delay of the time required to reach the rolling mill after the temperature of the material to be rolled is detected. As a result, even if the material to be rolled has a large deformation resistance, it is possible to sufficiently eliminate the deviation of the delivery side plate thickness.

Since the adjustment amount described above includes an error included in the measured value on the input side, the following configuration is added to eliminate this error.

In addition to the first aspect of the present invention, the thickness control device according to the second aspect of the present invention is such that a correction value for correcting the adjustment amount calculated by the adjustment amount calculation means is stored for each material and temperature of the material to be rolled. A storage unit and a correction unit that corrects the adjustment amount calculated by the adjustment amount calculation unit using the correction value read from the correction value storage unit based on the temperature detected by the thermometer and the material of the material to be rolled. It is characterized by being provided.

In the correction value storage means, the adjustment amount calculated by the adjustment amount calculating means by a test in advance and the correction value obtained from the actual result of rolling in accordance with the adjustment amount are stored for each material and temperature of the material to be rolled. I remember. And the correction means is
Based on the temperature detected by the thermometer and the material of the material to be rolled, the corresponding correction value is read from the correction value storage means, and the correction value is multiplied by the adjustment amount calculated by the adjustment amount calculation means, Correct the adjustment amount. by this,
The error in estimating the temperature of the material to be rolled at the time of rolling is corrected from the input side plate thickness and the detection value of the thermometer, and the accuracy of thickness control is improved.

By correcting the above-mentioned correction value based on many rolling results, the correction accuracy is improved.

The thickness control device according to the third invention is, in addition to the second invention, a correction value calculation for calculating a new correction value based on the inlet side thickness and the outlet side thickness and the adjustment amount corrected by the correcting means. Means and a correction value updating means for updating the correction value by storing a new correction value in the correction value storage means in place of the read correction value.

The correction value calculation means obtains the ratio of the adjustment amount corrected by the correction means and the difference between the inlet side thickness and the outlet side thickness each time the adjustment amount calculation means calculates the adjustment amount, and the rolled material is rolled. For the material, the average of the obtained ratios is calculated as a new correction value. Then, the correction value update means updates the correction value stored in the correction value storage means to a new correction value. This further improves the accuracy of thickness control.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a thickness control device according to the present invention and a schematic side view showing a rolling mill, and a rolling position of a rolling mill 15 is controlled. A four-roll type rolling mill 15 provided with work rolls 11 and 11 and backup rolls 12 and 12 for sandwiching the work rolls 11 and 11 in a transfer region of a material S to be rolled which is rolled in a direction shown by an arrow in the figure. Has been placed. The work roll 11 of the rolling mill 15 is rotationally driven by the motor M, and the work rolls 11, 11 and the backup roll 12 are loaded by the rolling down device 7. And work roll 1
The roll gap between 1 and 11 and the rolling load are controlled by the reduction control device 8.

The rolling mill 15 includes a rolling load detector 10 for detecting a rolling load, a roll gap position detector 9 for detecting a gap position between the work rolls 11 and a rolling speed detector 13 for detecting a rolling speed. Each is provided. Rolling mill 15
Thickness gauges 4 and 5 for measuring the plate thickness of the material S to be rolled are arranged on the inlet side and the outlet side of the rolling mill, and a thermometer 6 for measuring the temperature of the material to be rolled S is arranged on the inlet side of the rolling mill 15. I am doing it.

The detection values of the rolling load detector 10 and the roll gap position detector 9 described above are given to the first calculator 1 provided in the controller 3. The first calculation unit 1 obtains the load deviation ΔP and the rolling position deviation ΔS from the given detection values, with the detection value detected at a preset timing as an initial value, and is calculated by the following equation (1). The adjustment amount of the rolling position of the rolling mill 15 is calculated so that the meter thickness deviation Δh becomes zero. Δh = ΔS + ΔP / M (1) where M: Mill constant

The surface temperature of the material to be rolled S measured by the thermometer 6 provided on the inlet side of the rolling mill 15 is given to the deformation resistance calculation unit 21 of the second calculation unit 2. The deformation resistance calculation unit 21 is also given material information of the material S to be rolled from the management computer, and the deformation resistance calculation unit 21 calculates the deformation resistance rt of the material S to be rolled by the following equation (2). Then, the result is the rolled material S
The rolling pattern is applied to the rolling pattern creating unit 22 that creates a rolling pattern that is a change in the rolling position during rolling over the entire length of the. rt = F (zai, T (t)) (2) where zai is a value quantifying the hardness based on the material of the material to be rolled T (t): When the material to be rolled reaches the rolling mill temperature

In the above-mentioned reduction pattern forming section 22, the thickness gauge 4 to the entrance side plate thickness of the rolling mill 15 and the rolling speed detector 13 are provided.
Also, the rolling speed in the rolling mill 15 is also given, and the reduction pattern creating unit 22 identifies the position where the sheet thickness deviation exists from the given distribution of the inlet side sheet thickness, in order to make the identified sheet thickness deviation zero, The rolling pattern of the material S to be rolled is created as follows.

FIG. 2 is a flow chart showing the procedure for forming the reduction pattern in the reduction pattern forming section 22. The reduction pattern creation unit 22 estimates that a reduction position change will occur according to the plate thickness deviation (step S1). That is, if the plate thickness deviation is positive, it is estimated that the negative rolling position deviation corresponding to the deviation amount occurs, and if the plate thickness deviation is negative, the positive rolling position deviation corresponding to the deviation amount is estimated to occur. From the estimated rolling position deviation and the deformation resistance given from the deformation resistance calculation unit 21, the rolling pattern creation unit 22 performs the following (3).
The load deviation ΔP is calculated based on the formula (step S
2). ΔP = F ′ (rt, Δs) (3) where rt: deformation resistance Δs: estimated value of reduction position deviation

The reduction pattern creating section 22 calculates the gauge meter thickness deviation from the calculated load deviation and the estimated reduction position deviation based on the above equation (1) (step S
3) determine whether it is zero (step S
4). When the reduction pattern creation unit 22 determines that the calculated gauge meter thickness deviation is not zero, the gauge meter thickness deviation is set as the reduction position deviation (step S5), and step S2
Returning to, the gauge meter thickness deviation is calculated as before, and steps S2 to S5 are repeated until the gauge meter thickness deviation is determined to be zero in step S4, and the reduction when the gauge meter thickness deviation is determined to be zero The position is stored (step S6). In this way, the rolling position is calculated over the entire length of the material to be rolled to obtain a rolling pattern.

FIG. 3 is a graph showing an example of the reduction pattern created by the reduction pattern creating unit 22, in which the vertical axis represents the reduction position change and the horizontal axis represents the length of the material to be rolled. There is. By changing the rolling position in the rolling mill in the positive or negative direction from the beginning to the end of the material to be rolled, it is possible to remove the plate thickness deviation existing in the material to be rolled.

Further, the reduction pattern creating unit 22 reads out the correction value for the material S to be rolled from the correction value storage unit 23 which stores the correction value for correcting the reduction pattern for each material and temperature range of the material S to be rolled. , The read correction value and the calculated reduction pattern are multiplied to obtain the correction reduction pattern, and the calculated correction reduction pattern is divided by the rolling speed to create a time chart of the reduction position change, and this time chart is output. Give to 27. Thereby, even if the detection error of the thickness gauge 4 and the thermometer 6 on the entry side or the temperature estimation error of the material to be rolled at the time of rolling is included, it is possible to always calculate an appropriate rolling position.

The output unit 27 is also given the adjustment amount of the rolling position from the first calculation unit 1, and the output unit 27 calculates the adjustment amount given from the first calculation unit 1 by the second calculation unit 2. The amount of adjustment is added according to the time chart, and the result is output to the reduction control device 8 to adjust the reduction position.
Control the plate thickness of.

An updating unit 25 for updating the stored correction value is connected to the correction value storage unit 23 described above. The updating unit 25 is provided with the entry side plate thickness of the rolled material S and the corrected reduction pattern from the reduction pattern creating unit 22, and the exit side sheet thickness of the rolled material S from the thickness gauge 5, respectively. The section 25 calculates the difference between the entrance side plate thickness and the exit side plate thickness. Then, the updating unit 25 obtains the deviation ratio between the calculated difference and the correction reduction pattern for each control cycle, calculates the average value of the found deviation ratios, and uses it as the correction value read from the correction value storage unit 23. The correction value is updated by storing it instead.

[0027]

EXAMPLES The results of the comparative tests will be described.
FIG. 4 is a graph showing the result of measuring the deviation of the outlet side plate thickness of the rolling mill. In FIG. 4A, the plate thickness control is performed so that the rolling position is at the reduction position calculated by the first calculator shown in FIG. (B) shows the result of performing the plate thickness control using the uncorrected rolling reduction pattern, and (c) shows the result of performing the plate thickness control by further correcting the rolling reduction pattern. Shown respectively.

As is apparent from FIG. 4 (a), when feedforward control based on the deviation of the entrance side plate thickness of the rolling mill is not applied, a large deviation remains in the exit side plate thickness,
Low product quality and long off-gauge length. Compared to this,
As is clear from FIG. 4 (b), in the plate thickness control in which the reduction pattern calculated based on the deviation of the entrance side plate thickness and the deformation resistance during rolling is taken into account, the deviation of the exit side plate thickness is significantly reduced. There is. Further, as is clear from FIG. 4 (c), when the corrected reduction pattern is used, the deviation of the delivery side plate thickness is almost eliminated.

[0029]

As described in detail above, in the thickness control device according to the first aspect of the present invention, the adjustment amount of the rolling mill and the entrance plate thickness obtained to eliminate the deviation based on the deviation of the exit side thickness are provided. Deviation and the amount of adjustment calculated based on the deformation resistance during rolling, the rolling mill is adjusted to roll the material to be rolled. Can be removed.

In the thickness control device according to the second invention,
Since the adjustment amount calculated based on the deviation of the entrance-side plate thickness and the deformation resistance during rolling is corrected using the correction value, the detection error by the detector such as the thickness gauge and the thermometer is compensated.

In the thickness control device according to the third invention,
Since the correction value is updated, the accuracy of thickness control is further improved, and the off-gauge length is reduced. The present invention has excellent effects.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a thickness control device and a schematic side view showing a rolling mill.

FIG. 2 is a flowchart showing a procedure for creating a reduction pattern in a reduction pattern creation unit.

FIG. 3 is a graph showing an example of a rolling pattern created by a rolling pattern creating unit.

FIG. 4 is a graph showing the results of measuring the deviation of the strip thickness of the rolling mill.

[Explanation of symbols]

 1 1st calculation part 2 2nd calculation part 3 Control device 6 Thermometer 21 Deformation resistance calculation part 22 Reduction pattern preparation part 24 Correction part

Claims (3)

[Claims] 1. An outlet thickness based on an outlet thickness of a rolled material on an outlet side of a rolling mill that hot-rolls a rolled material and an inlet thickness of the rolled material on an inlet side of the rolling mill. In the thickness control device that calculates the adjustment amount to remove the deviation between the target thickness and the adjustment amount, adjusts the rolling mill to realize the adjustment amount, and controls the thickness of the material to be rolled, Between the temperature of the material to be rolled, the speedometer to detect the rolling speed of the material to be rolled, the detected temperature detected by the thermometer, the rolling speed detected by the speedometer, the thermometer and the rolling mill On the basis of the distance, and the hardness of the material to be rolled, based on the deformation resistance calculation means for calculating the deformation resistance when the material to be rolled is rolled, and the calculated deformation resistance and the entry side thickness of the material to be rolled, Adjustment amount calculation that calculates the adjustment amount of the rolling mill to eliminate the deviation that occurs in the outlet thickness Thickness control apparatus characterized by and means. 2. A correction value storage unit that stores a correction value for correcting the adjustment amount calculated by the adjustment amount calculation unit for each material and temperature of the material to be rolled, and a detected temperature of the thermometer and the material to be rolled. The thickness control device according to claim 1, further comprising: a correction unit that reads a correction value from the correction value storage unit based on a material, and uses the correction value to correct the adjustment amount calculated by the adjustment amount calculation unit. 3. A correction value calculation means for calculating a new correction value based on the entrance side thickness and the exit side thickness and the adjustment amount corrected by the correction means, and a new correction value in place of the read correction value. The thickness control device according to claim 2, further comprising a correction value updating unit that stores a value in the correction value storage unit and updates the correction value.