WO2009136435A1

WO2009136435A1 - Board thickness controller for rolling machine

Info

Publication number: WO2009136435A1
Application number: PCT/JP2008/058497
Authority: WO
Inventors: 直博久保
Original assignee: 東芝三菱電機産業システム株式会社
Priority date: 2008-05-07
Filing date: 2008-05-07
Publication date: 2009-11-12
Also published as: CN102015136B; JPWO2009136435A1; JP5170240B2; CN102015136A; KR20100116714A; KR101208811B1

Abstract

A board thickness controller for a rolling machine which can fully reduce variation in board thickness arising from roll core eccentricity even in the event of deterioration over time of roll core eccentricity parameters or in any other cases. For such a purpose, the amount of roll core eccentricity is first determined from gauge meter board thickness and actual board thickness. Secondly, a curved surface corresponding to a distribution curve for the determined amount of roll core eccentricity is depicted to identify the curved surface using the Fourier analysis, thereby computing a phase and an amplitude of the roll core eccentricity for each of the upper and lower backup rolls. Subsequently, roll gaps are controlled in accordance with the computation result to reduce variation components in board thickness of an rolled material arising from the roll core eccentricity.

Description

Thickness control device for rolling mill

This invention relates to a plate thickness control device that suppresses fluctuations in the plate thickness of a rolled material by controlling a roll gap in a rolling mill that rolls the rolled material with rolls arranged vertically.

In plate rolling of a steel plate or the like performed by a rolling mill, sheet thickness control (AGC: Automatic Gage Control) has been conventionally applied. In this AGC, the roll gap is controlled so that the thickness in the rolling direction of the rolled material is kept constant by detecting (estimating) the thickness variation of the rolled material by some means. In addition, for the detection of the plate thickness variation performed by AGC, for example, a method of estimating the plate thickness variation during rolling from the rolling load, or the plate thickness during the rolling (gauge meter plate thickness from the rolling load and the roll gap). ) And a method of detecting a plate thickness deviation with a plate thickness meter.
However, it is impossible to detect the fluctuation component of the plate thickness variation caused by the eccentricity of the roller by the method for detecting the plate thickness variation performed by the AGC. In particular, in the method of using a rolling load for detecting the thickness variation, it is generally known that the variation in the rolling load caused by roll eccentricity causes erroneous detection of the thickness variation, and the variation in thickness becomes rather large. ing.

The roll eccentricity usually occurs when a key is used for assembling a backup roll. Roll eccentricity also occurs when the roll cross-section is not perfect due to non-uniform polishing of the roll, or when the roll is thermally expanded during rolling and the roll cross-section is no longer perfect. Will occur. And when roll eccentricity generate | occur | produces for the above reasons, a roll gap will fluctuate | variate periodically according to rotation of the roll in rolling. The fluctuation of the roll gap due to roll eccentricity cannot be detected by a reduction position control device that controls the reduction position of the roll. For this reason, the roll eccentricity becomes a disturbance of the plate thickness control.
Note that the roll eccentricity has the same amount (eccentricity amount) at the same rotation angle for the upper and lower rolls in the short term. However, the rotation angle at which roll eccentricity occurs and the amount of eccentricity may change as rolling progresses.

For such problems, various roll eccentricity controls have been proposed and put to practical use as methods for suppressing fluctuations in plate thickness caused by roll eccentricity. For the roll eccentricity control, the following three methods are mainly known.
(A) Roll eccentricity control 1
Before rolling, the roll is rotated by a kiss roll (a state in which a load is generated by contacting the upper and lower work rolls), and the load at that time is detected. Further, the detected load is analyzed by a fast Fourier transform or a means equivalent thereto, and the phase and amplitude of the roll eccentricity are identified. During rolling, feedback control using the rolling load is not performed, and the roll gap operation amount is output so as to compensate for roll gap fluctuation caused by roll eccentricity using the roll eccentricity parameter ( For example, see Patent Documents 1 and 2).
(B) Roll eccentricity control 2
The plate thickness variation is measured with a plate thickness meter installed on the exit side of the rolling mill. Then, a fluctuation component synchronized with the rotation of the roll is extracted from the measured thickness fluctuation, and the rotation position of the roll at which the fluctuation component is generated is specified. Based on the obtained information, the roll gap is operated according to the rotation of the roll.
(C) Roll eccentricity control 3
Measure rolling load fluctuations during rolling. Then, a fluctuation component synchronized with the rotation of the roll is extracted from the measured rolling load fluctuation and associated with the rotation position of the roll. And based on the obtained information, a rolling load fluctuation | variation is converted into a roll gap and operation of the roll gap according to rotation of a roll is performed.

Japanese Unexamined Patent Publication No. 60-141321 Japanese Unexamined Patent Publication No. Sho 62-254915 Japanese Unexamined Patent Publication No. 11-77128 Japanese Unexamined Patent Application Publication No. 2002-282919

In the method shown in the roll eccentricity control 1 described in

Patent Documents

1 and 2, it is assumed that the roll eccentricity parameters (that is, the phase (position) and amplitude of the roll eccentricity) are constant for a long time. . However, as described above, the roll eccentricity parameter may change over time. Therefore, in such a case, there has been a problem that the kiss roll must be performed again in order to identify the parameters, and the operation stop time increases. In addition, during operation, it is generally impossible to frequently stop and kiss roll frequently, and when the above parameters change with time, the method shown in the roll eccentricity control 1 can maintain sufficient control performance. could not.

In the method shown in the roll eccentricity control 2 described in Patent Document 3, the problem that the influence of the roll eccentricity cannot be removed during the rotation of the backup roll once after starting the plate thickness measurement at the tip of the rolled material. was there. In the thick plate rolling, since the rolling length of the rolled material is short, the section (tip portion) where control cannot be performed cannot be ignored.
In addition, since the phase and amplitude of roll eccentricity are not identified for each of the upper and lower backup rolls, there is a problem that sufficient control performance cannot be maintained when the roll diameters are greatly different. there were.

In the method shown in the roll eccentricity control 3 described in Patent Document 4, in order to extract the fluctuation component of the rolling load generated due to the roll eccentricity, the rolling load fluctuation is made corresponding to the rotation angle of the backup roll. Is remembered. For this reason, when the period of the fluctuation component of the rolling load caused by other factors (for example, skid marks) is close to the rotation period of the backup roll, it is difficult to separate the fluctuation component and the fluctuation component due to roll eccentricity. Become. Thick plate rolling has a problem that there are many fluctuation components that meet such conditions, and sufficient control performance cannot be maintained.
In roll eccentricity control 3, the rolling load fluctuation stored in correspondence with the rotation angle of the backup roll is directly read out and converted into a control amount of the roll gap. For this reason, the rolling load data needs to be sufficiently accumulated for each rotation angle, and when the distribution of the rolling record data is biased, sufficient control performance cannot be maintained.

The present invention has been made to solve the above-described problems, and its purpose is to achieve roll eccentricity even when roll eccentric parameters change over time or when the upper and lower roll diameters are different. The present invention is to provide a plate thickness control apparatus for a rolling mill that can sufficiently suppress the resulting plate thickness variation.
Further, even when there is a rolling load fluctuation component having a period close to the roll eccentricity period, or even when the distribution of the rolling record data is biased, the rolling mill capable of exhibiting the above effect similarly. It is providing the plate | board thickness control apparatus.

A sheet thickness control device for a rolling mill according to the present invention includes a work roll arranged vertically and a backup roll that supports the work roll from above and below, and controls the thickness of the rolling mill that rolls a rolled material by the work roll. A device that detects the rolling load, a roll position measuring device that measures the roll gap, a plate thickness meter that detects the thickness of the rolled material after rolling, and the rotation angle of the backup roll. Rotation angle calculating means for calculating each of the above, a rolling gauge detected by a load detector, and a gauge meter plate for calculating a gauge meter plate thickness of the rolled material based on the roll gap measured by the rolling position measuring instrument Thickness calculation means and the gauge meter thickness calculation means until an arbitrary point of the rolled material rolled by the work roll arrives at the thickness detection position of the thickness gauge. The gauge meter plate thickness delay means for storing the gauge meter plate thickness at the arbitrary point calculated in the above, the gauge meter plate thickness at the arbitrary point stored in the gauge meter plate thickness delay means, and the plate thickness Based on the thickness of the arbitrary point detected by the meter, the roll eccentric amount calculating means for calculating the roll eccentric amount when the arbitrary point is rolled by the work roll, and each calculated by the rotation angle calculating means Roll eccentricity that stores the roll eccentricity calculated by the roll eccentricity calculating means on the basis of the rotation angle in association with each rotation angle of the upper and lower backup rolls when the arbitrary point is rolled by the work roll Based on the roll eccentricity stored in the amount storage means and the roll eccentricity storage means, the phase and amplitude of the roll eccentricity are calculated for each of the upper and lower backup rolls. Based on the calculation results of the roll eccentricity parameter calculation means and the roll eccentricity parameter calculation means, depending on each rotation angle of the upper and lower backup rolls so as to suppress the thickness variation component of the rolled material due to roll eccentricity And a control operation amount calculation means for calculating the control operation amount.

Further, in the sheet thickness control device for a rolling mill according to the present invention, the roll eccentricity storage means sets the division number when the rotation angle of the upper backup roll is divided into a predetermined number and the rotation angle of the lower backup roll as the predetermined A table in which the division number when dividing into numbers is arranged vertically and horizontally, and by storing the roll eccentricity calculated by the roll eccentricity calculating means in the corresponding cell of the table, A distribution curved surface is obtained.

Further, in the sheet thickness control apparatus for a rolling mill according to the present invention, the roll eccentricity parameter calculation means approximates the curved surface by Fourier analysis to the roll eccentricity distribution curved surface obtained by the roll eccentricity storage means. By doing so, the phase and amplitude of roll eccentricity are obtained for each of the upper and lower backup rolls.

According to this invention, even when the roll eccentricity parameter changes with time or when the upper and lower roll diameters are different, it is possible to sufficiently suppress the plate thickness fluctuation caused by the roll eccentricity.
In addition, when there is a fluctuation component of the rolling load having a period close to the period of roll eccentricity,
Even if the distribution of the rolling record data is uneven, the thickness variation due to roll eccentricity can be sufficiently suppressed.

It is a block diagram which shows the plate | board thickness control apparatus of the rolling mill in Embodiment 1 of this invention. It is a figure for demonstrating the specific function of the plate | board thickness control apparatus of the rolling mill shown in FIG. It is a figure which shows the distribution curved surface of the roll eccentric amount memorize | stored in the roll eccentric amount memory | storage means. It is a figure which shows the distribution curved surface of the roll eccentric amount identified by the plate | board thickness control apparatus of the rolling mill shown in FIG.

Explanation of symbols

1 rolled material, 2 work rolls, 3 work rolls, 4 backup rolls,
5 Backup roll, 6 Load detector, 7 Rolling position control device,
8 Rolling position measuring device, 9 Thickness gauge, 10 Rotation angle detector,
11 rotation angle detector, 12 rotation angle calculation means,
13 gauge meter plate thickness calculation means, 14 gauge meter plate thickness delay means,
15 roll eccentricity calculation means, 16 roll eccentricity storage means,
17 roll eccentricity parameter calculation means, 18 control manipulated variable calculation means

In order to explain the present invention in more detail, this will be described with reference to the attached drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a sheet thickness control apparatus for a rolling mill according to Embodiment 1 of the present invention, and FIG. 2 is a diagram for explaining specific functions of the sheet thickness control apparatus for a rolling mill shown in FIG. In FIG. 1, reference numeral 1 denotes a rolled material such as a steel plate rolled by a rolling mill, and is rolled by work rolls 2 and 3 arranged above and below. 4 and 5 are backup rolls that support the work rolls 2 and 3 from above and below.

6 is a load detector for detecting the rolling load during rolling, and 7 is a rolling position control device for controlling the rolling position. The reduction position control device 7 controls the roll gap (the gap between the upper and lower work rolls 2 and 3) so that the thickness of the rolled material 1 becomes a desired value. The reduction position control device 7 is provided with a reduction position measuring device 8 that measures the reduction position. That is, the reduction position control device 7 can measure the roll gap by the function of the reduction position measuring device 8. However, a change (fluctuation component) in the roll gap caused by roll eccentricity cannot be measured by the above-described reduction position measuring instrument 8.

9 is a thickness gauge provided on the exit side of the rolling mill. The thickness gauge 9 detects the thickness of the rolled material 1 after being rolled by the work rolls 2 and 3. Reference numerals 10 and 11 denote rotation angle detectors for detecting the rotation angles of the backup rolls 4 and 5. The backup rolls 4 and 5 rotate in conjunction with the work rolls 2 and 3 when the work rolls 2 and 3 are driven (rotated). At this time, the rotation angle of the upper backup roll 4 is independently detected by the rotation angle detector 10, and the rotation angle of the lower backup roll 5 is independently detected by the rotation angle detector 11.

Note that FIG. 1 shows a configuration in which pulse generators attached to the backup rolls 4 and 5 are used as the rotation angle detectors 10 and 11. That is, in the method shown in FIG. 1, the rotation angle detectors 10 and 11 directly detect the rotation angles of the backup rolls 4 and 5. However, the rotation angle detectors 10 and 11 are not limited to such a method, and may employ another method having the same function as described above. For example, a proximity photo sensor or the like is attached to the backup rolls 4 and 5, and a reference pulse for each rotation of the backup rolls 4 and 5 is generated. Then, the reference pulse is detected, and the rotation angles of the backup rolls 4 and 5 are calculated using the rotation angles or rotation speeds of the work rolls 2 and 3. The rotation angle detectors 10 and 11 can also be configured by such a method.

Further, the plate thickness control apparatus according to the present invention includes a rotation angle calculation unit 12, a gauge meter plate thickness calculation unit 13, a gauge meter plate thickness delay unit 14, a roll eccentric amount calculation unit 15, and a roll eccentric amount storage unit 16. Various means such as a roll eccentricity parameter calculation means 17 and a control operation amount calculation means 18 are provided.

The rotation angle calculation means 12 has a function of calculating the rotation angles of the backup rolls 4 and 5 for each of the upper and lower sides. That is, the rotation angle calculation means 12 determines the rotation angle of the upper backup roll 4 based on the detection signal from the rotation angle detector 10 and the rotation of the lower backup roll 5 based on the detection signal from the rotation angle detector 11. The angles are calculated in the range of 0 to 360 degrees, respectively.

The gauge meter plate thickness calculating means 13 has a function of calculating the gauge meter plate thickness of the rolled material 1. The gauge meter plate thickness is the plate thickness of the rolled material 1 when being rolled by the work rolls 2 and 3, and means the thickness of the rolled material 1 directly under the rolling mill. Specifically, the gauge meter thickness calculation means 13 is based on the rolling load detected by the load detector 6 and the roll gap measured by the reduction position measuring device 8 (the reduction position control device 7), for example, The gauge meter plate thickness is calculated using the following formula (principle formula for gauge meter plate thickness calculation).

The gauge meter plate thickness delay means 14 is used until the arbitrary point (for example, point A) of the rolled material 1 rolled by the work rolls 2 and 3 reaches the plate thickness detection position of the plate thickness meter 9. It has a function of storing the gauge meter plate thickness at the point A calculated by the calculation means 13. Further, the gauge meter plate thickness delay means 14 uses the output value of the roll eccentricity control (control operation amount calculation means 18) when the point A is rolled directly under the rolling mill as the gauge meter plate thickness at the point A. Remember with it.
With this function, when the actual plate thickness at point A is measured by the plate thickness meter 9, the actual plate thickness can be compared with the gauge meter plate thickness at point A and the output value of roll eccentricity control. It becomes like this. The above operation by the gauge meter plate thickness delay means 14 is also performed from the leading end of the rolled material 1 to the tail end.

In this way, the roll eccentricity calculating means 15 estimates the roll eccentricity from the deviations of the gauge meter plate thickness and the actual plate thickness, so that, for example, the fluctuation component of the rolling load caused by the skid mark is the backup roll 4 and Even when the rotation period is close to 5, the roll eccentricity can be appropriately determined without being affected by the rolling load fluctuation component due to the skid mark.
Further, the above calculation by the roll eccentricity calculating means 15 is performed from the leading end to the tail end of the rolled material 1, and while the rolled material 1 is being rolled by a rolling mill, Performed while measurements are being taken.

Next, each function of the gauge meter plate thickness delay means 14, the roll eccentric amount calculation means 15, and the roll eccentric amount storage means 16 will be specifically described with reference to FIG.
In actual control, data storage and reading are managed by the division number by equally dividing each rotation of the backup rolls 4 and 5 into n equal parts. FIG. 2 shows an example in which one rotation is divided into 36 (n = 36).

On the other hand, when calculating the roll eccentric amount, the roll eccentric amount calculating means 15 calculates the gauge meter plate thickness and the roll eccentric amount (use value) at the point where the actual plate thickness is detected by the plate thickness meter 9. Read out from the gauge meter thickness delay means 14. FIG. 2 shows a state in which the A2 point of the rolled material 1 is arranged at the plate thickness detection position of the plate thickness gauge 9, and when the A2 point is rolled directly under the rolling mill, It shows that the division number is 10 and the division number of the lower backup roll 5 is 4. In such a case, the roll eccentricity calculation means 15 is stored in the column of the actual plate thickness A2 detected by the plate thickness meter 9 and the division No 4 of the backup roll 5 below the gauge meter plate thickness delay means 14. Based on the gauge meter plate thickness and the roll eccentricity (use value), the roll eccentricity is calculated.

The roll eccentricity storage unit 16 includes a table for storing the calculation result of the roll eccentricity calculation unit 15 in association with the division numbers of the backup rolls 4 and 5. That is, in this table, as shown in FIG. 2, the division numbers when the rotation angles of the upper and lower backup rolls 4 and 5 are divided into n are arranged vertically and horizontally. Then, the roll eccentricity storage means 16 stores the roll eccentricity calculated by the roll eccentricity calculation means 15 in the corresponding cell of this table, and obtains a roll eccentricity distribution curved surface.
For example, if the roll eccentricity calculation means 15 obtains a calculation result related to the A2 point, the result is transferred to the cell where the division number 10 of the upper backup roll 4 and the division number 4 of the lower backup roll 5 intersect. It is stored as the core amount (next value). FIG. 3 is a view showing a distribution curved surface of the roll eccentricity stored in the roll eccentricity storage means, and shows an example of the obtained distribution curved surface.

Then, the roll eccentricity parameter calculating means 17 is based on the roll eccentricity amount stored in the roll eccentricity amount storage means 16 for each of the upper and lower backup rolls 4 and 5, ie, the roll eccentricity parameter, that is, the roll eccentricity. The phase (position) and amplitude are calculated. Specifically, the roll eccentricity parameter calculating means 17 approximates the roll eccentricity distribution curved surface shown in FIG. 3 with a curved surface by Fourier analysis, so that the roll eccentricity is calculated for each of the upper and lower backup rolls 4 and 5. Calculate the phase and amplitude of the wick.
Here, if the roll eccentric waveform has a primary component and a secondary component, the waveform is represented by the following equation.

Also, the following formula shows how to calculate the roll eccentricity parameter. Here, as in the example shown in FIG. 2, a case where each rotation of the backup rolls 4 and 5 is divided into 36 parts (n = 36) is shown.

The roll eccentricity parameter obtained by the calculation of the roll eccentricity parameter calculating means 17 is updated for each rolling when the length of the rolled material 1 is short as in the case of thick plate rolling. Moreover, when the length of the rolling material 1 is long like thin plate rolling, renewal is repeated several times during rolling. With this configuration, even when the roll eccentricity parameter changes with time, the change can be followed and the latest state can always be maintained.
Moreover, since the distribution curved surface of the roll eccentric amount stored in the roll eccentric amount storage means 16 is identified by Fourier transform as described above, the rolling record data for the rotation angles of the backup rolls 4 and 5 is identified. Even if the distribution is biased, an appropriate control amount can be obtained for all rotation angles.

FIG. 4 is a diagram showing a distribution curved surface of the roll eccentricity identified by the sheet thickness control device of the rolling mill shown in FIG. That is, FIG. 4 is an example in which the roll eccentricity parameter is identified and the distribution curved surface of the roll eccentricity is reproduced, and corresponds to the actual distribution curved surface shown in FIG. As can be seen from FIG. 4, the primary waveform and secondary waveform of roll eccentricity are accurately reproduced.

According to Embodiment 1 of the present invention, as described above, even when the roll eccentricity parameter changes with time or when the diameters of the upper and lower backup rolls 4 and 5 are different, due to roll eccentricity. The thickness variation which generate | occur | produces can fully be suppressed. Further, even when there is a fluctuation component of the rolling load having a period close to the period of roll eccentricity, or even when the distribution of the rolling record data is biased, it similarly occurs due to roll eccentricity. Variations in plate thickness can be sufficiently suppressed.
For this reason, it becomes possible to manufacture a high-quality product.

The sheet thickness control device for a rolling mill according to the present invention can be applied to a rolling mill that rolls a rolled material with rolls arranged vertically.

Claims

Work rolls placed one above the other,
A backup roll that supports the work roll from above and below;
A thickness control device of a rolling mill that rolls a rolled material by the work roll,
A load detector for detecting the rolling load;
A rolling position measuring instrument for measuring the roll gap;
A thickness gauge for detecting the thickness of the rolled material after rolling,
Rotation angle calculation means for calculating the rotation angle of the backup roll for each of the upper and lower sides;
Based on the rolling load detected by the load detector and the roll gap measured by the rolling position measuring instrument, a gauge meter plate thickness calculating means for calculating the gauge meter plate thickness of the rolled material,
The gauge meter plate thickness at the arbitrary point calculated by the gauge meter plate thickness calculating means is stored until an arbitrary point of the rolled material rolled by the work roll arrives at a plate thickness detection position of the plate thickness meter. Gauge meter thickness delay means to be kept,
Based on the gauge meter plate thickness at the arbitrary point stored in the gauge meter plate thickness delay means and the plate thickness at the arbitrary point detected by the plate thickness meter, the arbitrary point is rolled by the work roll. Roll eccentricity calculating means for calculating the roll eccentricity when it has been,
Based on each rotation angle calculated by the rotation angle calculation means, the roll eccentricity calculated by the roll eccentricity calculation means is used as the upper and lower backup when the arbitrary point is rolled by the work roll. Roll eccentricity storage means for storing in association with each rotation angle of the roll;
Roll eccentricity parameter calculation means for calculating the phase and amplitude of roll eccentricity for each of the upper and lower backup rolls based on the roll eccentricity amount stored in the roll eccentricity storage means,
Based on the calculation result of the roll eccentricity parameter calculating means, the control operation amount corresponding to each rotation angle of the upper and lower backup rolls is calculated so as to suppress the thickness variation component of the rolled material due to the roll eccentricity. Control operation amount calculation means for
A sheet thickness control device for a rolling mill.
The roll eccentricity storage means is a table in which a division number when the rotation angle of the upper backup roll is divided into a predetermined number and a division number when the rotation angle of the lower backup roll is divided into the predetermined number are arranged vertically and horizontally. The roll eccentricity distribution curved surface is obtained by storing the roll eccentricity calculated by the roll eccentricity calculating means in the corresponding cell of the table. Thickness control device for rolling mills.
The roll eccentricity parameter calculating means approximates the curved surface by Fourier analysis to the distribution surface of the roll eccentricity obtained by the roll eccentricity storage means, so that the roll eccentricity is calculated for each of the upper and lower backup rolls. The thickness control device for a rolling mill according to claim 2, wherein the phase and the amplitude are obtained.