JP2007090437A - Thickness control system in revering mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain fine accuracy of thickness from the top end part. <P>SOLUTION: By obtaining memory pressure by performing filtering process to the actual value of the pressure of a hydraulic cylinder when the reduction position of the hydraulic cylinder is in a releasing direction on the basis of the actual value of the pressure and the reduction position of the hydraulic cylinder just before a rolling mill is stopped after the final rolling point of the last pass is rolled; calculating the gage meter thickness at the final rolling point of the last pass on the basis of the memory pressure the reduction position of the hydraulic cylinder, a detected value of the thickness on the outlet side, a detected value of thickness on the inlet side when the final rolling point is rolled; calculating the amount of correction to calculate the pressure reference in the starting point of the rolling of the next pass by taking rolling conditions at the moment when the memory pressure is detected into consideration on the basis of the gage meter thickness and the detected value of the thickness on the inlet side; and calculating the pressure reference on the basis of the memory pressure by taking the amount of correction; the rolling of the next pass is started by taking the pressure of the hydraulic cylinder as a prescribed pressure reference on the basis of the pressure reference. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plate thickness control apparatus in a reverse type rolling mill that reciprocally rolls a rolled material such as a plate according to a multiple pass (N pass) pass schedule, and in particular, provides good plate thickness accuracy from the most advanced part. The present invention relates to a plate thickness control device in a reverse rolling mill that can be realized to shorten the off-gauge length of the product and stabilize the operation itself.

  Conventionally, in a reverse type rolling mill that rolls a material to be rolled such as a plate material by a reverse method, it is important from the point of product yield to keep the thickness of the leading end with a predetermined accuracy. In addition to the economic effect of improvement, it is an indispensable element for realizing stable operations by preventing sudden accidents such as cutting of plates.

On the other hand, even in the reverse type reverse rolling mill, especially in the case of a 20-stage Sendzimir mill or the like, since the influence of hysteresis that is a mechanical characteristic of the rolling mill itself is large, it is not a method of presetting a general roll gap, A method of giving a predetermined pressure reference to the hydraulic cylinder of the reduction device is used.

In this case, in order to accurately target the thickness of the most advanced part of each pass, the pressure reference of the hydraulic cylinder immediately after the start of rolling of each pass is predicted with high accuracy and set in the hydraulic control device. It is necessary to perform constant pressure control.

This is the same as the basic method of presetting the roll gap or the rolling position, but the standard to be given is the pressure standard of the hydraulic cylinder or the position detector installed in the hydraulic cylinder is used. It is different whether it is the reduction position standard used.

However, in any method, unless the pressure reference and the reduction position reference are accurately given, it is difficult to accurately target the tip end plate thickness on the pass exit side to a predetermined target plate thickness.

Furthermore, it is technically difficult to accurately predict and give the pressure reference and the reduction position reference at the tip as follows.

That is, since the most advanced portion of each pass is a position where the rolling is completed at the final rolling point of the previous pass, it is usually impossible to actually measure the exit side plate thickness.

Also, when starting the rolling of the next pass in the reverse direction from the final rolling point of the previous pass, the effects of coolant lubrication, plate history, etc. are very unstable immediately after the start of rolling. In the prediction calculation using a typical rolling theory, there is a problem that the pressure reference and the reduction position reference cannot be given with sufficient accuracy.

Therefore, in order to solve these problems, various methods have been proposed so far in order to improve the roll gap during tip rolling or the accuracy and control accuracy of setting the pressure reference.

For example, in Patent Document 1, in order to consider that the plasticity of the tip and tail ends of the material to be rolled is not uniform, the roll gap is corrected according to the temperature change, and the plate thicknesses of the tip and tail ends are corrected. Although attempts have been made to improve accuracy, this sheet thickness control device assumes that the thickness of the inlet and outlet sides of the leading edge can be measured, so the final rolling point stops rolling in the previous pass. In addition, there must be a margin to reach the thickness gauge on the exit side, and the factor that makes the thickness control at the leading edge unstable is plastic, that is, due to uneven temperature in the previous process. There is a serious problem that only changes in the metallurgical deformation characteristics of the material are assumed, and other mechanical conditions such as the friction coefficient are not taken into consideration.

Also in Patent Document 2, when the material to be rolled is rolled by the reverse method, the temperature of the bite end is accurately predicted, the rolling load is predicted based on the temperature, and based on the rolling load. The method for determining the roll opening is shown.

However, even in this plate thickness control method, the temperature of the end bite at the beginning of each pass is accurately predicted, and although there is an effect of improving the prediction accuracy of the rolling load, factors other than the temperature, For example, because changes in the friction coefficient and other changes in rolling conditions are not taken into account, there is a limit to the accuracy of the rolling load prediction, and therefore the accuracy of the roll opening provided is not sufficient. There is.

As described above, in the conventional plate thickness control method or plate thickness control device, it is not possible to keep the error of the reduction position reference or pressure reference in the most advanced part (difference between the actual value and the predicted value) within the allowable range. Therefore, not only is the thickness accuracy of the tip portion of the product plate material not sufficient, but there is also a serious problem that sometimes induces operational instability.
Japanese Patent Laid-Open No. 9-295019 JP-A-8-99110

  As described above, at the most advanced part, the plate thickness accuracy is not sufficient, or the direct factor that causes operational instability is the rolling position reference at the start of rolling of the next pass, or the prediction calculation accuracy of the pressure reference This is because the prediction accuracy of the rolling load using the deformation resistance, rolling temperature, coefficient of friction, etc. of the material to be rolled at the start of rolling of the next pass is basically insufficient. .

Furthermore, one of the reasons why it is difficult to accurately calculate these parameters and to predict the rolling load with sufficient accuracy using these parameters is the theoretical mathematical model of the phenomenon at the start of rolling in the next pass. Therefore, information such as the actual value of the previous pass may not be correctly reflected in the rolling of the next pass.

In other words, in the reverse rolling mill that rolls sheet materials, etc., the calculation accuracy of the rolling position standard or pressure standard at the next pass rolling, which is necessary for maintaining the sheet thickness accuracy at the most advanced part and continuing the operation, is required. In order to achieve this, even if the phenomenon at the start of rolling is predicted using only a theoretical mathematical model and accuracy is improved by combining an appropriate learning method for mathematical model calculation, the phenomenon itself is fundamentally Since instability remains, it is not always possible to obtain the required reduction position reference and pressure reference accuracy.

Therefore, at the start of rolling of the next pass, there is a serious problem that the plate thickness accuracy of the most advanced part is not sufficient, and as a result, the rolling operation itself becomes unstable.

There have been various discussions about the understanding of the basic factors that cause the above problems, and several proposals have been made as cited as improvement methods.

However, in order to achieve accurate plate thickness accuracy at the most advanced part, it is possible to describe the phenomenon sufficiently accurately with only prediction calculation and prediction control using only a theoretical mathematical model and its learning means. However, it is recognized that some kind of improvement is essential.

The object of the present invention is to provide a plate thickness control device in a reverse rolling mill that realizes good plate thickness accuracy from the most advanced part, thereby shortening the off-gauge length of the product and stabilizing the operation itself. There is to do.

  In order to achieve the above object, in the present invention, a reverse type rolling mill in a plate thickness control apparatus in a reverse type rolling mill that reciprocally rolls a material to be rolled such as a plate according to a multi-pass (N pass) pass schedule. Pressure detecting means for detecting the pressure of the hydraulic cylinder in the reverse, rolling position detecting means for detecting the rolling position of the hydraulic cylinder in the reverse rolling mill, and the reverse rolling mill in which the final rolling point of the previous pass (i pass) is rolled Based on the actual pressure value of the hydraulic cylinder immediately before it stops, and the actual pressure value of the hydraulic cylinder when the hydraulic cylinder's reduction position is in the opening direction, the filtering process is performed on the hydraulic cylinder's actual pressure value. Pressure memory means to output as, the reduction position of the hydraulic cylinder when the final rolling point is rolled, the memory pressure, GM plate thickness calculating means for calculating a gauge meter plate thickness at the final rolling point in the previous pass (i pass) based on the detected exit plate thickness value by the side plate thickness meter and the input side plate thickness detected value by the input side plate thickness meter; Based on the gauge thickness at the final rolling point calculated by the GM plate thickness calculation means and the entry side plate thickness detection value by the entry side plate thickness meter, the next pass ( (i + 1 pass) a high-order computer that calculates the correction amount to calculate the pressure reference at the rolling start point, and a correction calculation unit that calculates the pressure reference based on the memory pressure in consideration of the correction amount. On the basis of the pressure reference calculated by the above, the next pass (i + 1 pass) rolling is started by the pressure setting means using the pressure of the hydraulic cylinder as a predetermined pressure reference.

In the present invention, the upper and lower limits are checked for the correction amount calculated by the host computer, and when the correction amount exceeds the limit, the lower limit value or the upper limit value is replaced with the correction amount. The tolerance of the lower limit value at that time is made narrower than the tolerance of the upper limit value.

Furthermore, in the present invention, an entry side and an exit side plate speed detecting means for detecting the speed of the material to be rolled on the entry side and the exit side in the reverse rolling mill are added, and instead of the GM plate thickness calculation means, the entry side And MF plate thickness calculation means for calculating the mass flow plate thickness of the final rolling point in the previous pass (i pass) based on the delivery side material speed and the entry side material speed by the delivery side plate speed detection means, and the upper computer Instead, the next pass (i + 1 pass) in consideration of the rolling condition at the moment when the memory pressure is detected based on the mass flow plate thickness calculated by the MF plate thickness calculation means and the input side plate thickness detection value by the input side plate thickness meter. ) Is provided with a host computer for calculating a correction amount to calculate a pressure reference at the rolling start point.

Furthermore, in the present invention, the gauge meter plate thickness is calculated based on the mass flow plate thickness calculated by the MF plate thickness calculation means, the input side plate thickness detection value by the input side plate thickness meter, and the memory pressure, and the mass flow plate GM plate thickness correction calculation means for calculating a corrected gauge meter plate thickness by weighted average of the thickness and the gauge meter plate thickness is added, and the corrected gauge meter plate calculated by the GM plate thickness correction calculation means is used in place of the host computer. Based on the thickness and the entry side plate thickness detection value by the entry side plate thickness gauge, the correction amount is calculated to calculate the pressure reference at the rolling start point of the next pass (i + 1 pass) in consideration of the rolling condition at the moment when the memory pressure is detected. Equipped with a host computer that calculates

Therefore, in the sheet thickness control apparatus in the reverse rolling mill according to the present invention, the actual pressure value of the hydraulic cylinder immediately before the reverse rolling mill stops after the final rolling point of the previous pass (i-pass) is rolled is the pressure detection means. In addition, based on the reduction position of the hydraulic cylinder, filtering is performed on the actual pressure value when the reduction position is in the release direction, and the pressure is detected as a memory pressure by outputting it as a memory pressure. In this case, noise caused by vibration that is unavoidably mixed can be reduced, and the influence of hysteresis due to the mechanical structure of the reverse rolling mill can be eliminated by using only the pressure detection value in the reduction direction of the hydraulic cylinder. Can do. Thereby, an accurate actual pressure value at the final rolling point can be obtained.

In addition, the rolling position detection means detects the rolling position of the hydraulic cylinder when the final rolling point is rolled. Separately, the memory pressure, the outlet thickness detection value by the outlet thickness gauge, and the input by the inlet thickness gauge are input. Based on the side plate thickness detection value, the gauge meter plate thickness at the final rolling point in the previous pass (i-pass) is calculated to obtain the gauge meter plate thickness at the final rolling point in the previous pass (i-pass), that is, the final rolling point. The delivery side plate thickness can be obtained by calculation. That is, in practice, the exit side plate thickness at the final rolling point cannot be measured with the exit side thickness gauge, and therefore the exit side plate thickness at the final rolling point can be obtained based on the actual results instead. Thereby, it is possible to calculate the actual delivery thickness of the final rolling point with good accuracy.

Furthermore, based on the calculated gauge meter plate thickness at the final rolling point and the entry side plate thickness detection value by the entry side plate thickness meter, the next pass (i + 1 pass) in consideration of the rolling conditions at the moment when the memory pressure is detected by the host computer ) By calculating the correction amount to calculate the pressure reference at the rolling start point, calculation based on the actual value of the previous pass (i pass) is possible, so the pressure at the rolling start point of the next pass (i + 1 pass) The accuracy of the reference can be greatly improved.

Furthermore, the next pass (i + 1 pass) is started by starting rolling of the next pass (i + 1 pass) with the pressure setting means taking the pressure of the hydraulic cylinder as a predetermined pressure reference based on the pressure reference considering the correction amount. The plate thickness accuracy is excellent from the cutting edge, and the off-gauge length of the product is shortened, and at the same time, the operation itself can be stabilized.

On the other hand, the upper and lower limits are checked for the correction amount calculated by the host computer, and if the correction amount exceeds the limit, the lower limit value or upper limit value is replaced with the correction amount and output to the correction calculation means. By making the tolerance of the lower limit value narrower than the tolerance of the upper limit value at that time, the thickness accuracy of the tip portion is improved and stable operation can be performed.

Further, the speeds of the rolled material on the entry side and the exit side in the reverse rolling mill are detected by the entry side and exit side plate speed detection means, and the exit side material speed by the entry side and exit side plate speed detection means is detected by the host computer. Based on the entry side material speed, the mass flow plate thickness at the final rolling point in the previous pass (i pass) is calculated, and based on the calculated mass flow plate thickness and the entry side plate thickness detection value by the entry side plate thickness meter, the memory In consideration of the rolling conditions at the moment when the pressure is detected, by calculating the correction amount to calculate the pressure reference at the rolling start point of the next pass (i + 1 pass), the plate thickness accuracy of the next pass (i + 1 pass) is maximized. It is good from the tip, shortening the off-gauge length of the product and at the same time stabilizing the operation itself.

Furthermore, the gauge meter plate thickness is calculated based on the mass flow plate thickness calculated by the MF plate thickness calculation unit by the GM plate thickness correction calculation unit, the input side plate thickness detection value by the input side plate thickness meter, and the memory pressure, and the mass flow is calculated. The corrected gauge meter plate thickness is calculated by weighted average of the plate thickness and the gauge meter plate thickness, and the corrected gauge meter plate thickness calculated by the GM plate thickness correction calculation means in the host computer and the input side plate thickness detection by the input side plate thickness meter The next pass (i + 1 pass) is calculated by calculating the correction amount to calculate the pressure reference at the rolling start point of the next pass (i + 1 pass) in consideration of the rolling condition at the moment when the memory pressure is detected based on the value. The plate thickness accuracy is excellent from the cutting edge, and the off-gauge length of the product is shortened, and at the same time, the operation itself can be stabilized.

  As described above, according to the plate thickness control apparatus in the reverse rolling mill of the present invention, the actual pressure of the hydraulic cylinder immediately before the reverse rolling mill stops after the final rolling point of the previous pass (i-pass) is rolled. The value is detected by the pressure detection means, and further, based on the pressure reduction position of the hydraulic cylinder, filtering processing is performed on the actual pressure value when the reduction position is in the release direction, and the result is output as a memory pressure. In the pressure detection using the pressure detection means, it is possible to reduce noise due to vibrations inevitably mixed, and the reduction position of the hydraulic cylinder uses only the pressure detection value in the opening direction, so reverse rolling It is possible to eliminate the influence of hysteresis due to the machine structure of the machine. Thereby, an accurate actual pressure value at the final rolling point can be obtained.

In addition, the rolling position detection means detects the rolling position of the hydraulic cylinder when the final rolling point is rolled. Separately, the memory pressure, the outlet thickness detection value by the outlet thickness gauge, and the input by the inlet thickness gauge are input. Since the gauge meter plate thickness at the final rolling point in the previous pass (i pass) is calculated based on the side plate thickness detection value, the gauge meter plate thickness at the final rolling point in the previous pass (i pass), that is, the final It becomes possible to obtain the exit side plate thickness of the rolling point by calculation. That is, in practice, the exit side plate thickness at the final rolling point cannot be measured with the exit side thickness gauge, and it is possible to determine the exit side plate thickness at the final rolling point based on the actual results instead. Thereby, it is possible to calculate the actual delivery thickness of the final rolling point with good accuracy.

Furthermore, based on the calculated gauge meter plate thickness at the final rolling point and the entry side plate thickness detection value by the entry side plate thickness meter, the next pass (i + 1 pass) in consideration of the rolling conditions at the moment when the memory pressure is detected by the host computer Since the correction amount is calculated to calculate the pressure reference at the rolling start point of), calculation based on the actual value of the previous pass (i pass) is possible, so the rolling of the next pass (i + 1 pass) is started. The accuracy of the pressure reference at the point can be remarkably improved.

Furthermore, based on the pressure reference in consideration of the correction amount, rolling of the next pass (i + 1 pass) is started with the pressure setting means using the pressure of the hydraulic cylinder as a predetermined pressure reference. The plate thickness accuracy of (i + 1 pass) is good from the leading edge, and the off-gauge length of the product is shortened, and at the same time, the operation itself can be stabilized.

On the other hand, the upper and lower limits are checked for the correction amount calculated by the host computer, and if the correction amount exceeds the limit, the lower limit value or upper limit value is replaced with the correction amount and output to the correction calculation means. Since the tolerance of the lower limit value at that time is made narrower than the tolerance of the upper limit value, the thickness accuracy of the tip portion is improved, and stable operation can be performed.

Further, the speeds of the rolled material on the entry side and the exit side in the reverse rolling mill are detected by the entry side and exit side plate speed detection means, and the exit side material speed by the entry side and exit side plate speed detection means is detected by the host computer. Based on the entry side material speed, the mass flow plate thickness at the final rolling point in the previous pass (i pass) is calculated, and based on the calculated mass flow plate thickness and the entry side plate thickness detection value by the entry side plate thickness meter, the memory In consideration of the rolling condition at the moment when the pressure is detected, the correction amount is calculated to calculate the pressure reference at the rolling start point of the next pass (i + 1 pass), so the thickness of the next pass (i + 1 pass) The accuracy is good from the cutting edge, and the off-gauge length of the product is shortened, and at the same time, the operation itself can be stabilized.

Furthermore, the gauge meter plate thickness is calculated based on the mass flow plate thickness calculated by the MF plate thickness calculation unit by the GM plate thickness correction calculation unit, the input side plate thickness detection value by the input side plate thickness meter, and the memory pressure, and the mass flow is calculated. The corrected gauge meter plate thickness is calculated by weighted average of the plate thickness and the gauge meter plate thickness, and the corrected gauge meter plate thickness calculated by the GM plate thickness correction calculation means in the host computer and the input side plate thickness detection by the input side plate thickness meter Based on the value, the correction amount is calculated so as to calculate the pressure reference at the rolling start point of the next pass (i + 1 pass) in consideration of the rolling condition at the moment when the memory pressure is detected. The plate thickness accuracy of (i + 1 pass) is good from the leading edge, and the off-gauge length of the product is shortened, and at the same time, the operation itself can be stabilized.

  In the present invention, in a reverse type rolling mill that reciprocally rolls a material to be rolled such as a plate according to a multi-pass (N-pass) pass schedule, the rolling load at the final rolling point of the previous pass (i-pass) or a hydraulic cylinder Collect actual pressure values and modify them using mathematical models based on rolling theory to consider the influence of sheet thickness, tension, speed, etc., which are rolling conditions for the next pass (i + 1 pass). The actual rolling load collected at the final rolling point of the previous pass (i pass) or the actual value of the hydraulic cylinder pressure is corrected by calculating the coefficient, and the rolling load or hydraulic pressure at the rolling start point of the next pass (i + 1 pass). Calculate cylinder pressure reference. In addition, by calculating a predetermined reduction position reference based on the rolling load and starting rolling of the next pass (i + 1 pass) based on these references (pressure reference of the hydraulic cylinder or reduction position reference), Rolling of the next pass (i + 1 pass) is started while maintaining the plate thickness accuracy satisfactorily, thereby enabling stable operation and further improving the quality accuracy of the product.

Hereinafter, embodiments of the present invention based on the above-described concept will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing an example of the overall configuration of a sheet thickness control apparatus in a reverse rolling mill according to this embodiment.

In FIG. 1, the reverse rolling mill ZRM normally rolls a material to be rolled such as a plate material reciprocally (left and right in the figure) in accordance with a multi-pass (N pass) pass schedule.

In FIG. 1, the path (previous path) is expressed as i path (i = 1 to N−1), and the next path (next path) is expressed as (i + 1 path).

Further, in FIG. 1, for the sake of simplicity, the previous pass (i pass) is rolled from the right to the left in the figure, and the next pass (i + 1 pass) is rolled from the left to the right in the figure. Is shown.

On the other hand, the plate thickness control apparatus in the reverse rolling mill ZRM according to the present embodiment is configured as follows.

That is, the pressure detector PT detects the actual pressure value pmi of the hydraulic cylinder HP immediately before the reverse rolling mill ZRM is stopped after the final rolling point of the previous pass (i pass) in the reverse rolling mill ZRM is rolled, Further, the reduction position si of the hydraulic cylinder HP is detected by a reduction position detector MG.

On the other hand, based on the actual pressure value pmi of the hydraulic cylinder HP and the reduction position si of the hydraulic cylinder HP, a filtering process is performed on the actual pressure value pmi when the reduction position of the hydraulic cylinder HP is in the opening direction, and the pressure memory Output as memory pressure pi in device 1.

Further, the rolling position detector MG detects the rolling position si of the hydraulic cylinder HP when the final rolling point is rolled, and separately detects the outlet side plate thickness by the memory pressure pi and the left (outside) plate thickness meter LX. Based on the value hi and the entry side plate thickness detection value Hi by the right side (entrance side) thickness gauge RX, the GM plate thickness calculator 2 calculates the gauge meter plate thickness hgi at the final rolling point in the previous pass (i pass). Calculate.

Further, the memory pressure pi was detected based on the gauge meter plate thickness hgi at the final rolling point calculated by the GM plate thickness calculator 2 and the entry side plate thickness detection value Hi by the right side (entrance side) thickness gauge RX. In consideration of the instantaneous rolling conditions, the correction amount gi is calculated by the host computer (P / C) 3 in order to calculate the pressure reference p (i + 1) at the rolling start point of the next pass (i + 1 pass).

Further, the correction calculation device 4 calculates the pressure reference p (i + 1) based on the memory pressure pi in consideration of the correction amount gi.

Then, based on the pressure reference p (i + 1) calculated by the correction calculation device 4, the pressure of the hydraulic cylinder HP is set to a predetermined pressure reference p (i + 1) by the pressure setting device PS, and rolling in the next pass (i + 1 pass). Like to start.

Next, the operation of the sheet thickness control apparatus in the reverse rolling mill according to the present embodiment configured as described above will be described with reference to FIGS.

In FIG. 1, the actual pressure value pmi of the hydraulic cylinder HP immediately before the final rolling point of the previous pass (i pass) is rolled and the reverse rolling mill ZRM stops is detected by the pressure detector PT, and further the hydraulic cylinder HP Based on the reduction position si, a filtering process is performed on the actual pressure value pmi when the reduction position is in the release direction, and the result is output as the memory pressure pi.

At this time, for example, processing as shown in the block diagram of FIG. 2 is performed together with filtering processing in order to eliminate the influence of hysteresis based on the mechanical structure of the Sendzimir mill.

That is, in FIG. 2, the data sampling is, for example, a data sampling device of the pressure detector PT of the hydraulic cylinder HP.

Thereby, the actual measurement value of the pressure of the hydraulic cylinder HP can be sampled at a constant pitch, for example, every 20 msec.

However, in order to eliminate the influence of the mill hysteresis, this data sampling is performed only when the gap is in the opening direction, and when the gap is moving in the closing direction, it is necessary to skip the sampling.

Then, every time data sampling is performed, moving average processing of the past several tens (20 points shown in the figure) is performed, and it is momentarily based on the reduction position at that time and the pressure of the filtered hydraulic cylinder HP. A changing gauge meter (GM) plate thickness hgi is calculated.

For example, the following arithmetic expression is used.

Here, hgi is a gauge meter plate thickness, Si is a reduction position, PDi is a rolling load converted based on the pressure pi and multiplied by the inner area A of the hydraulic cylinder HP, and M is a mill constant.

In general, the fact that the mill hysteresis is large is understood from the above equation that the mill constant M is greatly different between the opening direction and the closing direction of the reduction position.

Therefore, when data sampling is performed only on the pressure in the opening direction, naturally, the mill constant M must be a numerical value actually measured in the opening direction.

In FIG. 2, after calculating the gauge meter plate thickness hgi, the filtering process is performed again, and the gauge meter plate thickness hgi immediately before the mill stop is stored.

At this time, immediately before the stop of the mill, actually, the speed of the main motor of the mill is monitored every moment, and the gauge meter plate thickness hgi at the moment when the minimum speed such as 1 m / min is cut is stored.

The gauge meter plate thickness hgi stored in this way is the GM plate thickness hgi of the final rolling point in the previous pass (i-pass). Actually, the final rolling point of the previous pass (i-pass) is on the left side (exit side). ) Since it cannot be measured by the plate thickness meter LX, it can be said that it is the exit side plate thickness of the final rolling point based on the actual result instead.

Next, on the basis of the calculated gauge meter plate thickness hgi of the final rolling point and the entry side plate thickness detection value Hi of the final rolling point by the right side (entrance side) thickness gauge RX, the upper computer (P / C) 3 The rolling conditions at the moment when the memory pressure pi is detected are taken into consideration.

At this time, as will be described below, in actuality, in order to compensate for the absolute value accuracy of the gauge meter plate thickness hgi at the final rolling point, the final measurement in which the exit side plate thickness can be measured by the left side (exit side) plate thickness meter LX. Together with the conditions at the possible points, it is necessary to perform gauge meter calculations.

This will be described in detail below.

Now, the final rolling point of the previous pass (i pass) is denoted as Z point, and the final measurable point of the exit side plate thickness of the previous pass (i pass) is denoted as Y point.

The Y point is upstream of the Z point by a distance obtained by adding a margin to the net distance between the reverse rolling mill ZRM and the right side (entry side) thickness gauge RX.

FIG. 3 is a schematic diagram illustrating an example of data sampling regarding the Y point.

In the example of FIG. 3, the rolling direction is from the left to the right in the drawing, and the sheet thickness Hi (Y) on the input side of the reverse rolling mill ZRM at the Y point of the i pass (current pass) is changed to the right (input side) thickness gauge RX. Measure the pressure value pi (Y) and the reduction position si (Y) of the hydraulic cylinder HP when the Y point is conveyed directly under the reverse rolling mill ZRM and rolled, and the Y point is After the rolling, the exit side plate thickness hi (Y) when it reaches directly below the left side (exit side) thickness gauge LX is measured.

Thereby, the following actual values are obtained with respect to the Y point.

However, the actual pressure value pi (Y) is converted into the rolling load PDi (Y).

1) Entry side thickness: Hi (Y)
2) PD load: PDi (Y)
3) Outboard thickness: hi (Y)
4) Reduction position: si (Y)
Next, data sampling is similarly performed at a point Z which is the final rolling point of the previous pass (i-pass), for example, as shown in the schematic diagram of FIG.

Measure the thickness Hi (Z) of the reverse rolling mill ZRM at the Z point of the previous pass (i pass) with the right (incoming) thickness gauge RX, and the reverse rolling mill Z point is directly below the ZRM The actual pressure value pi (Z) and the reduction position si (Z) of the hydraulic cylinder HP when it is conveyed and rolled are measured.

In these data samplings, the inlet side plate thickness and the outlet side plate thickness are measured in accordance with a normal sampling pitch, but the actual pressure value pi of the hydraulic cylinder HP and the accompanying data sampling of the reduction position si are: Based on the block diagram shown in FIG. 2, a filtering process and a treatment that eliminates the influence of mill hysteresis are necessary.

Now, with respect to the Z point, the following actual value is obtained.

1) Incoming plate thickness: Hi (Z)
2) PD load: PDi (Z)
3) Reduction position: si (Z)
Here, the PD load is converted into the rolling load PDi (Z) in the same manner as the Y point.

In addition, it should be noted that the exit side plate thickness cannot be measured at the Z point, unlike the Y point.

Using these collected data, the exit side plate thickness at the final rolling point Z, that is, the gauge meter plate thickness hgi is obtained as follows.

The gauge meter arithmetic expression at the Y point and the Z point is as follows.

Therefore, the difference Δhgi (Z−Y) in the plate thickness at the Y point and the Z point is as follows.

From this, the gauge meter thickness hgi (Z) at the Z point is

It can ask for.

Here, for the Y point, since there is a measured value hi (Y) of the outlet side plate thickness by the left side (exit side) plate thickness meter LX, it is possible to replace the gauge meter plate thickness hgi (Y) with it.

Δsi (Z−Y) is a difference between the reduction positions at the Z point and the Y point, and is generally stored as a movement amount of the reduction position.

Next, the pressure reference of the hydraulic cylinder HP at the rolling start point of the next pass (i + 1 pass) (physically, the point at the same position as the final rolling point of the previous pass) is obtained.

At this time, it is necessary to calculate the correction amount gi by the host computer (P / C) 3.

This is done as follows.

For the Z point, the following quantities are known.

1) Incoming plate thickness: Hi (Z)
2) Outboard thickness: hi (Z)
3) PD load: PDi (Z)
The inlet side plate thickness Hi (Z) is the data actually measured by the right side (input side) plate thickness meter RX, the outlet side plate thickness hi (Z) is the data calculated by the above equation (5), and the PD load PDi (Z) is These are actual values from the hydraulic cylinder HP that has been subjected to the filtering process and the process of removing the mill hysteresis.

Further, the target plate thickness of the next pass (i + 1 pass) is set to h (i + 1) (A).

This is usually a set plate thickness given by the pass schedule calculation function held by the host computer (P / C) 3.

The set values are also used for the entry side tension tb (A) and the exit side tension tf (A) of the next pass (i + 1 pass).

Accordingly, the rolling start point (point A) of the next pass (i + 1 pass) is as follows.

1) Entrance side thickness: H (i + 1) (A) = hi (Z)
2) Outboard thickness: h (i + 1) (A) = set value 3) PD load: PD (i + 1) (A) ← This is predicted.

For the Z point, the load model can be written as follows, for example.

Here, kmi (z) is an average deformation resistance at the Z point, R is a work roll radius, B is a sheet width, and QPDi (Z) is a rolling force function determined by rolling conditions.

Further, α and β represent the influence coefficient of tension.

When expanded

Similarly, for point A,

Now, the change of the deformation resistance, the tension term, and the previous path / current path of the rolling force function is calculated by the host computer (P / C) 3 and output as gi.

Taking the ratio of the above equation (7) and equation (8),

When the upper computer (P / C) 3 calculates this right side and removes the width B from the denominator numerator, it is set as gi.

Therefore,

Get.

When deployed assuming that the flat roll radius does not change, the following is obtained.

The rolling load target value PD (i + 1) (A) for the rolling start point (point A) of the next pass (i + 1 pass) obtained here is divided by the inner area of the hydraulic cylinder HP to obtain a pressure reference p (i + 1). Ask for.

To start rolling in the next pass (i + 1 pass) based on the pressure reference p (i + 1) in consideration of the correction amount gi, using the pressure setter PS as the predetermined pressure reference p (i + 1). The plate thickness accuracy of the next pass (i + 1 pass) is good from the leading edge, and the operation itself is stabilized at the same time as the off-gauge length of the product is shortened.

FIG. 5 and FIG. 6 are characteristic diagrams respectively showing examples of actual values of actual thickness deviation.

FIG. 5 shows an example of the actual value of the thickness deviation when the present embodiment is not applied.

The horizontal axis indicates the normalized longitudinal position of each pass, and the left end is the most advanced, that is, the final rolling point of each pass and the rolling start point of the next pass.

In addition, the vertical axis is the deviation of the actual thickness value with respect to the target thickness of each pass. When this is 0, the actual thickness value is completely coincident with the target value, and good thickness accuracy is obtained. It is shown that is realized.

FIG. 6 shows an example of actual value data of the thickness deviation rolled based on the present embodiment.

5 and FIG. 6 clearly shows that the off-gauge length of the tip, that is, the length of the portion with poor plate thickness accuracy is shorter in FIG. 6R> 6.

As described above, in the plate thickness control apparatus in the reverse rolling mill according to the present embodiment, the pressure of the hydraulic cylinder HP immediately before the reverse rolling mill ZRM stops after the final rolling point of the previous pass (i-pass) is rolled. The actual value pmi is detected by the pressure detector PT. Further, based on the reduction position si of the hydraulic cylinder HP, the actual pressure value pmi when the reduction position is in the release direction is filtered and output as the memory pressure pi. Therefore, noise due to vibration inevitably mixed in pressure detection using the pressure detector PT can be reduced, and only the pressure detection value in the opening direction of the hydraulic cylinder HP is used. Therefore, it is possible to eliminate the influence of hysteresis due to the mechanical structure of the reverse rolling mill ZRM. This makes it possible to obtain an accurate actual pressure value at the final rolling point.

Further, a reduction position si when the final rolling point is rolled is detected by a reduction position detector MG. Separately, the memory pressure pi, and a delivery side thickness detection value hi by a left side (exit side) thickness gauge LX, Further, the gauge meter plate thickness hgi at the final rolling point in the previous pass (i pass) is calculated based on the entry side plate thickness detection value Hi by the right side (entry side) thickness gauge RX. The gauge meter plate thickness at the final rolling point of pass), that is, the exit side plate thickness at the final rolling point can be obtained by calculation.

That is, in practice, the delivery side plate thickness at the final rolling point cannot be measured by the left side (exit side) thickness gauge LX, so that the delivery side plate thickness at the final rolling point can be obtained based on the actual results. . Thereby, it is possible to calculate the actual delivery side plate thickness with good accuracy of the final rolling point.

Further, based on the calculated gauge meter plate thickness hgi at the final rolling point and the entry side plate thickness detection value Hi by the right side (entrance side) plate thickness meter RX, the host computer (P / C) 3 detected the memory pressure pi. Considering the instantaneous rolling conditions, the correction amount gi is calculated so as to calculate the pressure reference p (i + 1) at the rolling start point of the next pass (i + 1 pass). Since calculation based on the actual value is possible, the accuracy of the pressure reference at the rolling start point of the next pass (i + 1 pass) can be remarkably improved.

Furthermore, based on the pressure reference p (i + 1) considering the correction amount gi, the pressure setter PS sets the pressure of the hydraulic cylinder HP as the predetermined pressure reference p (i + 1), and the next pass (i + 1 pass) is rolled. Since it starts, a product with good thickness accuracy can be obtained from the most advanced part of the next pass (i + 1 pass), and the off-gauge length of the product can be shortened and the operation itself can be stabilized. It becomes.

(Second Embodiment) FIG. 7 is a block diagram showing an example of the overall configuration of a sheet thickness control device in a reverse type rolling mill according to this embodiment. The same elements as those in FIG. Show.

The plate thickness control apparatus in the reverse rolling mill ZRM according to the present embodiment is configured as follows.

That is, the pressure detector PT detects the actual pressure value pmi of the hydraulic cylinder HP immediately before the reverse rolling mill ZRM is stopped after the final rolling point of the previous pass (i pass) in the reverse rolling mill ZRM is rolled, Further, the reduction position si of the hydraulic cylinder HP is detected by a reduction position detector MG.

On the other hand, based on the actual pressure value pmi of the hydraulic cylinder HP and the reduction position si of the hydraulic cylinder HP, a filtering process is performed on the actual pressure value pmi when the reduction position of the hydraulic cylinder HP is in the opening direction, and the pressure memory Output as memory pressure pi in device 1.

Further, the rolling position detector MG detects the rolling position si of the hydraulic cylinder HP when the final rolling point is rolled, and separately detects the outlet side plate thickness by the memory pressure pi and the left (outside) plate thickness meter LX. Based on the value hi and the entry side plate thickness detection value Hi by the right side (entrance side) thickness gauge RX, the GM plate thickness calculator 2 calculates the gauge meter plate thickness hgi at the final rolling point in the previous pass (i pass). Calculate.

Further, based on the gauge meter plate thickness hgi of the final rolling point calculated by the GM plate thickness calculator 2, the inlet side plate thickness detection value Hi by the right side (entry side) plate thickness meter RX, and the memory pressure pi, the memory pressure In consideration of the rolling condition at the moment when pi is detected, the correction amount gi is calculated by the host computer (P / C) 3 in order to calculate the pressure reference p (i + 1) at the rolling start point of the next pass (i + 1 pass). To do.

Further, in considering the rolling conditions, the left and right ends are distinguished, the pressure-based actual calculation value and the deviation of the memory pressure pi are reflected on the individual ends, and the correction amount is determined by the left and right end learning device 3a. Compensate for gi.

Further, the correction calculation device 4 calculates the pressure reference p (i + 1) based on the memory pressure pi in consideration of the correction amount gi.

Then, based on the pressure reference p (i + 1) calculated by the correction calculation device 4, the pressure of the hydraulic cylinder HP is set to a predetermined pressure reference p (i + 1) by the pressure setting device PS, and rolling in the next pass (i + 1 pass). Like to start.

Next, the operation of the plate thickness control apparatus in the reverse rolling mill according to the present embodiment configured as described above will be described with reference to FIG.

The description of the operation of the same portion as that of the first embodiment described above will be omitted, and only the operation of the different portion will be described here.

In FIG. 7, in the reverse type rolling mill ZRM handled by the present embodiment, the rolling start point is necessarily the left end, as the rolling direction becomes the two directions from the right to the left in the figure or from the left to the right in the figure. Or it becomes the right end.

The left and right end learning device 3a added to the host computer (P / C) 3 operates as shown in the schematic diagram of FIG.

Note that FIG. 8 shows an example in which one pass is rolled from the left to the right in the drawing, and proceeds sequentially after the second pass.

As for the actual value, the ratio Z _PD (CH) = PD ^ACT / PD ^CAL of the rolling load actual value PD ^ACT and the rolling load actual calculation value PD ^CAL at the tip of the path, that is, the right end is obtained first ( Here, CH is the tip: current value of Head: current value), and then the tail end of one path, that is, the left end Z _PD (CT) is obtained.

Next, Z _PD (CH) at the _front end (left end) of the two passes is obtained, and Z _PD (CT) at the tail end (right end) of the two passes is obtained at the end of the second pass.

In other words, in the i-pass, the temporal order obtained is reversed, but the left and right end Z _PD (CH) or Z _PD (CT) is obtained.

Then, based on Z _PD (CH) and Z _PD (CT) obtained in this way, the correction amount gi of the corresponding path is corrected.

The calculation method at this time is a learning calculation method in which the left end and the right end are considered, and will be exemplified below.

Here, a case where the rolling direction starts from the left to the right in the figure is taken as an example. It should be noted that the subscripts are the same for the reverse. The learning end is simply swapped between the left end and the right end.

NH is a learning term (New value) that is applied to the head (Head) of the next pass. For example, Z _PD (NH: 1) that appears in the left-end learning of 3 passes is already completed at the time of 3 passes. A learning term applied to one pass is shown.

In addition, α and β are exponential smoothing and weight gain, and are usually adjusted to appropriate values that can be learned at an optimal speed without diverging from about 0.1 to 0.5.

1 pass: Left edge learning Z _PD (NH: 1) = (1-β) · Z _PD (initial value) + β · {(1-α) · Z _PD (CH: 1) + α · Z _PD (CT: 1) −Z _PD (initial value)}
Two passes: right end learning Z _PD (NH: 2) = (1−β) · Z _PD (initial value) + β · {(1−α) · Z _PD (CH: 2) + α · Z _PD (CT: 2) −Z _PD (initial value)}
3 passes: Left edge learning Z _PD (NH: 3) = (1−β) · Z _PD (NH: 1) + β · {(1−α) · Z _PD (CH: 3) + α · Z _PD (CT: 3 ) -Z _PD (NH: 1)}
4th pass: right end learning Z _PD (NH: 4) = (1−β) · Z _PD (NH: 2) + β · {(1−α) · Z _PD (CH: 4) + α · Z _PD (CT: 4 ) -Z _PD (NH: 2)}
…… i-path: left end learning Z _PD (NH: i) = (1−β) · Z _PD (NH: i−2) + β · {(1−α) · Z _PD (CH: i) + α · Z _PD (CT: i) -Z _PD (NH: i-2)}
i + 1 path: right end learning Z _PD (NH: i + 1) = (1−β) · Z _PD (NH: i−1) + β · {(1−α) · Z _PD (CH: i + 1) + α · _{Z PD (CT: i + 1} ) -Z PD (NH: i-1)}
As described above, each learning term is updated with an odd path and an even path for the same end portion.

Then, by calculating the pressure reference p (i + 1) of the next pass in consideration of the correction amount gi corrected based on this, the influence on the operation of the pressure reference error depending on the prediction error of the model is eliminated. As a result, it is possible to improve the thickness accuracy of the tip and to stabilize the operation.

As described above, in the plate thickness control device in the reverse rolling mill according to the present embodiment, it is possible to improve the plate thickness accuracy of the tip and to stabilize the operation.

(Third Embodiment) FIG. 9 is a block diagram showing an example of the overall configuration of a sheet thickness control device in a reverse rolling mill according to the present embodiment. The same reference numerals are used for the same elements as those in FIGS. It is attached.

The plate thickness control apparatus in the reverse rolling mill ZRM according to the present embodiment is configured as follows.

That is, the pressure detector PT detects the actual pressure value pmi of the hydraulic cylinder HP immediately before the reverse rolling mill ZRM is stopped after the final rolling point of the previous pass (i pass) in the reverse rolling mill ZRM is rolled, Further, the reduction position si of the hydraulic cylinder HP is detected by a reduction position detector MG.

On the other hand, based on the actual pressure value pmi of the hydraulic cylinder HP and the reduction position si of the hydraulic cylinder HP, a filtering process is performed on the actual pressure value pmi when the reduction position of the hydraulic cylinder HP is in the opening direction, and the pressure memory Output as memory pressure pi in device 1.

Further, the rolling position detector MG detects the rolling position si of the hydraulic cylinder HP when the final rolling point is rolled, and separately detects the outlet side plate thickness by the memory pressure pi and the left (outside) plate thickness meter LX. Based on the value hi and the entry side plate thickness detection value Hi by the right side (entrance side) thickness gauge RX, the GM plate thickness calculator 2 calculates the gauge meter plate thickness hgi at the final rolling point in the previous pass (i pass). Calculate.

Further, the memory pressure pi was detected based on the gauge meter plate thickness hgi at the final rolling point calculated by the GM plate thickness calculator 2 and the entry side plate thickness detection value Hi by the right side (entrance side) thickness gauge RX. In consideration of the instantaneous rolling conditions, the correction amount gi is calculated by the host computer (P / C) 3 in order to calculate the pressure reference p (i + 1) at the rolling start point of the next pass (i + 1 pass).

Further, the correction reference device p (i + 1) is calculated by the correction calculation device 4 based on the memory pressure pi in consideration of the correction amount gi.

Further, based on the pressure reference p (i + 1), the reduction position calculation device 5 calculates a reduction position reference s (i + 1) at the start of rolling in the next pass (i + 1 pass).

Then, based on the reduction position reference s (i + 1) calculated by the reduction position calculation device 5, the reduction position setting unit SS sets the reduction position of the hydraulic cylinder HP as a predetermined reduction position reference s (i + 1). i + 1 pass) rolling is started.

Next, the operation of the sheet thickness control device in the reverse rolling mill according to the present embodiment configured as described above will be described.

The description of the operation of the same portion as that of the first embodiment described above will be omitted, and only the operation of the different portion will be described here.

In FIG. 9, the pressure reference p (i + 1) of the hydraulic cylinder HP is not given to the rolling start point of the next pass (i + 1 pass), but the reduction position reference s (i + 1) is given.

That is, with respect to the first embodiment described above, the rolling load PD (i + 1) generated based on the calculated pressure reference p (i + 1) of the next pass (i + 1 pass) is calculated, and based on the rolling load. Then, the reduction position calculation device 5 calculates the reduction position reference s (i + 1).

At this time, the rolling position calculation device 5 stores, for example, a mill curve as a function such as Δs = f (P, M), and s (i + 1) = h (i + 1) −Δs = h (i + 1) −f ( p (i + 1), M)
Calculate as follows.

Here, f (P, M) is a function representing a mill curve, and its variables are, for example, load: P and mill constant: M.

Further, in response to the reduction position reference s (i + 1), the reduction position setting unit SS reduces the cylinder of the hydraulic cylinder HP to a predetermined position, and rolling of the next pass (i + 1 pass) is started.

Thereby, the plate | board thickness precision of a front-end | tip part improves, and the stable operation can be implement | achieved.

As described above, in the plate thickness control device in the reverse rolling mill according to the present embodiment, it is possible to improve the plate thickness accuracy of the tip and to stabilize the operation.

(Fourth Embodiment) FIG. 10 is a block diagram showing an example of the overall configuration of a sheet thickness control apparatus in a reverse rolling mill according to the present embodiment, which is the same as in FIG. 1, FIG. 7, and FIG. Are denoted by the same reference numerals.

The plate thickness control apparatus in the reverse rolling mill ZRM according to the present embodiment is configured as follows.

That is, the pressure detector PT detects the actual pressure value pmi of the hydraulic cylinder HP immediately before the reverse rolling mill ZRM is stopped after the final rolling point of the previous pass (i pass) in the reverse rolling mill ZRM is rolled, Further, the reduction position si of the hydraulic cylinder HP is detected by a reduction position detector MG.

On the other hand, based on the actual pressure value pmi of the hydraulic cylinder HP and the reduction position si of the hydraulic cylinder HP, a filtering process is performed on the actual pressure value pmi when the reduction position of the hydraulic cylinder HP is in the opening direction, and the pressure memory Output as memory pressure pi in device 1.

Further, the rolling position detector MG detects the rolling position si of the hydraulic cylinder HP when the final rolling point is rolled, and separately detects the outlet side plate thickness by the memory pressure pi and the left (outside) plate thickness meter LX. Based on the value hi and the entry side plate thickness detection value Hi by the right side (entrance side) thickness gauge RX, the GM plate thickness calculator 2 calculates the gauge meter plate thickness hgi at the final rolling point in the previous pass (i pass). Calculate.

Further, the moment when the memory pressure pi is detected based on the gauge meter plate thickness hgi of the final rolling point calculated by the GM plate thickness calculator 2 and the inlet side plate thickness detection value Hi by the right side (entry side) plate thickness meter RX. The correction amount gi is calculated by the host computer (P / C) 3 in order to calculate the pressure reference p (i + 1) at the rolling start point of the next pass (i + 1 pass).

Further, based on the correction amount gi, using a layered table in the rolling condition, the deviation from the previous value of the correction amount gi is stored, and the current value is smoothed with respect to the previous value and corrected. The learning operation value gi ^* of the correction amount gi is calculated by the amount learning device 4a.

Further, the correction calculation device 4 calculates the pressure reference p (i + 1) based on the memory pressure pi in consideration of the learning calculation value gi ^* of the correction amount.

Then, based on the pressure reference p (i + 1) calculated by the correction calculation device 4, the pressure of the hydraulic cylinder HP is set to a predetermined pressure reference p (i + 1) by the pressure setting device PS, and rolling in the next pass (i + 1 pass). Like to start.

Next, the operation of the sheet thickness control device in the reverse rolling mill according to the present embodiment configured as described above will be described.

The description of the operation of the same portion as that of the first embodiment described above will be omitted, and only the operation of the different portion will be described here.

In FIG. 10, in response to the correction amount gi calculated by the host computer (P / C) 3, the correction amount learning device 4a performs short-term and long-term learning calculations of the correction amount gi.

As a result of the learning calculation, the correction calculation device 4 performs the correction calculation of the memory pressure pi using the correction amount gi ^* corrected by the learning term to obtain the pressure reference p (i + 1) of the next pass (i + 1 pass). .

Here, the correction amount gi is learned as follows.

The correction amount gi is provided with a stratification table based on product information such as the path reduction rate, cumulative reduction rate, and steel grade received by the host computer (P / C) 3 calculated using the actual values at that time.

The initial value of the correction amount gi is set to 1.0, for example, and the deviation is smoothed using the correction amount gi obtained at the completion of rolling of one pass.

This process is performed not only on the initial value but also on the previously stored value in the following order.

Here, gi ^* is the correction amount corrected by the learning term, gi is the correction amount calculated by the host computer (P / C) 3, and gi (saved value) is stored in advance in the stratification table of the correction amount learning device 4a. It is a numerical value of the corresponding layer of the correction amount.

Α represents a smooth gain.

Now, based on the pressure reference p (i + 1) calculated in this way, the pressure setter PS sets the pressure of the hydraulic cylinder HP as the predetermined pressure reference p (i + 1), and starts rolling in the next pass (i + 1 pass). By doing so, the plate thickness accuracy of the next pass (i + 1 pass) is good from the leading edge, the off-gauge length of the product is shortened, and the operation itself is stabilized.

As described above, in the plate thickness control device in the reverse rolling mill according to the present embodiment, the off-gauge length of the product is shortened and the operation itself can be stabilized.

(Fifth Embodiment) A sheet thickness control apparatus in a reverse rolling mill according to the present embodiment is the same as the upper computer (P / P) in the sheet thickness control apparatus in the reverse rolling mill of the first embodiment described above. C) An upper / lower limit check is performed on the correction amount gi calculated in step 3. If the correction amount gi exceeds the limit, the lower limit value or the upper limit value is replaced with the correction amount gi, and the correction calculation is performed. It outputs to the apparatus 4, and it is set as the structure which makes the tolerance of the lower limit value narrower than the tolerance of an upper limit value at that time.

Next, the operation of the sheet thickness control device in the reverse rolling mill according to the present embodiment configured as described above will be described.

The description of the operation of the same portion as that of the first embodiment described above will be omitted, and only the operation of the different portion will be described here.

In the plate thickness control apparatus of the present embodiment, an upper / lower limit check is performed on the correction amount gi calculated by the host computer (P / C) 3, and the correction amount gi exceeds the limit. Replaces the lower limit value or the upper limit value with the correction amount gi and outputs it to the correction arithmetic unit 4.

At this time, the correction amount gi may be calculated to be lower than the true value due to the influence of the mill hysteresis, and when it is calculated to be lower, the return to the target value of the plate thickness at the tip is delayed. It is preferable to avoid this by all means.

Therefore, in setting the upper and lower limit values, it is effective to narrow the range from the median value (= 1.0) to the lower limit value and widen the range to the upper limit value.

For example, the tolerance to the lower limit value is 3%, the tolerance to the upper limit value is 10%, and so on.

Thereby, the plate | board thickness precision of a front-end | tip part improves, and the stable operation can be performed.

As described above, in the plate thickness control apparatus in the reverse rolling mill according to the present embodiment, the plate thickness accuracy of the tip portion is improved and stable operation can be performed.

(Sixth Embodiment) FIG. 11 is a block diagram showing an example of the overall configuration of a sheet thickness control apparatus in a reverse rolling mill according to the present embodiment. The same parts as those in FIG. The description is omitted, and only different parts are described here.

That is, as shown in FIG. 11, the sheet thickness control apparatus in the reverse rolling mill according to the present embodiment detects the speed of the material to be rolled on the entry side and the exit side in the reverse rolling mill ZRM (the exit side). ) A plate speed detector VL and a right (incoming) plate speed detector VR are added.

Further, instead of the GM plate thickness calculator 2, based on the output side material speed VXi and the input side material speed VEi by the left side (exit side) plate speed detector VL and the right side (input side) plate speed detector VR, An MF plate thickness calculator 2a that calculates the mass flow plate thickness hfi at the final rolling point in the previous pass (i pass) is provided.

Furthermore, instead of the host computer (P / C) 3, the mass flow plate thickness hfi calculated by the MF plate thickness calculator 2a and the input side plate thickness detection value Hi by the right side (input side) plate thickness meter RX are used. Based on the rolling condition at the moment when the memory pressure pi is detected, a higher-order computer that calculates the correction amount gi to calculate the pressure reference p (i + 1) at the rolling start point of the next pass (i + 1 pass) ( P / C) 3.

Next, the operation of the sheet thickness control device in the reverse rolling mill according to the present embodiment configured as described above will be described.

The description of the operation of the same portion as that of the first embodiment described above will be omitted, and only the operation of the different portion will be described here.

In FIG. 11, instead of calculating the gauge meter plate thickness, a mass flow plate is provided with a left side (outside) plate speed detector VL and a right side (inside) plate speed detector VR on the inlet side and the outlet side of the reverse mill. The thickness hfi is calculated by the mass flow (MF) plate thickness calculator 2a.

The mass flow plate thickness hfi immediately after the roll bit exit side of the final rolling point can be calculated as follows, for example.

Here, VEi and VXi are the plate speeds detected by the left (outside) plate speed detector VL and the right (inside) plate speed detector VR on the entry side and the exit side, respectively, Vi is the roll circumferential speed, h ^REF is the thickness standard on the output side, ΔHi is the actual value of the thickness deviation on the input side, Q is the plastic constant,

Is the influence coefficient of the rear tension on the rolling load, and Δh _MF is a correction value for the deviation between the mass flow thickness measured by the left side (exit side) thickness gauge LX and the measured thickness.

The mass flow plate thickness hfi calculated using the above formula is used instead of the gauge meter plate thickness hgi to determine the exit side plate thickness of the final rolling point in the previous pass (i pass), and based on this, the memory pressure By performing a correction calculation of pi, the pressure reference p (i + 1) of the next pass (i + 1 pass) is calculated, and based on that, the pressure of the hydraulic cylinder HP is set to a predetermined pressure reference p (i + 1) by the pressure setter PS. As a result, by starting rolling of the next pass (i + 1 pass), the plate thickness accuracy of the next pass (i + 1 pass) is good from the leading edge, the off-gauge length of the product is shortened, and the operation itself is stabilized.

As described above, in the plate thickness control apparatus in the reverse rolling mill according to the present embodiment, the plate thickness accuracy of the next pass (i + 1 pass) is good from the leading edge, and the off-gauge length of the product is shortened, and at the same time, the operation itself Can be stabilized.

(Seventh Embodiment) FIG. 12 is a block diagram showing an example of the overall configuration of a sheet thickness control device in a reverse rolling mill according to the present embodiment. The description is omitted, and only different parts are described here.

That is, as shown in FIG. 12, the plate thickness control apparatus in the reverse type rolling mill according to the present embodiment has a mass flow plate thickness hfi calculated by the MF plate thickness calculator 2a, the right side (entrance side) plate thickness meter. Based on the inlet side plate thickness detection value Hi by RX and the memory pressure pi, the gauge meter plate thickness hgi is calculated, and the mass flow plate thickness hfi and the gauge meter plate thickness hgi are weighted and averaged to obtain a corrected gauge meter plate thickness hgi ^*. A GM plate thickness correction calculator 2b is added.

Further, instead of the host computer (P / C) 3, the corrected gauge meter plate thickness hgi ^* calculated by the GM plate thickness correction calculator 2b and the inlet side plate thickness by the right side (input side) plate thickness meter RX are used. Based on the detection value Hi, the correction amount gi is calculated to calculate the pressure reference p (i + 1) at the rolling start point of the next pass (i + 1 pass) in consideration of the rolling condition at the moment when the memory pressure pi is detected. The host computer (P / C) 3 is provided.

Next, the operation of the sheet thickness control device in the reverse rolling mill according to the present embodiment configured as described above will be described.

Note that the description of the operation of the same portion as that of the above-described sixth embodiment is omitted, and only the operation of the different portion is described here.

In FIG. 12, in the plate thickness control apparatus of the present embodiment, as in the case of the sixth embodiment described above, after calculating the mass flow plate thickness hfi, the case of the first embodiment described above. The gauge meter plate thickness hgi is calculated using the same method.

At this time, in order to further improve the accuracy of the calculated gauge meter plate thickness hgi, the corrected gauge meter plate thickness hgi is taken into consideration by using a predetermined weighting factor for the gauge meter plate thickness hgi. hgi ^* is calculated by the GM plate thickness correction calculator 2b.

This is calculated as follows, for example.

Here, β is a weighting factor, and is set to a numerical value of 0.8 to 0.9 or more when the accuracy of the gauge meter plate thickness hgi is high.

By using this corrected gauge meter plate thickness hgi ^* , the exit side plate thickness of the final rolling point in the previous pass (i-pass) is obtained, and based on this, the memory pressure pi is corrected to calculate the next pass (i + 1 pass). By calculating the pressure reference p (i + 1), and based on that, the pressure setter PS sets the pressure of the hydraulic cylinder HP as the predetermined pressure reference p (i + 1), and starts rolling in the next pass (i + 1 pass), The plate thickness accuracy of the next pass (i + 1 pass) is good from the leading edge, and the off-gauge length of the product is shortened and the operation itself is stabilized.

As described above, in the plate thickness control apparatus in the reverse rolling mill according to the present embodiment, the plate thickness accuracy of the next pass (i + 1 pass) is good from the leading edge, and the off-gauge length of the product is shortened, and at the same time, the operation itself Can be stabilized.

(Other Embodiments) In each of the above embodiments, for the sake of simplicity of explanation, the previous pass (i-pass) is rolled from the right to the left in the figure, and the next pass (i + 1 pass) is reversed from the left in the figure. Although the situation of rolling in the right direction has been shown, the present invention is not limited to this, and if the previous pass (i-pass) is rolled from the left to the right in the figure, the left (exit) plate installed on the left side Needless to say, the same effects as those described above can be obtained by replacing the thickness gauge LX and the right (incoming) thickness gauge RX installed on the right side with the left and right sides.

The block diagram which shows 1st Embodiment of the sheet thickness control apparatus in the reverse type rolling mill by this invention. The block diagram which shows the detail of the filtering process with respect to the performance pressure of the hydraulic cylinder HP in the board thickness control apparatus of the said 1st Embodiment, and an averaging process. The schematic diagram which shows the position and data collection timing of Y point (final point which can be taken out board | plate thickness results acquisition) of the front pass (i pass) in the plate | board thickness control apparatus of the said 1st Embodiment. The schematic diagram which shows the position of Z point (final rolling point) of the front pass (i pass) in the board thickness control apparatus of the 1st Embodiment, and data collection timing. The figure which shows an example of the plate | board thickness performance of each path | pass by the conventional plate | board thickness control method. The figure which shows an example of the plate | board thickness performance of each path | pass in the plate | board thickness control apparatus of the said 1st Embodiment. The block diagram which shows 2nd Embodiment of the sheet thickness control apparatus in the reverse type rolling mill by this invention. The schematic diagram which shows an example of the procedure of the right-and-left end learning in the board thickness control apparatus of the said 2nd Embodiment. The block diagram which shows 3rd Embodiment of the sheet thickness control apparatus in the reverse type rolling mill by this invention. The block diagram which shows 4th Embodiment of the sheet thickness control apparatus in the reverse type rolling mill by this invention. The block diagram which shows 6th Embodiment of the sheet thickness control apparatus in the reverse type rolling mill by this invention. The block diagram which shows 7th Embodiment of the sheet thickness control apparatus in the reverse type rolling mill by this invention.

Explanation of symbols

ZRM ... reverse rolling mill,
R-TR ... Right tension reel,
L-TR ... Left tension reel,
RX ... Right side (entry side) thickness gauge,
LX ... Left side (exit side) thickness gauge,
HP ... hydraulic cylinder,
PT: Pressure detector,
MG ... reduction position detector,
1 ... Pressure memory device,
2 ... GM thickness calculator,
2a: MF thickness calculator,
2b ... GM plate thickness correction calculator,
3 ... Host computer (P / C),
3a ... Left and right edge learning device,
4 ... correction arithmetic unit,
4a ... Correction amount learning device,
5 ... Reduction position calculation device,
PS ... Pressure setter,
SS: Reduction position setting device,
VR: right (entrance) plate speed detector,
VL: Left (exit side) plate speed detector.

Claims (7)

In a plate thickness control device in a reverse rolling mill that reciprocally rolls a material to be rolled such as a plate according to a pass schedule of a plurality of passes (N passes),
Pressure detecting means for detecting the pressure of the hydraulic cylinder in the reverse rolling mill;
A reduction position detecting means for detecting a reduction position of a hydraulic cylinder in the reverse rolling mill;
Based on the actual pressure value of the hydraulic cylinder immediately before the reverse rolling mill is stopped after the final rolling point of the previous pass (i-pass) is rolled, and the reduction position of the hydraulic cylinder, the reduction position of the hydraulic cylinder is Pressure memory means for outputting the actual pressure value of the hydraulic cylinder at the time of opening direction as a memory pressure;
Based on the reduction position of the hydraulic cylinder when the final rolling point is rolled, the memory pressure, the outlet plate thickness detected value by the outlet plate thickness meter, and the inlet side plate thickness detected value by the inlet side plate thickness meter GM thickness calculation means for calculating the gauge thickness at the final rolling point in (i pass);
In consideration of the rolling condition at the moment when the memory pressure is detected based on the gauge thickness at the final rolling point calculated by the GM thickness calculation means, and the entry side thickness detection value by the entry side thickness gauge, A host computer that calculates a correction amount to calculate a pressure reference at the rolling start point of the next pass (i + 1 pass);
In consideration of the correction amount, correction calculation means for calculating a pressure reference based on the memory pressure, and based on the pressure reference calculated by the correction calculation means, the pressure setting means controls the pressure of the hydraulic cylinder. A sheet thickness control apparatus in a reverse rolling mill, wherein rolling of the next pass (i + 1 pass) is started as a predetermined pressure reference. In a plate thickness control device in a reverse rolling mill that reciprocally rolls a material to be rolled such as a plate according to a pass schedule of a plurality of passes (N passes),
Pressure detecting means for detecting the pressure of the hydraulic cylinder in the reverse rolling mill;
A reduction position detecting means for detecting a reduction position of a hydraulic cylinder in the reverse rolling mill;
Based on the actual pressure value of the hydraulic cylinder immediately before the reverse rolling mill is stopped after the final rolling point of the previous pass (i-pass) is rolled, and the reduction position of the hydraulic cylinder, the reduction position of the hydraulic cylinder is Pressure memory means for outputting the actual pressure value of the hydraulic cylinder at the time of opening direction as a memory pressure;
Based on the reduction position of the hydraulic cylinder when the final rolling point is rolled, the memory pressure, the outlet plate thickness detected value by the outlet plate thickness meter, and the inlet side plate thickness detected value by the inlet side plate thickness meter GM thickness calculation means for calculating the gauge thickness at the final rolling point in (i pass);
Based on the gauge meter plate thickness at the final rolling point calculated by the GM plate thickness calculation means, the entry side plate thickness detection value by the entry side plate thickness meter, and the memory pressure, the rolling condition at the moment when the memory pressure is detected is determined. In consideration, a high-order computer that calculates a correction amount to calculate a pressure reference at the rolling start point of the next pass (i + 1 pass);
When considering the rolling conditions, the left and right end learning means for distinguishing the left and right ends, reflecting the actual pressure calculation value of the pressure reference and the deviation of the memory pressure for each end, and compensating the correction amount; ,
In consideration of the correction amount, correction calculation means for calculating a pressure reference based on the memory pressure, and based on the pressure reference calculated by the correction calculation means, the pressure setting means controls the pressure of the hydraulic cylinder. A sheet thickness control apparatus in a reverse rolling mill, wherein rolling of the next pass (i + 1 pass) is started as a predetermined pressure reference. In a plate thickness control device in a reverse rolling mill that reciprocally rolls a material to be rolled such as a plate according to a pass schedule of a plurality of passes (N passes),
Pressure detecting means for detecting the pressure of the hydraulic cylinder in the reverse rolling mill;
A reduction position detecting means for detecting a reduction position of a hydraulic cylinder in the reverse rolling mill;
Based on the actual pressure value of the hydraulic cylinder immediately before the reverse rolling mill is stopped after the final rolling point of the previous pass (i-pass) is rolled, and the reduction position of the hydraulic cylinder, the reduction position of the hydraulic cylinder is Pressure memory means for outputting the actual pressure value of the hydraulic cylinder at the time of opening direction as a memory pressure;
Based on the reduction position of the hydraulic cylinder when the final rolling point is rolled, the memory pressure, the outlet plate thickness detected value by the outlet plate thickness meter, and the inlet side plate thickness detected value by the inlet side plate thickness meter GM thickness calculation means for calculating the gauge thickness at the final rolling point in (i pass);
In consideration of the rolling condition at the moment when the memory pressure is detected based on the gauge thickness at the final rolling point calculated by the GM thickness calculation means, and the entry side thickness detection value by the entry side thickness gauge, A host computer that calculates a correction amount to calculate a pressure reference at the rolling start point of the next pass (i + 1 pass);
In consideration of the correction amount, correction calculation means for calculating a pressure reference based on the memory pressure, and based on the pressure reference calculated by the correction calculation means, at the start of rolling in the next pass (i + 1 pass) A reduction position calculation means for calculating a reduction position reference;
And rolling of the next pass (i + 1 pass) is started based on the reduction position reference calculated by the reduction position calculation means, with the reduction position setting means using the reduction position of the hydraulic cylinder as a predetermined reduction position reference. A sheet thickness control device in a reverse rolling mill characterized by being configured as described above. In a plate thickness control device in a reverse rolling mill that reciprocally rolls a material to be rolled such as a plate according to a pass schedule of a plurality of passes (N passes),
Pressure detecting means for detecting the pressure of the hydraulic cylinder in the reverse rolling mill;
A reduction position detecting means for detecting a reduction position of a hydraulic cylinder in the reverse rolling mill;
Based on the actual pressure value of the hydraulic cylinder immediately before the reverse rolling mill is stopped after the final rolling point of the previous pass (i-pass) is rolled, and the reduction position of the hydraulic cylinder, the reduction position of the hydraulic cylinder is Pressure memory means for outputting the actual pressure value of the hydraulic cylinder at the time of opening direction as a memory pressure;
Based on the reduction position of the hydraulic cylinder when the final rolling point is rolled, the memory pressure, the outlet plate thickness detected value by the outlet plate thickness meter, and the inlet side plate thickness detected value by the inlet side plate thickness meter GM thickness calculation means for calculating the gauge thickness at the final rolling point in (i pass);
In consideration of the rolling condition at the moment when the memory pressure is detected based on the gauge thickness at the final rolling point calculated by the GM thickness calculation means, and the entry side thickness detection value by the entry side thickness gauge, A host computer that calculates a correction amount to calculate a pressure reference at the rolling start point of the next pass (i + 1 pass);
Based on the correction amount, the deviation from the previous value of the correction amount is stored using a stratified table in the rolling condition, and the current value is smoothed with respect to the previous value, and the correction amount learning calculation is performed. Correction amount learning means for calculating a value; correction calculation means for calculating a pressure reference based on the memory pressure in consideration of a learning calculation value of the correction amount;
And the rolling of the next pass (i + 1 pass) is started using the pressure setting means with the pressure of the hydraulic cylinder as a predetermined pressure reference based on the pressure reference calculated by the correction calculating means. A sheet thickness control device for a reverse type rolling mill.    In the plate thickness control apparatus in the reverse type rolling mill according to claim 1, an upper / lower limit check is performed on the correction amount calculated by the host computer, and when the correction amount exceeds the limit, the lower limit A plate in a reverse type rolling mill, wherein the value or upper limit value is replaced with the correction amount and output to the correction calculation means, and the tolerance of the lower limit value at that time is made narrower than the tolerance of the upper limit value Thickness control device.    In the sheet thickness control apparatus in the reverse type rolling mill according to claim 1, an entry side and an exit side plate speed detection means for detecting the speed of the material on the entry side and the exit side in the reverse type rolling mill are added, Instead of the GM plate thickness calculation means, the mass flow plate thickness at the final rolling point in the previous pass (i pass) is calculated based on the exit side material speed and the entry side material speed by the entry side and exit side plate speed detection means. The memory pressure based on the mass flow plate thickness calculated by the MF plate thickness calculating unit and the input side plate thickness detection value by the input side plate thickness gauge instead of the host computer. In consideration of the rolling conditions at the moment of detecting the reverse pressure, the reverse pressure is provided with a host computer for calculating the correction amount to calculate the pressure reference at the rolling start point of the next pass (i + 1 pass) Thickness control device in the machine.    In the plate thickness control apparatus in the reverse type rolling mill according to claim 6, based on the mass flow plate thickness calculated by the MF plate thickness calculation means, the input side plate thickness detection value by the input side plate thickness meter, and the memory pressure. Adding a GM plate thickness correction calculating means for calculating a gauge meter plate thickness and calculating a corrected gauge meter plate thickness by weighted averaging of the mass flow plate thickness and the gauge meter plate thickness, and replacing the host computer, Based on the corrected gauge meter plate thickness calculated by the GM plate thickness correction calculation means and the inlet side plate thickness detection value by the inlet side plate thickness meter, the next pass is considered in consideration of the rolling condition at the moment when the memory pressure is detected. A plate thickness control apparatus for a reverse rolling mill, comprising a host computer for calculating a correction amount so as to calculate a pressure reference at a rolling start point of (i + 1 pass).

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