JP2540249B2 - Method for determining rolling schedule of rolling mill - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a rolling condition including a plate thickness setting value and a bender pressure setting value of each rolling stand of a tandem rolling mill in order to correct a crown deviation of a final stand.
Relates to reduction schedule determination method of the rolling mill to determine comprehensively throughout the rolling machine, in particular, the plate of the rolling stands, such as the shape of the plate thickness at each rolling stand is a predetermined tolerance in the shape
It is possible to determine the thickness setting value and the vendor pressure setting value ,
The present invention relates to a rolling schedule determination method for a rolling mill.

[0002]

2. Description of the Related Art In plate thickness control of a tandem rolling mill, for example, a cold continuous finish rolling mill, various sensors arranged at various points of the rolling mill are used to obtain a desired plate thickness from the tip of the strip. It is necessary to set the reduction position of each stand to an appropriate position according to the data from.

Conventionally, the rolling position of each stand has been set by analogy from past rolling data, experience of operators, etc., but recently, rolling theoretical formulas (rolling load type, deformation resistance type, gauge meter) are set. Formulas, rolled material temperature formulas, etc.) are often used by computers.

Further, for example, in a cold continuous rolling mill, the material to be rolled must be rolled flat.

Therefore, various control methods have been proposed as a shape control method in a tandem rolling mill such as a cold continuous rolling mill.

For example, by rolling the rolling roll by correcting the shape of the rolling roll, by controlling the bending of the rolling roll, or by moving the intermediate rolling roll in the strip width direction in a tandem rolling mill, A method of controlling the bending of the roll, a method of controlling the shape of the rolling roll by the amount and pressure of a high-pressure fluid injected into the rolling roll, and the like have been proposed.

Also, as a shape control method for a tandem rolling mill, a control method has been proposed in which the shape of a material to be rolled is made flat by controlling the rolling position of each stand.

Further, a technique relating to a rolling schedule determination method for a rolling mill, which comprehensively determines the rolling conditions of each rolling stand of a tandem rolling mill for the purpose of plate thickness control and shape control of the material to be rolled. Is also disclosed.

For example, a technique called a table method has been disclosed as a technique relating to such a rolling schedule determination method for a rolling mill.

This rolling mill rolling schedule determination method called the table method is a technique of preparing in advance a rolling table change pattern as a data table in order to deal with a predicted sheet crown change and the like.

As a rolling mill rolling reduction schedule determining method, a technique related to a rolling mill rolling reduction schedule determining method called linear programming is disclosed.

For example, in Japanese Patent Laid-Open No. 59-73108, the widthwise plate thickness deviation realized when the widthwise load distribution between the material to be rolled and the work rolls is uniform, and the material to be rolled on the entrance side of the rolling mill. Disclosed is a technique of obtaining each pass delivery side plate thickness through a calculation formula for obtaining the width direction plate thickness deviation of the rolled material on the rolling mill output side configured as a linear combination of the plate width direction plate thickness deviations. There is.

According to the technique disclosed in Japanese Patent Application Laid-Open No. 59-73108, it is possible to perform various rolling schedule change patterns such as an operation in which the rolling unit (each pass) of the tandem rolling mill greatly changes. It is possible to respond.

As a rolling mill rolling reduction schedule determining method which is a linear programming method, Japanese Patent Laid-Open No. 61-42408 discloses a technique relating to a rolling mill rolling reduction schedule determining method according to the following procedure.

That is, first, an expected crown or crown ratio on the stand-out side of each stand in the standard pass schedule to which the load distribution and the work roll shift are applied is obtained. Last n
When the expected crown or crown ratio on the stand exit side is different from the target value, the maximum allowable crown and the minimum allowable crown determined from the shape change of the n-1th stand immediately before the final stand are obtained. If the expected crown or crown ratio of the (n-1) th stand in the standard pass schedule does not fall within the allowable range, the expected crown or crown ratio is changed so as to fall within the allowable range with a minimum change. The expected crown or crown ratio will be changed sequentially until the first-stage stand. The crown is changed by changing the work roll shift amount. If the change of the expected crown ratio up to the first stage is within the work roll shift amount, the pass schedule is changed to the work roll shift amount. Just adopt. When a stand exceeding the capacity of the work roll shift amount occurs due to the change of the expected crown or crown ratio up to the first stage, the rolling load of the stand is also changed, and the pass schedule is changed to the work roll shift amount and the rolling load. Make changes and adopt.

Japanese Patent Application Laid-Open No. 61-
According to the technique disclosed in 42408, it is possible to easily perform the optimum value search without increasing the amount of calculation performed by the computer.

Further, as a rolling mill rolling schedule determining method which is a linear programming method, Japanese Patent Laid-Open No. 61-42409 discloses the following technique.

That is, first, the expected crown or crown ratio on the stand-out side of each stand in the pass schedule to which the load distribution and the work roll bending force are applied is obtained. If the expected crown or crown ratio on the exit side of the final n-th stand is different from the target value, the n-th one before the final stand.
Obtain the maximum allowable crown and the minimum allowable crown determined from the shape change of one stand. If the expected crown or crown ratio of the (n-1) th stand in the standard pass schedule does not fall within the allowable range, the expected crown or crown ratio is changed so as to fall within the allowable range with a minimum change. The expected crown or crown ratio will be changed sequentially until the first-stage stand. The crown is changed by changing the bending force of the work roll. If the change of the expected crown or crown ratio up to the first stage is within the capability of the roll bender, the pass schedule is adopted only by making the change in the roll bending force. When a stand exceeding the capability of the roll bender occurs due to the change of the expected crown or the crown ratio up to the first stage, the rolling load of the stand is also changed, and the pass schedule is changed to the roll bending force and the rolling load. To adopt.

According to the technique disclosed in Japanese Patent Application Laid-Open No. 61-42409 described above, in addition to the target value of the outlet plate thickness and temperature required for hot rolling, the outlet crown is also set to the target value. It is possible to

[0020]

However, in the above-mentioned method of determining the rolling schedule of the rolling mill called the table method, the strict concept of the crown shape is not introduced, and it is not suitable for roll-chance free rolling. There is. For this reason, the capability of the crown control mechanism such as the shift and the vendor may be exceeded, and the rolling conditions that can be set in each rolling stand may be exceeded.

In the technique disclosed in the above-mentioned Japanese Patent Laid-Open No. 59-73108, a combination of several thousand to tens of thousands of intermediate stand plate thicknesses is set in advance, and a predetermined evaluation function is selected from these combinations. It is a method of adopting a rolling schedule of the intermediate stand plate thickness that minimizes the above. Therefore, even with the technique disclosed in Japanese Patent Laid-Open No. 59-73108, there is a problem in that the crown shape cannot be set to an optimum plate thickness that satisfies all rolling stands. Further, the amount of calculation performed in this Japanese Patent Laid-Open No. 59-73108 is very large, and there is a problem that hardware such as a computer capable of high-speed processing is required and a problem that calculation time becomes long.

Incidentally, in the above-mentioned JP-A-61-42408 and JP-A-61-42409, since the pass schedule is changed sequentially, the above-mentioned JP-A-59-7310.
Although the amount of calculation is somewhat reduced as compared with the dynamic programming method disclosed in No. 8, there is a problem in that it also has a large amount of calculation load.

The present invention has been made to solve the above-mentioned conventional problems. In order to correct the crown deviation of the final stand, the plate thickness of each rolling stand of the tandem rolling mill is set.
In the rolling mill rolling schedule determination method for comprehensively determining rolling conditions including a value and a vendor pressure setting value in the rolling mill as a whole, without increasing the processing such as calculation performed by the computer, crown amount and thickness as well as to be the target value, the shape of the plate material at each rolling stand is a predetermined tolerance in shape, and a plate of the rolling stand so as to satisfy even the mill capacity of the rolling stand
It is possible to determine the thickness setting value and the vendor pressure setting value ,
It is an object to provide a method for determining a rolling schedule of a rolling mill.

[0024]

In order to correct the crown deviation of the final stand, the present invention provides a rolling condition including a plate thickness setting value and a bender pressure setting value of each rolling stand of a tandem rolling mill. In the rolling mill rolling schedule determination method that is comprehensively determined as a whole, the plate of each rolling stand is set to an intermediate value that can mainly increase or decrease the setting.
The thickness setting value and vendor pressure value as the initial value, the plate thickness setting
In the final stand at the initial value and the initial value of the vendor pressure setting value, the crown deviation with respect to the target crown is determined, and from the crown deviation and the shape condition of each rolling stand, the sheet thickness change amount of each rolling stand is simultaneously determined, and each rolling It is judged whether the amount of change in plate thickness of the stand satisfies the mill ability of each rolling stand.If there is a rolling stand whose amount of change in plate thickness does not satisfy the mill ability, first change the vendor pressure of the rolling stand. After that, the above object is achieved by re- calculating the plate thickness change amount.

Further, the above-mentioned object is achieved by setting the shape condition for obtaining the amount of change in plate thickness of each rolling stand as the shape condition of each rolling stand after the third stand.

[0026]

In the present invention, when the rolling conditions including the plate thickness setting value and the bender pressure setting value of each rolling stand of the tandem rolling mill are comprehensively determined in the rolling mill as a whole, first, the setting value is increased or The initial values of the plate thickness setting value and the bender pressure setting value of each rolling stand are calculated while taking into consideration the reduction.

That is, first, at least the plate thickness setting value and the bender pressure setting value of each rolling stand are set to have a margin with respect to the upper limit and the lower limit allowed by each rolling stand, and these rolling stands are set. The initial value of the plate thickness setting value and the initial value of the vendor pressure setting value are calculated.

Alternatively, the initial values of other rolling conditions may be determined so that these initial values become such initial values.

Further, in the present invention, the shape condition of each rolling stand (for example, all rolling stands before the final stand) is used to correct the crown deviation of the final stand. That is, the plate thickness and the like of each rolling stand can be set within a predetermined allowable range. Thereby, the stability of rolling control of each rolling stand can be improved.

Further, even if the plate thickness set value of each rolling stand is changed by the plate thickness change amount of each rolling stand thus obtained, as described above, the plate thickness set value of each rolling stand is changed. Since the initial value is determined in consideration of the fact that it is possible to increase or decrease the set value, the upper and lower limits of the plate thickness set value of each rolling stand will be exceeded by such changes in the plate thickness set value. Fear is diminished.

Further, even if there is a rolling stand that exceeds the upper limit or the lower limit of the plate thickness setting value due to such a change in the plate thickness setting value of each rolling stand, in the present invention, the predetermined rolling is performed. It is possible to deal with this by changing the vendor pressure of the stand.

The rolling stand for changing the bender pressure may be the rolling stand itself in which the changed sheet thickness setting value exceeds the upper limit or the lower limit, or
Other rolling stands may be used, or all rolling stands may be used.

Further, in the present invention, the initial value of the set value of the vendor pressure is also determined in consideration of the fact that the set value can be increased or decreased thereafter, so that an appropriate bender pressure can be promptly set. It is possible to decide.

FIG. 1 is a flow chart showing the gist of the present invention.

In step 102 of FIG. 1, first, the plate thickness set value of each rolling stand and the bender pressure are taken into consideration while considering that the set value can be increased or decreased when the crown deviation of the final stand is corrected. Calculate the initial setting value . That is, in this step 102, the plate thickness setting value and the vendor pressure setting value are determined while taking into consideration the upper limit and the lower limit of each rolling stand so as to have a margin.

Although the present invention is not limited to rolling conditions other than the plate thickness setting value and the vendor pressure setting value, other rolling conditions also affect the plate thickness setting value and the vendor pressure setting value. There is also. Therefore, it is desirable to determine such other rolling conditions while considering the plate thickness setting value and the vendor pressure setting value so that each rolling stand can have a margin with respect to the upper limit and the lower limit. .

In step 104, the crown deviation in the final stand is obtained from the initial value of the rolling condition of each rolling stand of the tandem rolling mill obtained in step 102. The crown deviation obtained in step 104 is the difference (deviation) between the crown quantity on the exit side of the final stand and the crown quantity under the calculated rolling conditions.

The rolling schedule determination method for a rolling mill according to the present invention is to set the crown amount on the delivery side of the final stand within a predetermined crown deviation.

In step 106, in order to set the exit side crown deviation of the final stand obtained in step 104 to a predetermined target value, the shape conditions of each rolling stand are used as necessary and each rolling of the tandem rolling mill is performed. Calculate the stand thickness change amount.

Further, when obtaining the plate thickness change amount of each rolling stand in step 106, the following conditions are satisfied.

The exit crown of the final stand is made equal to the target crown. Set the plate thickness on the exit side of the final stand to the target plate thickness. Use the necessary rolling stand shape conditions. Satisfy the mill ability of each stand.

In the embodiment of the present invention described later, the function for obtaining the plate thickness change amount of each rolling stand has a variable of the crown deviation and the crown amount of a predetermined stand. It is a linear function (for the number of stands to be controlled).

As described above, when the plate thickness change amount of each rolling stand is obtained by using the function of each rolling stand, the plate thickness change amounts of a plurality of rolling stands are simultaneously obtained in parallel. It is possible to do.

Further, when the function used at this time is a linear function, it is possible to easily obtain the plate thickness change amount from the crown deviation and the crown amount of the predetermined stand.

The shape condition used in the step 106 does not have to be for all the rolling stands of the tandem rolling mill, and it affects the fluctuation of the crown amount on the exit side of the final stand and the stability of rolling control. In consideration of the above, the necessary shape condition of the rolling stand may be used.

For example, in the embodiment of the present invention described later, the shape condition for obtaining the plate thickness change amount of each rolling stand is the shape condition of each rolling stand after the third stand.

In step 108, it is judged whether the strip thickness change amount obtained in step 106 satisfies the milling ability, or at least the rolling stand on which the strip thickness is changed. Satisfies the mill ability in this step 108
Whether or not to do this can be determined by, for example, rolling mills by changing the plate thickness.
The allowable rolling load is determined by the facility strength of the rolling mill.
It can be carried out depending on whether the weight is equal to or less than the weight. That is,
The rolling load caused by changing the plate thickness is less than the allowable load.
If the mill capacity is satisfied and the allowable load is exceeded,
It is judged that the ability is not satisfied.

If it is determined in step 108 that the mill capacity cannot be satisfied, the bending pressure of a predetermined rolling stand is changed in step 110, and then the processes in steps 104 and 106 and step 108 described above are performed again. Run. When changing the vendor pressure, allow the rolling load.
Instead of limiting the amount of change in plate thickness so as to keep the load
In addition, in order to supplement the amount of reduction of the plate crown,
Decrease the pressure. The amount of weakening of the vendor pressure is stepped in Fig. 1.
It is clear from 104 to 110 that it is a loop
In this way, for example, the weakening amount of the vendor pressure is set to a predetermined amount, and
If the allowable load is still exceeded, return the loop.
Suppresses the amount of change in plate thickness, and further reduces the bender pressure to the predetermined value.
It can be decided by the procedure of adding only the amount and weakening
it can.

On the other hand, when it is determined in step 108 that the mill ability can be satisfied, the following step 1
At 12, the optimum plate thickness and bender pressure of each rolling stand are determined according to the amount of change in plate thickness and bender pressure of each rolling stand obtained by executing the processing of each step up to this point.

As described above, according to the present invention, processing such as calculation performed by a computer or the like (repetitive loop) is performed while the shape of the plate material as the material to be rolled in the rolling stand is within a predetermined allowable shape. It is possible to determine the rolling conditions of each rolling stand without increasing the number of times).

[0051]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a flow chart of the embodiment of the present invention.

[0053] In step 202 of FIG. 2, as in step 102 of FIG. 1 described above, taking into account so as to allow increase or decrease of the set value, the thickness of each rolling stand <br/> Obtain the initial values for the set value and the vendor pressure set value .

[0054]

At step 204, the i-th rolling stand is calculated from the entry-side crown amount C rs (i −1) of each i-th rolling stand, the roll crown amount φ s (i) and the following equation. Then, the crown amount Crs (i) of is calculated .

[0056]

[Equation 1]

In the equation (1), i is 1 to 7
Is.

In step 206, the crown deviation ΔCr (7) is obtained from the target crown amount Cro (7), the calculated crown amount Crs (7) and the following equation in the seventh and last stand.

[0059]

[Equation 2]

Next, at step 208, the plate thickness change amount Δh (for each rolling stand) for correcting (set to 0) the crown deviation ΔCr (7) of the final stand while using the shape condition of each rolling stand. 1) to Δh (7) are calculated.

This step 208 of FIG. 2 corresponds to the step of FIG.
This corresponds to step 106 of step (1) and will be described later (1
The calculation is performed using the equation (8).

It should be noted that the following steps 212 of FIG.
214 and 216 respectively correspond to step 10 of FIG.
8, 110, and 112, and similar processing is performed.

The calculation formula (function) for obtaining the plate thickness change amounts Δh (1) to Δh (7) of each rolling stand used in the above-mentioned step 208 will be described below using mathematical formulas.

Amount Δh of change in plate thickness of each rolling stand
The functions for obtaining (1) to Δh (7) are the calculation formula (corresponding to the above formula (2)) for correcting the crown deviation ΔCr (7) at the final stand to 0, and the shape condition formula,
That is, it is a function that is obtained by a combination of shape condition equations (corresponding to equation (6) described later) for keeping the shape of the plate thickness of the material to be rolled in each rolling stand of the tandem rolling mill within a predetermined allowable shape. is there.

In the actual operation of this embodiment, paying attention to the fact that the shape change coefficients of the first and second rolling stands from the entrance side of the tandem rolling mill are small, and the irregularity of the shape can be ignored. Only the shape conditions of the third to seventh rolling stands are considered.

As described above, it is not necessary to use the shape conditions of all the rolling stands that make up the tandem rolling mill when the plate thickness change amount of each rolling stand is obtained, but according to the characteristics of the target tandem rolling mill. It suffices to consider only the necessary shape conditions of the rolling stand.

Amount of change in thickness of each rolling stand for correcting the crown deviation of the final stand Δh (1) to Δh
In order to obtain the function for obtaining (7), first, by using the above equation (1), the substitution is repeated from the front stage (first from the inlet side) to the rear stage (final stage) of the tandem rolling mill. , The following equation can be obtained.

[0068]

(Equation 3)

Incidentally, D1 (i) and D1 (o) in the equation (3) are as follows.

[0070]

[Equation 4]

Further, the roll crown amount φ s (i) is calculated by setting the plate thickness set value h (i) of the corresponding rolling stand and the plate thickness set value h (i − i of the adjacent rolling stand on the entry side of the corresponding rolling stand.
Since it is a function of 1), Crs (7) is h (1) to h
It is understood that the relationship of (7) is established. Therefore, the crown deviation ΔCr (7) at the final stand can be expressed by the following equation.

[0072]

(Equation 5)

Further, by substituting the equation (3) into the equation (4), the following equation can be obtained.

[0074]

(Equation 6)

In the expression (5), i is an integer of 1 to 6, and F1 (i) is as follows.

[0076]

(Equation 7)

On the other hand, the shape condition expression of each rolling stand is expressed by the following expression.

[0078]

(Equation 8)

It should be noted that L (i) is the amount of change in the allowable crown ratio in the i-th rolling stand, and as described above, in the present embodiment, the shape in the third to seventh rolling stands. Since only the condition is taken into consideration, i in this equation (6) is an integer from 3 to 7.

The expression (6) is an expression focusing on the relative difference between the crown ratio on the inlet side and the crown ratio on the outlet side in the i-th rolling stand, but in the present embodiment, the tandem rolling mill is used. As the plate material to be rolled passes through each of the rolling stands, the target crown ratio is approached. Therefore, at least in the third to seventh rolling stands, the outgoing crown ratio is the incoming crown ratio. It is larger than the crown ratio. Therefore, the shape condition of the above equation (6) can be a shape condition expression such as the following expression.

[0081]

[Equation 9]

Also in the equation (6), i is an integer of 3 to 7.

While substituting 7 for i in equation (6),
If the crown amount on the delivery side is the target crown amount and the strip thickness setting value on the delivery side is the target strip thickness setting value, the shape conditions in the final stage of the seventh rolling stand are as follows.

[0084]

[Equation 10]

The left side of the equation (8) can be expressed as the following equation.

[0086]

[Equation 11]

Further, the equation (9a) can be further transformed into the following equation.

[0088]

(Equation 12)

Further, the crown amount Crs (6) calculated by the calculation of the sixth rolling stand of the equation (9b) is performed.
Is as follows.

[0090]

(Equation 13)

In this equation (10), D2 (i
) And D2 (o) are as follows.

[0092]

[Equation 14]

Substituting this equation (10) into the above equation (9b), the left side becomes the following equation.

[0094]

(Equation 15)

F2 (i) in the equation (11) is as follows. That is, when i is an integer of 1 to 5, F2 (i) is the following formula (11a), and when i is 6, it is the following formula (11b).

[0096]

[Equation 16]

Further, substituting this equation (11) into the above equation (8) and rearranging it in a matrix form, the shape condition equation of the seventh rolling stand from the entry side of the tandem rolling mill is as follows. Like

[0098]

[Equation 17]

The shape condition expression of the third rolling stand is as follows.
Similarly, it can be expressed as the following equation.

[0100]

(Equation 18)

In this equation (13), i is an integer of 1 to 4, F3 (i), F3 (5), and F3
(6) is as follows.

[0102]

[Formula 19]

Furthermore, the shape condition equation of the fourth rolling stand from the entrance side of the tandem rolling mill can be expressed as the following equation.

[0104]

(Equation 20)

In the equation (14), i is an integer of 1 to 3, F4 (i), F4 (4), and F4 (4)
(5) and F4 (6) are as follows.

[0106]

[Equation 21]

The shape condition expression of the fifth rolling stand can be similarly expressed as the following expression.

[0108]

[Equation 22]

In this equation (15), F5 (i) in which i is 1 or 2, F5 (3), and F5 (4)
And F5 (5) are as follows.

[0110]

(Equation 23)

The shape condition expression of the sixth rolling stand from the entrance side of the tandem rolling mill can be similarly expressed as the following expression.

[0112]

[Equation 24]

In this equation (16), F6
(1), F6 (2), F6 (3), and F6 (4) are as follows.

[0114]

(Equation 25)

Summarizing the above results, the above equation (5) and (12), (13), (14), (15) and (1
The following equation can be obtained from the equation (6).

[0116]

(Equation 26)

Also, in this equation (17), 6 × on the left side
Letting 6 matrices be F, an inverse matrix of this matrix F be F ^−1, and a 6 × 1 matrix on the right side be G, Δh (1) to Δh (6)
Can be obtained by the following equation.

[0118]

[Equation 27]

Thus, the thickness change amount Δh (1) to Δ
When h (6) is calculated, the previous thickness setting value hs (1) ~
From hs (6) and the following six formulas, the optimum plate thickness setting value h
(1) to h (6) can be obtained.

[0120]

[Equation 28]

As described above, according to the embodiment of the present invention, the crown amount and the plate thickness on the delivery side of the final stand are set to the target values without increasing the processing such as calculation performed by the computer. At the same time, the plate thickness of each rolling stand is such that the shape of the plate material at each rolling stand is within the predetermined allowable shape and the milling capability of each rolling stand is also satisfied.
It is possible to determine the setpoint and the vendor pressure setpoint .

As an example, the rolling schedule of the rolling mill according to the above-described embodiment of the present invention is determined under the operating conditions shown in FIG. 3 and the allowable range of the plate thickness range in each rolling stand shown in FIG. The inventors actually perform various calculations depending on the method.

The result of this calculation is the optimum plate thickness h (i) obtained by the calculation shown in FIG. 5, the crown amount Crs (i) obtained by the calculation shown in FIG. 6, and the crown ratio shown in FIG. (Determined by the optimum plate thickness h (i) and the calculated crown amount Crs (i))
And the flatness of the plate material which is the material to be rolled as shown in FIG. 8 can be obtained.

The optimum plate thickness h (i) in each rolling stand shown in FIG. 5 is within the allowable range of the plate thickness shown in FIG. Further, as shown in FIG. 6, the crown amount Crs (7) on the delivery side of the final rolling stand, which is the seventh rolling stand.
Is the target crown amount. Further, as shown in FIG. 7, the crown ratio of the final rolling stand is also the target crown ratio. Further, it can be seen from FIG. 8 that the flatness of the plate material on all stands is within 0.3%.

As described above, according to the embodiments of the present invention, the crown deviation σ is halved, and it is possible to obtain the excellent effects that the control accuracy of the crown amount is improved and the strip passing property is stabilized. You can

[0126]

As described above, according to the present invention, the plate thickness setting value and the bender pressure setting value of each rolling stand of the tandem rolling mill are adjusted in order to correct the crown deviation of the final stand.
In the rolling mill reduction schedule determination method for collectively determining the rolling conditions including the above, the amount of crown and the plate thickness on the exit side of the final stand can be increased without increasing the processing such as calculation performed by a computer. When the target values are set, the plate thickness of each rolling stand is set so that the shape of the plate material in each rolling stand is within a predetermined allowable shape, and the milling capability of each rolling stand is also satisfied. it is possible to obtain an excellent effect that it is possible to <br/> determine vendor pressure setpoint.

[Brief description of drawings]

FIG. 1 is a flowchart showing the gist of the present invention.

FIG. 2 is a flowchart of an embodiment of the present invention.

FIG. 3 is a diagram showing one of operating conditions in the embodiment.

FIG. 4 is a graph showing an example of an allowable setting range (upper limit and lower limit) of a plate thickness setting value in each rolling stand in the above-mentioned embodiment.

FIG. 5 is a graph showing the optimum plate thickness in each rolling stand as a result of the calculation according to the above-mentioned embodiment.

FIG. 6 is a graph showing the amount of crown in each rolling stand obtained in the above example.

FIG. 7 is a graph showing a crown ratio in each rolling stand obtained in the above example.

FIG. 8 is a graph showing the flatness of each rolling stand obtained in the above example.

[Explanation of symbols]

i ... Roll stand number of tandem rolling mill, h (i) ... Optimum plate thickness setting, Crs (i) ... Crown amount of each roll stand calculated.

Claims (2)

(57) [Claims] 1. A sheet thickness setting value for each rolling stand of a tandem rolling mill and a set value for correcting the crown deviation of the final stand.
In the rolling mill reduction schedule determination method that comprehensively determines the rolling conditions including the set value of the vendor pressure, the plate of each rolling stand is set to an intermediate value that can mainly increase or decrease the setting. the thickness and the set value and vendor pressure value initial value, in the final stand at the thickness set value and vendor pressure value initial value, determine the crown deviation from the target crown, the crown difference and the shape conditions of each rolling stand From the above, the plate thickness change amount of each rolling stand is obtained at the same time, and it is judged whether or not the plate thickness change amount of each rolling stand satisfies the mill capability of each rolling stand. If there is a stand, first after the change of the vendor pressure rolling stands, rolling schedule determination side of the rolling mill, characterized in that re-determined the thickness change amount . 2. The rolling schedule of a rolling mill according to claim 1, wherein the shape condition for obtaining the amount of change in plate thickness of each rolling stand is the shape condition of each rolling stand after the third stand. How to decide.