KR100983734B1 - Crown shape controlling device and method for hot tandem rolled mill - Google Patents

Abstract

An object of the present invention is to simultaneously realize a uniform crown and a flat shape in the longitudinal direction of the steel sheet.

When performing the crown-shaped feedback control, the bender amount of the downstream stand is corrected in correspondence with the steel plate portion for the steel plate portion in which the bender correction effect of the upstream stand is not among the stands sharing the crown control, thereby making the crown control highly responsive. . In addition, the stand which shares the crown control and the stand which performs shape control are optimized according to the value of crown deviation (or crown ratio deviation) and shape flatness. As a result, both crown accuracy and shape flatness in the longitudinal direction can be increased.

Stand, steel plate, crown shape control device, control model, set-up means

Description

Crown shape control device and method of hot tandem rolling mill {CROWN SHAPE CONTROLLING DEVICE AND METHOD FOR HOT TANDEM ROLLED MILL}

The present invention relates to a method for controlling the crown shape of a hot rolling mill, and more particularly to a control method suitable for uniformizing them in the longitudinal direction of a steel sheet in a calculation using the values of crowns and shapes detected during rolling.

Conventionally, the following method is known as a crown control apparatus of a hot rolling mill. Patent Document 1 calculates a bender command in which the crown ratio of the inlet side and the outlet side of each stand is constant by using the deviation between the crown ratio and the target crown ratio of the steel sheet obtained during rolling, and the plate crown change point reaches each stand. The method of changing each bending operation amount at the time point is shown. Here, the crown ratio is a value obtained by dividing the crown by the plate thickness. As a result, the crown can be brought close to the target value without affecting the shape (flatness) of the plate.

In Patent Document 2, one of the intermediate stands is used as a check stand in the setup control, and the target crown ratio in the stand is obtained. To control. Moreover, the method of changing the crown ratio setting value of this stand and an upstream stand is shown by the stand whose crown control operation amount reaches the limit.

[Patent Document 1] Japanese Patent Application Laid-open No. 63-123509

[Patent Document 2] Japanese Patent Application Laid-open No. Hei 4-200912

However, in the technique of Patent Literature 1, there is a problem that the constant limit of the target crown ratio of each stand becomes a limitation of the crown control range. As described above, the crown ratio is calculated from the crown and the plate thickness, but the thickness of the entrance and exit side plates of each stand is in accordance with the rolling schedule and cannot be changed according to the state of the crown control. There was a problem that only the crown ratio could be realized as the target crown ratio. In addition, correcting the disturbance of the shape during rolling at the same time as the crown was not considered.

In addition, when the method of patent document 2 is used for feedback control using a detection crown, the effect of feedback control is fully reflected in the steel plate part which is higher upstream than all the stands whose operation amount is corrected, but feedback control is carried out in the steel plate part downstream from here. There was a problem that the effect of only partially reflected. For example, when the operation amount of the 1 to 5 stands is changed by the feedback control, the steel sheet portion located directly below the 3 stand at the feedback control start timing does not change the operation amount of the 1 stand and the 2 stand, so that the effect of the feedback control is ineffective. There was a problem of becoming insufficient. In this case, there was a problem that all the effects of the feedback control were reflected only in the steel plate portion located before one stand. In addition, since the check stand is fixed, the number of stands secured for the crown control is constant. For this reason, according to the magnitude | size of a crown deviation, there existed a problem that the number of stands which were secured was inadequate or excessive.

In addition, although it is considered to reduce the influence of the crown control on the steel sheet shape by performing the deviation elimination from the target crown of the actual crown at the upstream stand, it is not considered to correct the disturbance of the shape at the same time as the crown.

The technical problem to be solved by the present invention is to solve the deviation of the actual crown against the target crown by maximizing the control capability of the operation stage while also considering the correction of the shape (flattening of the steel sheet). In addition, it is to maximize the response of feedback control by making a change of the operation amount step by the passage of the stand of a tracking steel plate part. In addition, by optimally distributing the stand used for eliminating the crown deviation and the stand used for shape correction during rolling, eliminating the oversufficiency of the operation stage and optimizing the feedback control of the crown and the shape from both sides of the crown deviation elimination and shape flattening.

In order to solve this problem, in the present invention, the crown ratio calculation unit for obtaining the actual crown ratio from the actual crown detected from the steel sheet, the deviation of the actual crown ratio and the target crown ratio are determined, and the stand for solving the deviation is determined. Calculates the correction amount of the rear-end stand and calculates the correction amount of the rear-end stand for the manipulated-variable distribution unit which calculates the manipulated variable change amount of each stand from the deviation to be eliminated in each stand, and the steel plate site where the effect of feedback control is not fully reflected on the distributed manipulated value. An operation amount correction unit for switching the operation amount at the stand passing timing of the steel plate portion and outputting the operation amount; and a shape control unit for outputting an operation amount for correcting the shape detected from the steel plate; and outputting the output of the operation amount correction unit and the output of the shape control unit. Synthesize the feedback correction amount of each stand. The feedback manipulated variable output part was computed.

In addition, focusing on the relative magnitude of the deviation from the target value of the crown or the crown ratio and the shape correction amount, a control stand determination unit for optimizing the stand used for the crown control and the shape control during rolling was provided.

The operation of the present invention will be described. With respect to the crown ratio calculated by the crown ratio calculation unit, the manipulated-variable distribution unit calculates a deviation from the crown ratio of the outlet side of the downstream stand among the stands used for crown control, and distributes the deviation to each stand used for crown control to solve the problem. The ratio is determined to calculate the operation amount of each stand. The manipulated variable correcting unit corrects the manipulated amount distributed to the rear end stand for the steel plate portion where the effect of the feedback control is only partially reflected, and switches the manipulated amount after correction in correspondence with the steel plate portion and outputs it.

According to the present invention, it is possible to maximize the effect of the feedback control on the steel sheet portion. In addition, the control means determining unit pays attention to the relative relationship between the deviation of the crown ratio and the shape correction amount, and when the deviation of the crown ratio is large and the shape is relatively flat, the number of stands as required from the upstream is secured for the crown control thereafter. To the final stand are used for shape planarization. On the other hand, when the ratio of crown deviation is small, the number of stands for crown control secured from upstream is made small, and many downstream stands are used for shape flattening. The control means determination unit optimizes the stand used for crown control and shape correction in this manner according to the actual values of the crown and the shape obtained during rolling.

In a hot tandem mill, as a result of optimally allocating the control capability of each stand to crown control and shape control, a steel sheet is produced in which the crown close to the target value and the flat shape are distributed in the longitudinal direction. As a result, high quality steel sheet can be produced.

<First Embodiment>

Fig. 1 shows the configuration of a crown shape control device according to an embodiment of the present invention. The crown shape control apparatus 100 receives various signals from the control object 150, and outputs a control signal to the control object 150.

First, the structure of the control object 150 is demonstrated. In this embodiment, the control object 150 is a hot rolling tandem mill consisting of a plurality of stands, and the mill 151 in this example has a configuration in which seven stands 152 are arranged in succession. In Fig. 1, the steel sheet moves from the left side to the right side, and a w-steel material 161 having a thickness of about 30 mm produced by a rough rolling mill as a previous step is subjected to rolling at each stand of the mill 151. It is processed thinly one by one, and is finally discharged as the steel sheet 160 of about 1 mm to 10 mm at the F7 outlet side. In the present embodiment, the crown-shaped measuring instrument 170 for measuring the crown and the shape (flatness) of the steel plate 160 is provided on the exit side of the final stand F7 of the mill 151.

2 shows the definition of the crown and the shape. The crown C is an index showing the shape of the plate in the width direction, and is represented by the difference between the thickness in the center and the thickness of a certain distance from the edge. Using the notation of drawing, the crown C is represented by (1) Formula.

… (1)

… (One)

The value obtained by dividing the crown C by the plate thickness is called the crown ratio ε. Although the distance from the edge which is the measuring point of he1 and he2 is often defined as 40 mm, it may be 25 mm or 70 mm. The crown shape measuring instrument 170 has a plurality of measuring points 201 in the plate width direction as shown in the drawing, and calculates the crown amount after detecting the plate thickness distribution in the plate width direction. In the present embodiment, the thickness distribution in the plate width direction is mainly described as a case of being controlled by the bending force in the steel plate width direction applied to the work roll 153. The same can be applied. Hereinafter, the bending force is referred to as bending force.

On the other hand, the shape divides the plate length difference of the steel plate center part and the edge part by plate length (unit length), and is represented by the value which multiplied predetermined coefficient. When the distance of the end is longer than the center of the steel plate 160, the end is elongated, and the end is bent into a wavy shape. On the other hand, if the distance in the center portion is longer than the end portion, the center portion is in a shape called center portion extension, and the vicinity of the center portion is pitted or protruded. In the description of the drawings, the shape (flatness) Iunit of the plate is represented by the formula (2).

… (2)

… (2)

When Iunit is 0, it shows that the plate length of a center part and an edge part coincides and becomes flat shape.

The manipulated variable output from the crown shape control apparatus 100 to the mill 151 is a setting value of a bending force. In addition, the crown shape measuring instrument 170 detects the crown and shape values of the steel sheet 160 obtained as a result of the control, and outputs them to the crown shape controlling apparatus 100 as measured values. In practice, many signals are exchanged, but the compression is described here as necessary.

Next, the structure of the crown shape control apparatus 100 is demonstrated. The crown shape control apparatus 100 determines the target crown ratio (it becomes equivalent to the target crown by multiplying the plate thickness) of each stand for the purpose of obtaining a flat shape with the target steel plate crown. Here, as a general policy of crown shape control, a case of realizing a flat shape by creating a target crown ratio from upstream to a predetermined number of stands and controlling the crown ratio to be constant in the remaining downstream stands will be described as an example. As an example, the bender is controlled to obtain the target crown ratio under the control of F1 to F5, and the bender is controlled to maintain the crown ratio constant in F6 and F7 by reducing the crown in response to the reduction of the plate thickness by rolling. do.

The crown shape control apparatus 100 refers to the control model 102, and the set-up means 101 which calculates the vendor command sequence B0 of each stand for realizing a target crown and a flat shape, and the steel plate 160 During rolling, the measurement result of the crown shape measuring instrument 170 is received via the crown shape receiving means 103, the deviation from the target value of the crown and the deviation from the flat shape of the shape are calculated and the final stand F7. The crown-shaped feedback control means 104 which calculates correction amount (DELTA) B of the vendor command of each stand is obtained in order to obtain a target crown and a flat shape at the exit side. The manipulated variable calculating means 130 which adds the output B0 of the setup means 102 and the output ΔB of the crown-shaped feedback control means 104 to output the final vendor set value Bref to each stand. ).

In addition, the crown shape feedback control means 104 receives the crown amount from the crown shape receiving means 103, and calculates the deviation of the crown ratio calculation means 110, the target crown ratio, and the calculated crown ratio from the crown ratio. And a manipulated variable distributing means 111 for calculating a vendor correction amount for elimination and distributing to a stand allocated for crown control. In addition, the positional information of the steel plate 160 obtained from the tracking means 112 in order to achieve a high response of the crown control with respect to the increase in the delay time for eliminating the crown deviation by the change in the operation amount of the upstream stand relatively among the assigned stands. In accordance with this, the operation amount correction means 113 performs an operation amount correction calculation for temporarily supplementing the control response delay of the upstream stand with the vendor operation amount correction of the downstream stand. Furthermore, the shape control means 114, the manipulated-variance correction means 113, and the shape control means which receive the measured value of the shape from the crown shape reception means 103, and calculate the bender correction amount of the stand allocated for shape control. And a feedback manipulated variable output means 115 for combining and outputting the output of 114 to calculate and output the final vendor correction amount of each stand.

Hereinafter, the process of each part is demonstrated in detail. The control model 102 is a formula for estimating the crown amount of the steel sheet after rolling (each stand exit side), and the crown is mainly the crown amount of the steel sheet before rolling (each stand inlet side) and the rolling load in addition to the value of the bender. It is determined by the roll diameter profile shape (work roll crown) of the width direction of the work roll 152, and becomes an algebraic formula like (3)-(5) formula as an example. As described above, the value obtained by dividing the crown by the plate thickness is referred to as the crown ratio. In algebraic expression,? H represents the crown ratio before rolling, and? H represents the crown ratio after rolling.

… (3)

… (3)

… (4)

… (4)

… (5)

… (5)

CH: Steel plate inlet crown amount (crown amount before rolling), Ch: Steel plate outlet side crown amount (crown amount after rolling), Hc: Inlet plate thickness, hc: Outlet plate thickness, B: Bending amount, P : Coefficient of rolling load, CRW: work roll crown, A1 to A5: sheet thickness, sheet width, steel type, and the like.

The setup means 101 is a target on each stand exit side from which the target crown is obtained in the final pass from the rolling load of each stand F1 to F7 determined to obtain the target plate thickness, the temperature, width, steel type, etc. of the steel sheet 160, etc. After determining the crown ratios, using the inlet crown, the inlet plate thickness, the outlet plate thickness, the rolling load, and the estimated values of the work roll crown, From the relationship, the vendor value of each stand which realizes the target crown on each stand exit side is calculated and output. In addition, the estimation of the work roll crown is determined by calculation considering the amount of thermal expansion during rolling, the effect of reducing the roll diameter due to wear after replacing the work roll 153, and the shift amount of the steel roll width direction of the work roll 153.

3 shows the processing of the crown ratio calculating means. In S3-1, the crown ratio calculating means 110 takes in the crown measurement value Cact of the steel sheet 160 taken from the crown shape receiving means 103 and the plate thickness h7 on the exit side of the final stand F7. do. The measured value from the steel plate 160 may be sufficient as h7, and may use the predetermined manufacturing instruction (target plate | board thickness). Next, the crown ratio εact is calculated by dividing the crown measurement value Cact by the sheet thickness h7 in S3-2.

4 shows the processing of the manipulated variable distributing means 111. In normal crown-shape control, the target crown ratio is made in the upstream stand which can control the crown largely, and in the downstream stand, the bender is set so that the crown decreases in accordance with the plate thickness with the target of the crown ratio constant. It is known that flatness is improved by rolling a constant crown ratio at the downstream stand.

This embodiment shows an embodiment in which the crown deviation is eliminated at F1 to F5 and the crown ratio constant control is performed at F6 and F7 after achieving the target crown ratio at the exit side of F5. With respect to the deviation (Δεh) of the actual and target crown ratio of the crown ratio which is the output of the crown ratio calculating means 110 in S4-1, the crown ratio deviation elimination ratio indicating how much to resolve in which stand of F1 to F5 γ1 to γ5) are calculated. The gamma 1 to gamma 5 may be determined in accordance with a predetermined norm, and may be solved as far as possible in upstream stands such as F1 and F2, and the resolution ratio in downstream stands such as F5 and F4 may be increased in consideration of responsiveness.

Next, the vendor correction amount of each stand is calculated according to gamma 1 to gamma 5 distributed to each stand in S4-2. The bender correction amount Δb is calculated by the equation (6) for each stand.

… (6)

… (6)

However, α: feedback control gain, i: stand number.

Here, (∂b / ∂εh) is an influence coefficient of the crown ratio deviation and the amount of vendor correction, and is given by the coefficient A2 of the vendor of the formula (3). By using this, it is possible to derive the amount of vendor correction necessary to solve the crown ratio deviation of Δεh. The crown ratio to be eliminated in each stand is obtained by the equation (7) according to γ1 to γ5 (generally, the sum of γ1 to γ5 is 1).

… (7)

… (7)

α may be a different value for each stand or may be the same. On the other hand, the vendor has mechanical upper and lower limits (maximum value and minimum value).

In S4-3, it is determined whether or not there is a stand whose output is saturated at either the upper limit or the lower limit. The determination may be made based on whether or not the output of the vendor coincides with the upper limit value or the lower limit value. If there is no stand whose output is saturated, the process ends. If there is a stand whose output is saturated, the desired crown is not obtained on the exit side of the stand, and therefore, a process for checking whether there are other stands with a margin for vendor output is performed in S4-4. If no stand is available in the vendor's output, the process is terminated in that the control capability is exhausted and no further crown control improvement can be expected.

If there is a stand with a margin for the vendor output, the use of the margin of these stands can also be expected to improve the crown control performance. Therefore, in the S4-5, the vendor output is allocated to a stand (constraint violation stand) that is saturated at the upper and lower limits. Of the solved cancellation ratios γ, the stand is allocated to a stand with a margin that cannot be eliminated in the stand. Taking the case where the vendor output is saturated at the upper limit as an example, the crown ratio that cannot be eliminated in the stand can be calculated by the expression (8).

… (8)

… (8)

Where b0 is the current vendor setting, i is the stand number, Bmax is the maximum vendor output, and Δεhl1i is the crown ratio that cannot be eliminated at the i-th stand.

The process of canceling (DELTA) (epsilon) hl is performed by changing the vendor output of the stand which has a margin in a vendor output according to a margin. By correction | amendment, the crown ratio which can be eliminated in the said stand is shown by (9) Formula.

… (9)

… (9)

Where Δεhl2i is the ratio of the crown that can be eliminated from the calibration of the i-th stand, and i is the stand number.

According to the formula (9),? 1 to? 5 allocation of the crown ratio deviation cancellation ratio is performed while calculating the ratio of the crown that can be eliminated in the stand having a margin. In this way, the vendor output of each stand is utilized to the maximum, and the deviation of the crown ratio is eliminated. In S4-6, the final vendor correction amounts Δb1 to Δb5 of F1 to F5 are calculated and output to the manipulated variable correcting means.

In the present embodiment, the start cycle (feedback control cycle) of the manipulated variable distributing means 111 increases the feedback control gain α, and then the steel sheet upstream of the F1 after the vendor correction reaches the crown shape measuring instrument 170, The completion of the measurement in the crown-shaped measuring instrument 170 may be the next starting timing, or the control frequency can be increased by decreasing the feedback control gain α according to a conventional feedback control system design method.

5 shows the processing of the manipulated variable correcting means. The manipulated-variable correction means 113 performs a process of correcting Δb1 to Δb5 in accordance with the movement of the steel sheet portion starting from the timing at which the feedback control is started.

Fig. 6 shows an example in which regions of the steel sheet portion at the timing at which the feedback control is activated are defined by? To?. Since the vendor of F1 to F5 is corrected for the deviation of the crown ratio, ① is an area in which only the vendor correction effect of F5 is effective, ② is F5 and F4, ③ is F5 to F3, and ④ is a valid vendor fix effect of F5 to F2. Area. 5 is an area in which the vendor correction effect of all the stands F5 to F1 assigned to the crown control is effective. From the above, since the effect of resolving the crown ratio deviation of the vendor correction is not sufficient in the areas ① to ④, the manipulated variable correcting means 113 uses the control margin for the purpose of increasing the elimination effect of the crown ratio deviation when the downstream stand has a control margin. The used vendor output is corrected.

In S5-1, the vendor correction amounts Δb51, Δb52, Δb53, Δb54, Δb42, Δb43, Δb44, Δb33, Δb34, and Δb24 are calculated in the transient areas ① to ④. Δbxy represents the correction amount of the x stand for the area y.

The correction amount is calculated by the following calculation. That is, Δb51 is calculated by calculating the vendor value for eliminating the crown ratio deviation, and allocating all of the crown ratio deviation cancellation ratios γ1 to γ4 shared by F1 to F4 to F5 in the region ①. That is, when γ5 is 1, Δεh5 = 1 from Equation (7), and therefore, the bender correction amount Δb51 of the fifth stand in this case is calculated by Equation (6) under these conditions. In the region ②,? B52 and? B42 are calculated by allocating? 1 to? 3 to F4 and F5. That is, under the distribution where the predetermined gamma 4 + gamma 5 is 1, the crown ratio to be corrected in F4 and F5 is calculated from Eq. (7), and the bender correction amount of the fourth stand and the fifth stand in this case is expressed by the equation (6). (Δb52, Δb42) are calculated. Similarly, in the region 3, gamma 1 to gamma 2 are allocated to F3 to F5, and Δb53, Δb43, and Δb33 are calculated in the calculation under the distribution in which γ3 + γ4 + γ5 is 1. In the area (4) by the same calculation,? 1 is allocated to F2 to F5, and? B52,? B42,? B32, and? B22 are calculated in the calculation under the distribution where? 2 +? 3 +? 4 +? 5 is 1.

The distribution calculation can be realized by the calculation shown in Fig. 4 by changing the stands to be distributed from F1 to F5 to respective ones in the processing of the manipulated variable distributing means 111. By performing the processing of S5-2 to S5-7 for each stand, the amount of vendor correction when each area passes the stand is calculated and output.

In S5-2, the control area which each stand is currently rolling is determined from the output of the tracking means 112. FIG. The tracking means takes in the roll speed V from the control object 150, and the feedback control is started to calculate the amount of movement of the steel sheet 160 afterwards to determine which area of each stand is currently rolling. Determine. In this embodiment, only F5 is available for rolling the region ①, and thus S5-3 outputs Δb5 + Δb51 as the vendor correction amount of F5. When rolling the area (2), Δb5 + Δb52 as the vendor correction amount of F5 and Δb4 + Δb42 are output as the vendor correction amount of F5 from S5-4 to F5 and F4 which are likely. In the case of rolling the region ③, Δb5 + Δb53 as the vendor correction amount of F5 in the S5-5, Δb4 + Δb43 as the vendor correction amount in the F4, and Δb3 + as the vendor correction amount in the F3 with respect to the likely F5 to F3. Outputs Δb33. In the case of rolling the region ④, for the potential F5 to F2, Δb5 + Δb52 as the vendor correction amount of F5 in the S5-6, Δb4 + Δb42 as the vendor correction amount for the F4 and Δb3 as the vendor correction amount of the F3 DELTA b2 + DELTA b22 is outputted as a vendor correction amount of + DELTA b32 and F2. When rolling the area | region (5), correction is not necessary and (DELTA) b5, (DELTA) b4, (DELTA) b3, (DELTA) b1 and (DELTA) b1 are output as Fender correction amount of F5-F1 in S5-7 about F5-F1. The response of crown control can be improved by the correction process for making full use of the crown control capability of each stand.

7 shows the processing of the shape control means 114. In S3-1, the shape Fact blown in from the crown shape control means 103 is blown in. And as an example, the vendor correction amount of F6 and F7 is computed by Formula (10).

… (10)

… 10

However, β1, β2: control gain.

Generally, the shape of the shape is flattened by increasing the output of the bender for the edge wave (end extension) shape and decreasing the output of the bender for the center buckle (center extension). As the amount of vendor correction, it is also considered to calculate by adding an operation to offset the influence of correcting the crown ratio in F1 to F5. That is, when the bender of F1 to F5 is modified so that the crown ratio on the outlet side of F5 becomes large, the influence of the end extension tendency is exerted on the shape, so that the benders of F6 and F7 are enlarged with respect to the value obtained by the expression (9), Counteract this effect. On the contrary, when the benders of F1 to F5 are modified so that the crown ratio on the outlet side of F5 becomes smaller, the influence of the central extension tendency is exerted on the shape, so that the benders of F6 and F7 are smaller than the value calculated by the expression (9). To counteract this effect.

In the present embodiment, F1 to F5 are used as crown deviation correction stands, F6 and F7 as shape flattening stands, but for example, F1 to F4 are different allocations such as crown deviation correction stands and F5 to F7 as flattening stands. Is also contemplated. In addition, although the measuring device was made into the crown shape measuring device 170 for simplicity, both may be integrated in a single unit and may be physically separated by the crown measuring device and the shape measuring device. The present invention can be similarly applied to either. In addition, even when there is a stand (dummy stand) which cannot be used due to a failure or the like, the present invention can be similarly applied by setting the crown ratio deviation cancellation ratio at the stand to zero.

Second Embodiment

Next, a second embodiment of the present invention is shown. In the first embodiment, predetermined stands are assigned to crown control and shape control, respectively. However, in the present embodiment, the stands allocated to crown control and the stand assigned to shape control according to the crown deviation and flatness detected during rolling are real-time. An example of optimizing is shown.

Fig. 8 shows the configuration of the crown shape control device according to the second embodiment. The newly installed control stand determining means 801 performs optimization processing of the stand allocated to the crown control and the shape control based on the detected values of the crown and the shape (flatness) taken from the crown shape receiving means 103, The result is output to the crown-shaped feedback control means 104.

9 shows the processing of the control stand determination means 801. In S9-1, the crown detection value Cact, the shape detection value Fact, and the final side thickness F7 of the final stand F7 are taken in. In S9-2, the crown ratio? Act at the final stand exit side is calculated by (Cact / h7), and the deviation? T from the target crown ratio? T of? Act is ?? h. In S9-3, the stand allocated to crown control and the stand allocated to shape control are determined from the relative relationship between εact and Fact.

Qualitatively, the larger Δε h, the larger the number of stands to be assigned to the crown control. However, in the simple example, it is considered to determine the number of stands to be assigned to the crown control by the following guidelines. That is, when the flatness Fact is small (when the steel plate is flat, for example, │Fact│ <30IUNIT) and when it is not, according to the magnitude of Δεh (11), Change it according to (12).

…(11)

… (11)

… (12)

… (12)

Stands not assigned to crown control are automatically assigned to shape control. The crown-shaped feedback control means 104 calculates the vendor correction amount by performing the processing shown in the first embodiment in accordance with the information of the determined crown control sharing stand and the shape control sharing stand.

In the present embodiment, a stand for sharing crown control is determined by focusing on the crown ratio deviation, but instead of the crown ratio deviation, attention may be paid to the crown deviation.

Third Embodiment

Next, the control stand determination means 801 shows an embodiment in which more stands are allocated to the shape control by allocating the necessary minimum stand to the crown control in consideration of each stand crown correction capability.

In this embodiment, instead of S9-3 in FIG. 9, the control stand is determined in the processing shown in FIG. Fig. 10 illustrates the case where the crown ratio deviation is a positive value, for example, of the process of determining the control stand. Set the stand number to 1 in S10-1. In S10-2, the maximum value is substituted as the vendor value of the first to nth stands, and the crown ratio on the stand exit side is calculated by the equation (3). It is determined whether or not the value obtained by subtracting the target crown ratio from the crown ratio obtained in S10-3 is Manius. In the case of minus, since it means that the correction of the positive crown ratio deviation is possible by the crown correction by the conventional stand, the first to nth stands are used for the crown control in S10-5, and the (n + 1) ) To the seventh stand for shape control. If the crown ratio deviation is positive in S10-3, since the first to n-th stand crown correction capability is insufficient, increase the number of stands that share the crown control in S10-4 by one and return the processing to S10-2. And S10-2 to S10-4 are repeated until S10-3 is satisfied.

In the present embodiment, the case where the deviation of the crown ratio is positive has been described as an example, but when the value is negative, the bender of each stand is set to the minimum value in S10-2, and if the crown ratio deviation &gt; 0 is determined in S10-3, FIG. The same processing as can be performed.

The present invention can be effectively applied to crown shape control of a tandem mill provided with a crown measuring device at least on the final stand exit side.

1 is a block diagram of a crown shape control device according to an embodiment of the present invention.

2 is an explanatory diagram showing the definition of a crown and a shape (flatness);

3 is a flowchart showing processing of a crown ratio calculating means.

4 is a flowchart showing processing of the manipulated variable distributing means;

5 is a flowchart showing processing of the manipulated variable correcting means.

6 is a schematic diagram showing a region of a steel sheet.

7 is a flowchart showing processing of shape control means.

8 is a configuration diagram of a crown-shaped control device according to another embodiment of the present invention.

9 is a flowchart showing processing of the control means determining means according to another embodiment.

Fig. 10 is a flowchart showing part of the processing of the control means determination means according to another embodiment.

<Explanation of symbols for the main parts of the drawings>

100: crown shape control device, 101: setup means, 102: control model, 103: crown shape reception means, 104: crown shape feedback control means, 111: manipulated variable distribution means, 113: manipulated variable correction means, 114: shape Control means, 115: feedback manipulated variable output means, 130: manipulated variable calculating means, 150: control target, 170: crown-shaped measuring instrument, 801: control stand determining means

Claims (8)

In the hot tandem rolling mill which consists of a plurality of stands provided with the crown measuring device which detects the crown of the steel plate after rolling, and the shape measuring device which detects flatness, and at least a bender as an operation end for controlling a crown and a shape, A set-up model having a control model for predicting the crown after rolling, the set-up section for detecting the bender setting value of each stand by the setup calculation using the control model prior to rolling the steel sheet, and from the crown value of the steel sheet blown from the crown measuring instrument during rolling. The crown ratio calculation unit that calculates the crown ratio, calculates the deviation between the obtained crown ratio and the target crown ratio, determines which stand of the stand allocated to the crown control, and how much to resolve the deviation, thereby calculating the vendor correction amount. The manipulated variable distribution unit, a shape control unit for calculating a bender correction amount for flattening the steel plate shape taken from the shape measuring instrument with respect to the stand assigned to the shape control, and a vendor corrected value for each stand from the outputs of the manipulated variable distribution unit and the shape control unit. A feedback manipulated variable calculating unit for calculating a value; Hot tandem rolling mill crown-control device further calculates a final command value for the vendor from the correction value, characterized in that comprising a manipulated variable output to output the hot tandem rolling mill. The said manipulated-variable distribution part determines the presence or absence of the stand which the output of a bender reached the upper and lower limit as a result of a setup calculation, and, when there exists the stand which reached the upper and lower limit, the deviation which cannot be eliminated among the said crown deviations And calculating the non-resolvable deviation from the stand assigned to the crown control to the stand whose bender output has not reached the upper and lower limits after calculating the crown shape control apparatus of the hot tandem rolling mill. The tracking part according to claim 1 or 2, wherein the roll speed of each stand is blown from the hot tandem rolling mill, and each stand specifies a steel plate part during rolling based on the movement amount of the steel sheet calculated according to the roll speed. And calculating the bender correction amount corresponding to the steel plate position for compensating the above effect at the downstream stand for the steel plate portion in which the effect of the bender correction amount of the upstream stand does not affect the steel plate between the stands at the time of calculating the feedback operation amount. And an operation amount corrector for adding the corrected amount corresponding to the bender correction amount and the steel plate part during rolling, and outputting the tracked part to a specific steel plate part. The control stand of Claim 1 which compares the deviation from the target value of the crown or crown ratio of the steel plate during rolling, and the flatness of a steel plate, and specifies the stand used for crown control and the stand used for shape control from a comparison result. And a control unit, wherein the control stand determination unit changes the allocation of the stand used for crown control and the stand used for shape control during rolling, wherein the crown shape control apparatus for hot tandem rolling mill is used. The stand according to claim 4, wherein the control stand determination unit increases the number of stands used for crown control when the deviation from the target value of the crown or crown ratio of the steel sheet during rolling is large, and stands used for crown control when the deviation is small. Crown shape control device for hot tandem rolling mill, characterized in that the number is reduced. The method according to claim 4, wherein the control stand determination unit calculates the number of stands required to solve the deviation from the target value of the crown or the crown ratio of the steel sheet during rolling by calculation using the control model, and determines the crown control according to the calculation result. The stand shape control apparatus of the hot tandem rolling mill characterized by specifying the stand to be used, and using the remaining stand for shape control. Crown shape control of a hot tandem rolling mill consisting of a plurality of stands provided with a crown measuring device for detecting the crown of the steel sheet after rolling and a shape measuring device for detecting the flatness, and having at least a bender as an operating end for controlling the crown and the shape. In the method, According to the deviation from the target value of the crown or crown ratio of the steel sheet during rolling and the flatness of the steel sheet, the stand used for crown control and the stand used for shape control are determined, and the crown deviation is reduced in the stand used for crown control. And a vendor command value in a direction in which flatness is increased in a stand used for shape control. Crown shape control of a hot tandem rolling mill consisting of a plurality of stands provided with a crown measuring device for detecting the crown of the steel sheet after rolling and a shape measuring device for detecting the flatness, and having at least a bender as an operating end for controlling the crown and the shape. In the method, Deviation from the target value of the crown or crown ratio of the steel sheet during rolling and the change of the steel sheet flatness are detected. When the deviation from the target value of the crown ratio is large, more stands are used for crown control, and the steel sheet flatness is disturbed. The method for controlling the crown shape of a hot tandem rolling mill, wherein more stands are used for shape control when there is, and the stand used for crown control and the stand used for shape control are changed during rolling.

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