JP3275802B2 - Shape control method in sheet rolling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a sheet shape in sheet rolling, and more particularly to an automatic shape control method based on an output of a shape detector of a rolling facility having a plurality of shape control mechanisms.

[0002]

2. Description of the Related Art Conventionally, as an automatic control method of a sheet shape in a sheet rolling, a feedback control method of performing an arithmetic process based on an output from a shape detector arranged on the exit side of a rolling mill and operating a shape control mechanism is known. Are known. In recent years, the requirements for the sheet rolling shape have become more severe, and as a result, a rolling mill having a plurality of shape control mechanisms has been developed, and an automatic shape control arithmetic processing logic for operating the plurality of shape control mechanisms has been proposed.

[0003] The above-mentioned shape control arithmetic processing logic includes, for example, approximating an output of a shape detector to a fourth-order power series or a fourth-order orthogonal function, and calculating a coefficient of the approximate expression or a shape calculated from the coefficient. Logic for calculating the optimal operation amount of a control device having the same number as the number of evaluation variables using the evaluation variables is disclosed in, for example, Japanese Patent Application Laid-Open Nos.
No. 5,194,401 and Japanese Patent Application Laid-Open No. 55-42144.

[0004] However, the above control method has the following problems. Problem (1): Unless the number n of control means that can be controlled simultaneously is equal to or less than the number m of shape variables to be controlled, an optimal solution of the operation amount of the control means cannot be obtained. Therefore, in order to solve the above problems, all the control means of the rolling mill can be simultaneously operated effectively without being limited by the number m of control variables and the number n of control means, and a certain shape control device The present applicant has disclosed a general-purpose sheet shape control method for sheet rolling capable of calculating the operation amount of the control means using a common optimum operation amount calculation formula even when the operation limit has been reached.
It was proposed by the official gazette.

[0005]

However, the conventional plate shape control method (JP-A-6-523) which solves the above problem (1) also has the following problems. Problem (2): Depending on the operation pattern of a specific control device, there are cases where flaws are generated in the rolled material. For example,
In a rolling mill having a split backup roll adjustment mechanism, when the amount of eccentricity between adjacent adjustment mechanisms is extremely greatly different, or when the amount of eccentricity of a specific adjustment mechanism protrudes,
Division marks called bearing marks may be transferred to the rolled material. Further, in the case of a rolling mill having an intermediate roll shift mechanism, when the end portion of the intermediate roll is located inside the plate end portion of the rolled material, a phenomenon in which a flaw called an edge mark is transferred is observed. Each mark becomes a serious defect of the product, and the probability that the product will not be able to be shipped or that the grade will be deteriorated even if it can be shipped increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is intended to prevent a bearing mark, an edge mark, and the like from being transferred, thereby reducing the probability of inducing a product defect. It is an object of the present invention to provide a shape control method.

[0007]

[Means for Solving the Problems]

(1) A shape control method in strip rolling according to the present invention (claim 1) detects a shape at a plurality of locations in a rolled sheet width direction by a shape detector and controls a plurality of shapes based on an output of the shape detector. In the shape control method in sheet rolling in which each operation amount of the mechanism is obtained and each shape control mechanism is controlled based on the operation amount to control the shape of the plate, (a) a shape distribution is detected in advance from a shape distribution detected by a shape detector. Subtracting the set target shape distribution to obtain a shape deviation; and (b) classifying the shape control mechanisms into a plurality of groups and giving priorities, and, based on the shape deviation, selecting a group having the highest priority. A step of obtaining a first operation amount for the shape control mechanism; (c) a step of obtaining a shape residual by subtracting a plate shape corrected by the first operation amount from the shape deviation; Based on the shape residual, the above operation Obtaining a second manipulated variable for the shape control mechanism of the group for which the is obtained and the shape control mechanism of the next highest priority group; and (e) calculating the second manipulated variable from the shape residual using the second manipulated variable. Subtracting the plate shape to be corrected to further obtain a shape residual. And
The steps (d) and (e) / or (d) are repeated according to the number of groups of the classified shape control mechanisms, and each shape control mechanism is controlled by adding the above-mentioned corresponding operation amount. (2) A plate shape control method for plate rolling according to the present invention (Claim 2)
Detects the shape of a plurality of locations in the width direction of the rolled sheet with a shape detector, obtains respective operation amounts of the plurality of shape control mechanisms based on the output of the shape detector, and determines each shape control mechanism based on the operation amount. In the shape control method in the sheet rolling in which the shape of the sheet is controlled by operating the shape, a target shape set in advance from the shape distribution (first function as a function of the position x in the sheet width direction) detected by the shape detector. A step of subtracting the distribution (a second function as a function of the position x in the width direction of the sheet) to obtain a shape deviation, and a step of targeting only the shape control mechanism to which priority has been previously given based on the shape deviation. (1) a step of obtaining the manipulated variable, (2) a step of subtracting the plate shape corrected by the first manipulated variable from the shape deviation to obtain a shape residual, and subjecting all the shape control mechanisms based on the shape residual. Calculating the second manipulated variable, A shape control mechanism to which priority has been given is controlled based on an operation amount obtained by adding the first operation amount and the second operation amount, and another shape control excluding the shape control mechanism to which priority has been given in advance. Controlling the mechanism based on the second manipulated variable. That is, in the present invention, the shape control mechanism group is divided into two groups, and the operation amount is first determined from the group having the higher priority. (3) A method for controlling the shape of a sheet in sheet rolling according to the present invention (Claim 3)
In the plate shape control method (2) described above, the shape control mechanisms to which priority has been given in advance are an intermediate roll bender and a work roll bender.

In the present invention, a group of shape control mechanisms is classified into a plurality of groups, and a high priority is given to a shape control mechanism of a group in which a defect is unlikely to occur in a product. Since the operation amount is obtained only by the control mechanism, the control by the shape control mechanism that the user wants to positively operate can be surely performed. In addition, for a shape residual that cannot be removed by the shape control mechanism of the higher priority group, the shape control mechanism of the relatively lower priority group is sequentially incorporated to obtain the operation amount. Optimal control mainly by a shape control mechanism that desires a preferential operation can be performed, and at the same time, the probability that the shape control induces a product defect can be reduced.

[0009]

FIG. 1 is a block diagram showing the configuration of a control device to which a shape control method in sheet rolling according to an embodiment of the present invention is applied and related equipment. In the figure, reference numeral 1 denotes a rolling mill. In this example, a 12-high cluster rolling mill has a structure in which a pair of upper and lower work rolls 3, an intermediate roll 4, a backup roll 5, and a small-diameter backup roll 6 are arranged in a cluster. It is. Reference numeral 2 denotes a rolled plate, and 7 denotes a shape detector for detecting the shape of the rolled plate 2 at a plurality of positions in the width direction. Physical quantities detected by the shape detector 7 include, for example, tension and strain. 8 is a shape detector 7
Functionalized operation device for performing an operation to convert the output distribution of the function into a function, 9
Is a target shape setting circuit for setting a target shape distribution of the rolled plate 2, and 10 is an optimum operation amount calculating device (1). The calculation result of the optimum operation amount calculation device 10 is supplied as an operation command signal to a roll bending mechanism 13 which is a shape control mechanism. Reference numeral 11 denotes a shape residual calculation device. The calculation result by the shape residual calculation device 11 is supplied to the optimal manipulated variable calculation device (2) 12 as a shape residual. The calculation result by the optimum operation amount calculation device 12 is supplied as an operation command signal to the roll bending mechanism 13 and the backup roll crown adjustment mechanism 14 which is a shape control mechanism.
The roll bending mechanism 13 is an optimal operation amount calculating device 10
The rolling mill 1 is individually controlled based on the operation command signals respectively supplied from the first and second rolling units. Further, the backup roll crown adjusting mechanism 14 individually controls the rolling mill 1 based on an operation command signal supplied from the optimum operation amount calculating device 12.

FIG. 2 is a view showing a roll portion and a shape control mechanism of the rolling mill shown in FIG. In the same figure, 2 to 5 correspond to FIG.
15, 16 and 17 are backup roll crown adjustment mechanisms, respectively, which are shown in FIG.
Corresponds to the backup roll crown adjustment mechanism 14. Reference numeral 18 denotes an intermediate roll bender, 19 denotes a work roll bender, and these are the roll bending mechanism 13 shown in FIG.
Is equivalent to In FIG. 2, backup roll 5 is 7
It is a structure that is divided and the other divided rolls can be independently eccentric in the direction of the intermediate roll 4 with respect to the fixed center portion, so that any crown pattern can be set, As symmetrical shape control means, there are a total of five intermediate roll benders 18, work roll benders 19, and backup roll crown adjustment mechanisms 15 to 17.

The characteristics of the five shape control means shown in FIG. 2 are roughly classified into an intermediate roll bender 18 and a work roll bender 19 (hereinafter, referred to as a first group of control means) capable of high-speed response. And backup roll crown adjusting mechanisms 15 to 17 which respond slowly (hereinafter referred to as a second group of control means). The first group of control means includes:
Since it is driven by hydraulic pressure, high-speed operation is possible, and operation is possible without any particular restrictions, except for the drawback that the operation range is relatively limited. Further, since the second group of control means is driven by the electric motor, the operation is slower than that of the first group of control means, but the operation range is wide and the shape correction ability is large. However, when operating the second group of control means, the following problems may occur depending on the positions of the backup roll crown adjusting mechanisms 15 to 17.

For example, when the amount of eccentricity between the adjacent backup roll crown adjusting mechanisms 15 and 16 or the amount of eccentricity between the backup roll crown adjusting mechanisms 16 and 17 is extremely different, especially the backup roll crown adjusting mechanism 16 or 17 is used. When the amount of eccentricity of the adjustment mechanism of (1) protrudes, a division mark called a bearing mark may be transferred to the rolled material.

In general, when shape control is performed, most deviations can be removed only by the first group of control means that do not cause the above-mentioned problems, and the shape cannot be removed by the first group of control means. If the residuals are handled by all the shape control mechanisms including the second group of control means as needed, the probability that the extreme positional relationship of the problematic second group of control means will occur is Significantly reduced.

Therefore, in the optimum manipulated variable computing device 10, the output of the target shape setting circuit 9 is subtracted from the output of the shape function computing device 8 in the same manner as in the prior art (Japanese Patent Laid-Open No. 6-523). I do. Then, assuming that only the first group of control means controls the calculated shape deviation, the operation amounts of the respective control means are obtained. The method of obtaining the operation amount of each control means itself is described in the prior art (Japanese Unexamined Patent Application Publication No.
523).

Next, the shape residual calculating device 11 calculates the corrected predicted shape residual Y ₁ by the first group of control means based on the equation (1).

[0016]

(Equation 1)

Here, Y (x) is the output distribution of the shape detector 7, and x is the position in the plate width direction. Y ^* (x) is a target shape distribution, and ΔY _j (x) is an output change of the shape detector with respect to the operation amount of each shape control device j.

These Y (x) and Y ^* (x) can be converted into a series by an orthogonal polynomial, and are represented by the following equations (2) and (3).

[0019]

(Equation 2)

[0020]

(Equation 3)

Here, a _i and a ^* _i are expansion coefficients of the function approximation by the orthogonal function φ _i (x), and m is the highest order of the function approximation. Also, when ΔY _j (x) is measured in advance and is converted into a function, it is expressed by the following equation (4).

[0022]

(Equation 4)

Here, b _ij is a function approximation expansion coefficient of a value obtained by partially differentiating Y (x) by the orthogonal function φ _i (x) with δ _j ,
That is, the rate of change of a _i with respect to δ _j (shape influence coefficient). δ _j is an operation amount of an arbitrary shape control device, j is an arbitrary shape control device (j = 1 to n), m is the highest order of function approximation,
n is the number of shape control devices. Next, a function expressed by the following equation (5) is defined as a function for evaluating the shape.

[0024]

(Equation 5)

Here, w is a plate width dimension. Equation (5) φ ₁ defined by is the predicted shape residual evaluation function after correction based on the output of the optimum operation amount calculation unit 10, the actual shape and a target shape after operating the certain shape control device It corresponds to the square of the deviation, and minimizing it corresponds to bringing the actual shape closer to the target shape. If predicted shape residual evaluation function phi ₁ of the operation result after the correction is long and converges to a constant range, the control by the control means of the second group is not required, operation instruction the operation amount by only the control unit of the first group Give as. If the calculation result does not converge to a certain range, the expression (1)
Of the predicted residual Y ₁ calculated by the following formula (1)
Supply to 2.

[0026] Optimal the operation amount calculation unit 12, a conventional method (e.g., Japanese Patent Laid-Open the operation amount of the control means of the overall shape control machine構構including control means of the second group on the basis of the prediction residual Y ₁ 6-523 ). Then, the roll bending mechanism 13 (the intermediate roll bender 18 and the work roll bender 19) adds commands from the optimum operation amount calculation devices 10 and 12, and gives operation commands to the respective control means to control them. The backup roll crown adjusting mechanism 14 (backup roll crown adjusting mechanism 15,
In steps 16 and 17), an operation command is given to each control means on the basis of a command from the optimum manipulated variable calculation device 12 for control.

In this embodiment, the shape control mechanisms are classified into two groups. However, even when the priorities of the shape control mechanisms are classified into three or more types, the optimum operation amount calculation is performed for each priority. It goes without saying that the present invention can be applied by doing so. For example, the shape control mechanisms are classified into three groups, and when the priorities are in the order of the first group, the second group, and the third group, the operation amounts of the shape control mechanisms of the first group are obtained. An operation amount of the first group + second group shape control mechanism is obtained, and further, an operation amount of the first group + second group + third group shape control mechanism is obtained. In the present embodiment, only the shape deviation of the symmetric component in the plate width direction has been described, but the present invention can be applied to the shape deviation of the asymmetric component.

[0028]

As described above, according to the present invention, a high priority is given to a shape control mechanism of a group in which a defect is unlikely to occur in a product, and an operation is first performed only by the shape control mechanism of the group having a high priority. Since the amount is obtained, the control by the shape control mechanism that the user wants to positively operate can be surely performed. For a shape residual that cannot be removed by the shape control mechanism of the higher priority group, the shape control mechanism of the relatively lower priority group is sequentially incorporated to obtain the operation amount. Optimal control mainly by a shape control mechanism that desires a preferential operation can be performed, and at the same time, the probability that shape control induces a product defect can be reduced. For this reason, products are less likely to have defects,
Optimum control mainly by a shape control mechanism for which a preferential operation is desired can be performed. Therefore, the probability that shape control induces product defects can be reduced, and the shape quality and quality of the product can be reduced.
Further improvement in surface properties can be expected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a control device to which a shape control method in sheet rolling according to an embodiment of the present invention is applied and related equipment.

FIG. 2 is a view showing a roll section and a shape control mechanism of the rolling mill shown in FIG.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B21B 29/00 B21B 37/00-37/78 G05B 13/02

Claims (3)

(57) [Claims] 1. A shape detector for detecting a shape at a plurality of positions in a width direction of a rolled sheet by a shape detector, and obtaining respective operation amounts of a plurality of shape control mechanisms based on an output of the shape detector. A shape control method in strip rolling in which a shape control mechanism is controlled to control a shape of a plate, wherein (a) a shape deviation is obtained by subtracting a preset target shape distribution from a shape distribution detected by the shape detector. And (b) classifying the shape control mechanisms into a plurality of groups and giving priorities, and based on the shape deviation, a first operation amount for a shape control mechanism in a group having the highest priority. (C) subtracting the plate shape corrected by the first operation amount from the shape deviation to obtain a shape residual;
(D) obtaining a second operation amount for the shape control mechanism for which the operation amount has been obtained based on the shape residual and for the shape control mechanism of the next highest priority group; (E) subtracting the plate shape corrected by the second manipulated variable from the shape residual to further obtain a shape residual, wherein (d) and (e) / or (d) A shape control method in sheet rolling, wherein the steps are repeated in accordance with the number of groups of the classified shape control mechanisms, and each of the shape control mechanisms is controlled by adding the corresponding operation amount. 2. A shape detector for detecting shapes at a plurality of positions in the width direction of the rolled sheet, obtaining respective operation amounts of a plurality of shape control mechanisms based on an output of the shape detector, and obtaining respective operation amounts based on the operation amounts. In a shape control method in strip rolling for controlling a shape of a sheet by controlling a shape control mechanism, a step of obtaining a shape deviation by subtracting a preset target shape distribution from a shape distribution detected by the shape detector, A step of obtaining a first operation amount for only the shape control mechanism to which priority has been given in advance based on the shape deviation; and subtracting a plate shape corrected by the first operation amount from the shape deviation. Calculating a second operation amount for all the shape control mechanisms based on the shape residuals; and Is the first manipulated variable The control is performed based on the operation amount obtained by adding the second operation amount, and for the other shape control mechanisms excluding the shape control mechanism to which the priority has been given in advance, the second operation amount is used. And a step of controlling based on the shape control method. 3. The shape control method according to claim 2, wherein the shape control mechanism to which the priority has been given in advance is an intermediate roll bender and a work roll bender.