JP4470667B2 - Shape control method in temper rolling mill - Google Patents

Description

  The present invention relates to a shape control method in a temper rolling mill that performs temper rolling of a cold-rolled steel sheet (hereinafter also simply referred to as a steel sheet) after continuous annealing.

  In recent years, cold-rolled steel sheets are made into products by being passed through a series of continuous production lines in which a continuous annealing furnace, a temper rolling mill, and a finishing apparatus are continuously arranged. As a temper rolling mill in such a continuous production line, a six-fold rolling mill has been widely used. In temper rolling of steel sheets, shape feedback control is performed to detect the strip shape after temper rolling with a shape detector installed on the exit side of the temper rolling mill and bring the steel plate shape after temper rolling closer to the target shape. It has been implemented (Patent Document 1).

  In addition, as shown in FIG. 8, the 6-type temper rolling mill includes upper and lower work rolls (WR) 13 for sandwiching the steel plate 1, intermediate rolls (IMR) 12 and backup rolls ( (BUR) 11 in six stages. Then, temper rolling is performed by rolling down the chock of the backup roll (BUR) 11 with the mill reduction device 14. The work roll (WR) 13 and the intermediate roll (IMR) 12 are provided with a work roll vendor (WR vendor) 16 and an intermediate roll vendor (IMR vendor) 15, respectively. The shape of the steel sheet is controlled by adjusting the bender pressure.

For example, when controlling the shape of a steel sheet by approximating a strip shape after temper rolling detected by a shape detector to a higher order function, a quartic equation is used, and shape parameters Λ _{1 to} Λ ₄ combined with the coefficients are used. It is known. Here, the shape parameters Λ _{1 to} Λ ₄ are described in Non-Patent Document 1, for example.

By the way, regarding a shape control method in a six-fold temper rolling mill, for example, Patent Document 1 discloses that the intermediate roll position is shifted and the work roll bending control is performed to prevent a shape defect of the plate material. A temper rolling method for flattening and uniforming is disclosed.
Japanese Patent No.2541989 Japan Iron and Steel Institute Joint Study Group, Rolling Theory Division, "Theory and Practice of Sheet Rolling", 1984, p98

  However, when temper rolling of a steel sheet after continuous annealing is performed, it is difficult to actually put it to practical use because responsiveness is poor only by shape feedback control. That is, in the temper rolling of the steel sheet after continuous annealing, the line speed is frequently accelerated and decelerated, and the rolling load fluctuates accordingly.

  Therefore, the operator must determine the shape by looking at the shape parameters (steepness, etc.) detected by the shape detector, and manually intervene the rolling load of the temper rolling mill, the bender pressure of the work roll, and the bender pressure of the intermediate roll. The steel plate shape is controlled by Therefore, it was no exaggeration to say that the shape accuracy of the steel sheet in temper rolling is determined by the experience and skill of the operator.

  In addition, the method of Patent Document 1 cannot be applied to a six-fold temper rolling mill that does not include an intermediate roll shift device.

  In the present invention, when temper rolling by a six-fold temper rolling mill equipped with a work roll bender and an intermediate roll bender, the shape control is performed so that the steel plate shape can be quickly within the target range without intervention by the operator. A shape control method to be performed is provided.

The present invention controls the shape of a steel sheet using a work roll bender and an intermediate roll bender when performing temper rolling of a steel sheet after continuous annealing by a six-fold rolling mill in which an intermediate roll is disposed between a work roll and a backup roll. A shape control method in a temper rolling mill, wherein a target range of a shape parameter is determined in advance based on a relationship with an actual shape for each standard / dimension of the steel sheet, and the changes in the standard / dimension of the steel sheet Is passed through the temper rolling mill, the control target of the steel plate shape is set to the target range of the shape parameter according to the steel plate after the change, and then the steel plate shape after the temper rolling is within the target range In this way, the shape feedback control is performed in combination with each roll bender, and the load correction bender pressure is calculated according to the load fluctuation amount of the rolling load accompanying the acceleration / deceleration of the line speed. The Nda pressure in addition to the vendor pressure of each roll bender, the shape control method in a temper rolling machine and performing shape control of the steel sheet.

At that time, the steel plate shape is approximated by a quartic function, and the shape parameters Λ ₂ and Λ ₄ representing the defined symmetric components are used as follows by the quadratic and quadratic coefficients of the approximated quartic function. , or even primary, shape parameter lambda ₁ that represents the asymmetric component as defined by a cubic _coefficient, using lambda _3, intends line shape control of the steel sheet.

Λ ₂ = λ ₂ + λ ₄ , Λ ₄ = (1/2) · λ ₂ + (1/4) λ ₄
Λ ₁ = λ ₁ + λ ₃ , Λ ₃ = (1 / √3) · λ ₁ + (1 / 3√3) · λ ₃
However, λ ₁ , λ ₂ , λ ₃ , λ ₄ takes the elongation rate as the steel plate shape y, and takes the coordinate x (−1 ≦ x ≦ 1) made dimensionless by the plate width in the width direction. The coefficient when approximated by a quartic function of y = λ ₀ + λ ₁ · x ¹ + λ ₂ · x ² + λ ₃ · x ³ + λ ₄ · x ⁴
Further, it is preferable to control the shape of the steel sheet by setting the control target of the steel sheet shape to the weighted shapes δ2, δ3 or further δ1 shown below.

δ1 = ΔΛ ₁ + α · ΔΛ ₃
ΔΛ ₁ = Λ ₁ −Λ ₁ ^* , ΔΛ ₃ = Λ ₃ −Λ ₃ ^*
Where Λ ₁ ^* , Λ ₃ ^* : target value range of shape parameters Λ ₁ , Λ ₃ , 0 ≦ α ≦ 1
δ2 = ΔΛ ₂ + β · ΔΛ ₄
δ3 = ΔΛ ₂ −γ · ΔΛ ₄
ΔΛ ₂ = Λ ₂ −Λ ₂ ^* , ΔΛ ₄ = Λ ₄ −Λ ₄ ^*
Where Λ ₂ ^* , Λ ₄ ^* : target value range of shape parameters Λ ₂ , Λ ₄ , 0 ≦ β ≦ 1,
0 ≦ γ ≦ 1
Further, when setting the target range of the shape parameter, the allowable range of the shape parameter is also set, and the steel plate shape data is detected based on the steel plate shape data detected by the shape detector installed on the exit side of the temper rolling mill. It is preferable to perform pass / fail determination.

  According to the present invention, automation of shape control can be achieved, and shape control can be performed quickly so that the steel plate shape is within the target range without operator intervention. Therefore, compared with the past, the outstanding effect that a steel plate shape can be made flat and uniform efficiently is acquired.

  The shape control method in the temper rolling mill of this invention is applied suitably to the shape control system as shown in FIG. 1 which performs temper rolling of the steel plate after continuous annealing.

  The shape control system in FIG. 1 is a six-type temper rolling mill 10 provided with a backup roll (BUR) 11, an intermediate roll (IMR) 12, and a work roll (WR) 13, and an actuator for controlling the shape of the steel sheet. A work roll bender 16 and an intermediate roll bender 15 (see FIG. 8), a shape detector 2 installed on the exit side of the temper rolling mill 10, and a shape control device (DDC) 3 are provided. The shape control device (DDC) 3 is connected to a process computer (P / C) 4 and a host computer (O / C) 5 that is higher than that.

  When temper rolling the steel plate 1 after annealing, the shape of the steel plate 1 after temper rolling is detected by the shape detector 2, and the actual shape is taken into the shape control device 3. The rolling load is also taken into the shape control device 3, and the shape control of the present invention is specifically executed by the shape control device 3, and the IMR vendor command for the intermediate roll 12 and the WR vendor command for the work roll 13 are output. At that time, a target range of shape parameters determined in advance for each standard / dimension of the steel sheet is input from the host computer 5 to the shape control device 3 via the process computer 4. As the shape detector 2, for example, a detector using a piezoelectric element that can measure the shape of a steel plate at a constant pitch in the width direction, for example, about 50 mm can be used.

  In FIG. 1, A indicates the change point of the standard / dimension, and the change point A of the standard / dimension is a weld point where the steel plates are connected by welding in order to perform continuous rolling. Normally, when the steel sheet standard / dimension change point A passes through the temper rolling mill 10, it passes at a low speed, for example, about 5% of the maximum speed during feeding. Control by the roll bender and intermediate roll bender is interrupted.

  The shape control method in the temper rolling mill of the present invention is such that when the change point A of the standard / size of the steel sheet passes through the temper rolling mill 10, that is, the shape control by the work roll bender and the intermediate roll bender is interrupted as described above. While the steel plate passes through the temper rolling mill at the low speed as described above, the shape control target is set to the target range according to the steel plate after the change point A, and then the specification and dimensions of the steel plate are changed. After the point A passes through the temper rolling mill 10, when the speed of transmission exceeds the above low speed, the interrupted control is resumed, and the shape feedback control is performed to put the steel plate shape after the temper rolling into the target range. The shape of the steel plate after temper rolling is detected by a shape detector 2 installed on the exit side of the temper rolling mill 10.

  In addition to the shape feedback control, the shape correction of the steel sheet is performed by using a load correction bender control described later.

Here, the target range of the shape parameter is determined in advance based on the actual shape for each standard / dimension of the steel plate 1. For example, in FIGS. 2 and 3, the values of the shape parameters Λ ₂ and Λ ₄ of the steel sheet 1 at the time of temper rolling by the temper rolling machine 10 to which the present invention is applied are taken on the horizontal axis, respectively, The shape was measured off-line and shown on the vertical axis as an abdominal stretch and an ear stretch shape.

From the relationship between the shape parameters Λ ₂ and Λ ₄ of the steel sheet 1 during the temper rolling and the actual steel sheet shape, the allowable ranges of Λ ₂ and Λ ₄ are determined so that the belly extension is X mm or less and the ear extension is Y mm or less. . Therefore, when the shape control of the steel sheet 1 is performed in the temper rolling mill, the target range of the shape parameter is set within the allowable range of Λ ₂ and Λ ₄ and the steel plate shape after the temper rolling is the target of Λ ₂ and Λ ₄ . By making it fall within the range, the actual steel plate shape can be set to Xmm or less and the ear extension Ymm or less.

2 and 3 show a low carbon steel having a plate thickness of less than 1.0 mm and a plate width of less than 1000 mm.
Here, the shape parameters Λ ₂ and Λ ₄ are widths defined as follows by approximating the width direction distribution of the steel sheet shape with a quartic function, and with quadratic and quadratic coefficients of the approximated quaternary function. It is a shape parameter that represents a symmetric component that is symmetric with respect to the center.

Λ ₂ = λ ₂ + λ ₄ , Λ ₄ = (1/2) · λ ₂ + (1/4) λ ₄
Further, the shape parameters Λ ₁ and Λ ₃ representing the asymmetric component that is asymmetric with respect to the center of the width are defined as follows by the first and third order coefficients of the approximated quartic function.

Λ ₁ = λ ₁ + λ ₃ , Λ ₃ = (1 / √3) · λ ₁ + (1 / 3√3) · λ ₃
However, λ ₁ , λ ₂ , λ ₃ , λ ₄ generally take the elongation rate as the steel plate shape y, and take the coordinate x (−1 ≦ x ≦ 1) dimensionless by the plate width in the width direction. This is a coefficient when approximated by the quartic function of (1).

y = λ ₀ + λ ₁ · x ¹ + λ ₂ · x ² + λ ₃ · x ³ + λ ₄ · x ⁴ (1)
Typical steel plate shapes are shown in FIGS. FIG. 4 shows a steel plate shape that is symmetric with respect to the width center, and FIG. 5 shows a steel plate shape that is asymmetric with respect to the width center. However, the elongation at the center of the width is shown as a reference (λ ₀ = 0).

Thus, it is preferable to approximate the steel plate shape with a quaternary function and use the shape parameters Λ _{1 to} Λ ₄ defined by the coefficients, because parameters representing the steel plate shape can be obtained quickly and accurately.

The concrete steel plate shape control target when the shape parameters Λ _{1 to} Λ ₄ are used is the weighted shape deviation δ2, δ3 or further δ1 shown below, and the weighted shape deviation δ2, δ3 or further δ1 is proportionally integrated. Based on this, the vendor pressure of each roll bender was manipulated.

δ1 = ΔΛ ₁ + α · ΔΛ ₃ (2)
ΔΛ ₁ = Λ ₁ −Λ ₁ ^* , ΔΛ ₃ = Λ ₃ −Λ ₃ ^*
Where Λ ₁ ^* , Λ ₃ ^* : target value range of shape parameters Λ ₁ , Λ ₃ , 0 ≦ α ≦ 1
δ2 = ΔΛ ₂ + β · ΔΛ ₄ (3)
δ3 = ΔΛ ₂ −γ · ΔΛ ₄ (4)
ΔΛ ₂ = Λ ₂ −Λ ₂ ^* , ΔΛ ₄ = Λ ₄ −Λ ₄ ^*
Where Λ ₂ ^* , Λ ₄ ^* : target value range of shape parameters Λ ₂ , Λ ₄ , 0 ≦ β ≦ 1,
0 ≦ γ ≦ 1
According to the control targets δ ₂ and δ ₃ using the shape parameters Λ ₂ and Λ ₄ , for example, the steel plate shapes symmetrical with respect to the width center as shown in FIG. 4 can be controlled. Further, a control target δ1 using the shape parameters Λ ₁ and Λ ₃ can be added when necessary. According to the control target δ1, for example, a steel plate shape that is asymmetric with respect to the width center as shown in FIG. Can be controlled. The specific operation of each roll vendor is as shown in Table 1.

6 and 7, changes in the steel plate shape when the shape parameters Λ ₂ and Λ ₄ are used will be described. In this case, control of the steel plate shape using the shape parameters Λ ₁ and Λ ₃ is not performed.

  In the monitor screen of FIG. 6, 21 indicates that the steel plate shape has reached the point 21 via the locus 22. Reference numeral 23 indicates an allowable range of the steel sheet shape that is currently temper-rolled by a six-fold temper rolling mill 10 (see FIGS. 1 and 8), and reference numeral 24 indicates a target range of the steel sheet shape.

This monitor screen does not show that the steel plate shape deviates from the target range 24. However, if the steel plate shape deviates from the allowable range 23 outside the target range 24 and is near the four corners, The shape control is performed so that the steel plate shape approaches the target range 24 and leads to the start of the locus 22 shown in FIG. That is, at the start of shape control, if the steel plate shape is a simple ear extension shape near the upper right corner or a simple belly extension shape near the lower left corner in FIG. If the quarter bender shape near the lower right corner or the symmetric complex component stretch shape near the upper left corner is operated, the control that mainly controls the symmetric complex component as control symmetry (by weighted shape deviation δ3) The operation of each roll bender) works, and the steel plate shape can be brought close to the target range 24 rapidly. The control using the shape parameters Λ ₂ and Λ ₄ to make the symmetric component control symmetric and the control to make the symmetric composite component control symmetric make it possible to reliably and quickly bring the steel plate shape within the target range 24. It can be put in.

  In FIG. 7, the monitor screen shows only the allowable range 23 of the shape and the target range 24 of the shape that falls within the allowable range 23.

  By the way, in the shape control of the steel plate in the present invention, after the change point of the standard / size of the steel plate passes through the temper rolling mill, the load correction bender control is used together with the shape feedback control as described above.

  This load correction bender control calculates the load correction bender pressure command value (kN / chock) according to the load fluctuation amount of the rolling load accompanying acceleration / deceleration of the line speed, and calculates the calculated load correction bender pressure command value (kN / chock). ) Is added to the bender pressure command value (kN / chock) for each roll bender, and shape control is performed to correct the shape change caused by the load fluctuation amount.

Specifically, in the shape control device (DDC) 3, ΔF (kN / chock) is calculated by the following calculation formula, and four corrections are made for four roll benders. Equally, ΔF / 4 is superimposed on the vendor pressure command value (kN / chock) of each roll bender. ΔF is the term for the adjustment gain K _pf, the term for calculating the influence coefficient of the sheet width fitted by the model, and the linear load conversion of the actual load fluctuation amount excluding the bender pressure from the temper rolling sum load. It is calculated by multiplying the three terms.

W: Plate width mm
P: Temper rolling sum load (kN)
F _IMR : Actual IMR bender pressure (per side chock) (kN / chock)
F _WR : Actual WR bender pressure (per side chock) (kN / chock)
_Kpf : Adjustment gain a, b: Constant L: Subscript indicating control lock-on value The constants a and b in the calculation formula are the uniform linear pressure of the load in the roll axis direction, the plate width of the steel sheet, and the bender pressure. After calculating the roll deflection with various changes (per chock), it is assumed to be derived by calculating the appropriate bender pressure by organizing the plate crown amount at a certain position, for example, 25 mm from the edge of the steel plate. That's fine. The lock-on value of control is a value stored in the shape control device (DDC) 3 when rolling is stabilized at the initial stage of continuous rolling performed by connecting a series of steel plates.

  As described above, the present invention predetermines the target range of the shape parameter for each standard / dimension of the steel sheet based on the relationship with the actual shape, and the change in the standard / dimension of the steel sheet is a temper rolling mill. When passing, that is, while the control dead zone is passing through the temper rolling mill, the steel plate shape control target is set to a target range corresponding to the steel plate after the change point, and then the steel plate shape after temper rolling is the target The shape feedback control is performed in combination with each roll bender so that it is within the range, and the load correction bender pressure is calculated according to the load fluctuation amount of the rolling load accompanying the acceleration / deceleration of the line speed, and the bender pressure of each roll bender is calculated. In addition, the shape of the steel sheet is controlled.

  Therefore, according to the present invention, since the target range of the shape parameter is determined in advance for each standard / dimension of the steel plate, it is possible to quickly control the shape when changing the standard / dimension of the steel plate, calculate the load correction bender pressure, Therefore, each roll bender can be operated more quickly than when only the shape feedback control is performed, and the change in shape caused by the load fluctuation amount can be corrected.

Further, in the shape control of the steel sheet according to the present invention, since the shape control target has a certain range, it is possible to prevent the bender pressure from divergence and to accurately control the target shape. In addition, the operator monitors the monitor screen of FIG. 7 when performing the shape control of the steel plate using the monitor screen of FIG. 6 or further asymmetric shape parameters Λ ₁ and Λ _3, and the shape of the steel plate Confirm that the value converges within the target range 24. However, if it is likely to deviate from the allowable range 23 of the shape, it is also possible to perform necessary care.

  In the shape control of the steel sheet according to the present invention, not only the target range of the shape parameter but also the allowable range of the shape allowed for each standard / dimension of the steel sheet is set, and the data of the steel plate shape detected by the shape detector 2 is formed. The information is sent from the control device (DDC) 3 to the host computer 5, and the host computer 5 determines whether or not the shape is within the allowable range and performs a pass / fail determination of the steel sheet shape. By utilizing this function, it is preferable because the shape of a shape-strict material can be determined strictly based on the data of the steel plate shape detected by the shape detector 2.

  An embodiment of the present invention is shown in FIG.

Fig. 9 shows the temporal transition of the exit speed, rolling load, work roll and intermediate roll bender pressure, and shape parameters Λ ₂ and Λ ₄ when temper rolling the steel sheet with a 6-fold temper rolling mill. It is shown. In this embodiment, the shape parameters Λ ₂ and Λ ₄ previously determined as described above for each standard and dimension of the steel plate were used for shape control of the steel plate. In addition, the constant of the calculation formula for the load correction bender pressure command value was derived by organizing the plate crown amount at a position 25 mm from the edge of the steel plate.

  In this example, after changing the steel type and dimensions, the operator changes the exit speed due to the need for another work, and although there is a temporary speed fluctuation, in addition to the shape feedback control, acceleration / deceleration of the line speed Because the load correction bender control is used together with the rolling load fluctuations accompanying the rolling, there is no operator intervention for the work roll bender and the intermediate roll bender, and the shape control of the steel sheet has succeeded. ing.

At that time, when the change in specifications and dimensions from ultra-low carbon material to low carbon material passes through the temper rolling mill, the shape control target is the target of the shape parameter that is predetermined for the low carbon material to be passed through. Range Λ ₂ = −1.0 to −0.1, Λ ₄ = −0.2 to 0.4, allowable range Λ ₂ = −1.3 to 0.2, Λ ₄ = −0.4 to 0. Since the setting was changed to 6, the work roll bender and the intermediate roll bender are operating to bring the steel plate shape into the target range of the shape parameter of the low carbon material, and the line acceleration / deceleration is performed while the low carbon material is passing through the plate. Even so, it can be seen that Λ ₂ and Λ ₄ are stable, the shape is flat and uniform, and the shape is within the allowable range and within the acceptable range.

On the other hand, from the time chart of the steel plate shape in the temper rolling mill before carrying out the present invention shown in FIG. 10, before carrying out the present invention, the steel plate is subjected to fluctuations in rolling load accompanying acceleration / deceleration of the line speed. It can be seen that there are places where the shape deviates from the allowable range of the shape. When the steel plate shape deviated from the allowable range, the shape was controlled by the operator's assistance so that Λ ₂ and Λ ₄ were within the allowable range.

It is a schematic diagram which shows the outline | summary of the shape control system of the temper rolling mill to which this invention is applied. It is a figure which illustrates the relationship between an actual steel plate shape and shape parameter (LAMBDA) ₂ . It is a figure which illustrates the relationship between an actual steel plate shape and shape parameter (LAMBDA) ₄ . It is a figure explaining shape parameters Λ ₂ and Λ ₄ . It is a figure explaining shape parameters Λ ₁ and Λ ₃ . It is a schematic diagram of the monitor screen of shape feedback control which performs symmetrical control. It is a schematic diagram of the monitor screen of shape feedback control which performs asymmetric control. It is a schematic diagram which shows arrangement | positioning of the six-stage roll of a temper rolling mill, and a reduction device. It is a time chart of the Example which applied the shape control method of this invention. It is a time chart of the steel plate shape before applying this invention.

Explanation of symbols

A Change 1 Steel plate 2 Shape detector 3 Shape control device (DDC)
4 Process computer (P / C)
5 Host computer (O / C)
10 Temper rolling mill
11 Backup roll (BUR)
12 Intermediate roll (IMR)
13 Work roll (WR)
14 mil reduction device
15 Intermediate roll vendor (IMR vendor)
16 Workroll vendor (WR vendor)
21 points
22 locus
23 Shape tolerance
24 Target range of shape

Claims (3)

Tempering that controls the shape of a steel sheet using a work roll bender and an intermediate roll bender when performing temper rolling of a steel sheet after continuous annealing using a 6-fold rolling mill in which an intermediate roll is placed between a work roll and a backup roll. A shape control method in a rolling mill, wherein a target range of a shape parameter is predetermined based on a relationship with an actual shape for each standard / dimension of the steel sheet, and the change in the standard / dimension of the steel sheet is temper rolling When passing through the machine, set the steel plate shape control target to the target range of the shape parameter according to the steel plate after the change point, and then shape feedback so that the steel plate shape after temper rolling is within the target range Control is performed in combination with each roll bender, and the load correction bender pressure is calculated according to the load fluctuation amount of the rolling load accompanying acceleration / deceleration of the line speed. Perform shape control of the steel sheet in addition to the vendor pressure of each roll bender, approximated by quartic function the steel sheet shape on the shape control, secondary quartic function that approximates, in the following fourth order coefficient shape parameter lambda ₂ representing the defined symmetric element _to, using a lambda _4, or even primary, shape parameter lambda ₁ that represents the asymmetric component as defined by a cubic _coefficient, tone and characterized in that a lambda ₃ protein Shape control method in a rolling mill.
Λ ₂ = λ ₂ + λ ₄ , Λ ₄ = (1/2) · λ ₂ + (1/4) λ ₄
Λ ₁ = λ ₁ + λ ₃ , Λ ₃ = (1 / √3) · λ ₁ + (1 / 3√3) · λ ₃
However, λ ₁ , λ ₂ , λ ₃ , λ ₄ takes the elongation rate as the steel plate shape y, and takes the coordinate x (−1 ≦ x ≦ 1) made dimensionless by the plate width in the width direction. Coefficient when approximated by a quartic function
y = λ ₀ + λ ₁ · x ¹ + λ ₂ · x ² + λ ₃ · x ³ + λ ₄ · x ⁴   Steel plate shapeThe control target is set to the weighted shape δ2, δ3 or δ1 as shown below.The shape control method in the temper rolling mill according to claim 1, wherein shape control of the steel sheet is performed.
          δ1 = ΔΛ ₁ + Α ・ ΔΛ ₃
          ΔΛ ₁ = Λ ₁ −Λ ₁ ^* , ΔΛ ₃ = Λ ₃ −Λ ₃ ^*
Where Λ ₁ ^* , Λ ₃ ^* : Shape parameter Λ ₁ , Λ ₃ Target value range, 0 ≦ α ≦ 1
δ2 = ΔΛ ₂ + Β ・ ΔΛ _Four
δ3 = ΔΛ ₂ -Γ ・ ΔΛ _Four
          ΔΛ ₂ = Λ ₂ −Λ ₂ ^* , ΔΛ ₄ = Λ ₄ −Λ ₄ ^*
Where Λ ₂ ^* , Λ ₄ ^* : Shape parameter Λ ₂ , Λ ₄ Target value range, 0 ≦ β ≦ 1,
0 ≦ γ ≦ 1 When setting the target range of the shape parameter, set the allowable range of the shape parameter, and pass / fail judgment of the steel plate shape based on the steel plate shape data detected by the shape detector installed on the exit side of the temper rolling mill The shape control method in the temper rolling mill according to claim 1, wherein the shape control method is performed .

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