JPH0636926B2 - Shape control method in strip rolling - Google Patents

Description

TECHNICAL FIELD The present invention relates to a shape control method in strip rolling.

[Prior Art] Improving the shape of a sheet rolled by a rolling mill leads to improvement in productivity and yield in subsequent steps.
Moreover, when a steel plate having a good plate shape is used, the quality of the product can be stabilized. For this reason, a number of plate shape control methods have been proposed and implemented in order to meet the demand for improving the plate shape.

Recent rolling mills are equipped with a plurality of shape control actuators having a shape control function for rolled plate. Shape control actuators include a VC roll that changes the roll profile using hydraulic pressure, a work roll bender and an intermediate roll bender that adjust the bending and bending of the roll, and a CVC roll that applies a sine wave in the axial direction of the roll as the upper and lower intermediate rolls. There is CVC shift etc. which uses this and shifts this in the roll axis direction. These shape control actuators have different responsiveness, controllability, and shape control characteristics such as shape characteristics of high-order components and low-order components. Therefore, when a plurality of shape control actuators are provided, it is necessary to effectively utilize the different characteristics of them to perform shape control. That is, these shape control actuators are generally preset with operation amounts such as the roll bending force and the CVC shift amount of the intermediate roll based on the material plate and rolling conditions before the start of rolling, and during steady rolling, the plate shape is set on the delivery side of the rolling mill. Is detected and the work roll vendor with high responsiveness or the intermediate roll vendor is feedback-controlled. During the steady rolling, load fluctuations due to plate thickness fluctuations, fluctuations in the inlet side shape due to changes in the thermal crown or the lubrication state of the rolls, the operation amount for the work roll bending force or the intermediate roll bending force may be above the operation limit, The plate shape cannot be controlled. As a method of transferring the operation amount when the operation limit is reached, there is a method disclosed in JP-A-62-168607. This method operates the work roll bending force and the intermediate roll bending force at the same time, and when the work roll bending force or the intermediate roll bending force reaches the operation limit, the bending force of the amount exceeding the operation limit is operated. The bending force of another shape control actuator that has not reached the value is transferred.

[Problems to be Solved by the Invention]

However, if the transfer control is performed when the operation amount reaches the operation limit, the control characteristics or responsiveness of the transferred shape control actuator is different from the control characteristics or responsiveness of the shape control actuator before transfer, and thus the control delay However, there is a problem that the shape control may be disabled during that time. The problem causes a particularly noticeable control delay when a large load variation and a short-cycle shape variation occur.

The present invention has been made in order to solve such a problem, and the first and second aspects of the present invention constantly maintain the operation position within the operation limit range so that the operation control limit is not reached and the shape cannot be controlled. The third aspect of the present invention is a method of controlling a highly responsive shape control actuator so as to be located at the central portion within the operation limit range so that the shape control is not disabled during the control delay. Therefore, all of them aim to provide a shape control method for improving the shape of the rolled plate.

[Means for Solving the Problems]

The first method of shape control in sheet rolling of the present invention is a method for controlling the shape of a sheet to be rolled using at least two shape control actuators provided in a rolling mill,
When the operation amount of the first shape control actuator exceeds a preset threshold value within the operation limit range, the operation amount of the first shape control actuator which exceeds the threshold value is transferred to the operation amount of the second shape control actuator. In the second method, the operation result of the second shape control actuator is obtained by performing an integration operation on the operation amount of the first shape control actuator exceeding a preset threshold value within the operation limit range. And the amount of operation is subtracted from the amount of operation of the first shape control actuator.
Is a method of controlling the shape of a plate to be rolled by using at least two shape control actuators provided in a rolling mill, and the operation amount of the shape control actuator with high responsiveness is preset within an operation limit range. When the specified threshold value is exceeded, another shape control actuator having lower responsiveness than the shape control actuator is operated so that the shape control actuator is located at the center of the operation limit range.

[Action]

In the first and second methods of the present invention, when the operation amount of the first shape control actuator exceeds a preset threshold value within the operation limit range, the amount exceeding the threshold value is set as the operation amount of the second shape control actuator. The transfer is performed, and the result of subtracting the operation amount from the operation amount of the first shape control actuator is controlled so as to be the operation amount of the first shape control actuator. Then, it becomes possible to operate the shape control actuator within the operation limit range, and the shape control actuator will not be disabled because the operation amount of the shape control actuator reaches the operation limit.

Further, the third method of the present invention is such that when the operation amount of the highly responsive shape control actuator exceeds a preset threshold value within the operation limit range, the operation amount of the highly responsive shape control actuator is set to the optimum position in control. That is, the operation amount of the shape control actuator is transferred to the operation amount of the shape control actuator having a lower response than the shape control actuator so that the operation amount is maintained at the center of the operation limit range. Therefore,
A wide range of highly responsive control is possible with respect to load fluctuations, human side shape fluctuations, roll thermal crown changes, and changes in lubrication conditions, improving shape accuracy.

〔Example〕

The present invention will be described below with reference to the drawings showing an embodiment thereof.

FIG. 2 is a schematic fiber diagram showing an example of a rolling mill for carrying out the present invention. A rolling mill 50 includes work rolls 14, 14 and an intermediate roll 1.
This is a 6-high rolling mill comprising 5, 15 backup rolls 16, 16 and is provided with CVC shifts such as a work roll bender 11, an intermediate roll bender 12 and an intermediate roll shift 13 as roll claw control means. That is, in this embodiment, the plate shape of the rolled plate 100 is controlled by operating the above three shape control actuators. Workroll vendor 1
1, the intermediate roll vendor 12 and the intermediate roll shift 13,
A work roll bender controller, an intermediate roll bender controller, and an intermediate roll shift controller, which are not shown, are provided for detecting each bending force and shift amount and controlling each operation amount.

In the present embodiment, the work roll bender 11 is the first shape control actuator described above, the intermediate roll bender 12 is the second shape control actuator described above, and the intermediate roll shift is performed.
When 13 is a third shape control actuator subordinate to the intermediate roll bender 12, when the operation amount of the first shape control actuator exceeds a preset threshold value within an operation limit range, the first shape exceeding the threshold value is exceeded. When the operation amount of the control actuator is transferred to the operation amount of the second shape control actuator, and when the operation amount of the second shape control actuator exceeds a preset threshold value within the operation limit range, the operation amount of the second shape control actuator is exceeded. The operation amount of the shape control actuator is controlled so as to be transferred according to the operation amount of the third shape control actuator. Further, among the work whirl bender 11, the intermediate roll bender 12, and the intermediate roll shift 13, the former two are high-responsive shape control actuators, and the latter are low-responsiveness control actuators.
When the intermediate roll bender 12 reaches the operation limit, it shifts the intermediate roll shift 13 to control the work roll bender 11 and the intermediate roll bender 12 so as to be located at the central portion within the operation limit range.

The swing change control method according to the present invention will be described with reference to the block diagram of FIG.

The calculator 20 inputs the target shape K _aim and the actual shape K _act obtained from a shape meter (not shown) set on the output side of the rolling mill to calculate a shape error K _err which is a deviation and calculates a low-order component. Output to the shape error extractor 1. The shape control actuator used in this embodiment cannot perform shape control for high-order component errors, and therefore performs shape control for low-order component shape errors. Low-order component shape error extractor 1
Outputs the result e _rr of the PI control of the low-order component shape error, which is a value obtained by multiplying the shape error K _err by the width-direction low-order component error extraction parameter by statistical processing, to the first manipulated variable calculator 2. The first operation amount calculation unit 2 obtains the work roll bending operation amount F _kw for low-order component shape error e _rr based on low-order component shape error e _rr that PI control, this preset amount of the work roll bender 11 The added value is output to the work roll bender controller 8 and the first transfer amount calculator 3 as the work roll bending total operation amount F _w .
When the total work roll bending operation amount F _w exceeds a preset threshold value within the operation limit range of the work roll bender 11, the first transfer amount calculator 3 integrates the excess amount of the work roll bending operation amount threshold. The amount F _wos is calculated and output to the first manipulated _variable calculator 2. Further, the first transfer amount calculator 3 _converts the amount F _wos obtained by integrating the excess of the threshold value into the intermediate roll bending operation amount, and _{outputs it} to the second operation amount calculator 4 as the intermediate roll bending operation amount F _FI for the shape error e _rr . Output. The first operation amount calculator 2 to which the threshold value of the work roll bending operation amount, that is, the work roll bending transfer amount F _wos is input, is the result of subtracting the work roll bending transfer amount F _wos from the work roll bending total operation amount F _w. Is output to the work roll bender controller 8 as a new total work roll bending operation amount F _w . The second manipulated variable calculator 4 which is input an intermediate roll bending operation amount F _FI whereas on the shape error e _rr is a value obtained by adding the preset amount of the intermediate roll bender 12 to the intermediate roll bending operation amount F _FI on the shape error e _rr Intermediate roll bending total operation amount F
It is output as _I to the intermediate roll bender controller 9 and the second transfer amount calculator 5. Similarly, the second transfer amount calculator 5 integrates the excess amount of the intermediate roll bending operation amount over the threshold value when the intermediate roll bending total operation amount F _I of the preset threshold value within the operation limit range of the intermediate roll bender 12 exceeds. The calculated amount F _IOS is obtained and the power is extracted to the second manipulated variable calculator 4. Further, the second transfer amount computing unit 5 converts the amount F _IOS obtained by integrating the excess of the threshold value into the intermediate roll shift operating amount and outputs it to the third operating amount computing unit 6 as the intermediate roll shift operating amount S _FI for the shape error e _rr . To do. The second operation amount calculator 4 to which the threshold roll amount of the intermediate roll bending operation amount, that is, the intermediate roll bending transfer amount F _IOS is input, is the result of subtracting the intermediate roll bending transfer amount F _IOS from the intermediate roll bending total operation amount F _I. Is output to the intermediate roll bender control unit 9 as a new intermediate roll bending total operation amount F _I. The third manipulated variable calculator 6 which is input an intermediate roll shifting operation amount S _FI whereas on the shape error e _rr is a value obtained by adding the preset amount of the intermediate roll shifting operation amount S _FI on an intermediate roll shifting 13 on the shape error e _rr Is output to the intermediate roll shift control unit 10 as the intermediate roll shift total operation amount S _I.

In this embodiment, the case where three shape control actuators are provided has been described, but the present invention can also obtain the same effect when two shape control actuators are provided.

In addition to the dynamic transfer control as described above, in this embodiment, the optimum position control according to the third method of the present invention is performed.

The first, second, and third operation amount calculators 2, 4, and 6 respectively supply the work roll bending total operation amount F _w , the intermediate roll bending total operation amount F _I , and the intermediate roll shift operation amount S _I to the work roll bender respectively. It is input to the control unit 8, the intermediate roll bender control unit 9, and the intermediate roll shift control unit 10 and also to the optimum position transfer computing unit 7. When the work roll bending total operation amount F _w or the intermediate roll bending total operation amount F _I exceeds a preset threshold value in the vicinity of the operation limit, the optimum position transfer calculator 7 determines the work roll bending total operation amount F _w and the intermediate roll. The total bending operation amount F _I is transferred to the intermediate roll shift operation amount. The third operation of the intermediate roll shift operation amount ΔS for controlling the work roll bender 11 and the intermediate roll bender 12 having high responsiveness to the central portion of the operation limit range, that is, the optimum position so that they can respond in response to the shape control request Input to the quantity calculator 6. The work roll bending operation amount transferred to the intermediate roll shift operation amount, in other words, the work roll bending optimum position control amount ΔF _cw is input to the first operation amount calculator 2. Similarly, the intermediate roll bending optimum position control amount ΔF _CI is input to the second manipulated variable calculator 4.

The first, second and third manipulated variable calculators 2, 4 and 6 respectively calculate the work roll bending optimum position control amount ΔF _cw , the intermediate roll bending force optimum position control amount ΔF _CI and the intermediate roll shift optimum control amount ΔS. The values are set as new work roll bending total operation amount F _w , intermediate roll bending total operation amount F _I , and intermediate roll shift total operation amount S _I , respectively, respectively, work roll bender control unit 8, intermediate roll bender control unit 9, and intermediate roll shift control. Enter in Part 10.

The calculation of each manipulated variable and the transfer amount will be described below.

First, from the regression equation obtained from the actual test rolling result, the transfer influence coefficients C _WB , C _IB , and C _IS of the material plate to be rolled this time and the shape control actuator under the rolling conditions are obtained from the equation (1).

C _WB = f _WB (W, h, r, Q, δ _f , δ _b ) C _IB = f _IB (W, h, r, Q, δ _f , δ _b ) C _IS = f _IS (W, h, r, Q, δ _f , δ _b ) (I) where w: strip width h: delivery side strip thickness r: reduction ratio Q: plate plasticity coefficient δ _f : front unit tension δ _b : rear unit tension C _WB : low Next component error / work roll bending force influence coefficient C _IB : Low order component error / intermediate roll bending force influence coefficient C _IS : Low order component error / intermediate roll shift influence coefficient The method of obtaining these influence coefficients will be described.

The work roll bending force, intermediate roll bending force, and intermediate roll shift are each ΔW during rolling on the actual machine.
Only B, ΔIB and ΔIS are changed, the shape change is obtained by a shape meter, and respective low order components ΔK _WB , ΔK _IB and ΔK _IS are extracted. Then, a regression equation is obtained from these values, the plate width W, the outlet plate thickness h, the rolling reduction r, the plate plasticity coefficient Q, the front unit tension δ _f, and the rear unit tension δ _b .

here Is.

Next, from the actual shape at the n points in the width direction obtained by the shape meter installed on the delivery side, and the target shape at the n points in the width direction determined by the plate width, the material, the delivery side plate thickness, the lower process, etc. The shape error at n points is calculated by the equation (2).

K _err (i) = K _aim (i) -K _ack (i) (2) where K _aim (i): target shape at i-th point in width direction K _act (i): actual shape at i-th point in width direction K _err (i): Shape error at the i-th point in the width direction From the shape error at the n-th point in the width direction obtained by the equation (2), the low-order component shape error e _rr is obtained by the equation (3).

However, α _i : An example of a method of obtaining the low-order component error extraction parameter α _i at the i-th point in each width direction by statistical processing is shown.

The low-order component is used as the second-order component, and the second-order component shape error e _rr is obtained by the least square method. K _err is y, second-order component coefficients are a, N
Is the number of width-direction detection zones for shape detection, Where the quadratic component coefficient a is Therefore Becomes

The work roll bending operation amount F _KW for the shape error e _rr is obtained by multiplying the low-order component shape error e _rr obtained by the expression (3) by the work roll bending transfer influence coefficient C _WB obtained by the expression (1).

F _KW = e _rr × C _WB (4) The work roll bending operation amount F _KW for the shape error e _rr obtained by the equation (4) and the preset operation amount F _PW obtained based on the rolling conditions of the material plate and the optimum described later. Position control operation amount Δ
F _CW and the work roll bending transfer amount F _WOS transferred to the intermediate roll bending operation amount are calculated according to the equation (5). The total work roll bending operation amount F _W is obtained from the equation (5).

F _W = F _KW + F _PW F _WOS + ΔF _CW (5) where F _PW : Work roll bending preset amount F _WOS : Work roll bending transfer amount ΔF _CW : Work roll bending optimum position control amount Work roll bending total operation amount F _W Is smaller than a preset threshold value, it is not necessary to move the work roll bender 11 to the optimum position, and therefore ΔF _CW = 0. Δ
The calculation method of F _CW will be described later.

The threshold value is appropriately set empirically in consideration of the transfer state, the influence on the shape, and the like by the actual operation.

Next, the intermediate roll bending total operation amount F _I is obtained. The threshold excess amount F _WO in the work roll bending operation amount that is the basis of the intermediate roll bending operation amount F _FI for the shape error is an amount defined by the equations (a) to (c).

However, F _WL1 : Work roll bending operation amount lower limit threshold F _WU1 : Work roll bending operation amount upper limit threshold Integrate the excess amount of work roll bending operation amount specified by equations (a) to (c) by equation (6). _{Find the} work roll bending transfer amount F _WOS .

F _WOS = C ₁ × (F _WO −F _WO ′) + F _WOS ′ (6) F _WO ′: Previous work roll bending threshold excess amount F _WOS ′: Previous work roll bending transfer amount C ₁ : Integral coefficient Equation (6) expresses the integral in a discretized form.

The above-mentioned integration coefficient C ₁ is ΔT: Sampling cycle T _i : Integration time of continuous system The intermediate roll bending operation amount when the work roll bending transfer amount F _WOS is converted into the operation amount of the intermediate roll bender 12 is obtained. As shown in the equation (7), it is obtained by multiplying the work roll bending transfer amount F _WOS by the work roll bender / intermediate roll bender transfer influence coefficient.

However, C _WIB : Work roll bender / intermediate roll bender transfer influence coefficient Intermediate roll bending operation amount F _FI and preset amount F _PI for shape error e _rr , transfer amount to intermediate roll shift F _IOS and optimum position control amount ΔF _CI described later The result of calculating and according to Eq. (8) is the total amount of intermediate roll bending operation F
_It is output as _I to the intermediate roll bender controller 9.

F _I = F _FI + F _PI −F _IOS + ΔF _CI (8) where F _PI : Intermediate roll bending preset amount F _IOS : Intermediate roll bending transfer amount ΔF _CI : Intermediate roll bending optimum position control amount Intermediate roll bending total operation amount F _{When I} is smaller than the preset threshold, ΔF _CI = 0 because it is not necessary to move the intermediate roll bender 12 to the optimum position. The method of calculating ΔF _CI will be described later. Further, the intermediate roll bending transfer amount F _IOS to the intermediate roll shift is an amount that exceeds a preset threshold value of the intermediate roll bending operation amount, that is, an amount defined by (d) to (f) is integrated (9). Calculated from the formula.

However, F _IL1 : Intermediate roll bending operation amount lower limit threshold F _IU1 : Intermediate roll bending operation amount upper limit threshold F _IOS = C ₂ × (F _IO −F _IO ′) + F _IOS ′ (9) However, F _IO ′: Previous Intermediate roll bending threshold excess amount F _IOS ′: Previous intermediate roll bending transfer amount C ₂ : Integral coefficient Note that this integral is expressed by a discretization formula.

Similarly, the intermediate roll bending transfer amount F _IOS is multiplied by the intermediate roll bender / intermediate roll shift transfer influence coefficient CF _IBS to obtain the intermediate roll shift operation amount S _FI for the shape error e _rr by the formula (10).

However, C _IBS : Intermediate roll bending / intermediate roll shift transfer influence coefficient Intermediate roll shift operation amount S _FI for the shape error e _rr obtained by the equation (10)
_The result of calculating _PI and the optimum position control amount ΔS described later according to the equation (11) is output to the intermediate roll shift control unit 10 as the intermediate roll shift total operation amount S _I.

S _I = S _FI + S _PI ΔS (11) where S _PI : Intermediate roll shift preset amount ΔS: Intermediate roll shift operation amount for optimum position control Work roll bending operation amount, intermediate roll bending operation amount and intermediate roll Although the shift operation amount is obtained, the optimum position control amounts of the work roll bender 11, the intermediate roll bender 12, and the intermediate roll shift 13 in each operation amount will be described below.

The optimum position control is performed when the work roll bending operation amount upper / lower limit thresholds F _WL1 and F _WU1 and the intermediate roll bending operation amount upper / lower limit thresholds F _IL1 and F _IU1 are exceeded. That is, when the work roll bender 11 and the intermediate roll bender 12 are smaller than the operation limit value and larger than the operation amount upper / lower limit threshold value and exceed the threshold values arbitrarily defined by the expressions (g) to (j).
The work roll bending total operation amount F _w and the intermediate roll bending total operation amount F _I are controlled so that is at the optimum position, that is, the center of the operation limit range.

_{F WL1> F WL2> F WL3} ... (g) F WU1 <F WU2 <F WU3 ... (h) F IL1> F IL2> F IL3 ... (i) F IU1 <F IU2 <F IU3 ... (j) F WL3 , F _WU3: operation limit of the work roll bender F _IL3, F _IU3: intermediate roll bender operation limits the work roll bending total operation amount F _W and intermediate roll bending total operation amount F _I work roll bending position control on / lower When the values F _WL2 , F _WU2 and the upper / lower limit values F _IL2 , F _IU2 for intermediate roll bending position control are _exceeded ,
The intermediate roll shift operation amount ΔS when the excess amount is multiplied by the influence coefficient to be converted into the intermediate roll shift is obtained by the equation (12).

Work roll bending operation center point Intermediate roll bending operation amount center point ΔS = ΔF _wc × C _WBIS + ΔF _IC × C _IBIS (12) However, in the case of the upper limit ΔF _WC = F _WC −F _WU2 ΔF _IC = F _IC −F _{IU 2 In} the case of the lower limit ΔF _WC = F _WC −F _WL2 ΔF _IC = F _IC −F _IL2 C _WBIS = C _IS / C _WB C _IBIS = C _IS / C _{IB The} intermediate roll operation amount ΔS obtained by the equation (12) is the optimum position of the intermediate roll shift used in the equation (1). It is a controlled variable. Based on this optimum position control amount of the intermediate roll shift, that is, the operation amount ΔS of the intermediate roll shift for setting the work roll bender and the intermediate roll bender to the optimum positions, ΔF _CI used in equation (8) and equation (5) Find the ΔF _CW used.

Since the intermediate roll shift has a lower response than the work roll bender 11 and the intermediate roll bender 12, it is impossible to instantaneously shift by the optimum position control amount ΔS. The shift speed S _v of the intermediate roll shift is expressed by the equation (13), and the operation amount S _Δs by which the intermediate roll shift can be shifted during one cycle of performing the shape control based on the shape error e _rr is expressed by the equation (14). It seems that.

S _v = f (V, P) (13) where V: rolling speed P: rolling load Ask as.

G is a mechanically determined constant.

S _Δs = S _v × t (14) where t: control cycle time and possible operation amount S _Δs of intermediate roll shift during control cycle t
The work roll bending operation amount and the intermediate roll bending operation amount, that is, the work roll bending optimal position control amount ΔF _CW and the intermediate roll bending optimal position control amount ΔF _CI are calculated.

ΔF _CW = S _Δs × A × C _ISWB (15) ΔF _CI = S _Δs × (1-A) × C _ISIB (16) where A: Work roll bending / intermediate roll bending transfer ratio From the above, if there is no error in the load fluctuation and transfer influence coefficient while the intermediate roll shift is shifting, by operating the intermediate roll shift 13 by ΔS, the low roll bender is operated.
11 and the intermediate roll bender 12 can be maintained at the optimum positions in control, that is, the work roll bending operation amount central point F _WC and the intermediate roll bending operation amount central point F _IC .

The results of carrying out the plate shape control method of the present invention are shown in FIG.

In the figure, (a), (b) and (c) show time charts of control outputs of the work roll bender 11, the intermediate roll bender 12 and the intermediate roll shift 13, respectively. The horizontal axis represents time t, and the vertical axis represents the manipulated variable output value. In this embodiment, the shape control is performed in parallel with the dynamic transfer control and the optimum position control. The broken line in the figure is the output value when the transfer is not performed, and the shaded area surrounded by the broken line showing the actual output value is the transfer amount.

Threshold F _LU1 in work roll bending operation amount
When it exceeds, it is transferred to the intermediate roll bending operation amount. That is, dynamic transfer control is performed. However, when the work roll bending operation amount and the intermediate roll bending operation amount exceed the thresholds F _WL1 and F _IL1 and exceed the work roll bending position control lower limit values F _WL2 and F _IL2 , the above-mentioned optimum position control for the intermediate roll shift is performed. The operation amount is transferred to the intermediate roll shift operation amount, and the work roll bending operation amount and the intermediate roll bending operation amount are controlled to reach the optimum position, that is, the zero point. Therefore, the work roll bending operation amount and the intermediate roll bending operation amount are the operation limits F _WL3.
And F _IL3 are not exceeded.

As described above, the optimum position control controls the work roll bender 11 and the intermediate roll bender 12, which are high-responsive shape control actuators, so as to be located at the central portion within the operation limit range. The operable amount of the roll bender 12 is increased, and the demand for shape control can be instantly met.

In the present embodiment, the case where the work roll bender 11 and the intermediate roll bender 12 are provided as the high responsiveness shape control actuator has been described, but the present invention is the same when the single high responsiveness shape control actuator is provided. Has the effect of.

In this embodiment, the shape control in the case where the shape control methods of the first, second and third inventions are used together has been described, but the shape control method of the present invention is the first, second or third invention.
Even if the shape control method of the invention is individually used for control, it is effective.

〔The invention's effect〕

As described above, in the first and second shape control methods of the present invention, the threshold value is set in advance within the operation limit range, and when the request for the operation amount of the shape control actuator exceeds the threshold value, the excess amount of the threshold value is exceeded. Since the operation amount is transferred to the operation amount of another shape control actuator, the operation amount of each shape control actuator does not reach the operation limit.

Further, according to the third shape control method of the present invention, since the operation amount of the shape control actuator having high responsiveness is controlled so as to be maintained at the optimum position in control, that is, in the center of the operation limit range, load fluctuation, This has the effect of enabling highly responsive control over a wide range in response to variations in the inlet side shape, changes in the roll's thermal crown, and changes in the lubrication state, thus improving the accuracy of the plate shape.

[Brief description of drawings]

FIG. 1 is a calculation block diagram for implementing the shape control method in strip rolling of the present invention, FIG. 2 is a schematic perspective view of a rolling mill used in an embodiment of the present invention, and FIG. 3 is a shape control of the present invention. It is a graph which shows the result of having implemented. 11 ... Work roll vendor, 12 ... Intermediate roll vendor, 13 ... Intermediate roll shift

Claims (3)

[Claims] 1. A method for controlling the shape of a rolled sheet using at least two shape control actuators provided in a rolling mill, wherein an operation amount of a first shape control actuator is preset within an operation limit range. When exceeding the threshold, the shape control method in strip rolling is characterized in that the operation amount of the first shape control actuator exceeding the threshold is transferred to the operation amount of the second shape control actuator. 2. The shape control method for strip rolling according to claim 1, wherein a result of performing an integral calculation on an amount by which the operation amount of the first shape control actuator exceeds a preset threshold value within an operation limit range, A shape control method in strip rolling, wherein the operation amount of the second shape control actuator is used and the operation amount is subtracted from the operation amount of the first shape control actuator. 3. A method for controlling the shape of a sheet to be rolled using at least two shape control actuators having different responsiveness provided in a rolling mill, wherein the operation amount of the shape control actuator having high responsiveness is an operation limit. When a preset threshold value within a range is exceeded, another shape control actuator having a lower response than the shape control actuator is operated so that the shape control actuator is located at the center of the operation limit range. Shape control method for strip rolling.