JP2004243376A - Device and method for controlling meandering of strip in tandem mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controlling device and a controlling method of the meandering of a strip in a tandem mill for surely preventing the strip from meandering without measuring the amount of the meandering of the strip on the outlet side of a rolling stand and without causing abnormal control such as hunting. <P>SOLUTION: The meandering controlling device of the strip in the tandem mill is provided with tension measuring means 3a, 3b for respectively measuring the working-side tension T<SB>WS</SB>and the driving-side tension T<SB>DS</SB>of the strip 2 on the outlet side of the rolling stand 1, calculation means 4 for calculating the difference tension ΔT<SB>i</SB>between the the working-side tension T<SB>WS</SB>of the strip and the driving-side tension T<SB>DS</SB>of the strip and judgement means 5 for judging whether the difference tension ΔT<SB>i</SB>is within a prescribed range or not. Leveling control means 6 for performing the leveling control of the rolling stand 1 so that the difference tension ΔT<SB>i</SB>is within the prescribed range when it is judged that the difference tension ΔT<SB>i</SB>is out of the prescribed range and a motion control means 8 of a meandering correction roll for controlling the motion of the meandering correction roll 11 so that the amount of meandering of the strip 2 is within the prescribed range on the basis of the difference tension ΔT<SB>i</SB>when it is judged that the difference tension ΔT<SB>i</SB>is out of the prescribed range are included. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a meandering control device and meandering control method for preventing strip meandering in a tandem rolling mill.
[0002]
[Prior art]
Conventionally, there is known a method of controlling the leveling of each stand according to the following equation (1) in order to prevent meandering of a strip in a tandem rolling mill.
ΔT _{i, i + 1} = AΔS _li + BΔW + CΔC (1)
Where ΔT _{i, i + 1} : the i-th stand forward differential tension, ΔS _li : the i-th stand leveling amount, ΔW: the amount of displacement in the width direction of the plate, ΔC: the crown difference in the width direction of the plate, A, B, C: rolling An example in which strip rolling is performed based on equation (1) determined by a schedule will be described with reference to FIG. In FIG. 2, 101 is a rolling mill, 102 is a strip, 103 is a rolling direction, 104 is a tensiometer, 105 is a meandering correction device, 106 is a leveling device, 107 is a differential tension signal, and 108 is a bias device.
[0003]
Here, the front differential tension ΔT _{i, i + 1} is detected from the tension meter 104 installed between the i-th stand and the (i + 1) -th stand. The differential tension is obtained by measuring the tension at both ends (work side end, drive side end) of a strip at one stand, and calculating the difference. Further, ΔW is detected by a CPC device (not shown) installed between the i-th stand and the (i + 1) -th stand, and a crown meter (not shown) installed between the i-th stand and the (i + 1) -th stand. To detect ΔC. Then, as the output of the bias signal 108 the _{BΔW + CΔC, AΔS li = ΔT} i, i + 1 - a (BΔW + CΔC) seeking [Delta] S _li, and it sends the signal to the meandering correction unit 105. The meandering correction device 105 controls the leveling of the i-th stand by the leveling device 106 based on the ΔS _li signal.
[0004]
JP-A-63-188415 discloses that in controlling the leveling of the i-th stand, not only the i-th stand, but also the front differential tension of the (i + 1) -th stand, the amount of displacement in the width direction of the strip, and the width of the strip. There is disclosed a technique of detecting a crown difference in a direction and controlling a leveling amount of an i-th stand based on the detected crown difference.
[0005]
Further, Japanese Patent Application Laid-Open No. H11-151514 discloses that the width and meandering amount of a strip 202 are measured by an electromagnetic type position detector 205 installed on the exit side of an i-th stand, as shown in FIG. measuring the total tension and differential tension of the strip 202 with a tension meter 204 installed on the exit side of the i-stand, controlling the leveling of the i-th stand based on the measured values, Measuring the amount of meandering of the strip 202 by the position detector 205 of the type, and controlling the position of the uncoiler 208 based on the measured value. In FIG. 3, reference numeral 201 denotes a rolling mill, 203 denotes a rolling direction, 206 denotes a calculator, and 207 denotes a leveling device. The total tension is obtained by measuring the tension at both ends (work side end and drive side end) of a single stand and calculating the sum of the measured tensions.
[0006]
Japanese Patent Application Laid-Open No. Hei 7-124620 discloses that the working side tensions T _0WS , T _1WS and the driving side tensions T _0DS , T _1WS of the strip 302 on the entrance side and the exit side of the rolling stand 301, respectively, as shown in FIG. calculating _1DS measuring the respective tension gauge _{303 0WS, 303 1WS,} and _{303 0DS,} 303 _1DS, strip working side tension _{T 0WS, T 1WS} the strip drive side tension _{T 0DS,} difference tension [Delta] T ₀ and _{T 1DS,} the [Delta] T ₁ tension deviation calculating unit ₃₀₄ 0 to 304 ₁ and the difference tension [Delta] T _0, and leveling amount computing unit ₃₀₅ 0, 305 ₁ for calculating a pressing position control amount based on the [Delta] T _1, the entry side and pressing position control amount of the exit side a control leveling amount calculator 306 for calculating the work side leveling amount [Delta] S _WS and drive side leveling amount [Delta] S _DS based on, work Meandering controller having a side leveling amount [Delta] S _WS and respective rolling position controller 307 controls the pressing position of the rolling stands 301 based on W of the drive-side leveling amount [Delta] S _DS, 307 _D is disclosed.
[0007]
[Problems to be solved by the invention]
However, these conventional strip meandering control devices and meandering control methods have the following problems.
That is, when the meandering control is performed by using the equation (1) shown in FIG. 2, the meandering control method disclosed in JP-A-63-188415, and in the JP-A-11-151514 shown in FIG. In the case of the meandering control method disclosed in Japanese Patent Application Laid-Open No. H11-260, it is necessary to measure the amount of deviation in the width direction of the plate (the amount of meandering of the plate) between the rolling stands or at the exit side of the rolling stand. Is very difficult in a cold rolling mill, and there is a problem that a substantial remodeling is required in practice.
[0008]
Further, in the meandering control method disclosed in Japanese Unexamined Patent Publication No. Hei 7-124620 shown in FIG. 4, the control leveling amount calculator 306 controls the working side leveling amount based on the entrance side and exit side rolling down position control amounts. Although ΔS _WS and the drive-side leveling amount ΔS _DS are calculated, there is a possibility that abnormal control such as hunting may be caused because the system outputs one input from two inputs.
[0009]
Therefore, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to measure a meandering amount of a plate between rolling stands or at the exit side of a rolling stand, and to perform abnormal control such as hunting. An object of the present invention is to provide a meandering control device and a meandering control method for a strip in a tandem rolling mill, which can surely prevent the meandering of the strip without causing the meandering.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a meandering control apparatus for a strip in a tandem rolling mill according to claim 1 of the present invention is a strip tandem rolling mill provided with a meandering correction roll installed on an entrance side of the tandem rolling mill. A meandering control device, based on tension measuring means for measuring a working side tension and a driving side tension of the strip at a rolling stand exit side of the tandem rolling mill, respectively, based on each tension of the strip measured by the tension measuring means. Calculating means for calculating a differential tension between the strip working side tension and the strip driving side tension; determining means for determining whether the differential tension calculated by the calculating means is within a predetermined range; When it is determined that the differential tension is out of the predetermined range, the rolling stand is adjusted so that the differential tension is within the predetermined range. Leveling control means for performing ring control, and the meandering correction roll so that the meandering amount falls within a predetermined range based on the meandering amount of the strip detected by the plate position detector installed on the entry side of the rolling stand. Controlling the operation, and operating the meandering correction roll so that the meandering amount of the strip falls within a predetermined range based on the difference tension when the determining means determines that the differential tension is outside a predetermined range. And a meandering correction roll operation control means for controlling the operation.
[0011]
A meandering control method of a strip in a tandem rolling mill according to claim 2 of the present invention includes a step of measuring a working side tension and a driving side tension of the strip at a rolling stand exit side of the tandem rolling mill, respectively, A step of calculating a difference tension between the strip operation side tension and the strip driving side tension based on each tension; a step of determining whether the difference tension is within a predetermined range; and Performing a leveling control of the rolling stand such that the differential tension falls within a predetermined range when the deviation is within a predetermined range; and, when the differential tension deviates from the predetermined range, a meandering amount of the strip is determined based on the differential tension. Controlling the operation of the meandering correction roll so as to be inside.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram of the meandering control device according to the present invention.
In FIG. 1, a strip 2 is unwound from an uncoiler (not shown), is conveyed in the direction of arrow A via a meandering correction roll 11, and is rolled by a tandem rolling mill including a plurality of rolling stands 1.
[0013]
The meandering correction roll operation cylinder 10 for operating the meandering correction roll 11 is connected to the meandering correction roll 11, and the meandering correction roll operation controller 8 is connected to the meandering correction roll operation cylinder 10. A plate position detector 9 that detects the amount of meandering ΔW of the strip 2 that has passed through the meandering correction roll 2 is provided slightly downstream of the meandering correction roll 11 and on the entry side of the rolling stand 1. The plate position detector 9 is connected to the meandering correction roll operation controller 8, and the meandering amount ΔW of the strip 2 detected by the plate position detector 9 is sent to the meandering correction roll operation controller 8. The meandering correction roll operation controller 8 normally calculates the movement amount Δd ₁ of the meandering correction roll 11 in which the meandering amount ΔW of the strip 2 is within a predetermined range based on the detected meandering amount ΔW of the strip 2, The calculation result is sent to the meandering correction roll operation cylinder 10 to control the operation of the meandering correction roll 11. The operation of the meandering correction roll 11 is controlled so that the meandering amount ΔW of the strip 2 is, for example, within 10 mm.
[0014]
On the other hand, on the output side of each rolling stand 1 (in FIG. 1, the output side of the i-th stand and the (i + 1) _-th stand), a working-side tensiometer 3a for measuring the working-side tension Tws of the strip 2 and the strip 2 are provided. a drive-side tensiometer 3b for measuring the driving-side tension T _DS is installed in. The working-side tensiometer 3a and the driving-side tensiometer 3b constitute "tension measuring means" defined in claim 1. As each of the tension meters 3a and 3b, a conventionally known device that measures a vertical load using a load cell, for example, and detects a strip tension based on a fixed contact angle of the strip 2 is used.
[0015]
These tensiometers 3a and 3b are provided to appropriately maintain the tension between the rolling stands 1 and 1, but in the present invention, they are also used for the meandering control of the strip 2.
The working side tensiometer 3a and the drive-side tensiometer 3b, the difference tension calculator 4 for calculating the strip working side tension _{T ws} and difference tension [Delta] T _i of the strip drive side tension _{T DS (= T ws -T DS} ) is It is connected. The differential tension calculator 4 constitutes "calculating means" defined in claim 1.
[0016]
Further, the differential tension calculator 4 is connected to a determiner 5 for determining whether or not the differential tension ΔT _i calculated by the differential tension calculator 4 is within a predetermined range. Determining unit 5, the result of differential tension [Delta] T _i is determined whether or not within the predetermined range, the difference tension [Delta] T _i is the data signal value of the signal and the difference tension [Delta] T _i of that effect in the case of out of the predetermined range sent to each of the later-described leveling controller 6 and meandering correction roll motion controller 8, the difference tension [Delta] T _i when is within the predetermined range, Belling controller 6 and meandering correction roll motion controller a signal indicating that 8 To each of them. This determiner 5 constitutes “determination means” defined in claim 1. The reference in the case where the difference tension [Delta] T _i is whether within a predetermined range, becomes within a predetermined range in the following cases the difference tension [Delta] T _i, for example -5t than 5t, a predetermined range otherwise.
[0017]
In addition, based on the signal from the determiner 5, when the differential tension ΔT _i is out of the predetermined range, the determiner 5 provides the working-side leveling amount ΔS _WS and the drive-side leveling amount in which the differential tension ΔT _i falls within the predetermined range. A leveling controller 6 for calculating ΔS _DS is connected. The leveling controller 6 outputs the working-side leveling amount ΔS _WS and the driving-side leveling amount ΔS _DS to the working-side rolling-down position controller 7a and the driving-side rolling-down position controller 7b provided in the rolling stand 1, respectively. The leveling control of the rolling stand 1 is performed. This leveling controller 6 constitutes “leveling control means” defined in claim 1. When the differential tension ΔT _i is within the predetermined range, the leveling controller 6 sets the working-side leveling amount ΔS _WS and the driving-side leveling amount ΔS _DS to 0, and does not perform leveling control.
[0018]
The above-mentioned meandering correction roll operation controller 8 is connected to the determiner 5. The meandering correction roll operation controller 8 normally calculates the movement amount Δd ₁ of the meandering correction roll 11 in which the meandering amount ΔW of the strip 2 is within a predetermined range based on the detected meandering amount ΔW of the strip 2, The calculation result is sent to the meandering correction roll operation cylinder 10 to control the operation of the meandering correction roll 11, but based on a signal from the determiner 5, when the differential tension ΔT _i is out of the predetermined range, Based on the differential tension ΔT _i , the moving amount Δd ₂ of the meandering correction roll 11 in which the meandering amount ΔW of the strip 2 falls within a predetermined range is calculated, and the calculation result is sent to the meandering correcting roll operation cylinder 10 to correct the meandering. The operation of the roll 11 is controlled. The meandering correction roll operation controller 8 constitutes “meandering correction roll control means” defined in claim 1.
[0019]
As described above, when the difference tension ΔT _i is out of the predetermined range, the control reference in the meandering roll operation controller 8 is switched from the meandering amount ΔW of the strip 2 to the difference tension ΔT _i because the difference tension ΔT _i is within the predetermined range. If it is outside, the meandering amount of the strip 2 becomes large, and the meandering amount of the strip 2 cannot be detected by the plate position detector 9.
[0020]
When the differential tension ΔT _i is out of the predetermined range, not only the leveling control of the rolling stand 1 but also the operation of the meandering correction roll 11 to control the meandering amount of the strip 2 This is because it is difficult to reliably correct the meandering of the strip 2 using only the leveling control.
Next, a method of meandering control of the strip 2 will be specifically described.
[0021]
In FIG. 1, the meandering correction roll operation controller 8 normally includes a meandering correction roll 11 in which the meandering amount ΔW of the strip 2 is within a predetermined range based on the meandering amount ΔW of the strip 2 detected by the plate position detector 9. and of calculating the amount of movement [Delta] d _1, so as to control the operation of the meandering correction roller 11 and sends the calculation result to the meandering correction roll operating cylinder 10. The operation of the meandering correction roll 11 is controlled so that the meandering amount ΔW of the strip 2 is, for example, within 10 mm.
[0022]
Then, the working side tension T _ws and the drive-side tension T _DS of the strip 2 that is output measured by the installed working side tensiometer 3a and the drive-side tensiometer 3b Zhang side of the i stands, the difference tension calculator 4 Sent out. The differential tension calculator 4 calculates a differential tension ΔT _i (= T _ws −T _DS ) based on the working-side tension T _ws and the driving-side tension T _DS . Then, the differential tension calculator 4 sends the data of the value of the differential tension ΔT _i to the determiner 5.
[0023]
The determiner 5 determines whether or not the differential tension ΔT _i calculated by the differential tension calculator 4 is within a predetermined range. Here, the criterion for determining whether the differential tension ΔT _i is within the predetermined range is within the predetermined range when the differential tension ΔT _i is, for example, -5t or more and 5t or less, and is outside the predetermined range otherwise. . When the differential tension ΔT _i is larger than 5t or smaller than −5t, the meandering of the strip 2 in the rolling mill increases, and the rolling shape of the strip 2 also becomes one-sided with the meandering, and the drawing fracture occurs. Because you do. In addition, a phenomenon such as squeezing due to the meandering of the strip 2 occurs, which causes a large rolling trouble.
[0024]
Then, the decision unit 5, as a result of differential tension [Delta] T _i is determined whether or not within the predetermined range described above, when the difference tension [Delta] T _i is out of the predetermined range, i.e., or greater than the difference tension [Delta] T _i is 5t It is smaller than -5t sends a data signal value of the signal and the difference tension [Delta] T _i to that effect to the respective leveling control unit 6 and the meandering correction roll motion controller 8. The determination unit 5, when the difference tension [Delta] T _i is within a predetermined range, i.e. when the difference tension [Delta] T _i is 5t inclusive -5t is Belling control signal indicating the difference tension [Delta] T _i is within a predetermined range To the control unit 6 and the meandering correction roll operation controller 8, respectively.
[0025]
In the leveling controller 6, based on a signal from the determination unit 5, when the difference tension [Delta] T _i is out of the predetermined range, the working side leveling amount [Delta] S _WS and drive side leveling amount [Delta] S difference tension [Delta] T _i is within a predetermined range Calculate _DS . That is, when the differential tension ΔT _i is greater than 5t, the leveling controller 6 calculates the work-side tightening amount G _WS as the work-side leveling amount ΔS _WS and calculates 0 as the drive-side leveling amount ΔS _DS . output to each of the working side tightening amount G _WS and 0 working side pressure under the position of the drive-side leveling amount [Delta] S _DS controller 7a and the drive side pressure under the position controller 7b as a working side leveling amount [Delta] S _WS, the i stand Is performed. When the differential tension ΔT _i is −5 t or more and 5 t or less, the leveling controller 6 sets the working-side leveling amount ΔS _WS and the driving-side leveling amount ΔS _DS to 0, since the difference is within a predetermined range. Leveling control of the i-stand is not performed. Further leveling controller 6, when the difference between the tension [Delta] T _i is -5t smaller calculates the working side tightening amount 0 as a work side leveling amount [Delta] S _WS, calculate the _{G DS} as the drive-side leveling amount [Delta] S _DS, output to each of the working side leveling amount working side tightening amount 0 and G _DS working side pressure under the position of the drive-side leveling amount [Delta] S _DS controller 7a and the drive side pressure under the position controller 7b as [Delta] S _WS, the i stand Is performed. As a result, the meandering of the strip 2 in the rolling mill can be reduced to some extent, and the half-stretching phenomenon of the strip 2 caused by the meandering can be suppressed to some extent.
[0026]
Then, in the meandering correction roll operation controller 8, based on the signal from the determiner 5, when the differential tension ΔT _i is within a predetermined range, that is, when the differential tension ΔT _i is not less than −5 t and not more than 5 t, the above-described operation is performed. The control of the operation of the meandering correction roll 11 based on the meandering amount ΔW of the strip 2 is continued, and the meandering amount ΔW of the strip 2 becomes within a predetermined range, that is, within 10 mm based on the detected meandering amount ΔW of the strip 2. The movement amount Δd ₁ of the roll 11 is calculated, and the calculation result is sent to the meandering correction roll operation cylinder 10 to control the operation of the meandering correction roll 11.
[0027]
Then, based on the signal from the determiner 5, the meandering correction roll operation controller 8 determines that the differential tension ΔT _i is out of the predetermined range, that is, when the differential tension ΔT _i is larger than 5t, the differential tension ΔT _i. , The amount of movement Δd ₂ of the meandering correction roll 11 in which the meandering amount ΔW of the strip 2 is within a predetermined range, that is, within 10 mm (in this case, the strip 2 is moved toward the working side), and the calculation result is referred to as meandering. It is sent to the correction roll operation cylinder 10 to control the operation of the meandering correction roll 11. When the differential tension ΔT _i is out of the predetermined range, that is, when the differential tension ΔT _i is smaller than −5t, the meandering correction roll operation controller 8 sets the meandering amount ΔW of the strip 2 based on the differential tension ΔT _i. The movement amount Δd ₂ (in this case, the strip 2 is moved to the drive side) of the meandering correction roll 11 that is within a predetermined range, that is, within 10 mm, is calculated, and the calculation result is sent to the meandering correction roll operation cylinder 10 to meander. The operation of the correction roll 11 is controlled.
[0028]
As described above, when the differential tension ΔT _i is out of the predetermined range, not only the leveling control of the rolling stand 1 but also the operation of the meandering correction roll 11 is controlled to control the meandering amount of the strip 2, so that the inside of the rolling mill can be controlled. Of the strip 2 can be completely prevented, and the one-stretch phenomenon of the strip 2 caused by the meandering can also be completely prevented. The leveling control of the rolling stand 1, the difference tension [Delta] T _i is within a predetermined range, i.e. if the difference tension [Delta] T _i is equal to or less than 5t above -5T, meandering correction roll operation controller 8, based on a signal from the determination unit 5, the strip The control returns to the control of the operation of the meandering correction roll 11 based on the meandering amount ΔW of No. 2.
[0029]
The leveling control of the (i + 1) th stand is performed in the same manner as the leveling control of the (i) th stand.
In the present invention, when the difference between the tension [Delta] T _i at the delivery side of the rolling stand 1 is out of the predetermined range, the leveling control based on the difference tension [Delta] T _i and the operation control of the meandering correction roller 11 based on the difference tension [Delta] T _i The meandering of the strip 2 in the rolling mill can be completely prevented by using together, so that in the meandering control of the strip 2, the deviation amount of the plate in the width direction between the rolling stands or at the exit side of the rolling stand (the meandering of the plate) It is not necessary to measure the amount and the like, and there is no possibility of causing abnormal control such as hunting since the system does not output one output from two inputs.
[0030]
The embodiment of the present invention has been described above, but the present invention is not limited to this, and various changes can be made.
For example, the leveling control is performed so that the differential tension ΔT _i is within a range of −5 t to 5 t, but the range is appropriately changed in consideration of the material, the plate width, the plate thickness, the unit tension, and the like of the strip 2. can do. The operation of the meandering correction roll 11 is controlled so that the meandering amount of the strip 2 is within 10 mm, but the range is appropriately changed in consideration of the material, the width, the thickness, the unit tension, and the like of the strip 2. can do.
[0031]
【The invention's effect】
As described above, according to the meandering control device and the meandering control method for preventing the strip from meandering in the tandem rolling mill according to the present invention, the working side tension and the drive side tension of the strip on the exit side of the rolling stand of the tandem rolling mill are reduced. Each of them is measured, and based on each of the measured tensions of the strip, a difference tension between the strip working side tension and the strip driving side tension is calculated, and it is determined whether the difference tension is within a predetermined range, and the difference is determined. When the tension deviates from a predetermined range, the leveling control of the rolling stand is performed so that the differential tension falls within a predetermined range. When the differential tension deviates from a predetermined range, the meandering amount of the strip is determined based on the differential tension. The operation of the meandering correction roll is controlled so that the value falls within a predetermined range. Without measuring the amount, and without causing abnormal control such as hunting, it is possible to reliably prevent meandering of the strip.
[Brief description of the drawings]
FIG. 1 is a system diagram of a strip meandering control apparatus according to the present invention.
FIG. 2 is a schematic diagram for explaining a conventional strip meandering control method.
FIG. 3 is a schematic diagram for explaining a strip meandering control method according to another conventional example.
FIG. 4 is a schematic diagram for explaining a strip meandering control method according to still another conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rolling stand 2 Strip 3a Work side tension meter 3b Drive side tension meter 4 Differential tension calculator (calculation means)
5 Judgment device (judgment means)
6. Leveling controller (leveling control means)
7a Work-side rolling position controller 7b Drive-side rolling position controller 8 Meandering correction roll operation controller (meandering correction roll operation control means)
9 plate position detector 10 meandering correction roll operation cylinder 11 meandering correction roll

Claims (2)

A meandering control device for a strip in a tandem rolling mill having a meandering correction roll installed on an entrance side of a tandem rolling mill,
Tension measuring means for measuring the working-side tension and the driving-side tension of the strip on the rolling stand exit side of the tandem rolling mill, respectively.
Calculating means for calculating a differential tension between the strip working side tension and the strip driving side tension based on each of the strip tensions measured by the tension measuring means;
Determining means for determining whether the differential tension calculated by the calculating means is within a predetermined range,
When the determining means determines that the differential tension is outside a predetermined range, a leveling control means for performing leveling control of the rolling stand such that the differential tension is within a predetermined range,
The operation of the meandering correction roll is controlled so that the meandering amount is within a predetermined range based on the meandering amount of the strip detected by the plate position detector installed on the entrance side of the rolling stand, and the determination means When it is determined that the differential tension is out of the predetermined range, a meandering correction roll operation control unit that controls the operation of the meandering correction roll based on the differential tension so that the meandering amount of the strip falls within the predetermined range. A meandering control device for a strip in a tandem rolling mill. A step of measuring the working side tension and the drive side tension of the strip at the rolling stand exit side of the tandem rolling mill, respectively,
Based on each measured tension of the strip, a step of calculating a difference tension between the strip working side tension and the strip drive side tension,
Determining whether the differential tension is within a predetermined range;
When the differential tension deviates from a predetermined range, a step of performing leveling control of the rolling stand so that the differential tension is within a predetermined range,
Controlling the operation of the meandering correction roll such that the meandering amount of the strip falls within a predetermined range based on the difference tension when the differential tension deviates from a predetermined range. A meandering control method for a strip in a rolling mill.

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