JP6323384B2 - Steel plate meander control method, steel plate meander control device, and steel plate manufacturing method - Google Patents

Description

  The present invention relates to a meandering control method of a steel plate, a meandering control device for a steel plate, and a meandering control device for a steel plate, which controls the meandering amount of a steel plate by manipulating the leveling amount of a continuous rolling mill comprising a plurality of rolling stands arranged in the conveying direction of the steel plate, and The present invention relates to a method of manufacturing a steel plate.

  When rolling a steel sheet using a continuous rolling mill, the center position in the width direction of the steel sheet deviates from the rolling center position (mill center position) of the rolling roll, and the steel sheet moves toward the end in the width direction of the rolling roll. A meandering phenomenon of the steel sheet may occur. When such a meandering phenomenon occurs, the load applied to the housing of the continuous rolling mill on the side to which the steel plate has moved is greater than the load applied to the housing on the other side. It becomes larger than the mill elongation at the side, and as a result, the meandering phenomenon is further promoted.

  When the meandering phenomenon of a steel plate occurs, a plate thickness difference occurs in the width direction of the steel plate, and the quality of the steel plate deteriorates. In addition, when the amount of meandering of the steel sheet increases, the steel sheet comes into contact with the side guide, resulting in narrowing of the rolled steel sheet in a bent state, wrinkling of the rolling roll, and a reduction in steel sheet productivity. There are things to do. The meandering phenomenon is likely to occur particularly when the tail end portion of the steel sheet passes through the rolling roll, in other words, when there is no tension of the steel sheet on the entry side of the rolling roll.

  For this reason, when rolling a steel sheet using a continuous rolling mill, the difference between the rolling load on the working side of the rolling roll and the rolling load on the driving side is measured, and the working side is determined from the measured rolling differential load. By estimating the difference between the mill elongation and the drive side mill elongation, and operating the difference between the work side roll opening and the drive side roll opening based on the estimated mill elongation difference, that is, the leveling amount, A meandering control method for suppressing the meandering amount of the steel sheet is applied. This meandering control method is also called a parallel stiffness control method and is the most common control method. In addition, in this specification, the drive side of a rolling roll means the side where the drive motor in a rolling roll is attached, and the working side of a rolling roll is the opposite side to the driving side in a rolling roll. Means that.

  In addition to the meandering control method of the parallel stiffness control method described above, the amount of meandering of the steel sheet on the entry side or the exit side of the rolling roll and its first-order differential value are measured, and the steel sheet is measured based on the measured value. There has also been proposed a method of adjusting the leveling amount so that the meandering amount is within an allowable range within a predetermined time (see Patent Document 1). Also, the theoretical value of the difference between the advance coefficient and the reverse coefficient of the steel sheet between the end portions in the width direction of the rolling roll is calculated based on the rolling theory, and the difference between the advanced coefficient and the reverse coefficient is zero based on the calculation result. A method for adjusting the leveling amount has also been proposed (see Patent Document 2).

  Also, based on a method using an optimal regulator that corrects the leveling amount so that the value of the evaluation function with the amount of meandering and leveling of the steel plate measured based on the meandering motion model as a variable is minimized, and from the rolling differential load of the rolling roll There has also been proposed a method using an optimal regulator that estimates the meandering amount of a steel sheet and corrects the leveling amount so that the value of the evaluation function with the estimated meandering amount and leveling amount as variables is minimized (Patent Document 3). reference).

  In addition, using a meandering motion model in which the meandering motion model directly under one rolling stand and the motion of the upstream steel plate are coupled, the meandering amount of the steel plate directly under the rolling stand and the entry side from the rolling differential load according to the observer theory There has also been proposed a method for calculating a leveling amount by estimating angles and applying an optimum gain based on the optimum regulator theory to these estimated values (see Patent Document 4).

JP-A-3-90207 Japanese Patent Laid-Open No. 10-5840 JP 2004-74207 A JP 2014-117743 A

  However, in the meandering control method of the parallel stiffness control method, if the control gain is increased too much, the amount of meandering becomes larger. Therefore, the control gain needs to be set small, and the sufficient meandering suppression capability cannot be exhibited. In addition, the meandering control method described in Patent Document 1 cannot be applied to on-line meandering control because the leveling amount calculation process for suppressing the meandering amount within a predetermined range is very complicated.

  In order to solve such a problem, a method of performing meandering control online using a table in which solutions of some leveling amounts calculated offline in advance are described. However, when this method is used, a very large table must be prepared in order to output an appropriate leveling amount for various rolling conditions, which is not realistic.

  On the other hand, since the meandering control method described in Patent Document 2 adjusts the leveling amount based on the advanced coefficient and the reverse coefficient of the steel sheet, the meandering quantity of the steel sheet cannot be estimated. Further, in the meandering control method described in Patent Document 2, since the model representing the amount of meandering of the steel plate in the continuous rolling mill is a static (steady) model, modern control such as an optimal regulator, state feedback, and observer is performed. The theoretical control method cannot be used, and control optimization is difficult. Furthermore, in the meandering control method described in Patent Document 2, there is a concern that the calculation reliability is lowered because the camber and rigidity of the steel plate between the rolling stands are not taken into consideration.

  Further, in the meandering control method described in Patent Document 3, since the model representing the meandering amount of the steel plate in the continuous rolling mill is a model based on kinematics, it is not possible to use dynamic information such as a rolling differential load. It is necessary to install a meandering meter for measuring the amount of meandering of the steel sheet. In addition, in the meandering control method described in Patent Document 3, since the mathematical formula representing the rotation speed of the steel plate of the continuous rolling mill has been simplified, the parameter of the mathematical formula representing the rotation speed of the steel plate under the new rolling conditions is changed to the rolling condition. It needs to be adjusted according to the situation and requires a lot of labor.

  In addition, the meandering control method described in Patent Document 4 is intended for the state immediately before the steel plate passes through the rolling stand, and therefore there is a concern that the model correction time by the observer is short and the calculation reliability is low.

  The present invention has been made in view of the above problems, and an object thereof is to provide a meandering control method for a steel plate and a meandering control device for a steel plate capable of optimally controlling the meandering amount of the steel plate online. Another object of the present invention is to provide a method of manufacturing a steel plate that can manufacture a steel plate by optimally controlling the meandering amount of the steel plate online.

  The meandering control method for a steel sheet according to the present invention is a meandering control method for a steel sheet that controls the meandering amount of a steel sheet by manipulating the leveling amount of a continuous rolling mill provided with a plurality of rolling stands arranged in the conveying direction of the steel sheet. A rolling differential load detection step for detecting a difference between a rolling load on the work side of the rolling roll and a rolling load on the driving side as a rolling differential load, and a load distribution detection for detecting a load distribution acting on a looper between the rolling stands. Step, and the rolling differential load detected in the rolling differential load detection step and the load distribution detection step, and the load distribution acting on the looper, the meandering amount of the steel plate and the approach angle of the steel plate to the rolling roll. Based on the estimation step of estimating the incoming side angle, the meandering amount of the steel sheet estimated in the estimating step, the incoming side angle and the integral value of the meandering amount A meandering control step of operating the serial leveling amount, characterized in that it comprises a.

  In the above invention, the meandering control method for a steel sheet according to the present invention includes a meandering amount detection step for detecting a meandering amount between rolling stands, and the estimation step is detected in the rolling differential load detection step and the load distribution detection step. The meandering amount and the entrance angle of the steel sheet are estimated using the rolling difference load and the load distribution acting on the looper and the meandering amount between the rolling stands detected in the meandering amount detection step. And

  The meandering control method for a steel sheet according to the present invention includes a camber amount detecting step for detecting a camber amount of the steel sheet on the entry side of the most upstream rolling stand in the above invention, wherein the estimating step includes the rolling differential load detecting step and The rolling differential load detected in the load distribution detecting step and the load distribution acting on the looper, the meandering amount between rolling stands detected in the meandering amount detecting step, and the camber of the steel plate detected in the camber amount detecting step The amount of meandering of the steel sheet and the angle of entry side are estimated using the quantity.

  The meandering control method for a steel sheet according to the present invention includes a wedge amount detection step of detecting a wedge amount of the steel plate on the entry side of the most upstream rolling stand in the above invention, wherein the estimation step includes the rolling differential load detection step and The rolling differential load detected in the load distribution detecting step and the load distribution acting on the looper, the meandering amount between rolling stands detected in the meandering amount detecting step, and the camber of the steel plate detected in the camber amount detecting step The meandering amount of the steel plate and the entry side angle are estimated using the amount and the wedge amount of the steel plate detected in the wedge amount detection step.

  A meandering control device for a steel plate according to the present invention is a meandering control device for a steel plate that controls the meandering amount of a steel plate by operating the leveling amount of a continuous rolling mill having a plurality of rolling stands arranged in the conveying direction of the steel plate. A rolling difference load detecting means for detecting a difference between a rolling load on the working side of the rolling roll and a rolling load on the driving side as a rolling difference load, and a load distribution detection for detecting a load distribution acting on a looper between the rolling stands. Means, the rolling differential load detected by the rolling differential load detection means and the load distribution detection means, and the load distribution acting on the looper, the meandering amount of the steel sheet and the angle of approach of the steel sheet to the rolling roll. The leveling amount is manipulated based on an estimation means for estimating the incoming side angle, and the meandering amount of the steel sheet estimated by the estimating means, the incoming side angle and an integral value of the meandering amount. Characterized in that it comprises a meander control means.

  The steel sheet manufacturing method according to the present invention includes a step of manufacturing a steel sheet while controlling a continuous rolling mill using the steel plate meandering control method according to the present invention.

  According to the meandering control method and the meandering control device for a steel sheet according to the present invention, the meandering amount of the steel sheet can be optimally controlled online without requiring labor. Moreover, according to the steel plate manufacturing method of the present invention, the steel plate can be manufactured by optimally controlling the meandering amount of the steel plate online without requiring labor.

FIG. 1 is an input / output block diagram showing a configuration of a rolling mill meandering model. FIG. 2 is an input / output block diagram showing the configuration of the rolling mill stiffness model. FIG. 3 is an input / output block diagram showing the configuration of a coupled model of a rolling mill meandering model and a rolling mill stiffness model. FIG. 4 is an input / output block diagram of the rolling stand model. FIG. 5 is a schematic diagram showing a steel plate between rolling stands. FIG. 6 is an input / output block diagram showing the configuration of the steel plate deformation model. FIG. 7 is an input / output block diagram showing the configuration of a coupled model of a steel plate deformation model, a wedge advection model, a camber advection model, and a tension control model. FIG. 8 is an input / output block diagram showing the configuration of the steel plate model. FIG. 9 is an input / output block diagram showing a configuration of a meandering model of a steel plate in a continuous rolling mill. FIG. 10 is an input / output block diagram showing a configuration of a meandering model of a steel plate in a continuous rolling mill to which a meandering controller is added. FIG. 11 is an input / output block diagram showing the configuration of a coupled model of a steel plate meandering model and a rolling mill rigidity model in a continuous rolling mill to which an observer is added. FIG. 12 is an input / output block diagram showing a configuration of a rolling stand model to which an observer is added. FIG. 13 is an input / output block diagram showing a configuration of a meandering model of a steel plate in a continuous rolling mill. FIG. 14 is a schematic diagram for explaining a load acting on the looper. FIG. 15 is an input / output block diagram showing a configuration of a meandering model of a steel plate in a continuous rolling mill. FIG. 16 is an input / output block diagram showing the configuration of the meandering controller of the entire rolling stand of the continuous rolling mill. FIG. 17 is a schematic diagram showing a configuration of a continuous rolling mill having six rolling stands.

  Hereinafter, the concept of the meandering control method for a steel sheet according to the present invention will be described.

  First, a dynamic model of the meandering motion of a steel plate in a continuous rolling mill composed of a plurality of rolling stands arranged in the steel plate conveyance direction will be described.

Now, in each rolling stand, _assuming that the steel plate directly under the rolling roll does not slide in the width direction (the movement speed in the width direction is zero), the meandering amount w _{n at the} center in the width direction of the steel plate is _expressed by the following formula (1 ). Here, in Equation (1), v _c0 is the speed of the central portion in the width direction of the steel plate on the exit side of the rolling stand (outside plate speed), and θ ₁ is the width of the steel plate relative to the center line in the width direction of the rolling roll on the entrance side of the rolling stand. The angle of the center line in the direction (entrance side angle), λ is the thickness of the central part in the width direction of the steel sheet at the entrance side of the rolling stand relative to the thickness of the central part in the width direction of the steel sheet at the exit side of the rolling stand (outside plate thickness) (Thickness) ratio.

The ratio λ of the inlet side plate thickness with respect to the outlet side plate thickness is expressed as the following formula (2), where h _c0 is the outlet side plate thickness and h _c1 is the inlet side plate thickness.

The entry-side angle θ ₁ is expressed as the following formula (3). Here, in Equation (3), ψ ₁ indicates the rotational angular velocity (entrance side angular velocity) of the steel plate on the rolling stand entry side, and ρ _c1 indicates the curvature (entrance side camber) of the steel plate on the rolling stand entry side.

The angle (exit side angle) θ ₀ of the width direction center line of the steel sheet with respect to the width direction center line of the rolling roll on the exit side of the rolling stand is expressed by the following equation (4) using the input side angle θ _1. (See "Theory and Practice of Plate Rolling", p.241, "Conditions for Centerline Gradient").

For the curvature of the steel sheet on the exit side of the rolling stand ( _outside camber) ρ _c0 , the following equation (5) holds kinetically (“Theory and practice of sheet rolling”, page 241 “Camber curve connection conditions” "reference). Here, in Formula (5), Ψ ₀ indicates the rotational angular velocity (exit side angular velocity) of the steel plate on the exit side of the rolling stand.

Therefore, a kinematic state space model of the meandering motion of the steel sheet is constructed using the above mathematical formula. Specifically, the thrust direction constraint equation shown in Equation (1), the input side angular velocity ψ ₁ and the input side camber ρ _c1 shown in Equation (3), the output side angle θ ₀ and the input side shown in Equation (4) From the relational expression of the angle θ ₁ and the expression of the outgoing camber ρ _c0 shown in the equation (5), the kinematic state space model of the meandering motion of the steel plate is expressed by the following equations (6) and (7): expressed.

Next, the exit angular velocity Ψ ₀ is calculated from the primary rolling theory using the following formula (8). Here, in Equation (8), v _x0 represents the speed of the steel sheet at the rolling stand exit side, f _s represents the advance rate, v _R represents the peripheral speed of the rolling roll of the rolling stand, and y represents the position in the width direction of the steel sheet. .

For the advanced rate f _s , the following formula (9) is established. Here, in Formula (9), h ₀ is the plate thickness of the steel plate on the rolling stand exit side, h ₁ is the plate thickness of the steel plate on the entrance side of the rolling stand, σ ₀ is the tension on the exit side of the rolling stand (exit side tension), σ ₁ indicates the entry side tension on the entry side of the rolling stand.

  Substituting Equation (9) into Equation (8) yields Equation (10) shown below.

The thickness h ₀ , h ₁ of the steel plate at the exit side and the entrance side of the rolling stand and the tension (exit side tension, entrance side tension) σ ₀ , σ _{1 at} the exit side and the entrance side of the rolling stand with respect to the width direction of the steel plate As a result, the following formulas (11) and (12) are established. Here, in Equations (11) and (12), b is the sheet width of the steel sheet, h _0df is the amount of wedge of the steel sheet on the exit side of the rolling stand (exit side wedge), and h _1df is the amount of wedge of the steel sheet on the entrance side of the rolling stand. (Entrance on the entry side), M ₀ represents the moment amount of the steel sheet on the exit side of the rolling stand (exit side moment), and M ₁ represents the amount of moment of the steel sheet on the entry side of the rolling stand (entrance on the entry side).

As a result, by substituting the equations (11) and (12) into the equation (10), the outgoing angular velocity Ψ ₀ can be obtained as shown in the following equation (13). Here, in Equation (13), k is the deformation resistance of the steel sheet, β _h0df (=-(h _c0 / (1 + f _s )) (δf _s / δh ₀ )) is the influence coefficient for the outlet wedge h _0df , β _h1df (=-(h _c0 / (1 + f _s )) (δf _s / δh ₁ )) is the influence coefficient for the entrance wedge h _1df , β _M0 (=-(k / (1 + f _s )) ( δf _s / δσ ₀ )) is the influence coefficient for the outgoing moment M ₀ , β _M1 (=-(k / (1 + f _s )) (δf _s / δσ ₁ )) is the influence coefficient for the incoming moment M ₁ Show.

Next, the incoming side angular velocity Ψ ₁ is calculated. The relationship shown in the following formula (14) is established between the exit side wedge h _0df and the entrance side wedge h _1df (see “Theory and Practice of Sheet Rolling”, page 241, “Volume Invariance Principle”).

As a result, when the formula (13) is substituted into the formula (14), the incoming angular velocity Ψ ₁ can be obtained as the following formula (15).

  Therefore, the following formulas (16) and (17) are obtained by substituting the formulas (13) and (15) into the formulas (6) and (7).

  The above mathematical formulas (16) and (17) are dynamic state space models of the meandering motion of the steel sheet, whereby the meandering model of the steel sheet in the rolling stand (roller meander model) is expressed as shown in FIG. Is done.

On the other hand, the parallel rigidity model (rolling mill rigidity model) of the rolling stand is expressed as shown in the following equations (18) and (19) and FIG. Here, in Equations (18) and (19), P is the rolling load of the rolling stand, P _df is the rolling differential load of the rolling stand, K _l is the mill parallel rigidity, and M _l is the parallel plasticity of the steel plate on the exit side of the rolling stand. Constant (outgoing steel plate parallel plastic constant), M _l ^′ is the parallel plastic constant of the steel plate at the entrance of the rolling stand (incoming steel plate parallel plastic constant), b _l is the screw spacing of the rolling stand, S _df is the screw position of the rolling stand The roll opening difference (leveling amount, leveling difference) and κ _r in Fig. 2 indicate the maximum bending curvature of the work roll.

  FIG. 3 shows the configuration of a coupled model of a rolling mill meandering model and a rolling mill stiffness model. When the coupled model shown in FIG. 3 is put together, the rolling stand model shown in FIG. 4 is obtained. Here, in the present invention, as the deformation model of the steel sheet S between the rolling stand ST1 and the rolling stand ST2 shown in FIG. 5, the calculation amount is large in the flat plate model, so a large displacement strip model (reference literature (Aoe et al. , Large deformation strip model for continuous strip passing problem, Japan Society of Mechanical Engineers, Proceedings (A), vol.77, No.779 (2011), pp.1102-1111)). In FIG. 5, the symbol R indicates a looper provided between the rolling stand ST1 and the rolling stand ST2.

At this time, the functional of the deformation model of the steel sheet is expressed as the following formula (20). Here, in Equation (20), h is the thickness of the steel plate, b is the width of the steel plate, L is the distance between the rolling stands (see FIG. 5), y is the lateral displacement of the steel plate, and z is the vertical displacement of the steel plate. Ω represents the torsion angle of the steel sheet, κ represents the curvature of the steel sheet (camber), s represents the position in the line direction of the steel sheet, E represents the longitudinal elastic modulus, ν represents the Poisson's ratio, and D represents the bending rigidity of the steel sheet. In addition, the bending rigidity D of a steel plate is represented like numerical formula (21) shown below. Y ^U , θ ^U , u ^U , F _y ^U , M _z ^U , F _x are the steel plate lateral displacement, in-plane angle, axial displacement, lateral acting force, in-plane on the upstream side of the rolling stand It shows moment and tension. Y ^D , θ ^D , u ^D , F _y ^D , and M _z ^D are the lateral displacement, in-plane angle, axial displacement, lateral acting force, and in-plane moment of the steel plate downstream of the rolling stand. Show. Further, ω ^L , z ^L , M _x ^L , and F _z ^L indicate the torsion angle, vertical displacement, torsion moment, and vertical acting force of the steel plate at the looper R. Moreover, y ^LP and F _y ^LP indicate the lateral displacement and lateral acting force of the steel plate at a certain position s ^LP between the rolling stands.

  Here, in Equation (20), variables y, z, and ω, which are functions of the line direction position s, are approximated by element division, and the finite element method (FEM) is applied to the functional. Then, a variational operation is performed on the functional to which the FEM is applied, and when the variational principle is applied, a nonlinear algebraic equation is obtained. By differentiating the nonlinear algebraic equation with respect to time, the following formula (22), The differential equation shown in (23) is obtained.

At this time, _assuming that {x _Strip } is a state variable, {u _Strip } is an input, and {y _Strip } is an output, the deformation model of the steel sheet is expressed as shown in FIG. At this time, since the steel plate is moving, the camber and the wedge are advected. Therefore, in order to obtain the camber and wedge in the steel plate, the advection equation is solved. Further, assuming that the tension of the steel plate is controlled by the looper R, the law of motion for applying the tension to the steel plate is expressed by the following formulas (24) and (25). Here, in Equations (24) and (25), du ₀ / dt is the axial speed of the steel sheet on the rolling stand exit side, z _ref ^L is the target looper height, and F _{z_ref} ^L is the target for applying the target tension. It shows the contact force. FIG. 7 shows a coupled model of steel plate deformation, camber and wedge advection, and looper tension control. Then, when the coupled model shown in FIG. 7 is put together, a steel plate model shown in FIG. 8 is obtained.

When the rolling stand model shown in FIG. 4 and the steel plate model shown in FIG. 8 are coupled, the meandering model of the steel plate in the continuous rolling mill is as shown in FIG. The meandering model shown in FIG. 9 is composed of one rolling stand and upstream and downstream steel plate models. By connecting the meandering model in a daisy chain, a meandering model of steel plates in a plurality of rolling stands (simulator ) Can be constructed. Further, when a meander controller is added to the meander model shown in FIG. 9, the result is as shown in FIG. The meandering controller shown in FIG. 10 is expressed as the following formula (26). Here, in Equation (26), K ₁ , K ₂ , and K ₃ are gains, and s is a Laplace variable. The meandering model shown in FIG. 10 is merely a simulator because actual information is not used.

Next, we consider capturing real-world observation data using observer theory. Since the information of the rolling differential load of the rolling stand can be obtained from the actual machine, when the observer term is added to the equation (16), the following equation (27) is obtained. Here, in Equation (27), G ₁ and G ₂ are observer gains, and P _{(−) df} ( ₍₋₎ indicates a superscript bar of P ₎ indicates an actually measured value of the rolling differential load.

The coupled model of the rolling mill meandering model and the rolling mill stiffness model with the observer added is as shown in FIG. 11, the rolling stand model is as shown in FIG. 12, and the meandering model shown in FIG. 10 is shown in FIG. It becomes like this. Here, it is assumed that the information on the load distribution acting on the looper R is obtained from the actual machine. That is, as shown in FIG. 14, loads F _{(−) z} ^DR and F _{(−) z} ^OP ( ₍₋₎ indicates a superscript bar of F) are measured from a load cell installed on the bearing of the looper R. Further, the estimated value M _{(−) x} ^L ( ₍₋₎ indicates a superscript bar of M ₎ of the torsional moment at the looper R is expressed as the following formula (28). Here, in equation (28), b _L denotes the distance between the bearings looper R. By expressing the torsional angular velocity dω ^L / dt at the looper as shown in the following formula (29), load distribution information at the looper can be captured.

If information on the lateral displacement y _(-) ^LP ( _(-) indicates the superscript bar of Y ₎ at a certain position s ^LP between the rolling stands can be obtained, the lateral displacement speed dy ^LP / By expressing dt as shown in Equation (30) below, information on the lateral displacement y ₍₋₎ ^LP is captured. If a large amount of information can be captured, the state variable estimation accuracy is improved. FIG. 15 shows a meandering model of a steel plate in a continuous rolling mill in which an observer is added to the steel plate model. In the meandering model shown in FIG. 15, the meandering amount between the stands, the looper contact force, the rolling differential load and the leveling difference outputted from the meandering controller, which are input to the steel plate model including the observer, are obtained from an actual continuous rolling mill. It is a variable, and other variables are variables (state variables) in the system.

  As a result, the information on the wedge, entry camber, contact force of each looper, meandering amount between rolling stands, and rolling differential load in the most upstream rolling stand is input, and the leveling amount of each rolling stand is output as seven stages. A control model of the continuous rolling mill is expressed as shown in FIG. The control model shown in FIG. 16 is a case where information is obtained from all the seven rolling stands F1 to F7, but information is not necessarily obtained from all the rolling stands. By using such a control model, the amount of meandering of the steel sheet can be optimally controlled online without requiring labor.

In order to design the meandering control model, it is necessary to obtain influence coefficients β _h0df , β _h1df , β _M0 , β _M1 . The influence coefficients β _h0df , β _h1df , β _M0 and β _M1 can be obtained from the advanced rate f _s . Specifically, in the present invention, the Sims approximation theory represented by the following formula (31) is used as the advanced rate model. Where σ ₀ = -Q ₀ / h _c0 b-12M ₀ y / h _c0 b ³ , σ ₁ = -Q ₁ / λh _c0 b-12M ₁ y / λh _c0 b ³ , Q ₀ is the output compression force , Q ₁ indicates the inlet compression force.

By using the equation (31), the influence coefficients β _h0df , β _h1df , β _M0 , β _M1 are expressed as the following equations (32) to (35). Here, ξ represents h _c0 / R, and R represents the work roll radius.

  In this example, the present invention was applied to the meandering control of the steel sheet in the continuous hot finishing rolling mill from the six rolling stands ST1 to ST6 shown in FIG. In FIG. 17, reference numerals 1a to 1f are rolling load meters that measure the rolling differential load at each rolling stand, reference numerals 2a to 2e are meandering instruments that measure the meandering amount of the steel sheet S between the rolling stands, and reference numerals 3a to 3f are each The rolling reduction cylinders 4a to 4e of the rolling stand indicate load meters that measure the load distribution (contact force) acting on the loopers R1 to R5.

  In this example, the meandering controller 10 shown in FIG. 17 acquired information on the rolling differential load, the looper differential load, and the inter-stand meandering amount from the continuous hot finishing mill. In addition, the meandering controller 10 receives the position (rolling length), material characteristics (sheet thickness, sheet width, deformation resistance, temperature, etc.), rolling conditions (rolling rate, tension between stands, outlet side speed, etc.) from the upper process computer. And information (camber, wedge, etc.) of the steel sheet on the entry side of the most upstream rolling stand.

  The meandering controller 10 calculates the leveling amount of the reduction cylinders 3a to 3f from the acquired information, and drives the reduction cylinders 3a to 3f according to the leveling amount. Here, since the rolling length of the steel sheet is measured, it is possible to calculate the timing at which the tail end of the steel sheet comes out of the continuous hot finish rolling mill. The observer of the meandering controller 10 calculates a meandering motion model in which the number of rolling stands of the continuous hot finishing mill is changed based on the calculated timing.

  Conventionally, the squeezing rate (required for work roll replacement) for thin objects (1.8 mm or less) was about 1%, but the squeezing rate was 0.8% by utilizing the loader load distribution information. Furthermore, by using the information on the meandering amount between the loopers, the drawing rate is 0.5%, and by using the camber information of the entrance material at the most upstream rolling stand, the drawing rate is 0.2%. Furthermore, we succeeded in reducing the squeezing rate to about 0.1% by using the wedge information of the incoming material at the most upstream rolling stand. This system uses multiple sensors, but even if some sensors are damaged, the observer's estimation capability is reduced by the amount of information, but it can be used.

  As mentioned above, although the embodiment to which the invention made by the present inventors was applied has been described, the present invention is not limited by the description and the drawings that constitute a part of the disclosure of the present invention according to this embodiment. That is, other embodiments, examples, operation techniques, and the like made by those skilled in the art based on the present embodiment are all included in the scope of the present invention.

1a to 1f Rolling load cell 2a to 2e Meander meter 3a to 3f Reduction cylinder 4a to 4e Load cell 10 Meander controller R, R1 to R5 Looper S Steel plate ST1 to ST6 Rolling stand

Claims (5)

A meandering control method for a steel sheet that controls the meandering amount of a steel sheet by manipulating the leveling amount of a continuous rolling mill provided with a plurality of rolling stands arranged in the conveying direction of the steel sheet,
A rolling differential load detection step for detecting a difference between the rolling load on the working side of the rolling roll and the rolling load on the driving side as a rolling differential load;
A load distribution detecting step for detecting a load distribution acting on the looper between the rolling stands;
A meandering amount detecting step for detecting a meandering amount between rolling stands;
Using the rolling differential load and the load distribution acting on the looper detected in the rolling differential load detection step and the load distribution detection step, and the meandering amount between rolling stands detected in the meandering amount detection step, the steel plate An estimation step for estimating a meandering amount and an entrance angle that is an approach angle of the steel sheet to the rolling roll;
A meandering control step of manipulating the leveling amount based on the meandering amount and the entrance angle of the steel plate estimated in the estimating step;
A meandering control method for a steel sheet, comprising: A camber amount detecting step for detecting a camber amount of the steel plate on the entry side of the most upstream rolling stand,
The estimation step includes the rolling differential load detected in the rolling differential load detection step and the load distribution detection step and the load distribution acting on the looper, the meandering amount between the rolling stands detected in the meandering amount detection step, by using the camber quantity of the detected steel in the camber quantity detecting step, meander control method of steel sheet according to claim 1, characterized in that for estimating the amount of meandering and the entering-side angle of the steel sheet. A wedge amount detecting step for detecting the amount of wedge of the steel plate on the entry side of the most upstream rolling stand;
The estimation step includes the rolling differential load detected in the rolling differential load detection step and the load distribution detection step and the load distribution acting on the looper, the meandering amount between the rolling stands detected in the meandering amount detection step, Estimating the meandering amount of the steel plate and the entry angle using the camber amount of the steel plate detected in the camber amount detection step and the wedge amount of the steel plate detected in the wedge amount detection step. The steel plate meander control method according to claim 2 . A meandering control device for a steel sheet that controls the meandering amount of a steel sheet by manipulating the leveling amount of a continuous rolling mill provided with a plurality of rolling stands arranged in the conveying direction of the steel sheet,
A rolling differential load detecting means for detecting a difference between a rolling load on the working side of the rolling roll and a rolling load on the driving side as a rolling differential load;
Load distribution detecting means for detecting the load distribution acting on the looper between the rolling stands;
Meandering amount detecting means for detecting the amount of meandering between the rolling stands;
Using the rolling difference load detected by the rolling difference load detecting means and the load distribution detecting means and the load distribution acting on the looper, and the meandering amount between the rolling stands detected by the meandering amount detecting means , the steel plate An estimating means for estimating the meandering amount and the entrance angle which is the approach angle of the steel sheet to the rolling roll;
Meandering control means for manipulating the leveling amount based on the meandering amount and the entrance angle of the steel plate estimated by the estimating means;
A meandering control device for a steel sheet, comprising: One of claims 1 to 3, the manufacturing method of the steel sheet, which comprises a step of producing the steel sheet while controlling the continuous rolling mill by using a meander control method of the steel sheet according to any one.

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