JP2006110627A - Method and apparatus for rolling metal sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for rolling a metal sheet which does not have a camber. <P>SOLUTION: In a metal sheet rolling method, a rolling mill having at least a work roll and a back-up roll is used for rolling the metal sheet. The metal sheet rolling method comprises the steps of: measuring the force in the rolling direction working on roll chocks of the work roll on both operation side and drive side; calculating the difference of the forces in the rolling direction; controlling asymmetrical elements of roll gap of the rolling mill so that the difference of the forces in the rolling direction comes to match the control target value; measuring further the sheet thickness at the inlet and/or the outlet side on the work side and the drive side of the workpiece to be rolled; and learning the control target value for the difference of the forces in the rolling direction, based on the difference of the forces in the rolling direction or the change in the wedge ratio of the sheet thickness. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rolling method and a rolling apparatus for a metal plate, and more particularly, to a rolling method and a rolling apparatus for a metal plate that can stably produce a light metal plate having no camber or extremely camber.

In the rolling process for metal sheets, rolling the rolled sheet without cambers, that is, without bending left and right, not only avoids poor planar shape and poor dimensional accuracy of the rolled material, but also avoids troubles such as meandering and squeezing. It is also important to do. In the present invention, in order to simplify the notation, the working side and the driving side of the rolling mill, which are the left and right when the rolling direction is the front, are referred to as left and right.
For such a problem, in Patent Document 1, a device for measuring the width direction position of the rolled material is provided on the entry side and the exit side of the rolling mill, and the camber of the rolled material is calculated from the measured value, and this is corrected. Thus, a camber control technique for adjusting the position of an edger roll disposed on the entrance side of the rolling mill is disclosed.

Further, Patent Document 2 discloses a camber control technique for controlling the left-right difference of the roll opening degree of the rolling mill, that is, the reduction leveling, based on the left-right difference between the loads of the edger rolls arranged on the entry side and the exit side of the rolling mill. Is disclosed.
Patent Document 3 discloses a camber control technique for analyzing an actually measured value of a left-right difference in rolling load and controlling a left-right difference in roll opening, that is, a leveling reduction, or a position of a side guide. Yes.
Further, Patent Document 4 discloses a method of controlling a camber by restraining a rolled material with an entrance edger roll, a side guide, and an exit side guide.
JP-A-4-305304 JP-A-7-214131 JP 2001-105013 A Japanese Patent Laid-Open No. 8-323411

However, in the invention relating to the camber control technique based on the measurement of the position in the width direction of the rolled material described in Patent Document 1 described above, it is fundamental to correct the camber that has already occurred, thus preventing the occurrence of camber. It is virtually impossible.
In the invention related to the camber control technology based on the left-right difference between the edger roll load on the entry / exit side of the rolling mill described in Patent Document 2, if the camber already exists in the rolled material on the entry side, this is a disturbance of the edger roll load difference on the entry side. Thus, it becomes difficult to obtain high control accuracy. Also, the exit edger roll needs to be retracted when the rolling material tip passes through to prevent the rolling material tip from colliding with the edger roll, and it is difficult to control the camber from the rolling material tip. It is.

Further, in the invention relating to the camber control by the rolling load left / right difference described in Patent Document 3, the thickness of the entrance side of the rolled material is not uniform in the sheet width direction, or the temperature distribution of the rolled material is not uniform in the sheet width direction. In this case, the method of estimating the camber from the difference between the rolling loads is extremely impractical and impractical.
In the invention relating to the camber control by the entry side edger roll, the entry side guide and the exit side guide described in Patent Document 4, if the exit side guide can completely restrain the exit side rolled material, the exit side camber is removed. Although it is possible to make it zero, it is necessary to make the exit side guide wider than the width of the rolled material plate in order to smoothly carry out the rolling operation, and camber is generated in the rolled material by this margin. Become.
It can be said that the problems of the prior art as described above are due to the fact that there is no method for measuring and controlling the camber generated due to various causes with high accuracy and without time delay.

  As a technology that can possibly solve the problems of the above-described technology, the rolling direction force on the working side and the rolling direction force on the driving side are measured by measuring the rolling direction force acting on the work side and driving side roll chock of the work roll. The difference between the rolling direction force and the left-right difference in the rolling direction is calculated, and in the direction to reduce the rolling direction force left-right difference, the left-right asymmetric component of the roll opening of the rolling mill, that is, the reduction leveling, is A rolling method for preventing the above is conceivable.

However, in the above method, if a roll diameter difference or a friction coefficient difference occurs due to roll wear or the like, this may cause a shift in the rolling direction force. There is a concern that the occurrence of camber cannot be prevented even if the reduction leveling is operated in the direction of reducing the difference.
Therefore, the present invention advantageously solves the above-mentioned problems of the prior art relating to camber control, and stably manufactures a light metal plate material having no camber or extremely camber regardless of the number of rollings. An object of the present invention is to provide a rolling method and a rolling apparatus for a metal sheet.

The inventors have obtained the following findings after extensive research.
Generally, the cause of camber due to rolling includes poor roll gap setting, left-right difference in the thickness of the entry side of the rolled material, or left-right difference in deformation resistance, but in any case, the cause is ultimately caused by rolling. By causing a left-right difference in the elongation strain in the rolling direction, the advance rate and the reverse rate change in the sheet width direction, resulting in a left-right difference in the exit side speed and the entry side speed of the rolled material, resulting in camber. At this time, for example, at the time of rolling the front end portion of the rolled material, the length of the rolled material on the exit side, which has already been rolled, is short, so it is relatively free to produce a left-right difference in the exit side speed. In order to make a difference, it is necessary to rotate the entire rolled material existing on the entry side in a horizontal plane within a horizontal plane. However, since a long unrolled material is generally left on the entrance side during tip rolling, a moment against the rigid body rotation is generated by the friction between the weight of the rolled material itself and the table roller. Since this moment is transmitted as a reaction force to the work roll of the rolling mill, it is finally supported by causing a difference in the rolling direction acting on the work roll chock part.

  The moment acting mainly from the entry side rolling material at the time of tip rolling as described above is the measurement of the rolling direction force acting on the work side and driving side roll chock of the work roll, and the working side rolling direction force and drive. It can be detected by calculating the difference from the rolling direction force on the side, that is, the difference between the rolling direction force left and right. This moment is generated only when the left-right difference in elongation strain causing camber generation occurs as described above, and the moment also occurs almost simultaneously with the occurrence of the elongation strain difference. It is possible to prevent the occurrence of camber by manipulating the asymmetrical component of the roll opening degree of the rolling mill, that is, the rolling leveling, in the direction of decreasing the rolling angle.

  The above principle is the same when rolling the tail end of the rolled material. When the tail end is rolled, the length of the rolled material on the exit side, which has already been rolled, is long. When trying to do so, a moment to resist this is generated mainly from the rolled material on the exit side, and this is transmitted as a reaction force to the work roll. In this case as well, the left-right difference in the rolling direction force acting on the work roll chock is measured and calculated. It is possible to detect the occurrence of left-right difference in elongation strain by operating the asymmetrical component of the roll opening of the rolling mill, that is, the reduction leveling, in the direction to reduce the rolling direction force left-right difference. It is possible to prevent the occurrence of camber in the section.

Based on the principle as described above, the force in the rolling direction acting on the work side and the drive side roll chock of the work roll is measured, and the difference between the rolling direction force on the working side and the rolling direction force on the driving side, that is, the rolling direction force. A rolling method is conceivable in which the difference between left and right is calculated and the rolling leveling of the rolling mill is manipulated in a direction to reduce the rolling direction force left and right difference.
Further, when the research is further advanced, in the above method, if the roll diameter or the like causes a difference in the roll diameter or the friction coefficient, a difference in the rolling direction force may be shifted due to this. For this reason, it has been found that there is a concern that the occurrence of camber cannot be prevented even if the rolling leveling is operated in the direction of reducing the rolling direction force left-right difference.

The gist of the present invention for solving the problems of the prior art as described above is as follows.
(1) In a method for rolling a metal plate material using a rolling machine for a metal plate material having at least a work roll and a reinforcing roll, the force in the rolling direction acting on the work chock and the drive side roll chock of the work roll is measured, The roll opening degree of the rolling mill is calculated so that the difference between the working side and the driving side of the rolling direction force (hereinafter also referred to as the difference in rolling direction force) is calculated and the difference in rolling direction force becomes the control target value. The left and right asymmetric components are controlled, and the exit side plate thicknesses of the work side and drive side of the material to be rolled are measured, and the difference between the plate side and the drive side (hereinafter also referred to as plate thickness wedge) is calculated. And based on this difference, the control target value of the difference of the said rolling direction force is learned, The rolling method of the metal plate material characterized by the above-mentioned.
(2) Further, the entry side plate thickness of the work side and the drive side of the material to be rolled is measured, and instead of the calculation of the exit side plate thickness wedge of the material to be rolled, the entry side plate thickness of the work side and the drive side of the material to be rolled and The plate thickness wedge ratio change is calculated from the measured value of the exit side plate thickness, and the plate thickness wedge ratio change is used in place of the exit side plate thickness wedge. Method.

(3) The rolling direction of the work roll chock that measures the force in the rolling direction acting on the work side and drive side roll chocks of the work roll in a rolling apparatus including a rolling mill of a metal plate material having at least a work roll and a reinforcing roll. A load detecting device provided on both the entry side and the exit side, an arithmetic device for calculating a difference in rolling direction force acting on the work roll chock based on a measurement value by the load detecting device, and a difference in the rolling direction force An arithmetic device that calculates a left-right asymmetric component control amount of the roll opening degree of the rolling mill based on the calculated value, and a roll opening degree of the rolling mill based on the calculated value of the left-right asymmetric component control amount of the roll opening degree A control device for controlling, a plate thickness measuring device for measuring the outgoing side plate thickness on the work side and the drive side of the material to be rolled, and an outgoing side plate thickness wedge based on the measured value by the plate thickness measuring device An arithmetic unit for calculating, characterized in that it has an arithmetic unit for learning a control target value of the difference of said rolling direction force on the basis of the calculated value based on the delivery side thickness wedge rolling apparatus of the metal sheet.
(4) It has a plate thickness measuring device for measuring the entry side plate thickness on the work side and the drive side of the material to be rolled, and based on the measured values of the entry side plate thickness and the exit side plate thickness on the work side and drive side of the material to be rolled It has an arithmetic unit that calculates a thickness wedge ratio change, and has an arithmetic unit that learns a control target value of the difference in rolling direction force based on the calculated value of the thickness wedge ratio change, The rolling device for a metal sheet according to (3).

ここで、h_WS ^defが作業側の板厚、h_DS ^defが駆動側の板厚である。
また、板厚ウェッジ比率変化ΔΨは、次式で表せる。

ここで、H_dfが入側の板厚ウェッジ、h_df が出側の板厚ウェッジ、Hが入側の板厚、ｈが出側の板厚である。尚、入出側の板厚H、hは、作業側および駆動側の板厚の平均値として算出しても良い。
圧延方向力の差異は特に断らないかぎり、作業側と駆動側との差異とする。 Here, the difference in the plate thickness between the working side and the drive side, that is, the definition of the plate thickness wedge and the plate thickness wedge ratio change will be described.
The difference in plate thickness between the working side and the drive side, that is, the plate thickness wedge h _df ^def can be expressed by the following equation.

Here, h _WS ^def is the plate thickness on the working side, and h _DS ^def is the plate thickness on the drive side.
Further, the plate thickness wedge ratio change ΔΨ can be expressed by the following equation.

Here, H _df is the inlet side thickness wedge, h _df is the outlet side thickness wedge, H is the inlet side thickness, and h is the outlet side thickness. The plate thicknesses H and h on the entry / exit side may be calculated as an average value of the plate thicknesses on the work side and the drive side.
Unless otherwise specified, the difference in rolling direction force is the difference between the working side and the driving side.

In the rolling method of the metal sheet material of the present invention described in (1), in order to solve the above-described problems, the force in the rolling direction acting on the work chock and the driving roll chock of the work roll is measured, and the rolling The difference between the working side and the driving side of the directional force is calculated, and when the rolling leveling control is performed based on this difference, that is, the rolling direction force left / right difference, a control target value of the rolling direction force left / right difference is set, The reduction leveling control is performed so that the control target value is reached. And this control target value is normally zero, but the working side and driving side thicknesses of the material to be rolled after rolling or during rolling are measured, and the difference between the working side and driving side of the plate thickness is measured. A rolling method is proposed that calculates and learns the control target value based on this difference, that is, the thickness wedge.
In this way, based on the difference in sheet thickness after rolling, the control target value is corrected, that is, learned, and the learned control target value is set to the pass, the next pass, or the rolling of the next material, so that the wear of the roll, etc. Corrects the deviation of the horizontal difference in rolling direction force caused by the cause, enables accurate detection and measurement of the horizontal difference in elongation strain due to rolling, which is the direct cause of camber generation, and implements a reduction leveling operation to make this uniform Accordingly, it is possible to realize substantially no camber generation or extremely light camber rolling.

In the rolling method of the metal sheet material of the present invention described in (2), in the rolling method of the metal sheet material described in (1), the work-side and driving-side sheet thicknesses of the material to be rolled are measured, and the material to be rolled out. Instead of calculating the difference between the working side and the driving side of the side plate thickness, the change in the thickness wedge ratio is calculated from the measured values of the inlet side thickness and the outgoing side plate thickness on the working side and driving side of the material to be rolled, and the outgoing side plate thickness Instead of the difference between the working side and the driving side, a rolling method has been proposed in which the control target value of the difference between the working side and the driving side of the rolling direction force is learned based on the change in the thickness wedge ratio.
Compared with the method described in (1), this rolling method requires measurement of the plate thickness on the working side and the drive side before and after rolling for learning the control target value. Since the information on the thickness of the sheet is obtained, the relationship between the rolling direction force left and right difference generated in the rolling and the ratio of the sheet thickness wedge to the sheet thickness before and after rolling, that is, the change in the sheet thickness wedge ratio, can be understood. A highly accurate control target value can be learned.

Next, the present invention relating to a rolling apparatus for carrying out the method for rolling a metal sheet according to the present invention described in (1) will be described.
The rolling device for a metal sheet according to the present invention described in (3) has the following functions.
1) Since load detection devices are provided on both the entry side and exit side of the rolling direction of the work chock on the work roll and the drive side of the work roll, the direction of the load measurement values on both the entry and exit sides is taken into consideration. By calculating the resultant force, it is possible to determine the rolling direction force acting on the work chock and the drive side roll chock regardless of which direction the force is acting on.
2) Since a calculation device is provided for calculating the difference between the working side and the driving side of the rolling direction force acting on the work roll chock, the rolling direction force acting on the working side roll chock and the rolling direction force acting on the driving side roll chock are provided. Difference, that is, the rolling direction force left-right difference can be calculated.
3) By determining the lateral difference in rolling direction force, the moment acting on the work roll from the rolled material due to the lateral difference in elongation strain in the rolling direction that causes camber can be detected.
4) Since the work side and drive side plate thickness measuring devices of the material to be rolled are provided, the work side and drive side exit plate thickness of the material to be rolled can be measured. Since the calculation device for calculating the difference is provided, the difference between the working side and the driving side of the thickness of the material to be rolled, that is, the thickness wedge can be obtained.
5) Since an arithmetic unit that learns the control target value of the rolling direction force left / right difference is provided, even when the difference in the rolling direction force acting on the work roll chock is shifted due to roll wear or the like, this shift occurs. Since the amount can be corrected by learning based on the difference between the working side and the driving side of the plate thickness of the material to be rolled, that is, the plate thickness wedge, an appropriate control target value can be calculated.
6) An arithmetic device for calculating a left-right asymmetric component control amount of the roll opening degree of the rolling mill for equalizing the elongation strain left and right based on the rolling direction force left-right difference and the control target value, and the left-right asymmetry of the roll opening degree Since a control device for controlling the roll opening degree of the rolling mill based on the calculated value of the component control amount is provided, camber control based on the rolling direction force left-right difference can be performed.

Eventually, the above function makes it possible to carry out the method for rolling a metal plate described in (1), preventing the occurrence of left-right difference in elongation strain, and having no camber or a very light camber with a camber. Can be rolled.
Moreover, in the rolling apparatus for the metal sheet material of the present invention described in (4), in the rolling apparatus for the metal sheet material of the present invention described in (3), the work-side and driving-side exit plate thicknesses of the material to be rolled are measured. In place of the plate thickness measuring device, a plate thickness measuring device for measuring the inlet side thickness and the outlet side plate thickness on the work side and drive side of the material to be rolled, and an operation for calculating the plate thickness wedge of the outlet side plate thickness of the material to be rolled Instead of the device, it is equipped with an arithmetic unit that calculates the thickness wedge ratio change based on the measured values of the entry side plate thickness and the exit side plate thickness on the work side and drive side of the material to be rolled. In place of the arithmetic device that learns the control target value of the rolling direction force left / right difference based on the calculated value of the thickness wedge of the material to be rolled, the control target value is set based on the calculated value of the thickness wedge ratio change. Because it is equipped with an arithmetic device to learn, rolling direction force left and right The control target value can be modified in learning based on thickness wedge ratio change of. Therefore, the metal plate material rolling method described in (2) can be performed by the above functions, and more accurate control target value can be learned, and more accurate camber control can be performed. Become.
As described above, by using the rolling method and rolling apparatus of the present invention, it becomes possible to stably produce a metal plate material having no camber or extremely light camber without depending on the number of rollings, The productivity and yield of the metal sheet rolling process can be greatly improved.

Next, embodiments of the present invention will be described more specifically with reference to the drawings.
FIG. 1 shows a preferred embodiment of a rolling apparatus for realizing the rolling method of the present invention described in (1) or the rolling apparatus of the present invention described in (3). FIG. 1 basically shows only the apparatus configuration on the work side, but there is a similar apparatus on the drive side. The rolling direction force acting on the upper work roll 1 of the rolling mill is basically supported by the upper work roll chock 5, but the upper work roll chock includes an upper work roll chock outlet load detection device 9 and an upper work roll inlet load detection. The apparatus 10 is provided, and the force acting between a member such as a project block (not shown) that fixes the upper work roll chock in the rolling direction and the upper work roll chock can be measured. These load detection devices are usually preferably configured to measure compressive force in order to simplify the device configuration. In the upper work roll rolling direction force calculation device 14, the difference between the measurement results obtained by the upper work roll exit side load detection device 9 and the upper work roll entry side load detection device 10 is calculated, thereby rolling direction acting on the upper work roll chock 5. Calculate the force. Further, the rolling direction force acting on the lower work roll 2 is also measured by the lower work roll outlet load detecting device 11 and the lower work roll inlet load detecting device 12 provided on the outlet side and the inlet side of the lower work roll chock 6. Based on the above, the lower work roll rolling direction force calculation device 15 calculates the rolling direction force acting on the lower work roll chock 6. Next, in the lower work roll rolling direction resultant force calculation device 16, the sum of the calculation result of the upper work roll rolling direction force calculation device 14 and the calculation result of the lower work roll rolling direction force calculation device 15 acts on the upper and lower work rolls. The resultant rolling direction force is calculated. The above procedure is performed not only on the work side but also on the drive side with the same apparatus configuration, and the result is obtained as a work roll rolling direction resultant force 17 on the drive side. Then, the difference between the calculation result on the work side and the calculation result on the drive side is calculated by the work side-drive side rolling direction force difference calculation device 18, and thereby the difference between the work side and the drive side in the rolling direction force acting on the work roll chock. That is, the rolling direction force left-right difference is calculated.

ここで、λは延伸、bは板幅、αは圧延材の入出側の拘束条件によって決まる定数である。 Next, in the control target value calculation device 24, the control target value of the rolling direction force left-right difference is calculated. This calculation method will be described. Normally, the control target value of the rolling direction force left-right difference is zero, and camber generation is prevented by controlling the left-right asymmetric component of the roll opening of the rolling mill so that the rolling direction force left-right difference becomes this control target value. can do. However, if there is a left / right difference in roll diameter or a left / right difference in friction coefficient due to roll wear or the like, this may cause a shift in the rolling direction force left / right difference. In this case, the control target value is zero. It is necessary to change to an appropriate value.
In general, the plate thickness wedge ratio change ΔΨ and the camber curvature change Δκ are in a one-to-one correspondence, for example, a paper pp published in the Showa 55 Plastic Working Spring Conference (1980). 61-64 "Study on meandering control method in hot strip rolling (1st report)" (by Nakajima, Kikuma, Matsumoto, Kashio, Kimura, Tagawa) can be expressed by the following equation.

Here, λ is a stretching, b is a sheet width, and α is a constant determined by a constraint condition on the entry / exit side of the rolled material.

  As described above, the plate thickness wedge ratio change is an amount corresponding to the camber curvature change Δκ on a one-to-one basis. Therefore, when the influence of the plate thickness wedge and the camber on the entry side material can be ignored, the camber generated during the rolling It can be considered that controlling is substantially equivalent to controlling the thickness wedge. In other words, even if the equipment does not have a camber meter, if the difference between the working side and the driving side of the plate thickness, that is, the plate thickness wedge, can be measured, it is equivalent to measuring the camber. The value can be learned.

FIG. 4 is a diagram showing the relationship between the rolling direction force left-right difference and the plate thickness wedge.
As shown in FIG. 4, when the relationship straight line A between the rolling direction force left / right difference and the thickness wedge is shifted as the relationship straight line B due to roll wear or the like, the thickness wedge, that is, the camber curvature is made zero. Needs to change the control target value A ′ (initially 0) to the control target value B ′. Further, the shift of the relationship line between the rolling direction force left / right difference and the plate thickness wedge and the change of the control target value can be easily determined by measuring the plate thickness wedge during or after rolling.

Therefore, as a result of performing the control so as to become the control target value A ′ as shown in FIG. 4, if the sheet thickness wedge is not zero but is the actual value C of the sheet thickness wedge, the rolling direction force left-right difference And the plate thickness wedge are considered to be shifted like a straight line B, and the control target value may be changed to B ′ by rolling the pass, the next pass, or the next material. Further, since the deviation in the rolling direction force difference due to roll wear may change as the number of rolling rolls increases, it is necessary to always learn and change the control target value. In the figure, δ _A and δ _B are inclinations of the relational lines A and B between the rolling direction force left-right difference and the sheet thickness wedge, and are constants determined by the dimensions of the rolling mill, rolling conditions, deformation resistance of the rolled material, and the like. is there. When these inclinations change due to roll wear or the like, it is necessary to identify them in advance by a preliminary experiment or the like. However, δ _A and δ _B may be approximately equal to δ _A = δ _B (= δ) in a first order approximation if the conditions may be changed depending on rolling conditions and rolling material. However, since it may change over time depending on rolling conditions, the values of δ _A and δ _B may be measured periodically.

ただし、Ｃ⁽ⁿ⁾はnパス目または圧延材ｎ本目の制御目標値、 Ｃ_r ⁽ⁿ⁾はnパス目または圧延材ｎ本目の板厚ウェッジの実績値に基づき修正された制御目標値、γは学習ゲイン(0〜1.0)である。 Therefore, in the present invention, the control target value of the rolling direction force left-right difference is learned by the following method. As shown in FIG. 1, a plate thickness measuring device 23 is provided on the rear surface of the rolling mill, and the working side and driving side outgoing plate thicknesses of the material to be rolled during or after rolling are measured, and these measurements are made. Based on the value, the difference between the work side and the drive side of the plate thickness, that is, the plate thickness wedge is calculated by the work side-drive side plate thickness difference calculating device 25, and this plate thickness wedge is sent to the control target value calculating device 24. At this time, the average value of the plate thickness measured on the working side and the drive side is obtained as the delivery side plate thickness, and the value of the plate thickness wedge ratio obtained by dividing the plate thickness wedge by the plate thickness is sent to the control target value calculation device 24. Also good. In the control target value calculation device 24, the control target value in the rolling of the pass, the next pass or the next material is calculated based on the difference between the work thickness and the drive side of the plate thickness, that is, the plate thickness wedge or the plate thickness wedge ratio. . Since this control target value needs to be learned and changed as the number of rolled sheets increases, for example, the control target value may be learned for each pass or number of rolled materials using the following equation (4).

However, C ⁽ⁿ⁾ is the control target value for the nth pass or the nth rolled material, and _Cr ⁽ⁿ⁾ is the control target value corrected based on the actual value of the thickness wedge of the nth pass or the nth rolled material, γ is a learning gain (0 to 1.0).

  On the basis of the control target value calculated as described above and the calculation result of the difference between the working side and the driving side of the rolling direction force, the rolling-down leveling control amount calculation device 19 opens the roll of the rolling mill for preventing camber. A right / left asymmetric component control amount is calculated. In the stage where the thickness wedge at the first rolling is not actually measured, for example, the control target value may be set to the value of the left-right difference in rolling direction force generated when tightening the kiss roll or zero. In addition, here, for example, a PID calculation in consideration of a proportional (P) gain, an integral (I) gain, and a differential (D) gain with respect to the left-right difference of the rolling direction force and the control target value obtained from the equation (4). Is used to calculate the left-right asymmetric component control amount of the roll opening. Based on the control amount calculation result, the rolling leveling control device 20 controls the left-right asymmetric component of the roll opening degree of the rolling mill, so that camber generation or extremely light camber rolling can be realized. In the pass, when the control target value is changed, the control target value may be dynamically changed during rolling at the stage where the difference in plate thickness between the working side and the drive side, that is, the plate thickness wedge is actually measured.

FIG. 2 shows a preferred embodiment of the rolling device relating to the rolling method of the present invention described in (2) or the rolling device of the present invention described in (4). In the embodiment of FIG. 2, compared with the embodiment of FIG. 1, a plate thickness measuring device 26 is provided on the front surface of the rolling mill, and a plate thickness wedge ratio change calculating device is used instead of the work side-drive side plate thickness difference calculating device 25. 27 is provided, and the rolling method of the present invention described in (2) can be carried out.
In the rolling method of the present invention described in (2), the control target value of the rolling direction force left-right difference is learned as follows. 2 is used to measure the entry side thickness and the exit side thickness of the work side and the drive side of the material to be rolled during or after rolling, from the thickness measurement device 23 on the rear surface and the thickness measurement device 26 on the front surface. Based on these measured values, the plate thickness wedge ratio change is calculated by the plate thickness wedge ratio change calculating device 27, and this plate thickness wedge ratio change is sent to the control target value calculating device 24. At this time, the calculation of the plate thickness wedge ratio is calculated by calculating the average value of the plate thickness measured on the work side and the drive side for each plate thickness on the input and output sides, and calculating the plate thickness wedge ratio obtained by dividing the plate thickness wedge by the plate thickness. The plate thickness wedge ratio change can be calculated by subtracting the entry side plate thickness wedge ratio from the exit side plate thickness wedge ratio. Further, instead of the plate thickness wedge ratio change, a plate thickness wedge change obtained by subtracting the entry side plate thickness wedge from the output side plate thickness wedge may be used. In the control target value calculation device 24, the control target value in the rolling of the pass, the next pass or the next material is calculated based on the change in the thickness wedge ratio. Since this control target value needs to be learned and changed as the number of rolling rolls increases, as in the rolling method of the present invention described in (1) above, each control or What is necessary is to learn for every rolling material number. In the case of this method, the relationship between the rolling direction force left-right difference and the plate thickness wedge shown in FIG. 4 is replaced with the relationship between the rolling direction force left-right difference and the plate thickness wedge ratio change as shown in FIG. Relationship between the rolling direction force left-right difference and the plate thickness wedge ratio change The values of the constants ζ _D and ζ _E representing the slopes of the straight lines D and _E are determined in the same manner as in the rolling method of the present invention described in (1) above. Measured and used for learning.

As described above, in the rolling method of the present invention described in (2), by measuring the plate thicknesses on the working side and the drive side before and after rolling, the inlet side is compared with the rolling method of the present invention described in (1). Information on the thickness of the plate and information on the thickness on the entry / exit side can be obtained, and the relationship between the difference in the rolling direction force generated by the rolling and the change in the plate thickness wedge ratio can be understood. By setting the learned control target value for the relevant pass, the next pass or the rolling of the next material, it is possible to correct the deviation in the rolling direction force left-right difference. High camber control can be realized.
FIG. 3 shows another preferred embodiment of a rolling device relating to the rolling method of the present invention described in (2) or the rolling device of the present invention described in (4). In the embodiment of FIG. 3, compared with the embodiment of FIG. 2, a plate thickness measuring device on the front surface (rear surface during reverse pass), a rolling direction force detecting device acting on the lower work roll chock, and a computing device are omitted. . In general, the moment acting on the work roll from the rolled material due to the left-right difference in elongation strain does not necessarily act equally on the upper and lower work rolls, but the time series change behavior is reversed in the upper and lower work rolls. However, there is a possibility that the zero point of the difference in the rolling direction force is shifted.

  Thus, when the rolling method of the present invention described in (2) is applied to equipment in which the rolling mill does not have any one of the front and rear surface thickness measuring devices, the thickness on both the input and output sides cannot be measured. When the forward pass is a dummy pass that does not perform rolling as shown in FIG. 6 and rolling is performed during the reverse pass, even in the rolling device shown in FIG. 3 that has a plate thickness measuring device on only one of the front and rear surfaces, Since it is possible to measure the plate thickness on the entry / exit side, the rolling method of the present invention described in (2) can be applied. In this case as well, the plate thickness on the working side and the drive side of the material to be rolled during or after rolling is measured, and the change in the plate thickness wedge ratio is obtained. By setting the rolling of the material, it is possible to correct the deviation in the rolling direction force left-right difference, so that it is possible to realize good camber control based on the left-right difference in the rolling direction force acting on one of the upper and lower work rolls.

  Also, in the case of so-called pair-cross rolling, in which work rolls and reinforcing rolls are crossed up and down, a force that tears the upper and lower work rolls in the opposite directions on the work side and drive side due to the offset of the upper and lower work rolls (here, “crotch tear”) A force difference between the rolling direction forces other than the occurrence of the camber is generated. In the case where the rolling method of the present invention is applied to such pair-cross rolling, when either the upper or lower rolling direction force left-right difference cannot be detected, the rolling direction force left-right difference due to crotch tearing force during pair-cross rolling is calculated, Based on this, it is necessary to set the control target value. Since the crotch tearing force can be calculated from the geometric relationship of the upper and lower work rolls during pair cross rolling, the rolling load, the cross angle, the upper and lower work roll diameters, the plate thickness, the width, and the rolling direction force measuring device What is necessary is just to calculate and obtain a relational expression from the interval or the like. In addition, when the difference between the upper and lower rolling direction forces can be measured by adding the upper and lower rolling direction force left and right, the effect of the crotch tearing force during pair cross rolling can be canceled up and down. This operation is not necessary.

  However, due to the above-mentioned effect of pair cross rolling, if the measurement of the rolling direction force is either up or down, due to an error in the calculation of the crotch tearing force, Although there is a possibility that the difference in rolling direction force between the left and right is caused by unevenness in the vertical direction, the rolling method of the present invention measures the thickness of the work side and the drive side of the material to be rolled during or after rolling. The difference in rolling direction force left and right can be corrected by determining the thickness wedge or the thickness wedge ratio change and setting the learned control target value for the pass, the next pass, or the rolling of the next material based on this. Therefore, it is possible to achieve good camber control based on the left-right difference in rolling direction force even during pair cross rolling.

    The example at the time of applying the plate rolling method as described in (1) of this invention using the rolling mill shown in FIG. 1 is demonstrated. A sheet thickness wedge is calculated from the output of the sheet thickness measuring device 23 on the rear surface of the rolling mill, and learning of the control target value of the rolling direction force left-right difference based on this is calculated. The learning gain γ is 0.3 and the initial control target value is zero. As implemented. The constant δ, which indicates the slope of the relationship line between the rolling direction force left-right difference and the sheet thickness wedge, was set to a value in the range of −20 to −200 ton / mm for each rolling condition and rolled material.

  Table 1 shows the control target value of the rolling direction force left-right difference and the actual measured value of the camber with respect to the representative number of rollings in this example. Table 1 also shows a control target value and a measured value of the camber when learning of the rolling direction force left / right difference is not performed as a comparative example. As shown in Table 1, it can be seen that the actual camber value per meter is suppressed to a relatively small value of 0.25 mm / m or less in any representative rolling number in this example. It can also be seen that as the number of rolling increases, the control target value of the rolling direction force left-right difference changes by learning based on the measured thickness values on the working side and the driving side. Such a change in the control target value is considered to be due to wear of the reinforcing roll and work roll, and in the comparative example method of Table 1 in which the control target value is not learned as in the plate rolling method of the present invention. Since the control including these error factors is performed, it can be seen that the camber becomes larger than the method of the present invention.

As described above, based on the actual value of the thickness wedge after rolling as in the plate rolling method of the present invention, learning the control target value, and setting the learned control target value to the next pass rolling, By correcting the difference in rolling direction force left-right difference, it is possible to accurately detect and measure the left-right difference in elongation strain due to rolling, which is the direct cause of camber generation, and by carrying out a rolling leveling operation to make this uniform, It was confirmed that it was possible to realize extremely light rolling of the camber constantly without depending on the number of rolling.

  The Example at the time of applying the plate rolling method as described in (2) of this invention using the rolling mill shown in FIG. 2 is demonstrated. The thickness wedge ratio change is calculated from the outputs of the sheet thickness measuring device 23 on the rear surface of the rolling mill and the plate thickness measuring device 26 on the front surface, and learning of the control target value of the rolling direction force left and right based on this is calculated. The initial control target value was set to zero at 0.3. The constant ζ indicating the slope of the relationship line between the rolling direction force left-right difference and the plate thickness wedge ratio change was set to a value in the range of −500 to −5000 tonf for each rolling condition and rolled material.

  Table 2 shows the control target value of the rolling direction force left-right difference and the actual measured value of the camber with respect to the representative number of rollings in this example. Table 2 also shows a control target value and a measured value of the camber when learning of the rolling direction force left / right difference is not performed as a comparative example. As shown in Table 2, it can be seen that the actual measured value of camber per 1 m is smaller than that of the comparative example in all the representative rolling numbers, and is further suppressed to 0.15 mm / m or less and smaller than that of Example 1.

As described above, in Example 2, since the information on the thickness wedges on both the input and output sides can be obtained, the exact relationship between the rolling direction force left-right difference and the thickness wedge ratio change can be understood, and a more accurate control target value can be obtained. Since learning can be performed and the learned control target value is set to the rolling of the relevant pass, the next pass or the next material, the deviation in the rolling direction force can be corrected. It was confirmed that accurate camber control can be realized.

It is a figure which shows typically preferable embodiment of the rolling apparatus which implement | achieves the rolling method of this invention as described in (1), or the rolling apparatus of this invention as described in (3). It is a figure which shows typically preferable embodiment of the rolling apparatus which implement | achieves the rolling method of this invention as described in (2), or the rolling apparatus of this invention as described in (4). It is a figure which shows typically preferable embodiment of the rolling apparatus which implement | achieves the rolling method of this invention as described in (2), or the rolling apparatus of this invention as described in (4). It is the figure which showed the relationship between a rolling direction force right-and-left difference and a sheet thickness wedge. It is the figure which showed the relationship between a rolling direction force left-right difference and a plate | board thickness wedge ratio change. It is a figure which shows the rolling schedule for implement | achieving the rolling method of this invention as described in (2), when a plate | board thickness measuring apparatus is only in the front and back one side.

Explanation of symbols

1 Upper work roll 2 Lower work roll 3 Upper reinforcement roll 4 Lower reinforcement roll 5 Upper work roll chock (working side)
6 Lower work roll chock (work side)
7 Upper reinforcement roll chock (working side)
8 Lower reinforcement roll chock (working side)
9 Upper work roll outlet load detector (work side)
10 Upper work roll entry side load detection device (work side)
11 Lower work roll exit side load detector (work side)
12 Lower work roll entry side load detector (work side)
13 Reduction device 14 Upper work roll rolling direction force calculation device (work side)
15 Lower work roll rolling direction force calculation device (work side)
16 Work roll rolling direction resultant force calculation device [adder] (work side)
17 Work roll rolling direction resultant force (drive side)
DESCRIPTION OF SYMBOLS 18 Work side-drive side rolling direction force difference calculating device 19 Rolling leveling control amount calculating device 20 Rolling leveling control device 21 Metal plate material 22 Rolling direction 23 Plate thickness measuring device (rear surface)
24 Control Target Value Calculation Device 25 Work Side-Drive Side Plate Thickness Difference Calculation Device 26 Plate Thickness Measurement Device (Front)
27 Thickness wedge ratio change calculation device

Claims (4)

  In the method of rolling a metal sheet using a rolling machine for a metal sheet having at least a work roll and a reinforcing roll, the force in the rolling direction acting on the work chock and the drive side roll chock of the work roll is measured, and the rolling direction The difference between the force working side and the driving side (hereinafter also referred to as the difference in rolling direction force) is calculated, and the roll opening degree of the rolling mill is asymmetrical so that the difference in rolling direction force becomes the control target value. The ingredients are controlled, and the work-side and drive-side exit thicknesses of the material to be rolled are measured, and the difference between the work-side and drive sides of the exit-side board thickness (hereinafter also referred to as a plate thickness wedge) is calculated. Based on this difference, the control target value of the difference in the rolling direction force is learned.   Furthermore, the entry side plate thickness of the work side and the drive side of the material to be rolled is measured, and instead of the calculation of the exit side plate thickness wedge, the measured values of the entry side plate thickness and the exit side plate thickness on the work side and drive side of the material to be rolled The method for rolling a metal sheet according to claim 1, wherein a change in the plate thickness wedge ratio is calculated, and the change in the plate thickness wedge ratio is used in place of the outlet plate thickness wedge.   In a rolling apparatus including a rolling mill of a metal plate material having at least a work roll and a reinforcing roll, a rolling direction entry side of the work roll chock that measures a force in a rolling direction acting on a work chock and a drive side roll chock of the work roll; A load detection device provided on both the output side, a calculation device that calculates a difference in rolling direction force acting on the work roll chock based on a measurement value by the load detection device, and a calculation value of the difference in rolling direction force And a control device for calculating the roll opening degree of the rolling mill based on the calculated value of the left and right asymmetric component control amount of the roll opening. Equipment, plate thickness measuring device that measures the exit side thickness of the work side and drive side of the material to be rolled, and calculating the exit side thickness wedge based on the measured value by the plate thickness measurement device That an arithmetic unit, characterized in that it has an arithmetic unit for learning a control target value of the difference of said rolling direction force based on the delivery side thickness wedge rolling apparatus of the metal sheet. Thickness wedge measuring device that measures the work-side and drive-side entry side thicknesses of the material to be rolled, and based on the measured values of the work-side and drive-side entry and exit side thicknesses of the material to be rolled It has a calculating device which calculates a ratio change, and has a calculating device which learns a control target value of a difference of the rolling direction force based on a calculated value of the sheet thickness wedge ratio change. The rolling apparatus of the metal plate material of description.

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