WO2024042936A1

WO2024042936A1 - Cold-rolling method and cold-rolling equipment

Info

Publication number: WO2024042936A1
Application number: PCT/JP2023/026602
Authority: WO
Inventors: 信一郎青江; 昇輝藤田; 拓弥藤沢; 義典沼澤; 悦充原田; 行宏松原
Original assignee: Ｊｆｅスチール株式会社
Priority date: 2022-08-26
Filing date: 2023-07-20
Publication date: 2024-02-29
Also published as: JP2024031268A

Abstract

This cold-rolling method includes a calculation step for calculating the levelling amount of a rolling machine using the out-of-plane deformation amount of a steel sheet measured on the upstream side of the rolling machine, a control step for controlling the levelling of the rolling machine on the basis of the levelling amount calculated in the calculation step, and a cold rolling step for cold-rolling the steel sheet using the rolling machine controlled in the control step.

Description

Cold rolling method and cold rolling equipment

The present invention relates to a cold rolling method and cold rolling equipment.

Generally, when cold-rolling rolled materials such as cold-rolled thin steel sheets, it is necessary to improve the shape (or flatness) of the rolled material while maintaining good thickness accuracy in the longitudinal and width directions of the rolled material. Therefore, it is desirable that cold rolling be performed in a state where the threadability of the rolled material is stabilized. On the other hand, for the purpose of reducing fuel consumption through weight reduction, there is an increasing need for materials that are difficult to roll, such as thin hard materials that can handle high loads and have a thin plate thickness before rolling. During cold rolling of such a difficult-to-roll material, in order to suppress the rolling load, the difficult-to-roll material is thinned in the previous hot rolling process and then sent to the cold rolling process.

In recent years, many of the control factors of cold rolling mills are automatically controlled by actuators installed in the cold rolling mill. As a method for automatic shape control, shape feedback (FB) control is often used, in which a shape meter is installed on the exit side of the rolling mill and the shape data of the shape meter is used to automatically control the leveling and bender of the rolling mill. However, when cold-rolling the above-mentioned difficult-to-roll materials, the coil may be joined to the next coil with bends remaining at the leading and trailing ends due to poor shape during hot rolling. When bending or shape defects change sharply along the longitudinal direction of the coil, the rolling load (and the accompanying calculated advance rate and torque), roll gap of the cold rolling mill, leveling, work roll bender, etc. Variations in roll deflection correction, typified by roll shift, intermediate roll shift, and roll expansion caused by thermal crowns, cannot be absorbed by automatic control. As a result, the shape of the rolled material after cold rolling is poor, and plates often break during cold rolling. The weakness of FB control is that it cannot cope with rapid fluctuations, and feedforward (FF) control is also used to compensate for this.

Patent Document 1 discloses a leveling method in which one-sided elongation or bending of a steel plate on the entry side of the rolling mill is predicted from the differential tension measured by a differential tension meter upstream of the rolling mill, and the predicted one-sided elongation or bending is corrected. An FF control method for controlling the FF is disclosed. Furthermore, Patent Document 2 discloses a method of suppressing rollability defects by performing FF control of the bender of the rolling mill based on the torsion of the steel plate shape data obtained from the cross-sectional profile meter upstream of the rolling mill and the C height. has been done. Furthermore, Patent Document 3 discloses a method for suppressing rollability defects by stopping rolling if the steel sheet shape data measured by a cross-sectional profile meter upstream of the rolling mill is distorted and the C height is outside a predetermined range. has been done.

Japanese Patent Application Publication No. 2012-161806 Japanese Patent Application Publication No. 2022-14800 JP 2021-133411 Publication

In the method disclosed in Patent Document 1, the differential tension between the stands is measured, but what is predicted from the differential tension is the average one-sided elongation or bending between the stands. Therefore, it is good if the change in one-sided elongation or bending is gradual, but if the change is sudden such as at a joint point, the one-sided elongation or bending predicted from the differential tension and the one-sided elongation at the exit side of the rolling mill are Or, since there is a difference in bending, it cannot be well controlled. This is because if the one-sided elongation or bending is too large, the steel plate cannot stick to the roll, and the differential tension cannot be measured by a differential tension meter. In the methods disclosed in Patent Document 2 and Patent Document 3, in order to calculate the unilateral elongation or bending of a steel plate with large unilateral elongation or bending, the torsion and C height of the steel plate cross section are calculated by measuring the cross-sectional shape of the steel plate. is being calculated. However, the torsion and C height are only a part of the steel plate shape information, and it is difficult to accurately calculate one-sided elongation or bending from the cross-sectional shape, so it is difficult to control it well.

The present invention has been made in view of the above-mentioned problems, and its purpose is to ensure the stability of cold rolling even when cold rolling a difficult-to-roll material with a thin plate thickness before rolling. It is an object of the present invention to provide a cold rolling method and cold rolling equipment that can perform cold rolling with high productivity and yield.

In order to solve the above-mentioned problems and achieve the objectives,
(1) The cold rolling method according to the present invention includes a calculation step of calculating the leveling amount of the rolling mill using the amount of out-of-plane deformation of the steel plate measured on the upstream side of the rolling mill, and and a cold rolling step of cold rolling a steel plate using the rolling mill controlled by the controlling step. This is a characteristic feature.

(2) In the cold rolling method according to the present invention, in the invention described in (1) above, the amount of out-of-plane deformation of the steel plate is determined on the upstream side of the rolling mill and immediately upstream of the steering device that changes the conveyance direction of the steel plate. Alternatively, it is an amount of out-of-plane deformation measured immediately downstream.

(3) In the cold rolling method according to the present invention, in the invention (1) or (2) above, when the amount of out-of-plane deformation of the steel plate measured on the upstream side of the rolling mill exceeds a threshold value, the cold rolling method This method is characterized in that cold rolling is not performed on the steel plate in the rolling step.

(4) In the cold rolling method according to the present invention, in any one of the above (1) to (3), in the calculation step, the leveling amount is determined by applying a leveling amount calculation program to the out-of-plane deformation amount. The leveling amount calculation program takes each out-of-plane deformation amount of a plurality of steel plates as an input variable, and performs a physical simulation for each out-of-plane deformation amount. This method is characterized by machine learning using each leveling amount obtained as a result of the above as an objective variable.

(5) In the cold rolling method according to the present invention, in any one of the above (1) to (4), in the calculation step, the leveling amount is determined to be outside the plane of the steel plate on the upstream side of the rolling mill. It is characterized in that it is calculated using the amount of deformation and the amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill.

(6) The cold rolling equipment according to the present invention includes a rolling mill that cold-rolls a steel plate, a shape measuring device that is disposed upstream of the rolling mill and measures an amount of out-of-plane deformation of the steel plate, and a shape measuring device that measures the amount of out-of-plane deformation of the steel plate, and a calculation device that calculates the leveling amount of the rolling mill using the amount of out-of-plane deformation of the steel plate measured by the measuring device; and controlling the leveling of the rolling mill based on the leveling amount calculated by the calculation device. The present invention is characterized by comprising a control device.

(7) The cold rolling equipment according to the present invention, in the invention described in (6) above, is provided with a steering device that is disposed upstream of the rolling mill and changes the conveying direction of the steel plate, and the cold rolling equipment is provided with a steering device that changes the direction of conveyance of the steel plate. The amount is an amount of out-of-plane deformation measured upstream of the rolling mill and immediately upstream or downstream of the steering device.

(8) In the invention of (6) or (7) above, in the cold rolling equipment according to the present invention, when the amount of out-of-plane deformation of the steel plate measured on the upstream side of the rolling mill exceeds a threshold value, the cold rolling equipment The method is characterized in that the steel plate is not cold rolled.

(9) In the cold rolling equipment according to the present invention, in any one of the above-mentioned (6) to (8), the calculation device is configured to calculate the amount obtained as a result of applying a leveling amount calculation program to the out-of-plane deformation amount. The leveling amount calculation program uses each out-of-plane deformation amount of a plurality of steel plates as an input variable, and calculates each out-of-plane deformation amount obtained as a result of physical simulation for each out-of-plane deformation amount. This method is characterized by machine learning using the leveling amount as the objective variable.

(10) In the cold rolling equipment according to any one of the above (6) to (9), the calculation device calculates the amount of out-of-plane deformation of the steel plate on the upstream side of the rolling mill, and The leveling amount is calculated using the amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill.

The cold rolling method and cold rolling equipment according to the present invention ensure stability of cold rolling even when cold rolling difficult-to-roll materials with high load and thin plate thickness before rolling, while improving productivity. Also, there is an effect that cold rolling can be carried out with good yield.

FIG. 1 is an overall view showing a schematic configuration of a cold rolling line according to an embodiment. FIG. 2 is a diagram showing an example of a method for measuring the amount of out-of-plane deformation. FIG. 3 is a diagram showing the measurement results of one-sided elongation or bending, which is the amount of out-of-plane deformation of the steel plate, measured by a shape measuring device installed on the exit side of the entrance looper. FIG. 4 is an explanatory diagram of leveling control. FIG. 5 is a diagram showing the transition of true one-sided elongation or bending as a result of a simulation of cold rolling a steel plate with one-sided elongation or bending. FIG. 6 is a diagram showing the transition of one-sided elongation or bending calculated from the differential tension as a result of a simulation of cold rolling a steel plate with one-sided elongation or bending. FIG. 7 is a diagram showing the transition of true one-sided elongation or bending as a result of a simulation of cold rolling a steel plate with one-sided elongation or bending when leveling FB control is performed. FIG. 8 is a diagram showing the transition of one-sided elongation or bending calculated from the differential tension as a result of a simulation of cold rolling a steel plate with one-sided elongation or bending when leveling FB control is performed. FIG. 9 is a diagram showing the transition of true one-sided elongation or bending as a result of leveling FB control to reduce the true one-side elongation or bending on the exit side of the first rolling mill through simulation. FIG. 10 is a diagram showing the transition of one-sided elongation or bending calculated from the differential tension as a result of leveling FB control to reduce the true one-side elongation or bending on the exit side of the first rolling mill through simulation. FIG. 11 is a diagram showing the transition of true one-sided elongation or bending as a result of a simulation in which a steel plate S with one-sided elongation or bending was cold-rolled by performing leveling FF control and leveling FB control. FIG. 12 is a diagram showing the transition of one-sided elongation or bending calculated from the differential tension as a result of a simulation in which a steel plate S with one-sided elongation or bending was cold-rolled by performing leveling FF control and leveling FB control. .

Embodiments of the cold rolling method and cold rolling equipment according to the present invention will be described below. The cold rolling equipment according to the embodiment includes a rolling mill that cold-rolls a steel plate, a shape measuring device that is disposed upstream of the rolling mill, and that measures the amount of out-of-plane deformation of the steel plate, and a shape measuring device that measures the amount of out-of-plane deformation of the steel plate. The present invention includes a calculation device that calculates the amount of leveling of the rolling mill using the amount of out-of-plane deformation of the steel plate, and a control device that controls the leveling of the rolling mill based on the amount of leveling calculated by the calculation device. The cold rolling method applied to the cold rolling equipment according to the embodiment includes a calculation step of calculating the amount of leveling of the rolling mill using the amount of out-of-plane deformation of the steel plate measured on the upstream side of the rolling mill, and a calculation step. The method includes a control step of controlling the leveling of the rolling mill based on the leveling amount calculated in the step, and a cold rolling step of cold rolling the steel plate using the rolling mill controlled by the control step. Note that the present invention is not limited to this embodiment.

FIG. 1 is an overall view showing a schematic configuration of a cold rolling facility 1 according to an embodiment. In the cold rolling equipment 1 according to the embodiment, a payoff reel 2 for paying out the steel plate S from the coil is installed at the most upstream portion. Further, the cold rolling equipment 1 according to the embodiment includes a welding machine 3 that joins the tail end of the steel plate S that has been discharged and the tip of the steel plate that has been discharged from the next coil, and a welding machine 3 that suppresses stress concentration. For this purpose, a notcher 4 is installed to cut the steel plate S into a semi-elliptical shape at the end of the weld line. Further, the cold rolling equipment 1 according to the embodiment is provided with an entry side looper 5 for absorbing the line speed difference between the joining process and the rolling process. Furthermore, a steering device 6 equipped with CPC meandering control is installed on the exit side of the entrance looper 5, and a shape measuring device 7 is installed immediately downstream thereof. Note that the shape measuring device 7 may be placed immediately upstream of the steering device 6. Further, the cold rolling equipment 1 according to the embodiment includes a deflector steering roll 8 equipped with CPC meandering control, a bridle roll group 9 for creating a tension step between the rolling process and its upstream process, and a bridle roll. A deflator steering roll 10 equipped with CPC meandering control is installed immediately downstream of the group 9. Further, the cold rolling equipment 1 is equipped with a five-stage continuous cold rolling mill 11 for rolling the steel sheet S. Further, the cold rolling equipment 1 is equipped with a bridle roll 12 for creating a tension step between the rolling process and its downstream process, a cutting machine 13, and a tension reel 14 for winding up the steel plate S. There is.

At the tip and tail ends of the steel sheet S discharged from the payoff reel 2, there are defective portions with uneven elongation or bending due to the hot rolling process. Further, if the steel plates S are not straight when joined by the welding machine 3, they will be welded in a dogleg shape, and further elongation or bending will increase. When such a defective shape portion is cold rolled by the cold rolling mill 11, a crack occurs at the width end of the steel plate S during the rolling process, and a break occurs from the crack as a starting point. Furthermore, when a differential tension between the rolling mills (between stands) of the cold rolling mill 11 due to one-sided elongation or bending is applied to the steel plate S, a fracture occurs due to a crack, or a fracture occurs even if there is no crack. do. Note that the differential tension refers to a tension difference between both ends of the steel plate S in the width direction, which is detected by a pressure detection means such as a tension meter disposed on the exit side of the rolling mill.

Here, the geometry of the shape of the steel plate S will be explained. Shape defects occur in the steel sheet S mainly due to non-uniformity in the width direction of elongation in the longitudinal direction during the rolling process. This shape defect is a combination of one-sided elongation or bending, ear waves (belly elongation), etc., and one-sided elongation or bending is the shape defect that has the greatest effect on breakage during rolling. In particular, when a thin plate is cut, out-of-plane deformation due to one-sided elongation or bending disappears, making it difficult to measure one-sided elongation or bending. On the other hand, ear waves (belly extension) can be measured because out-of-plane deformation remains even if the plate is cut.

When the steel plate S is a curved line, the geometric definition of the curvature κ of one-sided elongation or bending can be expressed by the following formula (1).

Here, in the above formula (1), x is the position in the line direction, v is the displacement in the width direction at the width center, w is the displacement in the vertical direction at the width center, and ω is the twist angle. Since it is difficult to calculate the above formula (1), the longitudinal average of one-sided elongation or bending is considered. The average curvature Κ can be defined as shown in Equation (2) below.

Here, in the above formula (2), L is the length for averaging. By substituting the above equation (1) into the above equation (2), the average curvature K can be expressed by the following equation (3).

The first term on the right side of the above equation (3) is the amount observed as meandering or oblique movement. Further, the second term on the right side of the above equation (3) is the amount observed as out-of-plane deformation. From the above equation (3), it can be seen that even if only meandering is observed, one-sided elongation or bending cannot be detected. If there is no meandering, the first term on the right side of the above formula (3) becomes zero, and the average one-sided elongation or bending can be determined from only the observed amount of out-of-plane deformation. Here, if the twist angle ω is small, the above equation (3) becomes the following equation (4).

Furthermore, the above formula (4) can be transformed into the following formula (5).

Here, let us consider the observable amount of out-of-plane deformation in the second term on the right side of Equation (5) above. Assuming that the twist angle ω is small, the deflection W of the steel plate S is expressed by the following equation (6).

Here, in the above formula (6), y is the position in the width direction. Further, the length l along the curved surface of the steel plate S can be expressed by the following formula (7).

Further, the elongation difference rate Δε _l can be defined as in the following formula (8).

Here, in the above formula (8), l ₀ is the average length in the width direction, and can be expressed by the following formula (9).

Here, in the above formula (9), b is the plate width. Then, by substituting the above equation (6) and the above equation (7) into the above equation (9), the following equation (10) holds true.

Here, assuming that the deflection w and the twist angle ω are small, the above equation (10) becomes the following equation (11).

Then, when the above formula (11) is further transformed, the following formula (12) is obtained.

When the above equation (6), the above equation (7), and the above equation (12) are substituted into the above equation (8), the elongation difference rate Δε _l can be expressed by the following equation (13).

The curvature Κ ₁ of the average one-side elongation (average bending) converted from the elongation difference rate Δε ₁ can be defined as in the following equation (14).

Then, by substituting the above formula (13) into the above formula (14), the following formula (15) is obtained.

The above formula (15) is the second term on the right side of the above formula (5), and the above formula (5) can be expressed as the following formula (16).

It is possible to calculate the curvature Κ ₁ from the out-of-plane deformation amount or the measured value of its slope measured by the shape measuring device 7 using the above equation (14). If the steel plate S does not meander or the like and the first term on the right side of the above equation (14) becomes zero, the curvature _K1 of the inherent one-sided elongation or bending will be the same as the measurable curvature _K1 . Since the first term on the right side of the above equation (16), which is related to the meandering in the above equation (16), is difficult to measure, it is recommended to measure the amount of out-of-plane deformation of the steel plate S using the shape measuring device 7 at a place where the steel plate S does not meander. desirable.

Here, the amount of out-of-plane deformation is one of the indicators indicating the bending and one-sided elongation of the steel plate S. As a method for measuring the amount of out-of-plane deformation, the following two methods can be considered with reference to FIG. FIG. 2 is a diagram showing an example of a method for measuring the amount of out-of-plane deformation.

The first method is to apply normal force to the steel plate S by winding the steel plate S around a roll 20 or pressing the steel plate S to smooth out the wrinkles, as shown in FIG. 2(a). This method measures the bending (one-sided elongation) of the steel plate S.

The second method is to straighten the steel plate S in the longitudinal direction (do not meander) as shown in FIG. 2(b), and calculate the bending (unilateral elongation) from the height of the wrinkles in the steel plate S.

In the first method, it is difficult to measure if the longitudinal length of the steel plate S to which wrinkles are straightened is short, so it is desirable to adopt the second method.In this embodiment, the amount of out-of-plane deformation is Measure (convert).

In the field of rolling, the shape of an asymmetric component is often expressed by the left-right difference (shape parameter) in the elongation difference distribution. A shape parameter λ ₁ representing one-sided elongation or bending is defined as shown in the following equation (17).

The unit of the shape parameter λ ₁ is I-unit. Here, y' can be expressed by the following formula (18).

Then, by substituting the above formula (18) and the above formula (14) into the above formula (17), the following formula (19) is obtained.

As can be seen from the above equation (19), the shape parameter λ ₁ has a proportional relationship with the curvature Κ ₁ .

FIG. 3 is a diagram showing the measurement results of one-sided elongation or bending, which is the amount of out-of-plane deformation of the steel plate S, measured by the shape measuring device 7 installed on the exit side of the entrance looper 5. Note that the horizontal axis in FIG. 3 is time, and the vertical axis is the shape parameter λ ₁ defined by the above equation (17) and the above equation (19). In this case, the shape parameter λ ₁ changes rapidly at the junction. In the preceding material, there is no unilateral elongation or bending due to the hot rolling process, and in the succeeding material, there is unilateral elongation or bending due to the hot rolling process, and the magnitude of the unilateral elongation or bending gradually decreases as the distance from the tip increases. There is.

In order to detect one-sided elongation or bending with the shape measuring device 7, it is better that the steel plate S does not meander, and in this embodiment, the shape measuring device 7 is installed directly downstream of the steering device 6. The shape measuring device 7 is a real-time 3D laser scanner that measures the position of the steel plate surface as a point group by rotating a plurality of laser beams and measuring the distance and rotation angle between the center of rotation and the steel plate surface. Note that the rotation period of the laser beam is, for example, 0.1 seconds. By using a 3D scanner as the shape measuring device 7, a single sensor can be installed outside the line, so there are fewer installation restrictions and maintenance is simple. In addition, it has the advantage of being able to measure the surface of a steel plate in an instant, making it resistant to vibration without depending on the line speed, and being able to measure large shapes because it can be measured without contact. Since there is a measurement error in the position of the point group and the point group is irregular, the measurement error is removed by the smoothing thin plate spline method and the steel plate curved surface W is calculated from the point group. Note that calculations using the smoothed thin plate spline method take time, so in order to speed up calculations, it is preferable to use, for example, the technique disclosed in Japanese Patent Application Laid-Open No. 2017-49071. Then, the curvature Κ ₁ is calculated from the above equation (14) and the steel plate curved surface W, and the shape parameter λ ₁ is further calculated from the above equation (19).

Here, if the steel plate S had one-sided elongation or bending as shown in FIG. Since the shape measuring device 7 is installed on the upstream side of the cold rolling mill 11, information on the shape of the steel sheet S on the rolling mill entry side can be obtained before cold rolling. The risk of the steel plate S breaking can be predicted based on the magnitude of one-sided elongation or bending obtained from this information. Therefore, if the one-sided elongation or bending on the entrance side of the rolling mill is too large, the operation can be performed so as not to roll in order to prevent the steel sheet S from breaking. In the cold rolling equipment 1 according to the embodiment, the shape measuring device 7 measures one-sided elongation or bending on the entry side of the rolling mill as the amount of out-of-plane deformation of the steel sheet S. If the measured amount of out-of-plane deformation (one-sided elongation or bending) exceeds a preset threshold, cold rolling of the steel plate S by the cold rolling mill 11 is not performed. However, if it is not rolled, that part will not become a product, resulting in a lower yield.

Therefore, in order to more actively utilize information on the shape of the steel sheet S on the rolling mill entry side, leveling control will be explained using FIG. 4. Generally, leveling FB control is performed in order to correct one-sided elongation or bending of the steel plate S in the cold rolling mill 11. As shown in FIG. 4, in the cold rolling mill 11, the exit sides of the first rolling mill 110a, the second rolling mill 110b, the third rolling mill 110c, the fourth rolling mill 110d, and the fifth rolling mill 110e are , a first shape meter roll 111a, a second shape meter roll 111b, a third shape meter roll 111c, a fourth shape meter roll 111d, and a fifth shape meter roll 111e are installed, respectively. In the following description, if the first rolling mill 110a, the second rolling mill 110b, the third rolling mill 110c, the fourth rolling mill 110d, and the fifth rolling mill 110e are not particularly distinguished, they will simply be referred to as the rolling mill 110. Also written as In addition, when the first shape meter roll 111a, the second shape meter roll 111b, the third shape meter roll 111c, the fourth shape meter roll 111d, and the fifth shape meter roll 111e are not particularly distinguished, simply the shape meter roll Also written as 111.

The shape meter roll 111 measures the contact force distribution between the shape meter roll 111 and the steel plate S, and estimates the one-sided elongation or bending, which is the amount of out-of-plane deformation of the steel plate S, from the contact force distribution. Although the measurement method of the shape meter roll 111 is highly accurate, it is difficult to measure large shape defects because it needs to be brought into contact with the steel plate S. Therefore, simply estimating one-sided elongation or bending from the contact force distribution measured by the shape meter roll 111 may cause breakage due to bending stress during rolling by the rolling mill 110.

The cold rolling mill 11 also includes a first rolling mill 110a, a second rolling mill 110b, a third rolling mill 110c, a fourth rolling mill 110d, and a fifth rolling mill 110e. A leveling control device 151a, a second leveling control device 151b, a third leveling control device 151c, a fourth leveling control device 151d, and a fifth leveling control device 151e are provided. In the following description, when the first leveling control device 151a, the second leveling control device 151b, the third leveling control device 151c, the fourth leveling control device 151d, and the fifth leveling control device 151e are not particularly distinguished, , also simply referred to as a leveling control device 151.

The leveling control device 151 calculates a leveling target value by multiplying the time-integrated value of one-sided elongation or bending on the exit side of the rolling mill by a gain. Note that the leveling target value is determined by the rolling position difference between the left and right bearings of the backup roll of the rolling mill 110, and as a result, the rolling reduction on one side in the thickness direction and on the other side in the thickness direction, with the center of the steel plate S in the thickness direction as a border. It is equal to the amount difference (the difference in the amount of reduction between the left and right sides of the steel plate S). Then, leveling feedback control is performed on the corresponding rolling mill 110 so that the calculated leveling target value is achieved. By performing such leveling FB control on the rolling mill 110, the contact force distribution on the shape meter roll 111 on the exit side of the rolling mill becomes symmetrical, and as a result, one-sided elongation or bending can be reduced. However, the drawback of the leveling FB control is that it cannot respond to sudden disturbances, and is insufficiently responsive to one-sided elongation or bending as shown in FIG.

In the cold rolling equipment 1 according to the embodiment, the cold rolling mill 11 is provided with a five-high rolling mill 110, but the rolling mill 110 to be controlled to the leveling target value is at least used for conveying the steel plate S. It suffices if the rolling mill 110 provided most upstream in the direction is included. Therefore, in the cold rolling equipment 1 according to the embodiment, one or more rolling mills 110 including the most upstream rolling mill 110 (first rolling mill 110a) are subject to leveling FB control. .

FIG. 5 is a diagram showing the transition of true one-sided elongation or bending as a result of a simulation of cold rolling a steel plate S with one-sided elongation or bending. FIG. 6 is a diagram showing the transition of one-sided elongation or bending calculated from the differential tension as a result of a simulation of cold rolling a steel plate S with one-sided elongation or bending. Note that the one-sided elongation or bending on the entry side of the first rolling mill is based on the one-sided elongation or bending shown in FIG. 3.

As shown in FIG. 5, the true one-sided elongation or bending on the exit side of the first rolling mill is smaller than the true one-sided elongation or bending on the inlet side of the first rolling mill. This is considered to be because the rolling phenomenon itself has the effect of reducing one-sided elongation or bending. However, as shown in Figure 5, during the time (0 to 10 seconds) when the true one-sided elongation or bending on the first rolling mill entry side changes rapidly, the true one-sided elongation or bending on the first rolling mill exit side changes rapidly. The size has also increased.

The true one-sided elongation or bending on the exit side of the first rolling mill shown in FIG. 5 is compared with the one-sided elongation or bending calculated from the differential tension on the exit side of the first rolling mill shown in FIG. Then, it can be seen that during the time (0 to 10 seconds) when the true one-side elongation or bending changes rapidly, the one-side elongation or bending calculated from the differential tension is different from the true one-side elongation or bending. On the other hand, when the change is relatively slow (10 to 50 seconds), the two values are relatively consistent. In addition, the one-sided elongation or bending calculated from the differential tension on the exit side of the first rolling mill and the one-sided elongation or bending calculated from the differential tension at the first shape meter roll 111a shown in FIG. 6 are relatively different. Match.

From the above, it can be seen that the one-sided elongation or bending calculated from the differential tension at the first shape meter roll 111a arranged on the exit side of the first rolling mill 110a does not necessarily match the true one-sided elongation or bending. Therefore, true one-sided elongation or bending cannot be observed in an actual machine. Therefore, the results of a simulation in which a steel plate S having one-sided elongation or bending was cold-rolled when leveling FB control was performed are shown in FIGS. 7 and 8.

FIG. 7 is a diagram showing the transition of true one-sided elongation or bending as a result of a simulation of cold rolling a steel plate S with one-sided elongation or bending when leveling FB control is performed. FIG. 8 is a diagram showing the transition of one-sided elongation or bending calculated from the differential tension as a result of a simulation of cold rolling a steel plate S with one-sided elongation or bending when leveling FB control is performed.

In the leveling FB control, the magnitude of the differential tension in each of the first shape meter roll 111a to the fifth shape meter roll 111e, which are arranged on the exit side of the first rolling mill 110a to the fifth rolling mill 110e, is reduced. Thus, the leveling of the first rolling mill 110a to the fifth rolling mill 110e is controlled. Therefore, the magnitude of one-sided elongation or bending calculated from the differential tension shown in FIG. 8 can be made significantly smaller than the magnitude of one-sided elongation or bending calculated from the differential tension shown in FIG. On the other hand, the magnitude of the true one-sided elongation or bending on the exit side of the first rolling mill shown in FIG. It is small during the time when elongation or bending changes slowly (10 to 50 seconds). However, the time (0 to 10 seconds) when the true one-sided elongation or bending changes rapidly is almost the same, and the leveling FB control cannot cope with it.

Originally, it would be desirable to reduce the magnitude of the true one-sided elongation or bending on the exit side of the first rolling mill, but it is not possible to observe these in an actual machine. Therefore, the results of leveling FB control performed by simulation to reduce the true one-sided elongation or bending on the exit side of the first rolling mill are shown in FIGS. 9 and 10.

FIG. 9 is a diagram showing the transition of true one-side elongation or bending as a result of leveling FB control to reduce the true one-side elongation or bending on the exit side of the first rolling mill through simulation. FIG. 10 is a diagram showing the transition of one-sided elongation or bending calculated from the differential tension as a result of leveling FB control to reduce the true one-side elongation or bending on the exit side of the first rolling mill through simulation.

The leveling FB control in this embodiment controls leveling so as to reduce the magnitude of true one-sided elongation or bending on the exit side of the first rolling mill. Therefore, the true one-sided elongation or bending size on the exit side of the first rolling mill shown in FIG. 9 is greater than the true one-side elongation or bending size on the first rolling mill exit side shown in FIGS. It can be made significantly smaller. On the other hand, the magnitude of one-sided elongation or bending calculated from the differential tension shown in FIG. 10 is larger than the one-sided elongation or bending calculated from the differential tension shown in FIG. True one-sided elongation or bending on the exit side of the first rolling mill cannot be observed, but one-sided elongation or bending on the inlet side of the first rolling mill can be measured. Therefore, by using simulation, it is possible to calculate the amount of leveling that reduces the magnitude of the true one-sided elongation or bending on the first rolling mill exit side from the one-sided elongation or bending on the first rolling mill entry side. Even in an actual machine, in principle, if a simulation is performed when one side elongation or bending on the entry side of the first rolling mill is known, an appropriate leveling amount can be calculated in advance. Then, at the timing when the one-sided elongation or bending reaches the first rolling mill 110a, leveling FF control is performed on the actual first rolling mill 110a using the calculated leveling amount. Thereby, true one-sided elongation or bending on the exit side of the first rolling mill can be reduced.

Note that simulation requires calculation time. Therefore, the machine calculates the partial elongation or bending on the entry side of the first rolling mill and the appropriate leveling amount in multiple cases, and outputs the appropriate leveling amount from the partial elongation or bending on the entry side of the first rolling mill. By learning, you can find the appropriate leveling amount online.

For example, the value obtained as a result of the calculation device 150 shown in FIG. 4 applying a leveling amount calculation program to the amount of out-of-plane deformation (unilateral elongation or bending) on the entry side of the first rolling mill obtained from the shape measuring device 7. is used to calculate the leveling amount used for leveling FF control of the first rolling mill 110a. In addition, the applied leveling amount calculation program uses machine learning with each out-of-plane deformation amount of multiple steel plates as an input variable, and each leveling amount obtained as a result of physical simulation for each out-of-plane deformation amount as an objective variable. It is something that

In reality, since there are differences between the simulation and the actual machine, it is preferable to use the leveling FF control in combination with the leveling FB control rather than using it alone. Therefore, the results of a simulation in which a steel plate S having one-sided elongation or bending was cold-rolled by performing leveling FF control and leveling FB control are shown in FIGS. 11 and 12. Note that in the first rolling mill 110a, the leveling FF control output and the leveling FB control output are added together to obtain a control output.

FIG. 11 is a diagram showing the transition of true one-sided elongation or bending as a result of a simulation in which a steel plate S with one-sided elongation or bending was cold-rolled by performing leveling FF control and leveling FB control. FIG. 12 is a diagram showing the transition of one-sided elongation or bending calculated from the differential tension as a result of a simulation in which a steel plate S with one-sided elongation or bending was cold-rolled by performing leveling FF control and leveling FB control. .

The true one-sided elongation or bending on the exit side of the first rolling mill shown in FIG. 11 is smaller than the true one-sided elongation or bending on the exit side of the first rolling mill shown in FIG. This is larger than the true one-sided elongation or bending at the exit side of the first rolling mill. By adjusting the weighting of the leveling FF control and the leveling FB control, it is adjusted whether the true one-sided elongation or bending on the exit side of the first rolling mill approaches the result of the leveling FF control or the result of the leveling FB control. be able to.

In the leveling control applied to the cold rolling equipment 1 according to the embodiment, data processing is performed on the shape measuring device 7, which is a shape meter disposed on the entrance side of the first rolling mill 110a, and Calculate one-sided extension or bending. Then, using a machine learning program, a leveling FF control output, which is appropriate leveling, is calculated from the calculated one-sided elongation or bending on the entrance side of the first rolling mill. The first leveling control device 151a uses the one-sided elongation or bending on the exit side of the first rolling mill, which is the amount of out-of-plane deformation of the steel sheet S measured by the first shape meter roll 111a, to determine the leveling amount of the first rolling mill 110a. Calculate. The first leveling control device 151a then performs leveling FB control to control the leveling of the first rolling mill 110a based on the calculated leveling amount. Further, the first leveling control device 151a tracks the steel plate S based on the line speed, and adjusts the leveling FF control output at the timing when the one-sided elongation or bending measured by the shape measuring device 7 reaches the first rolling mill 110a. Leveling FB control is weighted and added together, and the added value is used as a target value to control leveling. By performing such leveling control, it was possible to reduce the probability of breakage from 2% due to poor leveling control to 1%.

As described above, the present invention enables cold rolling with high productivity and yield while ensuring stability of cold rolling even when cold rolling difficult-to-roll materials with a thin plate thickness before rolling. A cold rolling method and cold rolling equipment capable of rolling can be provided.

1 Cold rolling equipment 2 Payoff reel 3 Welding machine 4 Notcher 5 Entrance looper 6 Steering device 7 Shape measuring device 8 Deflector steering roll 9 Bridle roll group 10 Defrator steering roll 11 Cold rolling machine 12 Bridle roll 13 Cutting machine 14 Tension Reel 110 Rolling mill 110a First rolling mill 110b Second rolling mill 110c Third rolling mill 110d Fourth rolling mill 110e Fifth rolling mill 111 Shape meter roll 111a First shape meter roll 111b Second shape meter roll 111c Third shape meter Roll 111d Fourth shape meter roll 111e Fifth shape meter roll 150 Calculation device 151 Leveling control device 151a First leveling control device 151b Second leveling control device 151c Third leveling control device 151d Fourth leveling control device 151e Fifth leveling control device

Claims

a calculation step of calculating the amount of leveling of the rolling mill using the amount of out-of-plane deformation of the steel plate measured on the upstream side of the rolling mill;
a control step of controlling leveling of the rolling mill based on the leveling amount calculated in the calculation step;
a cold rolling step of subjecting a steel plate to cold rolling using the rolling mill controlled by the controlling step;
A cold rolling method characterized by comprising:
Claim 1, wherein the amount of out-of-plane deformation of the steel plate is an amount of out-of-plane deformation measured upstream of the rolling mill and immediately upstream or downstream of a steering device that changes the conveyance direction of the steel plate. The cold rolling method described in .
The cold rolling method according to claim 1 or 2, characterized in that when the amount of out-of-plane deformation of the steel plate measured on the upstream side of the rolling mill exceeds a threshold value, cold rolling is not performed on the steel plate in the cold rolling step. Inter-rolling method.
In the calculation step,
The leveling amount is calculated using a value obtained as a result of applying a leveling amount calculation program to the out-of-plane deformation amount,
The leveling amount calculation program is
Machine learning is performed using each out-of-plane deformation amount of a plurality of steel plates as an input variable and each leveling amount obtained as a result of a physical simulation for each out-of-plane deformation amount as an objective variable. The cold rolling method according to claim 1 or 2.
In the calculation step,
The leveling amount is calculated using a value obtained as a result of applying a leveling amount calculation program to the out-of-plane deformation amount of the steel plate,
The leveling amount calculation program is
Machine learning is performed using each out-of-plane deformation amount of a plurality of steel plates as an input variable and each leveling amount obtained as a result of a physical simulation for each out-of-plane deformation amount as an objective variable. The cold rolling method according to claim 3.
In the calculation step,
The leveling amount is calculated using an amount of out-of-plane deformation of the steel plate on the upstream side of the rolling mill and an amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill. 2. The cold rolling method according to 1 or 2.
In the calculation step,
The leveling amount is calculated using an amount of out-of-plane deformation of the steel plate on the upstream side of the rolling mill and an amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill. 3. The cold rolling method described in 3.
In the calculation step,
The leveling amount is calculated using an amount of out-of-plane deformation of the steel plate on the upstream side of the rolling mill and an amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill. 4. The cold rolling method described in 4.
In the calculation step,
The leveling amount is calculated using an amount of out-of-plane deformation of the steel plate on the upstream side of the rolling mill and an amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill. 5. The cold rolling method according to 5.
A rolling mill that cold-rolls a steel plate;
a shape measuring device that is disposed upstream of the rolling mill and measures the amount of out-of-plane deformation of the steel plate;
a calculation device that calculates the amount of leveling of the rolling mill using the amount of out-of-plane deformation of the steel plate measured by the shape measuring device;
a control device that controls leveling of the rolling mill based on the leveling amount calculated by the calculation device;
A cold rolling facility characterized by comprising:
A steering device is provided upstream of the rolling mill and changes the conveyance direction of the steel plate,
Cold rolling according to claim 10, characterized in that the amount of out-of-plane deformation of the steel plate is the amount of out-of-plane deformation measured upstream of the rolling mill and immediately upstream or downstream of the steering device. Facility.
Cold rolling according to claim 10 or 11, wherein when the amount of out-of-plane deformation of the steel plate measured on the upstream side of the rolling mill exceeds a threshold value, the rolling mill does not perform cold rolling on the steel plate. Facility.
The calculation device calculates the leveling amount using a value obtained as a result of applying a leveling amount calculation program to the out-of-plane deformation amount,
The leveling amount calculation program is
Machine learning is performed using each out-of-plane deformation amount of a plurality of steel plates as an input variable and each leveling amount obtained as a result of a physical simulation for each out-of-plane deformation amount as an objective variable. The cold rolling equipment according to claim 10 or 11.
The calculation device calculates the leveling amount using a value obtained as a result of applying a leveling amount calculation program to the out-of-plane deformation amount,
The leveling amount calculation program is
Machine learning is performed using each out-of-plane deformation amount of a plurality of steel plates as an input variable and each leveling amount obtained as a result of a physical simulation for each out-of-plane deformation amount as an objective variable. The cold rolling equipment according to claim 12.
The calculation device calculates the leveling amount using an amount of out-of-plane deformation of the steel plate on the upstream side of the rolling mill and an amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill. The cold rolling equipment according to claim 10 or 11.
The calculation device calculates the leveling amount using an amount of out-of-plane deformation of the steel plate on the upstream side of the rolling mill and an amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill. The cold rolling equipment according to claim 12.
The calculation device calculates the leveling amount using an amount of out-of-plane deformation of the steel plate on the upstream side of the rolling mill and an amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill. The cold rolling equipment according to claim 13.
The calculation device calculates the leveling amount using an amount of out-of-plane deformation of the steel plate on the upstream side of the rolling mill and an amount of out-of-plane deformation of the steel plate measured on the downstream side of the rolling mill. The cold rolling equipment according to claim 14.