JP6772918B2 - Rolling control method, rolling control device and program - Google Patents

Description

The present invention relates to a rolling control method, a rolling control device, and a program for more accurately manufacturing a plate crown of a material to be rolled, particularly a thick plate material.

In plate rolling, a material to be rolled (for example, a steel plate) is rolled to a desired product plate thickness by reverse rolling of a plurality of passes using a plate rolling machine. At this time, in order to control the plate crown and flatness with high accuracy, a path schedule (rolling amount distribution) is set in advance before rolling so that the finally manufactured thick plate has the desired plate crown and flatness. Then, rolling is performed according to this set path schedule.

However, in reality, the predicted values such as the temperature and deformation resistance of the material to be rolled deviate from the actual values, which causes an error in the rolling load and an error in the roll profile used for setting the path schedule. Therefore, it is difficult to perform rolling according to the set value, and even if rolling is performed according to the set path schedule, a thick plate having a desired plate crown and flatness may not be produced.

Here, many techniques have been developed to improve the accuracy of forming the plate crown in rolling by learning the roll profile in the middle pass. For example, Patent Documents 1-3 describe that the predicted value of the roll profile is learned by using the measured value of the plate crown in the middle pass. Patent Document 1 shows a method of learning a roll profile by actually measuring a plate crown. Further, Patent Document 2 discloses a technique for changing the reduction amount distribution of the subsequent rolling pass by using the learned roll profile. Further, Patent Document 3 discloses a technique for improving the accuracy of gauge meter plate thickness control by modifying the roll gap setting based on the learned roll profile. Further, in Patent Document 4, a roll profile learned based on the plate crown and flatness measured in the intermediate pass is used, and the subsequent rolling pass is used in order to suppress the occurrence of poor flatness of the material to be rolled. The technology for changing the roll bending force to achieve the originally set crown is disclosed in.

JP-A-59-215205 JP-A-2002-28708 Japanese Unexamined Patent Publication No. 7-185624 Japanese Unexamined Patent Publication No. 3-32412

However, Patent Document 1 does not mention a specific changing method when changing the setting conditions in the subsequent rolling path by using the modified roll profile. On the other hand, in Patent Document 2, as a specific method for changing the setting conditions, a modified roll profile is used, and a path schedule (reduction amount distribution) in the remaining paths is used so as to achieve a desired plate crown and flatness. ) Is described to be reset. However, resetting the reduction amount distribution requires a calculation time that is not short. Therefore, in the technique described in Patent Document 2, there is a concern that the total working time related to rolling will increase and the operating efficiency will decrease.

Further, the technique described in Patent Document 3 is aimed at improving the control accuracy of the plate thickness, and does not consider the achievement of the plate crown and the flatness. Further, in the technique described in Patent Document 4, in the rolling after the roll profile is modified, the roll bending force is adjusted for each rolling pass so that the set value of the plate crown calculated before the start of rolling is realized. Here, not only is it essential that the rolling mill is equipped with a roll bender in order to carry out the technique, but in general, the amount of crown control by roll bending is not very large. Therefore, in the technique described in Patent Document 4, even if the rolling mill is provided with a roll bender, for example, when the deviation between the actual plate crown and its set value is large, the plate crown is used. It may not be properly controlled to match the set value. Further, in the technique described in Patent Document 4, it is necessary to measure both the plate crown and the flatness of the rolled material in order to learn the roll profile. Therefore, the installation of the plate crown measuring instrument and the flatness measuring instrument is indispensable, which not only complicates the equipment but also increases the cost for installation and maintenance.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is a subject having a higher quality plate crown and plate shape by simpler control in rolling consisting of a plurality of passes. It is an object of the present invention to provide a new and improved rolling control method, a rolling control device and a program capable of obtaining a rolled material.

In order to solve the above problem, according to a certain viewpoint of the present invention, in rolling where the total number of rolling passes is N pass (N ≧ 2), before the execution of the rth pass (2 ≦ r ≦ N). , The roll profile is modified and modified so that the measured value of the plate crown or flatness on the entry side of the rolling pass of the r-th pass matches the calculated value of the plate crown or flatness based on the model formula. The plate crown on the exit side of each rolling pass in the r to m-1th pass (r ≦ m ≦ N) was calculated using the roll profile, and the modified roll profile and the calculated r to m-1st pass were calculated. Using the plate crown on the exit side of each rolling pass, calculate the crown control amount so that the plate crown on the exit side of the t-pass, which is one of the m to Nth rolling passes, matches the desired plate crown. , The rolling control method for imparting the calculated crown control amount in the rolling in each rolling pass of the m to t pass is provided.

Further, in the rolling control method, the crown control amount may be uniform in rolling in each rolling pass of the mtth pass.

Further, in the rolling control method, the crown control amount may be given by adjusting the roll cross angle or the roll shift amount of the rolling mill.

Further, in the rolling control method, r = m may be used.

Further, in the rolling control method, t = N may be used.

Further, in the rolling control method, the t-pass may be a rolling pass having an entry-side plate thickness of 20 mm or more.

Further, in order to solve the above problem, according to another viewpoint of the present invention, in rolling where the total number of rolling passes is N pass (N ≧ 2), the r-th pass (2 ≦ r ≦ N) rolling pass. Prior to execution, the roll profile was modified so that the measured value of the plate crown or flatness on the entry side of the rolling pass of the r-th pass matches the calculated value of the plate crown or flatness based on the model formula. Then, using the modified roll profile, the plate crown on the exit side of each rolling pass of the r to m-1th pass (r ≤ m ≤ N) was calculated, and the modified roll profile and the calculated r to m- Using the plate crown on the exit side of each rolling pass in the first pass, a crown control amount such that the plate crown on the exit side of the t pass, which is one of the rolling passes m to N, matches the desired plate crown. Is provided, and a rolling control device is provided that gives the calculated crown control amount in rolling in each rolling pass in the m to t pass.

Further, in order to solve the above problem, according to another viewpoint of the present invention, it is a program for causing a computer to execute a rolling control method in rolling in which the total number of rolling passes is N (N ≧ 2). In the rolling control method, the measured value of the plate crown or flatness on the entry side of the rolling pass of the r-th pass (2 ≦ r ≦ N) before the execution of the rolling pass of the r-th pass is the plate crown based on the model formula. Alternatively, the roll profile is modified so as to match the actual calculated value, which is the calculated value of flatness, and each rolling pass of the r to m-1th pass (r ≦ m ≦ N) is output using the corrected roll profile. The side plate crown is calculated, the modified roll profile, and each rolling pass on the r to m-1th pass calculated. The rolling pass on the exit side is one of the m to Nth passes. Provided by the program, the crown control amount is calculated so that the plate crown on the exit side of the t-pass matches the desired plate crown, and the calculated crown control amount is given in the rolling in each rolling pass from the m to t-pass. Will be done.

As described above, according to the present invention, in rolling consisting of a plurality of passes, it is possible to obtain a material to be rolled having a higher quality plate crown and plate shape by simpler control.

It is a figure which shows one structural example of the system which concerns on one Embodiment of this invention. It is a flow chart which shows an example of the processing procedure of the conventional rolling control method. It is a flow chart which shows an example of the processing procedure of the rolling control method which concerns on 1st Embodiment. It is a block diagram which shows an example of the functional structure of the rolling control apparatus which concerns on 1st Embodiment. It is a flow chart which shows an example of the processing procedure of the rolling control method which concerns on 2nd Embodiment. It is a graph which shows the simulation result in thick plate rolling which applied the rolling control method which concerns on 1st Embodiment. It is a graph which shows the result when the target path is set other than the final path in the thick plate rolling which applied the rolling control method which concerns on 1st Embodiment. It is a graph which shows the result of the thick plate rolling which applied the rolling control method which concerns on 2nd Embodiment.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

(1. First Embodiment)
(1-1. System configuration)
The configuration of the system according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing a configuration example of a system according to an embodiment of the present invention.

Referring to FIG. 1, the system 1 according to the first embodiment is mainly composed of a rolling mill 10 and a rolling control device 20 for controlling the operation of the rolling mill 10.

The rolling mill 10 is a reversible rolling mill, and rolling is performed by passing the material 2 to be rolled through the rolling mill 10 a plurality of times (multiple passes) while the transport direction is changed by the table roll 170. Specifically, in the first rolling pass, the material 2 to be rolled is sent from the front side (left side in the drawing) to the rolling mill 10 by the table roll 170, and rolling is started. Then, the rolled material 2 that has been rolled escapes to the rear surface side (right side in the drawing) of the rolling mill 10. Further, in the next rolling pass, the material 2 to be rolled is sent from the rear surface side of the rolling mill 10 to the rolling mill 10 by the table roll 170 to start rolling, and after the rolling is performed, it comes out to the front side of the rolling mill 10. To go. Hereinafter, by repeating this rolling pass a plurality of times, the material 2 to be rolled is reduced to a desired plate thickness.

The rolling mill 10 is provided with a pair of upper work rolls 121 and lower work rolls 122 inside the housing 110, and upper and lower backup rolls 123 and lower backup rolls are provided above and below the upper work rolls 121 and lower work rolls 122, respectively. It is a quadruple rolling mill provided with 124. However, the rolling mill 10 is not limited to the quadruple type, and may be a multiple type rolling mill other than the quadruple type. In the following description, when at least one of the upper work roll 121, the lower work roll 122, the upper backup roll 123, and the lower backup roll 124 is expressed, these may be simply referred to as rolls.

The upper work roll 121 and the lower work roll 122 are provided inside the housing 110 in a state of being pivotally supported by the work roll chocks 131 and 132, respectively. Further, the upper backup roll 123 and the lower backup roll 124 are provided inside the housing 110 in a state of being pivotally supported by the backup roll chocks 133 and 134, respectively.

In the first embodiment, the rolling mill 10 is a so-called roll cross mill. The rolling mill 10 includes a roll cloth mechanism (not shown) for changing the roll cloth angle. Further, the system 1 is provided with a roll cloth drive device (not shown) for driving the roll cloth mechanism. An instruction from the rolling control device 20 is input to the roll cloth drive device, and the roll cloth mechanism is driven by the roll cloth drive device according to the instruction, so that a desired roll cloth angle according to the instruction is set on the upper work. It is set to the roll 121, the upper backup roll 123, the lower work roll 122, and the lower backup roll 124.

Further, although the detailed mechanism is not shown, the rolling mill 10 may be a so-called roll bending mill or roll shift mill. The rolling mill 10 is configured so that its roll bending force or roll shift amount can be changed by control from the rolling control device 20.

Note that, in FIG. 1, the instruction for drive control from the rolling control device 20 is simply input to the upper work roll 121, the lower work roll 122, the upper backup roll 123, and the lower backup roll 124. As shown, in reality, the system 1 is provided with a roll cross drive device that operates to cross the rolls or a roll shift drive device that operates to shift the rolls (both not shown in FIG. 1). Be done. An instruction from the rolling control device 20 is input to the roll cloth drive device or the roll shift drive device, and the roll is driven by the roll cloth drive device or the roll shift drive device according to the instruction to obtain a desired roll cloth. An angle or roll shift amount is realized.

Here, in general, a roll bender mechanism, a roll cross mechanism, and a roll shift mechanism are known as crown control mechanisms that are adjusted when controlling the plate crown of the material 2 to be rolled in rolling, respectively. Crown control can be performed by controlling the roll bending force (more specifically, the bender pressure applied to the roll bender mechanism), the roll cross angle, and the roll shift amount. In the first embodiment, any of the roll bending force (roll bender pressure), the roll cross angle, and the roll shift amount may be adjusted when the crown is controlled.

In general, the response of the roll cross mechanism or the roll shift mechanism is slower than the response of the roll bender mechanism, while the roll cross mechanism or the roll shift mechanism has a large crown control capability as compared with the roll bender mechanism. ing. Therefore, in the first embodiment, whether to change the roll bender pressure, the roll cross angle, and / or the roll shift amount when controlling the plate crown is determined in total in consideration of such characteristics. It may be appropriately determined in consideration of the request for the time required for rolling, the required control amount (change amount) of the plate crown, and the like.

The backup roll chock 133 of the upper backup roll 123 of the rolling mill 10 is provided with a reduction device 150 for adjusting the interval (roll interval) between the upper work roll 121 and the lower work roll 122. The rolling control device 150 adjusts the roll interval, that is, the rolling position, under the control of the rolling control device 20. Further, the reduction device 150 may be integrally configured with the load cell, and can measure the rolling load applied to the upper work roll 121 and the lower work roll 122 during rolling. The measured rolling load value is transmitted to the rolling control device 20.

The first embodiment is not limited to this example, and a load cell may be provided in the rolling mill 10 as a device separate from the rolling mill 150. Further, the position where the reduction device 150 and the load cell are provided is not limited to the above example, and the reduction device 150 and the load cell may be provided on the backup roll chock 134 of the lower backup roll 124.

A plate crown measuring instrument 160 is provided on the rear surface side of the rolling mill 10. The plate crown measuring instrument 160 measures the plate crown of the material 2 to be rolled after passing through the rolling mill 10, that is, at the stage when a predetermined rolling pass is completed. The measured plate crown value is transmitted to the rolling control device 20.

The first embodiment is not limited to this example, and the plate crown measuring instrument 160 may be provided on the front side of the rolling mill 10 or on both sides. Further, instead of the plate crown measuring instrument 160, a flatness measuring instrument for measuring the flatness of the material 2 to be rolled may be provided.

The rolling control device 20 controls the operation of the rolling mill 10 to perform rolling of a plurality of passes on the material 2 to be rolled. The rolling control device 20 may be a processor such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), for example. Alternatively, the rolling control device 20 may be a control board or a computer on which storage elements such as these processors and memories (for example, ROM (Read Only Memory) and RAM (Random Access Memory)) are mounted. When the processor constituting the rolling control device 20 executes various arithmetic processes according to a predetermined program, various operations in the rolling mill 10 are executed. Further, the rolling control device 20 may include a communication device for exchanging various information with the rolling mill 10, a storage device capable of storing various information, and the like.

Specifically, the rolling control device 20 sets the type of the material 2 to be rolled (for example, the steel type in the case of a steel plate), the thickness at the start of rolling, the thickness at the end of rolling, the plate width, and Based on the rolling conditions such as the roll profile state and the temperature of the material to be rolled, a predetermined pass schedule calculation is performed to determine the desired plate thickness, plate crown and number of rolling passes for obtaining flatness, and the pass schedule (each rolling). Initialize the rolling amount distribution of the path). At this time, the rolling load of each rolling pass is predicted and calculated based on information such as the rolling reduction amount and rolling speed of each rolling pass, the temperature and type of the material to be rolled, and based on this information, the output side of each rolling pass The crown control amount (for example, roll bending force) in the plate crown and each rolling pass is set. Then, the rolling control device 20 executes rolling according to the set value by driving the rolling device 150 and the crown control mechanism (for example, a roll cross mechanism) according to the respective set values before executing each rolling pass. To do. Since various known methods may be applied as the method of calculating the path schedule before the start of rolling, detailed description thereof will be omitted here.

In the first embodiment, after the start of rolling, until the rolling pass of the m-1th pass (2 ≦ m ≦ N, N is the total number of passes), crown control (for example, roll) according to the above set value is performed. Vendor pressure control) is executed. Then, before starting the rolling pass of the m-th pass (that is, at the stage of completing the rolling pass of the m-1th pass), the roll is rolled using the measured value of the plate crown or flatness of the material 2 to be rolled. A process of correcting the predicted value of the profile, that is, a process of learning the role profile is performed. Then, using the modified roll profile, the crown control amount (the amount of change of the plate crown from the set value) in the rolling pass after the mth pass is calculated, and the rolling pass after the mth pass is calculated according to the crown control amount. Is rolled.

Hereinafter, the above-mentioned roll profile correction process and rolling control using the corrected roll profile, which are performed in the rolling control device 20 according to the first embodiment, will be described in detail. In the following description, for the sake of simplicity, the "m-th pass rolling pass" is also abbreviated as "m-pass" and the like.

(1-2. Processing by rolling control device)
(1-2-1. Outline of processing)
First, an outline of the rolling control method according to the first embodiment, which is executed by the rolling control device 20, will be described. As described above, in rolling with multiple passes related to thick plate rolling, a pass schedule (rolling amount distribution of each rolling pass) is set in consideration of the plate crown and flatness of the final product before the start of rolling. Will be done. Then, rolling is started so as to realize a set value of the plate thickness on the exit side of each rolling path according to the rolling reduction amount distribution.

However, due to the temperature prediction error of the material to be rolled in each rolling pass, a prediction error occurs in the rolling load, and the set calculated value of the rolling load does not always match the actual value. Therefore, the plate crown of the material to be rolled on the exit side of each rolling pass (that is, the entry side of each of the following rolling passes) does not necessarily match the set calculated value.

On the other hand, even if there is no prediction error in the rolling load, if there is an error in the roll profile used in the setting calculation, it will be on the exit side of each rolling path (that is, the entry side of each next rolling path). The set calculated value or the actual calculated value of the plate crown of the material to be rolled does not always match the measured value. Here, as the actual calculated value, the measured value of the rolling load and the measured value of the inlet / output side plate thickness (for the plate thickness, the gauge meter plate thickness calculated from the measured value of the rolling load and the rigidity of the rolling mill is used. It is a calculated value calculated from the plate crown calculation model using the roll profile. In actual equipment, the measured value (for example, plate crown) is not always obtained due to the relationship between the installation position of the measuring instrument and the number of installed units, so the actual value can be represented (the measured value can be substituted). ), Such an actual calculated value can be preferably used.

Therefore, in the first embodiment, when the rolling pass of the m-1th pass (2 ≦ m ≦ N) is completed, the plate crown or flatness of the material 2 to be rolled on the rolling pass entry side of the mth pass is completed. The roll profile is learned using the measured values of, and the learned roll profile is used to perform rolling after the m-pass. In the roll profile learning process, the roll profile is modified so that the measured value of the plate crown or flatness on the m-pass entry side matches the actual calculated value.

For rolling after the mth pass, the modified roll profile was used to calculate the crown control amount so that the plate crown on the exit side matches the desired value for each rolling pass from the m to Nth pass. The crown control amount is given in each rolling pass of the m to Nth pass (that is, the crown control mechanism (roll bender mechanism, roll cross mechanism and / or roll shift mechanism) is driven so as to realize the crown control amount). ), Rolling is performed in the rolling pass after the mth pass. Here, the desired value of the plate crown for each rolling pass of the m to Nth pass is the target value of the plate crown of the product on the final pass (N pass) exit side (that is, on the N pass exit side). It is obtained by calculating from the rolling conditions using an existing crown model as a value that matches the initially set value of the plate crown). Further, for example, when the crown control capability of the rolling mill is insufficient, the target value of the plate crown of the product may be changed to a larger value within the tolerance range to give a desired value.

At this time, as the crown control amount, a crown control amount such that the plate crown matches the desired plate crown on the exit side of each rolling pass after the mth pass may be calculated and given for each rolling pass. Then, a uniform crown control amount in the rolling pass from the mth pass to the Nth pass is calculated and given so that the plate crown on the N pass exit side (that is, the plate crown in the final product) matches the desired plate crown. May be done. In the following description, for convenience, the plate crown control according to the former crown control amount is referred to as "plate crown control that gives a different crown control amount for each rolling path", and the latter crown control amount is followed. The plate crown control is referred to as "plate crown control that imparts a uniform crown control amount to all rolling paths".

Here, in plate crown control in which a different crown control amount is applied to each rolling pass, it is necessary to change the crown control amount for each rolling pass, so rolling provided with a highly responsive crown control mechanism such as a roll bending mechanism. The machine is indispensable for practical use. Focusing on the rolling pass of the mth pass, if the difference between the measured value of the plate crown and the set value on the exit side of the m-1 pass is large, the plate crown is significantly changed in the mth rolling pass. It becomes necessary to perform rolling so as to make it. However, as described above, the crown control ability by the roll bending force is not so large. Therefore, when the difference between the measured value of the plate crown on the m-1 pass output side and the set value is large, the plate crown on the m-1 pass output side matches the set value even if the roll bending force is adjusted. It may be difficult to roll the m-pass.

Here, it is known that the roll cross mechanism or the roll shift mechanism has a larger crown control ability than the roll bending mechanism. Therefore, in the plate crown control in which a different crown control amount is applied for each rolling pass, it is conceivable to control the plate crown by changing the roll cross angle or the roll shift amount instead of the roll bending force. However, while the change in roll bending force is relatively high in response, the change in roll cross angle or roll shift amount is relatively low in response. Therefore, changing the roll cross angle or the roll shift amount for each rolling pass is not very realistic because it may lead to an increase in the total working time related to rolling. In addition, increasing the working time for changing the roll cross angle or the roll shift amount is not preferable from the viewpoint of lowering the temperature of the material to be rolled.

On the other hand, in the plate crown control in which a uniform crown control amount is given to all rolling passes, a "uniform" crown control amount is calculated and given to the rolling passes from the mth pass to the Nth pass. According to the crown control amount, the crown control mechanism may be driven only once before the execution of the m-th rolling pass. Therefore, it is possible to realize a desired plate crown in the final product with simpler control without performing complicated control of changing the roll cross angle, roll shift amount and / or roll bending force for each rolling pass. it can. Therefore, in the first embodiment, in rolling after the m pass using the modified roll profile, a uniform crown is applied to all rolling passes rather than a plate crown control in which a different crown control amount is given to each rolling pass. It can be said that it is preferable that the plate crown control that imparts the control amount is executed.

In the plate crown control in which a uniform crown control amount is applied to all rolling passes, the roll cross angle, roll shift amount and / or roll bending force according to the crown control amount performed before the execution of the m-th rolling pass is performed. In the adjustment of, the roll cross angle or the roll shift amount can be preferably adjusted. As described above, when the roll cross angle or the roll shift amount is changed, the plate crown can be changed in a larger range than when the roll bending force is changed. Therefore, the roll cross angle or the roll shift amount can be changed. By changing the roll shift amount, it becomes possible to control the plate crown more appropriately even when the deviation between the measured value and the set value of the plate crown on the m-1 pass exit side is large. At this time, in the plate crown control in which a uniform crown control amount is given to all rolling passes, the roll cross angle or the roll shift amount needs to be changed only once as described above, so that the change is relatively long. Even if it takes time, the influence on the total working time related to rolling is small. Further, if the roll cross angle or the roll shift amount is changed in the middle pass with a relatively thick plate thickness, the temperature drop of the material to be rolled can be suppressed even if the change takes some time.

The outline of the rolling control method according to the first embodiment has been described above. As described above, in the first embodiment, the roll profile is learned in the middle of the rolling consisting of a plurality of rolling passes, and the learning result is reflected in the rolling in the subsequent rolling passes.

Here, conventionally, in rolling, it is widely practiced to modify the roll profile based on the rolling performance of the preceding material and use the modified roll profile for the setting calculation at the time of rolling for the next material to be rolled. There is. However, in this method, for example, when the plate width of the material to be rolled is significantly different from that of the preceding material, even if the roll profile modified based on the rolling performance of the preceding material is used, the roll in the next material to be rolled is not necessarily used. The accuracy of profile estimation does not always improve. In addition, in order to stabilize the roll profile learning even when the plate width change from the preceding material is large as described above, the gain has to be set small. On the other hand, according to the first embodiment, in the rolling of a plurality of passes for the same material to be rolled in the same rolling mill, the roll profile is modified based on the measured value of the plate crown in the intermediate pass, and the modified roll is used. The profile is used to control the plate crown in rolling in the remaining rolling paths. In this case, since the material to be rolled (the material to be rolled by measuring the plate crown) used for the roll profile learning and the material to be rolled to be controlled are the same, the roll profile error can be estimated and compensated with high accuracy. .. Therefore, the effect of roll profile learning can be obtained more preferably.

The rolling control method according to the first embodiment can be preferably applied to rolling on a relatively thick thick plate having a plate thickness of 15 mm or more, for example. This is because, in a relatively thick material to be rolled, the change in the plate crown ratio has a small effect on the flatness.

More specifically, the elongation strain difference is known as an index showing the flatness of the material to be rolled. The elongation strain difference Δε _i on the exit side of the i-pass (1 ≦ i ≦ N) is expressed by the following mathematical formula (1).

Here, the thickness of the H _i is i pass entry side, h _i is the thickness of the i-pass exit side, C _Hi is i pass entry side strip crown, C _hi is the i-path outlet side of the strip crown. Further, ξ is a coefficient of variation of shape. It can be said that the material to be rolled is flat as the elongation strain difference Δε _i approaches zero.

As is apparent from the equation (1), in general, if the strip crown ratio _{(C Hi / H i, C} hi / h i) is carried out rolling to be constant at the outlet side and the inlet side It is known that high quality flatness can be ensured. Conversely, the strip crown ratio _{(C Hi / H i, C} hi / h i) when changes significantly between the outlet side and the inlet side is flatness defects occur called middle elongation and edge waving (end elongation) , The flatness of the material to be rolled deteriorates.

However, the shape coefficient of variation ξ in the above formula (1) takes a relatively small value when the plate thickness of the material to be rolled is thick, and takes a relatively large value when the plate thickness of the material to be rolled is thin. It has been known. Therefore, when the plate thickness of the material to be rolled is relatively thick, the influence of the change in the plate crown ratio on the flatness of the material to be rolled is small. Therefore, when the rolling control method according to the first embodiment is applied to rolling on a relatively thick thick plate, the influence of the change in the plate crown ratio on the flatness of the material to be rolled is small, and therefore rolling. A relatively large change in the plate crown ratio can be tolerated in the path, and a desired plate crown can also be realized.

(1-2-2. Processing procedure)
The processing procedure of the rolling control method according to the first embodiment will be described with reference to FIGS. 2 and 3. Here, for comparison, the processing procedure of the conventional rolling control method will also be described. FIG. 2 is a flow chart showing an example of the processing procedure of the conventional rolling control method. FIG. 2 shows a processing procedure corresponding to the method described in Patent Document 4 as an example of a conventional rolling control method. Further, FIG. 3 is a flow chart showing an example of the processing procedure of the rolling control method according to the first embodiment. FIG. 3 shows, as an example of the rolling control method according to the first embodiment, a processing procedure corresponding to plate crown control in which a uniform crown control amount is applied to all the above-mentioned rolling paths.

First, the processing procedure of the conventional rolling control method will be described. With reference to FIG. 2, in the conventional rolling control method, first, the pass schedule calculation is performed before the start of rolling, and the number of passes, the rolling reduction distribution in each rolling pass, and the crown control amount are determined (step S101).

Next, the rolling load at each rolling pass and the set value of the plate crown for the set pass schedule are calculated (step S103).

Next, rolling is executed so as to realize the set value of the plate thickness on the exit side of each pass according to the calculated pass schedule (step S105).

Next, the roll profile is learned (corrected) based on the measured values of the plate crown and flatness on the m-pass (2 ≦ m ≦ N) entry side (step S107). In the illustrated example, the roll profile is modified by using both the plate crown and the measured value of the flatness. However, for example, if the method described in Patent Document 1-3 is used, the plate crown and the flatness are measured. It is also possible to modify the roll profile using only one of the values.

Next, using the modified roll profile, the crown control amount of each rolling pass after the m pass is calculated so that the plate crown on the exit side of each rolling pass matches the set value (step S109). As a specific procedure in step S109, first, the plate crown on the m-pass exit side is calculated using the modified roll profile. Then, based on the calculated plate crown on the exit side of the m pass, the plate crown on the exit side of each rolling pass after the m pass matches the set value calculated in step S103. The crown control amount for each rolling path is calculated (see below (1-2-3. Processing details) for detailed procedures).

Then, rolling after the m pass is executed according to the calculated crown control amount (step S111).

Next, the processing procedure of the rolling control method according to the first embodiment will be described. Referring to FIG. 3, in the rolling control method according to the first embodiment, the processing in steps S201 to S205 is the same as the processing in steps S101 to S105 in the conventional rolling control method shown in FIG.

That is, in the rolling control method according to the first embodiment, first, the pass schedule calculation is performed before the start of rolling, and the number of passes, the rolling reduction distribution in each rolling pass, and the crown control amount are determined (step S201). Next, the rolling load at each rolling pass and the set value of the plate crown for the set pass schedule are calculated (step S203). Then, according to the calculated pass schedule, rolling is executed so as to realize the set value of the plate thickness on the exit side of each pass (step S205).

In the rolling control method according to the first embodiment, the roll profile is then learned (corrected) so that the measured value of the plate crown or flatness on the m-pass entry side matches the actual calculated value (step). S207).

Then, using the modified roll profile, a uniform crown control amount is applied after the m-pass so that the plate crown on the N-pass exit side (ie, the final product plate crown) matches the desired plate crown. It is calculated (step S209). As a specific procedure in step S209, first, the plate crown on the m-pass exit side is calculated using the modified roll profile. Then, based on the calculated plate crown on the m-pass exit side, a uniform crown after the m-pass such that the plate crown on the N-pass exit side matches the target value (set value calculated in step S203). The control amount is calculated (see (1-2-3. Processing details) below for the detailed procedure).

Then, rolling after the m pass is executed according to the calculated crown control amount (step S211). Specifically, before the start of the m-pass, the roll cross angle, roll shift amount and / or roll bending force are adjusted only once according to the calculated crown control amount, and the changed roll cross angle and roll shift are adjusted. Rolling after m-pass is performed according to the amount and / or roll bending force.

The processing procedure of the conventional rolling control method and the rolling control method according to the present embodiment has been described above.

Here, as described above, in the conventional rolling control method, in the plate crown control in each rolling pass after the m pass using the modified roll profile, the plate crown on the exit side of each rolling pass initially set is used. Plate crown control is performed to achieve this. Therefore, it may be necessary to significantly change the crown control amount in the rolling pass (m pass) immediately after the roll profile learning is performed. In this case, the crown control capability of the rolling mill may be insufficient. On the other hand, in the rolling control method according to the first embodiment, the plate crown control that gives a different crown control amount for each rolling pass and the plate crown control that gives a uniform crown control amount to all the rolling passes. In each case, although there is a difference in how to give the crown control amount to each rolling pass after the m pass, each rolling pass after the m pass so that the plate crown matches the desired plate crown on the N pass exit side. The plate crown is controlled in. At this time, it is not essential that the plate crown on the exit side of the rolling pass (m pass) immediately after the roll profile learning is made equal to the initially set plate crown on the exit side of the path. Therefore, the crown control amount in the rolling pass after the m pass can be made smaller than that in the conventional method, and can be kept within the range of the crown control capacity of the rolling mill. Therefore, according to the first embodiment, the plate crown can be built with higher accuracy than the conventional method.

Further, in the conventional rolling control method, a different crown control amount is given to each rolling pass after the m pass. Therefore, the same inconvenience as the plate crown control that imparts a different crown control amount for each rolling path according to the first embodiment described above (that is, substantially only the roll bender mechanism can be used as the crown control mechanism. The plate crown cannot be controlled with a change of a large plate crown, etc.) can be manifested. On the other hand, according to the plate crown control in which a uniform crown control amount is given to all the rolling passes according to the first embodiment, it is not necessary to change the crown control amount for each rolling pass after the m pass. , The above inconvenience can be eliminated.

Further, in the plate crown control in which a uniform crown control amount is given to all the rolling passes according to the first embodiment, in the rolling of a plurality of passes on the same material to be rolled in the same rolling mill, the m-pass entry side is used. Roll profile modifications are made using plate crown or flatness measurements. Therefore, according to the first embodiment, the material to be rolled (the material to be rolled whose plate crown is measured) used for the roll profile learning and the material to be rolled to be controlled are the same, so that the roll profile error is high. Since it can be estimated and compensated with accuracy, the effect of roll profile learning can be obtained more preferably.

Further, according to the first embodiment, in the rolling control after the m-pass, the reduction amount distribution is not recalculated as in the technique described in Patent Document 2, for example. Therefore, the time required for control can be suppressed to a shorter time, and the total working time related to rolling is not increased. Therefore, it is possible to obtain a product with higher manufacturing accuracy of the plate crown without causing a decrease in operating efficiency. Further, by improving the manufacturing accuracy of the plate crown, it is possible to suppress a decrease in yield due to the plate crown deviating from the standard, and it is possible to improve productivity.

(1-2-3. Details of processing)
The process executed in the rolling control device 20 in the first embodiment will be described more specifically. Since the processes in steps S201 to S205 and step S211 shown in FIG. 3 can be executed by various conventionally used methods, the description thereof will be omitted here. Here, among the processes shown in FIG. 3, the processes in steps S207 and S209, that is, the processes for modifying the roll profile, and the plate crown on the N-pass exit side, which are the processes characteristic of the first embodiment. The process of calculating a uniform crown control amount after the m-pass so that the desired plate crown is obtained will be described in detail.

In the following, as an example, the processing in steps S207 and S209 when the following mathematical formula (2) is used as the model formula indicating the change in the crown will be described.

_{Here, H i, h i, C} Hi and _{C hi} are similar to the above equation (1). Also, C _i is the crown ratio genetic factor in the mechanical crown, eta _i is i paths in i path. In the above equation (2), the thickness of the i-pass outlet side _{h i} and plate crown _{C hi} It is noted that each equal to, i + 1 thickness pass entry side _{H i + 1} and strip crown _{C Hi + 1.}

Here, the crown ratio genetic coefficient η _i is a constant that can be obtained by various physical models. Further, the mechanical crown C _i is dependent on the roll deformation caused by the roll profile and the rolling load. Regarding the fact that the roll bending force (roll bender pressure), roll cross angle, roll shift amount, etc. are known as control amounts that can be adjusted to control the plate crown in the above (1-1. System configuration). As mentioned, any of these can be controls for the mechanical crown. As described above, the plate crown can be controlled by controlling the roll bending force (roll bender pressure), the roll cross angle and / or the roll shift amount, which are the control amounts related to the mechanical crown, also from the above equation (2). You can see that.

In the above equation (2), and includes an error of the roll profile in mechanical crown C _i. If the roll profile compensation amount as may compensate for the error and [Delta] C _R ^err, from the equation (2), the relational expression roll profile error is compensated, it can be written as following equation (3).

When the above formula (3) is written down from i = 1 to m-1, the following formula (4) is obtained.

In the first embodiment, when the rolling of the m-1th pass is completed, the rolling control device 20 uses the above formula (4) to determine the measured value of the plate crown on the exit side of the m-1 pass. , The roll profile compensation amount ΔC _R ^err is obtained so as to match the actual calculated value _Chm-1 . This corresponds to the process of modifying the roll profile, that is, the process in step S209 shown in FIG.

Here, by using a roll profile compensation amount [Delta] C _R ^err determined, by obtaining the crown control amount after m paths in accordance with the above equation (3), crown control amount roll profile error is compensated can be calculated. However, since there is already a discrepancy between the actual calculated value (= measured value) of the plate crown and the set value at the stage when rolling of the m-th pass is started, the amount of the discrepancy is compensated. Above, it is necessary to obtain the crown control amount after the m pass.

Therefore, the rolling control device 20 calculates the plate crown _ChN on the N pass exit side according to the following mathematical formula (5) for the rolling pass (m pass to N pass) to be performed, and the calculated value is a desired value (final). The crown control change amount ΔC _roll that matches the plate crown required for the product) is obtained (corresponding to the process in step S211 shown in FIG. 3).

Then, the rolling control device 20 changes the roll cross angle, the roll shift amount and / or the roll bender pressure so as to realize the obtained crown control change amount ΔC _select , and executes rolling after the m pass.

The processing executed in the rolling control device 20, particularly the processing in steps S207 and S209 shown in FIG. 3 has been described in detail. In the above specific example, the above mathematical formula (2) is used as the crown model, but the first embodiment is not limited to such an example. Various crown models are known in addition to the above mathematical formula (2). In the first embodiment, various known models may be used as the crown model. Further, in the above specific example, the measured value of the plate crown was used to correct the roll profile, but as described above, based on the measured value of flatness (specifically, the measurement of flatness). The role profile may be modified (so that the values match the actual measurements).

(1-3. Functional configuration of rolling control device)
With reference to FIG. 4, a functional configuration of the rolling control device 20 for executing the rolling control method according to the first embodiment described above will be described. FIG. 4 is a block diagram showing an example of the functional configuration of the rolling control device 20 according to the first embodiment.

Referring to FIG. 4, the rolling control device 20 according to the first embodiment has a measurement value acquisition unit 201, a calculation unit 203, a drive control unit 205, and a storage unit 207 as its functions.

The measured value acquisition unit 201 is realized by a communication device that receives the measured values of the rolling load, the plate thickness, and the plate crown from the reduction device 150 and the plate crown measuring device 160. The measured value acquisition unit 201 can acquire the measured value of the rolling load at any time during rolling. Further, the measured value acquisition unit 201 can acquire the measured values of the plate thickness and the plate crown at the timing when any of the rolling passes is completed. The measured value acquisition unit 201 provides the calculation unit 203 with information about various acquired measured values.

The measured value acquisition unit 201 may store information about various acquired measured values in the storage unit 207, and the calculation unit 203 stores the information about the measured values by accessing the storage unit 207. You may get it.

The calculation unit 203 is realized by a processing circuit such as a CPU. In the calculation unit 203, each process in steps S201 to S209 shown in FIG. 3 is executed. Since the details of each of these processes have already been described, the description thereof will be omitted here. The calculation unit 203 provides the drive control unit 205 with information about the calculated crown control amount.

The calculation unit 203 may store the calculated information about the crown control amount in the storage unit 207, and the drive control unit 205 acquires the information about the crown control amount by accessing the storage unit 207. You may.

The drive control unit 205 is realized by a processing circuit such as a CPU and a communication device that transmits a signal to an external device. The drive control unit 205 executes the process in step S211 shown in FIG. Specifically, the drive control unit 205 drives the rolling mill 10 according to the crown control amount calculated by the calculation unit 203. For example, the drive control unit 205 operates a roll cross drive device or a roll shift drive device (both not shown in FIG. 1) to move the roll by an amount corresponding to the calculated crown control amount. Alternatively, the drive control unit 205 operates a roll bending drive device (not shown in FIG. 1) to load the roll with a roll bending force according to the calculated crown control amount by the roll bender.

The storage unit 207 can be realized by various storage devices such as a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor storage device, an optical storage device, or an optical magnetic storage device. Various information related to the processing in the rolling control device 20 can be stored in the storage unit 207. For example, the storage unit 207 stores various measured values acquired by the measured value acquisition unit 201. Further, for example, the storage unit 207 stores various parameters used for the arithmetic processing by the arithmetic unit 203, the progress of the arithmetic processing, the result of the arithmetic processing, and the like.

The above is an example of the function of the rolling control device 20 according to the first embodiment. Each of the above components may be configured by using general-purpose members or circuits, or may be configured by hardware specialized for the function of each component. Further, the configuration for realizing the rolling control device 20 can be appropriately changed according to the technical level at each time of implementation.

The specific device configuration of the rolling control device 20 is not limited. For example, the function of the rolling control device 20 described above does not necessarily have to be realized by one device. For example, one device that executes some of the functions shown in the figure and another device that executes the remaining functions are communicably connected to provide a plurality of functions similar to those of the rolling control device 20. It may be realized by the cooperation of the devices of.

Further, it is possible to create a computer program for realizing each function of the rolling control device 20 according to the first embodiment as described above and implement it on a personal computer or the like. It is also possible to provide a computer-readable recording medium in which such a computer program is stored. The recording medium may be, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, or the like. Further, the above computer program may be distributed via a network, for example, without using a recording medium.

(1-4. Modification example)
The first embodiment described above may be configured as follows.

For example, in the above-described embodiment, the crown control amount in each rolling pass of the m to Nth pass is calculated by using the modified roll profile so that the plate crown matches the desired value. The amount was calculated as a value such that the plate crown matches the target value of the plate crown of the product on the exit side of the final pass (N pass). However, the first embodiment is not limited to such an example. For example, the plate crown that is finally targeted when calculating the crown control amount in each rolling pass of the m to Nth pass does not have to be the plate crown on the N pass exit side. That is, in the first embodiment, on the exit side of each rolling pass of the m to t pass such that the plate crown on the exit side of the t pass (m ≦ t ≦ N) matches the target value (initially set value). The desired value of the plate crown is calculated, the crown control amount in each rolling pass of the m to tth pass that realizes the desired value is calculated, and the calculated crown control amount is given to m ~. Rolling may be performed in each rolling pass of the t-th pass (the above-described embodiment corresponds to the case of t = N). Hereinafter, the target rolling path (t path) for making the output side plate crown a desired value when calculating the crown control amount is also referred to as a target path. When t ≠ N, for example, for each rolling pass in the t + 1 to Nth passes, the crown control amount in each rolling pass such that the plate crown on the exit side of each of these rolling passes matches the initially set value is , It is calculated again reflecting the corrected roll profile, and the calculated crown control amount is given to perform rolling in each rolling path.

However, when t = m, or when t is close to m, the side plate crown is used in the rolling pass immediately after the roll profile is modified (that is, m pass) or in the rolling pass several passes later. Will be rolled so that is in agreement with the initially set value. In this case, it may be necessary to significantly change the crown control amount in the rolling pass (m pass) immediately after the roll profile learning, so that the crown control capability of the rolling mill is insufficient. There is a possibility that the same inconvenience as the rolling control method of. Therefore, t is preferably set to a value close to N, and more preferably t = N.

A specific example of plate crown control when t ≠ N will be described later with reference to FIG. 7.

Further, in the above-described embodiment, as the plate crown control in each rolling pass after the m pass, a plate crown control that gives a different crown control amount for each rolling pass and a uniform crown control amount are given to all the rolling passes. The plate crown control has been described. However, the first embodiment is not limited to such an example. In the first embodiment, if the plate crown on the exit side of each rolling pass on the m to t pass is controlled so that the plate crown on the exit side of the t pass matches the target value (initially set value). Often, the method of giving the crown control amount to each rolling pass at the m to t pass may be arbitrary. For example, to explain with a specific example, as shown in FIG. 6 described later, the change in the plate crown when the rolling control method according to the first embodiment is applied with m = 6 is shown in FIG. Shown by a thick solid line. FIG. 6 shows, as an example, the change in the plate crown when the plate crown control that gives a uniform crown control amount to all rolling passes is applied, but the value of the plate crown on the exit side of 5 passes (about 0). The change of the plate crown from the initial setting value (about 0.070 mm) of the plate crown on the exit side of 11 passes (11 is the final pass N) (that is, the trajectory of the thick solid line from 5 passes to 11 passes). ) Is not limited to that shown in FIG. 6, and may be arbitrary.

For example, different uniform crown control amounts may be given to the m-th to k-pass (m ≦ k <t) and the k + 1-th to t-pass. Alternatively, for example, the rolling pass of the m to t pass may be divided into more sections, and a uniform crown control amount may be given to each section (the section is finely divided into each rolling pass. Corresponds to plate crown control that gives different crown control amounts for each rolling path). However, even in this case, if it becomes necessary to change the crown control amount significantly, the crown control capability of the rolling mill may be insufficient. Therefore, the change amount of the crown control amount is the crown control of the rolling mill. It is preferable that the method of giving the crown control amount for each rolling pass in the m to t pass is set so as to be within the range of the capacity. Further, the more divisions that give a uniform crown control amount are provided, the more times the crown control amount is changed. Therefore, considering that it is necessary to stop rolling while changing the crown control amount, there is a concern that the operation efficiency will decrease. Therefore, from the viewpoint of improving the operation efficiency, it is preferable that the number of the divisions is small, and the number of the divisions is set to 1, that is, the plate crown control that gives a uniform crown control amount to all rolling passes is applied. It is considered more preferable to do so.

Further, the method of rolling control may be changed between rolling in each rolling pass of m to t pass and rolling in each rolling pass of t + 1 to N pass. Specifically, as described with reference to the above mathematical formula (1), when the plate thickness of the material to be rolled is relatively thin, the effect of the change in the plate crown ratio on the flatness of the material to be rolled has an effect. growing. That is, if rolling is performed such that the plate crown ratio changes significantly after the plate thickness of the material to be rolled becomes relatively thin, the flatness of the material to be rolled may deteriorate. On the other hand, in the rolling control method according to the present embodiment, rolling is performed according to the crown control amount recalculated using the modified roll profile in each rolling pass of the m to t pass. In rolling in each rolling pass of the t-th pass, the plate crown ratio may change relatively significantly. Therefore, in the first embodiment, for each rolling pass of the t + 1 to Nth pass, the rolling control aiming at the set value of the plate crown on the N pass exit side initially set is not performed, but the plate at each rolling pass. Rolling control may be performed so that the crown ratio becomes constant. By switching the rolling control in this way, it is possible to further improve the flatness while realizing a plate crown close to the desired plate crown on the N-pass exit side.

When such switching of rolling control is performed, the specific value of t is appropriately set based on the plate thickness of the material to be rolled in each rolling pass so that the desired flatness can be realized in each rolling pass. May be decided. Specifically, the t-pass is in a region where the flatness defect can become apparent unless rolling is performed so that the plate thickness on the entry side of the t-pass is constant in each subsequent rolling pass. A rolling path that does not belong may be selected. The specific plate thickness of the material to be rolled, which is the boundary of the region where poor flatness can become apparent unless rolling is performed so that the plate crown ratio is constant in each rolling pass, is the type of material to be rolled (for example, steel plate). If this is the case, it may be appropriately set according to the steel type), size (plate width), etc., but is, for example, about 20 mm. That is, for example, any of the rolling passes having an entry side plate thickness of 20 mm or more can be set as the t-th pass. At this time, among the rolling passes having an entry-side plate thickness of 20 mm or more, the rolling pass having the thinnest entry-side plate thickness may be the t-th pass. In this case, the initial set value of the plate crown on the N-pass exit side is up to the rolling pass immediately before entering the region where flatness defects can become apparent unless rolling is performed so that the plate crown ratio is constant in each rolling path. Rolling control is performed aiming at, and rolling control is performed so that the plate crown ratio becomes constant from the rolling pass immediately after entering the region. Therefore, while obtaining good flatness, on the N-pass exit side. It becomes possible to realize a plate crown closer to the desired plate crown.

(2. Second embodiment)
As described above, in the first embodiment, the crown control according to the initially set value is executed until the rolling pass (2 ≦ m ≦ N) of the m-1th pass after the start of rolling. Then, in the stage before the start of the m-th rolling pass, the roll profile learning process is performed using the measured value of the plate crown or flatness of the material to be rolled. Then, using the modified roll profile, a crown control amount is calculated so that the plate crown matches the target value (initially set value) for the Nth pass rolling pass, and the crown control amount is given to the m pass. Rolling is performed in the rolling path after the first.

However, the present invention is not limited to such an example. For example, a crown calculated by using a roll profile learned on the entry side of the r pass (2 ≦ r ≦ N) and modified in each rolling pass after the m pass (r ≦ m ≦ N). When rolling is performed according to the controlled amount, r ≠ m may be used. That is, it is not necessary to perform plate crown control using the modified roll profile from the rolling path immediately after the roll profile learning process is performed. The above-mentioned first embodiment corresponds to the case of r = m.

Hereinafter, as a second embodiment of the present invention, a rolling control method in such a case where r ≠ m will be described. In the second embodiment, the first embodiment is different from the rolling path in which the roll profile learning process is performed on the entry side and the rolling path in which the plate crown control based on the modified roll profile is started. It is the same as the embodiment. For example, the system to which the rolling control method according to the second embodiment can be applied is the same as the system 1 illustrated in FIG. Further, for example, the details of the roll profile learning process in the rolling control method according to the second embodiment and the details of the crown control amount calculation process using the modified roll profile are described in (1-2-3) above. It is the same as that explained in (Details of processing). Further, for example, the functional configuration of the rolling control device according to the second embodiment is the same as the functional configuration of the rolling control device 20 illustrated in FIG. Therefore, in the following description of the second embodiment, the description of the matters overlapping with the first embodiment will be omitted, and the matters different from the first embodiment will be mainly described.

(2-1. Processing procedure of rolling control method)
The processing procedure of the rolling control method according to the second embodiment will be described with reference to FIG. FIG. 5 is a flow chart showing an example of the processing procedure of the rolling control method according to the second embodiment. In the second embodiment as well, the plate crown control that gives a different crown control amount to each rolling pass may be applied to each rolling pass after the m-th pass, and is uniform for all rolling passes. A plate crown control that imparts a crown control amount may be applied. FIG. 5 shows, as an example of the rolling control method according to the second embodiment, a processing procedure corresponding to plate crown control in which a uniform crown control amount is applied to all rolling passes.

With reference to FIG. 5, in the rolling control method according to the second embodiment, the processes in steps S301 to S307 are the processes in steps S201 to S207 in the rolling control method according to the first embodiment shown in FIG. The same is true.

That is, in the rolling control method according to the second embodiment, first, the pass schedule calculation is performed before the start of rolling, and the number of passes, the rolling reduction distribution in each rolling pass, and the crown control amount are determined (step S301). Next, the rolling load at each rolling pass and the set value of the plate crown for the set pass schedule are calculated (step S303). Then, according to the calculated pass schedule, rolling up to r-1 pass (2 ≦ r ≦ N) is executed so as to realize the set value of the plate thickness on the exit side of each pass (step S305). Next, the roll profile is learned (corrected) so that the measured value of the plate crown or flatness on the r-pass entry side matches the actually calculated value (step S307).

In the rolling control method according to the second embodiment, the rolling up to m-1 pass (r ≦ m ≦ N) is then performed according to the calculated pass schedule so as to realize the set value of the plate thickness on the exit side of each pass. Is executed (step S309). As described above, in the second embodiment, the roll profile is corrected on the r-pass entry side, but for each rolling pass from the r to m-1th pass, the initial set value is the same as in step S305. Rolling according to is performed.

Next, using the modified roll profile, the plate crown on the exit side of the r to m-1 pass is calculated (step S311).

Then, using the calculated r-m-1 pass exit side plate crown, m such that the plate crown on the N pass exit side (ie, the final product plate crown) matches the desired plate crown. A uniform crown control amount is calculated after the pass (step S313). Note that, for convenience, FIG. 5 describes that the process shown in step S309, the process shown in step S311 and the process shown in step S313 are executed in this order, but in reality, the process shown in step S311 is executed. The process shown in step S313 may be performed after the process shown in step S307 is performed until the process shown in step S315 described later is started. For example, the process shown in step S311 and the process shown in step S313 may be performed in parallel while the process shown in step S309 is being performed.

Then, rolling after the m pass is executed according to the calculated crown control amount (step S315). Specifically, before the start of the m-pass, the roll cross angle, roll shift amount and / or roll bending force are adjusted only once according to the calculated crown control amount, and the changed roll cross angle and roll shift are adjusted. Rolling after m-pass is performed according to the amount and / or roll bending force.

The processing procedure of the rolling control method according to the second embodiment has been described above. In the second embodiment as well, as in the first embodiment, the crown control amount in each rolling pass after the m pass is calculated so that the plate crown matches the desired plate crown on the N pass exit side. According to the calculated crown control amount, plate crown control is performed in each rolling pass after the m pass. Therefore, the same effect as that of the first embodiment, that is, the crown control amount in each rolling pass after the m pass can be reduced as compared with the conventional method, and can be kept within the range of the crown control capacity of the rolling mill. Therefore, it is possible to obtain the effect that the plate crown can be built with higher accuracy.

In addition, also in the 2nd Embodiment, each modification described above (1-4. modification) may be applied. Specifically, in the second embodiment, the target path does not necessarily have to be an N path (that is, t ≠ N). Further, in the second embodiment, the method of giving the crown control amount in each rolling pass after the m pass may be arbitrary. Further, in the second embodiment, for each rolling pass of the t + 1 to Nth pass, rolling control may be performed so that the plate crown ratio in each rolling pass becomes constant, and in that case, the input side plate thickness Any of the rolling passes having a value of 20 mm or more may be set as the t-th pass.

In order to confirm the effect of the present invention, the rolling control method according to the first embodiment described above was applied to actual thick plate rolling, and the value of the plate crown on the exit side of each rolling pass was measured. The rolling conditions are as follows.

(Rolling conditions)
・ Number of passes: 11
-Transfer thickness (plate thickness before rolling start): 150 mm
-Product plate thickness (plate thickness at the end of rolling (at the end of 11 passes)): 30 mm
-Product plate crown (plate crown at the end of rolling (at the end of 11 passes)): 0.070 mm

As an example of the rolling control method according to the first embodiment, 11-pass rolling was performed according to the processing procedure shown in FIG. 3 according to the above conditions (that is, all rolling control after roll profile correction was performed). Plate crown control was performed to give a uniform crown control amount to the rolling path of. At the end of the 5th pass, the roll profile is learned (corrected), the crown control amount is calculated, and the roll cross angle is changed according to the crown control amount (that is, in the processing procedure shown in FIG. 3, m). = 6).

The results are shown in FIG. FIG. 6 is a graph showing the result of thick plate rolling to which the rolling control method according to the first embodiment is applied. In FIG. 6, when the number of passes is taken on the horizontal axis, the value of the plate crown on the exit side of each rolling pass is taken on the vertical axis, and the rolling control method according to the first embodiment obtained as a result of rolling is applied. The value of the plate crown on the exit side of each rolling pass after the 5th pass is plotted with a thick solid line ("crown control amount change"). In addition, in FIG. 6, the actual calculated value of the plate crown on the exit side of each rolling pass up to the fifth pass calculated using the corrected roll profile is plotted with a thick broken line (“roll profile correction”). After-actual calculation value "). Further, in FIG. 6, the set value of the plate crown calculated before the start of rolling is plotted together with a thin solid line (“set value”). Further, in FIG. 6, the estimated value of the subsequent plate crown when the crown control amount is not changed at the end of the fifth pass (that is, when the plate crown is controlled according to the initially set value) is plotted together with a broken line. ("Estimated value"). The estimated value is a plot of the actual calculated value of the plate crown reflecting the correction of the roll profile when the crown control amount is not changed.

Hereinafter, a specific processing procedure in this embodiment will be described with reference to FIG. In this embodiment, first, the rolling reduction amount distribution in each rolling path was set so that the product plate crown was 0.070 mm, and rolling was started. At this time, the error between the set load and the actual load was so small that it could be ignored, and it was considered that there was almost no prediction error of the rolling load.

At the stage where rolling was performed up to the fifth pass according to this initially set value, the output side plate crown was measured and found to be 0.300 mm. As shown in FIG. 6, the set value of the plate crown on the 5-pass exit side is 0.189 mm. This deviation of the plate crown was considered to be due to an error between the predicted value (estimated value) of the roll profile used in the initial setting calculation and the actual roll profile.

Therefore, according to the above formula (4), the roll profile compensation amount so that the prediction error of the plate crown on the 5-pass exit side becomes zero (that is, the measured value of the plate crown and the actual calculated value of the plate crown match). ΔC _R ^err was determined. As a result, the roll profile compensation amount [Delta] C _R ^err was 0.144 mm.

Furthermore, by using the value of the roll profile compensation amount [Delta] C _R ^err, according to the above equation (5), such as N-pass outlet side of the strip crown is consistent with the desired product strip crown (0.070 mm), 6 to 11 A uniform crown control change amount ΔC _collect was obtained in the path. As a result, the crown control change amount [Delta] C _correct was -0.169Mm.

Thus, after adjusting the amount corresponding roll cross angle corresponding to the crown control change amount _{ΔC correct (-0.169mm),} the six passes after rolling, a plate to impart crown control amount of uniform for all rolling pass This was done by crown control. As a result, as shown in FIG. 6, a desired plate crown (0.070 mm) could be realized on the 11-pass exit side.

As shown as an "estimated value" in the figure, the final estimated value of the plate crown when the roll cross angle is not changed at the end of the fifth pass is 0.153 mm, which is a target of 0.070 mm. The value deviated from. As described above, it was confirmed that the final plate crown can be controlled to a desired value with high accuracy by applying the rolling control method according to the first embodiment.

As another example, in the rolling control method according to the first embodiment, thick plate rolling was performed with the target path as a rolling path other than the final path (that is, t ≠ N). The rolling conditions are the same as in Example 1 described above. In this embodiment, similarly to the first embodiment, rolling of all 11 passes was basically performed according to the processing procedure shown in FIG. Specifically, the processes shown in steps S201 to S207 shown in FIG. 3 were the same as those in the first embodiment. At that time, m = 6 was set, and the roll profile was learned (corrected) at the end of the fifth pass. However, in this embodiment, in the process shown in step S209, the modified roll profile is used to uniformly control the crown to 6 to 9 passes so that the plate crown on the 9-pass exit side matches the desired plate crown. The quantity was calculated (ie, t = 9). Further, for the 10-pass and 11-pass, the plate crown on the 9-pass exit side and the plate crown on the 11-pass exit side are set values calculated in step S203 based on the modified roll profile. The crown control amount that matches the above was calculated again, and rolling was performed according to the calculated crown control amount.

The results are shown in FIG. FIG. 7 is a graph showing the results when the target path is set to a path other than the final path in the thick plate rolling to which the rolling control method according to the first embodiment is applied. In FIG. 7, similarly to FIG. 6, the number of passes is taken on the horizontal axis, the value of the plate crown on the exit side of each rolling pass is taken on the vertical axis, and each rolling pass after the sixth pass obtained as a result of rolling is taken. The value of the plate crown on the exit side is plotted with a thick solid line ("crown control amount change"). Further, in FIG. 7, similarly to FIG. 6, the actual calculated value of the plate crown on the exit side of each rolling pass up to the fifth pass calculated using the modified roll profile (“roll profile modified actual calculated value”). ), The set value of the plate crown calculated before the start of rolling (“set value”), and the estimated value of the subsequent plate crown (“estimated value”” when the crown control amount is not changed at the end of the 5th pass. ) Are plotted together with a thick broken line, a thin solid line, and a thin broken line, respectively.

Specific processing procedure in this embodiment, until the process for obtaining the roll profile compensation amount [Delta] C _R ^err is the same as that of the first embodiment. That is, in this embodiment, first, the rolling reduction amount distribution in each rolling path was set so that the product plate crown was 0.070 mm, and rolling was started. Next, when the output side plate crown was measured at the stage where rolling was performed up to the 5th pass according to this initial set value, the measured value was 0.300 mm, and the set value of the plate crown on the 5 pass exit side was 0.189 mm. It was divergent. Then, according to the above formula (4), the roll profile such that the prediction error of the plate crown on the 5-pass exit side becomes zero (that is, the measured value of the plate crown and the actual calculated value of the plate crown match). The compensation amount ΔC _R ^err was ^calculated . As a result, the roll profile compensation amount [Delta] C _R ^err was 0.144 mm.

In this embodiment, then, using the value of the roll profile compensation amount [Delta] C _R ^err, according to the above equation (5), 9 to pass the delivery side of the strip crown is consistent with the desired product strip crown (0.091 mm) In addition, a uniform crown control change amount ΔC _collect was obtained in 6 to 9 passes. As a result, the crown control change amount [Delta] C _correct was -0.195Mm.

Then, after adjusting the only roll cross angle amount corresponding to the crown control change amount ΔC _correct (-0.195mm), was rolled 6-9 path (i.e., by applying a crown control amount of uniform 6-9 passes of rolling). Then, 9 path outlet side of the strip crown and (0.091 mm), with the roll profile compensation amount ΔC _R ^err (0.144mm), 10 pass and 11 pass the delivery side of the strip crown is initially set value (respectively, The crown control change amount was calculated so as to match 0.079 mm and 0.070 mm), respectively, and 10-pass and 11-pass rolling was performed according to the crown control change amount. As a result, as shown in FIG. 7, the initially set value, that is, the desired plate crown (0.070 mm) could be realized on the 11-pass exit side.

As shown as an "estimated value" in the figure, the final estimated value of the plate crown when the roll cross angle is not changed at the end of the fifth pass is 0.153 mm, which is a target of 0.070 mm. The value deviated from. As described above, it can be confirmed that the final plate crown can be controlled to a desired value with high accuracy even when t ≠ N in the rolling control method according to the first embodiment. It was.

As yet another embodiment, the rolling control method according to the second embodiment was applied to actual thick plate rolling, and the value of the plate crown on the exit side of each rolling pass was measured. The rolling conditions are the same as in Example 1 described above. In this embodiment, 11 passes of rolling were performed according to the rolling conditions and according to the processing procedure shown in FIG. 5 (that is, as the rolling control after the roll profile correction, a uniform crown control amount was given to all rolling passes. The plate crown was controlled). At the end of the 5th pass, the roll profile is learned (corrected), and the roll cross angle is changed according to the crown control amount calculated by reflecting the corrected roll profile on the 8th pass entry side (the roll cross angle is changed). That is, in the processing procedure shown in FIG. 5, r = 6 and m = 8).

The results are shown in FIG. FIG. 8 is a graph showing the result of thick plate rolling to which the rolling control method according to the second embodiment is applied. In FIG. 8, similarly to FIG. 6, the number of passes is taken on the horizontal axis, the value of the plate crown on the exit side of each rolling pass is taken on the vertical axis, and each rolling pass after the fifth pass obtained as a result of rolling is taken. The value of the plate crown on the exit side is plotted with a thick solid line ("crown control amount change"). Further, in FIG. 8, similarly to FIG. 6, the actual calculation value of the plate crown on the exit side of each rolling pass up to the fifth pass calculated using the modified roll profile (“roll profile modified actual calculated value”). ), The set value of the plate crown calculated before the start of rolling (“set value”), and the estimated value of the subsequent plate crown (“estimated value”” when the crown control amount is not changed at the end of the 5th pass. ) Are plotted together with a thick broken line, a thin solid line, and a thin broken line, respectively.

Specific processing procedure in this embodiment, until the process for obtaining the roll profile compensation amount [Delta] C _R ^err is the same as that of the first embodiment. That is, in this embodiment, first, the rolling reduction amount distribution in each rolling path was set so that the product plate crown was 0.070 mm, and rolling was started. Next, when the output side plate crown was measured at the stage where rolling was performed up to the 5th pass according to this initial set value, the measured value was 0.300 mm, and the set value of the plate crown on the 5 pass exit side was 0.189 mm. It was divergent. Then, according to the above formula (4), the roll profile such that the prediction error of the plate crown on the 5-pass exit side becomes zero (that is, the measured value of the plate crown and the actual calculated value of the plate crown match). The compensation amount ΔC _R ^err was ^calculated . As a result, the roll profile compensation amount [Delta] C _R ^err was 0.144 mm.

In this embodiment, then, for each rolling pass of 6,7 pass without reflecting the roll profile compensation amount [Delta] C _R ^err, it was rolled in accordance with the initial setting value. Then, in the middle of performing a rolling at the rolling path of the 6,7-pass, the strip crown at the roll profile compensation amount ΔC reflect _R ^err 6,7 pass each rolling pass the delivery side of the with calculating the value using the value of the strip crown at the roll profile compensation amount [Delta] C _R ^err and each rolling pass exit side of the calculated 6,7-pass, according to the above equation (5), the exit side 11 pass A uniform crown control change amount ΔC _roll was obtained in 8 to 11 passes so that the plate crown of the above product matches the initially set value, that is, the desired product plate crown (0.070 mm). As a result, the crown control change amount [Delta] C _correct was -0.208Mm.

Then, after adjusting the amount corresponding roll cross angle corresponding to the crown control change amount _{ΔC correct (-0.208mm),} the rolling 8 subsequent passes, the plate to impart crown control amount of uniform for all rolling pass This was done by crown control. As a result, as shown in FIG. 8, a desired plate crown (0.070 mm) could be realized on the 11-pass exit side.

As shown as an "estimated value" in the figure, the final estimated value of the plate crown when the roll cross angle is not changed at the end of the fifth pass is 0.153 mm, which is a target of 0.070 mm. The value deviated from. As described above, it was confirmed that the final plate crown can be controlled to a desired value with high accuracy by applying the rolling control method according to the second embodiment.

(3. Supplement)
Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person having ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or modifications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.

1 System 10 Roller 20 Rolling Control Device 110 Housing 121 Upper Work Roll 122 Lower Work Roll 123 Upper Backup Roll 124 Lower Backup Roll 131, 132 Work Roll Chock 133, 134 Backup Roll Chock 140 Bender 150 Rolling Device 160 Plate Crown Measuring Instrument 170 Table Roll 201 Measurement value acquisition unit 203 Calculation unit 205 Drive control unit 207 Storage unit

Claims (8)

In rolling where the total number of rolling passes is N passes (N ≧ 2)
Before executing the rolling pass of the rth pass (2 ≦ r ≦ N),
The roll profile was modified so that the measured value of the plate crown or flatness on the entry side of the rolling pass of the r-th pass matches the calculated value of the plate crown or flatness based on the model formula.
Using the modified roll profile, the plate crown on the exit side of each rolling pass for the r to m-1st pass (r ≤ m ≤ N) was calculated.
Using the modified roll profile and the calculated plate crown on the exit side of each rolling pass on the r to m-1th pass, the plate crown on the exit side of the t pass, which is any rolling pass on the m to Nth pass, is Calculate the crown control amount to match the desired plate crown and
The crown control amount calculated in the rolling in each rolling pass of the m to t pass is given.
Rolling control method. The crown control amount is uniform in rolling in each rolling pass from the m to t pass.
The rolling control method according to claim 1. The crown control amount is given by adjusting the roll cross angle or roll shift amount of the rolling mill.
The rolling control method according to claim 1 or 2. r = m,
The rolling control method according to any one of claims 1 to 3. t = N,
The rolling control method according to any one of claims 1 to 4. The t-pass is a rolling pass having an entry side plate thickness of 20 mm or more.
The rolling control method according to any one of claims 1 to 5. In rolling where the total number of rolling passes is N passes (N ≧ 2)
Before executing the rolling pass of the rth pass (2 ≦ r ≦ N),
The roll profile was modified so that the measured value of the plate crown or flatness on the entry side of the rolling pass of the r-th pass matches the calculated value of the plate crown or flatness based on the model formula.
Using the modified roll profile, the plate crown on the exit side of each rolling pass for the r to m-1st pass (r ≤ m ≤ N) was calculated.
Using the modified roll profile and the calculated plate crown on the exit side of each rolling pass on the r to m-1th pass, the plate crown on the exit side of the t pass, which is any rolling pass on the m to Nth pass, is Calculate the crown control amount to match the desired plate crown and
The crown control amount calculated in the rolling in each rolling pass of the m to t pass is given.
Rolling control device. A program for causing a computer to execute a rolling control method in rolling in which the total number of rolling passes is N (N ≧ 2).
The rolling control method is
Before executing the rolling pass of the rth pass (2 ≦ r ≦ N),
The roll profile was modified so that the measured value of the plate crown or flatness on the entry side of the rolling pass of the r-th pass matches the calculated value of the plate crown or flatness based on the model formula.
Using the modified roll profile, the plate crown on the exit side of each rolling pass for the r to m-1st pass (r ≤ m ≤ N) was calculated.
Using the modified roll profile and the calculated plate crown on the exit side of each rolling pass on the r to m-1th pass, the plate crown on the exit side of the t pass, which is any rolling pass on the m to Nth pass, is Calculate the crown control amount to match the desired plate crown and
The crown control amount calculated in the rolling in each rolling pass of the m to t pass is given.
program.

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