JP2017196662A - Rolling control method, rolling control device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rolled material having higher-quality flatness by easier control in rolling.SOLUTION: In a rolling control method, concerning rolling in which the total pass number of rolling is N pass (N≥2), crown control following a set value calculated before start of rolling is performed until a rolling pass of (m-1)-th pass (2≤m≤N), and in each rolling pass after m-th pass, crown control is performed so that a difference between a plate crown ratio on the rolling pass inlet side and a plate crown ratio on the rolling pass outlet side falls within a prescribed range in which a flatness failure is not visualized.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a rolling control method, a rolling control device, and a program for better controlling the flatness of a material to be rolled, particularly a thick plate material.

  In thick 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 thick plate rolling machine. At this time, in order to control the plate crown and flatness with high accuracy, a pass schedule (rolling amount distribution) is set in advance before rolling so that the material to be rolled has a desired plate crown and flatness as a thick plate product. Rolling is performed according to the set pass 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 the roll profile used for setting the pass schedule includes an error. I'm going. For this reason, it is difficult to perform rolling according to a set value, and even if rolling is performed according to a set pass schedule, a thick plate having a desired plate crown and flatness may not be manufactured.

  Here, many techniques for controlling the plate shape with higher accuracy have been developed when rolling a plurality of passes with the same rolling mill, such as thick plate rolling. For example, Patent Documents 1 and 2 disclose a technique for building a desired plate crown by controlling the roll bender pressure. Further, for example, in Patent Documents 3 to 5, the predicted value of the roll profile is corrected using the measured value of the sheet crown in the middle pass, and the setting in the subsequent rolling pass is performed using the corrected roll profile. Techniques for changing conditions are disclosed.

JP-A-55-109510 JP 60-213304 A JP 59-215205 A JP 2002-28708 A JP 02-217108 A

  Patent Document 1 discloses a technique for controlling the roll bender pressure so as to achieve the initially set plate crown by offsetting the plate crown change caused by the difference between the set value and the measured value of the rolling load. . However, in general, a roll bender does not necessarily have a crown control capability that can sufficiently absorb the setting error of the rolling load. Therefore, even if an attempt is made to control the plate crown by the roll bender pressure, the roll bender results in the roll bender. In many cases, the pressure sticks to the upper and lower limits, and a desired plate crown cannot be obtained. Patent Document 2 discloses a technique for controlling the roll bender pressure so as to compensate for a load variation associated with plate thickness control (AGC: Automatic Gauge Control). However, even though the technology can build a uniform plate crown in the longitudinal direction of the material to be rolled, it cannot always ensure the flatness of the material to be rolled.

  Further, Patent Document 3 does not mention a specific change method when changing the setting conditions in the subsequent rolling pass using the corrected roll profile. On the other hand, in Patent Document 4, as a specific method of changing the setting condition, a path schedule in the remaining paths is realized by using the corrected roll profile so that the initially set plate crown setting value is realized. It is described that the (reduction amount distribution) is reset. However, resetting the path schedule requires a calculation time that is not short. Therefore, in the technique described in Patent Document 4, the total work time related to rolling is increased, and for example, the temperature of the material to be rolled is reduced by temporarily suspending rolling for reset calculation of a pass schedule. There is a concern that the operational efficiency will decrease. Furthermore, in the technique described in Patent Document 5, although roll profile learning is performed in an intermediate path, the technique described in Patent Document 1 described above is used to control the roll vendor pressure to achieve the initially set plate crown. Similarly, the roll bender pressure sticks to the upper and lower limits, and a desired plate crown cannot be obtained in many cases.

  Then, this invention is made | formed in view of the said problem, The place made into the objective of this invention is the novel which can obtain the to-be-rolled material which has higher quality flatness by simpler control. Another object of the present invention is to provide an improved rolling control method, rolling control device, and program.

  In order to solve the above-described problem, according to a certain aspect of the present invention, in the rolling in which the total number of rolling passes is N passes (N ≧ 2), the rolling passes up to the m−1 pass (2 ≦ m ≦ N). Performs crown control according to the set value calculated before the start of rolling. In each rolling pass after the m-th pass, the difference between the plate crown ratio on the rolling pass entry side and the plate crown ratio on the rolling pass exit side is There is provided a rolling control method in which crown control is performed so that a flatness defect does not appear within a predetermined range.

  Further, in the rolling control method, in each rolling pass after the m-th pass, the difference between the actual calculated value or measured value of the plate crown ratio on the rolling pass entry side and the predicted value of the plate crown ratio on the rolling pass exit side. The crown may be controlled so that is substantially zero.

  In the rolling control method, the rolling pass of the m-th pass may be a rolling pass whose exit side plate thickness is 30 mm or less.

  In the rolling control method, crown control in rolling after the m-th rolling pass may be performed by adjusting a bending force applied to a work roll or a backup roll of the rolling mill.

  Further, in the rolling control method, the roll is measured so that the measured value of the plate crown or flatness on the entry side of the r-th pass (2 ≦ r ≦ N) matches the actual calculation value of the plate crown or flatness. When the profile is corrected and r ≦ m, the crown control is performed for each rolling pass after the m-th pass using the control amount calculated using the corrected roll profile, and when r> m For the rolling passes of the m-th to r-1 passes, crown control is performed using a control amount calculated using the roll profile before correction, and for each rolling pass after the r-th pass, Crown control may be performed using a control amount calculated using the corrected roll profile.

  In the rolling control method, r = m may be satisfied.

  Moreover, in the said rolling control method, correction | amendment of the said roll profile may be performed before performing the rolling pass from which an entrance side plate | board thickness becomes 20 mm or less.

  Moreover, in order to solve the said subject, according to another viewpoint of this invention, in the rolling whose total number of rolling passes is N pass (N> = 2), it is m-1 pass (2 <= m <= N). Until the rolling pass, crown control is performed according to the set value calculated before the start of rolling. In each rolling pass after the m-th pass, the plate crown ratio on the rolling pass entry side and the plate crown ratio on the rolling pass exit side A rolling control device is provided that performs crown control so that the difference between the two is within a predetermined range in which flatness defects are not apparent.

  In order to solve the above problems, according to another aspect of the present invention, there is provided a program for causing a computer to execute rolling control, wherein the number of rolling passes is N passes (N ≧ 2). , The crown control is performed in accordance with the set value calculated before the start of rolling up to the m-1th pass (2 ≦ m ≦ N), and in each rolling pass after the mth pass, the rolling pass entry side There is provided a program for controlling the crown so that the difference between the plate crown ratio at the rolling pass and the sheet crown ratio at the exit side of the rolling pass falls within a predetermined range where flatness defects are not apparent.

  As described above, according to the present invention, it is possible to obtain a material to be rolled having higher quality flatness by simpler control in rolling.

It is a figure showing an example of 1 composition of a system concerning a 1st embodiment of the present invention. It is a figure for demonstrating the difference between the conventional rolling control method and the rolling control method which concerns on 1st Embodiment. It is a flowchart which shows an example of the process sequence of the conventional rolling control method. It is a flowchart which shows an example of the process sequence of the rolling control method which concerns on 1st Embodiment. It is a block diagram which shows an example of a function structure of the rolling control apparatus which concerns on 1st Embodiment. It is a flowchart which shows an example of the process sequence of the rolling control method which concerns on 2nd Embodiment. It is a graph which shows the simulation result in the plate rolling which applied the rolling control method which concerns on 1st Embodiment. It is a graph which shows the simulation result in the plate rolling which applied the rolling control method which concerns on 2nd Embodiment.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(1. First embodiment)
(1-1. System configuration)
With reference to FIG. 1, the configuration of a system according to the first embodiment of the present invention will be described. FIG. 1 is a diagram illustrating a configuration example of a system according to the first embodiment of the present invention.

  Referring to FIG. 1, the system 1 according to the first embodiment mainly includes a rolling mill 10 and a rolling control device 20 that controls the operation of the rolling mill 10.

  The rolling mill 10 is a reversible rolling mill, and rolling is performed by passing the material to be rolled 2 through the rolling mill 10 a plurality of times (multiple passes) while the conveyance direction is changed by the table roll 170. Specifically, in the first rolling pass, the material to be rolled 2 is fed into the rolling mill 10 from the front side (left side of the drawing) by the table roll 170, and rolling is started. And the to-be-rolled material 2 by which rolling was carried out slips out to the rear surface side (drawing right side) of the rolling mill 10. FIG. Furthermore, in the next rolling pass, the material 2 to be rolled is fed into the rolling mill 10 from the rear surface side of the rolling mill 10 by the table roll 170 and rolling is started. To go. Hereinafter, by repeating this rolling pass a plurality of times, the material to be rolled 2 is rolled down to a desired thickness.

  The rolling mill 10 is provided with a pair of upper work roll 121 and lower work roll 122 inside a housing 110, and an upper backup roll 123 and a lower backup roll above and below the upper work roll 121 and the lower work roll 122, respectively. This is a quadruple rolling mill provided with 124. However, the rolling mill 10 is not limited to a quadruple type, and may be a multiple type rolling mill other than the quadruple type. In the following description, when expressing 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, 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 where they are pivotally supported by 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 where they are pivotally supported by the backup roll chock 133 and 134, respectively.

  Between the work roll chock 131 of the upper work roll 121 and the backup roll chock 133 of the upper backup roll 123 and between the work roll chock 132 of the lower work roll 122 and the backup roll chock 134 of the lower backup roll 124, the upper work roll 121 and A roll bender 140 for bending the lower work roll 122 in the axial direction is provided. The roll bender 140 is, for example, a hydraulic cylinder, and applies a desired roll bending force to the upper work roll 121 and the lower work roll 122 under the control of the rolling control device 20.

  In FIG. 1, it is illustrated that an instruction for drive control from the rolling control device 20 is simply input to the roll vendor 140, but in reality, the system 1 includes the roll vendor. A roll bending driving device (not shown) for driving 140 (for example, changing the hydraulic pressure) is provided. An instruction from the rolling control apparatus 20 is input to the roll bending driving apparatus, and the roll bending machine 140 is driven according to the instruction by the roll bending driving apparatus, so that a desired roll bending force according to the instruction is applied to the upper work roll. 121 and the lower work roll 122.

  Here, in general, in rolling, as a crown control mechanism adjusted when controlling the sheet crown of the material 2 to be rolled, a roll bender mechanism, a roll cloth mechanism, and a roll shift mechanism are known, Crown control can be performed by controlling the roll bending force (more specifically, the roll bender pressure applied to the roll bender 140), the roll cross angle, and the roll shift amount.

  In the first embodiment, when the crown control is performed, any of these roll bending force (roll bender pressure), roll cross angle, and roll shift amount may be adjusted. For example, when the rolling mill 10 is a so-called pair cross mill or work roll shift mill, the roll cross angle and the roll shift amount can be adjusted for crown control. In this case, the system 1 may be 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. An instruction from the rolling control device 20 is input to the roll cloth driving device or the roll shift driving device, and the roll moves according to the instruction by the roll cloth driving device or the roll shift driving device, so that the instruction is met. A desired roll cross angle or roll shift amount is realized.

  In general, the control of the roll bender pressure has a relatively high response compared to the control of the roll cross angle or the roll shift amount. The roll bender pressure can be changed even while the material to be rolled 2 is biting into the rolling mill 10. In the first embodiment, when the crown control is performed, whether the roll bender pressure, the roll cross angle and / or the roll shift amount is changed depends on such characteristics and the total rolling time. It may be determined as appropriate in consideration of the request for the above.

  Further, in the example shown in FIG. 1, the rolling mill 10 includes a roll bender 140 (that is, a work roll bender) that loads the upper work roll 121 and the lower work roll 122 as a mechanism that loads a roll bending force to the roll. However, the first embodiment is not limited to such an example. The rolling mill 10 may include a backup roll bender that applies a roll bending force to the upper backup roll 123 and the lower backup roll 124 together with or in place of the roll vendor 140. In the first embodiment, the roll bending force adjusted when performing crown control may be applied to the upper work roll 121 and the lower work roll 122, or may be applied to the upper backup roll 123 and the lower backup roll 124. May be loaded.

  The backup roll chock 133 of the upper backup roll 123 of the rolling mill 10 is provided with a reduction device 150 that adjusts the interval (roll interval) between the upper work roll 121 and the lower work roll 122. The reduction device 150 adjusts the roll interval, that is, the reduction position, under the control of the rolling control device 20. The reduction device 150 may be configured integrally 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.

  In addition, 1st Embodiment is not limited to this example, A load cell may be provided in the rolling mill 10 as an apparatus different from the rolling-down apparatus 150. FIG. Further, the position at which 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 device 160 is provided on the rear surface side of the rolling mill 10. The plate crown measuring device 160 measures the plate crown of the material to be rolled 2 after passing through the rolling mill 10, that is, at the stage when a predetermined rolling pass is completed. The measured value of the sheet crown is transmitted to the rolling control device 20.

  In addition, 1st Embodiment is not limited to this example, The plate crown measuring device 160 may be provided in the front side of the rolling mill 10, or may be provided in both sides. Further, instead of the plate crown measuring device 160, a flatness measuring device 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 execute a plurality of passes of rolling on the material to be rolled 2. The rolling control device 20 may be a processor such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor). 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. Various operations in the rolling mill 10 are executed by a processor constituting the rolling control device 20 executing various arithmetic processes according to a predetermined program. Further, the rolling control device 20 may include a communication device for exchanging various types of information with the rolling mill 10, a storage device that can store various types of information, and the like.

  Specifically, before the rolling of the material 2 to be rolled, the rolling control device 20 determines the type of the material 2 to be rolled (for example, a steel type in the case of a steel plate), the rolling start plate thickness, the rolling end plate thickness, the plate width, Based on the rolling conditions such as the roll profile state and the temperature of the material to be rolled, a predetermined pass schedule is calculated to determine the number of rolling passes for obtaining the desired plate thickness, plate crown and flatness, and the pass schedule (each rolling Initialize the pass reduction amount distribution). At this time, the rolling load of each rolling pass is predicted and calculated on the basis of information such as the rolling amount and rolling speed in each rolling pass, the temperature and type of the material to be rolled, and on the outgoing side of each rolling pass based on these information. The roll bending force in the plate crown and each rolling pass is set. Then, the rolling control device 20 drives the reduction device 150 and the roll bender 140, respectively, and starts rolling so that the set outlet side plate thickness and outlet side plate crown are realized. In addition, since various well-known methods may be applied as a method of pass schedule calculation before the rolling start, the detailed description is abbreviate | omitted here.

  In the first embodiment, for a material to be rolled, after the start of rolling, up to the m-1th rolling pass (2 ≦ m ≦ N, where N is the total number of passes) is set before starting rolling as described above. Crown control (for example, roll bender pressure control) is performed so as to realize the set value of the exit plate crown (hereinafter also referred to as crown control according to the set value). Then, at the stage before starting the m-th rolling pass (that is, at the stage when the (m-1) -th rolling pass is completed), the plate crown ratio is kept constant from the crown control according to the set value up to that point. The control is switched to a control that keeps the pressure at a constant value (hereinafter referred to as constant plate crown ratio control), and the constant plate crown ratio control of the material to be rolled is executed in the rolling passes after the m-th pass.

  Hereinafter, the above-described control switching and plate crown ratio constant control 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 rolling pass” is also abbreviated as “m-pass” or the like.

(1-2. About processing in the rolling control device)
(1-2-1. Overview of Processing)
The outline of the rolling control method according to the first embodiment, which is executed by the rolling control device 20, will be described while being compared with the conventional rolling control method.

  As described above, in rolling in a plurality of passes related to thick plate rolling, a pass schedule (a reduction amount distribution of each rolling pass) is set in consideration of the plate crown and flatness in the final product before the start of rolling. The Then, rolling is started so as to realize the set value of the sheet thickness on the exit side of each rolling pass according to the reduction amount distribution. At this time, on the exit side of each rolling pass, crown control is performed so as to realize a preset plate crown.

  Here, due to a temperature prediction error of the material to be rolled in each rolling pass, a prediction error occurs in the rolling load, and the setting value calculated for the rolling load and the actual value do not necessarily match. Therefore, the plate crown of the material to be rolled on the exit side of each rolling pass (that is, the entry side of the next rolling pass) does not necessarily match the set calculation value.

  Therefore, conventionally, in each rolling pass, the sheet crown of the material to be rolled on the exit side of the rolling pass is set or predicted based on the measured value or the actual calculation value of the sheet crown on the entry side of the rolling pass. Control is performed to change the crown control amount such as roll bender pressure in the rolling pass to a value different from the initial set value so as to be a value. That is, as a conventional rolling control method, in each rolling pass, crown control (that is, crown control according to the set value) is performed so as to make the exit side plate crown coincide with the initial set value. The actual calculation value is a measured value of rolling load or a measured value of input / output side plate thickness (the thickness of the gauge meter is calculated from the measured value of rolling load and the rigidity of the rolling mill. It is a calculated value calculated from a calculation model using (good). In actual equipment, a measured value (for example, a plate crown) is not always obtained from the relationship between the installation position of the measuring instrument, the number of installed devices, etc., and can represent an actual value (a measured value can be substituted) ), Such a performance calculation value can be suitably used. In addition, the predicted value of the sheet crown on the rolling pass exit side is, for example, the rolling pass output predicted by reflecting the rolling performance up to the rolling pass immediately before the rolling pass and learning between passes based on this. This is the calculated value of the plate crown on the side.

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

Here, H _i is the plate thickness on the i-pass entry side, h _i is the plate thickness on the i-pass exit side, C _Hi is the plate crown on the i-pass entry side, and C _hi is the plate crown on the i-pass exit side. Ξ _i is a shape change coefficient in the i-pass. It can be said that the material to be rolled becomes flat as the elongation strain difference Δε _i approaches zero. The ratio _{(C Hi / H i, C} hi / h i) between the plate thickness and the plate crown that the strip crown ratio.

  As is clear from the above formula (1), it is generally known that high flatness can be ensured when rolling is performed so that the plate crown ratio is constant between the entry side and the exit side. It has been. Conversely, when the plate crown ratio changes greatly between the entry side and the exit side, flatness defects called ear waves (end elongation) and medium elongation occur, and the flatness of the material to be rolled deteriorates.

  Therefore, as in the conventional rolling control method described above, when rolling is performed by changing the crown control amount such as the roll bender pressure so that the sheet crown becomes the initial set value in each rolling pass, the set value Although there is a possibility that a plate crown close to can be realized, the plate crown ratio changes in any rolling pass, and the flatness of the material to be rolled may be deteriorated.

Note that the shape change coefficient ξ _i in the above formula (1) takes a relatively small value when the thickness of the material to be rolled is thick, and takes a relatively large value when the thickness of the material to be rolled is thin. It is known. Therefore, when the plate thickness of the material to be rolled is thick, the influence of the change in the plate crown ratio on the flatness of the material to be rolled is small. On the other hand, when the plate thickness of the material to be rolled is thin, the influence of the change in the plate crown ratio on the flatness of the material to be rolled becomes large. Therefore, it is considered that the deterioration of the flatness of the material to be rolled in the conventional rolling control method appears remarkably in the subsequent rolling pass in which the plate thickness is relatively thin.

  Therefore, in the first embodiment, at the stage where the rolling pass of the m-1th pass (2 ≦ m ≦ N) is completed, the measured value or actual calculated value of the plate crown is different from the initially set value. In this case, the control is switched from the crown control according to the set value so far to the constant plate crown ratio control. And in each rolling pass after the m-th pass, plate crown ratio constant control is performed. Specifically, in the sheet crown ratio constant control, the difference in the sheet crown ratio between the entry side and the exit side of the rolling pass is zero (or Crown control amount (roll bending force (roll bender pressure), roll cross angle, and / or roll shift amount) to realize the plate crown ratio on the exit side so that the flatness failure becomes a predetermined value or range that does not become apparent. ) Is calculated for each rolling pass. Then, rolling in each rolling pass is performed according to the calculated crown control amount (that is, the calculated roll bender pressure, roll cross angle and / or roll shift amount are adjusted). As a result, since the plate thickness of the material to be rolled becomes thin, the change in the plate crown ratio is likely to appear remarkably as a flatness failure of the material to be rolled, so that the plate crown ratio is kept substantially constant in the subsequent rolling pass. Further, it is possible to realize rolling that can ensure higher flatness.

  In the first embodiment, the roll bending force (roll bender pressure) is preferably adjusted in order to change the plate crown in accordance with the crown control amount in the plate crown ratio constant control. As described above, changing the roll bending force is relatively fast. That is, the roll bending force can be easily changed in a relatively short time, whereas the roll cross angle or the roll shift amount needs a relatively long time. Since the crown control amount is calculated for each rolling pass and rolling is performed in accordance with the crown control amount, roll crowning with higher response is performed in consideration of the total work time related to rolling. This is because the crown control amount is preferably changed by the force.

  Further, the timing for switching the control may be appropriately determined based on the thickness of the material to be rolled in each rolling pass so that a desired flatness can be realized in the final product. For example, the timing at which the control is switched may be determined depending on whether or not the plate thickness of the material to be rolled is a region where a flatness failure can be manifested by a change in the plate crown ratio. This is because when the sheet thickness of the material to be rolled is in such a region, if the crown control according to the initial set value is continued, the sheet crown ratio may change and the flatness may deteriorate.

  Here, the specific thickness of the material to be rolled that becomes the boundary of the region in which the flatness ratio is manifested by the change in the plate crown ratio is the type of the material to be rolled (for example, the steel type in the case of a steel plate), the size (plate) The width may be appropriately set depending on, for example, about 30 mm. That is, in the first embodiment, the plate crown ratio constant control can be preferably started from a rolling pass in which the exit side plate thickness is about 30 mm or less. In other words, the m-th rolling pass described above can be a rolling pass that preferably has an exit side plate thickness of 30 mm or less.

  Furthermore, the thickness of the material to be rolled, in which the change in the plate crown ratio appears prominently in flatness failure, depends on the type of material to be rolled (for example, steel type for steel plate), size (sheet width), etc. It is known from experience through actual operation that it is about 20 mm or less. Therefore, more preferably, in the first embodiment, the plate crown ratio constant control can be started before the rolling pass in which the entry side plate thickness is about 20 mm or less is executed. In other words, the m-th rolling pass described above may be any rolling pass before the entry side plate thickness is 20 mm or less.

  As described above, the rolling control method according to the first embodiment can be suitably applied to thick plate rolling for relatively thin thick plates.

  In this specification, for convenience, the term “constant plate crown ratio control” is used. However, in the constant crown crown ratio control according to the first embodiment, the change in the plate crown ratio is not necessarily zero. It is not necessary to perform such control, and it is only necessary to perform control so that the change in the plate crown ratio falls within a predetermined range (for example, “within 2% of steepness” or the like) in which flatness failure is not apparent. Further, depending on the definition of the plate crown, the change in the plate crown ratio that makes the flatness (for example, elongation strain difference) of the material to be rolled good is not always zero. In such a case, it is only necessary to perform control so that the plate crown ratio change is kept at a value (or range) in which the flatness of the material to be rolled is optimal or within a desired range.

  Differences between the conventional rolling control method described above and the rolling control method according to the first embodiment are summarized in FIG. FIG. 2 is a diagram for explaining the difference between the conventional rolling control method and the rolling control method according to the first embodiment.

  As shown in FIG. 2, it is assumed that the initial set value of the sheet crown ratio is different from the actual calculation value on the entry side of the m-th rolling pass (that is, on the entry side of the m-th rolling pass). , Suppose that the initial set value of the plate crown was different from the actual calculation value).

  At this time, in the conventional rolling control method, in the rolling pass of the m-th pass, the roll bender pressure and the like are changed so as to realize the set value of the initially set sheet crown, similarly to the rolling pass so far. Rolling is performed. As a result, as shown in FIG. 2, the difference between the entrance-side plate crown ratio and the exit-side plate crown ratio in the m-th rolling pass becomes large, which may cause poor flatness.

  On the other hand, in the rolling control method according to the first embodiment, when there is a concern that poor flatness will occur, the plate crown ratio constant control is performed in the rolling passes after the m-th pass. As a result, as shown in FIG. 2, the inlet-side plate crown ratio and the outgoing-side plate crown ratio in the rolling passes after the m-th pass are kept substantially constant. Therefore, it is possible to suppress the occurrence of poor flatness.

  Further, according to the first embodiment, when switching the crown control in the m-th rolling pass, a certain amount of time is required, for example, recalculation of the reduction amount distribution in the technique described in Patent Document 4 above. No calculation is performed. Therefore, rolling after the m-th pass can be started immediately, and the total work time related to rolling is not increased. In addition, there is no increase in deformation resistance of the material to be rolled due to a temperature drop of the material to be rolled over a remarkable time with a thin material, and the accompanying increase in rolling load. Therefore, a product with higher flatness can be obtained without causing a decrease in operation efficiency. Further, since the flatness is improved, operational troubles that may occur due to the deterioration of the flatness and the occurrence of defective products can be suppressed, so that productivity can be improved.

  The outline of the rolling control method according to the first embodiment executed in the rolling control device 20 according to the first embodiment has been described above.

(1-2-2. Processing Procedure)
With reference to FIG.3 and FIG.4, the process sequence of the rolling control method which concerns on 1st Embodiment is demonstrated. Here, for comparison, a processing procedure of a conventional rolling control method will also be described. FIG. 3 is a flowchart showing an example of a processing procedure of a conventional rolling control method. FIG. 4 is a flowchart showing an example of a processing procedure of the rolling control method according to the first embodiment. Note that the series of processes shown in FIG. 4 can be executed by the processor of the rolling control apparatus 20 shown in FIG. 1 operating according to a predetermined program.

  First, the processing procedure of the conventional rolling control method will be described. Referring to FIG. 3, in the conventional rolling control method, first, k = 0 is set (step S101).

  Next, pass schedule calculation is performed before rolling starts, and the number of passes, the reduction amount distribution in each rolling pass, and the crown control amount are determined (step S103).

  Next, the rolling load in each rolling pass with respect to the set pass schedule and the set value of the plate crown are calculated (step S105).

  Next, k = k + 1 is set (step S107) (that is, k = 1 is set), the set value or predicted value of the rolling load in the k pass, and the actual calculated value of the plate crown on the k pass entry side. Alternatively, based on the measured value, a crown control amount in the k pass that realizes the set value of the plate crown on the k pass exit side is calculated (step S109).

  Then, k-pass rolling is performed according to the calculated crown control amount (step S111).

  When the k-pass rolling is finished, it is determined whether k = N, that is, whether the N-th rolling is finished (step S113). If k ≠ N, the process returns to step S107, k = k + 1 is set, and the processing of step S109 and step S111 is repeated in the next rolling pass. If k = N, rolling of all N passes is complete, so the rolling control is finished.

  Next, with reference to FIG. 4, the processing procedure of the rolling control method according to the first embodiment will be described. In FIG. 4, the rolling pass for starting the constant crown ratio control is the m pass. The m pass can be appropriately set by the user as any rolling pass before the flattening failure becomes apparent.

  Referring to FIG. 4, in the rolling control method according to the first embodiment, the processes in steps S201 to S211 are the same as the processes in steps S101 to S111 in the conventional rolling control method shown in FIG. Specifically, in the rolling control method according to the first embodiment, first, k = 0 is set (step S201). Next, pass schedule calculation is performed before rolling starts, and the number of passes, the reduction amount distribution in each rolling pass, and the crown control amount are determined (step S203). Next, the rolling load and the set value of the sheet crown in each rolling pass with respect to the set pass schedule are calculated (step S205). Next, k = k + 1 is set (step S207) (that is, k = 1 is set), and crown control according to the set value is performed in the k-th rolling (that is, the first pass) (step S209). , S211).

  In the rolling control method according to the first embodiment, when the k-th rolling is finished, next, whether k = m−1 (2 ≦ m ≦ N), that is, the m-1th rolling is finished. It is determined whether or not it has been done (step S213). If k ≠ m−1, the process returns to step S207, k = k + 1 is set, and the processing of step S209 and step S211 is repeated in the next rolling pass. That is, crown control according to the set value is performed for the k + 1 path. If k = m−1, the process proceeds to step S215.

  In step S215, k = k + 1 is set. In step S217 and step S219, the plate crown ratio constant control is performed. Specifically, in step S217, the difference between the actual calculated value or the measured value of the plate crown ratio on the k-pass entry side and the predicted value of the plate crown ratio on the k-pass exit side is zero. The crown control amount in the pass is calculated. In addition, when the plate crown ratio constant control is performed by changing the roll bending force, the roll bending force can be changed even while the material to be rolled 2 is biting into the rolling mill 10. The actual values such as the rolling load at the k-th pass may also be taken into account in the calculation of the predicted value of the plate crown on the k-pass exit side.

  Then, rolling in the k pass is executed according to the calculated crown control amount (step S219).

  When the k-pass rolling is finished, it is determined whether k = N, that is, whether the N-th rolling is finished (step S221). If k ≠ N, the process returns to step S215, k = k + 1 is set, and the processing of step S217 and step S219 is repeated for the next rolling pass. That is, the plate crown ratio constant control is performed for the k + 1 pass. If k = N, rolling of all N passes is complete, so the rolling control is finished.

  The processing procedure of the conventional rolling control method and the rolling control method according to the first embodiment has been described above. In the example shown in FIG. 4, in step S217, the crown control amount for which the change in the plate crown ratio is zero is calculated as the crown control amount related to the constant plate crown ratio control. The form is not limited to such an example. In step S217, as the crown control amount related to the constant plate crown ratio control, a crown control amount may be calculated such that the change in the plate crown ratio falls within a predetermined range in which flatness defects are not manifested.

(1-2-3. Details of processing)
The process performed in the rolling control apparatus 20 in 1st Embodiment is demonstrated more concretely. Note that the processes in steps S201 to S215, step S219, and step S221 shown in FIG. 4 can be executed by various conventionally used methods, and thus the description thereof is omitted here. Here, among the processes shown in FIG. 4, the process in step S <b> 217, which is a characteristic process of the first embodiment, that is, a process for calculating the crown control amount so that the plate crown ratio change becomes zero. This will be described in detail.

  Hereinafter, as an example, the processing in step S217 in the case where the following formula (2) is used as a model formula indicating the change in the plate crown will be described.

Here, H _i , h _i , C _Hi and C _hi are the same as those in the formula (1). C _i is a mechanical crown in i-path, and η _i is a crown ratio genetic coefficient 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 depends on a roll profile, a roll deformation accompanying a rolling load, and the like. In the above (1-1. System configuration), the roll bending force (roll bender pressure), roll cross angle, roll shift amount, and the like are known as control amounts that can be adjusted to control the plate crown. It has been described, any of which may be a control amount regarding the mechanical crown C _i. Thus, from the above equation (2), roll bending force is control amount regarding the mechanical crown C _i (roll bender pressure), by controlling the roll cross angle and / or roll shift amount, capable of controlling the strip crown It turns out that it is.

  In the following, in order to distinguish between the setting value calculated before the start of rolling and the actual calculation value, the setting value is represented by adding “s” to each variable, and the actual calculation value is indicated by “*” for each variable. ". The formula (2) for the set value can be written as the following formula (3), and the formula (2) for the actual calculation value can be written as the following formula (4).

Assuming that the desired crown control amount (amount of change from the set value) is ΔC ^C _i , the plate crown relational expression when the i-th rolling is performed is given by the following formula (5). Here, in the derivation of the following mathematical formula (5), since the rolling has already been performed up to the i-1th pass, the actual calculation value is used as the value related to the i-1th pass. On the other hand, although rolling of the i-th pass will be performed from now on, values related to the i-th pass can be predicted reflecting the rolling performance up to the i-1th pass and learning between passes based on this. Predicted values reflecting such learning between paths are represented by adding “s ′” to each variable.

Here, the crown ratio genetic coefficient η _i generally takes a non-zero value. Therefore, in order to make the plate crown ratio change in the i-th rolling zero, a crown control amount ΔC ^C _i that satisfies the following formula (6) is obtained, and rolling is performed according to the crown control amount ΔC ^C _i. It's fine. In other words, rolling may be performed by adjusting the roll bender pressure or the like according to the crown control amount ΔC ^C _i .

Specifically, the rolling control device 20 calculates C _Hi ^* and H _i ^* , which are actual calculation values on the right side of the formula (6), based on actual values such as rolling load and sheet thickness. Further, h _i ^{s on} the left side is a set value calculated in advance by the rolling control device 20, and C _i ^{s ′} is based on the rolling results up to the i−1th pass by the rolling control device 20 as described above. It can be calculated by reflecting the learning between paths. Therefore, the rolling control device 20 can obtain the crown control amount ΔC ^C _i that satisfies the above formula (6).

The processing in step S217 shown in FIG. 4 has been described above in detail. In the first embodiment, the roll bending force (roll bender pressure) can be suitably controlled in order to perform rolling according to the crown control amount. When the sheet crown is controlled by a control amount that can be changed even when the material to be rolled 2 is biting into the rolling mill 10 as in the roll vendor pressure, during rolling of the i-th pass, Based on the measured value of the rolling load, a control amount for the roll bender pressure is calculated as needed so that the plate crown ratio becomes zero, and even if the roll bender pressure in the roll bender 140 is dynamically controlled to realize this. Good. Specifically, based on measurements of the rolling force during rolling of i pass, determine the roll bender pressure control amount Delta] p _i that satisfies the following equation (7), the roll bender 140 so as to achieve this The roll bender pressure at may be controlled.

  Further, in the above example, the case where the crown control amount is calculated such that the change in the plate crown ratio is zero has been described. However, as described above, in the first embodiment, in the plate crown ratio constant control, Control may be performed so that the change in the plate crown ratio falls within a predetermined range. In this case, the crown control amount can be calculated from Equation (5) above so that the change in the plate crown ratio falls within a predetermined range.

  In the above example, the above mathematical formula (2) is used as the crown model, but the first embodiment is not limited to this example. Various crown models are known in addition to the above formula (2). In the first embodiment, various known models may be used as the crown model.

(1-3. Functional configuration)
With reference to FIG. 5, 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. 5 is a block diagram illustrating an example of a functional configuration of the rolling control device 20 according to the first embodiment.

  Referring to FIG. 5, the rolling control device 20 according to the first embodiment includes a measurement value acquisition unit 201, a calculation unit 203, a drive control unit 205, and a storage unit 207 as its functions.

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

  Note that the measurement value acquisition unit 201 may store information about various acquired measurement values in the storage unit 207, and the calculation unit 203 accesses the storage unit 207 to obtain information about the measurement values. You may get it.

  The arithmetic unit 203 is realized by a processing circuit such as a CPU. In the calculation unit 203, the processes in steps S201 to S209, steps S213 to S217, and step S221 shown in FIG. 4 are executed. Since the details of each of these processes have already been described, the description thereof is omitted here. The calculation unit 203 provides the drive control unit 205 with information about the various set values and crown control amounts that have been calculated.

  The arithmetic unit 203 may store information on the calculated crown control amount in the storage unit 207, and the drive control unit 205 obtains information on the crown control amount by accessing the storage unit 207. May be.

  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 each process in step S211 and step S219 shown in FIG. Specifically, the drive control unit 205 drives the rolling mill 10 according to various set values and crown control amounts calculated by the calculation unit 203. For example, the drive control unit 205 operates the reduction device 150 and the roll bending drive device according to the calculated pass schedule, and starts rolling so that the set values of the exit side plate thickness and the exit side plate crown are realized. Further, for example, the drive control unit 205 operates the roll bending drive device according to the calculated crown control amount, loads the roll bending force to the roll by the roll bender 140, and performs crown control or crown ratio constant control according to the set value. Execute. Alternatively, the drive control unit 205 operates a roll cross drive device or a roll shift drive device (both not shown in FIG. 1) when performing crown control or constant crown ratio control according to the set value, Further, the movement may be made by an amount corresponding to the calculated crown control amount.

  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 a magneto-optical storage device. The storage unit 207 can store various types of information related to processing in the rolling control device 20. For example, the storage unit 207 stores various measurement values acquired by the measurement 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.

  Heretofore, an example of the function of the rolling control device 20 according to the first embodiment has been described. Each component described above may be configured using a general-purpose member or circuit, or may be configured by hardware specialized for the function of each component. Moreover, the structure for implement | achieving the rolling control apparatus 20 may be suitably changed according to the technical level at the time of implementation.

  In addition, the specific apparatus structure of the rolling control apparatus 20 is not limited. For example, the function of the rolling control device 20 described above may not necessarily be realized by one device. For example, one device that performs some of the illustrated functions and another device that performs the remaining functions are communicably connected to each other, so that the same function as the rolling control device 20 has a plurality of functions. You may implement | achieve by cooperation of an apparatus.

  Moreover, it is possible to produce a computer program for realizing each function of the rolling control apparatus 20 according to the first embodiment as described above, and to implement it on a personal computer or the like. It is also possible to provide a computer-readable recording medium storing such a computer program. The recording medium can 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.

(2. Second Embodiment)
As described above, in the first embodiment, the plate crown ratio constant control can be performed based on the actual calculation value of the plate crown ratio. Here, the predicted value of the roll profile is used for the calculation of the actual calculation value. Accordingly, when there is an error between the predicted roll profile value and the actual roll profile, a deviation occurs between the actual calculated value of the plate crown ratio and the actual value of the plate crown ratio. It may be difficult to perform constant control with high accuracy.

  Therefore, in the second embodiment, when calculating the crown control amount that makes the plate crown ratio constant in the rolling control method according to the first embodiment described above, the measured value of the plate crown or flatness is calculated. A process for correcting the predicted value of the roll profile is used, that is, a roll profile learning process is performed. Then, the crown control amount is calculated using the corrected roll profile. As described above, according to the second embodiment, it is possible to obtain the crown control amount related to the constant control of the sheet crown ratio in consideration of the error of the roll profile, so that the flatness of the material to be rolled can be made with higher accuracy. It becomes possible to secure.

  Hereinafter, the second embodiment will be described in more detail. Note that the second embodiment may be the same as the first embodiment except that the roll profile learning process is performed when the crown control amount related to the constant plate crown ratio control is obtained. Therefore, in the following description, the second embodiment will be described mainly with respect to matters that are different from the first embodiment, and detailed descriptions of items that overlap with the first embodiment will be omitted.

(2-1. System configuration)
The system according to the second embodiment is the same as the system 1 according to the first embodiment shown in FIG. 1 except that the processing related to rolling control performed in the rolling control device 20 is different. Therefore, detailed description thereof is omitted here. Hereinafter, the process performed in the rolling control apparatus 20 which concerns on 2nd Embodiment is demonstrated in detail.

(2-2. Processing procedure)
With reference to FIG. 6, the process sequence of the rolling control method which concerns on 2nd Embodiment performed in the rolling control apparatus 20 is demonstrated. FIG. 6 is a flowchart showing an example of a processing procedure of the rolling control method according to the second embodiment. Note that the series of processes shown in FIG. 6 can be executed by the processor of the rolling control device 20 operating according to a predetermined program.

  Referring to FIG. 6, in the rolling control method according to the second embodiment, the processes in steps S301 to S313 are the same as the processes in steps S201 to S213 in the rolling control method according to the first embodiment shown in FIG. 4. It is the same. Therefore, the details of the processing in steps S301 to S313 are omitted.

  In the rolling control method according to the second embodiment, when k = m−1 (2 ≦ m ≦ N) in step S313, m-pass is entered at the stage where the rolling of the m−1th pass is completed. The roll profile compensation amount is calculated based on the measured value of the plate crown on the side (that is, the m-1 path exit side) (step S315). Specifically, in the process shown in step S315, a roll profile compensation amount is obtained such that the measured value of the plate crown on the m-pass entry side matches the actual calculation value. Here, the roll profile compensation amount is a compensation amount of a roll profile error (refer to (2-3. Details of processing) below for details).

  Next, k = k + 1 is set (step S317). Then, the difference between the actual calculated value or the measured value of the plate crown ratio on the k-pass inlet side calculated using the roll profile compensation amount and the predicted value of the plate crown ratio on the k-pass outlet side is zero. A crown control amount for the k path is calculated (step S319). In addition, since the roll profile is compensated so that the actual calculated value and the measured value of the plate crown on the k-pass entry side coincide with each other, the actual calculated value and the measured value of the plate crown ratio on the k-pass entry side are Naturally they agree. Therefore, in step S319, when calculating the crown control amount, there is no problem in using either the actual calculated value or the measured value of the plate crown ratio.

  Then, k-pass rolling is performed according to the calculated crown control amount (step S321).

  When the k-pass rolling is finished, it is determined whether k = N, that is, whether the N-pass rolling is finished (step S323). If k ≠ N, the process returns to step S317, k = k + 1 is set, and the processing of step S319 and step S321 is repeated for the next rolling pass. That is, the plate crown ratio constant control is performed for the k + 1 pass. If k = N, rolling of all N passes is complete, so the rolling control is finished.

  The processing procedure of the rolling control method according to the second embodiment has been described above. As described above, in the rolling control method according to the second embodiment, the plate crown ratio constant control is performed after correcting the roll profile error in the m-th and subsequent rolling passes. Therefore, the flatness of the material to be rolled can be maintained at a higher quality.

  Here, conventionally, in rolling, the roll profile is corrected based on the rolling performance of the preceding material, and it is widely performed to use the corrected roll profile for setting calculation at the time of rolling for the next material to be rolled. Yes. However, in this method, for example, when the sheet width of the material to be rolled is significantly different from the preceding material, even if a 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 is not always improved. In addition, in order to make the roll profile learning stable even when the plate width change with the preceding material is large as described above, the gain has to be set small. On the other hand, according to the second embodiment, the roll profile is corrected based on the measured value of the sheet crown in the intermediate pass in the rolling of a plurality of passes on the same material to be rolled in the same rolling mill, and the roll after the correction The profile is used to control the flatness in rolling in the remaining rolling passes. In this case, the roll profile error can be estimated and compensated with high accuracy because the material to be rolled used for roll profile learning (the material to be rolled with the crown measured) and the material to be controlled are the same. . Therefore, the effect of role profile learning can be obtained more suitably.

  In the example shown in FIG. 6, the roll profile compensation amount is calculated based on the measured value of the plate crown in step S315. However, the second embodiment is not limited to such an example. In step S315, the roll profile compensation amount may be calculated based on the measured value of flatness (specifically, the measured value of flatness matches the actual calculated value).

  Further, in the rolling control method according to the second embodiment, the timing at which the roll profile is corrected and the plate crown ratio constant control is started (that is, the timing at which the processing in steps S315 to S323 is started) is the first. It may be similar to the embodiment. For example, in the second embodiment, the plate crown ratio constant control can be preferably started from a rolling pass in which the exit side plate thickness is about 30 mm or less. More preferably, in the second embodiment, the plate crown or flatness for calculating the roll profile compensation amount is measured before executing the rolling pass in which the entry side plate thickness is about 20 mm or less, and the plate Crown ratio constant control can be initiated.

  In the example shown in FIG. 6, in step S319, the crown control amount for which the change in the plate crown ratio is zero is calculated as the crown control amount related to the constant control of the plate crown ratio. The form is not limited to such an example. As in the first embodiment, in step S319, the crown control amount related to the constant control of the plate crown ratio is such that the change in the plate crown ratio falls within a predetermined range in which flatness failure is not manifested. It may be calculated.

(2-3. Details of processing)
A specific example of processing executed in the rolling control device 20 in the second embodiment will be described. Note that the processing in step S301 to step S313, step S317, step S321, and step S323 shown in FIG. 6 is the same as that in the first embodiment. Accordingly, here, the processing in steps S315 and S319 shown in FIG. 6, which is processing characteristic of the second embodiment, that is, processing for obtaining the roll profile compensation amount, and the roll profile compensation amount are taken into account. The process for calculating the crown control amount so that the plate crown ratio change becomes zero will be described in detail.

  Below, the process in step S315 and step S319 in the case of using the said Numerical formula (2)-(4) as a model formula which shows the change of a plate crown as an example is demonstrated.

In the above formula (4), the mechanical crown C _i used for the calculation of the actual calculation value includes a roll profile error. Assuming that the roll profile compensation amount that can compensate for the error is ΔC _R ^err , the relational expression in which the roll profile error is compensated can be written from the above formula (4) as the following formula (8).

  When the mathematical formula (8) is written down to i = 1 to m−1, the following mathematical formula (9) is obtained.

In the second embodiment, at the stage where the rolling of the (m−1) th pass is completed, the rolling control device 20 uses the above formula (9) to determine the measured value of the plate crown on the m−1 pass exit side. Then, a roll profile compensation amount ΔC _R ^err that matches the actual calculation value C _hm-1 ^* is obtained (corresponding to the process in step S315 shown in FIG. 6).

Then, the rolling control apparatus 20, the roll profile compensation amount [Delta] C _R ^err is consideration, rolling passes (i.e., m and subsequent rolling i th such as strip crown ratio is constant (i = m to n) The crown control amount (change amount from the set value) ΔC ^C _i in (pass) is obtained so as to satisfy the following formula (10) (corresponding to the processing in step S319 shown in FIG. 6).

The m-th and subsequent rolling pass, roll bender pressure or the like in accordance with the crown control amount determined [Delta] C ^C _i is adjusted, rolling is carried out. As a result, it is possible to carry out constant plate crown ratio control after correcting the error of the roll profile.

  In the above specific example, the description has been given of the case where the crown control amount is calculated such that the change in the plate crown ratio becomes zero. However, as described above, in the second embodiment, the constant plate crown ratio control is performed. Control may be performed so that the change in the plate crown ratio falls within a predetermined range. In this case, the crown control amount can be calculated from Equation (9) so that the change in the plate crown ratio falls within a predetermined range. In the above specific example, the measured value of the plate crown is used to obtain the roll profile compensation amount. However, as described above, based on the measured value of the flatness (specifically, the flatness The roll profile compensation amount may be calculated so that the measured value matches the actual calculated value). Various known model formulas other than the above formulas (2) to (4) may be used as model formulas showing the change in the plate crown.

(2-4. Functional configuration)
The functional configuration of the rolling control device 20 according to the second embodiment is the same as the functional configuration of the rolling control device 20 according to the first embodiment shown in FIG. 5 except that the specific processing in the calculation unit 203 is different. It is. That is, the measurement value acquisition unit 201 acquires the measurement 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 arithmetic unit 203 uses these measured values to execute each process in Step S301 to Step S309, Step S313 to Step S319, and Step S323 shown in FIG. 6, and calculates various setting values and roll profiles. Compensation amount calculation and crown control amount calculation. The drive control unit 205 executes rolling control according to the pass schedule, crown control according to the set value, or plate crown ratio constant control according to the various set values calculated, roll profile compensation amount or crown control amount. Then, the rolling mill 10 is driven (corresponding to each process in step S311 and step S321 shown in FIG. 6). In addition, the storage unit 207 stores various types of information related to processing in the rolling control device 20.

  The functional configuration of the rolling control device 20 according to the second embodiment has been described above. As in the first embodiment, a computer program for realizing each function of the rolling control device 20 according to the second embodiment described above can be produced and mounted on a personal computer or the like. . It is also possible to provide a computer-readable recording medium storing such a computer program. The recording medium can 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.

(2-5. Modification)
A modification of the second embodiment will be described. As shown in FIG. 6, in the rolling control method according to the second embodiment described above, a roll profile learning process is performed on the m-pass entry side, and the plate crown ratio constant control is performed using the corrected roll profile. The crown control amount was calculated, and the plate crown ratio was controlled at each rolling pass after the m pass. However, the second embodiment is not limited to such an example. For example, the rolling pass for performing the roll profile learning process and the rolling pass for starting the plate crown ratio constant control may be different. In other words, in the second embodiment, when performing constant control of the sheet crown ratio in each rolling pass after the m pass, the roll profile learning process is performed on the entrance side of the r pass (r ≠ m, 2 ≦ r ≦ N). May be.

  In this case, r <m or r> m may be satisfied. In the case of r <m, after performing the roll profile learning process on the r-pass entry side, for each of the r-pass, r + 1-pass,. Rolling is performed with a crown control amount that realizes the set value of the sheet crown on the exit side (that is, the roll profile is corrected on the r-pass entry side, but the r to m-1 passes are the same as the r-pass. The plate crown is controlled). Then, on the m-pass entry side, the crown control amount related to the plate crown ratio constant control is calculated using the corrected roll profile, and the plate crown ratio constant control is performed in each rolling pass after the m pass.

  On the other hand, when r> m, on the m-pass entry side, the crown control amount related to the constant plate crown ratio control is calculated using the roll profile before correction, and the constant plate crown ratio control is started from the m pass. . Thereafter, at the stage where the rolling to the r-1 pass is completed (that is, at the r pass entry side), the sheet crown or flatness of the material to be rolled is measured, and the learning process of the roll profile is performed using the measured value. Then, the crown control amount related to the plate crown ratio constant control is calculated again using the corrected roll profile, and the plate crown ratio constant control is continued using the newly calculated crown control amount after the r pass.

  Here, in order to change the crown control amount, it is necessary to change the roll bending force, the roll cross angle or the roll shift amount. In particular, a certain amount of time is required to change the roll cross angle or the roll shift amount. Cost. On the other hand, for example, in thick plate rolling, there is a preferable temperature of the material to be rolled for each rolling pass, so that rolling may be performed continuously without much time between rolling passes in order to avoid a decrease in temperature. For example, in order to lower the temperature, after the rolling in the previous rolling pass is completed, the rolling of the next rolling pass may be performed after waiting for a predetermined time. Therefore, in order to change the crown control amount when the timing for changing the crown control amount in order to start the plate crown ratio constant control is between rolling passes in which rolling is continuously performed without leaving time. Since a standby time that should not be originally set occurs between rolling passes, the temperature of the material to be rolled may be out of the preferred range, and the operation efficiency may be reduced. On the other hand, when the timing of changing the crown control amount in order to start the plate crown ratio constant control is between rolling passes in which processing for waiting for a predetermined time for temperature management of the material to be rolled occurs. Since the crown control amount may be changed during the standby time originally provided, the temperature of the material to be rolled can be controlled within a preferable range, and there is no risk of lowering the operation efficiency. As described above, the timing for changing the crown control amount to start the plate crown ratio constant control is between the rolling passes in which the process of waiting for a predetermined time originally occurs due to the temperature management of the material to be rolled. Is preferred.

  As in the above-described embodiment, the roll profile learning process is performed on the m-pass entry side, and when the plate crown ratio constant control is performed in each rolling pass after the m pass, the plate crown ratio constant control is started. Since the rolling pass is limited to the rolling pass that performs the roll profile learning process on the entry side, the degree of freedom in selecting the rolling pass for starting the plate crown ratio constant control is low. Therefore, it may be difficult to change the crown control amount at the preferred timing as described above. In addition, as described above, the timing for switching the plate crown control to the plate crown ratio constant control is a region in which the plate thickness of the material to be rolled becomes relatively thin and the flatness failure can be manifested by the change in the plate crown ratio. It can be the timing. However, for example, when the roll profile is corrected at a relatively early stage after starting rolling in a series of rolling passes, that is, at a stage where the plate thickness is still relatively thick, the rolling according to the above-described embodiment. In the control method, the sheet crown ratio constant control is performed from the stage where the sheet thickness of the material to be rolled is relatively thick. That is, since it becomes impossible to switch the plate crown control to the plate crown ratio constant control at the preferred timing as described above, it may be difficult to control the plate crown of the material to be rolled to a desired value.

  On the other hand, according to the present modification, the timing for starting the plate crown ratio constant control can be arbitrarily set independently of the timing for performing the roll profile learning process. Therefore, the plate crown ratio constant control can be started (that is, the crown control amount is changed) at a more preferable timing as described above. Therefore, according to the present modification, the crown control amount can be changed without affecting the temperature management of the material to be rolled, and it becomes possible to perform higher-quality rolling and lower the operation efficiency. Things can be avoided. Further, by appropriately selecting the timing for starting the plate crown ratio constant control, the plate crown of the material to be rolled can be controlled to a desired value with higher accuracy.

  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 ratio on each rolling pass exit side was measured. The rolling conditions are as follows.

(Rolling conditions)
・ Number of passes: 8
・ Transfer thickness (plate thickness before starting rolling): 100 mm
-Product thickness (thickness at the end of rolling (at the end of 8 passes)): 9.0 mm
・ Plate width: 2500mm

  As an example of the rolling control method according to the first embodiment, 8-pass rolling was performed according to the above-described conditions and according to the processing procedure shown in FIG. At the end of the fifth pass, the control is switched to the constant plate crown ratio control (that is, m = 6 in the processing procedure shown in FIG. 4). Further, as a comparative example, a conventional rolling control method according to the processing procedure shown in FIG. 3 was performed for rolling under the same conditions, and the value of the plate crown ratio on each rolling pass exit side was measured.

  The results are shown in FIG. FIG. 7 is a graph showing the results of thick plate rolling to which the rolling control method according to the first embodiment is applied. In FIG. 7, the horizontal axis represents the number of passes, the vertical axis represents the value of the sheet crown ratio on the exit side of each rolling pass, and the rolling control method according to the first embodiment obtained as a result of rolling was executed. The value of the plate crown ratio at the exit side of each rolling pass is plotted with a thick solid line (“Example”). In FIG. 7, the setting value of the sheet crown ratio calculated before the start of rolling is also plotted with a broken line (“setting value”). Further, in FIG. 7, the value of the plate crown ratio, which is the result of the above-described comparative example, is also plotted with a thin solid line (“comparative example”).

  Hereinafter, a specific processing procedure in the present embodiment will be described with reference to FIG. In this example, first, the rolling amount distribution in each rolling pass was set so that the product sheet thickness was 9.0 mm, and rolling was started.

  According to this initial set value, rolling was performed up to the fifth pass. As shown in FIG. 7, there is a difference between the actual sheet crown ratio and the set value due to a rolling load prediction error or the like. It was not possible to build the plate crown as set.

Therefore, in the embodiment, at the end of the fifth pass, the control is switched from the control according to the initial set value to the constant plate crown ratio control, and the control is performed so that the plate crown ratio is constant in the sixth to eighth passes. It was. Specifically, a crown control amount ΔC ^C _i (i = 6 to 8) was obtained according to the above formula (6) so that the plate crown ratio becomes constant. Then, by adjusting the roll bending force, so that an amount corresponding plate crown corresponding to the crown control amount [Delta] C ^C _i may be varied, were rolled at the rolling path of the sixth and subsequent. As a result, as shown in FIG. 7, in 6 to 8 passes, rolling can be performed such that the plate crown ratio is substantially constant, and a product with good flatness is obtained at the end of the 8th pass. I was able to.

  On the other hand, in the comparative example, in 6 to 8 passes, the crown control amount in each rolling pass is obtained so that the exit plate crown in each rolling pass matches the set value of the exit plate crown in each rolling pass. Rolling was performed while adjusting the roll bending force according to the crown control amount. Here, since the crown control amount in the sixth to seventh passes exceeded the upper limit value of the roll bending force, the roll bending force was set to the upper limit value. As a result, the final plate crown was able to realize a value almost equal to the initial set value. However, as shown in FIG. 7, in the comparative example, rolling with a large change in the plate crown ratio was performed in 6 to 8 passes in which the plate thickness was relatively thin, and the flatness in the final product was deteriorated. It was.

  From the above results, it has been confirmed that good flatness can be secured by applying the rolling control method according to the first embodiment.

  Next, the rolling control method according to the second embodiment of the present invention was applied to thick plate rolling, and the value of the plate crown ratio at each rolling pass exit side was measured. The rolling conditions are as follows.

(Rolling conditions)
・ Number of passes: 8
・ Transfer thickness (plate thickness before starting rolling): 80 mm
-Product thickness (thickness at the end of rolling (at the end of 8 passes)): 6.0 mm
・ Plate width: 3500mm

  As an example of the rolling control method according to the second embodiment, 8-pass rolling was performed according to the above-described conditions and according to the processing procedure shown in FIG. At the end of the fifth pass, the roll profile is corrected and the control is switched to the constant plate crown ratio control (that is, m = 6 in the processing procedure shown in FIG. 6). In addition, as a comparative example, for rolling under the same conditions, when the crown control according to the initial set value is continued without performing any processing such as roll profile learning at the end of the fifth pass, each rolling pass The value of the plate crown ratio on the delivery side was measured.

  The results are shown in FIG. FIG. 8 is a graph showing the results of thick plate rolling to which the rolling control method according to the second embodiment is applied. In FIG. 8, the horizontal axis represents the number of passes, the vertical axis represents the value of the sheet crown ratio at the exit side of each rolling pass, and the rolling control method according to the second embodiment obtained as a result of rolling was executed. The value of the plate crown ratio on the 6-8 pass exit side is plotted with a thick solid line ("Example"). In the embodiment, the roll profile compensation was actually performed at the end of the fifth pass. However, for reference, the roll profile compensation is obtained in consideration of the roll profile compensation (that is, there is a roll profile error). The actual calculated value of the plate crown ratio on the exit side of 1 to 5 passes (when not done) is plotted with a thick broken line ("roll profile compensation").

  In FIG. 8, the setting value of the sheet crown ratio calculated before the start of rolling is also plotted with a thin broken line (“setting value”). Further, in FIG. 8, the value of the plate crown ratio on the exit side of 6 to 8 passes, which is the result of the comparative example described above, is also plotted with a thin solid line (“comparative example”).

  Hereinafter, a specific processing procedure in the present embodiment will be described with reference to FIG. In this example, first, the rolling amount distribution in each rolling pass was set so that the product plate thickness was 6.0 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 rolling load prediction error.

  Rolling was performed up to the fifth pass according to the initial set value, but when the plate crown on the exit side of the five passes was measured, there was a difference from the actual calculation value. This deviation of the plate crown was considered to be caused by an error between the predicted value of the roll profile used in the initial setting calculation and the actual roll profile.

Therefore, in the embodiment, at the end of the fifth pass, according to the above formula (9), the prediction error of the plate crown on the exit side of the five passes becomes zero (that is, the measured value of the plate crown and the actual calculated value of the plate crown). Roll profile compensation amount ΔC _R ^err was ^calculated . Further, the control was switched from the control according to the initial set value to the constant plate crown ratio control, and the control was performed so that the plate crown ratio was constant in 6 to 8 passes. Specifically, according to the above equation (10), the roll profile compensation amount ΔC _R ^err is used to control the crown control amount ΔC ^C _i (in which the sheet crown ratio is constant between the entry side and the exit side in each rolling pass. i = 6-8) was determined.

Then, the roll bending force was adjusted, and rolling was performed in each rolling pass after the sixth pass so that the plate crown could be changed by an amount corresponding to the crown control amount ΔC ^C _i . In each rolling pass after the sixth pass, the roll bending force is dynamically controlled based on the measured value of the rolling load so that the sheet crown ratio is constant between the entry side and the exit side in the rolling pass. did. As a result, as shown in FIG. 8, in 6 to 8 passes, rolling can be performed such that the plate crown ratio is substantially constant, and a product with good flatness is obtained at the end of the 8th pass. I was able to.

  On the other hand, in the comparative example, as shown in FIG. 8, rolling with a large change in the plate crown ratio was performed in 6 to 8 passes in which the plate thickness was relatively thin, so the flatness in the final product was deteriorated. .

  From the above results, it has been confirmed that good flatness can be ensured by applying the rolling control method according to the second embodiment.

(3. Supplement)
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above embodiment, thick plate rolling by reverse rolling is the target of rolling control, but the present invention is not limited to such an example. For example, the present invention may be applied to the rolling of a thin plate material. The present invention may be applied not only to single stand rolling but also to tandem rolling.

  In the above description, the total number of passes N for rolling is regarded as the total number of passes for reverse rolling in the rolling mill 10, but the present invention is not limited to this example. For example, when thick plate rolling is composed of tenter rolling in a roughing mill, longitudinal rolling in a roughing mill, and longitudinal rolling in a finishing mill, these roughing mills The total number of passes in rolling by the finish rolling mill may be regarded as the total number of passes N in the thick plate rolling, and the number of rolling passes in the longitudinal direction in the finish rolling mill is defined as the total number of passes N in the thick plate rolling. May be considered. Thus, in the present invention, the “total number of passes N” may mean all of a series of rolling passes in the target rolling, or some of them (for example, in a series of rolling passes) Or only the total number of rolling passes executed in a certain rolling mill, or only the rolling passes after waiting for the temperature for controlled rolling, etc.).

DESCRIPTION OF SYMBOLS 1 System 10 Rolling machine 20 Rolling control apparatus 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 Roll bender 150 Reduction device 160 Plate crown measuring device 170 Table Roll 201 Measured value acquisition unit 203 Calculation unit 205 Drive control unit 207 Storage unit

Claims (9)

In rolling where the total number of rolling passes is N passes (N ≧ 2),
The crown control according to the set value calculated before the start of rolling is performed up to the rolling pass of the m-1th pass (2 ≦ m ≦ N),
In each rolling pass after the m-th pass, crown control is performed so that the difference between the plate crown ratio on the rolling pass entry side and the plate crown ratio on the rolling pass exit side falls within a predetermined range in which flatness failure is not manifested. ,
Rolling control method. In each rolling pass after the m-th pass, the difference between the actual calculated value or measured value of the plate crown ratio on the rolling pass entry side and the predicted value of the plate crown ratio on the rolling pass exit side is substantially zero. Crown control,
The rolling control method according to claim 1. The rolling pass of the m-th pass is a rolling pass whose exit side plate thickness is 30 mm or less.
The rolling control method according to claim 1 or 2. Crown control in rolling after the m-th rolling pass is performed by adjusting the bending force applied to the work roll or backup roll of the rolling mill,
The rolling control method according to any one of claims 1 to 3. The roll profile is corrected so that the measured value of the sheet crown or flatness on the rolling pass entry side of the r-th pass (2 ≦ r ≦ N) matches the actual calculated value of the sheet crown or flatness,
In the case of r ≦ m, for each rolling pass after the m-th pass, crown control is performed using a control amount calculated using the corrected roll profile,
In the case of r> m, for each rolling pass from the m-th pass to the (r-1) -th pass, crown control is performed using the control amount calculated using the roll profile before correction, and the r-th pass and thereafter For each rolling pass, crown control is performed using the control amount calculated using the modified roll profile.
The rolling control method of any one of Claims 1-4. r = m.
The rolling control method according to claim 5. Correction of the roll profile is performed before executing a rolling pass with an entry side thickness of 20 mm or less.
The rolling control method according to claim 5 or 6. In rolling where the total number of rolling passes is N passes (N ≧ 2),
The crown control according to the set value calculated before the start of rolling is performed up to the rolling pass of the m-1th pass (2 ≦ m ≦ N),
In each rolling pass after the m-th pass, crown control is performed so that the difference between the plate crown ratio on the rolling pass entry side and the plate crown ratio on the rolling pass exit side falls within a predetermined range in which flatness failure is not manifested. ,
Rolling control device. A program for causing a computer to execute rolling control,
In rolling where the total number of rolling passes is N passes (N ≧ 2),
The crown control according to the set value calculated before the start of rolling is performed up to the rolling pass of the m-1th pass (2 ≦ m ≦ N),
In each rolling pass after the m-th pass, crown control is performed so that the difference between the plate crown ratio on the rolling pass entry side and the plate crown ratio on the rolling pass exit side falls within a predetermined range in which flatness failure is not manifested. ,
program.

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