Finishing-rolling mill roll balancing device

Abstract

This finishing-rolling mill roll balancing device is provided with a roll-balancing adjuster that before the leading end of rolled material wraps onto the coiler, adjusts respective rolling devices on the working end and driving end of the final mill stand to reduce asymmetrical flatness defects measured by a flatness gauge and eccentricity measured by an eccentricity gauge, and that after the leading end has wrapped onto the coiler, adjusts the rolling devices on the working end and driving end of the final mill stand to reduce wedges measured by a sheet-profile gauge.

Description

Leveling control device for finishing rolling mill

[0001] The present disclosure relates to a leveling control device for a finishing mill. More particularly, the present disclosure relates to a leveling control device for adjusting the leveling of a final stand of a finishing mill.

[0002] A finishing rolling mill that rolls rolled materials such as steel plates is equipped with a screw-down device on each of the work side and drive side of the rolls in the width direction to adjust the gap between a pair of upper and lower rolls (hereinafter also referred to as the "roll gap"). By differentiating the screw-down positions on the work side and drive side, the width-direction distribution of the roll gap can be changed, a process known as screw-down leveling. In a rolling line, a flatness measuring device, an off-center measuring device, and a strip profile measuring device are generally installed on the exit side of the finishing rolling mill. The flatness measuring device measures the width-direction distribution of the elongation of the rolled material, and in particular, the difference in elongation between the left and right sides of the rolled material in the width direction is referred to as asymmetric flatness. The off-center measuring device measures the off-center, which is the deviation of the rolled material from the center line position of the conveying table. The strip profile measuring device measures the width-direction thickness distribution of the rolled material, and in particular, the difference in thickness between the left and right sides of the rolled material is referred to as wedge. The roll leveling is adjusted to adjust the asymmetric flatness, off-center, and wedge to an appropriate state. The roll leveling may be adjusted manually by an operator, but Patent Documents 1 to 3 listed below propose various control methods using the roll leveling as an operating element.

[0003] In a shape control method disclosed in Patent Document 1 below, in order to effectively reduce shape defects at the rear end of a rolled material, closed-loop control is performed with a small gain until the front end of the rolled material is wound around a coiler, and then closed-loop control is switched to a large gain at a predetermined timing. A wedge control device disclosed in Patent Document 2 below aims to achieve a target wedge while minimizing the impact on unstable phenomena such as meandering and one-sided elongation. This wedge control device changes the roll leveling sequentially from upstream, and the changed position is used as a tracking point. In a rear-stage stand, the roll leveling is changed when the tracking point from the previous stage stand arrives. In a hot-rolled steel strip manufacturing method disclosed in Patent Document 3 below, based on the off-center (amount of meandering) measured by a meandering detector installed on the delivery side of the rolling mill, pinch roll leveling is feedforward controlled before the front end of the rolled material starts winding around a coiler, and the roll leveling of the stand is adjusted after the start of winding around the coiler.

[0004] Thus, conventionally, methods for controlling leveling have been proposed that aim to improve any one of the flatness, wedge, and off-center of the rolled material.

[0005] Japanese Patent Publication No. 2011-161473 Japanese Patent Publication No. 2020-11256 Japanese Patent Publication No. 2004-290990

[0006] However, when observing the manual adjustment of the roll leveling performed by skilled operators in actual finish rolling, it was found that the roll leveling was frequently adjusted to improve the large asymmetric flatness and off-center that appeared when the tip of the rolled material passed through the table.

[0007] As a result of extensive research, the inventors have reached the following findings. Specifically, once the leading edge of the rolled material wraps around the coiler and tension is applied between the final stand and the coiler, noticeable flatness defects disappear and off-center changes to a gradual change. Once tension is applied and flatness is stabilized, the plate profile measuring instrument can measure normally, and the roll leveling can be adjusted so that the wedge falls within the allowable value. It is more desirable to adjust the roll leveling for different purposes, such as ensuring operational stability or improving product quality, rather than adjusting the roll leveling for the purpose of improving any one of flatness, wedge, and off-center over the entire length of the rolled material. In particular, at the delivery side of the final stand, it is important to prioritize stable threading of the leading edge of the rolled material before wrapping around the coiler, and to adjust the roll leveling to improve product quality after wrapping around the coiler.

[0008] The present disclosure has been made based on the above findings, and aims to provide a roll leveling control device for a finishing rolling mill that can improve product quality while ensuring operational stability of the finishing rolling mill.

[0009] The first aspect relates to a leveling control device for a finishing rolling mill. The finishing rolling mill is equipped with a plurality of stands each having a screw down device on the work side and drive side of the rolling rolls. A flatness measuring device for measuring the flatness of the rolled material, an off-center measuring device for measuring the off-center of the rolled material, and a plate profile measuring device for measuring the wedge of the rolled material are arranged on the delivery side of the final stand. A coiler for winding the rolled material is arranged downstream of these measuring devices. The leveling control device is equipped with a leveling adjustment unit. Before the leading end of the rolled material is wound around the coiler, the leveling adjustment unit adjusts the screw down devices on the work side and drive side of the final stand so as to reduce the asymmetrical flatness defect measured by the flatness measuring device and the off-center measured by the off-center measuring device. After the leading end is wound around the coiler, the screw down leveling adjustment unit adjusts the screw down devices on the work side and drive side of the final stand so as to reduce the wedge measured by the plate profile measuring instrument.

[0010] The second aspect has the following features in addition to those of the first aspect. The roll gap leveling control device further includes a performance record collection unit, a roll gap leveling correction amount calculation unit, a roll gap leveling set value learning unit, and a setting unit. The performance record collection unit collects flatness measurement values ​​measured by a flatness measuring instrument, off-center measurement values ​​of the leading edge measured by an off-center measuring instrument, wedge measurement values ​​measured by a plate profile measuring instrument after the leading edge is wound around the coiler, first roll gap leveling performance values ​​when the leading edge passes the final stand, and second roll gap leveling performance values ​​when the position where the wedge is collected passes the final stand. The roll gap leveling correction amount calculation unit calculates roll gap leveling correction amounts required to correct the flatness measurement values, off-center measurement values, and wedge measurement values ​​collected by the performance record collection unit. The roll gap leveling set value learning unit updates the first roll gap leveling set value based on the roll gap leveling correction amount for correcting the flatness measurement value and the off-center measurement value calculated by the roll gap leveling correction amount calculation unit and the first roll gap leveling actual value collected by the result collection unit, and updates the second roll gap leveling set value based on the roll gap leveling correction amount for correcting the wedge measurement value calculated by the roll gap leveling correction amount calculation unit and the second roll gap leveling actual value collected by the result collection unit. The setting unit sets the next rolled material as the next rolled material, and sets the first roll gap leveling set value and the second roll gap leveling set value updated by the roll gap leveling set value learning unit before starting rolling of the next rolled material. The roll reduction leveling adjustment unit adjusts the positions of the work side and drive side roll reduction devices so that the first roll reduction leveling setting value set by the setting unit is satisfied before the next rolled material enters the finishing rolling mill, and adjusts the positions of the work side and drive side roll reduction devices so that the second roll reduction leveling setting value set by the setting unit is satisfied after the next rolled material is wound around the coiler.

[0011] A third aspect has the following features in addition to the first or second aspect: The leveling control device further includes a closed-loop control unit. The closed-loop control unit periodically calculates a leveling correction amount based on flatness measurement values ​​measured by the flatness measurement device and off-center measurement values ​​measured by the off-center measurement device during a period from when the leading end of the rolled material passes directly below the flatness measurement device or the off-center measurement device until it is wound around the coiler, and periodically calculates a leveling correction amount based on wedge measurement values ​​measured by the plate profile measurement device during a period from when the trailing end of the rolled material is wound around the coiler until it leaves the front stand. The leveling adjustment unit adjusts the positions of the work-side and drive-side screw down devices, respectively, to satisfy the leveling correction amount calculated by the closed-loop control unit.

[0012] According to the present disclosure, it is possible to provide a rolling leveling control device for a finishing rolling mill that can improve product quality while ensuring operational stability of the finishing rolling mill.

[0013] FIG. 1 is a diagram showing an example of the configuration of a hot finishing rolling mill to which a roll gap leveling control device according to the present disclosure is applied. FIG. 2 is a block diagram showing the configuration of a roll gap leveling control device according to embodiment 1. FIG. 3 is a diagram for explaining the relationship between the difference in elongation between the work side and the drive side, the asymmetric flatness, and the off-center measurement value. FIG. 4 is a timing chart for explaining a method of controlling roll gap leveling. FIG. 5 is a block diagram showing the configuration of a roll gap leveling control device according to embodiment 3. FIG. 6 is a conceptual diagram showing an example of the hardware configuration of a processing circuit possessed by a roll gap leveling control device.

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that elements common to the various drawings are given the same reference numerals and redundant explanations will be omitted.

[0015] Embodiment 1. FIG. 1 is a diagram showing an example configuration of a hot finish rolling mill 1 to which a roll leveling control device 10 according to the present disclosure is applied. The hot finish rolling mill 1 is installed downstream of a heating furnace in a hot rolling line (not shown). The hot finish rolling mill (hereinafter also referred to as a "finishing mill") 1 is a multi-stage rolling mill equipped with multiple stands F1, F2, ..., Fn. n is a natural number equal to or greater than 2, and in the example shown in FIG. 1, n = 7. The rolled material M is steel or other metal material. The rolled material M is hot rolled to a predetermined thickness while moving on a table (not shown) from left to right in the figure. The rolled material M is rolled into a plate shape and wound by a coiler 5 (described later) to form a steel strip coil (rolled product).

[0016] Each stand Fi (1≦i≦n) is equipped with two upper and lower work rolls Rw and two upper and lower backup rolls Rb, each positioned on the vertical outside of the work rolls Rw. Screw down devices Hi (1≦i≦n) are provided on the work side and drive side of the backup rolls Rb, respectively, to adjust the gap (roll gap) between the upper and lower work rolls Rw. Adjusting both the work side and drive side screw down devices Hi, or adjusting only one of the screw down devices Hi, adjusts the parallelism of the upper and lower work rolls Rw in the width direction, thereby changing the screw down leveling (the difference between the work side and drive side roll gaps).

[0017] A flatness measuring device 2, an off-center measuring device 3, and a plate profile measuring device 4 are arranged on the outlet side of the final stand F7 of the finishing rolling mill 1, and a coiler 5 is arranged downstream of these measuring devices 2, 3, and 4.

[0018] The flatness measuring instrument 2 measures the elongation distribution in the width direction of the rolled material M as the flatness of the rolled material M. The off-center measuring instrument 3 measures the off-center of the rolled material M. The off-center measuring instrument 3 detects the left and right end positions of the rolled material M and outputs the deviation of the center position of the rolled material M, determined from the detected left and right end positions, from the table center line as the off-center. The plate profile measuring instrument 4 measures the thickness distribution in the width direction of the rolled material M. The difference in plate thickness at a position a predetermined length inward from both the left and right ends of the rolled material M is output as a wedge. The coiler 5 winds the rolled material M rolled by the finishing rolling mill 1 into a coil.

[0019] The finishing rolling mill 1 is equipped with a roll gap leveling control device 10. Fig. 2 is a block diagram showing the configuration of the roll gap leveling control device 10 according to embodiment 1. The roll gap leveling control device 10 is equipped with a performance record collecting unit 11, a roll gap leveling correction amount calculating unit 12, a roll gap leveling set value learning unit 13, a setting unit 14, and a roll gap leveling position adjusting unit 15.

[0020] The result collecting unit 11 collects asymmetric flatness measurement values ​​of the leading edge of the rolled material measured by the flatness measuring device 2. The result collecting unit 11 also collects off-center measurement values ​​of the leading edge of the rolled material measured by the off-center measuring device 3. Furthermore, the result collecting unit 11 collects wedge measurement values ​​measured by the plate profile measuring device 4 at a predetermined timing after winding is started by the coiler 5. Furthermore, the result collecting unit 11 also collects the first reduction leveling result value when the leading edge of the rolled material passes through the final stand F7, and the second reduction leveling result value when the position for collecting the wedge measurement value passes through the final stand F7.

[0021] The roll reduction leveling correction amount calculation unit 12 calculates a roll reduction leveling correction amount required to reduce (correct) the asymmetric flatness measurement value (collected value) using the asymmetric flatness measurement value (hereinafter also referred to as "asymmetric flatness collected value") collected by the result collection unit 11. The roll reduction leveling correction amount required to correct the asymmetric flatness measurement value (collected value) can be calculated as shown in the following formula (1).

[0022]

[0023] The roll gap leveling correction amount calculation unit 12 calculates a roll gap leveling correction amount required to reduce (correct) the off-center measurement values ​​(collected values) using the off-center measurement values ​​(hereinafter also referred to as "off-center collected values") collected by the result collection unit 11. The roll gap leveling correction amount required to reduce (correct) the off-center measurement values ​​(collected values) can be calculated as shown in the following formula (2).

[0024]

[0025] Furthermore, the roll gap leveling correction amount calculation unit 12 calculates a roll gap leveling correction amount required to reduce (correct) the wedge measurement values ​​(collected values) using the wedge measurement values ​​(hereinafter also referred to as "wedge collected values") collected by the result collection unit 11. The roll gap leveling correction amount required to reduce (correct) the wedge measurement values ​​(collected values) can be calculated as shown in the following formula (3).

[0026]

[0027] The roll gap leveling correction amount calculation unit 12 calculates a roll gap leveling setting value for the tip of the rolled material using a roll gap leveling correction amount for reducing (correcting) the flatness measurement value (collected value) and a roll gap leveling correction amount for reducing (correcting) the off-center measurement value (collected value).

[0028] FIG. 3 is a diagram illustrating the relationship between the difference in elongation between the work side and the drive side, asymmetric flatness, and the off-center measurement value. FIG. 3 illustrates a case where the elongation of the rolled material M on the drive side is greater than that on the work side at the exit of the final stand F7, and the thickness of the rolled material M on the drive side is thinner than that on the work side. Generally, when there is a difference in elongation between the work side and the drive side of the rolled material M on the exit of the final stand F7, as shown in the upper part of FIG. 3, the rolled material M will be off-center in the opposite direction (work side) to the side with greater elongation (drive side). However, when the difference in elongation is large, as shown in the lower part of FIG. 3, one side (the drive side with greater elongation) will ripple, which is measured (detected) as asymmetric flatness. In this case, the off-center measurement value may appear in the opposite direction (drive side) to the direction caused by the actual elongation difference.

[0029] In consideration of this phenomenon, when the asymmetric flatness measurement value is large, the roll reduction leveling correction amount calculation unit 12 determines (calculates) to use only the roll reduction leveling correction amount for reducing (correcting) the asymmetric flatness measurement value, without considering the off-center measurement value. On the other hand, when the asymmetric flatness measurement value is small, the roll reduction leveling correction amount calculation unit 12 determines (calculates) taking into consideration both the off-center measurement value and the asymmetric flatness measurement value. The roll reduction leveling correction amount calculation unit 12 can make the determination, for example, as shown in the following formula (4). In this case, the allocation ratio a can be used.

[0030]

[0031] The roll gap leveling set value learning unit 13 updates the first roll gap leveling set value as shown in the following equation (5) using the roll gap leveling correction amount for the tip of the rolled material calculated by the roll gap leveling correction amount calculation unit 12 and the first roll gap leveling actual value for the tip of the rolled material.

[0032]

[0033] Furthermore, the roll gap leveling set value learning unit 13 updates the roll gap leveling set value for after coiler winding (hereinafter referred to as the "second roll gap leveling set value") using the roll gap leveling correction amount for the wedge calculated by the roll gap leveling correction amount calculation unit 12 and the first roll gap leveling actual value when the wedge collection position passes through the final stand F7. Using the roll gap leveling correction amount for the tip end of the rolled material determined as described above, the second roll gap leveling set value is updated, for example, as shown in the following formula (6).

[0034]

[0035] The roll reduction leveling set value learning unit 13 has a memory device 131, and stores the first roll reduction leveling set value and the second roll reduction leveling set value in the memory device 131. The memory device 131 may have different levels depending on the steel grade of the rolled material M and the heating furnace conditions.

[0036] The setting unit 14 sets the next rolled material to be rolled as the next rolled material, and at a predetermined timing before the start of rolling of the next rolled material, reads out the first rolled leveling set value and the second rolled leveling set value from the memory device 131 of the rolled leveling set value learning unit 13 and sets them in the rolled leveling adjustment unit 15.

[0037] The roll leveling adjustment unit 15 adjusts the positions of the work-side and drive-side roll leveling devices H7 so that the first roll leveling set value is reached before rolling of the next rolled material begins (before entering the final stand F7). After rolling of the next rolled material begins, the leading end of the next rolled material is wound around the coiler 5, tension is applied between the final stand F7 and the coiler 5, and then the positions of the work-side and drive-side roll leveling devices H7 are adjusted so that the second roll leveling set value is reached.

[0038] A method for controlling roll leveling by the roll leveling control device 10 will be described with reference to Fig. 4. Fig. 4 is a timing chart for explaining the method for controlling roll leveling. The ON / OFF of F7 shown in Fig. 4 indicates whether the next rolled material enters or does not enter the final stand F7.

[0039] Prior to rolling the next rolled material, the first roll reduction leveling set value and the second roll reduction leveling set value are updated by the roll reduction leveling set value learning unit 13 as described above, and the updated set values ​​are set in the roll reduction leveling adjustment unit 15 by the setting unit 14.

[0040] At time t1, the roll leveling (position of the roll leveling device H7) is adjusted to the first roll leveling set value. Thereafter, at time t2, the next rolled material enters the final stand F7, and at time t3, the leading edge of the next rolled material arrives directly below the flatness measuring device 2, and at time t4, the leading edge of the next rolled material is wound around the coiler 5. At time t5, a predetermined time Δt has elapsed since time t4, the roll leveling is reduced. The time Δt can be set in advance, taking into account the length of the rolled material to be wound around the coiler 5. Then, at time t6, the roll leveling is changed to the second roll leveling set value.

[0041] As described above, in the first embodiment, before the leading edge of the rolled material is wound around the coiler 5, the asymmetric flatness and meandering (off-center) on the delivery side of the final stand F7 can be reduced by adjusting the roll leveling to the first roll leveling set value. After the leading edge of the rolled material is wound around the coiler 5, the wedge quality can be improved by adjusting the roll leveling to the second roll leveling set value. Therefore, according to the first embodiment, it is possible to provide a roll leveling control device 10 that can improve product quality while ensuring the operational stability of the finishing rolling mill 1.

[0042] Second Embodiment Next, a second embodiment of the present disclosure will be described. The second embodiment differs from the first embodiment in that closed-loop control, which is feedback control, is performed without using the first and second roll-down leveling set values, which are preset values. Figure 5 is a block diagram showing the configuration of a roll-down leveling control device according to the second embodiment. As shown in Figure 5, the roll-down leveling control device 10 includes a roll-down leveling position adjustment unit 15 and a closed-loop control unit 16. Figure 6 is a control block diagram of the closed-loop control unit 16 shown in Figure 5.

[0043] The closed-loop control unit 16 acquires the asymmetric flatness measurement value measured by the flatness measuring instrument 2, the off-center measurement value measured by the off-center measuring instrument 3, and the wedge measurement value measured by the plate profile measuring instrument 4. The closed-loop control unit 16 starts closed-loop control based on the asymmetric flatness measurement value and the off-center measurement value after the leading edge of the rolled material M has passed under the flatness measuring instrument 2 and the off-center measuring instrument 3. Furthermore, after the leading edge of the rolled material M has wound around the coiler 5 and tension has been applied to the rolled material M between the final stand F7 and the coiler 5, the closed-loop control unit 16 ends the closed-loop control based on the asymmetric flatness measurement value and the off-center measurement value and starts closed-loop control based on the wedge measurement value.

[0044] The closed-loop control unit 16 includes a calculator 161 that receives a flatness measurement value as an input, a calculator 162 that receives an off-center measurement value as an input, and a calculator 163 that receives a wedge measurement value as an input. These calculators 161, 162, and 163 periodically calculate a roll-down leveling correction amount. As described with reference to FIG. 3 , when a large flatness measurement value is detected, the off-center measurement value appears on the opposite side in the width direction from the off-center measurement value caused by the actual differential elongation. Therefore, the output of calculator 161 that receives a flatness measurement value as an input and the output of calculator 162 that receives an off-center measurement value as an input are switched depending on the magnitude of the flatness measurement value. Before the leading end of the rolled material is wound around the coiler 5, if the flatness measurement value is greater than a predetermined threshold value a (e.g., 20 [I-unit]), the closed-loop control unit 16 outputs the calculation result of calculator 161 that receives a flatness measurement value as an input. On the other hand, when the flatness measurement value is equal to or less than the threshold value a, the closed-loop control unit 16 outputs the calculation result of a calculator 162 that receives the off-center measurement value as an input. After the leading end of the rolled material is wound around the coiler 5, the closed-loop control unit 16 outputs the calculation result of a calculator 163 that receives the wedge measurement value as an input. The roll gap leveling correction amount, which is the output (calculation result) of the closed-loop control unit 16, is output to the roll gap leveling adjustment unit 15.

[0045] As described above, in the second embodiment, before the leading end of the rolled material wraps around the coiler 5, the roll gap leveling is adjusted based on the roll gap leveling correction amount calculated by the calculator 161 or the calculator 162, so that it is possible to reduce asymmetric flatness and off-center on the delivery side of the final stand F7. After the leading end of the rolled material wraps around the coiler 5, the roll gap leveling is adjusted based on the roll gap leveling correction amount calculated by the calculator 163, so that it is possible to improve wedge quality. Therefore, according to the second embodiment, it is possible to provide a roll gap leveling control device 10 that can improve product quality while ensuring the operational stability of the finishing rolling mill 1.

[0046] Third Embodiment Next, a third embodiment of the present disclosure will be described. The third embodiment is a combination of the first embodiment and the second embodiment. Fig. 7 is a block diagram showing the configuration of a roll gap leveling control device 10 according to the third embodiment. The roll gap leveling control device 10 includes a performance record collection unit 11, a roll gap leveling correction amount calculation unit 12, a roll gap leveling set value learning unit 13, a setting unit 14, a roll gap leveling position adjustment unit 15, and a closed-loop control unit 16.

[0047] The leveling adjustment unit 15 adjusts the positions of the work-side and drive-side screw down devices H7 so that the first leveling setting value set by the setting unit 14 is reached before rolling of the next rolled material begins. After the material passes directly below the flatness measuring device 2 or the off-center measuring device 3, the leveling adjustment unit 15 adjusts the leveling adjustment value based on a leveling adjustment correction amount periodically output from the closed-loop control unit 16. After the leading end of the rolled material is wound around the coiler 5 and tension is applied between the final stand F7 and the coiler 5, the leveling adjustment unit 15 adjusts the positions of the work-side and drive-side screw down devices so that the second leveling adjustment value set by the setting unit 14 is reached. Thereafter, the leveling adjustment unit 15 adjusts the leveling adjustment value based on a leveling adjustment correction amount periodically output from the closed-loop control unit 16.

[0048] As described above, in this embodiment 3, in addition to using the first roll gap leveling set value and the second roll gap leveling set value as in the above-mentioned embodiment 1, by performing closed-loop control based on the roll gap leveling correction amount as in the above-mentioned embodiment 2, it is possible to provide a roll gap leveling control device 10 that can further stabilize the operation of the finishing rolling mill 1 and further improve product quality.

[0049] The specific structure of the roll-down leveling control device 10 is not limited, and may be as follows, for example. FIG. 8 is a diagram showing an example of the hardware configuration of a processing circuit included in the roll-down leveling control device 10. The functions of the roll-down leveling control device 10 can be realized by the processing circuit shown in FIG. 8. This processing circuit may be dedicated hardware 10a. This processing circuit may include a processor 10b and a memory 10c. This processing circuit may be partially formed as dedicated hardware 10a, and may further include a processor 10b and a memory 10c. In the example of FIG. 8, part of the processing circuit is formed as dedicated hardware 10a, and the processing circuit also includes a processor 10b and a memory 10c.

[0050] At least part of the processing circuitry may be at least one piece of dedicated hardware 10a, such as a single circuit, multiple circuits, programmed processors, parallel programmed processors, ASICs, FPGAs, or any combination thereof.

[0051] The processing circuit may include at least one processor 10b and at least one memory 10c. In this case, each function of the leveling control device 10 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the memory 10c. The processor 10b realizes the functions of each unit by reading and executing the programs stored in the memory 10c.

[0052] The processor 10b is also called a CPU (Central Processing Unit), central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or DSP. The memory 10c is, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM. The memory 10c can also be configured to function as the storage device 131.

[0053] In this way, the processing circuit can realize each function of the leveling control device 10 by hardware, software, firmware, or a combination thereof.

[0054] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure. The configuration of the finishing rolling mill 1 is not limited to the example shown in FIG. 1 , and the present disclosure can be applied to finishing rolling mills with various modified configurations. In the above embodiments, the case where the present disclosure is applied to a hot finishing rolling mill 1 installed in a hot rolling line has been described as an example, but the present disclosure can also be applied to a cold finishing rolling mill installed in a cold rolling line. Furthermore, when the numbers, quantities, amounts, ranges, etc. of each element are mentioned in the above embodiments, the present invention is not limited to the mentioned numbers unless specifically stated or clearly specified in principle. Furthermore, the structures, etc. described in the above embodiments are not necessarily essential to the present disclosure unless specifically stated or clearly specified in principle.

[0055] 1...Finishing rolling mill (hot finishing rolling mill), 2...Flatness measuring instrument, 3...Off-center measuring instrument, 4...Strip profile measuring instrument, 5...Coiler, 10...Leveling control device, processing circuit, 10a...Dedicated hardware 10a, 10b...Processor, 10c...Memory, 11...Actual result collection unit, 12...Leveling correction amount calculation unit, 13...Leveling setting value learning unit, 131...Storage device, 14...Setting unit, 15...Leveling position adjustment unit, 16...Closed loop control unit, 161, 162, 163...Calculator, Fi...Stand, Hi...Leveling device, M...Rolled material, Rb...Backup roll, Rw...Work roll

Claims

1. A roll-down leveling control device for a finishing rolling mill, wherein the finishing rolling mill includes a plurality of stands each having a roll-down device on the working side and the driving side of the rolling rolls, and on the outlet side of the final stand, a flatness measuring instrument for measuring the flatness of the rolled material, an off-center measuring instrument for measuring the off-center of the rolled material, and a plate profile measuring instrument for measuring the wedge of the rolled material are arranged, and a coiler for winding up the rolled material is arranged downstream of these measuring instruments. Before the tip of the rolled material is wound around the coiler, the roll-down devices on the working side and the driving side of the final stand are adjusted so as to reduce the asymmetry defect of the flatness measured by the flatness measuring instrument and the off-center measured by the off-center measuring instrument. After the tip is wound around the coiler, a roll-down leveling adjustment unit is provided which adjusts the roll-down devices on the working side and the driving side of the final stand so as to reduce the wedge measured by the plate profile measuring instrument. A roll-down leveling control device for a finishing rolling mill.

2. An actual result collection unit that collects the flatness measurement value measured by the flatness measuring device, the off-center measurement value of the tip measured by the off-center measuring device, the wedge measurement value measured by the plate profile measuring device after the tip is wound around the coiler, the first rolling reduction leveling actual result value when the tip passes through the final stand, and the second rolling reduction leveling actual result value when the position where the wedge is collected passes through the final stand; A rolling reduction leveling correction amount calculation unit that calculates the rolling reduction leveling correction amounts required to correct the flatness measurement value, the off-center measurement value, and the wedge measurement value collected by the actual result collection unit, respectively; Based on the rolling reduction leveling correction amount for correcting the flatness measurement value and the off-center measurement value calculated by the rolling reduction leveling correction amount calculation unit and the first rolling reduction leveling actual result value collected by the actual result collection unit, the first rolling reduction leveling set value is updated, and based on the rolling reduction leveling correction amount for correcting the wedge measurement value calculated by the rolling reduction leveling correction amount calculation unit and the second rolling reduction leveling actual result value collected by the actual result collection unit, a rolling reduction leveling set value learning unit that updates the second rolling reduction leveling set value; A setting unit that sets the first rolling reduction leveling set value and the second rolling reduction leveling set value updated by the rolling reduction leveling set value learning unit before the start of rolling of the next rolled material, with the next rolled material to be rolled next; The rolling reduction leveling adjustment unit adjusts the positions of the respective rolling reduction devices on the working side and the driving side so as to satisfy the first rolling reduction leveling set value set by the setting unit before the next rolled material enters the finishing rolling mill, and after the next rolled material is wound around the coiler, adjusts the positions of the respective rolling reduction devices on the working side and the driving side so as to satisfy the second rolling reduction leveling set value set by the setting unit. The rolling reduction leveling control device for a finishing rolling mill according to claim 1.

3. The period from when the tip of the rolled material passes under the flatness measuring instrument or the off-center measuring instrument until it is wound around the coiler is to periodically calculate a roll gap leveling correction amount based on the flatness measurement value measured by the flatness measuring instrument and the off-center measurement value measured by the off-center measuring instrument. The period from after it is wound around the coiler until the trailing end of the rolled material exits the foremost stand is further provided with a closed-loop control unit that periodically calculates a roll gap leveling correction amount based on the wedge measurement value measured by the plate profile measuring instrument. The roll gap leveling adjustment unit adjusts the positions of the roll gap devices on the working side and the driving side so as to satisfy the roll gap leveling correction amount calculated by the closed-loop control unit. The roll gap leveling control device for a finishing rolling mill according to claim 1 or claim 2.

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