Work roll opening / closing device

Abstract

To provide a work roll opening / closing device which can open / close a work roll during conveyance of a strip.SOLUTION: A work roll opening / closing device includes: a speed reference correction device for correcting a speed reference of a work roll of a rolling mill having an opening / closing work roll among a first roll and three or more rolling mills, and all the work rolls on the upstream of the rolling mills, by a correction value calculated according to the opening / closing of the opening / closing work roll, and applying the corrected speed reference; and a reduction reference correction device for correcting a reduction reference of the rolling mill adjacent to the downstream of the rolling mill having the opening / closing work roll by a correction value calculated according to the opening / closing of the opening / closing work roll, and applying the reduction reference. The rolling mill having the opening / closing work roll is arranged on the upstream of the rolling mill at the last stage among the three rolling mills.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a work roll opening and closing device that opens and closes work rolls of a rolling mill. [Background technology]

[0002] Cold rolling equipment has one or more rolling mills, and rolls strips by passing them through the rolling mills in either the forward or reverse direction. Among cold rolling equipment, continuous cold rolling equipment, which has a welding machine that welds the strip at the entrance of the rolling mill and a looper that stores the strip, increases the operating rate by rolling the strip continuously without stopping the transport of the strip.

[0003] The roughness of the work rolls of a rolling mill deteriorates during rolling. This causes fluctuations in the lubrication condition of the work roll gap and the rolling load, making it impossible to obtain the desired thickness and shape quality. Furthermore, as fluctuations in the lubrication condition of the work roll gap progress, it becomes difficult to continue rolling. For this reason, the work rolls of a rolling mill must be replaced periodically, and strip production must be stopped for this replacement. Such work roll replacement reduces the availability of continuous cold rolling equipment, so it is desirable to shorten the time required for replacement.

[0004] Furthermore, in continuous cold rolling equipment, strips are welded at the entry side of the rolling mill in order to continuously roll the strips. Depending on the production schedule, strips of different thicknesses and widths may need to be welded. If there is a large difference in thickness or width between the preceding and succeeding strips, the strips cannot be passed through the rolling mill while being rolled to the welding point. Therefore, the strip must be stopped temporarily, the work rolls must be released, and the work rolls must be tightened after the strip has passed the welding point. This work roll opening and closing operation, which stops the strip, reduces the operating rate of the continuous cold rolling equipment.

[0005] In continuous cold rolling mills, it is desirable to minimize strip stops in order to improve the operating rate and product quality. To achieve this, a technology is required to open and close the work rolls while the strip is being transported.

[0006] In the rolling state, the strip under the work rolls is in a plastically deformed state. When the work rolls are released from this state, the load acting on the strip decreases, and the strip enters an elastically deformed state. The work rolls are further released from this point until they are no longer in contact with each other. When the strip is in the rolling state, the strip speed increases from the entry side to the exit side of the strip rolling mill as the thickness is reduced. On the other hand, when the work rolls are released and the strip enters an elastically deformed state, the reduction rate becomes zero, so the speed does not increase from the entry side to the exit side. When the work rolls are released from the rolling state and the strip transitions from a plastically deformed state to an elastically deformed state, the strip transport speed suddenly changes at the entry side and the exit side of the rolling mill.

[0007] If this sudden speed change causes a mismatch between the peripheral speed of the work rolls of the opened rolling mill and the transport speed of the strip, slippage occurs. This not only causes slip defects on the strip or work rolls, but can also lead to strip breakage, making it difficult to continue operations. Furthermore, fluctuations in the strip speed cause fluctuations in the tension of the strip on the entry and exit sides of the rolling mill. This has the effect of causing fluctuations in the load and thickness of the strip in the rolling mills upstream and downstream.

[0008] Patent Documents 1 and 2 propose methods for opening and closing the work rolls of a rolling mill while transporting a strip. In these documents, when the work rolls are opened or tightened, the speed reference or torque reference of the work rolls, transport rolls, or take-up rolls of an adjacent rolling mill located upstream or downstream from where the work rolls are opened is corrected for the purpose of suppressing tension fluctuations that occur when plastic deformation transitions to elastic deformation.

[0009] The methods of Patent Documents 1 and 2 only correct the speed or torque standards of adjacent rolls, and do not correct the speed standards, torque standards, or rolling mill roll gap standards of upstream or downstream rolling mills, or of transport rolls and take-up rolls. In a continuous cold rolling mill, multiple rolling mills, transport rolls, and take-up rolls are connected by the strip, and the propagation of tension fluctuations cannot be sufficiently suppressed by correcting adjacent rolls alone. Furthermore, the methods of Patent Documents 1 and 2 do not take into consideration tension correction by opening and closing the work rolls of the upstream or downstream rolling mill when there is a rolling mill upstream or downstream. Furthermore, Patent Documents 1 and 2 In the method (2), the fluctuations in rolling load and thickness caused by the tension fluctuations are only indirectly compensated for by suppressing the tension fluctuations. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-039621 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-058001 Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, an object of an embodiment of the present invention is to provide a work roll opening and closing device that enables the work rolls to be opened and closed while the strip is being transported. [Means for solving the problem]

[0012] An embodiment of the present invention is a work roll opening / closing device for opening and closing the work rolls of any of three or more rolling mills in a rolling facility that has three or more rolling mills, a first roll provided upstream of the three or more rolling mills, and a second roll provided downstream of the three or more rolling mills, and that rolls a strip while transporting it. The work roll opening / closing device includes: a speed reference compensator that corrects and applies a speed reference for the first roll, the work rolls of a rolling mill among the three or more rolling mills that has an openable / closeable work roll, and all work rolls upstream of the rolling mill, by a correction value calculated in response to the opening and closing of the openable / closeable work roll; and a roll gap reference compensator that corrects and applies a roll gap reference for the rolling mill adjacent downstream of the rolling mill that has the openable / closeable work roll, by a correction value calculated in response to the opening and closing of the openable / closeable work roll. The rolling mill that has the openable / closeable work roll is located upstream of the final stage of the three rolling mills. [Effects of the Invention]

[0013] According to an embodiment, a work roll opening and closing device is provided that enables work rolls to be opened and closed while a strip is being transported. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic block diagram illustrating a work roll opening / closing device according to an embodiment. [Figure 2] FIG. 1 is a schematic block diagram illustrating a work roll opening / closing device according to an embodiment. [Figure 3] FIG. 1 is a schematic block diagram illustrating a work roll opening / closing device according to an embodiment. [Figure 4] FIG. 10 is a schematic block diagram illustrating a work roll opening / closing device according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In the present specification and the drawings, elements similar to those described above with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0016] FIG. 1 is a schematic block diagram illustrating a work roll opening / closing device according to an embodiment. FIG. 1 shows a work roll opening / closing device 10 according to an embodiment, as well as a schematic configuration of a rolling facility 100 in which the work roll opening / closing device 10 is used. First, the configuration of the rolling equipment 100 in FIG. 1 will be described.

[0017] As shown in FIG. 1, a work roll opening / closing device 10 according to the embodiment is applied to a rolling facility 100. The rolling facility 100 has a plurality of rolling mills 2a to 2e. In this example, five rolling mills 2a to 2e are shown. A strip 1 is transported to the first rolling mill 2a by transport rolls (first rolls) 3a and 3b. The strip 1 rolled and discharged from the final rolling mill 2e is wound around a winding roll (second roll) 4.

[0018] The rolling mills 2a to 2e each have upper work rolls 2wa1 to 2we1 and lower work rolls 2wa2 to 2we2. The strip 1 is rolled to a desired thickness by being engaged between the upper and lower work rolls.

[0019] The rolling mills 2a to 2e are driven by motors 5a to 5e, respectively. The transport rolls 3a and 3b are driven by motors 6a and 6b, respectively. The winding roll 4 is driven by a motor 9 (FIG. 3).

[0020] Motors 5a to 5e are controlled by speed controllers 20a to 20e, respectively. Motors 6a and 6b are controlled by speed controllers 22a and 22b, respectively. Motor 9 is controlled by torque controller 40. A master controller (not shown) supplies a speed reference to each of speed controllers 20a to 20e and speed controllers 22a and 22b. A master controller (not shown) also supplies a tension reference to torque controller 40.

[0021] Each motor is provided with a speed detector (not shown), which detects the speed of each motor and outputs the detected speed to speed controllers 20a-20e, 22a, and 22b, respectively. The speed controllers 20a-20e, 22a, and 22b drive the motors so that they follow the supplied speed reference. In the case of torque controller 40, motor 9 is driven so that the tension of strip 1, detected by tension meter 8f provided on the inlet side of winding roll 4, follows the tension reference supplied from the main control device.

[0022] The rolling mills 2a to 2e are provided with screw down devices 7a to 7e, respectively. The screw down devices 7a to 7e are each provided with a roll position measuring device and a roll load measuring device (not shown), which detect and output the positions of the upper and lower work rolls and the roll loads acting on the work rolls.

[0023] The screw down devices 7a to 7e are connected to screw down controllers 30a to 30e, respectively. A screw down reference is supplied to each of the screw down controllers 30a to 30e from the master control device. The screw down controllers 30a to 30e calculate the position of the work rolls and the load on the work rolls based on the supplied screw down reference, and output the calculated values ​​to each of the screw down devices 7a to 7e. The screw down devices 7a to 7e set the gap between the work rolls so that the position and load follow those calculated based on the screw down reference.

[0024] Tension meters 8a to 8f are provided between the motor-driven rolls. Tension meter 8a is provided between the transport roll 3a and the rolling mill 2a to measure the tension of the strip 1 on the inlet side of the rolling mill 2a. Tension meter 8b is provided between the rolling mill 2a and the rolling mill 2b to measure the tension of the strip 1. Tension meter 8c is provided between the rolling mill 2b and the rolling mill 2c to measure the tension of the strip 1. Tension meter 8d is provided between the rolling mill 2c and the rolling mill 2d to measure the tension of the strip 1. Tension meter 8e is provided between the rolling mill 2d and the rolling mill 2e to measure the tension of the strip 1. Tension meter 8f is provided between the rolling mill 2e and the winding roll 4 to measure the tension of the strip 1.

[0025] The configuration and operation of the work roll opening / closing device 10 will now be described. As shown in FIG. 1, a work roll opening / closing device 10 according to the embodiment includes a setting calculation device 12, a speed reference corrector 14c, a roll gap reference corrector 16d, and a work roll opening / tightening command device 18c.

[0026] FIG. 1 shows an example of opening and closing the work rolls 2wc1 and 2wc2 of the third rolling mill 2c. The work roll opening / closing command device 18c is connected to the roll gap controller 30c for the third rolling mill 2c. The roll gap reference corrector 16d is connected to the roll gap controller 30d for the adjacent rolling mill 2d downstream of the third rolling mill 2c. The speed reference corrector 14a is provided for the speed controllers 20a and 20b of the motor 5c that drives the third rolling mill 2c and the motors 5a and 5b that drive all of the rolling mills 2a and 2b upstream of the motor 5c. The speed reference corrector 14c is also provided for the speed controllers 22a and 22b of the motors 6a and 6b that drive the transport rolls 3a and 3b located upstream of the third rolling mill 2c.

[0027] In the work roll opening / closing device 10 according to the embodiment, all of the rolling mills 2a to 2e may be opened or closed. Therefore, a work roll opening / closing command device is provided for each rolling mill. A speed reference corrector is also provided for each rolling mill. A roll gap reference corrector is provided for each rolling mill adjacent to the rolling mill that is being opened or closed downstream. In order to avoid complexity in the illustration, FIG. 1 illustrates the case where the third rolling mill 2c is opened or closed as an example of a case where there is an adjacent rolling mill on the upstream side and a rolling mill on the downstream side.

[0028] 2 shows an example of opening and closing the first stage rolling mill 2a, and FIG. 3 shows an example of opening and closing the final stage rolling mill 2e. The setting calculation device 12 is commonly applied to all of the rolling mills 2a to 2e. These components are not limited to the above-mentioned examples, and for example, the work roll opening / threading command device, speed reference corrector, and roll gap reference corrector may of course be commonly applied to all speed controllers, roll gap controllers, and torque controllers.

[0029] Returning to Figure 1, the explanation will continue. The setting calculation device 12 is connected to a speed reference corrector 14c and a roll gap reference corrector 16d. The setting calculation device 12 is connected to, for example, a host computer (not shown) and acquires product-related parameters held by the host computer. The product-related parameters include, for example, the material properties of the strip, the steel thickness, the material quality, and the concentration of emulsion lubricant. The setting calculation device 12 uses these product-related material parameters to calculate the upper and lower yield points, the set thickness when the work rolls are opened and closed, and the like, and outputs these to the speed reference corrector 14c and the roll gap reference corrector 16d, respectively. The setting calculation device 12 also has information on the machine parameters of the rolling equipment 100. The machine parameters include the roll diameter of the rolling mill and the GD of the rotation drive system. 2 The setting calculation device 12 outputs these machine parameters to a speed reference corrector 14c and a roll reduction reference corrector 16d, respectively.

[0030] The work roll release / tightening command device 18c determines the timing for opening and closing the work rolls 2wc1 and 2wc2, for example, based on tracking information of the welded portion of the strip. When releasing the work rolls 2wc1 and 2wc2, the work rolls 2wc1 and 2wc2 are released so that they are out of contact with the strip 1 before the welded portion reaches the work rolls 2wc1 and 2wc2. When tightening the work rolls 2wc1 and 2wc2, they are tightened so that the strip 1 comes into contact with the work rolls 2wc1 and 2wc2 after the welded portion has passed the position of the work rolls 2wc1 and 2wc2.

[0031] The work roll opening / tightening command device 18c acquires the actual measured values ​​of the positions and roll loads of the work rolls 2wc1, 2wc2 via the screw-down controller 30c. The work roll opening / tightening command device 18c outputs the acquired actual measured values ​​of the positions and roll loads of the work rolls 2wc1, 2wc2 to the speed reference corrector 14c and the screw-down reference corrector 16d, respectively.

[0032] The speed reference corrector 14c and the roll gap reference corrector 16d acquire the value of the tension of the strip 1 detected by a tension meter 8d provided on the delivery side of the rolling mill 2c.

[0033] The speed reference corrector 14c calculates a speed reference correction value based on the material parameters, machine parameters, detected tension values, the positions of the work rolls 2wc1 and 2wc2, and the actual measured values ​​of the roll load. The speed reference correction value is subtracted from the speed reference values ​​for the motors driving the opening and closing work roll, all work rolls upstream thereof, and all transport rolls. The speed references for the motors driving the transport rolls 3a and 3b and each stage of work rolls are set to gradually increase from upstream to downstream. Therefore, the speed reference correction values ​​for the motors driving each roll upstream of the opening and closing work rolls are set to gradually increase from upstream to downstream. For example, the speed reference correction value for each motor is set by subtracting a value obtained by multiplying the speed reference value by a certain ratio.

[0034] The roll gap reference corrector 16d calculates a roll gap reference correction value based on the material parameters, machine parameters, detected tension values, the positions of the work rolls 2wc1 and 2wc2, and the actual measured values ​​of the roll loads. The roll gap reference corrector 16d adds the calculated roll gap reference correction value to the roll gap reference value for the work roll adjacent to the work roll that is downstream of the work roll that opens and closes, and outputs the result to the roll gap controller 30d.

[0035] The speed reference corrector 14c and the roll gap reference corrector 16d use, for example, a preset model to calculate their respective correction values. The model is set using data acquired by transporting and rolling a strip in an actual rolling process. Simulation techniques, etc., can be used to set the model in addition to or instead of the actual process.

[0036] In this way, speed reference corrector 14c corrects to decrease the speed references for motor 5e, which drives opening and closing work rolls 2wc1, 2wc2, and motors 6a, 6b, 5a, 5b, which drive all rolls upstream of that motor, and outputs the corrected speeds to speed controllers 22a, 22b, 20a, 20b. Then, roll gap reference corrector 16d corrects to increase the roll gap reference for work rolls 2wd1, 2wd2, which are adjacent to and downstream of opening and closing work rolls 2wc1, 2wc2, and outputs the corrected speed reference to roll gap controller 30d.

[0037] The speed reference corrector 14c and the roll gap reference corrector 16d sequentially calculate a speed reference correction value and a roll gap reference correction value based on the positions and roll loads of the work rolls 2wc1 and 2wc2. Therefore, the work roll opening / closing device 10 according to the embodiment can prevent slippage between the strip 1 and the rolls due to a sudden change in speed.

[0038] The speed reference corrector 14c calculates the speed reference of the motor that drives the opening and closing work rolls 2wc1 and 2wc2 and the speed reference of the motor that drives all rolls located upstream of that, and outputs the results to the speed controller. This makes it possible to align the speeds of the motor that drives the opening and closing rolling mill and all motors that drive rolls located upstream of that. By reducing the speed of the motor that drives the roll located upstream, it is possible to suppress a decrease in tension.

[0039] Furthermore, the roll gap reference corrector 16d outputs a roll gap reference correction value to the roll gap controller 30d so as to increase the roll gap of the adjacent rolling mill 2d downstream of the rolling mill 2c that is being opened and closed. This prevents the roll gap of the next stage and subsequent stages from being insufficient due to the opening of the work rolls 2wc1, 2wc2 of the rolling mill 2c, and suppresses thickness fluctuations due to the opening and closing of the work rolls 2wc1, 2wc2.

[0040] The above description has been given of the case where the work rolls of a rolling mill with other rolling mills located before and after it are opened and closed, and where the work rolls of the third rolling mill 2c are opened and closed. However, the same applies to the second rolling mill 2b and the fourth rolling mill 2d. That is, the speed reference corrector calculates speed reference correction values ​​for the motor driving the work roll to be opened and closed and all motors upstream of it, and outputs the speed reference correction values ​​to the speed controllers for these motors. The roll gap reference corrector calculates a roll gap reference correction value for the rolling mill adjacent to the downstream of the work roll to be opened and closed, and outputs the roll gap reference correction value to the roll gap controller for the rolling mill adjacent to the downstream of the work roll to be opened and closed. This allows the work rolls of the second and fourth rolling mills 2b and 2d to be opened and closed, similar to the case where the work rolls of the third rolling mill 2c are opened and closed as described above.

[0041] Next, the configuration and operation when opening and closing the work rolls 2wa1, 2wa2 of the rolling mill 2a arranged in the first stage will be described. FIG. 2 is a schematic block diagram illustrating a work roll opening / closing device according to the embodiment. As shown in FIG. 2, the work roll opening / closing device 10 according to the embodiment includes a setting calculation device 12, a speed reference corrector 14a, a roll gap reference corrector 16b, and a work roll opening / tightening command device 18a.

[0042] The work roll opening / threading command device 18a is connected to a roll gap controller 30a for the first stage rolling mill 2a. The speed reference corrector 14a is connected to a speed controller 20a for the motor 5a that drives the opening and closing work rolls 2wa1, 2wa2. The speed reference corrector 14a is also connected to speed controllers 22a, 22b for the motors 6a, 6b that drive the transport rolls 3a, 3b. The roll gap controller 16b is connected to a roll gap controller 30b for the adjacent rolling mill 2b located downstream of the rolling mill 2a having the opening and closing work rolls 2wa1, 2wa2.

[0043] The setting calculation device 12 is connected to a speed reference compensator 14a and a roll gap reference compensator 16b. The setting calculation device 12 acquires material parameters related to the product from a host computer, and uses the material parameters and preset machine parameters to calculate the upper and lower yield points, the set plate thickness when the work rolls are opened and closed, etc., and outputs the results to the speed reference compensator 14a and the roll gap reference compensator 16b, respectively. The setting calculation device 12 also has information on the machine parameters of the rolling equipment 100, and outputs these machine parameters to the speed reference compensator 14a and the roll gap reference compensator 16b, respectively.

[0044] As in the example of Figure 1, the work roll opening / tightening command device 18a determines the timing for opening and closing the work rolls 2wa1, 2wa2, for example, based on tracking information about the welded portion of the strip 1. The work roll opening / tightening command device 18a acquires the actual measured values ​​of the positions and roll loads of the work rolls 2wa1, 2wa2 via the screw-down controller 30a. The work roll opening / tightening command device 18a outputs the acquired actual measured values ​​of the positions and roll loads of the work rolls 2wa1, 2wa2 to the speed reference corrector 14a and the screw-down reference corrector 16b, respectively.

[0045] The speed reference corrector 14a and the roll gap reference corrector 16b acquire the value of the tension of the strip 1 detected by a tension meter 8b provided on the delivery side of the rolling mill 2a.

[0046] The speed reference corrector 14a calculates a speed reference correction value based on the material parameters, machine parameters, detected tension values, and the positions and roll loads of the work rolls 2wa1 and 2wa2. The speed reference correction value is calculated by subtracting it from the speed reference values ​​for the motors that drive the opening and closing work rolls and all of the transport rolls upstream of them. For example, the speed reference correction value for each motor is set by subtracting a value obtained by multiplying the speed reference value by a certain ratio.

[0047] The roll gap reference corrector 16b calculates a roll gap reference corrected value based on the material parameters, machine parameters, detected tension values, and the positions and roll load measurements of the work rolls 2wa1 and 2wa2. The roll gap reference corrector 16b adds a correction value to the roll gap reference value for the work roll adjacent to the opening and closing work roll downstream of the opening and closing work roll, and outputs the calculated roll gap reference corrected value to the roll gap controller 30b.

[0048] In this way, the work roll opening and closing device 10 successively corrects the speed reference for the motors of the transport rolls 3a and 3b in accordance with the opening and closing of the work rolls 2wa1 and 2wa2 of the first-stage rolling mill 2a. The work roll opening and closing device 10 also successively corrects the reduction amount of the rolling mill 2b adjacent to and downstream of the first-stage rolling mill 2a. This prevents a sudden change in speed before and after the opening and closing of the work rolls 2wa1 and 2wa2, and makes it possible to maintain a constant tension in the strip 1. Furthermore, by increasing the reduction amount of the rolling mill 2b adjacent to and downstream, it is possible to suppress fluctuations in plate thickness due to the opening and closing of the work rolls 2wa1 and 2wa2.

[0049] Next, the configuration and operation when opening and closing the work rolls 2we1 and 2we2 of the final stage rolling mill 2e will be described. FIG. 3 is a schematic block diagram illustrating a work roll opening / closing device according to the embodiment. As shown in FIG. 3, the work roll opening and closing device 10 according to the embodiment includes a setting calculation device 12, a speed reference corrector 14e, a tension reference corrector 19, and a work roll opening and tightening command device 18e.

[0050] When opening and closing the work rolls 2we1 and 2we2 of the final-stage rolling mill 2e, the speed reference corrector 14e corrects the speed references of the motor 5e that drives the work rolls 2we1 and 2we2 of the rolling mill 2e that are being opened and closed, and of all the upstream transport rolls 3a and 3b and motors 6a, 6b, and 5a-5d that drive the work rolls. In this example, there are no other rolling mills downstream of the rolling mill 2e that has the work rolls 2we1 and 2we2 that are being opened and closed. Therefore, the tension reference corrector 19 outputs a tension reference correction value to the torque controller 40 of the motor 9 that drives the winding roll 4 so that the torque controller 40 increases the tension of the strip 1.

[0051] As in the example of Figure 1, work roll opening / tightening command device 18e determines the timing for opening and closing work rolls 2we1, 2we2, for example, based on tracking information of the welded portion of strip 1. Work roll opening / tightening command device 18e acquires the actual measured values ​​of the positions and roll loads of work rolls 2we1, 2we2 via screw down controller 30e. Work roll opening / tightening command device 18e outputs the acquired actual measured values ​​of the positions and roll loads of work rolls 2we1, 2we2 to speed reference corrector 14e and tension reference corrector 19, respectively.

[0052] The speed reference corrector 14e and the tension reference corrector 19 acquire the value of the tension of the strip 1 detected by a tension meter 8f provided on the delivery side of the rolling mill 2e.

[0053] Speed ​​reference corrector 14e sequentially calculates a speed reference correction value based on material parameters, machine parameters, detected tension values, and the positions and roll loads of work rolls 2we1 and 2we2. Speed ​​reference corrector 14e outputs the calculated speed reference correction value to speed controllers 22a, 22b, and 20a-20e for the motors that drive the work rolls that open and close and all of the transport rolls upstream thereof. For example, the speed reference correction value for each motor is set by subtracting a value obtained by multiplying the speed reference value by a fixed ratio.

[0054] Tension reference compensator 19 sequentially calculates a tension reference compensation value based on the material parameters, machine parameters, detected tension values, and the positions and roll load measurements of work rolls 2we1 and 2we2. Tension reference compensator 19 adds the tension compensation value to the tension reference of motor 9 that drives take-up roll 4 downstream of the opening and closing work rolls, and outputs the result to torque controller 40.

[0055] In this way, speed reference corrector 14e corrects the speed references of motors 6a, 6b, 5a-5e that drive all rolls upstream of opening and closing work rolls 2we1, 2we2 to decrease the speed references, and outputs the corrected values ​​to speed controllers 22a, 22b, 20a-20e. Tension reference corrector 19 then corrects the tension reference of motor 9 that drives take-up roll 4 downstream of opening and closing work rolls 2we1, 2we2 to increase the tension, and outputs the corrected value to torque controller 40. These corrective measures prevent a sudden change in speed before and after opening and closing work rolls 2we1, 2we2, and enable the tension between rolling mill 2d and take-up roll 4 to be maintained constant.

[0056] (Variation) FIG. 4 is a schematic block diagram illustrating a work roll opening / closing device according to a modified example of the embodiment. The rolls arranged downstream of the final-stage rolling mill 2e are not limited to being driven by torque-controlled motors, and may also be driven by speed-controlled motors. In the example of Fig. 4, downstream of the final-stage rolling mill 2e, bridle rolls (second rolls) 4a, 4b are driven by motors 6c, 6d. The speeds of the motors 6c, 6d are controlled by speed controllers 22c, 22d, respectively.

[0057] As shown in Fig. 4, a work roll opening / closing device 10a according to the modified example is applied to a rolling mill 100a. Similar to the rolling mill 100 shown in Figs. 1 to 3, the rolling mill 100a has transport rolls 4a, 4b and multiple rolling mills 2a to 2e. The rolling mill 100a further has transport rolls 4a, 4b downstream of the final-stage rolling mill 2e. The speeds of motors 6c, 6d that drive the transport rolls 4a, 4b are controlled by speed controllers 22c, 22d, respectively.

[0058] A speed reference is supplied to the speed controllers 22c and 22d from the main control device. The speed controllers 22c and 22d for the motors 6c and 6d control the speeds of the motors 6c and 6d, respectively, so that the speeds of the motors 6c and 6d detected by speed detectors (not shown) follow the speed reference.

[0059] The work roll opening / closing device 10a includes a setting calculation device 12, speed reference correctors 14e and 19a, and a work roll opening / closing command device 18e. When opening or closing the work rolls 2we1 and 2we2 of the final-stage rolling mill 2e, as in the example shown in Figure 3, the speed reference corrector 14e corrects the speed references of all the transport rolls 3a and 3b upstream of the rolling mill 2e and the motors 6a, 6b, and 5a-5e that drive the work rolls, so as to reduce the speed. To maintain the tension of the strip 1, a speed reference correction value corrected to increase the speed reference is output to the speed controllers 22c and 22d for the motors 6c and 6d that drive the transport rolls 4a and 4b downstream of the rolling mill 2e being opened or closed.

[0060] As in the example of Figure 3, work roll opening / tightening command device 18e determines the timing for opening and closing work rolls 2we1 and 2we2, for example, based on tracking information of the welded portion of strip 1. Work roll opening / tightening command device 18e acquires the actual measured values ​​of the positions and roll loads of work rolls 2we1 and 2we2 via screw down controller 30e. Work roll opening / tightening command device 18e outputs the acquired actual measured values ​​of the positions and roll loads of work rolls 2we1 and 2we2 to speed reference correctors 14e and 19a, respectively.

[0061] As in the example of Figure 3, speed reference corrector 14e sequentially calculates a speed reference correction value based on the material parameters, machine parameters, detected tension values, and the positions and roll load measurements of work rolls 2we1 and 2we2. Speed ​​reference corrector 14e outputs the calculated speed reference correction value to speed controllers 22a, 22b, and 20a-20e for the motors that drive the work rolls that open and close and all of the transport rolls upstream thereof. For example, the speed reference correction value for each motor is set by subtracting a value obtained by multiplying the speed reference value by a fixed ratio.

[0062] Speed ​​reference corrector 19a sequentially calculates speed reference correction values ​​based on the material parameters, machine parameters, detected tension values, positions of work rolls 2we1 and 2we2, and actual measured values ​​of roll loads.Speed ​​reference corrector 19a sequentially calculates speed reference correction values ​​for speed controllers 22c and 22d based on the material parameters, machine parameters, detected tension values, positions of work rolls 2we1 and 2we2, and actual measured values ​​of roll loads, and outputs the values ​​to speed controllers 22c and 22d, respectively.

[0063] The work roll opening and closing apparatus 10 according to the embodiment and the work roll opening and closing apparatus 10a according to the modified example are realized, for example, by one or more computer devices. Part or all of the above-mentioned setting calculation device, speed reference corrector, screw down reference corrector, and work roll opening and closing command device are realized by executing one or more programs for the computer device. The main control device (not shown) is, for example, a programmable logic controller (PLC), and part or all of the elements constituting the work roll opening and closing apparatus 10, 10a may be realized by the program of this PLC.

[0064] The effects of the work roll opening / closing device 10 according to the embodiment will be described. The work roll opening / closing device 10 according to the embodiment includes a work roll opening / closing command device, a speed reference corrector, and a roll gap reference corrector. The work roll opening / closing command device and the speed reference corrector sequentially calculate speed reference correction values ​​for the motor driving the work roll to be opened / closed among the multiple rolling mills and all motors driving rolls located upstream thereof, and sequentially output these to the speed controller. The work roll opening / closing command device and the roll gap reference corrector also sequentially calculate roll gap reference correction values ​​for the rolling mill adjacent downstream of the rolling mill having the work roll to be opened / closed, and sequentially output these to the roll gap controller. As a result, sudden speed changes can be suppressed and the tension of the strip can be maintained by opening and closing the work rolls of all rolling mills located upstream and downstream among the multiple rolling mills.

[0065] The work roll opening / closing command device and speed reference corrector of the work roll opening / closing device 10 according to the embodiment sequentially output speed reference correction values ​​sequentially calculated for the motors driving the transport rolls located further upstream of the most upstream rolling mill to the speed controllers for those motors. The work roll opening / closing command device and roll gap reference corrector also sequentially output roll gap reference correction values ​​sequentially calculated for the rolling mill adjacent to the rolling mill downstream of the rolling mill having the work rolls to be opened or closed to the roll gap controller. This makes it possible to suppress sudden speed changes and maintain the tension of the strip, even when opening or closing the work rolls of the most upstream rolling mill.

[0066] The work roll opening / closing command device and tension reference corrector of the work roll opening / closing device 10 according to the embodiment outputs to the torque controller a tension reference correction value for the motor that drives the roll located further downstream of the rolling mill located most downstream. Therefore, even when opening or closing the work rolls of the most downstream rolling mill, it is possible to suppress sudden speed changes and maintain the tension of the strip.

[0067] The work roll opening / closing command device and roll gap reference corrector of the work roll opening / closing device 10 according to the embodiment output to the roll gap controller a roll gap reference correction value for the rolling mill adjacent to the downstream of the rolling mill having the work rolls to be opened and closed. Therefore, except for the case where the work rolls of the final rolling mill among the work rolls of multiple rolling mills are opened and closed, it is possible to suppress fluctuations in plate thickness due to the opening and closing of the work rolls.

[0068] In the work roll opening / closing device 10a according to the modified embodiment, the work roll opening / closing command device and the speed reference corrector output a speed reference correction value for a motor that drives a roll located further downstream of the most downstream rolling mill to a speed controller for that motor. Therefore, even when opening or closing the work rolls of the most downstream rolling mill, it is possible to suppress sudden changes in speed and maintain the tension of the strip.

[0069] In the above specific example, a rolling mill with five stages has been described, but the number of stages of the rolling mill is not limited to this, and may be three or more.

[0070] In this way, a work roll opening and closing device can be realized that allows the work rolls to be opened and closed while the strip is being transported.

[0071] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0072] 1...strip, 2a to 2e...rolling mill, 2wa1 to 2we2...work roll, 3a, 3b, 4a, 4b...transport roll, 4...winding roll, 5a to 5e, 6a to 6d, 9...motor, 7a to 7e...screw down device, 8a to 8f...tension meter, 10, 10a...work roll opening / closing device, 12...setting calculation device, 14a, 14c, 14e, 19a...speed reference compensator, 16b, 16d...screw down reference compensator, 18a, 18c, 18e...work roll release / tightening command device, 20a to 20e, 22a to 22d...speed controller, 30a to 30e...screw down controller, 40...torque controller, 100, 100a...rolling equipment

Claims

1. A rolling facility having three or more rolling mills, a first roll provided upstream of the three or more rolling mills, and a second roll provided downstream of the three or more rolling mills, wherein a strip is rolled while being transported, the rolling facility comprising: a work roll opening and closing device for opening and closing a work roll of any of the rolling mills that is arranged upstream of a final stage rolling mill among the three or more rolling mills, a speed reference corrector that corrects and applies the speed references of the first roll, the work rolls of any rolling mill that has an openable / closable work roll among those that are arranged upstream of the final stage rolling mill, and all the work rolls of rolling mills that are arranged upstream of the rolling mill that has the openable / closable work roll by subtracting a speed reference correction value calculated in accordance with the opening and closing of the openable / closable work roll based on material parameters that represent the characteristics of the material of the strip, machine parameters that represent the machine characteristics including the roll diameter and GD2 of the rotation drive system of the rolling mill in the rolling equipment, the tension value of the strip detected at the delivery side of the rolling mill that has the openable / closable work roll, and actual measurement values ​​of the position and roll load of the openable / closable work roll; a roll gap correction unit that corrects the roll gap of the adjacent rolling mill downstream of the rolling mill having the openable / closable work rolls by adding a roll gap correction value calculated in accordance with the opening and closing of the openable / closable work rolls based on material parameters that represent the characteristics of the material of the strip, machine parameters that represent the characteristics of the machine including the roll diameter and GD2 of the rotation drive system of the rolling mill in the rolling equipment, the tension value of the strip detected at the delivery side of the rolling mill having the openable / closable work rolls, and actual measured values ​​of the position and roll load of the openable / closable work rolls; and A work roll opening / closing device comprising:

2. A rolling facility having three or more rolling mills, first rolls provided upstream of the three or more rolling mills, and second rolls provided downstream of the three or more rolling mills, wherein a strip is rolled while being transported, comprising: a work roll opening and closing device for opening and closing work rolls of a rolling mill arranged in a final stage among the three or more rolling mills, a first speed reference corrector that corrects and applies the speed references of the first roll, the work roll of the rolling mill arranged in the final stage among the three or more rolling mills, and all work rolls upstream of the rolling mill arranged in the final stage by subtracting a speed reference correction value calculated in accordance with opening and closing of the work rolls of the rolling mill arranged in the final stage based on material parameters that represent the characteristics of the material of the strip, machine parameters that represent the machine characteristics including the roll diameters of the rolling mills in the rolling equipment and GD2 of the rotation drive system, the tension value of the strip detected at the delivery side of the rolling mill arranged in the final stage, and actual measurement values ​​of the positions and roll loads of the work rolls that open and close in the rolling mill arranged in the final stage; a second speed reference corrector that applies a correction to the speed reference of the second roll by adding a speed reference correction value calculated in accordance with opening and closing of the work rolls of the rolling mill arranged in the final stage, based on material parameters that represent the characteristics of the material of the strip, machine parameters that represent the machine characteristics including the roll diameter and GD2 of the rolling mill in the rolling facility, the tension value of the strip detected at the delivery side of the rolling mill arranged in the final stage, and actual measurement values ​​of the positions and roll loads of the work rolls that open and close in the rolling mill arranged in the final stage; A work roll opening / closing device equipped with the same.

3. A rolling facility having three or more rolling mills, first rolls provided upstream of the three or more rolling mills, and second rolls provided downstream of the three or more rolling mills, wherein a strip is rolled while being transported, comprising: a work roll opening and closing device for opening and closing work rolls of a rolling mill arranged in a final stage among the three or more rolling mills, a speed reference corrector that applies a correction by subtracting a speed reference correction value calculated in accordance with the opening and closing of the work rolls of the rolling mill located at the final stage based on material parameters that represent the characteristics of the material of the strip, machine parameters that represent the machine characteristics including the roll diameters and GD2 of the rotation drive systems of the rolling mills in the rolling equipment, the tension value of the strip detected at the delivery side of the rolling mill located at the final stage, and actual measurement values ​​of the positions and roll loads of the work rolls that open and close in the rolling mill located at the final stage; and a tension reference corrector that applies the tension reference for the second roll by correcting it by adding a tension reference correction value calculated in accordance with the opening and closing of the work rolls of the rolling mill arranged in the final stage based on material parameters that represent the characteristics of the material of the strip, machine parameters that represent the characteristics of the machine including the roll diameter and GD2 of the rotation drive system of the rolling mill in the rolling equipment, the tension value of the strip detected at the delivery side of the rolling mill arranged in the final stage, and actual measured values ​​of the positions and roll loads of the work rolls that open and close in the rolling mill arranged in the final stage; A work roll opening / closing device equipped with the same.

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