JP5597519B2 - Rolling control device and rolling control method - Google Patents

Description

  The present invention relates to a rolling control device and a rolling control method, and more particularly to control of a liquid supplied onto a material to be rolled.

  In the rolling mill, the rolling operation is performed by controlling the tension and rolling load applied to the material to be rolled using the roll gap, which is the distance between the upper and lower work rolls, and the roll speed of the equipment before and after the rolling mill. The material to be rolled is in contact with the work roll of the rolling mill, and the plate thickness of the material to be rolled is changed by rolling. At this time, slip occurs between the material to be rolled and the work roll, and a lubricant is required. Moreover, since the plate | board thickness of a to-be-rolled material reduces by rolling, a process heat generate | occur | produces, It is necessary to cool this. For the purpose of lubrication and cooling, a coolant supply device for supplying coolant, which is a liquid that also serves as lubrication and cooling, is installed on the entrance and exit sides of the rolling mill.

  On the inlet side of the rolling mill, the coolant supplied from the coolant supply device falls to the lower part of the rolling mill as it is supplied from the lower side of the material to be rolled, and the coolant supplied from the upper side temporarily accumulates on the material to be rolled. Then, it falls to the lower part of the rolling mill from both ends of the material to be rolled. During rolling operation, since the material to be rolled is supplied from the entry side, the coolant accumulated in the upper part of the material to be rolled does not flow toward the entry side, but from the coolant supply amount and the ends on both sides of the material to be rolled. It exists on the material to be rolled up to a certain distance from the portion where the material to be rolled and the work roll contact so that the amount of flow to the lower part of the rolling mill is balanced.

  As a mode of coolant supply control in a rolling mill, the friction coefficient changes with rolling speed in order to maintain the friction coefficient so as to suppress the occurrence of chattering due to an increase in the friction coefficient and the occurrence of slip due to the decrease in the friction coefficient. Using the speed at which the coefficient of friction reverses from rising to falling as the coolant supply decreases, the coolant supply in the medium speed range is less than the supply in the low and high speed ranges. A method has been proposed (see, for example, Patent Document 1).

  Further, even when performing high-speed rolling, a method for detecting the occurrence of chattering and increasing the coolant flow rate has been proposed in order to prevent the occurrence of rolling failure and sheet breakage due to chattering (for example, Patent Documents). 2).

JP 2000-317510 A JP 2001-25812 A

  The amount of coolant existing on the material to be rolled (hereinafter referred to as “coolant retention amount”) is a balance between the coolant flow rate and the flow rate of the material to be rolled into the rolling mill, and is therefore almost constant according to the rolling speed. However, depending on the inflow state of the material to be rolled into the rolling mill, the range in which the coolant exists on the material to be rolled, particularly the length in the conveyance direction of the material to be rolled (hereinafter referred to as “coolant retention length”) Is in a state with time fluctuation. In that case, the coolant flow rate flowing between the work roll of the rolling mill and the material to be rolled changes, and the lubrication state of the rolling phenomenon changes. The change in the lubrication state becomes a change in the rolling phenomenon, and even if the entry side plate thickness is the same, the exit side plate thickness obtained as a result of rolling becomes different. As a result, variations in the exit side plate thickness and the tension on the entry side and exit side of the rolling mill occur, which may cause deterioration of product accuracy and a decrease in operation efficiency.

  Even if the coolant retention length changes on the inlet side of the rolling mill, the fluctuation cycle is slow, or if the state is maintained once changed, it is normal By using an installed AGC (Auto Gauge Control: automatic plate thickness control), it is possible to remove the variation in the plate thickness on the exit side. However, if the coolant retention length fluctuates periodically, for example, the outlet side plate thickness fluctuation occurs periodically, but even if the automatic plate thickness control operates to suppress the plate thickness fluctuation, the outlet side plate thickness fluctuation Since the lubrication state, which is the cause of the occurrence, varies, it is difficult to follow the control, and a periodic variation in the thickness of the outlet side plate remains.

  The fluctuations in the strip thickness on the exit side of the rolling mill due to fluctuations in the coolant retention length are estimated plates obtained by detecting the strip thickness on the exit side of a conventional rolling mill directly with a thickness gauge or using a plate speedometer at a constant mass flow rate. Removal is difficult using a method in which the thickness is used to change the work roll interval or the plate speed on the entry or exit side of the rolling mill. In addition, even if a periodic fluctuation of the coolant retention length occurs, the thickness variation may be canceled by AGC in that state. Therefore, even if the outlet side thickness variation occurs, the coolant retention It is difficult to determine whether or not it is due to a variation in length.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to correct a variation in the outlet side plate thickness caused by a variation in the coolant retention length in the control of the rolling mill.

  One aspect of the present invention is a rolling control device that controls a rolling mill that rolls by supplying a continuous rolled material between at least a pair of rolls and sandwiching the rolled material, and the rolled material and the roll A staying amount fluctuation detecting unit that detects a staying amount of the liquid supplied between the rolls before being supplied between the rolls, and after being rolled by the roll When the thickness of the material to be rolled is obtained from the detection result by the detection unit and the thickness of the rolled material after rolling is detected, and the staying amount detection unit And a residence amount control unit for controlling the residence amount of the liquid based on the detection result.

  Further, another aspect of the present invention is a rolling control method for controlling a rolling mill for rolling by supplying a continuous rolled material between at least a pair of rolls and sandwiching the rolled material with the rolled material, Detecting fluctuations in the amount of staying of the liquid supplied between the rolls, obtaining the thickness of the material to be rolled after being rolled by the rolls from the detection results by the detection unit, A rolling control method, wherein when the thickness of the material to be rolled fluctuates, the retention amount of the liquid is controlled based on a detection result of the variation of the retention amount.

  By using the present invention, in the control of the rolling mill, it is possible to correct the variation in the outlet side plate thickness caused by the variation in the coolant retention length.

It is a figure showing the whole rolling device composition concerning an embodiment of the present invention. It is a figure which shows the example of the rolling state which concerns on embodiment of this invention. It is a figure which shows the coolant retention on the to-be-rolled material which concerns on embodiment of this invention. It is a figure which shows the fluctuation | variation of the coolant retention amount which concerns on embodiment of this invention. It is a figure which shows the example of the rolling state which concerns on embodiment of this invention. It is a figure which shows the structure of the coolant retention amount control which concerns on embodiment of this invention. It is a figure which shows the structure of the coolant retention amount control which concerns on embodiment of this invention. It is a figure which shows the content of TR performance database which concerns on embodiment of this invention. It is a figure which shows the judgment aspect of the coolant residence amount fluctuation | variation which concerns on embodiment of this invention. It is a figure which shows the aspect of coolant supply amount control which concerns on embodiment of this invention. It is a figure which shows the coolant retention on the to-be-rolled material which concerns on other embodiment of this invention. It is a figure which shows the fluctuation | variation of the coolant retention amount which concerns on other embodiment of this invention.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a case where the present invention is applied to a single stand rolling mill will be described as an example. FIG. 1 shows the configuration of a single stand rolling mill. The single stand rolling mill has an entry side TR (a tension reel is abbreviated as TR) 2 on the entry side with respect to the rolling direction of the rolling mill 1 and an exit side TR3 on the exit side. After the rolled material to be rolled is rolled by the rolling mill 1, the rolled material is wound by the exit side TR <b> 3.

  The rolling mill 1 includes a roll gap control device 7 for controlling the sheet thickness of the material to be rolled by changing the roll gap, and a mill speed control device 4 for controlling the speed of the rolling mill 1. Is installed. The entry-side TR2 and the exit-side TR3 are driven by an electric motor, and an input-side TR control device 5 and an output-side TR control device 6 are installed as devices for driving the electric motor and the electric motor.

  During rolling, a speed command is output from the rolling speed setting device 10 to the mill speed control device 4, and the mill speed control device 4 performs control to keep the speed of the rolling mill 1 constant. On the entry side and the exit side of the rolling mill 1, rolling is performed stably and efficiently by applying tension to the material to be rolled. It is the entry side tension setting device 11 and the exit side tension setting device 12 that calculate the necessary tension.

  Based on the entry side and exit side tension setting values calculated by the tension setting devices 11 and 12, the entry side TR2 and the exit side TR3 are passed through the entry side TR control device 5 and the exit side TR control device 6 to roll the set tension. A current value for obtaining a motor torque necessary for adding to the material is obtained by the entry side tension current conversion device 15 and the exit side tension current conversion device 16, and the input side TR control device 5 and the exit side TR control device 6 give. The entry-side TR control device 5 and the exit-side TR control device 6 control the motor current so as to obtain a given current, and a predetermined material is applied to the material to be rolled by the motor torque given from the motor current to the entry-side TR2 and the exit-side TR3. Give tension.

  The tension current converters 15 and 16 calculate a current setting value (motor torque setting value) that becomes a tension setting value based on the models of the TR mechanical system and the TR control device. However, since the control model includes an error, rolling Using the actual tension measured by the entry side tension meter 8 and the exit side tension meter 9 installed on the entry side and the exit side of the machine 1, the tension is corrected to the tension set value by the entry side tension control 13 and the exit side tension control 14. Is added to the tension current converters 15 and 16 to change the current values set in the entry side TR control device 5 and the exit side TR control device 6.

  Further, since the plate thickness of the material to be rolled is important for product quality, plate thickness control is performed. The sheet thickness on the outlet side of the rolling mill 1 is determined by the outlet side thickness controller 18 operating the roll gap of the rolling mill 1 using the roll gap controller 7 based on the actual sheet thickness detected by the outlet thickness gauge 17. Be controlled.

  In FIG. 1, the case of rolling from the left side to the right side of the drawing from the entry side TR2 to the exit side TR3 (hereinafter abbreviated as the rolling direction) is described. Directional (right to left) rolling is also possible. Although it depends on the product specifications, in general, there is an operation method to obtain a desired sheet thickness by rolling the material to be rolled a plurality of times. Even in a single stand rolling mill, the first rolling is performed from left to right. The material to be rolled on the entry side TR is wound around the exit side TR. In the second rolling, the rolling direction is changed from right to left, and the material to be rolled on the exit side TR is taken up on the entry side TR. To operate. By repeating this several times, a desired product plate thickness can be obtained.

  A coolant injection device 50 for securing lubrication between the material to be rolled and the work roll is installed on the entrance side of the rolling mill. The coolant is supplied from the coolant tank 52 to the coolant injection device 50 via the coolant flow rate adjusting device 51. The coolant injection angle from the coolant injection device 50 to the work roll can be adjusted by the coolant angle adjustment device 53. A pass line adjusting device 55 for adjusting the flow angle of the material to be rolled into the work roll can be installed on the entry side of the rolling mill. As will be described later, the coolant retention length can also be adjusted by installing the pass line adjusting device 55.

  FIG. 2 (a) shows an example of the rolling mill outlet side plate thickness variation in the case where periodic variation of the coolant retention length occurs. A large fluctuation periodically occurs in the outlet side thickness deviation as compared with the inlet side thickness deviation of the rolling mill, and the outlet side thickness fluctuation cannot be removed even though AGC is applied. FIG.2 (b) is a figure which shows the entrance side board thickness and the exit side board thickness fluctuation | variation at the time of performing the next round rolling to the to-be-rolled material after performing the rolling shown to Fig.2 (a). In FIG. 2B, the outlet side plate thickness fluctuation in FIG. 2A is the inlet side plate thickness fluctuation.

  2A and 2B, the same AGC is applied, but in the case of FIG. 2B, the variation in the outlet side plate thickness hardly occurs by controlling with AGC. That is, when there is an inlet side plate thickness variation in the same cycle, even if an AGC that can suppress the outlet side plate thickness variation is used, the outlet side plate thickness variation due to the coolant retention length variation cannot be removed. Therefore, when the outlet side plate thickness variation due to the coolant retention length variation occurs, it is difficult to remove it by AGC. Therefore, it is necessary to suppress the coolant retention length fluctuation itself.

  The factors of fluctuations in the exit side plate thickness in the rolling mill are as follows: variation in the entry side plate thickness of the material to be rolled, hardness variation of the material to be rolled, surface condition variation (friction coefficient unevenness) of the material to be rolled, mechanical vibration of the rolling mill, coolant Friction coefficient fluctuations due to fluctuations in residence amount can be considered. When there is a change in the outlet side thickness, it is judged which of the above-mentioned outlet side thickness fluctuation factors, and only when the cause is a change in the coolant residence length, the control for suppressing the coolant residence length fluctuation is performed. Need to be implemented. For this purpose, it is necessary to detect that when the outlet side plate thickness variation occurs, it is caused by the coolant retention length variation.

  FIG. 3 shows an outline of coolant retention. Rolling is performed by passing the material to be rolled between the upper and lower work rolls. At that time, the coolant is cooled between the material to be rolled and the work rolls, and the coolant is cooled by the coolant injection device 50 to cool the heat generated by the rolling. Inject against. Thereafter, the injected coolant 60 is directly applied to the lower work roll and the lower surface of the material to be rolled, and falls directly to the lower part of the rolling mill.

  On the other hand, the coolant sprayed onto the upper work roll and the upper surface of the material to be rolled falls from the end in the plate width direction of the material to be rolled, but falls from the plate end on the material to be rolled according to the amount of coolant to be sprayed. Until the coolant stays like 61. Since the material to be rolled is moving at a high speed (several hundreds m / min) with respect to the rolling mill, the amount of coolant remaining on the material to be rolled and the amount of coolant remaining on the entrance to the rolling mill and the material to be rolled The suspended length is maintained at the moving speed of the material. This is the coolant retention length 62.

  4 (a) to 4 (c) show an outline of fluctuations in the coolant retention length. The coolant retention length is generally considered to be determined by the rolling speed and the coolant flow rate. Therefore, if the rolling speed is constant, the coolant staying length is substantially constant (stable state). When this stable state breaks down, the coolant retention length 61 fluctuates. For example, the coolant retention length changes from the state shown in FIG. 4A to the state shown in FIG. 4B, and the state returns to the state shown in FIG. On the other hand, in this embodiment, the unidirectional change from the state of FIG. 4A to the state of (b) or from the state of FIG. It is not recognized as a variable state of length. That is, the fluctuation state of the coolant retention is a state in which the increase and decrease of the coolant retention amount on the material to be rolled within a predetermined time interval is equal to or greater than a predetermined threshold.

  Here, the predetermined time interval is a relatively short period of about several seconds, for example. As a method for determining the short period, for example, it is determined based on the rolling speed, such as a time during which the material to be rolled is conveyed by a predetermined length. In addition, the operator may arbitrarily determine. Similarly, the predetermined threshold value is a value at which fluctuation of the plate pressure is recognized, and a method for determining the value is determined based on, for example, a ratio to the target plate pressure.

  The main cause of fluctuations in the coolant retention length is the fact that the coolant flow rate and the rolling speed are not balanced, but the reasons for this are the “coolant injection angle” and “rolling material to the rolling mill. "Inflow angle" can be considered. In the rolling mill in which the strip thickness variation of the rolling mill shown in FIG. 2 occurs, when the same product is manufactured, the strip thickness variation occurs despite the same coolant flow rate for the same speed. There are cases where it does and does not occur.

  FIG. 5 shows a rolling state in the case of FIG. 2A in which the coolant residence length fluctuates and the outlet side plate thickness fluctuation occurs. When an exit thickness deviation occurs, there is a relationship that the exit thickness deviation is large, the entry side plate speed deviation is large, the exit side plate speed deviation is small, and the rolling load deviation is large. Each value shown in FIG. (The amount of coolant decreased and the coefficient of friction increased.) That is, it can be understood that the coefficient of friction changes due to the fluctuation of the coolant retention length, and as a result, the rolling state changes.

  Hereinafter, a method for suppressing fluctuations in the sheet thickness on the outlet side of the rolling mill by determining fluctuations in the coolant residence length and suppressing the length fluctuations according to the determination results will be described. In the rolling control according to the present embodiment, as shown in FIG. 6, the coolant retention length variation is detected by the coolant retention length variation determination device 101, and the length variation is detected by the coolant retention length variation control device 102. By controlling so as to suppress, the rolling mill delivery side plate thickness accuracy is improved.

  FIG. 7 is a diagram illustrating details of the coolant retention length variation determination device 101. In the coolant retention length variation determining device 101, as shown in FIG. 7, from the rolling state measured by the outlet side thickness gauge 17, the rolling load meter 19, and the inlet / outlet side plate speedometer installed in the rolling mill, It is determined whether the cause of the thickness variation is due to the coolant residence length variation. That is, the coolant retention length variation determination device 101 functions as a post-rolling plate thickness acquisition unit, a load acquisition unit, and a retention amount variation detection unit.

  As described above, factors for fluctuations in the exit side thickness of the rolling mill include fluctuations in the inlet side thickness of the material to be rolled, hardness fluctuations in the material to be rolled, surface condition fluctuation (friction coefficient unevenness) of the material to be rolled, and mechanical vibration of the rolling mill. Friction coefficient variation due to coolant residence length variation. When the friction coefficient variation occurs due to the coolant retention length variation, the rolling state variation occurs as shown in FIG. Among the above factors, the entry side thickness variation can be detected by a rolling mill entry side thickness gauge. The mechanical vibration affects the material to be rolled as a change in the vertical work roll interval of the rolling mill. In this case, when the rolling load becomes large, the outlet side thickness deviation becomes smaller, so that it can be distinguished from the thickness variation due to the coolant retention length variation.

  The surface treatment unevenness (friction coefficient variation) of the material to be rolled can be removed by performing rolling once. The same applies to the hardness unevenness of the material to be rolled, but since the same state is reproduced at the position on the material to be rolled, when the rolling operation is repeated, it is compared with the rolling state in the previous rolling operation. Therefore, it can be distinguished from the variation of the outlet side plate thickness due to the variation of the coolant retention length.

  Therefore, in the rolling control according to the present embodiment, the rolling operation is repeatedly performed, and the rolling performance database stores the rolling performance in each rolling operation in association with the position on the material to be rolled on the rolling mill delivery side. In addition, although the case where a rolling performance is input into the right TR rolling performance database 701 is shown in 7, this is a case where the right side is the outgoing side, and when the rolling direction is reversed, the left side is On the outgoing side, the left TR rolling record database 702 stores the rolling record.

  In the example of FIG. 7, the right TR rolling record database 701 stores the current rolling record, but the left TR rolling record database 702 already stores the previous rolling record. Therefore, the exit side plate thickness variation factor determination device 703 can acquire the previous rolling record from the left TR rolling record database 702 while sequentially acquiring the current rolling record.

  When the current rolling record and the previous rolling record are acquired, the exit side sheet thickness variation factor determination device 703 compares the current rolling record with the previous rolling record at the same position on the rolled material, At the same position, it is determined whether the same rolling state fluctuation has occurred in the previous time. As a result of comparing the two, when the fluctuation of the rolling state as shown in FIG. 5 occurs only in the current rolling state, the outlet side plate thickness variation factor determination device 703 generates the outlet side plate thickness variation due to the coolant residence length variation. Judge that you are doing. In the previous rolling, if the change in the rolling state occurs as shown in FIG. 5, it is determined that the hardness is uneven or the surface state is changed in the material to be rolled.

  With the configuration of the coolant retention length variation determination device 101 as shown in FIG. 7, it is possible to compare the rolling performance at the previous rolling and the current rolling at the same position on the material to be rolled. As described above, in FIG. 7, since the rolling direction is from left to right, the left side TR is the entry side TR2, and the right side TR is the exit side TR3. Depending on the rolling direction, TR that unwinds the material to be rolled and supplies it to the rolling mill entry side and TR that winds the rolled material on the rolling mill exit side after rolling are alternated. Therefore, each TR rotation position from a certain point after the start of rolling and the corresponding rolling performance are stored in the database, so that the rolling performance at the previous rolling is compared with the rolling performance at the current rolling. Is possible.

  FIG. 8 explains how to use the TR rolling record database (701 or 702). About delivery TR, it becomes the side which creates TR rolling performance database. The TR rotation angle at the start of rolling is set to 0, and the process of writing the TR rotation angle and the rolling record detected by the rotation angle detector of the outgoing side TR in the database is performed. If the rolling direction is reversed and becomes the entry side TR, the current entry side TR rotation angle can be obtained by subtracting the TR rotation angle detected by the entry side TR rotation angle detector without changing the TR rotation angle. calculate. From the current entry TR rotation angle, the data on the same database of the exit TR rotation angle in the previous rolling is searched, and the rolling performance at the current rolling material position is taken out.

  For example, when the rolling results A, B, and C are written in the TR rolling results database at the positions of the outgoing TR rotation angles (1), (2), and (3), the rolling direction is reversed to become the outgoing TR database. Since the TR rotation angle is subtracted, it is extracted in the order of C, B, A according to the TR rotation angle. Even in an actual material to be rolled, rolling is performed in the reverse direction because the rolling direction is changed.

  An outline of the operation of the outlet side plate thickness variation factor determination device 703 is shown in FIG. As shown in FIG. 9, the exit side plate thickness variation factor determination device 703 processes the rolling performance at the current rolling and the rolling performance at the previous rolling with a signal processing device, and uses the waveform of the processing result to process the material to be rolled. At the same upper position, it is determined whether the rolling load and the exit side plate thickness have increased, have not changed, or have decreased. Then, according to the determination rule based on the determination result, the exit side plate thickness variation factor determination device 703 determines that the exit side plate thickness variation during the current rolling is “hardness unevenness of the material to be rolled”, “coolant residence length variation”, “mechanical vibration” It is determined which of the factors is caused.

  As shown in FIG. 9, in the present embodiment, the outlet side thickness fluctuation factor determining device 703 has a plate thickness as the material of the material to be rolled when no rolling load fluctuation and outlet side thickness fluctuation have occurred during the previous rolling. It is determined that there is no variation occurrence factor, that is, there is no hardness unevenness on the material to be rolled. In that case, when the exit side plate thickness variation occurs in the current rolling operation, and the direction of the exit side plate thickness variation and the direction of the rolling load variation are the same direction, the exit side plate thickness variation factor determination device Judge that length variation has occurred. On the other hand, if the direction of the exit side plate thickness variation is opposite to the direction of the rolling load variation, the exit side plate thickness variation factor determination device determines that mechanical vibration is occurring.

  In addition, since the problem does not occur in the first place if there is no variation in the outlet side thickness in the current rolling operation, the outlet side thickness variation factor determination device 703 cancels the determination of whether or not the coolant retention length variation has occurred. . In addition, when the rolling load fluctuation and the outlet side plate thickness fluctuation occur during the previous rolling, and the rolling load fluctuation and the outlet side plate thickness fluctuation occur in the same rolling operation as well, the outgoing side plate thickness fluctuation factor determination device In step 703, it is determined that the unevenness of the material to be rolled is a factor.

  In addition, the recognition that the variation in the delivery side plate thickness or the rolling load variation occurs is recognized by a simple variation in the plate thickness or the load, similar to the variation in the coolant retention amount in FIGS. 4 (a) and 4 (b). Instead, as shown in FIG. 9, it is recognized when the increase and decrease in value occur continuously in a short period of time. That is, the exit side thickness variation factor determination device 703 recognizes that an exit side thickness variation or rolling load variation has occurred when a peak appears in the graph of sheet thickness and load over time.

  In other words, the outlet side thickness variation factor determination device 703 detects that a fluctuation has occurred when the increase and decrease in the outlet side thickness and load within a predetermined time interval are equal to or greater than a predetermined threshold. That is, the exit side plate thickness variation factor determination device 703 determines whether the increase and decrease in the exit side plate thickness and load are within a predetermined threshold, or even if the increase and decrease in the exit side plate thickness and load are greater than or equal to a predetermined threshold. If it occurs over a predetermined time interval, no change is detected.

  In the coolant retention length variation control device 102, when the coolant retention length variation determination device 101 determines that the coolant retention length variation has occurred, the coolant flow rate, coolant injection angle, Manipulate one of the pass line angles of the rolled material. That is, the coolant retention length fluctuation suppression control unit functions as a retention amount control unit. Here, a case where the coolant flow rate is operated will be described.

  The coolant flow rate is set as a function regarding the rolling speed. When the rolling speed is high, the calorific value of the rolling is also increased. Therefore, when the rolling speed is increased, the coolant flow rate is set to be increased. Since the coolant retention length is determined from the balance between the moving speed of the material to be rolled and the coolant flow rate, which is determined by the rolling speed, if this is fluctuating, the stable state is disturbed and the rolling speed is It is difficult to determine whether the length variation occurs because the coolant flow rate is excessive or whether it occurs because it is too small. Therefore, the coolant flow rate at which the coolant retention length does not vary within a predetermined coolant flow rate operation range is found by trial and error.

  An example of coolant flow rate setting with respect to rolling speed is shown in the upper part of FIG. In the case where the outlet side plate thickness variation due to the coolant retention length variation occurs when the rolling speed is (A), the coolant retention length variation suppression control device 102 sets the coolant flow rate in a preset range (for example, ± of the current set value) By changing within 10%), the control for suppressing the fluctuation of the coolant retention length is performed. As shown in the lower part of FIG. 10, the coolant retention length fluctuation suppression control device 102 changes the coolant flow rate according to a coolant flow rate change pattern (time series pattern) determined in advance in consideration of operational stability and the like. In the meantime, the coolant retention length variation determination device 101 monitors the occurrence of coolant retention length variation by the same method as described above. When the coolant retention length variation determining device 101 no longer detects the occurrence of the coolant retention length variation, the coolant retention length variation suppression control device 102 stops changing the coolant flow rate.

  In the example of FIG. 10, the change is stopped at the time (C). In this case, the coolant flow rate change amount is (B). By reflecting this in the current rolling speed-coolant flow rate setting curve and making it the changed coolant flow rate setting curve, it is possible to suppress in advance the occurrence of outlet plate thickness fluctuation due to coolant retention length fluctuation at the next rolling of the same type. It becomes.

  In addition, the coolant retention length fluctuation suppression control device 102 adjusts the coolant injection angle and the pass line angle of the rolling mill. The purpose of the coolant injection angle is to eliminate the setting error of the injection angle that occurs when the rolling mill is installed or when the machine is serviced. The pass line angle of the rolling mill adjusts the angle when the material to be rolled flows into the rolling mill.

  Since the pass line angle is changed by exchanging rolls such as a work roll of a rolling mill, it is necessary to adjust at the time of roll exchange. Accordingly, when the coolant maintenance length fluctuation occurs after the mechanical maintenance of the rolling equipment is performed and the coolant injection angle is changed, the coolant residence length fluctuation suppression control device 102 changes the coolant injection angle. Further, when the coolant retention length variation occurs after the roll of the rolling mill is changed and the pass line angle changes, the coolant retention length variation suppression control device 102 changes the pass line angle of the rolling mill. Moreover, when the coolant injection angle changing device 53 and the pass line changing device 55 are not installed due to the mechanical configuration of the rolling mill, the coolant retention length variation suppressing control device 102 changes the coolant flow rate. Further, even when the product specification of the material to be rolled changes and the coolant retention length variation occurs, the coolant retention length variation suppression control device 102 changes the coolant flow rate.

  As described above, the coolant retention length variation suppression control device 102 according to the present embodiment stores the control rules of the control operation ends according to the device status, and the control mode of each control operation end according to the device status. To decide.

  Regarding the coolant injection angle and coolant flow rate, the outside air temperature and coolant viscosity affect the occurrence of fluctuations in the coolant retention length, so these relationships are stored in the setting database 103 and set when the same conditions occur. By taking out and setting the set value from the database 103, it is possible to prevent the change in the outlet side plate thickness due to the change in the coolant retention length.

  The control operation end controlled by the coolant retention length variation control device 102 is not limited to the above-described coolant flow rate, coolant injection angle, and pass line angle of the material to be rolled, but various means capable of suppressing the coolant retention length variation. Can be used. A roll that can contact the material to be rolled is installed on the upper surface of the material to be rolled on the entry side of the rolling mill.When the coolant retention length fluctuates, the roll is brought into contact with the material to be rolled, and the coolant is damped up to reduce the coolant retention length. By limiting, it is also possible to suppress fluctuations.

  As described above, in the rolling control according to the present embodiment, the rolling operation is repeatedly executed, and at least the rolling state such as the rolling load and the exit side plate thickness in the previous rolling operation is compared with the current rolling state. Thus, the occurrence of fluctuation of the coolant retention length is detected. Thereby, it is possible to correct the variation in the outlet side plate thickness due to the variation in the coolant retention length.

  In the example of FIG. 9, three examples have been described as the determination rules for detecting the height unevenness of the material to be rolled, the coolant retention length, and the mechanical vibration. This is an example, and the gist of the present embodiment is merely to detect the occurrence of the coolant retention length fluctuation based on the comparison between the previous rolling record and the current rolling record. Therefore, various determination rules can be provided based on a comparison between the previous rolling record and the current rolling record.

  Moreover, in the example of FIG. 8, the case where the position on a to-be-rolled material was judged based on the rotation angle of TR demonstrated as an example. This is an example, and any information that can determine the position on the material to be rolled, such as the number of signals output according to the rotation of TR, can be applied in the same manner.

Embodiment 2. FIG.
In Example 1, when repeating rolling operation, it demonstrated as an example the case where a coolant residence length fluctuation | variation was detected based on the comparison result of the last rolling state and this rolling state. In addition, it is also possible to take a moving image of the coolant staying on the material to be rolled as shown in FIG. 4 and detect a change in the coolant staying amount with time by image processing. Such an embodiment is shown in FIG.

  As shown in the upper part of FIG. 11, when detecting a temporal change in the coolant retention length by image processing, the image recognition camera 20 is installed at a position where it can be photographed on the material to be rolled before entering the work roll. Thus, as shown in the lower part of FIG. 11, a predetermined range on the material to be rolled is photographed by the image recognition camera 20, and time-series image information is generated. The outlet side plate thickness variation factor determination device 703 according to the present embodiment acquires the time-series image information generated in this way, and the material to be rolled is “white” and the coolant retention portion as shown in the lower part of FIG. Binarization processing is performed so that becomes “black”. Then, the ratio of the area of the “black” portion in the image is monitored, and it is determined that the coolant retention length fluctuation has occurred based on the fluctuation of the ratio.

  FIGS. 12A to 12C show an example of the coolant retention length variation and the detection mode of the coolant retention length variation in the present embodiment. 4A to 4C of the first embodiment, the coolant retention length changes from the state of FIG. 12A to the state of FIG. 12B, and FIG. It is the fluctuation state of the coolant retention length that the return to the state of) is repeated.

  When fluctuation of the coolant retention length occurs, as shown in FIG. 12C, a black portion with respect to the entire area in the binarized image of the time series image generated by the image recognition camera 20, that is, the coolant The ratio of the portion indicates a peak. As a method of detecting a waveform having a peak as shown in FIG. 12 (c), the same method as the rolling load fluctuation and the outlet side board thickness fluctuation in the first embodiment can be used. That is, the outlet side thickness variation factor determination device 703 can detect a peak as shown in FIG. 9 when both the increase and decrease of the area ratio above a predetermined threshold value occur within a predetermined time interval. .

  After the outlet side plate thickness variation factor determination device 703 detects the coolant retention length variation in the above-described manner, the coolant retention length variation suppression control device 102 performs the coolant flow rate, the coolant injection angle, and the coolant flow rate in the same manner as in the first embodiment. Adjust the pass line angle of the rolling mill. As described above, in the rolling control according to the present embodiment, the first embodiment is performed without repeatedly performing a rolling operation by generating a time-series image information by capturing a moving image of a coolant or a still image continuously. The same effect can be obtained.

1 Rolling machine 2 Incoming TR
3 Outgoing TR
4 Mill Speed Control Device 5 Incoming TR Control Device 6 Outgoing TR Control Device 7 Roll Gap Control Device 8 Incoming Tension System 9 Outgoing Tension System 10 Rolling Speed Setting Device 11 Incoming Tension Setting Device 12 Outgoing Tension Setting Device 13 Entry-side tension control 14 Entry-side tension control 15 Entry-side tension current conversion device 16 Entry-side tension current conversion device 17 Exit-side plate thickness gauge 18 Exit-side plate thickness control device 19 Rolling load meter 20 Image recognition camera 50 Coolant injection device 51 Coolant flow rate Adjustment device 52 Coolant tank 53 Coolant angle adjustment device 55 Pass line adjustment device 60 Coolant 61 Coolant retention 62 Coolant retention length 101 Coolant retention length variation determination device 102 Coolant retention length variation suppression control device 103 Setting database 701 Right TR rolling results Database 702 Left TR rolling performance database 70 Delivery side thickness fluctuation factor determination device

Claims (4)

A rolling control device for controlling a rolling mill for rolling by supplying a continuous material to be rolled between at least a pair of rolls and sandwiching between the rolls,
The retention amount of the liquid supplied between the material to be rolled and the roll, and the retention amount on the material to be rolled before being supplied between the rolls is greater than or equal to a predetermined threshold value within a predetermined time interval. A residence amount fluctuation detection unit that detects that the increase in the range and the decrease in the range of the predetermined threshold value or more ;
The thickness of the material to be rolled after being rolled by the roll, the post-rolling plate thickness acquisition unit for acquiring from the detection result by the detection unit,
The thickness of the rolled material after the detected rolling is reduced in a range of more than a predetermined threshold with increase in a range of more than a predetermined threshold value within a predetermined time interval, and I by the amount of retention variation detecting unit A retention amount control unit that controls the retention amount of the liquid when it is detected that the retention amount increases within a predetermined threshold value or more and decreases within a predetermined threshold value within a predetermined time interval. A rolling control device characterized by that. In the case where the stay amount fluctuation detection unit is rolled a plurality of times by supplying the same range of the material to be rolled a plurality of times between the rolls, the staying amount fluctuation detection unit is configured to perform a plurality of times of the thickness in the same range of the material to be rolled 2. The rolling control according to claim 1, wherein, based on a detection result, it is detected that the staying amount increases within a predetermined threshold or more and decreases within a predetermined threshold or more within a predetermined time interval. apparatus. A load acquisition unit for acquiring the load of the roll applied to the material to be rolled from the detection result by the detection unit;
The stay amount fluctuation detection unit detects the load multiple times in the same range of the material to be rolled when the same range of the material to be rolled is rolled a plurality of times by supplying the same range between the rolls. based on the results, the rolling control apparatus according to claim 1, wherein the amount of retention and detecting that it has decreased in the range of more than a predetermined threshold with increase in a range of more than a predetermined threshold value within a predetermined time interval . In the case where the stay amount fluctuation detection unit is rolled a plurality of times by supplying the same range of the material to be rolled a plurality of times between the rolls, the thickness and the load within the same range of the material to be rolled In the latest detection results of the thickness and the load, the increase in the thickness and the load within a predetermined time interval is not less than a predetermined threshold and the decrease is not less than the predetermined threshold. In the previous detection result of the thickness and the load in the same range of the material to be rolled, the increase in the thickness and the load within a predetermined time interval is not less than a predetermined threshold and the decrease is predetermined. when the threshold value or less, the rolling system according to claim 3 for detecting that the retention amount is reduced in a range of more than a predetermined threshold with increase in a range of more than a predetermined threshold value within a predetermined time interval Apparatus.