JP5811077B2 - Method and apparatus for supporting maximum rolling speed during line acceleration of tandem rolling mill - Google Patents

Description

  The present invention relates to a maximum rolling speed setting support method and apparatus at the time of line acceleration of a tandem rolling mill, and in particular, a cold rolled steel sheet such as a tin plate and an automotive steel sheet is constituted by two or more continuous rolling mills. The present invention relates to a method and apparatus for assisting in setting the maximum rolling speed during line acceleration of a tandem rolling mill, which is suitable for use in rolling with a cold tandem rolling mill.

  In a cold rolling line as illustrated in FIG. 1, a rolled material (also referred to as a coil) 10 delivered from a plurality of payoff reels 12 (two in the figure) on the line entry side is subjected to previous rolling by a welding machine 14. After being welded to the material and rolled by the tandem rolling mill 20 through the entry-side looper 16, it is wound up by, for example, a carousel type tension reel (also referred to as a carousel reel) 22.

  In such a continuous cold rolling by the tandem rolling mill 20, the rolled material 10 is not a single material, and therefore the rolling conditions, particularly the plate thickness, may be changed during the rolling. Even in such a case, the rolling operation is not interrupted, so the plate thickness is changed between runs.

  Therefore, by implementing appropriate control with the process computer and its lower-level programmable logic controller (PLC), a technology has already been established to prevent troubles such as plate breakage and to efficiently change the running plate thickness. Yes.

  For that purpose, first, it is necessary to accurately predict the rolling load at the time of changing the running plate thickness and the advanced rate with a process computer, but in Patent Document 1, the friction coefficient is learned using the actual data of the rolling mill, This shows a method for improving the prediction accuracy of rolling load and the like.

  Next, it is necessary to appropriately control the roll gap and the roll peripheral speed when changing the running plate thickness with PLC. However, in Patent Document 2, timing is measured by tracking the running plate thickness change point according to the flow rate of the plate. The method of controlling the reduction position and tension of each stand is shown well.

  In addition, a technology for predicting rolling load at the maximum rolling speed obtained from a pass schedule has been established by learning actual data in a high-speed steady part.

  In addition, when the running plate thickness is changed, the surface temperature of the rolled material 10 may increase excessively, generating surface flaws called heat streaks, and chattering due to slips or sticks. Therefore, in Patent Document 3, before rolling of the current rolled material (coil), it is a stable rolling region that does not generate heat streak or chattering as illustrated in FIG. It has been proposed to set up the rolling speed within a range that falls within the value, collect the rolling record during rolling of the current rolled material, and perform the setup calculation of the next rolled material (coil).

JP 2006-122980 A Japanese Patent No. 2981797 Japanese Patent Laid-Open No. 11-57828

  As described in Patent Document 3, acceleration is performed automatically or after manual intervention by the operator after changing the running plate thickness. However, there is a problem in that the maximum rolling speed caused by the variation is caused by the operator. The reason is that it is difficult to accurately predict whether or not the rolling load that changes due to acceleration exists in a stable rolling region without any trouble. That is, as shown in FIG. 2, generally, as the rolling speed increases, the stable rolling region of the rolling load becomes narrower. If it deviates from this stable rolling region, troubles of chattering such as heat streak, which is seizure of the steel sheet, and slip, stick, etc. of the steel sheet and the rolling roll occur. Therefore, the operator must predict whether or not a rolling load will enter the stable rolling region during acceleration. However, since the prediction requires know-how based on many years of experience, the prediction result varies depending on the operator, and the setting of the maximum rolling speed varies.

  The present invention has been made to solve the above-mentioned conventional problems, makes it easy for an operator to predict whether or not a rolling load will enter a stable rolling region when accelerating the rolling speed, and variations in the setting of the maximum rolling speed. It is an object of the present invention to suppress the above and increase the maximum rolling speed to the upper limit.

The present invention, when setting the maximum rolling speed at the time of line acceleration from the time of passing through the welding point of the tandem rolling mill to the maximum rolling speed, the highest rolling speed from the time of passing the welding point including at least rolling load, tension, and plate thickness in each stand. line rolling performance data collected during acceleration up, before rolling the coils, with the rolling performance data against the respective speed point that the collected, the rolling load prediction calculates a predicted rolling load by multiple regression each This is achieved for each stand, and the rolling load prediction result is displayed on the screen to facilitate the prediction of the rolling load at the time of the line acceleration by the operator , thereby solving the above problem.

The present invention also the time of the maximum rolling speed setting during line acceleration from time pass welding point of a tandem rolling mill to a maximum rolling speed, including in the coil rolling, at least the rolling load at each stand, the tension, the thickness Collect rolling performance data during line acceleration from passing through the welding point to the maximum rolling speed , extract the rolling performance data and rolling performance data for each speed point collected before coil rolling, and during the coil rolling Rolling load prediction that calculates the predicted rolling load by multiple regression from rolling performance data in the region in the high speed region from the point of each speed at which data was collected is performed for each stand, and the rolling load prediction result is displayed on the screen and the operator The above problem is also solved by facilitating the prediction of the rolling load during the line acceleration .

  Here, the display can be performed on the screen of a process computer or PLC.

The present invention is also a maximum rolling speed setting support device at the time of line acceleration from the time of passing through the welding point of the tandem rolling mill to the maximum rolling speed, the welding point including at least rolling load, tension, and plate thickness in each stand. means for collecting the rolling performance data at line acceleration up rolling speed from the time passes, before rolling the coils, with the rolling performance data against the respective speed point that the collected, predicted rolling load by multiple regression A means for performing rolling load prediction for each stand and means for displaying the rolling load prediction result on a screen, and a maximum rolling speed setting support device during line acceleration of a tandem rolling mill Is to provide.

The present invention is also a maximum rolling speed setting support device at the time of line acceleration from the time when the tandem rolling mill passes through the welding point to the maximum rolling speed, and at least rolling load, tension, plate in each stand during the coil rolling. Means for collecting rolling performance data at the time of line acceleration from passing through the welding point including the thickness to the maximum rolling speed, and extracting the rolling performance data and rolling performance data for each speed point collected before coil rolling. , Means for performing rolling load prediction for each stand for calculating predicted rolling load by multiple regression from rolling performance data in a high speed region from each speed point at which data was collected during coil rolling, and the rolling load prediction result Providing a maximum rolling speed setting support device during line acceleration of a tandem rolling mill characterized by comprising: That.

  Here, the display can be performed on a screen of a process computer or PLC.

  According to the present invention, by displaying the rolling load prediction results on the screen before and during rolling, it becomes easy to predict whether or not the rolling load enters the rolling stable region that the operator performs during line acceleration. As a result, variation in setting of the maximum rolling speed can be suppressed, and the maximum rolling speed can be increased to the upper limit. Thereby, productivity can be significantly improved.

The figure which shows an example of the whole structure of the cold tandem rolling line to which this invention is applied Diagram showing relationship between rolling load and rolling speed and occurrence of trouble The figure which shows the structural example of the cold rolling mill system with which this invention is applied. The figure which shows the example of a display of the rolling load prediction for every point in the i-th stand before rolling by 1st Embodiment of this invention. The figure which shows the example of a display of the rolling load prediction for every point in the i-th stand in rolling by 2nd Embodiment of this invention. The figure which compares and shows the rolling load prediction error at the rolling speed of 1500 mpm in the conventional example and the first embodiment of the present invention. The figure which similarly shows the rolling load prediction error for every point in the 5th stand The figure which similarly shows the rolling load prediction error at the time of the maximum rolling speed 2000mpm rolling in 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  An example of a cold rolling mill system in which the present invention is implemented is shown in FIG.

  In this cold rolling mill system, each of the stands 31 to 35 includes rolling load detection means such as load cells 41 to 45, for example, a reduction position detection means (not shown) incorporated in a reduction device (not shown), and a tension meter 51. Tension detecting means such as .about.56, for example, plate thickness detecting means such as thickness gauges 61 and 62 provided on the entry side and the exit side are provided.

  The process computer 80 is a setting calculation means that calculates a pass schedule, a predicted rolling load value for each of the stands 31 to 35, and a roll gap target value according to information such as material dimensions and product target dimensions given from the host computer 70. Those values are set in the lower PLC 90. The PLC 90 continuously collects rolling data such as rolling load and tension and outputs them to the process computer 80.

  First, as a first embodiment, a predicted load display before rolling will be described.

1. Data collection during line acceleration In the first embodiment, the process computer 80 collects acceleration data output from the PLC 90 continuously or at a predetermined timing before the coil rolling. When collecting at a predetermined timing, the more points to be collected, the better. As data items to be collected, rolling data such as rolling load and tension for each stand is necessary.

2. Rolling Load Prediction The method for predicting rolling load during acceleration before coil rolling may be a method using conventional learning calculation or a method using a statistical method such as multiple regression. As the number of rolling speed points for predicting the rolling load at the time of line acceleration, the larger the number, the more preferable it is because the rolling behavior at the time of line acceleration can be finely reproduced.

3. Screen Display The rolling load prediction result at the time of line acceleration in the process computer 80 is displayed on a screen that the operator can see during operation. The screen display destination may be either the monitor screen 82 of the process computer 80 illustrated in FIG. 3 or the monitor screen of the PLC 90. As an example of the screen display, a rolling load prediction display example of the i-th stand (i is a stand number) is shown in FIG.

  Next, as a second embodiment, the rolling load prediction in a higher speed region than the speed at which the record data is collected will be described using the record data during rolling.

1. Data collection during acceleration The process computer 80 collects data during acceleration output from the PLC 90 continuously or at a predetermined timing during the coil rolling. When collecting at a predetermined timing, the more points to be collected, the better. As data items to be collected, rolling data such as rolling load and tension for each stand is necessary.

2. Rolling load prediction Next, the rolling load in a higher speed region than the speed at which the actual data was collected is used for the collected actual data at the time of line acceleration of the coil, using a conventional learning calculation, or multiple regression, etc. It is obtained by a method using the statistical method. As for the point of the rolling speed in the high speed region, compared with the rolling speed at which the performance data for performing the rolling load prediction is collected, it is preferable that the rolling behavior at the time of line acceleration can be reproduced more finely.

3. Screen display Rolling load prediction results are displayed on a screen that the operator can see during operation. As a display destination on the screen, either the monitor screen 82 of the process computer 80 illustrated in FIG. 3 or the monitor screen of the PLC 90 may be used. As an example of the screen display, a rolling load prediction display example of the i-th stand is shown in FIG.

  As a cold rolling system, the number of stands: 5, line speed: specification maximum 2000 mpm, work roll diameter: 500 to 600 mm, backup roll diameter: 1300 to 1500 mm, rolling load detector: installed on each stand (load cell 41 in FIG. 3) 45), reduction position detector: installed on each stand, tension detector: installed between the stands (tensometers 52-55 in FIG. 3), plate thickness detector: first stand entry side and fifth stand exit side (Plate thickness gauges 61 and 62 in FIG. 3).

  In the rolling load prediction simulation before rolling in the first embodiment, the process computer 80 collected data at the time of line acceleration at five rolling speeds of 500 mpm, 1000 mpm, 1500 mpm, 1800 mpm, and 2000 mpm when passing through the welding point. The collected items are rolling load, tension, and plate thickness.

  The rolling load was predicted by a method of directly calculating the rolling load using multiple regression. In addition, the rolling speed point at which the rolling load was predicted was 5 points for collecting rolling data.

  As a simulation result, first, rolling at a rolling speed of 1500 mpm for each stand of a method using learning of actual data in a conventional high-speed steady region (hereinafter referred to as a conventional method) and a method calculated in the first embodiment of the present invention. The standard deviation of the rolling load prediction error is shown in FIG. From FIG. 6, it can be seen that the accuracy of the method of the present invention is improved over the conventional method in all the stands. As a representative example, the standard deviation of the prediction error for each point where the rolling load prediction of the fifth stand is performed is shown in FIG. From FIG. 7, it was confirmed that the rolling load prediction at each point obtained in the first embodiment of the present invention was calculated with higher accuracy than the 9% error of the conventional method.

  Next, according to the second embodiment of the present invention, a prediction simulation of the rolling load in the high speed region was performed using the execution data during rolling, compared with the speed at which the actual data was collected. The method of collecting data and accelerating rolling load during line acceleration is the same as in the rolling load prediction simulation before rolling according to the first embodiment.

  As a representative, FIG. 8 shows a simulation result of a rolling load prediction error at the time of rolling at a maximum rolling speed of 2000 mpm, which is obtained from the result collection data for each rolling speed for the fifth stand. As is clear from the figure, the higher the actual data used, the lower the standard deviation of the prediction error and the higher the prediction accuracy. In particular, the maximum rolling speed of 2000 mpm rolling predicted using the actual data during 1800 mpm rolling. As compared with the conventional method without correction, the rolling load at the time is greatly improved by about half the prediction error. From these facts, the conventional method had no other choice but to rely on the know-how of the operator to predict the rolling load at the maximum rolling speed, and according to the present invention, an accurate rolling load prediction result was obtained. It became possible to display on the screen, and it became possible to suppress variations in the maximum rolling speed setting by the operator.

  In the embodiment, the present invention is applied to a 5-stand tandem rolling mill, but the number of stands is not limited to this. Further, the screen for displaying the rolling load prediction result is not limited to the monitor screen of the process computer 80 or the PLC 90.

DESCRIPTION OF SYMBOLS 10 ... Rolled material 20 ... Tandem rolling mill 31-35 ... 1st-5th stand 41-45 ... Load cell 51-56 ... Tension meter 61, 62 ... Sheet thickness meter 70 ... High-order computer 80 ... Process computer 82 ... Monitor screen 90 ... PLC

Claims (6)

When setting the maximum rolling speed at the time of line acceleration from passing through the welding point of the tandem rolling mill to the maximum rolling speed ,
Collect rolling performance data at the time of line acceleration from passing through the welding point to the maximum rolling speed , including at least rolling load, tension, and plate thickness in each stand .
Before the coil rolling, using a rolling performance data against the respective speed point that the collected, subjected to rolling load prediction calculates a predicted rolling load by multiple regression for each stand,
A method for assisting in setting a maximum rolling speed during line acceleration of a tandem rolling mill, wherein the rolling load prediction result is displayed on a screen so that an operator can easily predict the rolling load during line acceleration. When setting the maximum rolling speed at the time of line acceleration from passing through the welding point of the tandem rolling mill to the maximum rolling speed ,
During the coil rolling, collect the rolling performance data at the time of line acceleration from the time of passing through the welding point to the maximum rolling speed including at least rolling load, tension, and plate thickness in each stand ,
Its extracts rolling performance data for the rolling performance data and each speed points collected before the coil rolling, by multiple regression from rolling actual data area of the high speed region from the point of the speed data was collected during the coil rolling Perform rolling load prediction to calculate the predicted rolling load for each stand,
A method for assisting in setting a maximum rolling speed during line acceleration of a tandem rolling mill, wherein the rolling load prediction result is displayed on a screen so that an operator can easily predict the rolling load during line acceleration.   3. The maximum rolling speed setting support method at the time of line acceleration of a tandem rolling mill according to claim 1 or 2, wherein the display is performed on a screen of a process computer or a PLC. A maximum rolling speed setting support device at the time of line acceleration from the time of passing through the welding point of the tandem rolling mill to the maximum rolling speed ,
Means for collecting rolling performance data at the time of line acceleration from the time of passing the welding point to the maximum rolling speed , including at least rolling load, tension, and plate thickness in each stand ;
Before the coil rolling means carried out using a rolling performance data against the respective speed point that the collected, the rolling load prediction calculates a predicted rolling load by multiple regression for each stand,
Means for displaying the rolling load prediction result on the screen;
A maximum rolling speed setting support device at the time of line acceleration of a tandem rolling mill. A maximum rolling speed setting support device at the time of line acceleration from the time of passing through the welding point of the tandem rolling mill to the maximum rolling speed ,
During the coil rolling, means for collecting rolling performance data at the time of line acceleration from the time of passing the welding point to the maximum rolling speed including at least rolling load, tension, and plate thickness in each stand ;
Its extracts rolling performance data for the rolling performance data and each speed points collected before the coil rolling, by multiple regression from rolling actual data area of the high speed region from the point of the speed data was collected during the coil rolling Means for performing a rolling load prediction for each stand to calculate a predicted rolling load ;
Means for displaying the rolling load prediction result on the screen;
A maximum rolling speed setting support device at the time of line acceleration of a tandem rolling mill.   6. The maximum rolling speed setting support device at the time of line acceleration of a tandem rolling mill according to claim 4, wherein the display is performed on a screen of a process computer or a PLC.