JPH0760322A - Automatic plate thickness controlling method of rolling mill - Google Patents

Abstract

PURPOSE:To stably obtain the excellent plate thickness precision in a system to roll by changing a feed forward control and a mass flow control. CONSTITUTION:In a controlling system, the existence of slips against a rolling material 1 in velocity detecting rollers 6, 8 is judged by comparing an inlet side rolling material volume Vi and an outlet side rolling material volume Vo before and behind a rolling mill 4, when the occurrence of the slip over than a prescribed volume is judged in these velocity detecting rollers 6, 8, the thickness of plate is controlled based on the feed forward control. When the occurrence of the slip is not judged, the mass flow control with excellent plate thickness precision is continued.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic strip thickness control method for a rolling mill, and more particularly to an automatic strip thickness control method for a rolling mill capable of improving strip thickness accuracy over the entire length of a rolled material. It is a thing.

[0002]

2. Description of the Related Art Generally, in rolling equipment, the plate thickness is one of the important quality control items in determining the quality of rolled material to be rolled. Therefore, as a method of automatically controlling the strip thickness of a rolling mill, a feedforward method (FF-AGC) and a mass flow method (MF-AGC) are known. The feed-forward type automatic strip thickness control method described above detects the strip thickness deviation of the rolled material on the inlet side of the rolling mill and controls the rolling roll gap of the rolling mill based on this inlet side sheet thickness deviation. The thickness of the rolled material to be rolled is controlled. On the other hand, the mass flow type automatic strip thickness control method determines the volume of the rolled material on the inlet side and the outlet side of the rolling mill from the rolled material velocity on the inlet side and the outlet side detected by the speed detection rollers provided in each. Calculate,
By controlling the rolling roll gap of the rolling mill based on the law of constant mass flow rate, the strip thickness of the rolled material to be rolled is controlled. A conventional technique to which the above control method is applied is, for example, Japanese Patent Laid-Open No. 63-1607.
The one disclosed in Japanese Patent Publication No. 14 is known. In the technology disclosed in the above publication, mass flow type plate thickness control is performed when the rolling mill in the rolling equipment is in an accelerating / decelerating state, and feed forward type plate thickness control is performed when the rolling mill is in a constant speed state. It In this way, feedforward control is performed at constant speed because slippage may occur between the speed detection roller and the rolled material during high-speed rolling, and mass flow control is effective even at constant speed. This is because it may not be possible to obtain plate thickness accuracy.

[0003]

Generally, in a situation where there is no slip between the speed detection roller and the rolled material, the mass flow type plate thickness control is better than the feed forward type plate thickness control. Although it has been found that the plate thickness accuracy can be obtained, in the above-mentioned conventional technique, feed-forward control is always performed even when no slippage occurs in the speed detection roller during high-speed rolling. It is hard to say that it is possible to stably obtain good plate thickness accuracy. Therefore, the present invention was devised in view of the above circumstances, and enables the plate thickness control centered on the mass flow type control in the rolling system to stably achieve good plate thickness accuracy. An object of the present invention is to provide an automatic plate thickness control method for a rolling mill that can be obtained.

[0004]

To achieve the above object, the main means adopted by the present invention is to detect the plate thickness deviation of the rolled material to be rolled on the inlet side of the rolling mill. ， By controlling the rolling roll gap of the rolling mill on the basis of this deviation of the strip thickness, feed-forward control that controls the strip thickness of the rolled material to be rolled, and the rolling material at the inlet and outlet of the rolling mill The volume is calculated from the velocity of the rolled material on the inlet side and the outlet side detected by the speed detection roller, and the rolling roll gap of the rolling mill is controlled based on the law of constant mass flow rate to determine the thickness of the rolled sheet material. In an automatic plate thickness control method for a rolling mill, which switches between the mass flow control for controlling the rolling speed and the rolling speed, the slip between the speed detection roller and the rolled material is detected, and if the slip does not occur, the mass flow control is performed. Performs plate thickness control by control, if the predetermined amount or more of slip occurs an automatic gauge control method of a rolling mill according to the point of performing plate thickness control by the feedforward control.

[0005]

In the automatic plate thickness control method having the above structure,
In the normal case where the speed detection roller does not slip on the rolled material, the plate thickness is controlled by mass flow control.
When a slip of a predetermined amount or more occurs, the plate thickness control is performed by the feedforward control instead of the mass flow control. That is, during the normal rolling process, basically,
Plate thickness control is performed by mass flow control with excellent plate thickness accuracy.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples of embodying the present invention and are not intended to limit the technical scope of the present invention. Here, FIG. 1 is a schematic configuration diagram of a rolling system to which an automatic strip thickness control method according to an embodiment of the present invention can be applied, FIG.
3 is a flowchart showing a control procedure in the above rolling system. First, the rolling system shown in FIG. 1 will be described. Both ends of the rolled material 1 are wound around a rewind reel 2 and a take-up reel 3, and an intermediate portion thereof is rolled by a rolling roll 5 of a rolling mill 4. On the entrance side of the rolling roll 5, there are provided an entrance speed detection roller 6 for detecting the traveling speed and the plate thickness of the rolled material 1 on the entrance side, and an entrance plate thickness gauge 7 for the rolling roll 5. On the delivery side, a delivery speed detection roller 8 for detecting the traveling speed and strip thickness of the rolled material 1 on this delivery side, and a delivery side plate thickness gauge 9 are arranged.
The inlet side speed detection roller 6, the inlet side thickness gauge 7, the outlet side speed detection roller 8, and the outlet side thickness gauge 9 are connected to a control device 10. In the control device 10, the inlet side speed detection roller 6 is used. The value of the entrance-side unit plate length Li is calculated based on the detected entrance-side velocity of the rolled material 1, and the entrance-side unit plate length Li and the entrance-side plate thickness Gi detected by the entrance-side plate thickness gauge 7 are calculated. Based on this, the incoming-side rolled material volume Vi is calculated. Further, the delivery side unit plate length Lo is calculated based on the delivery side speed of the rolled material 1 detected by the delivery side speed detection roller 8, and is detected by the delivery side unit plate length Lo and the delivery side plate thickness gauge 9. Output side plate thickness G
The outgoing rolling material volume Vo is calculated based on o. Then, based on these values, mass flow type control is performed, and the rolling roll 5 is drive-controlled via the servo valve 11 and the hydraulic cylinder 12. Further, in the feedforward type control, the rolling roll 5 is drive-controlled based on the deviation of the entrance side plate thickness Gi obtained from the entrance side plate thickness gauge 7. Subsequently, the control procedure in the rolling system will be described with reference to FIGS. 1 and 2. In addition, in FIG.
S1, S2, ... Show each processing step.

First, in the course of performing the rolling process by the mass flow type control, based on the incoming speed and outgoing speed from the incoming speed detecting roller 6 and outgoing speed detecting roller 8, the incoming side of the rolled material 1 Unit plate length Li, output side unit plate length L
While the value of o is calculated (S1), the inlet side plate thickness gauge 7 and the outlet side plate thickness meter 9 are used to input the inlet plate thickness Gi and the outlet plate thickness G of the rolled material 1.
o is detected (S2). Subsequently, in S3, the slip amount S is calculated in order to determine whether or not a slip has occurred in any of the speed detection rollers 6 and 8. That is, the slip amount S is the incoming side rolled material volume Vi calculated from the incoming side unit strip length Li and the incoming side strip thickness Gi, and the outgoing side calculated from the outgoing side unit strip length Lo and the outgoing side strip thickness Go. It is obtained by comparing the rolled material volume Vo. Vi
= Vo, the situation in which no slippage has occurred in the detection rollers 6 and 8 is used, or when these values are not equal, V
The absolute value of i-Vo indicates the slip amount S described above. Then, in S4, the value of the slip amount S is compared with a preset threshold value C, and if S> C, it is determined that slip has occurred, and if S ≦, slip occurs. It is judged not to. The threshold value C is set on the basis of whether or not the slip of the speed detection roller has a bad influence in the mass flow control.
If it is determined in step S4 that no slip has occurred in any of the speed detection rollers 6 and 8, the mass flow type control excellent in control accuracy is continued (S
5), the rolling roll 5 is drive-controlled according to the amount of reduction with respect to the rolled material 1 calculated based on this control (S
6). On the other hand, if it is determined in step S4 that slip has occurred in any of the speed detection rollers 6 and 8, the control accuracy cannot be ensured by the mass flow type control. It is switched to the feedforward type (S7), and the rolling roll 5 is drive-controlled based on the calculation result (S6).
The series of processes described above is continuously performed until it is determined that the rolling process is completed (S8). As described above, in the rolling system according to the present embodiment, the control based on the mass flow method is mainly performed, so that good strip thickness accuracy can be stably obtained.

[0008]

As described above, the present invention detects the sheet thickness deviation of the rolled material to be rolled on the inlet side of the rolling mill, and controls the rolling roll gap of the rolling mill based on this inlet side sheet thickness deviation. The feed-forward control for controlling the strip thickness of the rolled material to be rolled, and the rolled material on the inlet side and the outlet side where the volume of the rolled material on the inlet side and the outlet side of the rolling mill are detected by the speed detection rollers. In the automatic strip thickness control method of the rolling mill, which is calculated from the velocity of the rolling mill, and by switching the rolling roll gap of the rolling mill based on the law of constant mass flow rate, the mass flow control for controlling the strip thickness of the rolled strip is switched The slip between the speed detection roller and the rolled material is detected, and if the slip does not occur, the plate thickness control is performed by the mass flow control. Since the feedforward control is automatic gauge control method for a rolling mill, characterized in that to perform gauge control, it is possible to obtain a good thickness accuracy in a stable manner.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a rolling system to which an automatic strip thickness control method according to an embodiment of the present invention can be applied.

FIG. 2 is a flowchart showing a control procedure in the rolling system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rolled material 4 ... Rolling machine 5 ... Rolling roll 6 ... Incoming speed detection roller 7 ... Incoming plate thickness gauge 8 ... Outgoing speed detection roller 9 ... Outgoing plate thickness gauge 10 ... Control devices S1 to S8 ... Processing steps

Claims (1)

[Claims] Claim: What is claimed is: 1. A sheet thickness deviation of a rolled material to be rolled on the inlet side of a rolling mill is detected, and a rolling roll gap of the rolling mill is controlled based on the sheet thickness deviation of the inlet side. Feed-forward control to control the strip thickness and the volume of the rolled material on the inlet and outlet sides of the rolling mill are calculated from the velocity of the rolled material on the inlet and outlet sides detected by the speed detection roller, and the mass flow rate is kept constant. In the automatic strip thickness control method for a rolling mill, which switches between the mass flow control for controlling the strip thickness of the strip to be rolled by controlling the rolling roll gap of the strip based on the law, The slip between the two is detected, and if this slip does not occur, the plate thickness is controlled by the above mass flow control.
An automatic plate thickness control method for a rolling mill, wherein the plate thickness is controlled by the feedforward control when a slip of a predetermined amount or more occurs.