JP5359388B2 - Sheet fracture determination method and apparatus, and rolling method and apparatus in hot finish rolling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device of rolling in hot finish rolling for appropriately controlling a next rolling material to enter into a finish rolling machine by correctly and quickly determining presence of plate breaking of a tail end of a rolling material. <P>SOLUTION: A shape of the tail end of the rolling material is detected in a side of the finish rolling machine, and presence of the plate breaking is determined based on the detected shape of the tail end. When presence of the plate breaking is determined, the next rolling material is prohibited from entering into the finish rolling machine, while resumption of the rolling is not performed until no plate breaking residue is confirmed, and when absence of the plate breaking is determined, the next rolling material is allowed to enter into the finish rolling machine, and the rolling is continued. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a rolling method and apparatus when a metal plate is ruptured due to drawing (meandering) or defective shape of a material to be rolled in a finish rolling mill of a hot rolling line. The metal plate referred to in the present invention is meant to include a metal strip.

  Hot rolling is generally a slab-like metal material produced by continuous casting, ingot-making, or ingoting, heated in a heating furnace to several hundred to several hundreds of degrees Celsius, and then placed on a hot rolling line. This is a series of processes in which the material is rolled and thinly wound into a coil shape by extracting and rotating the roll while sandwiching the material to be rolled with a pair or a plurality of pairs of rolls.

  FIG. 6 is a diagram showing a configuration example before and after a finish rolling mill of a commonly used hot rolling line. In the figure, 1 is a material to be rolled, 2 is a table roll, 3 is a crop shear, 4 is a finishing mill, 5 is a work roll, 6 is a backup roll, 7 is a looper, 8 is a run-out table, 9 is a cooling device, and 10 represents a coiler.

  A metal material (hereinafter referred to as a material 1 to be rolled) heated to several hundred to several hundreds of degrees Celsius by a heating furnace (not shown) and roughly rolled by a roughing mill (not shown) is a table roll 2. , Rolled to a thickness of 0.8 to 25 mm by the finishing mill 4, thinly stretched into a metal strip, cooled by the cooling device 9 on the run-out table 8, and then coiled by the coiler 10. It is wound up.

  In the case of the hot rolling line shown in FIG. 6, the number of rolling mills constituting the finish rolling mill 4 is seven of F1 to F7, but there are six. In many cases, the finishing mill 4 takes the form of a tandem rolling mill that simultaneously rolls on a plurality of rolling stands. Although there is also a term called a finishing tandem rolling mill, it is often simply referred to as a “finishing mill” for short. Each rolling stand is composed of a pair of work rolls 5 and a backup roll 6 facing each other, and a looper 7 is disposed between the rolling stands.

  The crop shear 3 cuts and removes the crop at the tail end of the material 1 to be rolled (finished portion at the tail end of the material 1 to be distorted) before the finish rolling, and smoothly engages the finish mill 4. Shape it into a generally rectangular planar shape.

  In rolling by the finish rolling mill 4, the meandering of the material 1 to be rolled often becomes a problem. That is, in any of the rolling stands upstream from the final rolling stand of the finish rolling mill 4, when the tip of the material to be rolled 1 meanders (including when it bends), the side guide installed on the entrance side of the next rolling stand This is because there is a case in which it becomes stuck to 12 and it becomes impossible to continue rolling.

  Further, when the tail end of the material 1 to be rolled meanders, as shown in FIG. 7, the tail end 11 of the material 1 to be rolled up approaches the side guide 12, and the material 1 to be rolled is folded and rolled. A phenomenon called narrowing 13 occurs, and the tail end 11 of the material 1 to be rolled may break, or the work roll 5 may be damaged and transferred to another material 1 to be rolled, resulting in a surface defect.

  At the time of passing through the tail end of difficult-to-roll materials such as thin materials, there is a problem that the trouble of the rear end breakage occurs due to drawing or shape failure. That is, when the next material collides with the fragments remaining in the rolling mill, the worst case is that it is stuck and rolling cannot be continued.

  On the other hand, as a technique for preventing meandering up to now, for example, in Patent Document 1, the shape of the longitudinal direction end of the material to be rolled to be rolled by a finish rolling mill is optically measured. The material to be rolled is detected at a plurality of positions as viewed in the conveying direction, and the difference in the lateral reduction in the subsequent rolling mill is controlled on the basis of the difference in elongation in the longitudinal direction of the material to be rolled between the plurality of positions. A method for correcting the meandering is disclosed.

  Here, the amount of reduction is generally the gap between the upper and lower work rolls 5 including the case of each rolling mill constituting the finish rolling mill 4. When control is performed so that the gap between the upper and lower work rolls 5 is different on the left and right, the difference between the left and right reduction screw equivalent positions and the left and right reduction cylinder equivalent positions is not shown. It is.

  Patent Document 1 also mentions a camera or the like used for optimal cutting control that minimizes cropping, as an optical means for detecting the shape of the longitudinal end of the material to be rolled. And the like, and the like.

  However, Patent Document 1 disclosed in Patent Document 1 described above is for preventing meandering, and cannot be dealt with once a breakage trouble has occurred. Thus, in actual operation, the operator visually monitors the presence or absence of a plate break at the tail end of the rolled material, or monitors the presence or absence of debris in the rolling mill on the mill side of the finish rolling mill.

JP-A-60-199513 Japanese Examined Patent Publication No. 63-060841

  However, in the above-described visual monitoring by the operator, the speed at the time of tail-end plate passing is high for thin materials, so the tail end shape of the end-plate member cannot be accurately grasped, and the breakage may be missed.

  In addition, the visual confirmation by the operation monitoring camera before the coiler, which has a low rolling speed, takes 10 seconds from the finish rolling mill exit side to reach the coiler. Therefore, in preparation for the occurrence of sheet breakage, the rolled material and the next material are rolled in advance. It is necessary to set the interval of the material long, and there is a problem that productivity is lowered.

The present invention has been made in view of the above circumstances, and can accurately and quickly determine the presence or absence of a plate break at the tail end of a rolled material, and can appropriately control the finishing mill entry of the next rolled material and An object is to provide an apparatus and a rolling method and apparatus in hot finish rolling.

The invention according to claim 1 of the present invention detects the tail end shape of the rolled material on the finish mill exit side,
A plate breakage determination method for automatically determining the presence or absence of a plate breakage by a plate breakage determination device based on a difference between a tail end shape expected when there is no plate breakage and a detected tail end shape. It is.

The invention according to claim 2 of the present invention uses the plate breakage determination method according to claim 1 to determine the presence or absence of plate breakage,
When it is determined that there is a sheet break, prohibiting the next rolling material from entering into the finishing mill and not resuming rolling until it is confirmed that there is no sheet break residue,
When it is determined that there is no sheet breakage, the rolling method in the hot finish rolling is characterized in that the next rolling material is allowed to enter the finishing mill and the rolling is continued .

Further, the invention according to claim 3 of the present invention is installed on the exit side of the finish rolling mill, and a tail end shape detector for detecting the tail end shape of the rolled material,
Based on the difference between the tail end shape expected when there is no plate breakage and the tail end shape detected by the tail end shape detector, a plate breakage determination device for determining the presence or absence of plate breakage,
It is a board fracture determination apparatus characterized by comprising .
The invention according to claim 4 of the present invention further includes a rolling material conveyance controller for controlling the entrance of the next rolling material into the finish rolling mill based on the determination of whether or not the plate is broken by the plate breaking determination device according to claim 3. A rolling apparatus in hot finish rolling.

  According to the present invention, since it is possible to accurately grasp the presence or absence of a plate break at the tail end of the rolled material, it is possible to prevent operational troubles such as bumping.

  In addition, since the presence or absence of sheet fracture can be determined simultaneously with the passage of the rolled material, it is not necessary to set a long interval between the rolled material and the next rolled material in advance, and productivity can be improved.

It is a figure which shows the apparatus structural example of this invention. It is a figure which shows the example of a process sequence of tail end fracture presence-absence determination. It is a figure which shows the tail end shape anticipated. It is a figure which shows an example of the basic shape of a tail end shape. It is a figure which shows typically the difference of prediction and measurement of a tail end shape, and difference area calculation. It is a figure which shows the structural example before and behind the finishing mill of the hot rolling line generally used. It is a figure which shows the narrowing-down phenomenon which is one of the subjects.

  Hereinafter, the present invention will be specifically described with reference to the drawings and mathematical expressions. FIG. 1 is a diagram showing an apparatus configuration example of the present invention. In the figure, 21 represents a tail end shape detector, 22 represents a tail end shape indicator, 23 represents a breakage determination device, and 24 represents a rolled material conveyance controller. Other symbols are the same as those in FIG.

  A tail end shape detector 21 for detecting the tail end shape of the material 1 to be rolled is installed on the exit side of the finish rolling mill 4. This tail end shape detector 21 has a method of detecting by a linear array by applying a backlight to a rolled material as described in Patent Document 2, for example. Any type of detector such as a method using light emission or a method using a two-dimensional camera instead of a linear array may be used.

  The tail end shape image at the time of passing the tail end of the material to be rolled 1 is sent from the tail end shape detector 21 to the tail end shape display 22 and displayed.

  There are two methods for determining the presence or absence of tail end breakage: a method in which the operator determines from the displayed image, or a method in which the breakage determination unit 23 automatically determines.

  The latter method of automatic determination is a method of comparing the expected tail end shape with the actual tail end shape and determining the presence or absence of the plate breakage from the difference, which will be described below. FIG. 2 is a diagram illustrating an example of a processing procedure for determining whether there is a tail end fracture.

  First, the expected tail end shape is calculated (Step 01). The expected tail shape refers to the shape of the tail that is expected when there is no break at the tail (see FIG. 3). In addition, as a method for calculating the expected tail end shape, for example, several basic shapes are prepared from past results, and a linear transformation (long) is performed so that a shape having a high correlation with the results matches the actual value. However, the present invention is not limited to this.

  FIG. 4 is a diagram illustrating an example of the basic shape of the tail end shape. Thus, it is good to register the tail end shape in several hot rollings, such as a tongue shape and a fish shape, as a basic shape. A tail end shape meter may be installed on the intermediate stand (for example, the F4 stand exit side where the frequency of occurrence of plate breakage is low), and the tail end shape detected in the intermediate stand may be used as the basic shape. .

  Next, a difference calculation in the plate width direction between the prediction and actual measurement of the tail end shape is performed (Step 02). The difference between the above-described expected tail shape and the tail shape measured by the tail shape detector is calculated. Then, based on the obtained difference value, the difference of half the width from the center in the plate width direction is integrated to calculate the area of the difference (Step 03).

  FIG. 5 is a diagram schematically illustrating the difference between the prediction and actual measurement of the tail end shape and the difference area calculation. The difference area calculated here corresponds to the area of plate breakage. The difference areas (S · Dr and S · Op) on the drive (Dr) side and the operation (Op) side are calculated by the following equations (1) and (2).

S · Dr = ∫ (forecast-actual measurement) d (Dr plate width direction) (1)
S · Op = ∫ (forecast-actual measurement) d (Op plate width direction) (2)
Then, it is determined whether or not the difference area exceeds a predetermined value determined in advance through experimentation or experience (Step 04). If Yes in Step 04, it is determined that there is a plate tail end break (Step 05), and if No, it is determined that there is no plate tail end break (Step 06). Above, description of the process sequence of FIG. 2 is complete | finished.

  Next, the description returns to FIG. The rolling material conveyance controller 24 controls each conveyance device of the hot rolling line based on the above-described determination of the presence or absence of the tail end breakage in the breakage determination unit 23. That is, when the determination that there is a break is transmitted, the entry of the next material into the finishing mill is prohibited, and an alarm is output to the operator that the plate is broken. On the other hand, if the determination that there is no break is transmitted, the next material is allowed to enter the finish rolling mill and the finish rolling operation is continued without interruption.

  If entry of the next material into the finishing mill is prohibited, immediately after taking necessary measures such as removing the residue, the operator must finally confirm that there is no residue in the finishing mill. Allow entry of the material into the finishing mill.

  A high-strength material of 1.2 mm thickness x 1000 mm width was difficult to roll, and a plate with a fear of drawing occurred in the finishing mill F6 stand. Until now, after the tail end of the rolled material has passed through the exit side of the finishing mill, after 10 seconds, the operation monitoring camera installed in front of the finishing coiler is visually checked for the presence or absence of plate breakage at the tail end, and then the next material is finished. It had entered the rolling mill.

  By applying the present invention, after the rolling material tail end passes through the finish rolling mill exit side, the tail end shape detector installed on the finishing rolling mill exit side can immediately determine whether the material tail end is broken or not. Therefore, the waiting time of the above 10 and several seconds is unnecessary, and the next material can enter the finishing mill.

  As a result, the rolling interval can be shortened, and the production efficiency of difficult-to-roll materials represented by thin materials has been improved.

DESCRIPTION OF SYMBOLS 1 Rolled material 2 Table roll 3 Crop shear 4 Finishing mill 5 Work roll 6 Backup roll 7 Looper 8 Runout table 9 Cooling device 10 Coiler 11 Tail end 12 Side guide 13 Narrowing down 21 Tail end shape detector 22 Tail end shape indicator 23 Break determination device 24 Rolled material conveyance controller

Claims (4)

Detecting the tail end shape of the rolled material on the finish mill exit side,
A plate breakage determination method for automatically determining the presence or absence of a plate breakage by a plate breakage determination device based on a difference between a tail end shape expected when there is no plate breakage and a detected tail end shape. . Using the plate breakage determination method according to claim 1, the presence or absence of plate breakage is determined,
When it is determined that there is a sheet break, prohibiting the next rolling material from entering into the finishing mill and not resuming rolling until it is confirmed that there is no sheet break residue,
A rolling method in hot finish rolling, characterized in that, when it is determined that there is no sheet breakage, the rolling of the next rolled material is allowed to enter the finishing mill and the rolling is continued. A tail end shape detector that is installed on the exit side of the finish rolling mill and detects the tail end shape of the rolled material,
Based on the difference between the tail end shape expected when there is no plate breakage and the tail end shape detected by the tail end shape detector, a plate breakage determination device for determining the presence or absence of plate breakage,
A plate breakage determination device comprising: Rolling in hot finish rolling, characterized by comprising a rolled material conveyance controller for controlling the entry of the next rolled material into the finishing mill based on the determination of whether or not the plate is broken by the plate breakage determination device according to claim 3. apparatus.