JP2024106100A - Method for controlling the stop position of the tail end of a hot rolled steel strip, device for controlling the stop position of the tail end of a hot rolled steel strip, and thin coil - Google Patents

Abstract

[Problem] To provide a method for controlling the stop position of the tail end of a hot rolled steel strip, which can improve the accuracy of distance tracking for stopping the tail end of a hot rolled steel strip constituting a thin coil at a target position. [Solution] The method includes a first step of detecting the position of the central recess of the tail end of the rough hot rolled steel strip and the positions of the first cut tail end and second cut tail end of the rough hot rolled steel strip after cropping using a two-dimensional shape meter, a second step of detecting the position of the first tail end on the pinch roll exit side of the finished hot rolled steel strip output from the pinch roll exit side using a first laser meter and detecting the position of the second tail end on the pinch roll exit side using a second laser meter, a third step of calculating a tail end correction amount for correcting the position of the tail end of the finished hot rolled steel strip, and a fourth step of controlling the stop position of the tail end of the finished hot rolled steel strip based on the tail end correction amount. [Selected Figure] Figure 4

Description

The present invention relates to a method for controlling the stopping position of the tail end of a hot-rolled steel strip, a device for controlling the stopping position of the tail end of a hot-rolled steel strip, and a thin coil.

The finished hot rolled steel strip produced by continuous hot rolling of steel plate is wound into a coil. The finished hot rolled steel strip wound into a coil becomes a thin coil. When manufacturing a thin coil by winding the finished hot rolled steel strip into a coil, it is necessary to control the tail end of the finished hot rolled steel strip so that it stops at a specified position when winding of the finished hot rolled steel strip is completed.

Figure 6 is a schematic diagram showing an overview of a conventional method of winding a finished hot rolled steel strip into a coil to produce a thin plate coil. As shown in Figure 6(a), the winding section of a continuous hot rolling mill winds the finished hot rolled steel strip as a hot rolled steel strip sent out from the pinch rolls around a mandrel to produce a thin plate coil. When winding of the finished hot rolled steel strip is completed, position control is performed so that the tail end of the finished hot rolled steel strip stops at a fixed position. As shown in Figure 6(b), the content of the stop position control of the tail end of the finished hot rolled steel strip is that after the computer recognizes the time when the tail end of the finished hot rolled steel strip passes through the in-machine laser sensor installed on the exit side of the pinch roll, the rotation speed of the mandrel motor is controlled from that time. Then, as shown in Figure 6(c), the mandrel and the thin plate coil are rotated together on the cradle roll until the tail end of the finished hot rolled steel strip is positioned at a fixed position when the thin plate coil is pulled out from the mandrel.

However, if control of the stopping position of the tail end of the finishing hot rolled steel strip is not performed, the stopping position of the tail end of the finishing hot rolled steel strip on the outer circumference of the thin coil will not be aligned for each thin coil. If it is desired to extract the thin coil from the mandrel of the coiler as is and transport it to the coil yard, the tail end of the finishing hot rolled steel strip that constitutes the thin coil will come into contact with other equipment or other thin coils during transport. As a result, if position control of the tail end of the finishing hot rolled steel strip is not performed, damage to other equipment and other thin coils will occur. For this reason, in order to control the stopping position of the tail end of the finishing hot rolled steel strip, manual intervention by the coiler operator is required from the time when the thin coil finishes winding to the time when it starts to be extracted from the coiler mandrel, which increases the workload.

From this perspective, a method has been disclosed for accurately detecting the tail end of a rolled material even if the tail end shape of the rolled material being wound around the winding machine of the rolling equipment is irregular (for example, Patent Document 1). The method for detecting the tail end of a rolled material described in Patent Document 1 arranges thermal lump detectors in the center of the conveying path and on both sides of the center, in line in the width direction of the rolled material being wound around the winding machine of the rolling equipment, and detects the tail end position of the rolled material based on the timing at which all thermal lump detectors go from on to off while the rolled material is being conveyed.

A method for controlling the winding of a hot rolled steel strip has also been proposed that can perform highly accurate fixed-position stopping control of the tail end (for example, see Patent Document 2). The method for controlling the winding of a hot rolled steel strip described in Patent Document 2 compares the tail end position in the width direction in the two-dimensional shape of the tail end of the roughly rolled steel strip output by the crop shape meter of the hot strip mill with the crop cut position, and when the tail end position in the width direction center is closer to the front end of the rough rolled steel strip than the crop cut position, corrects the tail end position in the width direction center detected by the in-machine laser sensor on the pinch roll exit side of the hot strip mill to a position behind that position.

Japanese Patent Application Publication No. 11-254034 JP 2013-94798 A

However, the above-mentioned conventional technology still has the following problems to be solved. That is, the method of detecting the tail end of the rolled material described in Patent Document 1 detects the tail end position of the rolled material using a thermal mass detector that is placed on the conveying path of the rolled material, before the position where the winder of the rolling equipment is installed, and controls the tail end position of the rolled material using the detected tail end position as the starting point.

For this reason, the method of detecting the tail end of the rolled material described in Patent Document 1 cannot detect the tail end of the rolled material while taking into account errors caused by changes in the shape of the rolled material after finish rolling by the finishing rolling mill, changes in the shape of the rolled material due to cooling the rolled material after finish rolling, and the amount of steel plate deflection that occurs on the hot run table. As a result, the method of detecting the tail end of the rolled material described in Patent Document 1 has the problem of a deterioration in the accuracy of distance tracking for stopping the tail end of the rolled material at the target position.

In addition, the hot rolled steel strip winding control method described in Patent Document 2 corrects the tail end position to a position rearward of the widthwise center detected by the on-board laser sensor on the exit side of the pinch rolls of the hot strip mill when the tail end position at the widthwise center in the two-dimensional shape of the tail end of the roughly rolled steel strip is closer to the front end of the roughly rolled steel strip than the crop cut position.

That is, the hot rolled steel strip winding control method described in Patent Document 2 controls the tail end position of the hot rolled steel strip using the tail end position of the hot rolled steel strip measured by a sensor placed at the center of the steel sheet as the starting point. Therefore, if the shape of the tail end of the hot rolled steel strip is irregular and the hot rolled steel strip is shifted in the width direction, the correct center of the steel sheet cannot be used as the starting point for controlling the tail end position of the hot rolled steel strip. Therefore, this hot rolled steel strip winding control method has a problem that the tail end position of the hot rolled steel strip corrected using the tail end position of the hot rolled steel strip measured by a sensor placed at the center of the steel sheet as the starting point does not match the tail end position of the finished hot rolled steel strip on the outer periphery of the thin coil after the finished hot rolled steel strip is wound around a mandrel to form a thin coil.

The present invention has been made in consideration of the above circumstances, and aims to provide a method for controlling the stopping position of the tail end of a hot rolled steel strip, a device for controlling the stopping position of the tail end of a hot rolled steel strip, and a thin coil, which can reduce the risk of the tail end of the hot rolled steel strip interfering with other equipment when the thin coil is pulled out of the mandrel by improving the accuracy of distance tracking to stop the tail end of the hot rolled steel strip that constitutes the thin coil at a target position.

The inventors conducted various experiments to solve the above problem, and discovered that it is possible to control the position of the tail end of the hot rolled steel strip by calculating a tail correction amount for correcting the position of the tail end of the finished hot rolled steel strip, taking into account the error caused by the shape change of the tail end of the hot rolled steel strip and the amount of steel sheet deflection on the hot run table, using the tail end of the rough hot rolled steel strip as the starting point. The present invention was made based on the above knowledge, and its gist is as follows.

That is, the method for controlling the stop position of the tail end of a hot rolled steel strip according to the present invention, which advantageously solves the above problems, comprises:
A method for controlling a stop position of a tail end of a finished hot rolled steel strip when the finished hot rolled steel strip is wound by a winding section having a mandrel to form a thin coil, comprising the steps of:
a first step of detecting a two-dimensional shape of a tail end of a rough hot rolled steel strip that has been roughly rolled, and detecting the position of a central concave portion of the tail end of the rough hot rolled steel strip and the position of a first cut tail end portion and a second cut tail end portion of the rough hot rolled steel strip after cropping, the first cut tail end portion and the second cut tail end portion being formed by cropping convex portions formed adjacent to the left and right of the central concave portion;
a second step of detecting, by a first laser meter, a position of a first tail end portion on the pinch roll exit side corresponding to the first cut tail end portion of the finished hot rolled steel strip output from the pinch roll exit side after the rough hot rolled steel strip after the crop cut is finish-rolled to form the finished hot rolled steel strip and then fed to the pinch roll; and detecting, by a second laser meter, a position of a second tail end portion on the pinch roll exit side corresponding to the second cut tail end portion of the finished hot rolled steel strip output from the pinch roll exit side.
A third step of calculating a tail correction amount for correcting the position of the tail of the finish hot rolled steel strip based on a first detection position of a first tail end portion on the exit side of the pinch roll by the first laser meter and a laser detection difference distance formed between the first detection position and a second detection position of a second tail end portion on the exit side of the pinch roll by the second laser meter;
and a fourth step of controlling a stop position of the tail end of the finish hot rolled steel strip based on the tail end correction amount.

In addition, it is considered that a more preferable solution for the method of controlling the stopping position of the tail end of a hot rolled steel strip according to the present invention is (a) to detect the position of the first tail end on the exit side of the pinch roll corresponding to the first cut tail end of the finished hot rolled steel strip and the position of the second tail end on the exit side of the pinch roll corresponding to the second cut tail end using an area sensor that can measure the width direction of the finished hot rolled steel strip.

The present invention provides a stop position control device for the tail end of a hot rolled steel strip, which advantageously solves the above problems, comprising:
A control device for controlling a stop position of a tail end of a finished hot rolled steel strip when the finished hot rolled steel strip is wound by a winding section having a mandrel to form a thin coil, comprising:
a first detection unit that detects a two-dimensional shape of the tail end of the rough hot rolled steel strip that has been roughly rolled, and detects the position of a central concave portion of the tail end of the rough hot rolled steel strip and the position of a first cut tail end portion and a second cut tail end portion of the rough hot rolled steel strip after cropping, the first cut tail end portion and the second cut tail end portion being formed by cropping the convex portions formed adjacent to the left and right of the central concave portion;
a second detection unit which detects, by a first laser meter, a position of a first tail end portion on the pinch roll outlet side corresponding to the first cut tail end portion of the finished hot rolled steel strip output from the pinch roll outlet side after the rough hot rolled steel strip after the crop cut is finish-rolled to form the finished hot rolled steel strip and then sent to the pinch rolls, and detects, by a second laser meter, a position of a second tail end portion on the pinch roll outlet side corresponding to the second cut tail end portion of the finished hot rolled steel strip output from the pinch roll outlet side;
a third detection unit that calculates a tail correction amount for correcting the position of the tail of the finish hot rolled steel strip based on a first detection position of the first tail end portion on the pinch roll exit side by the first laser meter and a laser detection difference distance formed between the first detection position and a second detection position of the second tail end portion on the pinch roll exit side by the second laser meter;
a position control unit that controls the stop position of the tail end of the finish hot rolled steel strip based on the tail end correction amount.

The thin coil of the present invention, which advantageously solves the above problem, is characterized in that it is manufactured using the above-mentioned device for controlling the stopping position of the tail end of the hot-rolled steel strip.

According to the present invention, even if the shape of the tail end of the hot rolled steel strip is irregular and shifted in the width direction of the hot rolled steel strip, the risk of the tail end of the hot rolled steel strip interfering with other equipment when the thin coil is removed from the mandrel can be reduced.

1 is a schematic diagram showing a thin coil production line for implementing a method for controlling the stopping position of the tail end of a hot-rolled steel strip according to the present invention. FIG. FIG. 1 is a schematic diagram showing the coordinates of the tail end of a hot rolled steel strip wound by the method for controlling the stop position of the tail end of the hot rolled steel strip according to the present invention, measured by a two-dimensional shape meter. FIG. 2 is a schematic diagram showing the coordinates of the tail end of a hot rolled steel strip wound by the method for controlling the stop position of the tail end of the hot rolled steel strip according to the present invention, measured by a laser meter. FIG. 1 is an explanatory diagram showing a relationship between the tail end coordinates measured by a laser meter at the winding tail end of a hot rolled steel strip wound by the method for controlling the stop position of the tail end of a hot rolled steel strip according to the present invention and the correction amount of the tail end position of the hot rolled steel strip calculated from the tail end coordinates. 1 is a graph showing the results of a simulation of control of the tail end of a finish hot rolled steel strip obtained in Example 1. FIG. 1 is a schematic diagram showing a conventional method for controlling the fixed position stopping of the tail end of a finish rolled steel strip.

[First embodiment]
A method for controlling the stopping position of the tail end of a hot rolled steel strip according to the first embodiment will be described.
The method for controlling the stop position of the tail end of a hot rolled steel strip according to the present embodiment includes a first step of detecting a two-dimensional shape of the tail end of a rough hot rolled steel strip that has been rough rolled, and detecting the position of a central concave portion of the tail end of the rough hot rolled steel strip and the position of a first cut tail end portion and a second cut tail end portion of the rough hot rolled steel strip after cropping, the first cut tail end portion and the second cut tail end portion being formed by cropping the rough hot rolled steel strip after the cropping is finished rolled, the finished hot rolled steel strip is formed, and the finished hot rolled steel strip is sent out to a pinch roll, and then the finished hot rolled steel strip is output from the outlet side of the pinch roll. a second step of detecting a position of a first tail end portion on the exit side of the pinch roll corresponding to the second cut tail end portion by a first laser meter and detecting a position of a second tail end portion on the exit side of the pinch roll corresponding to the second cut tail end by a second laser meter; a third step of calculating a tail end correction amount for correcting the position of the tail end of the finished hot rolled steel strip based on a first detection position of the first tail end portion on the exit side of the pinch roll by the first laser meter and a laser detection difference distance formed between the first detection position and a second detection position of the second tail end portion on the exit side of the pinch roll by the second laser meter; and a fourth step of controlling a stop position of the tail end of the finished hot rolled steel strip based on the tail end correction amount.
Hereinafter, each step included in the method for controlling the stopping position of the tail end of a hot rolled steel strip according to this embodiment will be described with reference to the drawings.

<About the first process>
The method for controlling the stopping position of the tail end of a hot rolled steel strip in this embodiment includes a step of detecting the two-dimensional shape of the rough rolled rough hot rolled steel strip, and detecting the position of the central concave portion of the tail end of the rough hot rolled steel strip and the position of the first cut tail end and the position of the second cut tail end of the rough hot rolled steel strip after cropping, which are formed by cropping the convex portions formed adjacent to the left and right of the central concave portion of the tail end, using a two-dimensional shape meter.
That is, the first step included in the method for controlling the stopping position of the tail end of a hot rolled steel strip in this embodiment is a step of detecting, using a two-dimensional shape meter, the position of the central concave portion of the tail end of the rough hot rolled steel strip and the position of the first cut tail end and the position of the second cut tail end of the rough hot rolled steel strip after cropping, which are formed by cropping the convex portions formed adjacent to the left and right of the central concave portion of the tail end.

Figure 1 is a schematic diagram showing a thin coil production line for implementing the tail end stop position control method of the present invention. As shown in Figure 1, the thin coil production line 100 for implementing the tail end stop position control method of the hot rolled steel strip is equipped with a roughing mill 101, a two-dimensional shape measuring device 102, a crop shear 103, a finishing mill 104, a pinch roll (PR inside the winder) 105, a laser meter 106, a tail end stop controller 107, a hot run table 108, a mandrel 109, and a mandrel drive unit M.

The slab used as the rolling material for the rough hot rolled steel strip is transported to the rough rolling mill 101, and is rough rolled by the rough rolling mill 101 to be processed into the rough hot rolled steel strip 200. The shape of the rough hot rolled steel strip 200 is detected by the two-dimensional shape measuring device 102. The two-dimensional shape measuring device 102 detects the two-dimensional shape of the rough hot rolled steel strip 200, and detects the position of the tail end central recess 201 of the rough hot rolled steel strip 200.

FIG. 2 is a schematic diagram showing the tail end coordinates measured by a two-dimensional shape measuring device of the winding tail end of the hot rolled steel strip according to the method for controlling the tail end stop position of the hot rolled steel strip according to the present invention. Specifically, FIG. 2(a) is a schematic diagram showing the position of the tail end central recess of the rough hot rolled steel strip. As shown in FIG. 2(a), the position of the tail end central recess 201 of the rough hot rolled steel strip 200 can be specified using two-dimensional coordinates (x, y). The position of the tail end central recess 201 of the rough hot rolled steel strip 200 is set as P ₀ (0, 0). After that, the rough hot rolled steel strip 200 is transported to the crop shear 103.

Figure 2 (b) is a schematic diagram showing an outline of the rough hot rolled steel strip after the convex parts formed adjacent to the left and right of the tail end central concave part of the rough hot rolled steel strip are cropped. As shown in Figure 2 (b), the left convex part 202 and the right convex part 203, which are convex parts formed adjacent to the left and right of the tail end central concave part 201 of the rough hot rolled steel strip 200, are cropped by the crop shear 103. After the left convex part 202 and the right convex part 203 are cropped, the rough hot rolled steel strip 204 has a first cut tail end part 205 located on the left side of the tail end central concave part 201 and adjacent to the left and right of the tail end central concave part 201, and a second cut tail end part 206 located on the right side of the tail end central concave part 201.

The cut of the rough hot rolled steel strip 200 by the crop shear 103 is performed so as to be parallel to the width direction of the rough hot rolled steel strip 200. Therefore, the first cut tail end 205 located to the left of the tail end central recess 201 and the second cut tail end 206 located to the right of the tail end central recess 201 are positioned opposite each other.

The two-dimensional shape measuring device 102 detects the two-dimensional shape of the rough hot rolled steel strip 200 before being cropped, and detects the first cut tail end 205 and the second cut tail end 206 of the rough hot rolled steel strip 204 after being cropped. For this reason, the two-dimensional shape measuring device 102 is preferably installed in front of and behind the crop shear 103 in order to measure the two-dimensional shape of the rough hot rolled steel strip 200 before being cropped and the two-dimensional shape of the rough hot rolled steel strip 204 after being cropped. In addition, the two-dimensional shape measuring device 102 may be installed either in front of or behind the crop shear 103 in order to measure the two-dimensional shape of either the rough hot rolled steel strip 200 before being cropped and the rough hot rolled steel strip 204 after being cropped.
Here, the position of the first cut tail end 205 and the position of the second cut tail end 206 of the rough hot rolled steel strip 204 after the crop cut can be specified using two-dimensional coordinates (x, y). The position of the first cut tail end 205 of the rough hot rolled steel strip 204 after the crop cut can be defined as Pcs1 (x1, ycs1), and the position of the first cut tail end 206 can be defined as Pcs2 (x2, ycs2).

Thus, the first step included in the method for controlling the stopping position of the tail end of a hot rolled steel strip according to this embodiment is to identify the position of the tail end central recess 201 of the rough hot rolled steel strip 200, and the position of the first cut tail end 205 and the position of the second cut tail end 206 of the rough hot rolled steel strip 204 after cropping, using two-dimensional coordinates.

<About the second process>
The method for controlling the stopping position of the tail end of a hot rolled steel strip in this embodiment includes a step of detecting, using a first laser meter, the position of a first tail end on the pinch roll exit side corresponding to the first cut tail end of the finished hot rolled steel strip that is output from the exit side of the pinch roll after the rough hot rolled steel strip after the crop cut is finish rolled to form a finished hot rolled steel strip and then sent to a pinch roll, and detecting, using a second laser meter, the position of a second tail end on the pinch roll exit side corresponding to the second cut tail end.
That is, the second step included in the method for controlling the stopping position of the tail end of a hot rolled steel strip in this embodiment is a step of detecting the position of the first tail end portion on the pinch roll outlet side and the position of the second tail end portion on the pinch roll outlet side of the finished hot rolled steel strip output from the outlet side of the pinch roll after the rough hot rolled steel strip after crop cutting is finish rolled and transported to the pinch rolls using a laser meter.

The rough hot rolled steel strip 204 after being cropped is transported to the finishing rolling mill 104 and finish rolled. The rough hot rolled steel strip 204 after being cropped is finish rolled to form a finish hot rolled steel strip 300. The finish hot rolled steel strip 300 is then transported to the pinch rolls 105. The finish hot rolled steel strip 300 transported to the pinch rolls 105 is rolled in the longitudinal direction of the finish hot rolled steel strip 300 by finish rolling. The finish hot rolled steel strip 300 transported to the pinch rolls 105 is then output from the outlet side of the pinch rolls 105 in the winding machine.

Figure 2(c) is a schematic diagram showing an overview of the finished hot rolled steel strip transported to the pinch roll. As shown in Figure 2(c), the finished hot rolled steel strip 300 output from the outlet side of the pinch roll 105 retains the tail end central recess 201 of the rough hot rolled steel strip 200 as the tail end central recess 301. In other words, the position of the tail end central recess 301 of the finished hot rolled steel strip 300 output from the outlet side of the pinch roll 105 coincides with the position of the tail end central recess 201 of the rough hot rolled steel strip 200.

The finished hot rolled steel strip 300 output from the exit side of the pinch roll 105 has a pinch roll exit side first tail end 302 corresponding to the first cut tail end 205 of the rough hot rolled steel strip 204 after being cropped, and a pinch roll exit side second tail end 303 corresponding to the second cut tail end 206 of the rough hot rolled steel strip 204. The pinch roll exit side first tail end 302 and the pinch roll exit side second tail end 303 are positioned opposite each other.

Here, the position of the first tail end 302 on the pinch roll exit side and the position of the second tail end 303 on the pinch roll exit side can be identified using two-dimensional coordinates (x, y). The position of the first tail end 302 on the pinch roll exit side can be identified as P1 (x1, y1), and the position of the second tail end 303 on the pinch roll exit side can be identified as P2 (x1, y2).

The relationship between the longitudinal coordinate y1 of the finished hot rolled steel strip 300 at position P1 of the first tail end 302 on the pinch roll exit side and the longitudinal coordinate ycs1 of the rough hot rolled steel strip 204 at position Pcs of the first cut tail end 205 of the rough hot rolled steel strip 204 after cropping can be calculated by the following formula (1), taking into account the reduction rate in the longitudinal finish rolling of the thin coil.

In relational formula (1),
y1: coordinate in the longitudinal direction of the finished hot rolled steel strip 300 at the position P1 of the first tail end portion 302 on the pinch roll exit side;
ycs1: the longitudinal coordinate of the first cut tail end 205 of the rough hot rolled steel strip 204 after being cropped;
R _in : the thickness of the finished hot rolled steel strip 300 before entering the pinch roll 105 in the winder,
R _out : indicates the thickness of the finished hot rolled steel strip 300 output from the pinch rolls 105 in the winder.
Here, (R _out /R _in ) is the reduction ratio of the finish hot rolled steel strip 300 .

Similarly, the relationship between the longitudinal coordinate y2 of the finished hot rolled steel strip 300 at position P2 of the second tail end 303 on the pinch roll exit side and the longitudinal coordinate ycs2 of the rough hot rolled steel strip 204 at position Pcs of the second cut tail end 206 of the rough hot rolled steel strip 204 after cropping can be calculated by the following formula (2), taking into account the reduction rate in the longitudinal finish rolling of the thin coil.

In relational expression (2),
y2: coordinate in the longitudinal direction of the finished hot rolled steel strip 300 at the position P2 of the second tail end portion 303 on the pinch roll exit side;
ycs2: the longitudinal coordinate of the second cut tail end 206 of the rough hot rolled steel strip 204 after being cropped;
R _in : the thickness of the finished hot rolled steel strip 300 before entering the pinch roll 105 in the winder,
R _out : indicates the thickness of the finished hot rolled steel strip 300 output from the pinch rolls 105 in the winder.

Thus, the second step included in the method for controlling the stopping position of the tail end of a hot rolled steel strip according to this embodiment is to detect the position of the first tail end 302 on the pinch roll exit side of the pinch roll 105 of the finished hot rolled steel strip 300 output from the exit side of the pinch roll 105 using a first laser meter 161, and to detect the position of the second tail end 303 on the pinch roll exit side of the pinch roll 105 using a second laser meter 162.

<About the third process>
The method for controlling the stopping position of the tail end of a hot rolled steel strip in this embodiment includes a step of calculating a tail end correction amount for correcting the position of the tail end of the finished hot rolled steel strip based on the position of the first tail end portion on the exit side of the pinch roll, the position of the second tail end portion on the exit side of the pinch roll, the first laser detection position by the first laser meter, the second laser detection position by the second laser meter, and the laser detection difference distance formed between the first laser detection position and the second laser detection position.
That is, the third step included in the method for controlling the stop position of the tail end of the hot rolled steel strip according to this embodiment is to calculate a tail end correction amount for correcting the position of the tail end of the finished hot rolled steel strip based on the first laser detection position by the first laser, the second laser detection position by the second laser, and the laser detection difference distance formed between the first laser detection position and the second laser detection position.

Figure 3 is a schematic diagram showing the tail end coordinates measured by a laser meter at the winding tail end of a hot rolled steel strip wound by the tail end stop position control method of the present embodiment. Specifically, Figure 3 shows the relationship between the first laser detection position Q1 by the first laser meter 161, the second laser detection position Q2 by the second laser meter 162, the laser distance α formed between the first laser meter 161 and the second laser meter 162, and the laser detection difference distance β formed between the first laser detection position Q1 and the second laser detection position Q2 when the laser meter 106 is composed of the first laser meter 161 and the second laser meter 162.

As shown in FIG. 3, the position of the pinch roll exit side first tail end 302 and the position of the pinch roll exit side second tail end 303 of the finished hot rolled steel strip 300 output from the exit side of the pinch roll 105 are detected by a laser meter 106 installed between the exit side of the pinch roll 105 and the mandrel 109. Two or more laser meters 106 must be installed. The laser meter 106 may be composed of, for example, a first laser meter 161 and a second laser meter 162 installed in front of and behind the conveying direction of the finished hot rolled steel strip 300.

The first laser meter 161 and the second laser meter 162 are installed with the equipment center line 181 of the hot run table 108 as their center line, spaced apart by the laser distance α. The distance between the first laser meter 161 and the equipment center line 181 of the hot run table 108 is 1/2 the laser distance α (α/2). The distance between the second laser meter 162 and the equipment center line 181 of the hot run table 108 is 1/2 the laser distance α (α/2).

The laser detection difference distance β formed between the first laser detection position Q1 and the second laser detection position Q2 is expressed by the following relational expression (3), focusing on the relationship between the speed V _coil at which the finished hot rolled steel strip 300 is wound around the mandrel 109 and the time difference ΔT between the time when the tail end of the finished hot rolled steel strip 300 passes the first laser detection position Q1 and the time when the tail end of the finished hot rolled steel strip 300 passes the second laser detection position Q2.

Figure 4 is an explanatory diagram showing the relationship between the tail end coordinates measured by a laser meter of the winding tail end of a hot rolled steel strip wound by the tail end stop position control method of the present embodiment and the tail end position correction amount of the hot rolled steel strip calculated from the tail end coordinates. Specifically, Figure 4(a) is an explanatory diagram showing the relationship between the first laser detection position Q1, the second laser detection position Q2, the laser distance α, and the laser detection difference distance β. Figure 4(b) is an explanatory diagram for explaining the tail end correction amount Y for correcting the position of the tail end of the finished hot rolled steel strip, assuming the relationship between the first laser detection position Q1, the second laser detection position Q2, the laser distance α, and the laser detection difference distance β.

As shown in Figures 4(a) and (b), the first laser detection position Q1 is located on a straight line connecting the tail end central recess 301 and the first tail end 302 on the pinch roll exit side. The second laser detection position Q2 is located on a straight line connecting the tail end central recess 301 and the second tail end 303 on the pinch roll exit side.

When the position of the first laser detection position Q1 is specified by two-dimensional coordinates (s, t), considering the relationship between the laser distance α and the laser detection difference distance β shown in FIG. 4(a), the position of the second laser detection position Q2 can be specified as two-dimensional coordinates (s+α, t+β). The relationship expressed by the following relational expressions (4) and (5) holds between the position P1 (x1, y1) of the first tail end 302 on the exit side of the pinch roll, the position P2 (x1, y2) of the second tail end 303 on the exit side of the pinch roll, the laser distance α, and the laser detection difference distance β.

The longitudinal coordinate t of the tail end of the finished hot rolled steel strip 300 at the two-dimensional coordinates (s, t) that identify the position of the first laser detection position Q1 using the above relationship equations (4) and (5) is calculated using the following relationship equation (6).

Based on the relationship between the longitudinal coordinate t of the tail end of the finished hot rolled steel strip 300 at the two-dimensional coordinates (s, t) which identify the position of the first laser detection position Q1 calculated in this manner, the longitudinal coordinate y1 of the tail end of the finished hot rolled steel strip 300 at P1 (x1, y1) which identifies the position of the first tail end portion 302 on the pinch roll exit side, and the longitudinal coordinate y2 of the tail end of the finished hot rolled steel strip 300 at P2 (x2, y2) which identifies the position of the second tail end portion 303 on the pinch roll exit side, and the laser detection difference distance β, the tail end correction amount Y for correcting the position of the tail end of the finished hot rolled steel strip can be calculated as follows.
Similarly, the two-dimensional coordinates (s+α, t+β) which are the position of the second laser detection position Q2 can be specified based on the two-dimensional coordinates (s, t) which specify the position of the first laser detection position Q1. That is, in the third step, the tail end correction amount Y is determined based on the magnitude relationship between the position of the tail end central recess 201 and the sum of the tail end central recess 201 and the laser detection difference distance β, in accordance with the positional relationship between the position of the pinch roll exit side first tail end portion 302 and the position of the pinch roll exit side second tail end portion 303. Specifically, the tail end correction amount Y is calculated as follows according to conditions A to D.

In this way, the third step included in the method for controlling the stopping position of the tail end of a hot rolled steel strip according to this embodiment calculates a tail end correction amount Y for correcting the position of the tail end of the finished hot rolled steel strip in accordance with conditions A to D, based on the relationship between the longitudinal coordinate t of the tail end of the finished hot rolled steel strip 300, the longitudinal coordinates y1, y2 of the tail end of the finished hot rolled steel strip 300, and the laser detection difference distance β. In other words, the tail end correction amount Y is determined based on the magnitude relationship between the position of the tail end central recess 301 and the sum of the tail end central recess 301 and the laser detection difference distance β, in accordance with the positional relationship between the position of the pinch roll exit first tail end 302 and the position of the pinch roll exit second tail end 303.

<About the fourth step>
The method for controlling the stop position of the tail end of a hot rolled steel strip according to this embodiment includes a step of controlling the stop position of the tail end of the finish hot rolled steel strip based on the tail end correction amount.
That is, the fourth step included in the method for controlling the stopping position of the tail end of a hot rolled steel strip in this embodiment is to send the value of the tail end correction amount Y obtained in the third step as a pulse wave to the tail end stop controller 107, transmit it to the mandrel driving unit M, and control the stopping position of the tail end of the finished hot rolled steel strip 300 by rotating and driving the mandrel 109.

The control of the stop position of the tail end of the finish hot rolled steel strip 300 is appropriately performed according to the value of the tail end correction amount Y. The control of the stop position of the tail end of the finish hot rolled steel strip 300 is performed by determining the rotation direction and rotation amount of the mandrel 109 according to the value of the tail end correction amount Y.
The value of the tail end correction amount Y is output to the tail end stop controller 107. The muller is rotated from the position where the tail end is removed to a tail end stop angle based on the outer circumferential distance of the thin plate coil, the remaining distance in the facility, and the value of the tail end correction amount Y. Then, by controlling the stopping position of the tail end of the finished hot rolled steel strip 300, a thin plate coil with a uniform tail end stopping position can be obtained.

In this way, the method for controlling the stopping position of the tail end of a hot rolled steel strip according to this embodiment includes the first to fourth steps, calculates the tail end correction amount, and can accurately control the stopping position of the finished hot rolled steel strip based on the tail end correction amount. In other words, the method for controlling the stopping position of the tail end of a hot rolled steel strip according to this embodiment can solve the problem of errors arising from changes in the shape of the hot rolled steel strip and the amount of deflection of the hot run table by installing two or more laser meters in the winding machine and comparing the measurement results from these laser meters with the tail end shape measured by a two-dimensional shape measuring instrument.

As described above, according to the invention of the first embodiment, even if the shape of the tail end of the hot rolled steel strip is irregular and shifted in the width direction of the hot rolled steel strip, the stopping position of the tail end of the hot rolled steel strip can be controlled.

[Second embodiment]
A method for controlling the stop position of the tail end of a hot rolled steel strip according to the second embodiment will be described. The method for controlling the stop position of the tail end of a hot rolled steel strip according to this embodiment is characterized in that, in the method for controlling the stop position of the tail end of a hot rolled steel strip according to the above embodiment, the position of a first tail end on the pinch roll exit side corresponding to the first cut tail end of the finished hot rolled steel strip and the position of a second tail end on the pinch roll exit side corresponding to the second cut tail end are detected by an area sensor capable of measuring the width direction of the finished hot rolled steel strip.
Hereinafter, characteristic steps included in the method for controlling the stopping position of the tail end of a hot rolled steel strip according to this embodiment will be described.

The method for controlling the stop position of the tail end of the hot rolled steel strip according to this embodiment uses an area sensor to detect the position of the first tail end 302 on the pinch roll exit side and the position of the second tail end 303 on the pinch roll exit side. The area sensor acquires information necessary for controlling the stop position of the tail end of the hot rolled steel strip within a range set on the hot run table 108. That is, in the method for controlling the stop position of the tail end of the hot rolled steel strip according to this embodiment, the area between the first laser detection position and the second laser detection position is set as the detection area, and the position of the first tail end 302 on the pinch roll exit side and the position of the second tail end 303 on the pinch roll exit side that have passed through the detection area are detected.

The area sensor may be any sensor capable of detecting the position of the first tail end 302 on the exit side of the pinch roll and the position of the second tail end 303 on the exit side of the pinch roll. For example, an infrared area sensor, an ultrasonic area sensor, a visible light area sensor, etc. may be used.

As described above, according to the invention of the second embodiment, the position of the tail end of the pinch roll outlet can be detected by an area sensor without installing multiple laser meters, and the tail end correction amount can be calculated to control the stopping position of the tail end of the hot rolled steel strip.

[Third embodiment]
A description will be given of a tail end stop position control device for a hot rolled steel strip according to the third embodiment. The tail end stop position control device for a hot rolled steel strip according to this embodiment is a device for realizing the tail end stop position control method for a hot rolled steel strip according to the above embodiment.

The tail end stop position control device of the present embodiment includes a first detection unit that detects the two-dimensional shape of the rough hot rolled steel strip that has been rough rolled, and detects the position of the central concave portion of the tail end of the rough hot rolled steel strip and the position of the first cut tail end portion and the position of the second cut tail end portion of the rough hot rolled steel strip after cropping, which are formed by cropping the convex portions formed adjacent to the left and right of the central concave portion of the tail end, using a two-dimensional shape measuring device; and a pinch roll exit position control device that detects the position of the pinch roll exit position of the finish hot rolled steel strip that is output from the exit side of the pinch roll after the finish hot rolled steel strip is sent out to the pinch rolls. the position of a first tail end portion on the pinch roll exit side using a first laser meter and a second tail end portion on the pinch roll exit side using a second laser meter; a calculation unit that calculates a tail end correction amount for correcting the position of the tail end of the finished hot rolled steel strip based on the position of the first tail end portion on the pinch roll exit side, the position of the second tail end portion on the pinch roll exit side, a first laser detection position by the first laser, a second laser detection position by the second laser, and a laser detection difference distance formed between the first laser detection position and the second laser detection position; and a control unit that controls the stop position of the tail end of the finished hot rolled steel strip based on the tail end correction amount.
Hereinafter, each component constituting the stop position control device for the tail end of a hot rolled steel strip according to this embodiment will be described.

<Regarding the First Detector>
The stop position control device for the tail end of the hot rolled steel strip according to this embodiment includes a first detection unit. The first detection unit is only required to detect the two-dimensional shape of the rough hot rolled steel strip 200 that has been roughly rolled and the position of the tail end central recess 201 of the rough hot rolled steel strip 200. Furthermore, the first detection unit is only required to detect the position of the first cut tail end 205 and the position of the second cut tail end 206 of the rough hot rolled steel strip 204 after crop cutting, which is formed by cropping the left convex portion 202 and the right convex portion 203 formed adjacent to the left and right of the tail end central recess 201. For this reason, the first detection unit is preferably installed before and after the crop shear 103 in order to measure the two-dimensional shape of the rough hot rolled steel strip 200 before crop cutting and the two-dimensional shape of the rough hot rolled steel strip 204 after crop cutting. The first detection unit may be installed either before or after the crop shear 103 in order to measure the two-dimensional shape of either the rough hot rolled steel strip 200 before the crop cut or the rough hot rolled steel strip 204 after the crop cut. The first detection unit corresponds to the two-dimensional shape measuring device 102. For example, the first detection unit may be a reflective two-dimensional laser displacement meter, and may be any one that can perform measurement by moving either the sensor head of the reflective two-dimensional laser displacement meter or the workpiece.

<Regarding the second detection unit>
The stop position control device for the tail end of the hot rolled steel strip according to this embodiment includes a second detection unit. The second detection unit is required only to detect the position of the pinch roll exit side first tail end 302 of the finish hot rolled steel strip 300 output from the exit side of the pinch roll 105 after the finish hot rolled steel strip 300 is formed by finish rolling the rough hot rolled steel strip 204 after the crop cut and the finish hot rolled steel strip 300 is sent out to the pinch roll 105, which is the PR in the winding machine, and to detect the position of the pinch roll exit side second tail end 303. Therefore, the second detection unit needs to be installed behind the exit side of the pinch roll 105. For example, the second detection unit may be a laser meter 106 equipped with a first laser meter 161 and a second laser meter 162, or may be a laser meter 106 further equipped with a third laser meter. The second detection unit may also be an area sensor.

<About the calculation section>
The stop position control device for the tail end of a hot rolled steel strip according to this embodiment includes a calculation unit. The calculation unit calculates a tail end correction amount Y for correcting the position of the tail end of the finished hot rolled steel strip 300. The calculation unit calculates a tail end correction amount Y for correcting the position of the tail end of the finished hot rolled steel strip 300 based on data on the rough hot rolled steel strip 200 detected and transmitted by the first detection unit and data on the finished hot rolled steel strip 300 detected and transmitted by the second detection unit. The calculation unit includes one or more processors, such as a general-purpose processor or a dedicated processor specialized for a specific process.

<Regarding the position control unit>
The stop position control device for the tail end of the hot rolled steel strip according to this embodiment includes a position control unit. The position control unit corresponds to the tail end stop controller 107. The position control unit is not particularly limited as long as it can receive a pulse wave and transmit the pulse wave to the mandrel driving unit M. The position control unit receives the value of the tail end correction amount Y calculated by the calculation unit as a pulse wave. The position control unit then transmits the pulse wave received as the value of the tail end correction amount Y to the mandrel driving unit M. The mandrel driving unit M transmits the pulse wave received as the value of the tail end correction amount Y transmitted from the position control unit to the mandrel 109. The mandrel 109 controls the stop position of the tail end of the finished hot rolled steel strip 300 by rotating and driving based on the received pulse wave.

As described above, according to the invention of the third embodiment, even if the shape of the tail end of the hot rolled steel strip is irregular and shifted in the width direction of the hot rolled steel strip, the stopping position of the tail end of the hot rolled steel strip can be controlled by calculating the tail end correction amount.

[Fourth embodiment]
A thin plate coil according to a fourth embodiment will be described. The thin plate coil according to this embodiment is characterized in that it is manufactured by winding a finished hot rolled steel strip obtained using the stop position control device for the tail end of the hot rolled steel strip according to the above embodiment. The thin plate coil according to this embodiment will be described below.

A thin plate coil manufactured by winding a finished hot rolled steel strip obtained using the tail end stop position control device of the hot rolled steel strip according to the above embodiment is controlled so that all winding tail ends of the finished hot rolled steel strip 300 constituting the thin plate coil are located at a fixed position. In other words, even if multiple thin plate coils are manufactured using the tail end stop position control device of the hot rolled steel strip according to the above embodiment, all winding tail ends of the finished hot rolled steel strip 300 constituting the multiple thin plate coils are located at the same fixed position. Therefore, when the thin plate coil is pulled out from the mandrel 109, the winding tail ends of the finished hot rolled steel strip 300 constituting the thin plate coil do not peel off from the thin plate coil and interfere with other equipment.

Furthermore, in the thin plate coil according to this embodiment, all winding tails of the finished hot rolled steel strip 300 constituting the thin plate coil are located at the same fixed position. Therefore, even when the thin plate coil is transported to the coil yard, the winding tails of the finished hot rolled steel strip 300 constituting the thin plate coil do not peel off from the thin plate coil, and the thin plate coil can be transported efficiently while ensuring safety.

As described above, according to the invention relating to the fourth embodiment, all winding ends of the hot-rolled steel strips constituting the thin coil are controlled to be located at fixed positions, ensuring safety when removing the thin coil from the mandrel and allowing the thin coil to be transported efficiently to the coil yard.

[Other embodiments]
Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-mentioned embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the technical scope of the present invention. In addition, systems or devices that combine the separate features included in each embodiment in any way are also included in the technical scope of the present invention.

The effects of the present invention will be specifically explained below based on examples, but the present invention is not limited to these examples.

(Example 1)
The tail end of the finish hot rolled steel strip constituting a thin coil was controlled by simulation using the method for controlling the stop position of the tail end of the hot rolled steel strip according to the present invention. The results of the simulation of the control of the tail end of the finish hot rolled steel strip obtained in Example 1 are shown in Table 1 and Figure 5(a).

(Comparative Example 1)
A method for controlling the winding of a hot rolled steel strip proposed as a conventional technique (JP Patent Publication No. 2013-94798) was applied to simulate the control of the tail end of the finish hot rolled steel strip constituting a thin coil under the same conditions as in Example 1. The results of the simulation of the control of the tail end of the finish hot rolled steel strip obtained in Comparative Example 1 are shown in Table 1 and FIG.

As is clear from Figures 5(a)-(b), the results of the simulation of the control of the tail end of the finished hot rolled steel strip obtained in Example 1 of the invention show that the standard deviation of the stop angle of the tail end of the final finished hot rolled steel strip is greatly improved from 25 degrees to 15 degrees. In this way, the method for controlling the stop position of the tail end of the hot rolled steel strip according to the present invention can precisely control the stop position of the tail end of the finished hot rolled steel strip. In other words, by adopting the method for controlling the stop position of the tail end of the hot rolled steel strip according to the present invention, the risk of the tail end of the thin coil made of the finished hot rolled steel strip interfering with other equipment can be reduced.

The method for controlling the stopping position of the tail end of a hot rolled steel strip according to the present invention makes it possible to control the winding tail ends of all hot rolled steel strips that make up a thin coil to a fixed position, which contributes to the development of the steel industry and is extremely useful industrially.

100 Thin coil manufacturing line 101 Rough rolling mill 102 Two-dimensional shape measuring device 103 Crop shear 104 Finishing rolling mill 105 Pinch roll (PR in winding machine)
106 Laser gauge 161 First laser gauge 162 Second laser gauge 107 Tail end stop controller 108 Hot run table 181 Equipment center line 109 Mandrel M Mandrel drive unit 200 Rough hot rolled steel strip 201 Tail end central recess (rough hot rolled steel strip)
202 Left convex portion 203 Right convex portion 204 Rough hot rolled steel strip after cropping 205 First cut tail end portion 206 Second cut tail end portion 300 Finished hot rolled steel strip 301 Tail end central concave portion (finished hot rolled steel strip)
302 Pinch roll exit first tail end 303 Pinch roll exit second tail end 304 Laser gauge distance α
305 Laser detection difference distance β

Claims (4)

A method for controlling a stop position of a tail end of a finished hot rolled steel strip when the finished hot rolled steel strip is wound by a winding section having a mandrel to form a thin coil, comprising the steps of:
a first step of detecting a two-dimensional shape of a tail end of a rough hot rolled steel strip that has been roughly rolled, and detecting the position of a central concave portion of the tail end of the rough hot rolled steel strip and the position of a first cut tail end portion and a second cut tail end portion of the rough hot rolled steel strip after cropping, the first cut tail end portion and the second cut tail end portion being formed by cropping convex portions formed adjacent to the left and right of the central concave portion;
a second step of detecting, by a first laser meter, a position of a first tail end portion on the pinch roll exit side corresponding to the first cut tail end portion of the finished hot rolled steel strip output from the pinch roll exit side after the rough hot rolled steel strip after the crop cut is finish-rolled to form the finished hot rolled steel strip and then fed to the pinch roll; and detecting, by a second laser meter, a position of a second tail end portion on the pinch roll exit side corresponding to the second cut tail end portion of the finished hot rolled steel strip output from the pinch roll exit side.
A third step of calculating a tail correction amount for correcting the position of the tail of the finish hot rolled steel strip based on a first detection position of a first tail end portion on the exit side of the pinch roll by the first laser meter and a laser detection difference distance formed between the first detection position and a second detection position of a second tail end portion on the exit side of the pinch roll by the second laser meter;
and a fourth step of controlling the stop position of the tail end of the finish hot rolled steel strip based on the tail end correction amount. The method for controlling the stop position of the tail end of a hot rolled steel strip according to claim 1, characterized in that the position of the first tail end on the pinch roll exit side corresponding to the first cut tail end of the finished hot rolled steel strip and the position of the second tail end on the pinch roll exit side corresponding to the second cut tail end are detected by an area sensor capable of measuring the width direction of the finished hot rolled steel strip. A control device for controlling a stop position of a tail end of a finished hot rolled steel strip when the finished hot rolled steel strip is wound by a winding section having a mandrel to form a thin coil, comprising:
a first detection unit that detects a two-dimensional shape of the tail end of the rough hot rolled steel strip that has been roughly rolled, and detects the position of a central concave portion of the tail end of the rough hot rolled steel strip and the position of a first cut tail end portion and a second cut tail end portion of the rough hot rolled steel strip after cropping, the first cut tail end portion and the second cut tail end portion being formed by cropping the convex portions formed adjacent to the left and right of the central concave portion;
a second detection unit which detects, by a first laser meter, a position of a first tail end portion on the pinch roll outlet side corresponding to the first cut tail end portion of the finished hot rolled steel strip output from the pinch roll outlet side after the rough hot rolled steel strip after the crop cut is finish-rolled to form the finished hot rolled steel strip and then sent to the pinch rolls, and detects, by a second laser meter, a position of a second tail end portion on the pinch roll outlet side corresponding to the second cut tail end portion of the finished hot rolled steel strip output from the pinch roll outlet side;
a third detection unit that calculates a tail correction amount for correcting the position of the tail of the finish hot rolled steel strip based on a first detection position of the first tail end portion on the pinch roll exit side by the first laser meter and a laser detection difference distance formed between the first detection position and a second detection position of the second tail end portion on the pinch roll exit side by the second laser meter;
a position control unit that controls the stop position of the tail end of the finish hot rolled steel strip based on the tail end correction amount. A thin coil produced by the tail end stop position control device for hot rolled steel strip according to claim 3.

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