JP2650549B2 - Winding method of steel strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for winding a steel strip without causing a break at the rear end of the steel strip.

[0002]

2. Description of the Related Art For example, in hot rolling, on a downstream side of a final finishing stand in a tandem rolling line of steel strip, a steel strip having a trailing end passing through the final finishing stand is transferred to a transport table comprising a plurality of transport rolls. Hot run table) and travels downstream, via pinch rolls on the downstream side of the transport table,
It is wound and coiled by a mandrel mill downstream of the pinch roll.

[0003] In particular, in a steel strip having a thickness of 2 mm or less, a phenomenon occurs in which the plate is wound into a mandrel mill while being double-folded at a position of about 100 m from the rear end of the total length of about 1000 m. . The reason for this is that after the rear end of the steel strip has passed through the final stand of the finishing mill, the steel strip becomes excessive due to excessive feeding of the steel strip on the conveyor table roll due to the reduction of the rotation speed of the mandrel mill, etc. Shape (accordion shape)
And the pinch roll may crush the plate that has entered as it is. In particular, the steel strip that has looped at a position close to the pinch roll is crushed.
In this way, the steel strip crushed by the pinch roll and folded twice does not become a product, and as a result, the yield is greatly reduced.

Conventionally, in order to prevent such folding, means described below, such as guide setting, pinch roll gap correction and lag rate correction, have been used.

(1) Guide setting: The guide is set by using equipment provided on the upstream side of the pinch roll for pressing the steel strip from both sides, and the equipment is used to press the steel strip from both sides to lift the plate. To prevent the occurrence of a loop.

(2) Pinch roll gap correction: Pinch roll gap correction is to control the lifting force of the steel strip by controlling the pressing force of the steel strip sandwiched between the upper and lower pinch rolls, which constitutes the pinch roll, and to generate a loop. Is to prevent.

(3) Lag ratio correction: The lag ratio is the ratio of the rotation speed of the rolls constituting the transfer table to the speed of the steel strip. The lag rate is corrected by controlling the rotation speed of the mandrel mill, i.e., by instantaneously increasing the rotation speed of the mandrel mill and instantaneously pulling the steel strip by the mandrel mill, the lifting of the steel strip is reduced. Pressing, thereby preventing the occurrence of a loop.

[0008]

However, the above-described guide setting, pinch roll gap correction, and lag rate correction have the following problems. (1) Guide setting: If the side of the steel strip is pressed with too much force, the edge of the plate is cut and the quality deteriorates. (2) Pinch roll gap correction: If the pressing force of the steel strip sandwiched between the upper and lower pinch rolls is too strong, the shape of the coil will be deteriorated and the quality will be degraded. on the other hand,
If loose, the gap between the pinch rolls increases (loose),
Pinch roll function cannot be performed. (3) Lag rate correction: The relationship between the occurrence of steel strip loops and the lag rate is unclear, and it is difficult to correct the mandrel mill rotation speed appropriately.

Accordingly, it is an object of the present invention to provide a method for winding a steel strip, which can prevent the steel strip from being bent.

[0010]

SUMMARY OF THE INVENTION The method of the present invention comprises a plurality of transport rolls provided on a downstream side of the final stand of the finishing mill, the steel strip having a rear end passing through the final stand of the finishing mill. Traveling by a transfer table, and then winding the steel strip through a pinch roll provided on the downstream side of the transfer table by a mandrel mill provided on the downstream side of the pinch roll. In the winding method, a distance detector is provided at the downstream end of the transfer table, the distance detector is connected to a rotation speed control mechanism of the mandrel mill, and the distance detector detects the distance detector and the surface of the steel strip. To detect the distance between
The detected distance is sent to the rotation speed control mechanism by a signal to control the rotation speed of the mandrel mill, thereby eliminating the lifting of the steel strip, and thus,
It is characterized by preventing the steel strip from being bent.

[0011]

The distance detector measures the distance between the distance detector and the lower surface of the steel strip. The lifting and looping of the steel strip increases the distance between the distance detector and the lower surface of the steel strip, and when the distance exceeds a certain value, the rotation speed of the mandrel mill from the distance detector. A signal is sent to the control mechanism. Accordingly, the mandrel mill is instantaneously accelerated by the rotation speed control mechanism and pulls the looped steel strip, so that slack is eliminated and no break occurs.

Next, the present invention will be described with reference to the drawings. FIG. 1 is a schematic explanatory view of a mechanical configuration from a final stand of a finishing mill to a mandrel mill in a tandem rolling line, showing a first embodiment of the present invention. As shown in FIG. 1, a transport table 2 including a plurality of transport rolls 3 is provided downstream of the final rolling mill final stand 1, and a pinch roll 4 is provided downstream of the transport table 2; A mandrel mill 5 is provided downstream of the pinch roll 4. The steel strip 6 whose rear end has passed through the final stand 1 of the finishing mill is moved by the transfer table 2 and then passed between the upper and lower pinch rolls 4a and 4b constituting the pinch roll 4, and the steel strip 6 is passed through the mandrel mill 5. The coil 6a is wound.

The transport roll 3a at the downstream end of the transport table 2
A distance detector 7 is provided below the steel strip 6 in a gap between the transport strip 3b and the upstream transport roll 3b.
The distance detector 7 is connected to a rotation speed control mechanism 8 of the mandrel mill 5. As the distance detector 7, for example,
A laser range finder can be used.

The distance detector 7 measures the distance between the distance detector 7 and the lower surface of the steel strip 6. When the steel strip 6 rises and forms a loop, the distance between the distance detector 7 and the lower surface of the steel strip 6 increases. When the distance exceeds a certain value, the distance detector 7 sends a signal to the rotation speed control mechanism 8 of the mandrel mill 5. As a result, the mandrel mill 5 is instantaneously accelerated by the rotation speed control mechanism 8 to pull the steel strip 6 formed into a loop, eliminate slack, and prevent the steel strip 6 from being bent.

FIG. 2 is a schematic explanatory view showing a second embodiment of the present invention. The second embodiment differs from the first embodiment only in that the position where the distance detector is provided is different, as described later. In the second embodiment, the distance detector 7 is provided above the steel strip 6 at the downstream end of the transport table 2. That is, for example, as shown in FIG. 2, the distance detector 7 is provided at the tip of the entry guide 9. The entry guide 9 is a device for smoothly inserting the steel strip 6 into the pinch roll 4 and is provided at a position close to the upstream side of the pinch roll 4.

The distance detector 7 measures the distance between the distance detector 7 and the upper surface of the steel strip 6. When the steel strip 6 is looped, the distance detector 7 and the steel strip 6
The distance between the upper surface and the upper surface becomes smaller. The distance detector 7
When the distance becomes smaller than a certain value, a signal is sent to the rotation speed control mechanism 8 of the mandrel mill 5. As a result, the mandrel mill 5 is instantaneously accelerated by the rotation speed control mechanism 8 to pull the looped steel strip 6,
Eliminates slack and prevents folding.

[0017]

Next, the present invention will be described with reference to embodiments.
Using the method of the present invention, a steel strip having a thickness of 1.6 mm or less is wound, and the amount of loop of the steel strip (the distance between the pass line and the steel strip) on the upstream side of the mandrel mill (coiler) is reduced. It was measured. FIG. 3 is a graph showing the measured loop amount and the number of steel strips indicating the loop amount as a percentage of the total measured steel strip number. As a comparative example, a steel strip having the same thickness was wound by a conventional winding method without performing any control, and the measurement result of the loop amount similarly measured was also shown in FIG. The mark ● in FIG. 3 indicates an example, and the number of measured steel strips was 131. And FIG.
The circles in the table indicate comparative examples, and the number of measured steel strips was 98.
It was a book.

As shown in FIG. 3, the steel strip wound by the winding method of the present invention has a small loop amount and a maximum loop amount of about 660 mm, which is extremely effective in preventing the occurrence of folding. It can be seen that it is.

On the other hand, according to the comparative example, the loop amount of the wound steel strip is larger than that of the example,
In addition, the maximum amount of loop reached 900 mm, which indicates that the possibility of occurrence of breakage is extremely high.

[0020]

As described above, according to the present invention, it is possible to obtain a method of winding a steel strip which can prevent the rear end portion of the steel strip from being bent, and thus is industrially useful. Effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram of a machine configuration from a final stand of a finishing rolling mill to a mandrel mill in a tandem rolling line, showing a first embodiment of the present invention.

FIG. 2 is a schematic explanatory view of a machine configuration from a final stand of a finishing rolling mill to a mandrel mill of a tandem rolling line, showing a second embodiment of the present invention.

FIG. 3 is a graph showing the measured loop amount and the number of steel strips indicating the loop amount as a percentage of the total measured steel strip number.

[Explanation of symbols]

 Reference Signs List 1 Final stand of finishing mill 2 Transport table 3, 3a, 3b Transport roll 4, 4a, 4b Pinch roll 5 Mandrel mill 6 Steel strip 6a Coil 7 Distance detector 8 Rotation speed control mechanism 9 Entry guide.

Claims (4)

(57) [Claims] 1. A steel strip, the rear end of which passes through a final stand of a finishing mill, is caused to travel by a transport table provided with a plurality of transport rolls provided on a downstream side of the final stand of the finish rolling mill. A method for winding a steel strip, comprising: winding a strip by a mandrel mill provided downstream of the pinch roll via a pinch roll provided downstream of the transfer table. Provided with a distance detector, the distance detector is connected to a rotation speed control mechanism of the mandrel mill, and the distance detector detects a distance between the distance detector and the surface of the steel strip. The rotation distance is sent to the rotation speed control mechanism by a signal to control the rotation speed of the mandrel mill. To eliminate the floating of the steel strip, thus winding method of the steel strip, characterized in that to prevent Orekomi the steel strip. 2. A distance detector is provided in a gap between the transport rolls at a downstream end of the transport table so as to be located below the steel strip, and the distance detector causes the distance detector and a lower surface of the steel strip to be in contact with each other. The method for winding a steel strip according to claim 1, wherein a distance between the steel strips is detected. 3. A distance detector is provided at a downstream end of the transfer table so as to be located above the steel strip, and the distance detector detects a distance between the distance detector and an upper surface of the steel strip. The method for winding a steel strip according to claim 1. 4. The method according to claim 3, wherein the distance detector is provided on an entry guide provided upstream of the pinch roll.