JP2003285118A - Winding method for metal strip and device used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate an obstacle to winding caused by the brake of a tip when a hot steel strip is wound, and also to propose a method for winding a steel strip in which winding and fastening are sufficiently carried out when the break of the tip is caused. <P>SOLUTION: The situation of the brake of the tip of the metal strip is measured immediately before the tip of the metal strip to be rolled into a predetermined thickness with a finishing rolling mill enters a winding machine. The strengthening operation of fastening is carried out in accordance with the measuring situation of the break of the tip. <P>COPYRIGHT: (C)2004,JPO

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 metal strip, particularly a hot-rolled steel strip, and more particularly to a method and a winding device for smoothly winding a metal strip having a broken head.

[0002]

2. Description of the Related Art A metal strip, for example, a steel strip rolled to a predetermined thickness by a continuous hot finishing mill is wound by a winding device into a coil. Specifically, as shown in FIG. 3, the steel strip S finished to a predetermined thickness by a hot rolling mill (not shown) is run on the run-out table 1 without restraining the head of the steel strip S. An operation is performed in which the pinch roll 2 of the winder is bitten and the wrapper roll 3 winds the mandrel roll 4 around the mandrel roll 4.

In such a steel strip winding operation, while the steel strip is traveling on the runout table, the tip of the steel strip is caused by troubles such as wind pressure caused by traveling or collision with equipment around the runout table. In some cases, a so-called "head break" may occur in which the sheet is double-folded as shown in. In the figure, is the tip of the steel strip S, is the broken portion, and the arrow indicates the traveling direction of the steel strip S.

At this time, if the winding operation of the steel strip is carried out as usual, the winding on the mandrel roll and the winding tightness of the wound coil are poor and the coil shape is deteriorated. If the coil shape deteriorates, scratches and the like tend to occur on the steel strip during handling. So usually,
The wrapper roll is subjected to AJC (Automatic Jumping Control: automatic step control, gradually increasing the roll diameter in synchronization with winding) so that winding and tightening can be sufficiently performed. There is also a method of winding and tightening by a double expand (a mechanism that expands the mandrel diameter in two steps).

However, even with such means, the winding operation is still hindered, the winding operation of the steel strip cannot be normally performed, and in the worst case, the winding machine stops. Sometimes. When such a winding operation is hindered, conventionally, even after the AJC operation of the normal wrapper roll is completed, the operator of the winder manually presses the wrapper roll at a constant pressure to prevent slipping. I was trying to complete the removal.

[0006]

However, in the case of a thin material whose production has increased especially in recent years, for example, a 1.6 mm hot-rolled steel strip, the tip of the steel strip is easily affected by wind pressure, so that head breakage occurs. Opportunities are increasing. In particular, thinning and increasing the rolling speed increase the chances of such winding failure. Therefore, conventional pressure adjustment of the winding machine cannot be handled, and the number of incomplete windings and stopping of the winding machine is increasing.

An object of the present invention is to solve a winding trouble due to a head break when winding such a thin hot-rolled steel strip, and even if the head break occurs, the winding is performed without error.
The purpose is to propose a method for winding a steel strip that is sufficiently tightened.

[0008]

The inventor of the present invention can measure the degree of head breakage of a metal band by, for example, the roll gap of a pinch roll installed immediately before a winder,
Further, if it is possible to automatically apply the winding tightening strengthening means to the winder according to the amount of head breakage thus measured, even if a head break occurs at the tip of the metal band, it will result from the head break. It was found that a winding tightness can be solved smoothly and a metal coil having a tight winding property can be obtained.

Therefore, the method for winding a metal strip according to the present invention is
Immediately before the end of the metal strip rolled to a specified thickness by the finishing rolling mill enters the winder, the head breakage of the metal strip is measured and the winding is tightened on the winder according to the measurement condition. It is to strengthen the operation.

In the above method, the tightening operation for tightening the winding is
It is an AJC operation that is added after the completion of the AJC operation that is normally applied when winding the metal strip, an operation that increases the winding tension when the winding machine starts winding, and a normal operation when winding the metal strip. It is preferable that any one of the operations of maintaining the pressing force of the wrapper roll against the mandrel roll at a predetermined value after the completion of the applied AJC operation, or a combination of two or more thereof.

In carrying out the above-described method of winding a metal strip, the head of the metal strip rolled to a predetermined thickness by a finishing rolling mill is measured for the state of head breakage at the tip of the metal strip immediately before entering the winding machine. A metal band front end head breakage measuring means,
A winding tightening amount calculating means for calculating the winding strengthening amount of the winder according to the output information of the metal band tip breaking condition measuring means, and an additional winding tightening by the output of the winding strengthening amount calculating means. It is preferable to use a winder provided with winder control means for performing a strengthening operation.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings, taking a case of winding a steel strip as a metal strip as an example. FIG. 1 is an explanatory view showing the essential parts of a steel strip winding device used when carrying out the present invention together with its control system. In this example as well as in the conventional example, the steel strip S
Is taken up by the winder 5 through the runout table 1 and the pinch roll 2.

In the present invention, the steel strip S
Sensor 1 that measures the position of pinch roll 2 when it travels on the runout table and enters pinch roll 2.
0 is used to measure the state of the steel strip S being broken. That is, when there is a head break, the thickness of the steel strip is apparently thicker in that range (see FIG. 4), and therefore it is possible to determine the presence or absence of a head break by the position variation of the sensor 10. If there is a head break, the range can be measured.

When the condition of the head break is measured as described above, the winding operation by the winding machine 5 is performed based on the result.
Particularly, the specific contents of the tightening operation for strengthening the winding at the initial stage of winding are determined. As the winding tightening strengthening operation when the steel strip S has a head break, for example, after the completion of the AJC operation normally applied when winding the metal strip, an additional AJC operation may be added. This additional AJC operation changes depending on various factors such as the thickness of the steel strip, the degree of head break (head break length), and other factors. Therefore, it suffices to analyze past operation data and determine the additional AJC operation time based on the analysis. Since AJC is a discontinuous operation, if it is excessively performed, the life of the mechanical part will be shortened, and frequent maintenance is required.

The winding tightening strengthening operation at the initial stage of winding is not limited to the additional AJC operation described above. For example, this can be done by increasing the winding tension at the start of winding the winding machine. In this case, the number of rotations of the mandrel roll may be increased according to the state of head breakage. However, for a long time to strengthen the tension,
Since there is a risk of necking of the steel sheet, such operations should be set to a minimum.

Further, the pressing force of the wrapper roll against the mandrel roll may be maintained at a predetermined value for a certain period of time after the completion of the AJC operation which is usually applied at the time of winding a metal band, as conventionally done by an operator. The additional pressing time in this case can also be determined based on the degree of head breakage detected by the sensor 10. However, if the pressing force is maintained when such AJC is not performed, the steel strip tip collision flaw inside the coil may occur. Therefore, the pressing force maintenance should be set to the minimum. The above operations can be combined appropriately.

In short, the winding strengthening operation may be added as necessary in consideration of various factors such as the degree of head breakage, the material of the steel strip and the rolling end temperature. Needless to say, the process computer can be used to determine such an additional operation, and so-called learning control can be used. Needless to say, the winding method when the head break is not detected by the sensor 10 is the same as that of the conventional method, that is, the winding tightening operation is not performed.

As a device for performing the above-mentioned operation, the tip end of the metal strip rolled to a predetermined thickness by a finishing rolling mill is used to measure the state of head breakage of the front end portion of the metal strip immediately before entering the winding machine. The head tightening amount measuring means and the tightening amount calculating means and the tightening amount calculating means for calculating the tightening amount of the winder according to the output information of the metal band tip part breaking condition measuring means. It suffices if it is provided with a winding machine control means for performing an additional winding tightening operation by output. One example is shown in FIG.

The position detecting device of the pinch roll 2 can be used as the metal band tip breakage condition measuring means for measuring the metal band tip breakage condition. Also,
It is also possible to measure the condition of head cracking by taking an image of the steel strip head by an optical means on the runout table 1 or between the pinch roll 2 and the winder 5 and performing image processing on the image. As these measuring means, all known measuring means can be used.

The measurement of the above-mentioned head breakage condition should be performed as close to the winding machine as possible. Especially the plate thickness is 1.6m
A thin hot-rolled steel sheet having a thickness of m or less is likely to be broken during the traveling process from the exit side of the finish rolling mill to the winding machine.
Therefore, the measurement position of the head break should be immediately before the winder, that is, between the tail of the runout table 1 and the winder 5.

A process computer can be used as the calculating means 11 for calculating the tightening amount of the winding machine. This process computer analyzes, for example, the relationship between the amount of head breakage calculated based on past operating results and the operating conditions such as the material of the steel material to be rolled, the plate thickness, and the winding temperature, and based on that, It has a function to calculate the additional AJC operation amount necessary to deal with breaks. Such means is publicly known, and other winding tightening strengthening means, for example, winding tightening quantity strengthening amount calculating means based on the winding tension increase amount at the start of winding of the winding machine can be configured in the same manner.

The control means for receiving the output of the winding amount strengthening amount calculating means 11 and causing the winding machine 5 to perform an additional winding operation is, for example, a means for performing the above-mentioned additional AJC operation. The timer 13 can be used as. That is, the additional AJ calculated by the calculation means 11
The C operation time may be input to the timer 13 so that the AJC can be operated for a required time. In this case, the control circuit may be configured such that the additional AJC operation time is performed without depending on the timer 13, for example, until the load current of the mandrel roll reaches a constant value.

When the winding amount strengthening means is to increase the winding tension at the start of winding of the winding machine, a rotation speed control mechanism of the motor 14 for driving the mandrel roll 5 may be provided. Also, if the pressing force of the wrapper roll against the mandrel roll that is normally applied when winding the metal strip is to be maintained at a predetermined value after completion of the AJC operation, the position control of the hydraulic cylinder directly connected to the wrapper roll 4 should be performed. ,
This may be done via the hydraulic control valve 15.

[0024]

EXAMPLE FIG. 2 is a graph showing the relationship between the elapsed time and the position of the wrapper roll when the present invention is performed by the additional AJC operation. The operating conditions are shown in Table 1. In this case, the position sensor attached to the pinch roll detects that a head break exists at the tip of the steel strip over a length of 500 mm, and based on that, an additional AJC operation is performed by the mandrel using the arithmetic unit and the control unit. The process was repeated until the load current of the roll reached a value indicating a completely wound state. In FIG. 2, the first part up to
It is the winding by AJC, and the part of and after it is the winding by additional AJC. In the figure, A is a case where no head break is detected, and additional AJC is not performed.

[0025]

[Table 1]

As a result of the operation for which the above head breakage countermeasure is taken, the occurrence rate of slip flaws due to head breakage, defective winding shape, etc. are shown in Table 2.
It decreased as shown in. The case of the first embodiment is the case according to the above-described example, the case of the second embodiment is the case of increasing the winding tension at the start of winding of the winding machine, and the case of the third embodiment. Is the case where the pressing force of the wrapper roll against the mandrel roll is maintained at a predetermined value after the completion of the normal AJC operation. Also, with the conventional example,
This is a case where the operator of the winding machine manually presses the wrapper roll at a constant pressure after completing the AJC operation of the normal wrapper roll to prevent slipping and complete the winding.

[0027]

[Table 2]

[0028]

As described above, according to the present invention, it is possible to surely wind the metal strip in a sufficiently wound state even when the head is broken, and thus, when handling the metal strip in the coil state. Defects such as scratches that occur can be significantly reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a winding device for a steel strip used when carrying out the present invention together with its control system.

FIG. 2 is a graph showing the relationship between the elapsed time and the position of the wrapper roll when the present invention is performed by an additional AJC operation.

FIG. 3 is a conceptual diagram showing a schematic configuration of a metal strip winding device.

FIG. 4 shows a state of head breakage occurring in a metal strip.
It is a side view and (b) top view.

[Explanation of symbols]

1: Run out table 2: Pinch roll 3: Wrapper roll 4: Mandrel roll 5: Winding machine 10: Position sensor (for pinch rolls) 11: arithmetic unit 12: Control device 13: Timer 14: Motor 15: Hydraulic control valve S: Steel strip

Claims (3)

[Claims] 1. A head strip of a metal strip which has been rolled to a predetermined thickness by a finishing rolling mill is measured immediately before the tip of the metal strip enters the winding machine. A method of winding a metal band, characterized in that a winding machine is subjected to a tightening operation. 2. The winding strengthening operation is an AJC operation that is additionally added after the completion of the AJC operation normally applied when winding a metal strip, and the winding tension at the start of winding of the winder. Any one of the increase operation and the operation of maintaining the pressing force of the wrapper roll against the mandrel roll at a predetermined value after the completion of the AJC operation that is usually applied when winding the metal strip, or a combination of two or more thereof. The method for winding a metal strip according to claim 1, wherein 3. A metal band tip breakage state measuring means for measuring the state of head breakage of the metal band tip immediately before entering the winder, with respect to the tip of the metal band rolled to a predetermined thickness by a finish rolling mill, A winding tightening amount calculating means for calculating the winding strengthening amount of the winder according to the output information of the metal band tip breaking state measuring means, and an additional winding tightening by the output of the winding strengthening amount calculating means. A winding device for winding a metal band, comprising: a winding machine control means for performing a strengthening operation.