KR20040107208A - A Method for Quick Open Control in Down Coiler - Google Patents

Abstract

PURPOSE: To provide a method for quick open control in down coiler to obtain rolling threadability and improve quality of strip by improving reliability of sensors for sensing position of the strip to accurately discriminate position of the strip during initial coiling of the strip and controlling open and close of unit rolls through improvement of sensor reliability. CONSTITUTION: In a method for quick open control by opening and closing a plural unit rolls(121-124) in a down coiler(130) for coiling a strip(101) passing through upper and lower pinch rolls(111,112), the method for quick open control in the down coiler comprises a step of sensing time at which a top end of the strip passes through a specific position by irradiating infrared light onto the surface of the strip being moved to the down coiler after passing through the upper and lower pinch rolls; a step of calculating position of the top end of the strip using a rotation speed of the pinch rolls and an elapsed time after sensing time at which a top end of the strip passes through a specific position; a first unit roll control step of starting coiling of the strip by controlling open and close of the plural unit rolls according to the top end of the strip; and a second unit roll control step of controlling open and close of the plural unit rolls using the sensed position of the top end of the strip after sensing position of the top end of the strip in a circumferential direction of the down coiler by irradiating infrared light onto the strip coiled on the down coiler.

Description

A Method for Quick Open Control in Down Coiler

The present invention relates to a Quick Open Control (QOC) method which is carried out to reduce the flaw that may occur on the strip surface by the strip tip when the strip produced in the hot rolling process is initially wound in the winding machine. In particular, the position of the front end of the strip can be detected more accurately by calculating the position of the front end of the strip, and the unit roll position control can be performed appropriately, thereby avoiding the step in the winding machine, which can secure the rolling passability and improve the surface quality of the strip. It relates to a control method.

In general, in the hot rolling process for manufacturing a hot rolled steel sheet, a slab supplied from a continuous casting machine in a steelmaking process is heated and cracked at a predetermined temperature in a heating furnace, followed by width rolling and thickness rolling. Into a state, and then the bar is rolled into strips of the desired size in a finishing mill using multiple stands, and then the strip passed through the final stand is subjected to lamina flow of a run out table. After cooling in a lamina flower to secure certain mechanical properties, it is wound in a winder to produce a coil product in the form of a roll.

In the initial stage of winding the strip by the winder, a plurality of unit rolls press the strip toward the winder while winding the strip on the winder installed at the rear of the run-out table, thereby preventing the strip from slipping or unwinding from the winder. prevent. On the other hand, when the leading edge of the wound strip passes the unit roll, a strip head mark may occur on the surface of the strip overlapping the leading edge of the strip due to the pressure of the unit roll pressing the strip. After the tip passes, the unit roll is closed again to control the pressing of the strip. The open / close control of the unit roll to avoid such a tip of the strip is referred to as Quick Open Control (QOC).

In the conventional step avoidance control (QOC) method, as illustrated in FIG. 1, an acceleration type vibration sensor 140 is installed on the upper pinch roll 111 to detect the tip of the strip 101. When the front end of the strip 101 enters 111 and 112, the change of vibration is detected to detect the front end of the strip 101, and the moving distance of the strip 101 is calculated through the acceleration type vibration sensor 140. When the front end of the strip 101 passes through the first unit roll 121, the first unit roll 121 is opened and the front end of the strip 101 passes through the first unit roll 121. After the first unit roll 121 is closed. Similarly, the strip 101 calculated by the acceleration type vibration sensor 140 also uses the moving distance between the second unit roll 122, the third unit roll 123, and the fourth unit roll 124. The tip of 101 is opened before passing through each unit roll and closed after passing through the unit roll, so that the initial pressure of the unit roll is wound on the mandrel 130 and the strip 101 is wound. This prevents the tip of the strip 101 from creating a flaw on the surface of the strip 101.

In the conventional step avoidance control (QOC) method, when the leading end of the strip 101 enters the downward (A) state, the leading end of the downward strip 101 hits the run-out table roller 150 to impact. Will be added. The vibration generated by this is transmitted to the acceleration type vibration sensor 140, and the acceleration type vibration sensor 140 incorrectly recognizes that the tip portion of the strip 101 has entered the pinch rolls 111 and 112, and thus the strip ( The movement distance of 101 is calculated so that the step avoidance control (QOC) of the unit roll is performed incorrectly, so that when winding the strip 101 in the winder, the surface of the strip 101 by the tip of the strip 101 There is a problem that a defect in the quality of the strip that is caused by scratches. In addition, even when the front end portion of the strip 101 enters the pinch rolls 111 and 112 with the upper portion B up, the malfunction of the vibration sensor 140 is performed in the same manner as the front end portion of the strip 101 is downward. By failing to calculate the exact position of the strip 101, there is a problem that the step avoidance control (QOC) is performed incorrectly, resulting in poor quality of the strip.

The present invention has been made to solve and to improve the above problems. Accordingly, an object of the present invention is to improve the reliability of the sensor for detecting the position of the strip in order to accurately determine the position of the strip during the initial winding of the strip, thereby controlling the open / close of the unit roll. It is to provide a step avoidance control (QOC) method in the winding machine that can secure the rolling sheet and prevent the flaw of the strip surface caused by the tip of the strip to contribute to the quality of the strip.

1 is a configuration diagram of a conventional step avoidance control device.

2 is a block diagram of a step avoidance control apparatus according to an embodiment of the present invention.

3 is a flowchart illustrating an example of a step avoidance control (QOC) method according to the present invention.

* Description of the symbols for the main parts of the drawings *

101: strip 111,112: upper and lower pinch roll

121,122,123,124: Unit roll 130: Winding machine

200: control unit 240: first infrared sensor

242: second infrared sensor 260: pulse logic generator (PLG)

280: pulse generator (PG)

As a technical means for achieving the above object of the present invention, the present invention, in the winding machine for winding the strip passing through the upper and lower pinch roll, the step by the open (close) and close (close) of the plurality of unit rolls In the avoidance control (QOC) method,

Irradiating infrared rays to the surface of the strip moving through the upper and lower pinch rolls to the winding machine to detect a time when the front end of the strip passes a specific position, and the rotational speed of the pinch roll and the front end of the strip Calculating the position of the front end of the strip using the elapsed time after the passing time is sensed, and controlling the opening and closing of a plurality of unit rolls according to the front end of the strip to start winding the strip. The first unit roll control step, and by irradiating infrared rays to the strip wound around the winder to detect the position of the end of the strip in the circumferential direction of the winder, using this to open and close the plurality of unit rolls It provides a step avoidance control (QOC) method in the winder comprising a second unit roll control step of controlling the (close) .

In addition, the step avoidance control (QOC) method in the winder according to the present invention,

Counting the opening and closing of at least one unit roll of the plurality of unit rolls, and opening the plurality of unit rolls if the number of open and close matches the predetermined number of times. (open) and stopping the control of the unit roll.

Hereinafter, with reference to the accompanying drawings, an embodiment of a step avoidance control (QOC) method in the winder according to the present invention will be described in more detail. In the drawings referred to in the following description, components having substantially the same configuration and function will use the same reference numerals.

Figure 2 illustrates one embodiment of an apparatus for implementing a step avoidance control (QOC) method in a winder according to the present invention. This embodiment,

A first infrared sensor 240 installed at the rear of the upper unit roll 111 and sensing the first position of the front end of the strip immediately after the strip 101 passes through the upper and lower pinch rolls 111 and 112, and the lower unit roll. A pulse logic generator (PLG) 260 installed on the 112 and detecting the rotational speed of the lower unit roll, and a guide 222 of the second unit roll 122, The second infrared sensor 242 for detecting the second position and the hydraulic cylinder for opening / closing the second unit roll 122 are installed to open the second unit roll 122. And a pulse generator (PG) 280 that counts the number of closes, first and second positions of the front end detected by the first and second infrared sensors, and a lower portion calculated by the pulse logic generator. Using the rotational speed of the unit roll and the running time after sensing the tip, Calculate the position and control the open / close of the unit roll accordingly, and the open / close of the second unit roll 122 counted by the pulse generator 280 The controller 200 may be configured to open the entire unit roll by comparing the number of times with a preset number of times and to stop the control of the unit roll. In addition, the embodiment may further include a display unit for visually showing the control state of the unit roll, that is, the step avoidance control (QOC) state.

The first infrared sensor 240 is a sensor that responds to temperature through irradiation of infrared rays. Unlike the conventional vibration sensor that detects the entry of the strip by detecting the vibration of the pinch roll, and malfunctions in response to other external vibration, the first infrared sensor 240 detects a strip having a high temperature compared to the ambient temperature ( error). The first infrared sensor 240 detects a time at which a position of the front end of the strip (first position of the front end of the strip) passing through the upper and lower pinch rolls 111 and 112 passes through the winding machine, preferably passing through a specific position. Is installed at the rear of the upper pinch roll 111 to recognize the strip immediately after passing through the upper and lower pinch rolls (111, 112).

The pulse logic generator (PLG) 260 may be installed in the lower pinch roll 112, and counts the rotation of the lower pinch roll to calculate its rotation speed.

The second infrared sensor 242 is a sensor that responds to temperature by irradiating infrared rays in the same manner as the first infrared sensor 240, and preferably may be installed in the guide 222 of the second unit roll 112. And, it enters the winder 130 and detects again the position (second position of the front end of the strip) in the circumferential direction of the winder of the leading end of the strip being wound. The position of the second infrared sensor 242 is not limited to the guide 222 of the second unit roll 112, and may be installed on any one of the plurality of unit roll guides.

The control unit 200 is the entry time of the strip according to the first position of the front end of the strip detected by the first infrared sensor 240 and the rotational speed of the lower pinch roll 112 calculated by the pulse logic generator 260. And calculate the current position of the front end of the strip using the elapsed time since the strip is detected by the first infrared sensor 240. Using the calculated position of the front end of the strip, when the front end of the strip passes through each unit roll, each unit roll is opened, and after passing, it is closed to close the step avoidance control (QOC). In addition, when the second position of the front end of the strip being wound on the winder is sensed by the second infrared sensor 242, the control unit 200 previously determines the front end of the strip calculated by the detection of the first infrared sensor 240. The control of the unit roll according to the first position is stopped, and the step avoidance control (QOC) is corrected according to the second position of the front end of the strip detected by the second infrared sensor 242. This is because after the start of the winding due to the deformation of the strip, the error of calculation, the positional change of the equipment itself, etc., when the tip position of the strip (the first position of the strip leading edge) detected / calculated during the movement from the pinch roll to the winding machine arrives at the winding machine. This is because the reliability is lower than the detected tip position (second position of the strip tip). That is, the second position of the front end of the strip detected by the second infrared sensor 242 is a value that more accurately displays the position of the front end of the strip that is actually wound than the first position of the front end of the strip. Through the operation of the control unit 200 as described above, more accurate step avoidance control (QOC) can be performed.

Meanwhile, the pulse generator (PG) 280 is installed in a hydraulic cylinder that opens / closes the second unit roll 122 to count the number of times of opening and closing. The installation position of the pulse generator (PG) is not limited to the hydraulic cylinder of the second unit roll 122, it may be installed in any one of the hydraulic cylinder of the plurality of unit rolls. When the counted number reaches a preset number, the controller 200 opens the entire unit rolls 121, 122, 123, and 124 and stops the step avoidance control (QOC). The progress of the step avoidance control (QOC) can be visually displayed through a display unit (not shown) to help the facility driver grasp the facility status.

3 is a flow chart showing an example of the operation of the present invention. First, when the produced strip passes through the pinch roll, the first infrared sensor passes the upper and lower pinch rolls to irradiate infrared rays onto the strip surface moving with the winding machine to detect a time when the front end of the strip passes through a specific position (S31). ). Subsequently, the control unit uses the elapsed time from the time when the front end of the strip sensed by the first infrared sensor passes a specific position and the rotation speed of the pinch roll calculated by the pulse logic generator (PLG) to determine the first end of the strip front part. The position is calculated (S32). Subsequently, the open / close of each unit roll is controlled according to the calculated first position of the front end of the strip, that is, the front end position calculated by detecting the strip of the first infrared sensor (S33). Subsequently, the second infrared sensor detects the position of the tip of the strip in the winding machine circumferential direction by irradiating infrared rays onto the strip wound around the winder, and the control unit uses the same to open and close the plurality of unit rolls. (close) to control (S34). The number of open and close counts of the unit roll counted by the pulse generator (PG) installed in the hydraulic cylinder of any unit roll during the end avoidance control (QOS) by controlling the unit roll as described above. When a predetermined number of times is reached (S35), the controller opens the entire unit roll and ends the step avoidance control (QOC).

According to the QOC method of the winding machine according to the present invention as described above, by using two infrared sensors more reliable than the conventional vibration sensor, the position of the strip tip is sensed twice so that the more accurate strip tip By performing the step roll avoidance control (QOC) of the unit roll at the position of, it is possible to contribute to the improvement of the quality of the strip by securing the rolling gutter and preventing the flaw of the strip surface caused by the leading edge of the strip during the initial winding of the strip. Excellent effect.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

Claims (2)

In the winding machine for winding the strip passing through the upper and lower pinch roll, in the step avoidance control (QOC) method by opening and closing a plurality of unit rolls, Irradiating infrared rays to the surface of the strip moving through the upper and lower pinch rolls to the winder to detect a time when the tip of the strip passes through a specific position; Calculating the position of the strip tip using the elapsed time after the rotational speed of the pinch roll and the time at which the strip tip passes the specific position are detected; A first unit roll control step of starting winding of the strip by controlling the opening and closing of the plurality of unit rolls along the leading edge of the strip; A second uni that controls the opening and closing of the plurality of unit rolls by sensing the position of the tip of the strip in the circumferential direction of the winder by irradiating infrared rays to the strip wound around the winder; A step avoidance control (QOC) method in a winder comprising a troll control step. The method of claim 1, wherein the step avoidance control (QOC) method of the winder comprises: Counting the opening and closing of at least one unit roll of the plurality of unit rolls, and opening the plurality of unit rolls if the number of open and close matches the predetermined number of times. and opening the step of stopping the control of the unit roll (QOC) method.