A method for controlling tower-shaped defects in hot rolling production lines

Abstract

This invention discloses a method for controlling tower-shaped defects in a hot rolling production line. Hot metal detectors are installed at the exit of the side guide plates of each coiler. By using the metal detectors in conjunction with the opening and closing of the side guide plates (W2 ≥ 10mm for a single side guide plate with a short stroke opening of 1 / 2), the side guide plates of the upstream coiler are used to center the strip during the winding process of the downstream coiler, effectively reducing tower-shaped defects. Since the side guide plates only close when the strip reaches the exit of the upstream stand, the risk of scrap is low. Furthermore, this invention does not require high precision and can be achieved using inexpensive hot metal detectors, eliminating the need for expensive laser detection equipment and significantly reducing production costs. Moreover, because the side guide plates close only after the strip head has passed, the invention avoids the wavy area at the strip head, reducing edge damage defects caused by wavy lines.

Description

Technical Field

[0001] This invention relates to the field of hot rolling technology in iron and steel metallurgy, and in particular to a control method for reducing tower-shaped defects by using the upstream coiler side guide plate to center the strip steel during the strip threading process of the coiler in a hot rolling production line. Background Technology

[0002] The coiler is a crucial piece of equipment on the hot rolling production line of various steel production enterprises. Located after the finishing mill, it is the final process in the hot continuous rolling production line, used to coil hot-rolled strip steel into coils. The entire process flow is as follows:

[0003] The strip steel is conveyed from the finishing mill to the coiler unit via roller conveyors, and then enters the pinch rolls after being centered by the side guides. The main function of the pinch rolls is to apply a certain clamping force to the strip steel during the initial biting stage, while simultaneously inducing its first bending deformation. During the tail coiling stage, the pinch rolls apply stable tension to the strip steel to ensure good coil quality. The next three auxiliary coiling rolls help bend the strip steel and tightly wrap it around the coil drum. After the strip steel is wrapped around the drum, tension is applied to ensure qualified coil quality. To ensure continuous and uninterrupted production, a typical hot rolling production line is equipped with 2 to 3 coilers, each equipped with a pair of side guides and a pair of pinch rolls.

[0004] After the strip steel is coiled into a coil by the coiler, some inner coil layers often bulge to one side. When the bulge exceeds a certain standard, it is called a tower defect. Tower defects are generally caused by the sickle bend of the strip head or poor centering function of the coiler's side guide plate. Steel coil products have strict requirements, and tower defects will cause users to be dissatisfied with their quality. If a tower defect that exceeds the user's requirements occurs, it must be re-coiled and repaired after the finishing process, which will result in quality cost losses.

[0005] Besides the tower-shaped defect, there is also an edge damage defect, which is the damage to the edge of the strip due to scratches from the side guide plate or during transportation. This is a common defect in hot-rolled steel plates. Hot-rolled plates with edge damage defects will seriously affect the user's use, and may lead to strip breakage accidents when cold rolling continues. Therefore, edge damage defects in strip steel are unacceptable and must be removed in the finishing process, resulting in time and quality cost losses.

[0006] The existing side guide plate control method is as follows:

[0007] To prevent the strip head from being clamped by the side guide plate and causing a jamming accident, the side guide plate has a pre-set opening degree based on the strip width before the strip head reaches it. The formula for this opening degree is:

[0008] S = B + 2W1 + B0

[0009] In the formula:

[0010] S: Opening degree of the side guide plate

[0011] B: Strip width

[0012] W 1： Short-stroke opening of the side guide plate on one side

[0013] B0: Additional Value

[0014] When the No. 1 coiler is coiling, short stroke a closes when the strip head reaches the exit T1 of the No. 1 side guide plate. When the No. 2 coiler is coiling, short stroke b closes when the strip head reaches the exit T2 of the No. 2 side guide plate. When the No. 3 coiler is coiling, short stroke c closes when the strip head reaches the exit T3 of the No. 3 side guide plate. After closing, the opening degree of the side guide plate is S' = B + B0.

[0015] However, after long-term observation by on-site operators, it was found that the existing side guide plate control method is prone to tower-shaped defects, for the following reasons:

[0016] Theoretically, the smaller the short-stroke opening 2W1 of the side guide plate before the strip head reaches the side guide plate, the closer the strip will be to centering when entering the pinch rolls, and the lower the probability of tower defects. However, in reality, if the short-stroke opening 2W1 of the side guide plate is too small, the strip head is more prone to jamming accidents. Generally, the short-stroke opening 2W1 of the side guide plate of a hot rolling coiler is ≥80mm, that is, the short-stroke opening W1 of the side guide plate on one side is ≥40mm. Although such an opening can avoid jamming accidents, the closing time is longer, resulting in a higher incidence of tower defects. In addition to tower defects, the existing side guide plate control method is also prone to strip edge damage defects. This is because the strip head usually has varying degrees of waviness or excessive width, and the coiler tension has not yet been established at this time. Therefore, during the short-stroke high-speed closing process, the strip edge is easily damaged by the side guide plate.

[0017] Through research and literature review, it was learned that, in order to reduce tower-shaped defects, researchers in the hot rolling field have developed a two-stage short-stroke control technology for side guide plates. This involves closing the first stage when the strip head reaches the middle of the side guide plate, and closing the second stage when the strip head reaches the exit of the side guide plate. This avoids the risk of scrap steel and helps the strip to be more aligned when entering the pinch rolls. However, practical experience has revealed that the two-stage short-stroke control of side guide plates also has drawbacks:

[0018] 1. High accuracy requirements for testing:

[0019] Because the strip head has a fast threading speed and the side guide plate is short, a high detection accuracy is required to close the first stage when the strip head reaches the middle of the side guide plate. If the first stage closes too early, it may result in scrap steel; if the first stage closes too late, it will not be effective.

[0020] 2. Laser equipment is expensive:

[0021] To ensure high detection accuracy, laser detection equipment was added. However, laser detection equipment is expensive, difficult to maintain, and has high spare parts costs, which indirectly increases production costs.

[0022] 3. Cannot resolve edge damage defects caused by wave-like patterns:

[0023] Since the two-stage short-stroke circuit also closes near the head of the strip, it is prone to edge damage defects.

[0024] Therefore, there is an urgent need for a control method that can effectively solve the tower-shaped defect, reduce scrap steel in the coiler, and reduce edge damage defects. Summary of the Invention

[0025] In summary, to address the shortcomings of existing technologies, this invention provides a method for controlling tower-shaped defects in hot rolling production lines. During the strip threading process of the downstream coiler, the side guide plate of the upstream coiler is used to center the strip, reducing scrap steel in the coiler and lowering the incidence of tower-shaped defects and edge damage defects.

[0026] A method for controlling tower-shaped defects in a hot rolling production line, comprising strip steel and a coiling unit, wherein the specific steps are as follows:

[0027] 1) The winding unit is equipped with 3 winding machines, which are winding machine No. 1, winding machine No. 2 and winding machine No. 3 in sequence. A hot metal detector is installed at the side guide plate outlet of each winding machine, which are hot metal detector No. 1, hot metal detector No. 2 and hot metal detector No. 3 in sequence.

[0028] Three winding machines are a common type of winding machine unit. There are also configurations with two or more winding machines. The number of hot metal detectors should be increased or decreased accordingly.

[0029] 2) After the strip is rolled out from the last stand of the finishing mill of the coiler, the speed measuring device connected to the motor of the last stand of the finishing mill uploads the measured speed to the finishing mill base automation computer. The finishing mill base automation computer transmits the known roll diameter and speed to the coiling base automation computer. The coiling base automation computer calculates the position of the strip head based on the roll diameter and speed.

[0030] 3) As the strip moves forward, when the No. 2 coiler is ready to coil the strip, the No. 1 hot metal detector detects the head of the strip and uploads the signal to the coiling base automation computer. The coiling base automation computer judges the confidence level of the signal from the No. 1 hot metal detector. If it is a reliable signal, the side guide plate in the No. 1 coiler area is closed 2W2 by the control system of the No. 1 side guide plate hydraulic servo valve and the No. 1 hydraulic cylinder at the No. 1 coiler position.

[0031] When the No. 2 coiler is ready to coil the strip, the side guide plate 2W2 of the No. 1 coiler area is closed. In fact, the head of the strip has already passed through the side guide plate of the No. 1 coiler area at this time. Closing the side guide plate 2W2 at this point will not cause scrap steel.

[0032] 4) When the strip head reaches the pinch roll of the No. 2 coiler, the hydraulic servo valve control system of the No. 1 side guide plate and the No. 1 hydraulic cylinder open the side guide plate of the No. 1 coiler area by 2W2.

[0033] 5) As the strip moves forward, when the No. 3 coiler is ready to coil the strip, the No. 1 hot metal detector detects the head of the strip and uploads the signal to the coiling base automation computer. The coiling base automation computer judges the confidence level of the signal from the No. 1 hot metal detector. If it is a reliable signal, the side guide plate in the No. 1 coiler area is closed 2W2 by the control system of the No. 1 side guide plate hydraulic servo valve and the No. 1 hydraulic cylinder at the No. 1 coiler position.

[0034] 6) The strip continues to move forward. When the No. 2 hot metal detector detects the head of the strip and uploads the signal to the coiling base automation computer, the coiling base automation computer judges the confidence level of the signal from the No. 2 hot metal detector. If it is a reliable signal, the No. 2 side guide plate hydraulic servo valve control system and the No. 2 hydraulic cylinder at the No. 2 coiling machine position will close the side guide plate in the No. 2 coiling machine area 2W2.

[0035] When the No. 3 coiler is preparing to coil the strip in steps 5) and 6), the side guide plate 2W2 of the No. 1 coiler area is closed. When the head of the strip reaches the position of the No. 2 hot metal detector, the side guide plate 2W2 of the No. 2 coiler area is closed.

[0036] 7) When the strip head reaches the pinch roll of the No. 3 coiler, the hydraulic servo valve control system of the No. 1 side guide plate, the No. 1 hydraulic cylinder, the hydraulic servo valve control system of the No. 2 side guide plate, and the No. 2 hydraulic cylinder will open the side guide plates in the No. 1 and No. 2 coiler areas again 2W2.

[0037] According to a method for controlling tower-shaped defects in a hot rolling production line based on the present invention, the hot metal detectors are all equipped with detection windows. When the calculated position of the strip head reaches the vicinity of the detection point of the corresponding hot metal detector, the corresponding detection window is opened. At this time, the strip signal detected by the hot metal detector within the corresponding window is determined to be a reliable signal.

[0038] According to a method for controlling tower-shaped defects applied to a hot rolling production line, the detection point of the hot metal detector is located within a range of ±0.5 to 15m from the hot metal detector.

[0039] The purpose of this design is to determine the confidence level of the hot metal detector signal in order to prevent problems caused by false signals. To this end, a detection window for the hot metal detector is set, and the specific location of the detection point is defined.

[0040] According to a method for controlling tower-shaped defects in a hot rolling production line, the value range of W2 in each step is: 1 / 2 of the short stroke opening of the side guide plate on one side ≥ W2 ≥ 10mm.

[0041] According to a method for controlling tower-shaped defects in a hot rolling production line, the method is characterized in that if the signal in step 3) is unreliable, the centering function of the side guide plate in the No. 1 coiler area is canceled and the side guide plate does not move.

[0042] According to a method for controlling tower-shaped defects in a hot rolling production line, the method is characterized in that if the signals in steps 5) and 6) are unreliable, the centering function of the side guide plates in the areas of the No. 1 coiler and the No. 2 coiler is cancelled, and neither side guide plate operates.

[0043] The present invention provides a method for controlling tower-shaped defects in a hot rolling production line. The overall control process is briefly described as follows:

[0044] 1) When the No. 2 winding machine is ready to wind, the side guide plate of the No. 1 winding machine area is closed by 2W2. At this time, the side guide plate of the No. 1 winding machine area is centered.

[0045] 2) When the position of the strip head in step 1) reaches within ±0.5 to 15m of the No. 1 hot metal detector, the detection window is opened, and the hot metal detector signal appearing within this window is considered a reliable signal.

[0046] 3) If the signal is reliable, then the side guide plate 2W2 in the No. 1 winding machine area will be turned off. If the signal is unreliable, then the centering function of the No. 1 side guide plate will be canceled and the No. 1 side guide plate will not operate.

[0047] 4) When the strip head reaches the pinch roll of the No. 2 coiler, the side guide plate of the No. 1 coiler area will reopen 2W2.

[0048] 5) When the No. 3 winding machine is ready to wind, the side guide plates in the No. 1 winding machine area and the No. 2 winding machine area are closed by 2W2. The centering control is performed on these two side guide plates.

[0049] 6) When the position of the strip head in step 5) above reaches within ±0.5 to 15m of the No. 1 and No. 2 hot metal detectors, the detection window is opened, and the hot metal detector signal appearing within this window is considered a reliable signal.

[0050] 7) If the signal is reliable, turn off the side guides of the No. 1 winding machine area and the No. 2 winding machine area 2W2. If the signal is unreliable, cancel the centering function of the side guides of the No. 1 winding machine area and the No. 2 winding machine area, and neither side guide will operate.

[0051] 8) When the strip head reaches the pinch roll of the No. 3 coiler, the side guide plates of the No. 1 coiler area and the No. 2 coiler area open 2W2 again.

[0052] The following beneficial effects were obtained by using the tower-shaped defect control method of the present invention applied to a hot rolling production line:

[0053] 1) Compared with the original technology, the method for controlling tower-shaped defects applied to hot rolling production lines of the present invention can effectively reduce tower-shaped defects by using the side guide plate of the upstream coiler to center the strip during the winding process of the downstream coiler.

[0054] 2) Compared with the two-stage short-stroke control technology of side guide plates, the tower-shaped defect control method of the present invention applied to the hot rolling production line has a lower risk of scrap steel because the side guide plates will only close when the strip reaches the outlet of the upstream stand.

[0055] 3) Compared with the two-stage short-stroke control technology of the side guide plate, the tower-shaped defect control method of the present invention applied to the hot rolling production line has lower precision requirements and is relatively easier to implement. It does not require the addition of expensive laser detection equipment and can be achieved by relying solely on inexpensive hot metal detectors, which greatly reduces production costs.

[0056] 4) The tower-shaped defect control method of the present invention applied to the hot rolling production line closes the side guide plate only after the strip head has passed, thus avoiding the wavy area of ​​the strip head and reducing edge damage defects caused by wavy shape. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of a specific structure of a tower-shaped defect control method applied to a hot rolling production line according to the present invention;

[0058] In the diagram: 1-Strip steel, 1a-Strip head, 2-Coiler unit, 2a-No. 1 coiler, 2a1-No. 1 side guide plate hydraulic servo valve control system, 2a2-No. 1 hydraulic cylinder, 2b-No. 2 coiler, 2b1-No. 2 side guide plate hydraulic servo valve control system, 2b2-No. 2 hydraulic cylinder, 2c-No. 3 coiler, 3a-No. 1 hot metal detector, 3b-No. 2 hot metal detector, 3c-No. 3 hot metal detector, 4-Finishing mill end stand, 5-Motor, 6-Speed ​​measuring device, 7-Finishing mill basic automation computer, 8-Coiler basic automation computer. Detailed Implementation

[0059] The technical means, creative features, objectives, and effects of the tower-shaped defect control method applied to hot rolling production lines of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0060] like Figure 1 As shown, a method for controlling tower-shaped defects applied to a hot rolling production line includes strip steel 1 and coiling unit 2, and its specific steps are as follows:

[0061] 1) The winding unit 2 is equipped with 3 winding machines, which are winding machine 1 2a, winding machine 2b and winding machine 3 2c in sequence. A hot metal detector is installed at the side guide plate outlet of each winding machine, which are hot metal detector 1 3a, hot metal detector 2 3b and hot metal detector 3c in sequence.

[0062] 2) After the strip 1 is rolled out by the last stand 4 of the finishing mill of the coiler 2, the speed measuring device 6 connected to the motor 5 of the last stand of the finishing mill uploads the measured speed to the finishing mill base automation computer 7. The finishing mill base automation computer transmits the known roll diameter and speed to the coiling base automation computer 8. The coiling base automation computer calculates the position of the strip head 1a based on the roll diameter and speed.

[0063] 3) As the strip moves forward, when the No. 2 coiler 2b is ready to coil the strip, the No. 1 hot metal detector 3a detects the strip head 1a and uploads the signal to the coiling base automation computer 8. The coiling base automation computer judges the confidence level of the signal from the No. 1 hot metal detector. If it is a reliable signal, the side guide plate in the area of ​​the No. 1 coiler is closed 2W2 by the control system 2a1 of the hydraulic servo valve of the No. 1 side guide plate at the position of the No. 1 coiler 2a and the No. 1 hydraulic cylinder 2a2.

[0064] 4) When the strip head reaches the pinch roll of the No. 2 coiler 2b, the No. 1 side guide plate hydraulic servo valve control system 2a1 and the No. 1 hydraulic cylinder 2a2 open the side guide plate of the No. 1 coiler area 2W2.

[0065] 5) As the strip moves forward, when the No. 3 coiler 2c is ready to coil the strip, the No. 1 hot metal detector 3a detects the strip head 1a and uploads the signal to the coiling base automation computer 8. The coiling base automation computer judges the confidence level of the signal from the No. 1 hot metal detector. If it is a reliable signal, the side guide plate in the No. 1 coiler area is closed 2W2 by the control system 2a1 and the No. 1 hydraulic cylinder 2a2 of the hydraulic servo valve of the No. 1 side guide plate at the position of the No. 1 coiler 2a.

[0066] 6) The strip continues to move forward. When the No. 2 hot metal detector 3b detects the strip head 1a and uploads the signal to the coiling base automation computer 8, the coiling base automation computer judges the confidence level of the signal from the No. 2 hot metal detector. If it is a reliable signal, the side guide plate in the No. 2 coiling machine area is closed 2W2 by the control system 2b1 and the No. 2 hydraulic cylinder 2b2 of the No. 2 side guide plate hydraulic servo valve at the No. 2 coiling machine 2b position.

[0067] 7) When the strip head reaches the pinch roll of the No. 3 coiler 2c, the No. 1 side guide plate hydraulic servo valve control system 2a1, the No. 1 hydraulic cylinder 2a2 and the No. 2 side guide plate hydraulic servo valve control system 2b1 and the No. 2 hydraulic cylinder 2b2 will reopen the side guide plates in the No. 1 and No. 2 coiler areas 2W2.

[0068] Each of the hot metal detectors 3 is equipped with a detection window. When the calculated position of the strip head reaches the vicinity of the detection point of the corresponding hot metal detector, the corresponding detection window is opened. At this time, the signal of the strip detected by the hot metal detector within the corresponding window is determined to be a reliable signal.

[0069] The detection point of the hot metal detector is located within ±0.5 to 15m of the hot metal detector.

[0070] The value range of W2 in each step: 1 / 2 of the short stroke opening of the single-sided guide plate ≥ W2 ≥ 10mm.

[0071] If the signal in step 3) is unreliable, the centering function of the side guide plate in the No. 1 winding machine area will be cancelled, and the side guide plate will not move.

[0072] If the signals in steps 5) and 6) are unreliable, the centering function of the side guide plates in the No. 1 winding machine and No. 2 winding machine areas will be canceled, and neither side guide plate will operate.

[0073] Example – Implemented on the side guide plate system of the coiler in a 2050 production line, as follows:

[0074] In this embodiment, W2 = 10 mm, and the detection point distance of the hot metal detector is 3.5 m.

[0075] When the No. 2 coiler is preparing to coil the strip, the No. 1 hot metal detector detects the strip head and uploads the signal to the coiling base automation computer. The coiling base automation computer determines the confidence level of the signal from the No. 1 hot metal detector. If the signal is reliable, the No. 1 side guide plate hydraulic servo valve control system and the No. 1 hydraulic cylinder in the No. 1 coiler area immediately close the side guide plate of the No. 1 coiler area by 2W2 = 20mm (hereinafter abbreviated as 20mm).

[0076] When the strip head reaches the pinch roll of the No. 2 coiler, the hydraulic servo valve control system of the No. 1 side guide plate and the No. 1 hydraulic cylinder immediately open the side guide plate of the No. 1 coiler area by 20mm. If the signal is unreliable, the centering function of the side guide plate of the No. 1 coiler area is canceled, and the side guide plate does not move.

[0077] When the No. 3 coiler is preparing to coil the strip, the No. 1 hot metal detector detects the strip head and uploads the signal to the coiling base automation computer. The coiling base automation computer determines the confidence level of the signal from the No. 1 hot metal detector. If the signal is reliable, the side guide plate in the No. 1 coiler area is immediately closed by 20mm via the No. 1 side guide plate hydraulic servo valve control system and the No. 1 hydraulic cylinder.

[0078] The strip continues to move forward. When the No. 2 hot metal detector detects the strip head, it uploads a signal to the coiling base automation computer. The coiling base automation computer determines the confidence level of the signal from the No. 2 hot metal detector. If the signal is reliable, the No. 2 side guide plate hydraulic servo valve control system and the No. 2 hydraulic cylinder in the No. 2 coiling machine area immediately close the No. 2 side guide plate by 20mm.

[0079] When the strip head reaches the pinch roll of the No. 3 coiler, the hydraulic servo valve control system of the No. 1 side guide plate, the No. 1 hydraulic cylinder, and the hydraulic servo valve control system of the No. 2 side guide plate, and the No. 2 hydraulic cylinder, open their respective side guide plates by 20mm. If the signal is unreliable, the centering function of the No. 1 and No. 2 side guide plates is canceled, and the No. 1 and No. 2 side guide plates do not move.

[0080] However, those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any changes or modifications to the above embodiments within the spirit and essence of this application will fall within the scope of the claims of this application.

[0081] Compared with the original technology, the method for controlling tower defects in hot rolling production lines of this invention utilizes the side guide plate of the upstream coiler to center the strip during the downstream coiler winding process, which can effectively reduce tower defects. Compared with the two-stage short-stroke control technology of the side guide plate, the method for controlling tower defects in hot rolling production lines of this invention closes the side guide plate only when the strip reaches the exit of the upstream stand, resulting in a lower risk of scrap steel. Compared with the two-stage short-stroke control technology of the side guide plate, the method for controlling tower defects in hot rolling production lines of this invention has lower precision requirements and is relatively easier to implement. It does not require expensive laser detection equipment and can be achieved using only inexpensive hot metal detectors, greatly reducing production costs. Since the method for controlling tower defects in hot rolling production lines of this invention closes the side guide plate only after the strip head has passed, it avoids the wavy area at the strip head, thus reducing edge damage defects caused by wavy patterns.

Claims

1. A method for controlling tower-shaped defects in a hot rolling production line, comprising strip steel (1) and a coiling unit (2), the specific steps of which are as follows: 1) The winding unit (2) is equipped with 3 winding machines, which are winding machine No. 1 (2a), winding machine No. 2 (2b) and winding machine No. 3 (2c) in sequence. A hot metal detector is installed at the side guide plate outlet of each winding machine, which are hot metal detector No. 1 (3a), hot metal detector No. 2 (3b) and hot metal detector No. 3 (3c) in sequence. 2) After the strip (1) is rolled out by the last stand (4) of the finishing mill of the coiler (2), the speed measuring device (6) connected to the motor (5) of the last stand of the finishing mill uploads the measured speed to the finishing mill base automation computer (7). The finishing mill base automation computer transmits the known roll diameter and speed to the coiling base automation computer (8). The coiling base automation computer calculates the position of the strip head (1a) based on the roll diameter and speed. 3) As the strip moves forward, when the No. 2 coiler (2b) is ready to coil the strip, the No. 1 hot metal detector (3a) detects the head of the strip (1a) and uploads the signal to the coiling base automation computer (8). The coiling base automation computer judges the confidence level of the signal from the No. 1 hot metal detector. If it is a reliable signal, the side guide plate in the area of ​​the No. 1 coiler is closed 2W2 by the No. 1 side guide plate hydraulic servo valve control system (2a1) and the No. 1 hydraulic cylinder (2a2) at the position of the No. 1 coiler (2a). 4) When the strip head reaches the pinch roll of the No. 2 coiler (2b), the No. 1 side guide plate hydraulic servo valve control system (2a1) and the No. 1 hydraulic cylinder (2a2) open the side guide plate of the No. 1 coiler area 2W2. 5) As the strip moves forward, when the No. 3 coiler (2c) is ready to coil the strip, the No. 1 hot metal detector (3a) detects the head of the strip (1a) and uploads the signal to the coiling base automation computer (8). The coiling base automation computer judges the confidence level of the signal from the No. 1 hot metal detector. If it is a reliable signal, the side guide plate in the area of ​​the No. 1 coiler is closed 2W2 by the control system (2a1) of the hydraulic servo valve of the No. 1 side guide plate at the position of the No. 1 coiler (2a) and the No. 1 hydraulic cylinder (2a2). 6) The strip continues to move forward. When the No. 2 hot metal detector (3b) detects the head of the strip (1a) and uploads the signal to the coiling base automation computer (8), the coiling base automation computer judges the confidence level of the signal from the No. 2 hot metal detector. If it is a reliable signal, the side guide plate in the area of ​​the No. 2 coiling machine is closed 2W2 by the control system (2b1) of the No. 2 side guide plate hydraulic servo valve at the position of the No. 2 coiling machine (2b) and the No. 2 hydraulic cylinder (2b2). 7) When the strip head reaches the pinch roll of the No. 3 coiler (2c), the hydraulic servo valve control system (2a1) of the No. 1 side guide plate, the hydraulic cylinder (2a2) of the No. 1 side guide plate, the hydraulic servo valve control system (2b1) of the No. 2 side guide plate, and the hydraulic cylinder (2b2) ​​of the No. 2 side guide plate will open the side guide plates in the No. 1 and No. 2 coiler areas again 2W2. 8) In steps 3) to 7) above, the value range of W2 is: 1 / 2 of the short stroke opening of the single-sided guide plate ≥ W2 ≥ 10mm.

2. The method for controlling tower-shaped defects applied to a hot rolling production line as described in claim 1, characterized in that, The hot metal detectors (3) are all equipped with detection windows. When the calculated position of the strip head reaches the vicinity of the detection point of the corresponding hot metal detector, the corresponding detection window is opened. At this time, the hot metal detector detects the strip signal within the corresponding window and then it is determined to be a reliable signal.

3. The method for controlling tower-shaped defects applied to a hot rolling production line as described in claim 2, characterized in that, The detection point of the hot metal detector is located within a range of ±0.5 to 15m from the hot metal detector.

4. The method for controlling tower-shaped defects applied to a hot rolling production line as described in claim 1, characterized in that, If the signal in step 3) is unreliable, the centering function of the side guide plate in the No. 1 winding machine area will be cancelled and the side guide plate will not move.

5. The method for controlling tower-shaped defects applied to a hot rolling production line as described in claim 1, characterized in that, If the signals in steps 5) and 6) are unreliable, the centering function of the side guide plates in the No. 1 winding machine and No. 2 winding machine areas will be cancelled, and neither side guide plate will operate.

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