A coiler guide control method

Abstract

The present invention provides a coiler guide control method. The present invention includes the following steps: after the secondary short-stroke completion signal arrives, the PLC controls the working side guide and the drive side guide to simultaneously enter the pressure closed-loop control, and judges the pressure feedback and duration of the working side guide and / or the drive side guide based on whether the control mode is the drive side force control mode or the working side force control mode. When the preset value is exceeded, the PLC sends a signal to stop the pressure control to the working side guide or the drive side guide based on whether the control mode is the drive side force control mode or the working side force control mode. After the present invention is put into operation, based on the method of detecting and controlling the pressure on both sides of the guide, the phenomenon of single-sided tower shape at the head of the steel coil after coiling is greatly eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of steel rolling processes, and particularly to a control method for coiler guide rails. Background Art

[0002] The guide rail is an essential device in strip steel rolling mills and finishing mills. Its function is to hold the strip steel through the guide rail, ensure that the strip steel is aligned with the rolling center line, and is correctly and smoothly fed into the subsequent units, so as to improve the running stability of the strip steel and reduce defects such as coil tower shape. The guide rail is divided into a working side guide rail and a driving side guide rail, and both sides of the guide rail are composed of a parallel section and a flare section. The centering of strip steel with different widths and specifications is controlled by adjusting the opening degrees of the guide rails on both sides.

[0003] In the prior art, such as the technology of "A Control Method for Thin Strip Threading of the Guide Rail of a Hot Rolling Coiler" with the application number 201210559466.6, after the short stroke action of the guide rail of the hot rolling coiler is in place when the strip head enters the guide rail, the position control is changed to single-sided pressure control, and the guide rail holds the strip steel by fitting with the single-sided pressure control as Figure 1 shown. During the process from the start of pressure control to holding the strip steel, only one-sided guide rail is operating, which causes all the mechanical clearances and set safety margins of the guide rail to be eliminated on one side. The strip steel is gradually pushed to one side by the guide rail, forming a tower shape defect as Figure 2 shown at the head of the steel coil. This defect will be very obvious when the mechanical clearance of the guide rail becomes larger and the strip steel feeding position biases towards the side of the force control guide rail.

[0004] For the "A Control Method for the Short Stroke of the Guide Rail of a Coiling Machine" with the application number 201810219073.8, it mainly focuses on the control of the short stroke of the guide rail and cannot fundamentally solve the tower shape defect. Summary of the Invention

[0005] In view of the above-mentioned technical problems, a control method for coiler guide rails is provided. The technical means adopted by the present invention are as follows:

[0006] A control method for coiler guide rails includes the following steps:

[0007] After the signal of the second short stroke is completed, the PLC controls the working side guide rail and the driving side guide rail to simultaneously enter the pressure closed-loop control. Based on whether the control mode is the driving side force control mode or the working side force control mode, the pressure feedback and duration of the working side guide rail and / or the driving side guide rail are judged. When the preset value is exceeded, the PLC sends a signal to stop the pressure control to the working side guide rail or the driving side guide rail based on whether the control mode is the driving side force control mode or the working side force control mode.

[0008] Further, after the strip head reaches the middle position of the guide ruler, the PLC controls the working side and the driving side of the guide ruler to perform a short stroke; after the first short stroke ends, the PLC controls the working side and the driving side of the guide ruler to perform a second short stroke; after the second short stroke ends, the second short stroke completion signal is generated.

[0009] Further, when the control mode is the force control mode on the driving side, the working side guide ruler stops pressure control when one of the following two conditions is met:

[0010] a1. After the pressure feedback of the working side guide ruler is greater than 50-90% of the preset value and lasts for more than 200-1000 ms.

[0011] a2. After the sum of the pressure feedback value on the driving side and the pressure feedback value on the working side reaches 1.5-2 times of the preset value and lasts for more than 100-500 ms.

[0012] Further, when the control mode is the force control mode on the working side, the driving side guide ruler stops pressure control when one of the following two conditions is met:

[0013] a1. The pressure feedback of the driving side guide ruler is greater than 50-90% of the preset value and lasts for more than 200-1000 ms.

[0014] a2. After the sum of the pressure feedback value on the driving side and the pressure feedback value on the working side reaches 1.8 times of the preset value and lasts for more than 100-500 ms.

[0015] Further, the preset value is specifically set based on different steel grades, and the preset value ≥ 10 kN.

[0016] The present invention has the following advantages: After the present invention is put into operation, based on the method of simultaneously detecting pressure and controlling on both sides of the guide ruler, the single-sided tower shape phenomenon of the strip head of the coiled strip after coiling is greatly eliminated. From the comparison of the blocked data, after the bilateral force control function of the guide ruler head is put into operation, the tower shape and the hemming blockage caused by the tower shape are basically reduced from more than 160 rolls per month to more than a dozen rolls. After implementing the present invention, the number of blocked reworks is reduced by at least more than 1700 rolls per year. It can create an efficiency of more than 2 million yuan per year. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1Schematic diagram of the working state where the strip steel is pushed towards the working side in the prior art.

[0019] Figure 2 Tower-shaped defect formed after adopting the prior art.

[0020] Figure 3 Schematic diagram of the working state where the guide rulers on both sides of the present invention are simultaneously force-controlled and pushed inward. Detailed implementation manners

[0021] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] As Figure 3 shown, the embodiments of the present invention disclose a method for controlling the guide rulers of a coiler, including the following steps:

[0023] After the strip steel head reaches the middle position of the guide rulers, the PLC controls the working side and the driving side of the guide rulers to perform a short stroke once; after the first short stroke ends, the PLC controls the working side and the driving side of the guide rulers to perform a second short stroke; after the second short stroke ends, the signal indicating the completion of the second short stroke.

[0024] Different from the prior art, after the signal indicating the completion of the second short stroke comes, the PLC controls the working side guide ruler and the driving side guide ruler to simultaneously enter the pressure closed-loop control, judges the pressure feedback and the duration of the working side guide ruler and / or the driving side guide ruler based on whether the control mode is the driving side force control mode or the working side force control mode, and when it exceeds the preset value, the PLC sends a signal to stop the pressure control to the working side guide ruler or the driving side guide ruler based on whether the control mode is the driving side force control mode or the working side force control mode.

[0025] When the control mode is the driving side force control mode, the working side guide ruler stops the pressure control when one of the following two conditions is met:

[0026] In this embodiment, the specific parameter values applied are as follows:

[0027] a1. After the pressure feedback of the working side guide ruler is greater than 85% of the preset value, the pressure setting exceeds 500 ms.

[0028] a2. After the sum of the pressure feedback value of the driving side and the pressure feedback value of the working side reaches 1.8 times the preset value, the pressure setting exceeds 100 ms.

[0029] When the control mode is the working side force control mode, the pressure control of the driving side guide ruler stops when one of the following two conditions is met:

[0030] a1. The pressure feedback of the driving side guide ruler is greater than 85% of the preset value, and the pressure setting exceeds 500 ms.

[0031] a2. After the sum of the pressure feedback value of the driving side and the pressure feedback value of the working side reaches 1.8 times the preset value, the pressure setting exceeds 100 ms.

[0032] The preset value is set specifically based on different steel grades, and the preset value ≥ 20 kN.

[0033] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coiler guide control method, characterized in that, The steps are as follows: After the signal of the second short stroke is completed, the PLC controls the working side guide and the driving side guide to simultaneously enter the pressure closed-loop control, and judges the pressure feedback and the duration of the working side guide and / or the driving side guide based on whether the control mode is the driving side force control mode or the working side force control mode. When the preset value is exceeded, the PLC sends a signal to stop the pressure control to the working side guide or the driving side guide based on whether the control mode is the driving side force control mode or the working side force control mode; When the head of the strip reaches the middle position of the guide, the PLC controls the working side of the guide and the driving side of the guide to perform a short stroke; after the short stroke is completed, the PLC controls the working side of the guide and the driving side of the guide to perform a second short stroke; after the second short stroke is completed, the signal of the second short stroke completion is generated; When the control mode is the driving side force control mode, the working side guide stops the pressure control when one of the following two conditions is met: a1. After the pressure feedback of the working side guide is greater than 50-90% of the preset value, the duration exceeds 200-1000 ms; a2. After the sum of the pressure feedback value of the driving side and the pressure feedback value of the working side reaches 1.5-2 times of the preset value, the duration exceeds 100-500 ms; When the control mode is the working side force control mode, the driving side guide stops the pressure control when one of the following two conditions is met: a1. The pressure feedback of the driving side guide is greater than 50-90% of the preset value, and the duration exceeds 200-1000 ms; a2. After the sum of the pressure feedback value of the driving side and the pressure feedback value of the working side reaches 1.8 times of the preset value, the duration exceeds 100-500 ms.

2. The coiler guide control method according to claim 1, wherein The preset value is set specifically based on different steel grades, and the preset value ≥ 10 kN.

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