A method for automatic straightening of a single stand reversing cold rolling mill

Abstract

The present application belongs to the field of cold rolling mill production process technology, and particularly relates to a method for automatic straightening of tail end of single stand reversible cold rolling mill, wherein the strip tail end is pre-straightened by automatic pressure of uncoiling and pressing roller on the strip surface; when the uncoiler head is separated from the coiling drum, the upper pinch roll is pressed down, the straightening roll is lifted to the positioning height for detection and is stopped, and the strip head end is straightened; after one-pass tail end parking, the tension is removed, the rolling mode of the main control console is converted to the auxiliary mode, the uncoiling and pressing roller and the upper pinch roll of the straightening machine are automatically lifted, the straightening roll is automatically lowered, the current automatic mode control is automatically released, and the next production is prepared. The method realizes automatic control of straightening of the strip head end during one-pass tail end parking, stabilizes the straightening quality, realizes full-automatic straightening of the strip head end, reduces labor intensity, saves human resources, improves the straightening quality of the strip head end, and effectively improves the production efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of cold rolling mill production process, specifically relating to a method for automatic straightening of a single-stand reversible cold rolling mill tail-swing. Background Technology

[0002] The production process of a single-stand reversible cold rolling mill involves single-strip rolling. Each steel strip undergoes several passes of reciprocating rolling to achieve the desired target thickness. The main equipment of the unit consists of, in order, an uncoiler, a front coiler, a main stand, and a rear coiler. The steel coil is first loaded onto the uncoiler drum, undergoes opening, straightening, and threading. The strip end bites into the jaws of the rear coiler drum and is pre-wound onto it. Then, the main stand presses down, establishing tension between the uncoiler, the rear coiler, and the main stand for the first pass of rolling. Near the end of the first pass, each steel strip undergoes a tail-spinning process, where the tail detaches from the uncoiler drum. Rolling continues between the uncoiler and the main stand in a state of tension loss until the strip tail reaches the front coiler drum, at which point the mill stops. After stopping, reverse the belt threading operation, bite the tail end of the belt into the winding drum jaws of the front winder, and establish tension after pre-winding, and then perform several reciprocating rolling passes.

[0003] When the first pass tape is unwound from the drum, the end of each tape has an inward curve, such as... Figure 1 As shown, the CPC (Cyclic Parallel Printing) automatic alignment device is located between the uncoiler drum and the straightener, with the lamp device serving as the light source below it. The moment the belt tail detaches from the drum and bends, it can collide with the light source and other equipment of the CPC automatic alignment system, causing displacement of the light source or damage to the lamps. Even with added anti-collision protection devices, these devices will eventually be damaged due to frequent impacts from the belt tail under prolonged exposure to this environment.

[0004] To ensure that the end of the belt can be smoothly bit into the jaws of the front winding machine when the belt is reversed, the belt tail also needs to be precisely straightened by a straightening machine during the tail swing to form a suitable reverse arc, that is, to straighten the downward-curving belt tail into a smooth, slightly upward-curving state.

[0005] Straightening machines are generally three-roll or five-roll straightening machines. Taking a three-roll straightening machine as an example, a three-roll straightening machine consists of an upper pinch roll, a deflecting pinch roll (lower roll), and a straightening roll. Figure 1As shown, the lower pinch roll is a fixed roll. During straightening, the upper pinch roll presses down, and the straightening roll lifts up, using the wrap angle formed between them to straighten the end of the steel strip into a smooth arc. During straightening, the operator observes the position of the strip tail and controls the timing and position of the pinch roll and straightening roll via switches. If the timing is not right, the upper pinch roll and straightening roll will move too early, which will adversely affect normal rolling and interfere with the CPC automatic centering; if the pinch roll and straightening roll move too late, the straightening of the strip head will be missed. Inaccurate control of the straightening roll height, excessive or insufficient arc of the steel strip end, or unevenness of the end laterally will all result in substandard straightening quality, causing difficulties for subsequent reverse strip threading, prolonging the reverse strip threading processing time, and reducing the production efficiency of the rolling mill. Due to the poor accuracy of manual operation timing, the end straightening quality of each steel strip is different. At the same time, since each steel strip is entirely controlled manually during the tail-off stage, the operator needs to pay close attention in advance, which also increases labor costs. Summary of the Invention

[0006] The purpose of this invention is to provide a method for automatic straightening of the tail end of a single-stand reversible cold rolling mill, which reduces labor intensity, saves human resources, and improves the straightening quality of the tail end.

[0007] The technical solution adopted by this invention to solve its technical problem is: a method for automatic straightening of a single-stand reversible cold rolling mill, comprising the following steps:

[0008] 1) Set up automatic and manual mode selection buttons on the computer. In maintenance mode, select manual mode control; in normal production mode, select automatic mode control.

[0009] 2) Install proximity switches for detection and positioning at the limit positions of the lifting and pressing of the uncoiler pressure rollers, respectively, to detect the lifting and pressing states of the uncoiler pressure rollers and to position the lifting and pressing positions.

[0010] 3) Install proximity switches on the straightening rollers of the three-roll or five-roll straightening machine to detect the lifting or pressing position of the straightening rollers, and pre-position the required appropriate height for detecting and controlling the position of the straightening rollers;

[0011] 4) Using the original data or functions of the unit: Utilize the unit's own strip length calculation function, pre-set the roll diameter and rolling procedure of the raw material to be rolled, use the speed value detected by the speed detection device of the lower roll of the straightener's steering pinch roll, and use the speed value detected by the lower roll of the uncoiling steering pinch roll to set the start conditions for automatic tail straightening: select the automatic tail straightening mode, rolling mode, first pass, speed change value of the lower roll of the steering pinch roll, and the remaining strip length is less than a certain set value;

[0012] 5) Issue the command to press down the uncoiling pressure roller. The uncoiling pressure roller automatically presses down onto the strip surface to pre-straighten the strip tail end. When the strip head of the uncoiler detaches from the drum, the tension between the uncoiler and the main frame is naturally released. The speed of the lower roller of the steering pinch roll will decrease to below 30m / min. At this time, the computer issues the command to press down the upper pinch roll and the command to lift and press down the straightening roller. The upper pinch roll presses down, and the straightening roller is lifted to the positioning height detection limit and stops to straighten the strip head end. After the tail-wagging stop of one pass, the tension is released, the rolling mode of the main control panel is switched to the auxiliary mode, and when the rolling pass is switched to the second pass, the uncoiling pressure roller and the upper pinch roll of the straightening machine are automatically lifted, the straightening roller is automatically lowered, the current automatic mode control is automatically released, and preparation is made for the next production.

[0013] Further, the automatic mode in step 1) is: set the middle position of the "press down" and "lift up" switches of the winding machine pressure roller, upper pinch roller and straightening roller to automatic mode respectively. When the switch is not in the lift or press down position, all three switches need to be turned to the middle position.

[0014] The present invention has the following beneficial effects: The present invention can realize the automatic control of the straightening of the strip end during the tailing of a single rolling process. The end is horizontally straight, the longitudinal curvature is standard, the timing of equipment start-up is precisely controlled, the straightening quality is stable, there is no manual intervention, the whole process of straightening the strip end is automated, the impact of the strip end on the equipment is avoided, the equipment operation is stabilized, the labor intensity is reduced, human resources are saved, the straightening quality of the strip end is improved, and the production efficiency is effectively improved. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the rolling process before the automatic straightening of the tail-swing of the single-stand reversible cold rolling mill of the present invention.

[0016] Figure 2 This is a schematic diagram of the automatic straightening process of the single-stand reversible cold rolling mill tail-swinging according to the present invention.

[0017] In the diagram, 1. Uncoiling drum, 2. Steel coil, 3. Uncoiling pressure roller, 4. CPC lens, 5. CPC light source protection, 6. Strip head, 7. Upper pinch roller, 8. Straightening roller, 9. Lower pinch roller, 10. Inlet turning roller, 11. Coiler drum, 12. Main rolling mill roll, 13. Rolling direction, 14. Wrap angle, 15. Strip head after uncoiling. Detailed Implementation

[0018] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention. However, the scope of protection of the present invention is not limited to these embodiments. All changes or equivalent substitutions that do not depart from the concept of the present invention are included within the scope of protection of the present invention.

[0019] A method for automatic straightening of a single-stand reversible cold rolling mill after tail-swing includes the following steps:

[0020] 1) Set up automatic and manual mode selection buttons on the computer. In maintenance mode, select manual mode control; in normal production mode, select automatic mode control.

[0021] 2) Install proximity switches for detection and positioning at the limit positions of the uncoiler pressure rollers when they are raised and lowered, respectively, to detect the raised and lowered states of the uncoiler pressure rollers and to position the raised and lowered positions.

[0022] 3) Install proximity switches on the straightening rollers of the straightening machine to detect the lifting or pressing position of the straightening rollers, and pre-position the required appropriate height for detecting and controlling the position of the straightening rollers;

[0023] 4) Use existing data or functions of the unit:

[0024] Using the unit's own strip length calculation function, the roll diameter and rolling procedure of the raw material to be rolled are preset in advance. The speed value detected by the speed detection device of the lower roll of the straightener's steering pinch roll is used, and the speed value detected by the lower roll of the uncoiling steering pinch roll is used to set the start conditions for automatic tail straightening: select automatic tail straightening mode, rolling mode, first pass, speed change value of the lower roll of the steering pinch roll, and the remaining strip length is less than a certain set value.

[0025] 5) Issue the command to press down the uncoiling pressure roller. The uncoiling pressure roller automatically presses down onto the strip surface to pre-straighten the strip tail end. When the strip head of the uncoiler detaches from the drum, the tension between the uncoiler and the main frame is naturally released. The speed of the lower roller of the steering pinch roll will decrease to below 30m / min. At this time, the computer issues the command to press down the upper pinch roll and the command to lift and press down the straightening roller. The upper pinch roll presses down, and the straightening roller is lifted to the positioning height detection limit and stops to straighten the strip head end. After the tail-wagging stop of one pass, the tension is released, the rolling mode of the main control panel is switched to the auxiliary mode, and when the rolling pass is switched to the second pass, the uncoiling pressure roller and the upper pinch roll of the straightening machine are automatically lifted, the straightening roller is automatically lowered, the current automatic mode control is automatically released, and preparation is made for the next production.

[0026] Further, the automatic mode in step 1) is: set the middle position of the "press down" and "lift up" switches of the winding machine pressure roller, upper pinch roller and straightening roller to automatic mode respectively. When the switch is not in the lift or press down position, all three switches need to be turned to the middle position.

[0027] Example 1

[0028] Set the control switches for the unwinding roller 3, upper pinch roller 7, and straightening roller 8 on the control panel to the middle position (automatic mode). Set the remaining strip length setting for the automatic tailing program activation, such as 12m.

[0029] like Figure 2 As shown, during a single rolling pass, when the actual remaining strip length is less than the set value (12m) near the tail end, the automatic program is activated. The uncoiling pressure roller 3 automatically presses down onto the surface of the steel strip, forming a certain wrap angle with the uncoiling drum 1 to straighten the tail end of the half-coiled steel strip into a relatively straight shape.

[0030] After being detached from the drum, the strip head 15 remains straight as it advances with the mill, preventing it from bending downwards and colliding with the CPC light source protection device 5.

[0031] When the belt head is about to detach from the unwinding drum 1, the upper pinch roller 7 automatically presses down and the straightening roller 8 automatically lifts up, forming a certain wrap angle 14 with the upper pinch roller 7, and straightening the belt head 6 again, so that the belt head 6 forms a shape that first slightly bends downward and then slightly curves upward at the end, making it easier to bite into the jaws when reversing the belt.

[0032] When the lead reaches the thickness gauge at the front of the mill, the mill stops running, switches to the minimum rolling force, and after changing to the second pass, it begins to reverse the strip. At this time, the uncoiling pressure roller 3 automatically lifts, the upper clamping roller 7 automatically lifts, and the straightening roller 8 automatically falls, starting the preparation for the next coil to be wound up, and the automatic tailing ends.

[0033] To prevent malfunctions during automatic operation, the system retains manual functions for pressing down and lifting the unwinding pressure roller, upper clamping roller, and straightening roller switches, allowing for easy switching between operations.

[0034] The uncoiling pressure roll has a detection device to detect and position its lifting and lowering limits; the straightening roll of the three-roll straightener has a straightening positioning detection; the lower roll of the three-roll straightener's steering pinch roll has a speed detection; the uncoiler has a roll diameter detection and calculation; positioning detection uses proximity switches, and speed detection uses encoders, all controlled by PLC programs; manual and automatic control modes can be selected through a human-machine interface; in automatic mode, the uncoiling pressure roll lowering signal is activated when the first pass, rolling mode, rolling speed is 60m / min (tailing speed), and the remaining strip length is less than 12 meters. The strip is rolled onto the surface of the strip and pre-straightened at the tail end. When the strip head of the uncoiler detaches from the drum, the speed of the turning pinch roll (lower roll) suddenly drops below 30 m / min. At this time, the upper pinch roll pressing signal and the straightening roll lifting signal are activated simultaneously. The upper pinch roll presses down, and the straightening roll lifts up to the positioning height detection limit and stops, straightening the strip head end. After the tail-swing stop in one pass, the tension is removed. When the rolling pass is changed to two passes, the uncoiler pressure roll and the upper pinch roll of the three-roll straightener automatically lift up, the straightening roll automatically falls down, the automatic mode control is released, and preparation is made for the next production.

[0035] This invention is applicable to all single-stand reversible cold rolling mills. It completely avoids the impact of the strip head end on the CPC automatic centering light source system during tail-wagging, ensuring the stability of the CPC automatic centering system, preventing starting deviation caused by centering, and guaranteeing the timeliness of strip tail straightening. The straightening quality of each strip's tail is also consistent, facilitating reverse strip threading operations for operators. Simultaneously, it reduces the labor intensity of uncoiling operators, saving time for other tasks. By modifying the remaining strip length, it can better meet the requirements of different rolling processes without manual intervention, saving manpower and stabilizing process operation.

[0036] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.

[0037] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A method for automatic straightening of a tail swing in a single stand reversing cold rolling mill, characterized in that, The method comprises the following steps: 1) setting automatic mode and manual mode selection buttons on a computer respectively, selecting manual mode control in maintenance state, and selecting automatic mode control in normal production state; 2) installing detection positioning proximity switches at the lifting and pressing limit positions of the opening mill press roller respectively, for detecting the lifting and pressing state of the opening mill press roller and positioning the lifting and pressing positions; 3) installing proximity switches for positioning detection of the lifting or pressing position of the straightening roll of the straightening machine, and positioning the required appropriate height in advance, for detecting and controlling the position of the straightening roll; 4) using original data or functions of the unit: using the strip length calculation function of the unit itself, presetting the coil diameter of the rolled raw material and the rolling schedule in advance, using the speed value detected by the speed detection device of the lower roll of the turning pinch roll of the straightening machine, using the speed value detected by the lower roll of the turning pinch roll of the opening machine, setting the start conditions of the tailing automatic straightening: selecting the tailing straightening automatic mode, the rolling mode, the first pass, the speed change value of the lower roll of the turning pinch roll, and the remaining strip length being less than a certain set value; 5) issuing a command to press down the opening press roller, and the opening press roller is automatically pressed down to the surface of the strip steel to pre-straighten the tail end of the strip, when the head of the opening machine is separated from the coil, the tension between the opening machine and the main frame is naturally released, the speed of the lower roll of the turning pinch roll is reduced to below 30 m / min, at this time, the computer issues a command to press down the upper pinch roll and a command to lift and press down the straightening roll, the upper pinch roll is pressed down, and the straightening roll is lifted to the positioning height detection limit position and stopped, the head end of the strip is straightened, after one-pass tailing parking, the tension is released, the rolling mode of the main control console is converted to the auxiliary mode, and the rolling pass is converted to the second pass, the opening press roller and the upper pinch roll of the straightening machine are automatically lifted, the straightening roll is automatically lowered, the current automatic mode control is automatically released, and the next production is prepared; the automatic mode in step 1) is that the middle positions of the "pressing down, lifting up" switches of the coiling machine press roller, the upper pinch roll and the straightening roll are set to the automatic mode, the switches are not in the lifting or pressing position, and when the automatic mode is used, all the three switches need to be turned to the middle position.

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