A method for full-line strip withdrawal of a tandem cold rolling mill

Abstract

The application discloses a kind of methods of cold continuous rolling mill set full-line strip drawing, belong to cold rolling strip drawing technical field.The application includes the following steps: step S1: full-line loop tension presetting;The tail of the steel coil strip that needs to be drawn is stopped at the entrance of welder, control full-line loop amount, the tension of each loop in the cold continuous rolling production line is uniformly preset as low tension value;Step S2: gradual tension release and segmented loop feeding based on loop sequence;Step S3: mill outlet tension control and final coiling;The safety of the application is significantly improved: point control and remote operation are used throughout the process, and the processing efficiency is greatly improved: through the process design of gradual loop tension release and segmented loop feeding, the traditional strip drawing processing time of more than 2 hours is shortened to within 1 hour.Process controllable, standardized operation: strip drawing operation is divided into clear steps and work position division of labor, reduces the dependence on operator experience, realizes the standardization and repeatability of strip drawing operation.

Description

Technical Field

[0001] This invention relates to the field of cold rolling strip drawing technology, and more specifically, to a method for full-line strip drawing in a cold continuous rolling mill. Background Technology

[0002] When a cold rolling mill is under maintenance or undergoing technical upgrades, it is necessary to promptly remove all strip steel from the production line. Current technologies for handling strip removal have the following drawbacks:

[0003] First, there is a lack of a comprehensive "whole-line" solution. Most existing technologies focus on strip extraction in a specific area after weld breakage, or on using micro-tension strip extraction technology to address localized strip extraction problems. For large-area strip extraction operations across the entire cold rolling mill line, there is a lack of a coordinated strip extraction method covering the entry section, central section, and mill section.

[0004] Second, there is no existing technology that provides an integrated process design for loop tension control from strip extraction confirmation to complete strip extraction along the entire line.

[0005] Third, the process is time-consuming and highly dangerous. Industry records show that traditional methods for handling belt-pulling accidents require at least two hours each time, and the operation relies heavily on manual labor for dragging, posing serious safety hazards. Therefore, developing a belt-pulling method that achieves full-line coordination, safety, efficiency, and gradual tension release is a pressing issue in this field.

[0006] Application number CN202311180390.X, entitled "A Stable Control Technology for Strip Drawing Operation in Acid Continuous Rolling Mill Based on Micro-tension", discloses a stable control technology for strip drawing operation based on micro-tension. This method reduces the stress on the connection points between the guide strip and the guide strip and between the guide strip and the strip steel by setting micro-tension and precisely adjusting the speed of the tension roller group. The core of this patent is to control the stability of strip drawing by applying micro-tension during the drawing process.

[0007] This invention employs a cold continuous rolling mill strip extraction method. Before extraction, the tension of each looper is pre-set to a low value of 1-2 tons. Then, tension is gradually released by sequentially unloading each looper from the inlet to the outlet, followed by jogging the tension rollers to feed the looper. The tension control strategies of the two methods differ fundamentally: the comparative literature applies micro-tension during extraction, employing dynamic control; this invention, however, pre-sets low tension before extraction and then completely unloads tension segment by segment, using a static, segment-by-segment release method. The technical principles of the two methods are different and they are not identical.

[0008] Application No. CN202210958598.X discloses a method for strip removal across the entire pickling and rolling line. Its core principle is to remove the strip in sections (strip removal in the entrance area → strip removal in the pickling section → strip removal before the mill). In each section, a perforated connection is used to traction the strip, and an overhead crane is used to lift the strip tail to assist in the removal. The removal operation is performed synchronously with the equipment at the crane's descent speed. The technical essence is "segmented perforation + overhead crane lifting to assist strip removal".

[0009] This invention employs a gradual looper tension release method. Its core technical principle is as follows: before the strip extraction operation begins, the tension of all loopers along the entire line is pre-set to a low value (1-2 tons). Then, following the sequence from the entrance section to the mill section, a cyclical operation of "unloading tension → jogging and feeding" is performed on each looper, utilizing the jogging of the tension rollers to complete the strip extraction across the entire line. The technical principles of the two methods are fundamentally different—comparing the patented method which uses an external force-assisted approach of "overhead crane hoisting + traction belt," this invention uses a jogging and feeding cyclical operation of "gradually releasing looper tension," and the two are not the same.

[0010] This invention focuses on achieving rapid and safe tape pulling throughout the entire line through gradual release of tension in the looper. Summary of the Invention

[0011] 1. The technical problem that the invention aims to solve

[0012] In response to the defects and shortcomings of existing technologies, this invention provides a method for strip extraction across the entire cold rolling mill, which solves the technical problems of strip extraction, such as reliance on manual labor, long processing time, high safety risks, lack of full-line coordination, and insufficient looper tension control. This method fundamentally changes the disorderly, high-risk, and low-efficiency state of traditional strip extraction operations, and realizes the safety, standardization, and high efficiency of strip extraction across the entire cold rolling mill, which has significant creative progress and broad industrial application prospects.

[0013] 2. Technical Solution

[0014] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0015] A method for full-line strip extraction in a cold continuous rolling mill according to the present invention includes the following steps:

[0016] Step S1: Preset tension of the entire looper

[0017] Stop the tail of the steel coil that needs to be pulled at the entrance of the welding machine, control the total number of loopers in the line, and set the tension of each looper in the cold rolling production line to a low tension value.

[0018] Step S2: Gradual tension release and segmented feeding of the looper based on the looper sequence

[0019] Perform the following sub-steps sequentially for each looper, from the entrance section to the mill section:

[0020] Perform the unwinding operation on the current loop;

[0021] By using the jogging control of the tension roller, the belt tail is fed into the current loop segment by segment;

[0022] Step S3: Mill Exit Tension Control and Final Coiling

[0023] The tension at the mill exit is controlled, and the winding operation is performed by jogging the mandrel until the entire strip is wound onto the mandrel, completing the strip drawing process for the entire line.

[0024] Furthermore, in S1, the low tension value is 1-2 tons. After the looper tension is preset, the strip amount of all loopers is reduced to the empty looper position by means of automatic strip threading of the rolling mill and automatic winding of the exit mandrel.

[0025] Furthermore, before step S2 begins, a tail pretreatment step is also included: the tail of the steel coil is swung to the welding machine entrance, the tail is trimmed into an arc shape, and a circular traction hole is cut on the tail. The tail rope is passed through the circular hole and tied and fixed so that the tail rope is transported synchronously with the tail, which is used to buffer the impact of the height difference when the tail enters the looper.

[0026] Furthermore, before step S2 begins, a pre-adjustment step for the equipment status is also included: switching all the straightening devices on the entire line to the intermediate position, opening the roller gap of the straightening machine, and opening the squeezing rollers in the acid tank and rinsing tank to eliminate the clamping resistance on the strip conveying path.

[0027] Furthermore, in step S2, the specific method for performing the gradual tension release and feeding operation on loop 1 is as follows: unload loop 1; press the bypass keys of the inlet section and the middle section on the No.1 operating table, and the operator jogs the No.1 tension roller forward to gradually feed the sleeve, sending the belt tail into loop 1.

[0028] Further, in step S2, after completing the operation of looper 1, the following operations are performed on looper 2: the operator jogs the central section group at the tension leveler to feed looper 2; the operating table 2 feeds the amount of looper 2 into looper 3, so that looper 2 is in the empty looper position, until the belt tail reaches tension roller 4 and the jogging operation stops; the tension is unloaded from looper 2, and the operator jogs tension roller 4 to feed the belt tail into looper 2.

[0029] Further, in step S2, after completing the operation of looper No. 2, the following operations are performed on looper No. 3 and the exit section: the bypass keys of the central section and the exit section are pressed on the No. 2 operating platform; the operator jogs the No. 5 tension roller to feed the strip into looper No. 3; the strip of looper No. 3 is wound onto the exit mandrel by the automatic strip threading method of the rolling mill until looper No. 3 is in the empty position; the strip tail is stopped in front of the No. 5 tension roller, and the No. 3 looper is unloaded; the operator jogs the No. 5 tension roller to feed the strip tail into looper No. 3 and removes the tail rope.

[0030] Further, the specific method of step S3 is as follows: the mill exit maintains tension, and the No. 3 operating table presses the mill inlet bypass key; the operator jogs at the mill inlet until the strip tail passes through the mill inlet; then the mill exit is unloaded, and the exit jogs the mandrel where the strip coil is located to perform a forward winding operation until the strip coil is completely wound onto the mandrel.

[0031] A cold continuous rolling mill has a full-line strip drawing structure. Along the strip conveying direction, from the inlet side to the outlet side, the following components are arranged in sequence: an uncoiler, a welding machine, No. 1 tension roll, No. 1 looper, No. 2 tension roll, a straightener, No. 2 tension roll, an acid tank, a squeeze roll, a rinsing tank, No. 4 tension roll, No. 2 looper, an edge trimmer, No. 4 tension roll, No. 3 looper, a rolling mill, and a mandrel. The section from the welding machine to No. 1 looper is the inlet section, which has a No. 1 operating platform. The section from No. 1 looper to the rolling mill inlet is the central section, which has a No. 2 operating platform. The section from the rolling mill inlet to the outlet is the rolling mill section, which has a No. 3 operating platform.

[0032] 3. Beneficial effects

[0033] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0034] This invention significantly improves safety: the entire process utilizes inching control and remote operation, eliminating the need for operators to enter hazardous areas for manual dragging and cutting, thus eliminating safety hazards during the tape extraction process. Processing efficiency is greatly improved: through a streamlined design of progressive looper tension release and segmented looper feeding, the traditional tape extraction time of over 2 hours is reduced to less than 1 hour. The process is controllable and standardized: the tape extraction operation is broken down into clearly defined steps and workstation assignments, reducing reliance on operator experience and achieving standardization and repeatability of the extraction operation. It has good compatibility with existing equipment: this invention does not rely on adding complex new equipment; it can be implemented simply by controlling the timing of existing tension rollers, loopers, mandrels, etc., resulting in low modification costs and high promotional value. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the cold continuous rolling production line equipment layout of the present invention.

[0036] In the diagram: 1. Uncoiler; 2. Welding machine; 3. Tension roll No. 1; 4. Loop No. 1; 5. Tension roll No. 2; 6. Straightener; 7. Tension roll No. 2; 8. Acid tank; 9. Squeeze roll; 10. Rinse tank; 11. Tension roll No. 4; 12. Loop No. 2; 13. Edge trimmer; 14. Tension roll No. 4; 15. Loop No. 3; 16. Rolling mill; 17. Mandrel. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0038] Example 1

[0039] from Figure 1 As can be seen, the structure of a cold continuous rolling mill in this embodiment, which involves the entire strip drawing process, is arranged sequentially from the inlet side to the outlet side along the strip conveying direction, including an uncoiler 1, a welding machine 2, a No. 1 tension roll 3, a No. 1 looper 4, a No. 2 tension roll 5, a tension leveler 6, a No. 2 tension roll 7, an acid tank 8, a squeeze roll 9, a rinsing tank 10, a No. 4 tension roll 11, a No. 2 looper 12, an edge trimmer 13, a No. 4 tension roll 14, a No. 3 looper 15, a rolling mill 16, and a mandrel 17. Among them, the section from the welding machine 2 to the No. 1 looper 4 is the inlet section, which is equipped with a No. 1 operating platform. The section from the No. 1 looper 4 to the inlet of the rolling mill 16 is the central section, which is equipped with a No. 2 operating platform. The section from the inlet to the outlet of the rolling mill 16 is the rolling mill section, which is equipped with a No. 3 operating platform.

[0040] Example 2

[0041] This embodiment of a method for full-line strip extraction in a cold continuous rolling mill includes the following steps:

[0042] Step S1: Preset tension of the entire looper

[0043] Stop the tail of the steel coil that needs to be pulled at the entrance of the welding machine, control the total number of loopers in the line, and set the tension of each looper in the cold rolling production line to a low tension value.

[0044] In S1, the low tension value is 1-2 tons. After the looper tension is preset, the strip amount of all loopers is reduced to the empty position by the automatic strip threading of the rolling mill and the automatic winding of the exit mandrel.

[0045] Step S2: Gradual tension release and segmented feeding of the looper based on the looper sequence

[0046] Perform the following sub-steps sequentially for each looper, from the entrance section to the mill section:

[0047] Perform the unwinding operation on the current loop;

[0048] By using the jogging control of the tension roller, the belt tail is fed into the current loop segment by segment;

[0049] Each time the tail of the strip enters each looper, there will be a height difference of 2-20 meters. In order to prevent damage to the tail or damage to the production line equipment, the tail rope must be tied until the tail is sent into looper No. 3 and then the tail rope is removed.

[0050] Before step S2 begins, a pre-treatment step for the strip tail is also included: the strip coil is swung to the welding machine entrance, the strip tail is trimmed into an arc shape, and a circular traction hole with a diameter of 45mm is cut on the strip tail. The swung rope with a diameter of 30mm and a length of 30 meters is passed through the circular hole and tied and fixed, so that the swung rope is transported synchronously with the strip tail to buffer the impact of the height difference when the strip tail enters the looper.

[0051] Before step S2 begins, there is also a pre-adjustment step for the equipment status: switch all the straightening devices on the entire line to the middle position, open the roller gap of the straightening machine, open the squeezing rollers in the acid tank and rinsing tank, and eliminate the clamping resistance on the strip conveying path.

[0052] In step S2, the specific method for performing the gradual tension release and feeding operation on loop 1 is as follows: unload loop 1; press the bypass keys of the inlet section and the middle section on the No.1 operating table, and the operator jogs the No.1 tension roller forward to gradually feed the sleeve, sending the belt tail into loop 1.

[0053] In step S2, after completing the operation of looper 1, the following operations are performed on looper 2: the operator jogs the central section group at the tension leveler to feed looper 2; the No. 2 operating table feeds the amount of looper 2 into looper 3, so that looper 2 is in the empty looper position, until the belt tail reaches the No. 4 tension roller and the jogging operation is stopped; the No. 2 looper is unloaded, and the operator jogs the No. 4 tension roller to feed the belt tail into looper 2.

[0054] In step S2, after completing the operation of looper No. 2, the following operations are performed on looper No. 3 and the exit section: the bypass keys of the central section and the exit section are pressed on the No. 2 operating platform; the operator jogs the No. 5 tension roller to feed the strip into looper No. 3; the strip of looper No. 3 is wound onto the exit mandrel by the automatic strip threading method of the rolling mill until looper No. 3 is in the empty position; the strip tail is stopped in front of the No. 5 tension roller, and the No. 3 looper is unloaded; the operator jogs the No. 5 tension roller to feed the strip tail into looper No. 3, and the tail rope is removed.

[0055] Step S3: Mill Exit Tension Control and Final Coiling

[0056] The tension at the mill exit is controlled, and the winding operation is performed by jogging the mandrel until the entire strip is wound onto the mandrel, completing the strip drawing process for the entire line.

[0057] The specific method for step S3 is as follows: maintain tension at the mill exit, press the mill inlet bypass key on operating panel 3; the operator jogs at the mill inlet until the strip tail passes through the mill inlet; then unload the tension at the mill exit, and jog at the exit to perform a forward rotation winding operation on the mandrel where the strip coil is located until the entire strip coil is wound onto the mandrel.

[0058] Example 3

[0059] This embodiment describes a method for full-line strip extraction in a cold continuous rolling mill, using a five-stand cold continuous rolling production line of a certain company as an example.

[0060] The production line is equipped with the following equipment in sequence: welding machine, No. 1 looper, No. 2 looper, No. 3 looper, tension leveler, acid tank, rinsing tank, rolling mill (F1-F5 stands), exit mandrel, etc., as well as multiple sets of tension rolls such as No. 1 tension roll, No. 4 tension roll, and No. 5 tension roll, and CPC correction devices No. 1-6. The entire production line is divided into an entrance section (from the welding machine to No. 1 looper), a central section (from No. 1 looper to the rolling mill entrance), and a rolling mill section (from the rolling mill entrance to the exit), and is equipped with an operating platform No. 1 (responsible for the entrance section), an operating platform No. 2 (responsible for the central section), and an operating platform No. 3 (responsible for the rolling mill section).

[0061] Step S1: Preset tension of the entire looper

[0062] Stop the tail of the steel coil that needs to be pulled at the entrance of the welding machine; the operator checks the looper quantity of the entire line in the secondary control screen to ensure that the looper quantity is within a controllable range.

[0063] Then, the tension of loopers 1, 2, and 3 in the cold rolling mill production line is uniformly preset to a low tension value. In this embodiment, based on the strip specifications (thickness 2.8mm, width 1200mm), the tension of each looper is set to 1.5 tons. For different strip specifications, the tension can be adjusted within the range of 1-2 tons.

[0064] After setting the looper tension, the amount of strip in loopers 1, 2, and 3 is gradually reduced through automatic strip threading and automatic winding of the exit mandrel on the rolling mill, until all loopers are in an empty loop position (i.e., there is basically no strip accumulation in the loopers). The purpose of this operation is to create empty loop conditions for subsequent strip extraction operations and to avoid mutual interference from residual strip in the loopers.

[0065] Step S2: Gradual tension release and segmented feeding of the looper based on the looper sequence

[0066] After completing step S1, perform gradual tension release and segmented feeding operations on each looper in sequence from the entrance section to the rolling mill section.

[0067] (a) Tail-related preprocessing (before step S2 begins)

[0068] Before formally feeding the strip into the loop, pre-treatment of the strip tail is performed: the strip coil is swung to the welding machine inlet, and the tail is trimmed into an arc shape using a shearing tool to prevent the right-angled edge from snagging on the equipment inside the loop. A circular hole with a diameter of 45mm is cut at the center of the strip tail. A 30-meter-long, 30-mm-diameter tail rope is taken, and one end of the rope is passed through the circular hole and tied securely to ensure a reliable connection between the tail rope and the strip tail.

[0069] (ii) Equipment status pre-adjustment (before step S2 begins)

[0070] Pre-adjustment of equipment status: Switch all CPC straightening devices (No. 1 to No. 6) on the entire line to the middle position to avoid lateral force interference from the straightening rollers on the strip; fully open the roller gap of the tension leveler to the maximum position; fully open (i.e., raise the rollers) in the pickling and rinsing tanks to eliminate resistance and clamping force when the strip passes through the pickling and rinsing sections. The above operations create pathways for unobstructed movement of the strip throughout the entire line.

[0071] (III) Handling of Loop 1

[0072] Following the order from the entrance section to the rolling mill section, the No. 1 looper is processed first.

[0073] Because the tail of the strip (strip tail) will have a height difference of 2-20 meters each time it enters each loop (the depth of the loop pit is different), in order to prevent the strip tail from being damaged or impacted and damaged the equipment inside the loop during the fall, a tail rope must be used for traction protection.

[0074] The specific operation is as follows: Unload the No. 1 looper to release the residual tension within it. The operator at the No. 1 control panel presses the bypass keys for the inlet and center sections, then jogs the No. 1 tension roller, gradually feeding the looper forward. Under this jogging control, the strip tail is slowly fed into the No. 1 looper. Since the pit depth of the No. 1 looper is approximately 8 meters, there will be a height difference of about 8 meters during the strip tail feeding process. At this time, the winding of the tail rope with the production line tension roller provides traction and protection, preventing the strip tail from falling freely and causing damage.

[0075] (iv) Handling of No. 2 loop

[0076] After completing the No. 1 looper, proceed to process the No. 2 looper.

[0077] The operator moves to the tension leveler and jogs the central section group to begin feeding the strip into looper number 2. The operator at control panel number 2 assists, gradually feeding the strip from looper number 2 into looper number 3, until looper number 2 gradually becomes empty. This jogging operation continues until the strip tail reaches the position in front of tension roller number 4. At this point, tension is released from looper number 2; the operator jogs tension roller number 4 to feed the strip tail into looper number 2.

[0078] (v) Handling of No. 3 loop

[0079] After completing the processing of loop #2, proceed to process loop #3.

[0080] The operator at control panel 2 presses the bypass keys for the central and exit sections. The operator then jogs the No. 5 tension roll to feed the strip into the No. 3 looper. Using the mill's automatic threading mechanism, the strip in the No. 3 looper is coiled onto the exit mandrel until the looper is completely empty. The strip tail is stopped in front of the No. 5 tension roll, the jogging operation is stopped, and the No. 3 looper is unloaded. The operator then jogs the No. 5 tension roll to feed the strip tail into the No. 3 looper, and finally removes the tail rope.

[0081] Step S3: Mill Exit Tension Control and Final Coiling

[0082] After completing the gradual tension release and segmented feeding of each loop, the final winding stage begins.

[0083] Maintain appropriate tension at the mill exit (in this embodiment, maintain a slight tension of approximately 0.5-1.0 tons) to ensure stable strip threading. The operator on control panel 3 presses the mill inlet bypass key. The operator then jogs the motor at the mill inlet, gradually feeding the strip tail forward until it is threaded onto the mill inlet (at the F1 stand inlet).

[0084] After confirming that the strip tail has reached the mill inlet, release the tension at the mill exit section. Then, at the exit, jog the mandrel containing the strip coil to perform a forward winding operation, slowly and smoothly winding the entire strip coil onto the mandrel. Maintain a uniform speed during winding to avoid strip deviation or mandrel slippage due to sudden speed changes.

[0085] At this point, the strip extraction operation is complete. Once the operators confirm that there is no residual strip steel in the production line, normal production line operation can be resumed.

[0086] Example 4

[0087] This embodiment describes a method for full-line strip extraction in a cold continuous rolling mill. This embodiment is basically the same as Embodiment 3, except that the preset value of the looper tension is adjusted according to the strip specifications.

[0088] For thin strip steel with a thickness of 2.0 mm, in step S1, the tension of loopers 1, 2, and 3 is preset to 1.0 ton. For thick strip steel with a thickness of 3.0 mm, the tension of each looper is preset to 2.0 ton. By selecting an appropriate low tension value according to the strip steel specifications, the strip pulling efficiency can be improved while ensuring the safety of the strip pulling process.

[0089] Example 5

[0090] This embodiment describes a method for full-line strip extraction in a cold continuous rolling mill. This embodiment is basically the same as Embodiment 3, except for the number and layout of loopers.

[0091] For a cold rolling mill with four loopers (e.g., loopers 1 and 2 at the entrance, looper 3 in the middle section, and looper 4 at the exit), simply repeat the cycle of "unloading tension → jogging the corresponding tension roller to feed the looper" for each looper in sequence from entrance to exit. In practice, the appropriate tension roller should be selected for jogging control based on the position and depth of each looper, and the necessity of rope protection should be confirmed based on the pit depth of each looper (rope protection is recommended when the pit depth is greater than 2 meters).

[0092] Example 6

[0093] This embodiment describes a method for full-line strip extraction in a cold continuous rolling mill. This embodiment is basically the same as Embodiment 3, except for the treatment method of the squeeze rolls in the acid tank and rinsing tank.

[0094] For some older production lines, the squeeze rollers in the acid tank and rinsing tank may not be able to lift completely. In this case, before starting step S2, the cylinder pressure of the squeeze roller can be adjusted to the lowest value (approximately 0.1-0.2 MPa) to minimize its clamping force on the strip. At the same time, the bearing seats on both sides of the squeeze roller can be manually loosened by 2-3 mm to reduce the frictional resistance when the strip passes through. This workaround can also achieve the effect of eliminating resistance.

[0095] The core innovation of this invention lies in proposing and implementing a novel strip-pulling technology principle of "gradual looper tension release," and based on this, constructing a "sequential unloading → jogging looper feeding cycle operation method with loopers as units." This method fundamentally changes the disordered, high-risk, and low-efficiency state of traditional strip-pulling operations, realizing the safety, standardization, and high efficiency of strip-pulling across the entire cold continuous rolling line, demonstrating significant creative progress and broad industrial application prospects.

[0096] This invention significantly improves safety: the entire process utilizes inching control and remote operation, eliminating the need for operators to enter hazardous areas for manual dragging and cutting, thus eliminating safety hazards during the tape extraction process. Processing efficiency is greatly improved: through a streamlined design of progressive looper tension release and segmented looper feeding, the traditional tape extraction time of over 2 hours is reduced to less than 1 hour. The process is controllable and standardized: the tape extraction operation is broken down into clearly defined steps and workstation assignments, reducing reliance on operator experience and achieving standardization and repeatability of the extraction operation. It has good compatibility with existing equipment: this invention does not rely on adding complex new equipment; it can be implemented simply by controlling the timing of existing tension rollers, loopers, mandrels, etc., resulting in low modification costs and high promotional value.

[0097] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for full-line strip drawing in a cold continuous rolling mill, characterized in that: Includes the following steps: Step S1: Preset tension of the entire looper Stop the tail of the steel coil that needs to be pulled at the entrance of the welding machine, control the total number of loopers in the line, and set the tension of each looper in the cold rolling production line to a low tension value. Step S2: Gradual tension release and segmented feeding of the looper based on the looper sequence Perform the following sub-steps sequentially for each looper, from the entrance section to the mill section: Perform the unwinding operation on the current loop; By using the jogging control of the tension roller, the belt tail is fed into the current loop segment by segment; Step S3: Mill Exit Tension Control and Final Coiling The tension at the mill exit is controlled, and the winding operation is performed by jogging the mandrel until the entire strip is wound onto the mandrel, completing the strip drawing process for the entire line.

2. The method for full-line strip extraction in a cold continuous rolling mill according to claim 1, characterized in that: In S1, the low tension value is 1-2 tons. After the looper tension is preset, the strip amount of all loopers is reduced to the empty looper position by the automatic strip threading of the rolling mill and the automatic winding of the exit mandrel.

3. The method for full-line strip extraction in a cold continuous rolling mill according to claim 1, characterized in that: Before step S2 begins, a tail pretreatment step is also included: the tail of the steel coil is swung to the entrance of the welding machine, the tail is trimmed into an arc shape, and a circular traction hole is cut on the tail. The tail rope is passed through the circular hole and tied and fixed so that the tail rope is transported synchronously with the tail, which is used to buffer the impact of the height difference when the tail enters the looper.

4. The method for full-line strip extraction in a cold continuous rolling mill according to claim 1, characterized in that: Before step S2 begins, a pre-adjustment step for the equipment status is also included: switching all the straightening devices on the entire line to the middle position, opening the roller gap of the straightening machine, and opening the squeezing rollers in the acid tank and rinsing tank to eliminate the clamping resistance on the strip conveying path.

5. The method for full-line strip extraction in a cold continuous rolling mill according to claim 1, characterized in that: In step S2, the specific method for performing the gradual tension release and feeding operation on loop 1 is as follows: unload loop 1; press the bypass keys of the inlet section and the middle section on the No.1 operating table, and the operator jogs the No.1 tension roller forward to gradually feed the sleeve, sending the belt tail into loop 1.

6. The method for full-line strip drawing in a cold continuous rolling mill according to claim 5, characterized in that: In step S2, after completing the operation of looper 1, the following operations are performed on looper 2: the operator jogs the central section group at the tension leveler to feed looper 2; the operating table 2 feeds the amount of looper 2 into looper 3, so that looper 2 is in the empty looper position, until the tail of the belt reaches the tension roller 4 and the jogging operation is stopped; the tension is unloaded from looper 2, and the operator jogs the tension roller 4 to feed the tail of the belt into looper 2.

7. A method for full-line strip extraction in a cold continuous rolling mill according to claim 6, characterized in that: In step S2, after completing the operation of looper No. 2, the following operations are performed on looper No. 3 and the exit section: the bypass keys of the central section and the exit section are pressed on the No. 2 operating platform; the operator jogs the No. 5 tension roller to feed the strip into looper No. 3; the strip of looper No. 3 is wound onto the exit mandrel by the automatic strip threading method of the rolling mill until looper No. 3 is in the empty position; the strip tail is stopped in front of the No. 5 tension roller, and the No. 3 looper is unloaded; the operator jogs the No. 5 tension roller to feed the strip tail into looper No. 3, and the tail rope is removed.

8. The method for full-line strip extraction in a cold continuous rolling mill according to claim 1, characterized in that: The specific method of step S3 is as follows: maintain tension at the mill exit, press the mill inlet bypass key on the No. 3 operating table; the operator jogs at the mill inlet until the strip tail passes through the mill inlet; then unload the tension at the mill exit, and jog at the exit to perform a forward rotation winding operation on the mandrel where the strip coil is located until the entire strip coil is wound onto the mandrel.

9. A method for full-line strip extraction in a cold continuous rolling mill according to claim 1, characterized in that: It also includes a structure for the entire cold continuous rolling mill to draw strip, which is arranged in sequence from the inlet side to the outlet side along the strip conveying direction, including an uncoiler (1), a welding machine (2), No. 1 tension roll (3), No. 1 looper (4), No. 2 tension roll (5), a straightener (6), No. 2 tension roll (7), an acid tank (8), a squeeze roll (9), a rinsing tank (10), No. 4 tension roll (11), No. 2 looper (12), an edge trimmer (13), No. 4 tension roll (14), No. 3 looper (15), a rolling mill (16), and a mandrel (17); wherein, the section from the welding machine (2) to the No. 1 looper (4) is the inlet section, which is equipped with a No. 1 operating platform; the section from the No. 1 looper (4) to the inlet of the rolling mill (16) is the central section, which is equipped with a No. 2 operating platform; and the section from the inlet to the outlet of the rolling mill (16) is the rolling mill section, which is equipped with a No. 3 operating platform.

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