A method for controlling the quality of a hot-rolled coil
By pre-setting the parameters of the auxiliary roll and the roll drum during the hot rolling coiling process, and detecting and feeding back the pressing pressure of the auxiliary roll and the torque of the roll drum, the problem of poor tension at the head of the hot rolled strip was solved, stable coil quality control was achieved, and coil defects and production losses were reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEBEI DAHE MATERIAL TECH CO LTD
- Filing Date
- 2023-08-11
- Publication Date
- 2026-06-02
AI Technical Summary
During the coiling process of hot-rolled strip steel, abnormal tension at the head can cause the inner strip steel to slip and deviate. After the steel coil is unloaded, it may overflow, become loose, or collapse, resulting in quality loss and increased production costs.
By presetting the parameters of the auxiliary winding rollers and drums corresponding to different varieties and specifications in the model data table, the pressing pressure of the auxiliary winding rollers and the torque of the drum are detected, and the auxiliary winding rollers and drums start to expand when the set maximum value is reached, so as to ensure the winding quality of the strip head.
It effectively reduces roll defects such as loose rolls, overflow, and collapsed rolls, improves roll quality, and reduces manual repair costs and production losses.
Smart Images
Figure CN117086106B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for controlling the quality of hot-rolled coils, belonging to the technical field of hot rolling equipment modification and hot rolling process control methods in the metallurgical industry. Background Technology
[0002] During the hot-rolled strip production process, if the head cannot establish tension properly, the inner strip will slip and deviate. After the steel coil is unloaded from the coiler, the inner strip will overflow, loosen, or even collapse, resulting in quality loss and increased production costs.
[0003] The main reasons why the take-up head cannot establish tension properly are as follows:
[0004] 1. After the strip head enters the coiler, the actual position of the strip head is not accurately estimated, resulting in deviations in the pressing time of the coiling roller;
[0005] 2. The roll gap setting of the auxiliary roll is unreasonable, the pressing force on the strip steel cannot reach the set value, the friction between the roll layers is insufficient, and the friction between the strip steel and the roll drum is insufficient;
[0006] 3. The pressing pressure of the auxiliary coiling roller is not set properly, and the pressing pressure applied by the auxiliary coiling roller to the strip and the friction of the strip are insufficient to support the establishment of tension;
[0007] 4. Excessive clearance between the mechanical components of the coiling roller causes the coiling roller to move away from the drum under the impact of the strip, resulting in an increased roller gap and insufficient pressing force exerted by the coiling roller on the strip.
[0008] 5. Due to the head tracking deviation, the drum expansion time and amplitude exceeded the set value.
[0009] Through actual measurement and analysis of the ODG curve, it was found that for steel coils with poor head tension, the difference between the actual inner diameter and the feedback value can reach 8-10 mm, and the drum expansion time exceeds the ideal value by up to 50%. This has a huge impact on the control of strip head shape and the overflow and loosening of the core.
[0010] Due to issues with the coiling function, hot rolling mills produce coils of various grades that are loose, have overflow edges, or have collapsed inner coils. These defects require manual repair in the finished product warehouse or recoiling and removal on the leveling line, increasing labor costs and reducing the leveling line's production efficiency. For some special-requirement steel grades, the coil repair process may generate other defects, further increasing losses and affecting delivery.
[0011] In conventional coiling machines, the pressure of the auxiliary coiling rollers is based on the HMD signal before the pinch rollers. However, this signal typically has an error of 0.5-1 second. This makes it difficult to ensure that the actual position control of the auxiliary coiling rollers achieves the required head strip tightness control, resulting in coil quality defects that require repair. This leads to contract non-delivery, increased inventory, and logistical disruptions. Therefore, a coiling method with stable coil quality control is needed to eliminate coil defects. Summary of the Invention
[0012] The purpose of this invention is to provide a method for controlling the quality of hot-rolled coils. By pre-setting the parameters of the auxiliary coiling rollers and coils corresponding to different varieties and specifications in a model data table, and by detecting and feeding back the pressing pressure of the auxiliary coiling rollers and the torque of the coils, when the feedback values of the pressing pressure of the auxiliary coiling rollers and the torque of the coils simultaneously reach the set maximum values, the auxiliary coiling rollers and the coils begin to expand in diameter. This method can ensure the coiling quality of the strip head within different specification ranges corresponding to the strength of each variety, reducing the coil shape defects such as loose coiling, overflow, and collapse caused by poor tensioning function of the strip head, and effectively solving the above-mentioned problems existing in the background art.
[0013] The technical solution of this invention is: a method for controlling the quality of hot-rolled coils, comprising the following steps:
[0014] a. First, in the secondary model, the strip steel is automatically classified and named into several "Famries" according to the strip steel hardness grade and specification range. At the same time, the target width, thickness and strength parameters are transmitted to the secondary setting computer of the coiler.
[0015] b. After the production order is started, the winding machine setting control computer first finds the pressing pressure of the auxiliary winding roller corresponding to the family, strength and specification from the winding machine parameter preset table, and transmits the setting data to the winding machine primary control computer.
[0016] c. After the production order is started, the winding machine setting control computer first finds the drum torque and expansion diameter parameters corresponding to the family, strength and specification from the winding machine parameter preset table, and transmits the setting data to the winding machine primary control computer.
[0017] d. After the production order is started, the winding machine setting control computer first finds the drum lead rate corresponding to the family, strength and specification from the winding machine parameter preset table, and transmits the setting data to the winding machine primary control computer.
[0018] e. When the strip head reaches the coiling pinch roll, the pinch roll loading signal is activated. This signal serves as the starting point for the auxiliary coiling roll pressure feedback and begins to pre-calculate the auxiliary coiling roll loading time.
[0019] f. The strip head enters the coiler and reaches the auxiliary coiling roller. Under the pressure of the auxiliary coiling roller, the strip is wound onto the drum. The pressure of the auxiliary coiling roller for thin specifications shall not be less than 240KN, and the pressure of the auxiliary coiling roller for thick specifications shall not be less than 420KN.
[0020] g. After the strip is tightly wound onto the drum, the feedback pressing pressure of the auxiliary winding roller reaches the set maximum value. The auxiliary winding roller opens up, and the number of pressing circles of the auxiliary winding roller is 3-6. Too many circles will reduce the pressing effect of the auxiliary winding roller and increase equipment wear and vibration.
[0021] h. The advance rate of the roll increases the interlayer friction of the strip under the pressing action of the roll assist roller, so that the strip head is tightly attached and tensioned to establish the winding tension.
[0022] i. Under the influence of lead rate and friction, the drum current and torque will increase rapidly. Generally, the feedback value reaches the set maximum torque within 0.4-0.7 seconds to complete the tensioning process. If the time is too long, it indicates that the head of the steel coil has slipped and the coil shape is poor.
[0023] j. When the winding torque reaches the set maximum value and the pressing pressure of the auxiliary winding roller reaches the set maximum value, the drum begins to expand in diameter. The expansion time is generally completed within 0.4-0.7 seconds. If the time is too long, it indicates that the expansion has failed and will make it difficult to unwind. The expansion range is generally 5-9mm. If the expansion is too large, it indicates that the tension is not ideal, the head slips, and loosening occurs.
[0024] The position control of the coiling roller is preset, that is, the coiling roller is preset with a roll gap. The roll gap is increased by a certain amount according to the target rolling thickness H of the strip. The roll gaps of the three coiling rollers are H+3, H+2 and H+1, which allows the strip to enter the coiler. As the coil diameter continues to increase during the coiling process, the coiling roller is pushed back by the increased coil diameter, so that the coiling roller generates pressing pressure.
[0025] Using the load connection signal of the pinch roll as the pressure feedback reference signal of the auxiliary coiling roll, once the pinch roll load is connected, it can be confirmed that the strip head has entered the coiler. Adding the distance from the pinch roll to the auxiliary coiling roll, with a delay of 0.3-0.7 seconds, the position of the strip head can be accurately predicted. The auxiliary coiling roll can then directly enter the pressure feedback control mode and be controlled according to the set target pressure, reaching the maximum pressure at the ideal time.
[0026] Under the pressure of the coiling roller, the steel coil is tightly wound onto the drum. The friction between the layers of the steel coil establishes tension between the coiler and the strip. At the same time, the feedback current and torque of the drum gradually increase to reach the set maximum value, triggering the drum expansion action or triggering the expansion action after the strip is coiled three times.
[0027] The beneficial effects of this invention are as follows: By presetting the parameters of the auxiliary winding rollers and drums corresponding to different varieties and specifications in the model data table, and by detecting and feeding back the pressing pressure of the auxiliary winding rollers and the torque of the drums, when the feedback values of the pressing pressure of the auxiliary winding rollers and the torque of the drums reach the set maximum values at the same time, the auxiliary winding rollers and drums begin to expand in diameter. This ensures the winding quality of the strip head within different specification ranges corresponding to the strength of each variety, and reduces the problems of loose winding, overflow, and collapse of the coils due to poor tensioning function of the strip head. Attached Figure Description
[0028] Figure 1 This is a diagram of the main equipment of the present invention;
[0029] Figure 2 The pressing pressure and drum expansion curve of the auxiliary winding roller when winding thin strip steel in this invention;
[0030] Figure 3 The curves showing the pressing pressure of the auxiliary winding roller and the expansion diameter of the winding drum during the second winding of thin strip steel in this invention;
[0031] Figure 4 This is a flowchart illustrating the operation of the winding aid roller and the winding drum in this invention.
[0032] In the diagram: lower pinch roller 1, upper pinch roller 2, No. 1 auxiliary winding roller 3, No. 2 auxiliary winding roller 4, No. 3 auxiliary winding roller 5, winding drum 6. Implementation
[0033] To make the purpose, technical solutions, and advantages of the invention's embodiments clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only a small part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.
[0034] A method for quality control of hot-rolled coils includes the following steps:
[0035] a. First, in the secondary model, the strip steel is automatically classified and named into several "Famries" according to the strip steel hardness grade and specification range. At the same time, the target width, thickness and strength parameters are transmitted to the secondary setting computer of the coiler.
[0036] b. After the production order is started, the winding machine setting control computer first finds the pressing pressure of the auxiliary winding roller corresponding to the family, strength and specification from the winding machine parameter preset table, and transmits the setting data to the winding machine primary control computer.
[0037] c. After the production order is started, the winding machine setting control computer first finds the drum torque and expansion diameter parameters corresponding to the family, strength and specification from the winding machine parameter preset table, and transmits the setting data to the winding machine primary control computer.
[0038] d. After the production order is started, the winding machine setting control computer first finds the drum lead rate corresponding to the family, strength and specification from the winding machine parameter preset table, and transmits the setting data to the winding machine primary control computer.
[0039] e. When the strip head reaches the coiling pinch roll, the pinch roll loading signal is activated. This signal serves as the starting point for the auxiliary coiling roll pressure feedback and begins to pre-calculate the auxiliary coiling roll loading time.
[0040] f. The strip head enters the coiler and reaches the auxiliary coiling roller. Under the pressure of the auxiliary coiling roller, the strip is wound onto the drum. The pressure of the auxiliary coiling roller for thin specifications shall not be less than 240KN, and the pressure of the auxiliary coiling roller for thick specifications shall not be less than 420KN.
[0041] g. After the strip is tightly wound onto the drum, the feedback pressing pressure of the auxiliary winding roller reaches the set maximum value. The auxiliary winding roller opens up, and the number of pressing circles of the auxiliary winding roller is 3-6. Too many circles will reduce the pressing effect of the auxiliary winding roller and increase equipment wear and vibration.
[0042] h. The advance rate of the roll increases the interlayer friction of the strip under the pressing action of the roll assist roller, so that the strip head is tightly attached and tensioned to establish the winding tension.
[0043] i. Under the influence of lead rate and friction, the drum current and torque will increase rapidly. Generally, the feedback value reaches the set maximum torque within 0.4-0.7 seconds to complete the tensioning process. If the time is too long, it indicates that the head of the steel coil has slipped and the coil shape is poor.
[0044] j. When the winding torque reaches the set maximum value and the pressing pressure of the auxiliary winding roller reaches the set maximum value, the drum begins to expand in diameter. The expansion time is generally completed within 0.4-0.7 seconds. If the time is too long, it indicates that the expansion has failed and will make it difficult to unwind. The expansion range is generally 5-9mm. If the expansion is too large, it indicates that the tension is not ideal, the head slips, and loosening occurs.
[0045] The position control of the coiling roller is preset, that is, the coiling roller is preset with a roll gap. The roll gap is increased by a certain amount according to the target rolling thickness H of the strip. The roll gaps of the three coiling rollers are H+3, H+2 and H+1, which allows the strip to enter the coiler. As the coil diameter continues to increase during the coiling process, the coiling roller is pushed back by the increased coil diameter, so that the coiling roller generates pressing pressure.
[0046] Using the load connection signal of the pinch roll as the pressure feedback reference signal of the auxiliary coiling roll, once the pinch roll load is connected, it can be confirmed that the strip head has entered the coiler. Adding the distance from the pinch roll to the auxiliary coiling roll, with a delay of 0.3-0.7 seconds, the position of the strip head can be accurately predicted. The auxiliary coiling roll can then directly enter the pressure feedback control mode and be controlled according to the set target pressure, reaching the maximum pressure at the ideal time.
[0047] Under the pressure of the coiling roller, the steel coil is tightly wound onto the drum. The friction between the layers of the steel coil establishes tension between the coiler and the strip. At the same time, the feedback current and torque of the drum gradually increase to reach the set maximum value, triggering the drum expansion action or triggering the expansion action after the strip is coiled three times.
[0048] In practical applications, the present invention mainly includes the pressing of the auxiliary winding roller and the control of the expansion diameter of the winding drum.
[0049] Step 1: In the secondary model, the strip steel is automatically classified and named into several "Famliy" according to the hardness grade and specification range of the strip steel. Each "Famliy" can be set and calculated and controlled. At the same time, various parameters such as target width, thickness and strength are transmitted to the secondary setting computer of the coiler.
[0050] Step 2: After the winder is started, the winder setting control computer first finds the data table corresponding to the family, strength, and specification from the winder parameter preset tables DC AreaPreset (Wrapper), DC Area Preset (Mandrel), and DC Area Preset (Tension), and transmits the setting data of the auxiliary winding roller pressing pressure, winding torque, lead rate, and expansion diameter parameters to the winder primary control computer;
[0051] The third step: Based on the equipment capacity, the design of the steel composition, and past production experience, the pre-set tables of data such as the pressure of the auxiliary coiling roller, the winding torque, and the lead rate are basically able to provide appropriate control data according to different specifications and strengths. During production, the control parameters of the equipment are further optimized and modified according to the actual quality of the steel coils.
[0052]
[0053]
[0054] The roll gap position of the coiling aid roll is preset, that is, the roll gap of the coiling aid roll is preset. The roll gap is increased by a certain amount according to the target rolling thickness H of the strip. The roll gaps of the three coiling aid rolls are: H+1 wrapper roll gap, H+2 wrapper roll gap, and H+3 wrapper roll gap, which allows the strip to enter the coiler. As the coil diameter continues to increase during the coiling process, the coiling aid roll is pushed back by the increased coil diameter, so that the coiling aid roll generates pressing pressure.
[0055] The drum extracts the set parameters according to the data table, presets the number of expansion turns (Mandrel fullexpand wrap) according to the winding specifications, and presets the lead ratio (Mandrel speed lead ratio [%]) according to the specifications.
[0056] After the winding machine's pinch rolls are loaded and the auxiliary winding rolls receive the pressure feedback starting point, the pre-calculation of the auxiliary winding rolls' loading time begins.
[0057] The strip head enters the coiler and reaches the auxiliary coiling roller. Under the pressing action of the auxiliary coiling roller, the strip is wound onto the drum. When the number of winding turns reaches the set value or the pressing force of the auxiliary coiling roller reaches the set value, the drum expands and the auxiliary coiling roller swings open.
[0058] The specific implementation process of the aforementioned auxiliary winding roller and winding drum control method is as follows:
[0059] After the strip head enters the winding roller, it is wound according to the preset roll gap, lead rate, number of turns, pressing pressure and drum torque. When either the pressing pressure of the winding roller or the number of turns reaches the set value, it means that the drum has successfully established tension, the winding roller opens, and the drum begins to expand in diameter.
Claims
1. A method for controlling the quality of hot-rolled coils, characterized in that... Includes the following steps: a. First, the strip steel is automatically classified and named into several "Famries" in the secondary model according to the strip steel hardness grade and specification range. At the same time, the target width, thickness and strength parameters are transmitted to the secondary setting computer of the coiler. b. After the production order is started, the winding machine setting control computer first finds the pressing pressure of the auxiliary winding roller corresponding to the family, strength and specification from the winding machine parameter preset table, and transmits the setting data to the winding machine primary control computer. c. After the production order is started, the winding machine setting control computer first finds the drum torque and expansion diameter parameters corresponding to the family, strength and specification from the winding machine parameter preset table, and transmits the setting data to the winding machine primary control computer. d. After the production order is started, the winding machine setting control computer first finds the drum lead rate corresponding to the family, strength and specification from the winding machine parameter preset table, and transmits the setting data to the winding machine primary control computer. e. When the strip head reaches the coiling pinch roll, the pinch roll loading signal is activated. This signal serves as the starting point for the auxiliary coiling roll pressure feedback and begins to pre-calculate the auxiliary coiling roll loading time. f. The strip head enters the coiler and reaches the auxiliary coiling roller. Under the pressure of the auxiliary coiling roller, the strip is wound onto the drum. The pressure of the auxiliary coiling roller for thin specifications shall not be less than 240KN, and the pressure of the auxiliary coiling roller for thick specifications shall not be less than 420KN. g. After the strip is tightly wound onto the drum, the feedback pressing pressure of the auxiliary winding roller reaches the set maximum value. The auxiliary winding roller opens up, and the number of pressing circles of the auxiliary winding roller is 3-6. Too many circles will reduce the pressing effect of the auxiliary winding roller and increase equipment wear and vibration. h. The advance rate of the roll increases the interlayer friction of the strip under the pressing action of the roll assist roller, so that the strip head is tightly attached and tensioned to establish the winding tension. i. Under the influence of lead rate and friction, the drum current and torque will increase rapidly. Generally, the feedback value reaches the set maximum torque within 0.4-0.7 seconds to complete the tensioning process. If the time is too long, it indicates that the head of the steel coil has slipped and the coil shape is poor. j. When the winding torque reaches the set maximum value and the pressing pressure of the auxiliary winding roller reaches the set maximum value, the drum begins to expand in diameter. The expansion time is generally completed within 0.4-0.7 seconds. If the time is too long, it indicates that the expansion has failed and will make it difficult to unwind. The expansion range is generally 5-9mm. If the expansion is too large, it indicates that the tension is not ideal, the head slips, and loosening occurs.
2. The hot-rolled coil quality control method according to claim 1, characterized in that: The position control of the coiling roller is preset, that is, the coiling roller is preset with a roll gap. The roll gap is increased by a certain amount according to the target rolling thickness H of the strip. The roll gaps of the three coiling rollers are H+3, H+2 and H+1, which allows the strip to enter the coiler. As the coil diameter continues to increase during the coiling process, the coiling roller is pushed back by the increased coil diameter, so that the coiling roller generates pressing pressure.
3. The hot-rolled coil quality control method according to claim 2, characterized in that: Using the load connection signal of the pinch roll as the pressure feedback reference signal of the auxiliary coiling roll, once the pinch roll load is connected, it can be confirmed that the strip head has entered the coiler. Adding the distance from the pinch roll to the auxiliary coiling roll, with a delay of 0.3-0.7 seconds, the position of the strip head can be accurately predicted. The auxiliary coiling roll can then directly enter the pressure feedback control mode and be controlled according to the set target pressure, reaching the maximum pressure at the ideal time.
4. The hot-rolled coil quality control method according to claim 1, characterized in that: Under the pressure of the coiling roller, the steel coil is tightly wound onto the drum. The friction between the layers of the steel coil establishes tension between the coiler and the strip. At the same time, the feedback current and torque of the drum gradually increase to reach the set maximum value, triggering the drum expansion action or triggering the expansion action after the strip is coiled three times.