Cold-rolled strip steel trimming quality control method

Abstract

The invention relates to the technical field of strip steel shearing, in particular to a cold-rolled strip steel trimming quality control method, which can realize a micron-scale precision and classification regulation mechanism, and through composite parameter calibration of hardness grading (150HV / 250HV threshold) and width segmentation (500mm / 1000mm threshold), the initial setting error of a lateral gap is less than or equal to + / -0.8 mu m, the burr height is stably controlled to be 2.5-3 mu m, and the trimming quality of the cold-rolled strip steel is controlled to be more than or equal to 2 mu m. In addition, differential adjustment paths of continuous burrs (reducing lateral gaps) and point burrs (increasing the overlapping amount) are innovatively distinguished, and 5-7 partition tension adjustment (the response time is less than 1 second) is combined, so that the straightness deviation of the strip steel is reduced from more than 1 mm / m to less than or equal to 0.8 mm / m.

Description

Technical Field

[0001] The present invention relates to the technical field of strip shearing, and particularly to a method for controlling the trimming quality of cold-rolled strip steel. Background Art

[0002] At present, the cold-rolled strip steel trimming process is a key link in precision cold-rolling processing, and its quality directly affects the subsequent processing performance of the strip steel and the qualified rate of the finished product. The existing methods for controlling the trimming quality of strip steel mainly rely on the setting of empirical parameters and off-line detection. The traditional methods for controlling the trimming quality of strip steel mainly rely on the following processes: 1. Empirical parameter setting: Set the initial parameters according to the strip steel thickness at a fixed ratio (for example, the lateral clearance is 6% of the thickness + 0.2 mm, and the overlap is 10% - 20%).

[0003] 2. Off-line detection and shutdown adjustment: Periodically stop the machine to take samples for detecting the notch quality (for example, once per kilometer). After detecting burrs or cracks, manually adjust the parameters. The response delay results in a waste rate as high as 10% - 15%.

[0004] In summary, the following technical defects exist in the above-mentioned prior art: 1. The prior art cannot achieve the pre-calibration of parameters with micron-level accuracy, resulting in unstable trimming quality, and there is no differential treatment for different types of burrs, making it difficult to effectively control the burr height.

[0005] 2. The prior art usually adopts a single-parameter adjustment method, lacking the ability of multi-parameter collaborative optimization, resulting in the trimming quality and production efficiency not reaching the optimal state. Moreover, the existing parameter setting does not fully consider the differences in the hardness and width of the strip steel, resulting in low shearing quality and efficiency.

[0006] 3. The off-line detection method in the prior art cannot monitor and adjust the quality problems in the production process in real time. Problems are often only discovered afterwards, increasing the scrap rate and rework cost. Moreover, there is no effective dynamic monitoring and instant adjustment mechanism, resulting in poor consistency of trimming quality and affecting the product quality.

[0007] Therefore, a method for controlling the trimming quality of cold-rolled strip steel that can solve the above problems is needed. Summary of the Invention

[0008] The present invention provides a method for controlling the edge trimming quality of cold-rolled strip steel. The present invention can achieve micron-level accuracy and classification control mechanism. Through the calibration of composite parameters of hardness grading (150HV / 250HV threshold) and width segmentation (500mm / 1000mm threshold), the initial setting error of the lateral gap is ≤±0.8μm, the burr height is stably controlled at 2.5 - 3μm, and the present invention innovatively distinguishes the differential adjustment paths for continuous burrs (reducing the lateral gap) and punctate burrs (increasing the overlap amount), combined with 5 - 7 zone tension adjustment (response time < 1 second), so that the straightness deviation of the strip steel is reduced from >1mm / m to ≤0.8mm / m.

[0009] The technical solution adopted by the present invention to solve the above technical problems is: a method for controlling the edge trimming quality of cold-rolled strip steel, comprising the following steps: S1. Parameter pre-calibration: S11. Calibrate the initial value of the lateral gap to 10% - 15% of the strip steel thickness, and the overlap amount to 3% - 5% of the strip steel thickness; Wherein the lateral gap refers to the relative position difference between the upper and lower shearing tools in the horizontal direction; Wherein the overlap amount refers to the overlapping part of the upper and lower shearing tools in the vertical direction; S12. Set the shearing speed of the upper and lower shearing tools according to the hardness grading of the strip steel; S13. Set the initial strip steel tension based on the ratio of the strip steel thickness to the width; S2. Dynamic adjustment: S21. During the shearing process of the strip steel, real-time monitor the burr height at the cut. When the burr height exceeds 3μm: a. If the burrs are continuous bands, reduce the lateral gap by a step of 0.5μm / time until the burr height drops below 2.5μm; b. If the burrs are intermittent dots, increase the overlap amount by a step of 0.2μm / time until the burr height is uniform; S22. Detect the straightness deviation during the strip steel conveying process, and adjust the strip steel tension and shearing speed according to the straightness deviation; S3. Adopt a three-stage parameter matching method to optimize the process parameters collaboratively: S4. Conduct quality feedback closed-loop control: S41. Collect a cut cross-section sample every 50m - 100m of the strip steel length, and detect the burr height, cut inclination angle and edge crack of the strip steel; S42. Reverse-correct the parameters according to the detection results.

[0010] Further, when the initial value of the lateral gap in step S11 is set to 12% of the strip thickness, an adjustment margin of ±0.5 μm is added; when the strip thickness < 0.3 mm, a compensation amount of 0.5 μm - 1 μm is additionally increased for the overlap amount.

[0011] Further, in step S12, when the strip hardness ≤ 150 HV, the shearing speed is 2.5 m - 3 m / s; when 150 HV < strip hardness ≤ 250 HV, the shearing speeds of the upper and lower shearing knives are 1.5 m - 2 m / s; when the strip hardness > 250 HV, the shearing speeds of the upper and lower shearing knives are 0.8 m - 1.2 m / s.

[0012] Further, in step S13, for strips with a thickness ≤ 0.5 mm: If the strip width ≤ 500 mm, the initial strip tension is set to 8 MPa - 9 MPa; If the strip width is between 500 mm - 1000 mm, the initial strip tension is set to 9 MPa - 10 MPa; If the strip width > 1000 mm, the initial strip tension is set to 10 MPa - 12 MPa; For strips with a thickness > 0.5 mm: If the strip width ≤ 500 mm, the initial tension of multiple strips is set to 15 MPa - 16 MPa; If the strip width is between 500 mm - 1000 mm, the initial strip tension is set to 16 MPa - 18 MPa; If the strip width > 1000 mm, the initial strip tension is set to 18 MPa - 20 MPa.

[0013] Further, in step S21, the burr height monitoring is carried out using a laser sensor. 3 - 5 laser displacement sensors are arranged equidistantly along the strip width direction, the sampling frequency ≥ 1 kHz, and the burr features are pattern - recognized through the laser displacement sensors to distinguish the proportion of continuous burrs and punctiform burrs.

[0014] Further, the three - stage parameter matching method in step S3 includes: S31. In the first stage, the strip tension is fixed, and the shearing speed is increased or decreased in steps of 0.1 m / s to screen the speed range where the burr height ≤ 2.8 μm; S32. In the second stage, the speed is fixed, and the strip tension is increased or decreased in steps of 0.3 MPa to screen the tension range where the straightness of the cut ≤ 0.8 mm / m; S33. In the third stage, the lateral gap and the overlap amount are adjusted synchronously, and each adjustment amount does not exceed ±2% of the initial value.

[0015] Further, in step S22, a laser rangefinder is used to detect the linear deviation of the strip during conveying operation. When the straightness deviation > 1 mm / m: a. Adjust the strip tension in segments along the width direction of the strip. Increase the tension on the side with the straightness deviation by 5% - 8%, and decrease the tension on the opposite side by 3% - 5%; b. Synchronously reduce the shearing speed to 70% - 80% of the current value.

[0016] Further, the method for adjusting the strip tension in segments along the width direction of the strip is as follows: Divide the strip into 5 - 7 control zones along the width direction, and synchronously increase the strip tension in two adjacent control zones on the side with the straightness deviation. The tension adjustment response time is controlled within 0.5 seconds - 1 second.

[0017] Further, in step S41, a laser scanner is used to measure the burr height of the strip cut in real time. A line-structured light sensor projects a light source onto the strip surface, and a camera captures its deformation to calculate the cut inclination angle. The cracks on the strip edge are identified by the camera combined with image processing software.

[0018] Further, the parameters reversely corrected according to the detection results in step S42 include: a. When the burr height of the strip exceeds the preset height, adjust in the order of "lateral clearance reduction → overlap increase → shearing speed reduction"; b. When the number of cracks on the strip edge > 3 per meter, reduce the strip tension by 10% - 15% and increase the shearing speed to 120% of the current value; c. Record the parameter combination into the process database and establish a "material - thickness - parameter" matching relation table for subsequent call.

[0019] The advantages of the present invention are as follows: 1. The present invention can achieve micron-level precision and classification control mechanism. Through the composite parameter calibration of hardness grading (150 HV / 250 HV threshold) and width segmentation (500 mm / 1000 mm threshold), the initial setting error of the lateral clearance ≤ ±0.8 μm, the burr height is stably controlled within 2.5 - 3 μm, and the present invention innovatively differentiates the differential adjustment paths for continuous burrs (reducing the lateral clearance) and punctate burrs (increasing the overlap), combined with 5 - 7 zone tension adjustment (response time < 1 second), so that the straightness deviation of the strip is reduced from > 1 mm / m to ≤ 0.8 mm / m.

[0020] ​2. The present invention introduces a dynamic monitoring and immediate adjustment strategy for burr height and straightness deviation, which not only improves the consistency and stability of the trimming quality, but also effectively reduces the rejection rate and rework cost. Moreover, through the three-stage parameter matching method, the present invention realizes the phased optimization of the shearing speed, strip tension, and lateral clearance and overlap amount, achieving the collaborative optimization of process parameters and further improving the trimming quality and production efficiency. Detailed implementation manners

[0021] The technical solutions of the present invention will be described clearly and completely below. 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] Example 1: In the cold-rolled strip production line, the trimming process is a key link. For example, a factory has a batch of cold-rolled strips with a thickness of 0.5 mm and a width of 800 mm that need to be trimmed. According to the traditional method, the operator may set the lateral clearance to 0.5 mm × 6% + 0.2 mm = 0.23 mm and the overlap amount to 0.5 mm × 15% = 0.075 mm. However, due to the lack of accurate parameter pre-calibration, the following problems may occur in actual processing: First, burrs with uneven heights may appear on the strip edges, and the burr height in some areas reaches 5 μm, far exceeding the expected range of 2.5 - 3 μm. Second, due to the lack of consideration of the strip hardness, the shearing speed may be set improperly, resulting in unstable cutting quality. Third, during the conveying process, the strip may have a straightness deviation of more than 1.5 mm / m, affecting the subsequent processing accuracy. Due to the lack of real-time monitoring, these problems may be discovered after producing hundreds or thousands of meters of strips, causing a large number of rejects. If these technical problems are not solved, serious consequences will occur. Therefore, the present invention provides a method for controlling the trimming quality of cold-rolled strips, including the following steps: S1. Parameter pre-calibration: S11. Calibrate the initial value of the lateral clearance to 10% - 15% of the strip thickness, and the overlap amount to 3% - 5% of the strip thickness; The lateral clearance refers to the relative position difference between the upper and lower shearing tools in the horizontal direction; The overlap amount refers to the overlapping part between the upper and lower shearing tools in the vertical direction; When the initial value of the lateral clearance is set to 12% of the strip thickness, add an adjustment margin of ±0.5 μm; when the strip thickness < 0.3 mm, an additional compensation amount of 0.5 μm - 1 μm is added to the overlap amount.

[0023] In the parameter pre-calibration stage of the present invention, key parameters such as the lateral clearance, overlap amount, shearing speed, and strip tension are precisely set according to the physical properties of the strip, such as thickness, hardness, and width. This pre-calibration method based on multiple factors can control the initial setting error of the lateral clearance within ±0.8 μm, laying a good foundation for the subsequent edge trimming process.

[0024] S12. Set the shearing speeds of the upper and lower shearing knives according to the hardness grading of the strip. Specifically, when the strip hardness ≤ 150 HV, the shearing speed is 2.5 m - 3 m / s; when 150 HV < strip hardness ≤ 250 HV, the shearing speeds of the upper and lower shearing knives are 1.5 m - 2 m / s; when the strip hardness > 250 HV, the shearing speeds of the upper and lower shearing knives are 0.8 m - 1.2 m / s. S13. Set the initial strip tension based on the ratio of the strip thickness to the width. Specifically, for strips with a thickness ≤ 0.5 mm: If the strip width ≤ 500 mm, the initial strip tension is set to 8 MPa - 9 MPa; If the strip width is between 500 mm and 1000 mm, the initial strip tension is set to 9 MPa - 10 MPa; If the strip width > 1000 mm, the initial strip tension is set to 10 MPa - 12 MPa; For strips with a thickness > 0.5 mm: If the strip width ≤ 500 mm, the initial strip tension of multiple strips is set to 15 MPa - 16 MPa; If the strip width is between 500 mm and 1000 mm, the initial strip tension is set to 16 MPa - 18 MPa; If the strip width > 1000 mm, the initial strip tension is set to 18 MPa - 20 MPa.

[0025] In the present invention, the initial tension of the strip steel depends not only on the thickness of the strip steel but also on its width. Wider strip steel requires greater tension to maintain its flatness and stability. By introducing a classification of strip steel widths (narrow: ≤500 mm, medium: between 500 mm and 1000 mm, wide: >1000 mm), the initial tension can be set more precisely, thereby improving the shearing quality. Suppose we have two strip steels with different thicknesses and widths: Strip steel A: thickness is 0.4 mm and width is 600 mm. According to the above rules, the initial tension of strip steel A should be set to 9 - 10 MPa (because the thickness ≤ 0.5 mm and the width is between 500 - 1000 mm). Strip steel B: thickness is 0.6 mm and width is 1200 mm. According to the above rules, the initial tension of strip steel B should be set to 18 - 20 MPa (because the thickness > 0.5 mm and the width > 1000 mm). In this way, the initial tension of the strip steel can be set more accurately, ensuring the stability and quality of the strip steel during the processing.

[0026] S2. Dynamic adjustment (Dynamic adjustment refers to the process of, during the edge trimming process, by real-time monitoring the height of the cut burrs and the deviation of the strip steel straightness, and instantaneously adjusting relevant parameters according to the monitoring results. Specifically, devices such as laser sensors and laser rangefinders can be used for real-time monitoring, and parameter adjustment is achieved through an automatic control system): S21. During the shearing process of the strip steel, the height of the cut burrs is monitored in real time. Specifically, the monitoring of the burr height is carried out using a laser sensor. 3 - 5 laser displacement sensors are arranged equidistantly along the width direction of the strip steel, and the sampling frequency ≥ 1 kHz. Through the laser displacement sensors, pattern recognition of the burr characteristics is performed to distinguish the proportion of continuous burrs and punctiform burrs. When the burr height exceeds 3 μm: a. If the burrs are in a continuous band shape, the lateral gap is reduced in steps of 0.5 μm / time until the burr height drops below 2.5 μm. Specifically, when it is detected that the burrs are in a continuous band shape and the height exceeds 3 μm, the control system will gradually reduce the lateral gap (the relative position difference between the upper and lower shearing tools in the horizontal direction). The amount reduced each time is 0.5 micrometers (μm) until the burr height drops below 2.5 μm. For example, if the initial lateral gap is 10 μm, it becomes 9.5 μm after the first adjustment, 9 μm after the second adjustment, and so on until the requirement of the burr height is met.

[0027] b. If the burrs are intermittent dots, increase the overlap amount in steps of 0.2 μm each time until the height of the burrs is uniform. Specifically, when it is detected that the burrs are intermittent dots and the height exceeds 3 μm, the control system will gradually increase the overlap amount (the overlapping part of the upper and lower shearing tools in the vertical direction), with each increase being 0.2 micrometers (μm), until the height of the burrs is uniform (i.e., reaches a relatively ideal uniform state). If the initial overlap amount is 3 μm, it becomes 3.2 μm after the first adjustment, 3.4 μm after the second adjustment, and so on until the height of the burrs is uniform.

[0028] To address the problem of insufficient real-time monitoring and adjustment capabilities, the present invention introduces a dynamic monitoring and immediate adjustment strategy. By installing devices such as laser rangefinders on the production line, the height of the burrs and the straightness of the strip steel are monitored in real time. When an abnormality is detected, the control system will immediately adjust the parameters. For example, when the straightness deviation exceeds 1 mm / m, the strip steel tension is adjusted in sections along the width direction of the strip steel, and the shearing speed is synchronously reduced. Specifically, the control of the strip steel tension is achieved by the following devices: Tension sensor: used to monitor the tension of the strip steel in real time. Actuator: such as a hydraulic cylinder or an electric motor, used to adjust the tension. Controller: receives data from the tension sensor and adjusts according to the set value. Through the real-time monitoring and adjustment mechanism, the present invention can significantly improve the consistency and stability of the edge trimming quality, enable rapid response, control the tension adjustment response time within 0.5 seconds to 1 second, and can promptly correct the deviation during the transmission of the strip steel. By implementing this dynamic adjustment scheme, the present invention can reduce the straightness deviation of the strip steel from greater than 1 mm / m to 0.8 mm / m or lower, significantly improving the stability and flatness during the transmission of the strip steel. This not only helps to improve the edge trimming quality but also reduces problems caused by the unevenness of the strip steel during subsequent processing, such as curling and wrinkling.

[0029] Compared with the prior art, this dynamic adjustment scheme of the present invention has obvious advantages. Traditional methods usually adopt fixed parameters or simple single-parameter adjustments and cannot cope with the real-time changes during the transmission of the strip steel. While the present invention can more effectively control the straightness deviation of the strip steel through real-time monitoring and multi-parameter coordinated adjustment. In addition, traditional methods often require shutdown for adjustment, while the scheme of the present invention can be carried out in real time during the production process, greatly improving the production efficiency.

[0030] S22. Detect the straightness deviation during the transmission of the strip steel (during the entire production line, whether before or after edge trimming, the straightness deviation of the strip steel needs to be detected in real time), and adjust the strip steel tension and shearing speed according to the straightness deviation. Specifically, detect the straightness deviation of the strip steel during transmission by a laser rangefinder. When the straightness deviation > 1 mm / m: a. Adjust the strip tension in sections along the width direction of the strip. Increase the tension on the side with straightness deviation by 5% - 8%, and decrease the tension on the opposite side by 3% - 5%. Specifically, the method of adjusting the strip tension in sections along the width direction of the strip is as follows: Divide the strip into 5 - 7 control zones along the width direction, and synchronously increase the strip tension in 2 adjacent control zones on the side with straightness deviation. The tension adjustment response time is controlled within 0.5 seconds - 1 second; b. Synchronously reduce the shearing speed to 70% - 80% of the current value.

[0031] In the dynamic adjustment stage, the height of the cut burrs is monitored in real time through a laser sensor, and the sampling frequency ≥ 1 kHz, which can quickly identify continuous burrs and dot - shaped burrs. For continuous strip - shaped burrs, the control system will reduce the lateral gap in steps of 0.5 μm / time; for dot - shaped burrs, the overlap amount will be increased in steps of 0.2 μm / time. At the same time, the straightness deviation of the strip is detected by a laser rangefinder. When the deviation exceeds 1 mm / m, the control system will adjust the tension in sections along the width direction of the strip and synchronously reduce the shearing speed. This real - time monitoring and rapid response mechanism ensures the continuous stability of the cut edge quality.

[0032] S3. Adopt the three - stage parameter matching method to carry out collaborative optimization of process parameters (the three - stage parameter matching method refers to a method for collaborative optimization of process parameters, which can be specifically achieved by optimizing the shearing speed, strip tension, and lateral gap and overlap amount respectively). Specifically, the three - stage parameter matching method includes: S31. In the first stage, fix the strip tension, increase or decrease the shearing speed in steps of 0.1 m / s, and screen the speed range with burr height ≤ 2.8 μm; S32. In the second stage, fix the speed, increase or decrease the strip tension in steps of 0.3 MPa, and screen the tension range with cut straightness ≤ 0.8 mm / m; S33. In the third stage, synchronously adjust the lateral gap and overlap amount, and each adjustment amount does not exceed ±2% of the initial value.

[0033] The three - stage parameter matching method proposed in the present invention optimizes the shearing speed, strip tension, and lateral gap and overlap amount respectively, and realizes the collaborative adjustment of process parameters. Specifically, in the first stage, the strip tension is fixed and the shearing speed is adjusted; in the second stage, the speed is fixed and the strip tension is adjusted; in the third stage, the lateral gap and overlap amount are synchronously adjusted. This method can improve production efficiency while ensuring the cut edge quality.

[0034] S4. Perform closed-loop quality feedback control (closed-loop quality feedback control refers to the process of regularly collecting samples of the cut cross-section, detecting the burr height, cut inclination angle, and edge cracks of the strip steel, and inversely correcting parameters based on the detection results. Specifically, equipment such as laser scanners, line-structured light sensors, and high-resolution cameras can be used for detection, and parameter correction can be achieved through data analysis and an automatic control system): S41. Collect a sample of the cut cross-section every 50m - 100m of strip steel length, and detect the burr height, cut inclination angle, and edge cracks of the strip steel. Specifically, use a laser scanner to measure the burr height of the strip steel cut in real time, project a line light source onto the surface of the strip steel using a line-structured light sensor, and calculate the cut inclination angle by capturing its deformation through a camera. Identify the cracks at the edge of the strip steel through a high-resolution camera combined with image processing software.

[0035] S42. Inversely correct parameters based on the detection results. Specifically, it includes: When the burr height of the strip steel exceeds the preset height, adjust it in the order of "decrease the lateral gap → increase the overlap amount → decrease the shearing speed". This adjustment order takes into account the influence degree of each parameter on burr formation and can effectively control the burr height. This adjustment order takes into account the influence degree of each parameter on burr formation and can more effectively control the burr height. For example, the lateral gap can be decreased by 0.5μm first. If the burr height is still beyond the standard, the overlap amount can be increased by 0.2μm, and finally, the shearing speed can be considered to be decreased by 10%.

[0036] When the number of edge cracks of the strip steel is greater than 3 per meter, reduce the strip steel tension by 10% - 15% and increase the shearing speed to 120% of the current value. This adjustment strategy aims to reduce the stress concentration during the edge cutting process, thereby reducing the risk of crack formation. For example, if the current strip steel tension is 10MPa and the shearing speed is 2m / s, after detecting that the number of edge cracks exceeds the standard, the tension can be reduced to 8.5 - 9MPa, and at the same time, the shearing speed can be increased to 2.4m / s.

[0037] Record the parameter combinations into the process database and establish a "material - thickness - parameter" matching relationship table for subsequent calls. Specifically, the "material - thickness - parameter" matching relationship table is as follows:

[0038]

[0039]

[0040] As can be seen from the above table, for strip steels of different materials and thicknesses during cold rolling edge cutting, the required lateral gap, overlap amount, shearing speed, and initial tension are all different. Through refined parameter settings, the present invention can ensure the consistency and stability of the edge cutting quality, thereby improving production efficiency and the qualified rate of finished products.

[0041] The present invention further ensures the long-term stability of the trimming quality through a quality feedback closed-loop control. The control system collects a sample of the cut section every 50m - 100m strip length, detects the burr height, cut angle, and edge crack of the strip, and according to the detection results, the control system will reverse-correct the parameters according to the preset adjustment strategy, such as reducing the strip tension or increasing the shearing speed, to deal with different types of quality problems. The quality feedback closed-loop control method proposed by the present invention can timely detect trimming quality problems by regularly collecting samples of the cut section and conducting detections. Through the analysis of the detection results and the reverse correction of the parameters, the continuous optimization and control of the trimming quality can be achieved. This closed-loop control mechanism can not only improve the stability of the trimming quality but also reduce the scrap rate and rework cost.

[0042] In summary, the core innovation of the present invention lies in proposing a comprehensive cold-rolled strip trimming quality control method. This method realizes the precise control and continuous optimization of the trimming quality by introducing parameter pre-calibration with micron-level accuracy, a differential burr treatment strategy, a three-stage parameter matching method, and a real-time monitoring and dynamic adjustment mechanism. This method not only improves the stability and consistency of the trimming quality but also significantly enhances the production efficiency and reduces the scrap rate. Specifically, for the problem of insufficient accuracy in parameter pre-calibration, the present invention introduces a parameter pre-calibration mechanism with micron-level accuracy. Specifically, by analyzing the physical properties of the strip, it is found that the thickness, hardness, and width of the strip are the key factors affecting the trimming quality. Therefore, a composite parameter calibration method based on these factors is proposed. For example, the initial value of the lateral clearance is set to 10% - 15% of the strip thickness, and the overlap amount is set to 3% - 5% of the strip thickness. This method is more accurate than the traditional fixed ratio setting and can control the initial setting error of the lateral clearance within ±0.8μm. For the problem of improper burr control, the present invention proposes a differential treatment strategy. Through observation, it is found that burrs can be divided into two types: continuous strip-shaped and intermittent dot-shaped, and their formation mechanisms are different, so different treatment methods are needed. Specifically, for continuous strip-shaped burrs, the method of reducing the lateral clearance is adopted; for intermittent dot-shaped burrs, the overlap amount is increased. This differential treatment can more effectively control the burr height and stabilize it within the range of 2.5 - 3μm.

[0043] As a preferred implementation mode, the present invention can be applied to a production line for processing cold-rolled strips with a thickness of 0.5mm and a width of 800mm. First, according to the strip specifications, the control system sets the initial value of the lateral clearance to 0.06mm (12% of 0.5mm), and the overlap amount to 0.02mm (4% of 0.5mm). Assuming the strip hardness is 200HV, the control system sets the shearing speed to 1.8m / s. The initial strip tension is set to 9.5MPa.

[0044] During the production process, the laser sensor detected continuous strip burrs with a height of 3.2 μm. The control system immediately reduced the lateral gap from 0.06 mm to 0.0595 mm. At the same time, the laser rangefinder detected a straightness deviation of 1.2 mm / m. The control system then divided the strip width direction into 5 control zones, increased the tension of 2 adjacent control zones on the deviation side by 7%, reduced the tension on the opposite side by 4%, and reduced the shearing speed to 1.44 m / s (80% of the original speed).

[0045] After the above adjustments, the control system began to implement the three-stage parameter matching method. In the first stage, the strip tension was fixed at 9.5 MPa, and the shearing speed was gradually adjusted. Finally, 1.7 m / s was determined as the optimal speed (burr height 2.7 μm). In the second stage, the speed was fixed at 1.7 m / s, and the tension was gradually adjusted. Finally, 9.8 MPa was determined as the optimal tension (straightness 0.75 mm / m). In the third stage, the lateral gap and the overlap amount were synchronously and finely adjusted. Finally, the lateral gap was determined to be 0.0592 mm, and the overlap amount was 0.0204 mm.

[0046] In subsequent production, the control system collected a cut cross-section sample every 80 m. When the number of edge cracks detected reached 4 per meter, the control system reduced the strip tension by 12% (to 8.624 MPa) and increased the shearing speed to 2.04 m / s. Through this continuous monitoring and adjustment, the edge trimming quality was effectively guaranteed, the burr height was stabilized within the range of 2.5 μm - 3 μm, and the straightness deviation was controlled below 0.8 mm / m.

[0047] As a preferred embodiment, the quality feedback closed-loop control method of the present invention can be combined with the foregoing parameter pre-calibration, dynamic adjustment, and three-stage parameter matching method to form a complete cold-rolled strip edge trimming quality control system. For example, when performing quality feedback closed-loop control, the results of parameter pre-calibration can be referred to as the initial values, combined with the real-time data of dynamic adjustment, optimized by the three-stage parameter matching method, and finally finely adjusted according to the quality feedback results. Suppose a batch of cold-rolled strips with a thickness of 0.4 mm, a width of 800 mm, and a hardness of 200 HV. According to the results of parameter pre-calibration, the initial settings are: the lateral gap is 0.048 mm (12% of the strip thickness), the overlap amount is 0.016 mm (4% of the strip thickness), the shearing speed is 1.8 m / s, and the strip tension is 9.5 MPa. During the edge trimming process, quality inspections are carried out every 75 m. In a certain inspection, it was found that: 1. The average burr height is 3.2 μm, exceeding the preset standard of 2.8 μm.

[0048] 2. The notch inclination angle is within 0.5°, meeting the requirements.

[0049] 3. The number of edge cracks is 2 per meter, not exceeding the standard of 3 per meter.

[0050] Based on the above detection results, the control system adjusts the parameters according to the following steps: 1. Since the burr height exceeds the standard, first reduce the lateral clearance from 0.048 mm to 0.0475 mm (reduce by 0.5 μm).

[0051] 2. After cutting the edge for about 10 m and detecting again, if the burr height still exceeds 2.8 μm, increase the overlap amount from 0.016 mm to 0.0162 mm (increase by 0.2 μm).

[0052] 3. If the burr height still exceeds the standard after the above adjustment, reduce the shearing speed from 1.8 m / s to 1.62 m / s (reduce by 10%).

[0053] At the same time, the control system records this set of parameters in the process database, establishes the optimal parameter combination for this batch of strip steel (0.4 mm thickness, 800 mm width, 200 HV hardness), and provides a reference for the edge cutting of strip steel with similar specifications in the future. Through continuous monitoring and adjustment, the quality feedback closed-loop control method in the present invention can effectively maintain the stability of the edge cutting quality, reduce the scrap rate, and improve the production efficiency. Compared with the traditional off-line detection and manual adjustment, the response time to edge cutting quality problems can be shortened from several hours to a few minutes, greatly reducing the material waste and production interruption caused by quality problems.

[0054] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled 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 method for controlling the trimming quality of cold-rolled strip steel, characterized in that, It includes the following steps: S1. Parameter pre-calibration: S11. Calibrate the initial value of the lateral clearance to 10%-15% of the strip thickness, and the overlap amount to 3%-5% of the strip thickness; wherein the lateral clearance refers to the relative position difference between the upper and lower shearing tools in the horizontal direction; wherein the overlap amount refers to the overlapping part of the upper and lower shearing tools in the vertical direction; S12. Set the shearing speeds of the upper and lower shearing tools according to the hardness grading of the strip; S13. Set the initial strip tension based on the ratio of the strip thickness to the width; S2. Dynamic adjustment: S21. During the shearing process of the strip, real-time monitor the height of the cut burr. When the burr height exceeds 3μm: a. If the burr is in a continuous band shape, reduce the lateral clearance by a step of 0.5μm each time until the burr height drops below 2.5μm; b. If the burr is in an intermittent dot shape, increase the overlap amount by a step of 0.2μm each time until the burr height is uniform; S22. Detect the straightness deviation during the strip conveying process, and adjust the strip tension and shearing speed according to the straightness deviation; S3. Adopt a three-stage parameter matching method to conduct collaborative optimization of process parameters: S4. Conduct quality feedback closed-loop control: S41. Collect a cut cross-section sample every 50m - 100m strip length, and detect the burr height, cut inclination angle and edge crack of the strip; S42. Reverse-correct the parameters according to the detection results.

2. The method for controlling the edge trimming quality of cold-rolled strip steel according to claim 1, characterized in that, In step S11, when the initial value of the lateral clearance is set to 12% of the strip thickness, an adjustment margin of ±0.5μm is added; when the strip thickness < 0.3mm, an additional compensation amount of 0.5μm - 1μm is added to the overlap amount.

3. A method for controlling the trimming quality of cold-rolled strip steel according to claim 1, characterized in that, In step S12, when the strip hardness ≤ 150HV, the shearing speed is 2.5m - 3m / s; when 150HV < strip hardness ≤ 250HV, the shearing speeds of the upper and lower shearing tools are 1.5m - 2m / s; when the strip hardness > 250HV, the shearing speeds of the upper and lower shearing tools are 0.8m - 1.2m / s.

4. A method for controlling the edge trimming quality of cold-rolled strip steel according to claim 1, characterized in that, In step S13, for strips with a thickness ≤ 0.5mm: If the strip width ≤ 500mm, the initial strip tension is set to 8MPa - 9MPa; If the strip width is between 500mm - 1000mm, the initial strip tension is set to 9MPa - 10MPa; If the strip width > 1000mm, the initial strip tension is set to 10MPa - 12MPa; For strips with a thickness > 0.5mm: If the strip width ≤ 500mm, the initial strip tension of multiple strips is set to 15MPa - 16MPa; If the strip width is between 500mm - 1000mm, the initial strip tension is set to 16MPa - 18MPa; If the strip width > 1000mm, the initial strip tension is set to 18MPa - 20MPa.

5. A method for controlling the trimming quality of cold-rolled strip steel according to claim 1, characterized in that, In step S21, the burr height monitoring is carried out by using a laser sensor. 3 - 5 laser displacement sensors are arranged equidistantly along the strip width direction, the sampling frequency ≥ 1kHz, and the burr characteristics are pattern-recognized through the laser displacement sensors to distinguish the proportion of continuous burrs and dot burrs.

6. A method for controlling the edge trimming quality of cold-rolled strip steel according to claim 1, characterized in that, The three-stage parameter matching method in step S3 includes: S31. Fix the strip tension in the first stage, increase or decrease the shearing speed in steps of 0.1 m / s, and screen the speed range with burr height ≤ 2.8 μm. S32. Fix the speed in the second stage, increase or decrease the strip tension in steps of 0.3 MPa, and screen the tension range with cut straightness ≤ 0.8 mm / m. S33. Synchronously adjust the lateral clearance and the overlap amount in the third stage, and the adjustment amount each time does not exceed ±2% of the initial value.

7. A method for controlling the trimming quality of cold-rolled strip steel according to claim 1, characterized in that In step S22, the linear deviation of the strip during transmission is detected by a laser rangefinder. When the straightness deviation > 1 mm / m: a. Adjust the strip tension in segments along the width direction of the strip. Increase the tension on the side with straightness deviation by 5% - 8%, and decrease the tension on the opposite side by 3% - 5%. b. Synchronously reduce the shearing speed to 70% - 80% of the current value.

8. A method for controlling the edge trimming quality of cold-rolled strip steel according to claim 7, characterized in that, The method of adjusting the strip tension in segments along the width direction of the strip is as follows: Divide the strip into 5 - 7 control zones along the width direction, synchronously increase the strip tension in 2 adjacent control zones on the side with straightness deviation, and control the tension adjustment response time within 0.5 s - 1 s.

9. A method for controlling the edge trimming quality of cold-rolled strip steel according to claim 1, characterized in that, In step S41, a laser scanner is used to measure the burr height of the strip cut in real time. A line-structured light sensor projects a light source onto the strip surface, and a camera captures its deformation to calculate the cut inclination angle. The cracks on the strip edge are identified by the camera combined with image processing software.

10. A method for controlling the trimming quality of cold-rolled strip steel according to claim 1, characterized in that, In step S42, the parameters reversely corrected according to the detection results include: a. When the burr height of the strip exceeds the preset height, adjust in the order of "decrease the lateral clearance → increase the overlap amount → decrease the shearing speed". b. When the number of strip edge cracks > 3 per meter, reduce the strip tension by 10% - 15% and increase the shearing speed to 120% of the current value. c. Record the parameter combination in the process database and establish a "material - thickness - parameter" matching relation table for subsequent calls.

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