Method for reducing reverse reconstruction distortion of curved copper plate of crystallizer

Abstract

The application discloses a method for reducing the distortion of reverse reconstruction of a curved copper plate of a crystallizer, which adopts multiple comparison and comprehensive judgment in a reverse modeling mode, obtains curved surface data through multi-party sampling detection, infers the curved surface type, compares the relationship between the detection data and deformation, and combines with process data to correct the cross-section curve within a certain range based on the above judgment basis, calculates a new curve equation, and then restores the curved copper plate curve closer to the original design through forward modeling by using a three-dimensional software tool modeling. The method can effectively reduce the distortion error between reverse design and original design, is especially suitable for reverse development of the curved copper plate with long-term storage, excessive surface deformation and slightly eroded local curved surface, and can realize accurate restoration of the original design to the maximum extent and improve the product quality of the funnel-shaped crystallizer.

Description

Technical Field

[0001] This invention relates to the field of mechanical equipment surveying technology, and in particular to a method for reducing the distortion of reverse reconstruction of curved copper plates in crystallizers. Background Technology

[0002] The funnel-shaped crystallizer is a core technology of thin slab continuous casting equipment. Unlike ordinary crystallizers, its internal opening features a wide copper plate on both sides with a vertically tapered funnel shape, rather than a conventional flat plate design. The quality of the curved surface shape of this funnel zone is closely related to the strain, strain rate, and stress level in the plastic deformation zone within the high-temperature slab shell, directly affecting the surface quality of the cast slab.

[0003] Reverse engineering of such products primarily employs reverse modeling techniques. This technology is widely used in the automotive and aerospace industries, employing testing equipment to acquire surface data of physical samples, and then using built-in or complementary software tools to generate a processing model through algorithmic optimization. However, for the reverse design of certain curved surface products, this method of directly using software tools and algorithms to reverse model after scanning the physical sample or taking data points with a probe carries significant uncertainties and risks.

[0004] In the steel industry, taking the reverse design of curved copper plates in funnel-shaped crystallizers as an example, the main features are: 1) The available physical copper plates have been stored for a long time, and their manufacturing precision and overall deformation have a significant impact on the accuracy of reverse engineering. 2) In the crystallizer, the copper plate and the water tank are rigidly connected and tightened. Different tightening methods and torques will affect the shape details of the curved copper plate. 3) The scanning process of the physical sample is affected by the accuracy of the testing equipment itself; 4) Surface reconstruction generation, especially surface splicing, may produce fundamental errors due to improper method selection, which may sometimes be unacceptable.

[0005] In summary, the traditional approach of simply acquiring physical sample data, optimizing algorithms, and reconstructing models is clearly unsuitable for reverse engineering such products. The reverse engineering results will inevitably deviate significantly from the original design, posing substantial technical risks to subsequent product design and manufacturing. Therefore, there is an urgent need to explore and find a reverse model reconstruction method that can effectively address these issues. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for reducing the distortion of reverse reconstruction of curved copper plates in crystallizers. This method overcomes the defects of traditional reverse modeling technology, effectively reduces the distortion error between reverse design and original design, maximizes the accurate restoration of the original design, and improves the product quality of funnel-shaped crystallizers.

[0007] To solve the above-mentioned technical problems, the method for reducing the reverse reconstruction distortion of the curved copper plate in the crystallizer according to the present invention includes the following steps: Step 1: Perform a full-area initial 3D scan of the sample curved copper plate. Through data processing, algorithm stitching and reconstruction, obtain a 3D model of the sample curved copper plate in a free state to understand and confirm the overall deformation state of the sample curved copper plate. Step 2: Use 3D software tools to project the mounting surface of the sample curved copper plate in the 3D model onto a plane and export a 2D engineering drawing; or use manual surveying to draw the mounting surface of the sample curved copper plate. Step 3: Based on the two-dimensional engineering drawing of the sample curved copper plate and referring to the connection relationship between the curved copper plate and the water tank, design and manufacture a special fixture. The special fixture is a positive pad plate with a flatness requirement of ≤0.02mm and sufficient structural rigidity. Step 4: Following the installation standard of tightening the bolts between the curved copper plate and the water tank, install and tighten the sample curved copper plate onto the positive pad. Step 5: After the sample curved copper plate and the positive pad are installed and tightened, check the state between the surface of the sample curved copper plate and the surface of the positive pad to obtain the on-machine flatness test data of the sample curved copper plate. Step 6: Use a non-contact 3D laser scanner to scan the curved copper plate of the sample again and reconstruct the initial 3D model; Step 7: By analyzing the sheet generated by scanning the sample curved copper plate again, and combining the knowledge and information of similar curved copper plates in the past, a preliminary inference is made about the original design of the curved copper plate construction. Step 8: Based on the preliminary inference, the initial 3D model reconstructed in Step 6 is divided into cross-sectional curves at equal intervals. The cross-sectional curves are then used to reconstruct the surface and draw the initial model of the curved copper plate. Step 9: Expand the number of original segmented surfaces of the initial model, divide it into more cross-sectional curves at equal intervals, and capture the data of each cross-sectional curve. For the curved area of ​​the sample copper plate, use a 3D table to detect and collect surface data point by point. Step 10: Compare and calculate the differences between the collected surface data and the data of each cross-section curve of the initial model. Step 11: Based on the difference between the on-machine flatness detection data in Step 5 and the data in Step 10, compare and analyze the deformation trend and state of the curved copper plate of the sample to determine the direction and pattern of its deformation. Step 12: By comparing and analyzing the surface data and combining it with the process data, based on each point on the surface, the difference points are eliminated or corrected by using the curvature diagrams of each section of the sample copper plate and the initial model, and the curve equations of each section are fitted and calculated. Step 13: Based on the established curve equations of each cross section, use 3D software tools to reconstruct the surface of the curved copper plate using the curve equations of each cross section.

[0008] Furthermore, in step five, after the sample curved copper plate and the positive pad are installed and tightened, the positive pad and the sample curved copper plate are placed on the CNC machine tool table. Taking the copper plate funnel plane of the sample curved copper plate as a reference, the side is aligned and straightened, and the curved surface of the sample curved copper plate and the remaining exposed surface of the positive pad are detected to obtain the in-machine test data of the sample curved copper plate.

[0009] Furthermore, by utilizing the survey data of other parts of the sample curved copper plate and combining it with the reconstructed surface of the curved copper plate, a complete three-dimensional model of the curved copper plate is constructed for subsequent processing and manufacturing of the curved copper plate. Because this invention reduces distortion in the reverse reconstruction of curved copper plates in crystallizers using the aforementioned technical solution, this method employs multiple comparisons, comprehensive judgments, and reverse modeling. It obtains surface data through multi-source sampling and detection, infers the surface type, compares the relationship between the detection data and deformation, and, in conjunction with process data, corrects the cross-sectional curve within a certain range based on the aforementioned judgment criteria, calculating a new curve equation. Then, using forward modeling and 3D software tools, it reconstructs a curved copper plate surface that more closely resembles the original design. This method effectively reduces distortion errors between the reverse design and the original design, and is particularly suitable for the reverse development of curved copper plates that have undergone excessive surface deformation due to long-term storage, resulting in slight erosion of local curved surfaces. It maximizes the accurate reconstruction of the original design and improves the quality of funnel-shaped crystallizer products. Attached Figure Description

[0010] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram showing the installation and tightening of the positive pad and the curved copper plate of the sample in this method; Figure 2 This is a schematic diagram of the initial 3D model reconstructed after rescanning the sample curved copper plate in this method; Figure 3 This is a schematic diagram of the curved copper plate surface reconstructed based on the curve equations of each cross section in this method. Detailed Implementation

[0011] Implementation, for example Figure 1 , Figure 2 and Figure 3 As shown, the method for reducing reverse reconstruction distortion of the curved copper plate in the crystallizer according to the present invention includes the following steps: Step 1: Perform a full-area initial 3D scan of the sample curved copper plate. Through data processing, algorithm stitching and reconstruction, obtain a 3D model of the sample curved copper plate in a free state to understand and confirm the overall deformation state of the sample curved copper plate. After 3D reconstruction, the maximum plane deformation of the sample curved copper plate is about 1.4mm, and it is convex. Step 2: Use 3D software tools to project the mounting surface of the sample curved copper plate in the 3D model onto a plane and export a 2D engineering drawing; or use manual surveying to draw the mounting surface of the sample curved copper plate; where the mounting surface of the sample curved copper plate is the water tank mounting surface.

[0012] Step 3: Based on the two-dimensional engineering drawing of the sample curved copper plate and referring to the connection relationship between the curved copper plate and the water tank, design and manufacture a special fixture. The special fixture is a positive pad plate with a flatness requirement of ≤0.02mm and sufficient structural rigidity. Step 4: Following the installation standards for tightening bolts between the curved copper plate and the water tank, install and tighten the sample curved copper plate onto the positive pad; for example... Figure 1 As shown, the mounting surface of the curved copper plate 1 is placed to coincide with the mounting surface of the positive pad 2. The external hex bolts 3 are tightened in sequence according to the standard pitch and installation order, and a feeler gauge is used to check for gaps. Step 5: After the sample curved copper plate and the positive pad are installed and tightened, check the state between the surface of the sample curved copper plate and the surface of the positive pad to obtain the on-machine flatness test data of the sample curved copper plate. Test results: The flatness of the curved copper plate of the sample is 0.13mm (three of the four points on the outer edge of the plane are close to 0, and the lower left corner is -0.05). The flatness of the detectable part of the positive pad plate increases to 0.18mm. Based on the above test, it can be concluded that the curved copper plate of the sample has a large convex deformation, which causes the positive pad plate to deform. Step Six: Use a non-contact 3D laser scanner to scan the curved copper plate sample again and reconstruct the initial 3D model, as shown in the figure. Figure 2 As shown; Step 7: By analyzing the sheet generated by scanning the sample curved copper plate again, and combining the knowledge and data of similar curved copper plates in the past, a preliminary inference is made on the original design of the curved copper plate construction; that is, it can be preliminarily inferred that the original design of the sample curved copper plate is a funnel-shaped curved surface composed of curves with certain regularity. Step 8: Based on the preliminary inference, the initial 3D model reconstructed in Step 6 is divided into cross-sectional curves at equal intervals. The cross-sectional curves are then used to reconstruct the surface and draw the initial model of the curved copper plate. Step 9: Expand the number of original segmented surfaces of the initial model, divide it into more cross-sectional curves at equal intervals, and capture the data of each cross-sectional curve. For the curved area of ​​the sample copper plate, use a 3D table to detect and collect surface data point by point. Step 10: Compare and calculate the difference between the collected surface data and the data of each cross-section curve of the initial model. By comparing the sample surface copper plate data with the point values ​​of the initial model, the maximum difference between the two is 0.176 mm, and the average difference is 0.065 mm. Among them, the maximum positive difference is 0.176 mm, and the maximum negative difference is -0.146 mm. Step 11: Based on the difference between the on-machine flatness detection data in Step 5 and the data in Step 10, compare and analyze the deformation trend and state of the curved copper plate of the sample to determine the direction and pattern of its deformation. Analysis shows that, considering the actual deformation of the lines on both sides of the copper plate curved surface, which are concave, if the average difference in the test data is compensated by straightening both sides, the adjustment value is estimated to be around 0.11mm. The overall trend of the funnel curved surface tends to be raised horizontally by 0.1mm. According to the process data consulted and the description of the curved copper plate repair process in the literature, after the copper plate completes the fine machining of the funnel curved surface, the flat surface still needs to be removed by 0.1mm. In other words, the actual positional relationship between the copper plate funnel surface and the flat surface will be raised by 0.1mm. Based on the above, the average difference between the test data of the sample curved copper plate and the initial model value is 0.11mm (adjustment value). Subtracting 0.1mm (the final removal amount of the plane required by the process), the average difference is only 0.01mm. The overall shape of the copper plate funnel surface tends to rise horizontally by 0.1mm, which matches the actual situation and can be used as the data correction amount for the next step. Step 12: By comparing and analyzing the surface data and combining it with the process data, based on each point on the surface, the difference points are eliminated or corrected by using the curvature diagrams of each section of the sample copper plate and the initial model, and the curve equations of each section are fitted and calculated. Step 13: Based on the established curve equations of each cross section, use 3D software tools to reconstruct the surface of the curved copper plate using the curve equations of each cross section.

[0013] Preferably, in step five, after the sample curved copper plate and the positive pad are installed and tightened, the positive pad and the sample curved copper plate are placed on the CNC machine tool table. Taking the copper plate funnel plane of the sample curved copper plate as a reference, the side is aligned and straightened, and the curved surface of the sample curved copper plate and the remaining exposed surface of the positive pad are detected to obtain the in-machine test data of the sample curved copper plate.

[0014] Preferably, by utilizing survey data from other parts of the sample curved copper plate and reconstructing the surface of the curved copper plate, a complete 3D model of the curved copper plate is constructed for subsequent processing and manufacturing. The complete 3D model of the curved copper plate is as follows: Figure 3 As shown.

[0015] This method was applied to the reverse engineering of curved copper plates. Verification showed that the curved copper plate machining model constructed using this method achieved an accuracy improvement of approximately 0.31 mm compared to models obtained through traditional data processing, algorithm splicing, and reconstruction. This difference can also be observed through… Figure 2 and Figure 3 The comparison clearly reflects the differences between the two. This reduces the distortion during reverse reconstruction of the curved copper plate of the crystallizer, maximizes the accurate reproduction of the original design, and improves the product quality of the funnel-shaped crystallizer.

Claims

1. A method for reducing reverse reconstruction distortion of curved copper plates in a crystallizer, characterized in that... This method includes the following steps: Step 1: Perform a full-area initial 3D scan of the sample curved copper plate. Through data processing, algorithm stitching and reconstruction, obtain a 3D model of the sample curved copper plate in a free state to understand and confirm the overall deformation state of the sample curved copper plate. Step 2: Use 3D software tools to project the mounting surface of the sample curved copper plate in the 3D model onto a plane and export a 2D engineering drawing; or use manual surveying to draw the mounting surface of the sample curved copper plate. Step 3: Based on the two-dimensional engineering drawing of the sample curved copper plate and referring to the connection relationship between the curved copper plate and the water tank, design and manufacture a special fixture. The special fixture is a positive pad plate with a flatness requirement of ≤0.02mm and sufficient structural rigidity. Step 4: Following the installation standard of tightening the bolts between the curved copper plate and the water tank, install and tighten the sample curved copper plate onto the positive pad. Step 5: After the sample curved copper plate and the positive pad are installed and tightened, check the state between the surface of the sample curved copper plate and the surface of the positive pad to obtain the on-machine flatness test data of the sample curved copper plate. Step 6: Use a non-contact 3D laser scanner to scan the curved copper plate of the sample again and reconstruct the initial 3D model; Step 7: By analyzing the sheet generated by scanning the sample curved copper plate again, and combining the knowledge and information of similar curved copper plates in the past, a preliminary inference is made about the original design of the curved copper plate construction. Step 8: Based on the preliminary inference, the initial 3D model reconstructed in Step 6 is divided into cross-sectional curves at equal intervals. The cross-sectional curves are then used to reconstruct the surface and draw the initial model of the curved copper plate. Step 9: Expand the number of original segmented surfaces of the initial model, divide it into more cross-sectional curves at equal intervals, and capture the data of each cross-sectional curve. For the curved area of ​​the sample copper plate, use a 3D table to detect and collect surface data point by point. Step 10: Compare and calculate the differences between the collected surface data and the data of each cross-section curve of the initial model. Step 11: Based on the difference between the on-machine flatness detection data in Step 5 and the data in Step 10, compare and analyze the deformation trend and state of the curved copper plate of the sample to determine the direction and pattern of its deformation. Step 12: By comparing and analyzing the surface data and combining it with the process data, based on each point on the surface, the difference points are eliminated or corrected by using the curvature diagrams of each section of the sample copper plate and the initial model, and the curve equations of each section are fitted and calculated. Step 13: Based on the established curve equations of each cross section, use 3D software tools to reconstruct the surface of the curved copper plate using the curve equations of each cross section.

2. The method for reducing reverse reconstruction distortion of curved copper plates in a crystallizer according to claim 1, characterized in that: In step five, after the sample curved copper plate and the positive pad are installed and tightened, the positive pad and the sample curved copper plate are placed on the CNC machine tool table. Taking the copper plate funnel plane of the sample curved copper plate as the reference, the side is aligned and straightened. The curved surface of the sample curved copper plate and the remaining exposed surface of the positive pad are inspected to obtain the in-machine inspection data of the sample curved copper plate.

3. The method for reducing reverse reconstruction distortion of curved copper plates in a crystallizer according to claim 1, characterized in that: By using the survey data of other parts of the sample curved copper plate, and combining the reconstructed surface of the curved copper plate, a complete three-dimensional model of the curved copper plate is constructed for subsequent processing and manufacturing.

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