Concentric circle numerical control turning method

Abstract

The invention discloses a numerical control turning method for concentric circles, and aims to provide a numerical control turning method which can be suitable for turning conical concentric circle workpieces of different sizes and models through parameterization configuration, can automatically generate a machining path and automatically finish machining by inputting corresponding parameters, and enables the machining of the conical concentric circle workpieces to be convenient and simple. And moreover, the machining precision can be controlled. The method comprises the following specific steps: step A, designing data preprocessing; step B, data import and parameter configuration; c, starting a turning function; step D, visual positioning and eccentricity acquisition; and step E, executing a tool path algorithm and compensation. The method is applied to the technical field of turning machining.

Description

Technical Field

[0001] The present invention is applied to the technical field of turning machining, and particularly relates to a concentric circle numerical control turning machining method. Background Art

[0002] In the traditional field of numerical control turning machining, it is relatively difficult to machine high-precision conical concentric circle workpieces. The reason is that the position difference of the blank placed manually each time is likely to result in parts with different eccentricities. According to different machining dimensions, multiple tool feeds are required to turn along the concentric circle tool path, and usually, it also requires technicians with particularly good professional knowledge to complete. However, not all numerical control machine operators have rich professional knowledge. On the other hand, even for professionals, the numerical control programs they compile often only complete turning by multiple arcs with a given cutting depth. Although such a numerical control program can achieve machining, it cannot meet the requirements of high-precision and rapid machining, and there are several disadvantages: First: The program compiled for machining conical concentric circle workpieces is very large (a large program volume is often not suitable for manual programming). A slight mistake will lead to errors. Once the product dimensions are changed, it is necessary to recompile, which is time-consuming and energy-consuming. Obviously, such a program is not conducive to product updating and machining quality requirements.

[0003] Second: Such a numerical control program does not have operability. The best cutting parameters for arc machining need to be determined through trial cutting on a numerical control lathe. Because the best cutting parameters for different machine tools, different tools, different workpiece materials, different surface finish requirements, and different machining precisions are different, it is not easy to obtain the best parameters in reality if the machining program cannot be changed in time during actual production.

[0004] Third: Conical concentric circle workpieces have dimensional accuracy requirements, but the tool itself also has tolerances, and in addition, the tool wears during the machining process. A numerical control program that cannot correct parameters in time cannot complete the machining of high-quality parts.

[0005] If a concentric circle numerical control turning machining method can be designed, which can be applied to the turning of conical concentric circle workpieces of different sizes and models through parametric configuration, and the machining path can be automatically generated by inputting corresponding parameters to automatically complete the machining, making the machining of conical concentric circle workpieces convenient and simple, and the machining accuracy can be controlled, then the above problems can be solved. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a concentric circle numerical control turning method for conical concentric circle workpieces that can be applied to different sizes and models through parametric configuration. By inputting corresponding parameters, the machining path can be automatically generated and the machining can be automatically completed, making the machining of conical concentric circle workpieces convenient and simple, and the machining accuracy can be controlled.

[0007] A concentric circle numerical control turning method, characterized in that it includes the following specific steps: Step A, design data preprocessing; Step B, data import and parameter configuration; Step C, start the turning function; Step D, visual positioning and eccentricity acquisition; Step E, execute the tool path algorithm and compensation; Among them, for visual positioning in step D, an industrial camera is used for image acquisition. The eccentricity is obtained by the industrial camera respectively collecting images of four Mark points on the workpiece. The four collected Mark point images are respectively subjected to Blob analysis. The mark area is screened out through the image gray value threshold, the length, width and area of the area. The pixel point set of the edge of the area is obtained according to the positional relationship of the Mark area in the image. , use the least squares method to fit a circle, by minimizing , solve the three optimal parameters A, B, and C in the standard circle equation to obtain the best Mark fitting circle, where represents the pixel X-axis coordinate value of each pixel point on the edge of the Mark area in the image, represents the pixel Y-axis coordinate value of each pixel point on the edge of the Mark area in the image. A, B, and C respectively represent the three item parameters of the general equation of the circle to be found. The fitting circle generated by the workpiece Mark point is compared with the template fitting circle, and the coordinate difference between the two is calculated as the eccentricity of the workpiece.

[0008] Further, step E includes the following sub-steps: Step E1, load the coordinate data and eccentricity compensation data of the workpiece, and set the locked axis. The locked axis can change the XYC three-axis interpolation motion into the XC or YC two-axis interpolation motion, simplify the motion planning, improve the efficiency and machining accuracy, and at the same time can also solve the problem that the workpiece cannot be machined by three-axis interpolation due to process and structural design reasons; Step E2, calculate the target position of the original coordinate data of the workpiece after eccentricity; Step E3, calculate the fine milling tool path according to the position coordinate set of the workpiece after offset using the spline curve inflation algorithm; Step E4, use the spline curve inflation algorithm again to calculate the rough milling tool path according to the feed per milling; Step E5: Perform XC or YC coordinate transformation on the rough milling and finish milling toolpaths to obtain the final toolpath and end the toolpath algorithm.

[0009] Furthermore, in the design data preprocessing of step A, professional software is first used to obtain the isometric plane design data of the turning workpiece, including the spline curve composition of the graphics. These data will be used for the subsequent generation of the turning machining path. The coordinates of the outer contour of the workpiece in the space coordinate system are reflected by the Value values of X, Y, Z, and C respectively, ensuring that the machining trajectory is consistent with the drawing design.

[0010] Furthermore, in step B, the workpiece data obtained in step A is imported into the motion control software to prepare for the subsequent machining process.

[0011] Furthermore, after the visual positioning and eccentricity acquisition are completed in step D, according to the visual positioning result, it is judged whether the eccentricity acquisition is successful. If it is not successful, step D is continued to be executed.

[0012] Furthermore, when the eccentricity acquisition in step D is successful, the toolpath algorithm is executed to compensate for the eccentricity.

[0013] Furthermore, the equipment starts two-step turning of rough milling and finish milling according to the compensated toolpath, which is divided into single-circle rough milling and multi-circle rough milling according to the different turning feed radii.

[0014] The beneficial effects of the present invention are as follows: Through parametric configuration, this application can be applied to the turning of conical concentric circle workpieces of different sizes and models. By inputting the corresponding parameters, the machining path can be automatically generated and the machining can be automatically completed, making the machining of conical concentric circle workpieces convenient and simple. Moreover, it is a concentric circle numerical control turning machining method that can control the machining accuracy. Users need to configure the workpiece size, material, cutting depth, cutting speed, etc. according to actual needs, and there is an error correction mechanism. The turning operation can only be realized after the eccentricity is obtained by visual positioning and the comparison is successful. The operation is convenient and the safety is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is the machining flow chart of the present invention; Figure 2 is the schematic diagram of the selection of Mark points on the workpiece; Figure 3 is the side view of the workpiece. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] As Figures 1 to 3 shown, in this embodiment, the present invention includes the following specific steps: Step A: Design data preprocessing; Step B: Data import and parameter configuration; Step C: Start the turning function; Step D, Visual positioning and eccentricity acquisition; Step E, Executing the tool path algorithm and compensation; Among them, in step D, industrial cameras are used for image acquisition in visual positioning. The eccentricity is obtained by the industrial cameras respectively acquiring images of four Mark points on the workpiece. Blob analysis is performed on the four acquired Mark point images respectively. The mark area is screened out through the image gray value threshold, the length, width and area of the area. The pixel point set of the edge of the area is obtained according to the positional relationship of the Mark area in the image , and the least squares method is used to fit a circle by minimizing , and three optimal parameters A, B, and C in the standard circle equation are solved to obtain the best Mark fitting circle, where represents the pixel X-axis coordinate value of each pixel point on the edge of the Mark area in the image, represents the pixel Y-axis coordinate value of each pixel point on the edge of the Mark area in the image. A, B, and C respectively represent the three terms of the general equation of the circle to be found. The fitting circle generated by the workpiece Mark point is compared with the template fitting circle, and the coordinate difference between the two is calculated as the eccentricity of the workpiece.

[0017] As Figure 1 shown, in this embodiment, step E includes the following sub-steps: Step E1, Loading the coordinate data and eccentricity compensation data of the workpiece, and setting the locked axis. The locked axis can change the XYC three-axis interpolation movement into the XC or YC two-axis interpolation movement, simplifying the motion planning, improving the efficiency and machining accuracy, and at the same time can also solve the problem that the workpiece cannot be machined by three-axis interpolation due to process and structural design reasons; Step E2, Calculating the target position of the original coordinate data of the workpiece after eccentricity; Step E3, Calculating the finish milling tool path according to the position coordinate set of the workpiece after offset using the spline curve inflation algorithm; Step E4, Using the spline curve inflation algorithm again to calculate the rough milling tool path according to the feed per milling; Step E5, Performing XC or YC coordinate transformation on the rough milling and finish milling tool paths to obtain the final tool path and end the tool path algorithm.

[0018] As Figure 1 shown, in this embodiment, in the design data preprocessing of step A, professional software is first used to obtain the isometric plane design data of the turning workpiece, including the spline curve composition of the graphics. These data will be used for the subsequent generation of the turning machining path. The coordinates of the outer contour of the workpiece in the space coordinate system are reflected by the Value values of X, Y, Z, and C respectively, ensuring that the machining trajectory is consistent with the drawing design.

[0019] AsFigure 1 As shown, in this embodiment, in step B, the workpiece data obtained in step A is imported into the motion control software to prepare for the subsequent machining process.

[0020] As Figure 1 shown, in this embodiment, after step D completes visual positioning and eccentricity acquisition, according to the visual positioning result, it is judged whether the eccentricity acquisition is successful. If the acquisition is not successful, step D is continued. Thus, through this error correction mechanism, the turning operation can be realized only after the eccentricity is acquired by visual positioning and the comparison is successful, with high safety.

[0021] As Figure 1 shown, in this embodiment, when the eccentricity acquisition in step D is successful, the tool path algorithm is executed to compensate for the eccentricity. Thus, this step will ensure the accuracy of the machining path, thereby meeting the requirements of high-precision machining.

[0022] As Figure 1 shown, in this embodiment, the device starts two-step turning of rough milling and finish milling according to the compensated tool path, which is divided into single-pass rough milling and multi-pass rough milling according to the different turning feed radii. Thus, it is divided into single-pass rough milling and multi-pass rough milling according to the different turning feed radii, and the feed amount per time is preferably less than the radius of the milling cutter to ensure the machining accuracy and surface roughness of the workpiece, and the turning is ended to complete the workpiece machining.

[0023] The working principle of the present invention: step A designs data preprocessing; step B, data import and parameter configuration; step C, starts the turning function; step D, visual positioning and eccentricity acquisition; step E, executes the tool path algorithm and compensation.

[0024] Although the embodiments of the present invention are described in terms of actual solutions, they do not constitute a limitation to the meaning of the present invention. For those skilled in the art, modifications to its implementation solutions according to this specification and combinations with other solutions are obvious.

Claims

1. A concentric circle numerical control turning processing method, characterized in that: It includes the following specific steps: Step A: Design data preprocessing; Step B: Data import and parameter configuration; Step C: Start the turning function; Step D: Visual positioning and eccentricity acquisition; Step E: Execute the tool path algorithm and compensation; Among them, in step D, industrial cameras are used for visual positioning to collect images. The eccentricity is obtained by the industrial cameras collecting images of four Mark points on the workpiece respectively. Blob analysis is performed on the four collected Mark point images respectively. The mark area is screened out by the image gray value threshold, the length, width and area of the area. The pixel point set of the edge of the area is obtained according to the positional relationship of the Mark area in the image , and the least squares method is used to fit a circle by minimizing . Three optimal parameters A, B, and C in the standard circle equation are solved to obtain the best Mark fitting circle, where represents the pixel X-axis coordinate value of each pixel point on the edge of the Mark area in the image, represents the pixel Y-axis coordinate value of each pixel point on the edge of the Mark area in the image. A, B, and C respectively represent the three item parameters of the general equation of the circle to be found. The fitting circle generated by the workpiece Mark point is compared with the template fitting circle, and the coordinate difference between the two is calculated as the eccentricity of the workpiece 2. The concentric circle numerical control turning method according to claim 1, wherein: Step E includes the following sub-steps: Step E1: Load the coordinate data and eccentricity compensation data of the workpiece, and set the locked axis. The locked axis can change the three-axis interpolation movement of XYC into the two-axis interpolation movement of XC or YC, which simplifies the motion planning, improves the motion efficiency and machining accuracy, and at the same time can also solve the problem that the workpiece cannot be machined by three-axis interpolation due to process and structural design reasons; Step E2: Calculate the target position of the original coordinate data of the workpiece after eccentricity; Step E3: Calculate the fine milling tool path using the spline curve inflation algorithm according to the set of position coordinates of the workpiece after offset; Step E4: Use the spline curve inflation algorithm again to calculate the rough milling tool path according to the feed per milling pass; Step E5: Perform XC or YC coordinate transformation on the rough milling and fine milling tool paths to obtain the final tool path and end the tool path algorithm.

3. A concentric circle numerical control turning method according to claim 2, characterized in that: In the design data preprocessing in Step A, first use professional software to obtain the equal-ratio plane design data of the turning workpiece, including the spline curve composition of the graphics. These data will be used for the subsequent generation of the turning processing path, and the coordinates of the outer contour of the workpiece in the space coordinate system are reflected by the Value values of X, Y, Z, and C respectively, ensuring that the machining trajectory is consistent with the drawing design.

4. A concentric circle numerical control turning method according to claim 3, characterized in that: Step B imports the workpiece data obtained in Step A into the motion control software to prepare for the subsequent machining process.

5. A concentric circle numerical control turning method according to claim 4, characterized in that: After Step D completes visual positioning and eccentricity acquisition, according to the visual positioning result, judge whether the eccentricity acquisition is successful. If it is not successful, continue to execute Step D.

6. A concentric circle numerical control turning method according to claim 5, characterized in that: When the eccentricity acquisition in Step D is successful, execute the tool path algorithm to compensate for the eccentricity.

7. A concentric circle numerical control turning method according to claim 6, characterized in that: The equipment starts to perform two-step turning of rough milling and fine milling according to the compensated tool path, and is divided into single-pass rough milling and multi-pass rough milling according to the different turning feed radii.

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