Analysis of the Processing Flow of High-Speed Precision Parts in Machining Centers
I. Introduction
Machining centers play a crucial role in the field of high-speed precision part processing. They control machine tools through digital information, enabling the machine tools to automatically execute the specified processing tasks. This processing method can ensure extremely high processing accuracy and stable quality, is easy to realize automated operation, and has the advantages of high productivity and a short production cycle. Meanwhile, it can reduce the usage amount of process equipment, meet the needs of rapid product renewal and replacement, and is closely connected with CAD to achieve the transformation from design to final products. For trainees learning the processing flow of high-speed precision parts in machining centers, it is of great importance to understand the connections between each process and the significance of each step. This article will elaborate on the entire processing flow from product analysis to inspection and demonstrate it through specific cases. The case materials are double-color boards or plexiglass.
Machining centers play a crucial role in the field of high-speed precision part processing. They control machine tools through digital information, enabling the machine tools to automatically execute the specified processing tasks. This processing method can ensure extremely high processing accuracy and stable quality, is easy to realize automated operation, and has the advantages of high productivity and a short production cycle. Meanwhile, it can reduce the usage amount of process equipment, meet the needs of rapid product renewal and replacement, and is closely connected with CAD to achieve the transformation from design to final products. For trainees learning the processing flow of high-speed precision parts in machining centers, it is of great importance to understand the connections between each process and the significance of each step. This article will elaborate on the entire processing flow from product analysis to inspection and demonstrate it through specific cases. The case materials are double-color boards or plexiglass.
II. Product Analysis
(A) Obtaining Composition Information
Product analysis is the starting point of the entire processing flow. Through this stage, we need to obtain sufficient composition information. For different types of parts, the sources of composition information are extensive. For example, if it is a mechanical structure part, we need to understand its shape and size, including geometric dimension data such as length, width, height, hole diameter, and shaft diameter. These data will determine the basic framework of subsequent processing. If it is a part with complex curved surfaces, such as an aero-engine blade, precise curved surface contour data are required, which may be obtained through advanced technologies such as 3D scanning. In addition, the tolerance requirements of parts are also a key part of the composition information, which stipulates the range of processing accuracy, such as dimensional tolerance, shape tolerance (roundness, straightness, etc.), and position tolerance (parallelism, perpendicularity, etc.).
(A) Obtaining Composition Information
Product analysis is the starting point of the entire processing flow. Through this stage, we need to obtain sufficient composition information. For different types of parts, the sources of composition information are extensive. For example, if it is a mechanical structure part, we need to understand its shape and size, including geometric dimension data such as length, width, height, hole diameter, and shaft diameter. These data will determine the basic framework of subsequent processing. If it is a part with complex curved surfaces, such as an aero-engine blade, precise curved surface contour data are required, which may be obtained through advanced technologies such as 3D scanning. In addition, the tolerance requirements of parts are also a key part of the composition information, which stipulates the range of processing accuracy, such as dimensional tolerance, shape tolerance (roundness, straightness, etc.), and position tolerance (parallelism, perpendicularity, etc.).
(B) Defining Processing Requirements
Besides composition information, processing requirements are also the focus of product analysis. This includes the material characteristics of parts. The properties of different materials such as hardness, toughness, and ductility will affect the choice of processing technology. For example, processing high-hardness alloy steel parts may require the use of special cutting tools and cutting parameters. Surface quality requirements are also an important aspect. For example, the surface roughness requirement is such that for some high-precision optical parts, the surface roughness may be required to reach the nanometer level. In addition, there are also some special requirements, such as the corrosion resistance and wear resistance of parts. These requirements may require additional treatment processes after processing.
Besides composition information, processing requirements are also the focus of product analysis. This includes the material characteristics of parts. The properties of different materials such as hardness, toughness, and ductility will affect the choice of processing technology. For example, processing high-hardness alloy steel parts may require the use of special cutting tools and cutting parameters. Surface quality requirements are also an important aspect. For example, the surface roughness requirement is such that for some high-precision optical parts, the surface roughness may be required to reach the nanometer level. In addition, there are also some special requirements, such as the corrosion resistance and wear resistance of parts. These requirements may require additional treatment processes after processing.
III. Graphic Design
(A) Design Basis Based on Product Analysis
Graphic design is based on a detailed analysis of the product. Taking seal processing as an example, first, the font should be determined according to the processing requirements. If it is a formal official seal, the standard Song typeface or imitation Song typeface may be used; if it is an art seal, the font selection is more diversified, and it can be seal script, clerical script, etc., which have an artistic sense. The size of the text should be determined according to the overall size and purpose of the seal. For example, the text size of a small personal seal is relatively small, while the text size of a large company official seal is relatively large. The type of seal is also crucial. There are different shapes such as circular, square, and oval. The design of each shape needs to consider the layout of the internal text and patterns.
(A) Design Basis Based on Product Analysis
Graphic design is based on a detailed analysis of the product. Taking seal processing as an example, first, the font should be determined according to the processing requirements. If it is a formal official seal, the standard Song typeface or imitation Song typeface may be used; if it is an art seal, the font selection is more diversified, and it can be seal script, clerical script, etc., which have an artistic sense. The size of the text should be determined according to the overall size and purpose of the seal. For example, the text size of a small personal seal is relatively small, while the text size of a large company official seal is relatively large. The type of seal is also crucial. There are different shapes such as circular, square, and oval. The design of each shape needs to consider the layout of the internal text and patterns.
(B) Creating Graphics Using Professional Software
After determining these basic elements, professional graphic design software needs to be used to create graphics. For simple two-dimensional graphics, software such as AutoCAD can be used. In these software, the outline of the part can be accurately drawn, and the thickness, color, etc. of the lines can be set. For complex three-dimensional graphics, three-dimensional modeling software such as SolidWorks and UG needs to be used. These software can create part models with complex curved surfaces and solid structures, and can perform parametric design, facilitating the modification and optimization of graphics. During the graphic design process, the requirements of subsequent processing technology also need to be considered. For example, in order to facilitate the generation of tool paths, the graphics need to be reasonably layered and partitioned.
After determining these basic elements, professional graphic design software needs to be used to create graphics. For simple two-dimensional graphics, software such as AutoCAD can be used. In these software, the outline of the part can be accurately drawn, and the thickness, color, etc. of the lines can be set. For complex three-dimensional graphics, three-dimensional modeling software such as SolidWorks and UG needs to be used. These software can create part models with complex curved surfaces and solid structures, and can perform parametric design, facilitating the modification and optimization of graphics. During the graphic design process, the requirements of subsequent processing technology also need to be considered. For example, in order to facilitate the generation of tool paths, the graphics need to be reasonably layered and partitioned.
IV. Process Planning
(A) Planning Processing Steps from a Global Perspective
Process planning is to reasonably establish each processing step from a global perspective based on an in-depth analysis of the appearance and processing requirements of the workpiece product. This requires considering the processing sequence, processing methods, and the cutting tools and fixtures to be used. For parts with multiple features, it is necessary to determine which feature to process first and which one to process later. For example, for a part with both holes and planes, usually the plane is processed first to provide a stable reference surface for subsequent hole processing. The choice of processing method depends on the material and shape of the part. For example, for outer circular surface processing, turning, grinding, etc. can be chosen; for inner hole processing, drilling, boring, etc. can be adopted.
(A) Planning Processing Steps from a Global Perspective
Process planning is to reasonably establish each processing step from a global perspective based on an in-depth analysis of the appearance and processing requirements of the workpiece product. This requires considering the processing sequence, processing methods, and the cutting tools and fixtures to be used. For parts with multiple features, it is necessary to determine which feature to process first and which one to process later. For example, for a part with both holes and planes, usually the plane is processed first to provide a stable reference surface for subsequent hole processing. The choice of processing method depends on the material and shape of the part. For example, for outer circular surface processing, turning, grinding, etc. can be chosen; for inner hole processing, drilling, boring, etc. can be adopted.
(B) Selecting Appropriate Cutting Tools and Fixtures
The selection of cutting tools and fixtures is an important part of process planning. There are various types of cutting tools, including turning tools, milling tools, drill bits, boring tools, etc., and each type of cutting tool has different models and parameters. When selecting cutting tools, factors such as the material of the part, processing accuracy, and processing surface quality need to be considered. For example, high-speed steel cutting tools can be used to process aluminum alloy parts, while carbide cutting tools or ceramic cutting tools are required to process hardened steel parts. The function of fixtures is to fix the workpiece to ensure the stability and accuracy during the processing process. Common fixture types include three-jaw chucks, four-jaw chucks, and flat-mouth pliers. For parts with irregular shapes, special fixtures may need to be designed. In process planning, appropriate fixtures need to be selected according to the shape and processing requirements of the part to ensure that the workpiece will not be displaced or deformed during the processing process.
The selection of cutting tools and fixtures is an important part of process planning. There are various types of cutting tools, including turning tools, milling tools, drill bits, boring tools, etc., and each type of cutting tool has different models and parameters. When selecting cutting tools, factors such as the material of the part, processing accuracy, and processing surface quality need to be considered. For example, high-speed steel cutting tools can be used to process aluminum alloy parts, while carbide cutting tools or ceramic cutting tools are required to process hardened steel parts. The function of fixtures is to fix the workpiece to ensure the stability and accuracy during the processing process. Common fixture types include three-jaw chucks, four-jaw chucks, and flat-mouth pliers. For parts with irregular shapes, special fixtures may need to be designed. In process planning, appropriate fixtures need to be selected according to the shape and processing requirements of the part to ensure that the workpiece will not be displaced or deformed during the processing process.
V. Path Generation
(A) Implementing Process Planning through Software
Path generation is the process of specifically implementing process planning through software. In this process, the designed graphics and planned process parameters need to be input into numerical control programming software such as MasterCAM and Cimatron. These software will generate tool paths according to the input information. When generating tool paths, factors such as the type, size, and cutting parameters of the cutting tools need to be considered. For example, for milling processing, the diameter, rotation speed, feed rate, and cutting depth of the milling tool need to be set. The software will calculate the movement trajectory of the cutting tool on the workpiece according to these parameters and generate corresponding G codes and M codes. These codes will guide the machine tool to process.
(A) Implementing Process Planning through Software
Path generation is the process of specifically implementing process planning through software. In this process, the designed graphics and planned process parameters need to be input into numerical control programming software such as MasterCAM and Cimatron. These software will generate tool paths according to the input information. When generating tool paths, factors such as the type, size, and cutting parameters of the cutting tools need to be considered. For example, for milling processing, the diameter, rotation speed, feed rate, and cutting depth of the milling tool need to be set. The software will calculate the movement trajectory of the cutting tool on the workpiece according to these parameters and generate corresponding G codes and M codes. These codes will guide the machine tool to process.
(B) Optimizing Tool Path Parameters
At the same time, the tool path parameters are optimized through parameter setting. Optimizing the tool path can improve processing efficiency, reduce processing costs, and improve processing quality. For example, the processing time can be reduced by adjusting the cutting parameters while ensuring processing accuracy. A reasonable tool path should minimize the idle stroke and keep the cutting tool in continuous cutting motion during the processing process. In addition, the wear of the cutting tool can be reduced by optimizing the tool path, and the service life of the cutting tool can be extended. For example, by adopting a reasonable cutting sequence and cutting direction, the cutting tool can be prevented from frequently cutting in and out during the processing process, reducing the impact on the cutting tool.
At the same time, the tool path parameters are optimized through parameter setting. Optimizing the tool path can improve processing efficiency, reduce processing costs, and improve processing quality. For example, the processing time can be reduced by adjusting the cutting parameters while ensuring processing accuracy. A reasonable tool path should minimize the idle stroke and keep the cutting tool in continuous cutting motion during the processing process. In addition, the wear of the cutting tool can be reduced by optimizing the tool path, and the service life of the cutting tool can be extended. For example, by adopting a reasonable cutting sequence and cutting direction, the cutting tool can be prevented from frequently cutting in and out during the processing process, reducing the impact on the cutting tool.
VI. Path Simulation
(A) Checking for Possible Problems
After the path is generated, we usually do not have an intuitive feeling about its final performance on the machine tool. Path simulation is to check for possible problems so as to reduce the scrap rate of actual processing. During the path simulation process, the effect of the workpiece appearance is generally checked. Through simulation, it can be seen whether the surface of the processed part is smooth, whether there are tool marks, scratches, and other defects. At the same time, it is necessary to check whether there is over-cutting or under-cutting. Over-cutting will cause the part size to be smaller than the designed size, affecting the performance of the part; under-cutting will make the part size larger and may require secondary processing.
(A) Checking for Possible Problems
After the path is generated, we usually do not have an intuitive feeling about its final performance on the machine tool. Path simulation is to check for possible problems so as to reduce the scrap rate of actual processing. During the path simulation process, the effect of the workpiece appearance is generally checked. Through simulation, it can be seen whether the surface of the processed part is smooth, whether there are tool marks, scratches, and other defects. At the same time, it is necessary to check whether there is over-cutting or under-cutting. Over-cutting will cause the part size to be smaller than the designed size, affecting the performance of the part; under-cutting will make the part size larger and may require secondary processing.
(B) Evaluating the Rationality of Process Planning
In addition, it is necessary to evaluate whether the process planning of the path is reasonable. For example, it is necessary to check whether there are unreasonable turns, sudden stops, etc. in the tool path. These situations may cause damage to the cutting tool and a decrease in processing accuracy. Through path simulation, the process planning can be further optimized, and the tool path and processing parameters can be adjusted to ensure that the part can be successfully processed during the actual processing process and the processing quality can be ensured.
In addition, it is necessary to evaluate whether the process planning of the path is reasonable. For example, it is necessary to check whether there are unreasonable turns, sudden stops, etc. in the tool path. These situations may cause damage to the cutting tool and a decrease in processing accuracy. Through path simulation, the process planning can be further optimized, and the tool path and processing parameters can be adjusted to ensure that the part can be successfully processed during the actual processing process and the processing quality can be ensured.
VII. Path Output
(A) The Link between Software and Machine Tool
Path output is a necessary step for software design programming to be implemented on the machine tool. It establishes a connection between the software and the machine tool. During the path output process, the generated G codes and M codes need to be transmitted to the control system of the machine tool through specific transmission methods. Common transmission methods include RS232 serial port communication, Ethernet communication, and USB interface transmission. During the transmission process, the accuracy and integrity of the codes need to be ensured to avoid code loss or errors.
(A) The Link between Software and Machine Tool
Path output is a necessary step for software design programming to be implemented on the machine tool. It establishes a connection between the software and the machine tool. During the path output process, the generated G codes and M codes need to be transmitted to the control system of the machine tool through specific transmission methods. Common transmission methods include RS232 serial port communication, Ethernet communication, and USB interface transmission. During the transmission process, the accuracy and integrity of the codes need to be ensured to avoid code loss or errors.
(B) Understanding of Tool Path Post-processing
For trainees with a numerical control professional background, path output can be understood as the post-processing of the tool path. The purpose of post-processing is to convert the codes generated by general numerical control programming software into codes that can be recognized by the control system of a specific machine tool. Different types of machine tool control systems have different requirements for the format and instructions of the codes, so post-processing is required. During the post-processing process, settings need to be made according to factors such as the model of the machine tool and the type of the control system to ensure that the output codes can correctly control the machine tool to process.
For trainees with a numerical control professional background, path output can be understood as the post-processing of the tool path. The purpose of post-processing is to convert the codes generated by general numerical control programming software into codes that can be recognized by the control system of a specific machine tool. Different types of machine tool control systems have different requirements for the format and instructions of the codes, so post-processing is required. During the post-processing process, settings need to be made according to factors such as the model of the machine tool and the type of the control system to ensure that the output codes can correctly control the machine tool to process.
VIII. Processing
(A) Machine Tool Preparation and Parameter Setting
After completing the path output, the processing stage is entered. First, the machine tool needs to be prepared, including checking whether each part of the machine tool is normal, such as whether the spindle, guide rail, and screw rod are running smoothly. Then, the parameters of the machine tool need to be set according to the processing requirements, such as the spindle rotation speed, feed rate, and cutting depth. These parameters should be consistent with those set during the path generation process to ensure that the processing process proceeds according to the predetermined tool path. At the same time, the workpiece needs to be correctly installed on the fixture to ensure the positioning accuracy of the workpiece.
(A) Machine Tool Preparation and Parameter Setting
After completing the path output, the processing stage is entered. First, the machine tool needs to be prepared, including checking whether each part of the machine tool is normal, such as whether the spindle, guide rail, and screw rod are running smoothly. Then, the parameters of the machine tool need to be set according to the processing requirements, such as the spindle rotation speed, feed rate, and cutting depth. These parameters should be consistent with those set during the path generation process to ensure that the processing process proceeds according to the predetermined tool path. At the same time, the workpiece needs to be correctly installed on the fixture to ensure the positioning accuracy of the workpiece.
(B) Monitoring and Adjusting the Processing Process
During the processing process, the running state of the machine tool needs to be monitored. Through the display screen of the machine tool, the changes in processing parameters such as spindle load and cutting force can be observed in real time. If an abnormal parameter is found, such as excessive spindle load, it may be caused by factors such as tool wear and unreasonable cutting parameters, and it needs to be adjusted immediately. At the same time, attention should be paid to the sound and vibration of the processing process. Abnormal sounds and vibrations may indicate that there is a problem with the machine tool or the cutting tool. During the processing process, the processing quality also needs to be sampled and inspected, such as using measuring tools to measure the processing size and observing the surface quality of the processing, and promptly discovering problems and taking measures to improve.
During the processing process, the running state of the machine tool needs to be monitored. Through the display screen of the machine tool, the changes in processing parameters such as spindle load and cutting force can be observed in real time. If an abnormal parameter is found, such as excessive spindle load, it may be caused by factors such as tool wear and unreasonable cutting parameters, and it needs to be adjusted immediately. At the same time, attention should be paid to the sound and vibration of the processing process. Abnormal sounds and vibrations may indicate that there is a problem with the machine tool or the cutting tool. During the processing process, the processing quality also needs to be sampled and inspected, such as using measuring tools to measure the processing size and observing the surface quality of the processing, and promptly discovering problems and taking measures to improve.
IX. Inspection
(A) Using Multiple Inspection Means
Inspection is the last stage of the entire processing flow and is also a crucial step to ensure product quality. During the inspection process, multiple inspection means need to be used. For the inspection of dimensional accuracy, measuring tools such as vernier calipers, micrometers, and three-coordinate measuring instruments can be used. Vernier calipers and micrometers are suitable for measuring simple linear dimensions, while three-coordinate measuring instruments can accurately measure the three-dimensional dimensions and shape errors of complex parts. For the inspection of surface quality, a roughness meter can be used to measure the surface roughness, and an optical microscope or an electronic microscope can be used to observe the surface microscopic morphology, checking whether there are cracks, pores, and other defects.
(A) Using Multiple Inspection Means
Inspection is the last stage of the entire processing flow and is also a crucial step to ensure product quality. During the inspection process, multiple inspection means need to be used. For the inspection of dimensional accuracy, measuring tools such as vernier calipers, micrometers, and three-coordinate measuring instruments can be used. Vernier calipers and micrometers are suitable for measuring simple linear dimensions, while three-coordinate measuring instruments can accurately measure the three-dimensional dimensions and shape errors of complex parts. For the inspection of surface quality, a roughness meter can be used to measure the surface roughness, and an optical microscope or an electronic microscope can be used to observe the surface microscopic morphology, checking whether there are cracks, pores, and other defects.
(B) Quality Assessment and Feedback
According to the inspection results, the product quality is assessed. If the product quality meets the design requirements, it can enter the next process or be packaged and stored. If the product quality does not meet the requirements, the reasons need to be analyzed. It may be due to process problems, tool problems, machine tool problems, etc. during the processing process. Measures need to be taken to improve, such as adjusting process parameters, replacing tools, repairing machine tools, etc., and then the part is reprocessed until the product quality is qualified. At the same time, the inspection results need to be fed back to the previous processing flow to provide a basis for process optimization and quality improvement.
According to the inspection results, the product quality is assessed. If the product quality meets the design requirements, it can enter the next process or be packaged and stored. If the product quality does not meet the requirements, the reasons need to be analyzed. It may be due to process problems, tool problems, machine tool problems, etc. during the processing process. Measures need to be taken to improve, such as adjusting process parameters, replacing tools, repairing machine tools, etc., and then the part is reprocessed until the product quality is qualified. At the same time, the inspection results need to be fed back to the previous processing flow to provide a basis for process optimization and quality improvement.
X. Summary
The processing flow of high-speed precision parts in machining centers is a complex and rigorous system. Each stage from product analysis to inspection is interconnected and mutually influential. Only by deeply understanding the significance and operation methods of each stage and paying attention to the connection between the stages can high-speed precision parts be processed efficiently and with high quality. Trainees should accumulate experience and improve processing skills by combining theoretical learning and practical operation during the learning process to meet the needs of modern manufacturing for high-speed precision part processing. Meanwhile, with the continuous development of science and technology, the technology of machining centers is constantly updated, and the processing flow also needs to be continuously optimized and improved to improve processing efficiency and quality, reduce costs, and promote the development of manufacturing industry.
The processing flow of high-speed precision parts in machining centers is a complex and rigorous system. Each stage from product analysis to inspection is interconnected and mutually influential. Only by deeply understanding the significance and operation methods of each stage and paying attention to the connection between the stages can high-speed precision parts be processed efficiently and with high quality. Trainees should accumulate experience and improve processing skills by combining theoretical learning and practical operation during the learning process to meet the needs of modern manufacturing for high-speed precision part processing. Meanwhile, with the continuous development of science and technology, the technology of machining centers is constantly updated, and the processing flow also needs to be continuously optimized and improved to improve processing efficiency and quality, reduce costs, and promote the development of manufacturing industry.