The application of CAXA manufacturing engineers in aerospace precision machining and manufacturing
I. preface
Shanghai Institute of Technical Physics, Chinese Academy of Sciences is a research institute based on infrared technology and physical research, which mainly undertakes the research and development of aerospace remote sensing technology in China. It has played an important role in the development of China's meteorological satellite industry and made great contributions. The Affiliated Experimental Factory mainly undertakes the processing and trial production of infrared aerial remote sensing instruments, infrared horizon instruments and other optical components developed by the laboratory in the Institute, and also undertakes the manufacturing tasks of important aerospace engineering projects. Due to the characteristics of the research direction, higher requirements are put forward for the machining level, especially for the machining of optical mechanical parts, it is necessary not only to ensure the requirements in mechanical accuracy, but also to meet the design needs in its complex machining shape. At present, our factory adopts caxa-cad/cam system to realize process design and processing for the processing of some complex parts
II. Application of cam numerical control machining technology
the design of optical parts generally requires to meet the requirements of its optical path, so the shape will be more complex, not the basic shape in traditional processing and manufacturing, and sometimes it can not meet the machining requirements through traditional milling, turning, planing, etc. if the requirements can be met by using wire cutting, EDM and other technologies, but the turnover process of the workpiece increases, and the production cycle is extended, And there will also be some inevitable shortcomings when the workpiece is clamped for many times, resulting in the change of size benchmark. Using numerical control technology can not only shorten the production cycle, but also avoid multiple clamping and improve the machining accuracy
for the programming of CNC machine tools, the traditional manual programming method is that programmers calculate and compile the processing G code program according to the requirements of two-dimensional drawings and a certain processing route, and then input it into the machine tool for processing. However, for complex parts, if three-dimensional programming is required, manual programming method is difficult to complete. Using appropriate CAM software, there is a team to do a good job in the production of each model. Instead of manual programming, the computer will automatically process the part drawing. The programmer only needs to input relevant parameters and requirements, and then the machining G code can be automatically generated. At the same time, for parametric surfaces and complex free-form surfaces that cannot be calculated by manual programming, The processing program can also be generated by processing the three-dimensional graphics drawn by the computer. According to relevant statistics, with manual programming, the ratio of programming time to the actual processing time of the machine tool for a part with an output value of 49.4 billion yuan is 30:1. If CAM software is used for programming, it will effectively save time, improve the accuracy of processing and the ability to process complex parts
III. based on the process processing of CAXA Manufacturing Engineer
caxa manufacturing engineer, as a cad/cam integrated domestic CAM software combining surface and solid, has flexible solid surface modeling function and rich data interface, and can realize the complex three-dimensional modeling design of parts. Through the setting of post-processing of processing parameters, select the parts to be processed, and automatically generate the appropriate NC system processing code, With the advantages of high efficiency, energy saving and high cost performance, we can test the processing technology and code quality through intuitive processing anti truth and code reverse reading
as shown in Figure 1, it is the process analysis and processing process for complex parts that need NC technology and NC machine tools, including the traditional manual programming process and the basic application process of process analysis and processing of caxa-cad/cam system with CAXA manufacturing engineers as the core
1. Receive processing tasks
receive two-dimensional or three-dimensional drawings and floppy disks from the laboratory to complete the three-dimensional data model that meets NC processing
taking the simple part in Figure 2 as an example, it is a solid modeling after three-dimensional modeling according to the two-dimensional design blueprint. By using the plane drawing functions such as lines, arcs, and splines provided by caxa-cad and the solid modeling functions such as stretching, material removal, lofting, and scanning, the design elements can be processed and mixed to model the three-dimensional processing data
the output of laboratory design is generally in the form of two-dimensional drawings, and there are also three-dimensional CAD designs, aiming at CAD5 of each laboratory department in the Institute Experiment start: click the experiment start button, and the engineering design software has different characteristics. CAXA-ME needs rich data interfaces. CAXA Manufacturing Engineers include DXF and IGES standard graphic interfaces based on surfaces, x-t and X-B based on entities, STL for rapid prototyping equipment, VRML for Internet and virtual reality, and other interfaces. The two-way data exchange with CAD software is ensured, so that the design and development of in plant production and laboratory can realize smooth exchange. In the process of part modeling, you can directly use the three-dimensional design provided by the design, or use the parameter lines and other elements in the two-dimensional drawing to be introduced into CAXA modeling to realize the accurate exchange of CAD data
2. Determine the processing scheme
analyze the three-dimensional modeling, determine the size of the parts to be processed according to the previous process, the next process and the necessary heat treatment specifications interspersed in the middle, and whether it needs to be re clamped in the middle of processing to meet the heat treatment requirements. First, analyze the process of solid modeling, modify and supplement the modeling according to the processing nature, and determine the three-dimensional solid surface to be processed according to the processing characteristics and processing capacity, as shown in Figure 3. Then analyze the composition of the entity and determine the processing steps
at the same time, the determination of processing technology also includes the approval of technical requirements such as part size and tolerance, determination of clamping mode, selection of cutting tools, machine tool adjustment and parameter setting. Determine whether dncg code transmission is required according to the workload of processing
3. Generate machining path
according to the shape characteristics and process requirements of the parts to be machined, use the surface, guide, parameter line, projection, and other advanced machining methods provided by CAXA manufacturing engineers to flexibly select the solid parts to be machined, input relevant data parameters and requirements, and quickly generate tool path and tool cutting path
as shown in Figure 4 and figure 5, rough machining and finish machining trajectories are generated by different machining methods for parts with different machining properties and machining characteristics. The programmer can flexibly select the processing position and processing method according to the actual needs. After the machining path is generated, the tool position
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