CNC machining process features

The processing technology of CNC machine tools has many similarities with the processing technology of ordinary machine tools, and the principles followed are basically the same. There are also many differences. The biggest difference is in the control of the cutting tool path. At the same time, because of the high degree of automation of CNC machine tools and the high cost of equipment, CNC machine tools have formed their own characteristics:
1. The process design of CNC machining is very specific. When using general-purpose machine tools, many specific process problems, such as the division and arrangement of steps in the process, the geometry of the tool, the path of the cutting tool and the amount of cutting, etc., to a large extent They are all considered and decided by the operating workers based on their own practical experience and habits. Generally, there is no need for the craftsman to make excessive regulations when designing the process rules. In the processing of numerically-controlled machine tools, the above-mentioned specific technological problems not only become the contents that must be considered when designing the numerical control process, but also must make correct choices and be incorporated into the processing program.
2. CNC machining process design is very strict Although CNC machine tools are highly automated, their adaptability is poor. It can't be more flexible and timely man-made adjustments when it comes to general machining. Even though modern CNC machine tools have made a lot of efforts and improvements in adaptive adjustment, their degree of freedom is not great. For example, when a numerically-controlled machine tool machined a threaded hole, it did not know whether the hole was already full of chips, whether it was necessary to retract the knife, or to clean the chips and then feed it. Therefore, in the process design of numerical control machining, every detail in the machining process must be paid attention to, and the calculation and programming must be correct.
3. CNC machining operations are quite procedural because of the high degree of automation of CNC machining and multi-axis linkage, which facilitates the centralized arrangement of processes. However, the numerically-controlled machine tools are expensive and require high technical requirements. The objects to be processed are also parts with complicated shapes and high values. Some parts that are damaged by accident or damage to the machine tools or cutting tools will cause great losses. Therefore, the procedural requirements for the basic steps of CNC machining operations are quite strict. From the process design → programming procedures → verification procedures → parts processing can not be ignored in every step, of which program verification is an important part. In practice, it is not uncommon for examples of major machine tool accidents and quality accidents to be caused by errors in one decimal point or one symbol.
4. Reasonable application of CNC machine tools According to the characteristics of CNC machining, the correct selection of processing methods and objects, and give full play to the advantages of CNC machine tools, to achieve good economic benefits is an important issue we must consider in the process design. The application of numerical control processing technology has great flexibility. For the same processing content, there may be many kinds of technological solutions, and specific analysis must be made on specific issues. On the one hand, when selecting processing methods and objects, the performance indicators of CNC machine tools and systems must be taken into consideration. The processing can be achieved and the machining accuracy and technical quality requirements can be guaranteed. On the other hand, sometimes the basic performance of the workpieces is not changed. Under the premise, do some necessary changes to the shape, size, structure, etc. of the CNC machine tool.
A part of the processing process is not fixed, the part of the processing process to meet the technical requirements of the parts, but also by the processing batch, equipment conditions, process level and other factors. From the perspective of the development of the production level and the improvement of the level of CNC machining technology, the design work of the NC machining process is also continuously improving and improving. In recent years, with the rapid development of CNC machining technology, metal cutting machining theory has been continuously enriched and improved. For example, the development of CNC high-speed machining technology has greatly changed the concept of process route design.