The customized technology of CNC machined parts has much in common with the processing technology of ordinary machine tools, but the processing rules of parts on CNC machine tools are much more complicated than those of ordinary machine tools. To program the machine tool motion process, part processing process, tool shape, cutting amount and tool path before cnc processing, the programmer must have a rich knowledge base. Qualified programmers first become qualified technicians. Otherwise, the whole process of parts processing and accurate and reasonable parts processing will not be fully considered.
1 The main content of CNC machining parts custom design CNC machining process design usually requires: CNC machining parts customization process content selection; CNC machining technology analysis; cnc machining process route design.
1.1 Selection of CNC machining process content For a single part, not all machining processes are suitable for CNC machine tools, but usually only part of the machining content is suitable for CNC machining. This requires a detailed process analysis of the part drawing, and should select the most needed content and process that are most suitable for CNC machining. When considering the choice, we must combine the actual situation of the equipment of the enterprise to solve the problems, overcome the main problems, improve productivity, and give full play to the advantages of CNC machining. 1. When selecting the content suitable for CNC processing, it can usually be considered in the following order: (1) It is necessary to prefer to select those that cannot be processed with ordinary machine tools. (2) It is important to select those that are difficult to process and whose quality is difficult to guarantee. (3) If the processing efficiency is low and the manual labor intensity of workers is large, it can be selected if the CNC machine tool still has the processing capability. 2. Parts that are not suitable for CNC processing Generally speaking, if the above processing content is processed by CNC, it will be greatly improved in product quality, production efficiency and comprehensive benefits. In contrast, CNC machining is not recommended. (1) It takes a long time to adjust the machine. To place the first finishing datum of machining on the rough datum of the blank, a special tool must be used to adjust the part. (2) The processing parts are scattered and need to be installed multiple times to set the origin. At this time, the use of CNC machining is very troublesome, the effect is not obvious, and it can be prepared for ordinary machine tool processing. (3) Contours processed according to specific manufacturing standards (such as templates, etc.). Because the data access is difficult, it is easy to contradict the inspection basis, and the difficulty of program design is increased.
When selecting and determining the processing content, factors such as production volume, production cycle, and internal turnover rate of the process must also be considered. In short, in order to achieve the purpose of being as reasonable as possible, as fast as possible, as good as possible, and in many places. Must prevent the reduction of CNC machine tools to ordinary machine tools.
1.2 CNC machining technology analysis The CNC machining technology problems of the parts being processed are very extensive. Combined with programmability and convenience, some main contents that need to be analyzed and discussed are proposed below.
- The size must match the characteristics of CNC machining.
In CNC programming, the size and position of all points, lines, and surfaces are based on the origin of the programming. Therefore, it is best to specify the coordinate label directly in the part array, or label with the same datum as much as possible.
- The conditions of the geometric features must be complete and accurate, and the programmer must fully understand the relationship between the geometric feature parameters constituting the part contour and each geometric feature. All geometric elements of the part contour are defined during automatic programming, so the coordinates of each node are calculated during manual programming, so even if a certain point is ambiguous or uncertain, it cannot be programmed. However, in the design process, parts designers are not well thought out or ignored, so the parameters are incomplete or unclear, such as the arc tangent to, intersect, or separate from the line. Therefore, when checking and analyzing the drawings, you must carefully scrutinize them. If you find any problems, you must contact the designer in time.
- Reliability of positioning reference
In the customization of CNC machining parts, the machining process is usually very concentrated, and it is important to locate with the same standard. Therefore, it is usually necessary to set some auxiliary benchmarks or add some process studs to the blank. In order to improve the dimensional stability of the parts, a process boss can be added to the floor and removed after processing.