CNC machining is a kind of technology, which is widely used in the machinery industry. It refers to the process of machining parts on NC machine tools. In numerical control processing, numerical control machine tools and numeriCcal control systems are used. Numerical control machine tools are machine tools controlled by computers, and the instructions of numerical control system are a set of instructions compiled by programmers according to the material of workpiece, processing requirements, characteristics of machine tools and the instruction format specified by the system. In NC programming, the dimensions and positions of all points, lines and surfaces are based on the programming origin. Therefore, the coordinate dimensions are directly given on the part drawing, or the dimensions are introduced with the same benchmark as far as possible.
Planning datum: the datum used to recognize the orientation of other points, lines and planes on the part drawing is called planning datum. Process benchmark: the benchmark used in the processing and device process of parts is called process benchmark. According to different uses, process datum can be divided into device datum, measurement datum and positioning datum. Device benchmark: the benchmark used to recognize the orientation of parts in components or products when installing, which is called device benchmark. Measurement datum: the datum used to check the size and orientation of the machined surface is called measurement datum. Positioning datum: the datum used for workpiece positioning during machining, which is called positioning datum. As the surface (or line, point) of the positioning datum, only the raw blank surface can be selected at the beginning of a process. This positioning surface is called the rough datum In the subsequent processes, the machined surface can be used as the positioning datum, and this positioning surface is called the precision datum.
Precision machining of precision machine parts is to meet the requirements of the workpiece for surface performance and dimensional accuracy. Therefore, the tools used in precision machining also need to be very sharp. Because the cutting amount is small, the measurement accuracy is very high. In fact, there are many parts that we can't see that have an inseparable relationship with the processing of precision mechanical parts, such as the very small nuts in mobile phones, because these nuts are actually customized according to the needs of mobile phone manufacturers, there are almost no standards, and the accuracy requirements are very high, so almost all of them rely on precision mechanical processing and production.
Precision machine parts processing is very important for the selection of cutting tools and cutting machine tools. These hardware equipment affect the efficiency of precision machine parts processing to a certain extent. If you want to improve the processing efficiency of machine parts, you have to choose a large mechanical processing plant with high level of technicians, so as to ensure the workpiece quality and workpiece processing efficiency to a greater extent.
The use of short cutting tools in precision machining is the main feature of precision hardware parts. The short tool will obviously reduce the tool deviation, so as to obtain good appearance quality, prevent rework, reduce the application of welding rods, and shorten the EDM processing time. When considering five axis machining, it is necessary to consider that the purpose of applying five axis machining die is to complete the machining of the whole workpiece with the shortest cutting tool as far as possible, including reducing programming, clamping and machining time, but getting a more perfect appearance quality.
