When the processing quality requirements for parts are high, it is often impossible to use one process to meet the requirements, and it is necessary to gradually achieve the required processing quality through several processes. To ensure the quality of CNC machining parts and make reasonable use of equipment and manpower, the machining process of parts can generally be divided into four stages according to the nature of the process; Rough machining, semi precision machining, precision machining, and finishing machining.
A CNC workpiece often has several surfaces that need to be machined, which not only have precision requirements, but also have certain orientation requirements between each surface. In order to meet these precision requirements, the machining sequence of each surface of CNC machining parts cannot be randomly arranged, but must follow certain criteria. This is the selection and transformation of positioning benchmarks that determine the machining sequence, as well as the criteria for preparing positioning benchmarks for subsequent processes in the previous process.
What are the importance of CNC machining sequence
1. Before surface processing, a rest should be carried out on the precision benchmark to ensure the machining accuracy of important surfaces.
2. After the precision reference machining is completed, rough machining, semi precision machining, and precision machining should be carried out on surfaces with high precision requirements. Surfaces with particularly high precision requirements also require finishing.
3. The surface used as a precision reference should be processed at the beginning of the CNC machining process, as it is used for positioning when processing other surfaces in subsequent processes. That is, 'benchmark first, then others'.
4. When machining precision reference surfaces, coarse reference positioning is required. In single piece, small batch production, and even batch production, for castings and forgings with complex shapes or larger scales, as well as blanks with larger scale errors, the marking process should be arranged first before the mechanical processing process to provide a alignment benchmark for precision machining.
