The precision and machining error of CNC precision parts are terms to evaluate the geometric parameters of machined surfaces. The measurement accuracy tolerance level used, smaller level, higher accuracy, the larger the value, the greater the error. High machining precision and small machining error On the contrary, the actual parameters obtained by the machining method are not accurate. From the perspective of function, as long as the hardware processing error of die parts in the tolerance diagram part is required, it can represent the processing accuracy of precision parts.
Position accuracy refers to the difference of actual position accuracy between CNC precision parts after machining. Positioning accuracy evaluation method 8: parallelism, verticality, inclination, concentricity, symmetrical position, and full beating. The position accuracy is controlled by the position tolerance, and the tolerance of each item can also be divided into 12 accuracy levels.
Analyze the relationship between dimensional accuracy, shape and position accuracy of die parts. Generally, when designing the machining accuracy of mechanical parts, the shape error should be controlled in the shape tolerance, and the position error should be less than the dimensional tolerance. That is, on the surface of important parts or precision parts, the required shape accuracy should be higher than the required position accuracy, and the position accuracy should be higher than the required higher dimensional accuracy.
Tool sequence method focus: For the tools used in the segmentation step, using the same tools, part finishing can be carried out on the part. In other places where other tools can be completed. This will reduce the number of tool changes, compressed air processing time and positioning error.
In the manufacturing process of precision parts, the processed parts can be divided into several parts according to their structural characteristics, such as internal shape, shape, surface or plane, etc Generally, the plane is machined first, the surface is positioned, and the hole is machined; Dealing with simple geometry before dealing with complex geometry; Under precision machining, the first part of high-precision reprocessing sites.
Rough machining and finish machining methods: For parts prone to machining deformation that need to be corrected due to possible deformation after rough machining, rough machining is generally required, and separate machining is required after finish machining
In short, the manufacturing process of precision parts depends on the structure and process, functions, various parts of CNC machine, and how many, installation and unit content of production parts, CNC machining flexibility and organizational state. It is suggested to adopt the principle of process concentration or process dispersion, which shall be determined according to the actual situation.
1. Benchmark first
Processing the base surface. In the processing of precision parts, the positioning of machining refers to the appearance, so as to provide a good reference for subsequent processing.
2. Divide processing stages
The appearance of machining quality requirements for CNC precision parts is divided into three stages: rough machining, semi finishing and finishing The main purpose of processing quality is to facilitate the scientific application of equipment, heat is easy to arrange treatment and blank defects found at a convenient time.
3. Face before hole
Carry out plane opening processing for parts such as box, support and connecting rod In this way, the machined hole can be positioned on a plane, which makes the hole position accurate and plane, and brings convenience to the treatment of the opening surface.
The finishing processes of grinding, honing, finishing, rolling and other main surfaces should be put in the later stage of the process The formulation of principles and procedures to develop the machining process route of CNC precision parts can be divided into two parts. The first is to formulate the process route of parts processing, and the second is to determine the process size, equipment used in each process, cutting specification, man hour quota, etc.
The above is our CNC precision parts machining process. If you want to know more about CNC precision parts processing, you can continue to focus on our news page.