(1) The dimension marking method in the CNC machining parts drawing

The size on the parts drawing is an important basis for manufacturing and inspecting parts. The production requires that the size in the parts drawing does not allow any errors. CNC machining generally CNC machining usually refers to computer digitally controlled precision machining, CNC machining lathe, CNC machining milling machine, CNC machining boring and milling machine, etc. The feed route for finishing is basically carried out along the contour of its parts. Therefore, the work of determining the feed route is to determine the feed route for rough machining and empty stroke. In addition to the requirements for correctness, completeness and clarity, dimensions should be considered on the part drawing. Consider rationality should be considered, which should not only meet the design requirements, but also be easy to process and measure. The dimensioning mainly includes functional dimensions, non-functional dimensions, nominal dimensions, basic dimensions, reference dimensions, repeat dimensions, etc. The illustrated dimensions of the part are all complete and error-free, so that the processor can easily analyze (Analyse), measure, and process. Based on these dimensional accuracy (accuracy), the blank is determined to be Φ95 * 250mm and the material is 45 steel.

(2).Analyse (Analyse) the geometric elements of CNC machining parts outline

The outline of the part is mainly composed of cylindrical surface, spherical surface, groove (gōucáo) and keyway, inner hole, etc. CNC machining is a process method for parts processing on CNC machine tools. The process specifications of CNC machine tool processing and traditional machine tool processing are generally the same, but obvious changes have also occurred. Mechanical processing method that uses digital information to control parts and tool displacements. It is an effective way to solve the problems of parts variety, small batch size, complex shape, high precision, etc., and to achieve efficient and automated processing.

(3) Analyse the structure and manufacturability of CNC machining parts

The part is a slender shaft. The slender shaft has the characteristics of small diameter and long length. The length of the slender shaft when processed is too long, it is prone to shock knife or the surface roughness value of the processing is too low, so it must be used for processing Auxiliary heel tool holder and auxiliary fixture. CNC machining generally CNC machining usually refers to computer digitally controlled precision machining, CNC machining lathe, CNC machining milling machine, CNC machining boring and milling machine, etc. The feed route for finishing is basically carried out along the contour of its parts. Therefore, the work of determining the feed route is to determine the feed route for rough machining and empty stroke. Also pay attention to during heat treatment, because cold work will deform after hardening, appear bow or S-shaped.

(4) Analyse the precision (accuracy) and technical requirements of CNC machining parts

• ① The accuracy (precision) of the part and various technical requirements are complete and reasonable
• ② The CNC machining accuracy (accuracy) in this process is high, which can be achieved in CNC machine tools (attribute: automatic machine tool). The requirements are divided into rough machining, semi-finishing machining, and finishing machining. The procedure proceeds.
• ③, the left end of the outer circle size of Φ90 in the figure has a higher position (position) accuracy (accuracy) requirements. All the procedures in this section should be completed in one clamping process, except for the keyway.
• ④ For surfaces with high surface roughness requirements, circumferential constant linear speed cutting should be used.