The precision and technical requirements for CNC machining

(1).Dimension marking method in the drawings.

The dimension on the part drawing is an important basis for the manufacture and inspection of the parts.No mistakes are allowed in the required dimensions in the drawing during production. Mark the dimensions on the part drawing,in addition to the requirements of correct, complete and clear dimensioning on the part drawing, the rationality should also be considered, both to satisfy the design requirements and to facilitate processing and measurement. The dimension marking mainly includes functional dimension, non-functional dimension, nominal dimension, fundamental dimension, reference dimension, repeated dimension and so on.This part drawing shows that the dimensions marked are complete and correct, so that the processor is easy to analyze, measure and process.Based on the dimensional accuracy, we determine the blank for Φ 95 * 250 mm, material is 45 steel.

(2) Analyze the geometric elements of CNC machining parts.

The outline of this part is mainly composed of cylinder, sphere, groove and keyway, inner hole and so on.

(3) Analyze the structural process of CNC machined parts.

This part is a slender shaft.The slender shaft is characterized by small diameter and too long length,because the length of the hanging body is too long,it is easy to show tool vibration or the surface roughness value of processing is too low.Therefore, auxiliary tool rest and auxiliary fixture must be used for machining. In addition, we need to pay attention to the hardened parts will be deformed and appear bent or s-shaped after the heat treatment.

(4)Analyze the precision and technical requirements of CNC machined parts.

①.The precision and technical requirements of this parts are complete and reasonable.

②.The process of CNC precision machining requirements are higher, it can be achieved by CNC machine tools, the processing is divided into rough machining, semi-finishing machining, finishing three processes.

③.The left end of the outer circle( Φ 90) has higher accuracy requirements,all this work shall be completed in a single clamping process,except for the slot.

④.If the surface roughness request high, the circular constant linear speed should be used.