In the process of non-standard parts machining, the foundation is the most important, precision mechanical parts processing is the same, always first processing the fine reference, and then use the fine reference positioning processing other surfaces. Next we will put me some details.
For the box parts, generally is the main hole for the rough benchmark processing plane, and then the plane for the fine benchmark processing hole system; for shaft parts, generally is the outer circle for the rough benchmark processing center hole, and then the center hole for the fine benchmark processing outer circle, end face and other surfaces. If there are several fine benchmark, it should be in accordance with the order of benchmark conversion and gradually improve the processing accuracy of the principle to arrange the base surface and the main surface processing.
For workpieces such as box, bracket and connecting rod, the plane should be machined first and then the hole. Because the contour of the plane is flat and large area, machining the plane first and then machining the hole with plane positioning can ensure that the hole has a stable and reliable positioning datum during machining, and is also conducive to ensuring the position accuracy requirements between the hole and the plane.
A part is usually composed of multiple surfaces, the processing of each surface generally need to be carried out in stages. In the arrangement of precision mechanical parts processing sequence, should first focus on the arrangement of the surface of the rough machining, in the middle according to the need to arrange in turn semi-finishing machining, and finally arrange finishing and finishing machining. For high precision requirements of the workpiece, in order to reduce the deformation caused by rough machining on the impact of finishing, usually rough and finish machining should not be carried out continuously, but in stages, interval appropriate time.
The general principle of non-standard parts processing cutting process arrangement is: the work in front must be ready for the work behind, lay a good foundation and good service. Non-standard parts processing specific working principles can be divided into four areas.
The main surface of the part is generally processing accuracy or surface quality requirements are relatively high surface, their processing quality is good or bad to the quality of the whole part has a great impact, its processing procedures are often more, so the main surface processing should be arranged first, and then other surface processing is properly arranged in the middle of them interspersed. Usually the assembly base surface, work surface, etc. as the main surface, and the keyway, fastening with the light hole and screw hole as a secondary surface
