CNC machining non-standard parts

1. In the machining process of parts, the surface as the positioning datum should be processed first, and the computer gong processing can provide precise reference for the subsequent processing as soon as possible.
2. The machining stage is divided into three stages: rough machining, semi finishing and finishing. It is mainly to ensure the quality of processing; it is conducive to the scientific application of equipment; it is convenient to arrange the heat treatment process; and it is convenient to find the blank defects.
3. For parts such as box, bracket and connecting rod, the plane should be machined first and then the hole should be processed. In this way, the hole can be processed by plane positioning, which ensures the position accuracy of plane and hole, and brings convenience to the processing of hole on the plane.
4. Finishing the main surface finishing, such as grinding, honing, finishing and rolling, should be placed at the end of the process route. The general principle of drawing up the process route of precision parts and the formulation of the process regulation of precision parts can be roughly divided into two links. First of all, it is to draw up the process route of parts processing, and then determine the process size of each process, the equipment and process equipment used, as well as the cutting specifications, man hour quota, etc. In the machining process of non-standard parts, the foundation is the most important, and the same is true for precision mechanical parts processing. The precision datum is always processed first, and then the other surfaces are positioned and processed by the precise datum. Next, we’ll go into details about me. For box parts, the main hole is generally used as the rough datum to process the plane, and then the plane is used as the precision datum to process the hole system; for the shaft parts, the outer circle is generally used as the rough datum to machine the central hole, and then the center hole is used as the fine datum to process the outer circle, end face and other surfaces. If there are several precision datum, the machining of base surface and main surface should be arranged according to the sequence of datum transformation and the principle of gradually improving machining accuracy.

For the box, bracket and connecting rod, the plane should be machined first and then the hole should be processed. Because of the flat contour and large area of the plane in high-speed CNC machining, machining the plane first and then machining the hole by plane positioning can not only ensure that the hole has a stable and reliable positioning reference, but also is conducive to ensuring the position accuracy requirements between the hole and the plane. A part is usually composed of multiple surfaces, and the machining of each surface generally needs to be carried out in stages. In high-speed CNC machining, when arranging the machining sequence of precision mechanical parts, the roughing of each surface should be arranged first, then the semi finishing should be arranged in turn according to the needs, and finally the finishing and finishing should be arranged. In order to reduce the influence of deformation caused by rough machining on finish machining, roughing and finishing should not be carried out continuously, but should be carried out in stages and at appropriate intervals. The general principle of machining non-standard parts is: the front work must be prepared for the later work, lay a good foundation, and do a good service.

The specific working principle of CNC machining non-standard parts can be divided into four aspects: the main surface of parts is generally the surface with high machining accuracy or surface quality requirements. Their processing quality has a great impact on the quality of the whole part, and its processing procedures are often more. Therefore, the processing of main surface should be arranged first, and then other surface processing should be properly arranged in them In the middle. Generally, the assembly base surface and working surface are regarded as the main surface, while the keyway, smooth hole and screw hole for fastening are regarded as the secondary surface.