The cnc machining process route design reference of the part is used to determine the position reference of other points, lines, and planes on the design drawings. It marks the key positions of the design dimensions and is an important guide in the machining of parts. When designing the parts processing route, you also need to pay attention to the following aspects.
First, the choice of positioning benchmark
In the process of designing the process specification, selecting the positioning reference plays a very important role in ensuring the requirements of the parts and arranging the processing sequence reasonably. The positioning reference has the difference between coarse precision and fine reference. When selecting the positioning reference, it is necessary to select the fine reference according to the processing requirements of the part, and then push the process route backwards. Finally, consider which set of surfaces is used as the rough reference to refine the reference. Process it out.
Second, the choice of surface processing methods
The structural shape of machine parts is generally composed of basic geometric surfaces. The machining process of machine parts is the process of obtaining geometrical surfaces. Different processing methods can be selected for the same surface, but the processing quality and processing time that each processing method can obtain can be obtained. And the fee is different. For the staff, it is necessary to select the processing method according to the specific processing conditions to ensure the requirements of the drawings.
When selecting the processing method, according to the technical requirements of the main surface of the part and the specific processing conditions, the final processing method of the first step is selected, and then the processing methods of the relevant front steps of the surface are selected one by one.
Third, the division of processing stages
If the processing quality of the parts is required to be very good, it is generally necessary to go through different stages of processing in order to gradually achieve the processing requirements. This is the principle of “gradual refinement” that we often say. Generally need to go through three stages of roughing, semi-finishing and finishing. If the parts require high machining accuracy and the surface roughness requirements are relatively small, they must go through a finishing process.
Fourth, the concentration and dispersion of processes
After the processing method can be determined, the number of processes in the process is determined according to the type of production of the part and the specific conditions of the factory. There are two different principles in determining the number of processes in a part process. One is the principle of process concentration, and the other is the principle of process dispersion.
The organization of the process according to the process dispersion principle means that the processing content included in each process is as small as possible. In the extreme case, each process includes only one simple step.
V. Arrangement of process sequence
The principles of the arrangement of mechanical processing sequences are:
The first cnc machining of the reference plane, and then processing other surfaces; the main surface of the first processing, after processing the secondary surface; first arrange the roughing process, after finishing the finishing process; the first processing plane, after the processing hole.