How are precision mechanical parts processed?

A mechanical part is composed of several surfaces. To study the relative relationship between the surfaces of a part, it is necessary to determine a benchmark. The benchmark is the point, line, and surface on the part that is used to determine the position of other points, lines, and surfaces. According to the different functions of the benchmark, the benchmark can be divided into two categories: design benchmark and process benchmark. According to the mechanism and characteristics of machining methods, precision machining can be divided into four categories: tool cutting, abrasive machining, special machining, and composite machining.

With the development of machining technology, many new machining mechanisms have emerged, so in precision machining, especially in micro machining, according to the forming mechanism and characteristics of parts. It is divided into three categories: removal processing, combination processing, and deformation processing. Removal processing, also known as separation processing, is the use of mechanical, thermal, electrical, and optical processing methods to remove a portion of material from a workpiece, such as cutting, grinding, and electrical processing.

So how are precision mechanical parts processed?

(1) Rough machining stage. Cut off most of the machining allowance on each machining surface and produce a precision benchmark. The primary consideration is to improve productivity as much as possible.

(2) Semi-finishing stage. Eliminate possible defects after rough machining, prepare for surface finishing, achieve a certain machining accuracy, ensure appropriate finishing allowance, and complete the processing of secondary surfaces together.

(3) Finishing stage. At this stage, large cutting speed, small feed rate, and cutting depth are selected to remove the finishing allowance left by the previous process, so that the appearance of the part meets the technical requirements of the drawing.

(4) Finishing stage. It is mainly used to reduce the surface roughness value or strengthen the processing surface, and is mainly used for surface processing with high requirements for surface roughness (ra≤ 0.32μ m).

(5) Ultrafine processing stage. The machining accuracy is within 0.— 0.0μ m. External roughness value ra≤ 0.00μ M processing stage. The primary processing methods include: fine cutting, fine mirror grinding, fine grinding, and polishing.