In terms of improving precision and productivity, mechanical manufacturing technology has been developed rapidly, while in terms of improving productivity, improving automation is the direction of efforts of all countries. In recent years, the machining of precision parts has developed rapidly from numerical control to CIMS, and has been used in a certain range. The transformation from finish machining to super finish machining is also the development direction of major developed countries in the world.
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. Therefore, the machining of precision parts, especially the micro machining of precision parts, must be carried out according to the forming mechanism and characteristics of parts.
There are three kinds of machining: cutting, combined machining and deformation machining. Cutting, also known as separate machining, refers to a processing method that uses force, heat, electricity, light and other processing methods to separate some materials from the workpiece. The combination processing is to use physical and chemical methods to bond and weld the workpiece surface to form a layer of surfacing of different materials, such as electroplating, gas phase surfacing, oxidation, carburization, bonding, welding, etc; Deformation processing is to use force, heat, molecular motion, etc. to deform the workpiece and change its size, shape and function, such as casting, forging, etc.
The concept of visual machining has broken through the traditional means of de machining. It has the characteristics of accumulation, growth, deformation, etc. It also emphasizes surface processing and forms surface processing skills.
Compared with chip free cutting, the cutting of precision parts has the following advantages: First, the cutting process has both a higher cutting rate and better economic effects, such as compared with laser plasma processing. The reason is that only by supplying a large amount of energy can we achieve a high material cutting rate. On the other hand, there are still problems whether the machined workpiece can meet the requirements of size and shape accuracy.
In the mass production process, the chip free pressure machining is mainly used, and the final qualified workpiece shape can be obtained only by subsequent cutting. Therefore, the step of machining is to make the workpiece reach a higher precision. The machining of precision parts, especially in the trend of small batch production, requires higher and higher precision of workpiece shape and dimension, opening up a wider new field of precision parts processing.
The use of lathe naturally requires various turning processes, but it should also be noted that drilling, milling, grinding and gear cutting can be completed on one lathe (process integration). This machining method is applicable to the modular machine tool of the turning and milling machining center being developed at present.
