CNC Knowledge: What are the “three major machines” of machine tools mentioned by the old master?

The editor once saw a description about our machine tool industry: “Actually, it’s really difficult, and you can survive with three main machines. » Zhan Wuya said: “When I was studying, I liked reading memoirs about the military industry. At this time, those who engage in the military industry are all talented people. They just rely on A lathe and a vise can make rifles, cannons and machine tools. » He thought for a moment: “But without good materials, the products will be compromised, and some cannot even be processed. the right steel.
Today, the editorial team will tell you about the “three major opportunities” mentioned in the article. The so-called “the three main machines can work together” means that most factories (not industrial machine tool factories that mass produce machines) have these three types of machine tools, and coupled with a group of good assemblers (manual correction of details), they can use standardized steel to make the most common mechanical parts. As long as the shape is not too weird, the functions of other machine tools can barely be replaced by these three types of machine tools and fitters. Although the quality and cost are certainly not as good as those of mass-produced accessories by professional manufacturers, they can still be used and ensure the daily repair and maintenance of the main production line, ensuring that production will not be stopped because of a small part. .

In fact, there are four basic operations for processing metal parts: turning, milling and planing. However, the most vulnerable parts do not have long planes that need to be “planed”. The work of the planer is often completed by a milling machine, so the four major cutting operations are Medium and therefore correspond only to“Three big machines”: lathes, milling machines and grinding machines。
Among the “three main machines”, lathes are used for cutting and processing rotating surfaces. Different tools can be replaced according to the different structures of mechanical parts to complete the shape of the car, drill the inner hole and even drill, ream, knurl, etc. processing of parts. The main function of the lathe is to complete the processing of the rotating surface of the workpieces. Its characteristic is that the turret is fixed and the part rotates at high speed. Milling machines are used to process flat surfaces and their main function is to complete the processing of contours and keyways of mechanical parts. Its characteristic is that the workpiece is fixed, and the high-speed rotating tool completes the cutting according to the component structure or groove shape, which is completely opposite to that of the lathe. The function of the grinder is to correct the roughness of the contact surface of the workpiece, that is, to treat the surface roughness. This is very important. Surface roughness is linked to the proper functioning and precision of a mechanical system.

The above is a brief introduction to the functions of the three types of machine tools. Before the emergence of universal CNC machine tools, almost all traditional workpiece processing was carried out by them. Complex cavity structures were mainly made by casting and turning complex sheets. The structure is completed by stamping and welding. Deburring corners or modifying components is carried out by auxiliary fitters. Of course, fitters sometimes do some of the casting work as well. The name “Three Major Machines” is quite classic. This is the name of the older generation of engineers trained during the process of assisting the construction of the former Soviet Union at the beginning of the founding of the People’s Republic of China. After the emergence of CNC machine tools, the production methods of the classic machine manufacturing industry have been completely disrupted. Since CNC machine tools are born from ordinary lathes, they actually integrate the functions of turning, milling and grinding. Therefore, many manufacturing companies have gradually stopped using grinders. If the roughness of CNC machine tool processing does not meet the requirements, polishing can be used to supplement it. Perhaps the once glorious machines and types of work such as the “three main machines” and fitters will slowly disappear into the long river of history as times change.