What are the "three major machines" of the machine tool in the mouth of the machinist?
The so-called "three major machines can work together" means that most factories (not industrial mother machine factories that mass-produce machinery) have these three types of machine tools, and with a group of good fitters (manually correcting details), they can use standardization. Steel manufactures most common mechanical parts. As long as the shape is not too weird, the functions of other machine tools can be barely replaced by these three machine tools and fitters. Although the quality and cost are definitely not as good as mass-produced accessories made by professional manufacturers, they can still be used. They can provide daily repairs and maintenance for the main production line, ensuring that production will not be stopped due to a small part.
In fact, the basic operations of processing metal parts are four kinds of "turning, milling, planing and grinding", but most of the vulnerable parts do not have a long plane that needs to be "planed". The means therefore only correspond to the "three major machines": lathes, milling machines and grinding machines.
Among the "three major machines", the lathe is used to cut and process the rotary surface. Different tools can be replaced according to the structure of the mechanical parts to complete the shape of the car, bore the inner hole, and even complete the drilling, reaming, and knurling of the parts. processing. The main function of the lathe is to complete the machining of the rotary surface of the parts. It is characterized by the fixed turret and the high-speed rotation of the workpiece. The milling machine is used to process the plane, and its main function is to complete the machining of the contour and keyway of the mechanical parts. Its feature is that the workpiece is fixed, and the high-speed rotating tool completes the cutting according to the structure of the part or the shape of the groove, which is completely opposite to the lathe. The function of the grinding machine is to correct the roughness of the mating surface of the workpiece, that is, the roughness of the processed surface. This is very important, the surface roughness is related to the running stability and precision of a mechanical system.
The above is a brief introduction to the functions of the three machine tools. Before the emergence of universal CNC machine tools, almost all the traditional parts were processed by them. The complex cavity structure was mostly completed by casting and turning. Complex sheet metal The structure is completed by stamping and welding, and the corner deburring or component correction is completed by the auxiliary fitter. Of course, sometimes the fitter will also complete part of the mold work.
The name "Three Big Machines" is quite classical. This is the name of the older generation of engineers trained by the Soviet Union in the early days of the founding of the People's Republic of China. After the appearance of CNC machine tools, it completely subverted the production mode of the classical machinery manufacturing industry. Since the CNC machine tool is born out of the ordinary lathe, it actually integrates the functions of turning, milling and grinding. Therefore, many manufacturing companies have gradually stopped using grinding machines. If the roughness of CNC machine tools does not meet the requirements, polishing may be used to supplement it. Perhaps, the once glorious machinery and types of work such as the "three major machines" and fitters will slowly disappear into the long river of history with the changes of the times.