Machine tools are essential tools for human production and a significant indicator of the level of social productivity.
Ordinary machine tools have a history of nearly two centuries. With the development and integrated application of electronic technology, computer technology, automation, precision machinery, and measurement technologies, a new type of mechatronic machine tool—the CNC machine tool—has emerged. CNC machine tools have demonstrated their unique advantages and strong vitality since their introduction, providing scientific solutions to many previously intractable problems. A CNC machine tool is a mechatronic machining equipment that uses digital information to control the machine tool to automatically perform machining along a given motion trajectory. After half a century of development, CNC machine tools have become one of the important symbols of modern manufacturing. In my country’s manufacturing industry, the application of CNC machine tools is becoming increasingly widespread, reflecting a company’s comprehensive strength. The CNC lathe, short for Digital Program Controlled Lathe, combines the characteristics of a versatile lathe, a high-precision lathe, and a high-efficiency special-purpose lathe. It is the most widely used and prevalent type of CNC machine tool in China. To master the theory and operation of CNC lathes, diligent study and practice are essential. A solid foundation in plane geometry, trigonometric functions, mechanical drawing, and the processes and operations of conventional lathes is crucial. Therefore, a basic understanding of conventional lathe machining processes is necessary before transitioning from manual to digital control. Furthermore, without a strong foundation in mathematics, electrical engineering, tolerances and chemical processes, and mechanical manufacturing, mastering CNC principles and programming will be extremely difficult. Familiarity with part process requirements and proper handling of process issues are also vital. Due to the unique nature of CNC machining, CNC machine tool operators are required to be both operators and programmers, possessing certain qualities of a junior technician. Therefore, operators must be familiar with all process (technical) requirements of the parts being machined, such as machining paths, cutting tools and their geometric parameters, cutting parameters, and dimensional and shape tolerances. Only by being familiar with these process requirements and correctly handling any problems can one minimize blind spots in work and ensure the successful completion of the entire machining process.
Classification of CNC Lathes: CNC lathes can be broadly classified into horizontal and vertical types. Horizontal lathes come in two types: those with horizontal guideways and those with inclined guideways. Higher-end CNC horizontal lathes generally use inclined guideways. Classified by the number of tool posts, they can be divided into single-tool-post CNC lathes and double-tool-post CNC lathes; the former uses two-axis control, and the latter uses four-axis control. Double-tool-post horizontal lathes mostly use inclined guideways. Like ordinary lathes, CNC lathes are used to machine rotating surfaces of parts. They can generally automatically complete the machining of external cylindrical surfaces, conical surfaces, spherical surfaces, and threads, and can also machine some complex rotating surfaces, such as hyperboloids. The workpiece mounting method is basically the same for lathes and ordinary lathes. To improve machining efficiency, CNC lathes often use hydraulic, pneumatic, and electric chucks. The external appearance of a CNC lathe is similar to that of an ordinary lathe, consisting of a bed, headstock, tool post, feed system, pressure system, cooling and lubrication system, etc. The feed system of a CNC lathe is fundamentally different from that of a conventional lathe. A conventional lathe has a feed box and a change gear set, while a CNC lathe directly uses a servo motor to drive the slide and tool post through a ball screw to achieve the feed motion, thus greatly simplifying the structure of the feed system.
