Development of Precision CNC Machine Tools and Brief Introduction of Processing Technology

Since 1952, CNC machine tools have gone through five generations according to the development of control machines.

In 1959, because of the development of transistor components in the computer industry, transistors and printed circuit boards were widely used in numerical control systems, thus entering the second generation.

In 1965, small-scale integrated circuits appeared. Because of its small size and low power consumption, the reliability of CNC system was further improved. CNC system has developed to the third generation.

The above three generations of systems are all hard-wired CNC systems with dedicated control computers. We call them hard-wired systems, which are collectively referred to as ordinary CNC systems (NCs).

With the development of computing technology, the price of minicomputers has dropped sharply, which has impacted the market severely. The manufacturer of NC system realizes that it is economical to replace the special control computer with a minicomputer. Many functions can be realized by compiling special programs in the memory of the computer and forming so-called control software, which improves the reliability and functional characteristics of the system. This kind of NC system is called the fourth generation system, namely computer numerical control system (CNC).

However, the development of computer technology is changing with each passing day. Just around 1970, Intel developed and used four-bit microprocessors. Microprocessor chips penetrated into various industries, and NC technology is no exception. We call the CNC system characterized by microprocessor technology the fifth generation system.

What are the contents of NC processing?

Answer: 1) Select parts suitable for processing on CNC machine tools and determine the process content.

2) Analyse the drawings of the processed parts, clarify the processing content and technical requirements, on this basis, determine the processing plan of the parts, and formulate the NC processing process route, such as the division of the process, the arrangement of the processing sequence, and the connection with the traditional processing process, etc.

3) Designing NC process. For example, the division of working steps, the positioning and fixture of parts, the selection of cutting tools, the determination of cutting parameters, etc.

4) Adjusting the process of NC machining. For example, the selection of tool point, tool change point, the determination of processing route and tool compensation.

5) Allocate tolerance in NC machining.

6) Processing some process instructions on NC machine tools.