The late 1940s, the United States began to study CNC machine tools, in 1952, the United States Massachusetts Institute of Technology (mit) servo mechanism laboratory successfully developed the first CNC milling machine, and put into use in 1957. This is a major breakthrough in the development of manufacturing technology, marking the beginning of the era of CNC machining in the manufacturing field. CNC machining is the basis of modern manufacturing technology, this invention for the manufacturing industry, with epoch-making significance and far-reaching impact. The world’s major industrial countries attach great importance to the research and development of CNC machining technology.
China began to develop CNC machine tools in 1958, the successful trial production with a sub-tube CNC system of CNC machine tools, 1965 began mass production with a transistor CNC system of three-coordinate CNC milling machine. After decades of development, the current CNC machine tools have been achieved in the computer control and widely used in industry, the application of the mould manufacturing industry is particularly popular.
For turning, milling, grinding, drilling and planing and other metal cutting process and electric processing, laser processing and other special processing technology needs, the development of a variety of categories of CNC machining machine tools. A wide range of CNC machine tools, generally divided into 16 categories of CNC machine tools.
1、CNC lathe (Turning centre with milling function)
2、CNC milling machine (with milling centre)
3、CNC clanging machine
4、Milling program-based machining centre.
5、CNC grinding machine (including grinding centre)
6、CNC drilling machine (including drilling centre)
7、CNC broaching machine
9、CNC cutting machine tools
10、CNC gear processing machine tools
11、CNC laser processing machine tools
12、CNC EDM wire cutting machine tools
13、CNC EDM machine tools (including electric machining centre)
14、CNC plate village forming machine tools
15、CNC tube material forming machine tools
16、Other CNC machine tools
Mould manufacturing commonly used CNC processing machine tools are: CNC milling machine, CNC EDM machine tools, CNC EDM wire cutting machine tools, CNC grinding machines and CNC lathes.
CNC machine tools are usually composed of control systems, servo systems, detection systems, mechanical drive systems and other auxiliary systems.
The control system is used for the calculation, management and control of CNC machine tools, through the input medium to get data, the interpretation and calculation of these data and the role of the machine tool; servo system according to the instructions of the control system to drive the machine tool, so that the tool and parts to perform the movement of CNC code provisions; detection system is used to detect the machine tool actuators (table, rotary table, slide, etc.) the amount of displacement and speed change, and will detect The results of the feedback to the input, and input instructions for comparison, according to its differences to adjust the machine movement; machine tool drive system is from the feed servo drive components to the machine tool between the executive mechanical feed drive; auxiliary systems of a wide variety, such as: fixed cycle (can be a variety of repeated processing), automatic tool change (can be exchanged for the specified tool), drive clearance compensation mechanical drive system to produce clearance errors) and so on.
In CNC machining, CNC milling is the most complex, and the problems to be solved are the most numerous. In addition to CNC milling, CNC wire-cutting, CNC EDM, CNC turning, CNC grinding, etc. have their own characteristics of CNC programming, this book will focus on the CNC programming of CNC milling, which has a guiding significance for the preparation of CNC machining programs. The role of the servo system is to convert the pulse signal from the CNC into the movement of the moving parts of the machine.