Machine tools (machinetools) refers to the equipment used for manufacturing machines, also known as "workhorses" or "tool machines". As early as the 15th century, the initial machine tools have appeared, and in 1774, the British Wilkinson invented a gun barrel boring machine is considered the world's first real sensealuminum prototype machining of the machine tool, which solved the problem of Watt steam engine cylinder processing. To the 18th century, a variety of types of machine tools and rapid development, such as thread lathes, gantry-type machine tools, horizontal milling machines, hobbing machines, etc., for the scientific and technological revolution and the creation of modern industry has laid the basic manufacturing tools. 1952, the world's first digital control (numericalcontrol, NC) machine tools in the United States, the Massachusetts Institute of Technology, meaning the beginning of the era of CNC machine tools . CNC lathe is a digital control system (referred to as "CNC system") of the machine tool, CNC system contains two major parts of CNC equipment and servo equipment, the current key choice of CNC equipment electronic digital computer to complete, also known as computer numerical control (computerizednumericalcontrol , CNC) equipment.
CNC lathe can be categorized according to the production process, movement, servo control methods, machine characteristics. From the processing target (parts) surface to produce process characteristics, traditionally, the CNC lathe is generally divided into two categories of CNC metal cutting machine tools, CNC metal forming machine tools. In recent years, because of the complicated commodities (such as aircraft, vehicles, aircraft engines, etc.) in the use of new materials increasingly elevated, CNC lathes are processed parts of the material is no longer limited to metal materials, has been extended to composite materials, structural ceramics and other non-metallic materials, and the production process also includes special processing methods. In addition, from the perspective of function and characteristics, CNC lathes can be divided into economic, medium (or popular) and high-end three categories. At present, there is no clear and unified definition of high-end CNC lathe, I think: high-end CNC lathe is a CNC lathe with high performance, intelligence and high-value characteristics and achieves the corresponding role and characteristic performance indicators. High-end CNC lathe is a typical representative of the technical level of CNC machine tool industry and the competitive ability of equipment manufacturing industry.
CNC lathe evolution history
Machine tools as "workhorses", the whole process of industrialization with the development of the industrial revolution in the 18th century, machine tools with the development of different industrial era and the evolution of the technical characteristics of each era. As shown in Figure 1, corresponding to the industrial 1.0 to industrial 4.0 era, machine tools from mechanical drive / manual production (machine tool 1.0), electric drive / digital control (machine tool 2.0) to the development of computer digital control (machine tool 3.0) and is to Cyber-physicalmachine (Cyber-physicalmachine) / cloud solutions (machine tool 4.0) evolution and development.
And the development of CNC lathe history, it has experienced several key inflection points.
In 1952, the world's first CNC lathe was successfully developed at the Massachusetts Institute of Technology, which was a revolutionary leap in production technology. CNC lathes choose data programming, program execution, servo control and other technologies to complete the digital processing program prepared in accordance with the part sample drawings automatically control the trajectory of the machine tool movement and operation, since then NC technology has prompted the development of machine tools and electronics, computers, control, information and other technologies are inseparable. Subsequently, in order to deal with NC programming automation problems, the choice of computers instead of manual automatic programming tools (APT) and the way into the core technology, computer-aided design / manufacturing (CAD / CAM) technology has also been rapidly developed and popularized with the use. It can be said that manufacturing intelligence began in the introduction of CNC lathes and key data control systems.
It is because the CNC lathe and CNC technology in the beginning of the introduction of several characteristics - digital control concept and way, "soft (parts) - hard (parts)" combination, "machine (mechanical) - electrical (electronic) - control (system) - information (information)" multidisciplinary intersection, so after the CNC lathe and CNC technology has been a major progress with the development of electronics and information technology is directly related (Figure 2).
The earliest CNC equipment is the use of electronic vacuum tubes composed of measurement and calculation module, the end of the 1940s transistor invention, the end of the 1950s release of integrated circuits, to the early 1960s the emergence of the choice of integrated circuits and large-scale integrated circuits of electronic digital computers, computers in the computational processing power, miniaturization and reliability of the breakthrough progress, for the development of CNC lathe technology brought the first inflection point --By the discrete component-based digital control (NC) towards the computer digital control (CNC), CNC lathes also began to enter the specific industrial production use.
The development of the PC machine, to add a second inflection point to the CNC lathe technology. 20 century 80 era IBM enterprise released the choice of 16-bit micro-controller personal microcomputer (personalcomputer, PC), prompting the previous special manufacturers to develop CNC equipment (including hardware and software), towards the general PC-based computer numerical control. In addition, the open structure of the CNC system should also be born, to promote CNC technology to a higher level of intelligence, network development, on this basis, high-speed machine tools, virtual like axis machine tools, composite machining machine tools and other new technologies rapidly iterate and use.
Since the 21st century, the third inflection point of CNC lathes began to become clear. Intelligent CNC technology also began to sprout, the current development of a new generation of information technology and a new generation of artificial intelligence applications, intelligent sensing, Internet of things, big data, digital twin, cyber-physical systems, cloud computing and artificial intelligence and other new technologies and CNC technology deep integration, CNC technology will usher in a new inflection point or perhaps even a new leap - -towards a new generation of intelligent CNC combined with Cyberphysics.
In this process, the machine tool processing efficiency and processing accuracy, has been continued progress. The continuous aluminum sheet metal fabricationdevelopment and use of advanced manufacturing technology has greatly reduced the processing time and improved the processing efficiency, Figure 7a is a widely cited trend chart, indicating the development of advanced manufacturing technology and processing time (efficiency) work progress. From the development trend, on the one hand, from 1960 to 2020, the total machining time (including cutting time, assistance time and preparation time) in manufacturing production is reduced to 16% of the original machining time, i.e., the machining efficiency is significantly improved; on the other hand, the ratio between the three "cutting time, assistance time and preparation time" On the other hand, the ratio between the three "cutting time, assistance time and preparation time" is slowly converging. Therefore, to improve the machining efficiency in the future, we should not only focus on the improvement of the process and automation, but also reduce the waiting time effectively from the perspective of the intelligence, network and intelligence of production management. Figure 7b is the 20th century 80 era Taniguchi (Taniguchi) to 2020 different machine tools can achieve the processing accuracy prediction (Figure 2000 to 2020 accuracy improvement dashed line for the editor added), can see, a variety of production process and machine tools (or equipment) technology development added to the continuous improvement of processing accuracy, but the machining industry is different from the integrated circuit manufacturing Industry, there is no short-cycle Moore's law (IC can accommodate the number of transistors every 18 to 24 months to improve 1 times), its precision improvement is a long-term technology accumulation and continuous iterative process (for example: precision machining to improve 1 precision level of time beyond 20 years).