What is the machine tool model commonly used in NC machining in China at present? What programming software is used?

Development trend of numerical control system

From 1952, MIT developed the first experimental numerical control system, which has gone through half a century. With the rapid development of electronic technology and control technology, the function of today's numerical control system has been very powerful. At the same time, the development of machining technology and other related technologies also puts forward new requirements for the development and progress of CNC system.

One of the trends: CNC system is developing to open architecture.

Since 1990s, due to the rapid development of computer technology, numerical control technology has been updated faster. Many CNC system manufacturers in the world use PC's rich software and hardware resources to develop a new generation of CNC systems with open architecture. The open architecture makes the CNC system more universal, flexible, adaptable and extensible, and can easily realize intelligence and networking. In recent years, many countries are researching and developing this kind of system, such as NGC, NCMS and "Next Generation Workstation/Machine Tool Controller Architecture" led by Air Force, "Open Architecture in Automation System" in Europe, and OSEC Plan in Japan. The open architecture can adopt a large number of general microcomputer technologies, which makes programming, operation and technical upgrading easier and faster. The hardware, software and bus specifications of the new generation CNC system with open architecture are all open to the outside world, and CNC system manufacturers and users can integrate their systems according to these open resources. At the same time, it also brings great convenience for users to flexibly configure the CNC system according to actual needs, promotes the development and wide application of multi-level and multi-variety CNC systems, and greatly shortens the development and production cycle. At the same time, this numerical control system can be upgraded with the upgrade of CPU, while the structure can remain unchanged.

The second trend: CNC system develops to soft CNC.

At present, there are mainly four types of CNC systems actually used in industrial field, which represent different development stages of CNC technology. After analyzing different types of CNC systems, it is found that CNC systems are not only developing from closed architecture to open architecture, but also from hard CNC to soft CNC.

Traditional numerical control systems, such as FANUC 0 system, Mitsubishi M50 system, SINUMERIK 8 10M/T/G system, etc. This is a special numerical control system with closed architecture. At present, this system still occupies most of the manufacturing market. However, due to the development of open architecture CNC system, the market of traditional CNC system is being challenged, and it has gradually shrunk.

Open CNC systems with "PC embedded in NC" structure, such as FANUC 18i, 16i, SINUMERIK 840D, Num 1060, AB 9/360, etc. This is a product developed by some numerical control system manufacturers by combining the numerical control software technology accumulated for many years with the rich software resources of today's computers. It has certain openness, but because its numerical control part is still a traditional numerical control system, users can't set foot in the core of the numerical control system. This system is complex in structure, powerful in function and expensive.

An open CNC system with "NC embedded in PC" structure consists of an open motion control card and a PC. This kind of motion control card usually uses high-speed DSP as CPU, which has strong motion control and PLC control ability. It is a numerical control system in itself and can be used alone. Its open function library allows users to develop and build their own control system under the WINDOWS platform. Therefore, this kind of open structure motion control card is widely used in various fields of manufacturing automation control. For example, the PMAC-NC numerical control system built by Delta Tau Company in the United States with PMAC multi-axis motion control card, and the MAZATROL 640 numerical control system built by Japanese MAZAK Company with mitsubishi electric's MELDASMAGIC 64, etc.

Soft open CNC system This is a CNC system with the latest open architecture. It provides users with the greatest choice and flexibility, and its CNC software is all installed in the computer, while the hardware part is only the standardized general interface between the computer and the servo driver and external I/O, just like a computer can install various brands of sound cards and corresponding drivers. Users can use the open CNC kernel on WINDOWS NT platform to develop various required functions and form various types of high-performance CNC systems. Compared with the previous numerical control system, the soft open numerical control system has the highest cost performance, so it has the most vitality. Replacing complex hardware with software intelligence is becoming an important trend in the development of contemporary CNC system. Its typical products are the open CNC of MDSI company in the United States and PA8000 NT of German electric power automation company.

The third trend: the control performance of CNC system is developing towards intelligence.

Intelligentization is a major direction of manufacturing technology development in 2 1 century. With the penetration and development of artificial intelligence in the computer field, the control mechanism of adaptive control, fuzzy system and neural network is introduced into the numerical control system, which not only has the functions of automatic programming, feedforward control, fuzzy control, learning control, adaptive control, automatic generation of process parameters, three-dimensional tool compensation, dynamic compensation of motion parameters and so on. It also has a friendly man-machine interface and fault diagnosis expert system, which improves the functions of self-diagnosis and fault monitoring. The intelligent spindle AC drive and intelligent feed servo device of the servo system can automatically identify the load and automatically optimize and adjust the parameters.

There are many intelligent machining systems being studied in the world, among which the drilling intelligent machining scheme of Japan Intelligent Numerical Control Device Research Association is representative.

Trend 4: CNC system is developing towards networking.

The networking of CNC system mainly refers to the network connection and network control between CNC system and other external control systems or upper computers. Generally, the CNC system is oriented to the local area network in the production site and the enterprise, and then leads to the outside of the enterprise through the Internet, which is the so-called Internet/Intranet technology.

With the maturity and development of network technology, the industry has recently put forward the concept of digital manufacturing. Digital manufacturing, also known as "e-manufacturing", is one of the symbols of the modernization of machinery manufacturing enterprises and the standard supply mode of international advanced machine tool manufacturers. With the wide application of information technology, more and more domestic users require remote communication service when importing CNC machine tools.

The networking of CNC system further promotes the development of flexible automation manufacturing technology. Modern flexible manufacturing system has developed from point (CNC single machine, machining center and CNC compound machining machine tool) and line (FMC, FMS, FTL and FML) to surface (workshop independent manufacturing island, FA) and body (CIMS, distributed network integrated manufacturing system). Flexible automation technology aims at easy networking and integration, and pays attention to the development and perfection of unit technology. Numerical control machine tools and their flexible manufacturing systems can be easily connected with CAD, CAM, CAPP and MTS, and develop in the direction of information integration, and the network system develops in the direction of openness, integration and intelligence.

The fifth trend: CNC system is developing towards high reliability.

With the increasing application of CNC machine tools, the high reliability of CNC system has become the goal pursued by CNC system manufacturers. For an unmanned factory with two shifts a day, if it is required to work continuously and normally within 16 hours, and the failure-free rate is above p (t) = 99%, the average failure-free running time MTBF of CNC machine tools must be greater than 3000 hours. Taking a numerical control machine tool as an example, the failure rate ratio of the main machine and the numerical control system is 10: 1 (the reliability of numerical control is one order of magnitude higher than that of the main machine). At this time, the MTBF of CNC system will be greater than 33,333.3 hours, and the MTBF of CNC device, spindle and drive must be greater than 65,438+million hours. If it is the whole production line, the reliability requirement is higher.

At present, the MTBF value of foreign numerical control devices has reached more than 6000 hours, and the driving device has reached more than 30000 hours. However, we can see that there is still a gap from the ideal goal.

The sixth trend: the numerical control system is developing towards compounding.

In the process of machining parts, a lot of useless time is spent on workpiece handling, loading and unloading, installation and adjustment, tool change and spindle speed. In order to minimize these useless time, people hope to integrate different processing functions on the same machine tool. Therefore, machine tools with compound functions have become a rapidly developing model in recent years.

The concept of machine tool compound machining in the field of flexible manufacturing refers to that after the workpiece is clamped once, the machine tool can automatically carry out multi-process machining with the same process method or different process methods according to the NC machining program, thus completing the main or all machining processes of turning, milling, drilling, boring, grinding, tapping, hinge and hinge of a complex shape part.

Ordinary CNC system software uses different software versions for different types of machine tools. For example, Siemens' 8 10M system and 802D system can be divided into lathe version and milling version. The requirement of compounding promotes the integration of CNC system functions. At present, mainstream CNC system developers can provide high-performance CNC systems for compound machine tools.

The seventh trend: the numerical control system is developing towards multi-axis linkage.

When machining free-form surfaces, the machine tool controlled by three-axis linkage can't avoid the end of the ball-end milling cutter with cutting speed close to zero, which will have a destructive impact on the machining quality of the workpiece. The NC programming of 5-axis ball-end milling cutter is relatively simple, and the ball-end milling cutter can always maintain a reasonable cutting speed in the process of milling 3D surfaces, thus significantly improving the roughness of the machined surface and greatly improving the machining efficiency. Major system developers spare no effort to develop 5-axis and 6-axis CNC systems. With the maturity and increasing popularity of five-axis CNC system and programming software, machining centers and CNC milling machines controlled by five-axis linkage have become the development focus at present.

Recently, major foreign system developers have made great progress in the research of six-axis linkage control system. In the 6-axis machining center, any 3-D curved surface can be machined with non-rotating tools, and the cutting depth can be very thin, but the machining efficiency is too low and impractical.

The development of electronic technology, information technology, network technology and fuzzy control technology has greatly improved the technical level of the new generation of CNC system, promoted the vigorous development of CNC machine tool industry and promoted the rapid development of modern manufacturing technology. The performance of CNC machine tools has made great progress in high speed, high precision, high reliability, compounding, networking, intelligence, flexibility and greening. Modern manufacturing industry is welcoming a new technological revolution. h