Application of the hottest CNC system in surface g

The application of numerical control system in surface grinding machines

in modern industrial production, the production of medium and small batches of parts accounts for an increasing proportion of the number of products, and the complexity and accuracy requirements of parts are rapidly improving. Traditional ordinary machine tools have become increasingly difficult to meet the requirements of modern production, while numerical control machine tools have the characteristics of high precision, high efficiency, one machine for multiple purposes, and can complete the processing of complex surfaces, Especially with the rapid development of computer technology and its wide application in numerical control system, the main functions of numerical control device are almost realized by software, and the hardware is almost universal, which makes it more flexible and powerful

the competition of manufacturing industry has developed from the competition of reducing labor costs and product costs in the early stage, and improving the overall efficiency and quality of enterprises to the competition of comprehensively meeting customer requirements and actively developing new products. It will face the shorter and shorter renewal cycle of knowledge technology products, the smaller and smaller product batches, and the higher requirements for quality and performance. At the same time, the awareness of society on environmental protection and green manufacturing will continue to strengthen. Therefore, agile and advanced manufacturing technology will become the main means for enterprises to win competition, survive and develop. The combination of computer information technology and manufacturing automation technology is getting closer and closer. As an important foundation of automatic flexible production, CNC machine tools will account for more and more proportion in production machine tools

II. Current situation of CNC flat grinding and main CNC systems

compared with lathes, milling machines, etc., the use of CNC system is relatively late, because of its special requirements for CNC system. In recent ten years, with the help of CNC technology, the continuous dressing of grinding wheels on grinding machines, automatic compensation, automatic exchange of grinding wheels, multiple worktables, automatic transmission and clamping of workpieces and other operating functions have been realized, and numerical control technology has been gradually popularized on surface grinding machines. In recent years, at large machine tool exhibitions in Hannover, Tokyo, Chicago, and China, CNC grinding machines have accounted for the majority of the grinding machine exhibits in the development of domestic large aircraft. Famous grinding machine manufacturers such as German Blohm company and ELB company no longer produce ordinary grinding machines. Japanese companies such as Okamoto and Nikko also produce full-function CNC flat grinding in batches. While developing high-end CNC flat grinding, they are actively developing Low grade CNC flat grinding

the brilliant series two-axis CNC forming grinding machine produced by German ELB company a few years ago, its vertical and horizontal are CNC axes, and its longitudinal is hydraulically controlled. The grinding wheel dressing adopts diamond rollers installed on the workbench, which has a wide range of applications; Super-brilliant series is a three-dimensional CNC plane and forming grinder. The bed is made of natural granite, with high geometric accuracy. The guide rail is a linear rolling guide rail, which is mechanically driven without recoil, so as to ensure that the workpiece has a good surface finish; Brilliant-future is the improved product of the above two series. The bed is made of artificial granite, the longitudinal is made of static pressure guide rail, toothed belt drive, the vertical and horizontal guide rails are preloaded linear rolling guide rail, ball screw drive, and three-axis CNC control occupies one seat in the market. AC servo motor, 0.5 μ M. At the same time, ELB company has developed grinding machine products with the latest contemporary technology, that is, cam-master series flexible grinding and machining units based on electromechanical integration and computer technology. Cad-master can control up to 24 axes according to the time series of stopwatch and compact-master series grinding and machining centers. In addition, because the full GX RTF avoids the modular design of tungsten and rubber slag surface in syringes, the manufacturing cycle of special grinding machines is shortened, ELB company has also developed a variety of high-efficiency special grinding machines, such as sfvg100/2 special grinding machine, which has the functions of tilting grinding head, continuous trimming, jogging and oblique cutting grinding. Eleven CNC control shafts are used, just like a grinding center. British Jones Shipman company and American A-B company have developed a-b8600 numerical control system for format5 numerical control flat grinding. The hydraulic valve is controlled by CNC to drive the longitudinal adjustable speed movement, the ball screw pair is used for horizontal and grinding head feeding, the DC servo motor is driven, the intermittent grinding wheel dressing, and the CRT graphic simulation display. At the same time, it can also be equipped with other types of CNC systems to meet the requirements of different users

at present, with the continuous improvement of semiconductor integration, the newly launched system is getting smaller and smaller in appearance, more and more compact in structure, and has added remote communication, remote diagnosis, multi machine connection and so on in function; The operation interface is close to the windows system, and the mouse, remote controller and other operation parts are added. Fanuc mainly launched 18i, 16i, 20i and 21i systems this year. Siemens 840D, 810D and 802D are all compact systems. Some other manufacturers, such as the pa8000nt series CNC controller developed by Taiwan precision machinery research and development center, use the windows NC operating system and the NT real-time multiplex processing core. The processing speed of a single section of program is up to 2000 blocks/s, and the number of pre reading processing of a single section is up to 1000 blocks. It has AART (pre adaptation adjustment technology) and parameter optimization learning functions, which can make the following error close to zero, and the software processing path filter can reduce the cutting process, Mechanical resonance caused by excessive acceleration change, so as to improve the surface roughness; Flexible servo, with +, -10v analog servo interface, and international standard SERCOS digital servo communication interface; PLC program design has five Grammars: ladder diagram, structure statement, function block, instruction code and flow chart, which are convenient for design, communication and maintenance; It has the functions of computer remote communication and instant remote maintenance; The control axis and spindle can be extended to 64 axes at most, and the i/o points can be extended to 792/528 points. Pentium processor is adopted, and the processing speed of high-speed PLC reaches 25K

in the world, in addition to the famous professional CNC systems factories such as Siemens and Fanuc, which have developed and produced many systems suitable for surface or forming grinding, some flat grinding factories themselves have actively developed CNC systems suitable for their grinding machines. It mainly includes:

Siemens' SINUMERIK 840D system, which has more than 20 servo axes, coordinate continuous stroke control, manual data input or input through external computer, remote diagnosis, travel can be changed with the reduction of wheel diameter, automatic compensation of wheel dressing amount, ball screw clearance error compensation, etc

Siemens 3G system is specially developed for grinding. It is equipped with an operation prompt device for man-machine dialogue. When the axis is tilted, it can also carry out straight-line and arc interpolation. The operation cycle that often occurs in grinding, such as spindle swing, interrupt the execution program with external signals, cut in the grinding wheel, dressing the grinding wheel and other special preparation functions, compile the fixed cycle program. It can not only use external measuring devices (on