机械设计制造及其自动化(数控技术)英语论文

Numerical control technology and equiping development trend and

countermeasure

Numerical control technology is the technology controlled to mechanical movement and working course with digital information, integrated products of electromechanics that the numerical control equipment is the new technology represented by numerical control technology forms to the manufacture industry of the tradition and infiltration of the new developing manufacturing industry, namely the so-called digitization is equipped, its technological range covers a lot of fields: (1)Mechanical manufacturing technology; (2)Information processing , processing , transmission technology; (3)Automatic control technology; (4)Servo drive technology; (5)Technology of the sensor ; (6)Software engineering ,etc..

1 Development trend of a numerical control technology

The application of numerical control technology has not only brought the revolutionary change to manufacturing industry of the tradition, make the manufacturing industry become the industrialized symbol , and with the constant development of numerical control technology and enlargement of the application, the development of some important trades (IT , automobile , light industry , medical treatment ,etc. ) to the national economy and the peoples livelihood of his plays a more and more important role, because the digitization that these trades needed to equip has already been the main trend of modern development. Numerical control technology in the world at present and equiping the development trend to see, there is the following several respect [1- ] in its main research focus .

1.1 A high-speed , high finish machining technology and new trend equipped

The efficiency , quality are subjavanufacturing technology. High-speed , high finish machining technology can raise the efficiency greatly , improve the quality and grade of the products, shorten production cycle and improve the market competitive power. Japan carries the technological research association first to classify it as one of the 5 great modern manufacturing technologies for this, learn (CIRP ) to confirm it as the centre in the 21st century and study one of the directions in international production engineering.

In the field of car industry, produce one second when beat such as production of 300,000 / vehicle per year, and many variety process it is car that equip key problem that must be solved one of; In the fields of aviation and aerospace industry,

spare parts of its processing are mostly the thin wall and thin muscle, rigidity is very bad, the material is aluminium or aluminium alloy, only in a situation that cut the speed and cut strength very small high, could process these muscles , walls . Adopt large-scale whole aluminium alloy method that blank " pay empty " make the wing recently, such large-scale parts as the fuselage ,etc. come to substitute a lot of parts to assemble through numerous rivet , screw and other connection way, make the intensity , rigidity and dependability of the component improved. All these, to processing and equiping the demand which has proposed high-speed , high precise and high flexibility. According to EMO2001 exhibition situation, high-speed machining center is it give speed can reach 80m/min is even high , air transport competent speed can up to 100m/min to be about to enter.

A lot of automobile factories in the world at present, including Shanghai General Motors Corporation of our country, have already adopted and substituted and made the lathe up with the production line part that the high-speed machining center makes up . HyperMach lathe of U.S.A. CINCINNATI Company enters to nearly biggest 60m/min of speed, it is 100m/min to be fast, the acceleration reaches 2g, the rotational speed of the main shaft has already reached 60 000r/min. Processing a thin wall of plane parts, spend 30min only, and same part general at a high speed milling machine process and take 3h, the ordinary milling machine is being processed to need 8h; The speed and acceleration of main shaft of dual main shaft lathes of Germany DMG Company are up to 12* separately! 000r/mm and 1g. In machining accuracy, the past 10 years, ordinary progression accuse of machining accuracy of lathe bring 5|ìm up to from 10|ìm already, accurate grades of machining center from 3- 5|ìm, rise to 1- 1.5|ìm, and ultraprecision machining accuracy is it enter nanometer grade to begin already (0.01|ìm). In dependability, MTBF value of the foreign numerical control device has already reached above 6 000h, MTBF value of the servo system reaches above 30000h, demonstrate very high dependability . In order to realize high-speed , high finish machining, if the part of function related to it is electric main shaft , straight line electrical machinery get fast development, the application is expanded further.

1.2 Link and process and compound to process the fast development of the lathe in 5 axes

Adopt 5 axles to link the processing of the three-dimensional curved surface part, can cut with the best geometry form of the cutter , not only highly polished, but also efficiency improves by a large margin . It is generally acknowledged , the efficiency of an 5 axle gear beds can equal 2 3 axle gear beds , is it wait for to use the cubic nitrogen boron the milling cutter of ultra hard material is milled and pared at a high speed while quenching the hard steel part, 5 axles link and process 3 constant axles to link and process and give play to higher benefit. Because such reasons as complicated that 5 axles link the numerical control system , host computer structure that but go over, it is several times higher that its price links the numerical control lathe than 3 axles , in addition the technological degree of difficulty of programming is relatively great, have restricted the development of

5 axle gear beds. At present because of electric appearance of main shaft, is it realize 5 axle complex main shaft hair structure processed to link greatly simplify to make, it makes degree of difficulty and reducing by a large margin of the cost, the price disparity of the numerical control system shrinks . So promoted 5 axle gear beds of head 无效 of complex main shaft and compound to process the development of the lathe (process the lathe including 5 ). At EMO2001 exhibition, new Japanese 5 of worker machine process lathe adopt complex main shaft hair, can realize the processing of 4 vertical planes and processing of the wanton angle , make 5 times process and 5 axles are processed and can be realized on the same lathe, can also realize the inclined plane and pour the processing of the hole of awls . Germany DMG Company exhibits the DMUVoution series machining center, but put and insert and put processing and 5 axles 5 times to link and process in once, can be controlled by CNC system or CAD/CAM is controlled directly or indirectly.

1.3 Become the main trend of systematic development of contemporary numerical control intelligently , openly , networkedlily

The numerical control equipment in the 21st century will be sure the intelligent system, the intelligent content includes all respects in the numerical control system: It is intelligent in order to pursue the efficiency of processing and process quality, control such as the self-adaptation of the processing course, the craft parameter is produced automatically; Join the convenient one in order to improve the performance of urging and use intelligently, if feedforward control , adaptive operation , electrical machinery of parameter , discern load select models , since exactly makes etc. automatically automatically; The ones that simplified programming , simplified operating aspect are intelligent, for instance intelligent automatic programming , intelligent man-machine interface ,etc.; There are content of intelligence diagnose , intelligent monitoring , diagnosis convenient to be systematic and maintaining ,etc..

Produce the existing problem for the industrialization of solving the traditional numerical control system sealing and numerical control application software. A lot of countries carry on research to the open numerical control system at present, such as NGC of U.S.A. (The Next Generation Work-Station/Machine Control), OSACA of European Community (Open System Architecture for Control within Automation Systems), OSEC (Open System Environment for Controller ) of Japan, ONC (Open Numerical Control System ) of China ,etc.. The numerical control system melts to become the future way of the numerical control system open.

The so-called open numerical control system is the development of the numerical control system can be on unified operation platform, face the lathe producer and end user, through changing, increasing or cutting out the structure target(numerical control function), form the seriation, and can use users specially conveniently and the technical know-how is integrated in the control system, realize the open numerical control system of different variety , different grade fast, form leading brand products with distinct distinction.

System structure norm of the open numerical control system at present, communication norm , disposing norm , operation platform , numerical control systematic function storehouse and numerical control systematic function software developing implement ,etc. are the core of present research. The networked numerical control equipment is a new light spot of the fair of the internationally famous lathe in the past two years. Meeting production line , manufacture system , demand for the information integration of manufacturing company networkedly greatly of numerical control equipment, realize new manufacture mode such as quick make , fictitious enterprise , basic Entrance that the whole world make too.

Some domestic and international famous numerical control lathes and systematic manufacturing companies of numerical control have all introduced relevant new concepts and prototypes of a machine in the past two years, if in EMO2001 exhibition, " CyberProduction Center " that the company exhibits of mountain rugged campstool gram in Japan (Mazak ) (intellectual central production control unit, abbreviated as CPC); The lathe company of Japanese big Wei (Okuma ) exhibits " IT plaza " (the information technology square , is abbreviated as IT square ); Open Manufacturing Environment that the company exhibits of German Siemens (Siemens ) (open the manufacturing environment, abbreviated as OME),etc., have reflected numerical control machine tooling to the development trend of networked direction.

1.4 Pay attention to the new technical standard , normal setting-up

1.4.1 Design the norm of developing about the numerical control system

As noted previously, there are better commonability , flexibility , adaptability , expanding in the open numerical control system, such countries as U.S.A. , European Community and Japan ,etc. implement the strategic development plan one after another , carry on the research and formulation of the systematic norm (OMAC , OSACA , OSEC ) of numerical control of the open system structure, 3 biggest economies in the world have carried on the formulation that nearly the same science planned and standardized in a short time, have indicated a new arrival of period of change of numerical control technology. Our country started the research and formulation of standardizing the frame of ONC numerical control system of China too in 2000.

1.4.2 About the numerical control standard

The numerical control standard is a kind of trend of information-based development of manufacturing industry. Information exchange among 50 years after numerical control technology was born was all because of ISO6983 standard, namely adopt G, M code describes how processes, its essential characteristic faces the processing course, obviously, he cant meet high-speed development of modern numerical control technologys needs more and more already. For this reason, studying and making a kind of new CNC system standard ISO14649 (STEP-NC) in the world, its purpose is to offer a kind of neutral mechanism not depending on the concrete system , can describe the unified data model in cycle of whole life of the products , thus

realize the whole manufacture process, standardization of and even each industrial field product information.

The appearance of STEP-NC may be a revolution of the technological field of the numerical control, on the development and even the whole manufacturing industry of numerical control technology , will exert a far-reaching influence. First of all, STEP-NC puts forward a kind of brand-new manufacture idea , in the traditional manufacture idea, NC processes the procedures to all concentrate on individual computer. Under the new standard, NC procedure can be dispersed on Internet, this is exactly a direction of open , networked development of numerical control technology. Secondly, STEP-NC numerical control system can also reduce and process the drawing (about 75% ) , process the procedure to work out the time (about 35% ) and process the time (about 50% ) greatly . At present, American-European countries pay much attention to the research of STEP-NC, Europe initiates IMS plan (1999.1.1- 2001.12.3 ) of STEP-NC. 20 CAD/CAM/CAPP/CNC users , manufacturers and academic organizations from Europe and Japan participated in this plan. STEP Tools Company of U.S.A. is a developer of the data interchange software of manufacturing industry in the global range, he has already developed the super model (Super Model ) which accuses of information exchange of machine tooling by counting, its goal is to describe all processing courses with the unified norm. Such new data interchange form has already been verified in allocating the SIEMENS , FIDIA and European OSACA-NC numerical control at present.

2 pairs of basic estimations of technology and industry development of numerical control of our country

The technology of numerical control of our country started in 1958, the development course in the past 50 years can roughly be divided into 3 stages:

The first stage is from 1958 to 1979, namely closed developing stage. In this stages, because technology of foreign countries blockade and basic restriction of terms of our country, the development of numerical control technology is comparatively slow.

The second stage is during " Sixth Five-Year Plan Period " , " the Seventh Five-Year Plan Period " of the country in second stage and earlier stage in " the Eighth Five-Year Plan Period ", namely introduce technology, digest and assimilate, the stage of establishing the system of production domesticization arisesing tentatively. At this stage , because of reform and opening-up and national attention , and study the improvement of the development environment and international environment, research , development and all making considerable progress in production domesticization of the products of the technology of numerical control of our country.

The third stage is during the " Ninth Five-Year Plan Period " on the later stage in " the Eighth Five-Year Plan Period " of the country, namely implement the research of industrialization, enter market competition stage. At this stage , made

substantive progress in industrialization of the domestic numerical control equipment of our country. In latter stage for " the Ninth Five-Year Plan ", the domestic occupation rate of market of the domestic numerical control lathe is up to 50%, it is up to 10% too to mix the domestic numerical control system (popular ).

Make a general survey of the development course in the past 50 years of technology of numerical control of our country, especially through tackling key problems of 4 Five-Year Plans, all in all has made following achievements.

a.Have establish the foundation of the technical development of numerical control, has mastered modern numerical control technology basically. Our country has already, the numerical control host computer , basic technology of special plane and fittings grasped and driven from the numerical control system and servoly basically now, among them most technology have already possessed and commercialized the foundation developed , some technology has already, industrialization commercialized.

b.Have formed the industrial base of numerical control tentatively. In tackling key problems the foundation that the achievement and some technology commercialize , set up the systematic factories of numerical control with production capacity in batches such as numerical control in Central China , numerical control of the spaceflight et

c.. Electrical machinery plant of Lanzhou, such factory and the first machine tool plant of Beijing , the first machine tool plant of Jinan ,etc. several numerical control host computer factories of a batch of servo systems and servo electrical machineries as the numerical control in Central China,etc.. These factories have formed the numerical control industrial base of our country basically.

c.Have set up a numerical control research, development , managerial talents basic team . Though has made considerable progress in research and development and industrialization of numerical control technology, but we will realize soberly, the research and development of the technology of advanced numerical control of our country, especially there is greater disparity in current situation and current demand of our country of engineering level in industrialization. Though very fast from watching the development of our country vertically, have disparity horizontally more than (compare foreign countries with ) not merely engineering level, there is disparity too in development speed in some aspects, namely the engineering level disparity between some high-grade , precision and advanced numerical control equipment has the tendency to expand .

Watch from world , estimate roughly as follows about the engineering level of numerical control of our country and industrialization level.

a.On the engineering level, in probably backward 10- 1 years with the advanced level in foreign countries, it is bigger in high-quality precision and sophisticated technology.

b.On the industrialization level, the occupation rate of market is low, the variety coverage rate is little, have not formed the large-scale production yet; The specialized level of production of function part and ability of forming a complete set are relatively low; Appearance quality is relatively poor; Dependability is not high, the commercialized degree is insufficient; Ones own brand effect that the domestic numerical control system has not been set up yet, users have insufficient confidence.

c.On the ability of sustainable development, research and development of numerical control technology , project ability are relatively weak to the competition; It is not strong that the technological application of numerical control expands dynamics;

Research , formulation that relevant standards are normal lag behind. It is analysed that the main reason for having above-mentioned disparity has the following several respect.

a.Realize the respect. Know to industrys process arduousness , complexity and long-term characteristic of domestic numerical control insufficiently; It is difficult to underestimate to add strangling , system ,etc. to the unstandard , foreign blockade of the market; It is not enough to analyse to the technological application level and ability of numerical control of our country.

b.System. Pay close attention to numerical control industrialization many in the issue , consider numerical control industrialization little in the issue synthetically in terms of the systematic one , industry chain in terms of technology; Have not set up related system , perfect training , service network of intact high quality ,et

c. and supported the system.

c.Mechanism. It causes the brain drain, restraining technology and technological route from innovating again , products innovation that the bad machine is made, and has restricted the effective implementation of planning , has often planned the ideal , implement the difficulty.

d.Technology. The autonomous innovation in technology of enterprises is indifferent, the project of key technology is indifferent. The standard of the lathe lags behind, the level is relatively low, it is not enough for new standard of the numerical control system to study.

3 pairs of strategic thinking of technology and industrialized development of numerical control of our country 3.1 Strategic consideration

Our country make big country, industry is it is it accept front instead of transformation of back end to try ones best to want in shifting in world, namely should master and make key technology advancedly, otherwise in a new round of

international industrial structure adjustment, the manufacturing industry of our country will step forward and " leave the core spaces ". We regard resource , environment , market as the cost, it is only an international " machining center " in the new economic pattern of the world to exchange the possibility got and " assemble the centre ", but not master the position of the manufacturing center of key technology , will so influence the development process of the modern manufacturing industry of our country seriously. We should stand in the height of national security strategy paying attention to numerical control technology and industrys question , at first seen from social safety, because manufacturing industry whether our country obtain employment most populous trade, the development of manufacturing industry not only can improve the peoples living standard but also can alleviate the pressure of employment of our country , ensure the stability of the society; Secondly seen from national defence security, the western developed country has classified all the high-grade , precision and advanced numerical control products as the strategic materials of the country, realizing the embargo and restriction to our country, " Toshiba incident " and " Cox Report " is the best illustration.

3.2 Development tactics

Proceed from the angles of the fundamental realities of the country of our country, regard the strategic demand of the country and market demand of national economy as the direction, regard improving our country and making the comprehensive competitive power of equiping industry and industrialization level as the goal, use the systematic method , be able to choose to make key technology upgraded in development of equiping industry and support technology supporting the development of industrialization in our country in initial stage of 21st century in leading factor, the ability to supply the necessary technology realizes making the jumping development of the equiping industry as the content of research and development.

Emphasize market demand is a direction, namely take terminal products of numerical control as the core, with the complete machine (Such as the numerical control lathe having a large capacity and a wide range, milling machine , high speed high precise high-performance numerical control lathe , digitized machinery of model , key industry key equipment ,etc.) drive the development of the numerical control industry. Solve the numerical control system and relevant functions part especially The dependability that (digitized servo system and electrical machinery , high speed electric main shaft system and new-style enclosure that equip ,etc. ) and production scale question. There are no products that scale will not have high dependability ; Will not have cheap and products rich in the competitiveness without scale ; Certainly, it is difficult to have day holding up ones head finally that there is no scale Chinese numerical control equipment.

In equiping researching and developing high-grade , precision and advancedly , should emphasize the production, learning and research and close combination of the end user, regard " drawing, using, selling " as the goal, tackle key problems

according to the national will, in order to solve the needing badly of the country. Numerical control technology, emphasized innovation, put emphasis on researching and developing the technology and products with independent intellectual property right before the competition, establish the foundation for the industry of numerical control of our country , sustainable development of equipment manufacture and even the whole manufacturing industry.

List of references:

[1]China machine tool industrial association Development department of the trade. CIMT2001 tour [J ]. The manufacturing technology in the world and equiping the market, 2001 (3): 18-20.

[2]The roof beam trains a king to declare , the distribution is helped. New tendency [J ] of the technical development of the lathe . The manufacturing technology in the world and equiping the market, 2001 (3): 21-28.

[3]China machine tool industrial association Systematic branch of numerical control. CIMT2001 tour [J ]. The manufacturing technology in the world and equiping the market, 2001 (5): 13-17.

[4]Yang XueTong, Li DongRu, He WenLi ,etc.? Numerical control lathe technical development strategic research [M ] from now to century. Beijing: State Bureau of Machinery Industries, 2000.