外文原文

Numerical control technology developmentNumerical control system develop biref history and trend the first electronic computer in the world borned in 1946, this indicates the mankind has created the tool that can strengthen and replace the mental labour partly . It, and mankind those that create to strengthen tool of manual labor compare among agriculture, industrial society, the qualitative leap has arisen , has established the foundation that the mankind enters the information-intensive society .6 years later, namely in 1952, the technology of the computer was applied to the lathe , the first numerical control lathe has emerged in U.S.A.. From then on, the traditional lathe had produced the change of the quality. In nearly half a century, numerical control system go through two stage and six development of generation.The stage of numerical control (NC ) (1952-1970 years) The operation of the early computer is low in speed, influence not also big scientific caculation and data processing at that time, but can't meet the needs of real-time control of the lathe . People have to adopt the digital logical circuit to " put up " and become the special-purpose computer of a lathe as the numerical control system, known as the hardware and connect numerical control (HARD-WIRED NC ) , abbreviate as the numerical control (NC ). With the development of components and parts, does this stage go through you of the sixth of the twelve Earthly Branches? First generation in 952 --Electron tube ; Second generation in 1959 --Transistor; The third generation in 1965 --Small-scale integrated circuit. The stage of numerical control of the computer (CNC ) (1970 - now) By 1970, the small-scale computer industry in common use has already appeared and produced by batch. Then transplant it over as the key part of system of numerical control, enter computer numerical control stage from now on (whether due " in common use two words " omit computer). By 1971, in the world for the first time two central part most of computer Company , INTEL of U.S.A. , --arithmetic unit and controller , adopt the technology intergration of the large scale integrated circuit on a chip, call it microprocessor (MICROPROCESSOR ) , can call central authorities punish Entrance (abbreviate as CPU).The microprocessor is applied the numerical control system by 1974. This because being function too strong, minicom control one lathe ability have rich (use for controlling many lathes at that time, call it team control ), have more rational economy than the adoption microprocessor. And the minicomputer dependability at that time was unsatisfactory. Early microprocessor speed and function although enough high, can solve through many processor structure. Because the microprocessor is a key part of the all-purpose computer , so still called the numerical control of the computer.By 1990, the performance of the PC (personal computer , is used to calling the computer at home ) has already developed into very high stage, can meet the demand which is regarded as the key part of the numerical control system . The numerical control system entered the stage based on PC from then on. In a word, the computer went through three generations too at numerical control stage. Namely the fourth generation in 1970 --Minicom ; The fifth generation in 1974 --The microprocessor and the sixth generation of 1990 --Because of PC (call PC-BASED abroad).The ones that were also wanted and is pointed out are, though has already renamed as the numerical control of the computer (namely CNC ) abroad, and our country is still used to being called the numerical control (NC ). So our daily " numerical control " that speak, has already referred to " the numerical control of the computer " in fact.Future development trend of numerical control 1. 3. 1 continue to open , based on PC six generation cubic meter to develop Characteristic of enriching on the basis of opening , low cost , high dependability , software and hardware resource that PC has etc., more systematic manufacturers of numerical control will go on this road . Adopt PC as front machine of it , is it deal with man-machine interface , programming , network communication ,etc. problem to come at least, undertaken the task of numerical control by the already existing system. The friendly man-machine interface that the PC has, will run through all numerical control systems. Telecommunication , will diagnose long-rangly and maintain more general.Develop to high speed and high accuracy This is meeting the need that the lathe is developed in the high-speed and high-accuracy direction. Develop toward intellectuality With the constant infiltration and development in the field of computer of artificial intelligence, the intelligent degree of the numerical control system will be improved constantly.1)Use the adaptive control technology Numerical control system can of the detection procedure some important information, and adjust the relevant parameters of the system automatically, achieve the goal of improving systematic operation state.2)Introduced to the expert system and guided and processedExperienced operator and experience of expert, universal law and special law of processing deposit system, regard parameter database of the craft as support, set up the expert system with artificial intelligence.3)Introduce the trouble and diagnose the expert system (4)Intelligent digital servo drive Can through discern load automatically , adjust parameter automatically, is it urge system win the best operation to make. Second, necessity 2 of lathe numerical control transformation. 1, Watch the necessity transformed a little Looking from microcosmic, the numerical control lathe has the following and outstanding superioritymore than the traditional lathe , and superiority the come from numerical control might of computer system include.2. 1. 1 can process such complicated parts as the curve coming out in traditional machine tooling , curved surface ,etc. Because computer have superb operation ability, can instantaneous to calculate out each coordinate axis instantaneous amount of exercise that should move accurate, so can compound into the complicated curve or curved surface .2. 1. 2 can realize automation that process, and flexible automation, thus efficiency raise than the traditional lathe by 3-7 times. Because the computer has memory and stores ability, can remember and store the procedure input , then carry out automatically according to the order that the procedure stipulates , thus realize automation. So long as numerical control lathe changes a procedure , can realize the automation that another work piece is processed , thus make single piece and produce automation of must using in small batches, so known as realizing " flexible automation ".2. 1. 3 The precision of 3 processing parts is high, the size is dispersed degree small, it is easy to enable assembling, no longer need to " repair the damaged parts of a machine and supply replacements ".2. 1. 4 concentration that can realize many processes , reduce the frequently carrying among the lathes of part.2. 1. 5 has such many kinds of self-containment functions as autoalarm , controlling , automatic compensation automatically ,etc., therefore can realize nobody guards and processes for a long time2. 1. 6 is by the above five spin-off advantages. For instance: Have reduce workers' labour intensity, has saved the workforce (a person can guard many lathes ), reduce frocks, shorten trial production of new products cycle and production cycle , can make fast reaction ,etc. to market demand . The above superiority could not be imagined by forefathers , was an extremely great break-through. In addition, the numerical control of the lathe pursues FMC Foundation in such enterprise's information-based transformations as (flexible manufacturing unit ) , FMS (flexible manufacturing system ) and CIMS (CIMS ) ,etc.. Numerical control technology has already become key technology of automation of manufacturing industry and basic technology.2. 2, See the necessity transformed in macroscopic Look from macroscopic, the army of the industrially developed country, the people's mechanical industry, by the end of the 70 s, already begin to use the numerical control lathe on a large scale at the beginning of the eighties. Its essence is, adopt the information technology to carry on technological transformation to the traditional industry (including the army , the people's mechanical industry ). Except that adopt the numerical control lathe in the course of making, FMC, outside the FMS , pursue CAD , CAE , CAM , fictitious to make and pursue MIS (the management information system ) , CIMS ,etc. inproduction management in product development also. And increase the information technology , including the content in artificial intelligence ,etc. in the products that its produce. Adopt information technology carry on the deep transformation to foreign countries army , the people mechanical industry (call it the informationization), make products of them competitiveness strengthen very at international military products and market of civilian goods finally. And we are 20 years for about backwardness than developed country in traditional industry of technological transformation of information. In the owning amount of lathe of our country, there is only 1 by 1995 in the proportion (numerical control rate ) of the numerical control lathe . 9%, and Japan had already been up to 20 in 1994. 8%, so a large number of electronic products are imported every year. This states the necessity of numerical control transformation of the lathe from macroscopic too. Third, the markets of the lathe and production line numerical control transformation 3. 1, Market of numerical control transformation of the lathe The total amount of the lathe at present of our country is more than 3,800,000, and the total amount of numerical control lathes is 11 among them. 340,000, namely the numerical control rate of lathe of our country is less than 3%. In the past 10 years, the annual production of numerical control lathe of our country is about 0. 6-0. 80,000, annual output is about 1,800 million yuan. The annual production numerical control of the lathe turns rate into 6%. To account for more than 60% of our country more than 10 years such as enlistment age such as lathe; In the lathe under 10 years, automatic / semi-automatic lathe is less than 20%, there are very fewer such automatic production lines as FMC/FMS ,etc. (the automatic and semi-automatic lathe of U.S.A. and Japan accounts for more than 60%). It is obvious most manufacturing and production of enterprise of us , is it equip hopeless great number traditional lathe to process, and more than half is the old lathe in above 10 years of enlistment age. Have quality to be poor with the equipment products come out to process variety little of low grade with high costs, thus uncompetitive on world, domestic market, influence products , market , benefit of an enterprise directly, influence the existence and development of enterprises. So must improve the numerical control rate of the lathe in a more cost-effective manner .3. 2, The numerical control of import equipment and production line transforms the market Our country has introduced the technology , equipment and production line to carry on technological transformation from foreign countries in a lot of enterprises since reform and opening-up. According to incomplete statistics, from 10 year past 1979-1988, the whole country introduce technological transformation project have 18446 items, about 165. 800 million dollars.In these projects, most projects have played a due role for the economic construction of our country. But some introduce projects forvarious reasons, equipment or the production line can't run well , even paralysed, make the benefits of enterprises influenced , the serious one makes enterprises get into a difficult position . After some equipment , production line introduce from foreign countries, it is kind for some to digest and assimilate, the spare part is not complete, it is improper to safeguard, the result operates badly ; Some only pay attention to introducing the equipment , instrument , production line while introducing , ignoring software , craft , management ,etc., causing the project to be incomplete, the potentiality of the equipment can't be given play to;Some can't even start and run , have not given play to the role of should have ing ; Some products of production line sell quickly, but because equipment fault can is it produce up to standard to reach; Some cause loss because energy consumption is high , the product percent of pass is low; Some have already introduced longer time, have needed to carry on technology innovation. All sorts of reasons make some equipment not create the wealth , is consuming the wealth insteadEquipment , production line that can't use these pieces of burden, one heavy stock assets very too, it is the wealth to repair. So long as find out main technological difficult point, solve key technology problem, can minimum investment vitalize the heaviest stock assets, strive for to the greatest economic benefits and social benefit. This is a great transforming the market too. Content and excellent and scarce of fourth , numerical control transformation 4. 1, Rise of the transforming industry abroad In such developed countries as U.S.A. , Japan and Germany ,etc., their lathe transformation is regarded as the new economic growth trade, full of life, the straight place is at gold age. Because the constant progress of the lathe and technology, the transformation of the lathe is an " eternal subject ". The industry that transforms lathe of our country, enter into the new trade relying mainly on numerical control technology from old trade too. In U.S.A. , Japan , Germany , transform with numerical control technology the lathe and production line have wide markets, have already formed the new trade transformed in the lathe and production line numerical control. In U.S.A., lathe transformation industry call lathe regeneration family property. The famous company which is engaged in the recycled family property is as follows, Bertsche project. U.S.A. get treasure Company already open and run the company in China. In Japan, lathe transformation industry call lathe refit (Retrofitting ) the family property. The famous company of the repacking industry is as follows, that engaged in Big Wei project group , hillock three mechanical company , a thousand generation Tian worker machine Company , wild rugged engineering company , Hamada engineering company , mountain this engineering company ,etc.. 4. 2, Content of the numerical control transformation There are the following several points in the numerical control of the latheand production line main content of transformation:First resume the original function , diagnose and resume to the trouble part existing in the lathe , production line ; Second NC, addend show the device at ordinary lathe, or add the numerical control system, transform into NC lathe , CNC lathe Third renovate , in order to improve the precision , efficiency and automatic degree , renovate to machinery , electric part, reassemble and process the mechanical part, resume original precision; Go on newer to his CNC system which is unsatisfied with the production demand with the newest CNC; Fourth technology innovation or technological innovation, in order to improve performance or grade, or in order to use the new craft , new technology, carry on more extensive technology innovation or technological innovation on the original foundation, the ones that improved the standard with grade were renovated by a relatively large margin. , Numerical control transformation excellent and scarce. The capital cost , delivery date are short that 1 reduces Compared with the situation that purchase the new lathe , can generally save 60%-80% of the expenses , it is low to transform the expenses. Especially the large-scale , special lathe is especially obvious. General large-scale lathe transformation, spend new lathe 1/3 to purchase expenses only, delivery date is short. But there are special circumstances, if the making and installation of high-speed main shaft , automatic switch of tray overly takes a lot of work , costly, transform cost raise 2-3 , compared with the situation that purchase the new lathe , can only save 50% investment to be about often. It is reliable that 2 mechanical performance is steady, the structure is limited Such basic parts as the lathe bed , post utilized ,etc. are all heavy and firm casting components, but not the welding component, transform lathe after performance high of high quality, can continue to use for many years as the new equipment . But receive mechanical restriction of structure originally, unsuitable to make the breakthrough transformation familiarizes with the equipment, benefits and operates maintaining While buying the new equipment , do not understand whether new equipment can meet its processing demand . It is quite different to transform , can calculate out the working ability of the lathe accurately ; In addition, has used because for many years, the operator has already understood about the characteristic of the lathe , training time is short , with instant effect in view of operation and maintaining. As soon as the lathe transformed can fully utilize the existing condition Can fully utilize the existing ground , needn't need to construct the ground again like the thing that while buying the new equipment . can adopt the newest control technology But according to the development speed of technological innovation , improve the automatic level and efficiency of the production equipment in time, improve the quality of the equipment and grade, make the old lathe into the lathe of the current level. Fifth, choice of thenumerical control system Numerical control system have three kind mainly , when transforming , should choose according to the concrete conditions.5. A one that walk into the electrical machinery and pull turns on the ring system System this servo drive to walk into electrical machinery , power walk into electrical machinery , electric liquid pulse motor ,etc. mainly. The ones that are sent by the numerical control system are entered to the order pulse, after urging the circuit to control and power amplification, is it walk into electrical machinery rotate , through vice guide screw urge and carry out the part while being vice with ball gear wheel have to make. So long as control quantity , frequency , order of pulse and set up an electric circuit order , can is it carry out displacement amount , speed and sport direction , part of sport to control. The system need actual position and speed had to examine feedback the input end, so is it hold ring system to call it, system this displacement precision is it walk into precision of angle displacement of electrical machinery to decide by mainly, gear wheel guide screw ,etc. section, transmission of component from precision, so systematic displacement relatively low in precision This system is of simple structure, debug and maintain it conveniently, it is reliable to work, with low costs, easy to repack successfully. Asynchronous motor or direct current machine pull, grating measure feedback close the numerical control system of the ring This system and difference of making ring system are: Measure by grating , reaction synchronizer ,etc. position device examine actual position feedback signal that have, compare with setting value at any time, enlarge and vary the difference of the two, drive the executive body, by moving towards the direction of dispelling the deviation for the speed definitely, until giving definitely the position and real position feedbacked Difference equal zero. Close ring enter give system at structure than turn on ring is it give system to be complicated to enter , have higher costs even, require the environmental room temperature tightly. Design and debug than hold ring to be system difficult. Can obtain than make ring is it give system high precision to enter , fast speed, drive the more powerful characteristic index . But according to the specification requirement of the products , determine whether to adopt this kind of system or not. Pay / pull by direct current servo electrical machinery, half-closed ring numerical control system that encoder feedback Half-closed ring system measure component installation spread moveable piece in the middle , is it carry out position of part to measure indirectly. It can only compensate the errors of some components within the systematic cycle , so, its precision is lower than to close the precision of the ring system, but structure and debugging of it close ring to be system simple relatively. Measure angle displacement component and speed measure component and servo electrical machinery is it consider position measure installation issue of device to need at making one whole.Present manufacturer which produce company of the numerical control system many, such as Company , Company , FANUC of Japan , , SIEMENS of Germany , foreign famous company; Such as Company , Beijing spaceflight lathe numerical control systematic group company , Central China numerical control company , Shenyang top-grade numerical control national project research center , Mount Qomolangma of China , domestic corporation. Choose numerical control lathe want various kinds of precision that up to , urge power and users' demand of electrical machinery after the transformation according to numerical control mainly at the system Sixth, numerical control the main mechanical part refits the discussion of transforming A new numerical control lathe , should reach in the design: There is high quiet dynamic rigidity ; The coefficient of friction between the vice sport is small, the transmission has no interval ; The power is large; Easy to operate and maintenance. Should try one's best to reach above-mentioned demands at the time of the numerical control transformation of the lathe . Can't is it is it meet the requirement of numerical control lathe right away to link numerical control device and ordinary lathe together to think, should go on corresponding transformation make their reach certain designing requirement to main part also, purpose of transforming that could be expected.Slip the guide pair To numerical control lathe, the guide is besides should have ordinary lathes to lead the precision and craft ing, still there should the good one that is able to bear rubing , wearing and tearing characteristic , reduce the causing death area because of rubing obstruction. There should be enough rigidity at the same time, in order to reduce the impact on machining accuracy out of shape of guides, there should rational guides that are protected and lubricated. The gear wheel of the general lathe concentrates on main shaft case and gearbox mainly. In order to guarantee the precision of transmission, the precision of gear wheel used at the numerical control lathe is higher than the ordinary lathe in grade . Can is it have interval transmission to reach at structure, therefore when transforming, lathe main gear wheel must meet demand , numerical control of lathe, so as to ensure the machining accuracy of the lathe . Slip the guide screw and ball guide screw. The guide screw transmission concerns the precision of drive chain directly. Exertion of guide screw depend on precision to process piece require and pull torsion not to require mainly. Can be adopted and slipped the guide screw while expecting much by a precision of processing, but should check the wearing and tearing situation of the original guide screw , if pitch error and pitch error match the nut interval totally. General situation slip guide screw should lower than 6 , nut interval too big to change nut. Is it slip guide screw relative guide screw price relatively low ball to adopt, but difficult to meet precision high part process. Ball guide screw friction loss light , with high efficiency, transmission its efficiency above 90%very; The precision is high , longe-lived; The moment is close while starting the moment and movement, can reduce the electrical machinery and start the moment . So can meet the more high-accuracy part and process the demand . Safe protection It is necessary if safe. It can't ignore to take the corresponding measure according to the actual conditions in the transformation of the lathe. The vice ball guide screw is the accurate component , prevent the dust especially smear metal and hard sand one strictly from entering and rolling dish while working. Can add the protection cover of whole iron plate on the vertical guide screw. Heavy to tow board and slip two terminal surface that guide exposed to is it seal kind to want , prevent hard quality foreign matter , particle of form from is it slip surface damage guide to enter definitely.Make the overall development strategy which accords with the China's actual conditions, establish the development path in line with international standards, technology and development of industry essential to 21st century of our country numerical control. This text is in the analysis on numerical control technology and industry's development trend, carry on the domain existing problem of numerical control of our country on the foundation of research, have carried on the discussion to the technology of numerical control of our country and approach to development of the industry in the 21st century, propose regarding scientific and technical innovation as the guide, regard commercializing as the backbone , regard managing and marketting as the focal point, is it for backing , insist sustainable overall development strategy of development path to serve with technical support. On this basis , have studied the concrete technological way to develop new-type numerical control system , numerical control function part , numerical control lathe complete machine ,etc..We hope sincerely , scientific and technological circle , industrial circle and education circle of our country work in concert, get hold of the rare opportunity that the kownledge economy brings to us, meet the severe challenge brought in competition globalization, arranging ago in order to make technology and industry of numerical control of our country more competitive in the world in the 21st century, make the economy of our country continue keeping the powerful growth momentum making joint efforts to struggle.。