外文翻譯--數(shù)控機床改造

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1、河北建筑工程學院 畢業(yè)設計外文資料翻譯 院別： 機械工程學院 專業(yè)： 機械設計制造及其自動化 班級： 姓名： 學號： 外文出處： Software Department, Polytechnical University of Catalonia, Spain 附 件： 1、外文原文； 2、外文資料翻譯譯文。 指導教師評語： 簽字： 年 月 日 1 The Numerical Control Engine Bed Transforms Harvey B.M ackey First numerical control system development summary brief histor

2、y and tendency In 1946 the first electronic accounting machine was born in the world, this indicated the humanity created has been possible to strengthen and partially to replace the mental labor the tool. It with the humanity these which in the agriculture, the industry society created only is stre

3、ngthens the physical labor the tool to compare, got up the quantitive leap, entered the information society for the humanity to lay the foundation. After 6 years, in 1952, computer technology applied to the engine bed , the first numerical control engine bed were born in US. From this time on, the t

4、raditional engine bed has had the archery target change. Since nearly half century, the numerical control system has experienced two stages and six generation of development. 1.1 Numerical control (NC) stage (1952 - 1970) The early computer operating speed is low, was not big to then science computa

5、tion and the data processing influence, but could not adapt the engine bed real-time control request. The people can not but use numeral logic circuit “ to build” to become an engine bed special purpose computer to take the numerical control system, is called the hardware connection numerical contro

6、l (HARD-WIRED NC), Jian Chengwei numerical control (NC). Along with the primary device development, this stage has had been through repeatedly three generations, namely 1952 first generation of - electron tube； 1959 second generation of - transistor； 1965 third generation - small scale integration e

7、lectric circuit. 1.2 Computer numerical control (CNC) stage (in 1970 - present) In 1970, the general minicomputer already appeared and the mass production. Thereupon transplants it takes the numerical control system the core part, from 2 this time on entered the computer numerical control (CNC) the

8、stage (which should have computer in front of the general two characters to abbreviate). In 1971, American INTEL Corporation in the world first time the computer two most cores part - logic units and the controller, used the large scale integrated circuit technology integration on together the chip,

9、 called it the microprocessor (MICROPROCESSOR), also might be called the central processing element (to be called CPU). The microprocessor is applied to 1974 in the numerical control system. This is because minicomputer function too strong, controlled an engine bed ability to have wealthily (therefo

10、re once uses in controlling the multi- Taiwan engine bed at that time, called it group control), was inferior to used the microprocessor economy to be reasonable. Moreover then small machine reliability was not ideal. The early microprocessor speed and the function although insufficiently are also h

11、igh, but may solve through the multi-processor structure. Because the microprocessor is the general-purpose calculator core part, therefore still was called the computer numerical control. In 1990, PC machine (personal computer, domestic custom had called microcomputer) the performance has developed

12、 to the very high stage, may satisfiedly take the numerical control system core part the request. The numerical control system henceforth entered based on the PC stage. In brief, the computer numerical control stage has also experienced three generations. Namely 1970 fourth generation of - minicompu

13、ter； 1974 five dynasties - microprocessor and 1990 sixth generation - (overseas was called PC-BASED) based on PC. Also must point out, although overseas already renamed as the computer numerical control (namely CNC), but our country still the custom called the numerical control (NC). Therefore we da

14、ily say “ numerical control” , the materially already was refers to “ computer numerical control”. 1.3 the numerical control future will develop tendency 1.3.1 open style continues to, to develop based on the PC sixth generation of 3 direction The software and hardware resources has which based on P

15、C are rich and so on the characteristic, the more numerical controls serial production factory can step onto this path. Uses PC machine to take at least its front end machine, processes the man-machine contact surface, the programming, the association, question and so on net correspondence, undertak

16、es the numerical control duty by the original system. PC machine has the friendly man-machine contact surface, will popularize to all numerical controls system. The long-distance communication, the long-distance diagnosis and the service will be more common. 1.3.2 approaches and the high accuracy de

17、velopment This is adapts the engine bed to be high speed and the high accuracy direction need to develop. 1.3.3 develops to the intellectualized direction Along with the artificial intelligence in the computer domain unceasing seepage and the development, the numerical control system intellectualize

18、d degree unceasingly will enhance. (1) applies the adaptive control technology The numerical control system can examine in the process some important information, and the automatic control system related parameter, achieves the improvement system running status the goal. (2) introduces the expert sy

19、stem instruction processing The skilled worker and experts experience, the processing general rule and the special rule store in the system, take the craft parameter database as the strut, the establishment has the artificial intelligence the expert system. (3) introduces the breakdown to diagnose t

20、he expert system (4) intellectualized numeral servo drive May through the automatic diagnosis load, but the automatic control parameter, causes the actuation system to obtain the best movement. Second, engine bed numerical control transformation necessity 4 2.1 microscopic looks at the transformatio

21、n the necessity From on microscopic looked below that, the numerical control engine bed has the prominent superiority compared to the traditional engine bed, moreover these superiority come from the computer might which the numerical control system contains. 2.1.1 may process the traditional engine

22、bed cannot process the curve, the curved surface and so on the complex components. Because the computer has the excellent operation ability, may the instant accurately calculate each coordinate axis instant to be supposed the movement physiological load of exercise, therefore may turn round the synt

23、hesis complex curve or the curved surface. 2.1.2 may realize the processing automation, moreover is the flexible automation, thus the efficiency may enhance 3 - 7 times compared to the traditional engine bed. Because the computer has the memory and the memory property, may the procedure which inputs

24、 remember and save, then the order which stipulated according to the procedure automatic carries out, thus realization automation. The numerical control engine bed so long as replaces a procedure, may realize another work piece processing automation, thus causes the single unit and the small batch o

25、f production can automate, therefore is called has realized “flexible automation”. 2.1.3 processings components precision high, size dispersion degree small, makes the assembly to be easy, no longer needs “to make repairs”. 2.1.4 may realize the multi- working procedures centralism, reduces the comp

26、onents in engine bed between frequent transporting. 2.1.5 has auto-alarm, the automatic monitoring, automatic compensation and so on the many kinds of autonomy function, thus may realize long time nobody to safeguard the processing. 2.1.6 advantage which derives by above five. For example: Reduced w

27、orkers labor intensity, saved the labor force (a 5 person to be possible to safeguard the multi- Taiwan engine bed), reduced the work clothes, reduced the new product trial manufacturing cycle and the production cycle, might to the market demand make rapid reaction and so on. Above these superiority

28、 are the predecessor cannot imagine, is an extremely significant breakthrough. In addition, the engine bed numerical control carries out FMC (flexible manufacture unit), FMS (flexible manufacture system) as well as CIMS (computer integration manufacture system) and so on the enterprise becoming an i

29、nformation based society transformation foundation. The numerical control technology already became the manufacturing industry automation the core technology and the foundation technology. 2.2 great watches the transformation the necessity From on macroscopic looked that, the industry developed coun

30、try armed forces, the airplane weapon industry, in the end of the 70s, at the beginning of the 80s started the large-scale application numerical control engine bed. Its essence is, uses the information technology to the traditional industry (including the armed forces, airplane weapon industry) carr

31、ies on the technological transformations. Except that uses outside the numerical control engine bed, FMC, FMS in the manufacture process, but also includes in the product development carries out CAD, CAE, CAM, the hypothesized manufacture as well as carries out MIS in the production management (mana

32、gement information system), CIMS and so on. As well as increases the information technology in its production product, including artificial intelligence and so on content. Because uses the information technology to the country foreign troops, the airplane weapon industry carries on the thorough tran

33、sformation (to call it becoming an information based society), finally causes them the product in the international military goods and in the goods for civilian use market the competitive power greatly is the enhancement. But we in the information technology transformation tradition industry aspect

34、compared to the developed country to fall behind approximately for 20 years. Like in our country engine bed capacity, numerical control engine bed proportion (numerical control rate) to 1995 only then 1.9%, 6 but Japan has reached 20.8% in 1994, therefore every year has the massive mechanical and el

35、ectrical products import. This also on from on macroscopic explained the engine bed numerical control transformation necessity. Third, the numerical control transformation content and superiorly lacks 3.1 Transformation industry starting In US, Japan and Germany and so on the developed country, thei

36、r engine bed transforms took the new economical growth profession, thrives abundantly, is occupying the golden age. As a result of the engine bed as well as the technical unceasing progress, the engine bed transformation is “the eternal” topic. Our countrys engine bed transformation industry, also e

37、nters from the old profession to by the numerical control technology primarily new profession. In US, Japan, Germany, have the broad market with the numerical control technological transformations engine bed and the production line, has formed the engine bed and the production line numerical control

38、 transformation new profession. In US, the engine bed transformation industry is called the engine bed regeneration (Remanufacturing) industry. Is engaged in the regeneration industry famous company to include: The Bertsche engineering firm, the ayton engine bed company, Devlieg-Bullavd (are valuabl

39、e) serves the group, the US equipment company and so on. The American valuable company has set up the company in China. In Japan, the engine bed transformation industry is called the engine bed to reequip (Retrofitting) industry. Is engaged in the reequipment industry famous company to include: Big

40、indentation project group, hillock three mechanical companies, thousand substitute fields labor machine company, wild engineering firm, shore field engineering firm, mountain this engineering firm and so on. 3.2 Numerical control transformation content The engine bed and the production line numerica

41、l control transformation main content has following several points: 7 First is extensively recovers the function, to the engine bed, the production line has the breakdown partially to carry on the diagnosis and the restoration； Second is NC, the addend reveals the installment on the ordinary engine

42、bed, or adds the numerical control system, transforms the NC engine bed, the CNC engine bed； Third is renovates, for increases the precision, the efficiency and the automaticity, to the machinery, the electricity partially carries on renovates, reassembles the processing to the machine part, extensi

43、vely recovers the precision； Does not satisfy the production request to it the CNC system to carry on the renewal by newest CNC； Fourth is the technology renews or the technical innovation, for enhances the performance or the scale, or in order to use the new craft, the new technology, carries on th

44、e big scale in the original foundation the technology to renew or the technical innovation, the great scope raises the level and the scale renewal transformation. 3.3 The numerical control transformation superiorly lacks 3.3.1 reduced investment costs, the date of delivery are short With purchases t

45、he new engine bed to compare, may save 60% - 80% expense generally, the transformation expense is low. Large-scale, the special engine bed especially is specially obvious. The common large-scale engine bed transforms, only spends the new engine bed purchase expense 1/3, the date of delivery is short

46、. But some peculiar circumstances, like the high speed main axle, the tray automatic switching unit manufacture and the installment too requires a lot of work, costs a great deal of money, often transforms the cost to enhance 2 - 3 times, with purchases the new engine bed to compare, only can econom

47、ical invest about 50%. 3.3.2 machine capability stable are reliable, the structure is limited Uses foundation and so on lathe bed, column all is heavy but the firm casting component, but is not that kind of welding component, after the transformation engine bed performance high, the quality is good,

48、 may take the new equipment 8 continues to use many years. But receives the original mechanism the limit, not suitably makes the unprecedented transformation. 3.3.3 familiar understood the equipment, is advantageous for the operation service When purchases the new equipment, did not understand wheth

49、er the new equipment can satisfy its processing request. The transformation then otherwise, may precisely calculate the engine bed the processing ability； Moreover, because many years use, the operator already understood to the engine bed characteristic, uses and services the aspect to train the tim

50、e in the operation short, effective is quick. The transformation engine bed as soon as installs, may realize the capacity load revolution. 3.3.4 may fully use the existing condition May fully use the existing ground, does not need to like buys when the new equipment such to have reto construct the g

51、round. 3.3.5 may use the newest control technology enhances the production equipment the automated level and the efficiency, improves the equipment quality and the scale, alters to the old engine bed now the horizontal engine bed. Fourth, numerical control system choice When the numerical control sy

52、stem mainly has three kind of types, the transformation, should act according to the special details to carry on the choice. 4.1 Step-by-steps the open system which the electrical machinery drives This system servo drive mainly is step-by-steps the electrical machinery, the power step-by-steps the e

53、lectrical machinery, the battery solution pulse motor and so on. Entering sends out which by the numerical control system for instruction pulse, after the actuation electric circuit control and the power enlargement, causes to step-by-step the electrical machinery rotation, through 9 gear vice- and

54、ball bearing guide screw vice- actuation executive component. So long as the control command pulse quantity, the frequency as well as the circular telegram order, then may control the executive component movement the displacement quantity, the speed and the heading. This kind of system does not need

55、 the physical location and the velocity feedback which obtains to the input end, therefore called it the open system, this system displacement precision mainly decided in step-by-steps the electrical machinery angular displacement precision, transmission part and so on gear guide screw pitches the p

56、recision, therefore the system displacement precision is low. This system structure simple, debugging service convenient, work reliable, cost low, is easy to reequip successfully. 4.2 The asynchronous motor or the direct current machine drive, diffraction grating survey feedback closed loop numerica

57、l control system This system and the open system difference is: Physical location feedback signal which by position detector set and so on the diffraction grating, induction synchromesh obtains, carries on the comparison as necessary with the given value, two interpolations enlargements and the tran

58、sformation, the actuation implementing agency, by the speed which assigns turns towards the elimination deviation the direction movement, until assigns the position and the feedback physical location interpolation is equal to the zero. The closed loop enters for the system. Enters for the system com

59、plex in the structure compared to the split-ring, the cost is also high, requests strictly to the environment room temperature. The design and the debugging is all more difficult than the open system. But may obtain compared to the split-ring enters for a system higher precision, quicker speed, actu

60、ation power bigger characteristic target. May act according to the product specification, decided whether uses this kind of system. 4.3 The direct current servo electrical machinery drives, encoder feedback semi-closure link numerical control system Half closed-loop system examination part installs

61、in among passes in the 10 moving parts, indirectly surveys the executive component the position. It only can compensate a system ring circuit interior part of part the error, therefore, its precision compared to closed-loop system precision low, but its structure and the debugging all compares the c

62、losed-loop system to be simple. In makes the angular displacement examination part and the speed examination part and the servo electrical machinery time a whole then does not need to consider the position detector set installs the question. The current production numerical control system company fa

63、ctory quite are many, overseas famous company like German SIEMENS Corporation, Japanese FANUC Corporation； Native corporation like China Mount Everest Corporation, Beijing astronautics engine bed numerical control system group company, Central China numerical control company and Shenyang upscale num

64、erical control country engineering research center. When choice numerical control system mainly is each kind of precision which the engine bed must achieve after the numerical control transformation, actuates the electrical machinery the power and users request. Fifth , in the numerical control tran

65、sformation the main mechanical part reequips the discussion A new numerical control engine bed, must achieve in the design that, Has the high static dynamic rigidity； Movement vice- between friction coefficient small, the transmission is ceaseless； The power is big； Is advantageous for the operation

66、 and the service. When engine bed numerical control transformation should meet the above requirements as far as possible. Cannot think the numerical control installment and the ordinary engine bed connects in has met the numerical control engine bed requirements together, but also should carry on th

67、e corresponding transformation to the major component to enable it to achieve the certain design request, can obtain the anticipated transformation goal. 5.1 Skids guide rail 11 Said to the numerical control lathe that, the guide rail besides should have the conventional lathe guidance precision and

68、 the technology capability, but also must have good bears the friction, the attrition characteristic, and the reduction but sends the dead area because of the friction drag. At the same time must have the enough rigidity, by reduces the guide rail to distort to processes the precision the influence,

69、 must have the reasonable guide rail protection and the lubrication. 5.2 Gear The common engine bed gear mainly concentrates in the headstock and the gear box. In order to guarantee the transmission precision, on the numerical control engine bed uses the gear precision class is all higher than the o

70、rdinary engine bed. Must be able to achieve the ceaseless transmission in the structure, thus transforms time, the engine bed main gear must satisfy the numerical control engine bed the request, by guarantees the engine bed processing precision. 5.3 Skids the guide screw and the ball bearing guide s

71、crew The guide screw transmission relates directly to the transmission chain precision. The guide screw selects mainly is decided requests and drives the torque request in the job precision. Is not used by job precision request Gao Shike skids the guide screw, but should inspect the original guide s

72、crew attrition situation, like the pitch error and the pitch accumulative error as well as matches the nut gap. The ordinary circumstances skid the guide screw to be supposed not to be lower than 6 levels, the nut gap oversized then replaces the nut. Uses skids the guide screw relative ball bearing

73、guide screw price to be low, but satisfies the precision high components processing with difficulty. The ball bearing guide screw rubs loses slightly, the efficiency is high, its transmission efficiency may above 90%； Precision high, the life is long； When start moment of force and movement the mome

74、nt of force approaches, may reduce the electrical machinery to start the moment of force. Therefore may satisfiedly compare the high accuracy components processing request. 5.4 Safe protection 12 The effect must take the security as a premise. Transforms in the engine bed must take the corresponding

75、 measure according to the actual situation, cuts noticeable. The ball bearing guide screw vice- is the precision part, when the work must take strict precautions against the dust is specially the scrap and the hard sand grains enters the roller conveyer. On longitudinal guide screw also coca overall

76、 sheet iron safety mask. The big carriage with skids two end surfaces which the guide rail contacts to have to seal, prevented absolutely the flinty granulated foreign matter enters the sliding surface damage guide rail. Sixth,veral examples 1st, transforms the X53 milling machine with SIEMENS 810M

77、In 1998, the company invested 200,000 Yuan, with German Simens the 810M numerical control system, the 611A exchange servo drive system sds was the X53 milling machine carries on X, Y, the Z three axle numerical control transformation to a companys model； Retained the original main axle system and th

78、e cooling system； The transformation three axle has used the roller lead screw and the gear drive organization on the machinery. The entire transformation work including the machine design, the electrical design, the PLC procedure establishment and the debugging, the engine bed overhaul, finally is

79、the entire machine installment and the debugging. After the milling machine transforms, processing effective stroke X/Y/The Z axis respectively is 88.0/270/28 billion mm； Maximum speed X/Y/The Z axis respectively is 5000/1500/800 mm/Min； Manual speed X/Y/The Z axis respectively is 3000/1000/500 mm/M

80、in； The engine bed processing precision achieves 0.001mm. The engine bed three coordinates linkage may complete each kind of complex curve or the curved surface processing. 2nd, transforms the C6140 lathe with GSK980T and the exchange servo drive system sds In 2000, with Guangzhou numerical control

81、plant production GSK980T numerical 13 control system, the DA98 exchange servo unit and 4 locations automatic tool rests to an electrical machinery branch factory C6140 lathe X, the Z two axes carries on the numerical control transformation； Retained the original main axle system and the cooling syst

82、em； The transformation two axes have used the roller lead screw and with the ambulacrum transmission system on the machinery. Entire transformation work including machine design, electrical design, engine bed overhaul and entire machine installment and debugging. After the lathe transforms, processi

83、ng effective stroke X/The Z axis respectively is 3.90/73 million mm； Maximum speed X/The Z axis respectively is 120.0/3 million mm/Min； The manual speed is 400mm/Min； Manual is fast is X/The Z axis respectively is 120.0/3 million mm/Min； The engine bed smallest migration unit is 0.001mm. 3rd, transf

84、orms the X53 milling machine with SIEMENS 802S In 2000, the company invests 120,000 Yuan, with German Simens the 802S numerical control system, step-by-steps the actuation system is the X53 milling machine carries on X, Y, the Z three axle numerical control transformation to companys another model；

85、Retained the original main axle system and the cooling system； The transformation three axle has used the roller lead screw and the gear drive organization on the machinery. The entire transformation work including the machine design, the electrical design, the engine bed overhaul, finally is the en

86、tire machine installment and the debugging. After the milling machine transforms, processing effective stroke X/Y/The Z axis respectively is 63.0/240/28 billion mm； Maximum speed X/Y/The Z axis respectively is 3000/1000/600 mm/Min； Manual enters for speed X/Y/The Z axis respectively is 200.0/800/5 b

87、illion mm/Min； The smallest motion unit is 0.001mm. 1 數(shù)控機床改造 1 數(shù)控系統(tǒng)發(fā)展簡史及趨勢 1946 年誕生了世界上第一臺電子計算機，這表明人類創(chuàng)造了可增強和部分代替腦力勞動的工具。它與人類在農(nóng)業(yè)、工業(yè)社會中創(chuàng)造的那些只是增強體力勞動的工具相比，起了質的飛躍，為人類進入信息社會奠定了基礎。 6 年后，即在 1952 年，計算機技術應用到了機床上，在美國誕生了第一臺數(shù)控機床。從此，傳統(tǒng)機床產(chǎn)生了質的變化。近半個世紀以來，數(shù)控系統(tǒng)經(jīng)歷了兩個階段和六代的發(fā)展。 1.1 數(shù)控（ NC）階段（ 1952-1970 年） 早期計算機的運算速度低，對

88、 當時的科學計算和數(shù)據(jù)處理影響還不大，但不能適應機床實時控制的要求。人們不得不采用數(shù)字邏輯電路 “ 搭 ” 成一臺機床專用計算機作為數(shù)控系統(tǒng)，被稱為硬件連接數(shù)控（ HARD-WIRED NC），簡稱為數(shù)控（ NC）。隨著元器件的發(fā)展，這個階段歷經(jīng)了三代，即 1952 年的第一代 -電子管； 1959 年的第二代 -晶體管；1965 年的第三代 -小規(guī)模集成電路。 1.2 計算機數(shù)控（ CNC）階段（ 1970 年 -現(xiàn)在） 到 1970 年，通用小型計算機業(yè)已出現(xiàn)并成批生產(chǎn)。于是將它移植過來作為數(shù)控系統(tǒng)的核心部件，從此進入了計算機 數(shù)控（ CNC）階段（把計算機前面應有的 通用 兩個字省略了）

89、。到 1971 年，美國 INTEL 公司在世界上第一次將計算機的兩個最核心的部件-運算器和控制器，采用大規(guī)模集成電路技術集成在一塊芯片上，稱之為微處理器（ MICROPROCESSOR），又可稱為中央處理單元（簡稱 CPU）。 到 1974 年微處理器被應用于數(shù)控系統(tǒng)。這是因為小型計算機功能太強，控制一臺機床能力有富裕（故當時曾用于控制多臺機床，稱之為群控），不如采用微處理器經(jīng)濟合理。而且當時的小型機可靠性也不理想。早期的微處理器速度和功能雖還不夠高，但可以通過多處理器結構來解決。由于微處理器是通用計算機的核心部件，故仍稱為計算機數(shù)控。 到了 1990 年， PC 機的性能已發(fā)展到很高的階段

90、，可以滿足作為數(shù)控系統(tǒng)核心部件的要求。數(shù)控系統(tǒng)從此進入了基于 PC 的階段。 總之，計算機數(shù)控階段也經(jīng)歷了三代。即 1970 年的第四代 -小型計算機； 1974 年的第五代 -微處理器和 1990 年的第六代 -基于 PC（ 也就是 為 PC-BASED）。 2 1.3 數(shù)控未來發(fā)展的趨勢 1.3.1 繼續(xù)向開放式、基于 PC 的第六代方向發(fā)展 基于 PC 所具有的開放性、低成本、高可靠 性、軟硬件資源豐富等特點，更多的數(shù)控系統(tǒng)生產(chǎn)廠家會走上這條道路。至少采用 PC 機作為它的前端機，來處理人機界面、編程、聯(lián)網(wǎng)通信等問題，由原有的系統(tǒng)承擔數(shù)控的任務。 PC 機所具有的友好的人機界面，將普及到

91、所有的數(shù)控系統(tǒng)。遠程通訊，遠程診斷和維修將更加普遍。 1.3.2 向高速化和高精度化發(fā)展 這是適應機床向高速和高精度方向發(fā)展的需要。 1.3.3 向智能化方向發(fā)展 隨著人工智能在計算機領域的不斷滲透和發(fā)展，數(shù)控系統(tǒng)的智能化程度將不斷提高。 （ 1）應用自適應控制技術 數(shù)控系統(tǒng)能檢測過程中一些重要 信息，并自動調整系統(tǒng)的有關參數(shù)，達到改進系統(tǒng)運行狀態(tài)的目的。 （ 2）引入專家系統(tǒng)指導加工 將熟練工人和專家的經(jīng)驗，加工的一般規(guī)律和特殊規(guī)律存入系統(tǒng)中，以工藝參數(shù)數(shù)據(jù)庫為支撐，建立具有人工智能的專家系統(tǒng)。 （ 3）引入故障診斷專家系統(tǒng) （ 4）智能化數(shù)字伺服驅動裝置 可以通過自動識別負載，而自動調整參

92、數(shù)，使驅動系統(tǒng)獲得最佳的運行。 2 機床數(shù)控化改造的必要性 2.1 微觀看改造的必要性 從微觀上看，數(shù)控機床比傳統(tǒng)機床有以下突出的優(yōu)越性，而且這些優(yōu)越性均來自數(shù)控系統(tǒng)所包含的計 算機的威力。 2.1.1 可以加工出傳統(tǒng)機床加工不出來的曲線、曲面等復雜的零件。 由于計算機有高超的運算能力，可以瞬時準確地計算出每個坐標軸瞬時應該運動的運動量，因此可以復合成復雜的曲線或曲面。 2.1.2 可以實現(xiàn)加工的自動化，而且是柔性自動化，從而效率可比傳統(tǒng)機床提高 3 7倍。 3 由于計算機有記憶和存儲能力，可以將輸入的程序記住和存儲下來，然后按程序規(guī)定的順序自動去執(zhí)行，從而實現(xiàn)自動化。數(shù)控機床只要更換一個程序

93、，就可實現(xiàn)另一工件加工的自動化，從而使單件和小批生產(chǎn)得以自動化，故被稱為實現(xiàn)了 “ 柔性自動化 ” 。 2.1.3 加工零件的精度高，尺寸分散度小，使裝配容易，不再需要 “ 修配 ” 。 2.1.4 可實現(xiàn)多工序的集中，減少零件 在機床間的頻繁搬運。 2.1.5 擁有自動報警、自動監(jiān)控、自動補償?shù)榷喾N自律功能，因而可實現(xiàn)長時間無人看管加工。 2.1.6 由以上五條派生的好處。 如：降低了工人的勞動強度，節(jié)省了勞動力（一個人可以看管多臺機床），減少了工裝，縮短了新產(chǎn)品試制周期和生產(chǎn)周期，可對市場需求作出快速反應等等。 以上這些優(yōu)越性是前人想象不到的，是一個極為重大的突破。此外，機 床數(shù)控化還是推

94、行 FMC（柔性制造單元）、 FMS（柔性制造系統(tǒng)）以及 CIMS（計算機集成制造系統(tǒng)）等企業(yè)信息化改造的基礎。數(shù)控技術已經(jīng)成為制造業(yè)自動化的核心技術和基礎技術。 2.2 宏觀看改造的必要性 從宏觀上看，工業(yè)發(fā)達國家的軍、民機械工業(yè)，在 70 年代末、 80 年代初已開始大規(guī)模應用數(shù)控機床。其本質是，采用信息技術對傳統(tǒng)產(chǎn)業(yè)（包括軍、民機械工業(yè)）進行技術改造。除在制造過程中采用數(shù)控機床、 FMC、 FMS 外，還包括在產(chǎn)品開發(fā)中推行 CAD、CAE、 CAM、虛擬制造以及在生產(chǎn)管理中推行 MIS（管理信息系統(tǒng)） 、 CIMS 等等。以及在其生產(chǎn)的產(chǎn)品中增加信息技術，包括人工智能等的含量。由于采用

95、信息技術對國外軍、民機械工業(yè)進行深入改造（稱之為信息化），最終使得他們的產(chǎn)品在國際軍品和民品的市場上競爭力大為增強。 3 數(shù)控化改造的內容及優(yōu)缺 3.1 數(shù)控 改造業(yè)的興起 在美國、日本和德國等國家，機床改造作為新的經(jīng)濟增長行業(yè)，生意盎然，正處在黃金時代。由于機床以及技術的不斷進步，機床改造是個 “ 永恒 ” 的課題。在美國、日本、德國，用數(shù)控技術改造機床和生產(chǎn)線具有廣闊的市場，已形成了機床和生產(chǎn)線數(shù)控改造的新的行業(yè)。在美國 ，機床改造業(yè)稱為機床再生（ Remanufacturing）業(yè)。從事再生業(yè)的著名公司有： Bertsche 工程公司、 ayton 機床公司、 Devlieg-Bulla

96、vd（得寶）服務集團、 US 設備公司等。在日本，機床改造業(yè)稱為機床改裝（ Retrofitting）業(yè)。 4 從事改裝業(yè)的著名公司有：大隈工程集團、崗三機械公司、千代田工機公司、野崎工程公司、濱田工程公司、山本工程公司等。 3.2、數(shù)控化改造的內容 機床與生產(chǎn)線的數(shù)控化改造主要內容有以下幾點： 其一是恢復原功能，對機床、生產(chǎn)線存在的故障部分進行診斷并恢復 ； 其二是 NC 化，在普通機床上加數(shù)顯裝置，或加數(shù)控系統(tǒng)，改造成 NC 機床、 CNC 機床； 其三是翻新，為提高精度、效率和自動化程度，對機械、電氣部分進行翻新，對機械部分重新裝配加工，恢復原精度；對其不滿足生產(chǎn)要求的 CNC 系統(tǒng)以最

97、新 CNC 進行更新； 其四是技術更新或技術創(chuàng)新，為提高性能或檔次，或為了使用新工藝、新技術，在原有基礎上進行較大規(guī)模的技術更新或技術創(chuàng)新，較大幅度地提高水平和檔次的更新改造。 3.3、數(shù)控化改造的優(yōu)缺 3.3.1 減少投資額、交貨期短 同購置新機床相比，一般可以節(jié)省 60 80的費用，改造費用低。特別是大型、特殊機床尤其明顯。一般大型機床改造，只花新機床購置費用的 1/3，交貨期短。但有些特殊情況，如高速主軸、托盤自動交換裝置的制作與安裝過于費工、費錢，往往改造成本提高 2 3 倍，與購置新機床相比，只能節(jié)省投資 50左右。 3.3.2 機械性能穩(wěn)定可靠，結構受限 所利用的床身、立柱等基礎件

98、都是重而堅固的鑄造構件，而不是那種焊接構件，改造后的機床性能高、質量好，可以作為新設備繼續(xù)使用多年。但是受到原來機械結構的限制，不宜做突破性的改造。 3.3.3 熟悉了解設備、便于操 作維修 購買新設備時，不了解新設備是否能滿足其加工要求。改造則不然，可以精確地計算出機床的加工能力；另外，由于多年使用，操作者對機床的特性早已了解，在操作使用和維修方面培訓時間短，見效快。改造的機床一安裝好，就可以實現(xiàn)全負荷運轉。 3.3.4 可充分利用現(xiàn)有的條件 可以充分利用現(xiàn)有地基，不必像購入新設備時那樣需重新構筑地基。 3.3.5 可以采用最新的控制技術 可根據(jù)技術革新的發(fā)展速度，及時地提高生產(chǎn)設備的自動化

99、水平和效率，提高設備質量和檔次，將舊機床改成當今水平的機床。 5 4 數(shù)控系統(tǒng)的選 擇 數(shù)控系統(tǒng)主要有三種類型，改造時，應根據(jù)具體情況進行選擇。 4.1 步進電機拖動的開環(huán)系統(tǒng) 該系統(tǒng)的伺服驅動裝置主要是步進電機、功率步進電機、電液脈沖馬達等。由數(shù)控系統(tǒng)送出的進給指令脈沖，經(jīng)驅動電路控制和功率放大后，使步進電機轉動，通過齒輪副與滾珠絲杠副驅動執(zhí)行部件。只要控制指令脈沖的數(shù)量、頻率以及通電順序，便可控制執(zhí)行部件運動的位移量、速度和運動方向。這種系統(tǒng)不需要將所測得的實際位置和速度反饋到輸入端，故稱之為開環(huán)系統(tǒng)，該系統(tǒng)的位移精度主要決定于步進電機的角位移精度，齒輪絲杠等傳動元件的節(jié)距精 度，所以系統(tǒng)

100、的位移精度較低。 該系統(tǒng)結構簡單，調試維修方便，工作可靠，成本低，易改裝成功。 4.2 異步電動機或直流電機拖動，光柵測量反饋的閉環(huán)數(shù)控系統(tǒng) 該系統(tǒng)與開環(huán)系統(tǒng)的區(qū)別是：由光柵、感應同步器等位置檢測裝置測得的實際位置反饋信號，隨時與給定值進行比較，將兩者的差值放大和變換，驅動執(zhí)行機構，以給定的速度向著消除偏差的方向運動，直到給定位置與反饋的實際位置的差值等于零為止。閉環(huán)進給系統(tǒng)在結構上比開環(huán)進給系統(tǒng)復雜，成本也高，對環(huán)境室溫要求嚴。設計和調試都比開環(huán)系統(tǒng)難。但是可以獲得比開環(huán)進 給系統(tǒng)更高的精度，更快的速度，驅動功率更大的特性指標?？筛鶕?jù)產(chǎn)品技術要求，決定是否采用這種系統(tǒng)。 4.3 交 /直流伺

101、服電機拖動，編碼器反饋的半閉環(huán)數(shù)控系統(tǒng) 半閉環(huán)系統(tǒng)檢測元件安裝在中間傳動件上，間接測量執(zhí)行部件的位置。它只能補償系統(tǒng)環(huán)路內部部分元件的誤差，因此，它的精度比閉環(huán)系統(tǒng)的精度低，但是它的結構與調試都較閉環(huán)系統(tǒng)簡單。在將角位移檢測元件與速度檢測元件和伺服電機作成一個整體時則無需考慮位置檢測裝置的安裝問題。 當前生產(chǎn)數(shù)控系統(tǒng)的公司廠家比較多，著名公司的如德國 SIEMENS 公司、日本 FANUC公司。 選擇數(shù)控系統(tǒng)時主要是根據(jù)數(shù)控改造后機床要達到的各種精度、驅動電機的功率和用戶的要求。 5 數(shù)控改造中主要機械部件改裝探討 一臺新的數(shù)控機床，在設計上要達到：有高的靜動態(tài)剛度；運動副之間的摩擦系數(shù)小，傳

102、動無間隙；功率大；便于操作和維修。機床數(shù)控改造時應盡量達到上述要求。不 6 能認為將數(shù)控裝置與普通機床連接在一起就達到了數(shù)控機床的要求，還應對主要部件進行相應的改造使其達到一定的設計要求，才能獲得預期的改造目的。 5.1 滑動導軌副 對數(shù)控車床來說，導軌除應具有普通 車床導向精度和工藝性外，還要有良好的耐摩擦、磨損特性，并減少因摩擦阻力而致死區(qū)。同時要有足夠的剛度，以減少導軌變形對加工精度的影響，要有合理的導軌防護和潤滑。 5.2 齒輪副 一般機床的齒輪主要集中在主軸箱和變速箱中。為了保證傳動精度，數(shù)控機床上使用的齒輪精度等級都比普通機床高。在結構上要能達到無間隙傳動，因而改造時，機床主要齒輪

103、必須滿足數(shù)控機床的要求，以保證機床加工精度。 5.3 滑動絲杠與滾珠絲杠 絲杠傳動直接關系到傳動鏈精度。絲杠的選用主要取決于加工件的精度要求和拖動扭矩要 求。被加工件精度要求不高時可采用滑動絲杠，但應檢查原絲杠磨損情況，如螺距誤差及螺距累計誤差以及相配螺母間隙。一般情況滑動絲杠應不低于 6 級，螺母間隙過大則更換螺母。采用滑動絲杠相對滾珠絲杠價格較低，但難以滿足精度較高的零件加工。 滾珠絲杠摩擦損失小，效率高，其傳動效率可在 90%以上；精度高，壽命長；啟動力矩和運動時力矩相接近，可以降低電機啟動力矩。因此可滿足較高精度零件加工要求。 5.4 安全防護 必須以安全為前提。在機床改造中要根據(jù)實際

104、情況采取相應的措施，切不可忽視。滾珠絲杠副是精密元件，工作時 要嚴防灰塵特別是切屑及硬砂粒進入滾道。在縱向絲杠上也可加整體鐵板防護罩。大拖板與滑動導軌接觸的兩端面要密封好，絕對防止硬質顆粒狀的異物進入滑動面損傷導軌。 6 數(shù)控改造幾個實例 1 用 SIEMENS 810M 改造 X53 銑床 2001 年，用德國西門子 810M 數(shù)控系統(tǒng)、 611A 交流伺服驅動系統(tǒng)對公司的一臺型號為 X53 的銑床進行 X、 Y、 Z 三軸數(shù)控改造；保留了原有的主軸系統(tǒng)和冷卻系統(tǒng)；改造的三軸在機械上采用了滾軸絲桿及齒輪傳動機構。整個改造工作包括機械設計、電氣設計、 PLC 程序的編制與調試、機床大修 ，最后

105、是整機的安裝和調試。銑床改造后，加 7 工有效行程 X/Y/Z 軸分別為 880/270/280 mm；最大速度 X/Y/Z 軸分別為 5000/1500/800 mm/min；手動速度 X/Y/Z軸分別為 3000/1000/500 mm/min；機床加工精度達到 0.001mm 。機床的三坐標聯(lián)動可完成各種復雜曲線或曲面的加工。 2 用 GSK980T 和交流伺服驅動系統(tǒng)改造 C6140 車床 2004 年， GSK980T 數(shù)控系統(tǒng)、 DA98 交流伺服單元及 4 工位自動刀架對電機分廠的一臺 C6140 車床 X、 Z 兩軸進行數(shù)控改 造；保留了原有的主軸系統(tǒng)和冷卻系統(tǒng)；改造的兩軸在機

106、械上采用了滾軸絲桿及同步帶傳動機構。整個改造工作包括機械設計、電氣設計、機床大修及整機的安裝和調試。車床改造后，加工有效行程 X/Z 軸分別為 390/730 mm；最大速度 X/Z 軸分別為 1200/3000 mm/min；手動速度為 400mm/min；手動快速為 X/Z軸分別為 1200/3000 mm/min；機床最小移動單位為 0.001mm。 3 用 SIEMENS 802S 改造 X53 銑床 2004 年，用德國西門子 802S 數(shù)控系統(tǒng)、步進驅動系統(tǒng)對公司的 另一臺型號為X53 的銑床進行 X、 Y、 Z 三軸數(shù)控改造；保留了原有的主軸系統(tǒng)和冷卻系統(tǒng)；改造的三軸在機械上采用了滾軸絲桿及齒輪傳動機構。整個改造工作包括機械設計、電氣設計、機床大修，最后是整機的安裝和調試。銑床改造后，加工有效行程 X/Y/Z 軸分別為630/240/280 mm；最大速度 X/Y/Z 軸分別為 3000/1000/600 mm/min；手動進給速度 X/Y/Z軸分別為 2000/800/500 mm/min；最小移動單位為 0.001mm。