Numerical control technology and equipment trend of development
The equipment industry technical level and the modernized degree were deciding the entire national economy level and the modernized degree, the numerical control technology and the equipment are the development emerging high technology and new technology industry and the state-of-art industry (for example defense industry industries and so on information technology and industry, biological technology and industry, aviation, astronautics) enables the technology and the most basic equipment. Marx had said “each kind of economical time difference, does not lie in produces any, but how lies in produces, with any means of labor production”. The technique of manufacture and the equipment is the humanity produces active the most basic producer goods, but the numerical control technology also is advanced now the technique of manufacture and the equipment most core technology. Now the various countries manufacturing industry widely uses the numerical control technology, sharpens the manufacturing capacity and the level, enhances to the dynamic changeable market adaptiveness and competitive ability. In addition in the world various industries developed country also lists as the national strategic resources the numerical control technology and the numerical control equipment, not only takes the significant measure to develop own numerical control technology and the industry, moreover implements the blockade and the limit policy in “precise and advanced” the numerical control key technologies and the equipment aspect to our country. In brief, develops vigorously take the numerical control technology has become the world each developed country acceleration economy development as the core advanced technique of manufacture, enhances the comprehensive national strength and the national status important way. The numerical control technology is carries on the control with the numerical information to the mechanical movement and the work process the technology, the numerical control equipment is take the numerical control technology as representative's new technology the integration of machinery product which forms to the traditional manufacture industry and the emerging manufacturing industry seepage, namely so-called digitized equipment, its technical scope cover very many domains: (1) machine manufacture technology; (2) information processing, processing, transmission technology; (3) automatic control technology; (4) servo actuates the technology; (5) sensor technology; (6) software technology and so on. 1 numerical control technology trend of development Not only the numerical control technology application has brought the revolutionary change for the traditional manufacturing industry, causes the manufacturing industry to become the industrialization the symbol, moreover along with numerical control technology unceasing development and application domain expansion, he to national economy and the people's livelihood some important professions (IT, automobile, light industry, medical service and so on) development more and more vital role, because these professions must equip the digitization already was the modern development major tendency. The numerical control technology and the equipment development tendency looked from the present world that, its main research hot
spot has following several aspect [1~4]. 1.1 high speed, high precision work technology and equipment new tendency The efficiency, the quality are the advanced technique of manufacture main bodies. High speed, the high precision work technology may enhance the efficiency enormously, enhances the product the quality and the scale, reduces the production cycle and sharpens the market competition ability. Lists as one of 5 great modern techniques of manufacture for this Japan Tip Technology Research board it, the international production project learns (CIRP) its determination is one of 21st century central research directions. In the passenger vehicle industry domain, yearly produces 300,000 production metres was 40/s, moreover the multi-variety processing is one of key questions which the passenger vehicle equipment must solve; In the aviation and the astronavigation industry domain, its processing spare part many for the thin wall and the thin muscle, the rigidity is very bad, material for aluminum or aluminum alloy, only then in the high cutting speed and the cutting force very small situation, can to these muscles, the wall carry on the processing. Recently uses the large-scale overall aluminum alloy semifinished materials “pull out spatially” the method to make the wing, the fuselage and so on the large-scale components substitutes many components through the multitudinous rivets, the bolt and other joint way assembling, causes the component the intensity, the rigidity and the reliability obtains the enhancement. These all to processed the equipment to propose high speed, Gao Jing and the high flexible request. Unfolds from EMO2001 meets the situation to look that, processes the center feed rate to be possible high speed to reach 80m/min, even higher, the aerial transport stroke speed may reach 100m/About min. At present in the world many automotive factories, including our country's Shanghai General Motors, already used by the high speed processing center composition production line part substitution aggregate machine-tool. American CINCINNATI Corporation's HyperMach engine bed feed rate reaches 60m/most greatlymin, fast is 100m/min, the acceleration reaches 2g, the main axle rotational speed has reached 60 000r/min. Processes a thin wall airplane part, only uses 30min, but the same components need 3h in the common high speed milling machine processing, needs 8h in the plain milling machine processing; The German DMG Corporation's double main axle lathe main axle speed and the acceleration respectively reach 12*! 000r/mm 和 1g。 In the processing precision aspect, in the recent 10 years, the ordinary level numerical control engine bed processing precision from 10μm enhanced 5μm, the fine level of secrecy processing center from 3~5 μm, enhances to 1~1.5 μm, and the ultra precise processing precision started to enter a nanometer level (0.01μm). In the reliable aspect, the overseas numerical control installment value has reached above 6 000h, the servosystem value achieved above 30000h, displays the extremely high reliability. In order to realize, the high precision work high speed, with it necessary function part like electricity main axle, the straight line electrical machinery obtained the fast development, the application domain further expanded. 1.2 5 axis linkage processing and compound processing engine bed fast development Uses 5 axis linkages to the three dimensional curved surface components processing, the available cutting tool best geometry shape carries on the cutting, not only the smooth finish is high, moreover the efficiency also large scale enhances. Believed generally that, 1 5 axis
linkage engine bed efficiency may be equal to 2 3 axis linkage engine bed, specially uses when the cubic boron nitride and so on the ultra hard material milling cutter carries on the high speed milling hardened steel components, 5 axis linkage processing may compared to 3 axis linkage processing display a higher benefit. Because but past 5 axis linkage numerical control system, main engine structure complex and so on reasons, its price must outdo the several fold compared to 3 axis linkage numerical control engine bed, added the programming technology difficulty to be big, has restricted 5 axis linkage engine bed development. Current as a result of electricity main axle appearance, causes to realize 5 axis linkage processing compound host axle neck structure is greatly the simplification, its manufacture difficulty and the cost reduce large scale, numerical control system price disparity reduction. Therefore promoted the compound host axle neck type 5 axis linkage engine bed and the compound processing engine bed (including 5 processing engine beds) development. Unfolds at the meeting in EMO2001, the new Japanese labor machine 5 processing engine beds use the compound host axle neck, may realize 4 vertical plane processings and the random angle processing, causes 5 processings and 5 axis processings may realize on the identical Taiwan engine bed, but also may realize the inclined plane and the back taper hole processing. German DMG Corporation displays the DMUVoution series processing center, may clamp the next 5 processings and 5 axis linkage processing in an attire, may by the CNC systems or CAD/CAM which are controled deract or inderact. 1.3 intellectualizations, open style, the network becomes the contemporary numerical control system development the main tendency The 21st century numerical control equipments will be has certain intellectualized system, the intellectualized content including in numerical control system each aspect: In order to pursue the processing efficiency and the processing quality aspect intellectualization, like processing process adaptive control, craft parameter automatic production; In order to enhance the actuation performance and the use connection convenient intellectualization, like feed-forward control, electrical machinery parameter auto-adapted operation, automatic diagnosis load automatic designation model, self regulating grade; Simplification programming, simplification operation aspect intellectualization, like intellectualized automatic programming, intellectualized man-machine contact surface and so on; Also has the intelligence to diagnose, the intelligent monitoring aspect content, the convenience system diagnosis and the service and so on. In order to solve the traditional numerical control system closeness and the numerical control application software industrial production production existence question. At present many countries conduct the research to the open style numerical control system, like US NGC(The Next Generation Work-Station/Machine Control)、European Economic Community OSACA(Open System Architecture for Control within Automation Systems) 、 Japanese OSEC(Open System Environment for Controller),Chinese ONC(Open Numerical Control System) and so on。The numerical control system will open already becomes the numerical control system road of the future. The so-called open style numerical control system is the numerical control system development may in the unified movement platform, face the engine bed factory and the end-user, through the change, the increase or the tailor structure object (numerical control function), forms the seriation, and may conveniently integrates user's special application and the technical knack in the control system, the fast realization different variety,
the different scale open style numerical control system, forms has the bright individuality famous brand goods. At present the open style numerical control system architecture standard, the correspondence standard, the disposition standard, the movement platform, the numerical control system function storehouse as well as the numerical control system function software development kit and so on is the current research core. The network numerical control equipment is a near two year international famous engine bed exposition new luminescent spot. The numerical control equipment network enormously will satisfy the production line, the manufacture system, the manufacture enterprise to the information integration demand, also will be realizes new manufacture pattern like agile manufacture, hypothesized enterprise, the global manufacture foundation unit. The domestic and foreign some famous numerical control engine bed and the numerical control system manufacture company all has promoted the related new concept and the prototype in the nearly two years. 1.4 takes the new technical standard, the standard establishment 1.4.1 about numerical control system design development standard As mentioned above, the open style numerical control system has a better versatility, the flexibility, the compatibility, the extension, countries and so on US, European Economic Community and Japan implements the strategy development plan in abundance, and carries on the open style architecture numerical control system specification (OMAC, OSACA, OSEC) the research and the formulation, the world 3 biggest economies have carried on the nearly same science plan and the standard formulation in the short-term, has indicated a numerical control technology new transformation time oncoming. Our country also started in 2000 to conduct China's ONC numerical control system standard frame research and the formulation. 1.4.2 about numerical control standard The numerical control standard is the manufacturing industry informationization development one tendency. The numerical control technology is born after 50 year exchanges of information all is based on the ISO6983 standard, how namely uses the G, M code to describe the (how) processing, its substantive characteristics faces the processing process, obviously, he has more and more not been able to satisfy modern numerical control technology high speed the need to develop. Therefore, on international is studying and formulates one kind of new CNC system standard ISO14649(STEP-NC), its goal is provides one kind not to rely on the concrete system neutral mechanism, can describe in the product entire life cycle unified data model, thus realizes the entire manufacture process, and even each industry domain product information standardization. The STEP-NC appearance is possibly a numerical control area of technology revolution, regarding the numerical control technology development and even the entire manufacturing industry, will have the profound influence. First, STEP-NC proposed one kind of brand-new manufacture idea, in the traditional manufacture idea, the NC processing procedure all concentrates on the single computer. But under the new standard, the NC procedure may disperse on the Internet, this is precisely the numerical control technology open style, the network development direction. Next, the STEP-NC numerical control system also may reduce the processing blueprint greatly (approximately 75%), the processing programming time (approximately 35%) and the process period (approximately 50%). At present, the European and American countries extremely took STEP-NC the research, Europe initiate STEP-NC IMS to plan (1999.1.1~2001.12.31). Participates in this plan to have
comes from European and Japan's 20 CAD/CAM/CAPP/CNC user, manufacturer and academic organization. US's STEP Tools Corporation is in the global scope the manufacturing industry data exchange software exploiter, he already developed has served as the numerical control engine bed processing exchange of information the super model (Super Model), its goal was with the unification standard description all processing process. At present this kind of recent data exchange form already in has provided SIEMENS, FIDIA as well as on the European OSACA-NC numerical control system prototype prototype has carried on the confirmation.
數(shù)控技術和裝備發(fā)展趨勢
裝備工業(yè)的技術水平和現(xiàn)代化程度決定著整個國民經濟的水平和現(xiàn)代化程度, 數(shù)控技 術及裝備是發(fā)展新興高新技術產業(yè)和尖端工業(yè) (如信息技術及其產業(yè)、 生物技術及其產業(yè)、 航空、航天等國防工業(yè)產業(yè))的使能技術和最基本的裝備。馬克思曾經說過“各種經濟時 代的區(qū)別,不在于生產什么,而在于怎樣生產,用什么勞動資料生產”。制造技術和裝備 就是人類生產活動的最基本的生產資料, 而數(shù)控技術又是當今先進制造技術和裝備最核心 的技術。當今世界各國制造業(yè)廣泛采用數(shù)控技術,以提高制造能力和水平,提高對動態(tài)多 變市場的適應能力和競爭能力。 此外世界上各工業(yè)發(fā)達國家還將數(shù)控技術及數(shù)控裝備列為 國家的戰(zhàn)略物資, 不僅采取重大措施來發(fā)展自己的數(shù)控技術及其產業(yè), 而且在“高精尖” 數(shù)控關鍵技術和裝備方面對我國實行封鎖和限制政策。 總之, 大力發(fā)展以數(shù)控技術為核心 的先進制造技術已成為世界各發(fā)達國家加速經濟發(fā)展、 提高綜合國力和國家地位的重要途 徑。 數(shù)控技術是用數(shù)字信息對機械運動和工作過程進行控制的技術, 數(shù)控裝備是以數(shù)控技 術為代表的新技術對傳統(tǒng)制造產業(yè)和新興制造業(yè)的滲透形成的機電一體化產品, 即所謂的 數(shù)字化裝備,其技術范圍覆蓋很多領域:(1)機械制造技術;(2)信息處理、加工、傳輸技 術;(3)自動控制技術;(4)伺服驅動技術;(5)傳感器技術;(6)軟件技術等。
1、 數(shù)控技術的發(fā)展趨勢
數(shù)控技術的應用不但給傳統(tǒng)制造業(yè)帶來了革命性的變化,使制造業(yè)成為工業(yè)化的象 征, 而且隨著數(shù)控技術的不斷發(fā)展和應用領域的擴大, 他對國計民生的一些重要行業(yè) (IT、 汽車、輕工、醫(yī)療等)的發(fā)展起著越來越重要的作用,因為這些行業(yè)所需裝備的數(shù)字化已 是現(xiàn)代發(fā)展的大趨勢。 從目前世界上數(shù)控技術及其裝備發(fā)展的趨勢來看, 其主要研究熱點 有以下幾個方面[1~4]。
1.1 高速、高精加工技術及裝備的新趨勢
效率、質量是先進制造技術的主體。高速、高精加工技術可極大地提高效率,提高產 品的質量和檔次, 縮短生產周期和提高市場競爭能力。 為此日本先端技術研究會將其列為 5 大現(xiàn)代制造技術之一,國際生產工程學會(CIRP)將其確定為 21 世紀的中心研究方向 之一。 在轎車工業(yè)領域,年產 30 萬輛的生產節(jié)拍是 40 秒/輛,而且多品種加工是轎車裝備 必須解決的重點問題之一;在航空和宇航工業(yè)領域,其加工的零部件多為薄壁和薄筋,剛 度很差,材料為鋁或鋁合金,只有在高切削速度和切削力很小的情況下,才能對這些筋、 壁進行加工。 近來采用大型整體鋁合金坯料“掏空”的方法來制造機翼、 機身等大型零件 來替代多個零件通過眾多的鉚釘、螺釘和其他聯(lián)結方式拼裝,使構件的強度、剛度和可靠 性得到提高。這些都對加工裝備提出了高速、高精和高柔性的要求。 從 EMO2001 展會情況來看,高速加工中心進給速度可達 80m/min,甚至更高,空運行 速度可達 100m/min 左右。目前世界上許多汽車廠,包括我國的上海通用汽車公司,已經
采用以高速加工中心組成的生產線部分替代組合機床。 美國 CINCINNATI 公司的 HyperMach 機床進給速度最大達 60m/min, 快速為 100m/min, 加速度達 2g, 主軸轉速已達 60 000r/min。 加工一薄壁飛機零件,只用 30min,而同樣的零件在一般高速銑床加工需 3h,在普通銑床 加工需 8h;德國 DMG 公司的雙主軸車床的主軸速度及加速度分別達 12*!000r/mm 和 1g。 在加工精度方面,近 10 年來,普通級數(shù)控機床的加工精度已由 10μm 提高到 5μm, 精密級加工中心則從 3~5μm,提高到 1~1.5μm,并且超精密加工精度已開始進入納米 級(0.01μm)。 在可靠性方面,國外數(shù)控裝置的 MTBF 值已達 6000h 以上,伺服系統(tǒng)的 MTBF 值達到 30000h 以上,表現(xiàn)出非常高的可靠性。 為了實現(xiàn)高速、高精加工,與之配套的功能部件如電主軸、直線電機得到了快速的發(fā)展, 應用領域進一步擴大。
1.2 五軸聯(lián)動加工和復合加工機床快速發(fā)展
采用 5 軸聯(lián)動對三維曲面零件的加工, 可用刀具最佳幾何形狀進行切削, 不僅光潔度 高,而且效率也大幅度提高。一般認為,1 臺 5 軸聯(lián)動機床的效率可以等于 2 臺 3 軸聯(lián)動 機床,特別是使用立方氮化硼等超硬材料銑刀進行高速銑削淬硬鋼零件時,5 軸聯(lián)動加工 可比 3 軸聯(lián)動加工發(fā)揮更高的效益。但過去因 5 軸聯(lián)動數(shù)控系統(tǒng)、主機結構復雜等原因, 其價格要比 3 軸聯(lián)動數(shù)控機床高出數(shù)倍, 加之編程技術難度較大, 制約了 5 軸聯(lián)動機床的 發(fā)展。 當前由于電主軸的出現(xiàn), 使得實現(xiàn) 5 軸聯(lián)動加工的復合主軸頭結構大為簡化, 其制造 難度和成本大幅度降低, 數(shù)控系統(tǒng)的價格差距縮小。 因此促進了復合主軸頭類型 5 軸聯(lián)動 機床和復合加工機床(含 5 面加工機床)的發(fā)展。 在 EMO2001 展會上, 新日本工機的 5 面加工機床采用復合主軸頭, 可實現(xiàn) 4 個垂直平 面的加工和任意角度的加工, 使得 5 面加工和 5 軸加工可在同一臺機床上實現(xiàn), 還可實現(xiàn) 傾斜面和倒錐孔的加工。德國 DMG 公司展出 DMUVoution 系列加工中心,可在一次裝夾下 5 面加工和 5 軸聯(lián)動加工,可由 CNC 系統(tǒng)控制或 CAD/CAM 直接或間接控制。
1.3 智能化、開放式、網絡化成為當代數(shù)控系統(tǒng)發(fā)展的主要趨勢。
21世紀的數(shù)控裝備將是具有一定智能化的系統(tǒng), 智能化的內容包括在數(shù)控系統(tǒng)中的各 個方面:為追求加工效率和加工質量方面的智能化,如加工過程的自適應控制,工藝參數(shù) 自動生成;為提高驅動性能及使用連接方便的智能化,如前饋控制、電機參數(shù)的自適應運 算、自動識別負載自動選定模型、自整定等;簡化編程、簡化操作方面的智能化,如智能 化的自動編程、智能化的人機界面等;還有智能診斷、智能監(jiān)控方面的內容、方便系統(tǒng)的 診斷及維修等。 為解決傳統(tǒng)的數(shù)控系統(tǒng)封閉性和數(shù)控應用軟件的產業(yè)化生產存在的問題。 目前許多國 家對開放式數(shù)控系統(tǒng)進行研究, 如美國的NGC(未來的工作站/ 機器控制)、 歐共體的OSACA、 日本的OSEC,中國的ONC等。數(shù)控系統(tǒng)開放化已經成為數(shù)控系統(tǒng)的未來之路。所謂開放式 數(shù)控系統(tǒng)就是數(shù)控系統(tǒng)的開發(fā)可以在統(tǒng)一的運行平臺上, 面向機床廠家和最終用戶, 通過 改變、增加或剪裁結構對象(數(shù)控功能) ,形成系列化,并可方便地將用戶的特殊應用和 技術訣竅集成到控制系統(tǒng)中,快速實現(xiàn)不同品種、不同檔次的開放式數(shù)控系統(tǒng),形成具有 鮮明個性的名牌產品。目前開放式數(shù)控系統(tǒng)的體系結構規(guī)范、通信規(guī)范、配置規(guī)范、運行 平臺、數(shù)控系統(tǒng)功能庫以及數(shù)控系統(tǒng)功能軟件開發(fā)工具等是當前研究的核心。 網絡化數(shù)控裝備是近兩年國際著名機床博覽會的一個新亮點。 數(shù)控裝備的網絡化將極
大地滿足生產線、制造系統(tǒng)、制造企業(yè)對信息集成的需求,也是實現(xiàn)新的制造模式如敏捷 制造、虛擬企業(yè)、全球制造的基礎單元。國內外一些著名數(shù)控機床和數(shù)控系統(tǒng)制造公司都 在近兩年推出了相關的新概念和樣機,如在EMO2001展中,日本山崎馬扎克(Mazak)公司 展出的“CyberProduction Center”(智能生產控制中心,簡稱CPC);日本大隈(Okuma) 機床公司展出“IT plaza”(信息技術廣場,簡稱IT廣場);德國西門子(Siemens)公司展 出的開放制造環(huán)境,簡稱OME)等,反映了數(shù)控機床加工向網絡化方向發(fā)展的趨勢。
1.4 重視新技術標準、規(guī)范的建立
1.4.1 關于數(shù)控系統(tǒng)設計開發(fā)規(guī)范 如前所述,開放式數(shù)控系統(tǒng)有更好的通用性、柔性、適應性、擴展性,美國、歐共體 和日本等國紛紛實施戰(zhàn)略發(fā)展計劃,并進行開放式體系結構數(shù)控系統(tǒng)規(guī)范(OMAC、OSACA、 OSEC)的研究和制定,世界 3 個最大的經濟體在短期內進行了幾乎相同的科學計劃和規(guī)范 的制定,預示了數(shù)控技術的一個新的變革時期的來臨。我國在 2000 年也開始進行中國的 ONC 數(shù)控系統(tǒng)的規(guī)范框架的研究和制定。 1.4.2 關于數(shù)控標準 數(shù)控標準是制造業(yè)信息化發(fā)展的一種趨勢。數(shù)控技術誕生后的 50 年間的信息交換都 是基于 ISO6983 標準,即采用 G,M 代碼描述如何(how)加工,其本質特征是面向加工過 程,顯然,他已越來越不能滿足現(xiàn)代數(shù)控技術高速發(fā)展的需要。為此,國際上正在研究和 制定一種新的 CNC 系統(tǒng)標準 ISO14649(STEP-NC),其目的是提供一種不依賴于具體系統(tǒng) 的中性機制,能夠描述產品整個生命周期內的統(tǒng)一數(shù)據(jù)模型,從而實現(xiàn)整個制造過程,乃 至各個工業(yè)領域產品信息的標準化。 STEP-NC 的出現(xiàn)可能是數(shù)控技術領域的一次革命, 對于數(shù)控技術的發(fā)展乃至整個制造 業(yè),將產生深遠的影響。首先,STEP-NC 提出一種嶄新的制造理念,傳統(tǒng)的制造理念中, NC 加工程序都集中在單個計算機上。而在新標準下,NC 程序可以分散在互聯(lián)網上,這正 是數(shù)控技術開放式、網絡化發(fā)展的方向。其次,STEP-NC 數(shù)控系統(tǒng)還可大大減少加工圖紙 (約 75%)、加工程序編制時間(約 35%)和加工時間(約 50%)。 目前,歐美國家非常重視 STEP-NC 的研究,歐洲發(fā)起了 STEP-NC 的 IMS 計劃 (1999.1.1~2001.12.31)。 參加這項計劃的有來自歐洲和日本的 20 個 CAD/CAM/CAPP/CNC 用戶、廠商和學術機構。美國的 STEP Tools 公司是全球范圍內制造業(yè)數(shù)據(jù)交換軟件的開 發(fā)者,他已經開發(fā)了用作數(shù)控機床加工信息交換的超級模型(Super Model),其目標是用 統(tǒng)一的規(guī)范描述所有加工過程。 目前這種新的數(shù)據(jù)交換格式已經在配備了 SIEMENS、 FIDIA 以及歐洲 OSACA-NC 數(shù)控系統(tǒng)的原型樣機上進行了驗證。