機加工外文翻譯-高速銑削【中英文WORD】【中文9230字】
機加工外文翻譯-高速銑削【中英文WORD】【中文9230字】,中英文WORD,中文9230字,加工,外文,翻譯,高速,銑削,中英文,WORD,中文,9230
【中文9230字】
高速銑削
高速切削加工是一種先進制造技術，不同于傳統(tǒng)加工方式。它的主軸轉(zhuǎn)速高、切削進給速度高、切削量小，單位時間內(nèi)的材料切除量卻增加3～6 倍。它以高效率、高精度和高表面質(zhì)量為基本特征，在汽車工業(yè)、航空航天、模具制造和儀器儀表等行業(yè)中獲得了廣泛的應用，取得了重大的經(jīng)濟效益，是當代先進制造技術的重要應用。長期以來，人們對模具的加工一直采用銑削一磨削或者電火花(EDM)加工、打磨、拋光的方法。雖然電火花可加工硬度很高的工件，但較低的生產(chǎn)率使它的應用受到制。隨著高速加工技術的發(fā)展，采用高速切削取代磨削拋光和電加工進行模具加工已成為可能。使加工周期大為縮短，加工質(zhì)量得到可靠保證，加工成本降低。
1 高速切削加工的優(yōu)勢
高速切削加工作為模具制造中集高效、優(yōu)質(zhì)、低耗于一身的先進制造技術。在常規(guī)切削加工中備受困擾的一系列問題，通過高速切削加工的應用得到了解決。
1.1 提高生產(chǎn)率
高速切削的主軸轉(zhuǎn)速、進給速度與傳統(tǒng)切削加工相比，發(fā)生了本質(zhì)性的飛躍，其金屬切除率提高了30%~40%，切削力降低了30%，刀具的切削壽命提高了70%。還可加工淬硬零件，許多零件一次裝夾可完成粗、半精和精加工等全部工序，對復雜型面也能達到零件表面質(zhì)量要求，進而提高了加工生產(chǎn)率和產(chǎn)品的市場競爭力。
1.2 改善加工精度和表面質(zhì)量
高速機床普遍具備高剛性和高精度等特點，加工時切削深度小，而進給速度較快，切削力低，工件熱變形減少，而加工精度很高，表面粗糙度很小。高速銑削可獲得無銑痕的加工表面，使零件表面質(zhì)量大大提高。加工鋁合金時可達Ra0.40.6um，加工鋼件時可達Ra0.2～0.4um。
1.3 減少切削產(chǎn)生的熱量
因為銑床主軸高速旋轉(zhuǎn)，切削加工是淺切削，同時進給速度很快，刀刃和工件的接觸長度和接觸時間非常短，減少了刀刃和工件的熱傳導。高速切削采用干銑或油一氣(油霧)潤滑系統(tǒng)，避免了傳統(tǒng)加工時在刀具和工件接觸處產(chǎn)生大量熱的缺點，保證刀具在溫度不高的條件下工作，延長了刀具的使用壽命。
1.4 有利于加工薄壁零件
高速切削時的切削力小，有較高的穩(wěn)定性，可加工高質(zhì)量同本公司內(nèi)部員工相比可能是非常優(yōu)秀的，但是同其他的公司的員工相比工作績效可能算不了優(yōu)秀。就我們中國實際來說，我們使用標桿分析法來確定員工培訓需求是簡單有效的。這種學習標桿對象可以是外部的，也可以是內(nèi)部和外部的結(jié)合。首先要明確企業(yè)的發(fā)展戰(zhàn)略。通過對企業(yè)內(nèi)外部環(huán)境和組織資源等分析，明確企業(yè)未來發(fā)展的目標和業(yè)務重點。根據(jù)企業(yè)的發(fā)展戰(zhàn)略尋找可以比照的標桿企業(yè)，通過比較分析，最后確定標桿企業(yè)。在確定標桿企業(yè)后，有一項，是了解其發(fā)展戰(zhàn)略，還是其市場占有率和市場增長率，還是員工各方面的情況等等，這要根據(jù)本企業(yè)的實際情況來確定。由于企業(yè)在不同的發(fā)展時期，其著力點是不同的，即企業(yè)需要投入的物力人力財力的重點是不同的。所以在一定的時期內(nèi)，企業(yè)要準確地選定其跟標桿企業(yè)比較的部門和崗位，這樣更加具有實際意義，因為標桿企業(yè)并不是處處都好，而且有些方面進行比較沒有多少實際意義，再者這樣可以更充分地集中利用企業(yè)的有限資源。確定標桿企業(yè)后，然后拿本企業(yè)的相應的部門和員工同標桿企業(yè)進行比較，可以發(fā)現(xiàn)兩者在工作績效的差距，比較分析，尋找原因，根據(jù)本企業(yè)的實際，最后確定培訓需求。培訓是需要成本的，如果沒有通過有效的方式，去確定企業(yè)是否需要培訓以及培訓的方式，而是盲目進行培訓，這樣的培訓是難以取得預期的效果。有比較才有區(qū)別，這種培訓分析模型簡單實用。
1.5 可部分替代某些工藝，如電火花加工、磨削加工
高速切削的一大特點，高速切削已可加工硬度達HRC60 的零件。采用帶涂層的硬質(zhì)合金刀具加工模具，直接將淬硬工具鋼一次安裝加工成形，有效地避免了零件多次安裝造成的裝夾誤差，提高了零件的幾何位置精度。在傳統(tǒng)加工模具的工藝中，對熱處理硬化后的工件需進行電火花加工，用高速切削加工替代傳統(tǒng)切削的加工方法，可以省去模具制造工藝中的電火花加工，簡化了加工工藝和投資成本。
高速銑削加工可在專用的CNC 機床或加工中心上進行，也可在加裝高速主軸的普通機床上進行。后者不僅具有普通機床的加工能力，而且還可進行高速銑削，減少了設備投資，增加了機床柔性。高速切削可以使加工效率提高、質(zhì)量提高、工序簡化，機床投資和刀具投資及維護費用上升，但綜合比較，可以顯著提高經(jīng)濟效益。
2 高速銑削加工
高速銑削加工的主要技術高速切削技術是切削加工技術的發(fā)展方向之一，它隨著C N C 技術、微電子技術、新材料和新工藝等技術的發(fā)展而邁上更高的臺階。高速機床和高速刀具是實現(xiàn)高速切削的前提和基本條件，在高速切削加工中對高速機床的性能和刀具材料的選擇有嚴格的要求。
2.1 高速銑削加工機床為了實現(xiàn)高速切削加工
一般采用高柔性的高速數(shù)控機床、加工中心，也有的采用專用的高速銑、鉆床。機床同時具有高速主軸系統(tǒng)和高速進給系統(tǒng)，高的主軸剛度特性，高精度定位功能和高精度插補功能，特別是圓弧高精度插補功能。高速切削加工對機床的工藝系統(tǒng)提出了更高的要求，主要表現(xiàn)在以下幾個方面：
高速銑削機床必須具有高速主軸，主軸的轉(zhuǎn)速10000~100000m/min，功率大于15kW。還應具有快速升速、在指定位置快速準停的性能。主軸的軸向間隙不大于0 .0 0 0 2 m m 。高速主軸常采用液體靜壓軸承式、空氣靜壓軸承式、混合陶瓷軸承、磁懸浮軸承式等結(jié)構形式。主軸冷卻一般采用內(nèi)部水冷或氣冷。
高速加工機床的驅(qū)動系統(tǒng)應能夠提供40～60m/min 的進給速度，具有良好的加速度特性，能夠提供0.4m/s2 到10m/s2的加速度和減速度。為了獲得良好的加工質(zhì)量，高速切削機床必須具有足夠高的剛度。機床床身材料采用灰鑄鐵，還可以在底座中添加高阻尼特性的混凝土，以防止切削時刀具顫振影響加工質(zhì)量。具有高速數(shù)據(jù)傳輸率，能夠自動加減速。加工工藝有利于切削加工和提高刀具壽命。目前高速機床的廠家，通常在普通機床上進行低速、大進給的粗加工，然后進行熱處理，最后在高速機床上進行半精加工和精加工，在提高精度和效率的同時盡可能地降低加工成本。
2.2 高速切削加工刀具
刀具是高速切削加工中最活躍重要的因素之一，它直接影響著加工效率、制造成本和產(chǎn)品的加工精度。刀具在高速加工過程中要承受高溫、高壓、摩擦、沖擊和振動等載荷，因此其硬度和耐磨性、強度和韌性、耐熱性、工藝性能和經(jīng)濟性等基本性能是實現(xiàn)高速加工的關鍵因素之一。高速切削加工的刀具技術發(fā)展速度很快，應用較多的如金剛石(P C D)、立方氮化硼(C B N)）、陶瓷刀具、涂層硬質(zhì)合金、(碳)氮化鈦硬質(zhì)合金T I C (N)等。立方氮化硼具有很高的硬度、極強的耐磨性和良好的導熱性，與鐵族元素之間有很大的惰性，在1300℃也不會發(fā)生顯著的化學作用，還具有良好的穩(wěn)定性。實驗表明，用CBN 刀具切削硬度HRC35～67 的淬火鋼可以達到很高速度。陶瓷材料具有良好的耐磨性和熱化學穩(wěn)定性，其硬度、韌性低于C B N ，可用于加工硬度H R C < 5 0 的零件。硬質(zhì)合金刀具耐磨性好，但硬度比立方氮化硼和陶瓷低。采用刀具涂層技術，可以提高刀具硬度和切削加工的速度，適合切削硬度在HRC40～50 之間的工件?？捎糜谀蜔岷辖?、鈦合金、高溫合金、鑄鐵、純鋼、鋁合金及復合材料的高速切削，應用最為廣泛。精密加工有色金屬或非金屬材料時，選用聚晶金剛石或金剛石涂層刀具。
2.3 高速加工工藝
高速切削的工藝技術也是進行高速切削加工的關鍵。切削方法選擇不當，會使刀具加劇磨損，達不到高速加工的目的。只有高速機床和刀具沒有好的工藝技術指導，高速切削加工設備也不能充分發(fā)揮作用。在高速切削加工中，應盡量選用順銑加工，順銑時刀具切入工件的切屑厚度為最大，隨后逐漸減小。高速切削加工適于淺的切深，切削深度不超過0.2mm，可避免刀具的位置偏差，確保加工零件的幾何精度。保證工件上的切削載荷恒定，以獲得好的加工質(zhì)量。高速切削采用單一路徑順銑切削模式，盡量不中斷切削過程和刀具路徑，減少刀具的切入切出次數(shù)，以獲得相對穩(wěn)定的切削過程。減少刀具的急速換向，在換向時NC機床必須立即停止或降速，再執(zhí)行下一步操作。由于機床的加速度限制，易造成時間浪費，而且急停或急動會破壞表面精度。在模具的高速精加工中，在每次切入、切出工件時，進給方向的改變應盡量采用圓弧或曲線轉(zhuǎn)接，避免采用直線轉(zhuǎn)接，以保持切削過程的平穩(wěn)性。
3 高速銑削在模具加工中的應用
高速銑削作為高效切削加工的新方法，在模具制造中得到了廣泛應用。在常規(guī)生產(chǎn)連桿鍛模時，用電火花加工型腔需12～15h，電極制作2h。改用高速銑削后，采用高速立銑刀對硬度H R C 6 0 的淬硬工具鋼進行加工。整個鍛模加工只需3h20min，工效提高4～5 倍，加工表面粗糙度達Ra0.5～0.6m ，質(zhì)量完全符合要求。
高速切削技術是切削加工技術的主要發(fā)展方向之一，目前主要應用于汽車工業(yè)和模具行業(yè)，尤其是在加工復雜曲面、工件本身或刀具剛性要求較高的加工領域等，是多種先進加工技術的集成，其高效、高質(zhì)量為人們所推崇。它不僅涉及到高速加工工藝，而且還包括高速加工機床、數(shù)控系統(tǒng)、高速切削刀具及C A D / C A M 技術等。模具高速加工技術目前已在發(fā)達國家的模具制造業(yè)中普遍應用，而在我國的應用范圍及應用水平仍有待提高，由于其具有傳統(tǒng)加工無可比擬的優(yōu)勢，仍將是今后加工技術必然的發(fā)展方向。
4 數(shù)控技術和裝備發(fā)展趨勢及對策
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(jīng)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(chǎn)業(yè)和尖端工業(yè)（如信息技術及其產(chǎn)業(yè)、生物技術及其產(chǎn)業(yè)、航空、航天等國防工業(yè)產(chǎn)業(yè)）的使能技術和最基本的裝備。馬克思曾經(jīng)說過“各種經(jīng)濟時代的區(qū)別，不在于生產(chǎn)什么，而在于怎樣生產(chǎn)，用什么勞動資料生產(chǎn)”。制造技術和裝備就是人類生產(chǎn)活動的最基本的生產(chǎn)資料，而數(shù)控技術又是當今先進制造技術和裝備最為核心的技術。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(chǎn)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?？傊罅Πl(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(jīng)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(chǎn)業(yè)和新興制造業(yè)的滲透形成的機電一體化產(chǎn)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(qū)動技術；(5)傳感器技術；(6)軟件技術等。
5 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］。
5.1 高速、高精加工技術及裝備的新趨勢
效率、質(zhì)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(chǎn)品的質(zhì)量和檔次，縮短生產(chǎn)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(chǎn)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(chǎn)30萬輛的生產(chǎn)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(jié)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(jīng)采用以高速加工中心組成的生產(chǎn)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(zhuǎn)速已達60 000r/min。加工一個薄壁飛機零件，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120000r/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6 000h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。
5.2 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(jié)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(jié)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，可在一次裝夾下實現(xiàn)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。
5.3 智能化、開放式、網(wǎng)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(nèi)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(zhì)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(qū)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(nèi)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(chǎn)業(yè)化生產(chǎn)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(The Next Generation Work-Station/Machine Control)、歐共體的OSACA(Open System Architecture for Control within Automation Systems)、日本的OSEC(Open System Environment for Controller)，中國的ONC(Open Numerical Control System)等。數(shù)控系統(tǒng)開放化已經(jīng)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(jié)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(chǎn)品。目前開放式數(shù)控系統(tǒng)的體系結(jié)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(wǎng)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(wǎng)絡化將極大地滿足生產(chǎn)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(nèi)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(chǎn)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Open Manufacturing Environment（開放制造環(huán)境，簡稱OME）等，反映了數(shù)控機床加工向網(wǎng)絡化方向發(fā)展的趨勢。
5.4 重視新技術標準、規(guī)范的建立
5.4.1 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(jié)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(jīng)濟體在短期內(nèi)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。
5.4.2 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(zhì)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(chǎn)品整個生命周期內(nèi)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(chǎn)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(chǎn)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(wǎng)上，這正是數(shù)控技術開放式、網(wǎng)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(nèi)制造業(yè)數(shù)據(jù)交換軟件的開發(fā)者，他已經(jīng)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(jīng)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。
6 對我國數(shù)控技術及其產(chǎn)業(yè)發(fā)展的基本估計
我國數(shù)控技術起步于1958年，近50年的發(fā)展歷程大致可分為3個階段：第一階段從1958年到1979年，即封閉式發(fā)展階段。在此階段，由于國外的技術封鎖和我國的基礎條件的限制，數(shù)控技術的發(fā)展較為緩慢。第二階段是在國家的“六五”、“七五”期間以及“八五”的前期，即引進技術，消化吸收，初步建立起國產(chǎn)化體系階段。在此階段，由于改革開放和國家的重視，以及研究開發(fā)環(huán)境和國際環(huán)境的改善，我國數(shù)控技術的研究、開發(fā)以及在產(chǎn)品的國產(chǎn)化方面都取得了長足的進步。第三階段是在國家的“八五”的后期和“九五”期間，即實施產(chǎn)業(yè)化的研究，進入市場競爭階段。在此階段，我國國產(chǎn)數(shù)控裝備的產(chǎn)業(yè)化取得了實質(zhì)性進步。在“九五”末期，國產(chǎn)數(shù)控機床的國內(nèi)市場占有率達50％，配國產(chǎn)數(shù)控系統(tǒng)（普及型）也達到了10％。
縱觀我國數(shù)控技術近50年的發(fā)展歷程，特別是經(jīng)過4個5年計劃的攻關，總體來看取得了以下成績。
a. 奠定了數(shù)控技術發(fā)展的基礎，基本掌握了現(xiàn)代數(shù)控技術。我國現(xiàn)在已基本掌握了從數(shù)控系統(tǒng)、伺服驅(qū)動、數(shù)控主機、專機及其配套件的基礎技術，其中大部分技術已具備進行商品化開發(fā)的基礎，部分技術已商品化、產(chǎn)業(yè)化。
b. 初步形成了數(shù)控產(chǎn)業(yè)基地。在攻關成果和部分技術商品化的基礎上，建立了諸如華中數(shù)控、航天數(shù)控等具有批量生產(chǎn)能力的數(shù)控系統(tǒng)生產(chǎn)廠。蘭州電機廠、華中數(shù)控等一批伺服系統(tǒng)和伺服電機生產(chǎn)廠以及北京第一機床廠、濟南第一機床廠等若干數(shù)控主機生產(chǎn)廠。這些生產(chǎn)廠基本形成了我國的數(shù)控產(chǎn)業(yè)基地。
c. 建立了一支數(shù)控研究、開發(fā)、管理人才的基本隊伍。
雖然在數(shù)控技術的研究開發(fā)以及產(chǎn)業(yè)化方面取得了長足的進步，但我們也要清醒地認識到，我國高端數(shù)控技術的研究開發(fā)，尤其是在產(chǎn)業(yè)化方面的技術水平現(xiàn)狀與我國的現(xiàn)實需求還有較大的差距。雖然從縱向看我國的發(fā)展速度很快，但橫向比（與國外對比）不僅技術水平有差距，在某些方面發(fā)展速度也有差距，即一些高精尖的數(shù)控裝備的技術水平差距有擴大趨勢。從國際上來看，對我國數(shù)控技術水平和產(chǎn)業(yè)化水平估計大致如下。
a. 技術水平上，與國外先進水平大約落后10～15年，在高精尖技術方面則更大。
b. 產(chǎn)業(yè)化水平上，市場占有率低，品種覆蓋率小，還沒有形成規(guī)模生產(chǎn)；功能部件專業(yè)化生產(chǎn)水平及成套能力較低；外觀質(zhì)量相對差；可靠性不高，商品化程度不足；國產(chǎn)數(shù)控系統(tǒng)尚未建立自己的品牌效應，用戶信心不足。
c. 可持續(xù)發(fā)展的能力上，對競爭前數(shù)控技術的研究開發(fā)、工程化能力較弱；數(shù)控技術應用領域拓展力度不強；相關標準規(guī)范的研究、制定滯后。
分析存在上述差距的主要原因有以下幾個方面。
a. 認識方面。對國產(chǎn)數(shù)控產(chǎn)業(yè)進程艱巨性、復雜性和長期性的特點認識不足；對市場的不規(guī)范、國外的封鎖加扼殺、體制等困難估計不足；對我國數(shù)控技術應用水平及能力分析不夠。
b. 體系方面。從技術的角度關注數(shù)控產(chǎn)業(yè)化問題的時候多，從系統(tǒng)的、產(chǎn)業(yè)鏈的角度綜合考慮數(shù)控產(chǎn)業(yè)化問題的時候少；沒有建立完整的高質(zhì)量的配套體系、完善的培訓、服務網(wǎng)絡等支撐體系。
c. 機制方面。不良機制造成人才流失，又制約了技術及技術路線創(chuàng)新、產(chǎn)品創(chuàng)新，且制約了規(guī)劃的有效實施，往往規(guī)劃理想，實施困難。
d. 技術方面。企業(yè)在技術方面自主創(chuàng)新能力不強，核心技術的工程化能力不強。機床標準落后，水平較低，數(shù)控系統(tǒng)新標準研究不夠。
7 對我國數(shù)控技術和產(chǎn)業(yè)化發(fā)展的戰(zhàn)略思考
7.1 戰(zhàn)略考慮
我國是制造大國，在世界產(chǎn)業(yè)轉(zhuǎn)移中要盡量接受前端而不是后端的轉(zhuǎn)移，即要掌握先進制造核心技術，否則在新一輪國際產(chǎn)業(yè)結(jié)構調(diào)整中，我國制造業(yè)將進一步“空芯”。我們以資源、環(huán)境、市場為代價，交換得到的可能僅僅是世界新經(jīng)濟格局中的國際“加工中心”和“組裝中心”，而非掌握核心技術的制造中心的地位，這樣將會嚴重影響我國現(xiàn)代制造業(yè)的發(fā)展進程。
我們應站在國家安全戰(zhàn)略的高度來重視數(shù)控技術和產(chǎn)業(yè)問題，首先從社會安全看，因為制造業(yè)是我國就業(yè)人口最多的行業(yè)，制造業(yè)發(fā)展不僅可提高人民的生活水平，而且還可緩解我國就業(yè)的壓力，保障社會的穩(wěn)定；其次從國防安全看，西方發(fā)達國家把高精尖數(shù)控產(chǎn)品都列為國家的戰(zhàn)略物質(zhì)，對我國實現(xiàn)禁運和限制，“東芝事件”和“考克斯報告”就是最好的例證。
7.2 發(fā)展策略
從我國基本國情的角度出發(fā)，以國家的戰(zhàn)略需求和國民經(jīng)濟的市場需求為導向，以提高我國制造裝備業(yè)綜合競爭能力和產(chǎn)業(yè)化水平為目標，用系統(tǒng)的方法，選擇能夠主導21世紀初期我國制造裝備業(yè)發(fā)展升級的關鍵技術以及支持產(chǎn)業(yè)化發(fā)展的支撐技術、配套技術作為研究開發(fā)的內(nèi)容，實現(xiàn)制造裝備業(yè)的跨躍式發(fā)展。
強調(diào)市場需求為導向，即以數(shù)控終端產(chǎn)品為主，以整機（如量大面廣的數(shù)控車床、銑床、高速高精高性能數(shù)控機床、典型數(shù)字化機械、重點行業(yè)關鍵設備等）帶動數(shù)控產(chǎn)業(yè)的發(fā)展。重點解決數(shù)控系統(tǒng)和相關功能部件（數(shù)字化伺服系統(tǒng)與電機、高速電主軸系統(tǒng)和新型裝備的附件等）的可靠性和生產(chǎn)規(guī)模問題。沒有規(guī)模就不會有高可靠性的產(chǎn)品；沒有規(guī)模就不會有價格低廉而富有競爭力的產(chǎn)品；當然，沒有規(guī)模中國的數(shù)控裝備最終難以有出頭之日。
在高精尖裝備研發(fā)方面，要強調(diào)產(chǎn)、學、研以及最終用戶的緊密結(jié)合，以“做得出、用得上、賣得掉”為目標，按國家意志實施攻關，以解決國家之急需。
在競爭前數(shù)控技術方面，強調(diào)創(chuàng)新，強調(diào)研究開發(fā)具有自主知識產(chǎn)權的技術和產(chǎn)品，為我國數(shù)控產(chǎn)業(yè)、裝備制造業(yè)乃至整個制造業(yè)的可持續(xù)發(fā)展奠定基礎。
英文資料
High-speed milling
High-speed machining is an advanced manufacturing technology, different from the traditional processing methods. The spindle speed, cutting feed rate, cutting a small amount of units within the time of removal of material has increased three to six times. With high efficiency, high precision and high quality surface as the basic characteristics of the automobile industry, aerospace, mold manufacturing and instrumentation industry, such as access to a wide range of applications, has made significant economic benefits, is the contemporary importance of advanced manufacturing technology. For a long time, people die on the processing has been using a grinding or milling EDM (EDM) processing, grinding, polishing methods. Although the high hardness of the EDM machine parts, but the lower the productivity of its application is limited. With the development of high-speed processing technology, used to replace high-speed cutting, grinding and polishing process to die processing has become possible. To shorten the processing cycle, processing and reliable quality assurance, lower processing costs.
1 One of the advantages of high-speed machining
High-speed machining as a die-efficient manufacturing, high-quality, low power consumption in an advanced manufacturing technology. In conventional machining in a series of problems has plagued by high-speed machining of the application have been resolved.
1.1 Increase productivity
High-speed cutting of the spindle speed, feed rate compared withtraditional machining, in the nature of the leap, the metal removal rate increased 30 percent to 40 percent, cutting force reduced by 30 percent, the cutting tool life increased by 70% . Hardened parts can be processed, a fixture in many parts to be completed rough, semi-finishing and fine, and all other processes, the complex can reach parts of the surface quality requirements, thus increasing the processing productivity and competitiveness of products in the market.
1.2 Improve processing accuracy and surface quality
High-speed machines generally have high rigidity and precision, and other characteristics, processing, cutting the depth of small, fast and feed, cutting force low, the workpiece to reduce heat distortion, and high precision machining, surface roughness small. Milling will be no high-speed processing and milling marks the surface so that the parts greatly enhance the quality of the surface. Processing Aluminum when up Ra0.40.6um, pieces of steel processing at up to Ra0.2 ~ 0.4um.
1.3 Cutting reduce the heat
Because the main axis milling machine high-speed rotation, cutting a shallow cutting, and feed very quickly, and the blade length of the workpiece contacts and contact time is very short, a decrease of blades and parts of the heat conduction. High-speed cutting by dry milling or oil cooked up absolute (mist) lubrication system, to avoid the traditional processing tool in contact with the workpiece and a lot of shortcomings to ensure that the tool is not high temperature under the conditions of work, extended tool life.
1.4 This is conducive to processing thin-walled parts
High-speed cutting of small cutting force, a higher degree of stability, Machinable with high-quality employees compared to the company may be very good, but other than the company's employees may Suanbu Le outstanding work performance. For our China practice, we use the models to determine the method of staff training needs are simple and effective. This study models can be an external object, it can also be a combination of internal and external. We must first clear strategy for the development of enterprises. Through the internal and external business environment and organizational resources, such as analysis, the future development of a clear business goals and operational priorities. According to the business development strategy can be compared to find the business models, through a comparative analysis of the finalization of business models. In determining business models, a, is the understanding of its development strategy, or its market share and market growth rate, or the staff of the situation, and so on, according to the companies to determine the actual situation. As enterprises in different period of development, its focus is different, which means that enterprises need to invest the manpower and financial resources the focus is different. So in a certain period of time, enterprises should accurately selected their business models compared with the departments and posts, so more practical significance, because the business models are not always good, but to compare some aspects did not have much practical significance, Furthermore This can more fully concentrate on the business use of limited resources. Identify business models, and then take the enterprise of the corresponding departments and staff with the business models for comparison, the two can be found in the performance gap, a comparative analysis to find reasons, in accordance with this business reality, the final identification of training needs. The cost of training is needed, if not through an effective way to determine whether companies need to train and the training of the way, but blind to training, such training is difficult to achieve the desired results. A comparison only difference between this model is simple and practical training.
1.5 Can be part of some alternative technology, such as EDM, grinding high intensity and high hardness processing
High-speed cutting a major feature of high-speed cutting machine has the hardness of HRC60 parts. With the use of coated carbide cutter mold processing, directly to the installation of a hardened tool steel processing forming, effectively avoid the installation of several parts of the fixture error and improve the parts of the geometric location accuracy. In the mold of traditional processing, heat treatment hardening of the workpiece required EDM, high-speed machining replace the traditional method of cutting the processing, manufacturing process possible to omit die in EDM, simplifying the processing technology and investment costs .
High-speed milling in the precincts of CNC machine tools, or for processing centre, also in the installation of high-speed spindle on the general machine tools. The latter not only has the processing capacity of general machine tools, but also for high-speed milling, a decrease of investment in equipment, machine tools increased flexibility. Cutting high-speed processing can improve the efficiency, quality improvement, streamline processes, investment and machine tool investment and maintenance costs rise, but comprehensive, can significantly increase economic efficiency.
2 High-speed milling
High-speed milling the main technical high-speed cutting technology is cutting the development direction of one of it with CNC technology, microelectronic technology, new materials and new technology, such as technology development to a higher level. High-speed machine tools and high-speed tool to achieve high-speed cutting is the prerequisite and basic conditions, in high-speed machining in the performance of high-speed machine tool material of choice and there are strict requirements.
2.1 High-speed milling machine in order to achieve high-speed machining
General use of highly flexible high-speed CNC machine tools, machining centers, and some use a dedicated high-speed milling, drilling. At the same time a high-speed machine tool spindle system and high-speed feeding system, high stiffness of the main characteristics of high-precision targeting and high-precision interpolation functions, especially high-precision arc interpolation function. High-speed machining systems of the machine a higher demand, mainly in the following areas:
General use of highly flexible high-speed CNC machine tools, machining centers, and some use a dedicated high-speed milling, drilling. At the same time a high-speed machine tool spindle system and high-speed feeding system, high stiffness of the main characteristics of high-precision targeting and high-precision interpolation functions, especially high-precision arc interpolation function. High-speed machining systems of the machine a higher demand, mainly in the following areas:
High-speed milling machine must have a high-speed spindle, the spindle speed is generally 10000 ~ 100000 m / min, power greater than 15 kW. But also with rapid speed or in designated spots fast-stopping performance. The main axial space not more than 0 .0 0 0 2 m m. Often using high-speed spindle-hydrostatic bearings, air pressure-bearing, mixed ceramic bearings, magnetic bearing structure of the form. Spindle cooling general use within the water or air cooled.
High-speed processing machine-driven system should be able to provide 40 ~ 60 m / min of the feed rate, with good acceleration characteristics, can provide 0.4 m/s2 to 10 m/s2 acceleration and deceleration. In order to obtain good processing quality, high-speed cutting machines must have a high enough stiffness. Machine bed material used gray iron, can also add a high-damping base of concrete, to prevent cutting tool chatter affect the quality of processing. A high-speed data transfer rate, can automatically increase slowdown. Processing technology to improve the processing and cutting tool life. At present high-speed machine tool manufacturers, usually in the general machine tools on low speed, the feed of the rough and then proceed to heat treatment, the last in the high-speed machine on the half-finished and finished, in improving the accuracy and efficiency at the same time, as far as possible to reduce processing Cost.
2.2 High-speed machining tool
High-speed machining tool is the most active one of the important factors, it has a direct impact on the efficiency of processing, manufacturing costs and product processing and accuracy. Tool in high-speed processing to bear high temperature, high pressure, friction, shock and vibration, such as loading, its hardness and wear-resistance, strength and toughness, heat resistance, technology and economic performance of the basic high-speed processing performance is the key One of the factors. High-speed cutting tool technology development speed, the more applications such as diamond (PCD), cubic boron nitride (CBN), ceramic knives, carbide coating, (C) titanium nitride Carbide TIC (N) And so on. CBN has high hardness, abrasion resistance and the extremely good thermal conductivity, and iron group elements between the great inertia, in 1300 ℃ would not have happened significant role in the chemical, also has a good stability. The experiments show that with CBN cutting tool
HRC35 ~ 67 hardness of hardened steel can achieve very high speed. Ceramics have good wear resistance and thermal chemical stability, its hardness, toughness below the CBN, can be used for processing hardness of HRC <5 0 parts. Carbide Tool good wear resistance, but the hardness than the low-CBN and ceramics. Coating technology used knives, cutting tools can improve hardness and cutting the rate, for cutting HRC40 ~ 50 in hardness between the workpiece. Can be used to heat-resistant alloys, titanium alloys, hightemperature alloy, cast iron, Chungang, aluminum and composite materials of high-speed cutting Cut, the most widely used. Precision machining non-ferrous metals or non-metallic materials, or the choice of polycrystalline diamond Gang-coated tool.
2.3 High-speed processing technology
High-speed cutting technology for high-speed machining is the key. Cutting Methods misconduct, will increase wear tool to less than high-speed processing purposes. Only high-speed machine tool and not a good guide technology, high-speed machining equipment can not fully play its role. In high-speed machining, should be chosen with milling, when the milling cutter involvement with the workpiece chip thickness as the greatest, and then gradually decreased. High-speed machining suitable for shallow depth of cut, cutting depth of not more than 0.2 mm, to avoid the location of deviation tool to ensure that the geometric precision machining parts. Ensure that the workpiece on the cutting constant load, to get good processing quality. Cutting a single high-speed milling path-cutting mode, try not to interrupt the process and cutting tool path, reducing the involvement tool to cut the number to be relatively stable cutting process. Tool to reduce the rapid change to, in other words when the NC machine tools must cease immediately, or Jiangsu, and then implement the next step. As the machine tool acceleration restrictions, easy to cause a waste of time, and exigency stop or radical move would damage the surface accuracy. In the mold of high-speed finishing, in each Cut, cut to the workpiece, the feed should try to change the direction of a curve or arc adapter, avoid a straight line adapter to maintain the smooth process of cutting.
3 Die in high-speed milling processing of
Milling as a highly efficient high-speed cutting of the new method,in
Mould Manufacturing has been widely used. Forging links in the regular production model, with EDM cavity to be 12 ~ 15 h, electrodes produced 2 h. Milling after the switch to high-speed, high-speed milling cutter on the hardness of HRC 6 0 hardened tool steel processing. The forging die processing only 3 h20min, improve work efficiency four to five times the processing surface roughness of Ra0.5 ~ 0.6m, fully in line with quality requirements.
High-speed cutting technology is cutting technology one of the major developments, mainly used in automobile industry and die industry, particularly in the processing complex surface, the workpiece itself or knives rigid requirements of the higher processing areas, is a range of advanced processing technology The integration, high efficiency and high quality for the people respected. It not only involves high-speed processing technology, but also including high-speed processing machine tools, numerical control system, high-speed cutting tools and CAD / CAM technology. Die-processing technology has been developed in the mold of the manufacturing sector in general, and in my application and the application of the standards have yet to be improved, because of its traditional processing with unparalleled advantages, the future will continue to be an inevitable development of processing technology Direction.
4 Numerical control technology and equipping development trend and countermeasure
Equip the engineering level, level of determining the whole national economy of the modernized degree and modernized degree of industry, numerical control technology is it develop new developing new high-tech industry and most advanced industry to equip (such as information technology and his industry, biotechnology and his industry, aviation, spaceflight, etc. national defense industry) last technology and getting more basic most equipment. Marx has ever said "the differences of different economic times, do not lie in what is produced, and lie in how to produce, produce with some means of labor ". Manufacturing technology and equipping the most basic means of production that are that the mankind produced the activity, and numerical control technology is nowadays advanced manufacturing technology and equips the most central technology. Nowadays the manufacturing industry all around the world adopts numerical control technology extensively, in order to improve manufacturing capacity and level, improve the adaptive capacity and competitive power to the changeable market of the trends. In addition every industrially developed country in the world also classifies the technology and numerical control equipment of numerical control as the strategic materials of the country, not merely take the great measure to develop one's own numerical control technology and industry, and implement blockading and restrictive policy to our country in view of " high-grade, precision and advanced key technology of numerical control " and equipping. In a word, develop the advanced manufacturing technology taking numerical control technology as the core and already become every world developed country and accelerate economic development in a more cost-effective manner, important way to improve the overall national strength and national position.
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..
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 people's 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 equipping the development trend to see, there is the following several respect [1- ] in its main research focus.
5 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 equipping 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
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