0295-活塞的機(jī)械加工工藝設(shè)計(jì)及夾具設(shè)計(jì),活塞,機(jī)械,加工,工藝,設(shè)計(jì),夾具 任務(wù)書(shū) 指導(dǎo)教師 學(xué)生姓名 課題名稱 CA6110型鋁活塞的機(jī)械加工工藝設(shè)計(jì)及夾具設(shè)計(jì) 內(nèi) 容 及 任 務(wù) 本設(shè)計(jì)對(duì)CA6110型鋁活塞的工藝過(guò)程進(jìn)行了全面的闡，內(nèi)容包括：活塞的技術(shù)條件分析，工序的安排，加工余量的確定，切削用量的計(jì)算，設(shè)備、工夾具的選擇，工序時(shí)間的計(jì)算、擬訂，工序卡片的制定。以及對(duì)兩套典型夾具進(jìn)行的分析計(jì)算.本文的重點(diǎn)就是工藝過(guò)程的分析、典型夾具的設(shè)計(jì)。 擬 達(dá) 到 的 要 求 或 技 術(shù) 指 標(biāo) 1、設(shè)計(jì)說(shuō)明書(shū)1份，達(dá)1.5萬(wàn)字以上，且要符合規(guī)范要求； 2、設(shè)計(jì)圖樣全部用AutoCAD繪制，總的繪圖量達(dá)3張A0以上； 其中：活塞零件圖,鉆油孔夾具圖,銑床夾具零件圖等． 3、全部有電子文檔． 進(jìn) 度 安 排 起止日期 工作內(nèi)容 調(diào)研、收集資料，熟悉課題內(nèi)容，完成開(kāi)題報(bào)告 完成整體設(shè)計(jì)方案及工序． 完成整體裝配尺寸計(jì)算及所有圖紙。 完成說(shuō)明書(shū)的編寫(xiě)和收尾工作。 主 要 參 考 資 料 1 徐灝.機(jī)械設(shè)計(jì)手冊(cè)［M］.北京：機(jī)械工業(yè)出版社，2001，第二版 2 王光斗、王春福.機(jī)床夾具設(shè)計(jì)手冊(cè)［M］.上海：上海科學(xué)技術(shù)出版社，2000，第三版 3 孟少農(nóng).機(jī)械加工工藝手冊(cè)［M］.北京：機(jī)械工業(yè)出版社，1991，第1、2卷 4 徐圣群.簡(jiǎn)時(shí)機(jī)械加工工藝手冊(cè)［M］.上海：上海科學(xué)技術(shù)出版社，1991 5 陸名彰.機(jī)械制造技術(shù)基礎(chǔ)［M］.湖南：湘潭工學(xué)院，2000 6 孫本緒、熊萬(wàn)武.機(jī)械加工余量手冊(cè)［M］.北京：國(guó)防工業(yè)出版社，1999 7 馮辛安.機(jī)械制造裝備設(shè)計(jì)［M］.北京：機(jī)械工業(yè)出版社，2003 8 周鳳云.工程材料及應(yīng)用［M］.湖北：華中科技大學(xué)出版社，2002，第二版 9 大連理工大學(xué)工程畫(huà)教組.機(jī)械制圖［M］.北京:高等教育出版社，2000，第四版 10 廖念釗、莫雨松.互換性與技術(shù)測(cè)量［M］.北京:中國(guó)計(jì)量出版社，2002 11 禹金云、吳曉.材料力學(xué)［M］.湖南:中南工業(yè)大學(xué)出版社，1998 12 邱宣懷.機(jī)械設(shè)計(jì)［M］.北京:高等教育出版社，2002 13 王紹俊.機(jī)械制造工藝設(shè)計(jì)手冊(cè)［M］.北京:機(jī)械工業(yè)出版社,1985 14 唐保寧,高學(xué)滿.機(jī)械設(shè)計(jì)與制造簡(jiǎn)明手冊(cè)［M］.上海:同濟(jì)大學(xué)出版社,1993. 15 顧崇锨.機(jī)械制造工藝學(xué)［M］.陜西:陜西科學(xué)技術(shù)出版社,1989. 教研室 意見(jiàn) 簽名： 年 月 日 院(系)主管領(lǐng)導(dǎo)意見(jiàn) 簽名： 年 月 日  開(kāi)題報(bào)告 畢業(yè)設(shè)計(jì)（論文）開(kāi)題報(bào)告 （1） 結(jié)合課題任務(wù)情況，根據(jù)所查閱的文獻(xiàn)資料，撰寫(xiě)1500～2000字左右的文獻(xiàn)綜述。 1. 課題來(lái)源、目的、意義 本畢業(yè)設(shè)計(jì)的課題“活塞的機(jī)械加工工藝，典型夾具及其CAD設(shè)計(jì)”來(lái)自湖南江濱機(jī)器廠湖南活塞生產(chǎn)線南。湖南江濱機(jī)器廠隸屬于中國(guó)兵器工業(yè)裝備總公司，主要生產(chǎn)發(fā)動(dòng)機(jī)活塞、齒輪、機(jī)油泵。地處長(zhǎng)沙、湘潭“金三角”地帶，京廣鐵路、107、320國(guó)道傍廠而過(guò)。八十年代，工廠從德國(guó)MAHLE公司引進(jìn)活塞設(shè)計(jì)、制造、檢測(cè)技術(shù)，九十年代又先后引進(jìn)CNC橢圓車(chē)床、CNC異形銷(xiāo)孔鏜床、CNC真空直讀光譜儀等先進(jìn)設(shè)備。工廠生產(chǎn)的活塞直徑Φ50－Φ250，種類(lèi)涉及單金屬活塞、鑲?cè)钊?nèi)冷油道活塞、可控膨脹鋼片活塞、電子束焊接活塞、擺體式活塞、鋼頂鋁裙組合活塞、鍛造活塞等八種。工廠奉行“不斷進(jìn)取，成為最佳”的質(zhì)量方針，通過(guò)中國(guó)新時(shí)代質(zhì)量體系認(rèn)證中心GJB/Z9002-ISO9002質(zhì)量體系認(rèn)證，活塞產(chǎn)品先后多次獲湖南省優(yōu)、部?jī)?yōu)稱號(hào)，暢銷(xiāo)歐美、中東、東南亞、臺(tái)灣等國(guó)家和地區(qū)。C6110型活塞是湖南江濱機(jī)器廠生產(chǎn)的一款針對(duì)大功率柴油發(fā)動(dòng)機(jī)生產(chǎn)的活塞，由于它的性能好，壽命長(zhǎng)，得到用戶的極大好評(píng)。 機(jī)械制造工藝問(wèn)題有三個(gè)指標(biāo)，首先是加工質(zhì)量。從滿足產(chǎn)品性能和耐用性而提出的零件加工質(zhì)量要求有兩個(gè)方面：加工精度和加工表面質(zhì)量。前者包括了零件的尺寸精度、形狀精度和位置精度；后者包括了零件表面的粗糙度、波度、物理和機(jī)械性能，國(guó)際上近年來(lái)稱之為“表面完整性”。 其次是要求生產(chǎn)時(shí)消耗的物質(zhì)、能源和勞動(dòng)量要盡量地少，也就是生產(chǎn)率要高，生產(chǎn)成本要低，這就需要對(duì)多種工藝過(guò)程方案進(jìn)行分析和比較，進(jìn)行優(yōu)化選擇。最后，要求機(jī)械零件的裝配工藝在質(zhì)量、生產(chǎn)率和經(jīng)濟(jì)性的達(dá)到一定的指標(biāo)。 機(jī)械制造中的質(zhì)量、生產(chǎn)率和經(jīng)濟(jì)性三者具有密切的辨證關(guān)系和靈活性。在解決某一具體工藝問(wèn)題時(shí)，需要全面地加以考慮。工藝部門(mén)在完成一臺(tái)機(jī)械的零件加工和裝配工藝過(guò)程的全面分析和方案比較、抉擇以后，最終將以工藝文件（卡片）的方式填寫(xiě)下來(lái)，通常稱為工藝規(guī)程，供生產(chǎn)準(zhǔn)備和車(chē)間實(shí)施之用。 本設(shè)計(jì)在參加江濱機(jī)器廠活塞生產(chǎn)線實(shí)習(xí)的基礎(chǔ)上，根據(jù)以上要求，對(duì)CA6110活塞生產(chǎn)的工藝過(guò)程進(jìn)行分析以后，擬訂了一個(gè)生產(chǎn)工藝規(guī)程，對(duì)其中涉及到的一個(gè)典型夾具進(jìn)行了設(shè)計(jì)分析。 (2).選題依據(jù)、主要研究?jī)?nèi)容、研究思路及方案 已有工作基礎(chǔ)和解決的主要問(wèn)題 有了相關(guān)設(shè)計(jì)原理及技術(shù)要求的原始資料，借到幾本工藝設(shè)計(jì)的相關(guān)書(shū)籍。在湖南江濱機(jī)器廠進(jìn)行考察，對(duì)活塞加工有了更深刻的認(rèn)識(shí)和理解。 已經(jīng)學(xué)習(xí)了<<機(jī)械原理>>,<<機(jī)械制造工藝學(xué)>>,<<夾具設(shè)計(jì)>>,<<金屬材料及熱處理>>等相關(guān)課程。 在設(shè)計(jì)中主要考慮工藝過(guò)程的分析、典型夾具的設(shè)計(jì)。 研究思路和研究方案 本課題為機(jī)械加工工藝的范疇,牽涉到內(nèi)燃機(jī)方面的科學(xué),所以 “活塞的機(jī)械加工工藝，典型夾具及其CAD設(shè)計(jì)”要求我有一定的內(nèi)燃機(jī)知識(shí)，熟悉活塞的工況和經(jīng)常發(fā)生的問(wèn)題。 以以往的課題設(shè)計(jì)經(jīng)驗(yàn)為基礎(chǔ)，采用理論和實(shí)際相結(jié)合的方法。實(shí)地參觀，考察廠里現(xiàn)有工藝加工設(shè)備及熱處理設(shè)備,以便在設(shè)計(jì)中盡量運(yùn)用現(xiàn)有設(shè)備及加工工藝。多查相關(guān)資料，多和老師、工人師傅、同學(xué)研究討論，選擇在現(xiàn)有生產(chǎn)條件下最合理的設(shè)計(jì)方案。 研究方案大體是: 1. 活塞的技術(shù)要求 2. 活塞的加工 3. 鉆油孔夾具設(shè)計(jì) 4. 銑氣門(mén)夾具設(shè)計(jì) (3).時(shí)間進(jìn)度計(jì)劃： 2007.03.28------2007.04.06　調(diào)研、收集資料，熟悉課題內(nèi)容，完成開(kāi)題報(bào)告2007.04.07------2007.04.20　完成整體設(shè)計(jì)方案及工序　 2007.04.21------2007.05.15　完成整體裝配尺寸計(jì)算及所有圖紙。］ 2007.05.16------2007.05.28　完成整體設(shè)計(jì)方案及工序． 4.指導(dǎo)教師意見(jiàn)（對(duì)課題方案的可行性、深度、廣度及工作量的意見(jiàn)）： 指導(dǎo)教師___________ 年 月 日 說(shuō)明：開(kāi)題報(bào)告作為畢業(yè)設(shè)計(jì)（論文）答辯委員會(huì)對(duì)學(xué)生答辯資格審查的依據(jù)材料之一，此報(bào)告應(yīng)在導(dǎo)師指導(dǎo)下，由學(xué)生填寫(xiě)，將作為畢業(yè)設(shè)計(jì)（論文）成績(jī)考查的重要依據(jù)，經(jīng)導(dǎo)師簽署意見(jiàn)及教研室審查后生效。 7 附件： 模具高速銑削加工技術(shù) 摘 要 介紹了高速銑削在模具加工中的應(yīng)用以及影響，并簡(jiǎn)要的介紹了高速銑削機(jī)床的結(jié)構(gòu)、控制系統(tǒng)和刀具。對(duì)高速加工的工藝進(jìn)行了簡(jiǎn)單的分析。 關(guān)鍵詞 高速銑削；模具加工 一、 前言 在現(xiàn)代模具生產(chǎn)中，隨著對(duì)塑件的美觀度及功能要求得越來(lái)越高，塑件內(nèi)部結(jié)構(gòu)設(shè)計(jì)得越來(lái)越復(fù)雜，模具的外形設(shè)計(jì)也日趨復(fù)雜，自由曲面所占比例不斷增加，相應(yīng)的模具結(jié)構(gòu)也設(shè)計(jì)得越來(lái)越復(fù)雜。這些都對(duì)模具加工技術(shù)提出了更高要求，不僅應(yīng)保證高的制造精度和表面質(zhì)量，而且要追求加工表面的美觀。隨著對(duì)高速加工技術(shù)研究的不斷深入，尤其在加工機(jī)床、數(shù)控系統(tǒng)、刀具系統(tǒng)、CAD/CAM軟件等相關(guān)技術(shù)不斷發(fā)展的推動(dòng)下，高速加工技術(shù)已越來(lái)越多地應(yīng)用于模具型腔的加工與制造中。 數(shù)控高速切削加工作為模具制造中最為重要的一項(xiàng)先進(jìn)制造技術(shù)，是集高效、優(yōu)質(zhì)、低耗于一身的先進(jìn)制造技術(shù)。相對(duì)于傳統(tǒng)的切削加工，其切削速度、進(jìn)給速度有了很大的提高，而且切削機(jī)理也不相同。高速切削使切削加工發(fā)生了本質(zhì)性的飛躍，其單位功率的金屬切除率提高了30%~40%，切削力降低了30%，刀具的切削壽命提高了70%，留于工件的切削熱大幅度降低，低階切削振動(dòng)幾乎消失。隨著切削速度的提高，單位時(shí)間毛坯材料的去除率增加了，切削時(shí)間減少了，加工效率提高了，從而縮短了產(chǎn)品的制造周期，提高了產(chǎn)品的市場(chǎng)競(jìng)爭(zhēng)力。同時(shí)，高速加工的小量快進(jìn)使切削力減少了，切屑的高速排出減少了工件的切削力和熱應(yīng)力變形，提高了剛性差和薄壁零件切削加工的可能性。由于切削力的降低，轉(zhuǎn)速的提高使切削系統(tǒng)的工作頻率遠(yuǎn)離機(jī)床的低階固有頻率，而工件的表面粗糙度對(duì)低階頻率最為敏感，由此降低了表面粗糙度。在模具的高淬硬鋼件(HRC45~HRC65)的加工過(guò)程中，采用高速切削可以取代電加工和磨削拋光的工序，從而避免了電極的制造和費(fèi)時(shí)的電加工，大幅度減少了鉗工的打磨與拋光量。對(duì)于一些市場(chǎng)上越來(lái)越需要的薄壁模具工件，高速銑削也可順利完成，而且在高速銑削CNC加工中心上，模具一次裝夾可完成多工步加工。 高速加工技術(shù)對(duì)模具加工工藝產(chǎn)生了巨大影響，改變了傳統(tǒng)模具加工采用的“退火→銑削加工→熱處理→磨削”或“電火花加工→手工打磨、拋光”等復(fù)雜冗長(zhǎng)的工藝流程，甚至可用高速切削加工替代原來(lái)的全部工序。高速加工技術(shù)除可應(yīng)用于淬硬模具型腔的直接加工(尤其是半精加工和精加工)外，在EDM電極加工、快速樣件制造等方面也得到了廣泛應(yīng)用。大量生產(chǎn)實(shí)踐表明，應(yīng)用高速切削技術(shù)可節(jié)省模具后續(xù)加工中約80%的手工研磨時(shí)間，節(jié)約加工成本費(fèi)用近30%，模具表面加工精度可達(dá)1 m，刀具切削效率可提高1倍。 二、 高速銑削加工機(jī)床 高速切削技術(shù)是切削加工技術(shù)的主要發(fā)展方向之一，它隨著CNC技術(shù)、微電子技術(shù)、新材料和新結(jié)構(gòu)等基礎(chǔ)技術(shù)的發(fā)展而邁上更高的臺(tái)階。由于模具加工的特殊性以及高速加工技術(shù)的自身特點(diǎn)，對(duì)模具高速加工的相關(guān)技術(shù)及工藝系統(tǒng)(加工機(jī)床、數(shù)控系統(tǒng)、刀具等)提出了比傳統(tǒng)模具加工更高的要求。 1. 高穩(wěn)定性的機(jī)床支撐部件 高速切削機(jī)床的床身等支撐部件應(yīng)具有很好的動(dòng)、靜剛度，熱剛度和最佳的阻尼特性。大部分機(jī)床都采用高質(zhì)量、高剛性和高抗張性的灰鑄鐵作為支撐部件材料，有的機(jī)床公司還在底座中添加高阻尼特性的聚合物混凝土，以增加其抗振性和熱穩(wěn)定性，這不但可保證機(jī)床精度穩(wěn)定，也可防止切削時(shí)刀具振顫。采用封閉式床身設(shè)計(jì)，整體鑄造床身，對(duì)稱床身結(jié)構(gòu)并配有密布的加強(qiáng)筋等也是提高機(jī)床穩(wěn)定性的重要措施。一些機(jī)床公司的研發(fā)部門(mén)在設(shè)計(jì)過(guò)程中，還采用模態(tài)分析和有限元結(jié)構(gòu)計(jì)算等，優(yōu)化了結(jié)構(gòu)，使機(jī)床支撐部件更加穩(wěn)定可靠。 2. 機(jī)床主軸 高速機(jī)床的主軸性能是實(shí)現(xiàn)高速切削加工的重要條件。高速切削機(jī)床主軸的轉(zhuǎn)速范圍為10000~100000m/min，主軸功率大于15kW。通過(guò)主軸壓縮空氣或冷卻系統(tǒng)控制刀柄和主軸間的軸向間隙不大于0.005mm。還要求主軸具有快速升速、在指定位置快速準(zhǔn)停的性能(即具有極高的角加減速度)，因此高速主軸常采用液體靜壓軸承式、空氣靜壓軸承式、熱壓氮化硅（Si3N4）陶瓷軸承磁懸浮軸承式等結(jié)構(gòu)形式。潤(rùn)滑多采用油氣潤(rùn)滑、噴射潤(rùn)滑等技術(shù)。主軸冷卻一般采用主軸內(nèi)部水冷或氣冷。 3. 機(jī)床驅(qū)動(dòng)系統(tǒng) 為滿足模具高速加工的需要，高速加工機(jī)床的驅(qū)動(dòng)系統(tǒng)應(yīng)具有下列特性： (1) 高的進(jìn)給速度。 研究表明，對(duì)于小直徑刀具，提高轉(zhuǎn)速和每齒進(jìn)給量有利于降低刀具磨損。目前常用的進(jìn)給速度范圍為20~30m/min，如采用大導(dǎo)程滾珠絲杠傳動(dòng)，進(jìn)給速度可達(dá)60m/min；采用直線電機(jī)則可使進(jìn)給速度達(dá)到120m/min。 (2) 高的加速度。 對(duì)三維復(fù)雜曲面廓形的高速加工要求驅(qū)動(dòng)系統(tǒng)具有良好的加速度特性，要求提供高速進(jìn)給的驅(qū)動(dòng)器(快進(jìn)速度約40m/min，3D輪廓加工速度為10m/min)，能夠提供0.4m/s2到10m/s2的加速度和減速度。 機(jī)床制造商大多采用全閉環(huán)位置伺服控制的小導(dǎo)程、大尺寸、高質(zhì)量的滾珠絲杠或大導(dǎo)程多頭絲杠。隨著電機(jī)技術(shù)的發(fā)展，先進(jìn)的直線電動(dòng)機(jī)已經(jīng)問(wèn)世，并成功應(yīng)用于CNC機(jī)床。先進(jìn)的直線電動(dòng)機(jī)驅(qū)動(dòng)使CNC機(jī)床不再有質(zhì)量慣性、超前、滯后和振動(dòng)等問(wèn)題，加快了伺服響應(yīng)速度，提高了伺服控制精度和機(jī)床加工精度。 4. 數(shù)控系統(tǒng) 先進(jìn)的數(shù)控系統(tǒng)是保證模具復(fù)雜曲面高速加工質(zhì)量和效率的關(guān)鍵因素，模具高速切削加工對(duì)數(shù)控系統(tǒng)的基本要求為： a. 高速的數(shù)字控制回路(Digital control loop)，包括：32位或64位并行處理器及1.5Gb以上的硬盤(pán)；極短的直線電機(jī)采樣時(shí)間。 b. 速度和加速度的前饋控制(Feed forward control)；數(shù)字驅(qū)動(dòng)系統(tǒng)的爬行控制(Jerk control)。 c. 先進(jìn)的插補(bǔ)方法( 基于NURBS的樣條插補(bǔ))，以獲得良好的表面質(zhì)量、精確的尺寸和高的幾何精度。 d. 預(yù)處理(Look-ahead)功能。要求具有大容量緩沖寄存器，可預(yù)先閱讀和檢查多個(gè)程序段(如DMG機(jī)床可多達(dá)500個(gè)程序段，Simens系統(tǒng)可達(dá)1000~2000個(gè)程序段)，以便在被加工表面形狀(曲率)發(fā)生變化時(shí)可及時(shí)采取改變進(jìn)給速度等措施以避免過(guò)切等。 e. 誤差補(bǔ)償功能，包括因直線電機(jī)、主軸等發(fā)熱導(dǎo)致的熱誤差補(bǔ)償、象限誤差補(bǔ)償、測(cè)量系統(tǒng)誤差補(bǔ)償?shù)裙δ堋?此外，模具高速切削加工對(duì)數(shù)據(jù)傳輸速度的要求也很高。 f. 傳統(tǒng)的數(shù)據(jù)接口， 如RS232串行口的傳輸速度為19.2kb，而許多先進(jìn)的加工中心均已采用以太局域網(wǎng)(Ethernet)進(jìn)行數(shù)據(jù)傳輸，速度可達(dá)200kb。 5. 冷卻潤(rùn)滑 高速加工采用帶涂層的硬質(zhì)合金刀具，在高速、高溫的情況下不用切削液，切削效率更高。這是因?yàn)椋恒娤髦鬏S高速旋轉(zhuǎn)，切削液若要達(dá)到切削區(qū)，首先要克服極大的離心力；即使它克服了離心力進(jìn)入切削區(qū)，也可能由于切削區(qū)的高溫而立即蒸發(fā)，冷卻效果很小甚至沒(méi)有；同時(shí)切削液會(huì)使刀具刃部的溫度激烈變化，容易導(dǎo)致裂紋的產(chǎn)生，所以要采用油/氣冷卻潤(rùn)滑的干式切削方式。這種方式可以用高壓氣體迅速吹走切削區(qū)產(chǎn)生的切削，從而將大量的切削熱帶走，同時(shí)經(jīng)霧化的潤(rùn)滑油可以在刀具刃部和工件表面形成一層極薄的微觀保護(hù)膜，可有效地延長(zhǎng)刀具壽命并提高零件的表面質(zhì)量。 三、 高速切削加工的刀具 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(guò)程中要承受高溫、高壓、摩擦、沖擊和振動(dòng)等載荷，高速切削刀具應(yīng)具有良好的機(jī)械性能和熱穩(wěn)定性，即具有良好的抗沖擊、耐磨損和抗熱疲勞的特性。高速切削加工的刀具技術(shù)發(fā)展速度很快，應(yīng)用較多的如金剛石(PCD)、立方氮化硼(CBN)、陶瓷刀具、涂層硬質(zhì)合金、(碳)氮化鈦硬質(zhì)合金TIC(N)等。 在加工鑄鐵和合金鋼的切削刀具中，硬質(zhì)合金是最常用的刀具材料。硬質(zhì)合金刀具耐磨性好，但硬度比立方氮化硼和陶瓷低。為提高硬度和表面光潔度，采用刀具涂層技術(shù)，涂層材料為氮化鈦(TiN)、氮化鋁鈦(TiALN)等。涂層技術(shù)使涂層由單一涂層發(fā)展為多層、多種涂層材料的涂層，已成為提高高速切削能力的關(guān)鍵技術(shù)之一。直徑在10~40mm范圍內(nèi)，且有碳氮化鈦涂層的硬質(zhì)合金刀片能夠加工洛氏硬度小于42的材料，而氮化鈦鋁涂層的刀具能夠加工洛氏硬度為42甚至更高的材料。高速切削鋼材時(shí)，刀具材料應(yīng)選用熱硬性和疲勞強(qiáng)度高的P類(lèi)硬質(zhì)合金、涂層硬質(zhì)合金、立方氮化硼（CBN）與CBN復(fù)合刀具材料（WBN）等。切削鑄鐵，應(yīng)選用細(xì)晶粒的K類(lèi)硬質(zhì)合金進(jìn)行粗加工，選用復(fù)合氮化硅陶瓷或聚晶立方氮化硼（PCNB）復(fù)合刀具進(jìn)行精加工。精密加工有色金屬或非金屬材料時(shí)，應(yīng)選用聚晶金剛石PCD或CVD金剛石涂層刀具。選擇切削參數(shù)時(shí)，針對(duì)圓刀片和球頭銑刀，應(yīng)注意有效直徑的概念。高速銑削刀具應(yīng)按動(dòng)平衡設(shè)計(jì)制造。刀具的前角比常規(guī)刀具的前角要小，后角略大。主副切削刃連接處應(yīng)修圓或?qū)Ы?，?lái)增大刀尖角，防止刀尖處熱磨損。應(yīng)加大刀尖附近的切削刃長(zhǎng)度和刀具材料體積，提高刀具剛性。在保證安全和滿足加工要求的條件下，刀具懸伸盡可能短，刀體中央韌性要好。刀柄要比刀具直徑粗壯，連接柄呈倒錐狀，以增加其剛性。盡量在刀具及刀具系統(tǒng)中央留有冷卻液孔。球頭立銑刀要考慮有效切削長(zhǎng)度，刃口要盡量短，兩螺旋槽球頭立銑刀通常用于粗銑復(fù)雜曲面，四螺旋槽球頭立銑刀通常用于精銑復(fù)雜曲面。 四、 模具高速加工工藝 高速加工包括以去除余量為目的的粗加工、殘留粗加工，以及以獲取高質(zhì)量的加工表面及細(xì)微結(jié)構(gòu)為目的的半精加工、精加工和鏡面加工等。 1. 粗加工 模具粗加工的主要目標(biāo)是追求單位時(shí)間內(nèi)的材料去除率，并為半精加工準(zhǔn)備工件的幾何輪廓。高速加工中的粗加工所應(yīng)采取的工藝方案是高切削速度、高進(jìn)給率和小切削用量的組合。等高加工方式是眾多CAM軟件普遍采用的一種加工方式。應(yīng)用較多的是螺旋等高和等Z軸等高兩種方式，也就是在加工區(qū)域僅一次進(jìn)刀，在不抬刀的情況下生成連續(xù)光滑的刀具路徑，進(jìn)、退刀方式采用圓弧切入、切出。螺旋等高方式的特點(diǎn)是，沒(méi)有等高層之間的刀路移動(dòng)，可避免頻繁抬刀、進(jìn)刀對(duì)零件表面質(zhì)量的影響及機(jī)械設(shè)備不必要的耗損。對(duì)陡峭和平坦區(qū)域分別處理，計(jì)算適合等高及適合使用類(lèi)似3D偏置的區(qū)域，并且可以使用螺旋方式，在很少抬刀的情況下生成優(yōu)化的刀具路徑，獲得更好的表面質(zhì)量。在高速加工中，一定要采取圓弧切入、切出連接方式，以及拐角處圓弧過(guò)渡，避免突然改變刀具進(jìn)給方向，禁止使用直接下刀的連接方式，避免將刀具埋入工件。加工模具型腔時(shí)，應(yīng)避免刀具垂直插入工件，而應(yīng)采用傾斜下刀方式(常用傾斜角為20°~30°)，最好采用螺旋式下刀以降低刀具載荷。加工模具型芯時(shí)，應(yīng)盡量先從工件外部下刀然后水平切入工件。刀具切入、切出工件時(shí)應(yīng)盡可能采用傾斜式(或圓弧式)切入、切出，避免垂直切入、切出。采用攀爬式切削可降低切削熱，減小刀具受力和加工硬化程度，提高加工質(zhì)量。 2. 半精加工 模具半精加工的主要目標(biāo)是使工件輪廓形狀平整，表面精加工余量均勻，這對(duì)于工具鋼模具尤為重要，因?yàn)樗鼘⒂绊懢庸r(shí)刀具切削層面積的變化及刀具載荷的變化，從而影響切削過(guò)程的穩(wěn)定性及精加工表面質(zhì)量。 粗加工是基于體積模型，精加工則是基于面模型。以前開(kāi)發(fā)的CAD/CAM系統(tǒng)對(duì)零件的幾何描述是不連續(xù)的，由于沒(méi)有描述粗加工后、精加工前加工模型的中間信息，故粗加工表面的剩余加工余量分布及最大剩余加工余量均是未知的。因此應(yīng)對(duì)半精加工策略進(jìn)行優(yōu)化以保證半精加工后工件表面具有均勻的剩余加工余量。優(yōu)化過(guò)程包括：粗加工后輪廓的計(jì)算、最大剩余加工余量的計(jì)算、最大允許加工余量的確定、對(duì)剩余加工余量大于最大允許加工余量的型面分區(qū)(如凹槽、拐角等過(guò)渡半徑小于粗加工刀具半徑的區(qū)域)以及半精加工時(shí)刀心軌跡的計(jì)算等。 現(xiàn)有的模具高速加工C A D /CAM軟件大都具備剩余加工余量分析功能，并能根據(jù)剩余加工余量的大小及分布情況采用合理的半精加工策略。如MasterCAM軟件提供了束狀銑削(Pencil milling)和剩余銑削(Rest milling)等方法來(lái)清除粗加工后剩余加工余量較大的角落以保證后續(xù)工序均勻的加工余量。 3. 精加工 模具的高速精加工策略取決于刀具與工件的接觸點(diǎn)，而刀具與工件的接觸點(diǎn)隨著加工表面的曲面斜率和刀具有效半徑的變化而變化。對(duì)于由多個(gè)曲面組合而成的復(fù)雜曲面加工，應(yīng)盡可能在一個(gè)工序中進(jìn)行連續(xù)加工，而不是對(duì)各個(gè)曲面分別進(jìn)行加工，以減少抬刀、下刀的次數(shù)。然而，由于加工中表面斜率的變化，如果只定義加工的側(cè)吃刀量(Step over)，就可能造成在斜率不同的表面上實(shí)際步距不均勻，從而影響加工質(zhì)量。 一般情況下，精加工曲面的曲率半徑應(yīng)大于刀具半徑的1.5倍，以避免進(jìn)給方向的突然轉(zhuǎn)變。在模具的高速精加工中，在每次切入、切出工件時(shí)，進(jìn)給方向的改變應(yīng)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(guò)程的平穩(wěn)性。 五、 結(jié)束語(yǔ) 高速切削技術(shù)是切削加工技術(shù)的主要發(fā)展方向之一，目前主要應(yīng)用于汽車(chē)工業(yè)和模具行業(yè)，尤其是在加工復(fù)雜曲面的領(lǐng)域、工件本身或刀具系統(tǒng)剛性要求較高的加工領(lǐng)域等，是多種先進(jìn)加工技術(shù)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(jī)床、數(shù)控系統(tǒng)、高速切削刀具及CAD/CAM技術(shù)等。模具高速加工技術(shù)目前已在發(fā)達(dá)國(guó)家的模具制造業(yè)中普遍應(yīng)用，而在我國(guó)的應(yīng)用范圍及應(yīng)用水平仍有待提高，由于其具有傳統(tǒng)加工無(wú)可比擬的優(yōu)勢(shì)，仍將是今后加工技術(shù)必然的發(fā)展方向 Mold high speed milling processing technology The abstract Introduced the high speed milling in the mold processing application as well as the influence, and brief introduction high speed milling engine bed structure, control system and cutting tool. Has carried on the simple analysis to the high speed processing craft. Key word high speed milling; mold processing First, foreword In the modern mold production, along with to models artistic and the function must obtain more and more high, models the internal structure to design more and more complex, the mold contour design day by day is also complex, the free curved surface accounts for the proportion to increase unceasingly, the corresponding mold structure also designs more and more complex. These all set a higher request to the mold processing technology, not only should guarantee the high manufacture precision and the surface quality, moreover must pursue the processing surface artistic. Along with is unceasingly thorough to the high speed processing engineering research, is processing the engine bed, the numerical control system, the cutting tool system, CAD/ especially Correlation technology and so on CAM software develops unceasingly under the impetus, high speed processes the technology more and more many to apply in the mold cavity processing and the manufacture. The numerical control high-speed cutting processing took in the mold manufacture a most important advanced manufacture technology, is the collection is highly effective, high quality, the low consumption in a body advanced manufacture technology. Is opposite in the traditional machining, its cutting speed, entered to the speed had the very big enhancement, moreover cut the mechanism not to be same. The high-speed cutting caused the machining to have the leap, its specific power metal excision rate enhanced 30%~40%, the cutting force reduced 30%, the cutting tool working durability enhanced 70%, remained hotly large scale reduces in the work piece cutting, the low step shudder vanished nearly. Along with the cutting speed enhancement, unit time semifinished materials material removing rate increased, the cutting time reduced, the processing efficiency enhanced, thus reduced the product manufacture cycle, enhanced the product market competitive power. At the same time, the high speed processing small amount entered quickly causes the cutting force to reduce, the scrap high speed discharged reduced the work piece cutting force and the thermal load distorts, enhances the rigidity to be bad and the thin wall components machining possibility. Because cutting force reducing, the rotational speed enhancement causes the cutting system the operating frequency to be far away the engine bed the low step natural frequency, but the work piece surface roughness is most sensitive to the low step frequency, from this reduced the surface roughness. In mold high hard steel stock (HRC45~HRC65) in the processing process, uses the high-speed cutting to be possible to substitute for the working procedure which the electrical finishing and rubs truncates polishes, thus has avoided the electrode manufacture and the time-consuming electrical finishing, large scale reduced fitter's polishing with to throw the light quantity. Thin wall mold work piece more and more needs which regarding some markets in, the high speed milling also may smoothly complete, moreover in the high speed milling CNC processing center, a mold attire clamps may complete the multiplex step of processing. The high speed processing technology has had the huge influence to the mold processing craft, changed the traditional mold processing to use "the annealing → milling processing → heat treatment → to rub truncates" or "the electric spark machining →manually polishes, polishes" and so on the complex long technical process, even might use the high-speed cutting processing substitution original complete working procedure. The high speed processing technology besides may apply in the hard mold cavity direct processing (in particular half precision work and precision work), in EDM aspect and so on electrode processing, fast type manufacture also obtained the widespread application. The mass productions practice indicated that, the application high-speed cutting technology may save in the mold following processing 80% handwork to grind the time approximately, saves the processing cost expense nearly 30%, the mold face work precision may reach 1 m, the cutting tool cutting efficiency may enhance one time. Second, high speed milling processing engine bed The high-speed cutting technology is one of machining technology main development directions, it along with foundation technology the and so on CNC technology, microelectronic technology, new material and new structure development but steps a higher stair. Because the mold processes particular as well as high speed processing technology own characteristic, (processed engine bed, numerical control system, cutting tool to the mold high speed processing related technology and the craft system and so on) proposed processed a higher request compared to the traditional mold. 1. High stable engine bed strut part The high-speed cutting engine bed lathe bed and so on supports the part to be supposed to have very well moves, the static rigidity, hot rigidity and best damping characteristic. The majority of engine beds all use high grade, the high rigidity and Gao Kangzhang the gray iron took the strut part material, some engine bed companies also increase the high damping characteristic in the foundation polymer concrete, by increases its vibration-proof and the thermostability, this not only may guarantee the engine bed precision is stable, also may prevent when cutting the cutting tool inspires trembles. Uses the enclosed lathe bed design, the overall casting lathe bed, the symmetrical lathe bed structure and has the densely covered stiffener and so on also enhances the engine bed stable important measure. Some engine bed companies' research and development departments in design process, but also uses the modality analysis and the finite element structure computation and so on, optimized the structure, stably causes the engine bed strut part to be reliable. 2. Engine bed main axle The high speed engine bed main axle performance is the realization high-speed cutting processing important condition. The high-speed cutting engine bed main axle rotational speed scope is 10000~100000m/Min, the main axle power is bigger than 15kW. Is not bigger than 0.005mm through the main axle compressed air of or axial play between the cooling system control hilt and the main axle. Also requests the main axle to have the fast vertical speed, to assign the performance which the position is fast stops (namely to have extremely high angle addition and subtraction speed), therefore the high speed main axle often uses the liquid static pressure bearing type, the air static pressure bearing type, the thermo-compression nitriding silicon (Si3N4) the ceramic bearing magnetism aerosol bearing type isostructuralism form. Lubricates uses technology and so on oil gas lubrication, splash lubrication. The main axle cools uses the main axle interior water cooling generally or air cooled. 3. The engine bed actuates the system In order to satisfy the mold high speed processing the need, high speed processes the engine bed the actuation system to be supposed to have the following characteristic: (1) high entering for speed. The research indicated that, regarding the minor diameter cutting tool, enhances the rotational speed and each tooth enters for the quantity is advantageous in reduces the cutting tool attrition. At present commonly used entering for the speed range is 20~30m/Min, like uses leads greatly the ball bearing guide screw transmission, enters may reach 60m/ for the speedMin; Uses the straight line electrical machinery then may enable to achieve 120m/ to the speedMin. (2) high acceleration. Has the good acceleration characteristic to the three dimensional complex curved surface silhouette high speed processing request actuation system, the request provides the driver which the high rapid advance or progress gives (to enter speed approximately 40m/ quicklyMin, the 3D outline processing speed is 10m/Min), can provide 0.4m/S2 to 10m/The s2 acceleration and reduces the speed. The engine bed manufacturer mostly uses the entire closed loop position servo-control slightly to lead, the great size, the high grade ball bearing guide screw or leads greatly many guide screws. Along with the electrical machinery technology development, the advanced straight line electric motor already was published, and the success applied in the CNC engine bed. The advanced straight line direct motor drive enable the CNC engine bed no longer to have the mass inertia, in advance, question and so on lag and vibration, sped up the servo speed of response, increased the servo-control precision and the engine bed processing precision. 4. Numerical control system The advanced numerical control system is guaranteed the mold complex curved surface high speed processing quality and the efficiency key aspect, the mold high-speed cutting processing to the numerical control system basic request is: A. High speed numerical control return route (Digital control loop), including: 32 or above 64 bit parallel processors and 1.5Gb hard disk; Extremely short straight line electrical machinery sampling time. B. Speed and acceleration feed-forward control (Feed forward control); Digital actuation system crawling control (Jerk control). C. Advanced inserts makes up the method (to insert based on the NURBS transect makes up), by obtains the good surface quality, the precise size and the high geometry precision. D. Pretreatment (Look-ahead) function. The request has the large capacity cushion register, may read in advance and inspects many segments (for example the DMG engine bed to be possible to reach 500 segments, the Simens system may reach a 1000~2000 segment), in order to when is processed the superficial shape (curvature) changes may promptly adopt changes for measure and so on speed by avoids cutting and so on. E. The error compensatory function, including because the straight line electrical machinery, the main axle and so on gives off heat the hot error which causes to compensate, the quadrantal error compensates, the measurement system error compensates and so on the function. In addition, the mold high-speed cutting processing very is also high to the data transmission speed request. F. The traditional data connection, like the RS232 serial mouth transmission speed is 19.2kb, but many advanced processings centers have used the ether local area network (Ethernet) to carry on the data transmission, the speed may reach 200kb. 5. Cooling lubrication The high speed processing uses the belt coating the hard alloy tools, in high speed, the high temperature situation does not need the cutting compound, the cutting efficiency to be higher. This is because: The milling main axle high speed revolves, the cutting compound if achieved the cutting area, first must overcome the enormous centrifugal force; Even if it overcame the centrifugal force to enter the cutting area, also was possible as a result of the cutting area high temperature but to evaporate immediately, the cooling effect very small did not even have; At the same time the cutting compound can cause the cutting tool edge of a sword the temperature intense change, is easy to cause the crack the production, therefore must pick the oil used/Gas cooling lubrication dry type cutting way. This way may use the compressed gas rapidly the cutting which the cutting area produces, thus the massive cuttings hotly will carry off, at the same time might forms extremely thin microscopic protective film after the atomization lubricating oil in the cutting tool edge of a sword and the work piece surface, but effectively will lengthen the cutting tool life and enhances the components the surface quality. Third, high-speed cutting processing cutting tool The cutting tool is in the high-speed cutting processing one of most active important factors, it is affecting the processing efficiency, the production cost and the product processing precision directly. The cutting tool must withstand load and so on high temperature, high pressure, friction, impact and vibration in the high speed processing process, the high-speed cutting cutting tool should have the good machine capability and the thermostability, namely has the good anti- impact, the wearability and resists heat the weary characteristic. The high-speed cutting processing cutting tool technological development speed is very quick, application many like diamonds (PCD), cubic boron nitride (CBN), ceramic cutting tool, coating hard alloy, (carbon) titanium nitrides hard alloy TIC (N) and so on. In the processing cast iron and in the alloy steel cutting tool, the hard alloy is the most commonly used cutting tool material. Hard alloy tools resistance to wear good, but the solidity ratio cube boron nitride and the ceramics are low. In order to enhance degree of hardness and the superficially attractive fineness, uses the cutting tool coating technology, the coating material for the titanium nitrides (TiN), the aluminium nitride titanium (TiALN) and so on. The coating technology causes the coating by the sole coating development for multilayered, the many kinds of coating material coating, has become one of enhancement high-speed cutting ability essential technical. The diameter in the 10~40mm scope, also has the carbon titanium nitrides coating the hard alloy bit to be able to process the Luo river degree of hardness to be smaller than 42 materials, but the titanium nitrides aluminum coating cutting tool can process the Luo river degree of hardness is 42 even higher materials. When high-speed cutting steel products, the cutting tool material should select the hot rigidity and the fatigue strength high P kind of hard alloy, the coating hard alloy, the cubic boron nitride (CBN) and the CBN compound cutting tool material (WBN) and so on. The cutting cast iron, should select the fine grain K kind of hard alloy to carry on the rough machining