基于UG NX軟件的CADCAM-典型零件的造型與數(shù)控模擬加工1【說明書+CAD+UG】,說明書+CAD+UG,基于UG,NX軟件的CADCAM-典型零件的造型與數(shù)控模擬加工1【說明書+CAD+UG】,基于,ug,nx,軟件,cadcam,典型,零件,造型,數(shù)控,模擬,摹擬,加工,說明書,仿單 蘇州市職業(yè)大學(xué) 畢 業(yè) 設(shè) 計(jì) 說 明 書 畢業(yè)設(shè)計(jì)題目 基于UG NX軟件的CAD/CAM ——典型零件的造型與數(shù)控模擬加工 系 機(jī)電工程系 專業(yè)班級(jí) 數(shù)控 姓 名 學(xué) 號(hào) 指導(dǎo)教師 2012 年 12 月 5 日 摘 要 摘要：21世紀(jì)科學(xué)技術(shù)突飛猛進(jìn)，自中國加入世界貿(mào)易組織后，制造業(yè)是我國為數(shù)不多而又有競(jìng)爭(zhēng)優(yōu)勢(shì)的行業(yè)之一。當(dāng)前世界上正在進(jìn)行著新一輪的產(chǎn)業(yè)調(diào)整，一些產(chǎn)品的制造正在向發(fā)展中國家轉(zhuǎn)移，中國已經(jīng)成為許多跨國公司的首選之地，中國正在成為世界制造大國，這已經(jīng)成為不爭(zhēng)的事實(shí)。隨著數(shù)控技術(shù)的發(fā)展，數(shù)控技術(shù)的應(yīng)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(shù)的不斷發(fā)展和應(yīng)用領(lǐng)域的擴(kuò)大，它對(duì)國計(jì)民生的一些重要行業(yè)的發(fā)展起著越來越重要的作用。 本文主要通過銑削加工數(shù)控工藝分析與加工，綜合所學(xué)的專業(yè)基礎(chǔ)知識(shí)，全面考慮可能影響在銑削、鉆削、絞削加工中的因素，設(shè)計(jì)其加工工藝和編輯程序，完成要求。 關(guān)鍵詞：銑削、鉆削、絞削、CAD/CAM、UG 目 錄 摘 要 II 目 錄 III 第1章 緒論 1 1.1 數(shù)控機(jī)床的發(fā)展過程 1 1.2 本論文的研究?jī)?nèi)容 2 1.3選題意義 2 第2章 零件的三維造型 3 2.1 UG軟件介紹 3 2.2 結(jié)構(gòu)形狀分析與造型思路 3 2.2.1零件結(jié)構(gòu)形狀分析 3 2.2.2 造型思路 5 2.3 三維造型設(shè)計(jì) 5 第3章 數(shù)控模擬加工準(zhǔn)備工藝編制 11 3.1 CAM編程的一般步驟 11 3.2工藝方案分析 11 3.3 工藝文件編制 12 3.3.1 工序卡片 12 3.3.2 刀具卡片 12 第4章 零件的UG數(shù)控加工編程 13 4.1 初始參數(shù)設(shè)定 13 4.2 創(chuàng)建刀具 13 4.3 創(chuàng)建粗加工操作 14 4.4 創(chuàng)建半精加工操作 17 4.5 鉆孔加工 19 結(jié)論 29 參考文獻(xiàn) 30 致 謝 31 第1章 緒論 1.1 數(shù)控機(jī)床的發(fā)展過程 20世紀(jì)中期，隨著電子技術(shù)的發(fā)展，自動(dòng)信息處理、數(shù)據(jù)處理以及電子計(jì)算機(jī)的出現(xiàn)，給自動(dòng)化技術(shù)帶來了新的概念，用數(shù)字化信號(hào)對(duì)機(jī)床運(yùn)動(dòng)及其加工過程進(jìn)行控制，推動(dòng)了機(jī)床自動(dòng)化的發(fā)展。 采用數(shù)字技術(shù)進(jìn)行機(jī)械加工，最早是在40年代初，由美國北密支安的一個(gè)小型飛機(jī)工業(yè)承包商派爾遜斯公司實(shí)現(xiàn)的。他們?cè)谥圃祜w機(jī)的框架及直升飛機(jī)的轉(zhuǎn)動(dòng)機(jī)翼時(shí)，利用全數(shù)字電子計(jì)算機(jī)對(duì)機(jī)翼加工路徑進(jìn)行數(shù)據(jù)處理，并考慮到刀具直徑對(duì)加工路線的影響，使得加工精度達(dá)到±0.0381mm（±0.0015in），達(dá)到了當(dāng)時(shí)的最高水平。 　　1952年，麻省理工學(xué)院在一臺(tái)立式銑床上，裝上了一套試驗(yàn)性的數(shù)控系統(tǒng)，成功地實(shí)現(xiàn)了同時(shí)控制三軸的運(yùn)動(dòng)。這臺(tái)數(shù)控機(jī)床被大家稱為世界上第一臺(tái)數(shù)控機(jī)床。這臺(tái)機(jī)床是一臺(tái)試驗(yàn)性機(jī)床，到了1954年11月，在派爾遜斯專利的基礎(chǔ)上，第一臺(tái)工業(yè)用的數(shù)控機(jī)床由美國本迪克斯公司正式生產(chǎn)出來。 　 在此以后，從1960年開始，其他一些工業(yè)國家，如德國、日本都陸續(xù)開發(fā)、生產(chǎn)及使用了數(shù)控機(jī)床。數(shù)控機(jī)床中最初出現(xiàn)并獲得使用的是數(shù)控銑床，因?yàn)閿?shù)控機(jī)床能夠解決普通機(jī)床難于勝任的、需要進(jìn)行輪廓加工的曲線或曲面零件。然而，由于當(dāng)時(shí)的數(shù)控系統(tǒng)采用的是電子管，體積龐大，功耗高，因此除了在軍事部門使用外，在其他行業(yè)沒有得到推廣使用。 到了1960年以后，點(diǎn)位控制的數(shù)控機(jī)床得到了迅速的發(fā)展。因?yàn)辄c(diǎn)位控制的數(shù)控系統(tǒng)比起輪廓控制的數(shù)控系統(tǒng)要簡(jiǎn)單得多。因此，數(shù)控銑床、沖床、坐標(biāo)鏜床大量發(fā)展，據(jù)統(tǒng)計(jì)資料表明，到1966年實(shí)際使用的約6000臺(tái)數(shù)控機(jī)床中，85%是點(diǎn)位控制的機(jī)床。 數(shù)控機(jī)床的發(fā)展中，值得一提的是加工中心。這是一種具有自動(dòng)換刀裝置的數(shù)控機(jī)床，它能實(shí)現(xiàn)工件一次裝卡而進(jìn)行多工序的加工。這種產(chǎn)品最初是在1959年3月，由美國卡耐·;特雷克公司（Keaney&TreckerCorp.）開發(fā)出來的。這種機(jī)床在刀庫中裝有絲錐、鉆頭、鉸刀、銑刀等刀具，根據(jù)穿孔帶的指令自動(dòng)選擇刀具，并通過機(jī)械手將刀具裝在主軸上，對(duì)工件進(jìn)行加工。它可縮短機(jī)床上零件的裝卸時(shí)間和更換刀具的時(shí)間。加工中心現(xiàn)在已經(jīng)成為數(shù)控機(jī)床中一種非常重要的品種，不僅有立式、臥式等用于箱體零件加工的鏜銑類加工中心，還有用于回轉(zhuǎn)整體零件加工的車削中心、磨削中心等。 1967年，英國首先把幾臺(tái)數(shù)控機(jī)床連接成具有柔性的加工系統(tǒng)，這就是所謂的柔性制造系統(tǒng)（FlexibleManufacturingSystem——FMS）之后，美、歐、日等也相繼進(jìn)行開發(fā)及應(yīng)用。 1974年以后，隨著微電子技術(shù)的迅速發(fā)展，微處理器直接用于數(shù)控機(jī)床，使數(shù)控的軟件功能加強(qiáng)，發(fā)展成計(jì)算機(jī)數(shù)字控制機(jī)床（簡(jiǎn)稱為CNC機(jī)床），進(jìn)一步推動(dòng)了數(shù)控機(jī)床的普及應(yīng)用和大力發(fā)展。80年代，國際上出現(xiàn)了1～4臺(tái)加工中心或車削中心為主體，再配上工件自動(dòng)裝卸和監(jiān)控檢驗(yàn)裝置的柔性制造單元（FlexibleManufacturingCell——FMC）。這種單元投資少，見效快，既可單獨(dú)長(zhǎng)時(shí)間少人看管運(yùn)行，也可集成到FMS或更高級(jí)的集成制造系統(tǒng)中使用。 在20余年間，我國數(shù)控機(jī)床的設(shè)計(jì)和制造技術(shù)有較大提高，主要表現(xiàn)在三大方面：培訓(xùn)一批設(shè)計(jì)、制造、使用和維護(hù)的人才；通過合作生產(chǎn)先進(jìn)數(shù)控機(jī)床，使設(shè)計(jì)、制造、使用水平大大提高，縮小了與世界先進(jìn)技術(shù)的差距；通過利用國外先進(jìn)元部件、數(shù)控系統(tǒng)配套，開始能自行設(shè)計(jì)及制造高速、高性能、五面或五軸聯(lián)動(dòng)加工的數(shù)控機(jī)床，供應(yīng)國內(nèi)市場(chǎng)的需求，但對(duì)關(guān)鍵技術(shù)的試驗(yàn)、消化、掌握及創(chuàng)新卻較差。至今許多重要功能部件、自動(dòng)化刀具、數(shù)控系統(tǒng)依靠國外技術(shù)支撐，不能獨(dú)立發(fā)展，基本上處于從仿制走向自行開發(fā)階段，與日本數(shù)控機(jī)床的水平差距很大。 1.2 本論文的研究?jī)?nèi)容 數(shù)控機(jī)床的編程方法分為手工編程和自動(dòng)編程。從零件圖樣分析、工藝處理、數(shù)據(jù)計(jì)算、編寫程序單、輸入程序到程序校驗(yàn)等各步驟主要由人工完成的編程過程稱為手工編程。自動(dòng)編程也稱為計(jì)算機(jī)輔助編程，即程序編制工作的大部分或全部由計(jì)算機(jī)完成。自動(dòng)編程工具分為語詞式自動(dòng)編程工具和圖形交互式自動(dòng)編程工具，當(dāng)今主流的自動(dòng)編程工具為圖形交互式自動(dòng)編程工具。目前，數(shù)控銑削加工中普遍采用UG或Mastercam自動(dòng)編程，而數(shù)控銑削加工中主要采用手工編程的方法，而手工編程效率低，準(zhǔn)確性差，本文討論了基于UG自動(dòng)編程的數(shù)控銑削加工方法， 1.3選題意義 在學(xué)習(xí)了《數(shù)控加工工藝與裝備》《機(jī)械制造基礎(chǔ)》《UG數(shù)控編程》《CAD/CAM應(yīng)用技術(shù)》《數(shù)控機(jī)床及編程》等課程后，為了將所學(xué)的知識(shí)應(yīng)用于實(shí)際中，加深對(duì)知識(shí)的掌握程度，提升自身的實(shí)際工作能力，故選取《基于UG的撥叉凹模的數(shù)控銑削加工》的課題，綜合所學(xué)知識(shí)，解決出現(xiàn)的問題，完成設(shè)計(jì)。 本課題主要內(nèi)容是數(shù)控銑削加工，包括了零件圖的審查、工藝的設(shè)計(jì)、刀具和機(jī)床夾具的選擇、切削用量的選擇、UG的建模與編程、后處理等，通過一系列的作業(yè)操作，完成對(duì)零件的加工任務(wù)。通過此次課題，可以學(xué)習(xí)到很多加工和工藝方面的知識(shí)，為以后工作打下基礎(chǔ)。 31 第2章 零件的三維造型 2.1 UG軟件介紹 NX是UGS PLM新一代數(shù)字化產(chǎn)品開發(fā)系統(tǒng)，它可以通過過程變更來驅(qū)動(dòng)產(chǎn)品革新。NX獨(dú)特之處是其知識(shí)管理基礎(chǔ)，它使得工程專業(yè)人員能夠推動(dòng)革新以創(chuàng)造出更大的利潤(rùn)。NX可以管理生產(chǎn)和系統(tǒng)性能知識(shí)，根據(jù)已知準(zhǔn)則來確認(rèn)每一設(shè)計(jì)決策。 NX建立在為客戶提供無與倫比的解決方案的成功經(jīng)驗(yàn)基礎(chǔ)之上，這些解決方案可以全面地改善設(shè)計(jì)過程的效率，削減成本，并縮短進(jìn)入市場(chǎng)的時(shí)間。通過再一次將注意力集中于跨越整個(gè)產(chǎn)品生命周期的技術(shù)創(chuàng)新，NX的成功已經(jīng)得到了充分的證實(shí)。這些目標(biāo)使得NX通過無可匹敵的全范圍產(chǎn)品檢驗(yàn)應(yīng)用和過程自動(dòng)化工具，把產(chǎn)品制造早期的從概念到生產(chǎn)的過程都集成到一個(gè)實(shí)現(xiàn)數(shù)字化管理和協(xié)同的框架中。 工業(yè)設(shè)計(jì)和風(fēng)格造型 NX為那些培養(yǎng)創(chuàng)造性的產(chǎn)品技術(shù)革新的工業(yè)設(shè)計(jì)和風(fēng)格提供了強(qiáng)有力的解決方案。利用NX建模，工業(yè)設(shè)計(jì)師能夠迅速地建立和改進(jìn)復(fù)雜的產(chǎn)品形狀，并且使用先進(jìn)的渲染和可視化工具來最大限度地滿足設(shè)計(jì)概念的審美要求。 產(chǎn)品設(shè)計(jì) NX包括了世界上最強(qiáng)大、最廣泛的產(chǎn)品設(shè)計(jì)應(yīng)用模塊。NX具有高性能的機(jī)械設(shè)計(jì)和制圖功能，為制造設(shè)計(jì)提供了高性能和靈活性，以滿足客戶設(shè)計(jì)任XX復(fù)雜產(chǎn)品的需要。NX優(yōu)于通用的設(shè)計(jì)工具，具有專業(yè)的管路和線路設(shè)計(jì)系統(tǒng)、鈑金模塊、專用塑料設(shè)計(jì)模塊和其他行業(yè)設(shè)計(jì)所需的專業(yè)應(yīng)用程序。 仿真、確認(rèn)和優(yōu)化 NX允許制造商以數(shù)字化的方式仿真、確認(rèn)和優(yōu)化產(chǎn)品及其開發(fā)過程。通過在開發(fā)周期中較早地運(yùn)用數(shù)字化仿真性能，制造商可以改善產(chǎn)品質(zhì)量，同時(shí)減少或消除對(duì)于物理樣機(jī)的昂貴耗時(shí)的設(shè)計(jì)、構(gòu)建，以及對(duì)變更周期的依賴。 開發(fā)環(huán)境 NX產(chǎn)品開發(fā)解決方案完全支持制造商所需的各種工具，可用于管理過程并與擴(kuò)展的企業(yè)共享產(chǎn)品信息。NX與UGS PLM的其他解決方案的完整套件無縫結(jié)合。這些對(duì)于CAD、CAM和CAE在可控環(huán)境下的協(xié)同，產(chǎn)品數(shù)據(jù)管理、數(shù)據(jù)轉(zhuǎn)換、數(shù)字化實(shí)體模型和可視化都是一個(gè)補(bǔ)充。 2.2 結(jié)構(gòu)形狀分析與造型思路 2.2.1零件結(jié)構(gòu)形狀分析 圖2-2所示為零件圖，該零件有腔體，臺(tái)階，孔，凸臺(tái)。 圖2-2零件的結(jié)構(gòu)圖 2.2.2 造型思路 首先創(chuàng)建 （1）畫一個(gè)長(zhǎng)方體； （2）以長(zhǎng)方體的面為參照草繪，形成凸臺(tái)； （3）凸臺(tái)的構(gòu)建以長(zhǎng)方體的面為參照草繪，形成菱形凸臺(tái) （4）長(zhǎng)方體上構(gòu)建畫出草圖并進(jìn)行拉伸 （5）鉆各個(gè)凸臺(tái)上的孔； （6）倒圓角 2.3 三維造型設(shè)計(jì) 一 以3.prt為名新建文件 打開軟件Unigraphics NX ,點(diǎn)擊新建圖標(biāo)，在文件名空白中輸入3,單位選擇毫米，點(diǎn)擊OK鍵即可建立以3.prt為名的新文件,如圖2-1。 圖2-3 點(diǎn)擊圖標(biāo)，出現(xiàn)下拉菜單后點(diǎn)擊圖標(biāo)， 接下來就可以開始三維造型過程了 1、繪制長(zhǎng)方體 點(diǎn)擊圖標(biāo)，出現(xiàn)下拉菜單后點(diǎn)擊，再點(diǎn)擊圖標(biāo) ，按圖紙要求繪制如圖2-4所示。 圖2-4 2 以長(zhǎng)方體的面為參照草繪，形成凸臺(tái) 繪制時(shí)需進(jìn)行坐標(biāo)系的移動(dòng)。點(diǎn)擊圖標(biāo)，出現(xiàn)下拉菜單后點(diǎn)擊，再點(diǎn)擊圖標(biāo)。點(diǎn)擊出現(xiàn)點(diǎn)的構(gòu)造器，修改坐標(biāo)后，按圖紙要求繪制。如圖2-5所示。 圖2-5 4．繪制草圖拉伸中間凸起部分，然后進(jìn)行求差切除； 5、鉆各個(gè)凸臺(tái)上的孔； 圖2-8 第3章 數(shù)控模擬加工準(zhǔn)備工藝編制 3.1 CAM編程的一般步驟 零件模型 ↓ 加工模塊 ↓ 指定加工環(huán)境 ↓ 分析/生成輔助幾XX ↓ 生成/修改“父”組 　　　　　　↓　　　　　　　　↓　　　　　　　　↓　　　　　　　　↓ 程序次序 加工刀具 幾XX體 加工方法 ↓ 生成/修改操作 ↓ 產(chǎn)生刀具路徑 ↓ 校核 ↓ 后處理 表3-1 CAM編程的一般步驟 3.2工藝方案分析 此工件從圖樣中可以看出零件的粗糙度值要求比較高零件的裝夾采用平口鉗裝夾。在工件安裝時(shí)，要注意工件安裝，要放在鉗口中間部位。安裝臺(tái)虎鉗時(shí)要對(duì)它的固定鉗口找正，工件被加工部分要高出鉗口，避免刀具與鉗口發(fā)生干涉。安裝工件時(shí)，要注意工件上浮。 3.3 工藝文件編制 3.3.1 工序卡片 單位 產(chǎn)品名稱或代號(hào) 零件名稱 零件圖號(hào) 名稱 / 1 工序號(hào) 程序編號(hào) 夾具名稱 使用設(shè)備 車間 / / 平口虎鉗 KVC650加工中心 / 工步號(hào) 工步內(nèi)容 刀具號(hào) 刀具規(guī)格 主軸轉(zhuǎn)速 進(jìn)給速度 背吃刀量 備注 mm r/min mm/min mm 1 粗加工 T01 D20 800 200 3 / 2 半精銑 T02 D10 1590 300 1 / 3 鉆孔加工 T03 D10 2230 400 0.1 編制 　 審核 　 批準(zhǔn) 　 共1頁 第1頁 3.3.2 刀具卡片 產(chǎn)品名稱或代號(hào) / 零件名稱 零件圖號(hào) 1 序號(hào) 刀具號(hào) 刀具規(guī)格名稱 直徑 長(zhǎng)度 刀具材料 加工部位 備注 1 T01 D20端面銑刀 20 166 硬質(zhì)合金 / / 2 T02 D6立銑刀 10 150 硬質(zhì)合金 / / 3 T03 鉆頭 16 130 硬質(zhì)合金 / / 編制 　 審核 　 批準(zhǔn) 　 共1頁 第1頁 第4章 零件的UG數(shù)控加工編程 4.1 初始參數(shù)設(shè)定 1.準(zhǔn)備毛坯：通過普通銑床機(jī)加工，將毛坯加工為方塊。 2.CNC加工：按照“粗→半精→精-清根加工”的一般順序進(jìn)行加工。 3.進(jìn)入加工模塊，初始化加工環(huán)境，選擇“mill_contour”進(jìn)入加工環(huán)境。 4.選擇“加工導(dǎo)航器”中的“幾XX視圖”在左側(cè)“操作導(dǎo)航器”欄選擇坐標(biāo)系設(shè)置“MCS_MILL”，指定坐標(biāo)系原點(diǎn)為工件正中央，在間隙設(shè)置里指定安全平面，選擇工件上表面，設(shè)定偏置為15。如圖所示： 4.選擇“WORKPIECE”打開，指定部件為加工幾XX體，指定毛坯為毛坯幾XX體，指定材料為CARBON STEEL，單擊顯示圖標(biāo)。 4.2 創(chuàng)建刀具 1.在插入工具條中點(diǎn)創(chuàng)建刀具按鈕，在刀具類型中選擇第一個(gè)立銑刀圖標(biāo)，輸入刀具名稱“D20”，在銑刀參數(shù)中選擇“5-參數(shù)”，直徑設(shè)置為20mm，長(zhǎng)度設(shè)置為166mm，刀刃長(zhǎng)度設(shè)置為100mm，刀刃數(shù)為2，刀具號(hào)設(shè)置為1。如圖所示： 同理，創(chuàng)建其余刀具：分別是D10、D10R0.5、D10R5。 D10刀具參數(shù)：直徑10mm，長(zhǎng)度150mm，刀刃長(zhǎng)度100mm，刀刃數(shù)3，刀具號(hào)為2 D10R0.5刀具參數(shù)：直徑10mm，長(zhǎng)度125mm，刀刃長(zhǎng)度55mm，刀刃數(shù)2，刀具號(hào)為3 D10R5刀具參數(shù)：直徑10mm，長(zhǎng)度130mm，刀刃長(zhǎng)度11mm，刀刃數(shù)2，刀具號(hào)為4 4.3 創(chuàng)建粗加工操作 在加工導(dǎo)航器中切換到“加工方法視圖”，在操作導(dǎo)航器中選擇MILL_ROUGH,右鍵彈出菜單，選擇插入→操作，在類型中選擇mill_contour，在操作子類型中選擇第一個(gè)型腔銑CAVITY_MILL，程序設(shè)置PROGRAM，刀具設(shè)置D20，幾XX體設(shè)置WORKPIECE，方法MILL_ROUGH，確定進(jìn)入型腔銑對(duì)話框。 在刀軌設(shè)置里切削模式選擇“跟隨周邊”，步距恒定，距離為5mm，全局每刀深度3mm。如圖所示： 編程基本參數(shù)表 參 數(shù) 參 數(shù) 值 參 數(shù) 參 數(shù) 值 刀具材料 硬質(zhì)合金 進(jìn)給速度 200 刀具類型 端面銑刀 主軸轉(zhuǎn)速 800 刀具刃數(shù) 2 公 差 0.03 刀具直徑 20 切削步距 5 刀具半徑 10 切削深度 3 圓角半徑 / 加工余量 側(cè)壁 1 快進(jìn)速度 5000 底面 0 打開“切削參數(shù)”按鈕，在“策略”選項(xiàng)卡里選擇“切削方向”為順銑，“切削順序”為深度優(yōu)先，“圖樣方向”向內(nèi)；在“余量”選項(xiàng)卡里設(shè)置部件側(cè)面余量1mm，部件底部面余量0,內(nèi)外公差為0.03mm；在“連接”選項(xiàng)卡中設(shè)置區(qū)域排序?yàn)閮?yōu)化，勾選區(qū)域連接；其余參數(shù)默認(rèn)設(shè)置。如圖所示： 打開“非切削移動(dòng)”按鈕，在進(jìn)刀選項(xiàng)卡封閉區(qū)域中設(shè)置進(jìn)刀類型為螺旋，直徑為刀具直徑的90%，傾斜角度15°；在開放區(qū)域中設(shè)置進(jìn)刀類型為線性，長(zhǎng)度為50%。 在傳遞/快速選項(xiàng)卡中設(shè)置安全設(shè)置為平面，指定平面為工件上表面偏置15mm傳遞類型為間隙。其余設(shè)置為默認(rèn)設(shè)置，如圖所示： 在進(jìn)給和速度選項(xiàng)里，設(shè)置主軸轉(zhuǎn)速為800，切削為200，其余參數(shù)如圖： 點(diǎn)擊生成按鈕，生成刀軌，如圖所示： 4.4 創(chuàng)建半精加工操作 在加工導(dǎo)航器中切換到“加工方法視圖”，在操作導(dǎo)航器中選擇MILL_SEMI_FINISH,右鍵彈出菜單，選擇插入→操作，在類型中選擇mill_contour，在操作子類型中選擇第一個(gè)型腔銑CAVITY_MILL，程序設(shè)置PROGRAM，刀具設(shè)置D10，幾XX體設(shè)置WORKPIECE，方法MILL_SEMI_FINISH，確定進(jìn)入型腔銑對(duì)話框。 在刀軌設(shè)置里切削模式選擇“配置文件”，步距為刀具直徑的50%，全局每刀深度1mm。 編程基本參數(shù)表 參 數(shù) 參 數(shù) 值 參 數(shù) 參 數(shù) 值 刀具材料 硬質(zhì)合金 進(jìn)給速度 300 刀具類型 立銑刀 主軸轉(zhuǎn)速 1590 刀具刃數(shù) 2 公 差 0.03 刀具直徑 10 切削步距 刀具直徑50% 刀具半徑 5 切削深度 3 圓角半徑 / 加工余量 側(cè)壁 0.25 快進(jìn)速度 5000 底面 0.25 打開“切削參數(shù)”按鈕，在“策略”選項(xiàng)卡里選擇“切削方向”為順銑，“切削順序”為層優(yōu)先；在“余量”選項(xiàng)卡里設(shè)置部件側(cè)面余量0.25mm，部件底部面余量0.25,內(nèi)外公差為0.03mm；在“連接”選項(xiàng)卡中設(shè)置區(qū)域排序?yàn)閮?yōu)化，勾選區(qū)域連接，“開放刀路”為保持切削方向；其余參數(shù)默認(rèn)設(shè)置。 打開“非切削移動(dòng)”按鈕，在進(jìn)刀選項(xiàng)卡封閉區(qū)域中設(shè)置進(jìn)刀類型為螺旋，直徑為刀具直徑的90%，傾斜角度15°；在開放區(qū)域中設(shè)置進(jìn)刀類型為線性，長(zhǎng)度為50%。 在傳遞/快速選項(xiàng)卡中設(shè)置安全設(shè)置為平面，指定平面為工件上表面偏置15mm傳遞類型為間隙。其余設(shè)置為默認(rèn)設(shè)置 在進(jìn)給和速度選項(xiàng)里，設(shè)置主軸轉(zhuǎn)速為1590，切削為300。 點(diǎn)擊生成按鈕，生成刀軌，如圖所示： 4.5 鉆孔加工 (2) 單擊“WORKPIECE”點(diǎn)擊右鍵點(diǎn)擊“插入”，選擇“幾何體”，如圖。類型選擇“drill” 。幾何子類型選擇第三項(xiàng)，如圖。名稱改為“DRILL-GEOM2”，單擊“確定”按鈕。開始創(chuàng)建幾XX體“DRILL-GEOM2”。 (3) 單擊“指定孔”的右邊圖標(biāo)，如圖2.5。單擊“選擇”，如圖。選擇中間所有孔，如圖。點(diǎn)擊“確定”按鈕。點(diǎn)擊“附加”按鈕，如圖，點(diǎn)擊“確定”。下面操作和創(chuàng)建上一個(gè)幾XX體一樣。點(diǎn)擊“指定部件表面”按鈕。選擇上表面，單擊“確定”。單擊“指定底面”。按鼠標(biāo)中間按鈕翻轉(zhuǎn)工件，選定下表面，單擊“確定”。幾XX體“DRILL-GEOM2”創(chuàng)建完畢。 第三步: 創(chuàng)建刀軌加工程序。 （1） 單擊“程序順序視圖”單擊“PROGROM”右鍵選擇“插入”，選擇“操作”。如圖，開始創(chuàng)建。 （2） 創(chuàng)建“DRILL-GEOM1”的刀軌程序。類型選擇“drill”，操作子類型選擇點(diǎn)鉆，如圖3.0。刀具選擇“SPOIDRILL-TOOL (DrillTooL)”如圖，幾XX體選擇“DRILL-GEOM1”，“確定”，如圖。彈出菜單選擇“選項(xiàng)”選項(xiàng)卡里的“編輯顯示”，如圖?！暗毒唢@示”選項(xiàng)選擇“”，如圖，“確定”。選項(xiàng)“操作”，單擊第一項(xiàng)，如圖?！按_定”，完成“DRILL-GEOM1”的程序，如圖。 (3) 創(chuàng)建“DRILL-GEOM2”的刀軌程序。 單擊“程序順序視圖”單擊“PROGROM”右鍵選擇“插入”，選擇“操作”。類型選擇“drill”，操作子類型選擇標(biāo)準(zhǔn)鉆，如圖3.8。刀具選擇“DRILLING TOOL (DrillTooL)”如圖3.9，幾XX體選擇“DRILL-GEOM2”，“確定”，如圖4.0。彈出菜單選擇“選項(xiàng)”選項(xiàng)卡里的“編輯顯示”，如圖4.1?！暗毒唢@示”選項(xiàng)選擇“3D”，如圖4.2，“確定”。選項(xiàng)“操作”，單擊第一項(xiàng)，如圖4.3?！按_定”，完成“DRILL-GEOM2”的程序， 第四步： 輸出刀軌。單擊“列出刀軌”，如圖4.5。結(jié)果如圖4.6。 % N0010 G40 G17 G90 G70 N0020 G91 G28 Z0.0 :0030 T00 M06 N0040 G0 G90 X.1268 Y-3.0339 S0 M03 N0050 G43 Z1.1024 H00 N0060 G1 Z.9843 F9.8 M08 N0070 Z.3937 N0080 G0 Z1.2205 N0090 X.0797 Y-2.9871 N0100 Z1.1024 N0110 G1 Z.9843 N0120 Z.3937 N0130 G0 Z.4772 N0140 X.0583 Y-3.0678 N0150 Z1.2205 N0160 X.0369 Y-2.9362 N0170 Z1.1024 N0180 G1 Z.9843 N0190 Z.3937 N0200 G0 Z.4772 N0210 X.0085 Y-3.0148 N0220 Z1.2205 N0230 X.3293 Y-3.0339 N0240 Z1.1024 N0250 G1 Z.9843 N0260 Z.3937 N0270 G0 Z1.2205 N0280 X.2339 Y-2.9702 N0290 Z1.1024 N0300 G1 Z.9843 N0310 Z.3937 N0320 G0 Z.4772 N0330 X.2285 Y-3.0535 N0340 Z1.2205 N0350 X.1517 Y-2.8903 N0360 Z1.1024 N0370 G1 Z.9843 N0380 Z.3937 N0390 G0 Z.4772 N0400 X.1312 Y-2.9712 N0410 Z1.2205 N0420 X.0852 Y-2.7967 N0430 Z1.1024 N0440 G1 Z.9843 N0450 Z.3937 N0460 G0 Z.4772 N0470 X.0504 Y-2.8727 N0480 Z1.2205 …… …… …… …… （中間省略了很多行） N3080 G1 Z.9843 N3090 Z.9646 N3100 G0 Z1.0481 N3110 X2.4831 Y-.9188 N3120 Z1.2205 N3130 M02 % 2020 Z1.1024 N2030 G1 Z.9843 N2040 Z.9646 N2050 G0 Z1.0481 N2060 X3.53 Y-1.5476 N2070 Z1.2205 N2080 X3.6024 Y-1.3873 N2090 Z1.1024 N2100 G1 Z.9843 N2110 Z.9646 N2120 G0 Z1.0481 N2130 X3.53 Y-1.429 N2140 Z1.2205 N2150 X3.6024 Y-1.2687 N2160 Z1.1024 N2170 G1 Z.9843 N2180 Z.9646 N2190 G0 Z1.0481 N2200 X3.53 Y-1.3105 N2210 Z1.2205 N2220 X3.6024 Y-1.1502 N2230 Z1.1024 N2240 G1 Z.9843 N2250 Z.9646 N2260 G0 Z1.0481 N2270 X3.53 Y-1.1919 N2280 Z1.2205 N2290 X3.6024 Y-1.0316 N2300 Z1.1024 N2310 G1 Z.9843 N2320 Z.9646 N2330 G0 Z1.0481 N2340 X3.53 Y-1.0734 N2350 Z1.2205 N2360 X3.5973 Y-.9137 N2370 Z1.1024 N2380 G1 Z.9843 N2390 Z.9646 N2400 G0 Z1.0481 N2410 X3.5268 Y-.9585 N2420 Z1.2205 N2430 X3.5082 Y-.8466 N2440 Z1.1024 N2450 G1 Z.9843 N2460 Z.9646 N2470 G0 Z1.0481 N2480 X3.498 Y-.9294 N2490 Z1.2205 N2500 X3.3897 Y-.8465 N2510 Z1.1024 N2520 G1 Z.9843 N2530 Z.9646 N2540 G0 Z1.0481 N2550 X3.4314 Y-.9188 N2560 Z1.2205 N2570 X3.2711 Y-.8465 N2580 Z1.1024 N2590 G1 Z.9843 N2600 Z.9646 N2610 G0 Z1.0481 N2620 X3.3129 Y-.9188 N2630 Z1.2205 N2640 X3.1526 Y-.8465 N2650 Z1.1024 N2660 G1 Z.9843 N2670 Z.9646 N2680 G0 Z1.0481 N2690 X3.1944 Y-.9188 N2700 Z1.2205 N2710 X3.0341 Y-.8465 N2720 Z1.1024 N2730 G1 Z.9843 N2740 Z.9646 N2750 G0 Z1.0481 N2760 X3.0758 Y-.9188 N2770 Z1.2205 N2780 X2.9155 Y-.8465 N2790 Z1.1024 N2800 G1 Z.9843 N2810 Z.9646 N2820 G0 Z1.0481 N2830 X2.9573 Y-.9188 N2840 Z1.2205 N2850 X2.797 Y-.8465 N2860 Z1.1024 N2870 G1 Z.9843 N2880 Z.9646 N2890 G0 Z1.0481 N2900 X2.8387 Y-.9188 N2910 Z1.2205 N2920 X2.6785 Y-.8465 N2930 Z1.1024 N2940 G1 Z.9843 N2950 Z.9646 N2960 G0 Z1.0481 N2970 X2.7202 Y-.9188 N2980 Z1.2205 N2990 X2.5599 Y-.8465 N3000 Z1.1024 N3010 G1 Z.9843 N3020 Z.9646 N3030 G0 Z1.0481 N3040 X2.6017 Y-.9188 N3050 Z1.2205 N3060 X2.4414 Y-.8465 N3070 Z1.1024 N3080 G1 Z.9843 N3090 Z.9646 N3100 G0 Z1.0481 N3110 X2.4831 Y-.9188 N3120 Z1.2205 N3130 M02 結(jié)論 ? 這次畢業(yè)設(shè)計(jì)，給我最大的體會(huì)就是熟練操作技能來源我們對(duì)專業(yè)的熟練程度。比如，我們想加快編程程度，除了對(duì)各編程指令的熟練掌握之外，還需要你掌握零件工藝方面的知識(shí)，對(duì)于夾具的選擇，切削參數(shù)的設(shè)定我們必須十分清楚。在上機(jī)操作時(shí)，我們只有練習(xí)各功能鍵的作用，在編程時(shí)才得心應(yīng)手。因此，我總結(jié)出一個(gè)結(jié)論“理論是指導(dǎo)實(shí)踐的基礎(chǔ)，只有不斷在實(shí)踐中總結(jié)驗(yàn)，并對(duì)先前的理論進(jìn)行消化和創(chuàng)新，自己的水平會(huì)很快的提高”。 參考文獻(xiàn) [1]XX華妹，杜智敏，杜志倫.UG NX4中文版產(chǎn)品模具設(shè)計(jì)入門一點(diǎn)通.北京：清華大學(xué)出版社，2006. [2]安杰，鄒煜章.UG后處理技術(shù).北京：清華大學(xué)出版社，2003.9 [3]肖世宏，UG NX5中文版數(shù)控加工[J].北京：人民郵電出版社，2008.9 [4]田偉，王建華.UGNX5.0數(shù)控加工技術(shù)指導(dǎo) [M].北京：電子工業(yè)出版社，2008：343 -454. [5]王磊.UGNX4在光學(xué)超精車削加工中的應(yīng)用 [J].工具技術(shù)，2008，42(5) :42-43． [6]吳正洪.基于UGNX的數(shù)控車削編程模板的建立及實(shí)踐 [J].機(jī)械設(shè)計(jì)與制造，2008，(6) :143-144． [7]鄭貞平，UG NX4.0中文版數(shù)控加工典型范例教程.北京：電子工業(yè)出版社，2007.1 [8]李錦標(biāo)，鐘平福，精通UG NX5數(shù)控加工.北京：清華大學(xué)出版社，2008.1 [9]張俊華，管殿柱，UG NX4.0數(shù)控加工實(shí)例教程.北京：電子工業(yè)出版社，2007.1 [10]梅梅，基于UG NX6.0環(huán)境的數(shù)控車削加工實(shí)踐教程.機(jī)械工業(yè)出版社，2009.8 [11]宋國旸，姚進(jìn)，《基于UG的數(shù)控車削加工編程技術(shù)及應(yīng)用》，《機(jī)械》，2007.1 [12]胡明江，《UGNX／POSTBUILDER結(jié)合TCL擴(kuò)展UGCAM后處理》，《金屬加工》，2009 [13]李鐵剛，《基于UG／Postbuilder的五軸后置處理器設(shè)計(jì)》，機(jī)床與液壓，2009：37-10 [14]唐人科技，《最新中文版UG NX5技術(shù)入門與案例應(yīng)用》，北京：中國青少年出版社. [15]徐衛(wèi)紅.UG在機(jī)床夾具設(shè)計(jì)中的應(yīng)用[J].鋼鐵,2006,(2):31-32. [16]周林 王寶瑞.UG在線切割編程中的應(yīng)用與技巧[J].CAD/CAM與制造業(yè)信息化,2006,(1):62-63. [17]陳曉英 徐誠.UG軟件在數(shù)控加工中的應(yīng)用[J].機(jī)床與液壓,2006,(1):64-66. [18周建安 孫衛(wèi)和.UG在平面銑削加工中的應(yīng)用[J].機(jī)械設(shè)計(jì)與制造,2005,(10):129-130. [19]杜潔.UG軟件在數(shù)控加工中的應(yīng)用[J].蘇州市職業(yè)大學(xué)學(xué)報(bào),2005,16(4):40-41,44. [20]吳磊，手把手教你學(xué)UG NX5中文版，北京：電子工業(yè)出版社.2007.12 [21]王華僑，張穎，實(shí)用數(shù)控加工技術(shù)應(yīng)用與開發(fā)，機(jī)械工業(yè)出版社.2007.7 [22]周志平，《機(jī)械實(shí)際基礎(chǔ)與實(shí)踐》，冶金工業(yè)出版社.2008.6 [23]楊楨，《機(jī)械實(shí)際應(yīng)用基礎(chǔ)》，上海交通大學(xué)出版社，2007 [24]洪如瑾，UGNX CAD快速入們指導(dǎo)，北京清華大學(xué)出版社，2003 致 謝 本論文是在XX老師的精心指導(dǎo)下，才得以順利完成的。在短短的大學(xué)幾年間，我深受XX老師的嚴(yán)謹(jǐn)治學(xué)態(tài)度和求真精神所感染，是您讓我對(duì)大學(xué)的學(xué)習(xí)有了正確的理解，是您不斷為我的求學(xué)之路指明了方向。尤其是在本論文的寫作過程中，XX老師給予了我極大的鞭策、鼓勵(lì)與支持。他的求真務(wù)實(shí)、一絲不茍的工作作風(fēng)對(duì)我產(chǎn)生了深深的影響，在對(duì)于我以后的工作、做人道路上有著長(zhǎng)足的鞭策。在此，深深的感謝XX老師，感謝您對(duì)我的無私付出。 在論文即將完成之際，也是我將要進(jìn)入社會(huì)參加工作之時(shí)，借此機(jī)會(huì)，向大學(xué)中關(guān)心過、幫助過、輔導(dǎo)過我的各位領(lǐng)導(dǎo)、輔導(dǎo)員、任課教師、代課教師致以誠摯的謝意和真誠的祝福。我親愛的同學(xué)們，我們一起奮斗、探索知識(shí)的道路上，是你們給予了我極大的幫助和鼓勵(lì)。 在此，感謝廣大同學(xué)們對(duì)我的照顧和關(guān)心，在我遇到困難時(shí)不停的幫助我，為我分憂，借此，預(yù)祝親愛的同學(xué)們，前程似錦，萬事如意。 同時(shí)，感謝家中的親人對(duì)我的默默支持和無私奉獻(xiàn)。 衷心地感謝在百忙之中評(píng)閱論文和參加答辯的各位老師、專家和教授。 A Noise-Free Servo-Spindle for High-speed NC Gear Grinding Machines Takashi Emura, Lei Wang, Hisashi Nakamura, Masashi Yamanaka and Yasushi Teshigawara Department of Mechatronics and Precision Engineering, Tohoku University Aoba, Aramaki, Aobaks, Sendai, 980-77 Japan Abstract- The authors developed a productive type NC (Numerically Controlled) gear grinding machine for automobile plants, This NC ma- chine requires high-accuracy synchronization between the grinding spin- dle and workspindle. We must use high-power servomotors and servo- amplifiers to satisfy the specification required for high-speed grinding. However, since the high-power servo-amplifier causes very large ripple of motor current at PWM (Pulse-Width Modulation) frequency and in- duces strong noise, it becomes difficult to get the stable synchronous rota- tion among spindles. Therefore, the authors tried to use two-phase type PU to achieve noise-free high-speed synchronous spindles and to reduce the noise caused by the current ripple with a kind of current filter. In this paper, an approach for suppressing the noise and experimental results are descrl bed. I. INTRODUCTION Gear grinding takes extremely long grinding time and it pre- vents increasing the productivity in mass production of gears. Thus, the authors developed a productive type NC gear grind- ing machine for automobile plants, which are the most produc- tive plants of gears. This machine requires two large-power servo-spindles for its grinding-spindle and workspindle. hese servo-spindles also have to be synchronously controlled with high precision even rotating at a high speed. The authors used high-power and high-speed servomotors to drive the spindles. For example, the servomotor for grinding-spindle has a rated power of 22 kW, rated output torque of 22 N-m and maximum rotary speed of 10 000 r/min. The servomotor for workspindle has a rated power of 16 kW, rated output torque of 82 N.m and maximum rotary speed of 2000 r/min. These servomotors are driven by PWM (Pulse-Width Mod- ulation) type servo-amplifiers, and the PWM type amplifier of large power causes a very large ripple in motor current which appears at PWM frequency. Since this large current ripple in- duces a strong noise which causes trouble to control systems, it is difficult to realize synchronous control of high accuracy. Therefore, the authors tried to use two-phase type PLL (Phase- Locked Loop) to get noise-free high-speed synchronous spin- dles and tried to use a kind of current filter to reduce the ripple of motor current. Experiments were carried out to confirm the ef- fectiveness of the noise-free systems. In this paper, an approach for suppressing the noise and getting the high-speed and high- precision synchronous spindles is described with experimental results. 11. NOISE CAUSED BY PWM Problems of noise of the grinding-spindle is more severe than that of the workspindle because the rated power of the grinding- spindle is larger than that of the workspindle. Thus we mainly 0-7803-3026-9195 $4.00 0 1995 IEEE describe about the case of grinding-spindle in the followings. The grinding-spindle is driven by a high-power brushless ser- vomotor. Since the maximum output voltage of the servo- amplifier is limited to 200 V and the rated power of the ser- vomotor is 22 kW, the current of field coil has to be more than 200 A at a peak load. For this large current, a wire diameter of field coil became large, and the number of turns became a few because of the limitation of winding space. Thus inductance of the field coil was constrained to a very small value. The mea- sured inductance of one phase is about 30 pH at l kHz and it is reduced to very small value of less than 1.5 pH at 25 kHz of PWM frequency. Since the coil inductance is extremely small like this, its electrical time constant is very small. This means that we can get a good control characteristics. However, the extremely short time constant causes very large current ripple at PWM frequency, and this current ripple induces the strong noise. The strong noise gives serious problems to control sys- tems. In order to analyze the ripple current, numerical simulation of motor current was carried out. Fig. l(a) is simplified model of synchronous motor for simulation, where coil inductance L is 1.44 pH, coil resistance R is 0.15 SZ and voltage of DC line E is 200 V. PWM output voltage Eu, Ev and Ew of servo-amplifier are supplied on terminal of three phases U, V, W. PWM pattern shown in Fig. l(b) are generated by compar- ing reference voltage eu, eV and ew with triangle wave eg of which frequency is 25 kHz. Fig. 2(a) is an example of simulated results, where the out- put frequency of the servo-amplifier is 300 Hz. As shown in Fig. 2(a), motor current is overlapped by large noise. Fig. 2(b) gives the detail situation by coniparing simulated and measured results of coil current, where simulated results agreed with the measured results. Thus the simulated results shows that the mo- tor current has very large current ripple at PWM frequency. This simulation shows clearly that the servomotor and power amplifier generate very strong noises for the sake of smallness of coil inductance. The coil inductance decreases sharply at high switching frequency in such large power motor because of the magnetic characteristic of field core. The noises caused by switching is a very severe problem in this NC machine and has to be overcome in order to achieve the high precision syn- chronous control. Therefore, the following sections describe two different ap- proaches for overcoming switching noise problem. Section HI presents a synchronous control method of two-phase type PLL which enables the system engage a high-precision and high- 692 U E v W EU EV EW (b) Fig. 1. Vu, V, , V, are back EMF (electromotive force) Motor model for numerical simulation. I, I, I, are line current and n 3 E s U E V . I, I -1001 I . I . I . I . I I 0 1 2 3 Time (ms) (a) Simulated motor current. In I Time (2Opddiv) (b) Comparison of simulated and measured results. Fig. 2. Ripple of motor current. speed synchronous control under strong noise situation. Sec- tion IV gives discussion of using large power filter to suppress switching noise and the experimental results. 111. SYNCHRONOUS SYSTEM BY TWO-PHASE TYPE PLL The developed gear grinding machine requires high-speed syn- chronous control with high accuracy. The high-speed and high- precision synchronous control systems are realized usually by using a high-resolution and high-speed encoder whose output is two-phase sinusoidal wave. However, the voltage of the sinusoidal waves is usually very small, and it is difficult to detect this small voltage without problems of the noise under the strong noise surroundings. This means that we cannot use the conventional control method of high-precision synchroniza- tion. Therefore, the authors used two-phase type PLL in this synchronous system. The two-phase type PLL was first pro- posed by Emura l and its noise rejection ability was already verified 2-4. Fig. 3 is blockdiagram of the high-speed synchronous sys- tem between grinding spindle and workspindle of the NC gear grinding machine. Both of the servo-spindles were controlled by two-phase type PLL. A command pulse generator generates two pulse trains whose frequency ratio is the velocity ratio of grinding-spindle to workspindle. Position controllers of two- phase type PLL control the spindles so as for them to follow each command pulse accurately. By using two-phase type PLL, high-speed and high-precision synchronous control was real- ized. Two interpolators of two-phase type PLL interpolate en- coder signal with high resolution and the interpolated output pulses of rotational angle are sent to servo-amplifiers. A. High-resolution detection of rotary angle with interpolator of two-phase type PLL The servo-amplifiers which we used this time require a two- phase rectangular signal for generating the three-phase field current that synchronizes with rotor angle. However, we could not use the conventional interpolators of comparator type be- cause of the noise induced by the ripple current. Therefore, the authors designed special interpolators which use two-phase type PLL as shown in Fig. 4 to detect rotary angles of spindles. Circuits of this interpolator was designed mainly according to the description in 3, and so they are only briefly described in the following. Input signal is a two-phase sinusoidal wave (sin , cos e;), and their phase is compared with the two-phase sinusoidal waves obtained from encoder by the following vector phase operation. cos 8i cos 8, - sin 8; sin 0, = cos 8d - cos 8; sin 8, + sin 8; cos 8, = sin 8d (1) * Hence wecan get a pair of two-phase sinusoidal waves of which argument is phase difference Bd = 8; - 8,. Since we can detect the phase difference 8d with the same principle as the interpola- tor mentioned previously, the servo-error detector of two-phase type PLL detects the servo-error with high resolution and high accuracy. Another feature of this loop is that the servo-error detector is able to detect angular velocity error with high accuracy. This is based on the excellent capability of PLL in frequency detection as known. By feedback of the angular velocity error obtained from the phase detector, we could realize the servo-controller whose D gain is high enough and consequently whose stabil- ity is significantly high. The resolution and maximum speed are 11.25 and 10 000 r/min for grinding spindle and 1.125 t Step-displacement Command *- -10.6 I I I I 0 0.2 0.4 Time SI Fig. 7. Step response of grinding-spindle el 18-bit BRM ROMs U sin/cos tables 11 converters t To grinding-spindle + To othor axis ROMs sin/cos tables 4 D/A converters + To workspindle Fig. 8. Reference signal generator for synchronous control system of two-phase typePLL and 2000 r/min for workspindle respectively. These values are extremely excellent values that have never been realized. Fig. 7(a) shows a step response of grinding-spindle. From Fig. 7, it is known that the grinding-spindle tracks command pluses precisely even under the existence of strong noise. C. Reference Signal Generator Both of workspindle and grinding-spindle controlled by the above mentioned two-phase type PLL is positioning ser- vomechanism. Their positioning command is given conse- quently two-phase sinusoidal wave of which angular frequency is decided by the specifications of work piece and tool. The structure of reference signal generator is simple as shown in Fig. 8. As shown in Fig. 8, the output pulse frequency of a refer- ence pulse generator is decreased by BRM (Binary Rate Mul- tiplier), of which decreasing rate is decided by the rotary speed 695 of each axis. Since bit length of BRMs is 18, the accuracy of synchronous rotation is 218. The output pulse of each BRM is counted by binary counter and transformed into two-phase sinu- soidal wave by two ROMs in which look-up tables are written, and after that it is converted to analog two-phase signal by two D/A converters. Iv. REDUCTION OF RIPPLE CURRENT BY LARGE-CURRENT FILTER As mentioned previously, the ripple of motor current generates very strong noise. Even the synchronous control system can work well under such circumstance, other detectors required for servo-controller are interfered by the switching noise and they did not work without misoperation. Therefore, the ripple of motor current is necessary to be reduced to a tolerable level. As the mean current of motor is about 100 A and the frequency of current ripple is 25 kHz, the authors Uied to decrease this current ripple by using a large-current filter whose frequency characteristics is high enough. A. Large-Current Filter This filter consists of 6 choke coils LO and L1, 3 capacitors C and 3 resistors R as illustrated in Fig. 9(a). 10 is current of servo-amplifier, 11 is current of motor and 1, is current dissi- pated by RC circuits. Because the purpose of this filter is to reduce the ripple of switching frequency, choke coils of ferrite core areused to obtain good characteristics at PWM frequency. The rated current of the coils is 110 A. B. Frequency-Domain Analysis One phase of the filter can be simplified as Fig. 9(b), where winding inductance of motor is omitted because it is very small compared with that of filter. If output current of servo-amplifier is Io and output voltage is E, impedance of one phase Zo = E/Io is given by s(o + L) + s2(o + L) + s3co1 20 = * (2) 1 + sRC + s2CL1 If field current of motor is 11, we can use impedance 21 = E/11 for expressing suppression ability of current ripple of motor. 21 is given by s(L0 + Ll) + SRC(L + L1) + scLOL z1 l+sRC . (3) Frequency characteristics of 20 and 21 are shown inFig. 10. In Fig. 10, al, a2, a3 and a4 are constants defined by the following equations. a1 = LOCL1, (4) Power amplifier CL IL U (a) Arrangement of filter (b) Model of one phase of filter Fig. 9. Smcolre of filter used for reducing ripple of motor current where a1 is the overall inductance of the network. As shown in Fig. lO(a), we can obtain good ripple suppression ability over- all frequency range by increasing al. However, since large a1 lowers response frequency of motor current, the authors used a1 = 100pH. We must use large-size inductors because of large motor current and its large ripple. a2 means the undamped res- onant frequency of loop R - C - L1 and it has no effect on 21. a3 is the characteristic frequency of the filter. Fig. 1O(c) shows that a smsll u3 gives good suppression ability of ripple, but this requests to increase C, Lo and L1. Thus, for a certain sum of LO and L1, LO = L1 was used. As seen in Fig. 10(d), a4 is the damping ratio and kept below 0.7. By choosing the param- eters properly, we could effectively reduce the current ripple in high-frequency range more than 25 kHz of PWM frequency. C. Experiments Fig. 11 is the experimental results. The effectiveness can be confirmed by the comparison of motor current with and without the filter. Fig. ll(a) gives a sharp contrast of motor current, where LO = LI = 50pH, R = 1Q and C = 20pF. Rotary speed of motor is 3000 rpm, and spectrum of motor current shown in Fig. ll(b) shows that the induced noise nearby of 25 kHz was significantly reduced by the filter. V. CONCLUSIONS The authors used two high-power servomotors for getting a pro- ductive type NC gear grinding machine. Since inductance of 696 q-E-gq a,=lOpH 1 Frequency (Hz) - Frequencym -,=o.l El+ d lo0 1 I Frequency (Hz) Frequency (Hz) (d) ai = 100pH, a2 = SkHz, a3 = 7kHz. Fig. 10. Numeral results of impedanceof Zo, Z1. field coil of these motors is extremely small at PWM frequency, the ripple current of field coil became very large and large ripple current induced strong noise. The induced noise caused misop- eration of control systems. Therefore, the authors used two- phase type PLL to realize high-precision control of spindles under the strong noise surroundings. Moreover, a large-current filter was used to reduce ripple of motor current. From simula- tion and experiments, the following conclusions were obtained. (1) From simulation, it became clear that large ripple of mo- tor current is caused by extremely low inductance at PWM frequency of the field coil. Simulated results were coinci- dent with experimental results. (2) The two-phase type PLL is useful for getting the high- speed and high-precision synchronous spindles. It ro- tates the spindles stably without misoperation under strong noise surroundings. (3) The proposed large-current filter is effective for reducing the ripple of motor current. With filter (a) Motor current -50 IIIIIIIIIIIIL Time lms/div (a) Motor current “I 4,1 Without filter P v1 0 n 25 50 Frequency (kHz) a -. i With filter 3000 dmin Frequency (kHz) (b) Spectrum of motor current Fig. 11. Experimental results. VI. ACKNOWLEDGEMENTS The authors thank Mr. T. Sakaguchi (NEC) for his coopera- tion making control circuits of spindles. A part of this work was supported by the Grant-in-Aid for Scientific Reseach of the Ministry of Education of Japan and the Grant of Toyoda Machinery Co. Ltd. REFERENCES l T. Emura, “A study of a servomechanism for NC machines using 90 de- grees phase difference method,” hog. Rep. of JSPE, pp. 419-421, 1982. 2 T. Emura, A. Arakawa, and M. I-Iashitani “A study of high precision servo- spindle for hard gear finishing machines,” The Inter. Conf. on Advanced Mechatronics, pp.427-432,1989 3 T. Emura, L. Wang and A. Arakawa,”A high-resolution interpolator for incremental encoders by twephase type PLL method,” in Pruc. lEEE 4 T. Emura, L. Wang and A. Arakawa, “A Study on A High-speed NC Gear Grinding Machine Using Screw-Shaped CBN Wheel,” ASME Jomal of Mechanical Design, Vo1.116, No.4, pp.1163-1168, Dec. 1994. IECON93,1993, pp 1540-1545 697