基于UG NX軟件的CADCAM-典型零件的造型與數(shù)控模擬加工【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【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【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: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.然而UG包含了三維建模和數(shù)控銑削編程模塊,在對(duì)工件的加工過程中,可以利用UG進(jìn)行數(shù)控銑削自動(dòng)編程。結(jié)合UG強(qiáng)大的參數(shù)化功能和后處理器支持多種數(shù)控機(jī)床功能,可迅速自動(dòng)生成數(shù)控代碼,縮短編程人員的編程時(shí)間,提高程序的正確性和安全性,降低生產(chǎn)成本,提高工作效率。
本文以加工為例,詳細(xì)介紹了基于UG的自動(dòng)編程的方法和如XX創(chuàng)建數(shù)控銑床后處理文件的方法,并且單獨(dú)創(chuàng)建后置處理構(gòu)造器來生成出符合加工人員實(shí)際操作的機(jī)床程序。在數(shù)控銑床上完成該軸的銑削加工,結(jié)果表明加工精度符合圖紙要求、基于UC的自動(dòng)編程可以提高NC程序的正確性和安全性、同時(shí)還能提高工作效率。
關(guān)鍵詞:UG、自動(dòng)編程、數(shù)控
目 錄
摘 要 II
目 錄 III
第1章 緒論 1
1.1 UG來源及其優(yōu)缺點(diǎn) 1
1.2 本論文的研究內(nèi)容 1
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 4
2.2.1零件結(jié)構(gòu)形狀分析 4
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 10
3.1 CAM編程的一般步驟 10
3.2工藝方案分析 10
3.3 工藝文件編制 11
3.3.1 工序卡片 11
3.3.2 刀具卡片 11
第4章 零件的UG數(shù)控加工編程 12
4.1 初始參數(shù)設(shè)定 12
4.2 創(chuàng)建刀具 12
4.3 創(chuàng)建粗加工操作 13
4.4 創(chuàng)建半精加工操作 16
4.5 創(chuàng)建銑2側(cè)腰形槽加工操作 17
4.5 鉆孔加工 19
結(jié)論 28
參考文獻(xiàn) 29
致 謝 30
第1章 緒論
1.1 UG來源及其優(yōu)缺點(diǎn)
UG 是美國UGS 公司的一款集CAD/CAM/CAE于一身的高端三維CAD 軟件。其中包含零件設(shè)計(jì)、二維工程圖、零件加工和仿真以及有限元分析等模塊。通過模塊之間的無縫集成,實(shí)現(xiàn)了零件的三維信息在設(shè)計(jì)、數(shù)控加工以及有限元分析模塊之間的共享,具有設(shè)計(jì)修改方便,更新迅速等特點(diǎn)。隨著提高產(chǎn)品加工效率的需求越來越高,數(shù)控加工設(shè)備的使用也越來越普及,數(shù)控銑床、數(shù)控銑削加工中心、數(shù)控車銑復(fù)合加工中心已大量應(yīng)用于各制造行業(yè)中。UG NX6中提供了強(qiáng)大的數(shù)控銑削加工模塊,包含了粗車加工、精車加工、中心鉆孔加工、螺紋加工等操作,能夠?qū)崿F(xiàn)各種復(fù)雜回轉(zhuǎn)類零件的數(shù)控加工編程。
UG自從1990年進(jìn)入我國以來,以其強(qiáng)大的功能和工程背景,已經(jīng)在我國的航空、航天、汽車、模具和家電等領(lǐng)域得到廣泛的應(yīng)用。尤其UG軟件Pc版本的推出,為UG在我國的普及起到了良好的推動(dòng)作用。
UG NX 6.O是NX系列的最新版本,它在原版本的基礎(chǔ)上進(jìn)行了多處的改進(jìn)。例如,在特征和自由建模方面提供了更加廣闊的功能,使得用戶可以更快、更高效、更加高質(zhì)量。地設(shè)計(jì)產(chǎn)品。對(duì)制圖方面也作了重要的改進(jìn),使得制圖更加直觀、快速和精確,并且更加貼近工業(yè)標(biāo)準(zhǔn)。UG具有以下優(yōu)勢;
1、為機(jī)械設(shè)計(jì)、模具設(shè)計(jì)以及電器設(shè)計(jì)單位提供一安完整的設(shè)計(jì)、分析和制造方案。
2、是一個(gè)完全的參數(shù)化軟件,為零部件的系列化建模、裝配和分析提供強(qiáng)大的基礎(chǔ)
支持。
3、可以管理CAD數(shù)據(jù)以及整個(gè)產(chǎn)品開發(fā)用期中所有相關(guān)數(shù)據(jù),實(shí)現(xiàn)逆向工程(Reverse design)和并行工程(Concurrennt Engnieer既)等先進(jìn)設(shè)計(jì)方法。
4、可以完成包括自由曲面在內(nèi)的復(fù)雜模型的創(chuàng)建,同時(shí)在圖形顯示方面運(yùn)用了區(qū)域化管理方式,節(jié)約系統(tǒng)資源。
5、具有強(qiáng)大的裝配功能,并在裝配模塊個(gè)運(yùn)用了引用集的設(shè)計(jì)思想,為節(jié)省計(jì)算機(jī)資源提出了行之有效的解決方案,可以極大地提高設(shè)計(jì)效率。
1.2 本論文的研究內(nèi)容
由于UG 的應(yīng)用多集中在數(shù)控銑、加工中心等方面,并且相關(guān)銑削方面的學(xué)習(xí)資料較少,對(duì)于UG銑削加工應(yīng)該更多地與實(shí)際銑床相結(jié)合。本論文以一個(gè)加工為例,介紹了基于UG的自動(dòng)編程的方法和如XX創(chuàng)建數(shù)控銑床后處理文件的方法。在數(shù)控銑床上完成該軸的銑削加工,結(jié)果表明加工精度符合圖紙要求、基于UC的自動(dòng)編程可以提高NC程序的正確性和安全性、同時(shí)還能提高工作效率。
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
UG(Unigraphics NX)是EDS公司出品的一個(gè)產(chǎn)品工程解決方案,它為用戶的產(chǎn)品設(shè)計(jì)及加工過程提供了數(shù)字化造型和驗(yàn)證手段。Unigraphics NX針對(duì)用戶的虛擬產(chǎn)品設(shè)計(jì)和工藝設(shè)計(jì)的需求,提供了經(jīng)過實(shí)踐驗(yàn)證的解決方案。
來自UGS PLM的NX使企業(yè)能夠通過新一代數(shù)字化產(chǎn)品開放系統(tǒng)實(shí)現(xiàn)向產(chǎn)品全生命周期管理轉(zhuǎn)型的目標(biāo)。NX包含了企業(yè)中應(yīng)用最廣泛的集成應(yīng)用套件,用于產(chǎn)品設(shè)計(jì)、工程和制造全范圍的開發(fā)過程。
如今制造業(yè)所面臨的挑戰(zhàn)是,通過產(chǎn)品開發(fā)的技術(shù)創(chuàng)新,在持續(xù)的成本縮減以及收入和利潤的逐漸增加的要求之間取得平衡。為了真正地支持革新,必須評(píng)審更多的可選設(shè)計(jì)方案,而且在開發(fā)過程中必須根據(jù)以往經(jīng)驗(yàn)中所獲得的知識(shí)更早地做出關(guān)鍵性的決策。
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。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)長方體;
(2)以長方體的面為參照草繪,形成凸臺(tái);
(3)凸臺(tái)的構(gòu)建畫出草圖并進(jìn)行腰形凹槽
(4)長方體上構(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2.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2,單位選擇毫米,點(diǎn)擊OK鍵即可建立以2.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 以長方體的面為參照草繪,形成腰形凹槽
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
3.長方體上構(gòu)建畫出草圖并進(jìn)行拉伸
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
/
5
鉆孔加工
T03
D10R5
2230
400
0.1
/
6
鉆孔加工
T04
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
6
150
硬質(zhì)合金
/
/
3
T04
鉆頭
8
125
硬質(zhì)合金
/
/
4
T03
鉆頭
20
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,長度設(shè)置為166mm,刀刃長度設(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,長度150mm,刀刃長度100mm,刀刃數(shù)3,刀具號(hào)為2
D10R0.5刀具參數(shù):直徑10mm,長度125mm,刀刃長度55mm,刀刃數(shù)2,刀具號(hào)為3
D10R5刀具參數(shù):直徑10mm,長度130mm,刀刃長度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 創(chuàng)建銑2側(cè)腰形槽加工操作
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 _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FLOWCUT_SINGLE,程序設(shè)置PROGRAM,刀具設(shè)置D10R5和D10,方法MILL _FINISH,確定進(jìn)入清根對(duì)話框。
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
400
刀具類型
端面銑刀
主軸轉(zhuǎn)速
2230
刀具刃數(shù)
2
公 差
0.01
刀具直徑
10
步距
/
刀具半徑
5
切削深度
0.1
圓角半徑
/
加工余量
側(cè)壁
0
快進(jìn)速度
5000
底面
0
在“驅(qū)動(dòng)設(shè)置”里切削模式為“往復(fù)”
打開“切削參數(shù)”按鈕,在“余量”選項(xiàng)卡里設(shè)置部件側(cè)面余量0,部件底部面余量0,內(nèi)外公差為0.01mm;在“安全設(shè)置”選項(xiàng)卡中設(shè)置過切時(shí)退刀,檢查安全距離3mm,在“更多”選項(xiàng)卡中設(shè)置最大步長為30%刀具直徑,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)卡開放區(qū)域中設(shè)置進(jìn)刀類型為“圓弧-與刀軸平行,半徑為刀具直徑的50%,圓弧角度90°;在”根據(jù)部件/檢查”中設(shè)置進(jìn)刀類型為線性,長度為刀具直徑80%,旋轉(zhuǎn)角度180°,傾斜角度為45°。
在傳遞/快速選項(xiàng)卡中設(shè)置區(qū)域距離為刀具直徑200%,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2230,切削為400。
點(diǎn)擊生成按鈕,生成刀軌,如圖所示:
最后在PROGRAM上右鍵彈出菜單,選擇“后處理”選項(xiàng),彈出后處理器,在其中選擇后處理文件。
這里選擇已經(jīng)編輯設(shè)置好的FANUC 0I MC系統(tǒng)后處理文件,如下圖所示的“FANUC_0M”文件,指定存放位置,確認(rèn)輸出,生成G代碼,至此,加工完成。如圖:
4.5 鉆孔加工
(2) 單擊“WORKPIECE”點(diǎn)擊右鍵點(diǎn)擊“插入”,選擇“幾XX體”,如圖。類型選擇“drill” 。幾XX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,如圖4.4。
第四步: 輸出刀軌。單擊“列出刀軌”,如圖4.5。結(jié)果如圖4.6。
可按照上述實(shí)例進(jìn)行中心孔鉆削加工,由于設(shè)置一樣,在這不一一列舉了。只截圖表達(dá)
總體加工刀具路線圖
加工零件效果圖
信息清單創(chuàng)建者: Administrator
日期 : 2012-12-06 11:06:48
當(dāng)前工作部件 : F:\2.prt
節(jié)點(diǎn)名 : microsof-11830b
============================================================
%
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N0020 G91 G28 Z0.0
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N0050 G43 Z1.1024 H00
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N0210 G2 X-1.8045 Y-1.1969 I1.6735 J.7896
N0220 X-1.9706 Y-.8974 I1.8045 J1.1969
N0230 G0 X-2.0359 Y-.7541
N0240 X-2.1281
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N0340 G0 X-2.0008 Y-.2303
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N0360 Z.6693
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N0390 Z.6693
N0400 G1 Z.5512
N0410 X2.054
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N0500 Z.6693
N0510 G1 Z.5512
N0520 X2.0359
N0530 X1.9706 Y-.8974
……
……
……
……
……
……
……
(中間省略了很多行)
N5300 X-.4082 Y1.4349 I.8233 J-.7384
N5310 X.4088 Y1.4346 I.4082 J-.7819
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N5400 Z.5118
N5410 Z1.1024
N5420 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)
參考文獻(xiàn)
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[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.
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[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
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[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
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[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。
英文翻譯
【附】英文原文
翻譯文獻(xiàn):Five-axis milling machine tool kinematic chain design and analysis
作者:E.L.J. Bohez
文獻(xiàn)出處:International Journal of Machine Tools & Manufacture 42 (2002) 505–520
翻譯頁數(shù):
Five-axis milling machine tool kinematic chain design and analysis
1. Introduction
The main design specifications of a machine tool can be deduced from the following principles:
● The kinematics should provide sufficient flexibility in
orientation and position of tool and part.
● Orientation and positioning with the highest possible
speed.
● Orientation and positioning with the highest possible
accuracy.
● Fast change of tool and workpiece.
● Save for the environment.
● Highest possible material removal rate.
The number of axes of a machine tool normally refers to the number of degrees of freedom or the number of independent controllable motions on the machine slides.The ISO axes nomenclature recommends the use of a right-handed coordinate system, with the tool axis corresponding to the Z-axis. A three-axis milling machine has three linear slides X, Y and Z which can be positioned everywhere within the travel limit of each slide. The tool axis direction stays fixed during machining. This limits the flexibility of the tool orientation relative to the workpiece and results in a number of different set ups. To increase the flexibility in possible tool workpiece orientations, without need of re-setup, more degrees of freedom must be added. For a conventional three linear axes machine this can be achieved by providing rotational slides. Fig. 1 gives an example of a five-axis milling machine.
2. Kinematic chain diagram
To analyze the machine it is very useful to make a kinematic diagram of the machine. From this kinematic (chain) diagram two groups of axes can immediately be distinguished: the workpiece carrying axes and the tool carrying axes. Fig. 2 gives the kinematic diagram of the five-axis machine in Fig. 1. As can be seen the workpiece is carried by four axes and the tool only by one axis.The five-axis machine is similar to two cooperating robots, one robot carrying the workpiece and one robot carrying the tool.Five degrees of freedom are the minimum required to obtain maximum flexibility in tool workpiece orientation,this means that the tool and workpiece can be oriented relative to each other under any angle. The minimum required number of axes can also be understood from a rigid body kinematics point of view. To orient two rigid bodies in space relative to each other 6 degrees of freedom are needed for each body (tool and workpiece) or 12 degrees. However any common translation and rotation which does not change the relative orientation is permitted reducing the number of degrees by 6. The distance between the bodies is prescribed by the toolpath and allows elimination of an additional degree of freedom, resulting in a minimum requirement of 5 degrees.
3.Literature review
One of the earliest (1970) and still very useful introductions to five-axis milling was given by Baughman [1] clearly stating the applications. The APT language was then the only tool to program five-axis contouring applications. The problems in postprocessing were also clearly stated by Sim [2] in those earlier days of numerical control and most issues are still valid. Boyd in Ref. [3] was also one of the early introductions. Beziers’ book [4] is also still a very useful introduction. Held [5] gives a very brief but enlightening definition of multi-axis machining in his book on pocket milling. A recent paper applicable to the problem of five-axis machine workspace computation is the multiple sweeping using the Denawit-Hartenberg representation method developed by Abdel-Malek and Othman [6]. Many types and design concepts of machine tools which can be applied to five-axis machines are discussed in Ref. [7] but not specifically for the five-axis machine. he number of setups and the optimal orientation of the part on the machine table is discussed in Ref. [8]. A review about the state of the art and new requirements for tool path generation is given by B.K. Choi et al. [9]. Graphic simulation of the interaction of the tool and workpiece is also a very active area of research and a good introduction can be found in Ref. [10].
4. Classification of five-axis machines’ kinematic structure
Starting from Rotary (R) and Translatory (T) axes four main groups can be distinguished: (i) three T axes and two R axes; (ii) two T axes and three R axes; (iii) one T axis and four R axes and (iv) five R axes. Nearly all existing five-axis machine tools are in group (i). Also a number of welding robots, filament winding machines and laser machining centers fall in this group. Only limited instances of five-axis machine tools in group (ii) exist for the machining of ship propellers. Groups (iii) and (iv) are used in the design of robots usually with more degrees of freedom added. The five axes can be distributed between the workpiece or tool in several combinations. A first classification can be made based on the number of workpiece and tool carrying axes and the sequence of each axis in the kinematic chain. Another classification can be based on where the rotary axes are located, on the workpiece side or tool side. The five degrees of freedom in a Cartesian coordinates based machine are: three translatory movements X,Y,Z (in general represented as TTT) and two rotational movements AB, AC or BC (in general represented as RR).Combinations of three rotary axes (RRR) and two linear axes (TT) are rare. If an axis is bearing the workpiece it is the habit of noting it with an additional accent. The five-axis machine in Fig. 1 can be characterized by XYABZ. The XYAB axes carry the workpiece and the Z-axis carries the tool. Fig. 3 shows a machine of the type XYZAB, the three linear axes
carry the tool and the two rotary axes carry the workpiece.
5. Workspace of a five-axis machine
Before defining the workspace of the five-axis machine tool, it is appropriate to define the workspace of the tool and the workspace of the workpiece. The workspace of the tool is the space obtained by sweeping the tool reference point (e.g. tool tip) along the path of the tool carrying axes. The workspace of the workpiece carrying axes is defined in the same way (the center of the machine table can be chosen as reference point).These workspaces can be determined by computing the swept volume [6].Based on the above-definitions some quantitative parameters can be defined which are useful for comparison, selection and design of different types of machines.
6.Selection criteria of a five-axis machine
It is not the objective to make a complete study on how to select or design a five-axis machine for a certain application. Only the main criteria which can be used to justify the selection of a five-axis machine are discussed.
6.1. Applications of five-axis machine tools
The applications can be classified in positioning and contouring. Figs. 12 and 13 explain the difference between five-axis positioning and five-axis contouring.
6.1.1. Five-axis positioning
Fig. 12 shows a part with a lot of holes and flat planes under different angles, to make this part with a three axis milling machine it is not possible to process the part in one set up. If a five-axis machine is used the tool can process. More details on countouring can be found in Ref. [13]. Applications of five-axis contouring are: (i) production of blades, such as compressor and turbine blades; (ii) injectors of fuel pumps; (iii) profiles of tires; (iv) medical prosthesis such as artificial heart valves; (v) molds made of complex surfaces.
6.1.2. Five-axis contouring
Fig. 13 shows an example of five-axis contouring, tomachine the complex shape of the surface we need to control the orientation of the tool relative to the part during cutting. The tool workpiece orientation changes in each step. The CNC controller needs to control all the five-axes simultaneously during the material removal process. More details on countouring can be found in Ref. [13]. Applications of five-axis contouring are: (i) production of blades, such as compressor and turbine blades; (ii) injectors of fuel pumps; (iii) profiles of tires; (iv) medical prosthesis such as artificial heart valves; (v)
molds made of complex surfaces.
6.2. Axes configuration selection
The size and weight of the part is very important as a first criterion to design or select a configuration. Very heavy workpieces require short workpiece kinematic chains. Also there is a preference for horizontal machine tables which makes it more convenient to fix and handle the workpiece. Putting a heavy workpiece on a single rotary axis kinematic chain will increase the orientation flexibility very much. It can be observed from Fig. 4that providing a single horizontal rotary axis to carry the workpiece will make the machine more flexible. In most cases the tool carrying kinematic chains will be kept as short as possible because the toolspindle drive must also be carried.
6.3.five-axes machining of jewelry
A typical workpiece could be a flower shaped part as in Fig. 14. This application is clearly contouring. The part will be relatively small compared to the tool assembly. Also small diameter tools will require a high speed spindle. A horizontal rotary table would be a very good option as the operator will have a good view of the part (with range 360°). All axes as workpiece carrying axes would be a good choice because the toolspindle
could be fixed and made very rigid. There are 20 ways in which the axes can be combined in the workpiece kinematic chain (Section 4.2.1). Here only two kinematic chains will be considered. Case one will be a TTTRR kinematic chain shown in Fig. 15. Case two will be a RRTTT kinematic chain shown in Fig. 16.
For model I a machine with a range of X=300mmY=250 mm, Z=200 mm, C=n 360° and A=360°, and a machine tool table of 100 mm diameter will be considered. For this kinematic chain the tool workspace is a single point. The set of tool reference points which can be selected is also small. With the above machine travel ranges the workpiece workspace will be the space swept by the center of the machine table. If the centerline of the two rotary axes intersect in the reference point, a prismatic workpiece workspace will be obtained with as size XYZ or 300×250×200 mm3. If the centerlines of the two rotary axes do not intersect in the workpiece reference point then the workpiece workspace will be larger.
It will be a prismatic shape with rounded edges. The radius of this rounded edge is the excentricity of the bworkpiece reference point relative to each centerline. Model II in Fig. 15 has the rotary axes at the beginning of the kinematic chain (RRTTT). Here also two different values of the rotary axes excentricity will be considered. The same range of the axes as in model I is considered. The parameters defined in Section 5 are computed for each model and excentricity and summarized in Table 1. It can be seen that with the rotary axes at the end of the kinematic chain (model I), a much smaller machine tool workspace is obtained. There are two main reasons for this. The swept volume of the tool and workpiece WSTOOLWSWORK is much smaller for model I. The second reason is due to the fact that a large part of the machine tool workspace cannot be used in the case of model I, because of interference with the linear axes. The workspace utilization factor however is larger for the model I with no excentricity because the union of the tool workspace and workpiece workspace is relatively smaller compared with model I with excentricity e=50 mm. The orientation space index is the same for both cases if the table diameter is kept the same. Model II can handle much larger workpieces for the same range of linear axes as in model I. The rotary axes are here in the beginning of the kinematic chain, resulting in a much larger machine tool workspace then for model I. Also there is much less interference of the machine tool workspace with the slides. The other 18 possible kinematicchain selections will give index values somewhat in between the above cases.
6.4. rotary table selection
Two machines with the same kinematic diagram (TTRRT) and the same range of travel in the linear axes will be compared (Fig. 17). There are two options for the rotary axes: two-axis table with vertical table (model I), two-axis table with horizontal table (model II). Tables 2 and 3 give the comparison of the important features. It can be observed that reducing the range of the rotary axes increases the machine tool workspace. So model I will be more suited for smaller workpieces with operations which require a large orientation range, typically contouring applications. Model II will be suited for larger workpieces with less variation in tool orientation or will require two setups. This extra setup requirement could be of less importance then the larger size. The horizontal table can use pallets which transform the internal setup to external setup. The larger angle range in the B-axes 105 to +105, Fig. 17. Model I and model II TTRRT machines. compared to 45 to +20, makes model I more suited for complex sculptured surfaces, also because the much higher angular speed range of the vertical angular table. The option with the highest spindle speed should be selected and it will permit the use of smaller cutter diameters resulting in less undercut and smaller cutting forces. The high spindle speed will make the cutting of copper electrodes for die sinking EDM machines easier. The vertical table is also better for the chip removal. The large range of angular orientation, however, reduces the maximum size of the workpiece to about 300 mm and 100 kg. Model II with the same linear axes range as model I, but much smaller range in the rotation, can easily handle a workpiece of double size and weight. Model II will be good for positioning applications. Model I cannot be provided with automatic workpiece exchange, making it less suitable for mass production. Model II has automatic workpiece exchange and is suitable for mass production of position applications. Model I could, however, be selected for positioning applications for parts such as hydraulic valve housings which are small and would require a large angular range.
7.New machine concepts based on the Stewart platform
Conventional machine tool structures are based on Carthesian coordinates. Many surface contouring applications can be machined in optimal conditions only with five-axis machines. This five-axis machine structure requires two additional rotary axes. To make accurate machines, with the required stiffness, able to carry large workpieces, very heavy and large machines are required. As can be seen from the kinematic chain diagram of the classical five-axis machine design the first axis in the chain carries all the subsequent axes. So the dynamic responce will be limited by the combined inertia. A mechanism which can move the workpiece without having to carry the other axes would be the ideal. A new design concept is the use of a ‘HEXAPOD’. Stewart [16] described the hexapod principle in 1965. It was first constructed by Gough and Whitehall [20] in 1954 and served as tire tester. Many possible uses were proposed but it was only applied to flight simulator platforms. The reason was the complexity of the control of the six actuators. Recently with the amazing increase of speed and reduction in cost of computing, the Stewart platform is used by two American Companies in the design of new machine tools. The first machine is the VARIAX machine from the company Giddings and Lewis, USA. The second machine is the HEXAPOD from the Ingersoll company, USA. The systematic design of Hexapods and other similar systems is discussed in Ref. [17]. The problem of defining and determining the workspace of virtual axis machine tools is discussed in Ref. [18]. It can be observed from the design of the machine that once the position of the tool carrying plane is determined uniquely by the CL date (point + vector), it is still possible to rotate the tool carrying platform around the tool axis. This results in a large number of possible length combinations of the telescopic actuators for the same CL data.
8.Conclusion
Theoretically there are large number of ways in which a five-axis machine can be built. Nearly all classical Cartesian five-axis machines belong to the group with three linear and two rotational axes or three rotational axes and two linear axes. This group can be subdivided in six subgroups each with 720 instances.If only the instances with three linear axes are considered there are still 360 instances in each group. The instances are differentiated based on the order of the axes in both tool and workpiece carrying kinematic chain.If only the location of the rotary axes in the tool and workpiece kinematic chain is considered for grouping five-axis machines with three linear axes and two rotational axes, three groups can be distinguished. In the first group the two rotary axes are implemented in the workpiece kinematic chain. In the second group the two rotary axes are implemented in the tool kinematic chain. In the third group there is one rotary axis in each kinematic chain. Each group still has twenty possible instances. To determine the best instance for a specific application area is a complex issue. To facilitate this some indexes for comparison have been defined such as the machine tool workspace, workspace utilization factor, orientation space index, orientation angle index and machine tool space efficiency. An algorithm to compute the machine tool workspace and the diameter of the largest spherical dome which can be machined on the machine was outlined. The use of these indexes for two examples was discussed in detail. The first example considers the design of a five-axis machine for jewelry machining. The second example illustrates the selection of the rotary axes options in the case of a machine with the same range in linear axes.
翻譯題名:Five-axis milling machine tool kinematic chain design and analysis
期刊與作者:E.L.J. Bohez
出版社: International Journal of Machine Tools & Manufacture 42 (2002) 505–520
● 英文譯文
摘要:
現(xiàn)如今五軸數(shù)控加工中心已經(jīng)非常普及。大部分機(jī)床的運(yùn)動(dòng)學(xué)分析都 基于笛卡爾直角坐標(biāo)系。本文羅列了現(xiàn)有的概念設(shè)計(jì)與實(shí)際應(yīng)用,這些從理論上都基于自由度的綜合。一些有用的參數(shù)都有所規(guī)定,比如工件使用系數(shù),機(jī)床空間效率,方向空間搜索以及方向角等。每一種概念,它的優(yōu)缺點(diǎn)都有所分析。選擇的標(biāo)準(zhǔn)及機(jī)器參數(shù)設(shè)置的標(biāo)準(zhǔn)都給出來了。據(jù)于Stewart平臺(tái)的新概念最近行業(yè)內(nèi)已有介紹并作簡短討論。
1.緒論
設(shè)計(jì)一臺(tái)數(shù)控機(jī)床主要要遵循以下規(guī)則:
1,刀具和工件在空間方向上要有足夠的靈活性。
2,方向和位置的改變要盡可能的快。
3,方向和位置的改變要盡可能的準(zhǔn)確。
4,刀具和工件快速變、換。
5,環(huán)保
6,切削材料速度快
一臺(tái)數(shù)控機(jī)床的軸的數(shù)目通常取決于其自由度數(shù)目或者獨(dú)立控制運(yùn)動(dòng)的導(dǎo)軌數(shù)目。國際標(biāo)準(zhǔn)委員會(huì)推薦通過右手笛卡兒坐標(biāo)系來命名坐標(biāo)軸,刀具相應(yīng)的為Z軸。一個(gè)三軸銑床有三條導(dǎo)軌,X,Y,Z向,它們可用來在長度范圍內(nèi)可以在任意位置移動(dòng)。加工過程中刀具軸的位置始終不變。這就限制了刀具相對(duì)于工件在方向上變化的靈活性,并且導(dǎo)致許多偏差的出現(xiàn)。為了盡可能的提高刀具相對(duì)于工件的靈活性,無需重啟,必須要加入多個(gè)自由度。對(duì)于傳統(tǒng)三軸機(jī)床來說這可以通過提供旋轉(zhuǎn)滑臺(tái)來實(shí)現(xiàn)。圖1給出了一個(gè)五軸銑床的例子。
圖1 五軸數(shù)控機(jī)床
1.運(yùn)動(dòng)鏈圖表
通過制作機(jī)器的運(yùn)動(dòng)鏈圖表對(duì)于機(jī)器的分析來說十分有用。通過運(yùn)動(dòng)簡圖可知兩組軸可以迅速的區(qū)分開:工件裝夾軸和刀具軸。圖2給出了圖1.五軸機(jī)床的運(yùn)動(dòng)鏈簡圖。由圖上可以看出工件由四根軸承載,刀具僅在一根軸上。這個(gè)五軸機(jī)床與兩工位操作機(jī)器人很相似,一個(gè)機(jī)器人夾住工件,另一個(gè)夾住刀具。為了獲得刀具工件方向上的最大自由,五個(gè)自由度已是最低要求,這就意味著工件和刀具可以在任意角度位置相對(duì)定位。最低需求的軸數(shù)也可以通過剛體運(yùn)動(dòng)學(xué)的方法來分析。兩個(gè)剛體在空間確定相對(duì)位置,每個(gè)剛體需要6個(gè)到12個(gè)自由度。然而由于任意的移動(dòng)或轉(zhuǎn)動(dòng)并不改變相對(duì)位置就允許將自由度減少到6.兩個(gè)剛體之間的距離通過刀具軌跡來描述,并且允許去掉一個(gè)額外的自由度,結(jié)果也就是5個(gè)自由度。
圖2 運(yùn)動(dòng)鏈圖
2.參考文獻(xiàn)
最早(1970年)到目前并且仍就有參考價(jià)值的對(duì)五軸數(shù)控銑床的介紹之一是由 Baughman提出的并清楚的闡述了它的應(yīng)用(附錄1有他的介紹)。APT語言隨后成為唯一的五軸輪廓加工的編程語言之一。后處理階段的問題也在數(shù)控發(fā)展的早期由Sim清楚的表述出來(附錄2有對(duì)他的介紹),并且大部分問題到現(xiàn)在仍然有效。Boyd(詳見附錄3)也是最早引進(jìn)數(shù)控機(jī)床的先驅(qū)之一。Beziers的書(見附錄4)也是非常有用的介紹。Held(見附錄5)在他的小型銑削加工的書里對(duì)多軸機(jī)床也有非常簡短但啟發(fā)性的定義。目前一篇適用于解決五軸數(shù)控機(jī)床工作空間計(jì)算的文章,通過使用Denawit-Hartenberg發(fā)表并由 Abdel-Malek and Othman(見附錄6)改進(jìn)的算法 應(yīng)用于多弧段切削。許多對(duì)機(jī)床的類型和概念設(shè)計(jì),這些可以被應(yīng)用于五軸機(jī)床,Ref都有討論(見附錄8).關(guān)于對(duì)刀具路徑生成的技巧和新需求由B.K. Choi et al給出(見附錄9)。工件與刀具的圖像模擬也是研究的熱點(diǎn)并且可以在Ref(見附錄10)的書是一個(gè)好的入門讀物。
3.五軸機(jī)床運(yùn)動(dòng)結(jié)構(gòu)的分類
從R軸(旋轉(zhuǎn)軸)和T軸(移動(dòng)軸)劃分大致可以分為四大部分:(i)3個(gè)移動(dòng)軸和2個(gè)轉(zhuǎn)動(dòng)軸;(ii)2個(gè)T軸和3個(gè)R軸;(
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