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畢業(yè)設(shè)計(jì)(論文)開題報(bào)告題目名稱: 數(shù)控車床回轉(zhuǎn)刀架 學(xué) 院: 專 業(yè): 姓 名: 學(xué) 號: 指導(dǎo)教師: 二 年 3 月 18 日一、 畢業(yè)設(shè)計(jì)(論文)的目的與要求:通過本次畢業(yè)設(shè)計(jì),將微機(jī)原理、數(shù)控技術(shù)、檢測技術(shù)、零件設(shè)計(jì)、機(jī)械制圖等知識貫穿起來,是對學(xué)生綜合設(shè)計(jì)能力的一個鍛煉,另外數(shù)控行業(yè)是一個熱門的行業(yè),希望能夠把握這次設(shè)計(jì)的機(jī)會,多從設(shè)計(jì)中找到自己的不足,從而能夠提高自己。技術(shù)要求:1)要求設(shè)計(jì)一個四工位數(shù)控電動刀架2)重復(fù)定位精度(mm)0.0053)主軸電機(jī)功率(w) 204)電機(jī)轉(zhuǎn)速(rpm)1250二、 畢業(yè)設(shè)計(jì)(論文)的內(nèi)容:1)查閱相關(guān)資料,學(xué)習(xí)機(jī)床設(shè)計(jì)的相關(guān)知識,了解電動刀架的基本結(jié)構(gòu)2)確定具體設(shè)計(jì)方案3)零件草圖的繪制4)裝配圖繪制5)電氣部分設(shè)計(jì)6)圖紙打印7)編寫畢業(yè)論文三、 畢業(yè)設(shè)計(jì)(論文)課題應(yīng)完成的工作:1)裝配圖1張2)電氣原理圖1張3)零件圖2張4)盤1張5)外文翻譯1份6)畢業(yè)設(shè)計(jì)說明書1份四、畢業(yè)設(shè)計(jì)(論文)進(jìn)程的安排:序 號設(shè)計(jì)(論文)各階段名稱日 期備 注1收集相關(guān)資料3.143.21交開題報(bào)告2學(xué)習(xí)軟件3.224.17學(xué)習(xí)軟件的使用3確定總體方案4.184.20明確設(shè)計(jì)內(nèi)容,參數(shù)4零件草圖4.215.20繪制零件圖5裝配圖5.215.27繪制裝配圖6生成工程圖5.286.4出圖7編寫畢業(yè)論文6.56.12完成論文8910五、應(yīng)收集的資料及參考文獻(xiàn)1、位置檢測與數(shù)量技術(shù)李謀主編;機(jī)械工業(yè)出版社2、機(jī)床數(shù)控技術(shù)及其應(yīng)用林奕鴻編著;機(jī)械工業(yè)出版社3、現(xiàn)代數(shù)控機(jī)床伺服及檢測技術(shù)白恩遠(yuǎn),王俊元,孫愛國主編;國防工業(yè)出版社4、數(shù)控實(shí)用技術(shù)浙江工業(yè)大學(xué)王貴名編著;機(jī)械工業(yè)出版社5、數(shù)字控制技術(shù)與數(shù)控機(jī)床楊有軍主編;機(jī)械工業(yè)出版社6、電氣控制技術(shù)弭洪濤,宋宏主編;吉林科學(xué)技術(shù)出版社7、機(jī)電傳動控制鄧星鐘主編;華中科技大學(xué)出版社8、機(jī)械設(shè)計(jì)高等教育出版社9、機(jī)械零件鄭志祥,文天一主編;高等教育出版社10、實(shí)用機(jī)床設(shè)計(jì)手冊李洪主編;遼寧科學(xué)技術(shù)出版社六、任務(wù)執(zhí)行日期自 年 月 日起,至 年 月 日止。學(xué) 生(簽字) 指導(dǎo)教師(簽字) 系 主 任(簽字) 機(jī)電一體化課程設(shè)計(jì)計(jì)算說明書題 目: 自動回轉(zhuǎn)刀架設(shè)計(jì) 系: 專 業(yè): 學(xué)生姓名: 指導(dǎo)教師: 20*年 6 月 21 日 機(jī)電一體化課程設(shè)計(jì)計(jì)算說明書 目錄第1節(jié) 自動回轉(zhuǎn)刀架總體設(shè)計(jì).11.1 概述.11.2 控車床自動回轉(zhuǎn)刀架的發(fā)展趨勢.11.3 自動回轉(zhuǎn)刀架的工作原理.2第2節(jié) 主要傳動部件的設(shè)計(jì)計(jì)算.42.1 蝸桿副的設(shè)計(jì)計(jì)算.42.2 蝸桿軸的設(shè)計(jì).62.3 蝸輪軸的設(shè)計(jì).122.4 中心軸的設(shè)計(jì).132.5 齒盤的設(shè)計(jì).142.6 軸承的選用.16第3節(jié) 刀架體的設(shè)計(jì).17第4節(jié) 結(jié)論.18致謝.19參考文獻(xiàn).20第1節(jié) 自動回轉(zhuǎn)刀架總體設(shè)計(jì)1.1 概述數(shù)控車床的刀架是機(jī)床的重要組成部分。刀架用于夾持切削用的刀具,因此其結(jié)構(gòu)直接影響機(jī)床的切削性能和切削效率。在一定程度上,刀架的結(jié)構(gòu)和性能體現(xiàn)了機(jī)床的設(shè)計(jì)和制造技術(shù)水平。隨著數(shù)控車床的不斷發(fā)展,刀架結(jié)構(gòu)形式也在不斷翻新。其中按換刀方式的不同,數(shù)控車床的刀架系統(tǒng)主要有回轉(zhuǎn)刀架、排式刀架和帶刀庫的自動換刀裝置等多種形式。自1958年首次研制成功數(shù)控加工中心自動換刀裝置以來,自動換刀裝置的機(jī)械結(jié)構(gòu)和控制方式不斷得到改進(jìn)和完善。自動換刀裝置是加工中心的重要執(zhí)行機(jī)構(gòu),它的形式多種多樣,目前常見的有:回轉(zhuǎn)刀架換刀,更換主軸頭換刀以及帶刀庫的自動換刀系統(tǒng)。初步了解了設(shè)計(jì)題目(電動刀架)及發(fā)展概況,設(shè)計(jì)背景,對刀架有了一些印象,對整理設(shè)計(jì)思路 安排設(shè)計(jì)時間有很好的輔助作用。對一些參數(shù)的進(jìn)行了解同時按準(zhǔn)則要求來完成設(shè)計(jì)。1.2 數(shù)控車床自動回轉(zhuǎn)刀架的發(fā)展趨勢數(shù)控刀架的發(fā)展趨勢是:隨著數(shù)控車床的發(fā)展,數(shù)控刀架開始向快速換刀、電液組合驅(qū)動和伺服驅(qū)動方向發(fā)展。目前國內(nèi)數(shù)控刀架以電動為主,分為立式和臥式兩種。主要用于簡易數(shù)控車床;臥式刀架有八、十、十二等工位,可正、反方向旋轉(zhuǎn),就近選刀,用于全功能數(shù)控車床。另外臥式刀架還有液動刀架和伺服驅(qū)動刀架。電動刀架是數(shù)控車床重要的傳統(tǒng)結(jié)構(gòu),合理地選配電動刀架,并正確實(shí)施控制,能夠有效的提高勞動生產(chǎn)率,縮短生產(chǎn)準(zhǔn)備時間,消除人為誤差,提高加工精度與加工精度的一致性等等。另外,加工工藝適應(yīng)性和連續(xù)穩(wěn)定的工作能力也明顯提高:尤其是在加工幾何形狀較復(fù)雜的零件時,除了控制系統(tǒng)能提供相應(yīng)的控制指令外,很重要的一點(diǎn)是數(shù)控車床需配備易于控制的電動刀架,以便一次裝夾所需的各種刀具,靈活 方便地完成各種幾何形狀的加工。數(shù)控刀架的市場分析:國產(chǎn)數(shù)控車床將向中高檔發(fā)展,中檔采用普及型數(shù)控刀架配套,高檔采用動力型刀架,兼有液壓刀架、伺服刀架、立式刀架等品種。數(shù)控刀架的高、中、低檔產(chǎn)品市場數(shù)控刀架作為數(shù)控機(jī)床必需的功能部件,直接影響機(jī)床的性能和可靠性,是機(jī)床的故障高發(fā)點(diǎn)。這就要求設(shè)計(jì)的刀架具有具有轉(zhuǎn)位快,定位精度高,切向扭矩大的特點(diǎn)。它的原理采用蝸桿傳動,上下齒盤嚙合,螺桿夾緊的工作原理。1.3 自動回轉(zhuǎn)刀架的工作原理回轉(zhuǎn)刀架的工作原理為機(jī)械螺母升降轉(zhuǎn)位式。工作過程可分為刀架抬起、刀架轉(zhuǎn)位、刀架定位并壓緊等幾個步驟。圖1.1為螺旋升降式四方刀架,其工作過程如下: 刀架抬起 當(dāng)數(shù)控系統(tǒng)發(fā)出換刀指令后, 通過接口電路使電機(jī)正轉(zhuǎn), 經(jīng)傳動裝置、驅(qū)動蝸桿蝸輪機(jī)構(gòu)。蝸輪帶動絲桿螺母機(jī)構(gòu)逆時針旋轉(zhuǎn) ,此時由于齒盤處于嚙合狀態(tài),在絲桿螺母機(jī)構(gòu)轉(zhuǎn)動時,使上刀架體產(chǎn)生向上的軸向力將齒盤松開并抬起,直至兩定位齒盤脫離嚙合狀態(tài),從而帶動上刀架和齒盤產(chǎn)生“上抬”動作。 刀架轉(zhuǎn)位 當(dāng)圓套逆時針轉(zhuǎn)過150時,齒盤完全脫開,此時銷釘準(zhǔn)確進(jìn)入圓套中的凹槽中,帶動刀架體轉(zhuǎn)位。 刀架定位 當(dāng)上刀架轉(zhuǎn)到需要到位后(旋轉(zhuǎn)90、180或270),數(shù)控裝置發(fā)出的換刀指令使霍爾開關(guān)中的某一個選通,當(dāng)磁性板與被選通的霍爾開關(guān)對齊后,霍爾開關(guān)反饋信號使電機(jī)反轉(zhuǎn),插銷在彈簧力作用下進(jìn)入反靠盤地槽中進(jìn)行粗定位,上刀架體停止轉(zhuǎn)動,電機(jī)繼續(xù)反轉(zhuǎn),使其在該位置落下,通過螺母絲桿機(jī)構(gòu)使上刀架移到齒盤重新嚙合, 實(shí)現(xiàn)精確定位。刀架壓緊 刀架精確定位后,電機(jī)及許反轉(zhuǎn),夾緊刀架,當(dāng)兩齒盤增加到一定夾緊力時, 電機(jī)由數(shù)控裝置停止反轉(zhuǎn),防止電機(jī)不停反轉(zhuǎn)而過載毀壞,從而完成一次換刀過程。圖1.1 螺旋升降式四方刀架第2節(jié) 主要傳動部件的設(shè)計(jì)計(jì)算2.1 蝸桿副的設(shè)計(jì)計(jì)算自動回轉(zhuǎn)刀架的動力源是三相異步電動機(jī),其中蝸桿與電動機(jī)直聯(lián),刀架轉(zhuǎn)位時蝸輪與上刀體直聯(lián)。已知電動機(jī)額定功率P1=90W,額定轉(zhuǎn)速n1=1440rmin,上刀體設(shè)計(jì)轉(zhuǎn)速n2=30rmin,則蝸桿副的傳動比i= =48。刀架從轉(zhuǎn)位到鎖緊時,需要蝸桿反向,工作載荷不均勻,起動時沖擊較大,今要求蝸桿副的使用壽命Lh=10000h。(1)蝸桿的選型 GBT10085-1988推薦采用漸開線蝸桿(ZI蝸桿)和錐面包絡(luò)蝸桿(ZK蝸桿)。本設(shè)計(jì)采用結(jié)構(gòu)簡單、制造方便的漸開線型圓柱蝸桿(ZI型)。(2)蝸桿副的材料 刀架中的蝸桿副傳遞的功率不大,但蝸桿轉(zhuǎn)速較高,因此,蝸桿的材料選用45鋼,其螺旋齒面要求淬火,硬度為4555HRC,以提高表面耐磨性;蝸輪的轉(zhuǎn)速較低,其材料主要考慮耐磨性,選用鑄錫磷青銅ZCuSnl0P1,采用金屬模鑄造。(3)按齒面接觸疲勞強(qiáng)度進(jìn)行設(shè)計(jì) 刀架中的蝸桿副采用閉式傳動,多因齒面膠合或點(diǎn)蝕而失效。因此,在進(jìn)行承載能力計(jì)算時,先按齒面接觸疲勞強(qiáng)度進(jìn)行設(shè)計(jì),再按齒根彎曲疲勞強(qiáng)度進(jìn)行校核。按蝸輪接觸疲勞強(qiáng)度條件設(shè)計(jì)計(jì)算的公式為:1) 確定作用在蝸輪上的轉(zhuǎn)矩T2 設(shè)蝸桿頭數(shù)Z1=1,蝸桿副的傳動效率取=0.8。由電動機(jī)的額定功率P1=90W,可以算得蝸輪傳遞的功率P2=P1,再由蝸輪的轉(zhuǎn)速n2=30r min求得作用在蝸輪上的轉(zhuǎn)矩: 2)確定載荷系數(shù)K 載荷系數(shù)K=KAKBKV,。其中KA為使用系數(shù),由表6-3查得,由于工作載荷不均勻,起動時沖擊較大,因此取KA=1.15;KB為齒向載荷分布系數(shù),因工作載荷在起動和停止時有變化,故取KB=1.15;Kv為動載系數(shù),由于轉(zhuǎn)速不高、沖擊不大,可取Kv=1.05。則載荷系數(shù): K=KAKBKV=1.151.151.051.393)確定彈性影響系數(shù)ZE。 鑄錫磷青銅蝸輪與鋼蝸桿相配時,從有關(guān)手冊查得彈性影響系數(shù)。4)確定接觸系數(shù) 先假設(shè)蝸桿分度圓直徑d1和傳動中心距a的比值,從而可查出=2.95)確定許用接觸應(yīng)力H 根據(jù)蝸輪材料為鑄錫磷青銅ZCuSnl0P1、金屬模鑄造、蝸桿螺旋齒面硬度大于45HRC,查表可得蝸輪的基本許用應(yīng)力H =268MPa。已知蝸桿為單頭,蝸輪每轉(zhuǎn)一轉(zhuǎn)時每個輪齒嚙合的次數(shù)j=1;蝸輪轉(zhuǎn)速n1=30rmin;蝸桿副的使用壽命Lh=10000h。則應(yīng)力循環(huán)次數(shù): N=6Qjn2Lh=60130 x 10000=1.8107 壽命系數(shù): 許用接觸應(yīng)力: H=KHNH=0.929268Mpa 249Mpa6) 計(jì)算中心距 查表得,取中心距,已知蝸桿頭數(shù)=1,m=1.25mm,蝸桿分度圓直徑d1=22.4mm。這時0.448,從而可查得接觸系數(shù),因?yàn)?,因此以上?jì)算結(jié)果可用。蝸桿和蝸輪主要幾何尺寸計(jì)算(1)蝸桿 分度圓直徑:d1=28mm 直徑系數(shù):q=17.92, 蝸桿頭數(shù):Z1=1 分度圓導(dǎo)程角:=31138 蝸桿軸向齒距:PA=3.94mm;蝸桿齒頂圓直徑:蝸桿齒根圓直徑:蝸桿軸向齒厚: =2.512mm蝸桿軸向齒距:(2)蝸輪 蝸輪齒數(shù):Z2 =45 變位系數(shù)=0 驗(yàn)算傳動比:i=/=45/1=45 蝸輪分度圓直徑:d2=mz2=72mm 蝸輪喉圓直徑:da2=d2+2ha2=93.5 蝸輪喉母圓直徑:rg2=a-1/2 da2 =50-1/293.5=3.25 蝸輪齒頂圓直徑: 蝸輪齒根圓直徑: 蝸輪外圓直徑:當(dāng)在z=1時,2.2 蝸桿軸的設(shè)計(jì)(1) 蝸桿軸的材料選擇,確定許用應(yīng)力考慮軸主要傳遞蝸輪的轉(zhuǎn)矩,為普通用途中小功率減速傳動裝置。選用45號鋼,正火處理,(2) 按扭轉(zhuǎn)強(qiáng)度初步估算軸的最小直徑 (2-21) 扭轉(zhuǎn)切應(yīng)力為脈動循環(huán)變應(yīng)力,取=0.6 抗彎截面系數(shù)W=0.1d3 取dmin=15.14mm(3) 確定各軸段的直徑和長度 根據(jù)各個零件在軸上的定位和裝拆方案確定軸的形狀及直徑和長度。 圖2.1 蝸桿軸d1=d5 同一軸上的軸承選用同一型號,以便于軸承座孔鏜制和減少軸承類型。d5軸上有一個鍵槽,故槽徑增大5%d1=d5=d1(1+5%)=15.89mm ,圓整d1=d5=17mm所選軸承類型為深溝球軸承,型號為6203,B=12mm,D=40mm,d2起固定作用,定位載荷高度可在(0.070.1)d1范圍內(nèi),d2=d1+2a=19.3820.04mm,故d2取20mmd3為蝸桿與蝸輪嚙合部分,故d3=24mmd4=d2=20mm,便于加工和安裝L1為與軸承配合的軸段,查軸承寬度為12mm,端蓋寬度為10mm,則L1=22mmL2尺寸長度與刀架體的設(shè)計(jì)有關(guān),蝸桿端面到刀架端面距離為65mm,故L2=43mmL3為蝸桿部分長度L3(11+0. 6z2)m=38mm圓整L3取40mmL4取55mm,L5在刀架體部分長度為(12+8)mm,伸出刀架部分通過聯(lián)軸器與電動機(jī)相連長度為50mm,故L5=70mm兩軸承的中心跨度為128mm,軸的總長為230mm(4)蝸桿軸的校核作用在蝸桿軸上的圓周力 (2-22) (2-23) 其中d1=28mm則 (2-24) 徑向力 (2-25) 切向力 (2-26)圖2.2 軸向受力分析 (2-27) (2-28)求水平方向上的支承反力 圖2.3 水平方向支承力(2-27)(2-28) (2-29)求水平彎矩,并繪制彎矩圖(2-30)圖2.4 水平彎矩圖求垂直方向的支承反力 (2-31) 查文獻(xiàn)9表2.24,其中, (2-32)圖2.5 垂直方向支承反力(2-33)(2-34) 求垂直方向彎矩,繪制彎矩圖圖2.6 垂直彎矩圖求合成彎矩圖,按最不利的情況考慮 (2-38)(2-39)圖2.7 合成彎矩圖計(jì)算危險(xiǎn)軸的直徑 查文獻(xiàn)9表151,材料為調(diào)質(zhì)的許用彎曲應(yīng)力,則 所以該軸符合要求。(5)鍵的選取與校核 考慮到d5=105%15.14=15.89mm, 實(shí)際直徑為17mm,所以強(qiáng)度足夠由GB1095-79查得,尺寸bh=55,l=20mm的A型普通平鍵。 按公式進(jìn)行校核 ,。查文獻(xiàn)9表62,取則 (2-42)該鍵符合要求。由普通平鍵標(biāo)準(zhǔn)查得軸槽深t=3mm,轂槽深t1=2.3mm2.3 蝸輪軸的設(shè)計(jì)(1) 蝸輪軸材料的選擇,確定需用應(yīng)力考慮到軸主要傳遞蝸輪轉(zhuǎn)矩,為普通中小功率減速傳動裝置選用45號鋼,正火處理, (2) 按扭轉(zhuǎn)強(qiáng)度,初步估計(jì)軸的最小直徑 查文獻(xiàn)9表151,取45號調(diào)質(zhì)剛的許用彎曲應(yīng)力,則由于軸的平均直徑為34mm,因此該軸安全。(3) 確定各軸段的直徑和長度根據(jù)各個零件在軸上的定位和裝拆方案確定軸的形狀及直徑和長度即蝸輪輪芯為68mm為蝸輪軸軸徑最小部分取34mm軸段與上刀架體有螺紋聯(lián)接,牙形選梯形螺紋,根據(jù)文獻(xiàn)表8-45取公稱直徑為=44mm,螺距P=12mm,H=6.5mm查表8-46得,外螺紋小徑為31mm 內(nèi)、外螺紋中徑為38mm 內(nèi)螺紋大徑為45mm內(nèi)螺紋小徑為32mm 旋合長度取55mmL2尺寸長度為34mm,蝸輪齒寬b2 當(dāng)z13時,b20.75da1=15.6mm 取b2=15mm2.4 中心軸的設(shè)計(jì)(1) 中軸的材料選擇,確定許用應(yīng)力考慮到軸主要起定位作用,只承受部分彎矩,為空心軸,因此只需校核軸的剛度即可。選用45號鋼,正火處理,(2) 確定各軸段的直徑和長度根據(jù)各個零件在軸上的定位和裝拆方案確定軸的形狀及直徑和長度d1=15mm,d2與軸承配合,軸承類型為推力球軸承,型號為51203,d=17mm,d1=19,T=12mm,D=35mm所以d2=17mmd3與軸承配合,軸承類型為推力球軸承,型號為51204,d=25mm,d1=27mm,T=15mm,D=47mm分配各軸段的長度L1=80mm,L2=93mm,L3=20mm(3) 軸的校核軸橫截面的慣性矩車床切削力F=2KN,E=210GPa 因此yy中心軸滿足剛度條件2.5 齒盤的設(shè)計(jì)(1) 齒盤的材料選擇和精度等級上下齒盤均選用45號鋼,淬火,180HBS。初選7級精度等級(2) 確定齒盤參數(shù)考慮齒盤主要用于精確定位和夾緊,齒形選用三角齒形,上下齒盤由于需相互嚙合,參數(shù)可相同。當(dāng)蝸輪軸旋轉(zhuǎn)150時,上刀架上升5mm,齒盤的齒高取4mm由 得算式 4=(21+0.25)m,標(biāo)準(zhǔn)值ha*=1.0, c*=0.25。求出m=1.78mm,取標(biāo)準(zhǔn)值m=2mm。故齒盤齒全高h(yuǎn)=(2ha*+c*)m=(21+0.25)2=4.5mm。取齒盤內(nèi)圓直徑d為120mm,外圓直徑為140mm,齒頂高 ha=ha*m=12=2m齒根高 hf=(ha*+c*)m=2.5mm 齒數(shù)z=38,齒寬b=10mm,齒厚,齒盤高為5mm。(3) 按接觸疲勞強(qiáng)度進(jìn)行計(jì)算1)確定有關(guān)計(jì)算參數(shù)和許用應(yīng)力 2)取載荷系數(shù)kt=1.53)由文獻(xiàn)表9-12取齒寬系數(shù)d=1.04)由表9-10查得材料的彈性影響系數(shù)Ze=189.8,取=20,故ZH=2.55)查表取Hlim1=380,取Hlim2=3806)Lh=60241(830015)。N2=5.181077)由圖9-35查得接觸疲勞壽命系數(shù)ZN1=1.1 ,ZN2=1.18)計(jì)算接觸疲勞需用應(yīng)力 取安全系數(shù)SH=1。 (4)按齒根抗彎強(qiáng)度設(shè)計(jì)抗彎強(qiáng)度的設(shè)計(jì)公式為 確定公式內(nèi)的各參數(shù)數(shù)值1)由文獻(xiàn)圖9-37查得,抗彎疲勞強(qiáng)度極限2)由文獻(xiàn)圖9-38查得,抗彎疲勞壽命系數(shù)YN1=1.0,YN2=1.03)查圖取4)計(jì)算抗彎疲勞許用應(yīng)力,取抗彎疲勞安全系數(shù)=1.4 5)彎曲疲勞強(qiáng)度驗(yàn)算。故滿足彎曲疲勞強(qiáng)度要求2.6 軸承的選用圓錐滾子軸承是現(xiàn)代機(jī)器中廣泛應(yīng)用的部件之一。它是依靠主要元件的滾動接觸來支撐轉(zhuǎn)動零件的。與滑動軸承相比,滾動軸承摩擦力小,功率消耗少,啟動容易等優(yōu)點(diǎn)。并且常用的滾動軸承絕大多數(shù)已經(jīng)標(biāo)準(zhǔn)化,因此使用滾動軸承時,只要根據(jù)具體工作條件正確選擇軸承的類型和尺寸。驗(yàn)算軸承的承載能力。以及與軸承的安裝、調(diào)整、潤滑、密封等有關(guān)的“軸承裝置設(shè)計(jì)”問題。(1) 軸承的類型考慮到軸各個方面的誤差會直接傳遞給加工工件時的加工誤差,因此選用調(diào)心性能比較好的深溝球軸承。此類軸承可以同時承受徑向載荷及軸向載荷,安裝時可調(diào)整軸承的游隙。然后根據(jù)安裝尺寸和使用壽命選出軸承的型號為:6203(2)滾動軸承的配合滾動軸承是標(biāo)準(zhǔn)件,為使軸承便于互換和大量生產(chǎn),軸承內(nèi)孔于軸的配合采用基孔制,即以軸承內(nèi)孔的尺寸為基準(zhǔn);軸承外徑與外殼的配合采用基軸制,即以軸承的外徑尺寸為基準(zhǔn)。第3節(jié) 刀架體的設(shè)計(jì)刀架體設(shè)計(jì)首先要考慮刀架體內(nèi)零件的布置及與刀架體外部零件的關(guān)系,應(yīng)考慮以下問題: (a) 滿足強(qiáng)度和剛度要求。因?yàn)榈都荏w的剛度不僅影響傳動零件的正常工作,而且還影響部件的工作精度。 (b) 結(jié)構(gòu)設(shè)計(jì)合理。如支點(diǎn)的安排、開孔位置和連接結(jié)構(gòu)的設(shè)計(jì)等均要有利于提高刀架體的強(qiáng)度和剛度。 (c) 工藝性好。包括毛坯制造、機(jī)械加工及熱處理、裝配調(diào)整、安裝固定、吊裝運(yùn)輸、維護(hù)修理等各方面的工藝性。 (d) 造型好、質(zhì)量小。 刀架體的常用材料有: 鑄鐵,多數(shù)刀架體的材料為鑄鐵,鑄鐵流動性好,收縮較小,容易獲得形狀和結(jié)構(gòu)復(fù)雜的箱體。鑄鐵的阻尼作用強(qiáng),動態(tài)剛性和機(jī)加工性能好,價格適度。加入合金元素還可以提高耐磨性。 鑄造鋁合金,用于要求減小質(zhì)量且載荷不太大的箱體。多數(shù)可通過熱處理進(jìn)行強(qiáng)化,有足夠的強(qiáng)度和較好的塑性。 我所設(shè)計(jì)的下刀架體采用HT150鑄造。第4節(jié) 結(jié)論本次設(shè)計(jì)采用了四工位刀架,通過電機(jī)驅(qū)動,渦輪蝸桿的傳動,有效的實(shí)現(xiàn)了縮短輔助時間,減少多次安裝零件引起的誤差。本次設(shè)計(jì)的四工位自動回轉(zhuǎn)刀架結(jié)構(gòu)比較簡單,滿足時間短,刀具重復(fù)定位精度夠,足夠的刀具存儲以及安全可靠等基本要求。回轉(zhuǎn)刀架在結(jié)構(gòu)上必須具有良好的強(qiáng)度和剛度,以承受粗加工時的切削抗力和減少刀架在切削力作用下的位移變形,提高加工精度。由于車削加工精度在很大程度上取決于刀尖位置,對于數(shù)控車床來說,加工過程中刀架部位要進(jìn)行人工調(diào)整,因此更有必要選擇可靠的定位方案和合理的定位結(jié)構(gòu),以保證回轉(zhuǎn)刀架在每次轉(zhuǎn)位之后具有高的重復(fù)定位精度(一般為0.0010.005mm)。設(shè)計(jì)過程中所涉及的內(nèi)容有機(jī)械設(shè)計(jì)、傳動和電器控制三個方面的知識,通過本次課程設(shè)計(jì)使我受到一次對所學(xué)知識的運(yùn)用能力的鍛煉,從而使對所學(xué)基礎(chǔ)理論和專業(yè)技能有機(jī)的結(jié)合起來,提高自己的知識運(yùn)用能力和解決工程實(shí)際問題的能力。致謝終于完成了課程設(shè)計(jì)了,在這段的緊張生活中,首先我要感謝我的指導(dǎo)老師王偉老師,沒有他的指點(diǎn)和教誨,就沒有這次設(shè)計(jì)的完成,他在我無能為力的時候給我提出了很多建設(shè)性的意見和建議,開拓了我的思路。最后,對所有幫助過我的老師和同學(xué)表示感謝!參考文獻(xiàn)1 王三民.諸文俊. 機(jī)械原理與設(shè)計(jì)M.北京:機(jī)械工業(yè)出版社,2000.2 王愛玲.現(xiàn)代數(shù)控車床M.北京:國防工業(yè)出版社,2003 . 3 陳嬋娟.數(shù)控車床設(shè)計(jì)M.北京:化學(xué)工業(yè)出版社,2006. 4 王愛玲.現(xiàn)代數(shù)控車床結(jié)構(gòu)與設(shè)計(jì)M.北京:兵器工業(yè)出版社,1999.5 紀(jì)名剛.機(jī)械設(shè)計(jì)M.北京:高等教育出版社,2000,第七版. 6 舒志兵.嚴(yán)彩忠.黃益群.張海榮.數(shù)控機(jī)床和數(shù)控系統(tǒng)的發(fā)展綜述J.伺服控制,2006,(01):23-27 7 劉澤深. 鄭貴臣.陳保青. 機(jī)械基礎(chǔ)M. 北京:機(jī)械工業(yè)出版社,1997.8 李洪.實(shí)用機(jī)床設(shè)計(jì)手冊M.遼寧:遼寧科學(xué)技術(shù)出版社:1999.9 徐灝.機(jī)械設(shè)計(jì)手冊M.北京:機(jī)械工業(yè)出版社,2002.10 洪家娣.機(jī)械設(shè)計(jì)指導(dǎo)M.江西:江西高校出版社,2001.11 陳秀寧.機(jī)械設(shè)計(jì)基礎(chǔ)M.杭州:浙江大學(xué)出版社,1999. 12 徐灝.新編機(jī)械設(shè)計(jì)師手冊M.北京:機(jī)械工業(yè)出版社,199513 王曉明.電動機(jī)的單片機(jī)控制.北京:航空航天大學(xué)出版社,200714 何立民著.單片機(jī)原理及其接口技術(shù).北京航空航天出版社, 200615 鄭堤 唐可洪 機(jī)電一體化設(shè)計(jì)基礎(chǔ).機(jī)械工業(yè)出版社 ,200716 張建民等著.機(jī)電一體化系統(tǒng)設(shè)計(jì).高等教育出版社,200717 尹志強(qiáng)著.機(jī)電一體化系統(tǒng)設(shè)計(jì)課程設(shè)計(jì)指導(dǎo)書.機(jī)械工業(yè)出版社, 200827附件圖紙部裝圖電氣圖蝸桿軸裝配圖機(jī)電一體化課程設(shè)計(jì)計(jì)算說明書 目錄第1節(jié) 自動回轉(zhuǎn)刀架總體設(shè)計(jì).11.1 概述.11.2 控車床自動回轉(zhuǎn)刀架的發(fā)展趨勢.11.3 自動回轉(zhuǎn)刀架的工作原理.2第2節(jié) 主要傳動部件的設(shè)計(jì)計(jì)算.42.1 蝸桿副的設(shè)計(jì)計(jì)算.42.2 蝸桿軸的設(shè)計(jì).62.3 蝸輪軸的設(shè)計(jì).122.4 中心軸的設(shè)計(jì).132.5 齒盤的設(shè)計(jì).142.6 軸承的選用.16第3節(jié) 刀架體的設(shè)計(jì).17第4節(jié) 結(jié)論.18致謝.19參考文獻(xiàn).201 畢業(yè)設(shè)計(jì)(論文)任務(wù)書題目名稱: 數(shù)控車床回轉(zhuǎn)刀架 學(xué) 院: 專 業(yè): 姓 名: 學(xué) 號: 指導(dǎo)教師: 二 年 3 月 18 日一、 畢業(yè)設(shè)計(jì)(論文)的目的與要求:通過本次畢業(yè)設(shè)計(jì),將微機(jī)原理、數(shù)控技術(shù)、檢測技術(shù)、零件設(shè)計(jì)、機(jī)械制圖等知識貫穿起來,是對學(xué)生綜合設(shè)計(jì)能力的一個鍛煉,另外數(shù)控行業(yè)是一個熱門的行業(yè),希望能夠把握這次設(shè)計(jì)的機(jī)會,多從設(shè)計(jì)中找到自己的不足,從而能夠提高自己。技術(shù)要求:1)要求設(shè)計(jì)一個四工位數(shù)控電動刀架2)重復(fù)定位精度(mm)0.0053)主軸電機(jī)功率(w) 204)電機(jī)轉(zhuǎn)速(rpm)1250二、 畢業(yè)設(shè)計(jì)(論文)的內(nèi)容:1)查閱相關(guān)資料,學(xué)習(xí)機(jī)床設(shè)計(jì)的相關(guān)知識,了解電動刀架的基本結(jié)構(gòu)2)確定具體設(shè)計(jì)方案3)零件草圖的繪制4)裝配圖繪制5)電氣部分設(shè)計(jì)6)圖紙打印7)編寫畢業(yè)論文三、 畢業(yè)設(shè)計(jì)(論文)課題應(yīng)完成的工作:1)裝配圖1張2)電氣原理圖1張3)零件圖2張4)盤1張5)外文翻譯1份6)畢業(yè)設(shè)計(jì)說明書1份四、畢業(yè)設(shè)計(jì)(論文)進(jìn)程的安排:序 號設(shè)計(jì)(論文)各階段名稱日 期備 注1收集相關(guān)資料3.143.21交開題報(bào)告2學(xué)習(xí)軟件3.224.17學(xué)習(xí)軟件的使用3確定總體方案4.184.20明確設(shè)計(jì)內(nèi)容,參數(shù)4零件草圖4.215.20繪制零件圖5裝配圖5.215.27繪制裝配圖6生成工程圖5.286.4出圖7編寫畢業(yè)論文6.56.12完成論文8910五、應(yīng)收集的資料及參考文獻(xiàn)1、位置檢測與數(shù)量技術(shù)李謀主編;機(jī)械工業(yè)出版社2、機(jī)床數(shù)控技術(shù)及其應(yīng)用林奕鴻編著;機(jī)械工業(yè)出版社3、現(xiàn)代數(shù)控機(jī)床伺服及檢測技術(shù)白恩遠(yuǎn),王俊元,孫愛國主編;國防工業(yè)出版社4、數(shù)控實(shí)用技術(shù)浙江工業(yè)大學(xué)王貴名編著;機(jī)械工業(yè)出版社5、數(shù)字控制技術(shù)與數(shù)控機(jī)床楊有軍主編;機(jī)械工業(yè)出版社6、電氣控制技術(shù)弭洪濤,宋宏主編;吉林科學(xué)技術(shù)出版社7、機(jī)電傳動控制鄧星鐘主編;華中科技大學(xué)出版社8、機(jī)械設(shè)計(jì)高等教育出版社9、機(jī)械零件鄭志祥,文天一主編;高等教育出版社10、實(shí)用機(jī)床設(shè)計(jì)手冊李洪主編;遼寧科學(xué)技術(shù)出版社六、任務(wù)執(zhí)行日期自 年 月 日起,至 年 月 日止。學(xué) 生(簽字) 指導(dǎo)教師(簽字) 系 主 任(簽字) mapeng.net 加工基礎(chǔ)霍斯金斯,喬賽亞 美國作為產(chǎn)生形狀的一種加工方法,機(jī)械加工是所有制造過程中最普遍使用的而且是最重要的方法。機(jī)械加工過程是一個產(chǎn)生形狀的過程,在這過程中,驅(qū)動裝置使工件上的一些材料以切屑的形式被去除。盡管在某些場合,工件無承受情況下,使用移動式裝備來實(shí)現(xiàn)加工,但大多數(shù)的機(jī)械加工是通過既支承工件又支承刀具的裝備來完成。機(jī)械加工在知道過程中具備兩方面。小批生產(chǎn)低費(fèi)用。對于鑄造、鍛造和壓力加工,每一個要生產(chǎn)的具體工件形狀,即使是一個零件,幾乎都要花費(fèi)高額的加工費(fèi)用??亢附觼懋a(chǎn)生的結(jié)構(gòu)形狀,在很大程度上取決于有效的原材料的形式一般來說,通過利用貴重設(shè)備而又無需特種加工條件下,幾乎可以以任何種類原材料開始,借助機(jī)械加工把原材料加工成任意所需要的結(jié)構(gòu)形狀,只要外部尺寸足夠大,那都是可能的。因此對于生產(chǎn)一個零件,甚至當(dāng)零件結(jié)構(gòu)及要生產(chǎn)的批量大小上按原來都適于用鑄造、鍛造或者壓力加工來生產(chǎn)的,但通常寧可選擇機(jī)械加工。嚴(yán)密的精度和良好的表面光潔度,機(jī)械加工的第二方面用途是建立在高精度和可能的表面光潔度基礎(chǔ)上.許多零件,如果用別的其他方法來生產(chǎn)屬于大批量生產(chǎn)的話,那么在機(jī)械加工中則是屬于低公差且又能滿足要求的小批量生產(chǎn)了。另方面,許多零件靠較粗的生產(chǎn)加工工藝提高其一般表面形狀,而僅僅是在需要高精度的且選擇過的表面才進(jìn)行機(jī)械加工。例如內(nèi)螺紋,除了機(jī)械加工之外,幾乎沒有別的加工方法能進(jìn)行加工。又如己鍛工件上的小孔加工,也是被鍛后緊接著進(jìn)行機(jī)械加工才完成的?;镜臋C(jī)械加工參數(shù)切削中工件與刀具的基本關(guān)系是以以下四個要素來充分描述的:刀具的幾何形狀,切削速度,進(jìn)給速度,和吃刀深度。切削刀具必須用一種合適的材料來制造,它必須是強(qiáng)固、韌性好、堅(jiān)硬而且耐磨的。刀具的凡何形狀以刀尖平面和刀具角為特征對于每一種切削工藝都必須是正確的。切削速度是切削刃通過工件表面的速率,它是以每分鐘英寸來表示。為了有效地加工,切削速度高低必須適應(yīng)特定的工件刀具配合。一般來說,工件材料越硬,速度越低。進(jìn)給速度是刀具切進(jìn)工件的速度。若工件或刀具作旋轉(zhuǎn)運(yùn)動,進(jìn)給量是以每轉(zhuǎn)轉(zhuǎn)過的英寸數(shù)目來度量的。當(dāng)?shù)毒呋蚬ぜ魍鶑?fù)運(yùn)動時,進(jìn)給量是以每一行程走過的英寸數(shù)度量的。一般來說,在其他條件相同時,進(jìn)給量與切削速度成反比。吃刀深度以英寸計(jì)是刀具進(jìn)入工件的距離。它等于旋削中的切屑寬度或者等于線性切削中的切屑的厚度。粗加工比起精加工來,吃刀深度較深。切削參數(shù)的改變對切削溫度的影響金屬切削操作中,熱是在主變形區(qū)和副變形區(qū)發(fā)生的。這結(jié)果導(dǎo)致復(fù)雜的溫度分布遍及刀具、工件和切屑。圖中顯示了一組典型等溫曲線,從中可以看出:像所能預(yù)料的那樣,當(dāng)工件材料在主變形區(qū)被切削時,沿著整個切屑的寬度上有著很大的溫度梯度,而當(dāng)在副變形區(qū),切屑被切落時,切屑附近的前刀面上就解花趕高的溫度。這導(dǎo)致了前刀面和切屑離切削刃很近的地方切削溫度較高。實(shí)質(zhì)上由于在金屬切削中所做的全部功能都被轉(zhuǎn)化為熱,那就可以預(yù)料:被切離金屬的單位體積功率消耗曾家的這些因素就將使切削溫度升高。這樣刀具前角的增加而所有其他參數(shù)不變時,將使切離金屬的單位體積所耗功率減小,因而切削溫度也將降低。當(dāng)考慮到未變形切屑厚度增加和切削速度,這情形就更是復(fù)雜未變形切屑厚度的增加趨勢必導(dǎo)致通過工件的熱的總數(shù)上產(chǎn)生比例效應(yīng),刀具和切屑仍保持著固定的比例,而切削溫度變化傾向于降低.然而切削速度的增加,傳導(dǎo)到工件上的熱的數(shù)量減少而這又增加主變形區(qū)中的切屑溫上升。進(jìn)而副變形區(qū)勢必更小,這將在該區(qū)內(nèi)產(chǎn)生升溫效應(yīng)。其他切削參數(shù)的變化,實(shí)質(zhì)上對于被切離的單位體積消耗上并沒有什么影響,因此實(shí)際上對切削溫度沒有什么作用。因?yàn)槭聦?shí)已經(jīng)表明:切削溫度即使有小小的變化對刀具磨損率都將有實(shí)質(zhì)意義的影響作用.這表明如何人從切削參數(shù)來確定切削溫度那是很合適的。為著測定高速鋼刀具溫度的最直接和最精確的方法是W&T法,這方法也就是可提供高速鋼刀具溫度分布的詳細(xì)信息的方法.該項(xiàng)技術(shù)是建立在高速鋼刀具截面金相顯微測試基礎(chǔ)上,目的是要建立顯微結(jié)構(gòu)變化與熱變化規(guī)律圖線關(guān)系式當(dāng)要加工廣泛的工件材料時,Trent已經(jīng)論述過測定高速鋼刀具的切削溫度及溫度分布的方法。這項(xiàng)技術(shù)由于利用電子顯微掃描技術(shù)已經(jīng)進(jìn)一步發(fā)展,目的是要研究將已回過火和各種馬氏體結(jié)構(gòu)的高速鋼再回火引起的微觀顯微結(jié)構(gòu)變化情況。這項(xiàng)技術(shù)亦用于研究高速鋼單點(diǎn)車刀和麻花鉆的溫度分布。刀具磨損從已經(jīng)被處理過的無數(shù)脆裂和刃口裂紋的刀具中可知,刀具磨損基本上有三種形式:后刀面磨損,前刀面磨損和V型凹口磨損。后刀面磨損既發(fā)生在主刀刃上也發(fā)生副刀刃上。關(guān)于主刀刃,因其擔(dān)負(fù)切除大部金屬切屑任務(wù),這就導(dǎo)致增加切削力和提高切削溫度,如果聽任而不加以檢查處理,那可能導(dǎo)致刀具和工件發(fā)生振動且使有效切削的條件可能不再存在。關(guān)于副刀刃,那是決定著工件的尺寸和表面光潔度的,后刀面磨損可能造成尺寸不合格的產(chǎn)品而且表面光潔度也差。在大多數(shù)實(shí)際切削條件下,由于主前刀面先于副前刀面磨損,磨損到達(dá)足夠大時,刀具將實(shí)效,結(jié)果是制造出不合格零件。由于刀具表面上的應(yīng)力分布不均勻,切屑和前刀面之間滑動接觸區(qū)應(yīng)力,在滑動接觸區(qū)的起始處最大,而在接觸區(qū)的尾部為零,這樣磨蝕性磨損在這個區(qū)域發(fā)生了。這是因?yàn)樵谇邢骺ㄗ^(qū)附近比刀刃附近發(fā)生更嚴(yán)重的磨損,而刀刃附近因切屑與前刀面失去接觸而磨損較輕。這結(jié)果離切削刃一定距離處的前刀面上形成麻點(diǎn)凹坑,這些通常被認(rèn)為是前刀面的磨損。通常情況下,這磨損橫斷面是圓弧形的。在許多情況中和對于實(shí)際的切削狀況而言,前刀面磨損比起后刀面磨損要輕,因此后刀面磨損更普遍地作為刀具失效的尺度標(biāo)志.然而因許多作者已經(jīng)表示過的那樣在增加切削速度情況下,前刀面上的溫度比后刀面上的溫度升得更快,而且又因任何形式的磨損率實(shí)質(zhì)上是受到溫度變化的重大影響。因此前刀面的磨損通常在高速切削時發(fā)生的。刀具的主后刀面磨損帶的尾部是跟未加工過的工件表面相接觸,因此后刀面磨損比沿著磨損帶末端處更為明顯,那是最普通的。這是因?yàn)榫植啃?yīng),這像未加工表面上的己硬化層,這效應(yīng)是由前面的切削引起的工件硬化造成的不只是切削,還有像氧化皮,刀刃產(chǎn)生的局部高溫也都會引起這種效應(yīng)。這種局部磨損通常稱作為凹坑性磨損,而且偶爾是非常嚴(yán)重的。盡管凹坑的出現(xiàn)對刀具的切削性質(zhì)無實(shí)質(zhì)意義的影響,但凹坑常常逐漸變深,如果切削在繼續(xù)進(jìn)行的話,那么刀具就存在斷裂的危機(jī)。如果任何進(jìn)行性形式的磨損任由繼續(xù)發(fā)展,最終磨損速率明顯地增加而刀具將會有摧毀性失效破壞,即刀具將不能再用作切削,造成工件報(bào)廢,那算是好的,嚴(yán)重的可造成機(jī)床破壞。對于各種硬質(zhì)合金刀具和對于各種類型的磨損,在發(fā)生嚴(yán)重失效前,就認(rèn)為已達(dá)到刀具的使用壽命周期的終點(diǎn).然而對于各種高速鋼刀具,其磨損是屬于非均勻性磨損,已經(jīng)發(fā)現(xiàn):當(dāng)其磨損允許連續(xù)甚至到嚴(yán)重失效開始,最有意義的是該刀具可以獲得重磨使用,當(dāng)然,在實(shí)際上,切削時間遠(yuǎn)比使用到失效的時間短。以下幾種現(xiàn)象之一均是刀具嚴(yán)重失效開始的特征:最普遍的是切削力突然增加,在工件上出現(xiàn)燒損環(huán)紋和噪音嚴(yán)重增加等。自動夾具設(shè)計(jì)用做裝配設(shè)備的傳統(tǒng)同步夾具把零件移動到夾具中心上,以確保零件從傳送機(jī)上或從設(shè)備盤上取出后置于已定位置上。然而在某些應(yīng)用場合、強(qiáng)制零件移動到中心線上時,可能引起零件或設(shè)備破壞。當(dāng)零件易損而且小小振動可能導(dǎo)致報(bào)廢時,或當(dāng)其位置是由機(jī)床主軸或模具來具體時,再或者當(dāng)公差要求很精密時,那寧可讓夾具去適應(yīng)零件位置,而不是相反。為著這些工作任務(wù),美國俄亥俄州Elyria的Zaytran公司已經(jīng)開發(fā)了一般性功能數(shù)據(jù)的非同步西類柔順性夾具。因?yàn)閵A具作用力和同步化裝置是各自獨(dú)立的,該同步裝置可以用精密的滑移裝置來替換而不影響夾具作用力。夾具規(guī)格范圍是從0.2英寸行程,5英鎊夾緊力到6英寸行程、400英寸夾緊力。現(xiàn)代生產(chǎn)的特征是批量變得越來越小而產(chǎn)品的各種規(guī)格變化最大。因此,生產(chǎn)的最后階段,裝配因生產(chǎn)計(jì)劃、批量和產(chǎn)品設(shè)計(jì)的變更而顯得特別脆弱。這種情形正迫使許多公司更多地致力于廣泛的合理化改革和前面提到過情況,那樣裝配自動化。盡管柔性夾具的發(fā)展很快落后與柔性運(yùn)輸處理裝置的發(fā)展,如落后于工業(yè)機(jī)器人的發(fā)展,但仍然試圖指望增加夾具的柔頂性。事實(shí)上夾具的重要的裝置生產(chǎn)裝置的專向投資就加強(qiáng)了使夾具更加柔性化在經(jīng)濟(jì)上的支持。根據(jù)它們?nèi)犴樞?,夾具可以分為:專用夾具、組合夾具、標(biāo)準(zhǔn)夾具、高柔性夾具。柔性夾具是以它們對不同工件的高適應(yīng)性和以少更換低費(fèi)用為特征的。結(jié)構(gòu)形式可變換的柔性夾具裝有可變更結(jié)構(gòu)排列的零件(例如針形頰板,多片式零件和片狀頰板),標(biāo)準(zhǔn)工件的非專用夾持或夾緊元件(例如:啟動標(biāo)準(zhǔn)夾持夾具和帶有可移動元件的夾具配套件),或者裝有陶瓷或硬化了的中介物質(zhì)(如:流動粒子床夾具和熱夾具緊夾具)。為了生產(chǎn),零件要在夾具中被緊固,需要產(chǎn)生夾緊作用,其有幾個與夾具柔順性無關(guān)的步驟。根據(jù)被加工的即基礎(chǔ)的部分和工作特點(diǎn),確定工件在夾具中的所需的位置,接著必須選擇若干穩(wěn)定平面的組合,這些穩(wěn)定平面就構(gòu)成工件被固定在夾具中確定位置上的夾持狀輪廓結(jié)構(gòu),均衡所有各力和力矩,而且保證接近工件工作特點(diǎn)。最后,必須計(jì)算、調(diào)整、組裝可拆裝的或標(biāo)準(zhǔn)夾具元件的所需位置,以便使工件牢牢地被夾緊在夾具中。依據(jù)這樣的程序,夾具的輪廓結(jié)構(gòu)和裝合的規(guī)劃和記錄過程可以進(jìn)行自動化控制。結(jié)構(gòu)造型任務(wù)就是要產(chǎn)生若干穩(wěn)定平面的組合,這樣在這些平面上的各夾緊力將使工件和夾具穩(wěn)定。按慣例,這個任務(wù)可用人機(jī)對話即幾乎完全自動化的方式來完成。人機(jī)對話即以自動化方式確定夾具結(jié)構(gòu)造型的優(yōu)點(diǎn)是可以有組織有規(guī)劃進(jìn)行夾具設(shè)計(jì),減少所需的設(shè)計(jì)人員,縮短研究周期和能更好地配置工作條件。簡言之,可成功地達(dá)到顯著提高夾具生產(chǎn)效率和效益。在充分準(zhǔn)備了構(gòu)造方案和一批材料情況下,在完成首次組裝可以成功實(shí)現(xiàn)節(jié)約時間達(dá)60%。因此夾具機(jī)構(gòu)造型過程的目的是產(chǎn)生合適的編程文件。http:/www.mapeng.net/news/mechanical_English_article/2008/12/mapeng_08121123512175_6.htmlIntroduction of MachiningHosIdns,Josiah USAHave a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process. Drivers device on the workpiece material to be in the form of chip removal. Although in some occasions,the workpiece under no circumstances, the use of mobile equipment to the processing. However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.Strict precision and good surface finish, Machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.Primary Cutting ParametersCutting the work piece and tool based on the basic relationship between the following four elements to fully describe: the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry-to the tip plane and cutter angle characteristics-for each cutting process must be correct.Cutting speed is the cutting edge of work piece surface rate, it is inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts-with knives. Generally, the more hard work piece material, the lower the rate.Progressive Tool to speed is cut into the work piece speed. If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the workpiece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to.Depth of penetration of a cutting tool-to inches dollarsis the tool to the work piece distance. Rotary cutting it to the chip or equal to the width of the linear cutting chip thickness. Rough than finishing, deeper penetration of a cutting tool depth.Wears of Cutting ToolWe already have been processed and the rattle of the countless cracks edge tool, we learn that tool wear are basically three forms: flank wear, the former flank wear and V-Notch wear. Flank wear occurred in both the main blade occurred vice blade. On the main blade, shoulder removed because most metal chip mandate, which resulted in an increase cutting force and cutting temperature increase, If not allowed to check, That could lead to the work piece and the tool vibration and provide for efficient cutting conditions may no longer exist. Vice-bladed on, it is determined work piece dimensions and surface finish. Flank wear size of the possible failure of the product and surface finish are also inferior. In most actual cutting conditions, as the principal in the former first deputy flank before flank wear, wear arrival enough. Tool will be effective, the results are made unqualified parts. As Tool stress on the surface uneven, chip and flank before sliding contact zone between stress, in sliding contact the start of the largest, and in contact with the tail of zero, so abrasive wear in the region occurred. This is because the card cutting edge than the nearby settlements near the more serious wear, and bladed chip due to the vicinity of the former flank and lost contact wear lighter. This results from a certain distance from the cutting edge of the surface formed before the knife point Ma pit, which is usually considered before wear. Under normal circumstances, this is wear cross-sectional shape of an arc. In many instances and for the actual cutting conditions, the former flank wear compared light, Therefore flank wear more generally as a tool failure of scale signs. But because many authors have said in the cutting speed of the increase. Metal surface temperature than the knife surface temperatures have risen faster. But because any form of wear rate is essentially temperature changes by the significant impact. Therefore, the former usually wear in high-speed cutting happen.The main tool flank wear the tail is not processed with the work piece surface in contact, Therefore flank wear than wear along with the ends more visible, which is the most common. This is because the local effect, which is as rough on the surface has hardened layer, This effect is by cutting in front of the hardening of t he work piece. Not just cutting, and as oxidation skin, the blade local high to temperature will also cause this effect. This partial wear normally referred to as pit sexual wear, but occasionally it is very serious. Despite the emergence of the pits on the Cutting Tool nature is not meaningful impact, but often pits gradually become darker If cutting continued the case, then there cutter fracture crisis.If any form of sexual allowed to wear, eventually wear rate increase obviously will be a tool to destroy failure destruction, that will no longer tool for cutting, cause the work piece scrapped, it is good, can cause serious damage machine. For various carbide cutting tools and for the various types of wear, in the event of a serious lapse, on the tool that has reached the end of the life cycle. But for various high-speed steel cutting tools and wear belonging to the non-uniformity of wear, has been found. When the wear and even to allow for a serious 1apse, the most meaningful is that the tool can re-mill use, of course, In practice, cutting the time to use than the short time 1apse. Several phenomena are one tool serious lapse began features: the most common is the sudden increase cutting force, appeared on the work piece burning ring patterns and an increase in noise.The Effect of Changes in Cutting Parameters on Cutting TemperaturesIn metal cutting operations heat is generated in the primary and expected, there is a very large temperature gradient throughout the width of the chip as the workpiece material is sheared in primary deformation and there is a further large temperature in the chip adjacent to the face as the chip is sheared in secondary deformation. This leads to a maximum cutting temperature a short distance up the face from the cutting edge and a small distance into the chip.Since virtually all the work done in metal cutting is converted into heat, it could be expected that factors which increase the power consumed per unit volume of metal removed will increase the cutting temperature. Thus an increase in the rake angle, all other parameters remaining constant, will reduce the power per unit volume of metal removed and cutting temperatures will reduce. When considering increase in undeformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thickness tends to be a scale effect where the amounts of heat which pass to the work piece, the tool and chip remain in fixed proportions and the changes in cutting temperature tend to be small. Increase in cutting speed, however, reduce the amount of heat which passes into the workpiece and this increase the temperature rise of the chip in primary deformation. Further, the secondary deformation zone tends to be smaller and this has the effect of increasing the temperatures in this zone. Other changes in cutting parameters have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the cutting temperatures. Since it has been shown that even small changes in cutting temperature have a significant effect on tool wear rate, it is appropriate to indicate how cutting temperatures can be assessed from cutting data.The most direct and accurate method for measuring temperatures in high-speed-steel cutting tools is that of Wright&Trent which also yields detailed information on temperature distributions in high-speed-steel tools which relates micro structural changes to thermal history.Trent has described measurements of cutting temperatures and temperature distributions for high-speed-steel tools when machining a wide range of work piece materials. This technique has been further developed by using scanning electron microscopy to study fine-scale micro structural changes arising from over tempering of the tempered martensitic matrix of various high-speed-steels. This technique has also been used to study temperature distributions in both high-speed-steel single point turning tools and twist drills.Automatic Fixture DesignAsseml1y equipment used in the traditional synchronous fixture put parts of the fixture mobile center, to ensure that components from transmission from the plane or equipment plate placed after removal has been scheduled for position. However, in certain applications, mobile mandatory parts of the center line, it may cause parts or equipment damage. When parts vulnerability and may lead to a small vibration abandoned, or when their location is by machine spindle or specific to die. Tolerance again or when the request is a sophisticated, it would rather let the fixture to adapt to the location of parts, and not the contrary. For these tasks, Elyria, Ohio, the company has developed Zaytran a general non-functional data synchronization West category FLEXIBILITY fixture. Fixture because of the interaction and synchronization devices is independent, The synchronous device can use sophisticated equipment to replace the slip without affecting the fixture force. Fixture specification range from 0.2 inches itinerary, 5 pounds clamping force of the six-inch trip, 400-inch clamping force.The characteristics of modern production is becoming smaller and smaller quantities and product specifications biggest changes. Therefore, in the final stages of production, assembly of production, quantity and product design changes appear to be particularly vulnerable. This situation is forcing many companies to make greater efforts to rationalize the extensive reform and the previously mentioned case of assembly automatic on. Despite flexible fixture behind the rapid development of flexible transport and handling devices, such as backward in the development of industrial robots, it is still expected to increase the flexibility fixture. In fact the important fixture devices-the production of the devices to strengthen investment on the fixture so that more flexibility in economic support holders.According to their flexibility and fixture can be divided into special fixture, the fixture combinations, the standard fixture, high flexible fixture. Flexible fixture on different parts of their high adaptability and the few low-cost replacement for the characteristic. Forms can transform the structure of the flexible fixture can be installed with the change of structure components (such as needle cheek plate, Multi-chip components and flake cheek plate), a non-standard work piece gripper or clamping elements (for example: commencement standard with a clamping fixture and mobile components fixture supporting documents), or with ceramic or hardening of the intermediary substances (such as: Mobile particle bed fixture and heat fixture tight fixture). To production, the parts were secured fixture, the need to generate clamping function, its fixture with a few unrelated to the sexual submissive steps.According to the processing was part of that foundation and working characteristics to determine the work piece fixture in the required position, then need to select some stability flat combination. These constitute a stable plane was fixed in the work piece fixture set position on the clamp-profile structure, all balanced and torque, it has also ensured that the work features close to the work piece. Finally, it must be calculated and adjusted, assembly or disassembly be standard fixture components required for the position, so that the work piece firmly by clamping fixture in China. In accordance with this planning and recording process can be automated control. Structural modeling task is to produce some stable flat combination, Thus, these plane of the work pieces clamping force and will fixture stability. According to usual practice, this task can be human-machine dialogue that is almost completely automated way to completion. A man-machine dialogue that is automated fixture structure modeling to determine the merits can be conducted in an organized and planning fixture design, reduce the amount of the design, shortening the study period and better distribution of work conditions. In short, can be successfully achieved significantly improve fixture efficiency and effectiveness.Fully prepared to structure programs and the number of material circumstances, the completion of the first successful assembly can save up to 60% of the time. Therefore program have fixture process modeling agencies is the purpose of the appropriate documents.9
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