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ID:44552974
大小:65.50 KB
页数:12页
时间:2019-10-23
《牛头刨床钻床和铣削(机械系论文外文翻译)》由会员上传分享,免费在线阅读,更多相关内容在工程资料-天天文库。
1、译文题目牛头刨床、钻床和铳削专业机械设计制造及其自动化112学生姓名钱陈历学号11556222Shapers,DrillingandMillingMachinesAshapersutilizesasingle-pointtoolonatoolholdermountedontheendoftheram.Cuttingisgenerallydoneontheforwardstroke.Thetoolisliftedslightlybytheclapperboxtopreventexcessivedragacrossthework,wh
2、ichisfedunderthetoolduringthereturnstrokeinpreparationforthenextcut.Thecolumnhousestheoperatingmechanismsoftheshaperandalsoservesasamountingunitforthework-supportingtable.Thetablecanbemovedintwodirectionsmutuallyperpendiculartotheram.Thetoolslideisusedtocontrolthedept
3、hofcutandismanuallyfed.Itcanberotatedthrough90deg,oneithersideofitsnormalverticalposition,whichallowsfeedingthetoolatanangletothesurfaceofthetable.TwotypesofdrivingmechanismsforshapersareamodifiedWhitworthquick-returnmechanismandahydraulicdrive.FortheWhitworthmechanis
4、m,themotordrivesthebullgear,whichdrivesacrankarmwithanadjustablecrankpintocontrolthelengthofstroke.Asthebullgearrotates,therockerarmisforcedtoreciprocate,impartingthismotiontotheshaperram.Themotoronahydraulicshaperisusedonlytodrivethehydraulicpump.Theremainderofthesha
5、permotionsarecontrolledbythedirectionoftheflowofthehydraulicoil.Thecuttingstrokeofthemechanicallydrivenshaperuses220deg.Ofrotationofthebullgear,whilethereturnstrokeuses140deg.Thisgivesacuttingstroketoreturnstrokeratioof1.6to1.Thevelocitydiagramforahydraulicshapershows
6、thatformostofthetoolduringcuttingstrokeisneverconstant,whilethevelocitydiagramforahydraulicshapershowsthatformostofthecuttingstrokethecuttingspeedisconstant.Thehydraulicshaperhasanaddedadvantageofinfinitelyvariablecuttingspeeds.Theprincipaldisadvantageofthistypeofmach
7、ineisthelackofadefinitelimitattheendoftheramstroke,whichmayallowafewthousandthsofaninchvariationinstrokelength.Aduplicatingdevicethatmakespossiblethereproductionofcontoursfromasheet-metaltemplateisavailable.Thesheetmetaltemplateisusedinconjunctionwithhydrauliccontrol.
8、Uprightdrillingmachinesordrillpressesareavailableinavarietyofsizesandtypes,andareequippedwithasufficientrangeofapindlespeeds
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