外文翻译-- 车床及其切削加工.doc

毕业设计论文外文资料翻译系别机电信息系专业机械设计制造及其自动化班级姓名学号外文出处PNEUMATICTIPSNO87/1994附件1原文；2译文2013年3月11原文LATHESANDIT’SCUTTINGPROCESSLATHESAREMACHINETOOLSDESIGNEDPRIMARILYTODOTURNING,FACING,ANDBORINGVERYLITTLETURNINGISDONEONOTHERTYPESOFMACHINETOOLS,ANDNONECANDOITWITHEQUALFACILITYBECAUSELATHESALSOCANDODRILLINGANDREAMING,THEIRVERSATILITYPERMITSSEVERALOPERATIONSTOBEDONEWITHASINGLESETUPOFTHEWORKPIECECONSEQUENTLY,MORELATHESOFVARIOUSTYPESAREUSEDINMANUFACTURINGTHANANYOTHERMACHINETOOLTHEESSENTIALCOMPONENTSOFALATHEARETHEBED,HEADSTOCKASSEMBLY,TAILSTOCKASSEMBLY,CARRIAGEASSEMBLY,ANDTHELEADSCREWANDFEEDRODTHEBEDISTHEBACKBONEOFALATHEITUSUALLYISMADEOFWELLNORMALIZEDORAGEDGRAYORNODULARCASTIRONANDPROVIDESAHEAVY,RIGIDFRAMEONWHICHALLTHEOTHERBASICCOMPONENTSAREMOUNTEDTWOSETSOFPARALLEL,LONGITUDINALWAYS,INNERANDOUTER,ARECONTAINEDONTHEBED,USUALLYONTHEUPPERSIDESOMEMAKERSUSEANINVERTEDVSHAPEFORALLFOURWAYS,WHEREASOTHERSUTILIZEONEINVERTEDVANDONEFIATWAYINONEORBOTHSETSTHEYAREPRECISIONMACHINEDTOASSUREACCURACYOFALIGNMENTONMOSTMODEMLATHESTHEWAYSARESURFACEHARDENEDTORESISTWEARANDABRASION,BUTPRECAUTIONSHOULDBETAKENINOPERATINGALATHETOASSURETHATTHEWAYSARENOTDAMAGEDANYINACCURACYINTHEMUSUALLYMEANSTHATTHEACCURACYOFTHEENTIRELATHEISDESTROYEDTHEHEADSTOCKISMOUNTEDINAFIXEDPOSITIONONTHEINNERWAYS,USUALLYATTHELEFTENDOFTHEBEDITPROVIDESAPOWEREDMEANSOFROTATINGTHEWORKATVARIOUSSPEEDSESSENTIALLY,ITCONSISTSOFAHOLLOWSPINDLE,MOUNTEDINACCURATEBEARINGS,ANDASETOFTRANSMISSIONGEARSSIMILARTOATRUCKTRANSMISSIONTHROUGHWHICHTHESPINDLECANBEROTATEDATANUMBEROFSPEEDSMOSTLATHESPROVIDEFROM8TO18SPEEDS,USUALLYINAGEOMETRICRATIO,ANDONMODEMLATHESALLTHESPEEDSCANBEOBTAINEDMERELYBYMOVINGFROMTWOTOFOURLEVERSANINCREASINGTRENDISTOPROVIDEACONTINUOUSLYVARIABLESPEEDRANGETHROUGHELECTRICALORMECHANICALDRIVESBECAUSETHEACCURACYOFALATHEISGREATLYDEPENDENTONTHESPINDLE,ITISOFHEAVYCONSTRUCTIONANDMOUNTEDINHEAVYBEATINGS,USUALLYPRELOADEDTAPEREDROLLERORBALLTYPESTHESPINDLEHASAHOLEEXTENDINGTHROUGHITSLENGTH,THROUGHWHICHLONGBARSTOCKCANBEFEDTHESIZEDTHISHOLEISANIMPORTANTDIMENSIONOFALATHEBECAUSEITDETEMTINESTHEMAXIMUMSIZEOFBARSTOCKTHATCANBEMACHINEDWHENTHEMATERIALMUSTBEFEDTHROUGHSPINDLETHETAILSTOCKASSEMBLYCONSISTS,ESSENTIALLY,OFTHREEPARTSALOWERCASTINGFITSON2THEINNERWAYSOFTHEBEDANDCANSLIDELONGITUDINALLYTHEREON,WITHAMEANSFORCLAMPINGTHEENTIREASSEMBLYINANYDESIREDLOCATIONANUPPERCASTINGFITSONTHELOWERONEANDCANBEMOVEDTRANSVERSELYUPONIT,ONSOMETYPEOFKEYEDWAYS,TOPERMITALIGNINGTHETAILSTOCKANDHEADSTOCKSPINDLESTHETHIRDMAJORCOMPONENTOFTHEASSEMBLYISTHETAILSTOCKQUILLTHISISAHOLLOWSTEELCYLINDER,USUALLYABOUT51TO76MM2TO3INCHESINDIAMETER,THATCANBEMOVEDSEVERALINCHESLONGITUDINALLYINANDOUTOFTHEUPPERCASTINGBYMEANSOFAHANDWHEELANDSCREWTHESIZEOFALATHEISDESIGNATEDBYTWODIMENSIONSTHEFIRSTISKNOWNASTHESWINGTHISISTHEMAXIMUMDIAMETEROFWORKTHATCANBEROTATEDONALATHEITISAPPROXIMATELYTWICETHEDISTANCEBETWEENTHELINECONNECTINGTHELATHECENTERSANDTHENEARESTPOINTONTHEWAYSTHESECONDSIZEDIMENSIONISTHEMAXIMUMDISTANCEBETWEENCENTERSTHESWINGTHUSINDICATESTHEMAXIMUMWORKPIECEDIAMETERTHATCANBETURNEDINTHELATHE,WHILETHEDISTANCEBETWEENCENTERSINDICATESTHEMAXIMUMLENGTHOFWORKPIEEETHATCANBEMOUNTEDBETWEENCENTERSENGINELATHESARETHETYPEMOSTFREQUENTLYUSEDINMANUFACTURINGLLLEYAREHEAVYDUTYMACHINETOOLSWITHALLTHECOMPONENTSDESCRIBEDPREVIOUSLYANDHAVEPOWERDRIVEFORALLTOOLMOVEMENTSEXCEPTONTHECOMPOUNDRESTTHEYCOMMONLYRANGEINSIZEFROM305TO610MTN12TO24INCHESSWINGANDFROM610TO1219MM24TO48INCHESCENTERDISTANCES,BUTSWINGSUPTO1270MM50INCHESANDCENTERDISTANCESUPTO3658MM12FEETARENOTTMCOMMONMOSTHAVECHIPPANSANDABUILTINCOOLANTCIRCULATINGSYSTEMSMALLERENGINELATHESWITHSWINGSUSUALLYNOTOVER330MM13INCHESALSOAREAVAILABLEINBENCHTYPE,DESIGNEDFORTHEBEDTOBEMOUNTEDONABENCHORCABINETALTHOUGHENGINELATHESAREVERSATILEANDVERYUSEFUL,BECAUSEOFTHETIMEREQUIREDFORCHANGINGANDSETTINGTOOLSANDFORMAKINGMEASUREMENTSONTHEWORKPIECE,THEYALENOTSUITABLEFORQUANTITYPRODUCTIONOFTENTHEACTUALCHIPPRODUCTIONTIMEISLESSTHAN30OFTHETOTALCYCLETIMEINADDITION,ASKILLEDMACHINISTISREQUIREDFORALLTHEOPERATIONS,ANDSUCHPERSONSARECOSTLYANDOFTENINSHORTSUPPLYHOWEVER,MUCHOFTHEOPERATORSTIMEISCONSUMEDBYSIMPLE,REPETITIOUSADJUSTMENTSANDINWATCHINGCHIPSBEINGMADECONSEQUENTLY,TOREDUCEORELIMINATETHEAMOUNTOFSKILLEDLABORTHATISREQUIRED,TURRETLATHES,SCREWMACHINES,ANDOTHERTYPESOFSEMIAUTOMATICANDAUTOMATICLATHESHAVEBEENHIGHLYDEVELOPEDANDAREWIDELYUSEDINMANUFACTURINGTHEENGINELATHE,ONEOFTHEOLDESTMETALREMOVALMACHINES,HASANUMBEROF3USEFULANDHIGHLYDESIRABLEATTRIBUTESTODAYTHESELATHESAREUSEDPRIMARILYINSMALLSHOPSWHERESMALLERQUANTITIESRATHERTHANLARGEPRODUCTIONRUNSAREENCOUNTEREDTHEENGINELATHEHASBEENREPLACEDINTODAYSPRODUCTIONSHOPSBYAWIDEVARIETYOFAUTOMATICLATHESSUCHASAUTOMATICTRACERLATHES,TURRETLATHES,ANDAUTOMATICSCREWMACHINESALLTHEADVANTAGESOFSINGLEPOINTTOOLINGFORMAXIMUMMETALREMOVAL,ANDTHEUSEOFFORMTOOLSFORFINISHANDACCURACY,ARENOWATTHEDESIGNERSFINGERTIPSWITHPRODUCTIONSPEEDSONAPARWITHTHEFASTESTPROCESSINGEQUIPMENTONTHESCENETODAYTOLERANCESFORTHEENGINELATHEDEPENDPRIMARILYONTHESKILLOFTHEOPERATORTHEDESIGNENGINEERMUSTBECAREFULINUSINGTOLERANCESOFANEXPERIMENTALPARTTHATHASBEENPRODUCEDONTHEENGINELATHEBYASKILLEDOPERATORINREDESIGNINGANEXP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