车床加工(中英文对照)

车床加工J.J.RaphaelandJ.A.M.Boulet20231252023514少在其他种类的机床上进展,而且任何一种其他机床都不能像车床那样便利地进展车削加工。由于车床还可以用来钻孔和铰孔,车床的多功能性可以使工件在一次安装中完成几种加工。因此,在生产中使用的各种车床比任何其他种类的机床都多。制成。它是一个结实的刚性框架,全部其他根本部件都安装在床身上。通常在床角形导轨(即山形导轨),而有的制造厂则在一组中或者两组中都承受一个三角形和擦伤,大多数现代机床的导轨是经过外表淬硬的,但是在操作时还应当留神,以避开损伤导轨。导轨上的任何误差,常常意味着整个机床的精度遭到破坏。列变速齿轮(类似于卡车变速箱)所组成。通过变速齿轮,主轴可以在很多种转速或者机械的装置进展无级变速。由于机床的精度在很大程度上取决于主轴,因此,主轴的构造尺寸较大,通常安装在预紧后的重型圆锥滚子轴承或球轴承中。主轴中有一个贯穿全长的通孔,长棒料可以通过该孔送料。主轴孔的大小是车床的一个重要尺寸,因此当工件必需通过主轴孔供料时,它确定了能够加工的棒料毛坯的最大尺寸。尾座组件主要由三局部组成。底板与床身的内侧导轨协作,并可以在导轨上中的主轴对正。尾座的第三个组成局部是尾座套筒。它是一个直径通常大约在51~76mm(2~3座体中纵向移入和移出几个英寸。两个顶尖之间能够安装的工件的最大长度。一般车床是生产中最常常使用的车床种类。它们是具有前面所叙的全部那规格通常是:车床床面上最大加工直径为305~610mm(12~24英寸)；但是,床面3658mm并不少见。这些车床大局部都有切屑盘和一个安装在内部的冷却液循环系统。小型的一般车床—车床床面最大加工直径一般不超过330mm(13计成台式车床,其床身安装在工作台或柜子上。虽然一般车床有很多用途,是很有用的机床,但是更换和调整刀具以及测量人的工资高而且很难雇到。然而,操作工人的大局部时间却花费在简洁的重复调整和观看切屑过程上。因此,为了削减或者完全不雇用这类娴熟工人,六角车床,螺纹加工车床和其他类型的半自动和自动车床已经很好地研制出来,并已经在生产中得到广泛应用。先进制造技术中的一个根本的概念是数字把握(NC)。在数控技术消灭之前，技能有关。数字把握代表了从人工把握机床走出来的第一步。统。一个数控技师的工作不是去操纵机床,而是编写能够发出机床操纵指令的程解译出编程指令。进展数控技术是为了抑制人类操作者的局限性,而且它确实完成了这项工作。数字把握的机器比人工操纵的机器精度更高,生产出零件的全都性更好、生其他几项制造的产生:电火花加工技术、激光切割、电子束焊接。过程。数控可以使生产厂家担当那些对于承受人工把握的机床和工艺来说,在经济上是不划算的产品生产任务。同很多先进技术一样,数控诞生于麻省理工学院的试验室中。数控这个概念和有效地进展直线切割。然而,曲线轨迹成为机床加工的一个问题,在编程时应当承受一系列的水平与竖直的台阶来生成曲线。构成台阶的每一个线段越短,曲线就越光滑。台阶中1959(APT)义零件的几何外形,描述切削刀具的外形和规定必要的运动。APT语言的争论和数控系统是有很大差异的。在那时的机床中,只有硬线规律电路。指令程序写在穿孔纸带上(它后来被塑料带所取代),承受带阅读机将写在纸带或磁带上的指令给机器翻译出来。全部这些共同构成了机床数字把握方面的巨大进步。然而,在数控进展的这个阶段中还存在着很多问题。一个主要问题是穿孔纸带的易损坏性。在机械加工过程中,载有编程指令信息的纸带断裂和被撕坏是常见的事情。在机床上每加工一个零件,都需要将载有编程指令的纸带放入阅读机中重运行一次。因此,这个问题变得很严峻。假设100明显不能承受严配的车间环境和这种重复使用。载有编程指令,而在塑料带上通过承受一系列的磁点眯载有编程指令。塑料带的存在着两个问题。其中最重要的一个问题是,对输入到带中指令进展修改是格外加工,制作一条带。而且带通过阅读机的次数还必需与需要加工的零件的个数一样。幸运的是,计算机技术的实际应用很快解决了数控技术中与穿孔纸带和塑料(DNC)这个概念之后,可以不再承受纸带或都存储在这台主计算机中。当需要时,通过数据传输线路供给应每台机床。直接数字把握是在穿孔纸带和塑料带根底上的一大进步。然而,它敢有着同其他信任于主计算机技术一样的局限性。当主计算机消灭故障时,由其把握的全部机床都CNC在每台机床内部。它还可以在机床以外编制程序,并将其下载到每台机床中。计算机数控解决了主计算机发生故障所带来的问题,但是它产生了另一个被称为数据治理的问题。同一个程序可能要分别装入十个相互之间没有通讯联系的微机来,以得于更好地进展数据治理。一般车床一般车床作为最早的金属切削机床的一种,目前照旧有很多有用的和为人要的特性和为人们所需的特性。现在,这些机床主要用在规模较小的工厂中,进展小批量的生产,而不是进展大批量的和产。动仿形车床、六角车床和自动螺丝车床。现在,设计人员已经熟知先利用单刃刀具去除大量的金属余量,然后利用成型刀具获得外表光滑度和精度这种加工方相等。产零件时,应中选用经济的公差。六角车床六角车床对生产加工设备来说,目前比过去更留意评价其是否具有准确的和快速的重复加工力气。应用这个标准来评价具体的加工方法,六角车床可以获得较高的质量评定。在为小批量的零件(100~200件)设计加工方法时,承受六角车床是最经济数目减至最少。自动螺丝车床 自动螺丝车床通被分为以下几种类型:单轴自动,多轴自动和自动夹紧车床。自动螺丝车床最初是被用来对螺钉和类似的带有螺纹的零件26围。现在,它在很多种类的周密零件的大批量生产中起着重要的作用。工件的数算出最小经济批量,并且针对工件批量正确地选择机床,就会降低零件的加工本钱。自动仿形车床 在某些状况下,在连续生产过程中,只进展一次切削加工时对于某些零件,槽宽的公差可以到达0.125mm。镗孔和休用单刃刀具进展精加工时,公差可到达0.0125mm。在期望获得最大主量的大0.125mm零件的外表粗糙度在很大程度上取决于工件材料、刀具、进给量和切削速度,承受自动仿形车床加工所得到的最小公差确定是最经济。外文资料LatheJ.J.RaphaelandJ.A.M.BouletSubmitted5December2023;inrecisedform14May2023Lathesaremachinetoolsdesignedprimarilytodoturning,facingandboring,Verylittleturningisdoneonothertypesofmachinetools,andnonecandoitwithequalfacility.Becauselathesalsocandodrillingandreaming,theirversatilitypermitsseveraloperationstobedonewithasinglesetupoftheworkpiece.Consequently,morelathesofvarioustypesareusedinmanufacturingthananyothermachinetool.Theessentialcomponentsofalathearethebed,headstockassembly,tailstockassembly,andtheleadscrewandfeedrod.Thebedisthebackboneofalathe.Itusuallyismadeofwellnormalizedoragedgrayornodularcastironandprovidessheavy,rigidframeonwhichalltheotherbasiccomponentsaremounted.Twosetsofparallel,longitudinalways,innerandouter,arecontainedonthebed,usuallyontheupperside.SomemakersuseaninvertedV-shapeforallfourways,whereasothersutilize one invertedV and one flat way in one or both sets, They areprecision-machinedtoassureaccuracyofalignment.Onmostmodernlathesthewayaresurface-hardenedtoresistwearandabrasion,butprecautionshouldbetakeninoperatingalatheto assurethatthewaysarenotdamaged. Anyinaccuracyinthemusuallymeansthattheaccuracyoftheentirelatheisdestroyed.Theheadstockismountedinafoxedpositionontheinnerways,usuallyattheleftendofthebed.Itprovidesapoweredmeansofrotatingthewordatvariousspeeds.Essentially,itconsistsofahollowspindle,mountedinaccuratebearings,andasetoftransmissiongears-similartoatrucktransmission—throughwhichthespindlecanberotatedatanumberofspeeds.Mostlathesprovidefrom8to12speeds,usuallyinageometricratio,andonmodernlathesallthespeedscanbeobtainedmerelybymovingfrom2to4levers.Anincreasingtrendistoprovideacontinuouslyvariablespeedrangethroughelectricalormechanicaldrives.Becausetheaccuracyofalatheisgreatlydependentonthespindle,itisofheavyconstructionandmountedinheavybearings,usuallypreloadedtaperedrollerorballtypes.Thespindlehasaholeextendingthroughitslength,throughwhichlongbarstockcanbefed.Thesizeofmaximumsizeofbarstockthatcanbemachinedwhenthematerialmustbefedthroughspindle.Thetailsticdassemblyconsists,essentially,ofthreeparts.Alowercastingfitsontheinnerwaysofthebedandcanslidelongitudinallythereon,withameansforclampingtheentireassemblyinanydesiredlocation,Anuppercastingfitsontheloweroneandcanbemovedtransverselyuponit, onsometypeofkeyedways,topermitaligningthe28assemblyisthetailstockquill.Thisisahollowsteelcylinder,usuallyabout51to76mm(2to3inches)indiameter,thatcanbemovedseveralincheslongitudinallyinandoutoftheuppercastingbymeansofahandwheelandscrew.Thesizeofalatheisdesignatedbytwodimensions.Thefirstisknownastheswing.Thisisthemaximumdiameterofworkthatcanberotatedonalathe.Itisapproximatelytwicethedistancebetweenthelineconnectingthelathecentersandthenearestpointontheways,Thesecondsizedimensionisthemaximumdistancebetweencenters.Theswingthusindicatesthemaximumworkpiecediameterthatcanbeturnedinthelathe,whilethedistancebetweencentersindicatesthemaximumlengthofworkpiecethatcanbemountedbetweencenters.Enginelathesarethetypemostfrequentlyusedinmanufacturing.Theyareheavy-dutymachinetoolswithallthecomponentsdescribedpreviouslyandhavepowerdriveforalltoolmovementsexceptonthecompoundrest.Theycommonlyrangeinsizefrom305to610mm(12to24inches)swingandfrom610to1219mm(24to48inches)centerdistances,butswingsupto1270mm(50inches)andcenterdistancesupto3658mm(12feet)arenotuncommon.Mosthavechippansandabuilt-incoolantcirculatingsystem.Smallerenginelathes-withswingsusuallynotover330mm(13inches)alsoareavailableinbenchtype,designedforthebedtobemountedonabenchonabenchorcabinet.Althoughenginelathesareversatileandveryuseful,becauseofthetimerequiredforchangingandsettingtoolsandformakingmeasurementsontheworkpiece,thyarenotsuitableforquantityproduction.Oftentheactualchip-productiontineislessthan30%ofthetotalcycletime.Inaddition,askilledmachinistisrequiredforalltheoperations,andsuchpersonsarecostlyandofteninshortsupply.However,muchoftheoperator”stimeisconsumedbysimple,repetitiousadjustmentsandinwatchingchipsbeingmade.Consequently,toreduceoreliminatetheamountofskilledlaborthatisrequired,turretlathes,screwmachines,andothertypesofsemiautomaticandautomaticlatheshavebeenhighlydevelopedandarewidelyusedinmanufacturing.Oneofthemostfundamentalconceptsintheareaofadvancedmanufacturingtechnologiesisnumericalcontrol(NC).PriortotheadventofNC,allmachinetoolseremanuallyoperatedandcontrolled.Amongthemanylimitationsassociatedwithmanualcontrolmachinetools,perhapsnoneismoreprominentthanthelimitationofoperatorskills.Withmanualcontrol,thequalityoftheproductisdirectlyrelatedtoandlimitedtotheskillsoftheoperator.Numericalcontrolrepresentsthefirstmajorstepawayfromhumancontrolofmachinetools.Numericalcontrolmeansthecontrolofmachinetoolsandothermanufacturingsystemsthroughtheuseofprerecorded,writtensymbolicinstructions.Ratherthanoperatingamachinetool,anNCtechnicianwritesaprogramthatissuesoperationalinstructionstothemachinetool.Foramachinetooltobenumericallycontrolled,itmustbeinterfacedwithadeviceforacceptinganddecodingtheprogrammedinstructions,knownasareader.Numericalcontrolwasdevelopedtoovercomethelimitationofhumanoperators,andithasdoneso.Numericalcontrolmachinesaremoreaccuratethanmanuallyoperatedmachines,theycan producepartsmoreuniformly,they arefaster,andthelong-runtoolingcostsarelower.ThedevelopmentofNCledtothedevelopmentofseveral other innovations in manufacturing technology: Electrical machining,Lasercutting,Electronbeamwelding.Numericalcontrolhasalsomademachinetoolsmoreversatilethantheirmanuallyoperatedpredecessors.AnNCmachinetoolcanautomaticallyproduceawideofparts,eachinvolvinganassortmentofwidelyvariedandcomplexmachiningprocesses.Numericalcontrolhasallowedmanufacturerstoundertaketheproductionofproductsthatwouldnothavebeenfeasiblefromaneconomicperspectiveusingmanuallycontrolledmachinetollsandprocesses.Likesomanyadvancedtechnologies,NCwasborninthelaboratoriesoftheMassachusettsInstituteofTechnology.TheconceptofNCwasdevelopedintheearly1950swithfundingprovidedbytheU.S.AirForce.Initsearlieststages,NCmachineswereabletomadestraightcutsefficientlyandeffectively.However,curvedpathswereaproblembecausethemachinetoolhadtobeprogrammedtoundertakeaseriesofhorizontalandverticalstepstoproduceacurve.Theshorterthestraightlinesmakingupthesteps,thesmootheristhecurve,Eachlinesegmentinthestepshadtobecalculated.Thisproblemledtothedevelopmentin1959oftheAutomaticallyProgrammedTools(APT)language.ThisisaspecialprogramminglanguageforNCthatusesstatementssimilartoEnglishlanguagetodefinethepartgeometry,describethecuttingtoolconfiguration,andspecifythenecessarymotions.ThedevelopmentoftheAPTlanguagewasamajorstepforwardinthefurtherdevelopmentfromthoseusedtoday.Themachineshadhardwiredlogiccircuits.Theinstructionalprogramswerewrittenonpunchedpaper,whichwaslatertobereplacedbymagneticplastictape.Atapereaderwasusedtointerprettheinstructionswrittenonthetapeforthemachine.Together,allofthisrepresentedagiantstepforwardinthecontrolofmachinetools.However,therewereanumberofproblemswithNCatthispointinitsdevelopment.Amajorproblemwasthefragilityofthepunchedpapertapemedium.Itwascommonforthepapertapecontainingtheprogrammedinstructionstobreakortearduringamachiningprocess.Thisproblemwasexacerbatedbythefactthateachsuccessivetimeapartwasproducedonamachinetool,thepapertapecarryingtheprogrammedinstructionshadtobererunthroughthereader.Ifitwasnecessarytoproduce100copiesofagivenpart,itwasalsonecessarytorunthepapertapethroughthereader100separatetines.Fragilepapertapessimplycouldnotwithstandtherigorsofashopfloorenvironmentandthiskindofrepeateduse.Thisledtothedevelopmentofaspecialmagneticplastictape.Whereasthepapercarriedtheprogrammedinstructionsasaseriesofholespunchedinthetape,theplastictapecarriedtheinstructionsasaseriesofmagneticdots.Theplastictapewasmuchstrongerthanthepapertape,whichsolvedtheproblemoffrequenttearingandbreakage.However,itstilllefttwootherproblems.Themostimportantofthesewasthatitwasdifficultorimpossibletochangetheinstructionsenteredonthetape.Tomadeeventhemostminoradjustmentsinaprogramofinstructions,itwasnecessarytointerruptmachiningoperationsandmakeanewtape.Itwasalsostillnecessarytorunthetapethroughthereaderasmanytimesastherewerepartstobeproduced.Fortunately,computertechnologybecamearealityandsoonsolvedtheproblemsofNCassociatedwithpunchedpaperandplastictape.Thedevelopmentofaconceptknownasdirectnumericalcontrol(DNC)solvedthepaperandplastictapeproblemsassociatedwithnumericalcontrolbysimplyeliminatingtapeasthemediumforcarryingtheprogrammedinstructions.Indirectnumericalcontrol,machinetoolsaretied,viaadatatransmissionlink,toahostcomputer.Programsforoperatingthemachinetoolsarestoredinthehostcomputerandfedtothemachinetoolanneededviathedatatransmissionlinkage.Directnumericalcontrolrepresentedamajorstepforwardoverpunchedtapeandplastictape.However,itissubjecttothesamelimitationsasalltechnologiesthatdependonahostcomputer.Whenthehostcomputergoesdown,themachinetoolsalsoexperiencedowntime.Thisproblemledtothedevelopmentofcomputernumericalcontrol.Theenginelathe Theenginelathe,oneoftheoldestmetalremovalmachines,hasanumberofusefulandhighlydesirableattributes.Todaytheselathesare used primarily in small shops where smaller quantities rather than largeproductionrunsareencountered.Theenginelathehasbeenreplacedintoday”sproductionshopsbyawidevarietyofautomaticlathessuchasautomaticofsingle-pointtoolingformaximummetalremoval,andtheuseofformtoolsforfinishonaparwiththefastestprocessingequipmentonthescenetoday.Tolerancesfortheenginelathedependprimarilyontheskilloftheoperator.Thedesignengineermustbecarefulinusingtolerancesofanexperimentalpartthathasbeen produced on the engine lathe by a skilled operator. In redesigning experimentalpartforproduction,economicaltolerancesshouldbeused.TurretLathesTurretLathesProductionmachiningequipmentmustbeevaluatednow,morethaneverbefore,thiscriterionforestablishingtheproductionqualificationofaspecificmethod,thetu