毕业设计怎么翻译.docx

毕业设计怎么翻译.docx

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毕业设计怎么翻译

毕业设计怎么翻译

【篇一：

毕业设计英文翻译】

石峰毕业设计（论文）英文翻译

fundamentalsnumbercalcontrolofmachinetools

machinetools

machinetoolsaremachinesforcuttingmetals.themostimportantofmetalusedinindustryarelathes,drillingmachinesandmillingmachines.otherkindsofmetalworkingmachinesarenotsowidelyusedinmachiningmetalsasthesethree.

drillingisperfurmedwitharotatingtoolcalledadrill.mostdrillinginmetaldonewithatwistdrill.themachineusedfordrillingiscalledadrillpress.operationssuchasreamingandtapping,arealsoclassifiedasdrilling.reamingconsistsofremovingasmallamountofmetalfromaholealreadydrilled.

tappingistheprocessofcuttingathreadinsideaholesothatacapscreworboltmaybethreadedintoit.

thelatheiscommonlycalledthefatheroftheentiremachinetoolfamily.forturningoperations,thelatheusedasingle-point-cuttingtool,whichremovemetalasittravelspasttherevolvingworkpiece.turningoperationsarerequiredtomakemanydifferentcylindricalshapes,suchasaxes,gearblanks,pulleys,andthreadedshafts.boringoperationsareperformedtoenlarge,finish,andaccuratelylocateholes.milingremovesmetalwitharevolving,multiplecuttingedgetoolscalledmilingcutter.milingcutteraremadeinmanystylesandsizes.somehaveasfewastwocuttingedgesandothershave30ormore.milingcanproduceflatorangledsurfaces,grooves,slots,gearteeth,andotherprofile,dependingontheshapeofthecuttersbeingused.

shapingandplanningproduceflatsurfaceswithasingle-point-cuttingtool.inshaping,thecuttingtoolonashaperreciprocatesormovesbackandforthwhiletheworkisfedautomaticallytowardsthetool.inplanning,theworkpieceisattachedtoaworktablethatreciprocatespastthecuttingtool.thecuttingtoolisautomaticallyfedintotheworkpieceasmallamountoneachstroke.

grindingmakesuseofabrasiveparticlestodothecutting.grindingoperationsmaybeclassifiedasprecisionornon-precision,dependingonthepurpose.precision

grindingisconcernedwithgrindingtoclosetolerancesandverysmoothfinish.non-precisiongrindinginvolvestheremovalofmetalwhereaccuracyisnotimportant.

fundamentalsnumbercontrol

controllingamachinetoolbymeansofapreparedprogramisknownasnumericalcontrol,ornc.ncequipmenthasbeendefinedtheelectronicindustriesassociation（eia）as“asysteminwhichactionsarecontrolledbythedirectinsertionofnumericaldataatsomepoint.thesystemmustautomaticallyinterpretatleastsomeportionofthisdata.”

inatypicalncsystemthenumericaldatawhichisrequiredforproducingapartismaintainedonapunchedtapeandiscalledthepartprogram.thepartprogramisarrangedintheformofblockofinformation,whereeachblockcontainsthenumericaldatarequiredtoproduceonesegmentoftheworkpiece.thepunchedtapeismovedforwardbyoneblockeachtimethecuttingofasegmentiscompleted.thepunchedcontains,incodedform,alltheinformationneededforprocessingasegmentoftheworkpiece:

thesegmentlength,itscuttingspeed,feed,etc..dimensionalinformation（lenth,width,andradiiofcircles）andthecontourform（linear,circular,orother）aretakenformanengineeringdrawing.dimensionsaregivenseparatelyforeachaxisofmotion（x,y,etc.）.cuttingspeed,feedrate,andauxiliaryfunction（coolantonandoff,spindledirection,clamp,gearchange,etc.）areprogrammedaccordingtosurfacefinishandtoleracerequirements.

preparingthepartprogramforancmachinetoolrequiresapartprogrammer.thepartprogrammermustpossessknowledgeandexperiencesinmechanicalengineering.partprogrammersmustbefamiliarwiththefunctionofncmachinetoolsandmachiningprocessandhavetodecideontheoptimalsequenceofoperations.

inncmachinetoolseachaxisofmotionisequippedwithaseparatedrivingdevicewhichreplacesthehandwheeloftheconventionalmachine.thedrivingdevicemaybeadirectcurrent（dc）motor,ahydraulicactuator,orasteppingmotor.thetypeselectedisdeterminedmainlybythepowerrequirementofthemachine.

thencmachinetoolsystemcontainsthemachinecontrolunit（mcu）andthemachinetoolitself.themcuhastoreadanddecodethepartprogram,toprovidethedecodedinstructionstothecontrolloopsofthemachineaxesofmotion,andtocontrolthemachinetooloperation.

themcuconsistsoftwomainunits:

thedataprocessingunit（dpu）andthecontrolloopsunti（clu）.thefunctionofthedpuistodecodetheinformationreceivedformthetape,processitandprovidedatatothedlu.suchdatacontainsthenewrequiredpositionofeachaxis,itsdirectionofmotionandvelocity,andauxiliarycontrolsignalstorelays.ontheotherhand,thecluprovidesasignalannouncingthatthepreviousiscompletedandthatthedpucanreadanewblockofthepartprogram.thecluoperatesthedrivesattachedofthemachinelead-screwsandreceivesfeedbacksignalsontheactualpositionandvelocityofeachoneoftheaxes.eachlead-screwisequippedwithaseparatedrivingdeviceanfaseparatefeedbackdevice,butthelatterexistsonlyinaclosed-loopsystem.

incncsystem,thedpufunctionsareperformedbythecontrolprogramcontainedinthecnccomputer.themajorpartoftheclu,however,isalwaysimplementedinthemostsophisticatedcncsystem.

numbericalcontrolofmachiningprocess

numbericalcontrolofmachinetoolsbycomputershasgreatadvanceinrecentyears.generally,automaticmachinetoolsareefficientandaccuratewhenlargequantitiesofpartsofthesameshapearerequired,butchangingfromoneautomaticcycletoanotherisalongandexpensiveprocessandwouldonlybecarriedoutforalongrun.buttherearemanyexampleswhenonlyafewpartsarerequiredanditisinsuchworkthatthecomputer-controlledmachineisvaluable.

therearetwotypesofcomputers-digitalandanalogue.adigitalcomputerworkswithnumbersgivenindigitalform,adigitbeingoneofacertainsetofsymbolsusedtoshownumbers.itisthedigitalcomputerwhichisusedinelectronicdataprocessing.theanaloguecomputerisbasedonananalogyofquantity.itdealswithphysicalquantitiesandnotnumbers.

inadigitalcontrolsysteminformationformadrawingisputonadiscwhichis

putintoacomputerwhichcomputersfromtheinformationtothecontinuousmotionofthecuttingtool.theoutputisputonadiscwhichisputintothemachinetoolcontroluntilwhenrequired.onecomputerservicesanumberofmachines.disccanbestoredandusedanynumberoftimesinfuturecases,simplybyreplayingthemifthesamepartsarewantedagain.forbestresult,theelectronicequipmentandthemachinetoolmustbedesignedtogether.

thismethodhasalsobeenappliedtothecontrolofoxygencuttingofsteelplates.whenirregularshapesarerequired,asinshipbuilding,ithasbeenthepracticetomakeamodelandtofollowitsoutlinebyhandcontrol,amethodwhichdoesnotalwaysgiveaccuateresults.again,inf

ormationisprocessedbyaspecialcomputerwhichthenpreparesadiscforuseinthecontrolconsoleofthecuttingmachine.withthisdiscthemachinecanautomaticallycutplatesofcomplicatedshapesveryaccurately.thisdevelopmenthasparticularimportanceformakingsteelplatesandisagoodexampleofautomationappliedtobatchproduction.

programmingfornc

aprogramfornumericalconsistsofasequenceofdirectionsthatcausedancmachinetocarryoutacertainoperation,machiningbeingthemostcommonlyusedprocess.programmingforncmaybedonebyaninternalprogrammingdepartment,ontheshopfloor,orpurchasedfromanoutsidesource.also,programmingmaybedonemanuallyorwithcomputerassistance.

theprogramcontainsinstructionsandcommands.geometicinstructionspertaintorelativemovementbetweenthetoolandtheworkpiece.processinginstructionspertaintospindlespeeds,feed,tools,andsoon.travelinstructionspertaintothetypeofinterpolationandsloworrapidmovementsofthetoolorworktable.switchingcommandspertaintoon/offpositionforcoolantsupplies,spindlerotation,directionofspindlerotation,toolchange,workpiecefeeding,clamping,andsoon.

（1）manualprogramming.manualpartprogrammingconsistsoffirstcalculatingdimensionalrelationshipsofthetool,workpiece,andworktable,basedontheengineeringdrawingsofthepart,andmanufacturingoperationstobeperformedandtheirsequence.aprogramsheetisthenprepared,whichconsistsofthenecessary

informationtocarryouttheoperation,suchascuttingtools,spindlespeeds,feeds,depthofcut,cuttingfluids,power,andtoolorworkpiecerelativepositionsandmovements.basedonthisinformation,thepartprogramisprepared.usuallyapapertapeisfirstpreparedfortryingoutanddebuggingtheprogram.dependingonhowoftenitistobeused,thetapemaybemadeofmoredurablemylar.

someonekonledgeableabouttheparticarprocessandabletounderstand,read,andchangepartprogramscandomanualprogramming.becausetheyarefamiliarwithmachinetoolandprocesscapabilities,skilledmachinistscandomanualprogrammingwithsometraininginprogramming,however,theworkistedious,andtimeconsuming,anduneconomicalandisusedmostlyinsimplepointto-pointapplications.

（2）computer-aidedprogramming.computer-aidedpartprogramminginvolvesspecialsymbolicprogramminglanguagesthatdeterminethecoordinatepointsofcorners,edges,andsurfacesofthepart.becausenumericalcontrolinvolvestheinsertionofdataconcerningworkpiecematerialsandprocessingparameters,programmingmustbedonebyoperatorsorprogrammerswhoareknow