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无锡太湖学院2009届本科生毕业设计（论文）翻译1ADIESELENGINEWORKS【ABSTRACT】INADIESELENGINECYLINDER,THEPISTONINTHEPARTOFTHEWORKCYCLEOFCOMPRESSEDGAS,ANDINANOTHERPARTOFTHEWORKCYCLEOFTHECOMBUSTIONGASMIXTUREWITHINTHECYLINDERSOTHEPISTONTOPSURFACEEXPANSIONHIGHPRESSUREABOUT116120KGF/CM2UNDERHIGHTEMPERATUREABOUT569CGASROLE,ANDTHEPRESSURETHROUGHTHEPISTONPIN,CONNECTINGRODTOTHECRANKSHAFTCANBESEENTHATTHEPISTONISALONGTIMEUNDERHIGHTEMPERATUREANDHIGHPRESSUREINCONTINUOUSRECIPROCATINGMOTIONOFTHELOAD,ITSLOADANDWORKINGCONDITIONSWEREAPPALLINGDURINGTHEDESIGNPROCESSOFTHEPISTONWILLBEDESIGNEDTOENSURELONGTERMSTABILITYOFTHEWORKPISTONTHEDESIGNOFTHEWORKDONEBYABRIEFINTRODUCTIONASFOLLOWSDIESELENGINEPISTON180CREASONABLEPROCESSINGTECHNOLOGYISIMPORTANT,THEROLEOFPARTSANDTECHNOLOGYPROGRAMANALYSIS,PREPARATIONOFROUGHFORMANDPROCESSMANUFACTURINGLINE,THROUGHTHEANALYSIS,COMPARISON,USEOFTHERELATIVECONCENTRATIONOFPROCESSINGPROGRAMS,ANDULTIMATELYMOREREASONABLETODETERMINETHEMECHANICALLINEPROCESSINGTHEDEVELOPMENTPROCESSOFROUGHLINETHEMAINCONSIDERATION,FINISHINGARRANGEMENTS,CHOICEOFPROCESSINGMETHODS,CENTRALIZEDANDDECENTRALIZEDPROCESSES,SUCHASPROCESSINGTHEORDERREQUIREMENTSTHENDETERMINETHEALLOWANCE,PROCESSSIZE,AFTERTHEANALYSISOFTHECHARACTERISTICSOFTHEPROCESS,SELECTTHEAPPROPRIATEPROCESSINGEQUIPMENTANDTECHNICALEQUIPMENTCALCULATEDLOOKUPTABLETODETERMINETHENEXTMAJORPISTONCUTTINGPROCESSANDTHEMAPPINGOFPROCESSESCARD,THEDESIGNOFTHEFINALFIXTUREFIXTUREDESIGN,ITISNECESSARYTOTAKEVARIOUSASPECTSINTOACCOUNT,THESTRICTREQUIREMENTSOFTHEFIXTUREADIRECTIMPACTONTHESURFACEOFTHEWORKPIECEPROCESSINGPOSITIONACCURACYTHEREFORE,THEMACHINETOOLDESIGNFIXTUREDESIGNISANIMPORTANTTASKISTHEPROCESSINGOFONEOFTHEMOSTACTIVEDURINGTHEGRADUATIONPROJECTINASPECIALLYDESIGNEDPOSITIONINGACCURACY,SIMPLESTRUCTUREANDEASYTOUSEPRECISIONPINHOLEBORINGJIGKEYWORDSPISTON；TECHNOLOGY；PROCESSINGEQUIPMENT；CUTTING；FIXTUREANYTYPEOFMACHINETHATOBTAINSMECHANICALENERGYDIRECTLYFROMTHEEXPENDITUREOFTHECHEMICALENERGYOFFUELBURNEDINACOMBUSTIONCHAMBERTHATISANINTEGRALPARTOFTHEENGINEFOURPRINCIPALTYPESOFINTERNALCOMBUSTIONENGINESAREINGENERALUSETHEOTTOCYCLEENGINE,THEDIESELENGINE,THEROTARYENGINE,ANDTHEGASTURBINEFORTHEVARIOUSTYPESOFENGINESEMPLOYINGTHEPRINCIPLEOFJETPROPULSION,SEEJETPROPULSION；ROCKETTHEOTTOCYCLEENGINE,NAMEDAFTERITSINVENTOR,THEGERMANTECHNICIANNIKOLAUSAUGUSTOTTO,ISTHEFAMILIARGASOLINEENGINEUSEDINAUTOMOBILESANDAIRPLANES；THEDIESELENGINE,NAMEDAFTERTHEFRENCHBORNGERMANENGINEERRUDOLFCHRISTIANKARLDIESEL,OPERATESONADIFFERENTPRINCIPLEANDUSUALLYUSESOILASAFUELITISEMPLOYEDINELECTRICGENERATINGANDMARINEPOWERPLANTS,INTRUCKSANDBUSES,ANDINSOMEAUTOMOBILESBOTHOTTOCYCLEANDDIESELENGINESAREMANUFACTUREDIN无锡太湖学院2009届本科生毕业设计（论文）翻译2TWOSTROKEANDFOURSTROKECYCLEMODELSTHEESSENTIALPARTSOFOTTOCYCLEANDDIESELENGINESARETHESAMETHECOMBUSTIONCHAMBERCONSISTSOFACYLINDER,USUALLYFIXED,THATISCLOSEDATONEENDANDINWHICHACLOSEFITTINGPISTONSLIDESTHEINANDOUTMOTIONOFTHEPISTONVARIESTHEVOLUMEOFTHECHAMBERBETWEENTHEINNERFACEOFTHEPISTONANDTHECLOSEDENDOFTHECYLINDERTHEOUTERFACEOFTHEPISTONISATTACHEDTOACRANKSHAFTBYACONNECTINGRODTHECRANKSHAFTTRANSFORMSTHERECIPROCATINGMOTIONOFTHEPISTONINTOROTARYMOTIONINMULTICYLINDEREDENGINESTHECRANKSHAFTHASONEOFFSETPORTION,CALLEDACRANKPIN,FOREACHCONNECTINGROD,SOTHATTHEPOWERFROMEACHCYLINDERISAPPLIEDTOTHECRANKSHAFTATTHEAPPROPRIATEPOINTINITSROTATIONCRANKSHAFTSHAVEHEAVYFLYWHEELSANDCOUNTERWEIGHTS,WHICHBYTHEIRINERTIAMINIMIZEIRREGULARITYINTHEMOTIONOFTHESHAFTANENGINEMAYHAVEFROM1TOASMANYAS28CYLINDERSTHEFUELSUPPLYSYSTEMOFANINTERNALCOMBUSTIONENGINECONSISTSOFATANK,AFUELPUMP,ANDADEVICEFORVAPORIZINGORATOMIZINGTHELIQUIDFUELINOTTOCYCLEENGINESTHISDEVICEISEITHERACARBURETOROR,MORERECENTLY,AFUELINJECTIONSYSTEMINMOSTENGINESWITHACARBURETOR,VAPORIZEDFUELISCONVEYEDTOTHECYLINDERSTHROUGHABRANCHEDPIPECALLEDTHEINTAKEMANIFOLDAND,INMANYENGINES,ASIMILAREXHAUSTMANIFOLDISPROVIDEDTOCARRYOFFTHEGASESPRODUCEDBYCOMBUSTIONTHEFUELISADMITTEDTOEACHCYLINDERANDTHEWASTEGASESEXHAUSTEDTHROUGHMECHANICALLYOPERATEDPOPPETVALVESORSLEEVEVALVESTHEVALVESARENORMALLYHELDCLOSEDBYTHEPRESSUREOFSPRINGSANDAREOPENEDATTHEPROPERTIMEDURINGTHEOPERATINGCYCLEBYCAMSONAROTATINGCAMSHAFTTHATISGEAREDTOTHECRANKSHAFTBYTHE1980SMORESOPHISTICATEDFUELINJECTIONSYSTEMS,ALSOUSEDINDIESELENGINES,HADLARGELYREPLACEDTHISTRADITIONALMETHODOFSUPPLYINGTHEPROPERMIXOFAIRANDFUELINENGINESWITHFUELINJECTION,AMECHANICALLYORELECTRONICALLYCONTROLLEDMONITORINGSYSTEMINJECTSTHEAPPROPRIATEAMOUNTOFGASDIRECTLYINTOTHECYLINDERORINLETVALVEATTHEAPPROPRIATETIMETHEGASVAPORIZESASITENTERSTHECYLINDERTHISSYSTEMISMOREFUELEFFICIENTTHANTHECARBURETORANDPRODUCESLESSPOLLUTIONINALLENGINESSOMEMEANSOFIGNITINGTHEFUELINTHECYLINDERMUSTBEPROVIDEDFOREXAMPLE,THEIGNITIONSYSTEMOFOTTOCYCLEENGINESDESCRIBEDBELOWCONSISTSOFASOURCEOFLOWVOLTAGE,DIRECTCURRENTELECTRICITYTHATISCONNECTEDTOTHEPRIMARYOFATRANSFORMERCALLEDANIGNITIONCOILTHECURRENTISINTERRUPTEDMANYTIMESASECONDBYANAUTOMATICSWITCHCALLEDTHETIMERTHEPULSATIONSOFTHECURRENTINTHEPRIMARYINDUCEAPULSATING,HIGHVOLTAGECURRENTINTHESECONDARYTHEHIGHVOLTAGECURRENTISLEDTOEACHCYLINDERINTURNBYAROTARYSWITCHCALLEDTHEDISTRIBUTORTHEACTUALIGNITIONDEVICEISTHESPARKPLUG,ANINSULATEDCONDUCTORSETINTHEWALLORTOPOFEACHCYLINDERATTHEINNERENDOFTHESPARKPLUGISASMALLGAPBETWEEN无锡太湖学院2009届本科生毕业设计（论文）翻译3TWOWIRESTHEHIGHVOLTAGECURRENTARCSACROSSTHISGAP,YIELDINGTHESPARKTHATIGNITESTHEFUELMIXTUREINTHECYLINDERBECAUSEOFTHEHEATOFCOMBUSTION,ALLENGINESMUSTBEEQUIPPEDWITHSOMETYPEOFCOOLINGSYSTEMSOMEAIRCRAFTANDAUTOMOBILEENGINES,SMALLSTATIONARYENGINES,ANDOUTBOARDMOTORSFORBOATSARECOOLEDBYAIRINTHISSYSTEMTHEOUTSIDESURFACESOFTHECYLINDERARESHAPEDINASERIESOFRADIATINGFINSWITHALARGEAREAOFMETALTORADIATEHEATFROMTHECYLINDEROTHERENGINESAREWATERCOOLEDANDHAVETHEIRCYLINDERSENCLOSEDINANEXTERNALWATERJACKETINAUTOMOBILES,WATERISCIRCULATEDTHROUGHTHEJACKETBYMEANSOFAWATERPUMPANDCOOLEDBYPASSINGTHROUGHTHEFINNEDCOILSOFARADIATORSOMEAUTOMOBILEENGINESAREALSOAIRCOOLED,ANDINMARINEENGINESSEAWATERISUSEDFORCOOLINGUNLIKESTEAMENGINESANDTURBINES,INTERNALCOMBUSTIONENGINESDEVELOPNOTORQUEWHENSTARTING,ANDTHEREFOREPROVISIONMUSTBEMADEFORTURNINGTHECRANKSHAFTSOTHATTHECYCLEOFOPERATIONCANBEGINAUTOMOBILEENGINESARENORMALLYSTARTEDBYMEANSOFANELECTRICMOTORORSTARTERTHATISGEAREDTOTHECRANKSHAFTWITHACLUTCHTHATAUTOMATICALLYDISENGAGESTHEMOTORAFTERTHEENGINEHASSTARTEDSMALLENGINESARESOMETIMESSTARTEDMANUALLYBYTURNINGTHECRANKSHAFTWITHACRANKORBYPULLINGAROPEWOUNDSEVERALTIMESAROUNDTHEFLYWHEELMETHODSOFSTARTINGLARGEENGINESINCLUDETHEINERTIASTARTER,WHICHCONSISTSOFAFLYWHEELTHATISROTATEDBYHANDORBYMEANSOFANELECTRICMOTORUNTILITSKINETICENERGYISSUFFICIENTTOTURNTHECRANKSHAFT,ANDTHEEXPLOSIVESTARTER,WHICHEMPLOYSTHEEXPLOSIONOFABLANKCARTRIDGETODRIVEATURBINEWHEELTHATISCOUPLEDTOTHEENGINETHEINERTIAANDEXPLOSIVESTARTERSARECHIEFLYUSEDTOSTARTAIRPLANEENGINESTHEORDINARYOTTOCYCLEENGINEISAFOURSTROKEENGINE；THATIS,INACOMPLETEPOWERCYCLE,ITSPISTONSMAKEFOURSTROKES,TWOTOWARDTHEHEADCLOSEDHEADOFTHECYLINDERANDTWOAWAYFROMTHEHEADDURINGTHEFIRSTSTROKEOFTHECYCLE,THEPISTONMOVESAWAYFROMTHECYLINDERHEADWHILESIMULTANEOUSLYTHEINTAKEVALVEISOPENEDTHEMOTIONOFTHEPISTONDURINGTHISSTROKESUCKSAQUANTITYOFAFUELANDAIRMIXTUREINTOTHECOMBUSTIONCHAMBERDURINGTHENEXTSTROKE,THEPISTONMOVESTOWARDTHECYLINDERHEADANDCOMPRESSESTHEFUELMIXTUREINTHECOMBUSTIONCHAMBERATTHEMOMENTWHENTHEPISTONREACHESTHEENDOFTHISSTROKEANDTHEVOLUMEOFTHECOMBUSTIONCHAMBERISATAMINIMUM,THEFUELMIXTUREISIGNITEDBYTHESPARKPLUGANDBURNS,EXPANDINGANDEXERTINGAPRESSUREONTHEPISTON,WHICHISTHENDRIVENAWAYFROMTHECYLINDERHEADINTHETHIRDSTROKEDURINGTHEFINALSTROKE,THEEXHAUSTVALVEISOPENEDANDTHEPISTONMOVESTOWARDTHECYLINDERHEAD,DRIVINGTHEEXHAUSTGASESOUTOFTHECOMBUSTIONCHAMBERANDLEAVINGTHECYLINDERREADYTOREPEATTHECYCLETHEEFFICIENCYOFAMODERNOTTOCYCLEENGINEISLIMITEDBYANUMBEROFFACTORS,INCLUDINGLOSSESBYCOOLINGANDBYFRICTIONINGENERAL,THEEFFICIENCYOFSUCHENGINESIS无锡太湖学院2009届本科生毕业设计（论文）翻译4DETERMINEDBYTHECOMPRESSIONRATIOOFTHEENGINETHECOMPRESSIONRATIOTHERATIOBETWEENTHEMAXIMUMANDMINIMUMVOLUMESOFTHECOMBUSTIONCHAMBERISUSUALLYABOUT8TO1OR10TO1INMOSTMODERNOTTOCYCLEENGINESHIGHERCOMPRESSIONRATIOS,UPTOABOUT15TO1,WITHARESULTINGINCREASEOFEFFICIENCY,AREPOSSIBLEWITHTHEUSEOFHIGHOCTANEANTIKNOCKFUELSTHEEFFICIENCIESOFGOODMODERNOTTOCYCLEENGINESRANGEBETWEEN20AND25PERCENTINOTHERWORDS,ONLYTHISPERCENTAGEOFTHEHEATENERGYOFTHEFUELISTRANSFORMEDINTOMECHANICALENERGYTHEORETICALLY,THEDIESELCYCLEDIFFERSFROMTHEOTTOCYCLEINTHATCOMBUSTIONTAKESPLACEATCONSTANTVOLUMERATHERTHANATCONSTANTPRESSUREMOSTDIESELSAREALSOFOURSTROKEENGINESBUTTHEYOPERATEDIFFERENTLYTHANTHEFOURSTROKEOTTOCYCLEENGINESTHEFIRST,ORSUCTION,STROKEDRAWSAIR,BUTNOFUEL,INTOTHECOMBUSTIONCHAMBERTHROUGHANINTAKEVALVEONTHESECOND,ORCOMPRESSION,STROKETHEAIRISCOMPRESSEDTOASMALLFRACTIONOFITSFORMERVOLUMEANDISHEATEDTOAPPROXIMATELY440CAPPROXIMATELY820FBYTHISCOMPRESSIONATTHEENDOFTHECOMPRESSIONSTROKE,VAPORIZEDFUELISINJECTEDINTOTHECOMBUSTIONCHAMBERANDBURNSINSTANTLYBECAUSEOFTHEHIGHTEMPERATUREOFTHEAIRINTHECHAMBERSOMEDIESELSHAVEAUXILIARYELECTRICALIGNITIONSYSTEMSTOIGNITETHEFUELWHENTHEENGINESTARTSANDUNTILITWARMSUPTHISCOMBUSTIONDRIVESTHEPISTONBACKONTHETHIRD,ORPOWER,STROKEOFTHECYCLETHEFOURTHSTROKE,ASINTHEOTTOCYCLEENGINE,ISANEXHAUSTSTROKETHEEFFICIENCYOFTHEDIESELENGINE,WHICHISINGENERALGOVERNEDBYTHESAMEFACTORSTHATCONTROLTHEEFFICIENCYOFOTTOCYCLEENGINES,ISINHERENTLYGREATERTHANTHATOFANYOTTOCYCLEENGINEANDINACTUALENGINESTODAYISSLIGHTLYMORETHAN40PERCENTDIESELSARE,INGENERAL,SLOWSPEEDENGINESWITHCRANKSHAFTSPEEDSOF100TO750REVOLUTIONSPERMINUTERPMASCOMPAREDTO2500TO5000RPMFORTYPICALOTTOCYCLEENGINESSOMETYPESOFDIESEL,HOWEVER,HAVESPEEDSUPTO2000RPMBECAUSEDIESELSUSECOMPRESSIONRATIOSOF14ORMORETO1,THEYAREGENERALLYMOREHEAVILYBUILTTHANOTTOCYCLEENGINES,BUTTHISDISADVANTAGEISCOUNTERBALANCEDBYTHEIRGREATEREFFICIENCYANDTHEFACTTHATTHEYCANBEOPERATEDONLESSEXPENSIVEFUELOILSBYSUITABLEDESIGNITISPOSSIBLETOOPERATEANOTTOCYCLEORDIESELASATWOSTROKEORTWOCYCLEENGINEWITHAPOWERSTROKEEVERYOTHERSTROKEOFTHEPISTONINSTEADOFONCEEVERYFOURSTROKESTHEPOWEROFATWOSTROKEENGINEISUSUALLYDOUBLETHATOFAFOURSTROKEENGINEOFCOMPARABLESIZETHEGENERALPRINCIPLEOFTHETWOSTROKEENGINEISTOSHORTENTHEPERIODSINWHICHFUELISINTRODUCEDTOTHECOMBUSTIONCHAMBERANDINWHICHTHESPENTGASESAREEXHAUSTEDTOASMALLFRACTIONOFTHEDURATIONOFASTROKEINSTEADOFALLOWINGEACHOFTHESEOPERATIONSTOOCCUPYAFULLSTROKEINTHESIMPLESTT
