汽車構(gòu)造(英文版)

PTERAUTOMOTIVEBASICSntselectricalequipment.TheengineactsasthepowerunitTheinternalcombustionengineismostcommonthisofengine:gasoline(alsocalledaspark-ignitionengine)anddiesel(alsocalledacompressionignitionengineBothenginesarecalledheatenginestheburningfuelpowertorotateashaftconnectedtothetransmission.Anautomobilebodyisasheetmetalshellwithwindows,doors,ahood,andatrunkdeck....tprovidesaprotectivecoveringfortheenginepassengersandcargoanattractive,colorful,modernappearanceforthevehicle.Thechassisincludesthetransmission,suspension,steering,andbrakesystems.gearbox,driveshaft,finaldrive,anddifferential.Suspension―absorbstheroadshocks.Steering―controlsthedirectionofthemovement.Brake―slowsdownthevehicle.ElectricalEquipmentheelectricalsystemsupplieselectricityfortheignitionhornlightsheaterandPrincipalcomponentcategory種類，類型bodychassis底盤nginecylindergasoline汽油spark火compression壓縮shaft軸transmissionsheetmetal金屬板shell外殼hood(發(fā)動(dòng)機(jī))罩trunkdeck行艙蓋cargo貨物stylingassembly總成，裝配suspension置shock沖擊steeringbrake剎車，制動(dòng)器clutch離合器gearbox變速器driveshaft動(dòng)軸finaldrive主減速器，后橋differential差速器slowdown(使)慢下來，減速hornstarter起動(dòng)機(jī)charge充電alternator交流發(fā)電機(jī)sutomobileWhatarethecommontypesofavehicleaccordingtobodystyling?Whichsystemsdoesachassisincludeandwhatarethemainfunctionsofthechassis?Whyaresuspensionsystemsusedonvehicles?....TERINTERNALCOMBUSTIONENGINEcipleofoperationEngineandpowerneisusedtoproducepowerThechemicalenergyinfuelisconvertedtoheatbyIfcombustiontakesplaceoutsidethecylinder,theengineiscalledanexternalcombustionengine.developedwithinthecombustionchamberisappliedtotheheadofapistontoproduceausablemechanicalforce,whichisthenconvertedintousefulmechanicalpower.gineTermsnkingthepistonbyaconnectingrodtoacrankshaftcausesthegastorotatethetoexpeltheburntgasandrechargethecylinderwithafreshpetrol-airmixture:thistoenterattherighttimeandanexhaustvalveletsouttheburntgasafterthegashasdoneitsjob.Enginetermsare:TDCTopDeadCenterthepositionofthecrankandpistonwhenthepistonisfartherawayfromthecrankshaft.tothecrankshaft.Stroke:thedistancebetweenBDCandTDC;strokeiscontrolledbythecrankshaft.Bore:theinternaldiameterofthecylinder.Sweptvolume:thevolumebetweenTDCandBDC.acapacityoftwoliters(2000cm)hasacylindersweptvolumeof50cm.ClearancevolumethevolumeofthespaceabovethepistonwhenitisatTDC.Compressionratiosweptvolclearancevol)\(clearancevol)Two-stroke:apowerstrokeeveryrevolutionofthecrank.Four-stroke:apowerstrokeeveryotherrevolutionofthecrank..TheFourstrokeSpark-ignitionEngineCycleesparkignitionengineisaninternalcombustionenginewithexternallysuppliedrgycontainedinthefueltokineticenergyTheoperatingstrokesare:startswhenthepistonmovesdownwardfromapositionnearthetopofthecylinder.Asthepistonmovesdownward,avacuum,orlow-pressurearea,iscreated.....valveremainstightlyclosed.ionstrokesareclosedtightlyThiscompressionactionheatstheairfuelmixtureslightlyandconfinesitwithinasmallareacalledthecombustionchamber.eforethepistonreachesthetopofitscompressionstrokeanelectricalsparkdintothecylinderheadofthegasescompressedwithinthecylinderThispressureforcesthepistondownward.Thedownwardstroketurnsthecrankshaftwithgreatforce.nasitmovesupwardtopushthehotburnedgasesoutthroughtheopenexhaustvalve.itstartsbackdownagain.Thus,onecycleendsandanotherbeginsimmediately.ngineOverallMechanicstomakesystemsThesesystemsarethefuelsystemintakesystem,ignitionsystem,coolingsystemlubricationsystemandexhaustsystemEachofthesesystemshasadefinitefunction.Thesesystemswilldiscussedindetaillater.takevalveumekConnectingrodveetyatiotrokeoke比程EngineBlockandCylinderHead2.2.1EngineBlock....blockalsoholdsthecrankshaftwhichfastenstothebottomoftheblock.Thecamshaftorchromium.Engineblocksarecastings.Someengineblocksespeciallythoseinsmallercarsaremadeofcastaluminum.ThismetalismuchlighterthanironHowever,ironwearsbetterthanaluminum.Therefore,arecalledcylindersleeves.Someengineblocksaremadeentirelyofaluminum.2.2.2CylinderHeadThecylinderheadfastenstothetopoftheblockjustasarooffitsoverahouse.Theandtherockersontherockershaftthispartofthevalvegearbeingworkedbythecylinderblock,theheadismadefromeithercastironoraluminumalloy.2.2.3GasketThisisachievedbyusingcylinderheadgasketThisisasandwichgasket,i.e.asheetofasbestosbetweentwosheetsofcopperboththesematerialsbeingabletowithstandthehightemperatureandpressureswithintheengine.2.2.4OilPanorSumpTheoilpanisusuallyformedofpressedsteelTheoilpanandthelowerpartoftheTheoilpumpinthelubricatingsystemdrawsoilfromtheoilpanandsendsittoallworkingpartsintheengine.Theoildrainsoffandrunsdownintothepan.Thus,thereisconstantcirculationofoilbetweenthepanandtheworkingpartsoftheengine.軸缸體overheadcamOHC頂置凸輪oilpan油底殼with鑲有cylindersleeve氣缸套..rayironiumhemi半球形進(jìn)氣總管鋁camshaft凸輪ytingutorlined..semihemirocker搖臂push-rod推桿gasket襯墊high-tensile高強(qiáng)度的stud螺栓caseencasedrainoff排出，流出CstrokecompressionratioandenginecapacitystandforHowdoyoucalculatesweptvolumeandcompressionratio?hatcontrolsthelengthofthestrokeListthemainpartsoftheengineoverallmechanics?Whatarethemainfunctionoftheengineblock?istonConnectingRodandCrankshafttonAssemblyThepistonisanimportantpartofafourstrokecycleengineMostpistonsaremadetheforcecreatebytheburningfuelmixtureThisforceturnsthecrankshaft.Thin,circularsteelbandsfitintogroovesaroundthepistontosealthebottomofthearecalledringgroovesApistonpinfitsintoaroundholeinthepiston.Thepistonpistonisthepinboss.hepistonitselfitsringsandthepistonpinaretogethercalledthepistonassembly.tonTowithstandtheheatofthecombustionchamberthepistonmustbestrongItalsoThepistonishollowItisthickatthetopwhereittakethebruntoftheheatandtheexpansionforceItisthinatthebottomwherethereislessheat.Thetoppartofthepistonistheheadorcrown.ThethinpartistheskirtThesectionsbetweentheringgroovesarecalledringlands.ThepistoncrownmaybeflatconcavedomeorrecessedIndieselengine,thecombustionchambermaybeformedtotallyorinpartinthepistoncrown,dependingonthemethodofinjection.Sotheyusepistonswithdifferentshapes.tonRingsAsFigshows,pistonringsfitintoringgroovesneartheofthepiston.IntermspistonringsarethincircularpiecesofmetalthatfitintogroovesnessometimesvenfiveTheringsoutsidesurfacepressesagainstthecylinderonlytheringscontactthecylinderwalls.Thetoptworingsaretokeepthegasesin....thecylinderandarecalledcompressionringsTheloweronepreventstheoilsplashedChromefacecastironcompressionringsarecommonlyusedinautomobileengines.Thechromefaceprovideaverysmooth,wear-resistantsurface.Duringthepowerstoke,combustionpressureonthecombustionringsisveryhigh.sforcetheringfaceintofullcontactwiththecylinderwallThecombustionpressurembustionpressurecausesatightersealbetweentheringfaceandthecylinderwall.PistonPinthepistonpinholesandintoaholeinthetopendoftheconnectingrod.Thetopendofismuchsmallerthantheendthatfitsonthecrankshaft.ThissmallendfitsinsidethebottomofthepistonThepistonpinfitsthroughonesideofthepiston,throughthesmallendoftherodandthenthroughtheothersideofthepiston.Itholdsthehaveahollowcenter.Manypinsarechrome-platedtohelpthemwearbetter.2.3.3ConnectingrodnnectingrodismadeofforgedcrankshaftTheconnectingrodlittleendisconnectedtothepistonpin.AbushmadesteelbackedleadortinshellbearingareusedThesearethesameasthoseusedforthemainbearings.Thesplitofthebigendissometimesatanangle,sothatitisforgedalloysteel.nkshaftmotionofthepistontotherotarymotionneededtodrivethevehicle.Itisusuallygylinderblockandthebigendjournalsalignwiththeconnectingthecrankshaftisattachedtheflywheelandatthefrontendarethedrivingwhellsforthetiminggears,fan,coolingwaterandalternator.Thethrowofthecrankshaftthedistancebetweenthemainjournalandthebigendcenterscontrolsthelengthofthestroke.Thestrokeisdoublethethrow,andheel....thecrankshaftduringthetimethattheengineisperformingthenon-powerstrokes.Circular圓形的進(jìn)Groove凹槽Withstand抵抗Crown活塞頂Concave的Cylinderwall氣缸壁efaceplatedbackedplintAlignwith匹配Spaceout分隔ringorderelbandHollow空的Dome圓頂boreronzeteelOverlap重疊Viceverse反之亦然houtmpanionBrunt沖力glandRecessed隱蔽的haftjournalgearenceSystemtjusttherighttime.eOperationtakeplaceatexactlytherightmomentsTheopeningofeachvalveiscontrolledbyacamshaft.rheadthecrankshaftThemetalshaftcalledthecamshaft,typicallyhasindividualcamsforeachvalveintheengineAsthecamshaftrotatesthelobe,orhighspotofthecampushesagainstpartsconnectedtothestemofthevalve.Thisactionforcestheforanexhauststroke.thevalveseat.islocatedoverthecylinderheadthearrangementisknownasoverheadcamshaft(OHC)designSomehighperformanceenginehavetwoseparatecamshaftsoneforeachsetof....esareknownasoverheadcamshaftDHOCenginehrodValveTrainThecamshaftalsocanbelocatedinthelowerpartoftheengine,withintheengineblockTotransferthemotionofthecamupwardtothevalve,additionalpartsareneeds.calledfollowerupward(awayfromthecamshaft).Thecamfollowerridesagainstapushrod,rwThedownwardmovingsideoftherockerarmpushesonthevalvestemtoopenthevalve.BecauseapushrodvalvetrainhasadditionalpartsitismoredifficulttoneveClearancetightlyontheirseatstoproduceagastightsealandthuspreventthegasesescapingfillpowerAlsothevalveheadswillbeliabletobebruntbythepassinghotgases,theengine.SothatthevalvescanclosefullysomeclearanceisneededintheoperatingmechanismThismeansthattheoperatingmechanismmustbeabletomovesufficientlyfarenoughawayfromthevalvetallowthevalvestobefullyclosedagainstitsseatmetallictapingnoise.lveTimingThetimeatwhichvalvesopenandclosevalvetimingandthedurationofthetontravelsdowntoBDCandevenpastBDCThisisintakevalvedurationAnexampleofthiscouldbestatedasfollowsIOat17BTDC,ICat51ABDCfcrankshaftrotationisleavesdurationforthecompressionstrokesincecompressionendswhenthepistonreachesTDCAtthispointthepowerstrokebegins.Thepowerstrokeendswhentheexhaustvalvebeginstoopenapproximatelyat51beforebottomdeadcenter.Thedurationofthepowerstrokeinthiscaseisalso129.Sincetheexhaustvalveisopeningat51BBDC,thisbeginstheexhauststroke.theexhaustvalveclosingat17TTDC,thedurationoftheexhauststrokeis248.periodoftimeduringwhichtheintakevalveisalsoopenInotherwordstheendoftheexhauststrokeandthebeginningoftheintakestrokeoverlapforashortperiodof....timeThisiscalledvalveoverlapValvetimingandvalveoverlapvaryondifferentengines.OpeningtheintakevalvebeforeTDCandclosingitafterBDCincreasethefilloftheintakestrokewhileleavingtheintakevalveopenafterBDCtakesadvantageofthekentiaofthemovingair-fuelmixture.Thisincreasevolumetricefficiency.Asthepistonmovesdownonthepowerstrokepastthe90ATDCposition,pressureshafthasdecreasedduetostroke,andtheexhaustvalvecannowbeopenedtobeginexpellingtheburnedgases.toremoveasmuchoftheburnedgasesasispossibleandincreasevolumetricefficiency.CamDesignandControlDynamicsThefunctionofthecamistoopenandclosethevalvesasfaraspossible,asforceimposelimitsoncamandvalvelift.conversionfromstoredtofreeenergycausesforcevibrationValvetrainassemblieswithoverheadcamshaftscanberepresentedwithsufficientaccuracybya1-masssystemndingdamping).Forsystemwithvalvebottom-mountedcamshaftandpushrods,a2-masssystemisbeingincreasinglyused.aximumpermissiblecontactstressusuallyregardedastheparameterwhich600-700Mpadependinguponthematerialparingsused.CamshaftDriveMechanismhcammustrevolveonceduringthefourstrokecycletoopenavalveAcyclemustrevolveatexactlyhalfthespeedofthecrankshaft.ThisisaccomplishedwithaconnectedtothecrankshaftThegearsarelinkedinoneofthreeways:1.BeltDriveAcogtypebeltcanbeused.Suchbeltsaremadeofsyntheticrubberandreinforcedwithinternalsteelorfiberglassstrands.Thebeltshaveteeth,orslottedspacestoengageanddriveteethongearwheels.Abelttypicallyisusedonengineswithoverhead-camvalvetrains.2.ChainDriveMostpush-rodenginesandsomeOHCengineshavechains.3.GearDriveThecamshaftandcrankshaftgearscanbeconnecteddirectlyormeshedThistypeofoperatinglinkagecommonlyisusedonoldersix-cylinder,inlineengines.....nTimingbeltsareusedbecausetheycostlessthanchainsandoperatemorequietly.Atypicaltimingbeltismadeofneoprene(syntheticrubber)reinforcedwithfiberglass.lectronicValveControlSystemAnelectronicvaluecontrol(EVC)systemreplacesthemechanicalcamshaft,controllingeachvaluewithactuatorsforindependentvaluetiming.TheEVCsystemvalueintoindependentlycontrolledactuatorvalvesprovidesahugeamountofflexibilityinenginecontrolstrategy.VehiclesutilizingEVCcanrealizeseveralbenefitsincluding:dfueleconomy2)allowscentralizedanddistributedEVCsystemstoperformattheirfull3)adaptstoenginesofvariedcylindercounts.areeagertogettheirfirstEVCsystemsontheroad.TheEVCsystemistargetedtooperateintemperaturesuptowhiletheactuatoristargetedtorunuptorminTheactuatorcanbecontrolledinacentralizedsystemwithaspeedbus.enoughtofitintheenginespaceAvehiclethatusesa42VsystemisidealforEVCbecauseitrequireshighvoltagetocontrolthevalueactuators,andEVCisadaptabilityforanumberofcylinderengines.口 (運(yùn))動(dòng)的，動(dòng)力(學(xué))的杠桿作用haftrncevalvelift桿的，靜力的....thbelt側(cè)面neoprene氯丁(二稀)橡膠electronicvalvecontrol(EVC)電子式氣閥centralizedsystem集中系統(tǒng)distributedsystem分布系統(tǒng)variedcylindercount可變的汽缸數(shù)造processor處理器communicationlayer層ListthemainpartsoftheOHCvalvetrain.2.Howdoesapush-rodvalvetrainwork?3.howarethevalveclearanceadjustedbyhand?4.WhydotheintakevalvesopenbeforeTDCandcloseafterBDC?Whatdowemeanby“valveoverlap“6.Whydomostcarsusetimingbeltsratherthanchains?7.Whataretheadvantageoftheelectronicvalvecontrol(EVC)?olineFuelSystemlineGasolineisdistilledfromcrudepetroleumGasolineishighlyflammablemeaningGasolinemustvaporizeeasily.Thischaracteristic,calledvolatility,isimportantHoweveritmustnotvaporizetooeasily,oritwillturntovaporinsidethefueltankorfuellinesInsidethefuelline,fuelvapormayblocktheflowofliquidgasolineThisiscalledvaporlockVaporlockiscommoninfuellineswheretheinletsideofthepumpisexposedtohightemperatures.lammabilityofgasolinevarieswithitsqualityandtheadditivesmixedwiththegasolineThewaygasolineburnsinsidethecombustionchamberismostimportant.helpstoincreasethepowerofanengineThisisdonebycompressionthefuelmixturetoasmallervolumeHighercompressionrationotonlyboostpowerbutalsogivemoreefficientpowerButasthecompressionratiogoesup,knockingtendencyincrease.asanuncontrolledexplosionofthelastportionoftheburningfuel-airmixtureduetocreatesshockpressurewavesandhenceaudibleknock,rathertansmoothcombustion....temperatures,andenginedamageifsufficientlysevere.themotormethodandtheresearchmethodBothusedthesametypeoflaboratorysingleknockintensityUsingthetestsampleasfueltheenginecompressionratioandtherfuelmixtureareadjustedtodevelopaspecifiedknockintensityTwoprimarystandardreferencefuelsnormalheptaneandisooctanearbitrarilyassignedandasthetestsampleThusifthematchingreferenceblendismadeupof15n-heptanenumber,accordingtothetestmethodused.daptationtoOperatingConditionfromthebasicinjection-fuelquantitysothatcorrectiveisrequiredinmixtureformation.Duringacoldstart,theair-fuelmixturedrawninbytheengineleansoff.hisisduetothelowturbulenceatcrankingspeedscausingpoormixtureofthefuelparticleswiththeairandtotheminimalevaporationofthefuelandwettingofthecylinderwallsandintakeportswithfuelatlowtemperature.Inordertocompensateforthesephenomenaandthusfacilitatestaringofthecoldengine,additionalfuelmustbeinjectedduringcranking.startPhaseAfterstaringatlowtemperatures,itisnecessarytoenrichthemixtureforashortperiodinordertocompensateforpoormixtureformationandwettingofthetorqueandthereforebetterthrottleresponsewhenacceleratingfromidle.rmupThewarmupphasefollowsthecoldstartandthepoststartphaseTheenginecoldcylinderwallsAtlowtemperaturesmixtureformationispoorduetothelargemanifold,andonlyevaporatesathighertemperatures.withdecreasingtemperature.elerationIfthethrottleisopenedabruptly,theair-fuelmixtureismomentarily.PartLoadtheemissionvaluesarethecrucialfactors.oadst....beenrichedcomparedtothatatpartload.theentireenginespeedrangeThisalsoensureoptimumfuel-economyfiguresduringlinglydeterminesthefuelconsumptionatidle.ThehigherfrictionalresistancesinthecoldenginemustbeovercomebyincreasingtheairfuelmixtureinputInordertoachievesmootherrunningatidle,theidlespeedcontrolincreasestheidlespeedThisalsoleadstomorerapidwarm-upquantitycorrespondstothequantityrequiredformaintainingtheidlespeedattherelevantloadegcoldengineandincreasedfriction).Italsopermitsconstantidlespeedcontrolalsopartiallycompensatesforchargesintheengineresultingfromagingandensuresstableengineidlingthroughouttheservicelife.tingoffthefuelduringdecelerationreducesfuelconsumptionnotmerelyonlongdownhillrunsandduringbrakingbutalsointowntraffic.Becausenofuelisburnt,therearenoemission.EnginespeedLimitingdisreachedtheECUsuppressesthefuelinjectionpulses.lMixtureatHighAltitudesAthighaltitudesduetothelowerairdensity,thevolumetricfloemeasuredbytheairfuelsensorcorrespondstoalowerair-massfloe.Thiserrorcancompensatedforfuelconsumption.uretorAsshowninFig-20,thefuelsystemhasafueltank,fueltank,fuelpump,asneededStatedsimplythefueltankstoresthegasoline.ThefuellinescarrythefuelfromthetanktothecarburetorThefuelpumpmovesgasolinefromthetankandthroughthefuellinestocarburetorthefuelfilterremovesimpuritiesfromthegasolineThenthecarburetorsendsthefuelamixtureofairandgasoline━intothecombustionchamber.MotronicCombineIgnitionandFuelInjectionSystemThecarburetorsendsthecorrectairfuelmixturetotheengineHowevernotallcarshavecarburetors.Fuel-injectionsystemsareusedonmanymoderncars.linjectionsystemshavemanyadvantagesovercarburetorsForexampletheyfuel-injectionsystemdonotneedmanyofthepartsthatcarburetorhave.....howevermaycontainadditionalsubsystemsasrequiredforimprovesenginecontrol.mixturequantityandairfuelratio,butalsobytheignitionadvanceandtheenergyheignitionsparkAnoptimizedenginecontroltheairfuelratiothroughouttheinjectiontimeti.e.thequantityofinjectedfuel)aswellastheignitionadvanceangleandthedwellangleβ.ThemainparameterswhicheffectthecombustionprocessaredetectedasmeasurevaluesandprocessedtogethersuchthattheoptimumignitionandinjectiontimingiscalculatedforinstantaneousengineoperatingionsngVariablesSensorspeedandloadarethemainactuatingvariablesBecauseaspecificspeedloadmapitisimportantthatallvariableswhichpertaintothesamepointarecalculateonthesamespeedloadareaThisisonlypossibleiftheignitionadvancedetectedonlyoncewiththesamesensors).isavoidsstatisticalerrorswhichcanresultforexamplefromtolerancesofdifferentloadsensordevices.WhereasaslightlydifferentallocationintheneartheknocklimitthesusceptibilitytengineknockingincreaseClearallocationunderconditionsofdynamicengineoperation.ystemeMotonicsystemcompriseaseriesofsubsystemthetwobasicsubsystembeingignitionandfuelinjectionThecombinedsystemismoreflexibleandcanimplementaaternumberoffunctionsthanthecorrespondingindividualsystemAnimportantfeatureoftheMotronicsystemisitsimplementationofalargenumberoffreelyprogrammablemapsasdesiredformostsub-functions.andisthereforeprovideonlyasanalternativesystemsThelambdacontrolsystemcannsideredtodayifusedinconjunctionwithanadaptiveprecontrolforreasonsofreducedexhaustemissions.orintegratedintothesystemThiscombinationofsubsystemmakessenseaphysicalfunctionalcontrolinamanagementsystem.eidlespeedcontrolisrealizedbymeansofdatafromtheignitionsystemandelemissions.orintegratedintothesystemThiscombinationofsubsystemmakessenseaphysicalfunctionalcontrolinamanagementsystem.eidlespeedcontrolisrealizedbymeansofdatafromtheignitionsystemandthefuelinjectionsystemandispartoftheoverallsystemofcontrolwhichincludes....tankventilationandcamshaftcontrol.rocomputercontrolledsystemstodayarerequiredtoperformselfdiagnosisofsystemofthefuturewillthusincludeadiagnosticfeature.differentfromthoseusedbytheMotronicsystemarenotintegratedbutratherareandinjectionsystemviacorrespondinginterfaces.SystemConfigurationFig2-22isatypicalMotronicsystemwhichshowsthefuelcircuitandtheacquisitionofloadandtemperaturedataThesystemdosenotincludethecold-startauxiliaryairdevicehasbeenreplacedbytheidlespeedactuatorInadditiontotheignitioncoiltheignitionsectionalsoincludethehighvoltagedistributorwhichfunctionThecontrolunitelectronicallydeterminestheproperignitiontimingasafunctionofenginespeedandload.5.ControlUnit(ECU)TheECUdetectstheinstantaneousconditionoftheengineatveryshortintervalsfedtotheECUwhereinputcircuitsremoveanysignalinterferenceandconvertthesignalstototheleverrequiredbytheactuators.AllprogramsandmapsareresidentinausedforprocessingAnalogaccuracyisdeterminedbyconstancyandaccuracyofthereferencevolt-ages,andbythecomponentsusedintheinputcircuits.Programconfigurationmustallowfortheextremerealtimerequirementsoftheengine:theintervalbetweentwoignitionpulseinacylinderengineisonlyabout3msatmaximumspeedAllessentialcalculationmustbeperformedduringthisperiod.Inadditiontocrankshaft-synchronouscontrolprocessing,theECUalsohastocalculatetime-synchronousevents.Boththenfunctionshavetowaitifaninterruptoccurs.eCoolingepurposeoftheenginescoolingsystemistoremoveexcessheatfromtheengineuptothecorrecttemperatureassoonaspossibleafterstaring.Ideally,thetheoperationare.Therearetwotypesofcoolingsystemsliquidcoolingandaircooling.Most....autoenginesarecooledbytheliquidtypeaircoolingisusedmorefrequentlyforairplanes,motorcyclesandlawnmowers.uidCoolingtemconsistsofseveralinterdependentpartsthatfunctiontogethertank.iononcontrolandeaterstheradiatorAsthecoolantcirculatesthroughtheradiator,itgivesupmetalsthatconductheatwellAsairpassesthroughtheradiatorfinsandaroundthetubes,heatistransferredtoair.HoweverifcoolantcirculatedatalltimesfromtheenginetoradiatortheenginewouldrunverycooloncolddaysRememberthatchemicalreaction,includingtheburningofthefueloccurmoreefficientlyathightemperature.Thus,fortheenginetooperateefficiently,theremustbeacontrolmechanism.toflowthroughtheradiatorAfteryoustarttheengine,itshouldheatanefficientratingtemperatureasquicklyaspossibleandmaintainthattemperaturewithoutoverheating.eLubricationepurposeofthelubricationsystemistocirculateoilthroughtheengineAnenginemusthaveagoodlubricationsystem.Withoutit,thefrictionheatfromthecontactofmovingpartswouldwearthepartsandcausepowerloss.Oil,whenplacedquieterandsmootherengineoperating.Besideslubricatingengineparts,oilisalsousedto:nepcooltheengineromasealbetweenthecylinderwallsandpistonringsFrictionbetweenenginecomponentsisreducedby:noilbeingsplashedupontothesurfacesthesurfacesbyanoilpump.....bysplashandbearingarepressurefed.Themainpartsofalubricationsystemarepumpmainoilgallery,reliefvalveandfilters.umptdrawsoilthroughatubethatextendsdownwardoilthroughatubethatextendsdownwardintothesumpThistubehasafilterscreenoveritsbottomend.Thescreenkeepslargepiecesofsludgeanddirtfrombeingdrawnintothepump.Thetubemaybehingedonthepumpandtherotor–type.MainOilGalleryandReliefValvehisrunsthelengthoftheengineDrillingfromthegalleryallowoiltobesuppliedtothebearingsurfaces.Generallyfittedinthegallerythisspringloadedvalvesopenswhenthepressurereachesthemaximumallowed.tersdesthegauzescreenthatpreventspiecesofthemetalenteringthepumpthereisan