外文翻译--汽车发动机与系统.doc

附录EngineMechanicalandEFISystemAbstract:Theengineblockisthemainsupportingstructuretowhichallotherenginepartsareattached.Front-suspensionsystemdesignmustprovidegoodrideandstabilitycharacteristics.Inaddition,thefrontsuspensionmustmakeprovisionforturningthefrontwheelstobothrightandleftforturningcornersKeywords:EngineSystemcompartmentcarTheCruiseControlSystemallowsyoutomaintainasetspeedabove40km/h（25rpm）withoutkeepingyourfootontheacceleratorpedal.Atectioncircuit.ItsfunctionistomonitorengineRPManddisengagethecruisecontrolwhentheclutchisappliedorthetransmissionshiftleverismovedintoneutral.WhenasuddenriseinRPMisdetected,tection,thebluewiremustbeattachedtothenegativesideoftheignitioncoil.Forthisreasonmakesureallcruisecontrolwiringisatleast1ft.awayfromallelectromagneticsourcessuchas:ignitionwires,alternator,regulator,andallhighcurrentcarryingconductors.ToreduceyourSETSPEED,pressandholdtheSET/COASTbutton.ThiserasesthepreviousprogrammedSETSPEED,andallowsthevehicletocoastTheECMusesthesignalsderivedfromthecrankshaftpositionsensorandthecamshaftpositionsensortotriggereachinjectorseparatelyincylinderfiringorder.AthrottlepositionsensorismountedontheendofthethrottlevalvespindletoprovidetheECMwithaconstantly-varying(analogue)voltagesignalcorrespondingtothethrottleopening.Theoxygensensorintheexhaustsystemprovidesthemodulewithconstantfeedback“closed-loop”controlwhichenablesittoadjustthemixturetoprovidethebestpossibleconditionsforthecatalyticconvertertooperate.Whenworkingwithfuelsystemcomponents,payparticularattentiontocleanliness-dirtenteringthefuelsystemmaycauseblockageswhichwillleadtopoorrunning.BoththeidlespeedandmixtureareunderthecontroloftheECMmodule,andcannotbeadjusted.Notonlycantheynotbeadjusted,theycannotevenbechecked,exceptwiththeuseofspecialdiagnosticequipment.Whentheengineiswarm,thecoolingsystemisoverpressure.Itisnecessarytoreleasepressurebeforestartingrepairwork.Wheninstallingcoolanthoses,routestress-freesothattheydonotcomeintocontactwithothercomponents(observemarkingsoncoolantconnectionhoseEngineoilsaregradedaccordingtotheirviscosity.Thepropergradetobeusedinyourenginedependsonexistingclimaticorseasonalconditions.Wheninsertingtheoildipstick,insertthecurvedtipofthedipstickfacingthesamedirectionasthecurveoftheguide.Visuallyinspectthermostatforcorrosionandpropersealingofvalveandseat.Ifokay,suspendthermostatandthermometerina50/50mixtureofcoolantandwater.TheECMcontainsabuiltinselfdiagnosissystembywhichtroubleswiththeenginesignalnetworkaredetectedandaMalfunctionindicatorlampontheinstrumentpanellightsup.Amalfunctionindicatorinformsthedriverthatamalfunctionhasbeendetected.Thelightgoesoffautomaticallywhenthemalfunctionhasbeenrepaired.Atestmodefunctionhasbeenaddedtothefunctionsoftheselfdiagnosticsystemofthenormalmodeforthepurposeofdetectingmalfunctionssuchaspoorcontact,whicharedifficulttodetectinthenormalmode.TheMalfunctionindicatorlampwillcomeonwhentheignitionswitchisturnedONandtheengineisnotrunning.Whenthenormalcodeisdisplayedinthediagnostictroublecodecheck,troubleshootingshouldbeperformedintheorderforallpossiblecircuitstobeconsideredasthecausesoftheproblems.Theenginecontrolmodule(ECM)isprogrammedwithdataforoptimumignitiontimingunderalloperatingconditions.AlwaysswitchOFFtheignitionwhendisconnectingandconnectingthebattery,otherwisetheEngineControlModule(ECM)couldbedamaged.WhileperformingcertainchecksitispossiblethattheECMwillrecognizeandstoreaDiagnosticTroubleCode(DTC).Thereforeaftercompletingallchecksandrepairs,checkanderasetheDTCmemoryasnecessary.AllchargingsystemsusetheprincipleofelectromagneticinductiontogenerateElectricalpower.Electromagneticprinciplestatesthatavoltagewillbeproducedifmotionbetweenaconductorandamagneticfieldoccurs.Thebrushesandslipringsprovideameansofmaintainingelectricalcontinuitybetweenstationaryandrotatingcomponents.ApplyATFtofrictioncomponents,rotatingparts,andslidingpartsbeforeinstallation.ImmerseanewclutchdiscorbrakediscinATFforatleasttwohoursbeforeassemblingthem.ThemostcommoncompoundplanetarygearsetsaretheSimpsoncompoundplanetarygearsetandtheRavigneauxcompoundplanetarygeartrain.Acommontypeofautomatictransaxleortransmissionforpassengercarshasthreeforwardspeeds,reverse,neutral,andparkpositions.Theclutchislocatedbetweentheengineflywheelandthetransmissiononrear-wheel-drivevehicles.Onfront-wheel-drivevehiclesitislocatedinthetransaxleassemblybetweentheengineflywheelandtransmissionsectionofthetransaxle.Shockabsorbersaremountedbetweentheframeandthesuspensionbymeansofbracketsandrubberbushings.Thepiniongearsareinmeshwiththetwosideoraxlegears,andtheaxlegearsaresplinedtotheaxleshafts.Removetheadhesiveadheredtothethreadedholesofthedrivegearbyturningthespecialtool,andthencleanthethreadedholesbyapplyingcompressedair.Atwo-piecetubulardriveshaftwitharubberelementpressedbetweenthetwotubes,whichreducestorsionvibrations,isusedonsomevehiclesTheabilityofthebrakesystemtobringavehicletoasafecontrolledstopisabsolutelyessentialinpreventingaccidentalvehicledamage,personalinjury,andlossoflife.Uponseverebraking,thewheelsbecomelocked,atwhichtimethereisaslidingfrictionbetweenthetireandtheroadandstaticfrictionbetweentheshoeanddrumordiscandpad.Lockedwheelsaredangerousbecausethecarneedsamuchlongerdistancetostop.Lockedwheelsalsocancausethedrivertolosecontrol.Donotuseascrewdriverorsimilartooltoremovepistonseal.Thesemaydamagetheinnersideofthecylinder.Thesteeringlinkageincludesthesteeringarmsthatareattachedtothesteeringknuckle,tie-rodsandtie-rodends,adjustingsleevesandclamps,acenterlink(relayrodordraglink),anidlerarm,andapitmanarm.Thesteeringgearalsoabsorbsmuchoftheroadshock,whichtendstoturnthefrontwheelsrightorleft.Theintegraltypeofpower-steeringunitcombines,allinasingleassembly,thepowerpistonandcylinderwiththesteeringgearandflowcontrolvalve.Turningthesteeringwheelonavehicleequippedwithare-circulating-balltypeofsteeringgearturnsthegroovedwormshaftinthegear.Turningthegroovedwormshaftcausestheballnuttothreaditswayupordowntheworm.Diagnostictroublecodeswill,however,beerasedwhenabatteryterminalorthePCMconnectorisdisconnected.Inaddition,thediagnostictroublecodecanalsobeerasedbyscantool(MUT-III).IfasensorisdisconnectedwhentheignitionswitchisintheONposition,adiagnostictroublecodeisstoredinmemory.Inthiscase,erasetheDTCusingscantool。WhenamalfunctionofamainsensororactuatorisdetectedbythePCM,thetransmissioniscontrolledbypre-setcontrollogictomaintainsafeconditionsfordriving.Ifthelightstaysonorcomesonwhiletheengineisrunning,youhavelostoilpressureandcontinuedoperationwillcaus