卡特彼勒高压共轨C64

高压共轨系统被世界内燃机行业公认为20世纪三大突破之一,将成为21世纪柴油机燃油系统的主流。WhatisaC6.4?C

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CurrentnomenclatureforCATbranded engines6.4:EnginedisplacementinLiters1.06LiterperCylinder,6cylinderInlineBore:102mm,Stroke:130mmPistonDisplacement:6.373literRatedPower:110–117kW(148-157hP)@1800rpmCompressionratio:17.7Turbocharged-ATAACReplacesthe3066mechanicalengine高压共轨系统利用较大容积的共轨腔将油泵输出的高压燃油蓄积起来，并消除燃油中的压力波动，然后再输送给每个喷油器，通过控制喷油器上的电磁阀实现喷射的开始和终止。其主要特点可以概括如下：共轨腔内的高压直接用于喷射，可以省去喷油器内的增压机构；而且共轨腔内是持续高压，高压油泵所需的驱动力矩比传统油泵小得多。通过高压油泵上的压力调节电磁阀，可以根据发动机负荷状况以及经济性和排放性的要求对共轨腔内的油压进行灵活调节，尤其优化了发动机的低速性能。通过喷油器上的电磁阀控制喷射定时，喷射油量以及喷射速率，还可以灵活调节不同工况下预喷射和后喷射的喷射油量以及与主喷射的间隔。高压共轨系统由五个部分组成，即高压油泵、共轨腔及高压油管、喷油器、电控单元、各类传感器和执行器。供油泵从油箱将燃油泵入高压油泵的进油口，由发动机驱动的高压油泵将燃增压后送入共轨腔内，再由电磁阀控制各缸喷油器在相应时刻喷油。OverheadviewofC6.4enginecylinderheadwithrockercoverremoved

IntegratedCylinderhead4valvesCentrallylocatedInjectorsDesignedwithmostmajorservicepointslocatedontherightsideoftheengine.FuelInjectionpump(1),SecondaryFuelFilter(2),Fuelprimingpp(3),Oilfillcap(4),Dipstick(5),Enginebreather(6),ECM(7)AirInletheaterInletheaterrelaySystemcapacity:30ltrIncludingfilterOilpumpdelivery:66L/min@1800rpmWaterpump–centrifugaltype-BeltdriventogetherwithalternatorSealedbearing-nogreasingrequiredCoolantcapacity(enginewaterjacket9L)Total:approx.25ltrThermostat-Opensat71degC10mmliftat85degCC6.4FuelSystem

CaterpillardesignedandDevelopedHighFuelInjectionpressuresFullyElectronicallycontrolledMultipleInjection-reduce

NOxandPMFuelsystemOverviewFuelsystemusingcommonrailtechnologyHighpressurepump–upto160MPAHardenedFuellinesExternalfuelmanifoldFuelManifoldHighqualitysteelcomponentDesignedtowithstand23,000psiReliefValveReplaceLinesiffittingisloosenedPumpPressurizesFuelTransferpumpis serviceableLowpressurefuel43-58PSI

16000PSILOWpressurefuelsystem

Lowpressurefuelcircuit

systempressure:43-58psi

300-400kPA)LowpressurefuelutilizedtocoolengineECMConsistsofPrimaryfuelfilter/waterseparator(10micron)SecondaryFuelfilter(2micron)Tertiaryfuelfilter(2micron)–inseries321DrivenbyHighPressurePumpDrawsFuelthroughPrimaryFilterOutputPressure300to400kPa43to58PSITransferPumpPrimedbyPrimingPumpHandorElectricNoLiftPumpRequiredTransferPumpHighpressurecircuitComponentsHighpressureFuelInjectionpumpFuelManifoldHighpressurefuellinesNormalfuelrailpressure:11000-16000psiHIGHPRPPCRMINJECTORSFuelPumpFunctionPumpRaisesPressureECMtellsInjectortoFireRailPressureDropsECMDetectsPressureDropSensedbyFuelRailPressureSensorECMtellsPumpSolenoidtoIncreaseVolumeAlsotellsPumpSolenoidtoSpillfueloncepressureisreachedDoitAgain!

Transferpump–GeartypeHighpressurepumpSpeedtimingsensorFuelpumpsolenoid-controlinjectionpumpoutputpressuretocommonrail

InjectionpumpSolenoidisnotserviceableTransferpumpandthesecondaryspeed/timingsensoraretheonlyserviceablecomponentsHighPressureReliefValve

FuelPressureReliefValveProtectsSystemfromOver-PressureOpensatConstantPressureof160MPa(23,000PSI)WithstandsSpikesto190Mpa(27,500PSI)ReturnsfueltoTankTheprimaryfunctionofthefuelpressuresensoristoconstantlymonitorrailpressure.Thehighpressurereliefvalveprotectsthehighpressurefuelsystemfromexcessivepressures.EachInjectorhasasolenoid.ThesolenoidreceivescurrentfromECM&actuatestheInjector.WhennoInjection:Nocurrenttosolenoid-controlvalveclosed-fuelfromtherailstopsattheinjectorcontrolvalveInjection:Solenoidisenergized-armatureplatemovesup-valveisopened-Highprfuelflowstonozzlearea–Injectionbegins(nooforifice:6)Whenthecurrenttosolenoidisstopped,armatureplatepusheddown-valveseatisclosed.AnyremaininghighpressurefuelexitsthroughdrainportTonozzleSolenoidenergizedValveInjectorFunctionECMEnergizesInjectorValveLiftsFuelFlowstoNozzleSolenoidde-energizedInjectorDe-energizesValveClosesUnusedfuelflowsbacktoTransferPumpviapassageintheHeadWhenreplacinginjector,replaceallofthefollowingO–ringWasher–copperInjectorpipe RubberbootthatsealsvalvecoveropeningNote:WhenremovingapipeandreusinganInjector,AlwayscaptheinjectorImmediatelyuntilreadytoinstall.Donotovertightenthesolenoidconnectionterminals.FuelInjectorTrimcodeDoWritedowntheInjectorSerialNumberandConfirmationCodebeforeyouinstalltheInjectorDouseCatETtoProgramECMwithproperInjectorTrimFileDoLookfortheTrimFileCDintheInjectorBoxTrimfilecanbefoundinsiswebPrimaryandsecondaryspeed/timingsensorareofsamepartnumberFuelInjectionServiceabilityNEVERloosenhighpressurepipeswhenengineisrunning!23,000PSIUseElectronicServiceTooltoTroubleshootInjectorProblemsInjectorshavenoserviceableparts.PumpSolenoidisnonserviceable.Ifthesolenoidisremovedthewholepumpassemblymustbereplaced.Transferpumpisaserviceableitem,separatefromHighPressurepump.Speedsensorisserviceable.

GENEARALSERVICEPROCEDURES

Commonrailfueltechnologyrequiresahighdegreeofcleanliness.Beforeattemptinganyworkonthefuelsystemensurethattheengineiscleanedofanydirtthatmightcontaminatethefuelsystem.Partsmustbeinspectedpriortousetoensurecappingisintactandpartsarecleanandundamaged.Anyfuelsystemcomponentsthatareremovedorexposedshouldbecappedwithnew,cleancapstopreventdirtingressUseanticontaminationkitpartNo–278-4138GENEARALSERVICEPROCEDURES…CONTDonotprefillthefilters.InstallfilterdryanduseprimingtofillwithfuelCommonrailfuelsystemisaselfbleedingfuelsystemanddoesnotrequireairtobepurgedfromthesystem.Onceafittinghasbeenloosened,theentirefuelpipemustbereplacedwithanewparttoensureproperseatingandleak-freeperformance.Duetotheunique“internallyhardened”manufacturingprocess,highpressurepipesare

singleuseCommonrailfuelsystemsoperateatextremelyhighpressures(>20000psi).Neverloosenoropenahighpressurefuellinewhilecrankingorrunningacommonrailfuelsystem.GENEARALSERVICEPROCEDURES…CONTFUELtankdrain:DrainwaterandsedimentsfromFueltankdaily,Keepfueltankbreatherfilterclean.Ensure,oncetheengineisshutdown,fuelrailpressureisreducedtozero,beforeanyrepair.Ifaleakissuspected,donotcheck/repairthefittingsunlesstheengineisOFFandpressu