汽车故障诊断与排除的基本方法The basic method of automobile fault diagnosis and troubleshootingWord格式文档下载.docx
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Thebasicmethodofautomobilefaultdiagnosisandtroubleshooting
Thecorrectdiagnosisofthefaultlocationisthebasisoftroubleshooting,butalsoaneffectivemeanstoimprovetheefficiencyofvehiclemaintenance.Inordertodiagnosefaultsquicklyandaccurately,itisnecessarytounderstandthebasicthinkingandmethodsofdiagnosingfaults,andtomasterthebasicrequirementsandmethodsfortroubleshooting.
I.BasicThinkingandmethodofdiagnosingfaults
Thecomplexityanddiversityofautomobilefaultphenomenonreason,causedthediversityofideasandmethodsoffaultdiagnosisanduncertainty,butonthewhole,thebasicideasandmethodsshouldbebasedonthefirstmechanicalelectronics,firstspecial,easytodifficult,simpletocomplexprimarydiagnosis.
1,thebasicprocessofdiagnosingfaults
Thebasicprocessofdiagnosingautomobilefaultsusuallyincludesthefollowingsteps:
inquiringthesituation,reproducingthefaultphenomenon,determiningthefaultcharacteristics,analyzingthecauseofthetrouble,drawinguptheinspectionscopeandfindingthefaultpoint.
Askaboutthesituation.Mainlytothedrivertounderstandthevehiclebeforethefailureofsomebasicinformation,suchasvehiclemileage,vehiclemaintenanceandrepair,theuseofvehiclesatordinarytimes,beforethefailureofthespecialphenomenon.
Reproducethefaultphenomenon.Bymeansofacertainmethodandtechnicalmeans,thephenomenonoffailurewillbemanifested,suchasin-situlaunch,roadtest,etc..Forcontinuousreproductionoffault,faultphenomenaaregenerallyeasier;
butsomeoftheintermittentfault,becausethefaultoccursonlyinaparticularenvironment,sotheneedtoreproducebymeansoffaultsimulationenvironment,suchasthroughvibration,heating,water,orload(load)etc..
Determinefaultcharacteristics.Thefaultphenomenoncausedbyafaultisusuallycharacterizedbyitsspecificfault,thatis,faultcharacteristics,anditisveryimportanttofindoutthefaultcharacteristicsandreducethediagnosticrangeanddiagnosethefaultquickly.Forexample,aunitofSX2190commercialvehicles,intheexecutionofthetask,suddenlyappearedvehicleunderpowered,theenginerunningweak,untilslowflameout.Drivingonthephonereflects:
hitthestarter,nocar,usingelectricfuelpumpexhaust,foundalargenumberofbubblesdischarged,airdischargedafterthesmoothstart,butafteraperiodofmileage,thefaultoccurredagain.Tofurtherunderstandthesituationthatthiscarsincetwolevelmaintenanceaftertravelingaround5000km,whichfoundnosuchfault,buttherecentdifficultstarting,generallyaccordingtotheelectricfuelpump,andtheelectricfuelpumpandfoundnoleakagephenomenon.Thedieselfilterwascleanedtwodaysbeforethefailure.Fromtheabovebasicinformationreflectsthepeopledrivinginthecar,candeterminemanyfaults,suchasdifficulttostart,theengineisrunning,thevehicleenginepowershortage,unabletostall,butwhichonecanrepresentthecharacteristicsoffaultfaultphenomenon?
Itisclearthattheengineitselfisthemostrepresentativeofthebreakdowncharacteristicsofthecar.
Analyzethecauseofthetrouble.Accordingtothespecificstructureandfaultcharacteristicsofthecar,thecauseofthetroubleisanalyzed.Intheexampleabovecausestheenginetostall.
A.tankwithoutoil.
B,thediesellineisnotsealedandenterstheair.
C.dieselfilteranddieselpipeblocked.
D.thereiswaterinthefuel.
E.oilpumpdoesnotwork.
F.injectionpumpconnectionplatefixedboltsloose.
G.fuelinjectionpumphandlerodfalloff.
H.theoiloutletvalveandneedlevalveofthesamecylinderarenotsealed.
Sincethecarfaultisslowflameout,soF.Gcanbeexcluded(F.Gcausedbysuddenflameout);
thecarenginepowerisnotdecreased,Dcanbeexcluded;
thecarcanstillworkforaperiodoftime,ecanberuledout;
accordingtotheelectricfuelpumpcanbeinacar,andthefailureoccurredtwodaysbeforethefiltercleaning.AandCcanberuledout;
accordingtotheelectricfuelpumpfoundnoleakageoftheposition,
Bcanberuledout:
thentheremainingh,thesamecylinder,theoiloutletvalveandtheneedlevalvearenotsealedatthesametime,shouldbethecauseofthefailure.
Formulationofinspectionscope.Determinethescope,procedureandmethodoftheinspectioninaccordancewiththeconclusionsofthefailureanalysis.
Tofindthepointoffailure.Accordingtothescopeofinspection,themethodofsubsection,fixed-pointorpointbypointinspectionisadopted.Atthetimeofinspection,thetechnicalstandardsofthecheckedpartsshouldbewellknown,andatthesametime,theinspectionshouldbeavoided.
2analyzethemainpointsofthetrouble
Analysisoffaultreasoningisessentiallyaprocessofthinking,theprocessforthelengthoftime,thereasoningiscorrectornot,isaffectedbymanyfactors,suchastheaccumulationofexperienceandknowledge,usingthestructureofautomobilediagnosticinstrumentbyskilleddegreeandqualityofthinkingclarity,flexibility,sensitivityandstability,psychologythequalityofhealth,willbedifferentdegreesdirectlyorindirectlyinfluencethespeedandqualityofreasoning.
Intheprocessoffaultanalysis,experienceisaveryimportantfactor,especiallyforthosewhohavebeenengagedinsinglevehicletypeandfixedsystemmaintenanceforalongtime.Thespeedandaccuracyofcommonfaultanalysisareveryhigh.Thereason,ontheonehand,isduetothelongexperienceintheaccumulationofdirectexperienceisveryrich,ontheotherhand,italsobenefitsfromitscontinuoussummaryandimprovement.Inadditiontodirectexperience,throughcasestudyanddissection,itisaneffectivewaytoobtainmaintenanceexperience.Thisiscalledindirectexperience,andindirectexperienceisofgreathelptoimprovethequalityoffaultanalysis.Whetheritisdirectexperienceorindirectexperience,ingeneral,itcanplayapositiveroleintheprocessoffaultanalysis,thatis,experienceguidesthinkingquicklyandaccuratelytofindfaultpoints.Forexample,iffaultcodedisplayengine,shouldfirstcheckthefaultcodedisplaycontent,thisexperiencemaymakeyouwinallthetime,intheworktostrengthentheexperienceifthingsgoonlikethis,inyourmind,andgraduallysolidified,becomeamindset.However,ifonedayyoufindthatthisexperienceisnotworking,andwhenyouhavecheckedthecircuitaccordingtotheexperience,andreplacedtheelectricalcomponents,thefaultstillexists,thatis,experiencehasplayedamisleadingrole.Instead,itbecomesabarriertocorrectthinking.Sotheexperienceisvaluable,butisnotlimitedtospecificconditionsmethod.
Itishardtoimagineadoctorwhoknowslittleaboutthestructureofthehumanbodyandcanquicklyandaccuratelydiagnosethecauseofthedisease.Also,thebasicknowledgeofautomobilestructureknowledgeisalsoessentialvehiclemaintenance,inadditiontothe"
fivebase"
namelythebasicstructure,basicfunctionandcompositionofthebasiccontrolrelation,basicprinciple,basicperformanceparameters,thestructuralfeaturesofdifferenttypesofcarshouldalsobeunderstoodthatthespecificstructureofthefaultofthevehicletobeaware,otherwisemostofourpreparationbecameafalse,YongZhishui.Itshouldbeemphasizedthat,withtheincreasingapplicationofelectronictechnologyinthecarmorewidely,theelectroniccontrolsystemsoftwareupgradefaster,moreandmorewiderangeofcontrol,controlprecisionismoreandmorehigh,sothetaskisveryimportanttostudythecontrolsystemsoftware,hardwareandsoftwaretomatchknowledgethehardwarestructureofthecorrespondingsoftwareversionsarenotthesame.
Intheprocessoffaultanalysis,itisnecessarytousediagnosticinstrumentsandequipmentparametersorperformancetestingnecessary,commonlyusedinstrumentsandequipmentinadditiontobeabletouse,weshouldpayattentiontothedetectionaccuracyofcalibrationinstrument,theequipmentitself,topreventtheemergenceoflargedetectionerror,whichbringsdifficultiestofaultanalysis.
thebasicmethodofautomobilefaultdiagnosisandtroubleshootingisthebasisoftroubleshootingandtheeffectivemeanstoimprovetheefficiencyofvehiclemaintenance.Inordertodiag