康明斯柴油发动机维修保养注意事项

康明斯柴油发动机维修保养注意事项Cummingsdieselenginerepairandmaintenancemattersneedingattention我国客车制造商近期采用康明斯系列柴油机型越来越多，如常州长江双层城市客车装配B2230CNG发动机；EQ5061XXYK厢式客货两用车装用4BT319AA发动机；EQ6890LK豪华客车选用6BTA发动机；EQ6590(2000款)、EQ6690(2000款)客车也选用4BT319AA增压发动机。实践表明，康明斯发动机在客车上动力强劲，经济省油，使用可靠，排放污染低。为延长康明斯柴油机的使用寿命，以6BT系列机型为例，介绍几点维修注意事项及故障诊断方法，供修理时参考。ChinesebusmanufacturersrecentlyusingCummingsseriesdieselengineismoreandmore,suchastheYangtzeRiverinChangzhoucitybusassemblyB2230CNdoubleGengine;EQ5061XXYKvanvansfittedwiththe4BT319AAEQ6890LKluxurypassengercarengine;engineusing6BTA;EQ6590(2000),EQ6690(2000)busalsouse4BT319AAsuperchargedengine.Practiceshowsthat,Cumminsengineinbusdrivingpower,fueleconomy,reliableuse,lowemissionpollution.AsanextensionofCummingstheservicelifeofdieselengines,the6BTseriesmodelasanexample,introducesseveralrepairpointsforattentionandthemethodsoffaultdiagnosisforpassengercarsarerepaired,reference.１、维修注意事项1,repairthemattersneedingattention（１）6BT118机型镶装缸套(1)6BT118typeinsertingcylinder制造商未在该机上镶装缸套，但允许在气缸磨损量超过使用极限后镶装专用缸套。我公司对专用缸套和牟平102系列缸套都进行了镶装试验。镶专用缸套时，先将缸套承孔镗至φ104.94mm，并保证承孔与缸套的过盈量为0.05～0.07mm。注意在承孔下部留7～8mm高的止口，再将已在-20°C条件下冷却1h以上的缸套涂胶并压入承孔，最后切除缸套上端高出缸体上平面的部分，将缸套内孔镗至φ101.97mm(留0102～0.03mm的珩磨量)，使珩磨表面粗糙度为Ra0.4Lm，保证缸套与活塞之间的间隙符合规定。镶牟平102系列缸套时，先将缸套承孔上部加工出φ112.05mm、深10mm的台阶(俗称上止口)，再将缸套承孔镗至约φ107.95mm(留0.02～0.03mm的珩磨量)，然后珩磨，使承孔表面粗糙度为Ra0.4Lm，并保证承孔与缸套的过盈量为0.02～0.03mm。最后将缸套外圆表面涂少量机油，压入承孔。Themanufacturerisnotinthemachineinsertliner,butallowsthecylinderwearexceedsthelimitafterinsertingspecialcylinder.IcompanyforcylinderlinerandtheMuping102seriescylinderhavebeenembeddedtest.Insertspecialcylinder,thecylinderbearingholeboringtoφ104.94mm,andensurethebearingboreandcylinderinterferenceamountwas0.05~0.07mm.Attentioninthebearingholeoflowerpartof7~8mmhighport,andthenin-20°Cundertheconditionsofcoolingover1hcylindergluingandpressintothebearinghole,finallyresectedcylinderupperhighcylinderpart,thecylindersleeveinnerholeboringtoφ101.97mm(with0102～0.03mm),quantityofthehoninghoningsurfaceroughnessisRa0.4Lm,ensurethattheclearancebetweenthecylinderlinerandpistoninaccordancewiththeprovisions.WithMuping102seriescylinder,thecylinderbearingholeofupperprocessingofφ11205mm,10mmlevel(commonlyknownastheupperstop),thenthecylinderbearingholeboringtoφ107.95mm(with0.02~0.03mmhoningvolume),andthenmakethebearingholehoning,surfaceroughnessofRa0.4Lm,andtoensurethebearingboreandcylinderinterferenceamountwas0.02~003mm.Thelineroutersurfaceapplyasmallamountofoil,pressedintoabearinghole.通过这两种缸套镶装试验，总结如下：Thetwocylinderisinlaidwiththetest,summarizedasfollows:ａ、使用牟平102系列缸套装机可以大大缩短修理时间。因为该缸套的内孔面为成品面，不需镗、磨及在镗缸机上装夹缸体、定中心而费力费时；其次缸套在压入承孔前不需冷处理。但用专用缸套装机，每次修理时需镗旧缸套２次、珩磨1次、缸体装夹2次和定中心２次，还要冷处理缸套。A,usingtheMuping102seriescylindersetmachinecangreatlyshortentherepairtime.Becausethecylinderboresurfaceoffinishedsurface,neednotbeboring,millingandinthecylinderboringmachinewiththeclampingcylinder,centeringandlaboriousandtime-consuming;thesecondcylinderinpressinthebearingholeofnoneedofcoldprocessing.Butwithaspecialcylindersetmachinerepair,everytimewhenboringoldcylinderjacket2times,1times,honingcylinderclamping2andcenter2,andcoldtreatmentofcylinderliner.ｂ、使用牟平102系列缸套装机，维修质量容易保证。因为缸体在珩磨机上经过多次装夹和定中心后，会因定位误差积累而超差，增加了维修质量难度，尤其是用移动式镗缸机产生的误差更大。而使用牟平102系列缸套，只要第1次承孔镗磨质量符合技术要求，以后可以像五十铃载货车发动机一样直接压入、压出缸套，而且组装上活塞连杆后工作时不会产生偏缸。B,usingtheMuping102seriescylindersetmachinerepair,easyqualityassurance.Becauseofincylinderhoningmachineafterrepeatedclampingandcentering,duetopositioningerroraccumulationandtolerance,increasedthedifficultyofrepairquality,especiallythemobilecylinderboringmachineerrorisgreater.WhiletheuseofMuping102seriescylinder,aslongastheD,putthering,shouldmakethepartnumberisup.ｅ、将支盖、新垫片支架和新垫片装到冷却器体上，将螺钉拧紧至41～47N．m，然后装好所有螺钉。E,thesupportingcover,newgasketbracketandanewgasketfittedintothecoolerbody,thescrewsaretightenedto41～47N.m,andtheninstallallbolts.（４）柴油机冷却通道(4)dieselenginecoolingchannel在柴油机大修时，有的班组忽视对冷却通道的彻底清洗，具体表现在，散热器和缸盖拆下后扔到一旁，到总装时再将其表面擦拭干净。这是造成冷却系产生故障较多的原因之一。如装6BT系列柴油机，常常发生散热器上水室顶部和气缸盖出水管一端的两根除气管都不通。这样，在加注冷却液时，积聚在气缸体内套的空气和气、水混合物就无法排出，冷却液也无法充满水套。柴油机在工作过程中，当积滞的气体达到一定程度时，还会造成水泵流量下降，结果是在气缸体水套内部产生局部高温，最终造成气缸体局部热应力猛增而使缸体局部破裂。因此，在柴油机大修或其产生高温故障时，应认真清洗冷却系，切不可马虎了事。Inthedieselengineoverhaul,someteamsneglectingcoolingpassagesintheperformanceofspecific,thoroughcleaning,radiatorandcylinderheadremovedaside,totheassemblywhenthesurfaceiswipedclean.Thisiscausedbythecoolingsystemhasmorefaultsreasons.Asof6BTseriesdieselengine,radiatorwaterchambertopandoftenoccurredincylinderheadoutletendofthetwoairout.Thus,infillingincoolant,accumulateinthecylindersleeve,airandwatermixtureisunabletodischarge,coolingliquidcanfilledwithwaterjacket.Dieselengineinthecourseofwork,whentheaccumulatedgastoacertainextent,canalsocausewaterpumpflowdecreased,theresultisinacylinderwaterjacketinternallygeneratedlocalhightemperature,resultinginlocalthermalstressofcylinderbodyandthecylinderexplosionpartialrupture.Therefore,thedieselengineorthehightemperaturefailure,shouldbecarefullycleaningcoolingsystem,mustnotbesloppy.２、故障诊断2,faultdiagnosis（１）断油电磁阀故障(1)oilcut-offelectromagneticvalvefault6BT柴油机在波许高压分配泵右上角处装有一个断油电磁阀。当钥匙开关处于熄火断电档时，阀芯在弹簧作用下回位切断油路，使柴油机熄火；当钥匙开关位于起动档时，电磁阀通电产生磁力吸取阀芯，油路接通，柴油机正常工作。一些新技工由于对这种装置的原理和作用不太了解，导致不能诊断出柴油机不能起动或熄火的故障原因。The6BTdieseldistributionpumpPauschhighrightcornerisprovidedwithafuelcutsolenoidvalve.Whenthekeyswitchispowercutoffgear,valvespringreturntocutoffoil,dieselengineflameout;whenthekeyswitchlocatedinthestartingposition,theelectromagneticvalveisenergizedtoproducemagneticsuctionvalve,oilcircuitisswitchedon,thenormaloperationofdieselengines.Somenewcraftduetothisprincipleandeffectofdonotknow,canleadtodiagnosisofdieselenginecannotstartorflameoutfaultreason.若柴油机起动时起动机工作正常，柴油箱及滤清器无阻塞，供油管无漏气现象，但多次不能起动，一般是断油电磁阀处出现故障。首先检查电磁阀线路中左起第3个熔断器是否烧坏。若烧坏应立即更换。若未烧坏，再拆电磁阀上的接线，用示灯检查是否通电。若通电，一般是电磁阀烧坏或阀芯卡住，可改制一个专用扳手将电磁阀拆下。在无条件更换时，可将阀芯抽出后，再装回电磁阀体，即可起动柴油机。此时，可用挂档方法熄火。Ifthestartingofthedieselenginestarterwhennormalwork,adieseltankandfilterwithoutobstruction,theoilpipewithoutleakage,butmanycannotstart,isgenerallybrokenoilsolenoidvalvefailure.Firstcheckelectromagneticvalvecircuitthirdleftafuseisburned.Iftheburnshouldbereplacedimmediately.Ifnotburn,andthensplitonthesolenoidvalvewiring,withindicationlampcheckwhetherelectricity.Ifelectricity,generalelectromagneticvalveisburnedorvalvestuck,canmakeaspecialspanner,thesolenoidvalveisremoved.Inunconditionalreplacement,valvecorecanbeextracted,andthenloadedbackelectromagneticvalve,thenstartingdieselengine.Atthistime,thegearmethodavailable.（２）机油压力低(2)theoilpressurelow6BT系列柴油机采用机油冷却器芯，对冷却机油、加强润滑起了积极作用。但冷却器芯片焊点有破裂时，机油会大量进入水道，润滑油道的机油大量减少。机油警告灯亮时，从冷却系膨胀箱有机油溢出，应及时排除此故障。否则，将烧坏轴承甚至柴油机。6BTseriesdieselengineusingengineoilcoolercore,onthecoolingoil,hasplayedapositiveroleinstrengtheninglubrication.Butcoolerchipsolderjointrupture,oilwillenterthewater,lubricatingoilpassageoilcanreducethenumberof.Oilwarninglight,fromthecoolingsystemexpansiontankwiththeoilspill,shouldberuledoutthisfault.Otherwise,willburnevendieselenginebearing.机油泵垫片损坏也会导致机油从机油泵处泄漏，从而主油道压力降低，机油警告灯亮，曲轴齿轮处发生异响。拆检更换机油泵垫片并认真装合后，故障即可排除。Oilpumpgasketdamagecanalsocausetheoilfromtheoilpumpleakage,therebythemainoilpressureisreduced,theoilwarninglights,crankshaftgearisabnormalsound.Dismantlingthereplacementofoilpumpgasketandseriouscombination,faultcanberuledout.（３）柴油机异响(3)abnormalnoiseofdieselengine异响声发生在气门机构的现象比较普遍，表现为气门室盖处响声较大，声音清脆。油门加大转速升高响声加剧，是气门间隙过大所致。在准确判断出响声的缸号后，校准间隙并锁紧调整机构即可。其次，水泵处会发生连续的“嗡嗡”声，加速时响声加剧，通常为轴承因缺乏润滑而已被损坏。更换轴承时用榔头敲打不顶用，需用压床压出。Abnormalnoiseoccursinthevalvemechanismofthephenomenoniscommonner,performanceforthevalvechambercoverlargersoundcrispsound.Acceleratorenlargesspeedincreasednoiseaggravate,isthevalveclearanceistoolarge.Thejudgenoisecylindernumber,calibrationintervalsandlockingandadjustingmechanism.Secondly,thewaterpumpwillhappencontinuous"buzz"sound,accelerationnoiseincreased,usuallyduetolackoflubricationforbearingsonlydamaged.Replacementofbearingsinthehammerisnotavailable,usepresspress.（４）增压器漏机油(4)theturbochargeroilleakageａ、增压器空气压缩机漏机油。压缩机漏机油表现为:柴油机工作时烧机油，排蓝烟。如果打开压缩机出气口或柴油机进气软管时有油，需更换压缩机挡油环前端的甩油环和密封环并清洁或更换空气格；如果机油沿空气压缩机叶轮轴漏油，需拆检回油管并清洗。A,turbochargeraircompressorlubricatingoilleakage.Compressoroilleakageperformance:thedieselengineburningoil,exhaustsmoke.Ifyouopenthecompressoroutletordieselengineairinlethoseisneededtoreplaceoil,compressoroilringoilringandthefrontendofthesealingringandcleanorreplacetheairgrid;iftheoilalongtheaircompressorimpellershaftoilleakage,dismantlingandcleaningforoilreturnpipe.ｂ、增压器排气口漏机油。排气口漏机油将导致柴油机工作时烧机油。拆下排气口连接管，如排气口附近有机油漏的痕迹，应更换涡轮轴上的密封环。B,turbochargerexhaustoutletofoilleakage.Outletdrainoilwillcausethedieselengineburningoil.Removetheairoutletconnectingpipe,suchasanexhaustmouthnearbyorganicoilleakagetraces,shouldreplacetheturbineshaftsealring.（５）增压器轴承损坏(5)thesuperchargerbearingdamage增压器涡轮转子轴承损坏，涡轮轴转速下降，涡轮转子总成的径向或轴向摆差大，需要拆检增压器，必要时更换转子轴承、转子总成。组装增压器时，对组成涡轮转子总成的涡轮轴、叶轮、机油甩油环、止推套等高速旋转零件，在进行动平衡时打上的安装位置标记必须一一对应。此外，还应检查并保证静态时，涡轮转子总成的轴向间隙(0.03～0.07mm)和径向间隙(0.30～0.46mm)。Turbochargerrotorbearingdamage,theturbineshaftspeeddecreases,theturbinerotorassemblyofradialoraxialswingbig,needdismantlingthesupercharger,necessarywhenreplacingtherotorbearing,arotorassembly.Assemblyforturbocharger,onthecompositionofturbinerotorassemblyoftheturbineshaft,impeller,oiloilslinger,thrustsleeveofhigh-speedrotatingparts,indynamicbalancingtypeinstallationpositionmarkingmustbeoneone