2012年5月25日英文原文1.ThecarburetorCarburetorisundertheeffectsofthevacuumengineworking,willbeapercentageofthefuelandairmixingmechanism.Ittoimportantfunctionthattheenginecanbecalledtheheartoftheengine.Thecompletedeviceshallincludestartingdevice,idlespeeddevice,mediumload,fullloaddevice,acceleratingdevice.Carburetorwillaccordingtotherequirementsofdifferentworkingstateoftheengine,automaticallymatchingthecorrespondingconcentration,outputthecorrespondingamountofmixture,inordertomakethemixturemixedmoreevenly,carburetorhasmakefuelatomizationeffect,forthenormaloperationofmachine.Simplecarburetorismadeupof3threeparts,thepartwithairinletandthefloatchamber,themiddlesectiontherearepipes,orifice,nozzle,howaportionofthevalve,etc.Floatchamberisarectangularcontainer,storeofgasolinefromthegasolinepump,thereisafloatcontainerusingsurface(oillevelheightcontrolstheinput.Inthemiddleofanoilinletandtheamountoffloatchambernozzlehole,theotherendoiloutletinthroatthroat.Itisthroatwaist,twobigmiddlesmall,ofwhichtheminimumcross-sectionalareaofthroat.Suctionwhentheengineisstartedthepistondownward,inhalationofmaximumspeedwhentheairflowthroughthethroat,staticpressureisthelowest,sothethroatpressurelessthanatmosphericpressure,thatistosaythroatthroatandproducedthepressuredifferencebetweenthefloatchamber,thatisthepeopleoftensayvacuum,thegreaterthepressurerangeofvacuum.Undertheactionofgasinthevacuumfromtheoiloutletnozzlejet,becauseofthroatthroat25timesthatofgasflowrateofairflow,sothenozzlejetflowthatisdispersedbyhighspeedairflow,formingfogparticlesofvarioussizes,namelyatomization.Initialatomizingoilmixedwithairintoamixture,throughthethrottle,airintakepipeandinletvalveintothecombustionchamberofcylinder.Here,thethrottleopeningsizeandrotationalspeedofengine,determinedthethroatsofvacuumdegree,andthethrottleopeningchangedirectlyaffectsthemixtureratioofingredients,thesearetheimportantreasonforaffectingtheoperationoftheengine.Changesduetotheconcentrationofthemixturewithengineundervariousoperatingconditionsofloadchangeiscloselyrelated,simplecarburetorfarcannotsatisfythechangerequestatanytime,sopeopleonthesimplecarburetorconstantlyaddnewdeviceusedforadjustingtheworkingstateofthecarburetor.Developmenttoday,hasformedthecarburetorhasavarietyofauxiliaryequipment,mainlyareidle,tangy,accelerationandinitiatingdevice.Now4cylinderenginecommondynamiccarburetorcarburetorisdoublecavity,ithastwopipes,andaccordingtothedifferentengineoperatingconditionsorworkatthesametime,respectively.6cylinderenginecommoncarburetorisdoublecavityandcarburetor,itisactuallytwosinglecavitycarburetorandtogether,eachcavityisresponsibleforhalfofthenumberofmixturegascylinder.Andmulti-cavitycarburetor,usuallyassembledonlargepowerengine.Carburetorofthemultiplefunctionsofdevice,themainoilsupplyunitisinadditiontotheidlespeed,engineworkingconditionofvariousotherneedsofoilsupplydevice,isthebasicfuelsupplycarburetorstructure.Theidledeviceisinidlespeedruntimeprovidesfewbutstrongmixturedevice,withtheloweststableenginespeed.Adddeviceisbigengineloadextraoilsupplydevice,inordertomakeupfortheinadequacyofthemainoilsupply.Acceleratingdeviceisincreasedwhenthecarsuddenlyacceleratedtimeofvalveopeningextraoilsupplydevice,whentheenginespeedandpowercanbeincreasedrapidly.Starteristoprovideextremelyrichmixturewhentheenginecoldstartdevice,thecommonwayisinthefronthosetoachokevalvetocontrolthevolume.Thespeedofparticularmentionhere.Workingconditionofengineidlespeedisthemostcommonlyusedforenginethermalprocessandnoparkingstallandsoon.Forthecarperformancehasveryimportantsignificance,especiallyincitydriving,idlespeedconditionoftendeterminethecarsfuelconsumptionandemissionlevel.Engineidlespeedrunningspeedistypically600800RPM,throttleclosetoshutdown,thespeedofpipes,vacuumdegreecantfloatchambergasolineitsuckedoutsmoothly,butthethrottleatthebackofthevacuumdegreeishigh.Sojustonthebasisofsimplecarburetorofsettingupaidleoilduct,thenozzleislocatedinthethrottle,theproblemissolved.Duetoidleneedlessthickmixture,theengineoperationconditionismoresensitive,stableandshouldbetheminimumspeedoftheidlestate,tocontroltheoilamountoftheadjustmentandtheopeningofthrottle.Nowthecarburetorofidlespeeddevicehastwoadjustingscrew,adjusttheoilandthethrottleopeningrespectively.Atthesametime,inordertopreventthephenomenonofcloseautoignitionswitchandtheengineisstillrunning,theoilinthecarburetoridlewaywillalsoincludeaidlespeedsolenoidvalve,specificallyresponsibleforopeningandclosingtheidleoilduct,guaranteeenginecanquicklyshutdown.2.TheworkingprincipleofthecarburetorCarburetorisactuallyapipe,tubemiddlethereisacalledthethrottleadjustableplatedoorplank,isusedtocontroltheflowofairthroughthetube.Tubehasasectioncalledventuricontraction,theshrinkagewillformavacuum.Thecontractionsectionorifice,theuseofvacuumcanbeholeinhalefuelfromnowon.Motorcyclecarburetorlooksverycomplex,butaslongasgraspsomeprinciple,canadjustthemotorcycletothebeststate.Allcarburetorsareworkingunderthebasicprincipleofatmosphericpressure.Atmosphericpressureisapowertoputpressureoneverything.Itwillhaveslightvariations,butusuallyfifteenpoundsofpressurepersquareinch(PSI).Thismeansthattheatmosphericpressureinanythingisfifteenpoundspersquareinchpressure.Bychangingatmosphericpressurewithintheengineandcarburetor,youcanchangethepressureandmakethefuelandairflowthroughthecarburetor.Theatmosphericpressurewillspreadfromhighpressuretolowpressure.Whentwostrokeenginepistonattopdeadcenter(orfourstrokeenginespistonatthecheckpoint),underinthecrankcasepiston(four-strokeenginepistonabove)willformalowpressure.Atthesametime,thelowpressurecanalsocauselowpressureinthecarburetor.Becauseofthehighpressurecomparedtotheoutsideoftheengineandcarburetor,willburstintothecarburetorandairintotheengineuntilthepressureisbalanced.Airflowingthroughthecarburetorwilldrivethefuel,andfuelwillbemixedwithair.Insidethecarburetorisathroat.Throatisinsidethecarburetorforcedairspeedthroughthecontractionsection.Canallofasuddennarrowingrivertoillustratethesituationofoccurredinthecarburetor.NarrowtheriverneartheBanksoftheriverwillspeedup,ifBankscontinuousnarrowwillbefaster.Ifthesamethinghappeninthecarburetor,acceleratetheflowofairwillleadtotheinsideofthecarburetorairpressureisreduced.Gasolineisthefueltankthroughthefuelfilteragainintothecarburetor,fuelfiltertheimpuritiescanbemixedwithgasolineandthescalefilterinsidethetank.Ifthefilterqualitydefective,therearestillsomeimpuritiesthroughthefilterintothecarburetor.Othergasolinecontainedcanformgelingredientsafterlongtimedepositwillcondenseoutofthecolloid,attachedtothecarburetorparts(suchasorifice),oilandfloatonthesurface.Airisthroughairfilterintothecarburetor,basedontheairintakeresistancecannotbetoobigandotherfactorstoconsider,filteringdevicecannottootight,sopartofthetinyimpuritiesintheairwillenterthecarburetorthroughairfilter.Ifthefilterqualitydefective,cancausemoreseriousinfluence.Compositionintheairwaysofthecarburetoroilduct,morespareparts,suchasthemainmeasureholes,idleholeorifice,primaryair,idleairhole,thefoampipe,andsoonallhaveinsideasmallhole(diameterbetween0.31.5mm),intothecarburetorpetrolimpurity,colloidandimpuritiesintheair,tendtotheaperturechangeorjams,causecarburetorairway,pooroilduct,makethecarburetorfuelsupplycharacteristicschange,evencausethecarburetorperformancefailure.3.ThepneumaticsystemPneumatictechnologyisoneofthewaysinwhichindustrialproductionmechanizationandautomation.Pneumaticsystemtheuseofsafe,reliable,canbeinhightemperature,vibration,corrosion,inflammable,explosive,moredust,strongmagnetic,radiation,etc.Workunderthebadenvironment,whichapplicationisincreasinglywide.Pneumaticsystemandhydraulicsystem,aremadebyoneormoreofthemostsimpleofbasiccircuits.Pneumaticcircuitandcommonbasiccircuitisinordertoachievethespecificfunctionsandpneumaticcomponentsandpipesinacertainwayofcombinedstructure,analysis,designanduseofthepneumaticsystemis.Pneumatictransmissionandcontrolisoneofthemosteffectivewayintheproductionprocessautomationandmechanization,butitsworkingmedium(compressedair)manufacturingcostishigh,theenergyutilizationrateisquitelow.Pneumaticactuatorsismainlyusedtomakelinearreciprocatingmotion.Engineeringpractice,thiskindofmovementformusedmost,suchasmanymachinesordevicestransmittingdevice,productprocessingworkpiecefeeding,positioningandclampingworkpiece,workpieceassemblyandmaterialformingarelinearmotionform.Butsomepneumaticactuatorscanmakerotationmovement,suchastheoscillatingcylinder(swingAngleis360).Pneumatictechnologyapplicationrange,inadditiontotheindividualcircumstances,todolinearmotionform,fromthetechnologyfromacostpointofview,allmechanicalSheBicannotcomparedwithpneumaticequipment.(fromthetechnicalandcostpointofview,cylinderasactuatoristhebestformofcompletelinearmotion,likemotortocompleterotationmovement.)Pneumatictechnology,theinteractionbetweenactuatorsandcontrolelementisbasedonthesimpleelement.Missionrequirements,thesecomponentscanbeassembledintoavarietyofsystemsolutions.Pneumaticcontrolagenciesorequipmentgreatlyimprovethemechanizationdegree,andcanrealizefullyautomated,pneumatictechnologyhasmadeasignificantcontributiontothecheapautomation.Infact,asinglepneumaticcomponents,suchasvarioustypesofcylinderandcontrolvalve)canbeasmodularcomponents,thisispneumaticcomponentsmustbecombined,toformacontrolloopusedtocompleteaspecificassignments.Broadlyspeaking,pneumaticequipmentcanbeappliedtoanyengineeringfield.Pneumaticequipmentisoftenbyasmallamountofpneumaticcomponentsandseveralbasicloopcombination.Pneumaticcontrolsystemcompositionisreproducible,itlaidthefoundationforcombinationandpneumaticcomponentsandapplications.Ingeneral,thecombinationofpneumaticcomponentswithmanyreservationswithinfunctions.Batchfeederisalsooftenusedasacomponenttoprovidethewholemachine.Thusgreatlysimplifythepneumaticsystemdesign,reducetheworkloadofdesignandinstallationdebuggingpersonnel,makethepneumaticsystemcostisreducedgreatly.Pneumaticsystembasiccomposition:compositionofthepneumaticcircuittodrivemechanismforvariouspurposes,itscontentis:thethreemostimportantcontrolforce,thesizeoftheforcedirectionandspeedofmovement.Connectedtoproductiondevicesofvarioustypesofcylinder,bypressurecontrolvalves,directionalcontrolvalvesandflowcontrolvalve,thecontentsofthethreecontrolisimplemented,i.e.,thepressurecontrolvalve,pneumaticcontrolthesizeoftheoutputforce,directioncontrolvalves,controlthemovementdirectionofthecylinder,thespeedcontrolvalve-controlthemovemento