第一章發(fā)動(dòng)機(jī)的工作原理和總體構(gòu)造

第一章發(fā)動(dòng)機(jī)的工作原理和總體構(gòu)造內(nèi)燃機(jī)的工作原理與總體構(gòu)造OperationandBasicSystems主要內(nèi)容Contents發(fā)動(dòng)機(jī)的定義及分類Definition&Classifications四沖程發(fā)動(dòng)機(jī)及二沖程發(fā)動(dòng)機(jī)的工作原理Operation發(fā)動(dòng)機(jī)的基本工作系統(tǒng)BasicSystems發(fā)動(dòng)機(jī)的產(chǎn)品名稱和型號(hào)編制規(guī)則ProductNamesandTypeEstablishmentRules有關(guān)概念和排量的計(jì)算Terminology&Concept1.1IntroductionTheinternalcombustion(IC)engineisaheatenginethatconvertschemicalenergyinafuelintomechanicalenergy,usuallymadeavailableonarotatingoutputshaft.內(nèi)燃機(jī)是將熱能（來自于燃料化學(xué)能）轉(zhuǎn)變?yōu)闄C(jī)械能的一種熱機(jī)。Versussteamenginesandgasturbineenginesareexternalcombustionengines(i.e.，combustiontakesplaceoutsidethemechanicalenginesystem)外燃機(jī)

1.1發(fā)動(dòng)機(jī)的定義發(fā)動(dòng)機(jī)將某一種形式的能量轉(zhuǎn)化為機(jī)械能的機(jī)器。熱機(jī)（熱能機(jī)械能）外燃機(jī)內(nèi)燃機(jī)燃?xì)廨啓C(jī)活塞式往復(fù)活塞式reciprocatingengines旋轉(zhuǎn)活塞式rotaryengines1.2HistoricalBackgroundForcenturies,manwalkedorusedanimalsfortransportation.After

theinventionofmechanicalpropulsionsystems,peopleusedself-

propelledvehicles,whichmoveundertheirownpower.

Majormilestonesinvehicledevelopmentinclude:

ThefirstfairlypracticalenginewasinventedbyJ.J.E.Lenoir(1822-1900)andappearedonthesceneabout1860.1876Ottowasgivencreditwhenhisprototypeenginewasbuiltin1876.1892By1892,RudolfDiesel(1858-1913)hadperfectedhiscompressionignitionen-gineintobasicallythesamedieselengineknowntoday.1.2EarlyHistory2techno-logicaloccurrencesduringlatterhalfofthe1800sstimulatedtheemergenceoftheICEIn1859,thediscoveryofcrudeoilinPennsylvaniaThepneumaticrubbertirefirstmarketedbyJohnB.Dunlopin1888.1912

ElectricstarterinventedbyCharlesF.Kettering.

FirstusedonaCadillac,thestarterwasproduced

byDaytonElectricLaboratoriesCompany

1.2EarlyHistoryThesteamengineworkingprinciple內(nèi)燃機(jī)發(fā)展簡(jiǎn)史內(nèi)燃機(jī)是在蒸汽機(jī)的基礎(chǔ)上發(fā)明創(chuàng)制的：1700年，英國(guó)人鈕卡姆制成了直立汽缸，密封式活塞、缸內(nèi)噴水冷卻的蒸汽機(jī)；后由瓦特改良；1814——1829年，英國(guó)人史蒂芬森制成蒸汽機(jī)車，建成世界上第一段鐵路；1860年，法國(guó)人勒納（lenoir）仿蒸汽機(jī)制成世界上第一臺(tái)商用煤氣機(jī)（?=4%）；內(nèi)燃機(jī)發(fā)展簡(jiǎn)史內(nèi)燃機(jī)是在蒸汽機(jī)的基礎(chǔ)上發(fā)明創(chuàng)制的：1876年，德國(guó)人奧托制成四沖程火花點(diǎn)火內(nèi)燃機(jī)（?=16%）；1883年，英國(guó)人司派爾仿奧托四沖程煤氣機(jī)創(chuàng)制汽油機(jī)；1886年，德國(guó)人奔茨制成用汽油機(jī)做動(dòng)力的汽車；1892年，德國(guó)人狄塞爾創(chuàng)制柴油機(jī)成功，1898年，柴油機(jī)作為商品出售，熱效率為29%。1.3EngineOperationFour-StrokeSIEngineCycleIntakeorInductionStrokePowerorExpansionStrokeCompressionStrokeExhaustStroke1.3EngineOperationindicatordiagram1.3EngineOperation1、Piston-EngineConstructionPistonsmoveupanddown(orbackandforth)incylindersReciprocatingmotionischangedtorotarymotionbyconnectingrodandacrankpinonthecrankshaft2、OperationApistonstrokeisthemovementofthepistoninthecylinderfromtoptobottom,orbottomtotopFourpistonstrokes-----------intake,compression,powerandexhaust.Takestworevolutionsofthecrankshaft.Four-stroke-cycleengine1.3EngineOperationFour-StrokeCIEngineCycleIntakeorInductionStrokePowerorExpansionStrokeCompressionStroke1.3EngineOperation四沖程柴油機(jī)工作原理（seeanimation）/diesel1.htm1.3EngineOperation四沖程柴油機(jī)與汽油機(jī)比較同：四個(gè)沖程—進(jìn)氣、壓縮、膨脹和排氣異：燃油，可燃混合氣形成，著火方式汽油易蒸發(fā)，柴油不易揮發(fā)混合氣形成：高壓柴油從噴油器中直接噴入氣缸，形成時(shí)間很短（燃燒室形狀，組織進(jìn)氣渦流）著火方式：自燃溫度約600K（320℃）壓縮比較大。1.3EngineOperationQuestions:Whatmakestheairorair-fuelmixtureenterintothecylinder?Whatmakesthepistonsmoveupanddowninthecylinders?Whatisthepurposeofthevalves？Whatisthepropertimingofthevalves?Howdothecrankshaftandconnectingrodchangethereciprocatingmotionintorotarymotion？1.3EngineOperationAsinglecylinderfour-stroke-cycleenginehasonlyonepowerimpulseforeverytwocrankshaftrevolutions.Thepistondeliverspoweronlyone-fourthofthetime.四個(gè)沖程，只有一個(gè)行程做功，運(yùn)轉(zhuǎn)不平穩(wěn)；Foramoreevenflowofthepower,mostautomotiveengineshavefourormorecylinders.Thecylindersfireoneafteranothertoprovideasteadypowerflow.常采用多缸的方式;缸數(shù)曲軸做功間隔12周21周4半周8?周1.3EngineOperation1.3EngineOperationAcarengineusesafour-strokecycle--howcantwostrokesaccomplishthesametasks?想一想，兩沖程發(fā)動(dòng)機(jī)怎么工作？怎樣在活塞的兩個(gè)沖程完成一個(gè)（進(jìn)氣、壓縮、膨脹和排氣）完整的循環(huán)？結(jié)構(gòu)特點(diǎn)示功圖1.3EngineOperationYoucanseethattwo-strokeenginesareingeniouslittledevicesthatoverlapoperationsinordertoreducethepartcount.1.3EngineOperationTwo-StrokeSIEnginescheduleSpecialDesignofTwo-StrokeEnginesOnonesideofthepistonisthecombustionchamber,wherethepistoniscompressingtheair/fuelmixtureandcapturingtheenergyreleasedbytheignitionofthefuel.Ontheothersideofthepistonisthecrankcase,wherethepistoniscreatingavacuumtosuckinair/fuelfromthecarburetorthroughthereedvalveandthenpressurizingthecrankcasesothatair/fuelisforcedintothecombustionchamber.Meanwhile,thesidesofthepistonareactinglikevalves,coveringanduncoveringtheintakeandexhaustportsdrilledintothesideofthecylinderwall.1.3EngineOperation兩沖程汽油機(jī)在兩個(gè)活塞行程內(nèi)完成進(jìn)氣、壓縮、膨脹和排氣的工作循環(huán)。1、結(jié)構(gòu)三個(gè)口：進(jìn)氣口、排氣口和掃氣口2、工作過程活塞上行：壓縮、進(jìn)氣、點(diǎn)燃活塞下行：做功、結(jié)束進(jìn)氣、排氣、掃氣3、總結(jié)由于特殊結(jié)構(gòu)，方使得進(jìn)氣、壓縮、做功和排氣得以在兩個(gè)沖程中完成；有效行程的大小與孔的位置有關(guān)。1.3EngineOperationTwo-StrokeSIEngineCycle1.3EngineOperationTwo-StrokeCIEngineCycle1.3EngineOperationTwo-StrokeoverFourStrokeSIEngineAdvantage優(yōu)點(diǎn)：PowerStrokeeveryrevolution一周有一個(gè)做功行程，運(yùn)轉(zhuǎn)均勻平穩(wěn)；SimpleStructure無專門的換氣機(jī)構(gòu)，使用方便。Disadvantage缺點(diǎn)：RemainingofExhaustGases不易將廢氣排除干凈；LessEfficientStroke有效行程小于上下止點(diǎn)間距離；BlowoutofAir-FuelMixture掃氣時(shí)有燃油損失。1.3EngineOperationTwo-StrokeCIEngine1、overtwo-strokeSIengine與二沖程汽油機(jī)比較，不同之處：exhaustvalves采用排氣門排氣；moreinletports進(jìn)氣口不止一個(gè)，環(huán)布在氣缸周圍，且經(jīng)氣泵加壓；Scavengingwithpureair采用純空氣掃氣，沒有燃油損失；separatecrankcase不用曲軸箱貯存可燃混合氣及空氣。2、工作原理Upwardstroke:scavenge,compression,spray,self-ignition活塞上行沖程：換氣、壓縮、噴油著火；Downwardstroke:expansion,exhaust,intakeandscavenge活塞下行沖程：膨脹做功、排氣換氣。1.3EngineOperation柴油機(jī)與汽油機(jī)的特點(diǎn)比較柴油機(jī)壓縮比大，燃?xì)馀蛎洺浞?，膨脹終了燃?xì)鉁囟容^低，熱量利用程度較好，比汽油機(jī)省燃料。柴油機(jī)氣缸壓力較高，機(jī)件受力較大，剛度和強(qiáng)度要求較高，與相同功率的汽油機(jī)相比，其體積較大，重量也較大，但堅(jiān)固耐用，運(yùn)轉(zhuǎn)時(shí)噪聲也較大。柴油機(jī)中噴油泵和噴油氣的精密度高，加工比較困難，制造成本也較高。柴油機(jī)借助于壓縮終了空氣的高溫使柴油著火，所以較難起動(dòng)。汽油機(jī)轉(zhuǎn)速較高，柴油機(jī)轉(zhuǎn)速較低。柴油機(jī)廣泛用在農(nóng)用動(dòng)力、拖拉機(jī)、載重汽車、工程機(jī)械、機(jī)車、船舶等方面。汽油機(jī)則由于結(jié)構(gòu)輕巧、制造方便、工作平穩(wěn)、起動(dòng)容易等優(yōu)點(diǎn)，常用在小客車、輕型載貨汽車及小型農(nóng)用動(dòng)力上。1.4Terminology術(shù)語及概念Top-Dead-Center上止點(diǎn)（TDC)BottomDead-Center下止點(diǎn)(BDC)Stroke活塞行程(S)DisplacementorDisplacementVolume排量（發(fā)動(dòng)機(jī)工作容積或發(fā)動(dòng)機(jī)排量）Compressionratio壓縮比Knock爆震1.4術(shù)語及概念演示1.5EngineClassificationTypesofIgnitionSparkIgnitionCompressionIgnitionEngineCyclesFour-strokecycleTwo-strokecycleAirIntakeProcessFuelUsedTypeofCooling1.5發(fā)動(dòng)機(jī)的分類往復(fù)活塞式發(fā)動(dòng)機(jī)兩種基本類型汽油機(jī)柴油機(jī)所用燃料著火方式混合氣準(zhǔn)備方式發(fā)動(dòng)機(jī)的其他分類按每循環(huán)沖程數(shù)/按進(jìn)氣方式/按燃料/按冷卻方式按氣缸數(shù)目/按氣缸排列方式/按氣門數(shù)1.6BasicEngineSystems發(fā)動(dòng)機(jī)的總體構(gòu)造按照功能解體為下面幾個(gè)部分：FuelSystem燃油供給系統(tǒng)（）Intakesystem進(jìn)氣系統(tǒng)（）IgnitionSystem點(diǎn)火系統(tǒng)CoolingSystem冷卻系統(tǒng)（）LubricatingSystem潤(rùn)滑系統(tǒng)（）StartingSystem起動(dòng)系統(tǒng)EmissionControlSystem排放控制系統(tǒng)1.6BasicEngineSystems發(fā)動(dòng)機(jī)的總體構(gòu)造FuelSystem燃油供給系（）Thefuelsystemsuppliesgasolineordieselfueltotheengine.Thefuelismixedwithairtomakeacombustiblemixture.Eachcylinderisrepeatedlyfilledwiththemixture.Then,themixtureisignitedandburned,producinghighpressure.Thehighpressuremakesthepistonsmove.Thisturnsshaftsthatrotatethewheels,causingthevehiclestomove.1.6BasicEngineSystems發(fā)動(dòng)機(jī)的總體構(gòu)造AirIntake/ExhaustSystem

進(jìn)排氣系統(tǒng)

（）Allenginesdrawairfromtheatmosphere.AirIntake/ExhaustSystembringscleanairintotheenginefromoutsideandpushesexhaustgasestooutside.1.6BasicEngineSystems發(fā)動(dòng)機(jī)的總體構(gòu)造IgnitionSystem點(diǎn)火系統(tǒng)Deliveranelectricsparktoignitetheair-fuelmixture.Theactionisrepeatedmanytimeseachsecondwhiletheengineisrunning.Theignitionsystemtakesthelowvoltageofthebatteryandbuildsituptoaveryhighvoltage---ashighas47,000voltsinsomesystems.Thishighvoltagejumpsthegapsinthesparkplugs,producingthesparks.1.6BasicEngineSystems發(fā)動(dòng)機(jī)的總體構(gòu)造CoolingSystem冷卻系統(tǒng)（）Coolingsystemgivetheenginebetterheatcontrolbyremovalofthesurplusheatorwarminguptheenginequicklyatthecoldstart.1.6BasicEngineSystems發(fā)動(dòng)機(jī)的總體構(gòu)造LubricatingSystem潤(rùn)滑系統(tǒng)（）Theenginehasmanymovingmetalparts.Ifmetalpartsrubagainsteachother,theywillwearrapidly.Topreventthis,engineshavelubricatingsystemsthatfloodallmovingpartswithacoatingoflubricatingoil.Theoilgetsbetweenthemetalpartssotheyslideonoilandnotoneachother.1.6BasicEngineSystems發(fā)動(dòng)機(jī)的總體構(gòu)造StartingSystem起動(dòng)系統(tǒng)Thestartingsystemisneededtocranktheengine.Abatteryprovidestheelectricpowertooperatethestaringmotorandtheignitionsystemduringcranking1.6BasicEngineSystems發(fā)動(dòng)機(jī)的總體構(gòu)造EmissionControlSystem

Controlofvehicleemissionsincludescontrollinggasolinevaporsreleasedintotheatmosphereinadditiontoreducingexhaustemissions.發(fā)動(dòng)機(jī)參數(shù)承載車輛BETA發(fā)動(dòng)機(jī)DELTA發(fā)動(dòng)機(jī)發(fā)動(dòng)機(jī)型號(hào)伊蘭特索納塔1.6LGAS1.8LGAS2.0LGAS2.7LGAS發(fā)動(dòng)機(jī)形式1-4(4缸)V-6(6缸)BORE×STROKE77.4×8582×8582×93.566.7×75排氣量(CC)1.5991.7951.9752.656最大功率(PS/rpm)112/6,000132/6,000140/6,000178/6,000缸心距9196最大扭矩(Kg.m/rpm)14.6/4,50017.1/4,50018.6/4,50025.0/4,000Engine基本組成(Assembly)AirCleanerExhaustManifoldIntakeManifoldCatalystCylinderHeadWaterPumpAirCleanerAirCleanerElementFuelRailInjectorCatalystIntakeManifoldExhaustManifoldThrottleBody進(jìn)排氣系統(tǒng)Intake/ExhaustSystemValveTrainTimingBeltCamshaftIntake&ExhaustValveCamshaftSprocketCrankshaftSprocketValveSpringIdler配氣系統(tǒng)CoolingWaterCircuitThermostatThermostatHousingWaterPumpToRadiator冷卻系統(tǒng)曲柄連桿機(jī)構(gòu)

MovingPart（主運(yùn)動(dòng)系統(tǒng)）PistonPistonRingFlywheelConnecting-RodCrankshaftMainBearingDamperPulleySIMK43PCU

O?SENSOR

3-CATALYST碳罐清污閥CKPSKNOCKSENSORTPSIGNITIONCOILFUELPUMPWTS

INJECTORCMPSISASENSORSACTUATORS新世代

A/T?β-2.0DENGINEAirMAPSSPARKPLUGCMPS:CamshaftPositionSensorCKPS:CrankshaftPositionSensorTPS:ThrottlePositionSensorWTS:WaterTemperatureSensorISA:IdleSpeedActuatorEFCENGMANAGEMENTSYSTEM構(gòu)成圖ProductNames&TypeEstablishmentRules

內(nèi)燃機(jī)產(chǎn)品名稱和型號(hào)編制規(guī)則GB/T725-1991規(guī)定；內(nèi)燃機(jī)按所用燃料命名；型號(hào)由阿拉伯?dāng)?shù)碼和漢語拼音字母組成；內(nèi)燃機(jī)型號(hào)由下列四部分組成首部：產(chǎn)品系列符號(hào)或換代標(biāo)志符號(hào)；中部：缸數(shù)符號(hào)、沖程符號(hào)、汽缸排列符號(hào)和缸徑符號(hào)；后部：結(jié)構(gòu)特征、用途符號(hào)尾部：區(qū)分符號(hào)TrendGDIHCCIProblems:1.1ListfivedifferencesbetweenSIenginesandCIengines.1.2Afour-strokecycleenginemay