第一章發(fā)動機(jī)的工作原理和總體構(gòu)造

1、第一章汽車發(fā)動機(jī)構(gòu)造第一章第一章 發(fā)動機(jī)的工作原理和總體構(gòu)造發(fā)動機(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Operation and Basic Systems主要內(nèi)容主要內(nèi)容 Contents 發(fā)動機(jī)的定義及分類 Definition & Classifications 四沖程發(fā)動機(jī)及二沖程發(fā)動機(jī)的工作原理 Operation 發(fā)動機(jī)的基本工作系統(tǒng) Basic Systems 發(fā)動機(jī)的產(chǎn)品名稱和型號編制規(guī)則 Product Names and Type Establishment Rules 有關(guān)概念和排量的計(jì)算 Terminology & Concept1.11.1

2、Introduction The internal combustion (IC) engine is a heat engine that converts chemical energy in a fuel into mechanical energy, usually made available on a rotating output shaft. 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)。 Versus steam engines and gas turbine engines are external combustion engines (i.e.，combus

3、tion takes place outside the mechanical engine system) 外燃機(jī) 1.11.1 發(fā)動機(jī)的定義發(fā)動機(jī)的定義 發(fā)動機(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 reciprocating engines旋轉(zhuǎn)活塞式 rotary engines 1.2 Historical Background For centuries, man walked or used animals for transportation. Afterthe invention of mechanical prop

4、ulsion systems, people used self-propelled vehicles, which move under their own power.Major milestones in vehicle development include:The first fairly practical engine was invented by J.J.E. Lenoir (1822-1900) and appeared on the scene about 1860.1876 Otto was given credit when his prototype engine

5、was built in 1876. 1892 By 1892, Rudolf Diesel (1858-1913) had perfected his compression ignition en-gine into basically the same diesel engine known today. 1.2 Early History 2 techno-logical occurrences during latter half of the 1800s stimulated the emergence of the ICE In 1859, the discovery of cr

6、ude oil in Pennsylvania The pneumatic rubber tire first marketed by John B. Dunlop in 1888.1912Electric starter invented by Charles F. Kettering.First used on a Cadillac, the starter was producedby Dayton Electric Laboratories Company 1.2 Early History The steam engine working principle內(nèi)燃機(jī)發(fā)展簡史內(nèi)燃機(jī)發(fā)展簡

7、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； 18141829年，英國人史蒂芬森制成蒸汽機(jī)車，建成世界上第一段鐵路； 1860年，法國人勒納（lenoir）仿蒸汽機(jī)制成世界上第一臺商用煤氣機(jī)（ =4%）；內(nèi)燃機(jī)發(fā)展簡史內(nèi)燃機(jī)發(fā)展簡史內(nèi)燃機(jī)是在蒸汽機(jī)的基礎(chǔ)上發(fā)明創(chuàng)制的： 1876年，德國人奧托制成四沖程火花點(diǎn)火內(nèi)燃機(jī)（=16%）； 1883年，英國人司派爾仿奧托四沖程煤氣機(jī)創(chuàng)制汽油機(jī)； 1886年，德國人奔茨制成用汽油機(jī)做動力的汽車； 1892年，德國人狄塞爾創(chuàng)制柴油機(jī)成功，1898年，柴油機(jī)作為商品出售，熱效率

8、為29%。1.3 Engine Operation Four-Stroke SI Engine CycleIntake orInduction StrokePower or ExpansionStrokeCompression StrokeExhaust Stroke1.3 Engine Operationindicator diagram 1.3 Engine Operation1、Piston-Engine Construction Pistons move up and down (or back and forth) in cylinders Reciprocating motion

9、is changed to rotary motion by connecting rod and a crankpin on the crankshaft2、Operation A piston stroke is the movement of the piston in the cylinder from top to bottom, or bottom to top Four piston strokes-intake, compression, power and exhaust. Takes two revolutions of the crankshaft. Four-strok

10、e-cycle engine1.3 Engine Operation Four-Stroke CI Engine CycleIntake orInduction StrokePower or ExpansionStrokeCompression Stroke1.3 Engine Operation四沖程柴油機(jī)工作原理（see animation）http:/ Engine Operation 四沖程柴油機(jī)與汽油機(jī)比較 同：四個沖程進(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，形成時間很短（燃燒室形狀，組織進(jìn)氣渦

11、流） 著火方式：自燃溫度約600K（320）壓縮比較大。1.3 Engine Operation Questions:What makes the air or air-fuel mixture enter into the cylinder?What makes the pistons move up and down in the cylinders?What is the purpose of the valves？What is the proper timing of the valves?How do the crankshaft and connecting rod change

12、 the reciprocating motion into rotary motion？1.3 Engine Operation A single cylinder four-stroke-cycle engine has only one power impulse for every two crankshaft revolutions. The piston delivers power only one-fourth of the time. 四個沖程，只有一個行程做功，運(yùn)轉(zhuǎn)不平穩(wěn)； For a more even flow of the power, most automotive

13、 engines have four or more cylinders. The cylinders fire one after another to provide a steady power flow. 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 1.3 Engine Operation1.3 Engine Operation A car engine uses a four-stroke cycle - how can two strokes accomplish the same tasks? 想一想，兩沖程發(fā)動機(jī)怎么工作？怎樣在活塞的兩個沖程完成一個（進(jìn)氣、壓縮、

14、膨脹和排氣）完整的循環(huán)？ 結(jié)構(gòu)特點(diǎn) 示功圖1.3 Engine OperationYou can see that two-stroke engines are ingenious little devices that overlap operations in order to reduce the part count. 1.3 Engine Operation Two-Stroke SI Engine schedule Special Design of Two-Stroke Engines On one side of the piston is the combustion cha

15、mber, where the piston is compressing the air/fuel mixture and capturing the energy released by the ignition of the fuel. On the other side of the piston is the crankcase, where the piston is creating a vacuum to suck in air/fuel from the carburetor through the reed valve and then pressurizing the c

16、rankcase so that air/fuel is forced into the combustion chamber. Meanwhile, the sides of the piston are acting like valves, covering and uncovering the intake and exhaust ports drilled into the side of the cylinder wall. 1.3 Engine Operation 兩沖程汽油機(jī)在兩個活塞行程內(nèi)完成進(jìn)氣、壓縮、膨脹和排氣的工作循環(huán)。 1、結(jié)構(gòu) 三個口：進(jìn)氣口、排氣口和掃氣口 2、工

17、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沖程中完成；有效行程的大小與孔的位置有關(guān)。1.3 Engine Operation Two-Stroke SI Engine Cycle1.3 Engine Operation Two-Stroke CI Engine Cycle1.3 Engine Operation Two-Stroke over Four Stroke SI Engine Advantage 優(yōu)點(diǎn)：Power Stroke every revolution一周有一個做功行程，運(yùn)轉(zhuǎn)均勻平穩(wěn)

18、；Simple Structure無專門的換氣機(jī)構(gòu)，使用方便。 Disadvantage缺點(diǎn)：Remaining of Exhaust Gases不易將廢氣排除干凈；Less Efficient Stroke有效行程小于上下止點(diǎn)間距離；Blowout of Air-Fuel Mixture 掃氣時有燃油損失。1.3 Engine Operation Two-Stroke CI Engine 1、over two-stroke SI engine與二沖程汽油機(jī)比較，不同之處： exhaust valves采用排氣門排氣； more inlet ports 進(jìn)氣口不止一個，環(huán)布在氣缸周圍，且經(jīng)氣泵

19、加壓； Scavenging with pure air 采用純空氣掃氣，沒有燃油損失； separate crankcase 不用曲軸箱貯存可燃混合氣及空氣。 2、工作原理 Upward stroke :scavenge, compression, spray, self-ignition 活塞上行沖程：換氣、壓縮、噴油著火； Downward stroke : expansion, exhaust, intake and scavenge 活塞下行沖程：膨脹做功、排氣換氣。1.3 Engine Operation 柴油機(jī)與汽油機(jī)的特點(diǎn)比較柴油機(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?/p>

20、分，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。 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)用動力上。1.4 Terminology 術(shù)語及概念術(shù)語及概念 Top-Dead-

21、Center 上止點(diǎn)（TDC) Bottom Dead-Center 下止點(diǎn)(BDC) Stroke 活塞行程(S) Displacement or Displacement Volume排量（發(fā)動機(jī)工作容積或發(fā)動機(jī)排量） Compression ratio壓縮比 Knock 爆震1.4 術(shù)語及概念演示術(shù)語及概念演示1.5 Engine Classification Types of Ignition Spark Ignition Compression Ignition Engine Cycles Four-stroke cycle Two-stroke cycle Air Intake P

22、rocess Fuel Used Type of Cooling1.5 發(fā)動機(jī)的分類發(fā)動機(jī)的分類 往復(fù)活塞式發(fā)動機(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)1.6 Basic Engine Systems 發(fā)動機(jī)的總體構(gòu)造發(fā)動機(jī)的總體構(gòu)造 按照功能解體為下面幾個部分： Fuel System 燃油供給系統(tǒng)（ ） Intake system 進(jìn)氣系統(tǒng) （ ） Ignition System 點(diǎn)火系統(tǒng) Cooling System 冷卻系統(tǒng)（ ） Lubricating S

23、ystem 潤滑系統(tǒng)（ ） Starting System 起動系統(tǒng) Emission Control System排放控制系統(tǒng)1.6 Basic Engine Systems 發(fā)動機(jī)的總體構(gòu)造發(fā)動機(jī)的總體構(gòu)造 Fuel System 燃油供給系（ ） The fuel system supplies gasoline or diesel fuel to the engine. The fuel is mixed with air to make a combustible mixture. Each cylinder is repeatedly filled with the mixture

24、. Then, the mixture is ignited and burned, producing high pressure. The high pressure makes the pistons move. This turns shafts that rotate the wheels, causing the vehicles to move. 1.6 Basic Engine Systems 發(fā)動機(jī)的總體構(gòu)造發(fā)動機(jī)的總體構(gòu)造 Air Intake / Exhaust System 進(jìn)排氣系統(tǒng) （ ） All engines draw air from the atmosphe

25、re. Air Intake /Exhaust System brings clean air into the engine from outside and pushes exhaust gases to outside.1.6 Basic Engine Systems 發(fā)動機(jī)的總體構(gòu)造發(fā)動機(jī)的總體構(gòu)造 Ignition System 點(diǎn)火系統(tǒng) Deliver an electric spark to ignite the air-fuel mixture. The action is repeated many times each second while the engine is

26、running. The ignition system takes the low voltage of the battery and builds it up to a very high voltage- as high as 47, 000 volts in some systems. This high voltage jumps the gaps in the spark plugs, producing the sparks.1.6 Basic Engine Systems 發(fā)動機(jī)的總體構(gòu)造發(fā)動機(jī)的總體構(gòu)造 Cooling System 冷卻系統(tǒng)（ ） Cooling syst

27、em give the engine better heat control by removal of the surplus heat or warming up the engine quickly at the cold start.1.6 Basic Engine Systems 發(fā)動機(jī)的總體構(gòu)造發(fā)動機(jī)的總體構(gòu)造 Lubricating System 潤滑系統(tǒng)（ ） The engine has many moving metal parts. If metal parts rub against each other, they will wear rapidly. To prev

28、ent this, engines have lubricating systems that flood all moving parts with a coating of lubricating oil. The oil gets between the metal parts so they slide on oil and not on each other.1.6 Basic Engine Systems 發(fā)動機(jī)的總體構(gòu)造發(fā)動機(jī)的總體構(gòu)造 Starting System 起動系統(tǒng) The starting system is needed to crank the engine.

29、A battery provides the electric power to operate the staring motor and the ignition system during cranking 1.6 Basic Engine Systems 發(fā)動機(jī)的總體構(gòu)造發(fā)動機(jī)的總體構(gòu)造Emission Control System Control of vehicle emissions includes controlling gasoline vapors released into the atmosphere in addition to reducing exhaust e

30、missions.承載車輛承載車輛BETA發(fā)動機(jī)發(fā)動機(jī)DELTA發(fā)動機(jī)發(fā)動機(jī)發(fā)動機(jī)型號發(fā)動機(jī)型號伊蘭特伊蘭特索納塔索納塔1.6L GAS1.8L GAS2.0L GAS2.7L GAS發(fā)動機(jī)形式發(fā)動機(jī)形式1-4(4缸缸)V-6(6缸缸)BORESTROKE77.48582858293.566.775排氣量排氣量(CC)1.5991.7951.9752.656最大功率最大功率(PS/rpm)112/6,000132/6,000140/6,000178/6,000缸心距缸心距9196最大扭矩最大扭矩(Kg.m/rpm)14.6/4,50017.1/4,50018.6/4,50025.0/4,000

31、Engine 基本組成基本組成(Assembly)Air CleanerExhaust ManifoldIntake ManifoldCatalystCylinder HeadWater PumpAir CleanerAir CleanerElementFuel RailInjectorCatalystIntake ManifoldExhaust ManifoldThrottle Body進(jìn)排氣系統(tǒng)進(jìn)排氣系統(tǒng)Intake/Exhaust SystemIntake/Exhaust SystemValve TrainTiming BeltCamshaftIntake &ExhaustVal

32、veCamshaftSprocketCrankshaftSprocketValve SpringIdler配氣系統(tǒng)配氣系統(tǒng)Cooling Water CircuitThermostatThermostatHousingWater PumpTo Radiator冷卻系統(tǒng)冷卻系統(tǒng)曲柄連桿機(jī)構(gòu)曲柄連桿機(jī)構(gòu) Moving Part（主運(yùn)動系統(tǒng)）主運(yùn)動系統(tǒng)）PistonPiston RingFlywheelConnecting-RodCrankshaftMain BearingDamper PulleySIMK43 PCU OSENSOR 3-CATALYST碳罐清污閥碳罐清污閥CKPSKNOCK SE

33、NSOR TPSIGNITION COILFUEL PUMPWTS INJECTORCMPSISASENSORSACTUATORS新世代新世代 A/T -2.0D ENGINEAirMAPSSPARK PLUGCMPS : Camshaft Position SensorCKPS : Crankshaft Position SensorTPS : Throttle Position SensorWTS : Water Temperature SensorISA : Idle Speed ActuatorEFC ENG MANAGEMENT SYSTEM 構(gòu)成圖Product Names &am

34、p; Type Establishment Rules內(nèi)燃機(jī)產(chǎn)品名稱和型號編制規(guī)則內(nèi)燃機(jī)產(chǎn)品名稱和型號編制規(guī)則 GB/T 725-1991規(guī)定； 內(nèi)燃機(jī)按所用燃料命名； 型號由阿拉伯?dāng)?shù)碼和漢語拼音字母組成； 內(nèi)燃機(jī)型號由下列四部分組成 首部：產(chǎn)品系列符號或換代標(biāo)志符號； 中部：缸數(shù)符號、沖程符號、汽缸排列符號和缸徑符號； 后部：結(jié)構(gòu)特征、用途符號 尾部：區(qū)分符號TrendGDI HCCIProblems:1.1 List five differences between SI engines and CI engines.1.2 A four-stroke cycle engine may or may not have a pressur