第一章发动机的工作原理和总体构造汇总

1、第一章汽车发动机构造第一章第一章 发动机的工作原理和总体构造发动机的工作原理和总体构造内燃机的工作原理与总体构造Operation and Basic Systems主要内容主要内容 Contents 发动机的定义及分类 Definition & Classifications 四冲程发动机及二冲程发动机的工作原理 Operation 发动机的基本工作系统 Basic Systems 发动机的产品名称和型号编制规则 Product Names and Type Establishment Rules 有关概念和排量的计算 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. 内燃机是将热能（来自于燃料化学能）转变为机械能的一种热机。 Versus steam engines and gas turbine engines are external combustion engines (i.e.，combus

3、tion takes place outside the mechanical engine system) 外燃机 1.11.1 发动机的定义发动机的定义 发动机 将某一种形式的能量转化为机械能的机器。 热机（热能 机械能 ）外燃机内燃机燃气轮机活塞式往复活塞式 reciprocating engines旋转活塞式 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内燃机发展简史内燃机发展简

7、史内燃机是在蒸汽机的基础上发明创制的： 1700年，英国人钮卡姆制成了直立汽缸，密封式活塞、缸内喷水冷却的蒸汽机；后由瓦特改良； 18141829年，英国人史蒂芬森制成蒸汽机车，建成世界上第一段铁路； 1860年，法国人勒纳（lenoir）仿蒸汽机制成世界上第一台商用煤气机（ =4%）；内燃机发展简史内燃机发展简史内燃机是在蒸汽机的基础上发明创制的： 1876年，德国人奥托制成四冲程火花点火内燃机（=16%）； 1883年，英国人司派尔仿奥托四冲程煤气机创制汽油机； 1886年，德国人奔茨制成用汽油机做动力的汽车； 1892年，德国人狄塞尔创制柴油机成功，1898年，柴油机作为商品出售，热效率

8、为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四冲程柴油机工作原理（see animation）http:/ Engine Operation 四冲程柴油机与汽油机比较 同：四个冲程进气、压缩、膨胀和排气 异：燃油，可燃混合气形成，着火方式 汽油易蒸发，柴油不易挥发 混合气形成：高压柴油从喷油器中直接喷入气缸，形成时间很短（燃烧室形状，组织进气涡

11、流） 着火方式：自燃温度约600K（320）压缩比较大。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. 四个冲程，只有一个行程做功，运转不平稳； 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;缸数曲轴做功间隔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，两冲程发动机怎么工作？怎样在活塞的两个冲程完成一个（进气、压缩、

14、膨胀和排气）完整的循环？ 结构特点 示功图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 两冲程汽油机在两个活塞行程内完成进气、压缩、膨胀和排气的工作循环。 1、结构 三个口：进气口、排气口和扫气口 2、工

17、作过程 活塞上行：压缩、进气、点燃 活塞下行：做功、结束进气、排气、扫气 3、总结 由于特殊结构，方使得进气、压缩、做功和排气得以在两个冲程中完成；有效行程的大小与孔的位置有关。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 优点：Power Stroke every revolution一周有一个做功行程，运转均匀平稳

18、；Simple Structure无专门的换气机构，使用方便。 Disadvantage缺点：Remaining of Exhaust Gases不易将废气排除干净；Less Efficient Stroke有效行程小于上下止点间距离；Blowout of Air-Fuel Mixture 扫气时有燃油损失。1.3 Engine Operation Two-Stroke CI Engine 1、over two-stroke SI engine与二冲程汽油机比较，不同之处： exhaust valves采用排气门排气； more inlet ports 进气口不止一个，环布在气缸周围，且经气泵

19、加压； Scavenging with pure air 采用纯空气扫气，没有燃油损失； separate crankcase 不用曲轴箱贮存可燃混合气及空气。 2、工作原理 Upward stroke :scavenge, compression, spray, self-ignition 活塞上行冲程：换气、压缩、喷油着火； Downward stroke : expansion, exhaust, intake and scavenge 活塞下行冲程：膨胀做功、排气换气。1.3 Engine Operation 柴油机与汽油机的特点比较柴油机与汽油机的特点比较 柴油机压缩比大，燃气膨胀充

20、分，膨胀终了燃气温度较低，热量利用程度较好，比汽油机省燃料。 柴油机气缸压力较高，机件受力较大，刚度和强度要求较高，与相同功率的汽油机相比，其体积较大，重量也较大，但坚固耐用，运转时噪声也较大。 柴油机中喷油泵和喷油气的精密度高，加工比较困难，制造成本也较高。 柴油机借助于压缩终了空气的高温使柴油着火，所以较难起动。 汽油机转速较高，柴油机转速较低。 柴油机广泛用在农用动力、拖拉机、载重汽车、工程机械、机车、船舶等方面。 汽油机则由于结构轻巧、制造方便、工作平稳、起动容易等优点，常用在小客车、轻型载货汽车及小型农用动力上。1.4 Terminology 术语及概念术语及概念 Top-Dead-

21、Center 上止点（TDC) Bottom Dead-Center 下止点(BDC) Stroke 活塞行程(S) Displacement or Displacement Volume排量（发动机工作容积或发动机排量） Compression ratio压缩比 Knock 爆震1.4 术语及概念演示术语及概念演示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 发动机的分类发动机的分类 往复活塞式发动机两种基本类型 汽油机 柴油机 所用燃料 着火方式 混合气准备方式 发动机的其他分类 按每循环冲程数/按进气方式/按燃料/按冷却方式 按气缸数目/按气缸排列方式/按气门数1.6 Basic Engine Systems 发动机的总体构造发动机的总体构造 按照功能解体为下面几个部分： Fuel System 燃油供给系统（ ） Intake system 进气系统 （ ） Ignition System 点火系统 Cooling System 冷却系统（ ） Lubricating S

23、ystem 润滑系统（ ） Starting System 起动系统 Emission Control System排放控制系统1.6 Basic Engine Systems 发动机的总体构造发动机的总体构造 Fuel System 燃油供给系（ ） 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 发动机的总体构造发动机的总体构造 Air Intake / Exhaust System 进排气系统 （ ） 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 发动机的总体构造发动机的总体构造 Ignition System 点火系统 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 发动机的总体构造发动机的总体构造 Cooling System 冷却系统（ ） 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 发动机的总体构造发动机的总体构造 Lubricating System 润滑系统（ ） 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 发动机的总体构造发动机的总体构造 Starting System 起动系统 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 发动机的总体构造发动机的总体构造Emission Control System Control of vehicle emissions includes controlling gasoline vapors released into the atmosphere in addition to reducing exhaust e

30、missions.承载车辆承载车辆BETA发动机发动机DELTA发动机发动机发动机型号发动机型号伊兰特伊兰特索纳塔索纳塔1.6L GAS1.8L GAS2.0L GAS2.7L GAS发动机形式发动机形式1-4(4缸缸)V-6(6缸缸)BORESTROKE77.48582858293.566.775排气量排气量(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 基本组成基本组成(Assembly)Air CleanerExhaust ManifoldIntake ManifoldCatalystCylinder HeadWater PumpAir CleanerAir CleanerElementFuel RailInjectorCatalystIntake ManifoldExhaust ManifoldThrottle Body进排气系统进排气系统Intake/Exhaust SystemIntake/Exhaust SystemValve TrainTiming BeltCamshaftIntake &ExhaustVal

32、veCamshaftSprocketCrankshaftSprocketValve SpringIdler配气系统配气系统Cooling Water CircuitThermostatThermostatHousingWater PumpTo Radiator冷却系统冷却系统曲柄连杆机构曲柄连杆机构 Moving Part（主运动系统）主运动系统）PistonPiston RingFlywheelConnecting-RodCrankshaftMain BearingDamper PulleySIMK43 PCU OSENSOR 3-CATALYST碳罐清污阀碳罐清污阀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 构成图Product Names &am

34、p; Type Establishment Rules内燃机产品名称和型号编制规则内燃机产品名称和型号编制规则 GB/T 725-1991规定； 内燃机按所用燃料命名； 型号由阿拉伯数码和汉语拼音字母组成； 内燃机型号由下列四部分组成 首部：产品系列符号或换代标志符号； 中部：缸数符号、冲程符号、汽缸排列符号和缸径符号； 后部：结构特征、用途符号 尾部：区分符号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 pressure boost (supercharger, tur-bocharger) in the intake system. Why must a two-stroke cycle engine always have an in-take pressure boost?1.3 List two advantages o