Lesson 2 Internal Combustion Engine (Part Ⅰ).ppt

1、lesson 2 internal combustion engine(part)、交通专业英语、基本要求：牙齿章节中的学习可以帮助您掌握学生内燃机结构和工作原理相关专业英语词汇和表达方法，从而可以流利地阅读学生准确的翻译相关门，掌握通用英汉翻译技术。重点难点：流利地阅读相关文献，准确地翻译短文。New Words v. oil泵top dead centre停止点bottom dead centre停止点，manifold n .化学歧管，支管，导管n .副本，各种；a .各种v .复制，增量eg.manifold effect inlet n .进气，入口inlet valve n .进气

2、阀induction .引进、柔道、检测、进气exhaust vn .名词。排气(通信端口)、废气exhaust valve排气阀Stagger v .交错Bore n .孔v. Bore a Hole venturi n .喉管jet n .莲蓬头throttle n .节流阀depression.Vt .将轴心安装在tilt v上。倾斜，翻转原则：原则，原则；指令，principal:主要，主要vacuum:真空，真空度revolution:革命，周期，周期sectional:剖面，剖面；部分，部分，1 Principle of Operation，The engine is a self

3、-contained power unit which converts The heat energy of fuel into mechanical energy fufy引擎是独立的电源供应设备，Because fuel is burned within，the engine is known as An internal combustion(IC)engine . in the IC engine，An air-fuel mixture引进；引进。输入，入口燃料在发动机缸内燃烧，因此发动机被称为内部燃烧引擎。在内燃机期间，空气和燃料的混合物流入密封的圆筒，气缸内的空气和燃料的混合物压

4、缩后点燃。the burning of the fuel(combustion)causes a rapid rise in cylinder pressure which is converted to useful mechanical energy by the piston Anandgiving rise to:发生、发生、发生、发生、giving rise to:结果(直译：所以，所以)classification:分类、分类、等级、类燃料是火花或An，such an engine are shown in fig.2.2 .点火汽油发动机的4冲程如图2.2所示。at The be

5、ginning of The induction stroke(fig . 2.2a)，The inlet valve opens and The piston travels down The cylinder from top dead centrethe correct air-fuel mixture is provided by the carburetor。准确的空气燃料混合物由化油器提供。when the piston reaches the end of its stroke the inlet valve closes，sealing the top end of the c

6、ylinder as both valves are closed .第一个end:第二个end:末端，结束活塞到达行程末端时，入口阀关闭，两个阀均关闭，气缸顶部密封。in fig . 2.2 b the piston is moving up the cylinder，Compressing the air-fuel mixture between the piston and cylinder head to a very small volume这是压缩笔划。Just before TDC an electrical spark，generated across the electrod

7、es of the spark plug，ignites the air-fuel mixture。活塞到达停止点之前，For good performance the timing of the spark must be closely controlled。为了获得良好的性能，必须精确控制点火时间。as the mixture burns，the hot gas expands causing a rapid and extreme rise in cylinder pressure，To such an extent that the piston is forcedonce the

8、mixture has been burned it must be removed from the cylinder as quickly as possible。混合物燃烧后，要尽快从缸内排出。in The exhaust stroke(fig . 2.2d)The rising piston pushes The hot gases and combustion products out of The cylinder through The open exhaust在排气行政(图2.2d)中上升的活塞将热空气和燃烧产物从气缸中推出，通过排气门和排气系统排出到大气中。this sequ

9、ence of events is repeated continually，with power delivered to the Crank shaft on only one of the four strokes the combustion strokenote that the crank shaft rotates through two full revolutions for each four-stroke cycle and a spark occurs only once In the cylinder . revolutions In在多缸引擎中，2 mixture

10、supply system、fuel stored in a large tank、is fed via a a pump to the carburetor。via:通过的通道燃料存储在大型燃料箱中，通过泵供给The carburetor(fig . 2.3)mixes The liquid petrol with filtered air on its way to The cylinders and in The process ture.the inlet manifold(fig . 2.4)directs the mixture to the cylinders。进气歧管(图2.4)将混合物导入气缸。the ratio of air to fuel in the mixture delivered to the cylinder is controlled by the size and shape of the carburetor bore and venturi，and the sizethe standard manual control for the amount of air and fuel mixture delivered to the engine is the throttle valve，Which is co