数控技术应用专业英语教学课件作者刘小芹Lesson21IntroductiontoAutomobile课件幻灯片.ppt

Now we will come to the last paragraph, read it silently in 5 minutes, please! paragraph Ⅴ: Fuel injection system in an internal-combustion engine delivers fuel or a fuel-air mixture to the cylinders by means of pressure from a pump. It was originally used in diesel engines because of diesel fuels greater viscosity and the need to overcome the high pressure of the compressed air in the cylinders. A diesel fuel injector sprays an intermittent, timed, metered quantity of fuel into a cylinder, distributing the fuel throughout the air within. 内燃机上的燃油喷射系统通过泵产生的压力来将油或油气混合物传递给汽缸。燃油喷射系统最早用在柴油机上，因为柴油的黏度较大,且需克服汽缸里受压缩空气的高压。柴油喷射器间歇地、定时地将一定量的柴油喷洒到汽缸中，使燃油与空气充分混合。 Fuel injection is also now used in gasoline engines in place of a carburetor. In gasoline engines the fuel usually is injected into the intake manifold and mixed with air, and the resulting mixture is delivered to the cylinder. Modern fuel injection systems use computers to regulate the process. Fuel injection results in more efficient fuel combustion, improving fuel economy and engine performance and reducing polluting exhaust emissions. 内燃机上的燃油喷射系统通过泵产生的压力来将油或油气混合物传递给汽缸。燃油喷射系统最早用在柴油机上，因为柴油的黏度较大,且需克服汽缸里受压缩空气的高压。柴油喷射器间歇地、定时地将一定量的柴油喷洒到汽缸中，使燃油与空气充分混合。 Oral English practice : Fuel injection system can be used both in diesel engine and gasoline engine, however, is there any difference between them? Section Ⅲ： exercises Now it’s time to do the exercises. And please finish them in five minutes. This is the end for lesson 21. It will be pretty good if you could review lesson 21 and preview lesson 22 in your spare time. Lesson 21: Introduction to Automobile 词汇讲解 课文分析 练习答案 本课教学目标： 理解汽车差速器、燃油喷射器的作用； 掌握与汽车相关的专业词汇； 熟悉独立主格、伴随壮语等语法现象。 Section Ⅰ： words and phases 重点专业名词解析 词性转换 专有名词的通用含义 Now you will have 5 minutes to skim over the new words and phrases, marking the special words you can’t understand. 1. 重点专业名词解析 differential suspension transmission driving axle driving shaft differential 汽车发动机的动力经离合器、变速器、传动轴