汽车专业英语+Unit+3

1、Unit 3 21世纪普通高等院校汽车专业系列教材世纪普通高等院校汽车专业系列教材keynote speaker：L Bao-zhanUnit 3Unit 3Engine Fuel System发动机燃油供给系统Unit 3Part A Gasoline Engine Fuel SystemNew words，phrases and Expressions汽油机燃油供给系统Unit 3Try to remember themNew wordsUnit 3Try to remember themNew wordsUnit 3Try to remember themNew wordsUnit 3p

2、hrases and ExpressionsTry to remember thembfl e Unit 3phrases and ExpressionsTry to remember themp:rssnetk软管、胶皮管Unit 3Text All gasoline engines have substantially identical fuel systems and run on a mixture consisting of fuel vapor and airThe fuel system comprises the units designed to store，clear a

3、nd deliver fuel，the units intended to clean air and a unit for preparing a mixture from fuel vapor and air In a fuel system different components are used to supply fuel from the fuel tank into the engine cylinder Some of the important components are：fuel tank，fuel pump，fuel filter，carburetor，intake

4、manifold，and fuel lines or tubes connecting the tank，pump and the carburetor(Figure 31)sbstnli大体上、本质上进气歧管mnfld 所有的汽油机实质上都具有相同的燃油系统，燃烧燃油蒸气和空气组成的混合气运转。燃油系统由储存、清洁和输送燃油元件，净化空气元件和形成燃油蒸气、空气混合气元件组成。 在燃油系统中，用不同的元件从油箱中供油到发动机气缸中。一些重要的部件是汽油箱，汽油泵，汽油滤清器，化油器，进气歧管和连接汽油箱、汽油泵和化油器的油管（图3-1）。Unit 3Text The fuel tank is

5、 a fuel container used for storing fuelIt is made of sheet metalIt is attached to the vehicle frame with metal traps and is located at the rear of the vehicleIt is mounted in a boot or boot-floor pan in case of the front-engined car or the small commercial vehicleIn order to strengthen the tank as w

6、ell as to prevent surging of fuel when the vehicle rounds a curve or suddenly stops，baffle plates are attached to the inside of the tank 汽油箱是一个储油容器，用于储存汽油。它由金属板制成。用金属夹子连接在车架上，位于车辆的后部。如果是前置发动机汽车和小型商用车，汽油箱安放在行李箱或行李箱浅盘形地板上。当车辆转弯或急刹车时，为了加固油箱，也为了防止燃油振荡，汽油箱内(通常)有挡油板。trp转弯bfl pleit圈套、卡子隔板，挡板Unit 3Text A cu

7、p is used to close the filler opening of the tankThe fuel line is attached at or near the bottom of the tank with a filtering element placed at the connectionThe other components of the fuel tank are the fuel gauge sending unit，vent pipe，receiving unit 滤清器盖用于盖上汽油箱的滤清器口。油管连接到汽油箱底部或附近，过滤元件置于连接处。汽油箱的其他

8、元件是燃油表输出装置、通气孔塞、接收装置。edvent paip尺度、测量仪器通气管Unit 3Text To prevent the dirt and water from entering the luggage compartment，a sealing strip is fitted between the fuel tank and boot floor panMoreover to limit the transmission of frame distortion to the tank giving rise to squeaking as the metal parts ge

9、t rubbed together，rubber or felt pads are often fitted between the mountings and the tankProvision is also made against drumming of the tank by these mountingsThe tank may be placed at the side of the chassis frame for convenience in case of the large commercial vehicleThe length of the connecting l

10、ines or tubes from the tank to the carburetor is also restricted by this at the same time 为了防止污垢和水进入行李舱，在油箱和行李箱浅盘形地板之间加装密封条。更好地限制车架变形传递到油箱而产生像金属元件在一起摩擦的敲击声，在衬托和油箱之间安装橡胶垫或毛毡垫。这些衬托防止油箱敲击声。如果是大型商用车，为便利，油箱也可以安置在底盘车架的一侧。同时从油箱到化油器的连接线路或管子的长度也因此被限制。drm毛毡垫长条、条板Unit 3Text A porous filter is attached to the o

11、utlet lines By drawing fuel from the tank through the filter，any water in the bottom of the tank as well as any dirt into the fuel gathers on the surface of the filterTo keep the fuel always under atmospheric pressure，the filter pipe or the tank must be ventedp:rs 多孔滤清器连接到排气管道上。经过滤清器将燃油从汽油箱中吸出，汽油箱底中

12、的水分和燃油中的污垢聚集到滤清器的表面。为保持燃油压力低于大气压，滤清器管或汽油箱要通风。有孔的、漏洞多的排气管道Unit 3Text In order to prevent dirt in the fuel from entering the fuel pump or carburetorfuel filters and screens are used in the fuel systemIf the dirt is not removed from the fuelthe normal operation of these units will be prevented，the engi

13、ne performance will also be reduced 为了阻止燃油中的污垢进入汽油泵或化油器，燃油系统中要用汽油滤清器和滤网。如果污垢没有从燃油中移除，就会阻止这些装置的正常运行。发动机性能也会降低。燃油滤清器和滤网Unit 3Text The filter is either fitted inside the fuel tank and pump or operates as a separate unit connected between the fuel tank and pump or between pump and carburetor into the fu

14、el linesCarburetors are also provided with filter screens while a filter element is provided in the tank 滤清器或者安装在汽油箱和汽油泵内部，或者作为一个独立的装置分别连接到汽油箱和油泵之间或油泵和化油器之间后再进入油管。虽然油箱中有滤清元件，但化油器中也有滤网。Unit 3Text The fuel filter used is generally a sediment bowl made of glass or metal and a strainer screenWhen the fu

15、el drawn from the tank passes through the filter (through the bowl and strainer screen)，particles of dirt and water settle in the bottom of the bowlIn certain vehicles，a separate filter either of the disk or ceramic type is usedIt is located either between the fuel pump and carburetor or in the fuel

16、 line 汽油滤清器一般是玻璃或金属制成的沉淀杯和滤清器滤网。当燃油从油箱中吸出经过滤清器(通过沉淀杯和滤清器滤网)时，污垢颗粒和水沉淀在沉淀杯的底部。在某些车辆中，有一个盘形的或陶瓷的独立滤清器。它位于汽油泵和化油器之间或油管线路之间。sedmnt沉淀物、沉积物、沉渣过滤器滤网Unit 3Text For connecting the fuel tank to the fuel pump，metallic tubes or synthetic rubber hoses called fuel lines are usedThey are usually positioned with me

17、tallic clips along the frame side membersThe tubing or fuel lines are also used to connect fuel pump to the carburetor。In order to absorb vibration as well as prevent breakage of the fuel lines，a short flexible line is used between the fuel pump and the tank 为了连接油箱和油泵，要使用称为油管的金属管或(人造)合成橡胶软管。它们通常用金属夹

18、沿着车架边梁布置。管子或油管也用于连接油泵和化油器。为了减震也为了防止油管损坏，在油泵和油箱之间采用一根短柔性软管。软管、胶皮管snetk/Unit 3Text In order to meter and caution the driver of the motor vehicle about the quantity of fuel consumed and left in the tank，a fuel gauge is usedIt is generally fitted on dashboard for easy reading of the fuelIt is usually a

19、balancing coil type having construction similar to that of an oil gaugeIt is generally electrically operated 燃油表用来衡量和提醒机动车驾驶员已经消耗的汽油量与油箱中燃油剩余量。燃油表通常安装在驾驶室仪表板上，便于读取燃油量。燃油表通常是平衡线圈式的，具有类似于机油表的结构。它通常是电控的。燃油表仪表板、仪表盘Unit 3Text 燃油表由装在油箱上的输出装置和装在仪表板上的有刻度表的接收装置组成。 输出装置由可控浮子恒温器或可变电阻组成。整个装置由一个浮子和伸到油箱中的浮子臂，装在油箱

20、上，油箱中油面变化改变浮子的位置。电阻值取决于浮子的位置，可变电阻阻值控制输出到仪表板上的接收装置的电流值。 The fuel meter consists of a sending unit mounted on the fuel tank and a receiving unit having a calibrated gauge mounted on the instrument panel A sending unit consists of a float controlled thermostat or variable resistorWith a float and the f

21、loat arm extending into the fuel tank on which the unit is mountedthe level of fuel in the tank varies the position of the floatThe amount of electrical resistance within the variable resistor for controlling the amount of current sent to receiving unit on the instrument panel is determined by the f

22、loat position:mstt温控、恆溫器Unit 3Text The receiving unit mounted on the dashboard indicates the amount of fuel in the tank on a calibrated gauge by the amount of current received from the sending unit On modem automobiles，two types of fuel gauges，thermostatic type and electromagnetic type，are used 装在仪表

23、板上的接受装置通过从输出装置接收到电流量，从而在刻度表上指示出油箱中的燃油量。 在现代汽车上，应用两种类型的燃油表：恒温器型和电磁型。:msttk温度调节装置的、恒温的lektrmgnetk仪表板、仪表盘电磁的Unit 3Text In order to prevent the rapid wear and tear of engine operating components causing reduced performance， air cleaner is fitted to the carburetor air intake，and it is mounted on the carb

24、uretor air-horn for trapping dirtBefore entering the carburetor，the air must pass through it 为了阻止发动机运行元件快速磨损，引起性能下降，在化油器空气进口处装有空气滤清器，它装在化油器进气喇叭口上以隔离污垢。在进入化油器之前，空气必须经过空气滤清器。磨损和破坏 Unit 3Text To reduce the noise produced by the air rushing into the carburetor，a silencing chamber is built into the air c

25、leanerIn case the engine misfires back through the carburetor，it acts as the flame arrestor There are in general three types of air cleaners used in modern automobilesThey are：(i)oil bath cleaner；(ii)oil-wetted mesh air cleaner；(iii)dry type air cleanerThe first two are also known as heavy duty air

26、cleaner while the third is known as light duty air cleaner阻火器; 阻焰器 静音舱 为了降低空气流经化油器产生的噪声，在空气滤清器里面安装有静音舱。一旦经化油器后发动机不发火，它就担当火焰清除器。 在现代汽车中一般应用三种类型的空气滤清器：（i）油浴滤清器；（ii）油润湿网空气滤清器；（iii）干式空气滤清器。前两个也被认为是重型空气滤清器，而第三个被认为是轻型空气滤清器。Unit 3Text Fuel pumps are the devices used to supply fuel from the fuel tank to the

27、 carburetorThere are in general two main types of fuel pumps used in automobilesThey are：(i)mechanical fuel pump；(ii)electric fuel pump 汽油泵是用于从油箱供油到化油器的装置。一般地，应用在汽车上有两种主要类型的油泵。它们是：(i)机械(驱动)式燃油泵；(ii)电动式燃油泵。Unit 3New words，phrases and expressions柴油机燃油供给系统Part B Diesel Engine Fuel SystemUnit 3Try to re

28、member themNew wordsUnit 3Try to remember themNew wordsUnit 3Phrases and expressionsTry to remember themfrnssi:tennzlUnit 3Text The type of fuel available for use in diesel engine varies from highly volatile jet fuels and kerosene, to the heavier furnace oil. Automotive engines are capable of burnin

29、g a wide range of fuel between these two extremes. How well a diesel engine can operate with different types of fuel is dependent upon engine operation conditions, as well as fuel characteristics.f:ns熔炉、火炉kersi:n煤油vltal不稳的、易挥发的kstri:mz极端 柴油机可用的燃油类型从高挥发性喷射燃油和煤油，到重型炉用燃油不等。汽车发动机燃油能在介于二者之间的很宽范围内燃烧。柴油机在不

30、同类型的燃油下运行良好程度依赖于发动机运行条件，也依赖于燃油性能。Unit 3Text Diesel fuel is a mixture of kerosene, gas oil and solar oil fractions obtained after distillation of gasoline fraction from petroleum. The main characteristics of diesel fuel are ignitability estimated in cetane numbers, viscosity, pour point, purity, etc.

31、 Diesel fuel is produced in different grades, such as summer fuel, winter fuel, arctic fuel, which differ mainly in the pour points, flashing points and viscosity values.si:ten十六烷pjrtivskst粘性、粘度kersi:nfrknz馏分dstlen升华、蒸馏凝固点、 倾点p:(r)粘度值 柴油机燃油是煤油、柴油和太阳油在从石油产品中蒸馏出汽油（馏分）后得到的馏分混合物。柴油机燃油的主要性能是用十六烷值评定的发火性、粘

32、度、倾点、纯度等。柴油机燃油分为不同等级，例如：夏季用油、冬季用油、北极地区用燃油，这些燃油主要在倾点、闪点和粘度值方面不同。Unit 3Text A diesel engine fuel system consists of a fuel tank, a primary filter, a secondary filter, a fuel supply pump with a hand primer, an injector pump with a speed governor and automatic injection timing clutch, nozzle holders wit

33、h nozzles, low-and high-pressure fuel linespram(r)手动注油器调速器nzl喷油器壳体 柴油机燃油供给系统由油箱，初级滤清器，次级滤清器，带手动注油装置的燃油供应泵，有调速器的喷油泵，自动喷油正时离合器，带喷油嘴的喷油器壳体和高、低压燃油管路组成。Unit 3Text During operation of the engine, the fuel supply pump draws fuel from the tank, forces it through the primary filter and delivers through the s

34、econdary filter to the injector pump. From the injector pump the fuel is fed through the high-pressure lines to the nozzles; the fuel atomized by the nozzles is injected into the cylinders according to the engine firing order. Surplus fuel is returned from the injector pump and nozzles to the fuel t

35、ank. The air is supplied to the cylinders through the air cleaner.tmazd将喷成雾状s:pls过剩的、多余的 在发动机运行过程中，燃油供油泵从油箱中吸出燃油，迫使燃油流经初级滤清器，经过次级滤清器到喷油泵。从喷油泵出来的燃油流经高压油路到喷油嘴；被喷油嘴雾化的燃油根据发动机点火顺序喷射到气缸里，喷油泵和喷油嘴中多余的燃油返回到油箱中。空气经空气滤清器供应到气缸中。Unit 3Text The fuel injector pump is intended to inject fuel under high pressure to

36、 the engine cylinders in a particular sequence. The injector pump is disposed between the cylinder banks and is driven from the camshaft by means of a gear train.特定的顺序ptkjl(r)处置、安排气缸 燃油喷油泵按精确的次序以一定的高压将燃油喷射到发动机气缸中。喷油泵置于气缸组之间，通过齿轮传动由凸轮轴驱动。Unit 3Text The rear end of the pump camshaft mounts an injectio

37、n timing clutch which is used to change the instant of fuel injection depending on the engine speed. A section of the injector pump consists of a plunger and a barrel, a roller tappet and a delivery valve.plnd(r)柱塞brl圆筒、活塞筒rultpit滚柱挺杆排气阀、出油阀 喷油泵凸轮轴的后端装有依据发动机速度改变燃油喷射时刻的喷油正时离合器。 喷油泵由柱塞、柱塞套、滚子式气门顶杆(滚柱挺

38、柱)和出油阀组成。Unit 3Text The fuel metering is controlled from the pedal in the drivers cab through a system of rods and levers acting upon the positive speed governor. The nozzle is used to inject metered quantities of fuel under pressure into the cylinders. All the units of the diesel fuel system are in

39、ter-connected by high-and low-pressure lines. The low pressure 1ines are made from transparent oil-gasoline resistant plastic tubing, while the high-pressure lines are made from thick-walled steel pipes.调速器相互连接的trnsprnt 油量调节机构根据全速调速器通过杠杆系统由驾驶室的踏板控制。 喷油嘴用于喷射定量的燃油，以一定压力喷射到气缸中。 所有的柴油机燃油系统元件（装置）由高、低压管路交

40、互连接。低压燃油管路由透明的耐油塑料管制造，而高压燃油管路由厚壁钢管制造。有抵抗力的Unit 3Text The automatic injection timing clutch serves to change the instance of fuel injection depending on the engine speed for improving engine starting conditions and economy at acceleration. 自动喷油正时离合器依据发动机速度改变燃油喷射时刻提高发动机起动状况（性能）和加速时经济性。Unit 3Text The i

41、njection timing clutch consists of a driving part and a driven part. The driven part is secured to the shank of the injector pump camshaft. The driving part runs freely on a hub of the driven part and is rotated from the timing gear through flexible couplings. Hinged on the pivots of the driven part

42、 are the weights urged to the initial position by two springs. When the engine speed increases, the centrifugal forces move the weights apart, the shaped lugs on the weights turn the driven half, hence the camshaft forward（along the direction of its rotation） thus advancing timing. When the engine s

43、peed decreases, the spring return the cams to the initial position so that driven part turns in the opposite to slow timing.k 钥匙柄、轮轴 有铰链的、铰接的sentrfju:gl 离心力指“滚轮” 自动喷油正时离合器由主动部分和从动部分组成。喷油泵凸轮轴驱动主动部分。从动部分在主动部分（轮）毂上自由转动，通过挠性联轴节由正时齿轮驱动旋转。铰接到从动部分枢轴上的物体由两个弹簧拉到原始位置。当发动机速度提高时，离心力使（受力）物体向外（分散），在物体上的滚轮带动从动部件运行

44、，因此凸轮轴向前（沿着凸轮轴旋转的方向）这样推进正时（就是加速）。当发动机速度下降时，弹簧使凸轮返回到初始位置从而从动部分反向运行，正时推迟（减速）。Unit 3New words，phrases and expressions汽油机与柴油机的不同点Part C Differences between Diesel and Gasoline EnginesUnit 3Try to remember themNew words, phrases and expressionsptrlimvkjumreiUnit 3Text Before we see how they differ, lets

45、see how they are alike. Both types of engines run on liquid fuels. Gasoline, kerosene and diesel oil are all produced from natural petroleum(crude oil), and fire distinguished mainly by their volatility. Gasoline is quite volatile, that is, it evaporates or vaporizes at a low temperature. Kerosene n

46、eeds more heat to make it vaporize, while diesel fuel requires still more heat. Both types of engines fire internal combustion engines, that is, they burn the fuel inside their cylinders. Most gasoline engines and many diesel engines work on the four-stroke cycle.vltltvpretveprazkersi:n蒸发、使挥发蒸发、使汽化p

47、trlim 在看它们的不同点之前，让我们看看它们的相同点。两种类型的发动机运行都需要液体燃油。汽油、煤油和柴油全都是由原油生产出来的，主要区别在于它们的挥发性。汽油易挥发，也就是在低温下就可以成为蒸气或蒸发。煤油需要更多的热量使其蒸发，而柴油需要比煤油更多的热量。两种类型的发动机都是内燃机，也就是它们在气缸中燃烧燃油。大多数的汽油机和许多柴油机是四冲程循环工作的。Unit 3Text What, then are the main differences between diesel and gasoline engines? A diesel engine has no distributo

48、r, spark plugs, or spark plug wires. The fuel is ignited by heat produced by compressing the air in the cylinders. For this reason, the diesel is called compression-ignition engine. One of the basic principles to diesel operation is that the temperature of compressed air will rise. The more air is c

49、ompressed，the higher will be its temperature. In this aspect, a diesel engine differs from a gasoline engine. To get the high temperatures needed to ignite the diesel fuel, higher compression ratios are needed. Diesel engines have compression ratios between 18:1 and 22:1. Modern gasoline engines hav

50、e a compression ratio of about 9:1. The higher compression ratio means that the diesel engine must be built stronger to withstand the high pressure. The high compression ratio also gives the diesel engine better fuel economy than the gasoline engine does. 那么柴油机和汽油机主要的不同点是什么呢? 柴油机无分电器、火花塞或火花塞线路。燃油被在气缸内压缩空气所产生的热量点燃。由于这个原因，柴油机被称为压燃式发动机。柴油机基本工作原理之一是压缩空气的温度会升高。空气越被压缩，温度将会越高。在这点上，柴油机也不同于汽油机。为取得更高的温度点燃柴油，需要更高的压缩比。柴油机压缩比在18:1到22:1之间。现代汽油机的压缩比大约为9:1。更高的压缩