1、Unit 1 Automotive BasicsAutomobiles, trucks, and buses are essential forms of transportation. They are complex machines made up of many parts. These parts can be grouped into a number of systems. An understanding of how the system work will help you understand how the automobile works.轎車、卡車和客車是交通運輸的

2、重要組成部分。它們都是由許多部件組成的復雜機器。這些部件可以歸類為汽車的幾個組成系統。了解這些各個小系統是如何工作的將有助于我們理解整個汽車系統是如何工作。An automobile can be divided into two basic parts: a body and a chassis. The body is the enclosure that houses the engine, passengers, and cargo. It is the part of the automobile that you see. The chassis is that part of t

3、he automobile beneath the body.汽車可以分為兩個基本部分：車身和底盤。車身包圍發動機、乘客和行李，它是汽車你所看到的部分。而車身以下的部分就是底盤。1.1 THE BODY An automobile body is a sheet metal shell with windows, doors, a hood, and a trunk deck built into it. It provides a protective covering for the engine, passengers, and cargo. The body is designed t

4、o keep passengers safe and comfortable. For example, insulation in the body reduces noise and protects against heat and cold. The body styling provides an attractive, colorful, modern appearance for the vehicle. It is streamlined to lessen wind resistance and to keep the car from swaying at driving

5、speeds.轎車車身是一個鈑金件殼體，它上面有車窗、車門、發送機罩和行李艙門等部件，它給發動機、乘客和行李提供防護。車身設計來確保乘客乘坐的安全和舒適。比如：車身絕熱層可以減少噪音和抵御冷熱。車身造型設計使得汽車有一個華美、現代、吸引人的外觀。車身的流線型設計可以減少風阻，防止汽車行馳過程中發生擺動。The automobile body has two basic parts-the upper body and the under body.車身有兩個基本部分-車身上部和車身下部。1.2 The chassis The chassis is an assembly of those sy

6、stems that are the major operating parts of a vehicle. The chassis includes everything except the body. The three important parts of the chassis are the frame, the engine, and the power train (also called the drive train). Each of these three parts is made up of a number of systems. A system is a me

7、chanical or electrical unit that performs a specific function. Thus, each system (such as steering, brake, or fuel) has a certain job to do in running a vehicle. We shall look at each of these parts and systems to see how they fit together to form the automobile chassis.底盤集中了汽車大部分的運動組件，它包括除了車身以外的所有部

8、件。底盤有三個重要的系統：車架、發動機和傳動系統。這三個系統又都有許多個完成某一個特定功能的機械或電氣系統組成。為了保證汽車正常運轉，每個系統（比如：轉向、制動或燃油系統）都要實現一定的功能。下來我們看看這些系統和組件是如何相互連接從而組成汽車底盤的。 The frame The first major part of the chassis is the frame. It is made from tough steel sections welded, riveted, or bolted together. The frame looks like a steel ladder, th

9、ough it sometime has an X shape for extra strength. It forms a foundation for the car body and the parts of the several systems. The body is joined to the frame with bolts. Rubber shock mounts or washers are used at each joint. These reduce vibration and road noise. In most modern cars the frame is

10、built into the body. A car with the frame built into the body has a unitized body or unibody. The frame supports the suspension system, steering system, and the braking system.底盤最重要的部分就是車架。車架由鋼件通過焊接、鉚接或螺栓聯接而成，看上去就像一架鋼梯。有時為了得到額外的強度，車架做成了X形狀。車架為車身和很多系統部件提供了底座。車身和車架使用螺栓聯接。每個聯接使用橡膠防震支架或墊圈來減振降噪。現代轎車車架和車身

11、做在了一起。采用這個形式的汽車車身叫做承載式車身。車架支撐懸架、轉向和剎車系統。The front and rear wheels are attached to the chassis by a suspension system. This system is made up of springs, shock absorbers, control arms, and stabilizers. These support the vehicle and cushion it from road bumps for better ride and handling.前后輪通過懸架系統和底盤相

12、連。懸架系統由彈簧、減振器、控制臂和橫向穩定桿組成。它們支撐著車身，并減緩由于路面不平引起的顛簸，以獲得更好的乘坐舒適性和操作穩定性。The steering system controls the cars direction of travel. It includes a wheel and column, steering gears, rods, and linkages. As the steering wheel is turned, its motion is transferred to the idler arm and tie rods. These cause the

13、front wheels to turn to the right of left. On some cars, a power unit (called power steering) makes steering easier.轉向系統控制車輛行馳的方向。它包括方向盤、轉向管柱、轉向器、轉向拉桿和轉向傳動裝置。當轉動方向盤，方向盤的運動被傳遞到隨動臂和橫拉桿，從而使得前輪向左或向右轉動。有些車輛使用助力轉向裝置，從而使得轉向更加輕便。The brake system gives the automobile its stopping power. Hydraulic brakes are

14、found on all modern cars. As the brake pedal is pushed with the foot, brake fluid is forced through brake lines into cylinders that press the brake shoes against a drum. This stops the motion of the car. Power units (power brakes) are used to make braking easier. Most modern cars have disc brakes on

15、 the front wheels. (Some have them on both the front and rear wheels.) Disc brakes work like a pair of pliers squeezing a rotating disc. Drum brakes are also used.制動系統給車輛制動的動力。現代轎車都使用液壓制動。當踩下制動踏板，制動液通過制動管路流入制動缸，強迫制動蹄接觸制動鼓，從而阻止車輛運動。為了使剎車更加輕便，車輛也使用助力制動。現代轎車在前輪裝備盤式制動器。（一些轎車在前后輪都使用盤式制動器。）盤式制動器工作原理類似一對鉗子

16、夾住旋轉的盤片。也有前后輪都使用鼓式制動器的汽車。 The engine The engine provides power to move the automobile. The most common type of automobile engine is the gasoline-burning piston engine. It is found in most automobiles. Diesel-fuel burning engines are also used in modern passenger cars, as well as in large trucks. All

17、 engines have fuel, exhaust, cooling, and lubrication systems. Gasoline engines also have an ignition system.發動機給汽車提供動力。最常見的發動機是汽油機。大多數汽車都使用它。現代客車和大型卡車使用柴油機。所有的發動機都具有燃油、排放、冷卻和潤滑系統。汽油發動機還有一套點火系統。The ignition system supplies the electric spark needed to ignite the air-fuel mixture in the cylinders. Wh

18、en the ignition switch is turned on, current flows from the 12-volt storage battery to the ignition coil. The coil boosts the voltage to produce the strong spark of 20,000V needed to ignite the engine fuel. The distributor directs the electrical current to the right spark plug at the right time. Die

19、sel engines use the heat caused by engine compression to ignite the fuel charge. These engines are called compression ignition engines.點火系統提供點燃氣缸內油氣混和物的電火花。當打開點火開關，電流從12V電池流向點火線圈。點火線圈升高電壓，產生用于點火的20000V尖峰電壓。分電器引導電流在正確的時刻流向正確的火花塞。柴油機使用壓縮發動機產生的熱量來點燃燃料，因此被稱為壓燃式發動機。The automobile supplies all the electri

20、city it needs through its electrical system. For example, the electrical system supplies electricity for the ignition, horn, lights, heater, and starter. The electricity level is maintained by a charging circuit. This circuit consists of the battery, alternator (or generator), and the regulator. The

21、 battery stores electricity. The alternator changes the engines mechanical energy into electrical energy and recharge the battery. The regulator prevents damage to the system by regulating the maximum voltage in the circuit汽車通過自身的電氣系統給自身供電。比如：電氣系統給點火系統、喇叭、燈光、供暖系統和起動器供電。系統電壓通過充電系統保持穩定。充電系統由電池、發電機和調節器

22、組成。電池儲存電能。發電機將發動機的機械能轉變為電能，并給電池充電。調節器調節電氣系統的最大電壓，提供過壓保護。The fuel system stores liquid fuel and delivers it to the engines. The fuel is stored in the tank, which is connected to a fuel pump by a fuel line. The fuel is pumped from the fuel tank through the fuel lines. It is forced through a filter (wh

23、ich removes moisture and dirt) into the carburetor, where it is mixed with air, or into the fuel injection system. The fuel is mixed with air to form a combustible mixture in the carburetor, the manifold, or the cylinders themselves.燃油系統儲存液態燃料，并且把燃料送至發動機。燃料儲存在通過油管與油泵連接的油箱里。油泵通過油管將油箱內的油泵出，并通過濾清器（去除濕氣

24、和雜污）送達化油器與空氣混合或者噴油系統。燃油在化油器、歧管或氣缸自身內與空氣混合，形成可燃混和物。The exhaust system has four jobs:1.To collect burned gases from the engines.2.To remove dangerous emission that pollutes the air.3.To reduce exhaust noises.4.To get rid of the exhaust gases.排放系統要實現四個功能：1、收集發動機的廢氣。2、去除污染空氣的排放物。3、減少排放噪音。4、排出廢氣。Exhaust

25、gases contain carbon monoxide, unburned hydrocarbons, and oxides of nitrogen. Since all of these are harmful, the exhaust system is designed to reduce them as much as possible. In the United Stares all modern automobiles have emission control systems.汽車廢氣包含一氧化碳，未燃燒的碳氫化合物和氮氧化合物。所有的這些都是有害的，排放系統設計要盡可能多

26、減少這些有害物質。美國所有的現代車都配備了排放系統。The cooling system removes excessive heat from the engine. The temperature in engine combustion chambers is about 1094°C. Since steel melts at around 1354°C, this heat must be carried away to prevent engine damage. Air and a coolant are used to carry away the heat

27、. The radiator is filled with a coolant. The water pump circuits this coolant through the engine and the walls of the engine block and head. Heat also is removed by the radiator fan, which draws air through the narrow fins of the radiator. This system also supplies heat to the passenger compartment

28、and the window defroster.冷卻系統去除發動機多余的熱量。發動機燃燒室的溫度可以達到1094攝氏度。鋼的熔點大約是1354攝氏度，發動機多余的熱量必須消除來防止發動機過熱。空氣和冷卻劑用來帶走這個熱量。散熱器內裝滿了冷卻劑。水泵使冷卻劑在發動機、發動機殼體和發動機蓋循環流動。也可以使用冷卻風扇來降溫。冷卻風扇將風從散熱器狹窄的孔徑吹出，從而帶走熱量。這個系統可以給乘客艙和車窗除霜器提供熱量。The lubrication system is important in keeping the engine running smoothly. Motor oil is the

29、 lubricant used in the system. The lubrication system has four functions:1.It cuts down friction by coating moving parts with oil.2.It produces a seal between the piton rings and the cylinder walls.3.It carries away sludge, dirt, and acids.4.It cools the engine by circulating the motor oil.潤滑系統非常重要，

30、它使得發動機平滑工作。潤滑系統使用機油作為潤滑劑。潤滑系統有四個功能：1、通過運動部件油膜，它可以減小摩擦。2、它在活塞環和氣缸壁之間產生油封。3、它可以帶走金屬碎屑、雜污和酸。4、通過機油的循環，它可以冷卻發動機。To keep this system working effectively, oil filters and motor oil must be change regularly. All other moving parts in an automobile must also be lubricated. These include the transmission, di

31、fferential, wheel bearings, and steering linkage.為了使得潤滑系統有效工作，機油濾清器和機油必須定期更換。汽車內所有的運動部件都必須要潤滑，這包括變速器、差速器、輪軸軸承和轉向傳動機構。 The power train The power train, or drive system, delivers power from the engine to the wheels. The power from the engine moves through the transmission. Transmissions are either sta

32、ndard, with a manual shift lever and foot clutch, or automatic.傳動系統將發動機動力傳給車輪。來自發動機的動力傳遞給變速器。變速器可以是一個帶手動換檔桿和離合器的手動變速器或者自動變速器。The transmission has gears that control the amount of power delivered to the wheels. The transmission increases the power (torque) to start the car moving. This torque is redu

33、ced when the transmission changes gears at higher speeds. The transmission also contains a set of gears that can reverse the direction of the wheels. The transmission delivers the power to the differential. A drive (or propeller) shaft with universal joints at either end of the drive shaft allows ax

34、le movement of front-engine, rear-wheel drive cars. These flexible universal joint prevent the drive shaft from breaking. The differential delivers power to the wheels through axle. Certain gears allow one wheel to turn faster than the other wheel when the vehicle is turning a corner.變速器使用齒輪來控制傳遞到車輪

35、力矩的大小。當車輛起步時，變速器增大扭矩。當車速增大，變速器改變齒輪來減小扭矩。變速器還有一套使得車輪反向運動的齒輪。變速器將扭矩傳遞給差速器。發動機前置后輪驅動轎車的驅動軸兩側裝有萬向節，可允許產生軸向運動。萬向節防止驅動軸斷裂。差速器通過半軸將扭矩傳遞給車輪。當車輛轉彎時，齒輪使得一側車輪比另一側車輪旋轉得更快。These are the basic systems of the automobile. Each of the systems is designed for a specific job.以上就是汽車的基本系統。每個系統都為了一個專門的功能而設計。1 ExercisesTh

36、e automobiles further development will be determined by already existing and steadily increasing requirements, by additional further requirements and by the technical possibilities for meeting these requirements. The following focal points for development and research efforts can be discerned: 汽車的進一

37、步發展取決于已經存在的、目前穩定增長和未來的需求以及為了滿足這些需求的技術。下來給出發展研究的幾個要點：Further improvements of the automobile through products innovation in all classis functions, i. e. performance, fuel economy, environmental impact, safety, comfort and reliability. Further development of new technologies such as electrics, alternat

38、ive materials, new test and production methods. Long-range solutions for traffic problems such as highway congestion, smog in cities and carbon dioxide enrichment of our atmosphere.傳統功能的產品革新，比如：性能、燃油經濟性、環境友好、安全、舒適性和可靠性。 新技術的發展，比如：電氣、替代材料、新型測試和生產技術。 解決交通問題的技術，比如：交通擁堵，城市煙霧和溫室效應。Unit2 Automotive engine

39、2.1 Purpose and locations of engines The purpose of an automobile engine is to supply the power needed to move the vehicle. The engine produces this power by burning fuel inside it. Because the engine burns fuel inside, or internally, the engine is known as an internal combustion engine (ICE).汽車發動機的

40、功用是提供汽車行馳所需的動力。發動機通過發動機內部燃燒燃料來產生這個動力。由于燃料燃燒在發動機內部進行，這種發動機被稱作內燃機。Most automobile engines are located at the front of the vehicle. Many engines drive the rear wheels. This requires a long drive shaft extending from the front wheels to the rear wheels. Other engines drive the front wheels. In the rear-

41、wheel-drive arrangement, the engine sits longitudinally. Its long dimension is from front to back.對于大多數汽車，發動機布置在汽車前部。許多發動機驅動后輪，這就要求從前輪到后輪的長驅動軸。其余發動機驅動前輪。對于后輪驅動的汽車而言，發動機由前到后縱向布置。In the front-wheel-drive arrangement, the engine sits crosswise, transversely. With either arrangement, the power is carrie

42、d to the drive wheels (rear or front) by gears and shafts.對于前輪驅動的布置，發動機橫置。無論哪種布置方式，能量都是通過齒輪和傳動軸傳到驅動輪（前輪或后輪）。Some cars have the engine mounted in back of the front seat. This is called a mid-engine arrangement. Other cars have been built with the engine mounted at the rear, in back of rear seat. The

43、Volkswagen “beettle” is an example of rear.有些汽車的發動機位于前排座椅的后面。這種布置被稱為發動機中置。還有些汽車的發動機位于后部，安置在后排座椅后面。大眾汽車的甲殼蟲就是發動機后置的一個例子。2.2 Engine types Various kinds of engine are used in automotive vehicles. The two major types are:The piston engine inwhich pistons move up and down, or reciprocate, in the engine c

44、ylinder. This is the engine used in all cares today, except for some models of Mazda.2. The Wankel rotary engine in which rotate, or spin. The Mazda Motor Corporation of Japan is the major manufacturer of this engine.汽車上使用著不同種類的發動機。它們可以分成兩大類：1、往復活塞式發動機：發動機在氣缸內作上下往復運動。除了馬自達公司的幾款以外，現今幾乎全部轎車都采用這種發動機。2、

45、轉子發動機：活塞在氣缸內作旋轉運動。日本的馬自達公司是這類發動機的主要生產商。There are two types of piston engines-spark ignition (SI) and compression ignition (CI). Spark-ignition engines use an electric system with spark plugs. Electric sparks at the spark plugs ignite, or set fire, the fuel in the engine cylinders. The combustion of

46、the fuel makes the engine run and produce power. This is the engine used in most produce power. This is the type of engine used in most automotive vehicles.活塞式發動機可以分為兩類：點燃式和壓燃式。點燃式發動機使用帶火花塞的點火系統。火花塞的電火花點燃發動機氣缸內的燃料。燃料燃燒驅動發動機，并做功。這是大多數動力源采用的發動機，也是大多數汽車采用的發動機形式。The compression-ignition engine uses the

47、heat of compression to ignite the fuel.When air is compressed, it gets very hot. In the diesel engine, the air is compressed so much that its temperature goes up to 538 degrees Celsius or higher. The diesel fuel is sprayed into this very hot air and is ignited by the heat. Some automobiles have dies

48、el engines. Many heavy-duty trucks and buses are powered by diesel engines.壓燃式發動機使用壓縮產生的熱量來點燃燃料。當空氣被壓縮，它可以達到非常高的溫度。對于柴油式發動機，壓縮空氣可以使得空氣溫度達到538度或者更高。此時，柴油被噴射到這熾熱的空氣中，被空氣的熱量點燃。一些轎車使用柴油發動機。重型卡車和客車普遍使用柴油發動機。There are other engines still in the experimental stage that might someday become important. These

49、 include gas-turbine engines, steam engines, Stirling engines, and electric motors.還有一些目前尚且處于試驗階段，但未來可能會非常重要的發動機，比如：燃氣渦輪機、蒸汽機、斯特靈發動機和電動機。2.3 Basic engine systems A spark-ignition engine requires four basic systems to run. Diesel engines requires three of these systems. They are fuel system, ignition

50、 system (expect diesel), lubricating system and cooling system. Each performs a basic job in making the engine run. These are described briefly below. 點燃式發動機運轉需要4個基本系統，而柴油發動機需要3個基本系統。它們是燃油系統、點火系統（柴油發動機不需要），潤滑系統和冷卻系統。每個系統實現一個基本功能來使得發動機運轉。下文將簡短介紹這些系統。 fuel system The fuel system supplies gasoline or d

51、iesel fuel to the engine. This fuel is mixed with air to make a combustible mixture (a mixture that will run). Each cylinder is repeatedly filled with the mixture. Then, the mixture is ignited or burned, producing high pressure. The high pressure makes the piston move (or rotors spin). This turns sh

52、afts that rotate the wheels, causing the vehicle to move. 燃油系統給發動機提供汽油或柴油燃料。燃油與空氣混合形成可燃混合氣。發動機的每個氣缸重復充滿這種可燃混合氣，然后它們被點燃或壓燃，產生高壓。這個高壓使得發動機活塞運動（或者轉子旋轉），驅動軸來旋轉車輪，從而使得汽車行駛。 ignition system Every time the fuel system delivers air/fuel mixture to a cylinder, the ignition system follows up by a delivering a

53、n electric spark. This ignite the mixture which creates the high pressure that moves the pistons and turns the car wheels. The action is repeated many times each second while the engine is running. 每當燃油系統將可燃混合氣送至氣缸，點火系統接著就發出電火花來點燃缸內的可燃混合氣，從而產生高壓，使得活塞運動和汽車行駛。當發動機運轉時，每秒鐘要點火多次。The ignite system takes t

54、he 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 that ignite the air/fuel mixture in the engine cylinders.點火系統將電池的低電壓升壓到高壓。對于某些系統，可以達到47000伏。這個高壓擊穿火花塞間隙，產生電火花，點燃發動

55、機氣缸內的可燃混合氣。 The lubricating system The engine has many moving metal parts. If metal parts rub against each other, they will wear rapidly.To prevent this, engines have lubricating oil. The oil gets between the metal parts so they slide on the oil, and not on each other. 發動機有許多運動金屬部件。如果這些金屬部件相互摩擦，那它們磨

56、損就會很快。為了防止這種情況，發動機使用潤滑油。潤滑油在金屬部件之間，使得金屬部件在油膜上滑動，而不是彼此之間的摩擦。The lubricating system has an oil pan at the bottom of the engine which holds several quarts (liters) of oil. An oil pump, driven by the engine, sends oil from this reservoir through the engine. After circulating through the engine, the oil

57、drops back to the oil pan. The oil pump continues to circulate the oil as long as the engine is running.發動機潤滑系統在發動機底部有一個儲存幾升汽油的油底殼。由發動機驅動的油泵將油從油底殼泵到發動機循環流動。在發動機循環后，潤滑油流回到油底殼。只要發動機在運轉，油泵就始終使潤滑油循環流動。 2.3.4 Cooling system Where there is fire (combustion), there is heat. Burning of the air/fuel mixture

58、raises the temperature inside the engine cylinders several thousand degrees. Some of this heat produces the high pressure that moves the pistons to produce power. Some of the heat leaves the cylinders with the exhaust gas. The exhaust gas is what is left after the air/fuel mixture burns. It is clear

59、ed out of the cylinders after the combustion is complete. 哪里有燃燒，哪里就有熱量。可燃混合氣的燃燒使得發動機氣缸內溫度上升數千度。部分熱量產生高壓來驅動活塞產生動力。部分熱量伴隨排放氣體被帶出氣缸。排放氣體指的是可燃混合氣燃燒后剩余物。當燃燒結束，排放氣體被排出氣缸。Some of the heat is removed by the circulating oil. After the hot oil drops down into the oil pan, the oil gives up some of this heat to the air passing under the oil pan. The rest of the heat