UNIT 5 FUEL INJECTION SYSTEM燃油喷射系统Fuel injection systems have been used on vehicles for many years. The earliest ones were purely mechanical. As technology advanced, electronic fuel injection systems became more popular. Early mechanical and electronic fuel injection systems did not use feedback controls. As emissions became more of a concern, feedback controls were adapted to both types of fuel injection systems.feedback control 反馈控制As emissions became more of a concern 随着排放越来越受到关注were adapted to 被应用于Both mechanical and electronic fuel injection systems can be found on gasoline engines. Diesel engines are most commonly found with mechanical type systems, although the newest generations of these engines have been using electronic fuel injection(EFI) .gasoline engines 汽油发动机diesel engines 柴油发动机newest generations of 最新的5.1 Basic TheoryEFI uses solenoid valves called injectors to meter fuel delivery. Most vehicles today use 1 injector per cylinder. When the solenoid is energized, fuel sprays out into the valve port. Fuel is delivered to the injector by a high-pressure electric pump at around 40 psi. Fuel delivery is controlled by the injectors which are cycled by the computer. The computer produces a signal to open the injectors for a certain length of time depending on engine conditions relayed by sensors. The longer that the injector is open, the more fuel is injected. As engine load and rpm are increased, the injector open times are increased to match increasing airflow. This computer output signal is called the injector pulse width. The longer the pulse width, the more fuel is injected.solenoid valves 电磁阀injector 喷油嘴，喷油器，喷射器fuel delivery 燃油输送，燃油供给is energized v. 使通电,供能, 激发，加强adj. 通电的，激励的,增能的energized line 带电电路，带电线路valve port 阀口，喷油嘴psi [psai] 每平方英寸….磅=pounds per square inchare cycled by 周期性控制engine conditions relayed by sensors 传感器传送/输送回来的信号体现的发动机工作状况，简单的说，即：传感器信号体现的发动机工作状况injector pulse width 喷油器脉冲宽度5.3 Fuel System5.4 Air Metering and Measurement5.5 Most EFI systems measure the same basic 6 inputRPMAirflow空气流量Manifold Pressure 歧管压力On speed density type systems, this input is essential when combined with the rpm signal to calculate airflow. As the throttle is opened, the manifold pressure increases which will require more fuel.speed density type system “速度-密度”类型的系统，即：采用“速度-密度”方法来测量空气流量的系统Throttle Position 节气门位置This input is a secondary input on most systems. It is required mainly for acceleration enrichment when the throttle is rapidly opened. By looking at the rate of change of throttle blade angle, the computer can determine how quickly the throttle is being opened and can supply the extra fuel required momentarily to alleviate the lean condition. Throttle position is measured by a potentiometer attached to the throttle shaft.acceleration enrichment 加速加浓，即：汽车加速时的混合气加浓looking at the rate of change of throttle blade angle 查看节气门叶片转角的变化速率determine 确定momentarily ['məuməntərili] adv. 即刻，随时地，暂时地,立刻alleviate [ə'li:vieit] v. 减轻,使...缓和，使（痛苦等）易于忍受alleviate burdens 减负lean condition 稀混合气工况←←→→rich condition 浓混合气工况potentiometer [pə,tēnʃi'ɔmitə] 电位计,分压计，电位器，电势计Water TemperatureAir Temperature5.6 Oxygen Sensor 氧传感器This sensor is employed in closed loop systems to modify the basic pulse width after the fact. It is mounted into the exhaust manifold area. By looking at the oxygen content of the exhaust gasses after combustion, the computer can determine if the air/fuel ratio is too rich or too lean for optimum combustion and adjust the next few injections accordingly. This sensor is primarily employed for emission control and to a lesser degree, fuel economy. For the lowest average emissions, the air/fuel ratio must be kept around 14.7 to 1.is employed in 应用于，忙于，从事于closed loop systems 闭环控制系统modify the basic pulse width after the fact 事后调节基本脉冲宽度oxygen content 氧含量combustion 燃烧the next few injections 接下来的/后面的一些喷油(脉宽)emission control 排放控制to a lesser degree 在更轻的程度上，其次Under full throttle conditions, this sensor input is ignored by the computer so that the engine can produce more power. This is called open loop mode and the computer is supplying the injector pulse width from tables based on all of the other sensor inputs. Once throttle opening and rpm are reduced to cruising conditions, most systems will jump back into the closed loop mode where they will stay for a large portion of the time on most street driven applications.full throttle conditions 节气门全开的情况/工况open loop mode 开环控制模式supplying the injector pulse width from tables based on all of the other sensor inputs 根据（除了氧传感器之外的）其它所有的传感器输入信号得到的（喷油）数据表来提供喷油器脉宽cruising conditions 巡航工况street driven applications 街道驾驶应用，意译即：街道行驶情况5.7 Basic OperationAs explained in the Basic Theory section, the computer processes all of the voltage signals from the various sensors to determine the engine operating conditions at the moment and delivers the appropriate pulse width to the injectors. If engine airflow increases by 10%, the pulse width is also increased by about 10% to keep theair/fuel ratio constant. If the rpm is doubled from 2,000 to 4,000 rpm, the numbers of injections are also doubled to double the fuel flow.The computer looks at the changes in sensor inputs every few milliseconds in order to be ready to modify the pulse width if any parameter changes.Section 章节，部分at the moment 此刻,目前，现在at the right moment 适时appropriate [ə'prəuprī:ət] adj. 适当的v. 拨出（款项）(某目的)之用constant ['kɔnstənt] adj. 恒定的, 经常的,不变的，持久的n. 常数,恒量every few milliseconds 每隔几毫秒parameter [pə'ræmītə] n. 参数,参量NEW WORDS1. feedback 反馈2. injector 喷油嘴，注射者,注射器,喷射给水器3. sensor7. alleviate减轻,使...缓和8. momentarily 即刻，立刻, 随时地，暂时地PHRASES AND EXPRESSIONS1. electric pump 电动泵2. pulse width 脉冲宽度3. fuel rail 油轨4. return line 回油路5. fuel pressure regulator燃油压力调节器6. throttle body assembly节气门体总成8. measure off测量出9. hall effect sensor 霍尔效应传感器10. taper off使渐渐减少, 逐渐停止，使渐渐变尖,一头逐渐变细UNIT 6 EXHAUST SYSTEM排放系统The exhaust system carries exhaust gases from the engine’s combustion chamber to the atmo sphere and reduces, or muffles, engine noise. Exhaust gases leave the engine in a pipe, traveling through a catalytic converter and a muffler before exiting through the tailpipe.exhaust gases 废气combustion chamber 燃烧室muffle 抑制,发低沉的声音n. 低沉的声音,消音器catalytic converter 催化转化器muffler 消声器，围巾,头巾,厚手套tailpipe ['teilpaip] 排气尾管，尾管，尾喷管,排气管,吸管perforated tailpipe带眼尾管6.1 The TailpipeThe tailpipe is a long metal tube attached to the muffler. It sticks out from under the body of a car, at the rear, in order to discharge the exhaust gases from the muffler of the engine into the air outside the car.stick out 突出,伸出，显眼，坚持到底stick it out 坚持到底，顶住，忍耐到底6.2 The Muffler6.3 The Exhaust Manifold and Header排气歧管和集气管6.4 The Manifold to Exhaust Pipe Gasketsgasket['gæskit] n. 衬垫,垫圈，垫片，密合墊，橡胶垫6.5 Exhaust Pipe Hangers 吊耳6.6 Exhaust Pipe6.7 Dual Exhaust System 双排气系统The advantage of a dual exhaust system is that the engine exhausts more freely, thereby lowering the backpressure, which is inherent in an exhaust system. With a dual exhaust system, a sizable increase in engine horsepower can be obtained because the “breathing” capacity of the engine is improved, leaving less exhaust gases in the engine at the end of each exhaust stroke. This, in turn, leaves more room for an extra intake of the air-fuel mixture.inherent [īn'hiərənt] adj. 内在的,固有的，生来的，先天的sizable ['saizəbl] 相当大的，大的，可调大小的breathing capacity 呼吸能力，即：汽车的进气排气性能exhaust stroke 排气冲程NEW WORDS1. tremendous3. muffler4. tailpipe5. hanger6. manifold7. fiberglass ['faibəglɑ:s] 玻璃纤维，纤维玻璃，玻璃丝8. speaker扬声器9. header 集气管12. flat13. socket ['sɔkit] n. 插座,插口antenna socket 天线插座plug socket 插座，电源插座，安全阀、突开阀14. sizable16. bump 撞击, 碰撞, 颠簸而行n. 撞击,隆起物PHARSES AND EXPRESSIONS1. stick out2. the body of a car 车身3. cast iron铸铁4. catalytic converter5 . out of phase with adj. 与...有相位差，与...不同相6. collide with vt. 碰撞，互撞，和...抵触/冲突7. cancel out相互抵销,消除,抵偿,取消8. backpressureReading material: Emission Control Systems排放控制系统The purpose of the emission control system is just that it controls the emissions and exhaust from a vehicle. The idea is to turn the harmful gases a car manufactures into harmless ones that don't ruin the environment, or persons. Some of the problem gases are:1. hydrocarbons ( unburned ) .2. carbon monoxide. 一氧化碳3. carbon dioxide. 二氧化碳4. nitrogen oxides. 氮氧化合物5. sulfur dioxide. 二氧化硫6. phosphorus. ['fɔsfərəs] n. 磷7. lead and other metals.emissions and exhaust 排放和废气manufacture 在这里指“产生，导致”，=cause, producehydrocarbon ['haidrəu'kɑ:bən] n. 碳氢化合物，经常缩写成HClead [li:d] n. 铅,领引,榜样v. 引导,带领lead to 导致，引起，通向lead rail 导轨Crankcase Ventilation Systems曲轴箱强制通风系统Evaporative Emission Control System （燃油的）蒸发/挥发污染控制系统Air Injection System空气引入系统Exhaust Gas Re-Circulation (Egr) Systems废气再循环系统Catalytic Converter 催化转化器NEW WORDS1. hydrocarbon2. phosphorus3. contaminate [kən'tæmineit] v. 弄脏, 污染，沾污4. sludge [slʌdʒ] n. 泥,泥泞，污泥，淤泥，渣滓,泥状雪sludge pump 污泥泵，泥浆泵，电动泥浆泵sewage sludge 污水污泥，污水软泥，污泥5. byproduct 副产品6. cross-section n. 截痕，横截面，剖面，河流汇合处seismic cross-section 地震剖面constant cross-section 恒定截面PHRASES AND EXPRESSIONS1. sulfur dioxide2. carbon monoxide3. nitrogen oxides4. Exhaust Gas Re-circulation (EGR)5. tend to vt. 倾向于, 常常，易于,势必；有助于,引起,造成6. carburetor bowl （发动机的）化油器/汽化器的油杯7. charcoal canister木炭罐，活性碳罐charcoal canister purge 碳罐清除，活性碳罐净化10. diverter valve 换向阀，转换阀，分流阀，导流阀，偏向型元件11. as a result12. stepper motor 步进电机13. PCV = positive crankcase ventilation 强制曲轴箱通风UNIT 7 THE IGNITION SYSTEM点火系统There are many different types of ignition systems. Most of these systems can be placed into one of threedistinct groups: the conventional breaker point type ignition systems (in use since the early 1,900s); the electronic ignition systems (popular since the mid 70s) ; and the distributorless ignition system (introduced in the mid 80s).The automotive ignition system has two basic functions: it must control the spark and timing of the spark plug firing to match varying engine requirements, and it must increase battery voltage to a point where it will overcome the resistance offered by the spark plug gap and fire the plug.be placed into 分成，归结为conventional breaker point type ignition systems 传统的触点式点火系统electronic ignition systems 电子点火系统distributorless ignition system 无分电器点火系统introduced 引入，开始采用spark 火花timing of the spark plug firing 火花塞点火的定时varying 变化的battery voltage 蓄电池电压resistance （火花塞间隙的）阻力spark plug gap 火花塞间隙7.1 Point-Type Ignition System7.2 Electronic Ignition Systems7.3 Distributorless Ignition Systems (DIS)The third type of ignition system is the distributorless ignition. The spark plugs are fired directly from the coils. The spark timing is controlled by an Ignition Control Unit (ICU) and the Engine Control Unit (ECU). The distributorless ignition system may have one coil per cylinder, or one coil for each pair of cylinders.are fired 被点火coils （点火）线圈spark timing 火花定时，即：火花塞点火的时刻Ignition Control Unit (ICU) 点火控制单元cylinder ['sīlində] 汽缸,圆筒,圆柱体，汽缸套Some popular systems use one ignition coil per two cylinders. This type of system is often known as the waste spark distribution method. In this system, each cylinder is paired with the cylinder opposite it in the firing order (usually 1-4, 2-3 on 4-cylinder engines or 1-4, 2-5, 3-6 on V6 engines, Figure 7-4). The ends of each coil secondary leads are attached to spark plugs for the paired opposites. These two plugs are on companion cylinders, cylinders that are at Top Dead Center (TDC) at the same time. But, they are paired opposites, because they are always at opposing ends of the 4-stroke engine cycle. When one is at TDC of the compression stroke, the other is at TDC of the exhaust stroke. The one that is on compression is said to be the event cylinder and one on the exhaust stroke, the waste cylinder. When the coil discharges, both plugs fire at the same time to complete the series circuit.waste 荒芜[废]的, 荒凉的，废弃的, 无用的, 多余的; 排泄的，[喻]贫乏的; 单调的waste spark distribution method 多余的火花分配方法，即：有一气缸是无用的火花点火方法In this system, each cylinder is paired with the cylinder opposite it in the firing order (usually 1-4, 2-3 on4-cylinder engines or 1-4, 2-5, 3-6 on V6 engines, Figure 7-4). 在这种系统中，每一汽缸按照点火顺序与和它相对的/相反的那一汽缸配对使用（这配对使用是指成对同时点火），在四缸发动机中点火顺序通常是1、4缸配对先点火, 2、3缸配对后点火，或者在V型六缸发动机中，通常是1、4缸配对先点火, 其次是2、5缸配对点火, 最后是3、6配对点火，如图7-4coil secondary leads 点火线圈次级导线paired opposite 配对的相反的那一缸companion 成对的Top Dead Center (TDC) 上死点，上止点opposing ends 相反的那一端4-stroke engine cycle 四冲程发动机的循环周期compression stroke 压缩冲程exhaust stroke 排气冲程event cylinder 做功的气缸waste cylinder 不做功的气缸discharge 放电series circuit 串联电路The advantages of no distributor, in theory, are:1. No timing adjustments. 定时调节2. No distributor cap and rotor. 分电器盖和分火头3. No moving parts to wear out. 磨损4. No distributor to accumulate moisture and cause starting problems.5. No distributor to drive thus providing less engine drag.distributor [dīs'tribj utə] 分电器,分油盘，发行人，经销商，分销商exclusive distributor 独家经销商，特约经销，总代理in theory 理论上讲accumulate 积聚/积累moisture 水分/湿气drag 拖拽，拉NEW WORDS1. distributor2. condenser [kən'dēnsə] 电容器，凝结器,凝缩器,冷却器air condenser 空气冷凝器3. wear 磨损4. saturation [,sætʃə'rēiʃən] 饱和，浸湿, 浸透5. series 串联6. wind 绕组7. coil 线圈8. transformer 变压器9. turn 圈10. term 名词，（专业/专门）术语；期限，任期；学期；条件，条款PHRASES AND EXPRESSIONS1. breaker point type ignition system2. distributorless ignition system3. primary and secondary circuits （点火线圈的）初级和次级电路4. magnetic field 磁场5. high tension lead 高压导线7. spark plug8. nothing more than 仅仅，只不过是9. (be) different thanReading material: Basics of Engine Management发动机管理系统的基础Modern engine management systems (EMS) do a fine job of ensuring that engines run cleanly and efficiently in a wide variety of conditions, they are for the most part reliable and require little or no maintenance. The two basic functions performed by an EMS are as follows:1. To meter fuel to the engine in the right quantity.2. To provide a spark at the right time.in a wide variety of conditions （发动机的）各种工况part reliable 零部件的可靠性require little or no maintenance 几乎不需要维修Timing adjustmentsEngine temperatureAir temperatureKnock sensing爆震感应Start-up or cranking启动NEW WORDS1. prevailing [pri'věiliŋ]最普通的,一般的, 流行的，占主导地位的，占优势的prevailing price 当时价格，现价，现行价格4. telemetry [ti'lemitri] 遥测（法），遥感勘测, 自动测量记录传导5. relay ['ri:lei] vt. 中继，用继电器控制,接替n. 继电器，转播,备用品,替班人，接力，中继current relay 电流继电器time relay 时间继电器，延时6. acoustic [ə'ku:stik] 声的，声学的，美声的，听觉的, 音感教育, 音响学的7. figure 图，图解，图案；数字；轮廓，身体，身影，身材….PHRASES AND EXPRESSIONS1. little or no2. as follows 如下，如后面3. according to4. boil down toboil down to 简化为，归结为，归结起来是，（凡此种种）意味着6. the moment 一….就…，此刻，那时UNIT 8 CLUTCH离合器The engine produces the power to drive the vehicle. The drive line or drive train transfers the power of the engine to the wheels. The drive train consists of the parts from the back of the flywheel to the wheels. These parts include the clutch, the transmission, the drive shaft, and the final drive assembly (Figure 8-1).The clutch which includes the flywheel, clutch disc, pressure plate, springs, pressure plate cover and the linkage necessary to operate the clutch is a rotating mechanism between the engine and the transmission (Figure 8-2). It operates through friction which comes from contact between the parts. That is the reason why the clutch is called a friction mechanism. After engagement, the clutch must continue to transmit all the engine torque to the transmission depending on the friction without slippage. The clutch is also used to disengage the engine from the drive train whenever the gears in the transmission are being shifted from one gear ratio to another.drive line or drive train 传动系transmission 变速器，变速箱drive shaft 传动轴final drive assembly 末端传动总成flywheel 飞轮clutch disc 离合器盘，即：离合器从动盘pressure plate 压盘pressure plate cover 压盘盖linkage 操纵杆系friction 摩擦engagement 结合disengage the engine from….将发动机从…..分离gear ratio 齿轮齿数比，齿数比，齿轮比，即：传动比steering gear angle ratio 转向器角传动比gear reduction ratio 齿轮减速比being shifted from one gear ratio to another. 从一个传动比变化到另一传动比，即：发动机从一个档换到另一个档The advantages of a diaphragm type pressure plate assembly are its compactness, lower weight, fewer moving parts, less effort to engage, reduces rotational imbalance by providing a balanced force around the pressure plate and less chances of clutch slippage.diaphragm type pressure plate assembly 膜片式压盘总成compactness 结构紧凑effort ['ēfət] 努力，施力, 努力的成果，效能less effort to engage 结合更省力NEW WORDS1. clutch2. flywheel3. stationary ['steiʃ(ə)nəri] 不动的，稳定的，静止的n. 固定物，驻军4. torsional ['tɔ:ʃənəl] 扭力的,扭转的，扭转的5. crankshaft 曲轴6. stall 停止，停转，失速7. mount8. groove 槽9. lever ['li:və, 'levə] 杠杆，杆，似杠杆之工具，手段v. 撬开,使用杠杆10. pivot ['pivət] 在枢轴上转动, 旋转n. 旋转轴，支点, 枢, 枢轴, 中枢11. gearbox ['giəbɔks] 齿轮箱, 变速箱，减速器，传动箱12. retract 退回，拉回，缩进，收回，取消13. compactnessPHRASES AND EXPRESSIONS1. drive train2. drive shaft3. pressure plate4. clutch disc5. gear ratio6. release bearing 分离轴承7. release fork 分离叉8. master cylinder （液压缸的）主缸9. clutch pedal 离合器踏板10. coupling device 接合装置11. at idle 在怠速时12. couple with 与….接合13. ring gear 齿圈14. pinion gear 小齿轮15. splined hub 花键毂16. cast iron 铸铁17. diaphragm spring 膜片弹簧19. engage with 与….啮合/接合20. centrifugal force 离心力Reading material: Torque Converter液力变矩器，转矩变换器，变矩器The BasicsJust like manual transmission cars, cars with automatic transmissions need a way to let the engine turn while the wheels and gears in the transmission come to a stop. Manual transmission cars use a clutch, which completely disconnects the engine from the transmission. Automatic transmission cars use a torque converter.manual transmission 手动变速器automatic transmissions 自动变速器come to a stop 停止disconnect the engine from the transmission 将变速器动力和发动机断开A torque converter is a type of fluid coupling, which allows the engine to spin somewhat independently of the transmission. If the engine is turning slowly, such as when the car is idling at a stoplight, the amount of torque passed through the torque converter is very small, so keeping the car still requires only a light pressure on the brake pedal.fluid coupling 液力连接/耦合spin somewhat independently of 一定程度上独立于….旋转stoplight 刹车灯，停止灯，红色尾灯，停止前进的信号灯still 静止的，不动的Inside a Torque ConverterThere are four components inside the very strong housing of the torque converter:1. Pump. 泵2. Turbine. 涡轮3. Stator. 定子，即：导轮4. Transmission fluid. 变速器流体Benefits and Weak Points优点和不足In addition to the very important job of allowing a car come to a complete stop without stalling the engine; the torque converter actually gives the car more torque when you accelerate out of a stop. Modern torque converters can multiply the torque of the engine by two to three times. This effect only happens when the engine is turning much faster than the transmission.job 作用，功用stalling 停转，停止，卡住，失速accelerate out of a stop 从静止加速multiply ['mʌltiplai] v. 增加，扩大, 乘, 繁殖adv.多样地,多倍地,多重地At higher speeds, the transmission catches up to the engine, eventually moving at almost the same speed. Ideally, though, the transmission would move at exactly the same speed as the engine, because this difference in speed wastes power. This is part of the reason why cars with automatic transmissions get worse gas mileage thancars with manual transmissions.catche up to 赶上，= catche up withthis difference in speed wastes power 这速差的存在要浪费功率get worse gas mileage 燃油行驶里程变得更差，即：燃油经济性变差To counter this effect, some cars have a torque converter with a lockup clutch. When the two halves of the torque converter get up to speed, this clutch locks them together, eliminating the slippage and improving efficiency.to counter this effect 为了抵消这一作用/效果/影响lockup clutch 锁止离合器two halves of ….的两部分get up to speed 加速eliminating the slippage 消除/排除打滑，即：通过将泵论和涡轮两部分锁死成一体来达到消除速差，这样可以避免了wasting powerNEW WORDS1. pump 泵轮2. turbine 涡轮3. stator 导轮5. tricky 复杂的，狡猾的，机警的6. hinder 阻止，阻碍7. stall 使停转8. counter 抵消PHRASES AND EXPRESSIONS1. torque converter2. gas pedal 油门踏板3. one-way clutch 单向离合器4. gas mileage 燃油行驶里程5 . get up to 赶上，追上，达到。