UNIT 3 FUEL INJECTION SYSTEMS TEXT A Electronic Fuel Injection SystemsPROFESSIONAL ENGLISHUNIT 3 FUEL INJECTION SYSTEMSTEXT A Electronic Fuel Injection Systems Pulse Fuel Injection Pulse Fuel Injection System Components Air induction system Fuel delivery system Engine control computer Electronic Sensors Continuous Injection Systems(CIS)本次课学习内容本次课学习目标l掌握电控燃油喷射系统主要部件的英文名称、主要部件的作用及工作原理l掌握常用术语（phrases and expressions）l了解相关术语（related terms）l提高翻译能力NEW WORDSmanifoldmnifouldn.歧管歧管manipulatemnipjuleitv.操纵，控制，支配操纵，控制，支配venturiventu:rin.文丘里管，喉管文丘里管，喉管driveabilitydraivbilitin.运行性能，操纵性能运行性能，操纵性能laglgn.滞后，迟后，惯性，惰性滞后，迟后，惯性，惰性turbochargert:bout:n.涡轮增压器，增压器涡轮增压器，增压器compressorkmpresn.压压气气机机，压压缩缩机机，压压缩缩装装置置sensorsensn.传感器传感器passagewaypsiwein.通路通路Psi=poundpersquareinch磅力磅力/平方英寸（平方英寸（lbf/in2）injectorinektn.喷油器，注射器喷油器，注射器NEW WORDScircuits:kitn.电（气，油，回）路电（气，油，回）路complexitykmpleksitin.复杂性复杂性plugplgn.塞子，堵头，插头塞子，堵头，插头energizeenaizv.通电，励磁通电，励磁distributordistribjutn.分配器，分电器分配器，分电器throttlertln.节气门节气门relayrilei,ri:lein.继继电电器器，转转播播；v.中中继继，转播转播barometricbroumetrikn.大气压力的大气压力的vortexv:teksn.涡流，涡旋，旋风涡流，涡旋，旋风distinctlydistiktliad.显然，清楚地，明明显然，清楚地，明明spawnsp:nv.产卵产卵PHRASES AND EXPRESSIONSpulsefuelinjection脉冲燃油喷射脉冲燃油喷射continuousfuelinjection连续燃油喷射连续燃油喷射throttlebodyinjection节气门体喷射节气门体喷射single-pointinjection单点喷射单点喷射centralfuelinjection中央喷射中央喷射multi-pointsystems多点喷射多点喷射multi-portinjection多点喷射多点喷射tunedintakerunners调谐进气管调谐进气管intakemanifold进气歧管进气歧管airinductionsystem进气系统进气系统PHRASES AND EXPRESSIONSfueldeliverysystem供油系统供油系统aircleaner空气滤清器空气滤清器electricfuelpump电动燃油泵电动燃油泵pressureregulator压力调节器压力调节器fuelinletline进油管进油管fueltank燃油箱燃油箱fuelinjector喷油器喷油器fuelrail燃油分配管，油轨燃油分配管，油轨ignitioncoil点火线圈点火线圈Hall-effectswitch霍尔效应开关霍尔效应开关barometricpressure大气压力大气压力PHRASES AND EXPRESSIONSheatedwire热线式热线式airvalve空气阀式（空气阀式（=vanetype叶片式）叶片式）Karmannvortex卡曼涡旋式卡曼涡旋式Fuel injection systems deliver fuel by forcing it into the incoming air stream（Fig.3-1）.Fuel injection systems actually measure the incoming air and pressurize the fuel to deliver it in precise amounts based directly on that measurement.Because fuel is delivered to the manifold under pressure,the quantity of fuel delivered can be more positively controlled.With this more positive control,fuel delivery can be more easily manipulated to meet the unique demands of extreme operating conditions.This results in greater efficiency over a wider range of operation.Electronic Fuel InjectionElectronic Fuel Injection In the electronic injection system,the air-fuel mixture is controlled in one of two ways.The injector may be opened and closed by electrical signals.This is a pulse fuel injection system.In the other type of system,the injector is forced open by fuel pressure.Fuel pressure is controlled by an electronic control device,or by an airflow metering valve,depending on the system.This is the continuous fuel injection system.Electronic Fuel InjectionFig.3-1 Fuel injector is mounted on the intake manifoldElectronic Fuel Injection 1.Pulse Fuel Injection In pulse injection systems,the rate of fuel flow through the injectors remains constant.The total amount of fuel delivered is determined by the length of time the injectors are held open.Systems are classified by the type of timing sequence used and the location of the injectors.Types of Pulse Fuel Injection Systems The next section will discuss common fuel injection systems which are typical of the pulse systems now in use.The pulse injection system is usually electronically controlled.Although there are a number of design differences between various pulse fuel injection systems,the operating principles are very similar.Electronic Fuel Injection The throttle body injection system uses an assembly containing one or two fuel injectors.The assembly is mounted at the entrance to the intake manifold and injects fuel ahead of the throttle valve.These systems are also called single-point injection or central fuel injection.Multi-point systems,also called multi-port injection systems,deliver fuel at the engine intake ports near the intake valves.This means that the intake manifold delivers only air,in contrast to carburetors or single-point fuel injection systems in which the intake manifold carries the air-fuel mixture 1.As a result,these systems offer the following advantages:Electronic Fuel Injection greater power by avoiding venturi losses as in a carburetor,and by allowing the use of tuned intake runners for better torque characteristics improved driveability by reducing the throttle-change lag which occurs while the fuel travels from the throttle body to the intake ports 2 increased fuel economy by avoiding condensation of fuel on interior walls of the intake manifold(manifold wetting)simplified turbocharger applications;the turbocharger compressor need only handle air.Pulse Fuel Injection System Components The typical pulse system can be broken into three basic parts:Air induction system.Fuel delivery system.Electronic control system(including engine control computer and electroni