汽车专业英语(黄立新)第二部分4章

背景知识,生词,Unit4FuelSystem,译文及评析,背景知识,燃油喷射系统是指在一定的压力下，利用喷油器将一定数量的燃料直接喷入气缸或进气道内的燃油供给装置。根据喷射燃料种类的不同，可以分为汽油喷射系统、柴油喷射系统、气体燃料喷射系统等。而根据其控制方式的不同，可分为机械控制式、电子控制式以及机电混合控制式。,生词,carburetorn.化油器injectionn.喷射；注射supplyv.供给，补给combustibleadj.易燃的injectorn.喷油器contaminantn.污染物；致污物subsystemn.子系统；次要系统sensorn.传感器hosen.软管presetadj.预先装置的；预先调整的energizevt.供给能量springn.弹簧currentn.(水，气，电)流coiln.卷；线圈solenoidn.螺线管；螺线形电导管magneticadj.有磁性的armaturen.(电机的)转子，电枢squirtv.注射；喷射throttlen.节流阀pedaln.踏板depressvt.压低circuitn.电路resistancen.抵抗；抵抗力；反抗；电阻；阻力voltagen.电电压,译文及评析,Thefunctionofboththecarburetorfuelsystemandthefuelinjectionsystemistosupplyacombustiblemixtureofairandfueltotheengine.Agasolinefuelsystemdrawsfuelfromthetankandforcesitintothefuel-meteringdevice(carburetor,gasolineinjectors),usingeitheramechanical(engine-driven)orelectricfuelpump.Thebasicpartsofafuelsupplysystemincludethefollowing:FuelTank:storesgasoline.FuelPump:drawsfuelfromthetankandforcesittothefuel-meteringdevice.FuelFilter:removescontaminantsinthefuel.FuelLine:carriesfuelbetweenthetank,thepump,andotherparts.,过了一会，小男孩不哭了，睁开眼睛，用询问的目光看着越南护士。,柴油机供给系统和汽油机供给系统的主要功用都是将燃油或者油气混合物喷入发动机气缸内。汽油机供给系统从油箱吸取燃油利用机械式（发动机驱动）或电控式燃油泵提供高压使燃油进入燃油计量装置（化油器，汽油喷射器）。燃油供给系统主要包括四个部分：油箱：存储燃油。燃料泵：从油箱吸取燃料并将迫使其进入上述燃料计量装置。燃油滤清器：滤除燃料杂质。油管：连接油箱，油泵和其他部分。,译文及评析,Themorecommontypeoftimedfuelinjectionistheelectronic-timedfuelinjection,alsoknownaselectronicfuelinjection(EFI),asshown.Anelectronicfuelinjectionsystemcanbedividedintofoursubsystems:(1)Fueldeliverysystem.(2)Airinductionsystem.(3)Sensorsystem.(4)Computercontrolsystem.,过了一会，小男孩不哭了，睁开眼睛，用询问的目光看着越南护士。,电子定时燃油喷射，又叫电控燃油喷射是最常见的定时喷射系统。电控燃油喷射系统主要包括燃油供给、空气供给、传感器系统和控制器单元。,译文及评析,Thefuelpressureregulatorcontrolstheamountofpressureenteringtheinjectorvalves.Whensufficientpressureisattained,theregulatorreturnsexcessfueltothetank.Thismaintainsapresetamountoffuelpressureforinjectorvalveoperation.,掌握基本的名词词汇及上文内容,过了一会，小男孩不哭了，睁开眼睛，用询问的目光看着越南护士。,燃油压力调节器主要功用是调节喷油器与冷起动阀的燃油压力，是燃油压力与进气管压力之差保持常数。当燃油压力大于喷油阀预定压力值时，回油孔将打开，燃油流回油箱。,译文及评析,ThefuelinjectorforanEFIsystemisacoilorsolenoid-operatedfuelvalve.Whennotenergized,thespringpressurekeepstheinjectorclosed,keepingfuelfromenteringtheengine.Whencurrentflowsthroughtheinjectorcoilorsolenoid,themagneticfieldattractstheinjectorarmature.Theinjectoropens,squirtingfuelintotheintakemanifoldunderpressure.,掌握上文基本内容。,过了一会，小男孩不哭了，睁开眼睛，用询问的目光看着越南护士。,电控喷射系统的喷油器中有一个电磁线圈，当发动机未启动时，弹簧压力作用下，喷油器处于关闭状态。当发动起启动后，电控单元发出指令信号可讲喷油器头部的针阀打开，将准确配剂的一定量的燃油喷入进气门（汽油机）。,译文及评析,TheairinductionsystemfortheEFItypicallyconsistsofathrottlevalve,sensors,anairfilter,andconnectingducts.Thethrottlevalveregulateshowmuchairflowsintotheengine.Inturn,itcontrolsenginepoweroutput.Likethecarburetorthrottlevalve,itisconnectedtothegaspedal.Whenthepedalisdepressed,thethrottlevalveswingsopentoallowmoreairtorushintotheengine.,Sensor传感器,过了一会，小男孩不哭了，睁开眼睛，用询问的目光看着越南护士。,空气控制系统主要包括节气门、传感器，空气过滤器，和连接导管。节气门功用是调节进气量，即控制了发动机的输出功率。与化油器节流阀一样，它和油门踏板连接，当踩下油门踏板时，节气门开口增大，进入汽油机气缸的空气量增大。,译文及评析,TheEFIsensorsystemmonitorsengineoperatingconditionsandreportsthisinformationtothecomputer.Asensorisanelectricaldevicethatchangescircuitresistanceorvoltagewithachangeinacondition(temperature,pressure,positionofparts,etc.).,Temperature:温度,过了一会，小男孩不哭了，睁开眼睛，用询问的目光看着越南护士。,电控喷射系统的传感器系统时刻记录发动机运转状态并将收集的信息反馈到控制器。当发动机所处环境的温度、压力或其他因素变化时，传感器自身状态将发生变化，可以改变电路中电压或电流。,译文及评析,Forexample,theresistanceofatemperaturesensormaydecreaseastemperatureincreases.Thecomputercanusetheincreasedcurrentflowthroughthesensortocalculateanyneededchangeintheinjectorvalveopening.TypicalsensorsforanEFIsystemincludethefollowings:(1)Exhaustgasoroxygensensor.(2)Manifoldpressuresensor.(3)Throttlepositionsensor.(4)Enginetemperaturesensor.(5)Airflowsensor.(6)Inletairtemperaturesensor.(7)Crankshaftpositionsensor.,过了一会，小男孩不