汽車(chē)專業(yè)英語(yǔ) 5 FUEL INJECITON SYSTEM

1、Chapter 5 FUEL INJECTION SYSTEMu 背景知識(shí)背景知識(shí) 燃油燃油噴射系統(tǒng)噴射系統(tǒng)是指在一定的壓力下，利用噴油器噴油器將一定數(shù)量的燃料直接噴入氣缸或進(jìn)氣道氣缸或進(jìn)氣道內(nèi)的燃油供給燃油供給裝置。根據(jù)噴射燃料種類的不同，可以分為汽油噴射系統(tǒng)汽油噴射系統(tǒng)、柴油噴射系統(tǒng)柴油噴射系統(tǒng)、氣體燃料噴射氣體燃料噴射系統(tǒng)系統(tǒng)等。而根據(jù)其控制方式的不同，可分為機(jī)械控制式、電子控制式以及機(jī)電混合控制式。 u 背景知識(shí)背景知識(shí) 發(fā)動(dòng)機(jī)在不同工況下運(yùn)轉(zhuǎn)，對(duì)混合氣濃度的要求也不同。特別是在一些特殊工況下（如起動(dòng)、急加速、急減速等），對(duì)混合氣濃度有特殊的要求。ECU要根據(jù)有關(guān)傳感器測(cè)得的運(yùn)轉(zhuǎn)工況，

2、按不同的方式控制噴油量。噴油量的控制方式可分為起動(dòng)控制、運(yùn)轉(zhuǎn)控制、斷油控制和反饋控制。1、起動(dòng)噴油控制、起動(dòng)噴油控制2、運(yùn)轉(zhuǎn)、運(yùn)轉(zhuǎn)控制控制3、反饋控制、反饋控制 Chapter 5 FUEL INJECTION SYSTEMu 背景知識(shí)背景知識(shí)1、起動(dòng)噴油、起動(dòng)噴油控制控制 起動(dòng)時(shí)，發(fā)動(dòng)機(jī)由起動(dòng)馬達(dá)帶動(dòng)運(yùn)轉(zhuǎn)。由于轉(zhuǎn)速很低，轉(zhuǎn)速的波動(dòng)也很大，因此這時(shí)空氣流量傳感器所測(cè)得的進(jìn)氣量信號(hào)有很大的誤差?；谶@個(gè)原因，在發(fā)動(dòng)機(jī)起動(dòng)時(shí)，ECU不以空氣流量傳感器的信號(hào)作為噴油量的計(jì)算依據(jù)，而是按預(yù)先給定的起動(dòng)程序來(lái)進(jìn)行噴油控制。ECU根據(jù)起動(dòng)開(kāi)關(guān)及轉(zhuǎn)速傳感器的信號(hào)，判定發(fā)動(dòng)機(jī)是否處于起動(dòng)狀態(tài)，以決定是否按起動(dòng)

3、程序控制噴油。當(dāng)起動(dòng)開(kāi)關(guān)接通，且發(fā)動(dòng)機(jī)轉(zhuǎn)速低于300轉(zhuǎn)/分時(shí)，ECU判定發(fā)動(dòng)機(jī)處于起動(dòng)狀態(tài)，從而按起動(dòng)程序控制噴油。 在起動(dòng)噴油控制程序中，ECU按發(fā)動(dòng)機(jī)水溫、進(jìn)氣溫度、起動(dòng)轉(zhuǎn)速計(jì)算出一個(gè)固定的噴油量。這一噴油量能使發(fā)動(dòng)機(jī)獲得順利起動(dòng)所需的濃混合氣。冷車(chē)起動(dòng)時(shí)，發(fā)動(dòng)機(jī)溫度很低，噴入進(jìn)氣道的燃油不易蒸發(fā)。為了能產(chǎn)生足夠的燃油蒸氣，形成足夠濃度的可燃混合氣，保證發(fā)動(dòng)機(jī)在低溫下也能正常起動(dòng)，必須進(jìn)一步增大噴油量。由ECU控制，通過(guò)增加各缸噴油器的噴油持續(xù)時(shí)間或噴油次數(shù)來(lái)增加噴油量。所增加的噴油量及加濃持續(xù)時(shí)間完全由ECU根據(jù)進(jìn)氣溫度傳感器和發(fā)動(dòng)機(jī)水溫傳感器測(cè)得的溫度高低來(lái)決定。發(fā)動(dòng)機(jī)水溫或進(jìn)氣溫度愈

4、低，噴油量就愈大，加濃的持續(xù)時(shí)間也就愈長(zhǎng)。這種冷起動(dòng)控制方式不設(shè)冷起動(dòng)噴油器和冷起動(dòng)溫度開(kāi)關(guān)。 Chapter 5 FUEL INJECTION SYSTEMu 背景知識(shí)背景知識(shí)2、運(yùn)轉(zhuǎn)控制、運(yùn)轉(zhuǎn)控制 在發(fā)動(dòng)機(jī)運(yùn)轉(zhuǎn)中，ECU主要根據(jù)進(jìn)氣量和發(fā)動(dòng)機(jī)轉(zhuǎn)速來(lái)計(jì)算噴油量。此外，ECU還要參考節(jié)氣門(mén)開(kāi)度、發(fā)動(dòng)機(jī)水溫、進(jìn)氣溫度、海拔高度及怠速工況、加速工況、全負(fù)荷工況等運(yùn)轉(zhuǎn)參數(shù)來(lái)修正噴油量，以提高控制精度。 由于ECU要考慮的運(yùn)轉(zhuǎn)參數(shù)很多，為了簡(jiǎn)化ECU的計(jì)算程序，通常將噴油量分成基本噴油量、修正量、增量三個(gè)部分，并分別計(jì)算出結(jié)果。然后再將三個(gè)部分疊加在一起，作為總噴油量來(lái)控制噴油器噴油。 基本噴油量：基

5、本噴油量是根據(jù)發(fā)動(dòng)機(jī)每個(gè)工作循環(huán)的進(jìn)氣量，按理論混合比（空燃比14.7）計(jì)算出的噴油量。 修正量：修正量是根據(jù)進(jìn)氣溫度、大氣壓力等實(shí)際運(yùn)轉(zhuǎn)情況，對(duì)基本噴油量進(jìn)行適當(dāng)修正，使發(fā)動(dòng)機(jī)在不同運(yùn)轉(zhuǎn)條件下都能獲得最佳濃度的混合氣。修正量的內(nèi)容為：進(jìn)氣溫度修正、大氣壓力修正和蓄電池電壓修正（電壓變化時(shí)，自動(dòng)對(duì)噴油脈沖寬度加以修正）。 Chapter 5 FUEL INJECTION SYSTEMu 背景知識(shí)背景知識(shí)3、反饋控制反饋控制汽油噴射系統(tǒng)進(jìn)行反饋控制的傳感器是熱氧傳感器，使用熱氧傳感器的發(fā)動(dòng)機(jī)必須使用無(wú)鉛汽油。反饋控制（閉環(huán)控制）是在排氣管上加裝熱氧傳感器，根據(jù)排氣中氧含量的變化，測(cè)定出進(jìn)入發(fā)動(dòng)機(jī)

6、燃燒室混合氣的空燃比值，把它輸入ECU與設(shè)定的目標(biāo)空燃比值進(jìn)行比較，將誤差信號(hào)經(jīng)放大器控制電磁噴油器噴油量，使空燃比保持在設(shè)定目標(biāo)值附近。因此，閉環(huán)控制可達(dá)到較高的空燃比控制精度，并可消除因產(chǎn)品差異和磨損等引起的性能變化，工作穩(wěn)定性好，抗干擾能力強(qiáng)。但是，為了使三元催化裝置對(duì)排氣凈化處理達(dá)到最佳效果，閉環(huán)控制的汽油噴射系統(tǒng)只能運(yùn)行在理論空燃比14.7附近很窄的范圍內(nèi)。因此對(duì)特殊的運(yùn)行工況，如啟動(dòng)、暖機(jī)、怠速、加速、滿負(fù)荷等需加濃混合氣的工況，仍需采用開(kāi)環(huán)控制，使電磁噴油器按預(yù)先設(shè)定的加濃混合氣配比工作，充分發(fā)揮發(fā)動(dòng)機(jī)的動(dòng)力性能，所以采用開(kāi)環(huán)和閉環(huán)相結(jié)合的控制方式。 Chapter 5 FUEL

7、 INJECTION SYSTEM 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 emissi

8、ons became more of a concern, feedback controls were adapted to both types of fuel injection systems.譯文：譯文：燃油噴射系統(tǒng)已經(jīng)在汽車(chē)上運(yùn)用了許多年。最早期的噴燃油噴射系統(tǒng)已經(jīng)在汽車(chē)上運(yùn)用了許多年。最早期的噴射系統(tǒng)都是機(jī)械式的。隨著技術(shù)的進(jìn)步，電子燃油噴射射系統(tǒng)都是機(jī)械式的。隨著技術(shù)的進(jìn)步，電子燃油噴射系統(tǒng)逐漸得到普及。早期機(jī)械式和電子式燃油噴射系統(tǒng)系統(tǒng)逐漸得到普及。早期機(jī)械式和電子式燃油噴射系統(tǒng)都沒(méi)有采用反饋控制。由于排放問(wèn)題越來(lái)越得到重視，都沒(méi)有采用反饋控制。由于排放問(wèn)題越來(lái)越得到重視，反

9、饋控制在這兩種系統(tǒng)中都得到了應(yīng)用。反饋控制在這兩種系統(tǒng)中都得到了應(yīng)用。Chapter 5 FUEL INJECTION SYSTEM Both mechanical and electronic fuel injection system can be found on gasoline engines. Diesel engines are most commonly found with mechanical type systems, although the newest generation of these engines have been using electronic fu

10、el injection (EFI).譯文：譯文：汽油發(fā)動(dòng)機(jī)使用機(jī)械式或電子式燃油噴射系統(tǒng)。柴汽油發(fā)動(dòng)機(jī)使用機(jī)械式或電子式燃油噴射系統(tǒng)。柴油機(jī)通常使用機(jī)械式燃油噴射系統(tǒng)，但是最新一代油機(jī)通常使用機(jī)械式燃油噴射系統(tǒng)，但是最新一代的柴油發(fā)動(dòng)機(jī)也已經(jīng)在使用電子式燃油噴射系統(tǒng)了。的柴油發(fā)動(dòng)機(jī)也已經(jīng)在使用電子式燃油噴射系統(tǒng)了。Chapter 5 FUEL INJECTION SYSTEM1.Basic Theory EFI uses solenoid valves called injectors to meter fuel delivery. Most vehicles today use 1 inj

11、ector 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. 譯文：譯文：電子式燃油噴射系統(tǒng)使用被稱作噴油器的電磁閥來(lái)控制噴電子式燃油噴射系統(tǒng)使用被稱作噴油

12、器的電磁閥來(lái)控制噴油量。今天大多數(shù)汽車(chē)油量。今天大多數(shù)汽車(chē)1個(gè)氣缸使用個(gè)氣缸使用1個(gè)噴油器。電磁閥一個(gè)噴油器。電磁閥一上電，燃油就被噴射至電磁閥口。高壓電動(dòng)燃油泵以大約上電，燃油就被噴射至電磁閥口。高壓電動(dòng)燃油泵以大約40psi的壓力將燃油送到噴油器。噴油量是由噴油器控制的壓力將燃油送到噴油器。噴油量是由噴油器控制的，而噴油器的開(kāi)啟和關(guān)閉又是被計(jì)算機(jī)控制的。的，而噴油器的開(kāi)啟和關(guān)閉又是被計(jì)算機(jī)控制的。Chapter 5 FUEL INJECTION SYSTEMThe computer produces a signal to open the injectors for a certain

13、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.

14、The longer the pulse width, the more fuel is injected.譯文：譯文：計(jì)算機(jī)根據(jù)傳感器送來(lái)的工況信號(hào)，向噴油器發(fā)送開(kāi)啟以計(jì)算機(jī)根據(jù)傳感器送來(lái)的工況信號(hào)，向噴油器發(fā)送開(kāi)啟以及開(kāi)啟持續(xù)時(shí)間的信號(hào)。噴油器打開(kāi)時(shí)間越長(zhǎng)，噴出的燃及開(kāi)啟持續(xù)時(shí)間的信號(hào)。噴油器打開(kāi)時(shí)間越長(zhǎng)，噴出的燃油越多。隨著發(fā)動(dòng)機(jī)負(fù)載和轉(zhuǎn)速的增加，噴油器打開(kāi)的時(shí)油越多。隨著發(fā)動(dòng)機(jī)負(fù)載和轉(zhuǎn)速的增加，噴油器打開(kāi)的時(shí)間也要增加來(lái)匹配進(jìn)氣量的增加。計(jì)算機(jī)輸出信號(hào)被稱作間也要增加來(lái)匹配進(jìn)氣量的增加。計(jì)算機(jī)輸出信號(hào)被稱作噴油器脈沖寬度。脈沖寬度越大，噴出的燃油越多。噴油器脈沖寬度。脈沖寬度越大，噴出

15、的燃油越多。Chapter 5 FUEL INJECTION SYSTEM2. Engine Requirements Stand spark ignited, 4 stroke engines require that the correct proportion of fuel be mixed with the incoming air for efficient operation. This proportion is in the range of 13 parts air to 1 part fuel for best power, 15 to 1 for best emissi

16、on and 17 to 1 for best economy. 譯文：譯文：標(biāo)準(zhǔn)四沖程點(diǎn)火式發(fā)動(dòng)機(jī)為了獲得高的效率，要求合適標(biāo)準(zhǔn)四沖程點(diǎn)火式發(fā)動(dòng)機(jī)為了獲得高的效率，要求合適的空燃比。為了獲得最佳動(dòng)力性，空燃比是的空燃比。為了獲得最佳動(dòng)力性，空燃比是13比比1，為，為了獲得最佳排放，空燃比是了獲得最佳排放，空燃比是15比比1，為了獲得最佳經(jīng)濟(jì)，為了獲得最佳經(jīng)濟(jì)性，空燃比是性，空燃比是17比比1。Chapter 5 FUEL INJECTION SYSTEM Most modern engines aim for a ratio of around 14.7 to 1 for the major

17、ity of cruising and medium power conditions. This is the chemically correct ratio which results in the lowest average emissions and reasonable power. A rich condition is characterized by an excess of fuel, and a lean condition is characterized by an excess of air or lack of fuel.譯文：譯文：大多數(shù)現(xiàn)代發(fā)動(dòng)機(jī)在大多數(shù)巡航

18、工況和適中的動(dòng)力性條大多數(shù)現(xiàn)代發(fā)動(dòng)機(jī)在大多數(shù)巡航工況和適中的動(dòng)力性條件下，空燃比控制目標(biāo)為件下，空燃比控制目標(biāo)為14.7比比1。這是化學(xué)分析上適。這是化學(xué)分析上適當(dāng)?shù)目杖急龋梢垣@得最低的平均排放和適當(dāng)?shù)膭?dòng)力性。當(dāng)?shù)目杖急?，可以獲得最低的平均排放和適當(dāng)?shù)膭?dòng)力性。燃燒濃工況意味著燃料過(guò)多，稀工況意味著空氣過(guò)量或燃燒濃工況意味著燃料過(guò)多，稀工況意味著空氣過(guò)量或燃料不足。燃料不足。Chapter 5 FUEL INJECTION SYSTEMAs rpm is increased, up to a point, airflow also increases and fuel flow must in

19、crease to match it. As the throttle is opened at a given rpm, airflow increases to a certain point and again, fuel flow must follow airflow.譯文：譯文：當(dāng)發(fā)動(dòng)機(jī)轉(zhuǎn)速上升到某一點(diǎn)，空氣進(jìn)氣量也隨之上當(dāng)發(fā)動(dòng)機(jī)轉(zhuǎn)速上升到某一點(diǎn)，空氣進(jìn)氣量也隨之上升，此時(shí)進(jìn)油量也必須對(duì)應(yīng)隨之上升。在某一發(fā)動(dòng)升，此時(shí)進(jìn)油量也必須對(duì)應(yīng)隨之上升。在某一發(fā)動(dòng)機(jī)轉(zhuǎn)速下，當(dāng)節(jié)氣門(mén)打開(kāi)，空氣進(jìn)氣量上升到某一機(jī)轉(zhuǎn)速下，當(dāng)節(jié)氣門(mén)打開(kāi)，空氣進(jìn)氣量上升到某一數(shù)值下，同樣進(jìn)油量必須跟隨空氣進(jìn)氣量。數(shù)值下

20、，同樣進(jìn)油量必須跟隨空氣進(jìn)氣量。Chapter 5 FUEL INJECTION SYSTEM3. Fuel system EFI fuel system consists of a tank, pump, fuel rail, regulator, out an excess of fuel injectors and return line. Fuel is drawn from the tank by the pump which steps up pressure to around to 40 psi. Fuel pressure is controlled by the fuel

21、pressure regulator located on one end of the fuel rail by bleeding fuel back to the tank through the return line.譯文：譯文：電子噴油系統(tǒng)由油箱、油泵、油軌、調(diào)節(jié)器、噴油嘴和電子噴油系統(tǒng)由油箱、油泵、油軌、調(diào)節(jié)器、噴油嘴和回油管路組成。燃油由油泵從油箱吸出，并被加壓到大回油管路組成。燃油由油泵從油箱吸出，并被加壓到大約約40psi。油壓通過(guò)位于油軌一端的燃油調(diào)節(jié)器控制。油壓通過(guò)位于油軌一端的燃油調(diào)節(jié)器控制。燃油調(diào)節(jié)器將燃油通過(guò)回油管路放回到油箱實(shí)現(xiàn)對(duì)油壓燃油調(diào)節(jié)器將燃油通過(guò)回油管路放

22、回到油箱實(shí)現(xiàn)對(duì)油壓的控制。的控制。Chapter 5 FUEL INJECTION SYSTEMThe pump always puts out an excess of fuel so large quantities are returned back to the tank during idle and low speed conditions and less as engine demand increases. The fuel rail is essentially a tubular fuel manifold designed to carry fuel to the in

23、jectors as well as hold them in place on the intake manifold. 譯文：譯文：油泵總是泵出過(guò)多的燃油。因此，空轉(zhuǎn)或低速工況油泵總是泵出過(guò)多的燃油。因此，空轉(zhuǎn)或低速工況下，多余的燃油就返回到下，多余的燃油就返回到油油箱。隨著發(fā)動(dòng)機(jī)負(fù)載的箱。隨著發(fā)動(dòng)機(jī)負(fù)載的增加，返回增加，返回油油箱的燃油減小。油軌實(shí)際上就是油路箱的燃油減小。油軌實(shí)際上就是油路歧管，用來(lái)將燃油送到噴油嘴，同時(shí)把燃油存在進(jìn)歧管，用來(lái)將燃油送到噴油嘴，同時(shí)把燃油存在進(jìn)油歧管內(nèi)。油歧管內(nèi)。Chapter 5 FUEL INJECTION SYSTEMThe injectors a

24、re usually sealed with O-rings on each end. One end has the fuel entering from the rail and the other end spigots into the manifold. The injector has a 2 pin electrical plug to carry switching current to the solenoid winding. When energized, the solenoid core is pulled back which pulls back a sealin

25、g pintle, disc or ball, allowing fuel to spray out in a fine, conical pattern.譯文：譯文：通常使用通常使用O型環(huán)把噴油嘴的兩端密封。噴油嘴一端與油型環(huán)把噴油嘴的兩端密封。噴油嘴一端與油軌相連，另一端與歧管采用連接管接合。噴油嘴有一個(gè)軌相連，另一端與歧管采用連接管接合。噴油嘴有一個(gè)兩腳電子開(kāi)關(guān)來(lái)承載電磁線圈的開(kāi)關(guān)電流。當(dāng)電磁線圈兩腳電子開(kāi)關(guān)來(lái)承載電磁線圈的開(kāi)關(guān)電流。當(dāng)電磁線圈上電，銜鐵吸回，帶動(dòng)密封軸、密封盤(pán)或密封球，從而上電，銜鐵吸回，帶動(dòng)密封軸、密封盤(pán)或密封球，從而使得燃油細(xì)密呈圓錐形噴出。使得燃油細(xì)密呈圓錐形噴出

26、。Chapter 5 FUEL INJECTION SYSTEM4 Air metering and measurementThe amount of air entering the engine is controlled by a conventional butterfly valve on most engines located in a throttle body assembly.譯文：譯文：一般大多數(shù)發(fā)動(dòng)機(jī)使用一個(gè)蝶形閥來(lái)控制進(jìn)入到發(fā)一般大多數(shù)發(fā)動(dòng)機(jī)使用一個(gè)蝶形閥來(lái)控制進(jìn)入到發(fā)動(dòng)機(jī)的空氣。這個(gè)閥位于節(jié)氣門(mén)體總成上。動(dòng)機(jī)的空氣。這個(gè)閥位于節(jié)氣門(mén)體總成上。Chapter 5 FU

27、EL INJECTION SYSTEM4 Air metering and measurementAirflow measurement is by one of two basic methods: Mass Airflow and speed Density. The mass airflow method uses either a spring loaded flap attached to a potentiometer or a heated mire mounted in front of the throttle body to sense actual airflow. 譯文

28、：譯文：發(fā)動(dòng)機(jī)進(jìn)氣量的測(cè)量有兩種基本方法：空氣流量計(jì)發(fā)動(dòng)機(jī)進(jìn)氣量的測(cè)量有兩種基本方法：空氣流量計(jì)和速度密度法?？諝饬髁坑?jì)法使用與電位計(jì)相連的和速度密度法?？諝饬髁坑?jì)法使用與電位計(jì)相連的彈簧接片或位于節(jié)氣門(mén)體總成前端的熱線來(lái)測(cè)量實(shí)彈簧接片或位于節(jié)氣門(mén)體總成前端的熱線來(lái)測(cè)量實(shí)際空氣流量。際空氣流量。Chapter 5 FUEL INJECTION SYSTEM4 Air metering and measurementThe position of the flap or amount of current required to keep the wire heated to a certain

29、 temperature is relayed to the computer as a voltage signal. A certain voltage equals a certain airflow rate.譯文：譯文：彈簧接片的位置或保持熱線在一定溫度下所需的電彈簧接片的位置或保持熱線在一定溫度下所需的電流被轉(zhuǎn)換為電壓信號(hào)傳給計(jì)算機(jī)。一定的電壓信號(hào)流被轉(zhuǎn)換為電壓信號(hào)傳給計(jì)算機(jī)。一定的電壓信號(hào)對(duì)應(yīng)著一定的空氣進(jìn)氣速率。對(duì)應(yīng)著一定的空氣進(jìn)氣速率。Chapter 5 FUEL INJECTION SYSTEMThe speed density system uses a solid st

30、ate pressure transducer to measure the pressure in the intake manifold with rpm and air temperature to indirectly determine airflow. Again, a certain pressure relates to a certain voltage which is relayed to the computer.譯文：譯文：速度密度系統(tǒng)使用晶體管壓力傳感器測(cè)量進(jìn)氣歧管速度密度系統(tǒng)使用晶體管壓力傳感器測(cè)量進(jìn)氣歧管的壓力，并聯(lián)合發(fā)動(dòng)機(jī)轉(zhuǎn)速和空氣溫度來(lái)間接確定的壓力，并聯(lián)合

31、發(fā)動(dòng)機(jī)轉(zhuǎn)速和空氣溫度來(lái)間接確定進(jìn)氣量。同樣，一定的壓力對(duì)應(yīng)著一定的電壓信號(hào)，進(jìn)氣量。同樣，一定的壓力對(duì)應(yīng)著一定的電壓信號(hào)，然后被傳給電腦。然后被傳給電腦。Chapter 5 FUEL INJECTION SYSTEM5 Sensor Inputs5.1 RPM5.2 Airflow5.3 Manifold Pressure5.4 Throttle Position5.5 Water Temperature5.6 Air TemperatureChapter 5 FUEL INJECTION SYSTEM5.1 RPMMost systems measure rpm off of the ign

32、ition coil tachometer pulse or crank triggered magnetic/Hall effect sensors. Rpm is considered a primary input signal on all EFI systems. Most systems generate an injection pulse for every tach pulse so as rpm is increased, the frequency of injection pulses is also increased.Chapter 5 FUEL INJECTION

33、 SYSTEM5.1 RPMMost systems measure rpm off of the ignition coil tachometer pulse or crank triggered magnetic/Hall effect sensors. Rpm is considered a primary input signal on all EFI systems. Most systems generate an injection pulse for every tach pulse so as rpm is increased, the frequency of inject

34、ion pulses is also increased.Chapter 5 FUEL INJECTION SYSTEM譯文：譯文：大多數(shù)燃油噴射系統(tǒng)實(shí)用點(diǎn)火線圈轉(zhuǎn)速計(jì)脈沖或曲軸觸大多數(shù)燃油噴射系統(tǒng)實(shí)用點(diǎn)火線圈轉(zhuǎn)速計(jì)脈沖或曲軸觸發(fā)磁場(chǎng)發(fā)磁場(chǎng)/霍爾效應(yīng)傳感器來(lái)測(cè)量發(fā)動(dòng)機(jī)轉(zhuǎn)速。發(fā)動(dòng)機(jī)轉(zhuǎn)霍爾效應(yīng)傳感器來(lái)測(cè)量發(fā)動(dòng)機(jī)轉(zhuǎn)速。發(fā)動(dòng)機(jī)轉(zhuǎn)速是所有燃油噴射系統(tǒng)最重要的一個(gè)輸入信號(hào)。大多數(shù)速是所有燃油噴射系統(tǒng)最重要的一個(gè)輸入信號(hào)。大多數(shù)系統(tǒng)對(duì)每一個(gè)測(cè)速脈沖信號(hào)產(chǎn)生一個(gè)噴射脈沖信號(hào)。因系統(tǒng)對(duì)每一個(gè)測(cè)速脈沖信號(hào)產(chǎn)生一個(gè)噴射脈沖信號(hào)。因此，隨著發(fā)動(dòng)機(jī)轉(zhuǎn)速的增長(zhǎng)，噴射脈沖信號(hào)頻率也隨著此，隨著發(fā)動(dòng)機(jī)轉(zhuǎn)速的增長(zhǎng)，噴射脈沖信號(hào)

35、頻率也隨著增長(zhǎng)。增長(zhǎng)。5.2 airflowChapter 5 FUEL INJECTION SYSTEM5.2 airflowOn mass airflow type system, this input is also considered a primary input signal. X amount of air requires Y amount of fuel. As rpm and throttle opening is increased, airflow increases to a point.Chapter 5 FUEL INJECTION SYSTEM譯文：譯文：對(duì)于

36、空氣流量計(jì)系統(tǒng)，空氣進(jìn)氣量也是一個(gè)非常重要的對(duì)于空氣流量計(jì)系統(tǒng)，空氣進(jìn)氣量也是一個(gè)非常重要的輸入信號(hào)。輸入信號(hào)。X份的空氣要求份的空氣要求Y份的燃油。隨著發(fā)動(dòng)機(jī)轉(zhuǎn)份的燃油。隨著發(fā)動(dòng)機(jī)轉(zhuǎn)速和節(jié)氣門(mén)開(kāi)度的增加，空氣進(jìn)氣量也隨之增加到一個(gè)速和節(jié)氣門(mén)開(kāi)度的增加，空氣進(jìn)氣量也隨之增加到一個(gè)數(shù)值點(diǎn)上。數(shù)值點(diǎn)上。5. 3 Manifold PressureChapter 5 FUEL INJECTION SYSTEM5. 3 Manifold PressureOn speed density type systems, this input is essential when combined with t

37、he rpm signal to calculate airflow. As the throttle is opened, the manifold pressure increases which will require more fuel.Chapter 5 FUEL INJECTION SYSTEM譯文：譯文：對(duì)于速度密度式系統(tǒng)，歧管壓力非常重要，它需要對(duì)于速度密度式系統(tǒng)，歧管壓力非常重要，它需要和聯(lián)合發(fā)動(dòng)機(jī)轉(zhuǎn)速信號(hào)來(lái)計(jì)算空氣進(jìn)氣量。當(dāng)節(jié)氣和聯(lián)合發(fā)動(dòng)機(jī)轉(zhuǎn)速信號(hào)來(lái)計(jì)算空氣進(jìn)氣量。當(dāng)節(jié)氣門(mén)打開(kāi)，歧管壓力增加，這就需要更多燃油。門(mén)打開(kāi)，歧管壓力增加，這就需要更多燃油。5. 4 Thrott

38、le PositionChapter 5 FUEL INJECTION SYSTEM5. 4 Throttle PositionThis input is a secondary input on most systems. It is required mainly for acceleration enrichment when the throttle is rapidly opened. Chapter 5 FUEL INJECTION SYSTEM譯文：譯文：節(jié)氣門(mén)位置信號(hào)對(duì)于大多數(shù)系統(tǒng)是個(gè)較為次要的信節(jié)氣門(mén)位置信號(hào)對(duì)于大多數(shù)系統(tǒng)是個(gè)較為次要的信號(hào)。它主要是用于當(dāng)節(jié)氣門(mén)被快速打開(kāi)時(shí)，

39、加快燃號(hào)。它主要是用于當(dāng)節(jié)氣門(mén)被快速打開(kāi)時(shí)，加快燃油濃工況的過(guò)程。油濃工況的過(guò)程。5.5Water TemperatureWater temperature is a secondary input required mainly to ensure proper starting and warm-up of the engine. When the engine is cold, the air to fuel ratio must be very rich to enable enough fuel to vaporize for proper starting.Chapter 5 FU

40、EL INJECTION SYSTEM譯文：譯文：水溫信號(hào)也是一個(gè)次要輸入信號(hào)，主要用來(lái)保證發(fā)水溫信號(hào)也是一個(gè)次要輸入信號(hào)，主要用來(lái)保證發(fā)動(dòng)機(jī)適當(dāng)啟動(dòng)和熱機(jī)。當(dāng)發(fā)動(dòng)機(jī)處于冷態(tài)，為了保動(dòng)機(jī)適當(dāng)啟動(dòng)和熱機(jī)。當(dāng)發(fā)動(dòng)機(jī)處于冷態(tài)，為了保證發(fā)動(dòng)機(jī)較好的啟動(dòng)，空燃比必須變得很濃，來(lái)確證發(fā)動(dòng)機(jī)較好的啟動(dòng)，空燃比必須變得很濃，來(lái)確保足量的燃油被蒸發(fā)。保足量的燃油被蒸發(fā)。5.5Water TemperatureThe computer increases the injector pulse width to supply extra fuel when cold and tapers this fuel off

41、 as the water temperature increases. Once the water warms past 120 degrees or so, the computer does not need to add any extra fuel.Chapter 5 FUEL INJECTION SYSTEM譯文：譯文：當(dāng)發(fā)動(dòng)機(jī)處于冷態(tài)，為了保證發(fā)動(dòng)機(jī)較好的啟動(dòng)，當(dāng)發(fā)動(dòng)機(jī)處于冷態(tài)，為了保證發(fā)動(dòng)機(jī)較好的啟動(dòng)，空燃比必須變得很濃，來(lái)確保足量的燃油被蒸發(fā)?？杖急缺仨氉兊煤軡?，來(lái)確保足量的燃油被蒸發(fā)。冷態(tài)時(shí)，計(jì)算機(jī)增加噴油嘴脈沖寬度來(lái)提供額外的冷態(tài)時(shí)，計(jì)算機(jī)增加噴油嘴脈沖寬度來(lái)提供額外的

42、燃油，并隨著水溫的升高逐步減少額外的燃油噴射。燃油，并隨著水溫的升高逐步減少額外的燃油噴射。當(dāng)水溫超過(guò)大約當(dāng)水溫超過(guò)大約120度，計(jì)算機(jī)不再提供額外的燃度，計(jì)算機(jī)不再提供額外的燃油噴射信號(hào)。油噴射信號(hào)。5.6 Air TemperatureThis is a secondary input required especially on speed density systems. The sensor is usually mounted in the intake manifold or air filter area. As the air temperature drops, its d

43、ensity increases. Dense air requires more fuel.Chapter 5 FUEL INJECTION SYSTEM譯文：譯文：對(duì)于速度密度式系統(tǒng)，空氣溫度信號(hào)是一個(gè)次要的對(duì)于速度密度式系統(tǒng)，空氣溫度信號(hào)是一個(gè)次要的輸入信號(hào)。這個(gè)傳感器一般位于進(jìn)氣歧管或者空氣輸入信號(hào)。這個(gè)傳感器一般位于進(jìn)氣歧管或者空氣濾清器區(qū)域。當(dāng)空氣溫度下降，空氣密度上升?？諡V清器區(qū)域。當(dāng)空氣溫度下降，空氣密度上升?？諝饷芏仍酱螅蟮娜加驮蕉?。氣密度越大，所要求的燃油越多。6 Oxygen SensorThis sensor is employed in closed loop

44、systems to modify the basic pulse width after the fact. It is mounted into the exhaust manifold area. Chapter 5 FUEL INJECTION SYSTEM譯文：譯文：氧氣傳感器被用在閉環(huán)系統(tǒng)來(lái)根據(jù)實(shí)際情況調(diào)整基氧氣傳感器被用在閉環(huán)系統(tǒng)來(lái)根據(jù)實(shí)際情況調(diào)整基本脈沖寬度。它位于排氣歧管區(qū)域。本脈沖寬度。它位于排氣歧管區(qū)域。By looking at the oxygen content of the exhaust gases after combustion, the computer

45、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 emission, the air/fuel ratio must be kept around 14.7

46、 to 1.Chapter 5 FUEL INJECTION SYSTEM譯文：譯文：通過(guò)檢測(cè)燃燒后排放的廢氣中氧氣的含量，計(jì)算機(jī)通過(guò)檢測(cè)燃燒后排放的廢氣中氧氣的含量，計(jì)算機(jī)能判斷出對(duì)于最佳燃燒而言，空燃比是否過(guò)濃或過(guò)能判斷出對(duì)于最佳燃燒而言，空燃比是否過(guò)濃或過(guò)稀，從而調(diào)整接下來(lái)噴油量。氧氣傳感器首先被用稀，從而調(diào)整接下來(lái)噴油量。氧氣傳感器首先被用來(lái)排放控制，其次用于燃油經(jīng)濟(jì)性控制。對(duì)于最低來(lái)排放控制，其次用于燃油經(jīng)濟(jì)性控制。對(duì)于最低的平均排放，空燃比必須要控制在的平均排放，空燃比必須要控制在14.7：1左右。左右。Under full throttle conditions, this se

47、nsor 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 sensors inputs.Chapter 5 FUEL INJECTION SYSTEM譯文：譯文：當(dāng)節(jié)氣門(mén)全開(kāi)狀態(tài)下，氧氣傳感器的輸入被計(jì)算機(jī)當(dāng)節(jié)氣門(mén)全開(kāi)狀態(tài)下，氧氣傳感器的輸入被計(jì)算機(jī)忽略，從而使得發(fā)動(dòng)機(jī)產(chǎn)生更大的功率。這被稱作忽略，從而使得發(fā)動(dòng)機(jī)產(chǎn)生更大的功率。這被稱作開(kāi)環(huán)模式。此時(shí)，計(jì)算