【正文】 附錄：英文翻譯Common Rail accumulator fuelinjection systemSystem overview Field of applicationThe introduction of the first seriesproduction inline fuelinjection pump in 1927 marked the beginning of diesel fuelinjection system manufacture at Bosch. The inline fuelinjection pump’s main area of application is still in all sizes of mercialvehicle diesel engines, stationary diesel engines, lootives and ships. Injection pressures of up to approx. 1350bar are used to generate output powers of up to about 160kW per cylinder. Over the years, a wide variety of different requirements, such as the installation of directinjection (DL) engines in small delivery vans and passenger cars, have led to the development of various diesel fuelinjection systems which are aligned to the requirements of a particular application. Of major importance in these developments are not only the increase in specific power, but also the demand for reduced fuel consumption, and the call for lower noise and exhaustgas emissions. Compared to conventional camdriven systems, the Bosch “Common Rail” fuelinjection system for directinjection (DL) diesel engines provides for considerably higher flexibility in the adaptation of the injection system to the engine, for instance: Extensive area of application (for) passenger cars and light mercial vehicles with output powers of up to 30kW/cylinder, as well as for heavyduty vehicles, lootives, and ships with outputs of up to approx, 200 kW/cylinder, High injection pressures of up to approx, 1400 bar, Variable start of injection, Possibility of pilot injection, main injection, and post injection, Matching of injection pressure to the operating mode.FunctionsPressure generation and fuel injection are pletely decoupled from each other in the “Common Rail” accumulator injection system. The injection pressure is generated independent of engine speed and injected fuel quantity. The fuel is stored under pressure in the highpressure accumulator (the “Rail”) ready for injection. The injected fuel quantity is defined by the driver, and the start of injection and injection pressure are calculated by the ECU on the basis of the stored maps. The ECU then triggers the solenoid valves so that the injector (injection unit) at each engine cylinder injects accordingly. The ECU and sensor stages of such a CR fuelinjection system prise: ECU Crankshaftsensor, Camshaftspeed sensor, Acceleratorpedal sensor, Boostpressure sensor, Railpressure sensor, Coolant sensor and Airmass meter.Using the input signals from the above sensors, the ECU registers the driver’s requirements (acceleratorpedal setting) and defines the instantaneous operating performance of the engine and the vehicle as a whole. It processes the signals which have been generated by the sensors and which it receives via data lines. On the basis of this information, it can then intervene with open and closedloop controlling action at the vehicle and particularly at the engine. The engine speed is measured by the crankshaftspeed sensor, and the camshaftspeed sensor determines the firing sequence (phase length). The electrical signal generated across a potentiometer in the acceleratorpedal module informs the ECU about how far the driver has depressed the pedal, in other words about his (her) torque requirement.The airmass meter provides the ECU with data on the instantaneous air flow in order that bustion can be adapted so as to ply with the emissions regulations. Insofar as the engine is equipped with an exhaustgas turbocharger and boostpressure control, the boostpressure sensor also measures boostpressure. At low outside temperatures and with the engine cold, the ECU applies the data from the coolanttemperature and airtemperature sensors to adapt the set point values for start of injection,。在尤明福老師的耐心指導和啟發(fā)下，最后，我圓滿完成了本文的畢業(yè)設計，但是由于時間倉促及水平有限，缺點和錯誤在所難免，希望各位老師給予批評指正。但是，由于我的基礎知識還不夠扎實，再加上對汽車柴油機的理解還不夠，以致于我剛開始動手設計時有所茫然。在設計過程中，使我學會對待實際問題的方法及嚴謹?shù)墓ぷ鲬B(tài)度，提高了綜合運用所學的知識的能力，也是我的另外一大收獲。讓我真正體會到理論聯(lián)系實際，學以致用的正確性，通過查閱大量的文獻資料及研究大量汽車的相關書籍，詳細的汽車柴油機技術知識，使我對當前的許多新技術有了一定的了解。希望該設計方案的研究結果會為該實驗臺的制作能夠起到一定的拋磚引玉的作用。本實驗臺的故障設計是根據(jù)現(xiàn)實汽車發(fā)生故障設計出來的，將以較強的實踐應用價值，在實訓實驗教學中發(fā)揮作用，服務教學，協(xié)助教師獲得良好教學效果，同時使學生獲得好的學習效果。如果不給ECU供電，所有需要電源的傳感器就會不能正常使用，顯示值為負值三、參考電路圖 結 論本文以博世柴油共軌發(fā)動機電控系統(tǒng)為研究對象，通過對實驗臺設計研究使實驗臺從硬件結構到故障控制更具合理性，從而使該實驗臺無論是在性能指標上還是在耐用程度上相對于已有的電控實驗臺都具有一定的先進性。如果不給ECU供電，所有需要電源的傳感器就會不能正常使用，顯示值為負值三、參考電路圖 V BOSCHECU故障設置 （42）ECU電源 故障現(xiàn)象所有傳感器傳感器和執(zhí)行器都不工作發(fā)動機不能起動一、故障檢測：解碼器檢測：首先用解碼器調(diào)碼，無法進入電腦，電腦被鎖死 萬用表檢測：把點火開關達到ON檔，用萬用表的紅、黑表筆接ECU的接地的端子，如果電阻無窮大，這說明導線是斷開。若低速繼電器損壞，水溫只有達到高溫時，才開始運轉，同時還是間歇工作方式三、參考電路圖 V四、技術參數(shù)： *線圈阻值電磁閥阻值：1? *端子：886端子為線圈、 830端子為開關7 ECU故障設置BOSCHECU故障設置 （41）ECU電源 + 故障現(xiàn)象所有傳感器顯示負值發(fā)動機不能起動一、故障檢測：解碼器檢測：首先用解碼器調(diào)碼，無法進入電腦，電腦被鎖死 萬用表檢測：把點火開關達到ON檔，用萬用表的紅表筆接ECU的KO1的端子，黑表筆接地，兩端子間如果有12V的電壓差，這說明導線是斷開。二、總結分析當水溫達到800C時，風扇低速檔繼電器有ECU控制接地起作用，電源通過繼電器到降壓電阻后到電動機，風扇低速運轉，給冷卻水降溫，維持發(fā)動機的正常水溫。若低速繼電器損壞，水溫只有達到高溫時，才開始運轉，同時還是間歇工作方式三、參考電路圖 V四、技術參數(shù)： *線圈阻值電磁閥阻值：1? *端子：886端子為線圈、 830端子為開關BOSCH繼電器故障設置 （35）低速風扇繼電器故障現(xiàn)象冷卻風扇沒有低速運轉，只有高速運轉冷卻風扇間歇運轉頻繁一、故障檢測：解碼器檢測：首先用解碼器調(diào)碼，讀取故障碼，顯示結果是沒有故障代碼 萬用表檢測：運轉發(fā)動機，使發(fā)動機冷卻溫度達到80℃，用萬用表的電壓直流檔檢測，首先檢查散熱器風扇保險絲的一端與地的電壓是12V，但另一端與地的電壓也是12V，這說明保險絲是好的；因為只是沒有低速運轉，所以只要檢查低速控制電路，檢查低速風扇繼電器端子85和86與地之間有12V的電壓，檢查端子86所對應的電控單元端子K69，檢測到K69端子與地之間的電壓是0V。關閉發(fā)動機，關閉點火開關，把萬用表調(diào)到電阻檔，檢測繼電器端子86與電控單元端子K90的導線，顯示值為無窮大，這說明導線是斷開二、總結分析當水溫達到800C時，風扇低速檔繼電器有ECU控制接地起作用，電源通過繼電器到降壓電阻后到電動機，風扇低速運轉，給冷卻水降溫，維持發(fā)動機的正常水溫。關閉點火開關，用電阻檔檢測點火開關的ST端子與繼電器座的85端子是無窮大，說明起動繼電器的電源導線是斷開 二、總結分析發(fā)動機運轉必須借助與外力，若起動機出現(xiàn)故障，發(fā)動機是不會工作的。負責ECU的供電、ＥＧＲ的供電 、增壓控制、器預熱塞等裝置的供電，若主繼電器損壞，發(fā)動機相當于癱瘓狀態(tài)，解碼儀是無法連接到發(fā)動機的控制單元的，同時發(fā)動機是不能