以柴油引擎管理系統感知器訊號之噴油時間
作為引擎故障診斷之研究

本研究以SAAB四行程渦輪柴油引擎為實驗載具，探討引擎管理系統感知器信號輸出端斷路時對噴油時間影響。設定引擎在正常工作溫度且無負載狀態下，引擎轉速區分成五個階段(熱怠速800、1500、2000、2500、3000RPM)作為測量轉速基準，模擬各種感知器斷路故障於不同轉速；並利用Acute DS-1002數位儲存示波器，擷取噴油嘴波形及時間，藉此與正常狀態下引擎噴油時間作比較。實驗結果顯示，當空氣流量計感知器故障時，對於引擎性能及燃油噴射時間的影響因素最為顯著。本研究分析方式及成果可應用作為日後引擎管理系統感知器故障斷判分析之參考；亦可加強現場維修技師對於感知器故障的判斷能力，提高故障診斷的正確性，進而加速引擎的維修速度。

關鍵字

噴油時間；噴油波形；空氣流量計感知器

並列摘要

In this study, the four-stroke SAAB turbo-diesel engine is treated as the experimental vehicle to discuss the engine management system sensor output signal as the injector open time. The engine is set in the normal operating temperature without load. The engine rotation rate is divided into five phases (hot idle 800, 1500, 2000, 2500, 3000 RPM) as a baseline measurement of rotation rate to simulate a variety of sensor circuit fault at different rotation rates; and this study uses Acute DS-1002 digital storage oscilloscope to capture injector waveform and time in comparison with the normal state of the engine fuel injection time. The experimental results show that when the mass flow sensor failed, the engine performance and fuel injection timing are the most significant factors. The analysis of this study and the results can be applied to the future engine management system education and taken as a reference of the sensor fault analysis; it can help the site technicians to enhance the ability of determining sensor failure, improve the accuracy of fault diagnosis, and accelerate the maintenance speed of engine.