基于催化器放热效应的失火故障阀值匹配方法研究

Misfire Fault Threshold Calibration Research Based on the Thermal Response of the Catalyst

在各工况下发动机持续失火导致催化器损坏的失火故障阀值匹配是失火诊断的重要内容。文章基于对失火状态时催化器放热效应的特性研究及试验验证,提出了离线匹配该失火率的方法,并在多个项目上进行了试验验证。结果表明:通过该方法确定的失火率与常规通过转毂试验确定失火率的差异较小,该方法的实施及应用,可节省匹配工时及提升转毂试验匹配精度。

The calibration of misfire rate relevant to catalyst damage in the different engine operation with the sustained engine misfiring is the essential part of misfire diagnosis.Through the research and test validation on the thermal response of the catalyst during the sustained misfiring,the offline-calibration method about the misfire rate threshold is put forward.The test result shows:the misfire rate threshold by the offline analyses is closed to the general method by roller test;the offline method is ok for the calibration of general project,and the matching man-hours can be saved and the matching accuracy can be improved.