空燃比对离子电流信号影响的试验研究

利用自主研发的火花塞离子电流信号采集与分析系统,在1台4行程,4气门的丰田8A发动机上,采集了3种负荷下不同空燃比的火花塞离子电流信号,分析研究了空燃比与火花塞离子电流信号的3个典型特征参数的相关性。结果表明,离子电流信号的峰值(Ip)、信号对时间的积分值(S)及信号延续期(Tms)等特征参数值在空燃比为13左右时呈现最大值,而当混合气变稀或变浓时,这些特征参数值都将有不同程度的降低。

Experimental Study on the Influence of Air-fuel Ratio on Ionic Current Signal

The relativity of air-fuel ratio to three typical characteristic parameters was analyzed and researched by sampling different air-fuel ratio spark plug ionic current signals on a four-stroke four-valve Toyota 8A model engine under three different loads with self-developed signal collection and analysis system.The result shows that the three characteristic parameter values,which are the ionic current signal peak value(Ip),the signal integral value(S) with time and the signal continuing period(Tms),reach the maximum when the air-fuel ratio is 13 and will decrease to different extent when the mixture becomes lean or rich.