A method for determining a air force substance ratio of an internal combustion engine on the basis of an ionization current

摘要

A method for determining a air force substance ratio of an internal combustion engine on the basis of an ionization current for detecting an ionization current, of the ignition inside of a combustion chamber of the internal combustion engine, comprising the steps of:Measuring a generation duration, in which the ion current is greater than a set defining value, as long as the ion current is generated;Calculating a divisor for calculating a fluctuation rate of the generation duration of the ionization current, on the basis of a plurality of measured generating durations;Calculating the fluctuation rate of the generation duration of the ion current by means of weights in a direction for increasing the calculated divisor; andDetermining that an air fuel ratio in the case of excessively high that the calculated fluctuation rate equal to or larger than a predetermined value is.