NAINENKIKANYOCHATSUKAGENKAIKENSHUTSUSOCHI

摘要

PURPOSE:To detect the ignition limit at all times without depending upon the operating comditions of an internal combustion engine such as load by determining combustion time and put-out time from the pressure signals in cylinders and comparing the ratio of both times with a prescribed value. CONSTITUTION:A pressure detector 3 detects the pressure in the cylinders of an internal combustion engine. An angle position detector 1 detects the 1st angle positionI(-thetaA) of the prescribed internal combustion angle in the compression cycle prior to the explosion of the gaseous mixture in the entire stroke of each cylinder and the 2nd angle position II(+thetaA) of the prescribed internal combustion engine in expansion stroke which is in the target position with a top dead center TDC in-between. An ignition detection circuit 2 is constituted of a put-out time operating circuit which operates the put-out time Tm by the detection signal of the detector 1, a combustion time measuring circuit which measures the combustion time TF when the pressure in the cylinder goes higher than the pressure value P(-thetaA) in the angle positionI(-thetaA) and a decision circuit which decides whether the ratio of the time (TF/TM) determined by both circuits is larger or smaller than a prescribed value alpha.