Patent ID: 6196054
Filing Date: 2001-03-06
Classification: F02D,F02P,Y02T

Abstract:
A combustion state detecting device for an internal combustion engine, comprising:an ignition coil which develops an ignition high voltage;an ignition plug which discharges by application of said ignition high voltage to fire a fuel-air mixture within a cylinder of an internal combustion engine;ion current detector including bias means for applying a bias voltage to said ignition plug, said ion current detector operable to detect an ion current corresponding to a quantity of ions generated within said cylinder in which the fuel-air mixture is being burned as an ion current detection signal;knock signal processor operable to produce a knock decision signal representative of a knock occurrence state of said internal combustion engine on the basis of said ion current detection signal; andan ECU which arithmetically operates the control parameter of said internal combustion engine and detects the combustion state in said ignition plug on the basis of said ion current detection signal and said knock decision signal;wherein said knock signal processor sets a detection period of said knock decision signal on the basis of an integral value of said ion current detection signal.