Combustion state-determining system for internal combustion engines
AssigneeHonda Giken Kogyo Kabushiki Kaisha
InventorShigetaka Kuroda
Life of this patent
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Abstract
A combustion state-determining system for an internal combustion engine, includes an ECU which detects misfires occurring in the engine, calculates a rate of misfire occurrence every predetermined number of firing cycles, based on the detected misfires, and determines that the engine is in a misfiring state when the calculated rate of misfire occurrence exceeds a predetermined reference rate. Further, a temperature state of the engine is detected, and the predetermined reference rate is changed based on the detected temperature state.
Claims4
In a combustion state-determining system for an internal combustion engine, including misfire-detecting means for detecting misfires occurring in said engine, misfiring rate-calculating means for calculating a rate of misfire occurrence every predetermined number of firing cycles, based on the misfires detected by said misfire-detecting means, combustion state-determining means for determining that said engine is in a misfiring state when the rate of misfire occurrence, calculated by said misfiring rate-calculating means, exceeds a predetermined reference rate, the improvement comprising:
- temperature state-detecting means for detecting a temperature state of said engine;
- and
- reference rate-changing means for changing said predetermined reference rate, based on the temperature state of said engine detected by said temperature state-detecting means;
- said reference rate-changing means setting said predetermined reference rate to a larger value in one of predetermined low and high temperature regions of the intake air temperature of said engine than a value in a predetermined medium temperature region of the intake air temperature of said engine, and to a larger value in one of predetermined low and high temperature regions of said coolant temperature of said engine than a value in predetermined medium temperature region of said coolant temperature of said engine.
Dependencies are inferred from the claim text.