| 摘要 |
PROBLEM TO BE SOLVED: To always detect misfires occurring in an internal combustion engine with high accuracy irrespective of the running condition of the engine. SOLUTION: In the misfire detector of an internal combustion engine, a crank angular speed fluctuation amount is usually calculated for each cylinder based on a rotational angle signal NE corresponding to the rotation of a crankshaft and the occurrence of misfires in the engine is detected by comparing the calculated cylinder crank angular speed fluctuation amount with a specified misfire determination value. Here, under the condition that the engine is normally ignited, an inter-cylinder crank angle difference is calculated by an electronic controller 9 and the calculated crank angle difference is learned for each cylinder of the engine and each running condition. On the other hand, in the electronic controller 9, a crank angular speed is calculated for each cylinder by correcting the crank angle difference based on learned values regarding each corresponding cylinder and each running condition of the engine and crank angular speed fluctuation amount for each cylinder compared with the misfire determination value is calculated based on changes in the obtained crank angular speed. |
