| 摘要 |
PROBLEM TO BE SOLVED: To provide a misfire detection device which is excellent in the detection accuracy of a misfire.SOLUTION: In a misfire detection device 1 of an internal combustion engine, leveling value calculation means 30 levels actual measurement values ω0 in expansion strokes of cylinders 11a to 11f by using a specified leveling value ω60 sm in the past expansion stroke. First variation amount calculation means 40 calculates a difference (first variation amount) between the actual measurement value ω0 in the expansion stroke of the objective cylinder 11a and a leveling value ω1 sm in the expansion stroke immediately before the expansion stroke. Leveling value variation amount calculate means 50 calculates a difference (leveling value variation amount) between a leveling value ω3 sm in the expansion stroke before the integer-multiplied rotation of a crankshaft rather than the first cylinder 11a, and a leveling value ω4 sm immediately before the leveling value. Second variation amount calculation means 60 calculates a difference (second variation amount ΔΔω sm) between the first variation amount and the leveling value variation amount. Misfire detection means 70 detects a misfire by comparing the second variation amount ΔΔω sm and a prescribed value KMFω.SELECTED DRAWING: Figure 3 |
