| 摘要 |
PROBLEM TO BE SOLVED: To provide an abnormality determination device of an oxidation catalyst which is arranged in an exhaust passage.SOLUTION: An abnormality determination device comprises: a cetane number detection part which detects a cetane number of fuel; a required exhaust gas temperature calculation part which calculates a required exhaust gas temperature Tce on the basis of the detected cetane number so that the temperature becomes high as the detected cetane number becomes low; an upstream-side exhaust gas temperature raising part which raises a temperature of an exhaust gas flowing into a DOC; and an abnormality determination part which determines whether or not the DOC is abnormal on the basis of a comparison result of a temperature difference ΔT before and after the DOC and a prescribed threshold ΔTth after raising an upstream-side exhaust gas temperature Tin which is detected by using the upstream-side exhaust gas temperature raising part up to the required exhaust gas temperature Tce when it is determined that the detected upstream-side exhaust gas temperature Tin is lower than the calculated required exhaust gas temperature Tce when a condition that an abnormality of the DOC should be determined is established. By this constitution, the determination device can prevent erroneous determination.SELECTED DRAWING: Figure 4 |
