| 摘要 |
<p>The disclosed deterioration determination apparatus for an exhaust emission control device used for an internal combustion engine (1) is intended for the exhaust emission control device comprising the first catalyst (3), arranged in the exhaust passage of the engine, for conducting a catalytic action with respect to exhaust gas passed through the exhaust passage and the second catalyst (5), arranged in the downstream of the first catalyst in the exhaust passage (2), for conducting a catalytic action with respect to the exhaust gas passed through the exhaust passage. The deterioration determination apparatus includes the first sensor (6), arranged between the first catalyst and second catalyst, for detecting information about the air-fuel ratio of the exhaust gas passed through the exhaust passage; the second sensor (7), arranged in the downstream of the second catalyst, for detecting information about the air-fuel ratio of the exhaust gas passed through the exhaust passage; and a control unit. The control unit (9) measures the amplitude of the air-fuel ratio of the exhaust gas from the information detected by the first sensor, while feedback controlling an air-fuel ratio of mixture gas supplied to the engine based on the information detected by the second sensor, and determines whether or not the second catalyst deteriorates based on the measured amplitude of the air-fuel ratio. <IMAGE></p> |
