| 摘要 |
<p>PURPOSE:To attain the exhaust purification rate of nearly the same degree as that at the nondegraded time while preventing the excessive consumption of a bettery at the degradation generated time of a first catalyst carrier. CONSTITUTION:The exhaust passage 3 of an engine 1 is provided with a first catalyst carrier 4 disposed in proximity to the engine 1, a second catalyst carrier 5 disposed more on the exhaust lower reaches side than the first catalyst carrier 4, and an electrically heated carrier 6 disposed between the first and second catalyst carriers 4, 5 and changed in temerature according to the current flowing quantity. An exhaust emission control device is provided with degradation detecting means 7, 8 for detecting the degraded state of the first catalyst carrier 4, and a correcting means 9 for increase-correcting the current flowing quantity to the electrically heated carrier 6 at the time of detecting the degradation of the first catalyst carrier 4 by the degradation detecting means 7, 8. Accordingly, when the degradation of the first catalyst carrier 4 is generated, the current flowing quantity to the electrically heated carrier 6 is increase-corrected to activate the second catalyst carrier 5 early. The exhaust purification rate on the whole can be thereby maintained almost to the same as that in the nondegraded state.</p> |
