| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a controller capable of detecting unexpected fluctuation of amount of engine (combustion chamber) exhaust NOx and deterioration of performance of lean NOx catalyst separately to prevent erroneous diagnosis of deterioration of lean NOx catalyst and controlling the catalyst in the optimum condition. <P>SOLUTION: This engine controller is provided with the lean NOx catalyst having functions for storing NOx exhausted from the combustion chamber during lean operation and desorbing/purifying the stored NOx during rich operation in an exhaust passage. This controller is provided with a sensor detecting amount or concentration of NOx on the downstream side of the lean NOx catalyst, a computing means A for computing amount of NOx on the downstream side of the lean NOx catalyst during lean operation based on outputs of the sensor, a computing means B for computing amount of NOx stored in the lean NOx catalyst, and a means for computing NOx storage capacity of the lean NOx catalyst and amount of NOx exhausted from the combustion chamber during lean operation based on the results of computation by the computing means A and B. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
