| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device of an internal combustion engine which is hardly affected by an amount of NOx in an LNT (Lean NOx Trap) and deviation of an A/F sensor and the like and highly accurately detects sulfur poisoning (S poisoning) of the LNT. <P>SOLUTION: The LNT 6 is divided into an LNT 60 and an LNT 61, and A/F sensors 41, 42 and 43 are disposed respectively before, between and after the LNTs 60 and 61. During NOx reduction control of the LNT 6, a ratio of an NOx occlusion amount of the LNT 61 (rear part) to that of the whole LNT 6 is calculated by integration of difference of measurement values of the A/F sensors 41, 42 and 43 and when the ratio is large, it is determined that SOx is accumulated on a front part of the LNT 6 and that the LNT 6 is S-poisoned. <P>COPYRIGHT: (C)2012,JPO&INPIT |
