| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of securely maintaining cleaning efficiency higher than required cleaning efficiency even when a storage cleaning part formed of, for example, a NOx catalyst is deteriorated into sulfur poisoning or the like. <P>SOLUTION: The exhaust emission control device includes the NOx catalyst 21 which stores NOx in exhaust when an air-fuel ratio is rich, and cleans (reduces) and emits the stored NOx under a theoretical air-fuel ratio when the air-fuel ratio is lean, and recovers exhaust emission control capacity of the NOx catalyst 21 by executing complete purge which emits approximately all of the stored NOx at one time based on establishment of an execution condition. Such the exhaust emission control device is provided with a program for executing partial purge for emitting a part of the stored NOx partially prior to execution of the complete purge. Furthermore, the partial purge is constantly and repeatedly executed except for during execution of the complete purge. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
