| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust gas purging system of an internal combustion engine capable of preventing emissions of HC, CO into atmosphere when a rich control is complete, in an exhaust gas purging system that uses a NO<SB>X</SB>absorption and reduction type catalyst for purging NO<SB>X</SB>in the exhaust gas. <P>SOLUTION: An exhaust gas purging system is configured to provide a first exhaust gas purging device 31 consisting of the NO<SB>X</SB>absorption and reduction type catalyst at an exhaust passage 30 of an internal combustion engine 10, as well as oxygen concentration sensors 34, 35 at upstream and downstream of the first exhaust gas purging device 31, respectively. To the exhaust gas purging system 1 that controls to terminate the rich control, when differences between oxygen concentrations detected with the oxygen concentration sensors 34, 35 are smaller than the predetermined criterion, during a rich control stage for purpose of the recovery of a catalytic function of the first exhaust gas purging device 31, a second exhaust gas purging device 32 that purges HC and CO is disposed at the downstream of the first exhaust gas purging device 31. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
