| 摘要 |
PROBLEM TO BE SOLVED: To prevent unpurified exhaust gas containing a large amount of HC or CO from being emitted to the air, when rich spike is carried out in order to emit and reduce NOX absorbed by an NOX absorbent for an exhaust emission control device wherein the exhaust gas is flowed from one side and the other side of a filter 22 by switching an exhaust switch valve 71 and thereby soot (a fine particle) in the exhaust gas accumulated in the filter 22 whereon the NOX absorbent and an active oxygen releasing agent are carried is disturbed in order to continuously conduct combustion. SOLUTION: By switching the exhaust switch valve 71, the exhaust gas flows from one side and the other side of the filter 22, so that the soot (fine particles) in the exhaust gas accumulated in the filter 22, whereon the NOX absorbent and the active oxygen releasing agent are carried is disturbed. Thus, continuous combustion can be achieved, furthermore, switch of the exhaust switch valve 71, and the rich spike are prevented to be carried out simultaneously. |
