Patent ID: 6976356
Filing Date: 2005-12-20
Classification: B01D,F01N,F02D,Y02A,Y02T

Abstract:
1. An exhaust gas purifier for an internal combustion engine, comprising: a NOx catalyst device disposed in an exhaust path of the engine, and occluding NOx contained in an exhaust gas when an air-fuel ratio in the exhaust gas is lean and releasing occluded NOx when the air-fuel ratio in the exhaust gas is stoichiometric or rich; and reducer-supplying means for supplying a reducer for reducing NOx released from said NOx catalyst device when an actual air-fuel ratio in the exhaust gas substantially becomes a stoichiometric air-fuel ratio after an operating mode of the internal combustion engine is switched from a lean air-fuel ratio mode to a stoichiometric air-fuel ratio mode or a rich air-fuel ratio mode.