Exhaust purification device of internal combustion engine

摘要

PCT No. PCT/JP93/00778 Sec. 371 Date Feb. 14, 1994 Sec. 102(e) Date Feb. 14, 1994 PCT Filed Jun. 10, 1993 PCT Pub. No. WO93/25806 PCT Pub. Date Dec. 23, 1993.A NOx absorbent (17) is disposed in an exhaust passage of an internal combustion engine. This NOx absorbent (17) absorbs the NOx when the air-fuel ratio of the exhaust gas flowing into the NOx absorbent (17) is lean and releases the absorbed NOx when the air-fuel ratio of the exhaust gas flowing into the NOx absorbent (17) becomes rich. It estimates the amount of NOx absorbed in the NOx absorbent (17) from the engine load and the engine rotational speed and when the amount of the estimated NOx becomes the maximum NOx absorption capacity of the NOx absorbent (17), makes the air-fuel ratio of the exhaust gas flowing into the NOx absorbent (17) rich.