| 摘要 |
Provided is an exhaust purification apparatus for an internal combustion engine capable of reducing the quantity of a catalytic noble metal used in a catalytic converter without reducing the purification performance. A catalytic converter unit (3) contains an OSC material in addition to a catalytic noble metal, and includes an upstream catalytic converter (31) and a downstream catalytic converter (32) provided on the downstream side of the upstream catalytic converter (31). The upstream catalytic converter 31 contains more OSC material than the downstream catalytic converter (32), and the downstream catalytic converter contains more catalytic noble metal than the upstream catalytic converter (31). The exhaust purification apparatus (2) is equipped with an LAF sensor (61), an oxygen concentration sensor (62), and an ECU (5) that adjusts the air-fuel ratio of the engine (1) based on signals (KACT, VO2) output from the oxygen concentration sensor (62) and the LAF sensor (61) such that the air-fuel ratio of the exhaust flowing into the downstream catalytic converter (32) matches a target value set in the vicinity of a theoretic air-fuel ratio. |
