EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To efficiently emit SOx in addition to preventing of an offensive odor of exhaust gas, by low suppressing concentration of H2S generated to be accompanied with emission of SOx from a catalyst, in an exhaust purifying device for an internal combustion engine. SOLUTION: When a catalytic temperature Tcat of a storage type NOx catalyst 25 is a prescribed high temperature Tcat or more, a rich state is gradually generated in the case of making exhaust air/fuel ratio rich.