EXHAUST EMISSION CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an exhaust emission control device which achieves excellent NOx purifying performance by supplying a suitable amount of HC to a NOx occlusion catalyst during steady operation or the like, and surely suppresses an HC slip even when a rear stage catalyst is inactivated in the case of transient operation or the like at the time of rich spike for a NOx occlusion catalyst.

SOLUTION: An HC supply quantity correction part 103 in an ECU 10 sets a correction coefficient K to a smaller value further from 1.0 as exhaust temperature on an inlet side of a rear stage catalyst 43 falls. The correction coefficient K is multiplied to a basic HC supply quantity set in a basic HC supply quantity setting part so as to reduce and correct a target HC supply quantity. On the basis of the calculated value, a light oil adding injector 50 supplies light oil (HC) into the exhaust.

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