EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To reliably regenerate an NOX storage reduction catalyst device situated at an engine exhaust system and absorbing NOX when vicinity atmosphere is in a lean air-fuel ratio without worsening a fuel consumption rate and regenerated during a stoichiometric air-fuel ratio or regeneration air-fuel ratio being a rich air-fuel ratio. SOLUTION: This exhaust emission control device comprises a bypass means 71 enabling bypass of at least a part of exhaust gas through the NOX storage reduction catalyst device; and a fuel feed device 74 to feed fuel to the vicinity of the NOX storage reduction catalyst device. An internal combustion engine can execute low temperature combustion and ordinary combustion to execute combustion in a lean air-fuel ratio and select a first regeneration means to bring vicinity atmosphere into a regeneration air-fuel ratio by exhaust gas when low temperature combustion is executed in a regeneration air-fuel ratio during regeneration of the NOX storage reduction catalyst device; and a second regeneration means to bypass at least a part of exhaust gas by a bypass means during ordinary combustion and feeding fuel by a fuel feeding device to bring vicinity atmosphere into a regeneration air-fuel ratio.