Patent ID: 6679052
Filing Date: 2004-01-20
Classification: F01N

Abstract:
An emission control apparatus that is applied to an internal combustion engine having a combustion chamber, and that controls emissions discharged from the combustion chamber, the emission control apparatus comprising:an exhaust passage that conveys an emissions discharged from the combustion chamber, and that includes a trunk passage, and a loop passage having a first partial loop passage and a second partial loop passage that branch from the trunk passage; a path change portion that is provided in a connecting portion between the trunk passage and the loop passage, and that includes a switching valve that is set in a first state where emissions in the loop passage flows through the first partial loop passage and the second partial loop passage in that order, and is set in a second state where emissions in the loop passage flows through the second partial loop passage and the first partial loop passage in that order; a first emission control portion that is provided in the loop passage, and that has a filter that occludes and purifies at least a particulate substance present in the emissions, one side face of the filter communicating with the first partial loop passage, and another side face of the filter communicating with the second partial loop passage; a second emission control portion that is provided in the trunk passage downstream of the path change portion, and that purifies at least a specific gaseous substance present in the emissions; a recovery agent injection portion that injects a recovery agent which recover an emission control function of the first emission control portion and an emission control function of the second emission control portion, into at least one of the first partial loop passage and the second partial loop passage; and a control portion that recovers the emission control functions of the emission control portions by adjusting at least one of a switching operation of the switching valve and an injecting operation of the recovery agent injection portion.