초록 ▼

In a method of controlling an exhaust gas system of an internal combustion engine including a nitrogen oxide reducing catalyst capable of adsorbing nitrogen oxide under a lean atmosphere and a nitrogen oxide sensor disposed downstream of the nitrogen oxide reducing catalyst, the nitrogen oxide reduc

In a method of controlling an exhaust gas system of an internal combustion engine including a nitrogen oxide reducing catalyst capable of adsorbing nitrogen oxide under a lean atmosphere and a nitrogen oxide sensor disposed downstream of the nitrogen oxide reducing catalyst, the nitrogen oxide reducing catalyst and the nitrogen oxide sensor are disposed in the exhaust gas system operated mainly under a lean condition, respectively. An output value of the nitrogen oxide sensor is compared with a predetermined value, and an operation condition of the internal combustion engine is temporarily changed into a stoichiometric condition or a rich condition, or a fuel is injected upstream of the nitrogen oxide reducing catalyst, so that the nitrogen oxide adsorbed to the nitrogen oxide reducing catalyst is detached or decomposed, and again the internal combustion engine is operated under the lean condition.

대표청구항 ▼

[ What is claimed is:] [1.] A method of controlling an exhaust gas system of an internal combustion engine which operates mainly under a lean condition, which system comprises a nitrogen oxide reducing catalyst capable of adsorbing nitrogen oxide under a lean atmosphere and a nitrogen oxide sensor d

[ What is claimed is:] [1.] A method of controlling an exhaust gas system of an internal combustion engine which operates mainly under a lean condition, which system comprises a nitrogen oxide reducing catalyst capable of adsorbing nitrogen oxide under a lean atmosphere and a nitrogen oxide sensor disposed downstream of the nitrogen oxide reducing catalyst, said method comprising the steps of:(a) monitoring the output value of said nitrogen oxide sensor,(b) comparing said output value with a predetermined value and determining when nitrogen oxide adsorbed to said nitrogen oxide reducing catalyst is to be detached or decomposed,(c) changing temporarily in response to the determination made in step (b) the operation condition of said internal combustion engine into a stoichiometric condition or a rich condition so that the nitrogen oxide adsorbed to said nitrogen oxide reducing catalyst is detached or decomposed, and(d) returning the operational condition back to its normal value whereby said internal combustion engine is operating again under a lean condition.