| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an exhaust gas purification processing system capable of decontaminating a nitrogen oxide (NOx) in exhaust gas at high efficiency in a wide temperature range. <P>SOLUTION: In this exhaust gas purification processing system, a fuel injection control means has the function of controlling the fuel injection timing, injection frequency and injection quantity of an injection means for directly injecting fuel into the cylinder of a diesel engine, and a catalyst temperature detection means has the function of detecting and/or estimating the temperature of an NOx trap catalyst. The NOx trap catalyst has the function of trapping NOx in exhaust gas when the air-fuel ratio of exhaust gas is lean, and releasing the trapped NOx and decontaminating the NOx when the air-fuel ratio is rich. When the exhaust gas air-fuel ratio is set rich at an NOx trap catalyst temperature of 200°C or lower, the fuel injection control means makes the sub-injection timing of fuel close to a main injection timing, and an air quantity control means reduces the oxygen quantity to be carried into the engine to increase the H<SB>2</SB>quantity contained in the exhaust gas. <P>COPYRIGHT: (C)2004,JPO</p> |
