| 摘要 |
<p>PROBLEM TO BE SOLVED: To exactly remove a purification capacity lowering material adsorbed to a lean NOx catalyst by operating a fuel injection valve to supply additional fuel to the lean NOx catalyst according to the operating condition of an internal combustion engine detected by an operating condition detecting means. SOLUTION: A cylinder injection type internal combustion engine comprises an exhaust passage for discharging exhaust gas from a combustion chamber and a lean NOx catalyst 13A for absorbing nitrogen oxides (NOx) in the exhaust gas during the lean combustion operation. Further, the engine comprises an operating condition detecting means, wherein the means is provided with an adhering quantity estimating means 102 for estimating the adhering quantity of a purification capacity lowering material to the lean NOx catalyst 13A. Further, the engine comprises a fuel injection valve control means 103 for operating a fuel injection valve 3 according to the operating condition of the internal combustion engine detected by the operating condition detecting means to supply additional fuel to the lean NOx catalyst 13A. Thus, it is possible to remove the purification capacity lowering material absorbed in the lean NOx catalyst.</p> |
