| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance the warming performance of a catalyst in an internal combustion engine of inner cylinder injection type. SOLUTION: When a catalyst 33 is not activated, additional fuel injection in one or more runs is made in expansion stroke or exhaust stroke after ignition, and the exhaust temp. is raised for activation of the catalyst 33 by post- combustion the added fuel by the flames of the main combustion. At this time, the exhaust gas SCV21 is controlled to the close side, and the valve opening timing of the exhaust valve is controlled to the advance side, while swirls are produced in the gas flow in the cylinder in the exhaust stroke, and part of the combustion gas in the cylinder is allowed to flow toward one of the exhaust ports 19b. Thereby the gas flow in the cylinder is promoted, and turning the added fuel in particulates is promoted, and also the mixing ad agitation of the added fuel with inner cylinder gas are promoted, and thereby the injected additional fuel is completely combusted to preclude generation of smokes, and the exhaust temp. is raised to make smoke prevention and early activation of catalyst compatible.</p> |
