| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve exhaust emission when an internal combustion engine is in a cold state and restrain oil from being diluted. SOLUTION: During a cold state of an internal combustion engine, that is, during warming operation of the engine where a cooling water temperature representing an engine body temperature is less than a specified temperature, an opening/closing timming or operation angle of an intake valve 12 is changed by a variable valve system which changes valve lift curve of the intake valve 12 so that the maximum lift timming of the valve 12 may substantially coincide with the injection timming of fuel. Then, a part 26a of atomized fuel injected from a fuel injection valve 14 interferes with (collides on) a rear part of tappet 12a of the valve 12 so that the atomized fuel 26 reaching a cylinder inner wall 27 decreases. As a result, the atomized fuel 26 which is not yet vaporized, at the ignition timming of the atomized fuel 26, is decreased to improve quality of exhaust gas and to restrain oil from being diluted. With the opening/closing timing or operation angle of the valve 12 varied, there occurs no problem resulting from insufficient vaporization time of atomized fuel 26.</p> |
