| 摘要 |
<p>PURPOSE:To improve the filling efficiency of an intake extending from low revolution to high revolution of an engine by a method wherein a variable mechanism which controls the valve timing of at least one intake valve is provided as the total opening valve duration of a pair of valves is varied according to the operational condition of the engine. CONSTITUTION:A high load intake port 3b is closed by a open-close valve during low load operation of an engine, an intake is fed into through only low load intake port 3a. Thereby, the intake flow velocity is high speed and a swirl is generated in a cylinder, accordingly, the combustion ability is improved during low load operation of the engine. By variable mechanisms 11, 12 during low load operation of the engine, the valve timing of the second exhaust valve 6b is variably controlled to be turned at the delay side, also the valve timing of the high load intake valve 5b is variably controlled to be turned at the delay side. In this case, the valve timing of the low load intake valve 5a is fixed, the valve timing of the high load intake valve 5b having excellent filling efficiency is turned at the delay side, accordingly, said control is effective for improving of the filling efficiency.</p> |
