| 摘要 |
PURPOSE:To obtain long-life and powerful swirl and turbulence and improve combustion properties by directing a sub-intake port toward the tangential direction of a combustion chamber while providing a parallel component which is parallel to the surface of a cylinder deck, on the rear end opening of said sub- intake port. CONSTITUTION:One end of a sub-intake port 30 is opened to an intake port 2P while its other end is opened, being directed to the tangential direction 32 of a combustion chamber 8. And, a parallel component which is parallel to a cylinder deck surface 36, is provided on the rear end opening of a lower course side sub- intake port 30-2. Thereby, an intake air from the sub-intake port 30 is linearly introduced into the horizontal-direction component of the combustion chamber 8 via the lower course side sub-intake port 30-2, being guided to flow along the peripheries of the combustion chamber 8 and a cylinder. Accordingly, long-life and powerful swirl and turbulence can be given to the flow of intake air from an intake port 4. Therefore, in the sub-intake port 30, is provided a valve 38 for opening the port 30, which is driven by a locker arm 22, equally to a suction valve 6. |
