| 摘要 |
PURPOSE:To prevent the occurrence of knocking as well as to improve a degree of charging efficiency, by forming a guide wall situated more downward than a head part of a suction valve in time of maximum lifting, into a state of being substantially tilted. CONSTITUTION:A guide wall 7, directing suction air to a specified direction, is installed in position along a part of the circumference of a suction valve seat 5. At the guide wall 7, a lower side wall 7a situated more downward than a heat part 6a of a suction valve 6 in time of maximum lifting becomes a curved surface form being substantially tilted against an upper side wall 7b rising steeply. Thus, with the formation of a swirl, the occurrence of knocking is preventable and, what is more, especially in time of high load driving, suction resistance is reduced to some extent whereby a degree of charging efficiency can be well heightened. |
