| 摘要 |
PROBLEM TO BE SOLVED: To provide an internal combustion engine which improves fuel consumption by strengthening a tumble flow while suppressing knocking.SOLUTION: A valve shaft 16 of an intake valve 7 is inclined to a perpendicular line 19 of a shade-shaped valve element 17. The intake valve 7 is rotated only in a certain range on an initial side of a forward stroke and then advances in state of completing the rotation. A strong tumble flow can be obtained by suppressing the inflow resistance of air since the intake valve 7 completes the rotation at an initial stage of the advancement. The shade-shaped valve element 17 of the intake valve 7 is rotated so that an obtuse-angle end 17a escapes into a tumble flow forming recess 34 of a piston 4. Thus, a top face of the piston 4 requires no escape groove for avoiding collision of the intake valve 7. As a result, such problems that fuel retained in the escape groove self-ignites to cause knocking can be evaded. |
