| 摘要 |
PURPOSE:To improve combustibility of mixture and charging efficiency of an internal combustion engine, by employing an arrangement in which a swing cam having different cam surfaces is held in contact with the intake or exhaust valve so that the valve lift is increased with increase of engine speed. CONSTITUTION:A swing cam 4 having cam surface 10 consisting of basic arcuate portion 10A and lift arcuate portion 10B is held in contact with tappet 22 at the top of intake or exhaust valve 8. Rocker arm 3 is held in contact at its one end 3a with another contact surface 11 of rocker arm 4. On the other hand, arm 3 is held in contact at the other end portion with pivot 5 of piston 15 which is slided in hydraulic cylinder 6. Further, cam 1 rotated with operation of engine is held in contact with arm 3 at its top for transmitting motion of cam 1 to the valve 8 via swing cam 4. With such an arrangement, when piston 15 is raised with increase of engine speed, downward movement of arm 3 is increased and it becomes that valve 8 is opened and closed by the lift arcuate portion 10B of cam 4, so that the valve lift can be increased. |
