| 摘要 |
PROBLEM TO BE SOLVED: To miniaturize a valve mechanism equipped with a trigger mechanism, and consequently to miniaturize an internal combustion engine. SOLUTION: In an direct drive type valve mechanism equipped with a cam die 22 having a cam part 30a provided on a cam shaft 7 movable in the rotational shaft line and provided with a plurality of cams 31a, 32a, a lifter 24a, and a change-over means having a operation member 47 selectively changing-over a cam moving the lifter 24a and the cam die 22 to the rotational shaft axis line to slide with the lifter 24a, a trigger mechanism T setting the change-over starting timing of the change-over means is arranged below the cam shaft 7. The trigger mechanism T is prevented from the movement of the operation by coming in contact with the operation member 47 by staying in a moving passage of the operation member 47 and sets the change-over starting timing just after closing the engine valve. |
