| 摘要 |
PROBLEM TO BE SOLVED: To provide a more simple structure of an intake/exhaust valve enabling its maintenance work to be reduced.SOLUTION: A valve structure for an engine is provided in such a way that a valve stem 5b of a valve member 5 is supported through a valve guide 6 and it can be moved forward or backward in an axial direction in respect to a cylinder 1, the valve member 5 is moved forward or backward in an axial direction by a driving force of a motor 10 to open or close an intake/exhaust valve. The motor 10 can control a rotating direction, starting and stopping of rotation and a rotating speed of a rotating shaft 10a and has driving force converting means for converting a rotation of the rotating shaft 10a to moving-forward or moving-backward motion of the valve stem 5b in an axial direction. The driving force converting means is constituted by a thread part 11 formed at an outer peripheral surface around an axis of the valve stem 5b and a helical gear 12 fixed to the rotating shaft 10a and provided with teeth engaged with the thread part 11 of the valve stem 5b. In addition, the valve guide 6 is provided with an engagement part 15 engaged with the thread part 11 of the valve stem 5b.SELECTED DRAWING: Figure 1 |
