| 摘要 |
PURPOSE:To make it possible to dispose an ignition plug at the axial position of a cylinder and to lighten the valve mechanism by disposing one cam shaft, which opens or closes both of a suction valve and an exhaust valve, in the proximity of the one valve. CONSTITUTION:An ignition plug 14 is disposed at a position of the cylinder axis Ac and a suction valve 10 and an exhaust valve 11 are provided with a plane including the axis pinched therebetween. The cam shaft 21 which provides an opening and closing force to both valves 10 and 11 is disposed in the proximity of the suction valve 10, and the suction valve 10 is actuated through a first can follower 25. The exhaust valve 11 is actuated through a second cam follower 31 and a push rod 34 which are pivotally supported on a shaft 28 and a locker arm 33 which is pivotally supported on a shaft 29. Since the cam shaft 21 is drawn near to one side, the ignition plug can be disposed on the cylinder axis Ac, and hence one cam shaft 21 suffices. Accordingly, it is possible to simplify and lighten the valve mechanism. |
