| 摘要 |
PURPOSE:To obtain the highly reliable selective actuation of deactivating function by a simple structure wherein the connection between two rocker arms, which actuate each pair of valves, is selectively made possible by means of a hydraulically driven plunger in an internal-combustion engine providing with each one pair of suction and exhaust valves per one cylinder. CONSTITUTION:Two rockers arms 19 and 20 adjacent to each other are pivotally supported on a fulcrum shaft 18 at the upper part of a cylinder head 4. A cam splipper 27, with which the cam on a camshaft slidably contacts, is arranged on the upper surface of the rocker arm 19. In addition, a cylinder hole 33, in which a plunger 32 is slidably housed, is formed on the rocker arm 19 and at the same time a bottomed guide hole 34, in which the plunger 32 can be inserted, is bored on the rocker arm 20. A guide pin 42 is inserted in the guide hole 34 and energized by a spring 44 in the direction of the plunger 32. In such a structure as mentioned above, only a suction valve is open and closed at the low engine rotating speed and both the suction and exhaust valves are open and closed by making both the rocker arms 19 and 20 into an integral body through the protrusion of the plunger 32 by means of hydraulic pressure at the speed exceeding the set rotating speed. |
