Valve actuating mechanism having stopping function for internal

Abstract

Herein disclosed is a valve actuating mechanism having a stopping function for use in an internal combustion engine of the type, in which at least one pair of intake or exhaust valves having an identical function and disposed adjacent to each other are arranged for one cylinder. First and second rocker arms respectively having arms abutting against the upper ends of the paired intake or exhaust valves are rockingly supported on a common support shaft which is fixed on the engine body while having an axis perpendicular to the operating directions of the valves. The first rocker arm is formed with a cylinder bore which is opened toward the second rocker arm to bear a plunger therein whereas the second rocker arm is formed with a guide bore which is opened toward the first rocker arm to fit the plunger therein. A hydraulic actuation chamber defined between the bottom portion of the cylinder bore and the rear end of the plunger is connected with an oil-pressure source through a hydraulic change-over valve for changing the supply and stop of the oil pressure to the actuation chamber. Either of the first or second rocker arm is formed with a cam slipper for sliding contact with a cam which is adapted to rotate in accordance with the run of the engine.