Patent ID: 8893675

Claim:
A variable valve mechanism for an internal combustion engine, comprising: an input arm that rocks as the input arm is pressed by a cam; an output arm that rocks to actuate a valve; a switching pin that is extended through the input arm and the output arm and that is provided so as to be displaceable between a coupling position at which the switching pin couples the input arm to the output arm such that the input arm and the output arm are relatively non-rockable and a non-coupling position at which the switching pin releases the coupling between the input arm and the output arm; and a displacing device that displaces the switching pin, wherein the displacing device includes: a pressing device that presses the switching pin from any one of the coupling position and the non-coupling position to the other one of the coupling position and the non-coupling position; a return spring that presses the switching pin back from the other one of the coupling position and the non-coupling position to the one of the coupling position and the non-coupling position; and a stopper mechanism that stops a displacement of the switching pin at least at the non-coupling position, the return spring is provided outside of the input arm and the output arm so as to act on one end of the switching pin, the one end of the switching pin being exposed from the input arm and the output arm, and the stopper mechanism includes: a displacement restricting groove that is provided on an outer periphery of the switching pin and that extends in a direction in which the switching pin displaces; and a lock member that is engaged with the displacement restricting groove and that contacts one end of the displacement restricting groove when the switching pin is stopped at the non-coupling position.