Abstract: A variable valve operating apparatus for an internal combustion engine is provided which includes a helical wall part provided in a guide rail for changing valve opening characteristics of a valve and a projection part, and can secure a contact area between the two when the two are engaged, thus successfully reducing the contact pressure generated between the two. The placement of the projection part with respect to the helical wall part is determined such that the central axis line of the projection part and the central axis line of a camshaft perpendicularly intersect with each other in a state in which the projection part is protruded toward the guide rail by an actuator.

Abstract: Provided is a valve operating apparatus for an internal combustion engine that, with respect to a configuration including urging means that urges a transfer member that transfers an acting force of a cam to a valve, can facilitate manufacture of a support portion of the urging means and suppress an increase in the mass of the internal combustion engine. A first rocker arm is provided that is interposed between a main cam and a valve and that transfers an acting force of the main cam to the valve. A lost motion mechanism is provided that urges the first rocker arm in one direction. A holding member is provided that holds the lost motion mechanism. The lost motion mechanism is attached to a spark plug tube through the holding member.

Abstract: A variable valve operating apparatus for an internal combustion engine is provided which includes a helical wall part provided in a guide rail for changing valve opening characteristics of a valve and a projection part, and can secure a contact area between the two when the two are engaged, thus successfully reducing the contact pressure generated between the two. The placement of the projection part with respect to the helical wall part is determined such that the central axis line of the projection part and the central axis line of a camshaft perpendicularly intersect with each other in a state in which the projection part is protruded toward the guide rail by an actuator.