Variable valve actuation device for internal combustion engine

A variable valve actuation device far an internal combustion engine, far varying a phase difference between is pair of intake valves provided per cylinder of the engine or a phase difference between a pair of exhaust valves provided per cylinder of the engine, comprising:

• an assembled camshaft including a shaft member which is driven by an output from a crankshaft of the engine and which has a first cam formed thereon for actuating one of the pair of intake or exhaust valves, and a cam lobe having a second cam far actuating the other of the pair of intake or exhaust valves and fitted around the shaft member so as to be displaceable relative to the shaft member in a circumferential direction of the shaft member;
• and
• a cam phase change unit configured to vary a phase of the second cam relative to that of the first cam,
• wherein the cam lobe has a hollow boss fitted around the shaft member,
• the boss protrudes from one side of the second cam located opposite the first cam in a width direction of the second cam over a distance greater than the width of the second cam, and has a connecting member connected to a control member for transmitting a variable cam phase, and
• the connecting member is arranged in a position closer to an end portion of the boss opposite the second cam than to the second cam.