VALVE GEAR OF INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To provide a valve gear of an internal combustion engine, capable of fulfilling a lash adjustment function at relatively low cost and capable of stably fulfilling a valve lift according to a cam profile.SOLUTION: A valve gear of an internal combustion engine includes: a camshaft 4 supported rotatably by an engine body 2 and equipped with a first cam 5a which has a tapered cam face 18 expanding in diameter towards one of axial directions; a rocker shaft 6 supported by the engine body; a first rocker arm 7a supported rockably by the rocker shaft 6 and engaging with an engine valve 3; and a first roller 9a supported rotatably by the first rocker arm 7a and abutting against the tapered cam face 7a. The first rocker arm 7a is provided movably in an axial direction of the rocker shaft 6. The valve gear further includes a no-back biasing device 20 which biases the first rocker arm 7a to a large diameter side of the first cam 5a and prevents movement of the first rocker arm 7a to a small diameter side of the first cam 5a.