INTERNAL COMBUSTION ENGINE HAVING BREATHER DEVICE

PROBLEM TO BE SOLVED: To improve gas-liquid separation function in a breather chamber, and to reduce the number of parts of a breather device and reduce a size of an internal combustion engine in an axial direction of a camshaft, in a breather device performing gas-liquid separation by using rotation of the camshaft. SOLUTION: The internal combustion engine comprises: a valve gear 20 having the camshaft 21 provided with intake cams 22, 23 and exhaust cams 24, 25 respectively driving to open/close an intake valve 11 and an exhaust valve; the breather device provided with an upstream breather chamber 40 and a downstream breather chamber 50 in which blowby gas flows through a chain chamber 30. The breather chamber 40 is constituted of through holes 41 constituted by axially arranging a plurality of hole parts 42-44 formed to the camshaft 21 and having different diameters. The through holes 41 are opened to the chain chamber 30 at a shaft end part 21a of the camshaft 41, and is opened to the breather chamber 50 at the other shaft end part 21b of the camshaft 21. The breather chamber 50 is formed by a cam holder 32. COPYRIGHT: (C)2009,JPO&INPIT