Patent attributes
A cylinder head cover, on which a breather chamber wall and control valve device are mounted is not enlarged while the capacity of a breather chamber is increased. For an internal combustion engine, control valve devices, which control the operation of a hydraulic valve stop mechanism that serves as a cylinder stop mechanism, and an outer chamber wall of a breather chamber wall that forms a breather chamber into which a blow-by gas flows, project in a predetermined direction and are mounted on the outer surface of a top wall of a cylinder head cover. When viewed in the predetermined direction, the outer chamber wall has an overlap section that overlaps with a part of the control valve device. Therefore, the overlap section is covered in the particular direction by the control valve device.