Partially liquid-cooled type forced air-cooling system for internal combustion engine

摘要

In a partially liquid-cooled type forced air-cooling system for an internal combustion engine which includes an air-cooled cylinder and a liquid-cooled cylinder head, a centrifugal cooling fan is provided in front of a crankcase so as to rotate about the fore and rear axis thereof, and a cooling air delivery opening is provided at the back portion of a draft chamber within a fan casing which encircles the cooling fan, so as to orientate throughflow at least to the cylinder. A portion of the encircling wall of the fan casing which is arranged at the side of the cylinder head is provided with an opening. Cylinder is adapted to be cooled adequately by the cooling air flow delivered through the opening and a radiator is adapted to be cooled effectively by the cooling air flow passing through the opening provided in the encircling wall of the fan casing so that at least a portion of the cylinder head can be cooled intensively.