| 摘要 |
There is provided a forced air-cooling type internal combustion engine which excels in both castability and cooling efficiency of a cylinder head and/or a cylinder block. A forced air-cooling type internal combustion engine (101) includes: a cylinder block (103) molded by casting; a cylinder head (100) molded by casting and overlaid on the cylinder block; a shroud (130) covering at least a portion of the cylinder block and at least a portion of the cylinder head; and a fan (121) for rotating to introduce air to the inside of the shroud. At least one of the cylinder block and the cylinder head includes a cooling fin (10) formed at least in a portion covered by the shroud and a cross fin (20) provided so as to cross the cooling fin, the cross fin being connected to the cooling fin. A thickness ( t' ) of the cross fin at a leading edge ( 20a ) thereof is greater than a thickness ( t ) of the cooling fin at a leading edge thereof. |
