| 摘要 |
PURPOSE:To improve a supporting structure for each of the journals positioned at both sides of the cams of a cam shaft in an overhead cam type internal combustion engine, to facilitate a forming operation for each of the bearings supporting each of the journals and to make a shortened axial length of the cylinder head. CONSTITUTION:In a V-shaped four cylinder type internal combustion engine, an intake valve cam shaft 61 and an exhaust valve cam shaft 62 are arranged in parallel in a mechanism chamber R formed in an interior between the cylinder head 3 and the head cover 4. The cam shaft 61 (the same with 62) has a cam 7, first and second journals 81, 82 positioned at both sides of the cam. Lower half circumference of the first journal 81 is supported by a bearing 10 having a semi- circular sectioned inner circumference surface of an upper surface of the supporting part 9 positioned in the cylinder head 3 and its upper semi-circumference is supported by the bearing 16 of the cam shaft holder 15. In turn, the upper semi-circumference of the second journal 82 is supported by the bearing 17 of said holder 15 and its lower semi-circumference is released. |
