4-CYCLE INTERNAL-COMBUSTION ENGINE

摘要

PURPOSE:To enable the positive lubrication of the cam surface of a vertical cam shaft by a method wherein guide means for guiding lubricant oil toward the cam surface is arranged at a position where it is located above the cam surface of the cam shaft in a cylinder head. CONSTITUTION:Lubricant oil flowed from an upper oil passage 55 to a cam shaft 36 is fed to an upper bearing 64 sealed by an oil seal 63 at the upper surface of a cylinder head 22. Between the upper bearing 64 and the oil seal 63 is formed an oil reservoir capable of storing the lubricant oil which lubricated the upper bearing 64. To the oil reservoir is connected the guide pipe 67 acting as guide means through the oil passage. The guide pipe 67 is arranged in parallel with the cam shaft 36 and opened above the abutted part where an intake cam 39, exhaust cam 40 and locker arm 42 are contacted and then the lubricant oil can be guided toward the abutted part.