| 摘要 |
PURPOSE:To improve an oil removing effect as well as to reduce a rate of oil consumption, by interconnecting a return oil passage, opening beneath an oil level inside a crankcase, to an expansion chamber, while having it interconnected to an oil collection chamber. CONSTITUTION:Blow-by gas in a crankcase 12a is led into an air cleaner 6 in a suction system, making it flow back to a combustion chamber. A breather hole 18 is installed in a lower part of a cylinder 10, interconnecting to an expansion chamber 19 at the backside. A return oil passage 22, opening beneath an oil lever inside the crankcase 12a, is interconnected to this expansion chamber 19, while it is interconnected to an oil collection chamber 8 in the labyrinthine structure installed at the upstream side of the air cleaner 6, and this oil collection chamber 8 is set up in a higher position than the expansion chamber 19. Thus, with throttling of the breather hole and expansion in the expansion chamber, oil is efficiently removable from the blow-by gas. In addition, the flow-down of oil is in no case checked by a backflow of the blow-by gas and, what is more, such oil as being too much for removal is eliminated at the oil collection chamber 8 so that a rate of oil consumption is reducible. |
