| 摘要 |
PURPOSE:To primarily separate oil mist mixed in blow-by gas which flows through a throttle passage, so as to enhance the effect of separation by forming both the throttle passage in the way of a breather passage placed at the side of a cylinder block and an expansion chamber at the upper side of the throttle passage. CONSTITUTION:A breather passage 17, slanting to one side with respect to the longitudinal direction, is formed at the intake side of an engine body E. The passage 17 consists of a passage 17b formed in a cylinder block B and a passage 17h formed in a cylinder head H. The open lower end of the passage 17b is communicated with a crankcase 15 while the open upper end of the passage 17h is communicated with a tappet cam chamber 13. The passage 17b has both a throttle passage 18 formed in the way thereof and an expansion chamber 19 formed at the upper side of the passage 17b. The expansion chamber 19 opens on the deck face of the cylinder block B and is communicated with the passage 17h. When blow-by gas flows through the passage 17b, oil mist mixed in said gas is separated primarily. |
