| 摘要 |
PURPOSE:To enhance noise suppressing effect in a low-speed light-load operating area, by communicating an intermediate portion of an exhaust pipe in a ship propulsion machine with an intermediate portion of a drain pipe which is a water-sealed closed space during engine operation, and using the closed space as a resonance chamber of exhaust gas. CONSTITUTION:An expansion chamber 23 is formed in a sleeve member 22 supported at a central portion of a casing 14 of a ship propulsion machine. An exhaust gas from an exhaust pipe 26 inserted in the expansion chamber 23 is exhausted through a main exhaust passage 27 and a main exhaust passage 29 into the water. At low speed and light load, the exhaust gas is exhausted through a first auxiliary exhaust passage 30, a second auxiliary exhaust passage 31 and an auxiliary exhaust port 32 into the atmosphere. A drain after engine cooling is discharged from a drain passage 35 to a drain passage 36 of an intermediate member 15. During engine operation, small holes 37 and 38 are water-sealed, and an intermediate portion of a drain pipe 42 becomes a closed space which is utilized as a resonance chamber communicated with the expansion chamber 23 through a communication pipe 43. |
