| 摘要 |
PURPOSE:To decrease noise by forming the release expansion chamber sunk in water of a dropping cooling water storage chamber between inner walls of an exhaust tube housing and a drive shaft housing, for communicating it with a main expansion chamber and a release exhaust port. CONSTITUTION:An exhaust tube housing 33 is arranged in a drive shaft housing 21, and a water chamber 37 for storing dropping cooling water 38 is formed between both housings 21, 33. Moreover, a release expansion chamber 46 is formed so as to be sunk into water 38 in this water chamber 37. This release expansion chamber 46 is communicated with a main expansion chamber 34 through a release second hole 47 formed in the exhaust tube housing 33. At the same time, the release expansion chamber is also communicated with an release exhaust port 49 formed on the upper part of a drive shaft housing 21 through the water chamber 37 and a sub expansion chamber 48. |
