| 摘要 |
PURPOSE:To improve silencer effect through extension of a release exhaust route, and to reduce the size of a drive shaft housing and that of an exhaust tube, so as to facilitate the structure and to cut cost by forming a release expansion room in the fore part of the drive shaft housing. CONSTITUTION:Exhaust gas is released at the time of low rotation of the engine of an outboard motor, and the gas is released on the water by a release exhaust device. The released exhaust gas is let flown from a release hole 11 of an exhaust tube 8 to the upper part of a main expansion room 10. And the gas is sent to a release expansion room 12 of a drive shaft housing 3 through a passage 13 of an engine holder 1. The gas is then passed through the outside of an exhaust tube housing 9, and is placed on cooling water. The gas is then released from a release hole 16 on the water surface, through a second release expansion room 15 on the rear upper part of the drive shaft housing 3. The silencer effect of the release exhaust gas can thus be improved in a simple and inexpensive structure. |
