| 摘要 |
PROBLEM TO BE SOLVED: To make exhaust flow smooth in the inside of an exhaust passage, make its molds inexpensive, and provide an exhaust passage outlet structure for an outboard engine, in which the degree of freedom for its opening shape is great. SOLUTION: An exhaust port 11 opened to a cylinder bore 8 to be formed in the cylinder block 2 of a vertical type engine 1, is communicated with an exhaust passage 12 curved downward, and it is so constituted that a fitting part 26 can be mounted to the outlet port 25 of the exhaust passage 12. An exhaust cover 14 is mounted to a side releasing part in an exhaust space which is formed sideward in the side part at the exhaust port side of the cylinder block 2 by means of pattern draw molding, so as to be formed into an upper exhaust passage 12a, and an exhaust port outlet portion is formed at the lower part of the cylinder block by shaping the lower part of the cylinder block downward by means of pattern draw molding. The fitting part 26 is detachably mounted to the lower end surface of the cylinder block 2, and the exhaust guide 27 of the fitting part 26 is provided with a guide surface 28 continuous to the exhaust cover 14 while the aforesaid guide surface is being flush with the inner surface of the exhaust passage. |
