| 摘要 |
PURPOSE:To eliminate occurrence of a swirl stream in the rear of water guide ports and prevent exfoliation of paint or erosion of a body, by forming the cooling water guide port located in the rear end of a flow direction in such a manner that its opening is arranged at a right angle with or obliquely rearward to the flow direction. CONSTITUTION:An introducing port body 14 is mounted to a cooling water introducing port 13 in a lower casing 3 of an outer board engine main unit, then to the introducing port body 14 there are opened a quantity of cooling water guide ports 20a, 20b, 20c lined vertically in rows longitudinally with each row in parallel arrangement. The water guide ports 20a, 20b in front two rows are diagonally opened toward the front against a flow direction A of water while the water guide port 20c in the rearmost row is opened almost at a right angle with the before said direction A. At sailing water is sucked from the water guide ports 20a, 20b. Further if a surplus amount of water is produced in the sucked water or negative pressure is generated in the outside rear part, water in the inside flows out from the water guide port 20c toward the direction B. The water flowing out toward the direction B, being at a right angle with respect to the before described direction A, is easy to flow rearward with rare occurrence of turbulence in a flow of water to the direction A. |
