| 摘要 |
PURPOSE:To improve the steering characteristic, by setting a trim tab so as to constitute a trim tab surface by a surface, in which a Y-Z surface is parallel with a water stream is turned about a Y and Z axes by a required angle, when right angle crossing coordinate axes, in which the Y axis is parallelly set with a propeller shaft and two shafts crossing at a right angle with said Y axis are determined to an X axis and the Z axis in the horizontal direction, are formed. CONSTITUTION:A trim tab is set so that its trim tab surface P2 (A) has a surface rotated by a required angle of phi about a Y axis parallel with a propeller shaft while theta about a Z axis. In this way, every if a tilt angle changes by controlling an outboard engine, steering force (force holding a control handle to be caught), changing not so large in a predetermined speed, can be provided so as to obtain an almost fixed level. Concretely in the case of a screw rotating in the clockwise direction as viewed from the rear, when the trim tab sets its trim tab surface so that the outboard engine, even if it is tilted up, is prevented from being caught to the left, the outboard engine, when it is tilted down, is prevented from being strongly caught to the right, and the steering force is only require for changing not so large even if the tilt angle changes. |
