JPS6231677B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rudder arrangement for a high-speed watercraft.

1 and 2 show typical examples of the rudder arrangement of conventional high-speed boats. FIG. 1 is a side view, and FIG. 2 is a bottom view, where 1 is a rudder, 2 is a propulsion device, and 5 is a hull.

Normally, the rudder 1 of a ship is placed immediately after the propulsion device 2, but this means that if the rudder 1 is placed in the flow accelerated by the propulsion device 2, it will have a larger rudder force for the same rudder angle. This is because a large turning moment can be applied to the hull 5.

Even in a two-shaft high-speed boat, the rudder 1 is usually placed immediately after the propulsion device 2, as shown in FIGS. 1 and 2.

However, recently, when high-speed boats turn at maximum power, when the rudder angle is 15° to 20° or more, as shown in Figure 4,
Increasing the steering angle may actually reduce turning power,
Alternatively, a performance deterioration phenomenon occurs in which the expected turning force cannot be obtained even if the rudder angle is increased, which may lead to problems in ship handling.

This is related to the fact that the speed is faster than before, and the cause will be explained with reference to FIG.

The flow at the bottom of the high-speed boat is directed to the rudder 1 as shown by arrow 3.
Since the flow is outward at this position, if the rudder 1 is angled in the direction shown in the figure, the angle of attack of the rudder will be much larger than the rudder angle, and the inflow velocity will also change to the thruster 2. It is believed that these factors overlap and cause cavitation and separation as shown in 4 on the control surface, causing a decrease in the direct steering pressure.

On the other hand, for recent high-speed boats,
It is thought that even if the rudder 1 is not arranged immediately after the propulsion device 2 to increase the rudder force, it is possible to generate a sufficiently large rudder force just by using the forward speed. Moreover, if performance deterioration is caused by cavitation or other factors as described above, the advantage of placing it immediately after the propulsion device will be lost.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a high-speed boat that is designed to avoid deterioration of rudder performance during high-speed turns, and to allow the boat to be maneuvered in a manner similar to normal boat maneuvering in which the rudder angle and turning force are proportional. The purpose is

For this reason, the rudder of the high-speed boat of the present invention has a secondary rudder disposed rearward on the axis of the propulsion device disposed on both sides of the stern hull centerline, and a propulsion rudder located on the stern hull centerline. A main rudder that is larger than the auxiliary rudder, and a steering means that enables single-acting steering of the main rudder or interlocked steering with the auxiliary rudder when the steering of the auxiliary rudder is free. It is characterized by what it did.

A high-speed boat as an embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a bottom view of the stern of the high-speed boat of the present invention.

10 is the main rudder, which is connected to the hull 5 between the two thrusters 2.
It is located on the center line. Reference numeral 11 denotes an auxiliary rudder, which is a small rudder that is provided immediately after the propulsion device 2 and has an area of about 1/3 to 1/5 of the main rudder. The main rudder 10 is connected to a steering gear so that it can be moved independently (in which case the auxiliary rudder 11 is free) or simultaneously with the auxiliary rudder 11.

When the high-speed boat of the present invention travels at high speed, the main rudder 10
Only the rudder is operated, and the secondary rudder 11 is free (dangling)
It is being done. As a result, the flow velocity with respect to the main rudder 10 is several tens of percent lower than in the case where the main rudder 10 is placed immediately after the propulsion device 2, so cavitation can be eliminated. Moreover, the main rudder 10 is located on the hull center line,
Since there is no diagonal flow as shown in Figure 3 above, the angle of attack of the rudder does not become extremely large, and this also means that there is no deterioration in rudder performance during high-speed turns.
It is possible to obtain the turning moment characteristics expected in a normal ship as shown in FIG. Since the secondary rudder 11 is free and always faces the flow direction, no separation or cavitation occurs.

However, when sailing at high speed, the main rudder 10 alone can be used to freely maneuver the ship, such as turning and keeping the course, but when leaving and docking, the ship's speed is low, so the main rudder 10 alone may not be enough to maneuver the ship, so it is necessary to compensate for this. Tame thruster 2
A small auxiliary rudder 11 is placed immediately behind the main rudder 11, and is linked with the main rudder 10 as shown by the dotted line in FIG. 5 to enable maneuvering at low speeds.

Furthermore, when the rudder 1 is located immediately after the propulsion device 2 as in the conventional case, mutual interference between the propulsion device 2 and the rudder 1 causes a reduction in thrust, but in the case of the present invention, the small auxiliary rudder 11
Since the large main rudder 10 has little mutual interference and there is no such interference, it is expected that the propulsion efficiency will be improved.

As described above, the high-speed boat of the present invention has the advantage that the rudder performance does not deteriorate during sharp turns at high speed, and the boat can be maneuvered with a normal feeling of maneuvering a boat in which the rudder angle and turning force are proportional.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional high-speed boats.
The figure is the side view, the second figure is the bottom view, and the third figure is the second figure.
FIG. 4 is a graph showing the relationship between the rudder angle and turning moment of a conventional high-speed boat. FIG. 5 is a bottom view of the stern of a high-speed boat as an embodiment of the present invention. FIG. is a graph showing the relationship between the rudder angle and turning moment of the high-speed boat of the present invention. 2... Propulsion device, 5... Hull, 10... Main rudder, 1
1...Auxiliary rudder.

Claims (1)

[Claims] 1. An auxiliary rudder disposed rearward on the axis of the propulsion device disposed on both sides of the stern hull centerline, and a secondary rudder disposed rearward of the propulsion device on the stern hull centerline; A high-speed boat comprising: a main rudder larger than the auxiliary rudder; and a steering means that enables single-acting steering of the main rudder when the auxiliary rudder is in a free steering state or interlocked steering with the auxiliary rudder. rudder.