JPH045599B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rudder, and more particularly to a rudder for a ship having airfoil-shaped fins extending substantially horizontally on both sides.

Conventional rudders of this type have fins that extend substantially horizontally on both sides, and thus have many advantages, particularly energy saving. However, since the conventional method for attaching the fins was only by a cantilever method, when a large external force was applied to the fins, excessive stress was generated at the attachment portion. That is, in order for the fins to withstand a large external force, it is necessary to take measures such as shortening the overhanging length of the fins or increasing the thickness to maintain rigidity. However, with short fins or extremely thick fins,
There have been cases where the original energy saving effect cannot be achieved due to performance deterioration.

The present invention provides a fin in which the overhanging length of the fin is made as long as necessary, and the fin is made sufficiently thin so that the performance of the fin is exhibited, and there is no risk of undue damage even if a large external force is applied to the fin. The purpose of this invention is to provide a marine rudder with a built-in rudder.

For this reason, the structure of the present invention is a rudder for a ship having airfoil-shaped fins extending substantially horizontally on both sides, and includes a support member fixed to the tips of the fins to support the fins. It is characterized by

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show a first embodiment of the present invention. In FIG. 1, 1 is the stern of the hull, and 2 is a rudder (here, a rudder main body 2a and a rudder support member 2b are shown). ), 3 is an airfoil-shaped fin attached in a cantilever manner to both sides of the rudder support member 2b and extends almost horizontally, 4 is a support member for the fin 3, 5 is a propeller, 6 is the circle within which the propeller wake passes. That is, in this embodiment, the tip of the fin 3 which is extended almost all the way to the circle 6 where the propeller wake reaches, and the upper part of the rudder support part 2b are connected by a ring-shaped support member having an airfoil-shaped cross section. Connected by 4.

Therefore, the fin 3, which was conventionally cantilevered,
By changing the structure to a Ramen structure, Finn 3
It is possible to reduce the moment and shear force applied to the root of the tree. As a result, the fins 3 become thinner, so that better performance can be exhibited.
However, on the other hand, the addition of the support member 4 increases frictional resistance and induced resistance;
By making the cross section of the ring-shaped support member 4 airfoil-shaped, this can be avoided to a large extent, resulting in an energy-saving device with good overall performance.

To explain further, as shown in FIG. 2, the external force 7 applied to the fin 3 is distributed to the upper part of the rudder support member 2b through the support member 4, thereby reducing the moment and shearing force at the base of the fin 3. Furthermore, the mounting position of the ring-shaped support member 4 is as follows.
It is placed almost along the circle 6 covered by the propeller wake. This is to make effective use of the flow in this area, as shown in Figure 3. That is, the flow is fast on the inside and slow on the outside of the circle 6, which is the area covered by the propeller wake. The circle 6 covered by the wake of the propeller with a high flow velocity is slightly smaller than the diameter of the propeller. By attaching a ring-shaped support member 4 having an airfoil-shaped cross section as shown in FIG. An inward force 10 is generated, and this force 10 is slightly tilted forward due to the diagonal flow created by the contraction flow 11 generated by the rotation of the propeller 5, and its forward direction component becomes the thrust 12.
becomes. This thrust 12 can considerably compensate for the increase in resistance due to the attachment of the support member 4.

FIG. 5 shows a second embodiment of the present invention.
A so-called inverted G-type rudder is shown, and a ring-shaped support member 4 having an airfoil cross section is attached to the lower side of the fins 3. That is, the fins 3 and the support member 4 are
Both are attached to the rudder body 2a.

FIG. 6 shows a third embodiment of the present invention.
The support member 4, which has an airfoil cross-section, is not ring-shaped but straight or knuckle-shaped.

FIG. 7 shows a fourth embodiment of the present invention.
A support member 4 having an airfoil cross section is taken from the hull.

As described above, the rudder of the present invention includes a support member that is fixed to the tips of the airfoil-shaped fins extending substantially horizontally on both sides and supports the fins. The external force applied to the fins is transmitted in a dispersed manner, so that the overhanging length of the fins can be made as long as necessary and thin enough to exhibit the performance of the fins.
The fins can have a light structure, and the inherent energy saving effect of the fins can be improved.

[Brief explanation of drawings]

The drawings show embodiments of the present invention.
The figure is a perspective view of the first embodiment, Figure 2 is an enlarged cross-sectional view of the hull in Figure 1 seen from the rear, Figure 3 is an axial flow velocity distribution diagram at the fin position in Figure 2, and Figure 4 is the FIG. 5 is a perspective view of the second embodiment, FIG. 6 is a perspective view of the third embodiment, and FIG. 7 is a perspective view of the fourth embodiment. DESCRIPTION OF SYMBOLS 1... Stern part of the hull, 2... Rudder, 3... Fin, 4... Fin support member, 5... Propeller,
6...The circle covered by the propeller wake.

Claims (1)

[Claims] 1. A rudder for a ship having airfoil-shaped fins extending substantially horizontally on both sides, characterized by comprising a support member fixed to the tips of the fins to support the fins.