JPH11105794A - Deformation reaction rudder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve propulsion efficiency in using without much labor in manufacture by simplifying the shape of the whole rudder. SOLUTION: This rudder is formed so that with a more rearward position than the central part in the longitudinal direction of a rudder 1 taken as its origin and a position in an appropriate vertical area smaller than the diameter of a propeller boss whose center is the axial height HS of a propeller 25 in the height direction as its boundary, torsion may be given to the reverse side (port side) for the upper part 2B and to the normal side (starboard side) for the lower part 2A of the rear end 2 of a rudder 1 with regard to the rotational direction (for example, clockwise) of the propeller 25 at the upper and lower parts of its point of intersection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the shape of a rudder mounted on a ship, and more particularly to a modified reaction rudder for improving propulsion efficiency.

[0002]

2. Description of the Related Art In general, the original purpose of a rudder is to steer a hull, and plays a role of maintaining a course when a ship is traveling straight. In order to utilize the function of the rudder during straight traveling not only for the purpose of keeping the hands but also as a device for improving the propulsion efficiency, various contrivances have been made for this rudder.

As a known rudder, for example, there is a reaction rudder as shown in FIG. The reaction rudder 20 has a shape in which a front part 21 of the rudder is twisted up and down (represented by a cross section in the drawing) around a height near the axial center of the propeller 25 and faces a rear end part 22. It is designed to gradually reduce the rotational energy of the propeller wake, thereby improving the propulsion efficiency. It is said that 1-2% of the propulsion horsepower can be saved. In addition, a fin is attached to a part of the rudder exposed to the wake of the propeller, or a part of the rudder near the height of the propeller shaft is inflated to make it look as if the boss of the propeller is extended. There are many proposals, such as what was done or a combination of these.

[0004]

However, in the reaction rudder 20 as shown in FIG. 4 described above, the shape of the rudder is asymmetrical in cross section, and in particular, the asymmetrical cross section is formed in the front part 21 of the rudder. Being shaped, it is very expensive and expensive to manufacture.
In addition, other rudders generally have a high manufacturing cost and are expensive because the shape is complicated or the manufacturing is troublesome. Therefore, there is a problem in that there are many cases in which adoption is postponed judging from the cost-effectiveness in order to put it to practical use.

The present invention has been made in view of the above-mentioned circumstances, and has a simple configuration of the entire rudder so that the production is not troublesome and the propulsion efficiency can be improved in use. It is an object of the present invention to provide a modified reaction rudder.

[0006]

Means for Solving the Problems and Action / Effect The modified reaction rudder of the present invention, which has been made to achieve such an object, is a rudder mounted on a ship, and is provided in a longitudinal direction of the rudder before and after the rudder. The rear end of the rudder above and below the boundary, starting from a position behind the center and starting at a position within the appropriate range of the propeller boss diameter smaller than the propeller boss diameter centered on the propeller axis height in the height direction. The upper part is twisted to the reverse side and the lower part is twisted to the forward side with respect to the rotation direction of the propeller.

According to the present invention having the above structure, the rear portion of the rudder is twisted so as to receive the wake of the propeller in accordance with the rotation direction of the propeller. It is possible to improve the propulsion efficiency by collecting the rotational energy of the flow at the torsion portion of the rudder. That is, when the propeller rotates clockwise, the rudder receives the flow from the port side in the portion above the propeller shaft center height, and receives the flow from the starboard side in the portion below the propeller shaft average. . For this reason, the rudder generates a lift together with the resistance. If the angle at which the rudder flows is small, the lift is also small. However, twisting the rear end of the rudder has the effect of substantially increasing the angle into which the water flows.
The generated lift can be increased, and the increase in the lift provides an effect that a part of the thrust in the forward direction can be more effectively carried to improve the propulsion efficiency.

Further, the modified reaction rudder of the present invention has a torsion structure having the above-described structure at the rear portion of the rudder to improve the propulsion efficiency, and therefore, its shape is simple as a whole. Therefore, since it can be easily processed in the production, the construction cost does not increase, and an effect that can be easily realized in practical use is obtained.

In the present invention, the twisting direction of the rear part of the rudder is such that the rotational direction of the propeller is clockwise in the upper part on the port side, in the lower part on the starboard side, and each part is in the vertical direction of the rudder from the end. It is preferable that the amount of twist is constant or the boundary part is deformed so as to be gradually increased within the allowable range of twist. In addition, the rotation direction of the propeller is to the starboard side in the upper part with respect to the counterclockwise rotation, and to the port side in the lower part, and the twist amount of each part from the end in the vertical direction of the rudder is constant or within the allowable twist range. It is preferable that the boundary part is deformed so as to become gradually larger. With this configuration, it is possible to effectively recover the rotational energy of the wake of the propeller corresponding to the rotation direction of the propeller.

[0010] In the modified reaction rudder according to the present invention, in a rudder of a system in which a rudder rear end is movable, the movable rudder end is divided into an upper part and a lower part bordering the vicinity of the propeller axis. Can be configured to have an appropriate amount of twist.
This has the effect of further enhancing the characteristics of the rudder provided with the movable rudder end. Further, in a rudder having a special cross-sectional shape such as a scilling ladder, an appropriate amount of torsion is added to an upper portion and a lower portion of the rudder rear end portion bordering the vicinity of the propeller axis center line. Can be. Even in such a special rudder, the same operation and effect as described above are added.

[0011] In the movable rudder rear end and the special rudder described above,
Even with the configuration in which the torsion is added to the rudder rear end portion, the workability is easy to manufacture as described above,
The construction cost does not increase.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of a modified reaction steering according to the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the modified reaction steering system according to the present invention, and FIG. 2 is a side view showing the ratio of each portion of the modified reaction steering system of this embodiment.

In this embodiment, the rudder 1 corresponding to the case where the propeller 25 rotates clockwise is shown, and the propeller shaft center height HS
A required section LE in the front-rear direction of the rear end portion 2 of the rudder 1 at the upper and lower sides with respect to (the height from the base line) is twisted by a torsion amount SU and SL in plan view, respectively. Between the axis HL of the rudder and the height HL of the lower part 2A of the rudder, the torsion is changed at the lowermost end 2a of the rudder so as to make the torsion zero, and also between the height HU of the upper part 2B of the rudder. The torsion is changed similarly to the lower part 2A. Note that, other than the rear end 2 of the rudder 1, as shown in the cross section in the drawing, a streamlined bilaterally symmetrical shape is formed from the front to the rear similarly to the conventional one.

The outer shape of the rudder 1 thus formed is shown in FIG.
As shown in the above, the rear end portion 2 is a deformation reaction steering in which the upper and lower portions 2A and 2B are formed in a peculiar shape twisted right and left with respect to the axis a of the propeller (see FIG. 2). . In the figure, reference numeral 5 denotes a rudder horn, and 6 denotes a rudder shaft. The maximum amount of twist at the rear end 2 of the rudder is 20% of the length of the rudder.
It is preferably within the range. Further, it is preferable that the position at the rear end 2 of the rudder to be twisted, which is the boundary between the upper part 2B and the lower part 2A, be set within a range of 10% of the boss diameter of the propeller 25.

If the rudder 1 is formed in this manner, the wake of the propeller (represented by the arrow C) is in contact with the axis b of the rudder 1 as shown in FIG. It flows into the rudder 1 with the angle α formed. Then, when the rudder rear end 2 is twisted as described above, the rudder cross section becomes equivalent to having a virtual cross-sectional shape as indicated by a two-dot chain line 1s in terms of hydrodynamics, and flows into the rudder 1. The angle behind the propeller corresponds to the angle β with the axis b ′ of the virtual rudder 1s.

The force generated on the rudder 1 by this flow can be decomposed into a resistance R and a lift L. In the case of a normal rudder 4 in which the rear end of the rudder is not twisted as described above (the rear end of the rudder is indicated by a dotted line), the respective forces are resistance R0 and lift L0, and the rudder having the twisted rudder. In the case of 1, the resistance becomes R1 and the lift L1, but since the angle β of the water flow flowing into the rudder is larger than the angle α, the lift L1 becomes larger than the lift L0. Since the resistance of the rudder hardly changes even when the angle of the water flow flowing into the rudder increases, it can be considered that the resistances R1 and R0 are almost equal.

The force (thrust) in the forward direction of the rudder 1 is the difference between the forward direction components of the lift and the resistance. In the case of a rudder without twisting, as shown in FIG. , R
It becomes 0, and when it is twisted, it becomes t1, r1. Resistance r
Since 0 and r1 are almost equal, and the thrust t1 is greater than t0, the torsional force increases the force in the forward direction of the rudder, thereby improving the propulsion efficiency of the ship.

In the above-described embodiment, the amount of twist (SL, SU) of the rear end 2 of the rudder is changed by the propeller in the clockwise rotation direction so as to gradually decrease toward the end in the vertical direction. Although the case has been described, the amount of twist (S
L, SU) can be obtained in the case where the respective portions of the upper portion 2B and the lower portion 2A are fixed (represented by chain lines 2e and 3e in FIG. 2). When the rotation direction of the propeller 25 is counterclockwise, the rear end 2 of the rudder 1 may be twisted such that the upper part 2B is on the starboard side and the lower part 2A is on the port side.

Further, according to the gist of the present invention, the aforementioned twist is formed at the rear end of a rudder called a Becker ladder or a flapper that has a movable rear end, that is, at a movable portion. , The movable function can be further improved. Moreover, even if a twisting structure is added to the movable part of such a rudder, the cost-effectiveness does not impair the practicality because the workability is easy,
It is feasible. Also, in a rudder employing a special rudder section such as a silling rudder, it is needless to say that a similar effect can be obtained by adding a twist to the rear end of the rudder as described above.

The upper part of the rear end of the rudder in this embodiment corresponds to the upper part of the present invention, and the lower part of the rear end of the rudder of the embodiment corresponds to the lower part of the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an embodiment of a modified reaction steering according to the present invention.

FIG. 2 is a side view illustrating the ratio of each part of the modified reaction steering according to the present embodiment.

3A and 3B are views for explaining the operation of the modified reaction steering according to the present invention, wherein FIG. 3A is a sectional view taken along line AA of FIG. 2, and FIG. 3B is a vector diagram. is there.

FIG. 4 is a diagram showing a conventional reaction steering.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rudder 2 Rear end of rudder 2A Lower part of rear end of rudder 2B Upper part of rear end of rudder 4 Conventional normal rudder 20 Conventional recoil rudder 25 Propeller a Propeller axis line SL, SU Twist amount

Claims (5)

[Claims] 1. A rudder mounted on a ship, comprising a propeller boss diameter starting from a position behind a central portion in the longitudinal direction of the rudder and having a propeller shaft centered in the height direction. Twist the rear end of the rudder above and below the appropriate position within the appropriate range of the upper and lower boundaries, the upper part to the reverse side of the propeller rotation direction, and the lower part to the forward side to the forward side. Deformation reaction rudder characterized by having a configuration with addition of. 2. The torsion direction of the rear end of the rudder is such that the rotational direction of the propeller is clockwise in the upper part on the port side and in the lower part on the starboard side. The deformation reaction steering according to claim 1, wherein the boundary portion is deformed such that the amount of twist is constant in the direction or the boundary portion is gradually increased within an allowable range of the twist. 3. The torsional direction of the rear end of the rudder is such that the direction of rotation of the propeller is on the starboard side in the upper part with respect to the counterclockwise direction and on the port side in the lower part. The deformation reaction steering according to claim 1, wherein the boundary portion is deformed such that the amount of twist is constant in the direction or the boundary portion is gradually increased within the allowable range of the twist. 4. A rudder of a system in which a rear end portion of a rudder is movable, the movable rudder end is formed by applying an appropriate amount of twist to an upper portion and a lower portion bordering the vicinity of the propeller axis. The modified reaction steering according to any one of claims 1, 2, and 3, wherein 5. A rudder having a special cross-sectional shape such as a scilling rudder, wherein an appropriate amount of torsion is applied to an upper portion and a lower portion of the rudder rear end portion bordering the vicinity of the propeller axis. The modified reaction steering according to any one of claims 1, 2, and 3.