JPH06144380A - Rudder in ship - Google Patents

Abstract

PURPOSE:To easily improve hull efficiency by forming upper/lower swollen parts, swollen with a propeller rotary direction serving as the reference as viewed from a rudder tail, in upper/lower side surfaces of a rudder plate. CONSTITUTION:A rudder plate 1 is mounted on a rear part of a hull 2 further in a rearward position of a propeller 3 through a rudder shaft 4. An upper swollen part 5, swollen in a side surface position upper from a propeller center line (a) of this rudder plate 1 further in a rotational direction side of the propeller 3 as viewed from a stern side, is formed. A lower swollen part 6, swollen in a side surface position downward front the propeller center line (a) of this hull 1 further in the rotational direction side of the propeller 3 as viewed from the stern side, is formed. Thus by adding the swollen parts 5, 6 in a predetermined position of a surface of the rudder plate 1, a thrust reducing rate is increased to also decrease a wake factor, and accordingly, hull efficiency is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rudder in a ship.

[0002]

2. Description of the Related Art Conventionally, in order to improve the propulsion performance of a ship, that is, the efficiency of a hull, a rudder placed in the wake of a propeller is used to rectify the wake of the propeller or to react the rudder resistance by its reaction. There are contra rudder to reduce (generate thrust) and recoil rudder.

[0003]

According to the structure of the conventional contra rudder, reaction rudder, etc., the front edge of the rudder is aligned with the inflow direction of the rotary flow, and the rudder plate is moved up and down with the propeller center line as a boundary. There is a problem that it is necessary to twist in the opposite direction, and thus the processing becomes complicated.

Therefore, an object of the present invention is to provide a rudder capable of improving hull efficiency and being easily processed.

[0005]

In order to solve the above-mentioned problems, the rudder in a ship of the present invention has an upper bulge portion which bulges in the propeller rotation direction side when viewed from the stern on the upper side surface of the rudder plate, On the lower side surface of the rudder blade, a lower bulge portion that bulges on the side opposite to the propeller rotation direction when viewed from the stern is formed.

[0006]

According to the above construction, thrust can be generated in the rudder itself by the bulging portions formed on each side surface of the rudder blade. Therefore, the hull efficiency can be improved with a very simple structure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 4, reference numeral 1 denotes a rudder plate attached to the rear portion of the hull 2 and behind the propeller 3 via a rudder shaft 4, which is a side surface position above the propeller center line a of the rudder plate 1 and An upper bulge portion (also referred to as a bulge) 5 that bulges in the rotational direction side of the propeller 3 when viewed from the stern side is formed, and the propeller is located at a side surface position below the propeller center line a of the rudder blade 1 and when viewed from the stern side. A lower bulge portion (also called a bulge) 6 that bulges on the side opposite to the rotation direction of 3 is formed.

More specifically, when the propeller 3 shown in FIG. 1 rotates in the right direction (clockwise direction) when viewed from the stern side, as shown in FIGS. 2 and 3, the rudder blade 1 is used.
When the upper bulge portion 5 is formed on the right side surface and rotates in the left direction (counterclockwise direction), as shown in FIG. 2 and FIG. The lower bulging portion 6 is formed on the left side surface.

The upper bulging portion 5 is formed on the right side and the lower bulging portion 6 is formed on the left side. The propeller wake flows from the left front side at the upper side and flows from the right front side at the lower side. This is because.

The bulges 5 and 6 are formed, for example, by fixing a bent steel plate to the side surface which is the surface of the rudder blade 1. Thus, when the bulging portions 5 and 6 are formed on the side surface of the rudder blade 1, a larger thrust is generated than when the bulging portions are not formed. That is, for example, when focusing on the lower part of the rudder blade 1 for explanation, as shown in FIG.
Flows in from the front right, a counterclockwise circulation (Γ) is generated when viewed from above, lift (L) acts on the rudder blade 1, and the resultant force (N) with the resistance (R) acting on the rudder is increased. The longitudinal component acts as thrust (T).

The broken line in FIG. 5 shows the lift force (L ') when there is no bulging portion. The presence of the bulging portion causes stronger circulation, thus increasing the flow velocity on the surface of the rudder blade 1. Therefore, the thrust generated as the rudder resistance increases increases.

As described above, since the bulging portion is added at a predetermined position on the surface of the rudder blade 1, the thrust reduction rate (1-t) increases and the wake rate (1-w) decreases, so that the hull efficiency is increased. (Η _h ) is improved. Here, the wake rate (1−w), the thrust reduction rate (1−t) and the case where the bulge portion is added to FIG. 6 (shown by the one-dot chain line) and the case where it is not added (shown by the solid line) Show hull efficiency (η _h ),
It can be seen that the hull efficiency (η _h ) is improved by 2-3%, for example.

In the above embodiment, the case where the propeller rotates in the right direction when viewed from the stern side has been described. However, when the propeller rotates in the left direction, it is different from the above embodiment. On the contrary, the upper bulge portion is formed on the left side of the upper side surface of the rudder blade, and the lower bulge portion is formed on the right side of the lower side surface of the rudder plate.

[0014]

As described above, according to the structure of the present invention, since the bulging portion is formed on the side surface of the rudder plate to generate the thrust on the rudder, the hull efficiency can be improved even though the structure is very simple. Can be improved.

[Brief description of drawings]

FIG. 1 is a side view of a rudder according to an embodiment of the present invention.

FIG. 2 is a rear view of the rudder in the same embodiment.

FIG. 3 is a view on arrow AA of FIG.

FIG. 4 is a view as seen from the arrow BB of FIG.

FIG. 5 is a principle diagram illustrating a force acting on a rudder in the embodiment.

FIG. 6 is a graph showing respective efficiencies of the rudder of the same embodiment and the rudder of the conventional example.

[Explanation of symbols]

 1 Rudder plate 3 Propeller 5 Upper bulge 6 Lower bulge

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[Procedure amendment]

[Submission date] January 13, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

[0005]

In order to solve the above-mentioned problems, the rudder in a ship of the present invention has an upper bulge portion which bulges in the propeller rotation direction side when viewed from the stern on the upper side surface of the rudder plate, Also on the lower side surface of the rudder plate, a lower bulge portion that bulges toward the propeller rotation direction side when viewed from the stern is formed.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 4, reference numeral 1 denotes a rudder plate attached to the rear portion of the hull 2 and behind the propeller 3 via a rudder shaft 4, which is a side surface position above the propeller center line a of the rudder plate 1 and An upper bulge portion (also referred to as a bulge) 5 that bulges in the rotational direction side of the propeller 3 when viewed from the stern side is formed, and the propeller is located at a side surface position below the propeller center line a of the rudder blade 1 and when viewed from the stern side. A lower bulge portion (also referred to as a bulge) 6 that bulges toward the rotation direction side of 3 is formed.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

More specifically, when the propeller 3 shown in FIG. 1 rotates in the right direction (clockwise direction) when viewed from the stern side, as shown in FIGS. The upper bulge 5 is formed on the right side surface of the rudder blade 1 above
The lower bulging portion 6 is formed on the left side surface at the lower position.

Claims (1)

[Claims] 1. An upper bulge portion is formed on the upper side surface of the rudder plate to bulge toward the propeller rotation direction side when viewed from the stern, and on the lower side surface of the rudder plate, on the side opposite to the propeller rotation direction when viewed from the stern. A rudder in a ship, characterized in that a bulging lower bulge is formed.