JPH0441033Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a movable protruding bow structure for controlling the external shape of the bow according to the draft condition of a ship.

[Conventional technology]

Generally, a protrusion is provided at the front end of the bow of a ship to reduce wave resistance, and the external shape of the protrusion is set to achieve the best wave resistance reduction effect at the planned draft of the ship. has been done. In other words, the trailing free waves generated at the protrusion when the ship is navigating in the planned draft state and the trailing free waves at the end of the main hull excluding the protrusion are in opposite phases and cancel each other out, and as a result, the bow This reduces the wave-making resistance in the area.

In addition, even if the draft changes to a value other than the above-mentioned planned draft due to loading conditions, the bow structure is equipped with a variable bulge at the bow so that wave-making resistance can be efficiently reduced in response to such changes in draft. Conventionally, it has been proposed.

That is, as shown in FIGS. 2 and 3, a watertight bulkhead 05 is provided between decks 03 and 04 in the bow section 01 of the main hull S to form a chamber 02 that continues to the bow 01, and 01 is provided with an opening 06 in the vertical direction. Above room 0
2, a lower bearing 08 is formed on the bottom 07, and a bucking gland part 01
4 is formed by being bored in the deck 03. Further, an upper bearing 015 is formed above the deck 03 and is fixed to the bow outer plate 01a.

Then, the screw shaft 09 passes through the bucking gland part 014 and connects its upper part to the upper bearing 01.
5, and its lower end is supported by a lower bearing 08. This screw shaft 0
A worm wheel 016 is attached to the top end of 9, and this worm wheel 016 and
A worm 017 that is coaxially connected to the rotating shaft of the electric motor 018 meshes with each other.

On the other hand, on the outside of the bow 01, there is a variable bulge 0.
10 is provided so as to be slidable in the vertical direction along the bow 01 of the ship. A leg portion 011 is provided on the back surface of the variable bulge portion 010.
11 is inserted into the chamber 02 through the opening 06 and is fitted into the threaded shaft 09 so as to engage with a threaded portion formed on the threaded shaft 09. Further, the variable bulge 010 is provided with a plate-shaped closing portion 012 for covering the opening 06.
As shown in FIG. 3, the left and right end portions of 12 are held by guides 013 provided on the main hull S so as to be slidable in the vertical direction.

Then, the electric motor 018 is rotated forward and backward, and the screw shaft 09
By rotationally driving the variable bulge 010 in an appropriate direction around the vertical axis, the variable bulge 010 can be moved upward or downward.

With the above-mentioned configuration, in the conventional bow structure in which the bow section is provided with a variable bulge, the electric motor 018 is operated in a fully loaded draft state to control the variable bulge 01.
0 is moved to the top of its vertical range and fixed. In this state, the ship sails forward.

At this time, the trailing free liquid generated at the variable bulge 010 and the trailing free wave at the end of the main hull excluding the variable bulge 010 have opposite phases and cancel each other out, so that the bow part 01 of the ship The wave-making resistance generated in the wave is reduced.

In addition, in a light draft state, the electric motor 018
As shown in FIG. 2, the variable bulge 010 is moved to the lowest part of its vertical range and fixed, thereby reducing the wave-making resistance that occurs at the bow section 01 when the ship is sailing. be done.

[Problem that the invention attempts to solve]

By the way, a ship equipped with a protrusion at the front end of the bow has a problem in that if the draft changes to a value other than the planned draft due to loading conditions, the position of the protrusion is not necessarily optimal.

In particular, in cases where the difference between the full draft and the lightly loaded draft is extremely large, such as in tankers and bulk carriers, the wave-making resistance may actually increase depending on the draft condition.

In addition, in a bow structure with a conventional variable bulge in the bow as described above, the variable bulge is 0.
It is technically extremely difficult to construct a configuration in which the outer shape of the bow portion 10 and the outer shape of the bow portion 01 of the hull S form a continuous curved surface. Therefore, such a ship shape has discontinuous parts, and the wave resistance generated in these discontinuous parts increases the ship's hull resistance, which can actually cause the ship to There is a problem that the propulsion performance of the engine deteriorates. Furthermore, with the above-mentioned conventional means for moving the variable bulge using a mechanical up-and-down mechanism, a large-scale drive device must be installed within the narrow bow section, resulting in a complicated structure.

The present invention attempts to solve these problems, and uses simple electromagnetic means to configure the bow of the ship to form a continuous curved surface. In other words, it is an object of the present invention to provide a movable protruding bow structure that can efficiently reduce wave-making resistance in both a fully loaded draft state and a lightly loaded draft state.

[Means for solving problems]

Therefore, the movable protruding bow structure of the present invention has a protruding part for reducing wave-making resistance at the front end of the bow part, and the protruding protruding part is similar to the bag-like member made of an elastic membrane attached to the bow outer plate. A magnetic fluid filled inside the bag-like member, and a plurality of magnetic fluids provided inside the bag-like member to adjust the distribution state of the magnetic fluid in the bag-like member and control the outer shape of the bag-like member. The plurality of magnetic field generating members are arranged vertically in rows and fixed to the bow shell, and the excitation or demagnetization of these magnetic field generating members is individually controlled. It is characterized by being equipped with a control device.

[Effect]

In the above-mentioned movable protruding bow structure of the present invention, for example, a plurality of magnetic field generating members are arranged above and below, and the magnetic field generating member arranged above inside the bag-shaped member is excited in a fully loaded draft state. At the same time, the magnetic field generating member disposed below is demagnetized. The magnetic fluid inside the bag-like member is distributed such that most of the magnetic fluid is concentrated upward, and the maximum protruding portion of the bag-like member is moved upward.

Further, in a light draft state, the magnetic field generating member disposed below within the bag-shaped member is excited, and the magnetic field generating member disposed above is demagnetized. The magnetic fluid inside the bag-like member is distributed such that most of the magnetic fluid is concentrated downward, and the maximum protruding portion of the bag-like member is moved downward.

〔Example〕

Hereinafter, a movable protruding bow structure as an embodiment of the present invention will be explained with reference to the drawings. FIGS. 1A and 1B are longitudinal cross-sectional views showing the structure and operation thereof.

As shown in FIGS. 1a and 1b, the movable protruding bow structure of this embodiment includes a protruding part P for reducing wave-making resistance at the front end of the bow part 1, but the protruding part P is not shown in the figure. It is configured as follows.

That is, a bag-like member 4 made of a flexible elastic membrane is attached to the front end of the bow section 1, and the inside of the bag-like member 4 is filled with a magnetic fluid 6. Further, inside the bag-like member 4, a plurality of magnetic field generating members 5 are fixed to the bow shell plate 2 in a vertically arranged manner. The outer shape of the bag-like member 4 and the vertical position of the maximum protruding portion can be controlled by adjusting the distribution state within the bag-like member 4.

The bag-like member 4, the plurality of magnetic field generating members 5, and the magnetic fluid 6 constitute the wave-resistance reducing protrusion P in the movable protruding bow structure of this embodiment.

Further, inside the main hull S, there is provided a control device (not shown) connected to the plurality of magnetic field generating members 5 described above, which excites or demagnetizes each magnetic field generating member 5 to control the inside of the bag-like member 4. The strength of the magnetic field can be changed arbitrarily.

With the above-described configuration, in the movable protruding bow structure of this embodiment, in the fully loaded draft state, the control device excites the magnetic field generating member 5 disposed above within the bag-like member 4, and at the same time excites the magnetic field generating member 5 disposed below. The magnetic field generating member 5 is demagnetized. As a result, the bag-shaped member 4
The magnetic fluid 6 is distributed so as to concentrate upward in the inside of the bag-shaped member 4, that is, the protrusion P
The outer shape is formed into a continuous curved surface as shown in FIG.

Then, the protrusion P whose outer shape is controlled in this way
The trailing free waves generated at the end of the main hull S excluding the protrusion P have opposite phases and cancel each other out. This reduces wave resistance.

Further, in the reduced draft state, the control device excites the magnetic field generating member 5 disposed below within the bag-shaped member 4 and demagnetizes the magnetic field generating member 5 disposed above. As a result, inside the bag-like member 4, the magnetic fluid 6 is distributed such that most of it is concentrated downward, and the outer shape of the bag-like member 4, that is, the outer shape of the protrusion P, is as shown in FIG. 1b. It is formed as a continuous curved surface, and its maximum protrusion is
It is moved in a direction closer to the bottom of the ship so as not to be exposed above the waterline 3 during light draft.

Then, the protrusion P whose outer shape is controlled in this way
The trailing free waves that occur at the end of the main hull S excluding the protrusion P have opposite phases and cancel each other out, so that the trailing free waves that occur at the bow section 1 when sailing at a light draft state are generated at the bow section 1. Wave-making resistance is reduced.

As described above, according to the movable protruding bow structure of the present invention, the wave-resistance reducing protrusion P can be operated by simple electromagnetic means regardless of the draft state of the vessel, that is, at full draft and at light load draft. The outer shape is also controlled so that it forms a continuous curved surface and has an optimal shape. Therefore, the wave-making resistance at the bow section 1 can be reduced at all times, so that the propulsion efficiency of the ship is greatly improved and the ship can be operated more economically.

Note that the plurality of magnetic field generating members may not only be arranged vertically, but may also be arranged laterally.

[Effect of idea]

As described in detail above, according to the movable protruding bow structure of the present invention, the protruding part for reducing wave-making resistance is provided at the front end of the bow part, and the protruding part of the prow is connected to the elastic membrane attached to the outer plating of the bow. a bag-like member, a magnetic fluid filled inside the bag-like member, and a bag-like member for controlling the outer shape of the bag-like member by adjusting the distribution state of the magnetic fluid in the bag-like member. a plurality of magnetic field generating members provided inside the ship, and the plurality of magnetic field generating members are fixed to the bow outer plate in a vertically arranged manner;
Due to its simple structure, which includes a control device that can individually control the excitation or demagnetization of these magnetic field generating members, the wave-resistance reducing protrusion can reduce light loads regardless of the ship's draft condition, that is, even at full draft. Even when drafting, the outer shape is controlled so that it has an optimal shape with a continuous curved surface that maintains the maximum protruding portion at an appropriate position relative to the waterline. As a result, wave-making resistance at the bow can be reduced at all times, resulting in a significant improvement in the propulsion efficiency of the ship and the ability to operate the ship more economically.

In addition, the movable protruding bow structure of the present invention has the advantage that there is no need to provide a large-scale drive device in the narrow bow area, and the structure can be simple, compared to conventional movable protruding bow structures using mechanical means. .

[Brief explanation of drawings]

Figures 1a and 1b are longitudinal cross-sectional views showing the configuration and operation of a movable protruding bow structure as an embodiment of the present invention, and Figures 2 and 3 are longitudinal sectional views of a conventional bow with a variable bulge in the bow. 2 is a vertical cross-sectional view thereof, and FIG. 3 is a cross-sectional view taken along the - arrow in FIG. 2. DESCRIPTION OF SYMBOLS 1... Bow part, 2... Bow shell, 3... Waterline, 4... Bag-shaped member, 5... Magnetic field generating member, 6...
...Magnetic fluid, P... Protrusion for reducing wave-making resistance, S...
...Main hull.

Claims (1)

[Scope of utility model registration request] A protrusion for reducing wave-making resistance is provided at the front end of the bow, and the protrusion has a bag-like member made of an elastic membrane attached to the bow outer plate, and a magnetic fluid filled inside the bag-like member. , a plurality of magnetic field generating members provided in the bag-like member to adjust the distribution state of the magnetic fluid in the bag-like member and control the outer shape of the bag-like member, The magnetic field generating members are arranged vertically in rows and fixed to the bow shell, and a control device is provided which can individually control excitation or demagnetization of these magnetic field generating members. , movable protruding bow structure.