JP2021195013A - Thruster arranged stern structure - Google Patents

Abstract

To be capable of carrying out vessel position control without interference by an outboard engine or an inboard-outdrive engine to a main propeller, in addition to prevent imparting influence to vessel position control by unstable thruster propulsion by having a thruster exposed on water surface, furthermore eliminate danger of being a great resistance by receiving influence of water flow during navigation, and in addition, to prevent failure of the thruster due to strong water pressure.SOLUTION: A stern structure has two pieces of stern thrusters (20, 21) which are provided not in parallel to each other but inclining on a horizontal surface of a hull (10) on stern side (11) of a small vessel. The two pieces of stern thrusters (20, 21) have an intersection of propulsion axes (S) positioned closer to a bow side than an immersed portion (31) of a main propeller (30) so that water flow ejected from the thruster does not interfere with the main propeller (30) of an outboard engine or an inboard-outdrive engine.SELECTED DRAWING: Figure 1

Description

The present invention relates to a thruster-arranged stern structure and, in detail, to a thruster-arranged stern structure in a small vessel.

Patent Document 1 describes a ship position control device in order to achieve a position on the sea without being influenced by wind or tidal current by an easy and inexpensive means that does not take up a lot of space. ..
The ship position control device described in Patent Document 1 includes a wind direction wind speed sensor that detects a wind direction and a wind speed as an electric signal, and two left and right thrust axes that intersect at the rear of the hull except for a main engine mounted in water on the rear surface of the hull. A propulsion motor and a control device that controls the two propulsion motors on the left and right based on the signal from the wind direction and speed sensor to change the propulsive force of each ship so as to keep the position of the ship on the water surface constant. It is a thing.

Japanese Unexamined Patent Publication No. 2000-168692

In the ship position control device described in Patent Document 1, since the propulsion motors, which are two left and right thrusters attached to the water on the rear surface of the hull, are attached so that the thrust axes intersect at the rear of the hull, the thrust by the propulsion motor is used. However, unlike the main propulsion propeller using the Provera shaft shown in FIG. 1 of Patent Document 1, when the outboard motor is attached to the stern as the main propulsion like a general pleasure boat, the water flow ejected from the thruster. May interfere with the main propulsion device and be hindered, which may affect the ship position control.
Further, as shown in FIG. 4 of Patent Document 1, a propulsion motor for controlling the ship position is mounted underwater on the rear surface of the hull, but the stern bottom slope is in the range of 25 degrees or less, and the total ton number is 20. For small vessels with less than tons or total tons of 20 tons or more and a total length of less than 24 m, the thruster propulsion motor is installed near the water surface, so depending on the situation, part of it may be exposed above the water surface, and the thrust may be increased by entraining air. It could be dampened and affect ship position control.
Further, as shown in FIG. 3 of Patent Document 1, two propulsion motors, which are thrusters for generating thrust, are mounted near the starboard side and the port side, respectively, away from the hull body and the hull center line. Depending on the situation, the thruster may be affected by the water flow during driving, resulting in a large resistance, and at the same time, a strong water pressure may be applied to the thruster, which may cause the thruster to fail.

Therefore, according to the present invention, the stern position can be controlled without being hindered by interfering with the main propulsion device, and the thruster thrust becomes unstable due to the thruster being exposed on the water surface, which affects the stern position control. The challenge is to provide a thruster-arranged stern structure that can prevent this from happening, eliminate the risk of large resistance due to the influence of water flow during driving, and prevent thruster failure due to strong water pressure. And.

The means for solving the problem of the present invention is as follows.

First,
Has two thrusters,
The two thrusters are provided so as to be inclined not parallel to each other on the horizontal plane inside the stern side of the small vessel.
In order to prevent the water flow ejected from the two thrusters from interfering with the main propulsion unit of the outboard motor or the inboard / outboard motor, the intersection of the thrust axes of the two thrusters is the bow from the submerged part of the main propulsion unit. Thruster-arranged stern structure, characterized by being located on the side.
Second,
Has two thrusters,
The two thrusters are provided so as to be inclined not parallel to each other on the horizontal plane inside the stern side of the small vessel.
In order to prevent the water flow ejected from the two thrusters from interfering with the main propulsion unit of the outboard motor or the inboard / outboard motor, the intersection of the thrust axes of the two thrusters is the bow from the submerged part of the main propulsion unit. Located on the side,
The two thrusters are characterized in that the positions of the rear openings are located inside five-eighths, preferably inside one-half of the distance from the centerline of the hull to the outside of the hull. Thruster placement stern structure.
Third,
The first or the above, characterized in that the positions of the thrust axes of the two thrusters are within an angle of 45 degrees plus or minus 10 degrees on the horizontal plane with respect to the hull center line seen from above. The thruster arrangement stern structure described in the second.

The small vessel in the present invention means a vessel having a stern bottom slope of 25 degrees or less and a gross tonnage of less than 20 tons or a gross tonnage of 20 tons or more and a total length of less than 24 m.
Here, the stern bottom slope is the angle between the straight line connecting the apex of the keel to the apex of the chine and the horizontal plane passing through the apex of the keel.

When a thruster is installed at the stern of such a small vessel, the problem to be solved by the above invention arises.
Further, as the small vessel in the present invention, the vessel type is a single-body type.

Here, the main propulsion device is a mechanism for propelling a ship, and in addition to an outboard motor, a device integrated with the hull such as an inboard motor is also included, but an inboard motor is excluded. ..
The number of main propulsion units is not limited to one, but includes a large number of main propellers such as two.

The thrust axis of the thruster is an axis on a straight line that passes through the center of the thruster, is parallel to the center line of the circular cross section of the tunnel shape that covers the thruster, and is parallel to the thrust direction of the thruster.
In the present invention, it is desirable that the thrust and forward / reverse rotation of the thruster can be controlled independently.

According to the present invention, the following effects can be obtained.

Two thrusters tilted inside the stern of a small vessel were placed so that the intersection of the thrust axes was located on the bow side of the main propulsion unit of the outboard unit or the inboard / outboard unit. The stern position can be controlled without the ejected water flow interfering with the main thruster and being obstructed.
Further, when the thruster is exposed on the water surface, it is possible to prevent the thruster thrust from becoming unstable and affecting the ship position control.
Further, it is possible to eliminate the risk of large resistance due to the influence of water flow during traveling and prevent the thruster from breaking down due to strong water pressure.

As the first embodiment, it is a schematic diagram of the thruster arrangement stern structure in which two thrusters are arranged at the stern. It is the schematic which looked at the thruster arrangement stern structure of Example 1 from the rear diagonally lower side except the outboard motor which is a main propulsion device. It is a schematic view of the thruster arrangement stern structure of Example 1 as seen from the starboard side except for the outboard motor which is the main propulsion device. As the second embodiment, it is a schematic diagram of the thruster arrangement stern structure configured as a unit integrated with the hull.

Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings.
Here, in the attached drawings, the same members are designated by the same reference numerals, and duplicate explanations are omitted.
Since the description here is one embodiment of the present invention, the present invention is not limited to the corresponding embodiment.

The thruster-arranged stern structure of this embodiment is carried out on a small vessel having a total length of about 10 meters, a stern bottom slope of 18 degrees, and a total ton number of 7.3 tons. As two stern thrusters on the stern side of the hull 10 of the ship, a stern thruster 20 on the right side and a stern thruster 21 on the left side are provided.
Thrust and forward / reverse rotation of the stern thrusters 20 and 21 can be controlled independently.
The stern thrusters 20 and 21 are provided on the horizontal plane in the hull 10 on the stern side 11 so as to be inclined not parallel to each other.

The stern thrusters 20 and 21 have thrusts of the stern thrusters 20 and 21 so that the water flow ejected from the thrusters 20 and 21 does not interfere with one outboard motor which is the main propulsion device 30 (see FIG. 1). As shown in FIG. 1, the intersection X of the axis S is located on the bow side of the submerged portion 31 of the main propulsion device 30.
Here, as shown in FIG. 2, the angle α formed by the hull center line and the thrust axis S is 45 degrees on the horizontal plane with respect to the hull center line seen from above, but 45 degrees plus or minus. If the angle is 10 degrees, it can be arranged so as not to interfere with the main propulsion device 30.

Further, as shown in FIG. 2, the positions of the openings 20A and 21A behind the stern thrusters 20 and 21 are located inside the distance L2, which is about five-eighths of the distance L1 from the hull center line to the outside of the hull. It is arranged like this.

As shown in FIG. 3, the hull 10 related to this embodiment has a distance L3 from the bottom of the ship to the waterline of about 50 cm.
Here, the distance L4 from the bottom of the ship to the mounting position of the starboard thruster 20 is 30 cm.

In FIG. 2 or 3, 20B indicates an opening in front of the starboard stern thruster, and 21B indicates an opening in front of the port side stern thruster.

According to the thruster-arranged stern structure shown in the first embodiment, the stern thrusters 20 and 21 that generate a propulsive force for position control different from the main propulsion device 30 by one outboard unit are inside the hull 10 on the stern side. It is provided so as to be inclined not parallel to each other on the horizontal plane of the above, and the intersection X of the thrust axis S is arranged so as to be located on the bow side of the submerged portion 31 of the main propulsion device 30.
Therefore, the water flow ejected from the thruster does not interfere with the main propulsion device 30 and is not obstructed, so that the ship position can be controlled efficiently.

Further, since the stern thrusters 20 and 21 are provided in the hull 10 and near the center of the hull, it is possible to prevent the thruster thrust from becoming unstable and affecting the stern position control due to the thruster being exposed on the water surface. be able to.
Further, it is possible to eliminate the risk of becoming a large resistance due to the influence of water flow during traveling, and it is possible to prevent the thruster from breaking down due to strong water pressure as in the case of externally mounting.

In addition, since the two thrusters are installed by devising the mounting position, the structure is simple, it is easy to manufacture, it is hard to break, and it is compared with the conventional external thruster structure. It has many beneficial effects.

FIG. 4 is a schematic diagram showing that a unit for incorporating the structure of the first embodiment into an existing ship (a ship without thrusters) can be retrofitted to extend the function to the existing hull. ..
In the second embodiment, the structure including the thrusters described in the first embodiment is configured as one independent unit 40.
As shown in FIG. 4, the thruster-arranged stern structure of this embodiment is provided near the center of the unit 40 in the same manner as in the first embodiment so as to be retrofitted to the stern side 11 of the hull 10 and integrated with the hull 10. You can also do it.
Therefore, it can be attached to the existing hull 10 later.

10 Hull 11 Hull stern side 20 Right side stern thruster 20A Right side stern thruster rear opening 20B Right side stern thruster front opening 21 Left side stern thruster 21A Left side stern thruster rear Opening 21B Opening in front of the stern raster on the left side 30 Main propulsion unit 31 Submerged part of the main propulsion unit 40 Unit X Crossing S Thrust axis α Angle L1 Distance from the hull center line to the outside of the hull L2 From the hull center line to the hull Five-eighths of the distance to the outside L3 Distance from the bottom of the ship to the waterline L4 Distance from the bottom of the ship to the mounting position of the stern thruster

Claims (3)

Has two thrusters,
The two thrusters are provided in an inclined manner inside the stern side of the ship.
A thruster-arranged stern structure, characterized in that the intersection of the thrust axes of the two thrusters is arranged so as to be located on the bow side of the submerged portion of the main propulsion unit by the outboard motor or the inboard / outboard motor. Has two thrusters,
The two thrusters are provided in an inclined manner inside the stern side of the ship.
The intersection of the thrust axes of the two thrusters is located on the bow side of the submerged part of the main propulsion unit by the outboard motor or the inboard / outboard motor.
A thruster-arranged stern structure characterized in that the position of the opening on the rear side of the two thrusters is located inside five-eighths of the distance from the hull center line to the outside of the hull. The first aspect of the invention, wherein the positions of the thrust axes of the two thrusters are within an angle of 45 degrees plus or minus 10 degrees on the horizontal plane with respect to the hull center line seen from above. Or the thruster arrangement stern structure according to 2.

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