JP3426686B2 - Hull pitching prevention method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for preventing pitching of a hull, and more particularly to a method and an apparatus for preventing pitching of a ship using fins for preventing pitching of the ship .

[0002]

2. Description of the Related Art As a means for preventing pitching of a hull, as shown in FIG. 4 (side view of the hull) and FIG. 5 (front view of the hull), a strut 2 projecting downward to the bottom of the hull near the end of the hull 1. It is conceivable to provide the fins 3 supported by the strut 2 and control the blade angle of the fins 3 in the same manner as in the conventional fin stabilizer for hull roll prevention.

[0003]

However, in the pitch preventing means by controlling the blade angle of the fins 3 as described above,
In order to generate a very large moment required to prevent pitching, a huge fin must be provided under the bottom of the ship at the end of the hull, which causes a significant decrease in the propulsion performance of the hull. The present invention is intended to solve such a problem, and while the fins for hull vertical vibration prevention provided at the end of the hull are downsized, the vertical movement of the fins in water causes sufficient vertical movement. An object of the present invention is to provide a method and an apparatus for preventing vertical vibration of a ship so that a vibration suppressing effect can be obtained.

[0004]

In order to achieve the above-mentioned object, the hull pitching prevention method of the present invention comprises a strut capable of descending from the storage room inside the hull to the water below the hull near the end of the hull. , by using the hull pitching preventing fins substantially horizontally mounted on the lower end of the strut, ship the fin during pitching of the ship in the water with the strut
It is characterized and Turkey moved vertically in pitch phase and opposite phase of the body.

[0005] Longitudinal anti-swing device of the present invention, the hull
Near the edge of the
Struts that can descend into the water and the lower end of the strut
The hull vertical fins installed almost horizontally on the
In addition to the strut lifting mechanism, it also has a sensor that detects the pitching of the hull,
The fins together with the struts in the water
In order to move up and down in the record of the phase and antiphase, elevation control system for controlling the elevation driving mechanism based on the detection signal from the sensor is characterized in that provided.

Further, the hull pitching preventive device of the present invention is characterized in that the fins are fixedly mounted on the struts and the fins have wing-shaped cross sections which are vertically symmetrical.

[0007]

According to the above-described hull pitching prevention method of the present invention, when the hull is pitched during navigation, the fins are lowered together with the struts from the storage room in the bottom of the hull into the water below the bottom of the hull. , operation for vertically moving performed in pitch phase and antiphase hull underwater fins with struts
Be done. As a result , a lift is generated in the fin by the water flow that flows into the fin at an angle of attack corresponding to the direction of the composite vector of the vertical movement speed and flow velocity of the fin, and the moment of the lift causes the hull to pitch. The effect of offsetting is performed.

[0008] In the above hull pitching prevention device, based on a detection signal from a sensor for detecting the pitching of the ship, since the struts of the lifting drive mechanism is controlled by a strut elevation control system, the vertical movement of the fin Accurately performed in a phase opposite to the pitch of the hull, which effectively suppresses the pitch of the hull.

[0009] For attachment of the fin to said strut, but may be a blade angle control is also performed so the same fin, and fixed mounting of the fins, moreover vertically symmetrically airfoil section of the fin By forming the fins, the lift of the fins can be appropriately generated according to the control of the lifting and lowering of the struts, and the mounting strength of the fins can be increased.

[0010]

1 is a side view schematically showing a ship equipped with the ship vertical swing preventing method and apparatus according to an embodiment of the present invention.
3 is a front view of the hull showing a section of the arrangement of the above device, FIG.
(a), (b), (c) is explanatory drawing which shows the effect | action of the said apparatus.

As shown in FIGS. 1 and 2, in the vicinity of an end portion of the hull 1 (in the present embodiment, the bow portion may be the stern portion), it is provided from a storage chamber 9 opening downward in the bottom of the vessel. , Struts 2 and 2 in the same storage room 9
The fin 3 for hull vertical movement fixedly attached to the lower end of the hull is stored when not in use.

When the fin 3 is used, the strut 2 is lowered to the lower position in the water as shown by the dotted line through the connecting member 7 by the strut lifting / lowering drive mechanism 6, and the fin 3 is submerged when the hull 1 is vertically swung. In order to move the strut 2 up and down, the strut lifting / lowering drive mechanism 6 repeats the lifting and lowering of the strut 2. As the strut lifting / lowering drive mechanism 6, a hydraulic cylinder type or a rack and pinion type is used.

A sensor 4 for detecting the pitching of the hull 1 is provided, and a strut lifting / lowering drive mechanism 6 is controlled so as to generate a lift force for suppressing the pitching of the hull on the fins 3 based on a detection signal from the sensor 4. Lifting control system 5
Is provided. A gyro (inclinometer), an accelerometer, or the like is used as the sensor 4, and the control that should be given to the strut lift drive mechanism 6 by the lift control system 5 based on the pitch angle, angular velocity, angular acceleration, etc. detected by the sensor 4. The quantity is calculated. Regarding the angular accelerometer, it is desirable to set the mounting position on the bow or stern.

The fins 3 are fixed to the lower ends of the struts substantially horizontally, and the fin 3 has a wing-shaped cross section which is vertically symmetrical as shown in FIG. 3 (a). And the hull 1
When the fins 3 move downward at the speed V together with the strut 2 when the vehicle is traveling, as shown in FIG. The angle of attack of the fin 3 with respect to the flow from diagonally below is generated, and an upward lift L is generated in the fin 3.

Then, when the fin 3 moves upward,
As shown in FIG. 3C, the flow velocity U and the rising speed V of the fins 3 are increased.
The inclination angle α of the combined vector of and becomes the angle of attack of the fin 3 with respect to the flow from diagonally above, and the downward lift L is generated in the fin 3. A door (not shown) that can be opened and closed along the bottom of the ship is provided at the lower end opening of the storage room 9.

It is used in the method for preventing vertical pitching of a ship in this embodiment.
Since the device is configured as described above, when the hull 1 pitches during traveling, it is possible to operate the strut lifting drive mechanism 6 to lower the fins 3 together with the struts 2 from the storage chamber 9 into the water below the bottom of the ship. Done. Then, when the underwater fin 3 is moved up and down together with the strut 2 by the drive mechanism 6 in a phase opposite to the longitudinal phase of the hull 1, a composite vector of the vertical moving speed V and the flow velocity U of the fin 3 is generated. A lift L is generated on the fins 3 by the water flow flowing into the fins 3 at an attack angle α corresponding to the direction, and the moment of the lift L acts to cancel the pitching of the hull.

When the strut lifting / lowering drive system 6 is controlled by the strut lifting / lowering control system 5 based on the detection signal from the sensor 4 for detecting the pitching of the hull 1, the vertical movement of the fins 3 causes the vertical shaking of the hull 1. Accurately performed in the opposite phase, whereby the pitching of the hull 1 is efficiently suppressed.

Even when the fins 3 are not moved up and down, the fins 3 move up and down due to the movement of the hull 1 in the waves, but the fins are detected based on the signal from the sensor 4 for detecting the vertical vibration of the ship. By positively moving the fins 3 up and down, it is possible to give the fins 3 a large vertical movement speed, which makes it possible to efficiently generate a lift force on the fins 3. Therefore, it is sufficient to use the small fins 3. The effect of preventing vertical pitching is obtained. Also hull 1
In the case where the vertical pitching is small, by storing the struts 2 and the fins 3 in the storage chamber 9 in the bottom of the ship, it is possible to prevent the propulsive performance from being adversely affected.

Regarding the mounting of the fins 3 on the struts 2, it is possible to control the blade angle of the fins 3, but the mounting of the fins 3 is of a fixed type and the fin 3 has a wing profile cross section. By forming the halves symmetrically, the lift of the fins 3 can be appropriately generated according to the elevation control of the struts 2, and the mounting strength of the fins 3 can be increased.

[0020]

As described in detail above, the following effects can be obtained by the method and device for preventing hull pitching according to the present invention. (1) If the hull is pitched during sailing, the fins are lowered together with the struts from the storage room in the bottom of the hull near the end of the hull into the water below the bottom of the hull, and the the vertically moving the fin along with the strut
Then, a lift is generated in the fin by the water flow flowing into the fin at an angle of attack corresponding to the direction of the composite vector of the vertical movement speed and the flow velocity of the fin, and the vertical movement of the hull is offset by the moment due to this lift. can do. (2) based on a detection signal from a sensor for detecting the pitching of the ship, since the struts of the lifting drive mechanism is controlled by a strut elevation control system, vertical movement of <br/> the fin in the strut lower end hull It will be performed accurately in the opposite phase to the pitching of the ship, which effectively suppresses the pitching of the hull. (3) Even if the fins are not moved up and down, the fins move up and down due to the motion of the hull in the waves, but the fins are moved up and down positively based on the signal from the sensor that detects the pitching of the ship. By doing so, a higher vertical movement speed can be given to the fins, and thus lift can be efficiently generated in the fins, so that even if a small fin is used, a sufficient pitching prevention effect can be obtained. (4) If the hull pitch is small, by storing the struts and fins in the storage room inside the ship bottom,
It is possible to prevent the propulsion performance from being adversely affected. (5) By mounting the fins on the struts as a fixed type, and by forming the airfoil cross section of the fins vertically symmetrically,
Lifting force of the fins can be appropriately generated in accordance with the elevation control of the struts, and the fin mounting strength can be increased.

[Brief description of drawings]

FIG. 1 is a method for preventing vertical pitching of a ship according to an embodiment of the present invention.
It is a side view which shows typically the ship provided with the apparatus used for .

FIG. 2 is a front view of a hull showing a cross section of a portion where the device of FIG. 1 is provided.

3 (a), (b), and (c) are explanatory views showing the operation of the apparatus of FIG.

FIG. 4 is a side view of a ship having fins for pitching prevention according to a conventional blade angle control method.

5 is a front view of the ship of FIG. 4. FIG.

[Explanation of symbols]

1 hull 2 struts Three fins 4 Pitch detection sensor 5 Lifting control system 6 Strut lifting drive mechanism 7 Connection member 9 storage room

Claims (3)

(57) [Claims] 1. A near the edge of the hull, the struts capable of lowering the storage compartment in the vessel bottom portion of the vessel bottom downward to the water, the hull pitching preventing fins substantially horizontally mounted on the lower end portion of the strut using Te, the fin during the pitching of the ship body
With the above strut, the phase of the pitch of the hull is reversed in water.
It characterized the Turkey moved up and down in phase, hull heave prevention
Way . 2. A case inside the bottom of the ship near the end of the hull.
The same strut that can descend from the storage room to the water below the bottom of the ship.
Vertical motion of the hull mounted almost horizontally on the lower end of the strut
Install the prevention fins and the lifting mechanism for the strut.
In addition , it has a sensor to detect the pitching of the hull.
When the ship is pitching, the fins should be shared with the struts.
In addition, it is necessary to move up and down in the water in the opposite phase of the pitch of the hull.
Ku, wherein the lift control system for controlling the elevation driving mechanism based on the detection signal from the sensor is provided, the hull pitching prevention device. 3. The hull pitching prevention device according to claim 2 , wherein the fins are fixedly mounted on the struts, and the fins have wing-shaped cross sections that are vertically symmetrical. A hull pitching prevention device.