JP2003205895A - Ship provided with damping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ship equipped with a damping device capable of sufficiently suppressing vibration at a stage of a ship bottom plate adjacent to a propeller which is an exciting source in regard to vibration excited by rotation of the propeller, and positively reducing vibration within a wide frequency range by a small installation space in a portion requiring sufficient suppression of the vibration and noise such as a living quarter. <P>SOLUTION: The ship provided with the damping device mounted on a hull and reducing hull vibration is characterized by that the damping device is composed so that a multiplicity of spheres are housed in cases and vibration is damped by friction following mutual contact of the spheres, and the cases are fixed to hull components including a ship's bottom plate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ship body, and more particularly to a ship equipped with a vibration damping device attached to the bottom plate of the ship body to reduce ship vibration.

[0001]

2. Description of the Related Art Among the ship body vibrations of a ship, vibrations caused by the structure of the ship include vibrations caused by vibration from a propulsion engine, vibrations caused by the rotation of a propeller, and the like. To prevent such vibrations, by supporting the engine with anti-vibration, the propagation of the engine vibrations to the hull side is suppressed, and in areas such as residential areas where vibration and noise must be sufficiently suppressed, the vicinity of the residential area Mass / spring / damping material on the floor or wall of
Vibration is suppressed by a dynamic vibration suppressor that suppresses response by adding different structures. In addition, floating floors and damping materials are installed on the deck to suppress high frequency noise.

[0002]

SUMMARY OF THE INVENTION In the prior art described above, in order to suppress vibration and noise in a living area, etc.,
As mentioned above, with the main aim of blocking the transmission of vibrations and noise propagated to the vicinity of the living area into the living area, a dynamic vibration absorber is installed on the floor or wall or the deck around the living area. It is installed, or floating floors and damping materials are installed on the deck. However, in the case of vibration due to vibration from the propulsion engine, vibration is damped at the stage of vibration transmission from the vibration source to the hull side by supporting the engine with vibration isolation, but the rotation of the propeller is regarded as the vibration force. The vibration of the ship bottom plate caused by the vibration from the propeller side is propagated as it is to the neighborhood of the living area, and the dynamic vibration reducer or the floating floor or the vibration suppressor provided on the deck is surrounded around the living area. Since it is suppressed by materials, it is necessary to make the components such as the deck and pillars directly receiving the vibration from the propeller from the bottom of the ship to the vicinity of the living area to have a vibration isolation structure, which increases the weight of the hull and also the material cost. To rise.

Further, particularly in the case of a passenger ship, since the required frequency range for suppressing vibration and noise is wide, selection of a vibration damping device is complicated, and it is difficult to obtain the desired vibration suppressing effect in all frequency ranges. Accompanied by. Furthermore, especially in the case of passenger ships, many pipes are installed under the deck, so the installation space for the vibration control device is limited, and the required vibration suppression effect may not be obtained. Have

In view of the above-mentioned problems of the prior art, the present invention makes it possible to sufficiently suppress the vibration at the stage of the ship bottom plate near the propeller which is the vibration source for the vibration generated by the rotation of the propeller. An object of the present invention is to provide a ship equipped with a vibration damping device that can surely reduce vibration in a wide frequency range with a small installation space in a place such as a ward where sufficient suppression of vibration and noise is required. .

[0005]

In order to solve the above problems, the present invention provides, as an invention according to claim 1, a ship equipped with a vibration damping device which is attached to a hull to reduce hull vibration. The vibration device is configured such that a large number of spheres are housed in a case and the vibration is attenuated by friction caused by contact between the spheres, and the case is fixed to a hull component including a ship bottom plate. We propose a ship equipped with a vibration control device.

According to the above invention, the vibration generated on the bottom plate of the ship by the propeller fluctuation pressure of seawater generated by the rotation of the propeller is transmitted to the vibration control device installed on the inner surface of the bottom plate.
Due to the vibration, a large number of spheres housed in the case of the vibration damping device roll and come into contact with each other. Then, the vibration energy is converted into frictional heat by such contact, and the vibration of the ship bottom plate is attenuated. That is, according to this invention, the vibration damping device is installed on the ship bottom plate that is closest to the vibration source (propeller) and has the maximum vibration energy, and the vibration damping device reduces the number of spheres stored in the case. The vibration damping function can be increased as the number of spheres increases, and since the structure is simple and has a small space in which a large number of spheres are stored in the case, the vibration damping device allows the vibration energy to reach the maximum level at the bottom plate. It is possible to easily reduce the vibration to the target level.

Therefore, according to the present invention, the vibration damping device capable of increasing the vibration damping function by the structure having a simple and small space in which a large number of spheres are housed in the case is installed in the ship in which the vibration energy is at the maximum level. By installing on the bottom plate, the vibration due to the propeller fluctuation pressure is reliably damped by the vibration damping device on the bottom plate, and due to the rotation of the propeller to the components from the bottom of the ship such as a deck or pillar to the vicinity of the accommodation area. Vibration transmission is suppressed. Further, since the vibration damping device facilitates tuning of the vibration damping function (selection of the vibration damping possible frequency) by adjusting the amount of a large number of spheres housed in the case, it is possible to start from a low frequency component with a large vibration amplitude. It is possible to damp a wide range of vibrations of high frequency components that are noise sources, and reliably suppress vibrations due to propeller fluctuating pressure in the entire frequency range.

As described above, the vibrations transmitted from the bottom plate to the components from the bottom of the ship such as decks and pillars to the vicinity of the living area are suppressed, and it is not necessary to make such components a vibration-proof structure. As compared with the conventional hull structure, the hull weight can be significantly reduced, and the material cost can be reduced. In addition, the vibration control device having a simple and small space structure as described above is not installed under the deck where a lot of piping is provided unlike the conventional one, and the vibration control device is installed on the inner surface of the bottom plate with a sufficient space. Since the vibration damping device is installed, the installation space of the vibration damping device is not limited, and the vibration damping device having a required vibration suppressing function can be freely installed.

In the first aspect of the invention, it is preferable that at least two types of spheres having an outer diameter are mixed in the sphere. According to this structure, by combining the spheres having different outer diameters, the contact area is increased, and the damping frequency can be changed by adjusting the combination of the sphere outer diameters. Shaking is possible.

Further, in claim 1, preferably, as in claim 3, the case is provided with a supply port and a discharge port of the sphere, and either or both of the supply port and the discharge port of the sphere are provided. It is preferable to provide a sphere amount adjusting means for adjusting the supply amount or the discharge amount. With this configuration,
The amount of stored spheres in the case, that is, the total mass of the spheres, can be easily adjusted by means of a sphere amount adjusting means such as an on-off valve provided at either or both of the supply port and the discharge port, and vibration reduction including vibration-damping frequency Functions can be adjusted easily.

According to a fourth aspect of the present invention, in a ship equipped with two propellers for propulsion and a vibration damping device attached to the hull to reduce hull vibration, the two propellers are staggered in rotational phase. A flow control valve attached to a propeller shaft, provided with an opening above each propeller of the ship bottom plate and connecting the openings with a connecting pipe, and adjusting the flow rate of seawater flowing in the connecting pipe to the connecting pipe. It is characterized by being provided. In Claim 4, preferably, as in Claim 5, a vibration detector for detecting the vibration of the ship bottom plate, and a detection signal of the vibration of the ship bottom plate is input from the vibration detector, and the flow rate is determined based on the vibration detection value. It is preferable to provide a valve control device that adjusts the opening degree of the adjustment valve.

According to this invention, two propellers are attached to the propeller shaft with their rotational phases shifted, and a connecting pipe having a flow regulating valve interposed between the openings of the ship bottom plate above the respective propellers. Since the pressure waves having different phases are joined together in the connecting pipe from the propeller side with the rotational phase shifted, the two propellers are set so that the rotational phase is canceled by the pressure wave. Thus, the propeller fluctuating pressure due to the two propellers can be canceled in the connecting pipe. As a result, it becomes possible to reduce the vibration due to the propeller fluctuating pressure to a required level at the stage of the exciting force to the ship bottom plate.

According to a fifth aspect of the present invention, the vibration detector detects the vibration of the ship bottom plate and inputs the vibration to the valve control device, and the valve control device sets the opening of the flow control valve based on the detected vibration value. By changing the pressure, it becomes possible to adjust the pressure in the connecting pipe connected to the two propellers whose rotational phases are shifted so as to minimize the vibration of the bottom plate.

According to a sixth aspect of the present invention, in a ship equipped with a vibration damping device that is attached to a hull to reduce hull vibration, a part of the bottom plate of the ship is cut out, a manhole plate is provided in the cutout part, and the manhole is formed. A plate is connected to the ship bottom plate so as to be swingable in a certain range by a curved surface joint including a curved surface including a spherical surface, and seawater is formed in a case fixed to the ship bottom plate above the manhole plate. It is characterized in that a fluid chamber capable of flowing in is provided.

In addition to the sixth aspect, the invention according to the seventh aspect,
The fluid chamber has an air layer formed above the seawater layer,
The position of the boundary surface between the seawater layer and the air layer in the fluid chamber by adjusting the amount of air supplied to the air layer by opening and closing the air pipe that supplies air into the air layer And an air valve for changing

According to the sixth and seventh aspects of the present invention, a manhole plate formed by cutting out a part of the bottom plate is used as a bottom plate so that it can be swung within a certain range by a curved joint such as a spherical joint or a circular surface joint. Since the fluid chamber formed in the case fixed to the ship bottom plate is connected to the upper part of the manhole plate, the propeller fluctuating pressure due to the propeller rotation is relieved by the rotation of the manhole plate, and the upper part of the manhole plate is further connected. The residual fluctuating pressure propagating from the manhole plate side can be attenuated by the seawater stored in the fluid chamber. Therefore, the propeller fluctuating pressure is caused by the propeller fluctuating pressure transmitted to the bottom plate by a two-step action in which a large amplitude part is relaxed by the rotation of the manhole plate and the residual vibration is attenuated by seawater in the fluid chamber. Vibration force can be reduced.

Further, an air layer is formed above the seawater layer of the fluid chamber, and an air valve for adjusting the air supply amount is provided in the air pipe for supplying air into the air layer. Of the seawater layer and the air layer in the fluid chamber by adjusting the position of the boundary surface between the seawater layer and the air layer in the fluid chamber by adjusting the air supply amount into the air layer by changing the opening degree of The free surface (boundary surface) can be maintained and the vibration propagating in the seawater layer by the air layer can be damped, and the effect of reducing the vibration force due to the propeller fluctuating pressure transmitted to the ship bottom plate is further improved. To do.

According to a sixth aspect of the present invention, preferably, the case is formed of a hollow annular body in which an annular (doughnut-shaped) fluid chamber is formed so as to straddle the bottom plate and the manhole plate. Is good. With this configuration,
Since the upper part of the manhole plate is covered with a hollow annular body to form a donut-shaped fluid chamber, the vibration damping device has a low height and is compact and compact.

According to a sixth aspect of the invention, preferably, a damping material is interposed between the case fixed to the manhole plate and the inertial mass on the surface of the manhole plate facing the fluid chamber. It is better to attach a vibration absorber that is installed. According to this structure, the vibration of the manhole plate due to the propeller fluctuating pressure is attenuated by the vibration absorber on the manhole plate, so that the effect of further reducing the vibration propagated from the manhole plate to the ship bottom plate through the seawater in the fluid chamber is reduced. Is obtained.

According to a tenth aspect of the present invention, in a ship equipped with a vibration damping device attached to a hull to reduce hull vibration, a box-shaped case protruding from the bottom plate to the inside of the ship is provided, and the inside of the case is provided. In addition, a flexible chamber such as a rubber plate forms a fluid chamber partitioned from the sea, and a viscous fluid is enclosed in the fluid chamber.

According to the invention of claim 11, in addition to claim 10, the fluid chamber has an air chamber formed above the viscous fluid, and an air pipe for supplying pressurized air to the air chamber,
An air adjusting valve for adjusting the air pressure in the air chamber by opening and closing the duct of the air pipe is provided. In Claim 11, preferably, as described in Claim 12, the vibration acceleration detector for detecting the vibration acceleration in the flexible plate, and the vibration acceleration detector based on the detected value of the vibration acceleration input from the vibration acceleration detector. It is preferable to provide a control device that adjusts the opening of the air regulating valve so that the vibration acceleration of the flexible plate is zero.

According to the tenth to twelfth aspects of the present invention, the propeller fluctuating pressure due to the rotation of the propeller is relieved by a flexible plate such as a rubber plate having a high damping performance, and the viscous fluid is filled in the fluid chamber and has a large vibration damping ability. Thus, the residual fluctuating pressure propagated from the flexible plate side can be attenuated. Therefore, the vibrating force transmitted to the ship bottom plate by the propeller fluctuating pressure can be significantly reduced by the two damping bodies having a large vibration damping ability, namely the flexible plate and the viscous fluid in the fluid chamber.

According to the eleventh to twelfth aspects, the air chamber is formed above the viscous fluid in the fluid chamber, the air pressure in the air chamber can be adjusted by the air adjusting valve, and the flexible plate is The propeller is controlled by detecting the vibration acceleration and inputting it to the control device, and controlling the opening of the air adjusting valve to an air pressure that makes the vibration acceleration in the flexible plate zero based on the detected value of the vibration acceleration in the control device. The exciting force due to the fluctuating pressure can be significantly reduced at the stage of the flexible plate.

According to a thirteenth aspect of the present invention, in a ship equipped with a vibration damping device that is attached to a hull to reduce hull vibration, a box-shaped case protruding from the bottom plate to the inside of the ship is provided, and the inside of the case is provided. A flexible chamber such as a rubber plate is formed in the interior of the chamber to form a fluid chamber partitioned from the sea, a fluid containing a viscous fluid is enclosed in the fluid chamber, and a slit through which the fluid can pass is bored in the fluid in the fluid chamber. A plurality of slit plates are arranged side by side.

According to this invention, the propeller fluctuation pressure caused by the rotation of the propeller is alleviated by the flexible plate such as a rubber plate having a high damping performance, and the fluid filled in the fluid chamber and a plurality of fluids arranged in parallel in the fluid are provided. With the slit plate, the residual fluctuating pressure propagated from the flexible plate side can be attenuated. Therefore, the vibrational force transmitted to the ship bottom plate by the propeller fluctuating pressure can be greatly reduced by the synergistic damping action of the fluid in the flexible plate and the fluid chamber and the plurality of slit plates.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto, unless there is a specific description, and are merely illustrative examples. Nothing more.

FIG. 1 is a sectional view of a main portion of a vibration damping device for a ship according to a first embodiment of the present invention, and FIG. 2 is a structural view showing a mounting structure of the vibration damping device as viewed from the propeller side. FIG. 3 is a structural view of the vibration damping device according to the second embodiment as viewed from the propeller side.
4A and 4B show a vibration damping device according to a third embodiment, where FIG. 4A is a sectional view of a main part, FIG. 4B is a sectional view taken along line ZZ of FIG. Is. 5A and 5B show a vibration damping device according to a fourth embodiment. FIG. 5A is a sectional view of a main part, and FIG. 5B is a sectional view taken along line XX of FIG. FIG. 6 is a cross-sectional view of essential parts showing a vibration damping device according to the fifth embodiment. FIG. 7 shows a vibration damping device according to a sixth embodiment, where (A) is a main-part configuration diagram including a partial cross-section,
(B) is a vibration acceleration diagram. FIG. 8 is a perspective view of a dynamic vibration reducer applied to the above embodiment.

In FIG. 2 showing the mounting structure of the vibration damping device according to the present invention, 100 is the hull of a ship, 2 is a propeller, 3 is a propeller shaft connecting a propelling engine such as a diesel engine and the propeller 2, and 4 is a propeller shaft. It is the propeller shaft center. Although the propeller 2 and the propeller shaft 3 are biaxial in this embodiment, they may be monoaxial or multiaxial of three or more. 1 is the bottom plate,
101 is the hull center.

In FIG. 1 showing the vibration damping device according to the first embodiment, reference numeral 10 is a vibration damping device having the following structure. 0
Reference numeral 1 denotes a case fixed to the ship bottom plate, and a large number of spheres 11 are housed in a sphere housing chamber formed inside the case 01. Numeral 14 is a sphere insertion port of the sphere storage chamber 12,
Reference numeral 5 is a spherical discharge port, 013 is a spherical discharge pipe connected to the spherical discharge port 15, and 13 is a discharge valve for opening and closing the conduit of the spherical discharge pipe 013.

In a ship equipped with such a vibration damping device 10, the vibration generated on the ship bottom plate 1 is transmitted to the vibration damping device 10 by using the propeller fluctuating pressure of the seawater due to the rotation of the propeller 2 as the motive force, and this vibration suppresses the vibration. Case 01 of shaking device 10
A large number of spheres 11 housed inside roll in the case 01, and the spheres 11 come into contact with each other. And such a sphere 1
The vibration energy from the ship bottom plate 1 is converted into frictional heat due to the contact between the ship 1 and the vibration of the ship bottom plate 1 is attenuated. The vibration damping function of the vibration damping device 10 increases as the number of spheres 11 housed in the case 01 increases. Then, the amount of the spheres 11 accommodated in the case 01 is adjusted by changing the opening degree of the discharge valve 13.
Instead of the discharge valve 13 or together with the discharge valve 13, an opening / closing valve may be provided on the side of the spherical charging port 14.

Therefore, according to this embodiment, the vibration damping device 10 is installed on the ship bottom plate 1 which is closest to the propeller 3 which is the vibration source and has the maximum vibration energy, and the vibration damping device 10 is case 01. The vibration damping function can be increased as the number of spheres 11 accommodated therein is increased, and the number of spheres 11 can be increased because of the simple and small space structure in which a large number of spheres 11 are accommodated in the case 01. The vibration damping function can be easily increased. Also, the discharge valve 1
By opening and closing 3, the storage amount of the sphere 11 in the case 01, that is, the total mass of the sphere 11, can be easily adjusted, and the vibration reducing function including the vibration damping frequency can be easily adjusted. As a result, the vibration damping device 10 can easily reduce the vibration to the target level at the ship bottom plate 1 where the vibration energy is at the maximum level.

Therefore, according to such an embodiment, case 01
By installing the vibration damping device 10 capable of increasing the vibration damping function with a simple and small space structure in which a large number of spheres 11 are accommodated in the ship bottom plate 1 where the vibration energy is at the maximum level, A vibration damping device 10 installed on the bottom plate 1 can surely damp vibrations due to the propeller fluctuating pressure, and thereby the propeller 2 to a component member such as a deck or a pillar from the bottom of the ship to the vicinity of a living area. The transmission of vibration due to the rotation of is suppressed. Further, in the vibration damping device, the vibration damping function can be easily tuned (selection of the vibration damping possible frequency) by adjusting the amount of the large number of spheres 11 housed in the case 01. It is possible to damp a wide range of vibrations of the high-frequency component that is a noise source from the component, and it is possible to reliably suppress the vibration due to the propeller fluctuating pressure in the entire frequency range.

The sphere 11 may be a mixture of spheres having at least two kinds of outer diameters. According to this structure, by combining the spheres 11 having different outer diameters,
By increasing the contact area and adjusting the combination of the outer diameters of the spheres 11, it becomes possible to change the vibration suppression frequency, and it becomes possible to suppress various vibration modes.

In the second embodiment shown in FIG. 3, a vibration damping device 20 for a ship equipped with two propellers 2 for propulsion.
Indicates. In the figure, the two propellers 2 are attached to a propeller shaft 3 with a rotational phase shifted by θ.
Reference numerals 01a and 01b denote openings formed in the upper portion of each propeller 2 of the ship bottom plate 1, and reference numeral 24 denotes a connecting pipe connecting the openings 01a and 01b. The connecting pipe 24 has the connecting pipe 2
A flow rate adjusting valve 21 that adjusts the flow rate of seawater flowing inside 4 is provided. Reference numeral 23 is a vibration detector for detecting the vibration of the ship bottom plate 1, 22 is a detection signal of the vibration of the ship bottom plate 1 input from the vibration detector 23, and the opening of the flow rate adjusting valve 21 is adjusted based on the detected vibration value. Valve control device.

In such an embodiment, two propellers 2
Is attached to the propeller shaft 3 with a rotational phase shifted by a constant angle θ, and a connecting pipe 24 in which a flow rate adjusting valve 21 is interposed between openings 01a and 01b opening at the upper portion of each propeller 2 of the ship bottom plate 1. Due to the connection, pressure waves having different phases merge from the two propeller 2 sides with the rotational phase θ shifted from each other in the connection pipe 24. Therefore, by setting the rotational phase θ of the two propellers 2 so as to cancel the pressure wave in the connecting pipe 24, the propeller fluctuation pressure by the two propellers 2 is canceled in the connecting pipe 24. can do. As a result, it becomes possible to reduce the vibration due to the propeller fluctuating pressure to a required level at the stage of the exciting force applied to the ship bottom plate 1.

Further, the vibration detector 23 detects the vibration of the ship bottom plate 1 and inputs it to the valve control device 22. In the valve control device 22, the opening degree of the flow rate adjusting valve 21 is changed based on the vibration detection value, and the connecting pipe 24 connected to the two propellers 2 whose rotational phases are shifted by θ as described above. The internal pressure is adjusted so that the vibration of the bottom plate 1 is minimized. Therefore, the valve control device 22 can control the pressure in the connecting pipe 24 so that the vibration of the bottom plate 1 is minimized.

In the third embodiment shown in FIG. 4, 30 is a vibration damping device, which is constructed as follows. Reference numeral 31 denotes a hollow rectangular parallelepiped case having an opened lower surface, which is fixed to the inner surface 1a of the ship bottom plate 1 with the seal member 40 sandwiched between the lower surfaces. A manhole plate 37 is formed by cutting out a part of the ship bottom plate 1, that is, a portion of the ship bottom plate 1 surrounded by the case 31. The manhole plate 37 has two opposing surface sides connected to the ship bottom plate 1 so as to be swingable within a certain range by a curved surface joint 38 having a circular surface (may be a spherical surface).
That is, as shown in FIG. 4C, the curved joint 38
The semicircular convex surface 38a swings (rotates) on the semicircular concave surface 38b.
It is formed by fitting as much as possible. The manhole plate 37
The surface perpendicular to the curved joint 38 is a straight mating surface 4
It is 1. As a result, the manhole plate 37 is swingably connected to the ship bottom plate 1 by the curved joint 37 within a certain range. Reference numeral 39 denotes a flexible plate for holding the manhole plate 37, which is installed between the manhole plate 37 and the ship bottom plate 1 so as to cover the upper portion of the curved joint 37.

A fluid chamber 031 is formed in the hollow rectangular parallelepiped case 31, and the mating surface 4 is formed in the fluid chamber 031.
A seawater layer 32 such as 1, which has entered through the gap between the manhole plate 37 and the ship bottom plate 1, and an air layer 33 introduced from an air pipe 34 described later are formed above the seawater layer 32. 0
33 is a boundary surface between the seawater layer 32 and the air layer 33. Three
6 is an air inlet to the air layer 33, 34 is an air pipe for supplying air into the air layer 33, and 35 is an air supply amount into the air layer 33 by opening and closing the conduit of the air pipe 34. Is an air valve that adjusts.

In this embodiment, a manhole plate 37 formed by cutting out a part of the ship bottom plate 1 is connected to the ship bottom plate 1 by a curved joint 38 having a semicircular surface (or a hemispherical surface) so that the manhole plate 37 can swing within a certain range. And the inner surface 1a of the bottom plate 1
Fluid chamber 031 formed in case 31 fixed on top
By providing the upper part of the swingable manhole plate 37, the propeller fluctuation pressure due to the propeller rotation is relieved by the rotation of the manhole plate 37. The residual fluctuating pressure propagated from the manhole plate 37 side is attenuated by the seawater layer 32 stored in the fluid chamber 031 above the manhole plate 37.

Further, an air layer 33 is formed above the seawater layer 32 of the fluid chamber 031 to change the opening degree of the air valve 35 provided in the air pipe 34 to supply air into the air layer 33. Seawater layer 3 in the fluid chamber 031 by adjusting the amount
The position of the boundary surface 033 between the 2 and the air layer 33 is adjusted. This makes it possible to maintain the free surface (boundary surface 033) between the seawater layer 32 and the air layer 33 in the fluid chamber 031 and damp the vibration propagating through the seawater layer by the air layer 33. .

Therefore, according to such an embodiment, the propeller fluctuating pressure is relaxed in a portion having a large amplitude by the rotation of the manhole plate 37, the residual vibration is attenuated in the seawater layer 32 in the fluid chamber, and further the seawater layer is formed. It is possible to damp the vibration propagating through the inside 32, and to greatly reduce the exciting force due to the propeller fluctuating pressure transmitted to the ship bottom plate 1 by the above-described three-step damping action.

In the fourth embodiment shown in FIG. 5, the upper surface 37a of the manhole plate 37 which faces the fluid chamber 031.
Then, a plurality (or one) of the dynamic vibration absorbers 50 as shown in FIG. 8 are attached. In FIG. 8 showing the details of the dynamic vibration reducer 50, reference numeral 02 denotes a quadrangular case, 55 denotes a flange-shaped mounting piece fixed to the case 02, and 03 denotes a weight accommodated in the center of the inside of the case 02. , 04 are elastic members that are fixedly interposed between the four inner surfaces of the case 02, and are configured such that the range of the vibration absorption frequency can be changed by adjusting the amount of the elastic members 04. ing. The dynamic vibration reducer 50 is fixed by bolting or welding the flange-shaped mounting piece 55 to the inner surface 37a of the manhole plate 37. The structure of the dynamic vibration reducer 50 itself shown in FIG. 8 is the same as Japanese Patent Application No. 2000-339 filed by the applicant of the present application.
It is the same as the dynamic vibration absorber of No. 532.

According to this embodiment, the vibration generated by the propeller fluctuating pressure is caused by the swing of the manhole plate 37 and the plurality of dynamic vibration absorbers 50 installed on the upper surface 37a of the manhole plate 37.
Is damped by the synergistic effect of the inertial mass effect of the weight 04 and the vibration absorbing effect of the elastic material 04, and the seawater layer 32 and the air layer 33 in the fluid chamber 031 from the manhole plate 37 are damped.
A further reduction effect of the vibration propagated to the ship bottom plate 1 via the can be obtained. The other structure is the same as that of the third embodiment (FIG. 4), and the same members are designated by the same reference numerals.

In the fifth embodiment shown in FIG. 6, an annular duct 42 corresponding to the case 31 in the third and fourth embodiments is provided across the bottom plate 1 and the manhole plate 37.
An annular (donut-shaped) fluid chamber 033 is formed inside the annular duct 42. According to this embodiment, since the upper part of the manhole plate 37 is covered with the hollow annular duct 42 to form the doughnut-shaped fluid chamber 033, the height of the vibration damping device is low and the structure is small and compact. The other structure is the same as that of the third embodiment (FIG. 4), and the same members are designated by the same reference numerals.

The vibration damping device according to the sixth embodiment is shown in FIG.
Is a configuration diagram of a main part including a partial cross section, and (B) is a vibration acceleration diagram. In FIG. 7A, reference numeral 45 denotes a hollow rectangular parallelepiped case having an opened lower surface, and the lower end edge is fixed to the ship bottom plate 1. Reference numeral 60 denotes a flexible plate such as a rubber plate fixed to the lower surface of the case 45. In the hollow rectangular parallelepiped case 45, a fluid chamber 046 partitioned by the flexible plate 60 from the sea is formed. A viscous fluid layer 46 containing a viscous fluid is formed in the fluid chamber 046,
An air layer 47 made of air introduced from an air pipe 62 described later is formed on the viscous fluid layer 46. 0
Reference numeral 47 is a boundary surface between the viscous fluid layer 46 and the air layer 47. 61 is an air inlet to the air layer 47, and 62 is the air layer 4
7 is an air pipe for supplying air into the air pipe, and 63 is the air pipe 4
7 is an air regulating valve for controlling the air pressure in the air layer 47 by opening and closing the pipe line 7 to regulate the air supply amount into the air layer 47.

Reference numeral 48 is a slit plate provided in the fluid chamber 046 in a plurality of layers (may be one layer). Slit plate 48
Is immersed in the viscous fluid layer 46, and slits 49 through which the viscous fluid can pass are perforated at regular intervals. Reference numeral 65 is a vibration acceleration detector for detecting vibration acceleration in the flexible plate 60, and 64 is a vibration acceleration detection value input from the vibration acceleration detector 65, and vibration in the flexible plate 60 is detected based on the vibration acceleration detection value. This is a control device that adjusts the opening of the air adjusting valve 63 so that the acceleration becomes zero.

In this embodiment, the propeller fluctuating pressure due to the rotation of the propeller 2 is mitigated by the flexible plate 60 such as a rubber plate having a high damping performance.
The residual fluctuating pressure propagating from the side is damped by the viscous fluid having a large vibration damping capacity, which is filled in the viscous fluid layer 46 in the fluid chamber 046. Therefore, the vibration force transmitted to the ship bottom plate 1 due to the propeller fluctuating pressure is applied to the flexible plate 6
0 and the viscous fluid layer 46 in the fluid chamber 046, the two damping bodies having a large vibration damping ability can be greatly reduced.

The viscous fluid layer 4 in the fluid chamber 046
6, an air layer 47 is formed on the upper portion of 6, and the air pressure in the air layer 47 can be adjusted by the air adjusting valve 63, and the vibration acceleration due to the propeller fluctuating pressure in the flexible plate 60 is detected to detect the air pressure control device 64. To the air pressure control device 64 so as to make the vibration acceleration in the flexible plate 60 zero based on the detected value of the vibration acceleration.
By controlling the opening of the air regulating valve 63 to the internal air pressure, the vibration acceleration is reduced as shown in FIG. 7B, and the vibration force due to the propeller fluctuation pressure is significantly increased at the flexible plate 60 stage. Can be reduced to.

In addition, the vibrating fluid layer 4 formed in the fluid chamber 046 and the flexible plate 60 having the high damping performance as described above is capable of vibrating due to the propeller fluctuation pressure caused by the rotation of the propeller.
6 and the air layer 47, and the viscous fluid layer 46
The synergistic damping action of reducing the vibration propagated in the slits 48 of the plurality of slit plates 48 by moving the viscous fluid causes the vibration due to the residual fluctuating pressure propagated from the flexible plate 60 side. It becomes possible to attenuate almost completely.

[0050]

As described above, according to the inventions of claims 1 to 3, a large number of vibrations generated in the bottom plate of the ship by the propeller fluctuating pressure of seawater due to the rotation of the propeller are used as the motive force in the case of the vibration damping device. When the stored spheres roll and come into contact with each other, the vibration energy can be converted into friction heat and the vibration of the bottom plate can be attenuated. Therefore, according to such an invention, the vibration damping device is installed on the ship bottom plate which is closest to the propeller of the vibration source and has the maximum vibration energy, and the vibration damping device increases the number of spheres housed in the case. The vibration damping function can be increased in accordance with the above, and since the structure has a simple and small space in which a large number of spheres are stored in the case, the vibration damping device is used to suppress vibrations at the bottom plate where the vibration energy is at the maximum level. It is possible to easily reduce to the target level.

Therefore, in the bottom plate of the ship, the vibration due to the propeller fluctuating pressure is surely damped by the vibration damping device as described above, and the rotation of the propeller to the components from the bottom of the ship such as the deck or pillar to the vicinity of the accommodation area. The transmission of vibration due to is suppressed. Further, since the vibration damping device facilitates tuning of the vibration damping function (selection of the vibration damping possible frequency) by adjusting the amount of a large number of spheres housed in the case, it is possible to start from a low frequency component with a large vibration amplitude. It is possible to damp a wide range of vibrations of high frequency components that are noise sources, and reliably suppress vibrations due to propeller fluctuating pressure in the entire frequency range.

According to the present invention, the contact area is increased by combining the spheres having different outer diameters, and the damping frequency can be changed by adjusting the combination of the sphere outer diameters. Therefore, it is possible to suppress various vibration modes. According to the third aspect of the invention, the amount of stored spheres in the case, that is, the total mass of the spheres can be easily adjusted by the sphere amount adjusting means such as the on-off valve provided at either or both of the supply port and the discharge port. Therefore, it becomes easy to adjust the vibration reducing function including the frequency at which vibration can be suppressed.

According to the fourth to fifth aspects of the invention, pressure waves having different phases join from the two propeller sides whose rotational phases are shifted in the connecting pipe, and the propeller fluctuating pressure by the two propellers is connected. You can cancel within the jurisdiction. As a result, vibration due to propeller fluctuating pressure
It is possible to reduce the level to the required level at the stage of the vibration force applied to the ship bottom plate.

According to the present invention, the valve control device changes the opening of the flow rate adjusting valve based on the vibration detection value and connects the two propellers whose rotational phases are shifted. The pipe pressure can be adjusted so as to minimize the vibration of the bottom plate.

Further, according to the invention of claims 6 to 9, a manhole plate formed by cutting out a part of the bottom plate is used as a bottom plate so as to be swingable in a certain range by a curved joint such as a spherical joint or a circular surface joint. Since the fluid chamber formed in the case fixed to the bottom plate of the ship is connected to the upper part of the manhole plate, the propeller fluctuating pressure is relaxed by rotating the manhole plate to reduce the large amplitude part and the manhole plate side. Due to the two-step vibration damping effect of dampening the residual vibrations propagated from the ship by the seawater in the fluid chamber, the vibration force due to the propeller fluctuating pressure transmitted to the ship bottom plate can be reduced.

By changing the opening of the air valve and adjusting the amount of air supplied into the air layer to adjust the position of the boundary surface between the seawater layer and the air layer in the fluid chamber, the seawater layer in the fluid chamber can be adjusted. By maintaining the free surface (boundary surface) with the air layer, the vibration propagating in the seawater layer by the air layer can be attenuated, and the effect of reducing the excitation force by the propeller fluctuating pressure transmitted to the ship bottom plate. Is further improved.

According to the eighth aspect of the invention, since the upper part of the manhole plate is covered with the hollow annular body to form the donut-shaped fluid chamber, the vibration damping device has a low height and is compact and compact. Become. Further, according to the present invention, since the vibration of the manhole plate due to the propeller fluctuation pressure is damped by the vibration absorber on the manhole plate, the vibration transmitted from the manhole plate to the ship bottom plate through the seawater in the fluid chamber can be reduced. Further reduction effect can be obtained.

According to the tenth to twelfth aspects of the present invention, the propeller fluctuating pressure due to the propeller rotation is alleviated by a flexible plate such as a rubber plate having a high damping performance, and the viscous fluid is filled in the fluid chamber and has a large vibration damping capability. Thus, the residual fluctuating pressure propagated from the flexible plate side can be attenuated. Therefore, the vibration force transmitted to the ship bottom plate by the propeller fluctuating pressure can be greatly reduced by the synergistic action of the two vibration damping bodies, which are the flexible plate and the viscous fluid in the fluid chamber, which have a large vibration damping capability.

According to the eleventh to twelfth aspects, the air pressure in the air chamber formed above the viscous fluid in the fluid chamber can be adjusted by the air regulating valve.
The control device controls the opening of the air adjustment valve to control the air pressure to zero the vibration acceleration of the flexible plate based on the detected value of the vibration acceleration of the flexible plate. It can be greatly reduced at the plate stage.

According to the thirteenth aspect of the invention, the propeller fluctuating pressure due to the propeller rotation is alleviated by a flexible plate such as a rubber plate having a high damping performance, and the residual fluctuating pressure propagated from the flexible plate side is further reduced. The fluid filled in the fluid chamber and the plurality of slit plates arranged in parallel in the fluid can attenuate the fluid. Therefore, the vibrational force transmitted to the ship bottom plate by the propeller fluctuating pressure can be greatly reduced by the synergistic damping action of the fluid in the flexible plate and the fluid chamber and the plurality of slit plates.

In short, according to the present invention, by installing the nuclear vibration damping device configured as described above on the ship bottom plate that is directly subjected to the vibration force due to the propeller fluctuating pressure, the accommodation area from the bottom of the ship such as a deck or pillar can be set. Since the vibration transmitted to the components up to the vicinity is suppressed, there is no need to make such components a vibration-proof structure, and the hull weight can be significantly reduced compared to the conventional hull structure, Material costs can also be reduced. In addition, since the vibration damping device having a simple and small space structure is installed on the inner surface of the ship bottom plate, which does not have to be installed under the deck where many pipes are provided unlike the conventional one, it is possible to install it. The installation space of the vibration damping device is not limited, and the vibration damping device having a required vibration suppressing function can be freely installed.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts of a ship vibration damping device according to a first embodiment of the present invention.

FIG. 2 is a structural view of the mounting structure of the vibration damping device as viewed from the propeller side.

FIG. 3 is a structural view of the vibration damping device according to the second embodiment as viewed from the propeller side.

4A and 4B show a vibration damping device according to a third embodiment, where FIG. 4A is a sectional view of a main part, FIG. 4B is a sectional view taken along line ZZ of FIG. 4A, and FIG. It is a figure.

5A and 5B show a vibration damping device according to a fourth example, where FIG. 5A is a sectional view of a main part, and FIG. 5B is a sectional view taken along line XX of FIG.

FIG. 6 is a cross-sectional view of essential parts showing a vibration damping device according to a fifth example.

7A and 7B show a vibration damping device according to a sixth embodiment, FIG. 7A is a configuration diagram of a main part including a partial cross section, and FIG. 7B is a vibration acceleration diagram.

FIG. 8 is a perspective view of a dynamic vibration reducer applied to the embodiment.

[Explanation of symbols]

1 Ship bottom plate 01 case 01a, 01b Opening 1a Inner surface of ship bottom plate 2 propeller 3 propeller shaft 4 Propeller shaft center 10 Vibration control device 11 spheres 12 Sphere storage room 13 Discharge valve 14 Sphere input port 15 Sphere outlet 24 Connection pipe 20 Vibration control device 21 Flow rate adjustment valve 22 valve controller 23 Vibration detector 30 vibration control device 31 cases 031 fluid chamber 32 Seawater layer 33 Air layer 34 air tube 35 air valve 37 Manhole board 38 curved joint 42 annular duct 45 cases 46 Viscous fluid layer 046 Fluid chamber 47 Air layer 48 slit plate 49 slits 50 dynamic vibration absorber 60 flexible plate 62 air tube 63 Air regulating valve 64 Pneumatic control device 65 Vibration acceleration detector 100 hull

Claims (13)

[Claims] 1. A ship equipped with a vibration damping device attached to a hull to reduce hull vibration, wherein the vibration damping device damps vibration due to friction caused by contact between the spheres and a large number of spheres housed in a case. A ship provided with a vibration damping device, characterized in that the case is fixed to a hull constituent member including a ship bottom plate. 2. The marine vessel provided with the vibration damping device according to claim 1, wherein the sphere is formed by mixing spheres having at least two kinds of outer diameters. 3. The case is provided with a supply port and a discharge port of the sphere, and one or both of the supply port and the discharge port is provided with a sphere amount adjusting means for adjusting a supply amount or a discharge amount of the sphere. A ship provided with the vibration damping device according to claim 1. 4. Providing two propellers for propulsion,
In a ship equipped with a vibration damping device that is attached to a hull to reduce hull vibration, the two propellers are attached to a propeller shaft with their rotational phases shifted, and an opening is provided at a position above each of the propellers of a ship bottom plate. A ship provided with a vibration damping device, characterized in that the openings are connected by a connecting pipe, and the connecting pipe is provided with a flow rate adjusting valve for adjusting the flow rate of seawater flowing in the connecting pipe. 5. A vibration detector for detecting the vibration of the ship bottom plate, and a valve for inputting a detection signal of the vibration of the ship bottom plate from the vibration detector to adjust the opening of the flow rate adjusting valve based on the detected vibration value. A control device is provided, It is characterized by the above-mentioned.
A ship equipped with the described vibration damping device. 6. In a ship equipped with a vibration damping device attached to a hull to reduce hull vibration, a part of the bottom plate of the ship is cut out and a manhole plate is provided in the cut out part,
The manhole plate is connected to the ship bottom plate so as to be swingable within a certain range by a curved surface joint including a circular surface and a curved surface including a spherical surface,
A ship provided with a vibration damping device, characterized in that a fluid chamber, which is formed in a case fixed to the ship bottom plate and allows seawater to flow in, is provided above the manhole plate. 7. The fluid chamber has an air layer formed above a seawater layer, and an air pipe for supplying air into the air layer,
An air valve for opening and closing the conduit of the air pipe to adjust the amount of air supplied into the air layer and changing the position of the boundary surface between the seawater layer and the air layer in the fluid chamber. A ship provided with the vibration damping device according to claim 6. 8. The vibration damping device according to claim 6, wherein the case is formed of a hollow ring-shaped body in which a ring-shaped (doughnut-shaped) fluid chamber is formed across a ship bottom plate and a manhole plate. Ships equipped with. 9. A vibration absorber having a damping material interposed between a case fixed to the manhole and an inertial mass is attached to a surface of the manhole plate facing the fluid chamber. A ship provided with the vibration damping device according to claim 6. 10. In a ship equipped with a vibration damping device attached to a hull to reduce hull vibration, a box-shaped case protruding from the bottom plate to the inside of the ship is provided, and a rubber plate or the like can be provided inside the case. A ship provided with a vibration damping device, characterized in that a fluid chamber partitioned from the sea by a flexible plate is formed, and a viscous fluid is enclosed in the fluid chamber. 11. The fluid chamber comprises an air chamber formed above the viscous fluid, and an air pipe for supplying pressurized air into the air chamber and a channel of the air pipe are opened / closed to open the air chamber. A ship provided with the vibration damping device according to claim 10, further comprising an air adjusting valve for adjusting the air pressure of the ship. 12. A vibration acceleration detector for detecting a vibration acceleration of the flexible plate, and a vibration acceleration of the flexible plate set to zero based on a detected value of the vibration acceleration input from the vibration acceleration detector. A ship provided with the vibration damping device according to claim 11, further comprising a control device that adjusts the opening of the air regulating valve. 13. A ship equipped with a vibration damping device attached to a hull for reducing hull vibration, wherein a box-shaped case protruding from the bottom plate to the inside of the ship is provided, and a rubber plate or the like can be provided inside the case. A plurality of slit plates are formed by forming a fluid chamber partitioned from the sea by a flexible plate, enclosing a fluid containing a viscous fluid in the fluid chamber, and perforating slits through which the fluid can pass in the fluid in the fluid chamber. A ship equipped with a vibration damping device characterized by being installed in parallel.