JPS61122092A - Ship's vibration damping method and vibration prevention device of vibration absorbing type - Google Patents

Abstract

PURPOSE:To dampen a vibration by a system where a guide axis having a piston at the intermediate part is fixed to a base plate, a sliding element having oil chambers divided by a piston at the inner side and a weight at the outer side is coupled to the said guide axis and the weight is elastically supported on the base plate. CONSTITUTION:A guide axis 8 having a co-axial hollow part 18 and a piston 19 at its intermediate height is erected on a base plate 1 to be fixed to a ship's vibratory space. A sliding element 25 is so fitted to the guide axis 8 and the piston 19 as to be free to slide. Oil chambers 26 and 27 divided by the piston 19 are formed inside of the sliding element 25 and a weight 31 is fitted to its outside vis a flanged part 37a. On the base plate 1 is provided a coil spring 39 to support the weight 31. While the amount of oil continuously passing through the oil chambers 26 and 27 is controlled by a needle valve 22, the weight is adjusted, thereby keeping small the magnitude of an amplified vibration and enabling effective vibration control.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for suppressing vibrations of a ship and a dynamic vibration damping type vibration isolator for a ship.

<Conventional technology> Conventionally, in order to suppress local vibrations of a ship, reinforcing materials are added to the vibrating local areas to increase the rigidity of the local areas to avoid resonance and suppress the amplitude. If the ship's on-board equipment, such as the main engine or auxiliary equipment, is excited and resonates due to the vibrations of the ship, the main engine and auxiliary equipment will be subjected to severe vibrations that often result in damage, so it is important to stop the vibrations. Unavoidably, the main engine and auxiliary equipment mentioned above are tied to the nearest hull to alleviate their violent vibrations.

<Problem to be solved by the invention> By the way, when the range of local vibration of the ship's hull is wide, for example, when vibrations may occur in multiple panels around the engine room due to different causes, it is possible that some of the panels If reinforcing material is added to the structure, new resonance may be induced in other parts. In this case, there is a problem that it becomes difficult to plan the reinforcement work. Further, the additional installation of the reinforcing material increases the construction cost and has the problem of causing an imbalance in structural rigidity. Furthermore, when the equipment is secured to the ship's hull in order to suppress the vibrations of the tower-mounted equipment, there is a problem in that the vibrations generated by the equipment are transmitted to the ship's hull, posing a new vibration problem.

In addition, there are other problems such as the need to adjust the lashing condition every time the cargo condition, temperature, etc. change.

Therefore, the purpose of the present invention is to be able to be widely applied to vibration isolation characteristics without causing rigidity disharmony in the structure of the ship itself, and to offset the vibrational force transmitted from the vibration source and have a negative impact on the pond. The object of the present invention is to enable vibration to be suppressed easily, inexpensively, and easily.

<Means for Solving the Problems> In order to achieve the above object, the method for suppressing ship vibration of the present invention includes a slider that can be detachably attached to a weight and adjust the weight of the weight. is slidably fitted onto a shaft fixed to the substrate, and is elastically supported by an elastic member on the substrate, while the above provides viscous resistance due to the fluid against relative movement of the slider with respect to the substrate. using a vibration isolator equipped with a damper means capable of adjusting the magnitude of the viscous resistance, fixing the substrate of the vibration isolator to a vibrating part having a certain resonance point of the ship whose vibrations are to be suppressed, and Adjust the weight of the weight,
By reducing the vibration increase ratio in a desired region including the resonance region of the vibrating section and adjusting the magnitude of the viscous resistance of the damper means, the curve representing the vibration increase ratio with respect to the frequency of the vibrating section can be adjusted to A curve representing the vibration increase ratio with respect to the frequency of the vibrating part when no vibration isolator is attached to the vibrating part, and a curve representing the vibration increase ratio to the vibration frequency of the vibrating part when the damper means is not operated and a vibration isolator is attached to the vibrating part. The resonance area of the vibrating part itself and the resonance area of the vibrating part when the vibration isolator is attached to the vibrating part without operating the damper means pass through the intersection with the curve representing the vibration increase ratio to the vibration frequency. It is characterized by a curve in which the vibration increase ratio decreases with respect to the vibration frequency.

In addition, the dynamic vibration damping type vibration isolator for ships of the present invention includes a board fixed to a vibrating part of a ship, a pongee whose one end is fixed to the board and a piston is provided in the center part, It is slidably fitted on the guide shaft and the piston, and has a first oil chamber and a second oil chamber partitioned by the piston on the inside, while a weight is removably fixed on the outside. A slider whose height can be adjusted; an elastic member that elastically supports the slider with respect to a substrate; and an opening degree of a communication passage connecting the first oil chamber and the second oil chamber. It is characterized in that it is equipped with an adjustable control valve.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a cross-sectional view of a dynamic vibration damping type vibration isolator for a ship, in which a disk-shaped substrate 1 is fixed to a vibrating part 2 of a ship body via a mounting seat 3 and a bracket 4 with bolts 5. The brackets 4 are fixed to the four corners of the outer surface of the substrate 1. A hole 7 is formed in the center of the substrate 1, and one end 8a of the guide shaft 8 is inserted into the hole 7, and is stopped by the stepped portion 8b of the guide shaft 8 to protrude downward. The nut 9 and the communicating nut 10 on the outside thereof are screwed into the portion 8a to form the guide pongee 8.
is fixed to the substrate 1. The communication nut 10 is connected to a supply pipe 11. On the other hand, a cylindrical case 12 is erected on the outer circumference 1a of the substrate 1, and the other end 8c of the guide pongee 8 is inserted into a hole 14 made in the center of the upper cover 13, and the case 12 is inserted upward. Protrude and screw together with the nut 15, and attach the above case 1.
2 is sandwiched and fixed between the substrate 1 and the upper lid 13. A communicating nut 16 for air leakage is fitted onto the upper end of the guide pongee 8, and the communicating nut 16 is fixed with a presser nut 17 screwed onto the guide pongee 8. It is connected to the discharge pipe 42. Further, the guide pongee 8 is meticulously provided with a shaft hole 18 passing through it in the vertical direction. the above〃
A piston 19 is fixed approximately at the center of the id pongee 8. On both upper and lower sides of the piston 19, horizontal holes 20 and 21 are provided in the radial direction intersecting the shaft hole 18. A needle valve 22 as a control valve is inserted into the shaft hole 18 so as to be movable up and down. The tip of the needle valve 22 is tapered so as to be in close contact with a tapered valve seat 23 formed below the intersection of the shaft hole 18 and the horizontal hole 20.21. A hollow part 22a is carved into the upper end of the needle valve 22, and this hollow part 22a is screwed into a hollow part 18c provided on the inner periphery of the shaft hole 18 of the idle pongee 8, and fixed with a lock nut 40. There is. The tip of the needle valve 22 is fixed to a handle 41. A slider 25 is slidably fitted to the outer periphery of the id pongee 8 and the piston 19.

The slider 25 consists of a cylindrical main body portion 37 having a disk-shaped seven-runway portion 37a and a cover portion 35.

A space formed inside the main body part 37 and the cover part 35 is formed by the piston 19 to form a first oil chamber 26 and a second oil chamber 2.
It is divided into 7 sections. The first oil chamber 26 and the second oil chamber 27 communicate with each other through the horizontal holes 20 and 21 and the shaft hole 18. Note that the main body portion 37 and cover portion 35 of the slider 25 are
A bearing bushing 34 is interposed between the id pongee 8 and the opening.

Coil springs 38° and 39, which are elastic members, are interposed between the seven-run portion 37a of the slider 25 and the substrate 1,
Further, a coil spring 30, which is an elastic member, is also interposed between a spring receiver 29 supported by a nut 28 screwed onto the id pongee 8 and the upper surface of the seven run section 37a. A ring-shaped weight 3 is mounted on the upper surface of the seven-run part 37a of the slider 25.
1 and 31 are placed, and the weights 31 and 31 are brought into contact with the lower surface of the seven run section 37a using a jig (not shown). 3
It is fixed to the 7-run section 37a with bolts 32 and nuts 33 that pass through the 1, 31, 31 and 7-run sections 37a. In addition, the slider 25, the piston 19, the horizontal holes 20, 2
1, the shaft hole 18, the needle valve 22, and the handle 41 constitute a means for providing viscous resistance to the relative movement of the slider 25 with respect to the guide pongee 8.

By the way, when the vibration isolator is not fixed to the vibrating part 2 of the ship, as shown in Fig. 2, the vibration increase ratio of the vibrating part 2 is the vibration increase ratio with respect to the frequency of the vibrating part 2 with point A as the resonance point. It changes along a curve E representing the ratio.

Furthermore, when the vibration isolator is fixed to the vibrating section 2 by fully opening the space between the needle valve 22 and the valve seat 23, the resonance point A disappears and points B and B are newly set as resonance points. The songs #IF, Oage, and G that represent the vibration increase ratio are obtained. As the weights 31, 31, etc. are adjusted to make the resonance points B and B lighter, they will gradually approach the extinct resonance point A, and the intersections P and B of the curves E and F will become lighter. The vibration increase ratio at the intersection Q of the curves E and G gradually increases. On the contrary, the weight 31,3
1. As the weight is increased by increasing the amount of . Next, when the handle 41 is rotated to change the opening degree between the needle valve 22 and the valve seat 23, various curves H passing through the intersections P and Q are generated.
is obtained. Therefore, the weight 31.31. By increasing the amount of ... and making it heavier, the vibration increase ratio at the intersections P and Q is lowered,
In addition, by appropriately adjusting the opening degree of the needle valve 22, it is possible to obtain a curve H' that reduces the vibration increase ratio to the frequency of the vibrating part 2 over the resonance region of the vibrating part 2. Therefore, a dynamic vibration absorbing type vibration isolator for a ship in which Gunpa is applied to the above-mentioned vibration isolator is constructed as shown in FIG.
The vibration of each vibrating part can be suppressed by fixing them to the antinodes of the respective parts.

Hereinafter, the operation of suppressing vibration of each vibrating part will be specifically explained.

First, the above-mentioned vibration isolator is fixed vertically to the belly part of the ship to suppress the vibration as shown in Figure 1, while the vibration isolator is fixed vertically to the belly part of the ship, which has a large horizontal amplitude. The vibration isolator is fixed horizontally as shown in FIG. 4 so as to suppress the vibration. Then, as shown in FIG.
1 through the shaft hole 18 and the horizontal holes 20, 21 to the first oil chamber 2.
6 and the second oil chamber 27 are filled with hydraulic oil. At this time, the air that has already filled the pore 18, the first oil chamber 26, and the second oil chamber 27 passes through the gap between the needle valve 22 and the pore 18, the communication nut 16, and the discharge pipe 42 to the outside. is discharged to.

When filling of the hydraulic oil is completed, valves (not shown) provided in the supply pipe 11 and the discharge pipe 42 are closed. Considering the vibration characteristics of the vibrating section 2, the weights 31, 31. ... to adjust its weight, and the needle valve 22
Adjust the opening. Then, it is slidably fitted onto the idle shaft 8, supported in the air by springs 30, 38, 39, and fitted with an appropriate amount of weights 31, 31, . . . As shown in FIG. 2, the vibration of the vibrating part 2 is suppressed by the slider 25 provided with resistance. The above-mentioned viscous resistance is generated when the slider 25 slides against the piston 19.
The hydraulic oil in 7 flows in and out of each other through the horizontal holes 20, 21 and the shaft hole 18, and the degree of communication between the horizontal holes 20, 21 and the pore 18 is restricted by the needle valve 22, so that the operation The flow of oil is suppressed, and the vibration of the idle shaft 8, that is, the vibrating portion 2, with respect to the slider 25 is suppressed. Figure 85 shows the ratio of the natural frequency ωn of the vibrating section 2 to the externally applied forced frequency ω, and the amplitude Xst of the vibrating section 2 when the device is not fixed to the vibrating section 2. 2 represents the relationship between the amplitude X of the vibrating section 2 and the ratio of the amplitude X when the vibration section 2 is fixed. Curves 51 in FIG. 5 each represent a comparison between the planned value and the experimental value of the vibration increase ratio of the antinode of the ship. From this, it can be seen that when the second device is operated, the vibration increase ratio becomes smaller over the resonance region. It can be seen that when the above-mentioned dynamic vibration absorption type vibration isolator for ships is not installed in the vibrating section 2, the vibration increase ratio is extremely high.

The present invention can be modified in design other than the above-described embodiment, and as shown in FIG. One coil spring 47 is also provided between the upper side of the pulling part 45a of the child 45 and the spring receiver 29, and the slider 45
A pulling part 45a is provided at the upper end so that a fill spring 46 of sufficient length can support the slider 45 from the lower side, and a fill spring 47 of sufficient length can be used to support the slider 45. 45 can be supported from above. In addition, an annular groove 48 is provided on the upper end surface of the slider 45, and disk-shaped weights @5S, SS, etc. are bolted to the slider 45 for convenience of attachment and detachment from above. 49, and a stopper 50 for regulating the upward movement of the slider 45 is fixed to the upper lid 51.

<Effects of the Invention> As can be seen from the above description, the method for suppressing ship vibrations of the present invention includes removably attaching a weight to a slider, and fitting the slider to the guide shaft. , using a vibration isolating device equipped with a goomba means that provides viscous resistance by fluid to the relative movement of the slider and can adjust the magnitude of the viscous resistance, and this device is used to suppress vibrations that have a certain resonance point of the ship. Since the structure is fixed to the vibration part and the vibration increase ratio can be reduced over the resonance region of the vibration part, it is possible to reduce the vibration of ships with various vibration modes. ! ! It can be widely applied to the J1 section, and can extremely effectively achieve the purpose of vibration suppression without adversely affecting the pond, such as causing imbalance in the rigidity of the ship itself.

In addition, in the dynamic vibration damping type vibration isolator for ships of the present invention, the guide shaft is fixed to a substrate fixed to the vibrating part of the ship, and the guide shaft is detachably attached to the outside of the slider that is slidably fitted onto the guide shaft. A weight is fixed to the guide shaft, a piston is provided in the center of the guide shaft to separate the first oil chamber and the second oil chamber, and the opening degree of the communication passage that communicates the first oil chamber and the second oil chamber can be adjusted. Since a valve is provided, by adjusting the weight of the weight and the opening degree of the control valve, the locally generated vibrating force transmitted to each vibrating part can be canceled out, making it possible to reduce the cost without adversely affecting other parts. Vibration can be easily suppressed.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the present invention, Fig. 2 is a diagram showing the relationship between vibration frequency and vibration increase ratio, Fig. 3 is a schematic diagram showing the elastic curve of the hull, and Fig. 4 is a diagram showing the above embodiment. A schematic diagram of the example device installed horizontally in the vibrating section, Figure 5 shows the relationship between the ratio of the natural frequency of the vibrating section to the forced frequency and the increase ratio of the amplitude of the vibrating section to the amplitude of strong vibration. FIG. 6 is a cross-sectional view of an example of a pond. DESCRIPTION OF SYMBOLS 1... Board, 2... Vibrating part, 8... Guide shaft, 1
9...Piston, 20.21...Horizontal hole (communication path),
25.45...Slider, 26...1st oil chamber, 27.
... Second oil chamber, 30, 38, 39, 46° 47... Coil spring (elastic member), 31.55... Weight. Patent applicant: Daihatsu Diesel Co., Ltd. Agent
Patent attorney Said Ao and two others 2nd WJ Display Patent Application No. 2431342 Name of Invention Method for suppressing ship vibration and dynamic vibration absorption type vibration isolation system for ships
Relationship with the device 3 amendment case Patent applicant 1 is located at 1-80-4 Oyodonaka, Oyodo-ku, Osaka-shi, Osaka Prefecture.
6. Agent 5. Date of amendment order: Voluntary action 7. Contents of amendment 1. The following parts of the statement will be corrected. A1 Detailed explanation of the invention column (1) Page 11, line 3, ``with the belly part'' should be corrected to ``in the belly part.'' (2) On page 12, line 6, ``hollow'' is corrected to ``in the air.''that's all

Claims (2)

[Claims] (1) A slider capable of attaching and detaching a weight to adjust the weight of the weight is slidably fitted to a guide shaft fixed to a substrate, and an elastic member is used to attach a slider to the substrate. At the same time, a vibration isolator is provided with a damper means capable of applying viscous resistance by fluid to the relative movement of the slider with respect to the guide shaft, and adjusting the magnitude of the viscous resistance. fixing the substrate to a vibrating part having a certain resonance point of a ship whose vibrations are to be suppressed, adjusting the weight of the weight to reduce the vibration increase ratio in a desired region including the resonance region of the vibrating part; By adjusting the magnitude of the viscous resistance of the damper means, the curve representing the vibration increase ratio with respect to the frequency of the vibrating part can be adjusted to the frequency of the vibrating part when no vibration isolator is attached to the vibrating part. Passing through the intersection of the curve representing the vibration increase ratio and the curve representing the vibration increase ratio with respect to the frequency of the vibration part when the vibration isolator is attached to the vibration part without operating the damper means, the vibration part A curve is formed in which the vibration increase ratio becomes smaller with respect to the vibration frequency over the resonance region of the vibration damper itself and the resonance region of the vibration isolator when the vibration isolator is attached to the vibration portion without operating the damper means. A method for suppressing ship vibration, characterized by: (2) a substrate fixed to a vibrating part of a ship; a guide shaft having one end fixed to the substrate and a piston provided in the center; and a guide shaft slidably fitted on the guide shaft and the piston; A slider having a first oil chamber and a second oil chamber partitioned by the piston on the inside, and a weight removably fixed on the outside so that the weight of the weight can be adjusted. A ship comprising: an elastic member that elastically supports the slider with respect to the substrate; and a control valve that can adjust the opening degree of a communication passage that communicates the first oil chamber and the second oil chamber. Dynamic vibration absorption type vibration isolator.