JP2002310231A - Floating body mooring method by rotary body of floating body type damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mooring method capable of realizing smooth movement in the vertical direction while providing spring effect for movement in the horizontal direction of a floating body in a liquid tank in a floating body type damping device. SOLUTION: This floating body mooring method is used for damping vibration of a structure on the floating body 12 or various equipment and devices by the liquid tank 11 and the floating body 12 floating in a liquid 13 inside the liquid tank. A support means 20 of the floating body 12 consists of a rollerlike rotary body 21 and a support shaft 22. The support shaft 20 is fixed and provided together with a spring member 24 in a plurality of sections in the liquid tank 11 so as to rotate vertically and freely. The rotary body 21 is brought into contact with a side face 12a of the floating body by the spring member 24 to moor the floating body 12 elastically in the liquid tank 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating type in which a liquid tank and a floating body inside the liquid tank reduce vibrations from the outside or internal vibrations caused by mechanical vibrations or the like, which are received by a structure or various devices and devices. The present invention relates to a method of mooring a floating body using a rotating body of a vibration isolator.

[0002]

As shown in FIG. 5, there is a method of using a floating body 2 floating on a liquid 3 in a liquid tank 1, as a method of seismic isolation of a structure or vibration proof of mechanical vibration.
In this floating seismic isolation or vibration isolation (hereinafter referred to as vibration isolation) method, an ideal vibration isolation effect is exhibited for a short-period vibration component in the horizontal direction, but is represented by an earthquake, mechanical vibration, or the like. It is already known that no effect is exerted on the vertical component.

As one method of solving the problem with respect to the vertical component, as shown in FIG. 6, a bottom portion of a floating body 2 is formed in an air chamber 4 and the bottom of the floating body 2 is utilized by utilizing the compressibility of air in the air chamber 4. It has been proposed to reduce the vibration by a spring effect on the vibration in the direction.

However, in such a method, a large dead space is generated in the floating body, and the stability of the floating body 2 is also deteriorated. Some air-tight air chambers 4a, 4b, and 4n are partitioned to secure stability.

The floating body 2 provided with the air chamber 4 at the bottom has a difficulty in restoring performance as compared with the floating body 2 shown in FIG. 5, and the present inventors have solved such a problem in the structure shown in FIG. Resolved earlier by adoption. In this new configuration, the air chamber 4 is provided on both sides of the liquid tank 1 in a hermetically sealed manner, and the liquid chamber 1 is provided with an opening provided at a lower portion so that a part of the liquid 3 flows into and out of the liquid chamber 1. This is different from the conventional configuration shown in FIG. 6 in that it communicates with the inside.

In such a configuration, the liquid 3a that has flowed into the air chamber 4 from the liquid tank 1 through the opening keeps a balance at a position where the liquid level is lower than that of the floating body installation portion at rest due to the air pressure in the air chamber. The vertical vibration with respect to the floating body 2 is reduced by a spring effect due to the compressibility of air. In addition, since the floating body 2 has no air chamber, it has the same restoration performance as the case of FIG.

Furthermore, the stability of the floating body 2 is relatively high as compared with the case where an air chamber is provided at the bottom of the floating body. Since the floating body 2 descends while maintaining the horizontal level, the floating body 2 does not incline, so safety is high, and maintenance work such as adjustment of air pressure is much easier than when an air chamber is provided at the bottom of the floating body. With the characteristics of

[0008] All floating-type vibration-isolating devices, including this new configuration, require some type of mooring method to maintain the horizontal position of the floating body. The simplest method of mooring is to anchor the floating body 2 to the liquid tank 1 using a spring or a mooring line for boats (such as a nylon rope).
If the mooring line is significantly displaced by the floating body for some reason such as a decrease in the liquid level due to air leakage, an excessive load may be applied to the mooring line or a fixed portion thereof, and the mooring line may be broken. The effect of the mooring spring may also act in the vertical direction,
There is a problem that the vibration isolation effect for vertical vibration may be reduced.

The present invention has been conceived in order to solve the problem of mooring of a floating body by the mooring line, and its object is to facilitate mooring regardless of the presence or absence of an air chamber. An object of the present invention is to provide a floating body mooring method using a new rotating body which has a mooring effect on directional movement and is smooth with respect to vertical movement.

The present invention according to the above object is intended to provide a floating type vibration isolating device for performing vibration isolation of a structure on a floating body or various devices or devices by using a liquid tank and a floating body floating in a liquid in the liquid tank. The support means of the floating body consisting of the rotating body and the supporting shaft is provided by fixing the supporting shaft together with a spring member so as to be vertically rotatable at a plurality of positions in the liquid tank, and the spring body abuts the rotating body on the side surface of the floating body. The floating body is elastically moored in the liquid tank.

In such a method of mooring a floating body, since there is no fixed portion on the floating body side, even if the floating body descends greatly for some reason, there is no fear that the support means is broken. Further, even when the floating body is largely displaced in the horizontal direction, safety can be ensured by forming the rotating body from a material having high elasticity such as rubber.

Further, since the rotating body is used, the structure becomes smooth in the vertical direction, so that it has no effect on the seismic isolation / vibration-proof effect against the vertical vibration. Not only that, the spring effect can be exerted in the rotation direction.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, wherein reference numeral 20 denotes a means for supporting a floating body 12 floating on a liquid 13 in a liquid tank 11, and a rotating body formed in a roller shape. 21 and a support shaft 22 inserted through a through hole at the center of the rotating body 21. Although not shown in the figure, the floating body 1
Arbitrary structures, various devices, devices, and the like are installed on the upper surface and inside of 2.

Both ends of the support shaft 22 are connected to a metal seat plate 23.
A torsion spring 24, one end of which is fixed to the seat plate 23, is fitted and fixed to the shaft end inserted through and supported by the seat plate 23. I have.

The length of the support shaft 22 is determined by the mooring space between the liquid tank 11 and the floating body 12. However, since the mooring force of the torsion spring 24 needs to be applied to the floating body 12 efficiently, the support of the floating body 12 is required. Sometimes, the length is set so that the support shaft 22 is located downward at a predetermined angle.

The support means 20 having the above-described structure is adapted to move the seat plate 23 so that the support shaft 22 is rotated vertically.
1a, and is provided at a plurality of locations of the liquid tank 11, whereby the rotating bodies 21 and 21 at each location are evenly contacted and supported by the floating body side faces 12a, 12a by spring pressure, and the floating body 12
Is elastically moored in the liquid tank 11.

[0017] The following ones describing mooring force in the mooring process, the left and right both assuming use the same ones, if floating is Δ _X [m] minute displacement to the right, the support shaft of the right and left mooring apparatus The angle θ [rad] formed with the wall surface of the liquid tank is as follows. In the formulas, the subscripts L and R represent the values of the left and right mooring means, respectively. _{θ L = θ 0 + Δθ L} = θ 0 + Δ X / lsin θ 0 1.1 θ R = θ 0 + Δθ R = θ 0 -Δ X / lsin θ 0 1.2 Here, theta _0: initial angle of the support shaft , L: length of the support shaft.

The magnitude of the reaction moment generated in torsion spring by the displacement delta _X is as follows. Note that M ₀
Is the magnitude of the initial moment of the torsion spring when the floating body is stationary [N
m] and k are torsion spring constants [Nm / rad]. _{M L = M 0 -kΔθ L =} M 0 -kΔ X / lsin θ 0 ( _{counterclockwise) 2.1 M R = M 0 -kΔθ} R = M 0 + kΔ X / lsin θ 0 ( clockwise) 2.2

Thus, the force by which the mooring means pushes the floating body is as follows on the left and right (positive in the right direction). _{F L = M L cosθ L /} l 3.1 F R = M R cosθ R / l 3.2

The mooring force acting on the floating body is F = F _L + F _R
It is represented by By substituting Equations 1.1 and 2.1 for Equation 3.1 and Equations 1.2 and 2.2 for Equation 3.2, respectively, the following is obtained. F = −2 (k−M ₀ tan θ ₀ ) Δ _X / l ² In addition to the spring constant k of the torsion spring, the length l of the support shaft and the initial angle θ ₀ are not related to the strength of the mooring force. You can see that

FIG. 4 shows another embodiment in which a plurality of upper and lower portions of the side surface 12a of the floating body are supported and moored by the supporting means 20. In such mooring, the spring effect can be exerted not only in the horizontal direction but also in the rocking / rolling motion of the floating body and the inclination (rotation direction) of the floating body against uneven load.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a floating type vibration isolation device employing a floating body mooring method according to the present invention.

FIG. 2 is a perspective view of support means employed in the floating body mooring method of the present invention.

FIG. 3 is an explanatory view showing an installation state of a support means.

FIG. 4 is a schematic explanatory view of another embodiment of the present invention.

FIG. 5 is an explanatory view of a basic floating type vibration isolator.

FIG. 6 is an explanatory view of a conventional floating-type vibration-isolating device in which a floating body having an air chamber at the bottom can also perform vertical vibration isolation.

FIG. 7 is an explanatory view of a previously proposed floating type vibration isolating device in which vertical vibration can be isolated by an air chamber on the liquid tank side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Liquid tank 11a Liquid tank side surface 12 Floating body 12a Floating body side surface 13 Liquid 20 Support means 21 Rotating body 22 Support shaft 23 Seat plate 24 Torsion spring

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tsuyoshi Nozu 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation F-term (reference) 3J048 AA02 AC04 BC02 BG02 BG06 DA04 EA38

Claims (1)

[Claims] 1. A floating type vibration isolator for isolating a structure on a floating body or various devices and devices by a liquid tank and a floating body floating in a liquid in the liquid tank. A supporting means for a floating body comprising a shaft is provided at a plurality of positions in the liquid tank by fixing the supporting shaft together with a spring member so as to be rotatable up and down, and the rotating body is brought into contact with the side surface of the floating body by the spring member, and the floating body is placed in the liquid tank. A floating body mooring method using a rotating body of a floating type vibration isolator characterized by being elastically moored within the body.