JP2014163447A - Vibration reduction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration reduction device which is compact, has large capacity and is efficient and appropriate by combining a fluid pressure cylinder mechanism as an amplification mechanism to an inertia mass damper.SOLUTION: A vibration reduction device is configured such that an inertia mass damper 1 and a fluid pressure cylinder mechanism 11 which functions as amplification mechanism are integrally combined. The fluid pressure cylinder mechanism is configured such that a base end part of a main cylinder 12 is divided into a first compartment 12a and a second compartment 12b by a main piston 13, a sub-cylinder 14 having a diameter smaller than the main cylinder is arranged on the front side of the second compartment, the sub-cylinder is divided into a third compartment 14a and a fourth compartment 14b by a sub-piston 15, the second compartment is communicated with the third compartment and the first compartment is communicated with the fourth compartment via a bypass pipe 16. The inertia mass damper 1 is housed to the inner side of the top end part of the main cylinder 12 and the inertia mass damper is driven by the sub-piston 15.

Description

  The present invention relates to a vibration reducing device that is interposed between two members that vibrate relatively to reduce the relative vibration, and more particularly to a vibration reducing device that belongs to the category of an inertial mass damper that uses an inertial force generated by a rotating weight as a reaction force.

As is well known, the inertia mass damper is a device that generates a reaction force proportional to the relative acceleration at both ends of the damper, and has been put into practical use as a damping piece shown in Patent Document 1 and a seismic isolation device shown in Patent Documents 2 and 3. However, in recent years, an inertial mass damper that can obtain an inertial mass effect that is several thousand times as large as the actual mass of the rotating weight by using a ball screw mechanism has been widely spread.
In an inertial mass damper using such a ball screw mechanism, the inertial mass ψ is given by the following equation, where the rotary inertia moment I _θ of the rotary weight and the lead L _{d of the} ball screw are:

For example, as shown in Patent Documents 4 and 5, a so-called fluid inertia mass damper (also referred to as an inertia pump damper) that uses the inertia mass of a fluid is also known.
This applies pressure to the fluid (liquid) divided in the cylinder by damper displacement and returns it through a bypass pipe with a diameter smaller than the cylinder diameter. Bypassing the return speed is faster than the damper displacement speed. An inertial mass effect greater than the fluid mass in the tube is obtained.

JP-A-11-201224 Japanese Patent No. 3250795 JP 2007-10110 A JP 2007-205433 A JP 2011-158015 A

The reaction force generated in this type of inertial mass damper is proportional to the relative acceleration, so if the relative displacement, speed, and acceleration acting on both ends of the damper are multiplied by α on the output side using the amplification mechanism, the damper installed on the output side The reaction force is also multiplied by α.
On the other hand, since the reaction force of the amplification mechanism is α times larger on the input side than on the output side, the inertial mass ψ is α ² times that in the case of the above equation (1). This can be easily understood if the input side and output side energy (displacement × force) is considered the same.

It is effective to combine an amplifying mechanism with an inertial mass damper in this way, and there have been proposals for an amplifying mechanism using an insulator, a toggle mechanism, or a planetary gear. However, it is difficult to realize a large-capacity damper in a compact manner, and the energy loss due to internal friction of the amplification mechanism itself is large.
In addition, it is conceivable to use a fluid inertia mass damper as shown in Patent Documents 3 and 4 as an amplifying mechanism and incorporate the inertia mass damper in the bypass pipe, but a large reaction force is generated in the bypass pipe. Since it is difficult to reduce the size and weight, and the cost for dealing with the eccentric load increases, it is not very realistic.

  In view of the above circumstances, an object of the present invention is to provide an effective and appropriate vibration reduction device that is compact and can obtain a large capacity by combining a fluid pressure cylinder mechanism as a rational amplification mechanism with an inertial mass damper. To do.

  The invention according to claim 1 is a vibration reducing device that is interposed between two members that vibrate relatively to reduce the relative vibration, and in which a ball nut is screwed onto a ball screw shaft. An inertial mass damper that uses the inertial force generated by the rotating weight rotated by the mechanism as a reaction force, and a fluid pressure cylinder mechanism that functions as an amplifying mechanism for amplifying the relative displacement, speed, and acceleration acting on the inertial mass damper. The fluid pressure cylinder mechanism is configured such that the base end of the main cylinder is partitioned into a first compartment and a second compartment by a main piston, and the main cylinder is disposed in front of the second compartment. A sub-cylinder having a smaller diameter than the cylinder is arranged, and the sub-cylinder is divided into a third compartment and a fourth compartment by a sub-piston, and the second compartment and the second compartment are separated. The compartment and the first compartment and the fourth compartment are communicated via a bypass pipe, and the front end of the main cylinder and the main piston are respectively connected to the two members. The inertia mass damper is housed inside the tip of the main cylinder and the sub piston is connected to the inertia mass damper so that the inertia mass damper is connected to the sub piston. It is characterized by being driven.

  The invention according to claim 2 is the vibration reducing device according to claim 1, wherein the base end portion of the ball screw shaft is connected to the sub piston so as not to be rotatable relative to the sub piston and to be axially displaceable together with the sub piston. In addition, the ball nut is connected to the main cylinder so as to be rotatable relative to the main cylinder and not axially displaceable, and the rotary weight is connected to the ball nut so as to be integrally rotatable.

  The invention according to claim 3 is the vibration reducing device according to claim 2, wherein a rotation restraint plate is connected to the tip of the ball screw shaft, and the rotation restraint plate cannot rotate relative to the main cylinder. It is connected to be axially displaceable, and a restoring spring for returning the ball screw shaft to its original position is interposed between the rotation restricting plate and the tip of the main cylinder.

  A fourth aspect of the present invention is the vibration reducing device according to the first, second, or third aspect, wherein the main piston has a relief pressure difference between the first compartment and the second compartment. A relief valve is provided to allow fluid to flow when the pressure is exceeded.

  The vibration reducing device of the present invention integrally combines an inertial mass damper based on a ball screw mechanism and a fluid pressure cylinder mechanism that functions as an amplification mechanism for amplifying relative displacement, speed, and acceleration acting on the inertial mass damper. Since it is a structure, it is possible to obtain a large inertial mass while being a small rotating weight, and thus it is possible to realize a light, slim, inexpensive and large capacity vibration reducing device.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic structure of the vibration reduction apparatus which is embodiment of this invention is shown, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view (the bb line view in (a)).

FIG. 1 shows a schematic configuration of a vibration reducing apparatus according to an embodiment of the present invention.
The vibration reducing device of the present embodiment is a device that is interposed between two members (not shown) that relatively vibrate to reduce the relative vibration, and includes an inertial mass damper 1 and an inertial mass damper 1. The fluid pressure cylinder mechanism 11 that functions as an amplifying mechanism for amplifying relative displacement, speed, and acceleration acting on the cylinder is integrally combined.

  Inertial mass damper 1 according to the present embodiment is configured such that a rotating weight 4 is rotated by a ball screw mechanism in which a ball nut 3 is screwed onto a ball screw shaft 2, and an inertial force generated by the rotating weight 4 is used as a reaction force. belongs to.

  The fluid pressure cylinder mechanism 11 as an amplifying mechanism in the present embodiment uses water, oil, or various viscous fluids as a working fluid. The base end of the main cylinder 12 is connected to the first compartment 12a by the main piston 13. A sub-cylinder 14 having a diameter smaller than that of the main cylinder 12 is arranged in front of the second compartment 12b, and the sub-cylinder 14 is connected to the third compartment 14a and the second compartment by the sub-piston 15. A configuration in which the second compartment 12b and the third compartment 14a are communicated with each other, and the first compartment 12a and the fourth compartment 14b are communicated via the bypass pipe 16; Has been.

The entire inertial mass damper 1 is housed inside the tip of the main cylinder 12, and the inertial mass damper 1 is driven by the subpiston 15 by connecting the subpiston 15 to the inertial mass damper 1. It is said.
Specifically, the base end portion of the ball screw shaft 2 is coupled to the sub piston 15 so as not to rotate relative to the sub piston 15 and to be axially displaceable together with the sub piston 15, and the ball nut 3 is supported to the inner surface of the main cylinder 12. 5 is connected to the ball nut 3 so as to be relatively rotatable and axially displaceable, and a rotating weight 4 is connected to the ball nut 3 so as to be integrally rotatable.

A rotation restricting plate 6 is connected to the tip of the ball screw shaft 2, and the rotation restricting plate 6 is supported so as not to rotate relative to the main cylinder 12 and to be axially displaceable.
Specifically, as shown in FIG. 1B, a guide tube 7 is mounted on the inner surface of the tip of the main cylinder 12, and a groove 8 along the axial direction is formed in the guide tube 7. The rotation restricting plate 6 is disposed in a state in which the convex portion 6a formed on the outer peripheral portion thereof is engaged with the groove 8, so that the rotation restricting plate 6 is restrained from rotating relative to the main cylinder 12. However, it is possible to displace in the axial direction.

A restoring spring 9 for returning the ball screw shaft 2 to the original position is interposed between the rotation restraint plate 6 and the tip of the main cylinder 12.
In the illustrated example, a similar restoring spring 9 is also interposed between the rotation restricting plate 6 and the bearing 5 so that the rotation restricting plate 6 is held in its original position from both sides by both restoring springs 9. Energized.

  Furthermore, the main piston 13 is provided with a relief valve 17 that allows fluid to flow when the differential pressure between the first compartment 12a and the second compartment 12b exceeds a predetermined relief pressure.

  In the vibration reducing device of the present embodiment, the tip of the main cylinder 12 (the right end in FIG. 1A) and the main piston 13 constituting the fluid pressure cylinder mechanism 11 as an amplifying mechanism are respectively connected via the clevis 18. By connecting to the two members to be reduced in vibration, they are installed between the two members, and as a result, an excellent vibration reducing effect can be obtained by acting as follows. It is.

When a relative displacement that approaches and separates between two members that are subject to vibration reduction due to an earthquake or the like and causes them to generate relative vibration, the main piston 13 moves forward and backward in the main cylinder 12, thereby the sub-piston 15. Is increased in the sub-cylinder 14 and advances and retreats, and accordingly, the working fluid flows back through the bypass pipe 16 between the first compartment 12a and the fourth compartment 14b.
At this time, when the differential pressure between the first compartment 12a and the second compartment 12b exceeds a predetermined relief pressure set in advance, the relief valve 17 opens and the differential pressure reaches a peak, which causes an excessive reaction force. Is prevented from occurring.

  When the sub piston 15 is increased in speed and moved forward and backward, the ball screw shaft 2 moves forward and backward together with the sub piston 15. At this time, since the convex portion 6 a of the rotation restraint plate 6 is engaged with the groove 8 of the guide tube 7, the ball screw shaft 2 is allowed to be displaced only in the axial direction without rotating. The main cylinder 12 is displaced relative to the main cylinder 12 by being displaced in the axial direction from the original position against the urging force.

  When the ball screw shaft 2 is displaced relative to the main cylinder 12 in the axial direction, the ball nut is screwed to the ball screw shaft 2 and supported rotatably and undisplaceably with respect to the main cylinder 12 via the bearing 5. 3 rotates, and thus the rotating weight 4 connected to the ball nut 3 also rotates together, and the rotational inertia force becomes a reaction force to obtain a vibration reducing effect.

When the vibration between the two members converges, the sub-piston 15 returns to the original position via the rotation restraint plate 6 and the ball screw shaft 2 by the urging force of the restoring spring 9, and no residual displacement occurs.
In addition, about the main piston 13, by providing the main piston 13 with a small orifice (not shown), it is possible to return itself to the original position by a restoring force based on the elastic rigidity of the two members themselves. Since the orifice for that purpose has only a small flow rate, there is almost no effect on the characteristics at the time of the earthquake and it can be ignored.

The characteristics of the vibration reducing device of this embodiment will be described in detail.
The inner diameter D ₁ of the main cylinder 12, when the inner diameter D ₂ of the sub-cylinder 14, inner size area of the main cylinder ^{_{12 A 1 = πD 1 2/}} 4, clear width area of the sub-cylinder ^{_{14 A 2 = πD 2 2/}} 4, The speed increasing ratio α (speed ratio of the sub-piston 15 to the main piston 13) is an area ratio thereof, and α = A ₁ / A ₂ = (D ₁ / D ₂ ) ² .

Assuming that the burden force F, the displacement x, the force F ₂ acting on the sub-piston 15 and the displacement x ₂ of the sub-piston 15 of the entire vibration reducing device are assumed, F ₂ is proportional to the internal area of the main cylinder 12 and the sub-cylinder 14 Therefore, F ₂ is as follows.

Therefore, by driving the inertial mass damper 1 through the fluid pressure cylinder mechanism 11 as an amplification mechanism, the inertial mass damper 1 connected to the sub-piston 15 is displaced α times and (1 / α) times. The force acts, and the displacement x ₂ = αx of the sub-piston 15 and the force F ₂ = F / α acting on the sub-piston 15 are obtained.

The inertial mass Ψ ₂ of the inertial mass damper 1 is given by the following equation, assuming that the rotational inertia moment I _θ of the rotary weight 4 and the lead L _d of the ball screw mechanism.

  If the influence of the restoring spring 9 is ignored, the following relationship is obtained.

  Here, in consideration of the above speed increase relationship, the following equation is obtained.

That is, the inertial mass [psi in the vibration reduction device of the present embodiment is enlarged to alpha ² times the inertial mass [psi ₂ of the inertial mass damper 1, the burden force F of the vibration damping system of this embodiment bear the inertial mass damper 1 It becomes α times the force F _2.

  As described above, in the vibration reducing apparatus of this embodiment, the residual displacement does not become a problem by providing a small orifice in the main piston 13, but the sub-piston 15 does not have a restoring function by itself, and is restored. Since it is configured to be restored to the original position by the spring 9, the restoring spring 9 becomes a rigid element parallel to the inertia mass damper 1 and may affect the characteristics at the time of the earthquake. If not, it is as follows.

When the spring stiffness k ₂ of the restoring spring 9 and the relative displacement x ₂ of the sub-piston 15 with respect to the main cylinder 12 are given, the following equation is obtained.

  Further, considering the above speed increase relationship, the following equation is obtained.

In this case, the spring stiffness of the restoring spring 9 also becomes α ² times. However, since this spring stiffness only restores the sub-piston 15 and does not contribute to vibration reduction, the restoring spring prevents the spring reaction force from becoming unnecessarily large. The rigidity k ₂ of 9 is preferably made as small as possible while ensuring a desired restoring function.

`` Design example ''
The inner diameter D ₁ of the main cylinder 12 is 320 mm, the inner diameter D ₂ of the sub cylinder 14 is 160 mm, and the speed increasing ratio α is 4.
The ball screw shaft 2 has a shaft diameter of 50 mmφ, a lead L _d = 16 mm, and the rotating weight 4 made of steel and having an outer diameter of 310 mm, an inner diameter of 150 mm, a length of 350 mm, and a mass of 0.218 tons.
In this case, the rotational moment of inertia of the rotating weight is I _θ = 4.16 × 10 ⁻³ ton · m ² , the inertial mass of the inertial mass damper 1 Ψ ₂ = (2π / L _d ) ² I _θ = 641 ton, and the burden force F ₂ = 400kN.
Further, the inertial mass Ψ = α ² Ψ ₂ = 10256 ton of the entire vibration reducing device, and the burden force F = αF ₂ = 1600 kN.
That is, in this design example, the inertial mass Ψ ₂ of the inertial mass damper 1 is expanded by about 3000 times with respect to the actual mass of 0.218 ton of the rotary weight 4, and the inertial mass Ψ as a whole vibration reducing device is about 47000. It will be doubled.
In this way, according to this design example, an inertial mass exceeding 10,000 tons can be accommodated in a diameter equal to or less than that of a conventional 2500-ton class inertial mass damper, and a lighter, slim, and large-capacity vibration reduction device can be obtained. It can be realized.

Hereinafter, effects of the vibration reducing device of the present embodiment will be listed.
(1) Since the main piston 13, the sub piston 15, and the inertia mass damper 1 are arranged on the axis in the main cylinder 12, the eccentricity between the external force and the reaction force does not occur. For this reason, since the eccentric moment does not act, the entire vibration reducing device is not deformed in the direction perpendicular to the axis.
(2) The axial force acting on the ball screw mechanism is 1 / α of the axial force of the entire vibration reducing device. For this reason, since a large reaction force can be processed by a ball screw mechanism having a small screw diameter, the ball screw mechanism can be reduced in size and weight and can be manufactured at low cost.
(3) Compared to the conventional inertial mass damper using only a ball screw mechanism (without an amplification mechanism), a large inertial mass can be obtained with a small rotating weight, so the width when installing the damper can be reduced, When the damper is housed in the wall, the wall thickness can be reduced, so that the effective space in the room can be increased.

(4) By providing a relief valve 17 similar to a conventional oil damper to the fluid pressure cylinder mechanism 11 as an amplification mechanism, it is possible to prevent an excessive burden force from being generated.
In addition, since it is not a friction damper using slip, the performance is not deteriorated due to wear, and it becomes a fail-safe mechanism that exhibits stable performance.
(5) Since the restoring spring 9 is provided as a restoring mechanism for returning to the original position, any part in the damper can return to the original position after the earthquake. For this reason, even if there are multiple earthquakes such as aftershocks after a major earthquake, the main piston and sub-piston in the damper may drift in a specific direction, or the stroke of the ball screw mechanism may decrease due to residual deformation. The initial performance can be maintained.
(6) Since the fluid pressure cylinder mechanism 11 is used as an amplifying mechanism, a damping effect due to the viscous resistance of the fluid is added, and inertia can be achieved by selecting the type of fluid used (water, oil, various viscous fluids, etc.). In addition to mass, the desired attenuation can be obtained. For this reason, the damping device which needs to be arranged in parallel with the conventional inertial mass damper can be omitted.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and appropriate design changes and applications such as those listed below are possible.

In the above embodiment, the ball screw shaft 2 in the inertial mass damper 1 is installed so as not to be rotatable and axially displaceable with respect to the main cylinder 12, and the ball nut 3 is rotatable with respect to the main cylinder 12 and not axially displaceable. The rotary weight 4 is integrally connected to the ball nut 3 after being installed, but the main point is that the rotary weight 4 is rotated via the ball screw mechanism by the axial displacement of the sub-piston 15. As long as it is good, the installation pattern of the inertia mass damper 1 with respect to the main cylinder 12 is arbitrary.
For example, contrary to the above embodiment, the ball screw shaft 2 can be rotated and the ball nut 3 cannot be rotated, and the rotating weight 4 is integrally connected to the ball screw shaft 2 and rotated. That will work as well.

  In the above embodiment, the rotation restraint plate 6 is connected to the tip of the ball screw shaft 2 and the restoring spring 9 is interposed between the rotation restraint plate 6 and the main cylinder 12. However, when the restoration function is not particularly required. The restoration spring 9 may be omitted, or a restoration function may be provided by another restoration mechanism.

  In the above embodiment, the relief valve 17 as a fail-safe function is provided on the main piston 13, but may be omitted if it is unnecessary or may be provided on the sub piston. Further, a fail-safe function can be provided by adding a torque limiting mechanism to the ball screw mechanism instead of the relief valve 17.

DESCRIPTION OF SYMBOLS 1 Inertial mass damper 2 Ball screw shaft 3 Ball nut 4 Rotating weight 5 Bearing 6 Rotation restraint plate 6a Convex part 7 Guide tube 8 Groove 9 Restoring spring 11 Fluid pressure cylinder mechanism (amplification mechanism)
12 main cylinder 12a first compartment 12b second compartment 13 main piston 14 sub cylinder 14a third compartment 14b fourth compartment 15 sub piston 16 bypass pipe 17 relief valve 18 clevis

Claims (4)

A vibration reducing device that is interposed between two members that vibrate relatively to reduce the relative vibration,
An inertial mass damper that uses an inertial force generated by a rotating weight rotated by a ball screw mechanism in which a ball nut is screwed to the ball screw shaft as a reaction force, and a relative displacement, speed, and acceleration acting on the inertial mass damper. The fluid pressure cylinder mechanism that functions as an amplification mechanism for amplifying is integrally combined,
The fluid pressure cylinder mechanism divides a base end portion of a main cylinder into a first compartment and a second compartment by a main piston, and a sub-cylinder having a smaller diameter than the main cylinder in front of the second compartment. The sub-cylinder is divided into a third compartment and a fourth compartment by a sub-piston, and the second compartment and the third compartment are communicated with each other and the first compartment and the fourth compartment are connected. The chamber is configured to communicate with each other via a bypass pipe, and the front end portion of the main cylinder and the main piston are connected to the two members, respectively.
The inertial mass damper is driven by the subpiston by housing the inertial mass damper inside the tip of the main cylinder and connecting the subpiston to the inertial mass damper. A vibration reducing device characterized by that. The vibration reducing device according to claim 1,
The base end of the ball screw shaft is connected to the sub-piston so as not to be rotatable relative to the sub-piston and is capable of axial displacement along with the sub-piston, and the ball nut is relatively rotatable relative to the main cylinder and not axially displaceable. The vibration reducing apparatus is characterized in that the rotating weight is connected to the ball nut so as to be integrally rotatable. The vibration reducing device according to claim 2,
A rotation restraint plate is connected to the tip of the ball screw shaft, the rotation restraint plate is connected to the main cylinder so as not to be relatively rotatable and axially displaceable,
A vibration reducing device comprising a restoring spring for returning the ball screw shaft to its original position between the rotation restricting plate and the tip of the main cylinder. The vibration reducing device according to claim 1, 2, or 3,
A vibration reducing device, wherein the main piston is provided with a relief valve for allowing fluid to flow when a differential pressure between the first compartment and the second compartment exceeds a predetermined relief pressure. .

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