JPH11294528A - Vibration damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exert a vibration damping effect against a mechanical vibration, a vibration such as a fluid pulsation, and vibrations of wind and an earthquake by providing a first vibration damping means movably stored in a spherical shell body and a second vibration control means applying vibration damping via the motion of the spherical shell body in each hollow section of a box structure. SOLUTION: A valve device provided on a branch pipe extending from a main piping 12 is made a vibration control subject, and a vibration damping device 10 fixed to the branch pipe 14 above the valve device has a box structure 18 fixed to the branch pipe 14. The box structure 18 has hollow sections 22 in it, and the inside is partitioned into six hollow sections 22 by bulkheads 20. A spherical shell body 24 is stored in each hollow section 22, and a ball 28 is stored in the inside 26 of the spherical shell body 24. A recess 32 is formed on the lower face 30 of the hollow section 22, and a collision plate 46 is provided in the hollow section 22 to face the spherical shell body 24 via a spring 44. The vibration energy at the time of the vibration of an earthquake is absorbed as collision energy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention suppresses both steady vibration at a small input level such as mechanical vibration or fluid pulsation and transient vibration at a large input level such as wind and earthquake. The present invention relates to a vibration damping device capable of effectively damping a vibration target.

[0002]

2. Description of the Related Art A vibration damping device for damping vibration by arranging a rollable ball around an object to be damped is disclosed in, for example, Japanese Patent Laid-Open No. 57-134.
No. 037 and Japanese Patent Publication No. 2-8117.
As shown in FIG. 7, the former vibration damping device uses a vertically supported column 100 as a vibration damping target, a flange-shaped support 110 attached to the column 100, and a coil spring 120 from the support 110. And a ring-shaped weight 130 suspended through the
On the upper surface of the ring-shaped weight 130, a groove 140 is formed which is inclined downward toward the column, and a plurality of balls are formed in the groove 140.
150 are arranged to roll freely. With this configuration, when the vibration of the columnar body 100 has a large amplitude and a small amplitude, the ring-shaped weight 130 and the plurality of balls 150 respectively collide with the columnar body 100, thereby exerting a vibration damping effect.

[0003] The latter damping device uses a flywheel as an object to be damped, forms an arc-shaped rolling surface inside a flywheel body, and accommodates a rollable ball along the rolling surface. . Under this configuration, the radius of curvature of the rolling surface, the radius and the weight of the sphere are appropriately set so that the natural frequency when the ball rolls on the rolling surface matches the vibration frequency of the flywheel. , The ball can be a dynamic damper.

[0004]

However, in the case of the former vibration damping device, the ring-shaped weight 130 itself collides with the column when the amplitude is large, so that the vibration damping effect is large.
At low amplitude, only a plurality of spheres 150 collide,
The generated collision energy is small, and the vibration damping effect as large as when the amplitude is large cannot be expected. In the case of the latter damping device, the dynamic damper using the rolling of the ball has a large damping effect for small vibrations from the engine drive transmission system, but for large amplitudes, it has an arc-shaped rolling Large collision energy cannot be expected in the collision between a surface and a sphere. In this case, if both damping devices are provided for the damping object in order to cope with both large and small amplitudes, the damping device itself becomes large and costs increase. In particular, when a plurality of complicated pipes are to be damped, the effective space is limited, so that the installation of the damping device itself becomes difficult.

[0005] In view of the above-mentioned problems, an object of the present invention is to provide either steady vibration at a small input level such as mechanical vibration or fluid pulsation or transient vibration at a large input level such as wind or earthquake. Another object of the present invention is to provide a simple vibration damping device capable of effectively exhibiting a vibration damping effect.

[0006]

Means for Solving the Problems In order to solve the above problems,
A vibration damping device according to the present invention includes a box structure fixed to an object to be damped and having a hollow portion therein, a spherical shell housed in the hollow portion of the box structure, and a spherical shell. A spherical first vibration damping means movably accommodated inside the body, wherein the box structure is configured such that when vibration of a small input level less than a predetermined value acts on the vibration damping object, the spherical shell Holding the body in its position and, when vibration of a large input level equal to or more than a predetermined value acts, supporting means for supporting the spherical shell at the bottom surface of the hollow portion; When the vibration of (1) is applied, the hollow portion of the box structure has second vibration damping means for performing vibration suppression using the motion of the spherical shell inside the hollow portion, and the inner surface of the spherical shell has an inner surface. The ball is formed as a spherical rolling surface so that it can roll. It is constituted.

The second vibration damping means is preferably a spring-loaded collision plate provided in the hollow portion of the box structure so as to collide with the moving spherical shell. Further, the second vibration damping means may be a highly viscous liquid filled in a hollow portion of the box structure.

[0008]

According to the vibration damping device of the present invention, when a vibration having a small input level less than a predetermined value is applied to the vibration damping object, the vibration is transmitted to the box structure fixed to the vibration damping object, The spherical first vibration damping means movably accommodated inside the spherical shell is supported by the supporting means at the bottom surface of the box structure. In synchronization with the vibration, a circular motion is performed along the spherical rolling surface of the spherical shell, so that the vibration of the vibration damping target can be reduced. On the other hand, when a vibration having a large input level equal to or more than a predetermined value is applied to the vibration damping object, the spherical shell moves in the hollow portion of the box structure, and the second vibration damping means provided in the hollow portion of the box structure. However, the vibration of the object to be damped can be reduced by using this motion.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below in detail with reference to FIGS. As shown in FIG. 1, the vibration damping device 10 according to the present embodiment
A valve device 16 provided in a branch pipe 14 extending upward from the main pipe 12 is a vibration damping target, and is fixed to the branch pipe 14 immediately above the valve device 16. As shown in FIG. 2, the vibration damping device 10 is formed into a half-split configuration for convenience of attachment to the branch pipe 14, and the center opening 48 is formed by joining the respective half sections around the branch pipe 14. Thus, it can be quickly and easily attached to the branch pipe 14 by the attachment band 50 while having a donut shape.

Referring to FIG. 3, the vibration damping device 10 has a box structure 18 fixed to the branch pipe 14,
The box structure 18 has a donut-shaped hollow portion inside, and this hollow portion is further divided into six hollow portions 22 at equal angular intervals in the circumferential direction around the branch pipe 14 by six partition walls 20. I have. Each hollow part 22 has a spherical shell 2
4 is accommodated, and a sphere 28
Is housed. Box structure 18, spherical shell 24,
Both spheres 28 are preferably made of metal. Lower surface 3 of each hollow portion 22
At 0, a depression 32 for supporting the spherical shell 24 is formed. Thereby, at the time of steady vibration at a small input level such as mechanical vibration of the main pipe 12, the spherical shell 24 is
It is designed to stand inside. Each spherical shell 24 has a spherical rolling surface 34 formed on its inner surface so that the ball 28 can roll.

Further, in each hollow portion 22, a spherical shell 24
The collision plate 46 is provided toward the spherical shell 24 via a spring 44 from the inner surfaces 36 and 38 and the annular inner surfaces 40 and 42 respectively formed by the partition wall 20, that is, the inner surfaces 36 and 38 formed by the partition wall 20. As a result, in the event of an excessive vibration at a large input level such as an earthquake, the spherical shell 24 rolls out of the depression 32 and ramps up in the hollow portion 22, and repeatedly collides with the collision plate 46, so that the vibration energy is collided. It is designed to be absorbed as energy. Next, the operation of the vibration damping device 10 having the above configuration will be described below with reference to FIGS. FIG. 4 shows a case where a steady vibration of a small input level less than a predetermined value is input to the valve device 16 as shown in FIG. 4B, and as shown in FIGS.
In a state where the spherical shell 24 is supported by the depression 32, the sphere 28 rotates in the interior 26 of the spherical shell 24 as shown by an arrow A in FIG. At this time, as can be seen by comparing (b) and (d), since the rolling friction force generated by the rotation acts as a damping force having a phase shifted by 90 ° with respect to the external vibration, as shown in (c). In addition, vibration is suppressed. On the other hand, FIG. 5 shows a case where excessive random vibration of a large input level equal to or larger than a predetermined value is input to the valve device 16 as shown in FIG. 5B, and as shown in FIGS. The spherical shell body 24 rolls out of the depression 32 and ramps up in the hollow portion 22 of the box structure 18 as shown by the arrow B in FIG. 7A, and repeatedly collides with the collision plates 46 provided on all sides. (C), the vibration of the valve device 16 is reduced. When the vibration is stopped, the spherical spherical shell 24 returns to the original position where the depression 32 is provided in the hollow portion 22 while rolling.

Next, a second embodiment of the present invention will be described below with reference to FIG. In the following embodiments, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. The features will be described below. A characteristic part of the vibration damping device according to the second embodiment resides in vibration damping means for excessive vibration at a large input level. Instead of the collision plate 46 of the first embodiment, each hollow portion 22 has The point is that a highly viscous liquid 52, for example, oil is filled. This liquid 5
By appropriately selecting the two types and the filling amount, the viscous effect (damping force) occurs due to the movement of the spherical shell 24 in the liquid 52 during the large vibration, and as a result, the vibration is reduced. I have. In the present embodiment, unlike the first embodiment, the generation of noise due to repeated collision of the spherical shell 24 can be prevented. In addition, as for the steady vibration of the small input level, the vibration damping effect is exerted by the circular motion of the sphere 28 in the spherical shell 24 as in the first embodiment.

Although the embodiments of the present invention have been described in detail, various changes and modifications can be made within the scope of the present invention described in the claims. For example, the object to be damped is not limited to a valve device and a pipe, but can be applied to a general structure such as a building, a bridge, a tower, and a crane. The radius and the number of the sphere and the spherical shell may be appropriately selected in relation to the vibration input to the vibration damping target. In this case, when the building is to be a vibration damping object, the vibration damping device may be fixedly arranged on the roof of the building, for example.

[0014]

As described above in detail, according to the simple vibration damping device of the present invention, steady vibration of small input level such as mechanical vibration or fluid pulsation and large input of wind, earthquake and the like are obtained. An effective vibration damping effect can be exhibited for any level of transient vibration.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an attached state of a vibration damping device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a method of attaching the vibration damping device according to the first embodiment of the present invention.

FIG. 3 is a horizontal sectional view (a) and a vertical sectional view (b) of the vibration damping device according to the first embodiment of the present invention.

FIG. 4 illustrates a vibration damping device according to a first embodiment of the present invention.
5A and 5B are a schematic diagram and a graph showing a vibration damping action with respect to a small-level steady vibration, wherein FIG. 5A is a schematic diagram showing the movement of a sphere by taking out one of the hollow portions, and FIG. Showing the time history of typical external vibration, (c) and (d)
Is a graph showing the time history of the response vibration of the valve device and the ball, respectively.

FIG. 5 shows a vibration damping device according to the first embodiment of the present invention.
5A and 5B are a schematic diagram and a graph showing a vibration damping action against a large level of excessive vibration, wherein FIG. 5A is a schematic diagram showing the movement of a sphere by taking out one of the hollow portions, and FIG. Showing the time history of typical external vibration, (c) and (d)
Is a graph showing the time history of the response vibration of the valve device and the ball, respectively.

FIG. 6 is a view similar to FIG. 2 of a vibration damping device according to a second embodiment of the present invention.

FIG. 7 is a schematic sectional view of a conventional vibration damping device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration suppression device 12 Main piping 14 Branch pipe 16 Valve device 18 Box structure 20 Partition wall 22 Hollow part 24 Spherical shell 26 Inside 28 Sphere 30 Lower surface 32 Depression 34 Spherical rolling surface 36, 38 Inner surface 40, 42 Annular inner surface 44 Spring 46 Impact plate 48 Central opening 50 Mounting band 52 High viscous liquid

Claims (3)

[Claims] 1. A box structure fixed to an object to be damped and having a hollow portion therein, a spherical shell housed in the hollow portion of the box structure, and an inside of the spherical shell And a spherical first damping means movably accommodated in the box structure, wherein the box structure moves the spherical shell body when a small input level vibration less than a predetermined value acts on the vibration damping object. While maintaining the position, when there is a vibration of a large input level of a predetermined value or more, there is a support means for supporting the spherical body on the bottom surface of the hollow portion, further vibration of a large input level of a predetermined value or more When acted, the hollow structure has a second vibration damping means in the hollow portion for performing vibration control using the movement of the spherical shell in the hollow portion of the box structure, and the spherical surface of the spherical shell has an inner surface in which the sphere has the spherical shape. It is formed as a spherical rolling surface that can roll. And the vibration damping device. 2. The vibration damping device according to claim 1, wherein the second vibration damping means is a collision plate with a spring provided in a hollow portion of the box structure so as to collide with the moving spherical shell. . 3. The vibration damping device according to claim 1, wherein the second vibration damping means is a highly viscous liquid filled in a hollow portion of the box structure.