JP2000329187A - Vibration damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exhibit same vibration damping effect by a single device on different disturbance vibration frequencies as that by a plurality of devices by providing a plurality of mass pieces having a prescribed mass in such a state as adjusting their positions, changing the vibration mode, and adjusting the frequency to be damped. SOLUTION: A bass 2 is erected perpendicular to the vibration direction (a) in a vibration source on a floor 1 of a building, and fixes one end of an elastic member 3 so as to cantilever it in a horizontal attitude in the direction crossing at right angles with the vibration direction (a), and a plurality of mass pieces 41, 42, 43 which provide the elastic member 3 with a prescribed mass are provided in such a state as adjusting their positions. That is to say, the mass pieces 41, 42, 43 are installed in such a position as most absorbing the vibration based on the frequency according to the vibration frequency of the vibration source so that, if vibration of different frequencies are inputted, the vibration based o each frequency can be damped by a single vibration damper. This constitution can damp the vibration by fewer devices relative to a lot of vibration frequencies so as to be economical.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device (dynamic vibration damping device) for reducing or attenuating vibrations of structures such as machinery and its foundation.

[0002]

2. Description of the Related Art Conventionally, a vibration damping device for reducing or attenuating the vibration of a structure such as a machine and its foundation is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-136,637 as a dynamic vibration absorber.

A dynamic vibration damping device has two applications, an optimally tuned dynamic vibration absorber and an anti-resonance type dynamic vibration absorber, which differ in the purpose of use and how damping is applied to the dynamic vibration absorber. .

That is, an optimally tuned dynamic vibration absorber is used to reduce the resonance peak of a building when the input force has a spectrum distributed over a wide frequency range such as an impact or a random wave. For this purpose, the dynamic damper with a large damping capacity is matched to or close to the resonance peak of the building, so that the effect of increasing the attenuation of the building itself is given to the frequency near the resonance peak, and the sharp peak of the resonance peak of the building is given. Functions to reduce the vibration value by changing to a dull curve. This is effective when used in applications such as reducing the vibration of the building due to the wind or vibrations caused by transportation, or installing it on the floor of an aerobics field to reduce slab vibration.

[0005] On the other hand, an anti-resonance type dynamic vibration absorber is installed in order to reduce vibration in a machine or in the vicinity of the machine when the input force has a sharp peak such as a rotary machine or a transformer. . By matching the anti-resonance point at the installation point of the dynamic vibration absorber with the vibration frequency peak to be reduced, the vibration value of the dominant vibration peak is reduced.

In the place where the anti-resonance type dynamic vibration absorber is installed, a resonance point is generated at a near frequency together with the anti-resonance point.
When the input force is a discrete frequency peak, the resonance peak frequency has no adverse effect. In this case, the smaller the attenuation of the dynamic vibration absorber, the larger the amount of reduction. This is used for applications such as reducing the vibration by directly attaching to a rotating machine, or installing it on the floor near the machine to reduce slab vibration from the machine.

In the apparatus described in the above-mentioned publication, a plurality of leaf springs are arranged in parallel in a left and right direction from a support portion provided on a structure such as a building in order to reduce vibration of a specific frequency. The leaf springs are projectingly connected to each other in a layered manner by a viscoelastic body or a viscous body, and a weight is symmetrically attached to the free end side of the layered leaf springs.

[0008]

However, in the above-described conventional dynamic vibration absorbing device, when a large number of frequency peaks are to be reduced, a dynamic vibration absorbing device suitable for each frequency peak to be reduced is installed. Therefore, there is a problem that a large number of dynamic vibration absorbing devices must be prepared.

When the dynamic vibration absorber is used as an anti-resonance type, the frequency must be matched very accurately in order to obtain a large vibration reduction, and a delicate adjustment is required.

[0010] In view of the above, an object of the present invention is to provide a vibration damping device that can exhibit the same vibration damping effect as a single device provided with a plurality of vibration damping devices for different disturbance vibration frequencies. And

Further, there is provided a vibration damping device capable of adjusting the resonance frequency of the main mass very easily and accurately by utilizing the point at which the resonance frequency of the main mass changes minutely due to the movement of the sub mass. It is in.

[0012]

According to the present invention, there is provided an elastic member having one end supported by a base at one end and having a required mass on an elastic member placed in a horizontal position. It is characterized in that it is provided so as to be adjustable in position, and the frequency to be damped can be adjusted by changing the vibration mode by changing the position of the mass piece.

In addition, a plurality of mass pieces having a required mass are provided on an elastic member having a central portion supported by a base and placed in a symmetric horizontal position so as to be adjustable in position, and the position of the mass pieces is changed. A mode in which the frequency to be damped can be adjusted by changing the vibration mode, a mode in which the vibration direction expressing the vibration performance of the elastic member is changed by 90 °, a plurality of masses having a required mass in the horizontal direction The parts to be damped are arranged by stacking the pieces so as to be movable in the horizontal direction, a spring is stretched between the mass piece and the fixed side, and the spring constant of the mass piece and the spring is changed. The mode to be set, has a vibration suppression result for one vibration mode,
This includes a mode in which the damping member is arranged at a position where the vibration damping effect is small for other vibration modes, and has a different damping effect for each vibration damping frequency.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIGS. 1A and 1B schematically show the basic structure of the invention according to the first aspect of the present invention, and are erected perpendicularly to a vibration direction a on a vibration source such as a floor 1 of a building. One end of the elastic member 3 is fixed to the base 2 and is cantilevered in a horizontal posture in a direction perpendicular to the vibration direction a. The elastic member 3 has a required mass (three in the figure). ) Mass piece 4
₁ , 4, ₂ and 4 ₃ are mounted so that the position can be adjusted.

As means for attaching the mass piece (generally indicated by reference numeral 4), as shown in FIG. 6, an elastic member 3 is formed by a band-shaped flat plate, and the elastic member 3 is formed in a longitudinal direction. A hole 4a of the mass piece 4 placed on the upper surface of the elastic member 3
Through a washer 7 and fastened with a nut 8. As the means for attaching the mass piece 4, other appropriate means can be adopted.

Therefore, by installing the mass pieces 4 ₁ , 4 ₂ , 4 ₃ at the positions where the vibration based on the vibration frequency of the vibration source is most absorbed according to the vibration frequency of the vibration source, even if vibrations of different frequencies are input, respectively. Vibration based on each frequency can be damped by one damping device.

The principle of operation is shown in FIGS.
In three spring 3 ₁ shown schematically in (C), 3 _2, 3 ₃ and 3 parts by mass (mass pieces 4 _1, 4 _2, 4 ₃₎ vibration system with has three resonance frequencies.

FIG. 7A shows the primary mode, and FIG.
Next mode, FIG. 7C is called a third mode, and FIG.
Is the lowest frequency, and the higher the frequency, the higher the frequency in FIGS. These frequencies are
Each of the spring 3 _1, 3 _2, 3 ₃ of the spring constant and each of the mass pieces 4 _1, 4 _2, 4 can be calculated since the _third mass uniquely determined if Kimare. That is, the vibration system is determined as a set of three one-degree-of-freedom systems having respective resonance frequencies, and by determining the weight and spring constant of each system. This is generally called modal mass or modal stiffness.

By realizing such a vibration system, it is possible to achieve the same vibration suppression as when three one-degree-of-freedom dynamic vibration absorbers having respective modal masses and modal stiffness are arranged.

FIG. 9 shows the mass pieces 4 ₁ , 4 ₂ , 4 shown in FIG.
A graph showing the resonance point by ₃ installation position, the natural frequency indicates, the the pieces 4 _1, 4 _2, 4 ₃ waveform indicated by symbol b has the members constituting the vibration damping device 8 FIG. 8A shows the resonance point in the state shown in FIG.
FIG. 8 shows the resonance point in the state shown in FIG.
The resonance point in the state shown in FIG.

In other words, if the input vibration frequency is known, the positions of the mass pieces 4 ₁ , 4 ₂ , and 4 ₃ are set in accordance with the frequency, so that the primary mode, the secondary mode, the tertiary mode, etc. ,
Multiple modes of vibration control can be achieved. If the number of the mass pieces is increased, vibration of various vibration frequencies can be further suppressed.

[0023] Mass piece 4 _2, 4 ₃ main mass, the mass pieces 4 ₁ Looking and secondary mass, since the resonant frequency of the main mass varies minutely in large movement of the mass pieces 4 ₁ sub Movement of the mass can be seen as a means of adjusting the resonance frequency of the main mass. Therefore, by increasing the number of the mass pieces, adjustment for more frequencies can be performed.

FIGS. 2A and 2B schematically show the basic structure of the second aspect of the present invention, in which a symmetrical elastic member 3, 3 whose center is supported by a base 2 is vibrated. The elastic members 3, 3 are provided in a horizontal posture in a direction orthogonal to the direction a.
A plurality of mass pieces 4 ₁ , 4 ₂ , 4 ₃ having the required mass
Are mounted so as to be position-adjustable in the same manner as the above-mentioned mounting means.

Also in this embodiment, the left and right elastic members 3, 3
Show the same behavior as the case of FIG.
Vibration suppression in the secondary and tertiary modes can be achieved.

FIGS. 3 (A) and 3 (B) schematically show the basic structure of the third aspect of the present invention, in which the directions of vibration of the elastic member 3 which express the vibration performance are different by 90 °. .
That is, the elastic member 3 is erected vertically on a surface 1b perpendicular to the surface 1a to which the vibration is input, and a plurality of mass pieces 4 ₁ , 4 ₂ , 4 ₃ are attached to the elastic member 3 so as to be position-adjustable. It is a thing.

In this case, when it is desired to set one of the three equivalent one-degree-of-freedom dynamic vibration absorbers to the optimum tuning type and the other to the anti-resonance type, a portion c (node of vibration) which does not swing depending on the mode is formed. By connecting a damping mechanism 10 such as an oil damper between the position c and the surface 1a, vibration can be damped.

FIG. 4 shows a basic structure of the invention according to claim 4, wherein a plurality of mass pieces 4 ₁ , 4 having a required mass are provided.
4 _2, 4 ₃ at right angles to the plane 1a of the vibration is input plane 1
b, the elastic members 11, 11, 11 such as rubber are interposed therebetween so as to be horizontally movable and laminated, and the mass parts 4 ₁ , 4 ₂ , 4 ₃ and the surface 1a to which vibration is inputted are provided. The springs 12 ₁ , 12 ₂ and 12 ₃ are stretched between them.

Also in this case, the frequency of each vibration mode
Has a vibration damping function for ₁, 4_Two, 4_ThreeQuality
Quantity and spring 12₁, 12_Two, 12_ThreeChange the spring constant of
Thus, the damping frequency can be set.

Also in this embodiment, the damping mechanism 10 can be installed at a position c which is a node of vibration.

FIG. 5 shows a case where the damping mechanisms 10, 10 are installed in the form of FIG.

In any of the above embodiments, it is possible to cope with a plurality of different vibration frequencies.

[0033]

As described above, according to the present invention, not only the vibration of each frequency can be damped by a small vibration damping device for a large number of vibration frequencies, but also the frequency and the vibration to be reduced can be suppressed. It is possible to adjust the vibration control device to match the vibration control frequency of the vibration device, thereby providing an economical vibration control device.

Further, by providing the damping mechanism, a vibration damping frequency exhibiting a damping effect and an anti-resonance damping frequency exhibiting an effect due to no damping can coexist in one vibration damping device.

Further, the above-described adjustment of the vibration damping frequency can be easily performed at the installation site of the vibration damping device, and it is possible to achieve an effect such that the input vibration can be accurately adjusted.

[Brief description of the drawings]

FIG. 1 shows a basic configuration of an embodiment of the present invention, and FIG.
Is a front view, and (B) is an explanatory view showing a vibration mode.

FIG. 2 shows another embodiment of the present invention, in which (A) is a front view,
(B) is an explanatory view showing a vibration mode.

FIGS. 3A and 3B show still another embodiment, wherein FIG. 3A is a front view and FIG. 3B is an explanatory view showing a vibration mode.

FIGS. 4A and 4B show still another embodiment, wherein FIG. 4A is a front view and FIG. 4B is an explanatory view showing a vibration mode.

FIG. 5 is an explanatory view to which a damping mechanism is added.

FIG. 6 is a partial perspective view showing an example of an attaching means that enables the position of the mass piece to be adjusted.

FIGS. 7A to 7C are explanatory diagrams showing vibration modes.

FIGS. 8A to 8C are explanatory diagrams of a state in which the position of the mass piece is adjusted with respect to the vibration frequency.

FIG. 9 is a graph showing waveforms of resonance frequencies corresponding to FIGS. 8 (A) to 8 (C).

[Explanation of symbols]

One bed 1a input vibration surface 1b perpendicular to the input vibration plane surface 2 base plate 3 (3 _1, 3 _{2, 3} 3) the elastic member 4 (4 _1, 4 _2, 4 ₃₎ Mass piece 10 damping mechanism 11 elastic body 12 ₁ , 12 ₂ , 12 ₃ spring

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masanobu Morita 3-21-15 Seijo, Setagaya-ku, Tokyo Green Hill Seijo A-102 (72) Inventor Tomoe Nomura 79-3 Onomoto, Matsudo-shi, Chiba Permado 201 (72) Inventor Harumoto Nitta 62-1-611 Hisayo, Kawanishi-shi, Hyogo (72) Inventor Yoshika Tsuchiya 4-1-C74-206, Aoyamadai, Suita-shi, Osaka (72) Inventor Kato Kaname F-term (reference) 5-6-32 Makamicho, Takatsuki-shi, Osaka 3J048 AD06 BC01 BF01 CB17 CB24 EA38

Claims (5)

[Claims] 1. An elastic member having one end supported by a base and cantilevered and provided in a horizontal position, a plurality of mass pieces having a required mass are provided so as to be position-adjustable, and the position of the mass piece is changed. A vibration damping device characterized in that the frequency to be damped can be adjusted by changing the vibration mode. 2. A plurality of mass pieces having a required mass are provided on a resilient member having a central portion supported by a base and placed in a symmetric horizontal position so as to be position-adjustable, and the position of the mass pieces is changed. A vibration damping device wherein the frequency to be damped can be adjusted by changing the vibration mode. 3. The vibration damping device according to claim 1, wherein the elastic members exhibit a vibration performance in which directions of vibration differ by 90 °. 4. A plurality of mass pieces having a required mass are stacked so as to be movable in a horizontal direction, and a spring is stretched between said mass piece and a fixed side. And a spring constant of the spring, whereby a frequency to be damped is set. 5. A damping member is provided at a position having a vibration damping effect for one vibration mode and a small vibration damping effect for another vibration mode, and a different damping effect is provided for each vibration damping frequency. The vibration damping device according to any one of claims 1 to 4, wherein the vibration damping device is provided.