KR101266831B1 - Tuned Mass Damper Using Metal Plate Spring and Vibration Isolation Base Using the Tuned Mass Damper - Google Patents

Abstract

The present invention relates to a tuned mass damper using a metal plate spring and a dustproof base using the same. The tuned mass damper of the present invention comprises a metal plate spring, a mass weight, an upper cover and a lower cover. The mass weight is coupled to the coupling hole of the metal plate spring. The upper cover is configured in a cup shape that wraps around and secures the edge of the spring. The lower cover is coupled to the lower portion of the upper cover to seal the upper cover, and seals the metal plate spring and the mass weight. Viscous fluid is filled in the space sealed by the upper cover and the lower cover. When the mass addition vibrates, the vibration energy is converted into thermal energy by the metal plate spring, the friction between the mass weight and the viscous fluid, and has a damping function. The anti-vibration base using the tuned mass damper of the present invention is constructed by fabricating the base in a frame structure of two upper and lower layers, installing a dustproof mount between the two frames, and coupling the tuned mass damper to the center of the upper frame. The tuned mass attenuator of the present invention is compact and very simple in structure and can be manufactured at low cost, and can be easily installed in a narrow installation space such as the bottom of a machine. The anti-vibration base using the tuned mass damper of the present invention can effectively control the large vibration generated by resonance in the machine without using a heavy weight additional base, so that it is not necessary to use an additional base that is difficult to handle and install. It also reduces the load on building structures.

Description

Tuned Mass Damper Using Metal Plate Spring and Vibration Isolation Base Using the Tuned Mass Damper}

The present invention relates to a vibration control technique, and more particularly, to a tuned mass damper using a metal plate spring and a dustproof base using the same. The tuned mass attenuator of the present invention is used for the purpose of controlling the large vibration generated by resonance below a certain level without using a heavy weight additional base in a machine using a dustproof device using an elastic body.

Tuned Mass Damper (TMD) is a type of Dynamic Absorber, which vibrates with a separate mass and spring in a vibrating body that behaves similarly to the One Degree of Freedom Vibration System. It is a device that suppresses vibration by adding a system and changing the original vibrating body into a multi degree of freedom vibration system.

The tuned mass attenuator is mainly used for the purpose of preventing the amplification of vibration largely by resonance, and is known to be effective in controlling low frequency vibration of large structures such as high-rise buildings, bridges, steel towers, and airport control towers.

The effect of the tuned mass attenuator is shown in the graph of FIG. 1, where the original structure without the tuned mass attenuator has an infinite vibration amplification rate at the natural frequency (f ₀ ), and has a frequency (f ₀ ) corresponding to the natural frequency. Vibration is amplified to infinity theoretically due to the excitation force, whereas a structure with a tuned mass damper has its natural frequency as many degrees of freedom (f ₁ , f _2, etc.), and the amplification factor is limited to a certain size. It will not vibrate more than a certain time.

The design of the tuned mass damper is designed by calculating the vibration response characteristics of the target structure and calculating the mass and the spring that make the vibration response characteristics of the structure below the required level. In recent years, many structural analysis programs using the finite element method (FEM) have been widely used, and the mass, spring constant, and attachment position of a tuned mass damper have been calculated by simulation.

Recently, many patents relating to such a tuned mass damper have been filed, such as Korean Registered Patent No. 10-0463294 "Handrail with a tuned mass damper", Korean Patent Publication No. 10-2003-0068595 Device ”, etc., to control the vibration of a large structure, such that the mass can be adjusted to a large number of blocks, or that the position of the spring can be changed in part, or the structure of a structure such as a railing of a bridge. To facilitate attachment to the site.

Korean Patent No. 10-0691518 "Ceiling floor-mounted floor-to-floor noise reduction device using cantilever-type multi-tuned mass damper" relates to a tuned mass damper for controlling vibration of a building, which is a structure installed under the floor finish of the structure. I-shaped steel is attached to the bottom of the bottom plate, and a cantilever is attached to the bottom of the I-beam, and a cantilever-type multi-tuned mass damper with a mass at the end of the cantilever is posted.

According to the effect of the present invention, the present invention is attached to the ceiling or floor of the building to absorb vibrations of the floor of the building, it is possible to efficiently reduce the generation of floor impact sound, the height required for installation is less than 10cm It is described that it can be installed sufficiently in the ceiling space. However, considering that the tuned mass attenuator is mainly useful for controlling vibrations with large amplitudes at low frequencies, it is questionable whether the floor impact sound generated mainly by high frequency vibrations around 100 Hz can be reduced.

Rotating machines such as motors, pumps and fans generate vibrations at frequencies such as the machine's rotational frequency (RPM / 60 Hz) and propagate to the surroundings, causing problems. Is fixed to an additional base having a large mass, and a vibration isolator is used for supporting the additional base with an elastic body such as an air spring, a metal coil spring, a dustproof rubber, or a dustproof pad. What is provided with fixing means which can be fixed to an equipment or installation place on the upper and lower parts of an elastic body is generally called a dustproof mount.

Among the elastic materials, the air spring is typically 3 Hz or less in natural frequency, the metal coil spring is 3 Hz to 5 Hz, the vibration resistant rubber is 5 to 10 Hz, and the anti-vibration pad is used to construct a vibration proof device having a natural frequency of 10 Hz or more. do.

As described above, the vibration transmission ratio (TR, Transmission Ratio, ratio of vibration excitation force transmitted to the floor to vibration excitation force generated in the machine) is TR = 1 / (r ² -1) ( Where r is the ratio of frequencies), as can be seen in this formula, is determined by the ratio of frequencies, which is the ratio of vibration frequencies generated by the machine to the natural frequency of the vibration isolator. The ratio is increased to 3 or more to sufficiently lower the vibration transfer rate.

In such a dustproof apparatus, a large mass, i.e., a heavy weight additional base, functions to suppress vibration of a large amplitude during the operation of the dustproof target machine itself mounted on an elastically supported dustproof apparatus. Manufactured by pouring concrete inside. This additional base is very heavy due to its large mass, which makes it difficult to handle and install, and also causes a lot of load on the building.

A rotating machine that is dust-proofed by a vibration isolator using an elastic body always passes the critical speed at which the rotation frequency of the machine coincides with the natural frequency of the vibration isolator when it is first started or stopped. When the speed of rotation passes the dangerous speed, the vibration isolation device vibrates to a very large amplitude temporarily by resonance. In this way, when the rotational speed of the machine passes the dangerous speed, it can be observed that the machine vibrates to a considerable size even when the weight of the additional base is quite large due to the resonance of the vibration isolator. In the case of a temporary, even if such a large vibration is repeated frequently, there are problems caused by various vibrations, such as malfunction of the electronics inside the equipment, the generation of solid sound, the destruction of the characteristics of the character, damage to the structure connected to the machine, such as piping, loosening of the fasteners.

Until now, however, vibration control other than the method of suppressing the vibration generated by the resonance below a certain level when the rotational speed of the machine passes the dangerous speed by using the heavy base additional base as described above in the vibration isolator used in the rotating machine. The technology is unknown.

In the vibration isolator of a machine using an elastic body, the only method is to use a heavy weight additional base to suppress the large vibration caused by resonance below a certain level when the rotational speed of the machine passes the dangerous speed. Since additional base weight of 2 to 5 times the weight is required, handling and installation work are difficult, and the load on the building is a problem.

Therefore, a new dustproof method capable of controlling a large vibration generated by resonance below a certain level should be devised without using a heavy additional weight base.

The tuned mass attenuator using the metal plate spring of the present invention is a tuned mass attenuator used to control a large vibration generated by resonance in a machine to a predetermined level or less without using a heavy weight additional base.

The tuning mass damper according to an aspect of the present invention includes a metal plate spring having a spring function, made of an elastic metal plate, and having a coupling hole formed in the center thereof; A mass weight coupled to the coupling hole of the metal plate spring; A cup-shaped upper cover that wraps around and fixes the edge of the metal plate spring; It is coupled to the lower portion of the upper cover to be sealed with the upper cover, and includes a lower cover for sealing the metal plate spring and the mass weight. A viscous fluid is filled in the space sealed by the upper cover and the lower cover, and a damping function is provided in which vibration energy is converted into thermal energy and extinguished by friction between the metal plate spring, mass weight and viscous fluid when the mass is vibrated. .

delete

A dustproof base using a tuned mass damper according to another aspect of the present invention includes a base on which a dustproof target machine is mounted; The tuned mass damper described above attached to the base; The lower surface of the base includes a plurality of dust mounts that are attached to support the base and the machine to be mounted on it.

When the vibration isolating machine is mounted on the upper part of the vibration isolator using the tuned mass damper of the present invention, the 1-DOF vibration system of the type in which a vibration mount having a spring function supports the vibrating body that combines the mass of the upper frame and the dust-proofing machine. In addition, the vibration body of the vibration system is coupled to a tuning mass damper, which is a single degree of freedom vibration system, to form a two degree of freedom system vibration system as a whole.

The two-DOF vibration system as described above has two natural frequencies, and unlike the one-DOF vibration system, the vibration body having the vibration target machine has a constant vibration transmission rate even if the two natural frequencies coincide with the rotational frequency of the machine. As a result, the problem caused by resonance in the dustproof target machine is alleviated.

The tuned mass attenuator of the present invention is compact and very simple in structure and can be manufactured at low cost, and can be easily installed in a narrow installation space such as the bottom of a machine. In addition, the tuned mass attenuator of the present invention can easily adjust the mass by selecting and using a mass weight having an appropriate mass, and the spring constant can be easily adjusted by selecting a metal disc spring having an appropriate thickness. Natural frequency can be adjusted easily.

The dustproof base using the tuned mass damper of the present invention can effectively control the large vibration generated by resonance in the machine without using a heavy weight additional base. Therefore, there is no need to use a heavy additional base which is difficult to handle and install, and it is possible to reduce the load on the building structure in which it is used.

1 is an effect graph of a tuned mass damper.
2 is a block diagram of a tuned mass damper.
3 is a cross-sectional view of a tuned mass damper of another embodiment.
4 is a dustproof base using a tuned mass damper.
5 is a vibration system composed of a vibration isolator equipped with a tuned mass damper.

As shown in FIG. 2, the tuner mass damper using the metal plate spring of the present invention, a metal plate spring (1) having a spring function, a mass weight (2) coupled to the center of the metal plate spring (1), and the metal plate spring It consists of an upper cover (3) fixed to the edge of (1).

Metal plate spring (1) is produced by using a metal plate of a certain thickness with elasticity, such as spring steel plate, it is made of a square plate spring having a certain width and thickness or a disc spring having a certain diameter and thickness, in the center of the mass weight (2 ) Is provided with a coupling hole for engaging. When the disc is made of elastic material and the edge is fixed and the load is applied to the central part, it is deformed at the central part in proportion to the magnitude of the load acting on the central part within a certain load range, thus acting as a spring.

When the metal plate spring 1 is a disc spring, the edge of the disc is fixed so that rotational deformation does not occur, and when the load W is applied to the center, the amount of deformation of the center where maximum deformation occurs is calculated by the following equation.

, 여기서

,

, here

,

Where W is the load, a is the radius of the disc, D is the plate constant, E is the longitudinal modulus of the material, t is the thickness of the plate, and ν is the Poisson's ratio.

Since the spring constant k is the load W divided by the displacement y, the spring constant of the metal plate spring whose load is applied at the center and the edge is fixed is calculated by the following equation.

Therefore, the metal plate spring 1 used in the present invention can be easily obtained by knowing the mechanical properties of the material and the shape determined by the thickness and radius.

When the metal plate spring (1) is a narrow and long rectangular plate spring and both ends are fixed to the cover (3), the spring constant is fixed to both ends and behaves like a beam with concentrated load in the center, so that the spring Constants are easy to find.

Mass mass 2 is coupled to the center of the metal plate spring 1, it is convenient to form a screw hole on the upper surface to be coupled to the coupling hole formed in the center of the metal plate spring (1) with a fixing screw (21). The fixing screw 21 may be used together with the spring washer 22 so as not to be loosened by vibration.

The mass weight 2 preferably forms a screw hole on the lower surface in order to adjust the mass, so that the mass plate 23 of a certain mass can be coupled to the fixing screw 24. The mass plate 23 is provided with a plurality of masses having different masses, and it is convenient to make it possible to variously adjust the mass of the entire mass 2 by appropriately combining several mass plates 23.

The upper cover 3 is cup-shaped, it is preferable to form an edge 31 to be retracted inward in the opening so as to surround and fix the edge of the metal plate spring (1). The edge 31 of the upper cover 3 maintains the open shape at first. After attaching the metal plate spring 1 to the open edge, the edge of the metal plate spring 1 is closed by closing the end of the edge 31. It is convenient to be able to be fixed to the edge 31 of the upper cover (3).

If the nut plate 32 having one, two or more screw holes is formed on the upper surface of the upper cover 3, it is convenient to attach the tuned mass damper to the dustproof base or the vibration target machine.

The tuned mass damper configured as described above may be used as it is, but the metal plate spring (1) made of a thin plate may be exposed to the outside and be damaged, and the mass weight (2) may be exposed to the outside, thus causing a dangerous or aesthetic appearance. Therefore, as shown in the cross-sectional view of FIG. 3, it is preferable to include the lower cover 4 at the lower portion of the metal plate spring 1 to seal the metal plate spring 1 and the mass weight 2 exposed to the outside.

The lower cover 4 may be coupled to the metal plate spring 1 or the upper cover 3 in any manner, but the lower cover 4 has an edge 41 that extends outward and has a metal plate spring 1. It is convenient to couple to the edge 31 of the upper cover 3 together with the edge of the.

The tuned mass attenuator configured as described above has a damping function, which is a function of suppressing the vibration movement, although the metal plate spring 1 serves as a spring and the mass weight 2 acts as a tuned mass attenuator of the 1 DOF system. There is a problem that the mass weight (2) vibrates greatly in the natural frequency.

There is a method of attaching a separate damper as a method for imparting a damping function to the tuned mass damper, but the metal plate spring (1) and the top cover (3) of the tuned mass damper having the lower cover (4) as described above. A viscous fluid 5 having a high viscosity in a space sealed by the coupling portion of the lower cover 4 to prevent leakage of fluid and sealed by the inside of the tuning mass damper, that is, the upper cover 3 and the lower cover 4. ) Can be adopted. In particular, when the disc spring is used as the metal plate spring 1, a method of forming one or two or more orifices 11 on the surface of the spring plate can be applied. In this case, an oil inlet 51, an oil outlet 52, and an air outlet 53 are provided in the upper cover 3 or the lower cover 4 to easily fill the viscous fluid 5 inside the tuning mass damper. It is good to be able to do so.

If the tuning mass damper is filled with the viscous fluid 5 as described above, when the mass weight 2 vibrates, the vibration energy is converted into thermal energy and lost due to the friction between the spring or the mass weight and the viscous fluid. It has a damping function.

In particular, when the metal plate spring 1 is a disc spring, the viscous fluid 5 at the bottom (or top) of the metal plate spring 1 is deformed when the metal plate spring 1 deforms downwardly (or up). 11) it flows rapidly at the top (or bottom). At this time, since the vibration energy is converted into heat energy by the friction of the viscous fluid 5 and is lost, the tuned mass attenuator has a damping function.

The tuned mass attenuator 100 of the present invention configured as described above may be directly attached to an object in which vibration occurs, such as a machine or pipe, and may be used for the purpose of suppressing vibration of the object, as shown in FIG. 4. Can be attached to the base 200 to be mounted. When the tuned mass attenuator 100 is attached to the base 200 in this manner, the base 200 does not need to be manufactured as much as the weight of the additional base for dustproof, and is a lightweight frame composed of a horizontal member and a vertical member. Can be manufactured in a structure.

As described above, the base 200 having the tuned mass damper 100 constitutes a dustproof base installed directly on the floor of a building using a plurality of dustproof mounts 300. The dustproof mount 300 may be a dustproof mount using all kinds of elastic bodies such as air springs, metal coil springs, and dustproof rubbers.

If necessary, the base 200 is composed of two upper and lower frames, as shown in the figure, and an appropriate number of dustproof mounts 300 are disposed between the two frames, and the lower frame 220 is a building. It is convenient to fix the bottom of the upper surface of the upper frame 210 and mount the dustproof machine. In this case, when the dustproof target machine is shipped from the factory, the dustproof base of the present invention is pre-attached to the lower part of the machine, and the installation site is simply installed by fixing the lower frame 220 of the base 200 to the installation place. The machine can be installed on site.

When the target machine is mounted on the dustproof base of the present invention in which the tuning mass damper 100 is attached to the base 200 and supported by the dustproof mount 300, as shown in FIG. A single degree of freedom system vibration system in which a vibration mount 300 having a spring function is supported on a vibrating body in which the masses of the target machines are combined is formed. The 100 is combined to form a two-freedom vibration system as a whole.

The two-DOF vibration system as described above has two natural frequencies, and unlike the one-DOF vibration system, the vibration body having the vibration target machine has a constant vibration transmission rate even if the two natural frequencies coincide with the rotational frequency of the machine. As a result, the problem caused by resonance in the dustproof target machine is alleviated.

1: metal plate spring, 2: mass weight, 3: top cover,
4: lower cover, 5: viscous fluid,
11: orifice,
21: set screw, 22: spring washer, 23: mass plate, 24: set screw,
31: frame, 32: nut plate,
41: border,
51: oil inlet, 52: oil outlet, 53: air outlet,
100: tuning mass damper, 200: base, 300: dustproof mount,
210: upper frame, 220: lower frame.

Claims (8)

A metal plate spring (1) having a spring function, which is made of an elastic metal plate, and has a coupling hole formed in the center thereof;
A mass weight 2 coupled to the coupling hole of the metal plate spring 1;
A cup-shaped upper cover 3 for wrapping and fixing an edge of the metal plate spring 1;
It is coupled to the lower portion of the upper cover (3) to be sealed with the upper cover (3), and comprises a lower cover (4) for sealing the metal plate spring (1) and the mass weight (2),
The viscous fluid 5 is filled in the space sealed by the upper cover 3 and the lower cover 4, and the metal plate spring 1 and the mass weight when the mass weight 2 vibrates. A tuning mass damper having a damping function in which vibration energy is converted into thermal energy and extinguished by friction between (2) and the viscous fluid (5). The method of claim 1,
The metal plate spring (1) is a tuning mass damper, characterized in that the disc spring in the form of a disk. The method of claim 1,
A screw hole is formed in the lower surface of the mass weight 2, and a mass plate 23 having a constant mass is coupled to the screw hole by fastening the fixing screw 24 to adjust the mass. Tuned mass damper. The method of claim 1,
And a nut plate (32) having a plurality of screw holes formed thereon for attaching the machine to be dustproof on an upper surface of the upper cover (3). delete delete Base 200 and the dustproof target machine is mounted on the top:
A tuned mass attenuator (100) according to any one of claims 1 to 4 attached to the base (200);
Dustproof base comprising a plurality of dustproof mounts (300) attached to the base 200 on the lower surface of the base and the dustproof target machine mounted thereon. The method of claim 7, wherein
The base 200 is composed of an upper frame 210 and a lower frame 220 of a frame structure consisting of a horizontal member and a vertical member, the tuning mass damper 100 is attached to the upper frame 210, the plurality of Two vibration mounts 300 are coupled between the upper frame 210 and the lower frame 220, the lower frame 220 is fixed to the floor of the building, the upper surface of the upper frame 210, the dustproof target machine Dustproof base, characterized in that is mounted.

Images