CN213479037U

CN213479037U - Improved tuned mass damper

Info

Publication number: CN213479037U
Application number: CN202022326634.XU
Authority: CN
Inventors: 肖仕伟; 栾广扬; 梁立成; 田玲娣; 周益云; 张斌; 王永健; 张帅; 张磊; 邓大勇; 陈传勇; 冯开胜; 李建兴; 汪强; 范陶; 刘守松; 高强
Original assignee: China Huaxi Engineering Design & Construction Co ltd; Hebei Baoli Engineering Equipment Group Co Ltd
Current assignee: China Huaxi Engineering Design & Construction Co ltd; Hebei Baoli Engineering Equipment Group Co Ltd
Priority date: 2020-10-19
Filing date: 2020-10-19
Publication date: 2021-06-18
Anticipated expiration: 2030-10-19

Abstract

The utility model belongs to harmonious attenuator of quality and application thereof especially indicate a harmonious attenuator of modified quality. The damping device comprises an upper connecting plate, a lower connecting plate, a mass block, a spring and a damping system; the spring is arranged between the upper connecting plate and the lower connecting plate and is used for supporting the upper connecting plate and the mass block; the friction damper is characterized by further comprising a spring guide pillar assembly, the spring guide pillar assembly comprises an upper guide pillar assembly and a lower guide pillar assembly which are arranged inside the spring along the axial direction at relative intervals, the top end of the upper guide pillar assembly is fixed with the upper connecting plate, the bottom end of the lower guide pillar assembly is fixed with the lower connecting plate, and two ends of the friction damper assembly are connected with the upper connecting plate and the lower connecting plate respectively. The utility model provides a spring poor stability, the damping medium scheduling problem that easily runs off that prior art exists. The damping device has the advantages of simple structure, good stability, good damping effect, reliable performance and the like.

Description

Improved tuned mass damper

Technical Field

The utility model belongs to the tuned damper of quality especially indicates a tuned damper of modified quality.

Background

A mass tuning damper belongs to a structure passive control vibration damper. The passive tuning vibration damping control system is composed of a structure and a substructure which is attached on the main structure. The additional sub-structure has mass, rigidity and damping, so that the natural vibration frequency of the sub-structure can be adjusted, and the vibration frequency of the mass tuning damper is adjusted to the basic frequency or the vibration excitation frequency of the main structure, so that when the main structure vibrates under the vibration excitation, the sub-structure can generate an inertia force opposite to the vibration direction of the main structure to act on the main structure, the reaction of the main structure is attenuated and controlled, the vibration amplitude of the main structure under the action of external force is reduced, the use comfort is improved, and the structural resonance characteristic is changed, so that the vibration attenuation purpose is achieved.

The traditional tuned mass damper consists of an upper connecting plate, a lower connecting plate, a mass block, a spring (a compression spring or an extension spring) and a damping system (generally, a viscous fluid damper, a magnetorheological fluid damping medium, an eddy current damping system and the like). The mass tuning damper is mainly used for controlling vertical vibration of large-span structures, such as street-crossing pedestrian overpasses, stadium shell tops, cantilever beams and the like.

The mass tuned damper of the above conventional structure has the following problems:

a. the spring is not provided with a guide post, so that lateral instability is easy to occur, the resonance characteristic of the structure cannot be changed, and the aim of vibration reduction cannot be achieved;

b. the damping system adopts a viscous fluid damper which is generally arranged in the middle positions of the upper connecting plate and the lower connecting plate or in the middle positions of the four sides, damping medium leakage is easy to occur to the viscous fluid damper, and the damping performance is reduced along with the loss of the damping medium until the damping medium is completely lost, so that the use comfort level cannot be improved, and the purpose of vibration reduction cannot be achieved;

c. the mass block is generally arranged on the upper part of the upper connecting plate and fastened by bolts, so that the weight of the mass block is adjusted more complexly during field detection tests, and the mass is slightly adjusted due to the reduction or increase of the mass, so that the adjustment range is small, and inconvenience and waste of a large amount of time cost are brought to field detection.

Patent documents retrieved by the applicant include:

1. patent document CN09959796U discloses a TMD with frequency modulation of detachable mass block, which is based on a conventional tuned mass damper, and adds a detachable weight block (7) cooperating with a guide post on the top, a damper (4) is arranged between the center of the lower support plate (2) and the weight block, and a shock absorbing block (3) is arranged between the lower support plate (2) and the weight block.

The problems existing in the prior art are as follows:

a. the prior art structure is based on a conventional mass tuned damper, on which a removable weight (7) cooperating with the guide post is added, which increases the height of the damper compared to the conventional damper, so that the damper has a limit in specific applications.

b. A damper (4) is arranged between the center of the lower support plate (2) and the counterweight, and is a viscous damper which can cause the leakage of a damping medium, and when the leakage occurs, the vibration damping performance is reduced.

2. Patent document No. CN101457553B discloses a tuned mass damper with adjustable spring stiffness, in the embodiments in the prior art, springs are fixed in different forms, the effective number of turns of the springs is adjusted, and further the stiffness of the springs and the damping performance of the damper are adjusted;

the above prior art has the following problems:

the prior art adjusts the effective number of turns of the spring through different modes, adjusts the depth of the piston in the cylinder body, and changes different types of springs to achieve the natural frequency of the adjustable damper and the damping ratio of the damper. Four or a plurality of springs are required to be matched with each shock absorber, so that molten lead or epoxy resin needs to be injected into each curing cylinder when adjustment is carried out, a plurality of auxiliary devices need to be provided when the curing materials are molten, a large amount of heating equipment and curing materials need to be prepared when field detection and debugging are carried out, and certain difficulty exists in implementation: if the quality of the solidified substance is melted, the operation time of injecting the solidified substance in a molten state into the curing cylinder is limited to a certain extent, otherwise, the solidified substance can be cured, the adjustment and the test are inconvenient, not quick and complex in structure, and the adjustment of the effective number of turns of the spring and the damping ratio of the damper are complicated and complicated.

3. Patent document CN105386403A discloses a fabricated eddy current tuned mass damper for overpasses and a manufacturing method thereof. The guide posts in the prior art are two and penetrate through compression springs, the compression springs are arranged in mass blocks with holes, the mass blocks are arranged between a lower connecting plate and a steel plate d, the middle of each mass block is provided with the holes, magnets are arranged on the inner side faces of the holes, a conductor copper plate connected with the lower connecting plate is arranged between the two opposite magnets, and the whole structure is in a slender strip shape. The patent is that a conductor copper plate fixed on a lower connecting plate cuts a relative magnetic induction line arranged on the inner side of a mass block hole through the up-and-down movement of a mass block to play a damping role.

The problems of the prior art are as follows:

the magnetic properties of the permanent magnet decrease over time, and the magnetic properties of the permanent magnet may deviate or even fail when the magnetic properties decrease from the initially determined desired result; it is well known that magnets have a certain effect on test instruments, meters, electronics, etc., and more seriously, are a source of danger to the person installing the pacemaker, especially when the person is on the hand of a pedestrian bridge.

Therefore, a damping hole type viscous damper with simple structure, good piston damping effect and small piston thickness is needed in the field.

The applicant does not find the same patent literature reports in the domestic patent database as the present application.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a harmonious attenuator of modified quality can effectively keep the reliability of damping stable performance and spring work.

The whole technical concept of the utility model is that:

the improved tuned mass damper comprises an upper connecting plate, a lower connecting plate, a mass block, a spring and a damping system; the spring is arranged between the upper connecting plate and the lower connecting plate and is used for supporting the upper connecting plate and the mass block; the friction damper is characterized by further comprising a spring guide pillar assembly, the spring guide pillar assembly comprises an upper guide pillar assembly and a lower guide pillar assembly which are arranged inside the spring along the axial direction at relative intervals, the top end of the upper guide pillar assembly is fixed with the upper connecting plate, the bottom end of the lower guide pillar assembly is fixed with the lower connecting plate, and two ends of the friction damper assembly are connected with the upper connecting plate and the lower connecting plate respectively.

The specific technical concept of the utility model includes:

in order to form damping on the upper guide rod assembly, the preferable technical implementation means is that the upper part of the lower guide rod assembly is hollow, a damping medium is arranged in an inner cavity, and the bottom end of the upper guide rod assembly 3A is embedded in the damping medium.

In order to further improve the damping effect, the preferable technical implementation means is that a porous damping plate is arranged at the lower end of the upper guide rod component. The openings should be uniformly spaced and of a common geometry including, but not limited to, circular, oval or other regular polygonal shapes.

In order to facilitate the manufacturing and assembly of the upper guide rod assembly, the preferable technical implementation means is that the upper guide rod assembly consists of an upper guide rod connecting plate, an upper guide rod and a porous damping plate which are sequentially connected from top to bottom.

In order to avoid the overflow of the damping medium caused by overlarge volume change when the upper guide rod component goes in and out of the damping medium, the preferable technical implementation means is that the upper guide rod adopts a reducing structure which is sequentially contracted from top to bottom.

The preferable technical implementation means is that the damping medium is a liquid damping medium.

The more preferable technical implementation means is that the damping medium is selected from dimethyl silicone oil.

In order to facilitate the manufacture and assembly of the lower guide pillar assembly, the preferable technical implementation means is that the lower guide pillar assembly consists of a lower guide pillar connecting plate and a lower guide pillar with a hollow inner cavity formed at the top, which are sequentially connected from bottom to top.

In order to reduce the possibility of external impurities entering the damping medium in the hollow inner cavity, the preferable technical means is that a dust cover capable of accommodating the longitudinal movement of the upper guide rod assembly is fixed at the top of the hollow inner cavity of the lower guide column.

More preferably, the dust cover is fixed on the top side wall of the lower guide pillar assembly by an anchor screw.

The friction damper assembly is preferably realized in a mode that the friction damper assembly consists of an upper single-plate assembly and a lower double-plate, and the upper single-plate assembly and the lower double-plate are correspondingly connected with an upper connecting plate and a lower connecting plate respectively through connecting bolts; the upper single plate assembly comprises an upper single plate with a long circular hole in the middle, friction plates are arranged on two sides of the upper single plate, a round hole is formed in the middle of the lower double plate, and a pre-tightening bolt penetrates through a disc spring, the round hole and the long circular hole in the outer side of the lower double plate to connect the upper single plate assembly and the lower double plate and then is fixed through a fastening nut.

The friction damper assembly is preferably connected with the upper connecting plate and the lower connecting plate in a following mode, and the upper single-plate assembly and the lower double-plate assembly are respectively connected with a first connecting plate on the upper connecting plate and a second connecting plate on the lower connecting plate through connecting bolts.

The mass block is preferably realized by adopting the following technology, and is arranged in the lifting plate frame, and the mass block comprises an effective number of large mass blocks and small mass blocks.

In order to ensure the stability in the installation and use processes, the preferable technical implementation means is that the hanger plate frame is arranged in the center of the lower surface of the upper connecting plate.

The application of the improved tuned mass damper in the vertical vibration control of a large-span structure is to place and fix the improved tuned mass damper at the position with the maximum vertical deformation deflection of a beam body.

The applicant needs to state that:

in the description of the present invention, the terms "upper portion", "lower portion", "top end", "bottom end", "both ends", "lower end", "middle portion", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of simplifying the description of the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. The terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating importance.

The technical progress of the utility model lies in:

1. the utility model discloses a spring guiding mechanism who comprises upper portion guide bar subassembly and lower part guide post subassembly can effectively use the whole direction of being the spring to guarantee the stability and the reliability of spring in the course of the work.

2. The utility model discloses a lower part guide pillar subassembly adopts the splendid attire damping medium in the cavity inner chamber, combines the structural design of porous damping board, makes upper portion guide pillar subassembly attach a small amount of damping when carrying out the guided movement.

3. The utility model discloses the friction damper that the side direction set up replaces ordinary liquid damper, has firstly avoided causing the leakage of liquid medium, volatilizing the pollution that arouses because of sealed inefficacy, has secondly overcome the reduction of liquid damping medium simultaneously and has reduced damping performance, and then influence the problem of bridge normal use.

4. The mass block of the utility model is arranged between the top plate and the bottom plate, while the mass block of the existing product is arranged on the upper part of the top plate, which reduces the height of the device from the whole structure;

5. the mass block of the utility model adopts different mass specifications, the mass of the mass block is from hundreds of kilograms to dozens of kilograms, and the quantity of dozens of kilograms accounts for more, which is very convenient for the adjustment of the mass block during the field test and can quickly adjust the quantity of the mass block which is in line with the actual mass block, thereby meeting the requirements; however, in the prior art, field debugging is not carefully specified, or the actual application height of the spring is adjusted to adjust the stiffness of the spring, but the mass tuning damper generally needs to be provided with four springs, and the usage heights of the four springs need to be adjusted to be consistent, so that the required time and cost are greatly increased, and the mass tuning damper is low in economy and very inconvenient for field testing.

Drawings

The attached drawings of the utility model are as follows:

fig. 1 is a schematic view of the overall structure of the utility model.

Fig. 2 is a top view of fig. 1.

Fig. 3 is a right side view of fig. 1.

FIG. 4 is a schematic view of an upper web assembly.

FIG. 5 is a schematic view of a lower web assembly.

Fig. 6 is a left side view of fig. 5.

Fig. 7A is a view of the upper guide bar assembly.

FIG. 7B is a schematic view of the structure of the porous damping plate.

Fig. 8 is a view of the lower guide bar assembly.

FIG. 9 is a diagram of a friction damper assembly.

Fig. 10 is a left side view of fig. 9.

FIG. 11 is a schematic view of the upper veneer assembly construction.

Fig. 12 is a left side view of fig. 11.

Figure 13 is a schematic view of the lower double plate construction.

Fig. 14 is a left side view of fig. 13.

The reference numbers in the drawings are as follows:

1. an upper connecting plate; 1A, a first connecting plate; 2. a hanger frame; 2A, a large mass block; 2B, a small mass block; 3. a spring guide post assembly; 3A, an upper guide rod component; 3a1, upper guide bar attachment plate; 3a2, upper guide bar; 3a3, porous damping plate; 3B, a lower guide pillar component; 3B1, a lower guide pillar connecting plate; 3B2, lower guide post; 3B3, damping medium; 3B4, dust cover; 3B5, anchor screws; 4. a spring; 5. A lower connecting plate; 5A, a second connecting plate; 6. a friction damper assembly; 6A, an upper veneer component; 6a1, upper veneer; 6A2, friction plate; 6A3, oblong holes; 6B, a lower double plate; 6B1, round hole; 6C, a disc spring; 6D, pre-tightening the bolt; 6E, connecting bolts; 6F, fastening a nut.

Detailed Description

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings, but the present invention is not limited thereto. The protection scope of the present invention is subject to the content described in the claims, and any replacement by equivalent technical means made according to the specification does not depart from the protection scope of the present invention.

The whole structure of the embodiment is shown in the figure, and comprises an upper connecting plate 1, a lower connecting plate 5, a mass block, a spring 4 and a damping system; the spring 4 is arranged between the upper connecting plate 1 and the lower connecting plate 5 and is used for supporting the upper connecting plate 1 and the mass block; still including spring guide pillar subassembly 3, spring guide pillar subassembly 3 includes that the relative interval of edge axial locates the inside upper portion guide pillar subassembly 3A and the lower part guide pillar subassembly 3B of spring 4, and upper portion guide pillar subassembly 3A's top is fixed with upper junction plate 1, and lower part guide pillar subassembly 3B's bottom is fixed with lower connecting

plate

5, and 6 both ends of friction damper subassembly are connected with upper junction plate 1, lower connecting plate 5 respectively.

The upper part of the lower guide post component 3B is hollow, a damping medium 3B3 is arranged in an inner cavity, and the bottom end of the upper guide post component 3A is embedded in the damping medium 3B 3.

The lower end of the upper guide rod component 3A is provided with a porous damping plate 3A 3. The openings are uniformly distributed and are circular.

The upper guide rod component 3A consists of an upper guide rod connecting plate 3A1, an upper guide rod 3A2 and a porous damping plate 3A3 which are connected in sequence from top to bottom.

The upper guide rod 3A2 adopts a reducing structure which is sequentially contracted from top to bottom.

The damping medium 3B3 is selected from dimethyl silicone oil.

The lower guide post assembly 3B is composed of a lower guide post connecting plate 3B1 and a lower guide post 3B2 with a hollow inner cavity at the top, which are connected in sequence from bottom to top.

The top of the hollow cavity of the lower guide post 3B2 is fixed with a dust cover 3B4 which can accommodate the longitudinal movement of the upper guide post component 3A.

The dust cover 3B4 is fixed to the top side wall of the lower guide post assembly 3B by an anchor screw 3B 5.

The friction damper assembly 6 consists of an upper single-plate assembly 6A and a lower double-plate assembly 6B, and the upper single-plate assembly 6A and the lower double-plate assembly 6B are correspondingly connected with the upper connecting plate 1 and the lower connecting plate 5 through connecting bolts 6E respectively; the upper single-plate assembly 6A comprises an upper single plate 6A1 with a long circular hole 6A3 in the middle, friction plates 6A2 are arranged on two sides of the upper single plate 6A1, a round hole 6B1 is arranged in the middle of the lower double plate 6B, and a pretightening bolt 6D penetrates through a disc spring 6C, a round hole 6B1 and a long circular hole 6A3 on the outer side of the lower double plate 6B to connect the upper single-plate assembly 6A and the lower double plate 6B and then is fixed through a fastening nut 6F.

The upper single-plate assembly 6A and the lower double-plate assembly 6B are respectively connected with a first connecting plate 1A on the upper connecting plate 1 and a second connecting plate 5A on the lower connecting plate 5 through connecting bolts 6E.

The mass block is arranged in the lifting plate frame 2 and comprises a large mass block 2A and a small mass block 2B with effective quantity.

The lifting plate frame 2 is arranged in the center of the lower surface of the upper connecting plate 1.

The working principle of the embodiment is as follows:

the assembled improved tuned mass damper is arranged inside a beam body, the specific position is the position with the maximum vertical deformation deflection of the beam body obtained through analysis and is fixedly connected by welding, bolts or other modes, at the moment, the spring 4 supports the upper connecting plate 1, the hanging plate frame 2 fixed with the upper connecting plate 1, and all the weights of the large mass block 2A, the small mass block 2B and the upper guide rod component 3A arranged in the hanging plate frame 2, and the spring 4 is in a pressed state at the moment.

The beam body is a main structure, the improved tuned mass damper is a substructure, when the main structure is subjected to vertical deformation by external force, the deflection is downward, at the moment, the lower connecting plate 5, the lower guide pillar component 3B fixedly connected with the lower connecting plate 5 and the lower double plate 6B in the friction damper component 6 displace downward along with the main structure, at the moment, the hanging plate frame 2 fixedly connected with the upper connecting plate 1, the large mass block 2A, the small mass block 2B and the upper guide pillar component 3A arranged in the hanging plate frame 2 are in a static state due to the support of the spring 4, at the moment, the spring 4 is in a stage from compression to recovery, the friction damper component 6 is in an extension state, the porous damping plate 3A3 and the damping medium 3B3 in the lower guide pillar 3B2 move in opposite directions, the friction damper component 6 needs to overcome friction resistance when being stretched, and the damping medium 3B3 has certain viscosity, the two forces resist the downward movement of the lower connecting plate 5 fixed with the main structure and the related components in fixed relation with the lower connecting plate 5 under the action of the spring 4, so that the displacement caused by the two frictional resistances consumes the work which should be done by the external force, namely the displacement in the vertical direction, and the energy consumed by the two frictional resistances is released by the heat energy generated by friction; when the external force on the main structure disappears, the main structure recovers to deform and continues to deform upwards due to the action of inertia, at the moment, the friction damper assembly 6 recovers to deform and continues to displace to be in a compressed state, the porous damping plate 3A3 is changed to recover from the damping medium 3B3 and continues to displace downwards, the damping force of the friction damper assembly 6 and the porous damping plate 3A3 consumes the energy of the upward deflection deformation of the main structure, and the energy is also consumed in a heat mode, so that the main structure is quickly recovered to a balanced state.

The energy consumed by the reciprocating motion of the friction damper assembly 6 is generated by the friction between the friction plate 6a2 and the lower double plate 6B on the two sides of the upper single plate 6a1, and the magnitude of the friction energy consumption is determined by the magnitude of the deformation of the external main structure and the torque force of the pre-tightening bolt 6D and the pre-tightening nut 6F, a certain torque force is applied to enable the disc spring 6C to elastically deform, the friction material on the surface of the friction plate 6a2 is consumed in the reciprocating friction process, namely, the friction plate 6a2 becomes thinner, but the disc spring 6C which is elastically deformed gradually recovers and deforms in the process of the consumption of the friction material on the surface of the friction plate 6a2, namely, the friction material on the friction plate 6a2 is pressed by the pre-tightening bolt 6D and the disc spring 6C to keep a contact friction state with the lower double plate 6B although the friction plate 6a 2.

Claims

1. The improved tuned mass damper comprises an upper connecting plate (1), a lower connecting plate (5), a mass block, a spring (4) and a damping system; the spring (4) is arranged between the upper connecting plate (1) and the lower connecting plate (5) and is used for supporting the upper connecting plate (1) and the mass block; the spring guide post assembly is characterized by further comprising a spring guide post assembly (3), the spring guide post assembly (3) comprises an upper guide post assembly (3A) and a lower guide post assembly (3B) which are arranged inside a spring (4) at relative intervals along the axial direction, the top end of the upper guide post assembly (3A) is fixed with the upper connecting plate (1), the bottom end of the lower guide post assembly (3B) is fixed with the lower connecting plate (5), and the two ends of the friction damper assembly (6) are respectively connected with the upper connecting plate (1) and the lower connecting plate (5).

2. The improved tuned mass damper according to claim 1, characterized in that the lower guide post assembly (3B) is hollow at the top and has a damping medium (3B3) in its inner cavity, and the bottom end of the upper guide post assembly (3A) is embedded in the damping medium (3B 3).

3. The improved tuned mass damper according to claim 2, characterized in that said upper guide rod assembly (3A) is provided at its lower end with a perforated damping plate (3A 3).

4. An improved mass tuned damper according to any of the claims 1-3, characterized in that the upper guide bar assembly (3A) is composed of upper guide bar attachment plate (3A1), upper guide bar (3A2), porous damping plate (3A3) connected in sequence from top to bottom.

5. The improved tuned mass damper according to claim 4, characterized in that the upper guide rod (3A2) is of a tapered structure which is tapered from top to bottom.

6. An improved tuned mass damper according to claim 2, characterized in that the damping medium (3B3) is a liquid damping medium.

7. An improved mass tuned damper according to any of the claims 2 or 6, characterized in that the damping medium (3B3) is selected from dimethicone.

8. The improved tuned mass damper according to claim 1, characterized in that the lower guide post assembly (3B) is composed of a lower guide post connecting plate (3B1) and a lower guide post (3B2) with a hollow cavity opened at the top, which are connected in sequence from bottom to top.

9. The improved tuned mass damper according to claim 8, wherein a dust cap (3B4) is secured to the top of the hollow interior of the lower guide post (3B2) to accommodate longitudinal movement of the upper guide post assembly (3A).

10. The improved mass tuned damper according to claim 9, characterized in that said dust cap (3B4) is secured to the lower guide post assembly (3B) top side wall by anchor screws (3B 5).

11. The improved tuned mass damper according to claim 1, characterized in that the friction damper assembly (6) consists of an upper single plate assembly (6A) and a lower double plate (6B), the upper single plate assembly (6A) and the lower double plate (6B) being correspondingly connected with the upper connection plate (1) and the lower connection plate (5) respectively through connection bolts (6E); upper portion veneer subassembly (6A) has upper portion veneer (6A1) of slotted hole (6A3) including the middle part, the both sides of upper portion veneer (6A1) are equipped with friction disc (6A2), lower part doubleplate (6B) middle part is equipped with round hole (6B1), pretension bolt (6D) pass dish spring (6C) in the outside of lower part doubleplate (6B), round hole (6B1), slotted hole (6A3) are fixed through fastening nut (6F) after connecting upper portion veneer subassembly (6A) and lower part doubleplate (6B).

12. The improved tuned mass damper according to claim 11, characterized in that the upper single plate assembly (6A) and the lower double plate (6B) are connected to a first connection plate (1A) on the upper connection plate (1) and a second connection plate (5A) on the lower connection plate (5) by means of connection bolts (6E), respectively.

13. The improved tuned mass damper according to claim 1, characterized in that said mass is located within the hanger frame (2), the mass comprising an effective number of large (2A) and small (2B) masses.

14. The improved tuned mass damper according to claim 13, wherein said hanger frame (2) is centrally located on the lower surface of the upper attachment plate (1).