JPH0542789U - Dynamic vibration absorber with adjustment mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] To easily adjust the natural frequency of a dynamic vibration absorber using a horizontal leaf spring member that regulates lateral displacement of a weight. [Arrangement] An air spring bag is arranged in parallel with a horizontal leaf spring member that restricts the movement of the weight in one axis direction, and the spring constant of the dynamic vibration absorber is adjusted by the air pressure introduced into the air spring bag. ..

Description

[Detailed description of the device]

A. Purpose of the invention (1) Industrial field Vibration devices, so-called dynamic vibration absorbers (also called dynamic vibration absorbers or dynamic dampers).

(2) Conventional Technology Generally, a dynamic vibration absorber has a natural frequency that is almost the same as the frequency of a structure to be damped (a structure to be damped), or has a slightly smaller natural frequency. It is a vibration system having a frequency, and it is added to the structure to be controlled, that is, the main vibration system to reduce the vibration of the main vibration system, and its theory is already known. That is, as shown in FIG. 7, the device (2) is basically composed of a spring body, a mass body (weight) and a damper (attenuator), and when this is displayed as a main vibration system model, As shown in FIG. 8, it is analyzed as a vibration model of a two-free system. Here, M1, K1, and C1 are the equivalent mass, equivalent spring constant, and damping coefficient of the main vibration system (1), respectively.

The applicant previously proposed in Japanese Patent Application No. 2-108893 (hereinafter referred to as “prior art”) a dynamic vibration absorbing device applied to a lateral (horizontal) vibration system. That is, according to the dynamic vibration absorbing device of the prior art, a fixed support installed on the bottom plate; a weight supported by the fixed support via a support member and allowed to move in one axis direction; From a horizontal leaf spring member arranged between the fixed support and the opposite end in the moving direction of the weight portion; and a damping portion interposed between the fixed support and the weight portion. When the main vibration system vibrates due to an external force, relative displacement occurs between the bottom plate and the fixed support, which are the fixed system, and the weight section, which is the movable system, in this device. However, the laterally placed leaf spring member restricts this movement to only one-way movement due to its lateral rigidity, and little resistance is exerted to the movement due to the small spring constant characteristic of the leaf spring member. For this reason, the deadweight section satisfactorily follows the vibration of the external force, and at the same time, the damping section receives the damping force in the direction opposite to the displacement thereof and quickly damps the vibration of the main vibration system.

However, the natural frequency of the present dynamic vibration absorber is determined by the mass of the weight and the spring constant of the horizontal leaf spring member. The theoretical calculation value (design value) corresponding to the natural vibration period of the structure in which the device is installed, that is, the main vibration system is used. However, the natural vibration period of the main vibration system is not uniquely determined by the difference between the value at the time of design and the actual value after construction, and by various factors even after construction. In many cases, it is necessary to change the natural frequency of the dynamic vibration absorber set according to the cycle. In such a case, in the prior art, it is necessary to replace the weight or the leaf spring in order to change the natural frequency of the dynamic vibration absorbing device, which is difficult to achieve accuracy, and there is a problem that it takes time and labor. ..

(3) Problem to be Solved by the Invention The present invention has been made in view of the above circumstances, and a simple operation of changing the natural frequency of the main vibration system with respect to the change of the natural vibration period. The purpose of the present invention is to obtain a dynamic vibration absorber with an adjusting mechanism that allows accurate adjustment.

B. Configuration of the Invention (1) Means for Solving the Problems The dynamic vibration absorbing device with an adjusting mechanism of the present invention adopts the following technical means in order to achieve the above object. That is, in the first main configuration, a fixed support installed on the bottom plate; a weight supported by the fixed support through a support member and allowed to move in one axial direction; In the dynamic vibration-damping device, the fixed support body, in which the horizontal plate spring member is arranged, the horizontal plate spring member being arranged between the support member and the opposite end in the moving direction of the weight unit. An air spring bag is interposed between the weight section and the spring constant, and the spring constant is adjusted by the air pressure enclosed in the air spring bag. In the second main configuration, a square frame-shaped outer frame body installed on the bottom plate; accommodated in the frame of the outer frame body with a predetermined gap, and facing each other. A rectangular frame-shaped inner frame that is supported via vertical leaf spring members that are fixed on two sides and that is allowed to move in one axis direction by other horizontal leaf spring members that are fixed on two opposite sides. A body; a weight portion supported in the inner frame body via a support member and allowed to move only in a direction orthogonal to the moving direction of the inner frame body; and a body weight portion of the inner frame body and the weight portion. A laterally-displaced leaf spring member disposed between the opposite end portion in the moving direction; and between the outer frame body and the inner frame body at which the horizontally-disposed leaf spring member is disposed, Also, an air spring bag is interposed between the inner frame body and the weight portion, and the spring constant is controlled by the air pressure enclosed in the air spring bag. And adjusting the.

(2) When vibration occurs in the main vibration system due to an external force, relative displacement occurs between the fixed support or outer frame which is the fixed system and the inner frame and weight part which is the movable system in this device. The horizontal leaf spring member restricts this movement to one-way movement due to its lateral rigidity, and hardly resists the movement. For this reason, the weight portion follows the vibration of the external force well, and receives the damping force in the direction opposite to the displacement by the damping portion to damp the vibration of the main vibration system. The natural frequency of the main vibration absorber is adjusted by increasing or decreasing the air pressure inside the air spring bag in response to changes in the vibration cycle of the main vibration system.

(3) Embodiment An embodiment of the dynamic vibration absorbing device with an adjusting mechanism of the present invention will be described with reference to the drawings. (First Embodiment) FIGS. 1 to 3 show a dynamic vibration absorbing device D1 applied in one axial direction of the first embodiment (first embodiment). That is, FIG. 1 shows the overall plan structure, FIG. 2 shows the longitudinal sectional structure, and FIG. 3 shows the adjusting mechanism section. In the drawing, X indicates the vibration direction of the main vibration system to which the dynamic vibration absorbing device D1 corresponds, in other words, the moving direction of the weight portion, and Y indicates the direction orthogonal to X.

With reference to FIGS. 1 and 2, a dynamic vibration absorbing device D1 includes a bottom plate 1 and a quadrangular frame-shaped outer frame member 2 provided upright on the bottom plate 1 to form a fixed system. 3, a weight portion 5 supported in the outer frame body 2 of the casing 3 via a vertically placed leaf spring member 4 and movable only in one direction, and forming a movable system, and the casing 3 A horizontal leaf spring member 6 and an air spring bag 7 interposed between the outer frame body 2 and the end surface of the weight portion 5 in the moving direction, and a damping portion 8 installed on the lower surface of the weight portion 5. Consists of.

The detailed structure of each part will be described below. The casing 3 is composed of a flat plate-shaped bottom plate 1 and a square frame-shaped outer frame body 2 installed on the bottom plate 1. The outer frame body 2 has a storage space 9 inside which allows the weight portion 5 to move. Form. Note that 2X is a wall body of the outer frame body 2 along the X direction, and 2Y is a wall body orthogonal to the X direction, in other words, a wall body along the Y direction. The outer frame body 2 constitutes the fixed support body of the present invention. Reference numeral 10 is a reinforcing rib provided on the outside of the casing 3, and may be omitted as appropriate.

The vertically placed leaf spring member 4 is formed by bending a flat leaf spring body into a U-shape and used vertically, and one end thereof is attached to the wall body 2X of the outer frame body 2 by an appropriate attachment means (for example, The other end is also fixed to the side surface of the weight portion 5. In this embodiment, the vertically placed leaf spring members 4 are arranged at four locations on both sides of the weight portion 5, but the number is not limited, and the number can be increased or decreased. In addition, although it is free to be arranged in multiple stages, a vertically long one is recommended from the viewpoint of increasing the vertical rigidity (vertical rigidity) and increasing the bearing capacity. The vertical leaf spring member 4 has a large vertical rigidity and a large flexibility in the horizontal direction depending on its usage, and therefore supports the weight 5 which is a heavy object, and Allow 5 horizontal displacement without resistance.

The weight 5 has a rectangular parallelepiped shape and has a predetermined weight. Then, the housing 3 is arranged in the housing space 9 of the outer frame body 2 of the casing 3 with a predetermined gap.

The horizontal leaf spring member 6 is of the same quality as the vertical leaf spring member 4 described above, and is used by horizontally bending a flat leaf spring body into a U-shape and using the weight portion. 5 is installed between the end surface in the moving direction (X) and the inner wall surface of the outer frame body 2Y of the casing 3 facing the end surface in one step or in multiple steps (two steps in this embodiment). The horizontal spring member 6 has a large lateral rigidity and a large flexibility due to its use characteristics. In other words, it has a large spring constant characteristic. Therefore, the weight portion 5 interlocking with the laterally placed spring member 6 is allowed to move only in one direction, and the weight portion 5 is allowed to move in the horizontal direction without resistance.

The air spring bag 7 has a hollow cylindrical shape, is arranged between the horizontally placed leaf spring members 6 arranged side by side, and both ends thereof are fixedly mounted on the outer frame body 2 and the weight 5. The air bladder 7 of this embodiment adopts a bellows system, and compressed air is introduced and sealed inside by an air conduit 11.

FIG. 3 shows a compressed air supply mechanism for supplying compressed air to the air spring bag 7. That is, the air compressed by the air compressor 12 is guided to the main tank 13, then branched off via the air valve 14, and then pressure-fed to each air spring bag 7 via the auxiliary tank 15. It is a thing. The air compressor 12 is not always driven, but is driven by a control mechanism that detects the pressure in the air spring bag 7 and maintains a predetermined pressure based on the detection signal.

The air spring bag 7 has a small spring constant due to its characteristics, and by communicating with the auxiliary tank 15, the spring constant of the air spring can be further reduced.

Returning to FIG. 1 and FIG. 2 again, a so-called hydraulic damper is used as the damping unit 8 in this embodiment. The hydraulic damper is fixed on the bottom plate 1, and its piston rod 17 is pivotally attached to a rib 18 fixed to the lower surface of the weight 5, while the piston portion at the other end is connected to the oil enclosed in the cylinder 19. The movement of the weight portion 5 is damped with the orifice resistance of. The hydraulic damper corresponds to the displacement in the uniaxial direction and is arranged in the moving direction of the weight portion 5.

Such a dynamic vibration absorbing device D1 of the present embodiment is a main vibration system of a structure (for example, a middle-high-rise building having a rectangular planar shape) that is excellent in uniaxial vibration. Set up so that the direction of movement of 5 matches. When installing this device, it is a matter of course that it is installed at the antinode of the vibration of the structure (usually the top of the structure in the primary vibration system).

(Operation / Effect of Embodiment) The dynamic vibration absorbing device D1 of the present embodiment configured as described above operates as follows. When vibration occurs in the main vibration system due to an external force, in this device D1, relative displacement occurs between the casing 3 forming the fixed system and the weight portion 5 forming the movable system, but the horizontal leaf spring member 6 causes this movement. Its lateral rigidity limits movement in one direction only, and allows movement without resistance. Therefore, the weight portion 5 follows the vibration of the structure well, and the damping portion 8 receives the damping force in the direction opposite to the displacement thereof to damp the vibration of the main vibration system. According to the present device D1, since the weight portion 5 is further supported by the vertical leaf spring member 4, almost no resistance is generated in the movement of the weight portion 5 and the movement is satisfactorily followed, and it is possible to cope with minute vibrations. And can react sensitively.

The natural frequency of the main vibration damping device D1 is adjusted by increasing or decreasing the air pressure in the air spring bag 7 with respect to the change in the vibration cycle of the structure of the main vibration system. That is, the natural vibration period of the structure may differ from the design value after the construction, and the natural vibration period also changes after the construction due to expansion and remodeling. Correspondingly, in order to increase the natural frequency of the dynamic vibration absorbing device D1, the air pressure in the air bladder 7 is increased and the spring constant is increased. Further, when lowering the natural frequency of the device D1, the air pressure in the air spring bag 7 is reduced and the spring constant is reduced.

As described above, according to the device of this embodiment, the natural frequency of the device D1 is adjusted by adjusting the pressure of the compressed air to the air spring bag 7, and the vibration cycle of the main vibration system can be easily changed. Can respond. Further, since the air spring bags 7 arranged relative to each other maintain an equal pressure via the air conduit, it is possible to automatically obtain a uniform pressure balance. By arranging the auxiliary air tank 15 connected to the air spring bag 7, the spring constant of the air spring bag 7 can be further reduced.

In this embodiment, the weight 3 is supported by the vertical leaf spring 4, but it is supported by the rolling support composed of a spherical body (ball bearing) or a cylindrical body (roller bearing). Can be taken.

Second Embodiment FIGS. 4 to 6 show still another embodiment (second embodiment) of the present invention. In the figure, the same members as those in the previous embodiment are designated by the same reference numerals. The dynamic vibration absorbing device D2 of the present embodiment is one that allows all displacement in the plane direction.

In this dynamic vibration absorbing device D2, the casing 3 is in the shape of a rectangular box, and is composed of a flat plate-shaped bottom plate 1, a rectangular frame-shaped outer frame body 2 and a top lid 21 with a predetermined rigidity. It is fixed to the floor of the structure. Then, in the outer frame body 2 of the casing 3, a vertically placed leaf spring member 4A fixed to two opposite sides 2Y of the outer frame body 2 and a laterally placed leaf spring fixed to the other two sides 2X. The middle frame body 22 is arranged via the member 6A. The inner frame body 22 also maintains rigidity. 7A is an air spring bag arranged in the middle of the horizontal plate spring portion 6A. The vertical leaf springs 4A have a pair of leaf spring elements facing each other, but even if they are arranged in the same direction, there is no functional difference. Also, four horizontal leaf springs 6A are arranged on each side. However, the number is not limited. Then, in the middle frame body 22, a vertically placed leaf spring member 4B fixed to two opposite sides 22X of the inner frame body 22 and a laterally placed leaf spring member fixed to the other two sides 22Y. A rectangular parallelepiped weight portion 5 is arranged via 6B. 7B is an air spring bag arranged in the middle of the horizontal leaf spring member 6B. As can be seen from the figure, the vertical leaf springs 4A and 4B and the horizontal leaf springs 6A and 6B are arranged orthogonally to each other.

Compressed air is introduced into each of the air spring bag 7A for the middle frame and the spring bag 7B for the weight through the air conduit 11. FIG. 6 shows a compressed air supply mechanism for supplying compressed air to these air spring bags 7A and 7B. That is, compressed air is sent from the air compressor 12 to the tank 13, branched from the main tank 13 and guided to the air spring bags 7A, 7B by the respective air valves 14A, 14B via the auxiliary tanks 15A, 15B. .. Thus, the air spring bag 7A is used for adjusting the vibration cycle in the Y-axis direction, and the air spring bag 7B is used for adjusting the vibration synchronization in the X-axis direction.

The damping portion 8 is installed between the upper lid 21 of the casing 3 and the weight portion 5, and a viscous shear resistance type damper that responds to displacements in all directions (biaxial directions) is used. .. That is, the attenuating portion 8 includes a recess 5A recessed in the upper surface of the weight portion 5, a container 25 disposed in the recess 5A, and a support rod 26 attached to the upper lid 21 of the casing 3. It is composed of a disk-shaped resistance plate 27 at the lower end and a viscous fluid L filled in the container 25. The bottom surface of the container 25 and the lower surface of the resistance plate 27 are held at a predetermined distance s, and the vibration of the weight unit 5 is damped by viscous resistance generated by the viscous fluid L interposed therebetween.

However, in the device D2 of the present embodiment, the middle frame body 22 is allowed to move in the Y direction, and the weight portion 5 is allowed to move with respect to the middle frame body 22 in the X direction. As a whole, the displacement is freely allowed in all directions of the XY plane. Therefore, the device D2 of this embodiment is applied to a structure system that vibrates in all directions, such as a tower structure. In the present embodiment, the weight 5 is supported by the vertically placed leaf spring 4B, but the weight 5 may be supported by the rolling support. In this case, a spherical body (ball bearing) is supported so as to be movable in all horizontal directions, or a cylindrical body (roller bearing) movable only in the X direction and a cylindrical body movable only in the Y direction are provided as intermediate plates. They may be stacked one above the other and supported so as to be movable in all horizontal directions.

The present invention is not limited to the above embodiment, and various design changes can be made within the scope of the basic technical idea of the present invention. That is, the following aspects are included in the technical scope of the present invention. In all of the drawings of this embodiment, the fixed support has the form of the box-shaped casing 3. However, even if it is a pillar that is erected on the bottom plate 1, its function does not change.

C. Effect of the Invention According to the dynamic vibration absorber with the adjusting mechanism of the present invention, by using the horizontal leaf spring member, in the dynamic vibration absorber exhibiting good vibration sensitivity, the natural frequency can be adjusted by using the weight or the plate. The adjustment can be easily performed without modifying the spring. Moreover, it is possible to continuously and accurately adjust the amount of compressed air introduced into the air spring bag, so that the optimum value of the natural frequency can be found.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional plan view showing the overall configuration of an embodiment (first embodiment) of a dynamic vibration absorbing device with an adjusting mechanism according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a schematic view of an adjustment mechanism section.

FIG. 4 is a plan view of another embodiment (second embodiment) of the dynamic vibration absorbing device with an adjusting mechanism of the present invention.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a schematic view of an adjustment mechanism section.

FIG. 7 is a conceptual explanatory view of a dynamic vibration absorbing device.

FIG. 8 is a vibration model of the dynamic vibration absorbing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bottom plate, 2 ... Outer frame body, 3 ... Casing, 4, 4A, 4
B ... Vertically-placed leaf spring member, 5 ... Weight portion, 6, 6A, 6B ...
Horizontal leaf spring member, 7, 7A, 7B ... Air spring bag, 8 ...
Attenuator

Claims (5)

[Scope of utility model registration request] 1. A fixed support body installed on a bottom plate; a weight portion supported by the fixed support body via a support member and allowed to move in one axial direction; the fixed support body and the weight weight. A horizontal vibration leaf spring member arranged between the horizontal support leaf spring member and an opposite end portion in the moving direction of the portion; A dynamic vibration absorbing device with an adjusting mechanism, characterized in that an air spring bag is interposed therebetween, and a spring constant is adjusted by air pressure sealed in the air spring bag. 2. A square frame-shaped outer frame body installed on a bottom plate; housed in the frame of the outer frame body with a predetermined gap, and fixed to two opposite sides of the outer frame body. An inner frame body in the form of a rectangular frame, which is supported via the vertically placed leaf spring member and is allowed to move uniaxially by the other horizontally placed leaf spring members fixed to the opposite two sides; A weight portion supported through a support member in the frame body and allowed to move only in a direction orthogonal to the moving direction of the inner frame body; and opposite end portions in the moving direction of the inner frame body and the weight portion. A horizontal leaf spring member disposed between and;
In the dynamic vibration absorbing device, the air spring bag is interposed between the outer frame body and the inner frame body in which the horizontal leaf spring member is arranged, and between the inner frame body and the weight portion. A dynamic vibration absorbing device with an adjusting mechanism, wherein the spring constant is adjusted by the air pressure enclosed in the air spring bag. 3. The dynamic vibration absorbing device with an adjusting mechanism according to claim 1, wherein a damping portion is provided between the fixed support body or the outer frame body and the weight portion. 4. The supporting member is a vertical leaf spring member interposed between the side surface of the weight portion in the moving direction and the fixed supporting member or the inner frame member. A dynamic vibration absorber with an adjusting mechanism according to. 5. The dynamic vibration absorbing device with an adjusting mechanism according to claim 1, wherein the supporting member is a rolling supporting member interposed between the bottom plate and the lower surface of the weight portion.