JP2556226Y2 - Dynamic vibration absorber with adjustment mechanism - Google Patents

Description

[Detailed description of the invention]

A. Purpose of the invention (1) Industrial applications This invention is intended to increase the damping of vibrations in structures that vibrate under external forcing, such as buildings, tower structures, bridges, and machine bodies and their foundations. The present invention relates to a vibration device, a so-called dynamic vibration absorber (also referred to as a dynamic vibration absorber or a dynamic damper).

(2) Prior Art In general, a dynamic vibration absorbing device has a natural frequency substantially equal to or slightly lower than the frequency of a structure (vibration to be controlled) to be damped. This is a vibration system having a frequency, which is added to the controlled structure, that is, the main vibration system, to reduce the vibration of the main vibration system. The theory is already known. That is, as shown in FIG. 7, the device (2) basically includes a spring body, a mass body (weight), and a damper (attenuator). When this is displayed as a main vibration system model, 8, which is analyzed as a two-free-system vibration model. Where M1, K1,
C1 is an equivalent mass, an equivalent spring constant, and a damping coefficient of the main vibration system (1), respectively.

[0003] The present applicant has previously filed Japanese Utility Model Application No. 2-108889.
(Hereinafter referred to as “prior art”), a dynamic vibration absorber applied to a vibration system in a horizontal (horizontal) direction was proposed. That is, according to the prior art dynamic vibration absorbing device, a fixed support provided on the bottom plate; a weight supported by the fixed support via a support member and allowed to move in one axial direction; A horizontal leaf spring member disposed 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 vibration occurs in the main vibration system due to an external force, a relative displacement occurs between the bottom plate and the fixed support serving as the fixed system and the weight unit serving as the movable system in the present apparatus. The horizontal leaf spring member restricts this movement to only one-way movement due to its lateral rigidity, and has little resistance to the movement due to the small spring constant characteristic of the leaf spring member. For this reason, the weight portion satisfactorily follows the vibration of the external force, and receives the damping force in the direction opposite to the displacement by the damping portion, thereby rapidly damping the vibration of the main vibration system.

[0004] The natural frequency of the dynamic vibration absorber is
It is determined by the mass of the weight and the spring constant of the horizontal leaf spring member. At the beginning of design, these determined variables are made to correspond to the natural vibration period of the structure in which the dynamic vibration absorber is installed, that is, the main vibration system. The theoretical calculated value (design value) is used. However, the natural vibration period of the structure that is 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 also after construction. It often happens that the natural frequency of the dynamic vibration absorber set according to the cycle must be changed. In such a case, in the prior art, replacement of the weight or the leaf spring is required to change the natural frequency of the dynamic vibration absorbing device, and there is a problem that accuracy is not expected and work is required.

(3) Problems to be Solved by the Invention The present invention has been made in view of the above circumstances, and changes the natural frequency of the natural vibration cycle of the main vibration system by a simple operation. Another object of the present invention is to provide a dynamic vibration absorber having an adjustment mechanism that can be adjusted accurately.

B. Configuration of the Invention (1) Means for Solving the Problems The dynamic vibration absorber with the adjusting mechanism of the present invention employs the following technical means to achieve the above object. That is, in the first main configuration, a fixed support provided on a bottom plate; a weight portion supported by the fixed support via a support member and allowed to move in one axial direction; A horizontal leaf spring member disposed between the support and the opposite end of the weight portion in the moving direction; the fixed support body on which the horizontal leaf spring member is disposed; An air spring bag is interposed between the weight portion and a spring constant is adjusted by air pressure sealed in the air spring bag. In the second main configuration, a square frame-shaped outer frame body is provided on the bottom plate; and the outer frame body is accommodated in the frame of the outer frame body with a predetermined gap. A rectangular frame-shaped inner frame body supported via a vertical leaf spring member fixed to one side and allowed to move in one axial direction by another horizontal leaf spring member fixed to two opposite sides. A weight portion supported by a support member in the inner frame body and allowed to move only in a direction orthogonal to the moving direction of the inner frame body; and a moving direction of the inner frame body and the weight portion And a horizontal leaf spring member disposed between the opposed end portions of the outer frame body and the inner frame body, wherein the horizontal leaf spring member is disposed; and An air spring bag is interposed between the inner frame and the weight portion, and a spring constant is adjusted by air pressure sealed in the air spring bag. Characterized in that it.

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

(3) Embodiment An embodiment of a dynamic vibration absorber with an adjusting mechanism according to the present invention will be described with reference to the drawings. First Embodiment FIGS. 1 to 3 show a dynamic vibration damping device D1 applied in one axial direction of one embodiment (first embodiment). That is, FIG. 1 shows the overall plan configuration, FIG. 2 shows the vertical cross-sectional structure, and FIG. 3 shows the adjustment mechanism. In the figure,
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.

Referring to FIGS. 1 and 2, this dynamic vibration absorber D1 comprises a bottom plate 1 and a rectangular frame-shaped outer frame 2 erected on the bottom plate 1 to form a fixed system. 3 and
The casing 3 is supported in the outer frame 2 via a vertically placed leaf spring member 4 and is movable only in one direction.
A weight portion 5 forming a movable system; a horizontal leaf spring member 6 and an air spring bag 7 interposed between the outer frame 2 of the casing 3 and an 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.

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

The vertical leaf spring member 4 is formed by bending a flat leaf spring body into a U-shape and is used in a vertical shape, and has one end thereof attached to a wall 2X of the outer frame 2 by a suitable attaching means (for example, The other end is similarly fixed to the side surface of the weight portion 5. In the present embodiment, four vertical leaf spring members 4 are arranged on both sides of the weight portion 5, but the number is not limited to the number and can be increased or decreased. In addition, it is free to be arranged in multiple stages, but from the viewpoint of increasing the longitudinal rigidity (vertical rigidity) and increasing the supporting force, a vertically long one is recommended. The vertical leaf spring member 4 has a large vertical rigidity and a large flexibility in the horizontal direction depending on the mode of use, so that the vertical leaf spring member 4 supports the weight 5 which is a heavy object, and 5 is allowed in the horizontal direction without resistance.

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

The horizontal leaf spring member 6 is of the same quality as the vertical leaf spring member 4 described above, and is used by bending a flat leaf spring body into a U-shape and placing it horizontally. 5 in the movement direction (X) and the casing 3 facing the end surface.
Between the inner wall surface of the outer frame 2Y and one or more stages (two stages in this embodiment). The horizontal placing spring member 6 has high lateral rigidity and high flexibility due to its use characteristics. In other words, it has the large spring constant characteristic. For this reason, the weight portion 5 interlocked with the horizontal spring member 6
Is allowed to move only in one direction, and allows the horizontal displacement of the weight portion 5 without resistance.

The air spring bag 7 has a hollow cylindrical shape, is arranged between the horizontal leaf spring members 6 arranged side by side, and has both ends fixed to the outer frame 2 and the weight 5. The air spring bag 7 according to the present embodiment employs a bellows method, and compressed air is introduced and sealed therein 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 compressor 1
The air compressed in 2 is guided to the main tank 13, then branched via the air valve 14, and sent to the respective air spring bags 7 via the auxiliary tank 15. The air compressor 12 is not driven constantly, 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 the communication with the auxiliary tank 15 further reduces the spring constant of the air spring.

Returning to FIGS. 1 and 2, the attenuation unit 8
In this embodiment, a so-called hydraulic damper is used. 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 at the other end is connected to oil sealed in a cylinder 19. The movement of the weight 5 is attenuated by the orifice resistance. The hydraulic damper is arranged in the moving direction of the weight 5 in response to the displacement in the uniaxial direction.

The dynamic vibration absorbing device D1 of this embodiment is
In the main vibration system of a structure that excels in uniaxial vibration (for example, a middle-to-high-rise building having a rectangular planar shape), the weight unit 5 is installed so that the moving direction of the weight unit 5 matches the direction. When installing the present apparatus, it is a matter of course that the apparatus is installed at the antinode of vibration of the structure (usually the top of the structure in the primary vibration system).

(Operation / Effect of Embodiment) The dynamic vibration damping device D1 of the embodiment configured as described above operates as follows. When vibration occurs in the main vibration system due to an external force, a relative displacement occurs between the casing 3 forming the fixed system and the weight portion 5 forming the movable system in the apparatus D1.
The horizontal leaf spring member 6 restricts this movement to only one-way movement by its lateral rigidity, and allows the movement without resistance. For this reason, the weight portion 5 favorably follows the vibration of the structure, and receives the damping force in the direction opposite to the displacement thereof by the damping portion 8 to attenuate the vibration of the main vibration system. According to the present apparatus D1, since the weight 5 is further supported by the vertical leaf spring member 4, there is almost no resistance to the movement of the weight 5, and the weight 5 is favorably followed. Can react sensitively.

The natural frequency of the dynamic vibration absorber D1 is adjusted by increasing or decreasing the air pressure in the air spring bag 7 in response to a change in the vibration period of the structure of the main vibration system. That is, the natural vibration period of the structure may be different from the design value after the construction, and the natural vibration period also changes after the construction due to the extension or remodeling. Correspondingly, the main vibration absorber D1
In order to increase the natural frequency of, the air pressure in the air spring bag 7 is increased to increase the spring constant. In addition, the device D1
When the natural frequency of the air spring is lowered, 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 the present 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 change of the vibration period of the main vibration system can be easily performed. Can respond. Further, since the air spring bladders 7 arranged opposite to each other maintain an equal pressure via the air conduit, a uniform pressure balance can be automatically obtained. 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 springs 4. However, the weight is supported by a rolling support composed of a spherical body (ball bearing) or a cylindrical body (roller bearing). be able to.

(Second Embodiment) FIGS. 4 to 6 show still another embodiment (second embodiment) of the present invention. In the figure, the same reference numerals are given to members equivalent to those in the previous embodiment. Dynamic vibration absorber D2 of the present embodiment
Indicates that the total displacement in the plane direction is allowed.

In this dynamic vibration absorbing device D2, the casing 3 has a rectangular box shape, and is formed of a flat bottom plate 1, a rectangular frame-shaped outer frame body 2 and an upper lid 21 with a predetermined rigidity.
The bottom plate 1 is fixed to the floor of the structure. A vertical leaf spring member 4A fixed to two opposing sides 2Y of the outer frame 2 and a horizontal leaf spring fixed to the other two sides 2X in the outer frame 2 of the casing 3. The middle frame 22 is arranged via the member 6A. The middle frame 22 also maintains rigidity. 7A is an air spring bag disposed in the middle of the horizontal leaf spring portion 6A. The vertical leaf spring 4A has a pair of leaf spring elements opposed to each other. However, even if the leaf spring elements are arranged in the same direction, there is no functional change. Four horizontal leaf springs 6A are also disposed on each side. However, the number is not limited. The vertical leaf spring member 4B fixed to the two opposite sides 22X of the inner frame member 22 and the horizontal leaf spring member 6B fixed to the other two sides 22Y in the inner frame member 22 as well. A rectangular parallelepiped weight portion 5 is disposed via the. 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 orthogonal to each other.

Compressed air is introduced into the air spring bag 7A for the middle frame and the spring bag 7B for the weight via 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 and is branched from the main tank 13 to each of the air valves 14A, 14A.
B guides the air spring bags 7A and 7B via the auxiliary tanks 15A and 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 section 8 is interposed between the upper lid 21 of the casing 3 and the weight section 5, and a viscous shear resistance type damper corresponding to displacement in all directions (biaxial directions) is used. . That is, the damping portion 8 includes a concave portion 5A formed on the upper surface of the weight portion 5 and a container 25 disposed in the concave portion 5A.
And a support rod 26 attached to the upper lid 21 of the casing 3.
, And a viscous fluid L filled in the container 25. Bottom of container 25 and resistance plate 2
7 is held at a predetermined distance s from the lower surface of the weight 7 and attenuates the vibration of the weight 5 with viscous resistance generated by the viscous fluid L interposed therebetween.

Thus, in the device D2 of this embodiment, the middle frame 22 is allowed to move in the Y direction, and the weight 5 is allowed to move in the X direction with respect to the middle frame 22. As a whole, displacement is freely allowed in all directions on 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-like structure. In the present embodiment, the weight 5 is supported by the vertical leaf spring 4B, but a mode in which the weight 5 is supported by a rolling support can be adopted. In this case, a cylindrical body (roller bearing) that can be moved in all directions in a horizontal direction by a spherical body (ball bearing) or a cylindrical body that can be moved only in the X direction and a cylindrical body that can be moved only in the Y direction via an intermediate plate. And may be 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 basic technical concept of the present invention. That is, the following embodiments are included in the technical scope of the present invention. In each of the drawings of the present embodiment, the fixed support takes the form of a box-shaped casing 3, but the function thereof does not change even if it is a column material erected on the bottom plate 1.

C. According to the dynamic vibration absorbing device with the adjusting mechanism of the present invention, in the dynamic vibration absorbing device exhibiting good vibration sensitivity by using the horizontal leaf spring member, the natural frequency can be adjusted by the weight or the plate. The adjustment can be easily performed without any modification work of the spring. In addition, continuous and accurate adjustment can be performed by adjusting 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 the drawings]

FIG. 1 is a partial cross-sectional plan view showing an entire configuration of an embodiment (first embodiment) of a dynamic vibration absorber with an adjusting mechanism of 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.

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

FIG. 5 is a sectional view taken along line V-V in FIG. 4;

FIG. 6 is a schematic diagram of an adjustment mechanism.

FIG. 7 is a conceptual explanatory view of a dynamic vibration absorber.

FIG. 8 is a vibration model of a dynamic vibration absorber.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bottom plate, 2 ... Outer frame, 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 ...
Damping part

Claims (5)

(57) [Scope of request for utility model registration] 1. A fixed support mounted on a bottom plate; a weight portion supported by the fixed support via a support member and allowed to move in one axis direction; the fixed support and the weight A horizontal leaf spring member disposed between the opposed end portion in the moving direction of the portion, and a dynamic vibration damping device comprising: the fixed support body on which the horizontal leaf spring member is disposed; and the weight portion. A dynamic vibration absorbing device with an adjusting mechanism, wherein 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 mounted 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. A rectangular frame-shaped inner frame body supported via a set vertical leaf spring member and allowed to move in one axial direction by a horizontal leaf spring member fixed to two other sides facing each other; A weight portion supported in the frame via a support member and allowed to move only in a direction perpendicular to the direction of movement of the inner frame; and an opposite end in the direction of movement of the inner frame and the weight. And a horizontal leaf spring member disposed between;
Wherein the air spring bag is interposed between the outer frame and the inner frame where the horizontal leaf spring member is disposed, and between the inner frame and the weight portion. A dynamic vibration absorber with an adjustment mechanism, wherein a spring constant is adjusted by air pressure sealed in the air spring bag. 3. The dynamic vibration absorbing device with an adjusting mechanism according to claim 1, wherein a damping portion is interposed between the fixed support or the outer frame and the weight portion. 4. A vertical leaf spring member interposed between a side surface of the weight portion in the moving direction and the fixed support or the inner frame body. A dynamic vibration absorber with an adjusting mechanism according to item 1. 5. The dynamic vibration damping device with an adjusting mechanism according to claim 1, wherein the support member is a rolling support interposed between the bottom plate and the lower surface of the weight portion.