JPH0333524A - Damping device for structure - Google Patents

Abstract

PURPOSE:To reduce vibration of a structure by providing a rack extending in the vibrating direction on the upper face of a weight swingably arranged on the upper part of the structure so as to perform simple harmonic vibration, connecting a speed reducer to a shaft having a pinion engaged with the rack, and connecting a damper to the speed reducer. CONSTITUTION:When swinging is generated in a structure 1 by aerodynamic force and the like, the swinging energy is transmitted to a weight 3, simple harmonic vibration of the weight 3 is begun with delay of 90 deg. against the swinging of the structure 1, and the vibrating energy of the weight 3 is given to a shaft 9 as rotating energy through a racke 8 and a pinion 11. Then, as a speed reducer 13 is connected to the one end of the shaft 9, rotation of the shaft 9 is reduced with the speed reducer 13. In this case, an oil damper 15 is provided on the output shaft of the speed reducer 13, the oil damper 15 is swingingly operated through the speed reducer 13, the rotating energy of the shaft 9 is damped, and swinging of the structure 1 is restrained.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is particularly applicable to the 2L section of structures such as suspension bridge towers, skyscrapers, towers, and steel towers. ) and vibration amplitudes caused by earthquakes to quickly damp vibrations.

[Conventional RA i + li J] Conventionally, as this type of structure vibration damping device, for example,
Rainbow 1 shown in the figure shows a structure in which a tank C is installed on the top of a structure a, the inside of which is partitioned into multiple parts by horizontal wire mesh, and a required amount of liquid d such as water is placed in the tank C. The shaking of @Shipment A is suppressed by the sloshing phenomenon caused by the liquid d in tank C moving left and right while passing through a wire mesh ["Pilding Tower J"]
(published in December 1988), and TEGIST (1939) entitled "Technological development of vibration control and seismic isolation structures" at the New Architecture@Building Technology Seminar of the Japan Building Center Information Exchange Association.
Published by Nippon Kenchi Center, a closed corporation in October 2013)] Or, or (As shown in Figure 7, a laminated rubber e consisting of multiple layers stacked vertically is installed on the top of the structure a. death,
It is proposed that L has a configuration in which a plow f is supported on the upper end of the rubber lamination e, and the vibration of the structure a is damped by the vibration of the weight through the rubber lamination e. has been done.

[Problems to be Solved by the Invention] However, in contrast to the above-mentioned conventional method, in the case of example 1 shown in FIG. 0.Liquid d moves through the wire mesh in tank C, but the attenuation rate changes. (G) There are problems such as: it is difficult to synchronize the natural period of the device itself with the natural period of structure a; (g) poor response; and the impossibility of large strokes. , On the other hand, in the case of the example shown in Fig. 7 in which the laminated rubber e and the plow f are combined, (I) Since the plow f is supported by the stacked rubber e, the mass of the device cannot be made too large; The attenuation rate is determined by the laminated rubber, so the attenuation rate cannot be changed arbitrarily; Value It is difficult to synchronize the natural period of the device itself with the natural period of the structure a; 0 The laminated rubber e deteriorates. Therefore, there are problems such as short life and inability to obtain a large ω amplitude.

Therefore, the present invention attempts to solve the problems of the above-mentioned conventional methods and reduce the vibration of the structure by converting the vibration energy given to the structure into the kinetic energy of the weight and efficiently damping it. It is something to do.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a structure in which a weight capable of performing single string vibration is swingably disposed on the top of a structure, and the weight is A rack extending in the vibration direction is provided on the upper surface, a reducer is connected to a shaft having a pinion that meshes with the rack, and a damper is connected to the reducer.

Also, instead of the speed reducer, a variable drive type rotating device can be used.

[Function] When shaking energy is applied to the structure, this shaking energy is converted into vibration energy of the weight, and this vibration energy is transmitted to the damper through the rack, pinion, shaft, speed reducer, or variable drive rotating device. It is consumed indirectly and can effectively suppress the shaking of structures.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 to 3 show an embodiment of the present invention, in which a base 2 is provided on the top of a structure 1 that vibrates in response to an external nozzle. A plow 3, which is a vibration damping body curved in an arc, is arranged so as to vibrate a single chord in the direction of the shaking of the structure 1 via a support roller 4 provided on the base 2, and restoration using gravity is performed. The force forms a spring system, and the plows are in contact with the protrusions 5 provided on both sides of the plows 3 or with the left and right buffs 77 on the pedestal 6 installed at positions sandwiching the plows 3 at the front and back. In addition, a rack 8 is provided on the negative side of the plow 3 along the vibration direction, and a shaft 9 is provided above the rack 8 so as to be perpendicular to the rack 8. , and the axis 9
is rotatably supported by the front and rear frames 6 via bearings 10, and a pinion 11 is provided in the middle of the shaft 9 so as to mesh with the rack 8. is transmitted as rotational energy to the shaft 9 via the rack 8 and the pinion 11, and furthermore, one end of the shaft 9 described in
A lever 14 is connected to the output shaft of the reducer 13 and extends from side to side, and an oil damper 15 is provided as a damping device between the left and right ends of the lever 14 and the base 2. An interposed device is installed so that the rotational energy of the shaft 9 input to the reduction gear 13 can be attenuated by the oil damper 15 via the reduction gear 13. Note that 16 is a flywheel for applying inertia to the rotation of the shaft 9.

In the above configuration, when the weight 3 is considered as a pendulum as shown in Fig. 4, the center of gravity G under its natural vibration period is
The vibration radius is determined by the hole. R-(T/2π〉2 ・Q −ω2 ・g (ω: natural frequency) Furthermore, when the mass of the plow 3 is m and the maximum horizontal displacement is X, the vertical displacement amount y is It can be determined as mω2 X2 2mg ω2 X2 g.

Next, the principle of vibration damping control in the present invention will be explained with reference to FIG. In FIG. 5, 21 is a vibration table vibrated by an actuator 22, 17 is a specimen movably placed on the vibration table 21 (corresponding to structure 1 in FIG. 1), 18
is a plow (corresponding to plow 3 in Figure 1), and 19.20 is a bracket. Now, the aerodynamic force (wind load) acting on the specimen 17 is P, the mass of the specimen 17 is M, the converted spring constant of the specimen 17 is K, and the damping coefficient of the specimen 17 ((-1 additive damping constant: 2Mhω) is the horizontal linear displacement (absolute coordinates) of the C1 specimen 17, the mass of the weight 18 is m, the spring constant of the plow 18 is k, and the control force that controls the vibration of the plow 18 is p, and when the amount of linear displacement of the weight 18 in the horizontal direction (relative coordinate with respect to the specimen 17) is set to X, the specimen 17 and the weight 1
The equation of motion of 8 is MM+CX+KX+m(R+M)=
Pcasωt ・(1) (ω: natural frequency, t: time) mX+mM+kx=p (t) ・(
2) Here, assuming that the specimen 17 and the plow 18 are making a single string motion,
-<4> (B: amplitude, α: phase difference with respect to ωt) At this time, the spring constants K and k and the specimen 17
, between the weight 18, K-(M+m) ω2 ・(5)k
=rnω2...There is a relationship as shown in (6). Therefore, the terms including mass and spring constant in equations (3> and (4)) are always zero as shown below.

(M+m)X+KX−-(M+m>Aω2sinωt+
(M+m) Aω2sinωt=Q ・(
7) mM+kx=-mBω2 sin (ωt+α)
+mB ω2 sin (ωt + a) −Q
・((3)(c) Expression 0 as <1), (2
), Pcosωt=CX+mx −2VIh Aω2 casωt −mBω2 sin
(ωj +α) ・(9)p(t) −mX−−
mAω2stnωt ・(10) Here, 〈
In formula 9, as long as the first and second terms on the right side have the same phase,
The force due to the damping of the specimen 17 and the movement of the weight 18 is the aerodynamic force P.
It shows that it is balanced. That is, weight 1
8 is delayed by 90° with respect to the movement of specimen 17 (
-90°), it can be seen that the force moves in the same direction as the damping of the specimen 17 and attempts to stop the vibration. Therefore, if we rewrite equation (9) as α−−90°, then p
cosωt-2M h to ω2rnBω2CO5ω-[-
(2MhA+mB) ω2cos(I)t −(11
). Also, from equation (11), the amplitude B of the plow 18 is m
-B-(P/ω2)-2MhA ・=(12)
becomes.

What is clear from these equations is that this holds true whether the vibration damping device is an active type or a passive type, so the force p(t) shown in equation (10) is the controlling force in the case of an active type, In the case of a passive type, it can be thought of as a force that is attenuated.

The formula for the above-mentioned principle can be expressed as follows.

■ The force of a damping device that attempts to suppress the vibrations of a structure is obtained by the movement of the mass of the damping device.

- The vibration damping device provides stable vibration by using a force in the opposite direction of the same magnitude as the force that brings people onto the structure as a control force or damping force.

0 Therefore, when the structure vibration damping device of the present invention configured as described above is installed on the top of the structure 1, if a shaking occurs in the structure 1 due to aerodynamic forces, etc., the shaking energy will be reduced. is transmitted to the weight 3, so the weight 3 starts to vibrate a single string with a delay of 90° relative to the shaking of the structure 1. At this time, since the rack 8 provided on the upper surface of the weight 3 and the pinion 11 on the support 9 arranged above the plow 3 are in mesh with each other, the vibration energy of the plow 3 is transferred to the rack 8, The rotational energy is applied to the shaft 9 via the pinion 11. When rotational energy is applied to the shaft 9, the shaft 9
Since the reducer 13 is connected to one end, the reducer 1
3, the rotation of the shaft 9 is decelerated, and at this time, an oil damper 15 is installed on the output shaft of the speed reducer 13.
Since the oil damper 15 or the reducer 13 is
As a result of the rotational energy of the support 9 being attenuated, the swinging of the structure 1 is suppressed.

In other words, in the present invention, the energy of the air flowing into the structure 1 is converted into the kinetic energy of the plow 3, and this is transferred to the rack 8, pinion 11, shaft 9, and reducer 13.
The shaking of the structure 1 can be quickly suppressed by indirect energy consumption in which the energy is consumed by the oil damper 15 via the oil damper 15.

In the above, the damping force applied to the structure 1 can be changed by selecting the vibration stroke and mass of the plow 3. Further, the damping rate can be set to an optimum state by adjusting the pressure of the oil damper 15.

Furthermore, since the plow 3 is designed to vibrate on a single string, it can be easily synchronized with the natural period of the structure 1. However, even if the period is likely to deviate, the plow on the shaft 9 Synchronization can be achieved by the action of the flywheel 16.

In the above embodiment, the oil damper 15 is used as a damping machine for damping the vibration energy of the weight 3, but instead of the oil damper 15, an air damper, a spring type damper, or a hydraulic damper may be used. , it is possible to use an elastic damper, etc., and although the example shows a case where the reducer 13 is used to operate the damper, instead of the reducer 13, a generator, hydraulic motor, water pump, etc. Variable-drive rotating devices such as It goes without saying that each attenuation factor can be changed arbitrarily, and that various other changes can be made without departing from the gist of the present invention.

[Effects of the Invention] As described above, according to the structure vibration damping device of the present invention, the vibration energy of the weight capable of performing single string vibration is transmitted to the shaft via the rack and pinion, and Since it has a structure in which the information is transmitted from the damper to the attenuator, it exhibits the following excellent effects.

(1) Since the shaking energy of the structure can be easily converted into the kinetic energy of the weight, and this can be used as the optimal damping force by the damping machine, the shaking of the horizontal ternary object can be quickly suppressed.

11) Since the damping rate can be arbitrarily changed by adjusting the variable speed reducer A''JJ, the optimum damping can be provided and a large vibration damping effect can be obtained.

(iii) Since the weight uses single string vibration, it is easy to move and can be matched with the period of the structure, and the period can be easily adjusted using the flywheel.

(By selecting the 0 gentlemen's 1~rotor and trade ditch,
The vibration damping effect can be further enhanced.

(V) Weights with high specific gravity (solid: lead, liquid:
Mercury, etc.) can be used, so it is possible to convert it into a single container. Therefore, the installation area of the entire device can be small.

(Since the VD structure is simple, maintenance is easy.

[Brief explanation of drawings]

Fig. 1 is a front view showing an outline of an embodiment of the structure vibration damping device of the present invention, Fig. 2 is a plan view of Fig. 1, 4 Fig. 3 is a side view of Fig. 1, and Fig. 4 is a side view of Fig. 1. An explanatory diagram showing the vibration system of a pendulum. Figure 5 is a diagram showing the 1 quintillion pendulum of the present invention converted into seven columns. Figures 6 and 7 are both schematic diagrams showing examples of conventional devices. . 1... Structure, 3... Weight, 8... Rack, 9...
...shaft, 11... pinion, 13... reduction gear, 15
...Oil damper (dampener).

Claims (2)

[Claims] (1) At the top of the structure, a weight capable of single string vibration is arranged so as to be able to swing freely, and a rack extending in the vibration direction is provided on the top surface of the weight, and a pinion that meshes with the rack is provided. 1. A structure vibration damping device comprising: a reduction gear connected to a shaft having a structure; and a damping device connected to the reduction gear. (2) The structure vibration damping device according to claim (1), wherein a variable drive rotating device is used in place of the speed reducer.