JP2501341Y2 - Gravity restoration type dynamic vibration absorber - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a gravity-restoring dynamic vibration absorber used for vibration control of building structures, bridges, towers, and the like.

[Conventional technology]

At present, as buildings are becoming taller and more intelligent, vibration prevention against earthquakes and winds has been used to improve the strength of buildings and the performance of their equipment, and to provide a better living environment. It is more important than ever. In particular, in vibration control of a high-rise building, long-period vibration is targeted, and as a conventional technique, a pendulum type dynamic vibration reducer is known.

The pendulum type dynamic vibration reducer, as shown in FIG.
It is used for high-rise buildings to perform passive vibration control, and it does not require a drive device to drive the pendulum.
As shown in the figure, the above-mentioned pendulum type which is used for active vibration control reciprocates a pendulum by using an actuator, and the inertial reaction force is transmitted to a building as a vibration control force for vibration control.

[Problems to be solved by the device]

The principle of using a pendulum as a dynamic vibration absorber is to suppress the vibration of the building itself by absorbing the external force energy that the building receives from an earthquake or wind as the kinetic energy of the pendulum. It is realized by matching. However, in the case of a high-rise building, its natural period is long and the pendulum length needs to be long, which raises the problem that the height of the device becomes high and the size becomes large. Further, in the case of the active system using the actuator, the pendulum system is also used, which has the above problem.

The present invention has been proposed in view of such circumstances,
An object of the present invention is to provide a gravitational restoration type dynamic vibration absorber having a compact structure and exhibiting a long period and a large damping force.

[Means for solving the problem]

To this end, the present invention is fixed on the floor of the same structure at regular intervals in the front-rear direction, the left and right ends are symmetrically high, the central part is low, and the upper part is smoothly curved upward. A parallel guide rail member having a parallel concave curved arc guide surface, and a large-diameter cylindrical body in the front-rear direction whose axial length is slightly shorter than the front-rear clearance of the parallel concave curved arc-shaped guide surface, and its front and rear ends. And a movable rotary weight supported rotatably along the pair of front and rear parallel concave arc-shaped guide surfaces by relatively small diameter equal-diameter shaft necks coaxially protruding from each other. Characterize.

[Operation] According to such a configuration, since the movable weight is reciprocally rolled on the arc-shaped guide rail, a suspension support portion is not required unlike a pendulum, the device height is low, and the device is compact. Can be In the case of the conventional pendulum type, the kinetic energy of the weight is only the translational kinetic energy, but in the case of the present invention, the rotational energy at the time of rotation is added to the translational kinetic energy even if the weight of the same weight is used. Compared with the pendulum method, the energy absorption capability of the dynamic vibration absorber is greatly improved.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing the principle, FIG. 2 is a sectional view taken along line II-II of FIG.
FIG. 3 is a side view of the rotary body of FIG. 1 in a rotational vibration state, FIG. 4 is a side view of a pendulum having a pendulum length R-r, and FIG. 5 is of the structure of FIG. It is a side view similarly showing the case where an actuator is attached.

First, in FIGS. 1 to 3, the weight is W and the rotation axis thereof is
On a parallel arc-shaped guide rail 1 in which a shaft neck 3 having both ends r of a laterally placed short cylindrical weight (hereinafter referred to as a rotatable weight) 2 having an inertia moment around 18 is concavely curved upward with the same radius of curvature R. Put on.

Now, assuming that the rotatable weight 2 does not slip with respect to the guide rail 1, as shown in FIG.
The maximum value T _max of the kinetic energy is represented by the equation (1), where θ is the swing angle of.

Here, the first term on the right side of the equation (1) is the translational kinetic energy of the rotor 2, the second term is the rotational energy of the rotor 2,
g indicates gravitational acceleration.

As is clear from the equation, compared with the case of the normal pendulum motion shown in FIG. 4 (weight of weight = W, pendulum length = R-r), the kinetic energy is equivalent to the rotational energy in this device. It turns out to be great.

An approximate expression of the reciprocating angular frequency ωo can be expressed by Expression (2).

Now, assuming that the inertia moment I is zero, equation (2) becomes equation (3).

Therefore, the rotatable weight 2 vibrates on the guide rail at an angular frequency that matches the angular frequency of the normal pendulum motion with the pendulum length R-r shown in FIG.

Further, as can be seen from the equation (2), it can be understood that by increasing the inertia moment I, the ωo can be reduced as shown in the equation (4), that is, the period can be lengthened.

Here, D is the diameter of the rotatable weight 2, and even if W is constant according to the equation (4), it is possible to increase I and decrease ωo by increasing D. I understand.

Assuming that there is no slippage in the rotatable weight 2 as the above-mentioned assumption, this is because the shaft neck 3 of the rotatable weight 2 and the arc-shaped guide rail 1 are gear-cut like the relationship between the pinion and the rack. It can be realized by doing so.

It should be noted that, as shown in FIG. 5, the vibration damper shown in FIG. 3 has a guide groove 8 for slidingly guiding the vertical movement of the rotatable weight 2 associated with the swing movement of the shaft neck 3. A device 9 may be provided, a support surface 10 may be provided so that the guide device 9 can move in the left-right direction, and an actuator 11 that reciprocates the guide device 9 in the left-right direction can be provided.

Here, the actuator 11 is a fixed support portion 12 of the building 13.
When the actuator 11 is reciprocally driven in the left-right direction, the rollable weight 2 makes a swinging motion while rolling along the arc-shaped guide rail 1 via the guide device 9. As an inertial reaction force, actuator 11 can transmit damping force to building 13 through fixed support 12.

[Effect of device]

 According to such a device, the following effects can be obtained.

(1) Since the method of rolling and reciprocating the rollable weight on the arc-shaped guide rail 1, a suspension supporting portion such as a pendulum is not required, and the device becomes compact.

(2) Since the rotational energy is added to the translational kinetic energy as the kinetic energy of the rotatable weight, when compared with the pendulum type,
The energy absorption capacity per weight of the weight increases, and the weight of the vibration damping device can be reduced.

(3) By increasing the moment of inertia I of the rotatable weight, the vibration damping ability of the dynamic vibration absorber against long-period vibration is improved.

In short, according to the present invention, fixed to the floor of the same structure at regular intervals in the front-rear direction, the left and right ends are symmetrically high, the central part is low and the upper part is smoothly curved upward, and a pair of front and rear parts are appropriately spaced. A parallel guide rail member having a parallel concave curved arc-shaped guide surface, and a large-diameter cylindrical body in the front-back direction whose axial length is slightly shorter than the front-rear clearance of the parallel concave curved arc-shaped guide surface. And a movable rotary weight supported rotatably along the pair of front and rear parallel concave curved arc-shaped guide surfaces by means of relatively small-diameter equal-diameter shaft necks that are coaxially projected at the ends. As a result, a gravity restoring type dynamic vibration absorber that exhibits a long period and a large damping force with a compact structure is obtained. Therefore, the present invention is extremely useful industrially.

[Brief description of drawings]

1 is a side view showing the principle of the vibration damping device of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 shows a case where the rotating body of FIG. 1 is in a rotational vibration state. Similarly, FIG. 4 is a side view showing a pendulum having a pendulum length R-r, and FIG. 5 is a side view showing a case where an actuator is added to the structure of FIG. FIG. 6 is a vertical cross-sectional view showing a building equipped with a known pendulum type dynamic vibration absorber, and FIG. 7 is a side view showing a case where the pendulum of FIG. 6 is subjected to active vibration control. 1 ... Arc-shaped guide rail, 2 ... Short cylindrical weight (rotatable weight), 3 ... Shaft neck, 4 ... Center of radius of curvature R, 8 ...
… Guide groove, 9 …… Guide device, 10 …… Bearing surface, 11 ……
Actuator, 12 …… Fixed support, 13 …… Building, 18
…… Rotary axis, 19 …… Center of gravity of the rotatable weight,

Claims (1)

(57) [Scope of utility model registration request] 1. A pair of front and rear parallels, which are fixed to the floor of the same structure at regular intervals in the front-rear direction, have left and right ends symmetrically high, and have a low center and are smoothly concave upwards. A parallel guide rail member having a concave curved arc guide surface, and a large-diameter cylindrical body in the front-rear direction whose axial length is slightly shorter than the clearance in the front-rear direction of the parallel concave arc-shaped guide surface at the front and rear ends thereof. A movable rotary weight supported by a pair of front and rear parallel concave curved arc-shaped guide surfaces rotatably supported by relatively small-diameter equal-diameter shaft necks coaxially protruding from each other. A gravitational restoration type dynamic vibration absorber.