JP2553180Y2 - Inverted pendulum type vibration damping device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverted pendulum type vibration damping device.

[0002]

2. Description of the Related Art Architectural structures such as bridges and high-rise buildings are becoming longer and larger. In order to suppress the vibration of these structures due to the wind and the vibration due to the earthquake, a vibration damping device is receiving attention. Examples of the vibration damping device include a pendulum type vibration damping device and a spring-mass vibration damping device. Among these, the basic structure of the pendulum type vibration damping device has a structure as shown in FIG. 6, and an arm 1 having a length L is suspended in a structure j via a support shaft k, and is provided below the arm l. A weight m is attached, and a vibration damping force is generated on the structure j by the swing of the weight m. In general, it is necessary for the damping device to match the natural period with the object to be damped, but large building structures such as bridges and buildings have a very long natural period. Must be very long in order to match the length of the arm c, and the size of the arm c must be very large.

FIG. 7 shows a spring-mass vibration damping device including a weight n having a mass m and a spring p. In this device, the weight n reciprocates right and left to generate a vibration damping force on the structure j. However, in order to use this device for a long period, a spring q which is very soft and has a large amount of expansion and contraction is required, and there is a problem in feasibility. By the way,
Now, consider a case where a vibration damping device having a mass of 5 t in weight and a natural frequency of 0.1 Hz is manufactured, with reference to FIGS. 1) In the case of the conventional pendulum type shown in FIG.

[0004]

(Equation 1)

2) In the case of the conventional spring-mass system shown in FIG.

[0006]

(Equation 2)

[0007] A very soft spring is needed, which is only feasible.

FIG. 2 shows an inverted pendulum type vibration damping device of the pendulum type vibration damping device. This is the length L pivoted at the lower end with the pin a.
Arm b and a weight c of mass M ₀ fixed to the top of the arm b
When, weight c and the structure d, spring e spring constant K ₀ is attached between d, and consist e. Therefore, in order to put this inverted pendulum type vibration damping device to practical use, the arm b must have a considerable length L so that the weight c moves linearly. Therefore, it is difficult to make the inverted pendulum type vibration damping device compact.

Japanese Unexamined Patent Publication (Kokai) No. 2-102945 (see FIG. 5) discloses a downwardly protruding arc-shaped weight g supported above a structure d by a support roller f so as to perform single-string vibration. A rack h for applying a driving force to the arc-shaped weight g, a driving device including a pinion i meshing with the rack h, and a swing detection sensor (not shown) for detecting the swing of the structure d. There is disclosed a structural vibration damping device including a phase control device that sends a drive command to a drive device by controlling the phase of the signal. In the structure as shown in FIG. 5, in order to increase (increase) the natural period, the curvature of the arc-shaped weight g must be increased, which is a large change in design. In addition, even if a spring is added, the natural period becomes smaller. Therefore, this structure can cope only with vibration damping of the structure d alone, and has a drawback that is not applicable to a wide range of applications.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inverted pendulum type vibration damping device which is extremely compact and can be applied to various structures having different natural periods without a large design change. .

[0011]

Means for Solving the Problems A weight 1 movably supported on a structure 3 by a plurality of rollers 4 is connected to the structure 3 via a horizontally extending spring 2 on both sides of the weight 1. A curvature is given to the support surface 5 by the roller 4 to form a downward concave surface.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG.
It is constituted by a spring 2 having a spring constant K and a plurality of rollers 4 provided on the structure 3. The support surface 5 of the weight 1 by the roller 4 has a radius L of curvature. Therefore, the spring 2
, The weight 1 vibrates on an arc having a radius L. This radius L is the arm length L of the inverted pendulum shown in FIG.
And performs the same operation as the inverted pendulum. One or more springs 2 are used and are connected between the weight 1 and the structure 3. Further, a plurality of rollers 4 are provided via the weight 1 and the structure 3, and a plurality of rollers 4 are used. Thus, the arm length L required in the conventional inverted pendulum is set to be
By making the support surface 5 have a curvature by the rubber 4, the support surface 5 can be made compact.

The damping action of the present invention will be described with reference to FIG. A weight 1 having a mass M and a spring 2 having a spring constant K / 2
2 and an arm having a length L. In a range where the weight 1 linearly moves, if the counterclockwise direction is defined as positive, the restoring force in the tangential direction is given by Mg sin θ−KL θ (Mg sin θ: M Restoring force, KL
θ: restoring force by spring). Thus, the equation of motion becomes:

[0014]

(Equation 3)

[0015]

(Equation 4)

[0016]

(Equation 5)

In order to extend the natural period of the pendulum system, it is necessary to increase the length L of the arm. For example, even if a spring is attached to the mass, the natural period T ₂ becomes smaller as is apparent from Equation (5). I will. On the other hand, as is apparent from Expression 3, it is understood that the inverted pendulum type can extend the natural period not only by the arm length but also by a spring.

[0018]

According to the present invention, the support surface 5 of the weight 1 is provided with a curvature, and the support surface 5 is received by the roller 4 provided on the side of the building 3, so that it works similarly to the inverted pendulum as shown in FIG. As a result, the length L of the arm can be reduced, and the whole can be made compact. Further, the present invention can be applied to vibration suppression of various long-period structures by a simple design change simply by replacing a spring.

[Brief description of the drawings]

FIG. 1 shows the vibration damping device of the present invention.

FIG. 2 is an inverted pendulum damping device.

FIG. 3 is a principle diagram of an inverted pendulum type vibration damping device.

FIG. 4 is a principle view of a vibration damping device in which a spring is attached to a simple pendulum.

FIG. 5 shows a vibration damping device for a structure using a known arc-shaped weight.

FIG. 6 shows a known pendulum type vibration damping device.

FIG. 7 shows a known spring-mass type vibration damping device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Weight 2 Spring 3 Structure 4 Roller 5 Support surface

Claims (1)

(57) [Scope of request for utility model registration] A weight (1) movably supported by a plurality of rollers (4) on a structure (3) is connected to the structure (3) via springs (2) extending horizontally on both sides. An inverted pendulum type vibration damping device characterized in that a support surface (5) of the weight (1) by a roller (4) is provided with a curvature so as to have a downward concave surface.