JPS6268976A - Vibration preventing apparatus of cylindrical structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vibration damping device for cylindrical M4 structures.

Prior Art It is well known that cylindrical structures such as free-standing chimneys generate Karman vortex excitation when subjected to external forces such as relatively low wind speeds. As such an envelope, various vibration damping devices have been devised that apply the principle of a so-called dynamic damper.

Problems to be Solved by the Invention Conventional allocating devices have been designed to accommodate vibrations in the principal possible directions of the structure in which they are installed. However, cylindrical structures have the problem of having to deal with vibrations in all directions.

The present invention solves the above-mentioned problems and aims to provide a vibration prevention device for a cylindrical M4 structure that can cope with vibrations in all directions.

Means for Solving the Problems In order to solve the above problems, the present invention provides a ring-shaped ff! near the top of the cylindrical structure. Hanging the weight and hanging it over the moon, said! 1! The dynamic damper is supplemented by connecting a damper and a coil spring to the weight via a wire rope so as to produce C in accordance with the movement of the weight in any direction.

Effect In the above configuration, a weight suspended via a hanging material,
In order to make the natural frequency of the secondary vibration system composed of a damper and a coil spring connected to this weight via a wire rope equal to or close to the natural vibration vJ number of the cylindrical structure which is the main vibration system, Adjust the length of the hanging material or the spring constant of the coil spring.

If the cylindrical structure vibrates in this state, the circular vibrations of the secondary vibration system and the main vibration system will repel each other and reduce the vibration amplitude of the cylinder@pickle.Moreover, the damper and coil spring are wire rope Since the dynamic damper is configured to operate according to the movement of the weight in any direction through the damper, it can always be damped in the same way no matter which direction the cylindrical M4 structure vibrates.

EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings. In FIG. 1, reference numeral 1 denotes a cylindrical structure main body, and at least three mounting beams 2 are radially provided at equal intervals on the outer periphery near the top. Reference numeral 3 designates ring-shaped weights arranged around the periphery of the cylindrical M44 object 1 at appropriate intervals.

As shown in detail in FIG. 2, the ring-shaped weight 3 is attached to the tip of the beam 2 with a hanging member 4 suspended in the pendulum manner, and the upper and lower ends of this hanging member 4 are connected with universal pins. 6
a and 6b are incorporated, and the weight 3 swings smoothly in all directions! 111V is possible. Reference numeral 5 indicates a turnbuckle for adjusting the length of the hanging member 4. Reference numeral 7 indicates a turnbuckle for adjusting the length of the hanging member 4. Reference numeral 7 indicates a coil spring 8 weighted near the root of the mounting beam 2. A wire rope 9 is connected between the lower end of the damper 8 and the ring-shaped stack 3 via a pulley 114i10.

The pulley mechanism 10 has a horizontal pin 11.1 as shown in FIG.
Two pulleys 13.13 are rotatably attached to the arm 12 via the arm 12 so that their outer peripheral surfaces face each other, and the other end of the arm 12 is fixed to the cylindrical structure main body 1, and the other end of the arm 12 is connected to a vertical pin 14. The arm attachment that supports the arm 12 through the arm and allows the arm 12 to freely rotate in the horizontal direction is made of a metal fitting 15, and the wire row 19 is guided to the ring-shaped weight side through between the pulleys 13 and 13.

For the damper 8, use an oil damper or an air damper whose damping coefficient can be finely adjusted, and set f to maximize the damping effect of the dynamic damper.
The magnitude of f1fi and the damping coefficient are determined theoretically in advance.

Next, the effect of the above configuration will be explained. The sub-vibration system formed by the damper 8, coil spring 7, wire row 19, hanging material 4, and ring-shaped weight 3 is called a dynamic damper, and the natural frequency of this dynamic damper is determined by the cylindrical If4 structure of the main vibration system. In order to match or approach the natural frequency of the real body, adjust the length of the hanging member 4 to wJ using the turnbuckle 5, reduce the spring constant of the coil spring 7 so that pendulum vibration is the main component, or reduce the spring constant of the coil spring 7. The spring constant is selected as the main component, and the material 4 has the role of υ1 to hang the ring-shaped weight 3, so that a3 <.

If the cylinder @ pickle body 1 vibrates in this state, the circle Z M4
The circular vibrations of the W object body 1 and the dynamic damper repel each other, and the vibration amplitude of the cylinder @ pickle body 1 decreases 1
Jru. At this time, the wire rope 9 of the dynamic damper is connected to a pulley machine @10, that is, the wire rope 9 is held between the pulleys 13 of 211N, and the arm 12 is rotatable in the horizontal direction, so that it is protected against vibrations in all directions. It is possible to follow the movement of the ring-shaped weight 3.

Effects of the Invention As described above, according to the present invention, vibrations of a cylindrical structure main body in any direction can be mechanically suppressed by a dynamic damper composed of a pendulum-type weight, a damper, a coil spring, and a wire rope. I can do it.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view showing an embodiment of the present invention, FIG. 2 is a detailed view showing the configuration of a dynamic damper, and FIG. 3 is an enlarged perspective view of a pulley mechanism. 1...Cylindrical structure body, 2...Beam for installation, 3...
- Weight, 4... Hanging material, 5... Turnbuckle, 7
...Coil spring, 8...Damper, 9...
Wire rope, 10...Pulley mechanism, 11...Horizontal pin, 12...Arm, 13...Pulley, 14...Vertical pin, 15...Arm installation by metal agent Mori
Ki Yoshi Buddhist painting 7 figure β-damper/a-saito figure 2 figure 3 〆L-7 to child pin 12- arm

Claims (1)

[Claims] 1. A ring-shaped weight is suspended near the top of the cylindrical structure via a hanging material, and a damper and a coil spring are attached to the weight via a wire rope so as to operate according to the movement of the weight in any direction. A vibration prevention device for a cylindrical structure, characterized in that a dynamic damper is configured by connecting to a cylindrical structure.