JPH0330017B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a vibration damping device for a column for damping the vibration of a vertically supported column in the form of an elongated rod.

(Prior Art) Columns, which are generally vertically supported elongated rods, vibrate when external forces such as earthquakes are applied to them, which can lead to accidents such as fatigue, breakage, and contact of the columns. As a damping device for such vibrations, a flange-shaped support is installed at the part of the column where the vibration is large, and a ring-shaped weight is placed directly on the flange-shaped support, or a device is installed in which a ring-shaped weight is placed directly on the flange-shaped support, or a coil spring is placed on the support. A device in which a ring-shaped weight is indirectly provided is known.
Figures 5 and 6 show the latter of such conventional vibration damping devices for column bodies, in which a column 1 is fixed at one end by a fixed wall 2, and the other end is a free end and is vertically connected. Supported. A flange-shaped support 3 is attached to the free end side of the column 1, and a coil spring 4 is installed on this support 3. Further, in FIG. 5, a ring-shaped weight 5 is placed on the upper end of the coil spring 4, and in FIG. 6, a ring-shaped weight 5 is attached to the lower end of the coil spring 4. In the vibration damping device configured in this manner, when the column 1 vibrates due to an external force such as an earthquake, the free end of the column 1 swings significantly, and the weight 5 also vibrates accordingly. The phase difference between the vibrations of the column 1 and the weight 5 causes friction and collision between them, and the kinetic energy due to the vibration of the column 1 and the weight 5 is lost by the amount of energy lost due to this friction and collision. However, this suppresses the vibration of the column 1.

However, the conventional vibration damping device having the above structure has the following problems.

In other words, for a large amplitude of the column 1, the mass of the weight 5 is large, and the wider the distance between the column 1 and the weight 5, the better the vibration damping effect. If the gap is too wide, collision between the column 1 and the weight 5 cannot occur, and a sufficient vibration damping effect cannot be obtained. As described above, it is difficult to sufficiently damp both the large and small amplitudes of the column 1 using the conventional damping device shown in FIGS. 5 and 6.

(Problems to be Solved by the Invention) As mentioned above, collision between the weight and the column cannot occur for minute amplitudes less than 〓 between the weight and the column, and residual minute vibrations cannot be suppressed. Can not.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a vibration damping device for a column body that can effectively damp damp both large amplitudes and small residual widths.

[Structure of the invention]

(Means for Solving the Problems) A vibration damping device for a columnar body according to the present invention includes a columnar body that is vertically supported and formed in multiple stages having a plurality of different diameter portions, and a flange provided on the columnar body. a ring-shaped first weight placed on or supported by the support and provided concentrically with the column; and at least one ring-shaped weight placed on or supported by the first weight. The first and second weights each correspond to a different diameter portion of the column, and the distance between the inner circumferential wall of the first and second weights and the outer circumferential wall of the column is such that are arranged differently.

(Function) Columns that are fixed at one or both ends will vibrate when external forces such as earthquakes are applied to them. At this time, with the column vibration damping device of the present invention, during the first large amplitude, the weight that is placed corresponding to the small diameter part of the column and the distance between it and the outer peripheral wall of the column is large. collide with Due to this collision of the weights, the vibration energy of the column quickly disappears, and the amplitude of the column's vibration becomes smaller. When the amplitude becomes small, a weight arranged corresponding to the large diameter portion of the column and having a small distance from the outer circumferential wall of the column collides with the column.

In this way, by forming the diameter of the column in multiple stages and making the distance between the column and the weight different, it is possible to exert an effective damping effect on both large and small amplitudes.

In addition, during the assembly process, by inserting the ring-shaped weight from the small diameter side of the column, it is possible to assemble with a large distance between the weight and the column, making it easy to assemble even long columns. I can do it.

(Embodiments) Embodiments of the present invention will be described below with reference to the drawings, but the same reference numerals will be given to the same or equivalent parts as in FIGS. 5 and 6, and detailed explanation thereof will be omitted.
Furthermore, the fixed wall 2 that vertically supports the column 1 is not shown.

FIG. 1 shows a first embodiment, in which a column 1 is formed by coaxially connecting or integrally forming a diameter portion 1a and a diameter portion 1b, each having a different diameter. >diameter portion 1b. A support 3 is attached to the diameter portion 1b of such a column 1, a coil spring 4a is provided on this support 3, and a weight 5a is installed on this coil spring 4a. Furthermore, a coil spring 4b is provided on this weight 5a, and the weight 5b is placed on top of this.

Here, the inner diameters of the weights 5a and 5b are approximately equal, but the weight of the weights 5a is greater.

These weights 5a and 5b are arranged opposite to each other at the diameter portions 1b and 1a of the columnar body 1, respectively. Therefore, the weight 5a faces the diameter portion 1b, and the distance between the two is
G ₁ , and the weight 5b faces the diameter portion 1a, and the distance therebetween is G ₂ . Then, the diameter portion 1a of the columnar body 1,
Since the size of the weight 1b is such that the diameter portion 1a is greater than the diameter portion 1b, and the inner circumferential diameters of the weights _5a and 5b are approximately equal, the relationship between them is _{G 1 and} G ₂ .

With this configuration, when the fixed wall is vibrated due to an earthquake or the like, the weight 5a and the diameter portion 1b of the column 1 collide with each other for a relatively large amplitude during the excitation, reducing the vibration damping effect. Demonstrate. At this time, the weight 5a and the diameter part 1
During b 〓 The larger G ₁ is, the greater the damping effect is for large amplitudes.

The weight 5b and the diameter portion 1
a collides to exert a damping effect, and the residual minute amplitude of the column 1 can also be suppressed well.

FIG. 2 shows a second embodiment, and this embodiment differs from the first embodiment in that the weight 5a
The reason is that the weight 5b is directly placed on top of the holder without using a coil spring or the like. With this configuration, especially when the residual amplitude is small, the friction generated between the weights 5a and 5b also serves as a damper, increasing the vibration damping effect. Furthermore, friction between the weights 5a and 5b naturally occurs even when the amplitude is large.

Furthermore, the smaller the gap 〓G ₂ is, the more quickly the residual minute amplitude can be suppressed.

3 and 4 are the third and fourth embodiments of the present invention, respectively.
This is an example of the following. The difference between these embodiments from the first and second embodiments is that the weights 5a,
5b is suspended from the support 3, and the third embodiment corresponds to the first embodiment and the fourth embodiment corresponds to the second embodiment.
By making the diameter portions 1a and 1b of the column 1 different at the locations corresponding to the weights 5a and 5b, an excellent vibration damping effect can be achieved for both large and small amplitudes of the column 1, similar to the first embodiment described above. can demonstrate.

Furthermore, the smaller the gap 〓G ₂ is, the more quickly the residual minute amplitude can be suppressed. Furthermore, some columnar bodies that require such a vibration damping device are used in special environments and conditions, and it is desirable to quickly damp the residual minute amplitude. Therefore, the distance between the column and the weight must be quite small.

When considering the assembly process for installing such a vibration damping device for a pillar body, a process of arranging a ring-shaped weight concentrically around the outer periphery of the pillar body is necessarily required. Usually, a ring-shaped weight is inserted into the column until a predetermined position, but if the distance between the column and the ring-shaped weight is too small, the insertion process becomes complicated. In particular, if the gap is small and the insertion distance is long, there may be cases where insertion is impossible.

Therefore, if the diameters of the columns are made different as in the present invention, the weight can be inserted from the narrow diameter part until the inner circumferential wall of one of the weights faces the diameter of the thick part of the column. If so, between the column and the weight
The column can be inserted easily while remaining large, and the distance between the diameter of the thick part of the column and the weight facing it can be made sufficiently small, and an effective vibration damping effect can be obtained.

In addition, in all of the above-mentioned embodiments, the small diameter 1b of the column 1 is made to correspond to the large weight 5a to particularly enhance the damping effect at the time of large amplitude, but the present invention is not limited to this. .

Further, the number of weights is not limited to two, but the diameter of the column may be varied in three or more steps, and three or more weights may be arranged correspondingly to enhance the damping effect.

Although the embodiments of the present invention have been described with reference to the case where only one end of the column is fixed to the fixed wall, the present invention can also be implemented in the same way in the case where both ends of the column are respectively fixed to the fixed wall.

〔Effect of the invention〕

As is clear from the above description, by using the vibration damping device for a columnar body according to the present invention, it is possible to effectively damp both large and small amplitudes of vibration of a columnar body, and assembly becomes easy.

[Brief explanation of drawings]

1 to 4 are partial cross-sectional side views showing first to fourth embodiments of the vibration damping device for a columnar body according to the present invention, and FIGS. 5 and 6 are side views of a conventional columnar vibration damping device. FIG. 2 is a partially cross-sectional side view showing the shaking device. DESCRIPTION OF SYMBOLS 1... Column body, 1a... 1st diameter part, 1b... 2nd diameter part, 3... Support tool, 4... Coil spring (spring),
5a, 5b...Weight.

Claims (1)

[Scope of Claims] 1. A flange-shaped support provided on a column formed in multiple stages having a plurality of different diameters and installed in a vertically supported manner; A ring-shaped first weight provided concentrically with the column; and at least one ring-shaped second weight placed on or supported by the first weight. In the vibration damping device, the first and second weights are made to correspond to different diameter portions of the columnar body, and the inner circumferential walls of the first and second weights are connected to the outer circumferential wall of the columnar body. A vibration damping device for a column body, characterized in that the spaces between the columns are arranged differently. 2. The vibration damping device for a pillar body according to claim 1, wherein the first weight is supported by the support via an elastic body. 3. The vibration damping device for a pillar body according to claim 1, wherein the second weight is supported by the first weight via an elastic body. 4. Claim 1, characterized in that the weight of the weight corresponding to the large diameter section of the multi-stage diameter section of the column is smaller than the weight of the weight corresponding to the small diameter section. The vibration damping device for the column body described.