JP3160366B2 - Vertical 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 a vibration damping device which is mounted on a large structure such as a bridge girder of a bridge and controls the vertical vibration of the large structure.

[0002]

2. Description of the Related Art Conventionally, a cantilever type dynamic damper as shown in FIG. 3 has been used as a vertical vibration damper for a large structure such as a beam. That is, in FIG. 3, reference numeral 17 denotes a cantilever installed on the bridge girder 1, the mass 2 is attached to the tip of the cantilever 17, and the fulcrum 16 of the cantilever 17.
A portion close to is supported by the spring 14 and the damper 15.

The reason why the spring 14 is installed at a position closer to the fulcrum 16 than the mounting position of the mass 2 is to reduce the static deflection of the spring 14 and the increase in the dynamic amplitude due to the enlargement of the target structure by the lever ratio. This is because the strength of the spring 14 is desired to be ensured.

[0004]

However, since the conventional vertical vibration damping device is of a cantilever type as described above, as the amplitude increases, the rotational component of the mass motion becomes apparent and the vertical There is a problem in that the damping effect is hindered, and the relationship between the mass and the azimuth of the spring also increases in non-linearity, making tuning of the frequency difficult. In the cantilever type vibration damping device, the above problem is dealt with by increasing the length of the lever, but as a result, there is a disadvantage that the vibration damping device becomes long. The present invention seeks to solve such problems and inconveniences, and uses two sets of diamond-shaped link mechanisms having different sizes to change the mass in two vertical link mechanisms. It is an object of the present invention to provide a vertical vibration damping device that is reduced at a similarity ratio and transmitted to a spring.

[0005]

In order to achieve the above-mentioned object, a vertical vibration damping device according to the present invention comprises four elongated rod members whose respective ends are pivotally connected to each other at a rhombic shape in a side view. And two equal-length short rod members shorter than the above-mentioned rod members each having one end thereof at the upper two of the above-mentioned rod members forming the above-mentioned large link mechanism. A large-sized link mechanism which is pivotally attached to a portion of each of the rod members from each upper axle and which has the other end pivotally attached to each other via a rod and is formed in a rhombic shape in a side view. A mass is attached to a lower axle of the damper, and one end of a damping device attached to the damped body is attached to the rod, while being attached to the damped body by an upper axle of the large link mechanism. It is characterized by having.

[0006]

In the above-described vertical vibration damping device of the present invention, the vertical displacement of the mass is reduced by the similarity ratio of the two rhombic link mechanisms and transmitted to the spring. Further, the displacement of the mass and the spring is only in the vertical direction regardless of the magnitude of the amplitude, and does not result in rotational movement. Further, the relationship between the mass and the displacement of the spring is linear regardless of the magnitude of the amplitude.

[0007]

FIG. 1 is a perspective view of a vertical vibration damping device according to a first embodiment, and FIG. 2 is a perspective view of the vertical vibration damping device according to a second embodiment. It is a side view.

In FIG. 1 showing the first embodiment, reference numeral 3
Indicates a long rod member, and a set of four rod members 3, 3,
Two sets of 3a, 3a are used, and their respective ends are pivotally connected to each other by a lower axle 6, an upper axle 7, and side apexes 8, 9, to form a large link mechanism 10 having a diamond shape in side view. are doing.

[0009] Of the four rod members 3, 3, 3a, 3a constituting the large link mechanism 10, the upper two rod members (these two rod members).
In order to distinguish this rod member from the other rod members, reference numeral 3 is supplemented by an auxiliary code a) 3a is slightly extended, and each end is provided with a pivot 11 or 12 as a side top axis. Short rods (13, 13) are pivotally connected to each other, and the distal ends of both rods 13, 13 are pivotally connected to each other on the rod 5, and the upper axle 7 and Together with the extension of the rod member 3a, a small link mechanism 20 having a diamond shape in a side view is formed.

A mass 2 is attached to the lower axle 6 of the large link mechanism 10.
The upper axle 7 is rotatably mounted on the bridge girder 1. Further, a movable end of a damping device (a device incorporating a spring and a damper) 4 is rotatably mounted on a rod 5 as an upper axle of a small link mechanism 20. The damping device 4 is fixed to the bridge girder 1.

In the above configuration, when the vertical vibration of the bridge girder 1 is transmitted to the vibration damping device, the vertical displacement of the mass 2 is changed by a spring (the spring is incorporated in the damping device 4).
Is transmitted by being reduced by the similarity ratio between the small link mechanism 20 and the large link mechanism 10, so that the amplitude of the spring is smaller than the amplitude of the mass 2 and the strength of the spring is secured. .

Further, since the mass 2 is displaced only in the vertical direction and has no rotational motion, a large vibration damping effect can be obtained as compared with the conventional cantilever type device. Further, since there is no nonlinearity depending on the amplitude of the mass 2, there is an effect that the prediction accuracy of the vibration damping effect of the device is improved.

Next, the second embodiment shown in FIG. 2 differs from that of the first embodiment in that a small link mechanism 20 is formed inside a large link mechanism 10. That is, the short rod members 13, 13 are pivoted inwardly from the upper axle 7 of the rod members 3a, 3a, and the respective distal end portions of the rod members 13, 13 are pivotally coupled to the rod 5 to each other. A small link mechanism 20 having a diamond shape in side view is formed.

The movable end of the damping device 4 is rotatably mounted on the rod 5. In the second embodiment, in addition to the effects of the first embodiment, by forming the small link mechanism 20 inside the large link mechanism 10, the overall height of the vibration damping device is reduced. The effect that can be obtained is obtained.

[0015]

As described above, according to the vertical vibration damping device of the present invention, the following effects and advantages can be obtained. (1) Since the amplitude of the spring is smaller than the amplitude of the mass, the strength of the spring is secured. (2) Since the mass moves only in the vertical direction and does not rotate,
Greater damping effect than cantilever type. (3) Since there is no nonlinearity dependent on the amplitude of the mass, the prediction accuracy of the damping effect is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a vertical vibration damping device according to a first embodiment of the present invention.

FIG. 2 is a side view of a vertical vibration damping device according to a second embodiment of the present invention.

FIG. 3 is a side view of a conventional vertical vibration damper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bridge girder 2 Mass 3 and 3a Long rod member 4 Damping device 5 Rod 6 Lower vertex shaft 7 Upper vertex shaft 10 Large link mechanism 13 Short rod member 20 Small link mechanism

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-29836 (JP, A) JP-A-2-300540 (JP, A) JP-A-3-76013 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) F16F 15/02-15/08 E01D 1/00 E04H 9/02 341

Claims (1)

(57) [Claims] 1. A large link mechanism having four long rod members pivotally connected at their respective ends to each other to form a rhombus in a side view, and two equal length short members shorter than the rod members. Of the upper two rod members of the above-mentioned rod members forming the large-sized link mechanism are pivotally connected to the respective upper ends of the upper two rod members, and the other end portions thereof are connected to each other. A small link mechanism pivotally connected to each other via a rod and formed in a rhombus shape when viewed from the side, a mass is provided on the lower axle of the large link mechanism and A vertical vibration damping device, wherein movable end portions are respectively attached to the whole device so that an upper axle of the large-sized link mechanism can be attached to a damped body.