JPH0715852Y2 - Relative amplitude vibration damping device for cables arranged in parallel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a relative amplitude vibration damping device installed between cables arranged in parallel in a cable-stayed bridge.

(Prior Art) In this type of conventional vibration damping device, mounting brackets (b) and (b) are attached to cables (a) and (a) arranged in parallel as shown in FIG. An oil damper (c) interposed between and connected to the metal fittings (b) and (b) absorbs and damps relative vibrations of the cables (a) and (a), or is shown in place of the oil damper (c). It was damped by using a friction plate or the like.

(Problems to be solved by the invention) However, in a vibration damping mechanism in which relative vibration is directly absorbed and attenuated by an oil damper or a friction plate, when the relative amplitude is very small, there may be play in the mounting part, dead zones of the oil damper, etc. There are problems such as difficulty in obtaining the damping effect.

The present invention was developed to deal with such a problem, and its purpose is to expand the relative vibration between two points and to absorb the expanded relative amplitude by a vibration damping mechanism. Another object of the present invention is to provide a vibration damping device with a relative amplitude enlarging mechanism that improves the vibration damping performance and reliability of relative vibration by dampening it.

(Means for Solving the Problem) The configuration of the present invention for achieving the above object will be described with reference to FIGS. 1 to 3 corresponding to the embodiment. Cables (a) (a) arranged in parallel are described. ) Each mounting bracket (1)
(1) is attached to the pair of mounting metal fittings (1) and (1), and both ends of four arms are rotatably connected to each other to form a square arm. ) Is pivotally attached at one of the opposing connecting portions of the above), and the vibration damping mechanism (10) is attached between the other opposing connecting portions of the arm (50).

(Operation) And the present invention uses the above-mentioned means for the cables (a) (a)
Of the square arm is expanded by the amplitude expanding arm (50) attached to the cable at one of the connecting portions of the square arm facing each other, and the expanded relative amplitude is connected to the other connecting portion of the other arm (50). Is absorbed by the vibration damping mechanism (10) mounted on the machine, damped and damped, eliminating the effects of rattling of the mounting section and the dead zone of the vibration damping mechanism, and excellent vibration damping performance and reliability even for minute relative amplitudes. can get.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. (a) and (a) show cables arranged in parallel in a bridge. A square arm in which both ends of four arms (5), (5), (5), and (5) are rotatably connected to the fittings (1) and (1) that are respectively fitted through a shaft (4). The amplitude-enlarging arm (50) is pivotally attached at one of the connecting portions of the arm (50) facing each other, and the pivot shaft (7) is provided between the other connecting portions of the arm (50) facing each other.
The vibration damping mechanism (10) was attached via (7).

FIG. 3 shows another embodiment of the present invention. The mounting bracket (1) is provided with a rubber plate (2) on the inner surface side thereof to prevent damage to the cable (a) and the like, and to secure the nebolts and nuts (3). Is detachably fitted and fixed to the cable (a), and the amplitude expanding arm (50) is horizontally attached to the shaft (4) on the side of the mounting bracket (1) so that the center between the cables (a) and (a) is horizontal. It is attached at an angle θ ₁ with respect to the connected horizontal axis f.

The embodiment of the present invention has the above-mentioned structure, and its operation will be described in detail. For example, as shown in FIGS. 1 and 2, the main tower (d) and girder (e) of the bridge are extended in parallel. The vibration damping device (30) with the relative amplitude expanding mechanism is interposed and connected between the installed cables (a) and (a).

The operation of this embodiment will be described with reference to FIGS.

When axes (4) and (4) are points A and C and pivot axes (7) and (7) are points B and D, when points A and C move to A'and C ', respectively, points B and D are also Moving to B ′ and D ′ respectively, the moving amount of the point A and the moving amount of the point B at this time are AD (AB) = 1, AA ′ = Δl _A , BB ′ = Δl _B , AO ² + BO ² = l ² (constant) ……… (1) (AO + Δl _A ) ² + (BO−Δl _B ) ² = l ² ……… (2), and from equations (1) and (2), AO ² ＋ 2AO ・ Δl _A ＋ Δl _A ² ＋ BO ² −2BO ・ Δl _B ＋ Δl _B ² ＝ AO ²
＋ BO ² Δl _A ² ＋ 2AO ・ Δl _A + Δl _B −2BO ・ Δl _B ＝ O Δl _A ² , Δl _B ² <<＜ 2AO ・ Δl _A , 2BO ・ Δl _B Therefore, Δl
_{Since A} ² and Δl _B ² can be ignored, the following equation holds.

From 2AO ・ Δl _A = 2BO ・ Δl _B When AO> BO (that is, θ ₂ <45 °), Δl _B > Δl _{A and the} amplitude is expanded.

Further, in order to increase the sensitivity with respect to the vibration in the vertical direction, when the angle θ ₁ is provided with respect to the horizontal verse f that horizontally connects the centers of the cables as shown in FIG. The amplitude expansion ratio is the ratio of the device expansion ratio α × angle θ ₁ sin θ ₁ = αsi
nθ _{1 Further} , α × cos θ _{1 in the} horizontal direction. Needless to say, if θ ₁ = 45 °, the horizontal and vertical enlargement ratios are equal.

As described above, the relative amplitude is greatly expanded by the amplitude expanding arm (5), and the angle θ ₁ is provided with respect to the horizontal axis f connecting the amplitude expanding arm (5) between the centers of the cables. Both horizontal and vertical vibrations can be controlled together.

(Effect of the Invention) As described above, according to the present invention, a pair of mounting brackets (1) (1) mounted on the cables (a) (a) arranged in parallel
In this case, a square arm amplitude-enhancing arm (50) is axially attached to one of the opposite connecting portions of the arm (50), and a vibration damping mechanism is provided between the other opposite connecting portions of the arm (50). (1
0) is attached, the vibration of the cables (a) and (a) is magnified and transmitted to the connecting part of the amplitude expanding arm (50), and the expanded amplitude at the connecting part is reduced by the vibration damping mechanism (10). Since it is absorbed and dampened by, it eliminates the effects of mounting rattling at the time of minute amplitude, dead zone of the vibration damping mechanism, etc., and significantly improves the vibration damping performance and reliability of relative vibration. Even in the case of vibrating, there is an effect that it is possible to suppress vibrations in both directions by mounting each amplitude enlarging arm at an angle with respect to a horizontal axis that connects the center of the cable horizontally.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a perspective view showing an application example, FIG. 3 is a side view showing another embodiment of the present invention, and FIG. Principle diagram, FIG. 5 is a principle diagram of FIG. 3, and FIG. 6 is a perspective view of a conventional example. (A) …… Cable, (1) …… Mounting bracket, (50) ……
Amplitude expansion arm, (10) …… Vibration damping mechanism.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Haruo Takano Inventor Haruo Takano 2-25 Masago-machi, Naka-ku, Yokohama-shi, Kanagawa Metropolitan Expressway Public Corporation Kanagawa Construction Bureau (72) Hiroshi Kuroda 12 Nishiki-cho, Naka-ku, Yokohama Heavy Industries Co., Ltd.Yokohama Research Institute (72) Inventor Kei Katsuura 12 Nishiki-cho, Naka-ku, Yokohama-shi Kanagawa Mitsubishi Heavy Industries Ltd. Yokohama Research Institute (72) Katsura Miyake 12 Nishiki-cho, Naka-ku, Yokohama-shi Kanagawa Mitsubishi Heavy Industries Yokohama Works Co., Ltd. (56) References: Kohei 1-27926 (JP, Y2)

Claims (2)

[Scope of utility model registration request] 1. An amplitude-increasing arm, which is a square arm, in which mounting brackets are attached to cables arranged in parallel, and both ends of four arms are rotatably connected to the pair of mounting brackets. The arm is pivotally attached at one of the opposing connection portions of the arm,
A relative amplitude vibration damping device for cables arranged in parallel, characterized in that a vibration damping mechanism is attached between the other connecting portions of the arms facing each other. 2. The parallel arrangement according to claim 1, wherein the cable-side mounting portion of the amplitude enlarging arm is mounted at an angle with respect to a horizontal axis connecting the centers of the cables horizontally. Relative amplitude vibration suppressor for cables.