JP2002101541A - Damper for aerial wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper for an aerial wire having no risk of a fall down of a heavy weight. SOLUTION: The damper comprises a clamp 10 for holding the aerial wire 12, the heavy weight 14 having an arm 14a that extends to the lateral direction and rubber vibration insulators 16 interposed between the lower part of the clamp 10 and the arm 14a of the heavy weight. The rubber vibration insulators 16 are respectively mounted to branch plates 10a, 10b made by dividing the lower part of the clamp 10 into two sections so that the outside edge of the insulators shall not rotate. The arm 14a is so sandwiched by the inside edges of the rubber vibration insulator 16 as not to correlatively rotate. The lower part of the clamp 10, the rubber vibration insulator 16 and the arm 14a of the heavy weight are fastened with a through bolt 36 and a nut 38, and the heavy weight 14 is rotatively held around the central axis of the bolt 36. A reciprocating motion of the heavy weight 14 having the central axis at the bolt 36 gives a twist to the rubber vibration insulator 16 when the aerial wire 12 vibrates, and then vibrating energy of the aerial wire 12 is absorbed by an elastic hysteresis loss of the rubber vibration insulator 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper for preventing light wind vibration of an overhead line (an overhead transmission line, an overhead ground line, etc.).

[0002]

2. Description of the Related Art As this type of damper, a stock bridge damper, a torsional damper, and the like are conventionally known. These dampers are composed of a clamp for gripping the overhead wire, a steel stranded wire supported in the middle by the clamp, and weights attached to both ends of the steel stranded wire. It absorbs by frictional loss due to bending or twisting of the stranded wire.

[0003]

[Problems to be Solved by the Invention] Conventional dampers are:
Since vibration energy is absorbed by repeated bending or twisting of the steel stranded wire, the steel stranded wire is easily fatigued, and the weight may fall off due to fatigue fracture of the steel stranded wire. For this reason, securing safety under the track has become a problem. In particular, when the vibration frequency of the overhead wire becomes a specific frequency, the weight causes resonance and the steel stranded wire is sharply bent, so that the steel stranded wire is likely to be damaged.

Further, when the weight falls off, the function as a damper is lost, and a vibration-free state is established. Therefore, there is a risk that fatigue damage of the overhead wire is accelerated at an accelerated rate. Furthermore, when the overhead wire has an apparent outer diameter due to icing and snow on the overhead wire in winter, the input energy from the wind increases in proportion to the fourth power of the outer diameter of the overhead wire. In the damper described above, there is also a problem that the steel stranded wire cannot absorb the input energy, and the wire of the steel stranded wire breaks or the weight falls off in a short period of time.

In view of the above problems, an object of the present invention is to provide an overhead wire damper that does not cause the weight to fall off.

[0006]

Means for Solving the Problems To achieve this object, an overhead wire damper according to the present invention includes a clamp for holding an overhead wire, a weight having an arm portion extending in a lateral direction, and a lower portion of the clamp. And an anti-vibration rubber interposed between the arm portion of the weight and the anti-vibration rubber. The anti-vibration rubber is incorporated into the lower portion of the clamp so that one end thereof does not rotate with its center axis oriented in the lateral direction. The other end and the arm portion of the weight are combined so as not to rotate relatively, and the lower portion of the clamp, the vibration isolating rubber, and the arm portion of the weight are tightened by a fastening member penetrating them, and Is supported so as to be rotatable about the tightening member as a central axis, whereby when the overhead wire vibrates, the reciprocating rotation of the weight about the tightening member as the central axis imparts a twist to the vibration isolating rubber, and Elastic hysteresis The vibration energy of the overhead wire is absorbed by the loss.

The overhead wire damper of the present invention absorbs vibration energy by elastic hysteresis loss due to the torsion of the vibration isolating rubber, so that the problem of fatigue breakage of the steel stranded wire as in the conventional damper is solved and the weight is reduced. Is rotatably supported around the tightening member as a central axis, so that the weight does not fall off. Further, since no steel stranded wire is used, it exhibits excellent corrosion resistance even in a corrosive environment such as salt damage, NOx, and SOx, and can withstand long-term use.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. [Embodiment 1] FIG. 1 shows an embodiment of an overhead wire damper according to the present invention. In the figure, reference numeral 10 denotes a clamp for holding the overhead wire 12, 14 denotes a weight, and 16 denotes an anti-vibration rubber.

[0009] The upper part of the clamp 10 for gripping the overhead wire 12 is the same as the conventional one. The lower part of the clamp 10 is divided into two parallel branch plate portions 10a and 10b as shown in FIG. 1A, and one of the branch plate portions 10a has a hexagonal shape (a non-circular shape, the same applies hereinafter). A through hole 18a is formed, and a hexagonal bottomed hole 18b is formed in the other branch plate portion 10b.
It is formed on the same axis as a. The bottomed hole 18b is formed so that the bottom is on the outer surface side of the branch plate portion 10b and the opening faces the through hole 18a. A bolt hole 20 is formed at the center of the bottom of the bottomed hole 18b.

The weight 14 has an arm portion 14a extending laterally from the spherical weight body, and hexagonal protection members are provided on both side surfaces of the distal end portion of the arm portion 14a, as shown in FIG. A vibration rubber pressing portion 22 is formed. Anti-vibration rubber pressing part 22
Has a groove 24 radially formed therein, and a bolt hole 26 formed at the center thereof.

As shown in FIG. 1A, two rubber isolators 16 are used so as to sandwich the distal end of the arm 14a of the weight 14 from both sides, as shown in FIG. A short hexagonal column with a hexagonal metal anti-rotation plate on one end
28 are fixed together, and the other end face is
It is 30. A protrusion 32 is formed radially on the arm pressing portion 30. The projection 32 meshes with the groove 24 of the vibration isolating rubber pressing portion 22 of the arm portion 14a to prevent relative rotation between the vibration isolating rubber 16 and the arm portion 14a. Further, a bolt hole 34 is formed in the center of the anti-vibration rubber 16 and the rotation preventing plate 28.

The hexagon of the rotation preventing plate 28 is formed to be slightly larger than the hexagon of the vibration isolating rubber 16, and
It is sized to fit into ten hexagonal holes 18a, 18b.

Next, a method of assembling the damper will be described. First, as shown in FIG.
The anti-vibration rubber 16 is pushed into 18b with the anti-rotation plate 28 facing the hole bottom. Next, the arm pressing portion 30 of the vibration isolating rubber 16
The vibration isolating rubber pressing portion 22 on one side of the arm portion 14a of the weight
Is pressed so that the projection 32 and the groove 24 are engaged with each other. Next, another anti-vibration rubber 16 is inserted from the outside into the through hole 18a of the clamp 10 with the arm pressing portion 30 side facing inward, and the rotation preventing plate 28 is fitted into the through hole 18a. Let it. At this time, the projection 32 and the groove 24 are engaged with each other. Then, a bolt hole 20 in the lower portion of the clamp 10, a bolt hole 26 in the arm portion 14a of the weight, and a bolt hole
A bolt 36 is inserted through 34 and tightened with a nut 38. This completes the assembly of the damper.

Next, the operation of the damper will be described. When a slight wind vibration occurs in the overhead wire 12 to which the damper is attached, the clamp 10 vibrates up and down together with the overhead wire 12, but the weight 14 cannot vibrate together with the overhead wire 12 due to its weight. As a result, the clamp 10 and the weight 14 move differently, and when viewed from the clamp 10 side, the weight 14 reciprocates around the bolt 36 as a center axis. At this time, the outer end side of the vibration isolating rubber 16 is
a and 18b, it cannot rotate relative to the clamp 10. On the other hand, the inner end side of the anti-vibration rubber 16 is pressed against the arm portion 14a of the weight 14,
And the projection 32 are meshed with each other, so that they reciprocally rotate about the bolt 36 as a central axis integrally with the arm portion 14a. Therefore, the vibration-proof rubber 16 is repeatedly torsioned, and the vibrational energy of the overhead wire 12 can be absorbed by the elastic hysteresis loss due to the torsion.

In this damper, there is a gap G between the lower surface of the forked portion of the clamp 10 and the upper surface of the arm portion 14a of the weight 14, and when the deflection of the weight 14 increases, the arm portion
The upper surface of 14a hits the edge S of the lower surface of the forked portion of the clamp 10, so that the deflection of the weight 14 does not increase any more. That is, the edge S on the lower surface of the clamp 10 serves as a stopper for restricting the rotation range of the weight 14. With such a structure, when the weight 14 resonates with the vibration of the overhead wire 12, it is possible to prevent the deflection of the weight 14 from becoming excessive, and thus it is possible to prevent the damper from being damaged.

When the bolts and nuts 36 and 38 are tightened, the value of t / T is defined as T, where T is the thickness of the vibration-proof rubber 16 before tightening, and t is the thickness of the vibration-proof rubber contracted by tightening. It is preferable to set it in the range of 0.05 to 0.2, and it is particularly preferable to set t / T to about 0.1 because the influence on the compression set characteristics of the vibration-proof rubber can be reduced and the secular change of the energy absorption characteristics can be reduced.

The material of the vibration-proof rubber used in the present invention includes synthetic rubbers such as butadiene rubber, chloroprene rubber, liquid polymerized styrene-butadiene rubber, butyl rubber, silicone rubber, isoprene rubber, ethylene propylene rubber, and rubber materials of these rubbers. Can be used. Table 1 shows the physical properties required for the rubber cushion used in the present invention.
It is as follows.

[0018]

[Table 1]

Since the center of gravity of the weight 14 is eccentric from directly below the overhead wire 12 in this damper, when mounting a plurality of the dampers in one radius, the direction of the weight 14 is alternately reversed. Therefore, it is preferable to minimize the torsional moment applied to the overhead wire.

[Embodiment 2] FIG. 4 shows another embodiment of the present invention. In this embodiment, two weights 14 are attached to one clamp 10. The overhead wire 12 becomes thicker, and FIG.
If the weight 14 becomes too large with the above structure, the weight 14 may be formed as shown in FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals.

In the case of this damper, hexagonal bottomed holes 18 b are formed on both side surfaces of the lower part of the clamp 10, and a bolt hole 20 is formed at the center of the bottom of these holes 18 b. The anti-vibration rubber 16 as shown in FIG. 3 is inserted into the bottomed holes 18b on both sides with the rotation prevention plate 28 facing the hole bottom. Further, the outer end surfaces of the two anti-vibration rubbers 16 are pressed against anti-vibration rubber pressing portions 22 formed on one side surface of the arm portion 14a of the weight 14, respectively. In this case as well, the radial projections on the vibration-isolating rubber 16 and the radial grooves on the arm portion 14a engage with each other, and
And the arm portion 14a do not relatively rotate. The two weights 14 are attached so that the arm portions 14a extend horizontally in opposite directions. In this state, the bolt 36 is inserted into the bolt holes 20, 34, 26 of each member, and is tightened by the nut 38.

When a breeze vibration is generated in the overhead wire 12, the two damping rubbers 16 are moved by the two weights 14.
It receives torsional vibrations with different 0 ° phase and absorbs vibrational energy by the elastic hysteresis loss at that time. Since the momentum of the two weights 14 is balanced in this damper, no torsional moment acts on the overhead wire 12. Therefore, the construction is easier than the damper of FIG.

[0023]

According to the present invention as described above,
The vibration energy of the overhead wire is absorbed by the elastic hysteresis loss due to the torsion of the vibration isolating rubber, and the weight is supported so that it can rotate around the tightening member as a center axis. The problem of breakage is eliminated, and the falling off of the weight can be reliably prevented. Furthermore, since no steel stranded wire is used, it has excellent corrosion resistance even in a corrosive environment and has the advantage of being able to withstand long-term use.

[Brief description of the drawings]

1A and 1B show an embodiment of an overhead wire damper according to the present invention, wherein FIG. 1A is a front view, FIG. 1B is a side view, and FIG.

2A is a side view of the weight used for the damper of FIG. 1, and FIG. 2B is an end view of the tip of an arm.

FIG. 3 shows an example of the vibration-proof rubber used for the damper of FIG.
(A) is a front view, (B) is a side view.

4A and 4B show another embodiment of an overhead wire damper according to the present invention, wherein FIG. 4A is a side view and FIG.

[Explanation of symbols]

 10: Clamp 12: Overhead wire 14: Weight 14a: Arm 16: Vibration-proof rubber 18a: Hexagonal through hole 18b: Hexagonal bottomed hole 20: Bolt hole 22: Vibration-proof rubber pressing part 24: Radial Groove 26: Bolt hole 28: Anti-rotation plate 30: Arm pressing part 32: Radial projection 34: Bolt hole 36: Bolt 38: Nut

Claims (3)

[Claims] 1. A clamp for holding an overhead wire, a weight having a laterally extending arm portion, and a vibration isolating rubber interposed between a lower portion of the clamp and an arm portion of the weight. At the lower part, a vibration-proof rubber is incorporated such that one end thereof does not rotate with its central axis oriented in the lateral direction, and the other end of the vibration-proof rubber and the arm of the weight are combined so as not to rotate relatively. The lower portion of the clamp, the vibration isolating rubber, and the arm portion of the weight are fastened by a fastening member that penetrates them, and the weight is rotatably supported around the fastening member as a center axis, whereby the overhead wire vibrates. When the weight is reciprocated around the fastening member as a center axis, the vibration isolating rubber is twisted to absorb the vibration energy of the overhead line due to the elastic hysteresis loss of the vibration isolating rubber. For wire Damper. 2. Assuming that the thickness of the vibration isolating rubber before tightening is T and the thickness of the vibration isolating rubber shrinking by tightening is t, t / T
The damper for an overhead wire according to claim 1, wherein the value of? Is in the range of 0.05 to 0.2. 3. A stopper provided at a lower portion of the clamp for restricting a rotation range of the weight.
Or the damper for overhead wires according to 2.