JPH05292636A - Overhead power line suspension support device - Google Patents

Abstract

(57) [Summary] [Structure] An auxiliary arm 7 extending in the track direction is formed on the arm 5 of the suspended steel tower, and an auxiliary insulator 8 and a connecting metal fitting 9 are provided between the tip of the auxiliary arm 7 and the suspension clamp 6. Safety metal fitting 1 which is connected to each other and breaks when a predetermined load equal to or less than the allowable load in the line direction of the suspended steel tower is applied to the metal fitting 9.
1 was set. [Effect] It is possible to prevent the suspension insulator from flowing in the line direction and drastically drop the electric wire due to unevenly adhering snow and ice between adjacent spans, and to prevent a short circuit accident based on that. When there is a possibility that an excessive load in the rail direction will act on the suspended tower due to the restraint of the flow of the suspension insulator in the rail direction, the safety fitting will break and the tension of the wire will be relieved to prevent the suspension tower from being damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead power transmission line suspension support device for preventing a drooping short-circuit accident due to uneven icing snow on an overhead power transmission line.

[0002]

2. Description of the Related Art A suspension support device for an overhead transmission line suspends a suspension insulator vertically or V-suspended on an arm of a suspension tower,
It has a structure in which a suspension clamp for supporting an overhead power transmission line is attached to the lower end of the suspension insulator.

[0003]

In the suspension support device, the lower end side of the suspension insulator is movable in the line direction in accordance with the movement of the electric wire. Therefore, for example, after icing snow occurs on the electric wire of each span, the icing snow may fall in a part of the span,
If there is icing snow in one span across the suspended steel tower and no icing snow occurs in the other span, the weight of the icing snow will cause the suspended insulator of the tower to span the span with icing snow. A large flow (inclination) toward the direction, and the slack of the electric wire increases in the span with icing snow.

If such uneven ice accretion in the track direction occurs in the upper-phase or middle-phase electric wire and the electric wire below it does not have accretion snow, only the upper electric wire droops drastically and Since the electric wire maintains a normal slack, the clearance between the upper and lower electric wires becomes small, which may cause a short circuit accident.

In particular, as shown in FIG. 2, two or more suspended steel towers 1 are continuous, and only the upper-phase electric wire 2A between the two suspended steel towers 1 has icing snow 4, and the spans on both sides thereof. When there is no icing snow on the upper-phase electric wire 2A and the intermediate-phase electric wire 2B below the upper-phase electric wire 2A, both the suspension insulators 3A of the upper phase of the two suspended steel towers 1 flow inward, so The drooping amount of the phase electric wire 2A becomes extremely large, which easily causes a short circuit accident. When such a short-circuit accident occurs, the power cannot be transmitted at least temporarily, and in some cases, there is a risk that an arc may cause a disconnection and a serious accident. Although FIG. 2 shows the relationship between the upper phase electric wire 2A and the middle phase electric wire 2B, the middle phase electric wire 2B and the lower phase electric wire 2 are shown.
A similar problem can occur with C.

[0006]

SUMMARY OF THE INVENTION The present invention provides a suspension support device for an overhead power transmission line that solves the above problems. The suspension support device suspends and suspends a suspension insulator from an arm of a suspension tower. In an overhead power transmission line suspension support device in which a suspension clamp supporting an overhead power transmission line is attached to the lower end of an insulator, an auxiliary arm extending in the track direction is formed in the arm, and a tip portion of the auxiliary arm and the suspension clamp are provided. It is characterized in that it is connected through an auxiliary insulator and a connecting metal fitting, and a safety metal fitting is provided in the connecting metal fitting, which breaks when a predetermined load equal to or less than an allowable load in the line direction of the suspension tower is applied.

[0007]

[Operation] The auxiliary insulator and the connecting fitting for connecting the tip end of the auxiliary arm extending in the line direction and the suspension clamp prevent the suspension insulator from flowing in the line direction, and prevent an increase in the slack of the electric wire due to the flow of the suspension insulator. To do.

When the flow of the suspension insulator in the track direction is restricted by the auxiliary insulator and the connecting metal fitting, an excessive load in the track direction may act on the suspended tower. That is, since the suspension tower is generally designed to withstand a load in the line direction corresponding to 60% of the assumed maximum tension of the electric wire, damage will occur if a load in the line direction is further applied. In order to prevent this, in the present invention, a safety fitting is put in the connecting fitting, and when there is a possibility that an excessive load in the rail direction is applied to the suspension tower, the safety fitting is a predetermined load equal to or less than the allowable load in the suspension tower direction. At this point (that is, before the load higher than the allowable load in the line direction is applied to the suspension tower), the tension of the electric wire is relieved to prevent the suspension tower from being damaged.

It is desirable that the safety metal fitting be placed between the lower end of the auxiliary insulator and the suspension clamp. In this way, when the safety fitting is broken, the auxiliary insulator hangs from the auxiliary arm, and there is no possibility of causing any other obstacle.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a suspension support device according to an embodiment of the present invention as viewed from a direction perpendicular to the line direction.
Reference numeral 5 is an arm of a suspension tower, 3 is a suspension insulator suspended from the arm 5, 6 is a suspension clamp attached to the lower end of the suspension insulator 3, and 2 is an electric wire supported by the suspension clamp 6.

The characteristic feature of this suspension support device is that auxiliary arms 7 extending in the track direction are formed on both sides of the arm 5 of the suspension tower, and an auxiliary insulator 8 and a connection are provided between the tip of this auxiliary arm 7 and the suspension clamp 6. That is, they are connected via the metal fitting 9. In this embodiment, the connecting fitting 9 comprises a right angle socket clevis 10, a safety fitting 11, a parallel clevis 12, a connecting yoke 13 and the like.

Safety metal fitting 11 forming a part of the connecting metal fitting 9.
Is designed to break when a predetermined load equal to or lower than the allowable load in the line direction of the suspension tower is applied. That is, a normal connecting metal fitting is made of malleable cast iron, but the safety metal fitting 11 needs to have a lower strength than other metal fittings. If different material is used, it is manufactured by using a material having lower strength than malleable cast iron such as aluminum alloy.

The strength of the safety fitting 11 is designed as follows. For example, the angle formed by the connecting body of the auxiliary insulator 8 and the connecting metal fitting 9 with the suspension insulator 3 is 45 °, and the assumed maximum tension of the electric wire 2 is 5 °.
In the case of t, the permissible load in the suspended tower direction is 60% of the assumed maximum tension of the electric wire, which is 5t × 0.6 = 3t. Therefore, the safety fitting 11 is 3t / cos 45 ° = 4.24
It may be designed so that it will break under a load of t or less.

On the other hand, as a matter of course, the auxiliary insulator 8 needs to have insulation strength equal to or higher than that of the suspension insulator 3. However, since it is desirable that the auxiliary insulator 8 be as light as possible, it is preferable to use a polymer insulator (using FRP as a central core material and a polymer material such as silicon rubber formed in a multi-stage cap-shaped insulator shape).

According to the above construction, the flow of the suspension insulator 3 in the track direction is restricted by the auxiliary arm 7, the auxiliary insulator 8 and the connecting fitting 9, so that it is considered that there is icing snow only on one span of the suspended steel tower. Even so, the flow of the suspension insulator 3 is blocked, and the slack of the electric wire 2 can be prevented from increasing. Further, when there is a possibility that an excessive load in the line direction is applied to the suspended tower due to uneven snow accretion, the safety fitting 11 breaks and the tension of the electric wire 2 is relieved, so damage to the suspended tower can be prevented.

[0016]

As described above, according to the present invention, it is possible to prevent the suspension insulator from flowing into the line direction due to the unevenly accreted snow and drooping the electric wire, so that a short-circuit accident due to it can be eliminated. Also, restraining the flow of the suspension insulator in the track direction may cause an excessive load in the track direction on the suspended tower, but if there is a risk, the safety metal fitting will break and the tension of the wire will be relieved. ,
Excessive load in the rail direction does not act on the suspension tower,
It is possible to prevent the suspension tower from being damaged.

[Brief description of drawings]

FIG. 1 is a side view of a suspension support device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a situation of occurrence of a drooping short-circuit accident due to uneven icing and snow on the overhead power transmission line.

[Explanation of symbols]

 1: Suspended steel tower 2: Overhead transmission line 3: Suspended insulator 4: Ice snow 5: Suspended steel tower arm 6: Suspended clamp 7: Auxiliary arm 8: Auxiliary insulator 9: Connection fitting 11: Safety fitting

Claims (1)

[Claims] 1. A suspension insulator is suspended from an arm of a suspension tower.
In an overhead power transmission line suspension support device in which a suspension clamp supporting an overhead power transmission line is attached to the lower end of a suspension insulator, an auxiliary arm extending in the track direction is formed in the arm, and a tip portion of the auxiliary arm and the suspension clamp are formed. Is connected through an auxiliary insulator and a connecting metal fitting, and a safety metal fitting is provided in the connecting metal fitting, which breaks when a predetermined load equal to or lower than the allowable load in the line direction of the suspended steel tower is applied. Support device.