JPS649685B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-run insulator device for four conductors using a long insulator.

Insulators used in insulators for power transmission lines in desert regions have long, streamlined caps that are difficult to attract sand and are usually called aero caps, in order to prevent deterioration of electrical insulation performance due to sand adhesion or clogging. Trunk insulators are commonly used.

In addition, insulators are used when crossing rivers, railways, roads, etc., or when the transmission voltage exceeds 132KV, the number of wires per wire increases to 2 to 4 conductors or more, so it is necessary to use insulators due to strength and safety issues. It is common to use two insulators.

As a conventional two-strand insulator device for four conductors, for example, as shown in Figs. Two series are arranged in parallel, and the upper part of each is attached to the lower end of the tower arm 5 at a predetermined interval in the power transmission line direction via the clevis eye 4 and other connecting fittings, and the lower part is attached to a triangular insulator via the clevis eye 6. A substantially I-shaped conductor yoke 9 in which four suspension clamps 8 are connected in a square arrangement is connected at right angles to the lower end of the center of the triangular insulator yoke 7 via a connecting metal fitting. An intermediate horn 10 is attached to the right angle link 2 that connects the long insulators 1, an earth horn 11 is attached to the clevis eye 5 on the tower side, and a line side horn 12 is attached to the clevis eye 6 on the wire side.
A suspension system in which each of the two is attached with bolts and nuts is known. The purpose of arranging the two insulator chains in the direction of the power transmission line is to minimize the number of tower arms.

By the way, with the conventional equipment shown in Figures 1 and 2, tools such as spanners accidentally dropped from above by workers when attaching electric wires to insulators during the construction of power transmission lines, for example, are used to damage the lower tension. If the long insulator of one of the two insulator chains breaks due to an unexpected accident such as hitting a wired insulator device, the insulator chain yoke 7 rotates and the four electric wires 1 are destroyed as shown in Figure 3.
3 falls by the amount of rotation of the insulator yoke 7,
Due to the impact, the remaining insulator chain A receives a bending moment of inertia as it approaches the broken insulator chain B, and the entire vertical load that had been previously shared between the two insulator chains is due to the kinetic energy due to the fall. The initial tensile load applied to each insulator strand before the strand breaks is increased several times and acts as an impact tensile load. In this insulator device, as shown in Fig. 4, the central body of the long insulator 1 closest to the insulator yoke 7 of the remaining insulator chain A was instantly destroyed by the combination of the impact bending load and the impact tensile load. This has the disadvantage that it can cause secondary accidents such as injury to ground workers or pedestrians due to falling electric wires and insulators, or collapse of steel towers.

Therefore, as a method to prevent the remaining insulator strands A from being disconnected using this conventional device, it is possible to increase the section modulus by increasing the body diameter of each long insulator 1. Since the bending moment of inertia acting on the trunk insulator 1 increases in proportion not only to the length of the insulator but also to its weight, the margin expected by increasing the diameter of the body is largely offset by the increase in weight. Therefore, if we try to take measures against disconnection with this device, the body diameter of the long insulator 1 will be the insulator body diameter of the passage design, which is determined from the vertical load such as the weight of the electric wire, and the tensile load with a safety factor. We had no choice but to use a long stem insulator with a very unbalanced diameter and several ranks of strength. Therefore,
The cost per set of insulator devices is much higher than that of a normal design that does not take disconnection into account, and the weight of the long insulators is also very heavy, so it is difficult to use in a civilized vehicle such as a car in a desert or mountainous area. Another drawback was that transportation and assembly work was extremely difficult at power transmission line construction sites, where equipment was not available and people had to rely on human power.

On the other hand, Japanese Patent Publication No. 49-48116 discloses a configuration in which two upper and lower power transmission lines as conductors are gripped by suspension clamps placed apart in the direction in which they extend; When ruptures,
The conductor-side yoke will rotate about its connection point with the socket clevis until the suspension clamp associated with the broken suspension insulator is positioned substantially directly below the other suspension clamp. For this reason, the rotation angle of the conductor-side yoke and, by extension, the momentum associated with the rotation become large, and in the worst case, there is a risk of breaking the other suspension insulator. Further, due to the box-shaped structure, manufacturing the conductor yoke not only requires a relatively large amount of time, but also causes problems to be solved, such as an increase in weight.

The two-strand long trunk insulator for four conductors of the present invention is a new insulator device that eliminates the above-mentioned drawbacks, and one side is connected to the lower end of each of two long trunk insulators arranged at a predetermined interval in the direction of the power transmission line. A conductor yoke that supports the top two of the four conductors and a conductor yoke that supports the bottom two of the four conductors are attached to both ends of the insulator yoke, which has an inverted L-shaped flat plate shape with the other side extending below the insulator. This is a two-strand trunk insulator device for four conductors, in which the conductor yokes are arranged so as to be spaced apart from each other in the direction of the power transmission line and the extending direction of the insulator chain.

Hereinafter, the dual-length trunk insulator device for four conductors of the present invention will be explained by way of examples.

The first embodiment shown in FIGS. 5 and 6 is a double-length stem insulator device for a 380KV4 conductor according to the present invention. Two stations 3 are arranged in parallel, and the upper part of each is attached to the lower end of the tower arm 5 at a predetermined interval in the direction of the power transmission line via the clevis eye 4 and other connecting fittings, and the lower part is attached in the opposite direction via the clevis eye 6. They are connected by an L-shaped insulator yoke 14.

As shown in FIG. 7, this insulator link yoke 14 has an inverted L shape and has insulator link holes 1 on both upper sides.
5, and a conductor yoke connection hole 16 is provided at each lower end on the vertical line, and the distance L between the two conductor yoke connection holes 16 in the vertical direction is the distance between the electric wires.

Next, in this conductor yoke connection hole 16, an insulator chain yoke 1 having an inverted L shape is connected to the center upper part of a triangular conductor yoke 17 with two suspension clamps 8 connected to both ends.
4 and the triangular conductor yoke 17 are connected by right angle clevises 18 so that they are at right angles to each other, and the right angle link 2 that connects the long insulators 1 is connected to the intermediate horn 10, and the clevis eye 4 on the tower body side is connected to the ground. A side horn 11 is attached to the clevis eye 6 on the yoke side, and a line side horn 12 is attached to the clevis eye 6 on the yoke side using bolts and nuts (not shown).

In addition, in this two-strand trunk insulator device for four conductors, the insulator chain yoke is shaped like an inverted L, and the conductor is attached to the insulator chain yoke using a two-point support method, so that the wire weight can be reduced as shown in Figure 8. For example, even if the long insulator chain on the side supporting the lower two wires breaks due to an unforeseen accident under a constant operating load, only two of the four wires will fall. Furthermore, these two fallen wires are affected by the inertia bending moment and impact tensile load acting on the remaining insulator string A due to the buffering effect of lifting the two upper wires by the seesaw balance of the insulator string yoke with an inverted L shape. It was hoped that the situation would be eased.

Next, the second embodiment shown in FIGS. 9 and 10 is obtained by adding a buffer device 19 to the first embodiment shown in FIGS. 5 and 6. As shown in Figure 11, one buffer rod 21 with threaded parts 20 on both ends, aluminum,
Two pipes 22 and 2 made of copper or gas pipes, etc.
As shown in FIG.
4. Insert the buffer rod 21 into the shock absorber mounting hole 24 provided in the center of the downwardly extending portion of 4. Next, insert the buffer rod 21 so as to sandwich the insulator chain yoke 14 in the shape of an inverted L from both sides.
A pipe 22 is fitted into the pipe 1 and secured by tightening corona free nuts 23 from both sides.

Incidentally, the smaller the attachment position of the shock absorber 19, that is, the distance l between the upper two wires 13 and the shock absorber shown in FIG.
4 rotation, that is, the falling distance of the wire, is desirable in terms of disconnection characteristics. It will be decided as appropriate.

Further, in the embodiment, the shock absorber 19 is a combination of a shock absorber 21, a pipe 22, and a corona free nut 23, but the present invention may also have any other structure, such as fixing an iron plate, a round bar, or a pipe by welding or tightening with bolts. It achieves the purpose of
In either case, if the lower two wires fall due to disconnection, it is desirable that the shock absorber 19 deforms before it gets on the upper two wires.

In addition, in this second embodiment, as a result of comparing the data of the insulator continuous fracture on the upper two-strip side and the insulator continuous fracture on the bottom two-strip side in the disconnection test using the device of the first embodiment, the upper two-strip side was In the case of an insulator chain breakage, the upper two electric wires that fell due to the rotation of the insulator chain yoke in an inverted L-shape survive by riding on the upper part of the triangular conductor yoke that supports the lower two electric wires. Focusing on the fact that the bending moment of inertia and impact tensile load acting on the insulator chain are relaxed, and the properties of the insulator chain break on the lower two strands are lower than those on the lower two strands, the characteristics of the insulator strand fracture on the bottom two strands are compared to those of the upper two insulators. This is intended to have almost the same characteristics as the continuous breakage, and as shown in Fig. 13, when the lower two insulator links break, the insulator link yoke 1 in an inverted L shape
As shown in FIG. 14, the shock absorber 19 attached to the upper two wires 13 rests on the upper two wires 13 and deforms, thereby absorbing the impact force caused by the fall of the lower two wires and causing the remaining insulator chain A to This is expected to alleviate the acting bending moment of inertia and impact tensile load.

Next, we will discuss the two-run insulator system for four conductors of the present invention, in which the strength of the insulator is determined simply by considering the safety factor for the tensile load acting on the device, and the conventional design, which is a two-run insulator with one continuous link. The test was conducted under the same conditions, that is, insulator strand spacing 500mm Number of long stem insulators in each insulator strand Body diameter of 3 long stem insulators 75φ Length of long stem insulators 1612 mm Strength of long stem insulators 12000Kg Regular operating load of long stem insulators 2000Kg Electric wire As a result of testing on a full-scale test machine with a spacing of 400 mm (horizontal and vertical directions), as shown in Figure 15, the load was applied equally to each insulator strand before it was broken (hereinafter referred to as the initial load of the insulator strand). The characteristics of the bending strain generated in the long insulator of the remaining insulator chain (hereinafter referred to as insulator generated bending strain) are as follows. In contrast, the characteristics of the first embodiment of the present invention (without a shock absorber) shown by the solid line (b) are reduced to about 1/2, and the characteristics of the second embodiment of the present invention (with no shock absorber) shown by the dashed line (c) are In addition, in both examples, the conventional device was able to withstand even the initial load of the insulator (3300 kg), which is 1.5 times the normal operating load of the long-stem insulator (2200 kg) with a broken body. Not only did the insulator not break, but the bending strain that occurred was about 1/2 of the fracture strain of the insulator, which is said to be 1300×10 ^-6 .

Furthermore, as shown in Fig. 16, the load increase ratio, that is, the impact ratio of the remaining insulator chain to the initial load of the insulator chain is about 4 times that of the conventional device shown by the broken line A, while that of the first embodiment shown by the solid line B. The example (without a shock absorber) is about 2.8 times lower, which is a 30% decrease, and the second embodiment (with a shock absorber) shown by the dashed-dotted line C is
It was around 2.5 times, a 40% decrease.

As explained above, according to the two-strand insulator system for four conductors of the present invention, even if one of the two long-strand insulators arranged at a predetermined interval in the direction of the power transmission line breaks, Since the rotational angle of the insulator chain yoke, that is, the rotational momentum of the insulator chain yoke accompanying the breakage can be made smaller than that of the conventional one, breakage of the remaining insulator chain can be effectively prevented. Therefore, even if one of the two series is disconnected due to an unexpected accident, the remaining insulator series can be prevented from breaking, thereby preventing personal injury to ground workers or pedestrians due to falling electric wires and insulators.
It is also possible to prevent secondary accidents such as the collapse of steel towers.

In addition, the dimensions and weight of the insulator chain yoke can be made smaller and lighter than conventional ones, and when designing long-stem insulators, it is possible to simply take into account the safety factor for the constant working load acting on the insulator device. It is economical because all you have to do is design it, and it greatly contributes to the development of industry.

[Brief explanation of the drawing]

Figure 1 is a front view of a conventional two-strand trunk insulator for four conductors, Figure 2 is a side view, Figure 3 is an explanatory diagram showing one side of the insulator, and Figure 4 shows both sides of the insulator disconnected. 5 is a front view of a two-strand insulator for four conductors according to the present invention, FIG. 6 is a side view thereof, FIG. 7 is a detailed view of the insulator yoke, and FIG. 8 is one side thereof. 9 is a side view of main parts showing another embodiment of the present invention, FIG. 10 is a front view thereof, and FIG. 11 is a perspective view showing the structure of the shock absorbing device. Fig. 12 is an explanatory diagram showing how the shock absorber is attached to the insulator chain yoke, Fig. 13 is an explanatory diagram showing the situation where the insulator chain is disconnected on one side, Fig. 14 is a side view thereof, and Fig. 15 is a diagram showing the conventional device and the device of the present invention. Figure 16 shows the characteristics of the bending strain generated in the insulator against the initial load of the insulator chain, and the impact ratio characteristics of the conventional device and the device of the present invention against the initial load of the insulator chain. 1... Long stem insulator, 2... Right angle link, 3... Long stem insulator chain, 4... Clevis eye, 5... Steel tower arm, 6... Clevis eye, 7... Triangular insulator chain yoke, 8...
Suspension clamp, 9... substantially I-shaped conductor yoke, 10
...Intermediate horn, 11...Earth side horn, 12...
Line side horn, 13...Electric wire, 14...Inverted L-shaped insulator yoke, 15...Insulator yoke connection hole, 16...Conductor yoke connection hole, 17...Triangular conductor yoke, 1
8...Right angle clevis, 19...Buffer device, 20...Threaded portion, 21...Buffer rod, 22...Pipe, 23...Corona free nut, 24...Buffer device mounting hole.

Claims (1)

[Claims] 1. An inverted L-shaped flat plate having one side connected to the lower end of each of two long insulator chains arranged at a predetermined interval in the direction of the power transmission line and the other side extending below the insulator chains. Connect the top two of the four conductors to both ends of the insulator chain yoke.
A conductor yoke supporting the strip and a conductor yoke supporting the lower two strips are connected orthogonally to each other, and the conductor yokes are arranged at a distance from each other in the direction of the power transmission line and in the direction of extension of the insulator chain. 4
Double-length trunk insulator device for conductors. 2. In the middle of the downward protrusion of the insulator chain yoke in the shape of an inverted L, and at a position above the upper two wires,
A dual-length trunk insulator device for four conductors according to claim 1, wherein a shock absorber is installed perpendicular to a power transmission line.