JP2002216559A - Suspension insulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension insulator capable of reliably preventing electrolytic corrosion of a pin and destruction of the head of an insulator, and provide easy assembly and low cost manufacturing. SOLUTION: In order to improve a suspension insulator in which a pin 2 is secured on the back of a conical cap 1 with cement 3, a conductor ring 10 preferably made of zinc is embed and hold on the surface of the cement 3 provided around the pin 2. The conductor ring 10 conductively connects the outer peripheral surface of the pin 2 and the inner surface of the conical cap 1 so as to prevent electrolytic corrosion of the pin 2. Destruction of the head of the insulator resulting from the current to the inside of the cement 3 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension insulator for preventing electrolytic corrosion of a pin.

[0002]

2. Description of the Related Art A suspension insulator for power transmission has a structure in which a steel pin 2 is fixed to a back surface of a porcelain cap 1 with cement 3 as shown in FIG. It is known that when used, when pin 2 is charged to a positive polarity, pin 2 will undergo significant electrolytic corrosion. This electrolytic corrosion occurs when iron on the surface of the pin 2 is ionized and eluted when a current flows from the surface of the pin 2 to the shade 1 through the surface of the cement 3. Even when used for AC power transmission, the leakage current easily flows on the surface of the cement 3 in the soiled area, so that the electrolytic corrosion of the pin 2 is a problem.

Conventionally, as shown in FIG. 4, a zinc sleeve 4 as a sacrificial electrode for electrolytic corrosion is provided on the outer periphery of the pin 2 near the surface of the cement 3 so that electrolytic corrosion occurs on the surface of the zinc sleeve 4. , The pin 2 is prevented from being electrically eroded. With such a structure, zinc is eluted instead of iron, so that the pins 2 do not become thin and the strength does not decrease. Therefore, the zinc sleeve 4 is effective against electric current flowing on the surface of the cement 3.

However, when only the surface of the cement 3 is dried after the cement 3 is wetted by rainfall or the like, current may flow from the pin 2 to the shade 1 through the inside of the cement 3. As described above, the zinc sleeve 4 is ineffective against the electric current flowing inside the cement 3, and particularly when flowing inside the cement 3, the leakage current not only causes the pin fitting in the cement to be electrically eroded, but also causes the rust generated by the electrolytic corrosion. However, a large intrinsic stress may be generated inside the insulator, which may cause damage to the insulator. In addition, when a current flows into the inside of the cement 3 of the insulator pin portion due to the insulator creepage flashover at the time of lightning, the air existing in the cement 3 expands rapidly, and the porcelain is damaged by the internal pressure. Sometimes.

Therefore, as shown in FIG. 5, by forming an enlarged sleeve 5 on the pin 2, the influence of thinning due to electrolytic corrosion is reduced, and the distance between the pin 2 and the shade 1 is reduced to allow the inside of the cement 3 to be closed. Explosion-proof pendant insulators have been developed that make it difficult for the current to flow. However, the pin 2 having such an enlarged sleeve 5 has a high manufacturing cost and is difficult to assemble in the insulator manufacturing process (it is difficult to insert the pin 2 into the hollow portion on the back surface of the shade 1 and the back surface of the enlarged sleeve 5). Is difficult to uniformly fill the cement 3).

[0006] In addition, a suspension insulator has been developed in which the entire pin 2 is coated with an insulating material such as an epoxy resin to make it difficult for current to flow inside the cement 3, but the manufacturing cost is also increased. is there.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and can reliably prevent electrolytic corrosion of pins and destruction of the insulator head, and can be manufactured easily and at low cost. This was done to provide a hanging insulator.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a suspension insulator in which a pin is fixed to the back surface of a cap by cement. A conductor ring is embedded. In addition, the conductor ring is preferably of a size that allows conduction between the outer peripheral surface of the pin and the inner surface of the shade, and the conductor ring is formed by rolling a coil-shaped conductor into a ring shape, and extends halfway to the cement surface. It is preferably buried.

Since the suspension insulator of the present invention has a conductor ring buried in the cement surface around the pin, most of the current flowing from the pin toward the shade flows through the conductor ring. This prevents the pins from being electrolytically eroded and prevents current from flowing into the cement, thereby preventing the insulator head from being broken. Also, since the conductor ring is separate from the pins, there is an advantage that the increase in manufacturing cost is negligible and also functions as a pin positioning means at the time of assembling, so that assembling becomes easier.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. In FIG. 1, 1 is a porcelain shade of a suspension insulator,
Reference numeral 2 denotes a steel pin fixed to the cavity on the back surface of the shade 1 with cement 3. The surface of the pin 2 is plated with corrosion-resistant zinc. The above configuration is the same as the conventional suspension insulator, but in the present invention, the pin 2 is attached to the surface of the cement 3.
The conductor ring 10 is embedded so as to surround the periphery of the conductor ring 10.

The conductor ring 10 is preferably made of zinc, and has an inner diameter and an outer diameter substantially in contact with the outer peripheral surface of the pin 2 and the inner surface of the shade 1 as shown in FIG. It is preferable to have a size that allows conduction. Further, it is preferable that the conductor ring 10 is buried partway in the cement 3 as shown in FIG. The reason why zinc is preferably used as the material of the conductor ring 10 is that zinc is always more anodically than the iron of the pin 2 and that there is no abnormal expansion due to corrosion, so that the cement 3 does not crack. is there.

In this embodiment, the conductor ring 10 is formed by rolling a coiled conductive wire made of zinc into a ring shape. With such a structure, appropriate elasticity can be provided, so that the pin 2 can be easily embedded between the outer peripheral surface and the inner surface of the shade 1. In addition, since there is an appropriate gap between the wires, the wire can be easily pushed into the uncured cement 3 and can be reliably held by the cement 3. However, the conductor ring 10 is not necessarily limited to a coil-shaped conductor, and may be plate-shaped as long as it has a projection or the like that can be securely held by the cement 3.

In general, when assembling a suspension insulator, the cap 1 is turned upside down to inject the cement 3 into the cavity, and the pin 2 is inserted into the center of the cement 3 while the cement 3 is not yet cured to be cured. However, in the present invention, the cement 3 is hardened while the conductor ring 10 is inserted around the pin 2. At this time, the pin 2 itself does not have an enlarged portion, and the conductor ring 10 also functions as a positioning member that holds the pin 2 at the center of the hollow portion, so that there is an advantage that assembly is easy.

[0014] The suspension insulator of the present invention having the above-described structure can be provided around the pin 2 even when the pin 2 is used for DC power transmission and the pin 2 is positively charged or used in a soiled area. Since current flows through the cap 1 through the buried conductor ring 10, electrolytic corrosion of the pin 2 is prevented, and there is no possibility that the strength of the pin 2 is reduced.

Further, even when the inside of the cement 3 becomes wet due to rainfall or the like, a current may flow inside the cement 3 because the resistance of the conductor ring 10 is much smaller than the internal resistance of the cement 3. Absent. For this reason, it does not flow between the shade 1 and the pin 2 through the inside of the cement 3, and the insulator head is not destroyed. Furthermore, even when following the path of the insulator creepage flashover at the time of lightning strike, no current flows in the cement 3 and the porcelain is not damaged.

[0016]

As described above, the suspension insulator of the present invention has a structure in which a conductor ring is buried on the cement surface around the pin, so that the pin and the shade are electrically connected to each other, so that the electrolytic corrosion of the pin is achieved. In addition to the above, it is possible to reliably prevent the insulator head from being broken due to the flow of electric current inside the cement. Further, the suspension insulator of the present invention has many advantages such as being easy to assemble and requiring no special processing on the pin, so that there is almost no increase in manufacturing cost. The suspension insulator of the present invention is particularly suitable for DC power transmission, but is also preferable for AC power transmission in a soiled area.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of a conductor ring in the embodiment.

FIG. 3 is a partial cross-sectional view showing a general suspension insulator.

FIG. 4 is a partial sectional view showing a conventional suspension insulator having a zinc sleeve on the outer periphery of a pin.

FIG. 5 is a partial cross-sectional view showing a conventional suspension insulator having an enlarged sleeve on the outer periphery of a pin.

[Explanation of symbols]

1 cap, 2 pins, 3 cement, 4 zinc sleeve, 5
Expanding sleeve, 10 conductor ring

Claims (4)

[Claims] 1. A suspension insulator having a pin fixed to the back surface of a cap by cement, wherein a cement surface around the pin is
A suspension insulator having a conductor ring embedded therein. 2. The suspension insulator according to claim 1, wherein the conductor ring is of a size that allows conduction between the outer peripheral surface of the pin and the inner surface of the shade. 3. The suspension insulator according to claim 1, wherein the conductor ring is formed by rolling a coil-shaped conductive wire into a ring shape, and is partially buried in the cement surface. 4. The suspension insulator according to claim 1, wherein the conductor ring is made of zinc.