JPS5810928B2 - insulation spacer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulating spacer that supports a conductor placed in a conduit such as an aerial power transmission line or a gas insulated switchgear filled with an insulating gas, and more specifically relates to This invention relates to an insulating spacer in which a synthetic resin plate is embedded in the flange portion to prevent unevenness caused by the flange.

The insulating spacer insulates and supports the conductor installed in the conduit, and at the same time protects against electromagnetic force when a short-circuit current flows through the conductor, and when the conduit is divided into gas sections of a certain length, the insulating spacer acts as a partition wall for gas division. must withstand the pressure of

Therefore, the thickness of the insulating spacer is determined in accordance with the strength of the casting resin that is the spacer insulator.

Further, the flange portion of the insulating spacer is often tightened and fixed to the flange of the conduit using full-threaded bolts screwed into a plurality of internal threads disposed thereon, and is exposed to the outside air.

For this reason, it is necessary that the flange portion of the insulating spacer be brought into close contact with the flange of the conduit without any gaps to prevent moisture from entering through the joint surface between the flanges and to prevent corrosion of the flange.

This means that the insulating spacer flange portion is required to have a flatness comparable to that of a conduit flange formed by machining.

When manufacturing an insulating spacer, a metal member with a female thread is embedded in the spacer flange and the flange is cast simultaneously with the spacer insulator. In bad cases, when the piping flange is tightened and fixed, a gap is created between the two flanges, allowing moisture to infiltrate and preventing corrosion.

In order to avoid this, the method of machining the flange part of the cast insulating spacer to obtain flatness of the flange part gives machining strain to the insulating spacer, and the insulating spacer is exposed to decomposition products of the insulating gas SF6. Because alumina is used as a filler in the casting material because it needs to be durable, it has high hardness and is extremely difficult to cut, making it undesirable in terms of cost.

For this reason, a metal ring is generally used as the flange of the insulating spacer.

However, as mentioned above, insulating spacers require mechanical strength, and the weak point in the strength of a spacer using a metal ring for the spacer flange is the interface between the spacer insulator and the metal ring, where stress concentration occurs when mechanical stress is applied. Easy to wake up.

From this point of view, the present inventors conducted various studies to improve the flatness of the flange portion of the insulating spacer that contacts the conduit flange. As a result, the present inventors found that the unevenness of the flange portion caused by shrinkage of the cast resin during thermosetting can be prevented. For this purpose, the present invention was successfully completed by embedding a synthetic resin plate in the portion in contact with the pipe flange and integrally molding the flange to have a flatness comparable to that of a machined flange.

The present invention will be explained below with reference to the drawings.

Figure 1 shows an insulating spacer.
are a spacer insulator, a metal bush 22 having a female thread, a synthetic resin plate (particularly preferably a sheet material such as cloth or prepreg) in contact with the flange 28 of the conduit 27, and a shield electrode 23 embedded in the live part. configured.

Figure 2 is an enlarged view of the flange part, and the insulating spacer has an O-ring 30 on the flange part, and a female thread 25 of the metal bushing.
The fully threaded stud 26 is shown tightened to the flange 28 of the conduit 27 with a nut 31 via an O-ring.

Here, the synthetic resin plate 11 is made smooth in advance, and is integrally molded by filling the part in contact with the pipe flange with resin to be cast.

In this way, the insulating spacer of the present invention prevents shrinkage caused by heat curing and has good flatness, and a bond with the same level of flatness as that obtained by machining can be obtained, and since there is no distortion due to machining, it does not suffer from stress like a metal flange. It is a reliable insulating spacer with no concentration.

Furthermore, it is lightweight, inexpensive, and has good flatness, so there are no drawbacks such as moisture infiltration.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the relative positions of insulating spacers;
The figure is an enlarged view of the flange portion. 10...Insulating spacer, 11...Synthetic resin plate, 20...Joining surface, 22...Metal bushing, 23...Electrode, 25...
Female thread, 26...Full threaded stud, 27...
...Pipe line, 28...Pipe line flange, 30...
...O-ring, 31...Natsuto.

Claims (1)

[Scope of Claims] 1. An insulating spacer configured to communicate with each other between pipes filled with an insulating gas and having a conductor disposed therein, and to support the conductor disposed within the pipes, An insulating spacer formed by integrally molding a synthetic resin plate embedded with casting resin in a portion of the flange portion of the insulating spacer that is exposed to the atmosphere and tightened to the conduit flange, and in contact with the conduit flange. 2. The insulating spacer according to claim 1, wherein the synthetic resin plate is a sheet material of cloth or prepreg.