JPS5819783Y2 - Arc extinguishing chamber for oil breaker - Google Patents

Description

[Detailed explanation of the idea] This invention relates to an arc extinguishing chamber for an oil breaker.

In the arc extinguishing chamber of an oil breaker, a suppression resistance wire such as nichrome wire is connected between the fixed contact and the intermediate contact, and when the movable contact is in contact with the fixed contact, the intermediate contact is The suppressing resistance wire is short-circuited through the movable contact that is in contact with it, and when the movable contact and the fixed contact are separated, a resistance circuit is formed by the suppressing resistance wire between the movable contact and the fixed contact, thereby suppressing the re-electromotive voltage. New resistor systems are known.

Generally, the suppression resistance wire is installed in a coiled manner around the outer periphery of the insulating cylinder that constitutes the arc extinguishing chamber.

By the way, as described above, when the movable contactor is separated, a high voltage is applied to both ends of the suppression resistance wire, which causes the suppression resistance wire to generate heat and the surrounding area to become high in temperature.

The heat generated at this time decomposes the surrounding insulating oil and generates gas, but if this gas fills between adjacent turns of the suppression resistance wire, the insulation deteriorates and flash shorts occur, causing the suppression resistance wire to melt. Sometimes it happens.

In order to avoid such accidents, conventionally the distance between the turns is designed long enough to maintain the specified dielectric strength even when filled with gas, but this results in a winding force line of the suppression resistance wire. Therefore, a wide wrapping area is required, and in some cases, it may be necessary to increase the size of the insulating cylinder.

The purpose of this invention is to prevent bridging between turns caused by gas even when the suppression resistance wire is tightly wound.

This invention is characterized by inserting a heat-resistant insulator between the turns of the suppression resistance wire.

An embodiment of this invention will be explained with reference to the drawings. Reference numeral 1 denotes an insulating cylinder constituting an arc extinguishing chamber placed in insulating oil. It is fixed below the bushing so as to surround it.

A semicircular groove 3 is formed in a spiral shape on the outer periphery of the insulating tube 1, avoiding the oil injection hole 2. A coil-shaped suppressing resistance wire (for example, nichrome wire) 4 is fitted into this groove 3, and the insulating tube is closed. Wrap it around the outer circumference of 1.

That is, the suppressing resistance wire 4 was previously attached to the outer periphery of the insulating cylinder 1 in a single spiral shape over a plurality of turns along its axial direction.

These configurations are no different from known configurations, but according to this invention, the suppressing resistance wire 4 is wound around the outer periphery of the insulating tube 1 so that a heat-resistant insulator 5 is interposed between the turns of the resistive wire 4. Ru.

The insulator 5 is made of heat-resistant glass fiber, and is used as a mesh in the form of a belt or pine.

It has been experimentally confirmed that when the mesh is formed in this way, if surrounding insulating oil adheres to the mesh, the surface tension prevents gas from passing through.

Since the insulator 5 is made into a mesh shape in this manner, it becomes flexible, so that winding around the insulating tube 1 becomes easy.

6 is a screw, and when the suppression resistance wire 4 is wound around the insulating cylinder 1 avoiding the oil injection hole 2, the suppression resistance wire 4 is attached to the peripheral part of the oil injection hole 20.
It is used to fold back.

In this case, when winding the insulator 5, it is necessary to fold it back in the same way as the suppressing resistance wire 4, but the illustrated configuration uses the screw 6 also for this folding.

According to this, like the suppression resistance wire 4, it becomes possible to wind a long piece as the insulator 5 without cutting it in the middle, which improves workability and reliability, making it convenient. Good.

In the above configuration, when the insulating oil around the suppressing resistance wire 40 decomposes due to heat generation and gas is generated, the gas does not bridge between the turns of the suppressing resistance wire 4, and the insulating oil 5, it shifts upward and begins to float.

Therefore, bridging due to gas between the turns is avoided, and therefore no melting of the suppressing resistance wire due to flash fault occurs.

As detailed above, according to this invention, it is possible to avoid melting between the layers of the suppression resistance wire due to decomposition gas without having to wrap the suppression resistance wire with wide turns between turns as in the conventional case, and therefore, it is possible to avoid the suppression This has the effect of sufficiently reducing the winding area of the resistance wire.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of this invention, and FIG. 2 is a partially enlarged sectional view. 1...Insulating tube, 4...Suppressing resistance wire, 5
·····Insulator.

Claims (1)

[Scope of utility model registration request] A suppression resistance wire is attached in the axial direction of the insulating cylinder constituting the arc extinguishing chamber disposed in insulating oil over a plurality of turns in a single helical shape, and the suppression resistance wire is arranged in a single helical manner over a plurality of turns. to prevent gas from the insulating oil from filling between adjacent turns of the suppression resistance wire;
A single-use arc extinguisher comprising a belt-like or pipe-like insulator made of heat-resistant glass fiber and wound around the insulating tube so as to be interposed between each turn of the suppressing resistance wire. Room.