JPS62213025A - Gas-filled switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a gas switch (the concept is also used to include a circuit breaker), and more specifically, the invention relates to a gas switch (used as a concept that also includes a circuit breaker). This invention relates to a gas switch whose arc-extinguishing performance is improved by G-pulling.

<Prior Art> Conventionally, gas switches with various configurations have been provided in order to improve arc extinguishing performance.

FIG. 5 is a schematic diagram showing a conventional example of a gas switch that improves arc extinguishing performance by blowing gas. Child(
By surrounding the fixed contact (22) with the partitioning member (24), the fixed contact (22)
The side is configured as a pressurization chamber (25), the movable contact (23) side is configured as an exhaust chamber (26), and the partition member (2
A movable contact (23) is introduced into the pressurizing chamber (25) through a nozzle (20) fixed to the bottom of the pressurizing chamber (20). The upper half of the movable contact (23) is formed into a cylindrical shape, and an exhaust port (27) for gas circulation is provided at a predetermined position of the cylindrical portion.
is formed. SF6 gas as an arc-extinguishing gas is sealed inside the insulating container (21).

With the gas switch having the above configuration, the pressure in the pressurizing chamber (25) is increased by the arc (28) generated between the fixed contact (22) and the movable contact (23) during the cutoff operation. Then, a gas flow (29) is generated from the pressurization chamber (25) through the exhaust port (27) toward the exhaust chamber (26), and the gas flow is sprayed onto the arc (28), thereby quickly expelling the arc (28). The arc can be extinguished.

<Problems to be solved by the invention> However, according to the above switch, during the shutoff operation,
Since the entire pressure boosting chamber (25) is exposed to the radiant heat of the arc, it takes time for the arc-extinguishing gas in the pressure boosting chamber (25) to cool down after the shutdown is completed. Moreover,
The arc extinguishing gas in the pressurization chamber (25) has a higher temperature than the clean gas in the exhaust chamber (26), and contains many decomposed components, so it has a higher specific gravity than the clean gas. small,
As a result of remaining in the upper part of the pressurization chamber (25), the exhaust chamber (26)
It becomes impossible to effectively replace the clean gas on the side with the degraded gas on the pressurization chamber (25) side.

For this reason, when the cutoff operation is repeated in a short period of time, clean gas cannot be sprayed against the arc.
There is a problem that the blocking performance gradually deteriorates.

This invention was made in view of the above-mentioned problems, and it is intended to quickly and effectively replace the degraded gas in the pressurizing chamber with the clean gas in the exhaust chamber after the shutoff operation is completed. The object of the present invention is to provide a gas switch that can be operated.

Means for Solving the Problems> To achieve the above object, the gas switch of the present invention allows gas to flow in a predetermined part of the pressurizing chamber, and also provides a gas space that is thermally isolated from the arc. is provided.

With the gas switch configured as described above, the gas introduced into the gas space can be shut off while being prevented from being heated by the radiant heat of the arc, and after the shutoff operation is completed, the rise The gas whose temperature has been suppressed can be left in the pressurizing chamber to generate convection in the pressurizing chamber.

<Example> Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments.

Figure 1 is a schematic diagram showing the main parts of a gas switch, in which a fixed contact (12) is immovably mounted inside an insulating container (11) made of an insulating material such as synthetic resin. , a movable contact (13) is installed by airtightly penetrating the center of the bottom plate of the insulating container (11), and the fixed contact (12) is further surrounded by a partition member (14),
The fixed contact (12) side is used as a pressurizing chamber (15), and the movable contact (13) side is used as an exhaust chamber (16). The movable contactor (13) is introduced into the pressurizing chamber (15) through a nozzle (10) fixed to the bottom of the partitioning member (14). Further, the movable contactor (13) has a cylindrical upper portion, and an exhaust port (17) for gas circulation at the lower portion of the cylindrical portion.

The inner diameter of the upper end (10a) of the nozzle (10) has a predetermined gap (S) when the movable contact (13) is inserted.
The outer diameter of the tip of the movable contact (13) is a predetermined amount larger than the outer diameter of the tip of the movable contact (13). And nozzle (10)
The exhaust chamber (16) side is formed as a downwardly extending cylindrical body (10b), and the inner surface is formed to have a larger diameter than the upper end (10a), so that the inner surface and the movable contact (13) are connected to each other. A space (8) for gas suction is formed between the two. Further, the cylindrical body (
The stepped portion (13a) is in airtight contact with the inner surface of the iob.
), and the movable contact (13) is connected to the fixed contact (
By separating the space (8) from the space (8), the inner volume of the space (8) can be increased. A second exhaust port (10c) is provided at a predetermined portion on the lower end side of the nozzle (10).
By forming the space (A), the space (A) can be communicated with the exhaust chamber (16) when the movable contact (13) is opened to near the full stroke. Note that SF as an arc-extinguishing gas is contained inside the insulating container (11).
6 gases are sealed.

In the gas switch having the above configuration, the pressurizing chamber (15) is provided with a predetermined distance from the inner periphery of the partition member (14).
A cylindrical partition wall (18a) is installed.
A gas space (18) thermally isolated from the arc is formed between the space a) and the inner periphery of the partitioning member (14).

That is, the partition wall (18a) surrounds the contact portion between the fixed contact (12)-〇- and the movable contact (13), that is, the arc generation portion, as shown in FIG. , is supported in a floating state by fixing plates (18b) interposed at predetermined intervals between the partitioning member (14) and the partition wall (18a) to allow gas to flow in the vertical direction.

With the above configuration, the movable contact (13)
If an attempt is made to lower the electric circuit to break the electrical circuit, an arc will occur between the fixed contact (12) and the movable contact (13), and the pressure in the pressurization chamber (15) will rise, causing the pressurization chamber to (
15) and the exhaust chamber (16), a gas flow (19a) corresponding to this pressure difference is formed. Furthermore, when the movable contact (13) moves in a direction away from the fixed contact (12), the internal volume of the gas suction space (8) increases, and negative pressure is generated in the space (A), so that the pressure increases. Room (15
) and the space (A), the gas flow (19
b) is formed. Then, when the movable contact (13) opens to near the full stroke, the second exhaust port (10c
) is open, the gas flow (19b) can be exhausted to the exhaust chamber (16) through this exhaust port (10c).

At this time, the gas introduced into the gas space (18) can be shut off without being directly exposed to the radiant heat of the arc. In other words, it is possible to suppress the temperature rise of part of the gas in the pressurization chamber (15). Here, after the shutoff operation is completed, due to the temperature difference between the degraded gas remaining in the upper part of the pressurizing chamber (15) and the gas remaining in the gas space (18), the inside of the negative pressure chamber (15) This will cause convection. Therefore, the above deteriorated gas and the exhaust chamber (1
6) side can be quickly and effectively replaced with clean gas (see Fig. 2).

Incidentally, since the arc generated during the operation of the shield can be effectively cooled by the two gas flows (19a) and (19b) described above, good breaking performance can be exhibited. That is, when cutting off a small current, the arc input is small, so spraying with the gas flow (19a) is not very effective, but spraying with the gas flow (19b) is more effective than the above spraying. Therefore, compared to the conventional expansion type gas blowing, which was not very good or could not demonstrate the breaker performance in the type gas switch, it is possible to demonstrate better breaker performance. can.

In addition, when cutting off a medium to large current, blowing with the gas flow (19a) is highly effective at the initial stage of cutting off, but from the time when the movable contact (13) opens to near the full stroke, the space ( 8) communicates with the exhaust chamber (16), the gas flow (19b) can also be effectively blown against the arc, and as a result, the gas flow can also be effectively blown against the legs of the arc. can be made to do so. That is, it is possible to further improve the interrupting performance in medium and large current ranges.

As shown in FIG. 4, the gap Q (18a) may be formed by forming a circumferential groove (18c) with a V-shaped cross section on the inner circumferential side. In this case, the radiant heat of the arc By diffusing the radiant heat in an oblique direction, it is possible to effectively prevent the radiant heat from being reflected toward the arc side, suppress the further temperature rise of the arc, and improve the interrupting performance. More specifically, in the past, -〇 an lt structure in which the one-section member (14) is formed in a cylindrical shape;
The radiant heat of the arc is reflected by the inner surface of the partitioning member (14) and is intensively projected onto the arc, further increasing the temperature of the arc and increasing the temperature of the gas in the pressurization chamber (15) more than necessary. As a result, the cooling effect of arc spraying was reduced. However, as mentioned above, by forming the circumferential groove (18C), it is possible to effectively prevent the radiant heat from being reflected to the arc side, so the temperature of the arc itself will not increase further due to the radiant heat of the arc. This can suppress the increase in temperature of the gas in the pressurizing chamber (15). Therefore, electrons can be rapidly recombined with ions around the current zero point, and insulation recovery characteristics can be improved. In particular, by forming the circumferential groove (18c), the contact area between the partition wall (18a) and the gas on the arc side is increased, so heat exchange between the two can be promoted, and the high-temperature gas It can also be quickly cooled down.

Therefore, it is possible to further improve the shutoff performance when the shutoff operation is repeated in a short period of time, as in the case of operational duty. Moreover, the radiant heat reaching the circumferential groove (18c) from the arc can be scattered and attenuated by the reflected heat from the circumferential groove (18c).

Note that the temperature of other parts of the pressurizing chamber (15) increases due to the reflected heat from the circumferential groove (18c), but overall, the temperature increase of the gas in the pressurizing chamber (15) is suppressed. be able to. Further, the above-mentioned circumferential groove (18c) may be formed in the vertical direction, and its cross-sectional shape may be various groove shapes such as a knurled groove in addition to the V-groove shape shown in the figure. be able to. Note that the circumferential groove (18C) only needs to be formed so as to surround at least the vicinity of the arc occurrence.

Furthermore, instead of the above-mentioned circumferential groove (18c), the inner surface of the partition member (14) may be coated with a paint such as black heat-resistant paint, and in this case, by absorbing a certain amount of radiant heat, , it is possible to obtain an effect of suppressing reflection against arc.

On the other hand, the fixing plate (1811) supporting the partition wall (18a)
) is preferably made of a material with good heat dissipation.In this case, the fixed plate (18B) can act as a cooling fin, further enhancing gas convection and cooling effect. be able to.

In addition, in this invention, a coil is attached close to a fixed contact, and an arc current is guided to the coil to generate a magnetic field.
Of course, the present invention can also be applied to a gas switch whose arc extinguishing performance in a large current range is further improved by rotating the arc, and other horizontally moving gas switches.

Further, the gas switch of the present invention is not limited to the above-mentioned embodiments, and various design changes can be made without departing from the gist of the present invention.

<Effects of the Invention> As described above, according to the gas switch of the present invention, the degraded gas in the pressurizing chamber can be quickly and effectively replaced with the clean gas in the exhaust chamber, and the shutoff operation can be performed in a short time. It has the unique effect of being able to exhibit stable arc-extinguishing performance even when repeatedly applied.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing a gas switch as an embodiment of the present invention in the middle of being cut off, Fig. 2 is a longitudinal cross-sectional view showing the completion of the cut-off operation, Fig. 3 is a cross-sectional view taken from the previous time ■-■, FIG. 4 is a sectional view of a main part showing another embodiment, and FIG. 5 is a longitudinal sectional view showing an example of a conventional gas switch.

Claims (1)

[Claims] 1. Inside an insulating container filled with arc-extinguishing gas A pressurization chamber is provided in the pressurization chamber, and a fixed contact is installed in the pressurization chamber. In addition, there is an exhaust system for gas distribution. A movable contact with an air port is placed in the pressurization chamber. Pressure increase in the gas switch installed Allow gas to flow to a designated part of the chamber, and Gas space thermally isolated from the arc A gas machine characterized by a gap between the Switch switch.