JPH1055737A - Buffer type gas-blast circuit-breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-blast circuit-breaker with high breaking performance, small size, and low operation force by increasing gas pressure in a buffer chamber. SOLUTION: A gas-blast circuit-breaker has a first insulating nozzle 3 fixed to the tip of a buffer cylinder and a second insulating nozzle covering the outside and the tip of a moving contact. A groove 12 is formed in the first insulating nozzle 3 and the second insulating nozzle. When current of the gas-blast circuit-beaker is shut off, gas heated by arc comes in contact with the surface of the first insulating nozzle 3, and introduced into a buffer chamber. The surface of the insulating nozzle 3 is melted, gas is generated, and the pressure in the buffer chamber is raised. The groove 12 formed in the insulating nozzle 3 increases the contact area with the heated gas, and the amount of gas generated is increased. The pressure in the buffer chamber is increased, and the gas blast circuit-breaker with high breaking performance can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a puffer type gas circuit breaker used in a substation or the like.

[0002]

2. Description of the Related Art In recent years, puffer type gas circuit breakers have become small,
Light weight and low operating force are strongly required. In order to meet this demand, in addition to the conventional mechanical gas compression, an attempt has been made in general to increase the pressure in the puffer chamber by effectively utilizing the energy of the arc. This technology is called "combined use with heat puffer".

In a gas circuit breaker combined with a heat puffer, an insulating nozzle is closed by an arc generated between a fixed arc contact and a movable arc contact, and the energy of this arc is taken into the puffer chamber to increase the pressure in the puffer chamber. . The puffer chamber is formed between the puffer cylinder and the fixed piston, and the pressure in the puffer chamber is further increased by mechanical compression due to movement of the puffer cylinder.

[0004] The gas in the puffer chamber, which has been pressurized by the arc energy and mechanical compression, is blown toward the arc through an insulating nozzle to cool the arc and extinguish the arc. At the same time, the high-temperature gas existing between the contacts is removed at a high speed, and the insulation between the contacts is rapidly restored, whereby the current is successfully cut off.

[0005]

In order to ensure the breaking performance of the puffer type gas circuit breaker, it is necessary to blow gas from the puffer chamber to the arc at a high speed. Therefore, in the gas circuit breaker combined with heat puffer, if the pressure in the puffer chamber can be further increased, the shutoff performance can be further improved, and the device can be downsized and the operating force can be reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a puffer type gas circuit breaker which is excellent in shutoff performance and has a low operating force by further increasing the gas pressure in the puffer chamber.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object. The present invention provides a first insulating nozzle attached to a tip of a puffer cylinder,
In a puffer type gas circuit breaker having a second insulating nozzle covering an outer side and a tip of a movable contact, an inner peripheral portion where a gas flow heated by an arc and flowing into a puffer chamber comes into contact with a first insulating nozzle. A plurality of grooves are formed along the gas flow, and the second nozzle is formed with a plurality of grooves along the gas flow at a tip portion where the arc and the gas flow heated by the arc come into contact.

In a puffer type gas circuit breaker, a large current arc is generated between a fixed contact and a movable contact when current is interrupted. The gas heated by the arc energy is taken into the puffer chamber and increases the gas pressure in the puffer chamber. The pressure in the puffer chamber is further increased by the mechanical movement of the puffer cylinder. When the arc energy is taken into the puffer chamber, the arc or the hot gas decomposed by the arc touches the surfaces of the first and second insulating nozzles. This causes the surface of the insulating nozzle to melt and evaporate to generate gas, which contributes to an increase in gas pressure in the puffer chamber. This phenomenon has been experimentally confirmed.

In the present invention, since a plurality of grooves are formed in the surface of the insulating nozzle, the surface area of the arc or the hot gas contacting the insulating nozzle is increased. Thereby, the amount of gas generated by melting and evaporating by the arc or the hot gas increases, and the pressure rise in the puffer chamber becomes higher. Therefore, the gas pressure in the puffer chamber can be sufficiently increased by the rise due to the arc energy, the rise due to the mechanical gas compression, and the rise due to the generation of a large amount of evaporative gas.

Therefore, according to the present invention, it is possible to obtain a puffer-type gas circuit breaker having excellent shut-off performance, small size and low operating force.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a puffer type gas circuit breaker according to the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view of a puffer type gas circuit breaker, and FIG. 2 is an enlarged view showing a main part thereof. In the figure, 1 is a fixed arc contact, 5 is a fixed piston, 6 is a fixed main contact,
These are in the fixed part. 2 is a movable arc contact, 3 is a first insulating nozzle, 4 is a puffer cylinder, 7 is a movable main contact, 10 is a second insulating nozzle covering the tip of the movable arc contact 2, and these are insulating operations. Move with the rod 11. Reference numeral 8 denotes a sliding contact, which electrically connects the movable contacts 7, 2 and the fixed piston 5. 9 is a puffer chamber formed by the puffer cylinder 4 and the fixed piston 5. The insulating operating rod 11 is operated by an operating mechanism (not shown).
When the circuit breaker is turned on, the circuit breaker is driven upward, and when the circuit breaker is turned off, it is driven downward.

The first insulating nozzle 3 and the second insulating nozzle 10 are formed using PTFE containing an inorganic filler as a main material. The first and second insulating nozzles 3 and 10 will be described with reference to FIGS. In order to clarify the features of the insulating nozzle according to the present invention, each drawing also shows the configuration of a conventional insulating nozzle. FIG. 3 shows the structure of the first insulating nozzle. (A) and (b) show a side cross section and a bottom surface of the insulating nozzle of this embodiment, and (c) and (d) show a side cross section and a bottom surface of a conventional insulating nozzle. In the first insulating nozzle 3 of the present embodiment, a plurality of grooves 12 are formed in the base, that is, on the inner peripheral surface on the side of the puffer cylinder 4 in the longitudinal direction along the flow of gas described later. The groove 12 increases the surface area of the inner circumference of the insulating nozzle 3.

FIG. 4 shows the structure of the second insulating nozzle.
(A) and (b) show a side cross section and a bottom surface of the insulating nozzle of this embodiment, and (c) and (d) show a side cross section and a bottom surface of a conventional insulating nozzle. The second insulating nozzle 10 of the present embodiment has a tip, that is, a portion facing the fixed arc contact 1,
A plurality of grooves 13 are formed radially along the flow of gas described below. The groove 13 increases the surface area of the tip of the insulating nozzle 10.

The operation of the puffer type gas circuit breaker shown in FIGS. 1 and 2 will be described with reference to FIG. In FIG.
(A) shows the closed state of the circuit breaker, (b) and (c) show the state in the middle of breaking, and (d) shows the closed state. 5A, the fixed arc contact 1 and the movable arc contact 2
Are in contact. Although not shown in FIG. 5, the fixed main contact 6 and the movable main contact 7 are in contact with each other.
The current flows through the fixed main contact 6-movable main contact 7-sliding contact 8-fixed piston 5.

When the current is interrupted, the insulating operating rod 11 is rapidly moved downward in the figure by an operating mechanism (not shown). The movable portion is moved by the movement of the insulating operation rod 11, and the fixed main contact 6 and the movable main contact 7 are first separated. At this time, since the current is diverted to the fixed arc contact 1 and the movable arc contact 2, the fixed main contact 6 and the movable main contact 7 are separated from each other without arc.

As shown in FIG. 5B, when the movable portion further moves downward, the fixed arc contact 1 and the movable arc contact 2 are separated from each other, and an arc 14 is generated between the contacts 1 and 2. . This arc 14 closes the first insulating nozzle 3. The gas heated by the arc 14 is taken into the puffer chamber 9 formed by the puffer cylinder 4 and the puffer piston 5, and increases the gas pressure in the puffer chamber 9. Further, as the puffer cylinder 4 descends, the pressure inside the puffer chamber 9 also increases due to mechanical compression.

At this time, the arc 14 comes into direct contact with the tip of the second insulating nozzle 10, and further the hot gas heated by the arc 14 comes into contact. Also, the first insulating nozzle 3
The hot gas flowing into the puffer chamber 9 comes into contact with the inner peripheral surface of the puffer chamber 9. When an arc or a hot gas comes into contact with the surfaces of the first and second insulating nozzles 3 and 10, the surfaces are melted and evaporated to generate gas. This gas increases the gas pressure in the puffer chamber 9.

In the present embodiment, grooves 12 and 13 are formed on the surfaces of the first and second insulating nozzles 3 and 10 at portions where the arc or hot gas comes into contact. For this reason, the area where the arc or the hot gas comes into contact with the insulating nozzle increases, and accordingly, the amount of generated gas also increases, and the gas pressure in the puffer chamber 9 further increases. FIG. 5C shows a state in which the interruption process has further progressed. Due to the downward movement of the puffer cylinder 4, the gas in the puffer chamber 9 is mechanically compressed and the pressure is increased. This high-pressure gas is supplied to the first insulating nozzle 3 and the second insulating nozzle 3.
Is sprayed on the arc 14 through the insulating nozzle 10. The arc 14 is cooled by blowing gas, and is extinguished at a current zero point.

Since the grooves 12 and 13 formed in the first and second insulating nozzles 3 and 10 are formed along the flow of gas from the puffer chamber 9, it prevents the high pressure gas from being blown to the arc. Absent. Further, the width of the grooves 12, 13 is set to a value that does not hinder the gas flow. FIG. 5D shows a state where the cutoff is completed. The gas blown out of the puffer chamber 9 is blown between the contacts 1 and 2 even after the arc 14 is extinguished. As a result, the high-temperature gas existing between the contacts is removed, and a low-temperature insulating gas enters between the contacts, so that the insulation between the contacts is quickly restored.

[0020]

According to the present invention, by further increasing the gas pressure in the puffer chamber, it is possible to obtain a puffer-type gas circuit breaker having excellent shut-off performance and low operating force.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of a puffer type gas circuit breaker of the present invention.

FIG. 2 is a side sectional view showing a main part of FIG. 1;

FIG. 3 is a diagram showing details of a first insulating nozzle in the circuit breaker shown in FIGS. 1 and 2;

FIG. 4 is a diagram showing details of a second insulating nozzle in the circuit breaker shown in FIGS. 1 and 2;

FIG. 5 is a diagram for explaining the operation of the circuit breaker of FIGS. 1 and 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fixed arc contact 2 ... Movable arc contact 3 ... 1st insulating nozzle 4 ... Puffer cylinder 5 ... Fixed piston 6 ... Fixed main contact 7 ... Movable main contact 8 ... Sliding contact 9 ... Puffer chamber 10 ... second insulating nozzle 11 ... insulating operation rod 12,13 ... groove 14 ... arc

Claims (1)

[Claims] 1. A puffer type gas circuit breaker having a first insulating nozzle attached to a tip of a puffer cylinder, and a second insulating nozzle covering a tip and an outside of a movable contact. The nozzle has a plurality of grooves along the gas flow in an inner peripheral portion where the gas flow heated by the arc and flowing into the puffer chamber contacts, the second nozzle includes an arc and the gas heated by the arc. A puffer type gas circuit breaker having a plurality of grooves along a gas flow at a tip portion where the flow contacts.