JPH04315721A - Buffer type gas-blast circuit breaker - Google Patents

Abstract

PURPOSE:To provide a buffer type gas-blast circuit breaker possible to enhance arc-extinguishing performance by effectively utilizing heat energy of an arc, and further decreasing a temperature of gas jetted from a buffer chamber. CONSTITUTION:In a circuit breaker in which an arc-extinguishing gas is blasted from a nozzle 5 to an arc 7 generated between a fixed contact piece 1 and a movable contact piece 2 so as to execute arc extinguishing, a tip side of the nozzle 5 is formed of a low melting point substance 5A while a base end side is formed of a high melting point substance 5B.

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, and more particularly to a nozzle used in an arc extinguishing chamber.

0002

2. Description of the Related Art A conventional puffer type gas circuit breaker of this type is described in Japanese Patent Application Laid-Open No. 59-33724. As shown in FIG. 3, the puffer type gas circuit breaker described in this publication includes a fixed contact 1, a movable contact 2 that moves toward and away from the fixed contact 1, and a structure that surrounds the movable contact 2. A movable cylinder 4 forms a puffer chamber P with the fixed piston 3 and reciprocates integrally with the movable contact 2.
and an insulating nozzle 5 fixed to one end of the movable cylinder 4 and guiding the movable contact 2 to the fixed contact 1.
It is composed of: Note that 6 is a contact that surrounds the fixed contact 1 and contacts the base end of the nozzle 5.

[0003] When cutting off the current from the closed state of the puffer type gas circuit breaker shown in FIG. 3, the movable contactor 2 and the movable cylinder 4 move in the direction of arrow A in FIG. Then, both of these 2 and 4 are separated from the fixed contact 1. Along with this separation, as shown in FIG.
, 4 begins to generate arc 7. At this time, nozzle 5
is still in contact with the fixed contact 1, the puffer chamber P is in a closed state, and the arc-extinguishing gas sealed therein is compressed. Subsequently, the movable contact 2 is connected to the fixed contact 1.
When the nozzle 5 is released from the fixed contact 1, the puffer chamber P is opened, and arc-extinguishing gas is ejected from the nozzle 5 and blown onto the arc to extinguish the arc 7. In particular, at the beginning of the circuit breaker, the surrounding area is heated by the arc 7, the gas pressure increases and expands, which flows into the puffer chamber P from the nozzle 5 and further increases the internal pressure of the circuit breaker. Arc-extinguishing performance is further improved.

0004

[Problems to be Solved by the Invention] However, in the conventional puffer type gas circuit breaker, the gas heated by the high heat of the arc 7 generated when the circuit is shut off heats the nozzle 5 before flowing into the puffer chamber P. As the gas is evaporated and energy is taken away as latent heat of vaporization, the temperature of the gas flowing into the puffer chamber P decreases and the effect of increasing the pressure in the puffer chamber P decreases, resulting in a decrease in arc extinguishing performance. .

The present invention has been made to solve the above problems, and the temperature of the gas heated by the arc does not decrease until it flows into the puffer chamber, and the thermal energy of the arc is effectively utilized. It is an object of the present invention to provide a puffer type gas circuit breaker that can improve arc extinguishing performance by further lowering the temperature of gas ejected from a puffer chamber.

[0006]

[Means for Solving the Problems] The puffer-type gas circuit breaker of the present invention extinguishes the arc by spraying arc-extinguishing gas sealed in a puffer chamber from a nozzle onto the arc generated when a movable contact and a fixed contact are separated. In the puffer type gas circuit breaker, the tip side of the nozzle is made of a low melting point material, and the proximal end side is made of a high melting point material.

[0007]

[Operation] According to the present invention, an arc is generated when the movable contact and the movable cylinder dissociate from the fixed contact, and the arc-extinguishing gas in the vicinity is heated by the arc, becomes high temperature, and its pressure increases. When the heated gas flows into the puffer chamber, the heated gas flows into the puffer chamber without evaporating the high melting point substance on the nozzle base end, while the gas ejected from the nozzle evaporates the low melting point substance on the nozzle tip side. As a result, the temperature decreases, and the arc can be extinguished by the cold gas.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in FIGS. 1 and 2, with the same reference numerals assigned to the same or equivalent parts as in the prior art. FIG. 1 is a cross-sectional view showing a main part of an embodiment of the puffer type gas circuit breaker of the present invention in a closed state, and FIG.
FIG. 2 is a diagram corresponding to FIG. 1 showing a state in which the puffer type gas circuit breaker shown in FIG.

As is clear from FIG. 1, the puffer type circuit breaker of this embodiment includes a fixed contact 1 and a fixed contact 1.
A puffer chamber P is formed by a movable contact 2 that moves toward and away from the movable contact 2, and a fixed piston 3 that surrounds the movable contact 2,
It is equipped with a movable cylinder 4 that reciprocates integrally with the movable contact 2, and an insulating nozzle 5 fixed to one end of the movable cylinder 4 to guide the movable contact 2 to the fixed contact 1. It is structured in accordance with that of .

[0010] The nozzle 5 of the puffer type circuit breaker of this embodiment has its tip side made of a low melting point material 5A such as tetrafluoroethylene resin, and its proximal side made of a non-metallic material such as alumina. It is formed of a conductive high melting point substance 5B, and the low melting point substance 5A and the high melting point substance 5B are formed by sintering.

Therefore, according to the puffer type circuit breaker of this embodiment, the movable contact 2 and the movable cylinder 4 move in the direction of the arrow A in FIG. During this period, an arc 7 is generated, and when the arc 7 heats the vicinity and makes the gas high temperature, the gas pressure increases and flows into the puffer chamber P. At this time, even if the high melting point substance 5B on the proximal end side of the nozzle 5 is heated by the high temperature gas, it does not evaporate and maintains a high temperature state, and the high temperature gas is passed into the puffer chamber P without lowering the gas temperature. By causing the gas to flow in, the inside of the puffer chamber P can be brought into a higher pressure state. On the other hand, the low melting point substance 5A on the tip side of the nozzle 5
When heated by the high-temperature gas ejected from the arc 7, it evaporates and absorbs the thermal energy of the high-temperature gas, lowering the temperature of the gas and recovering the density of a lower temperature.The insulating performance gas can be sprayed onto the arc 7.

As described above, according to the puffer type circuit breaker of this embodiment, the arc 7 is extinguished by spraying high pressure arc extinguishing gas onto the arc 7 due to the synergistic action of the low melting point substance 5A and the high melting point substance 5B. can do. Furthermore, a low melting point substance 5A is evaporated by heating of the high temperature gas ejected from the nozzle 5.
Since it is a non-conductive material such as tetrafluoroethylene resin, it can improve insulation performance.

The present invention is not limited to the above-mentioned embodiments, but may be a puffer type circuit breaker in which the tip side of the nozzle is made of a low melting point material and the proximal end is made of a high melting point material. For example, in the above embodiment, the material formed by sintering the low melting point material 5A and the high melting point material 5B was explained, but it is possible to make the low melting point material, which is highly consumable, by screwing it in so that it can be easily replaced. You can also do this.

[0014]

According to the present invention, the temperature of the gas heated by the arc does not drop until it flows into the puffer chamber, and the thermal energy of the arc can be effectively utilized, and the gas ejected from the puffer chamber can be It is possible to provide a puffer type gas circuit breaker that can improve arc extinguishing performance by further lowering the temperature.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing essential parts of an embodiment of a puffer type gas circuit breaker of the present invention in a closed state.

FIG. 2 is a diagram corresponding to FIG. 1 showing a state in which the puffer type gas circuit breaker shown in FIG. 1 is in a breaking operation.

[Figure 3] Figure 3 is Figure 1 showing a conventional puffer type gas circuit breaker.
This is a corresponding diagram.

FIG. 4 is a diagram corresponding to FIG. 1 showing a state in which the puffer type gas circuit breaker shown in FIG. 3 is in a breaking operation;

[Explanation of symbols]

1 Fixed contact 2 Movable contact 3 Fixed piston 4 Movable cylinder 5 Nozzle 5A Low melting point substance 5B High melting point substance

Claims (1)

[Claims] Claim 1: A puffer chamber is formed by a fixed contact, a movable contact that moves toward and away from the fixed contact, and a fixed piston that surrounds the movable contact, and is integrated with the movable contact. A movable cylinder that reciprocates, and an insulating nozzle fixed to one end of the movable cylinder and guiding the movable contact to the fixed contact, the movable contact and the movable cylinder being separated from the fixed contact. In a puffer-type gas circuit breaker, the arc generated when the arc is extinguished by blowing arc-extinguishing gas sealed in the puffer chamber onto the arc from the nozzle, the tip side of the nozzle being formed of a low melting point material. A puffer-type gas circuit breaker characterized in that the base end is made of a high melting point material.