JP2592323Y2 - Gas circuit breaker - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas circuit breaker, and more particularly to a self-extinguishing type gas circuit breaker.

[0002]

2. Description of the Related Art Conventionally, a self-extinguishing type gas circuit breaker using a flow of gas pressurized by an arc has been known. This will be described with reference to FIG. FIG. 3 is a sectional view of a main part of the gas circuit breaker. In the figure, the left half from the center line shows the closed state of the circuit breaker, and the right half shows the closed state.

In the closed state of the circuit breaker, as shown in the left half of the figure, the fixed main contact 1 and the movable main contact 2 are in contact, and the fixed arc contact 3 and the movable arc contact 4 are in contact. The current mainly flows through the path of the upper electrode 5-fixed main contact 1-movable main contact 2-sliding contact 6-lead terminal 7. The movable arc contact 4 that comes into contact with the fixed arc contact 3 closes the nozzle 12 and seals the inside of the pressurizing chamber 11.

[0004] During the breaking operation of the circuit breaker, the insulating operating rod 8 is moved downward in the figure by an operating mechanism (not shown). Thereby, the fixed main contact 1 and the movable main contact 2 are separated first. The current passes through the path of the fixed arc contact 3 and the movable arc contact 4.

When the insulating operation rod 8 moves further downward, the fixed arc contact 3 and the movable arc contact 4 separate. This causes an arc between the contacts.

When the insulating operating rod 8 is further moved downward, one end of the arc is transferred from the fixed arc contact 3 to the arc runner 9, and the current is supplied to the upper electrode 5 -coil 10 -arc runner 9 -movable arc contact 4 -rib 17. -It flows through the path of the movable main contact 2-the sliding contact 6-the extraction terminal 7. An arc is generated between the arc runner 9 and the movable arc contact 4. A magnetic field is generated by the current flowing through the coil 10, and a force for driving the arc is generated by the magnetic field, and the arc rotates on the arc runner 9 around the central axis at a high speed.

While the movable arc contact 4 closes the nozzle 12, the arc rotates in the sealed pressurizing chamber 11, so that the gas inside the pressurizing chamber 11 is expanded by the arc and expanded and pressurized. The accumulated gas is accumulated in the pressurizing chamber 11. When the tip of the movable arc contact 4 comes off from the nozzle 12, the high-pressure gas in the pressurizing chamber 11 flows out of the nozzle 12 to the outside, and a gas flow A is generated. This gas flow exerts an arc-extinguishing effect on the arc by blowing gas. Then, the current is interrupted at the zero point of the current. This cut-off state is shown in the right half of the figure.

[0008]

In the above conventional example, a part of the gas flow A from the pressurizing chamber 11 stays between the fixed main contact 1 and the movable main contact 2 as staying gas C. This is because the gas cannot move between the fixed main contact 1 and the movable main contact 2 as is apparent from the drawing. The stagnant gas C may flash between the main contacts due to the re-motive voltage after the arc is extinguished.

The present invention prevents the gas flowing out of the pressurizing chamber from staying between the fixed main contact 1 and the movable main contact 2 and supplies a fresh gas flow between the two main contacts. This is to prevent flashover between contacts.

The above and other objects and novel features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

[0011]

According to the present invention, in the self-extinguishing type gas circuit breaker described above, a gas introducing cylinder is provided between the movable main contact and the outer shell container, and the gas introducing cylinder is connected to the gas introducing cylinder. A gap is provided between the shell container and the lower extraction terminal and the outer shell container, and a gas below the extraction terminal passes between the main contacts from above the gas inlet cylinder through both gaps. It was made to be crushed.

[0012]

According to the above-described means, a fresh gas flow is supplied between the fixed main contact and the movable main contact through the gap between the outer shell container and the gas introducing cylinder by the gas flow from the pressurizing chamber. You. Thus, the stagnant gas does not stay between the fixed main contact and the movable main contact, and flashing between the main contacts is prevented.

Hereinafter, the configuration of the present invention will be described together with embodiments.

[0014]

FIG. 1 is a sectional view of a main part of a gas circuit breaker according to one embodiment of the present invention. The left half from the center line shows the closed state of the circuit breaker, and the right half shows the closed state. FIG. 2 shows FIG.
FIG. 4 is a sectional view taken along line DD of FIG.

In the figure, 5 is an upper electrode, and 14 is an outer container. The upper electrode 5 is provided with a boosting chamber 11 surrounded by a boosting chamber wall 13 having a nozzle 12. In the boosting chamber 11, fixed arc contacts 3, coils 10,
The arc runner 9 is stored. The upper electrode 5 further includes
The fixed main contact 1 is provided outside the boosting chamber 11.

The movable arc contact 4 is attached to the insulating operation rod 8. The movable arc contact 4 has an opening 1
The movable main contact 2 formed in a cylindrical shape is attached via a rib 17 provided with 8. The outer periphery of the movable main contact 2 comes into contact with a sliding contact 6 provided on the lead terminal 7. The drawer terminal 7 exposes the terminal to the outside of the outer shell container 14.

A gas introduction tube 15 is formed integrally with the extraction terminal 7. The upper end of the gas introducing cylinder 15 is provided to extend to a position slightly higher than the height of the movable main contact 2 at the breaking position of the circuit breaker. Further, a gap 16 is provided between the gas introduction cylinder 15 and the outer shell container 14. As shown in FIG. 2, the extraction terminal 7 also leaves a part necessary for energization,
4 is provided with a gap 19. In FIG. 2, other displays are omitted.

The gaps 16 and 19 form a gas flow path connecting the lower part of the lead-out terminal 7 and the upper part of the movable arc contact 2. The cross-sectional area formed by the gap 16 is set to be slightly smaller than the area of the opening 18 provided in the rib 17 connecting the movable arc contact 4 and the movable main contact 2. Thereby, the flow velocity of the gas passing through the gap 16 is increased. The upper end of the gas introduction tube 15 has a large arc on the outside so that the gas flow from the gap 16 to the main contact can easily flow.

In the closed state of the circuit breaker, as shown in the left half of the figure, the fixed main contact 1 and the movable main contact 2 are in contact, and the fixed arc contact 3 and the movable arc contact 4 are in contact. The current is mainly supplied to the upper electrode 5
-Fixed main contact 1-Movable main contact 2-
It flows through the path of the sliding contact 6-the lead terminal 7.
The movable arc contact 4 that comes into contact with the fixed arc contact 3 closes the nozzle 12 and seals the inside of the pressurizing chamber 11.

During the breaking operation of the circuit breaker, the insulating operating rod 8 moves downward in the figure by an operating mechanism (not shown). Thereby, the fixed main contact 1 and the movable main contact 2 are separated first. The current passes through the path of the fixed arc contact 3 and the movable arc contact 4.

When the insulating operation rod 8 moves further downward, the fixed arc contact 3 and the movable arc contact 4 separate. As a result, an arc is generated between the two arc contacts.

When the insulating operating rod 8 moves further downward, one end of the arc moves from the fixed arc contact 3 to the arc runner 9, and the electric current flows to the upper electrode 5-coil 10-arc runner 9-movable arc contact 4-rib 17. -It flows through the path of the movable main contact 2-the sliding contact 6-the extraction terminal 7. An arc is generated between the arc runner 9 and the movable arc contact 4. A magnetic field is generated by the current flowing through the coil 10, and a force for driving the arc is generated by the magnetic field, and the arc rotates on the arc runner 9 around the central axis at a high speed. When the arc rotates in the gas, the arc is extinguished by relatively blowing the gas to the arc.

While the movable arc contact 4 closes the nozzle 12 of the pressurizing chamber 11 during the shut-off operation, the arc rotates in the sealed pressurizing chamber 11, so that the gas inside the pressurizing chamber 11 is changed by the arc. The expanded and pressurized gas is accumulated in the pressurizing chamber 11.

When the tip of the movable arc contact 4 comes off the nozzle 12, the high-pressure gas in the pressurizing chamber 11 flows out of the nozzle 12 to generate a gas flow A. This gas flow exerts an arc-extinguishing effect on the arc by blowing gas. Then, the current is interrupted at the zero point of the current. This cutoff state is shown in the right half of the figure.

The gas flow A from the pressurizing chamber 11 generates a force for sucking the gas in the space above the movable main contact 2 into the gas flow A. In addition, the gas flow A passes under the movable main contact 2 and increases the gas pressure below the extraction terminal 7. As a result, the gaps 19 and 16 can be
A fresh gas flow B is generated that flows between the fixed main contact 1 and the movable main contact 2 through the contact.

Since the gap 16 is set to be narrow as described above, the gas flow rate is increased, and the movable main contact 2
The fresh gas flow B led upwards flows quickly between the two main contacts. Therefore, the staying gas C does not stay between the fixed main contact 1 and the movable main contact 2. Therefore, no flashover occurs between the main contacts due to the re-motive voltage between the main contacts after the arc is extinguished.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and it is needless to say that various modifications can be made without departing from the gist of the invention. Absent. For example, the shapes of the extraction terminal and the gas introduction cylinder are not limited to those in the embodiment. In short, the flow of fresh gas passes through the gap between the gas introduction cylinder and the outer shell container, and the main contact Any structure can be arbitrarily changed as long as the structure is supplied between the two.

Further, in the embodiment, a coil for rotating and driving an arc is provided in the boosting chamber. However, the present invention is also applicable to a self-extinguishing circuit breaker having no coil.

[0029]

According to the present invention, the gas flowing out of the boosting chamber does not stay between the main contacts, and a fresh gas flow is supplied between the main contacts. As a result, no flashover occurs between the main contacts.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a gas circuit breaker according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line DD in FIG. 1;

FIG. 3 is a sectional view of a main part of a conventional gas circuit breaker.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 fixed main contact 2 movable main contact 3 fixed arc contact 4 movable arc contact 5 upper electrode 6 sliding contact 7 lead terminal
8 ... insulation operation rod, 9 ... arc runner, 10 ... coil,
11 ... booster chamber, 12 ... nozzle, 13 ... booster chamber wall, 14 ...
Outer shell container, 15: gas introduction cylinder, 16, 19: gap, 17
... ribs, 18 ... openings.

Claims (1)

(57) [Scope of request for utility model registration] 1. A self-extinguishing type gas circuit breaker having a fixed main contact and a movable main contact disposed outside a pressurizing chamber in an outer shell container, wherein a gas introducing cylinder is provided between the movable main contact and the outer shell container. A gap is provided between the gas inlet cylinder and the outer shell container, and a space is also provided between the extraction terminal and the outer shell container which come into contact with the outer periphery of the movable main contact and draws a terminal out of the outer shell container. A gas circuit breaker, wherein a gap continuous with the gap is provided, and gas below the extraction terminal is guided between the main contacts from above the gas inlet cylinder through the gaps.