JPH0541480Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a gas arc extinguishing device for a switch, and more specifically, a fixed-side auxiliary contact of a switch that has a main contact and an auxiliary contact. This invention relates to a gas arc extinguishing device for a switch equipped with a gas outlet for extinguishing an arc.

[Conventional technology]

FIG. 4 shows a conventional switch of this kind, in which a movable main circuit contact 2 is rotatably connected to a movable side terminal 1 about a shaft 3. The movable main circuit contact 2 operates to connect and separate from the fixed main circuit contact of the fixed main circuit terminal 4. Pressure spring 5 presses movable main circuit contact 2 against the fixed main circuit contact of fixed main circuit terminal 4 . The insulating rod 6 drives the movable main circuit contact 2 via a shaft 7 which is pivoted approximately in the center of the movable main circuit contact 2. The movable auxiliary contact arm 8 is rotatably attached to the shaft 3 and electrically connected to the movable terminal 1 via a sleeve 9. A movable auxiliary contact 10 is fixed to the other end of the movable auxiliary contact arm 8, and an arc contact 11 made of an arc-resistant metal such as copper or tungsten is fixed to the tip of the movable auxiliary contact 10. . The fixed side auxiliary contact 12 is made of arc-resistant metal like the arc contact 11, and is attached to a cylinder 13 that blows out insulating gas. cylinder 1
A piston 14 sliding within the piston 3 is moved by a piston rod 15. Fixed side auxiliary contact 12
There is a nozzle 16 made of an insulating material such as Teflon in the front part of the
is installed. A tension spring 17 is installed between the hook portion 8a provided on the movable side auxiliary contact arm 8 and the shaft 7.
is installed, and by the operation of the insulating rod 6,
A clockwise rotational force is applied to the movable auxiliary contact arm 8 about the shaft 3 to press the arc contact 11 against the fixed auxiliary contact 12.

As shown in FIGS. 5 and 6, the fixed side auxiliary contact 12 has a single gas blowing hole 18 in the center, and the front edge that contacts the arc contact 11 has a curved surface 19.

In the conventional switch having the above configuration, when the insulating rod 6 operates from the contact position between the movable main circuit contact 2 and the fixed main circuit terminal 4, the movable main circuit contact 2 is moved around the shaft 3 via the shaft 7. It is rotated counterclockwise to release the contact with the fixed circuit terminal 4. At this time, the movable side auxiliary contact 10 and the arc contact 1
1 is biased by a tension spring 17, and even if the movable main circuit contact 2 is operating, the arc contact 11 maintains contact with the fixed side auxiliary contact 12.
From this state, when the movable main circuit contact 2 hits the back surface 8b of the movable auxiliary contact arm 8, the movable auxiliary contact arm 8 operates in unison with the movable main circuit contact 2,
The contact between the arc contact 11 and the fixed side auxiliary contact 12 is separated, and the arc contact 11
An arc is generated between the fixed side auxiliary contact 12 and the fixed side auxiliary contact 12. On the other hand, due to the movement of the insulating rod 6, the piston rod 1
5 starts operating at the same time, and as a result, the piston 14 compresses the insulating gas sealed in the cylinder 13, and as the arc contact 11 opens, the gas is blown out from the gas blowing hole 18 of the fixed side auxiliary contact 12. The arc is blown out by the flow of insulating gas as shown by the broken line arrow in FIG.

[Problem that the invention attempts to solve]

In the conventional gas arc extinguishing device for a switch as described above, the arc is generated from the curvature surface 19 of the fixed side auxiliary contact 12, resulting in a large arc spot, so the arc contact 11 is opened due to arc energy. The immediate local gas temperature rise increases the pressure near the gas blowout hole 18, causing a state where the pressure becomes higher than the pressure inside the cylinder 13 that has been compressed by the piston 14, causing the gas to temporarily stagnate and extinguish the arc. It may become ineffective. This pressure imbalance phenomenon has the problem that the breaking current cannot be easily expanded because the arc energy increases as the breaking current increases.

This idea was made to solve the above problems, and it prevents the gas blowing from being stagnated due to the influence of arc energy, and the switch is equipped with a gas extinguisher that can easily expand the breaking current. The purpose is to obtain.

[Means for solving problems]

In the gas arc extinguishing device for a switch according to this invention, a fixed side auxiliary contact mounted on a cylinder is provided with a plurality of gas blowing holes. Further, the gas blowout hole is disposed facing the piston, and is disposed inside the arc generated between the movable side auxiliary contact and the fixed side auxiliary contact.

[Effect]

In this device, the insulating gas blown out from the gas blowout hole provided on the fixed side auxiliary contact is heated by the arc energy generated between the arc contacts, and the gas that rises in pressure near the gas blowout hole is The gas blown out from the blowout hole diffuses, creating a gas flow and extinguishing the arc.

〔Example〕

Figures 1 to 3 show an embodiment of this invention,
2 and 3, the fixed side auxiliary contact 22 has a plurality of gas blowing holes 23 formed on the side of the cylinder 13 shown in FIG.
A counterbore portion 24 for contacting the curved surface of the arc contact 11 is provided at the portion that contacts the arc contact 11 . Further, the tip end edge of the counterbore portion 24 forms a curved surface 25. Furthermore, a chamfering process 26 is applied to the rear end portion of the gas blowing hole 23.

The fixed side auxiliary contact 22 constitutes an arc extinguishing installation by replacing the fixed side auxiliary contact 12 shown in FIG. The other configurations are the same as shown in FIG. 4.

With the above configuration, when the movable main circuit contact 2 opens and closes, and subsequently the movable auxiliary contact 10 operates to open and close,
An arc is generated between the arc contact 11 and the fixed side auxiliary contact 22, but the gas flow blown out from the gas outlet 23 provided at the fixed side auxiliary contact 22 is
As shown by the broken line a in the figure, the flow is accompanied by turbulence. Due to such a gas flow and the independent gas blowing out from each gas blowing hole 23 as indicated by the broken line arrow b, the gas pressure near the gas blowing hole 23 is caused by the arc generated between the arc contact 11 and the fixed side auxiliary contact 22. The rising gas is diffused and cooled by the gas flow from other gas blowing holes 23, and the arc is extinguished.

Note that if an insulating gas such as SF ₆ gas is used as the insulating gas in the above embodiments, very good performance can be obtained.

[Effect of idea]

As is clear from the above explanation, this idea
A fixed main circuit contact and a movable main circuit contact of fixed main circuit terminals that come into contact with and separate from each other; a fixed side auxiliary contact that is attached to a cylinder that pumps insulating gas by the operation of a piston and has a plurality of gas blowing holes; The fixed side auxiliary contact and the movable side auxiliary contact are opened and opened following the opening and closing of the fixed and movable main circuit contacts, and the gas blowing hole is disposed opposite to the piston, and It is located inside the arc that occurs between the movable side auxiliary contact and the fixed side auxiliary contact, and the arc is extinguished by the gas flow of the insulating gas blown out from the back side of the arc through the gas blowout hole. The arc shape allows gas to be blown out and diffused effectively, resulting in high interrupting performance and the ability to easily expand the interrupting current.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of this invention,
FIG. 1 is a front sectional view of a main part showing an operating mode, and FIGS. 2 and 3 are a front sectional view and a side view of a part. Figures 4 to 7 show a conventional gas arc extinguishing device for a switch, with Figure 4 being a front view, Figures 5 and 6 being a partial front sectional view and side view, and Figure 7 being in operation. It is a main part front sectional view showing an aspect. 2...Movable main circuit contact, 4...Fixed main circuit terminal, 10...Movable side auxiliary contact, 13...Cylinder, 14...Piston, 22...Fixed side auxiliary contact, 23...Gas blowout hole. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] A fixed main circuit contact and a movable main circuit contact of fixed main circuit terminals that connect and separate from each other, and a fixed side auxiliary contact that is attached to a cylinder that pumps insulating gas by the operation of a piston and has a plurality of gas blowing holes,
a movable auxiliary contact that opens and opens with the fixed auxiliary contact following the opening and closing of the fixed and movable main circuit contacts, the gas blowing hole being disposed opposite to the piston; It is located inside the arc generated between the movable side auxiliary contact and the fixed side auxiliary contact, and the arc is caused by the gas flow of the insulating gas blown out from the back side of the arc through the gas blowout hole. A gas arc extinguishing device for a switch, characterized in that it is adapted to extinguish an arc.