JPS5831293Y2 - Patshua type gas breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a buffer type gas breaker, and particularly to a buffer type gas breaker with an improved gas blowing section.

In general, in a buffer type gas breaker, arc-extinguishing gas is sprayed from itself to the arc during the breaker operation, and the arc is generated by the relative movement of the cylinder and piston of the buffer device in conjunction with the opening operation. The blowout or shutoff performance is greatly influenced by the blowing gas flow.

Such a conventional buffer type gas breaker is shown in FIG.

In the figure, 1 is a tank with SF6 gas sealed inside.
A bushing 5 is provided on the upper protrusion of the tank 1 with an insulating spacer 3 interposed therebetween.

A fixed contact 6 is fixed to the tank 1 via an insulating stand 4, and a fixed current-carrying electrode 7 is provided around the contact 6.

Reference numeral 8 denotes a movable contact disposed opposite to the fixed contact 6, and a movable current-carrying electrode 9 is provided around the movable contact.

Reference numeral 10 denotes an insulating nozzle surrounding the movable contact 8, and the movable contact 8, the movable current-carrying electrode 9, and the insulating nozzle 10 are fixed to the cylinder 11.

Reference numeral 13 denotes a fixed piston provided within the cylinder 11, and the cylinder 11 and piston 13 form a buffer chamber 12a.

14 is a fixed stand fixed to the tank 1 via the insulating stand 4.

Reference numeral 15 indicates a connecting portion that connects the fixed base 14 and the conductor inside the bushing 5.

16 has one end fixed to the cylinder 11 and the other end connected to the operating device 2.
This is an operating rod connected to the lever 17 inside.

When disconnecting, the operating rod 16 operated by the operating device 2 moves the movable contact 8 and the movable current-carrying electrode 9 rightward from the closing position 18 indicated by the dashed line to open the circuit and disconnect the circuit.

At this time, the cylinder 11 connected to the operating rod 16 is moved to compress the gas in the buffer chamber 12a formed between the cylinder 11 and the piston 13.

This compressed gas passes through a passage 12b provided in the piston 11, and an arc 19 is generated between the fixed contact 6 and the movable contact 8.
spray in the direction of the arrow through the nozzle throat of the insulating nozzle 10.

Current interruption by such spraying of compressed gas is achieved by two main loss mechanisms.

One is the loss due to the internal energy of the arc being carried away by the gas flow parallel to the arc.
One is the loss carried away in the radial direction by heat conduction or turbulence.

It is said that the loss due to the gas flow parallel to the arc is dominant near the current peak of the cutoff current number 10 KA, but it is currently unclear which of these is dominant near the current zero where the cutoff occurs. It has not been done.

Moreover, the energy at the current peak is accumulated until the current reaches the zero point, so it is necessary to spray the gas at a higher speed to improve the interrupting performance.

FIG. 2 is an enlarged view of the upstream side of the gas passage of the nozzle throat, in which a contact support 21 that supports the movable contact 8 is integrated into the cylinder 11 connected to the operating rod.

The movable contactor 8 is pressed by a spring 23 and attached by a spring holder 22, and an insulated nozzle 10 is fixed to the outside of the spring holder 22 by a movable current-carrying electrode 9.

The gas compressed by the screws 1 to 1 in the cylinder 11 is passed through the passage 1.
2 b to the left to reach the nozzle throat.

The cross-sectional area of the gas passage from the buffer chamber to the nozzle changes as shown by the curve 30 in FIG. 4, corresponding to the positions a, l), c, d, and e.

In this way, the cross-sectional area of the gas passage becomes smaller at the exit e of the buffer chamber.

This is because a portion of the gas flow passage is blocked by the support that supports the cylinder 11.

For this reason, some of the gas discharged from the buffer chamber generates vortices and causes loss, or becomes a dead volume due to pressure increase, resulting in disadvantages such as ineffectiveness.

For this reason, conventionally, as shown in FIG.
2 in a radial manner to keep the flow in a constant direction and prevent vortices from forming, but although the gas flow is considerably improved, it is still not sufficient.

The present invention was developed in view of the above-mentioned drawbacks, and provides a buffer-type gas breaker that reduces the dead volume on the upstream side of the gas passage of the nozzle throat, reduces gas loss on the upstream side, and sprays gas effectively. The purpose is to provide.

An embodiment of the present invention shown in the drawings will be described below.

In FIG. 5, parts having the same functions as those in FIG. 2 are given the same reference numerals, and their explanations will be omitted.

The outer diameter side of the passage 12b from the buffer chamber of the cylinder 11 is increased to increase the cross-sectional area of the passage 12b.

On the other hand, in order to make the diameter of the gas passage between the wire edge nozzle 10 and the spring support 22 the same as the diameter of the passage 12b, the inner diameter on the cylinder side of the insulating nozzle 10 is made larger and the inner diameter on the downstream side of the gas passage is increased. Inclined portion 10 with a smaller inner diameter
Provide a.

In the gas passage formed between the opposing surfaces of the spring retainer 22 and the insulating nozzle 10, a cover 25 is supported by a spring so as to face the passage support 12C so as to close the dead volume created by the passage support 12C of the passage 12b. It is fixed at 22.

As a result, the cross-sectional area of the gas passage in the inclined portion 103 portion is made to be approximately constant.

That is, the cover 25 is formed into a pyramid shape that becomes narrower from the support 12C side to the nozzle throat side as shown in FIG.

Therefore, the cross-sectional area of the gas passage upstream of the nozzle throat remains almost constant without increasing or decreasing between positions c, d, and e, as shown by curve 31 in FIG. The volume can be reduced, and gas can be effectively blown onto the arc.

In addition, although the cover 25 is fixed to the spring support 22 in the above example,
It may be fixed to the insulating nozzle 10 or to the contact support 21.

As described above, according to the present invention, in a buffer type gas breaker, by providing an inclined part on the inner surface of the cylinder of the insulating nozzle so that the inner diameter becomes smaller toward the downstream side of the gas passage, the cylinder side end of the insulating nozzle The cross-sectional area of the gas passage at the cylinder outlet is made the same as the cross-sectional area of the gas passage at the outlet of the cylinder, and the dead volume part due to passage support is closed by installing a cover, and the cross-sectional area of the gas passage at the slope part is made almost the same. As a result, it is possible to eliminate the increase and decrease of the gas passage on the upstream side of the nozzle throat, reduce the flow loss on the upstream side of the nozzle, and effectively spray the gas to the arc, improving the current interrupting performance. There are effects that can be improved.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing a conventional buffer type gas breaker, Figure 2 is an enlarged vertical cross-sectional view of the main parts of Figure 1, Figure 3 is a left side view of the main parts, and Figure 4 is the nozzle throat. FIG. 5 is an enlarged vertical sectional view of the main part showing one embodiment of the buffer type gas breaker of the present invention, FIG. 6 is a left side view of the main part, and FIG. FIG. 7 is a diagram showing the passage cross-sectional area on the upstream side of the nozzle throat.

Claims (1)

[Scope of utility model registration request] A fixed contact, a movable contact provided on a buffer device opposite to the fixed contact, and a movable contact that surrounds the movable contact and traps the arc-extinguishing gas that is formed in the buffer device and passes through the gas passage when the circuit is cut off. It consists of an insulated nozzle that sprays between a contact and a movable contact, and an inclined part is provided on the inner surface of the insulated nozzle on the buffer device cylinder side so that the inner diameter decreases toward the gas downstream side, and this inclined part is located A cover is provided in the part of the gas passage facing the passage support,
A buffer type gas breaker characterized in that the cross-sectional area of the gas passage at the outlet of the buffer device and the cross-sectional area of the gas passage at the inclined part of the insulating nozzle are made almost the same by this cover.