JPH06187882A - Puffer type gas-blast circuit breaker - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the force required to operate the drive rod and downsize the drive device. A notch 20A is provided in at least one slide ring 20, and a compression spring 21 is interposed between this slide ring 20 and a circumferential groove 8A of a fixed piston 8.

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 as a large capacity power circuit breaker.

[0002]

2. Description of the Related Art A puffer type gas circuit breaker compresses arc extinguishing gas and blows the compressed gas onto a gap of a breaking portion to extinguish the generated arc and shut off a large current. . As a gas for extinguishing an arc, SF ₆ gas is very excellent and is used even for an ultra-high pressure, large capacity circuit breaker. Figure 8
FIG. 4 is a cross-sectional view showing a main part configuration of a conventional puffer type gas circuit breaker. A fixed contact 3 supported via an insulator 2 in a cylindrical metal container 1 filled with SF ₆ gas of several atmospheres as an arc extinguishing gas, and a movable contact 4 capable of contacting and separating from the fixed contact 3.
And are arranged to form a separation gap portion 9. A first insulating nozzle 10A and a second insulating nozzle 10B are arranged so as to surround the movable contactor 4, support the insulating nozzle and the movable contactor 4, and have a drive rod 12 at the center. A puffer cylinder 5 is arranged.
The puffer cylinder 5 includes a main puffer chamber 6 formed by inserting a fixed piston 8 fixed via an insulating porcelain tube 7. An insulating rod 13 for driving the movable contact 4 is connected to the drive rod 12, and a hollow portion of the drive rod 12 forms an exhaust passage 12A for connecting the separation gap 9 and the free space 11. .

FIG. 9 is an enlarged one-sided sectional view showing the periphery of the fixed piston 8 of FIG. There is a central shaft (not shown) on the left side of FIG. 9, and the fixed piston 8 has circular grooves 8A and 8B.
Is provided. The slide rings 17 and 18 are fitted in the orbiting grooves 8A and 8B, respectively, and form the inner wall surface of the main puffer chamber 6 and the puffer cylinder 5 and the drive rod 12.
Is sliding. By the slide rings 17 and 18,
The gas in the main puffer chamber 6 is prevented from leaking downward.

FIG. 10 is a plan view of only the slide ring of FIG. 9 seen from the Q direction. The slide rings 17 and 18 are provided with slits 19 at one position on the circumference. The slit 19 is for fitting it into the circumferential groove of the fixed piston by slightly expanding it. Returning to FIG. 8, when the driving force in the X direction is transmitted from the driving device (not shown) through the insulating rod 13 when the current is cut off, the movable contactor 4, which is an integrated movable portion, and the first insulating nozzle. 10A, the second insulating nozzle 10B, the drive rod 12, and the puffer cylinder 5 move in the X direction.
The fixed contact 3 is the throat portion 1 of the first insulating nozzle 10A.
In the state where the gas does not escape from 0, as shown in FIG. 8, the gas compressed by the fixed piston 8 in the main puffer chamber 6 blows out from the blowing hole 5A. The blowing gas becomes a gas flow 14A, flows through the gap between the first insulating nozzle 10A and the second insulating nozzle 10B, and blows and cools the arc 15 generated in the opening gap portion 9. The gas heated by the arc 15 is discharged into the free space 11 as gas flows 14B and 14C in the exhaust passage 12A. The arc 15 becomes larger as the breaking current becomes larger and tries to close the inlet of the exhaust passage 12A, so that the gas flow 14A from the main puffer chamber 6 tends to flow less easily. for that reason,
The gas pressure in the main puffer chamber 6 rises as the breaking current increases.

Such an arc extinguishing method, that is, a method of extinguishing the inlet side of the exhaust passage 12A with the arc 15 so as to close the inlet side of the exhaust passage 12A and increasing the pressure increase in the main puffer chamber 6 is called "puff". It is called a puffer shape derived from the meaning of "blowing out", and when the fixed contact 3 escapes from the throat portion 10 of the first insulating nozzle 10A, a large amount of gas to be blown to the arc 15 can be taken. It is used.

FIG. 11 is a cross-sectional view of an essential part showing the structure of a conventional puffer type gas circuit breaker, which has the structure already filed and published by the same applicant as the present invention (Japanese Patent Laid-Open No. 3-219515). Issue). In the puffer cylinder 50, an auxiliary puffer chamber 16 which is configured separately from the main puffer chamber 6 is provided, and this chamber is provided with a communication hole 16A communicating with the opening / closing gap 9. An intermediate insulating nozzle 10C that guides the gas flow 14D from the puffer cylinder 50 is interposed between the first insulating nozzle 10A and the second insulating nozzle 10B. Also, the spray hole 50A
A check valve 17 for passing only the gas flow 14D in the direction from the main puffer chamber 6 to the separation gap portion 9 is provided at the outlet of the. The other configuration is the same as that of FIG. 8, and the configuration around the fixed piston 8 is also the same as that of FIGS. 9 and 10.

In FIG. 11, the gas in the opening gap portion 9 expanded by the heat of the arc 15 is the intermediate insulating nozzle 10C.
And the first and second insulating nozzles 10A and 10B, and enters the auxiliary puffer chamber 16 through the communication hole 16A. When the fixed contactor 3 escapes from the throat portion 10 of the first insulating nozzle 10A, a large amount of gas from the auxiliary puffer chamber 16 becomes a gas flow 14E and blows out the arc 15.
The check valve 17 is for preventing the gas expanded by the arc 15 from flowing back to the main puffer chamber 6 side, and the auxiliary puffer chamber 16 temporarily takes in the expanded gas. Therefore, the device of FIG. 11 has a smaller amount of pressure increase in the main puffer chamber 6 in the former case, as compared with that of FIG. 10, because there is no backflow of the expansion gas. Therefore, there is an advantage that the drive device for compressing the gas in the main puffer chamber 6 can be made smaller.

[0008]

However, the conventional apparatus as described above has a problem that the gas pressure in the main puffer chamber rises more than necessary. As the drive rod moves, the main puffer chamber shrinks. Some gas is discharged from the spray hole to the opening gap portion, but the outlet of the spray hole is filled with the expansion gas, so that the pressure rises faster in the main puffer chamber. Therefore, the gas pressure in the main puffer chamber increases more than necessary. In the apparatus of FIG. 11, since the auxiliary puffer chamber 16 and the check valve 17 are provided, the pressure increase in the main puffer chamber 6 is reduced to some extent, but the gas pressure increase due to only the drive rod 12 in the main puffer chamber 6 is reduced. The minutes are not relaxed. For this reason, if the drive device is made too small, a retrograde phenomenon in which the movable contact is pushed back occurs and it becomes impossible to shut off.

An object of the present invention is to obtain a structure in which the gas pressure in the puffer chamber is prevented from rising more than necessary during operation of the puffer type gas circuit breaker as described above, and particularly a puffer chamber structure.

[0010]

In order to achieve the above object, according to the present invention, a fixed contact and a movable contact capable of coming into contact with and separating from the fixed contact are provided in a metal container filled with an arc-extinguishing gas. ,
A puffer cylinder that interlocks with this movable contactor, a fixed piston that forms a main puffer chamber inside this puffer cylinder, and a gas that surrounds the movable contactor and is compressed in the main puffer chamber is provided on the anti-fixed piston side of the puffer cylinder. An insulating nozzle that is guided from the spray hole to the open gap between the fixed contact and the movable contact is housed, and the fixed piston opens toward the inner peripheral side and the outer peripheral side of the main puffer chamber inner wall, respectively. In a case in which a slide ring that is provided with a circumferential groove and in which a slide ring that slides on the inner wall surface of the main puffer is fitted in both circumferential grooves, at least one of the slide rings has a circumferential notch on the blow hole side. A plurality of compression springs are provided between the slide ring and the bottom surface of the orbiting groove, which are provided at the corners of the main puffer chamber that slide with the wall surface.

In this structure, the cutout portion of the slide ring is formed in a triangular shape, or
It is assumed that the cutout portion of the slide ring is formed in a square shape.

[0012]

According to the structure of the present invention, at least one of the slide rings is provided with a circular notch at the corner of the spray hole side on the side sliding with the inner wall surface of the main puffer chamber. further,
A plurality of compressible springs are interposed between the slide ring and the bottom surface of the circumferential groove. When the gas in the main puffer chamber is compressed by the fixed piston, the gas pressure acts on the cutout portion of the slide ring to press the slide ring toward the bottom surface of the circumferential groove. When the pressing force of the slide ring exceeds the spring force of the compression spring, a gap is created between the slide ring and the wall surface of the puffer chamber. Since the gas escapes through this gap, it is possible to prevent the gas pressure in the main puffer chamber from rising excessively. If the spring force of the compression spring is set to an appropriate value, the gas pressure in the puffer chamber need only be raised to the minimum value necessary for shutting off, so that it is not necessary to increase the operating force of the drive rod.

By forming the cutout portion of the slide ring into a triangular shape or a quadrangular shape, the cutout processing of the slide ring can be performed by a very simple operation.

[0014]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is an enlarged sectional view of essential parts of a puffer type gas circuit breaker according to an embodiment of the present invention. The slide ring 20 is provided with a triangular notch 20A on the sliding surface 5B side of the inner peripheral wall of the main puffer chamber 6, and a compression spring 21 is interposed between the slide ring 20 and the bottom surface of the circumferential groove 8A. Other configurations are the same as those of the conventional device shown in FIG. The same parts are designated by the same reference numerals, and detailed description thereof is omitted.

FIG. 2 is a plan view of only the slide ring 20 of FIG. 1 viewed from the P direction. Three compression springs are evenly arranged on the circumference, and slits 22 are provided. In FIG. 1, when the gas in the main puffer chamber 6 is compressed, the gas pressure 6A acts at a right angle on the tapered surface of the cutout portion 20A of the slide ring 20. That gas pressure 6
Of A, the component force in the radial direction (left direction in the figure) acts to move the slide ring 20 to the inner diameter side.

FIG. 3 is an enlarged cross-sectional view of an essential part showing a state where the slide ring 20 of FIG. 1 has moved to the inner diameter side. Gas pressure 6
When the component force of A exceeds the spring force of the compression spring 21, the slide ring 20 moves to the left and the gas flow 6B is formed.
As a result, the gas pressure in the main puffer chamber 6 does not rise excessively and is kept at a constant value. Since the slide ring 20 has the slit 22, it can be contracted toward the inner diameter side until the clearance of the slit 22 disappears. The compression spring 21
The spring force is set so as to press the slide ring 20 against the sliding surface 5B until the gas pressure in the puffer chamber reaches the minimum value necessary for shutting off. Since the fixed piston 8 does not excessively compress the gas in the puffer chamber 6, it is not necessary to keep the operating force of the drive rod strong. Therefore, the driving device can be made smaller than the conventional one.

FIG. 4 is an enlarged cross-sectional view of essential parts according to a different embodiment of the present invention. The slide ring 23 has the same configuration as that of FIG. 1 except that the slide ring 23 has a rectangular cutout portion 23A. The notch 23A receives the gas pressure 6A to the left and tries to move the slide ring 23 to the inner diameter side. FIG. 5 is an enlarged sectional view of a main part according to a further different embodiment of the present invention. The slide rings 24 and 25 arranged in both the circumferential grooves 8A and 8B of the piston 8 are provided with notched portions 24A and 25A, respectively, which are notched in a fan shape.
The compression spring 21 is interposed between the bottom surface of B and the bottom surface. The slide rings 24 and 25 both have slits as in FIG.
Are evenly distributed on the circumference. The other configurations are the same as those in FIG.

The slide rings 24 and 25 in FIG. 5 both receive the gas pressure 6A and try to move to the inner diameter side and the outer diameter side, respectively. As a result, a gap is formed on the sliding surfaces of the slide rings 24 and 25 as described above, and the gas in the main puffer chamber 6 can be released downward from both the inner peripheral side and the outer peripheral side of the fixed piston 8. Generally, the cutout portion of the slide ring may be provided on both sides of the inner and outer sliding surfaces of the fixed piston as shown in FIG. 5, but as shown in FIG. May be. Further, the cutout portion may have a cutout position at a corner on the sliding surface side of the blowing hole side of the main puffer chamber. By receiving the gas pressure, the slide ring moves and a gap is formed. Further, the shape of the notch may be arbitrary, and may be, for example, a polygon such as a triangle or a quadrangle, or a triangle whose one side is curved convexly or concavely. A triangle or a quadrangle is the easiest to process to form the notch.

FIG. 6 is a cross-sectional view of an essential part of a puffer type gas circuit breaker showing an application example of the configuration of the present invention. 11 is different from the conventional device shown in FIG. 11 in that the check valve is not provided at the outlet of the spray hole 50A, and the fixed piston 8 and the puffer chamber 6 are not provided.
The same slide ring 20 and compression spring 21 as in FIG. 1 are interposed between the inner wall and the inner wall. Gas is allowed to escape downward by the circumferential gap between the fixed piston 8 and the inner wall surface of the main puffer chamber 6, and the gas pressure in the main puffer chamber 6 can be kept to a minimum value. Therefore, the check valve required in the device of FIG. 11 can be omitted by changing the shape of the slide ring.

FIG. 7 is a time chart showing the pressure characteristics in the main puffer chamber when the current is cut off. The vertical axis represents the pressure in the main puffer chamber, and the horizontal axis represents the drive rod drive start time t ₁ to drive end time. Up to t ₂ . Curve 30,
Reference numeral 31 is the case of the apparatus of FIG. 8 without the auxiliary puffer chamber, and curve 30 shows the characteristic in the conventional configuration of FIG. 9 and curve 31 shows the characteristic of the configuration of the embodiment of FIG. Curves 32 and 33 are for a device having an auxiliary puffer chamber.
11 and FIG. 9 provided with the characteristic of the conventional configuration, curve 3
3 is a characteristic when the slide ring 20 in the embodiment of FIG. 1 is used in the configuration of FIG. 6 which does not include a check valve.

In the apparatus of FIG. 8, the pressure in the main puffer chamber is greatly reduced from Pa ₁ to Pa ₂ by the embodiment of FIG. On the other hand, also in the case of the apparatus of FIG. 6, it can be seen that the pressure in the main puffer chamber is reduced from Pb ₁ to Pb ₂ by the embodiment of the invention of FIG.

[0022]

As described above, according to the present invention, at least one of the slide rings has the cutout portion, and the compression spring is interposed between the slide ring and the circumferential groove of the fixed piston. As a result, the gas pressure in the puffer chamber is prevented from rising more than necessary, so that the force required to operate the drive rod is relaxed and the drive device can be downsized. Further, in the case of the device provided with the auxiliary puffer chamber, the check valve that was conventionally required can be omitted by applying the slide ring of the present invention, and the drive device can be made more compact.

Further, by forming the cutout portion of the slide ring into a triangular shape or a quadrangular shape, the cutout processing of the slide ring can be simplified and the processing cost of the slide ring can be kept low.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part showing the configuration of a puffer type gas circuit breaker according to an embodiment of the present invention.

FIG. 2 is a plan view of the slide ring of FIG.

FIG. 3 is a cross-sectional view showing a state where the slide ring of FIG. 1 has moved to the inner diameter side.

FIG. 4 is an enlarged sectional view of an essential part showing the configuration of a puffer type gas circuit breaker of a different invention.

FIG. 5 is an enlarged sectional view of an essential part showing the configuration of a puffer type gas circuit breaker according to still another embodiment of the present invention.

FIG. 6 is a cross-sectional view of essential parts showing the configuration of a puffer type gas circuit breaker showing an application example of the present invention.

FIG. 7 is a time chart showing pressure characteristics in the main puffer chamber when the current is cut off.

FIG. 8 is a cross-sectional view of essential parts showing the configuration of a conventional puffer type gas circuit breaker.

FIG. 9 is a one-sided sectional view showing the periphery of the fixed piston of FIG. 8 in an enlarged manner.

FIG. 10 is a plan view of the slide ring of FIG.

FIG. 11 is a cross-sectional view of essential parts showing the configuration of a conventional different puffer type gas circuit breaker.

[Explanation of symbols]

3: fixed contactor, 4: movable contactor, 5,50: puffer cylinder, 50A: spray hole, 6: main puffer chamber, 1
6: Auxiliary puffer chamber, 7: Insulating porcelain tube, 8: Fixed piston, 9: Opening gap, 10: Throat part, 10A: First insulating nozzle, 10B: Second insulating nozzle, 10C: Intermediate insulating nozzle, 12: drive rod, 12A: exhaust passage,
13: Insulating rod, 14A, 14D, 14E, 6B: Gas flow, 15: Arc, 16A: Communication hole, 8A, 8B: Circular groove, 18, 20, 23, 24, 25: Slide ring, 20A, 23A, 24A , 25A: Notch, 6
A: gas pressure, 20B: gap, 5B: sliding surface, 21: compression spring, 22: slit

Claims (3)

[Claims] 1. A metal container filled with an arc-extinguishing gas, a fixed contact, a movable contact that can be brought into contact with and separated from the fixed contact, a puffer cylinder that interlocks with the movable contact, and a main inside the puffer cylinder. Between the fixed piston forming the puffer chamber and the movable contactor, the gas compressed in the main puffer chamber is blown between the fixed contactor and the movable contactor through the spray hole provided on the side of the puffer cylinder opposite the fixed piston. An insulating nozzle that leads to the separation gap is housed, and the fixed piston is provided with circumferential grooves that open toward the inner peripheral side and the outer peripheral side of the main puffer chamber inner wall. At least one slide ring is provided with a circular notch at a corner of the spray hole side on the slide side with the wall surface in the main puffer chamber, in which a sliding slide ring is fitted. Puffer type gas circuit breaker, wherein a plurality of compression springs is formed by interposed between the bottom of the ride ring and peripheral groove. 2. The puffer type gas circuit breaker according to claim 1, wherein the cutout portion of the slide ring is formed in a triangular shape. 3. The puffer type gas circuit breaker according to claim 1, wherein the cutout portion of the slide ring is formed in a square shape.