JP2010027558A - Gas breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas breaker capable of determining its exchange time by easily understanding a consumption degree of a throat section of an insulating nozzle. <P>SOLUTION: The insulating nozzle 17 is formed by having the throat section 19 with the minimum diameter in a blowing passage of an arc-extinguishing gas, a ring-shaped nozzle exchange yardstick groove 20 is formed on the throat section 19, and conditions of the nozzle exchange yardstick groove 20 formed on the throat section 19 are confirmed. When being damaged to such a degree that a cut depth on the nozzle exchange yardstick groove 20 disappears, it is determined that the throat section 19 is consumed to require exchange of the insulating nozzle 17, and the insulating nozzle 17 is exchanged for a new article. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas circuit breaker having an insulating nozzle for guiding an arc extinguishing gas against an arc generated between contacts.

  In general, the gas circuit breaker has a pair of contacts that can be separated, and an arc generated between the contacts that are separated when the current is interrupted is compressed by a compression device in connection with the interruption operation as well. An insulating nozzle is provided for guiding the arc-extinguishing gas to be blown. This insulating nozzle is formed of Teflon (registered trademark) or the like, and its throat portion is consumed under the influence of an arc when an accident current is interrupted. If this wear progresses and the throat portion diameter increases, the blocking performance is adversely affected. Therefore, the insulating nozzle is replaced depending on the degree of damage to the throat portion. In the conventional gas circuit breaker, when this throat part is damaged, it is noticed that the leakage of the blowing gas flow from the same part occurs, and this appears as a decrease in the pressure increase value in the compression device, A configuration has been proposed in which the correlation between the pressure in the compression device and the diameter expansion amount of the throat portion is grasped in advance and a pressure sensor for measuring the pressure in the compression device is provided (see, for example, Patent Document 1). ).

Japanese Patent Laid-Open No. 5-36333

  However, the conventional gas circuit breaker attempts to calculate the amount of expansion of the throat diameter by measuring the pressure in the compression device. However, the pressure increase value in the compression device is affected by the magnitude and phase of the interruption current. Therefore, it was not possible to simply calculate the amount of enlargement of the throat part diameter.

  An object of the present invention is to provide a gas circuit breaker that can easily grasp the degree of wear of a throat portion in an insulating nozzle and determine the replacement time.

  In order to achieve the above object, the present invention provides a pair of separable arc contacts, a compression device for compressing an arc extinguishing gas in connection with a breaking operation between the arc contacts, and a separation device. An insulating nozzle for guiding the arc generated between the arc contacts to blow arc extinguishing gas from the compression device, wherein the insulating nozzle blows arc extinguishing gas. The flow path has a throat portion with the smallest diameter, and a nozzle replacement guide groove is formed in the circumferential direction of the throat portion.

  According to the gas circuit breaker according to the present invention, the presence or absence of the nozzle replacement guide groove formed in the throat portion can be known by visual observation or touch. As a result, it is possible to correctly determine the replacement timing of the insulating nozzle with a simple configuration, and it is not necessary to perform skilled work such as measurement using a scale in a narrow space, and it can be shut off. No misjudgment is caused by the influence of the magnitude and phase of the current. In addition, since the nozzle replacement guide groove is formed in the circumferential direction of the throat portion, it is possible to correctly judge the overall situation rather than the local judgment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 3 is a partial cross-sectional front view showing a gas circuit breaker according to an embodiment of the present invention.
A pair of bushings 2a and 2b are respectively established at both ends in the axial direction of the sealed container 1 filled with an arc extinguishing gas excellent in insulation and arc extinguishing properties, and below the center conductor 3a of the bushing 2a. A fixed-side support conductor 5 is attached, and a movable-side support conductor 6 is attached below the center conductor 3b of the bushing 2b. A blocking portion 4, which will be described in detail later, is disposed between the fixed side support conductor 5 and the movable side support conductor 6, and this blocking portion 4 is configured to be opened and closed by an operating device 7. A gantry 8 is disposed at the lower portion of the hermetic container 1, and the entire gas circuit breaker is fixed to the attached surface by the gantry 8.

FIG. 1 is an enlarged cross-sectional view showing the breaker 4 of the gas circuit breaker described above.
The fixed support conductor 5 described above is fixed with a fixed main contact 9 that performs main energization in a put-on state and a fixed arc contact 10 that generates an arc by being released behind the fixed main contact 9. Has been. On the other hand, a fixed piston 14 is fixed to the movable support conductor 6 described above, and a movable shaft 11 is movably supported at the center of the fixed main contact 9 and the fixed piston 14. A movable arc contact 12 that is in contact with and away from the fixed arc contact 10 is attached. A puffer cylinder 13 slidably connected to the fixed piston 14 is connected to the movable shaft 11, and a puffer chamber 15 is formed by the puffer cylinder 13 and the fixed piston 14. Since the puffer cylinder 13 is connected to operate integrally with the movable arc contact 12, a compression device for compressing the arc extinguishing gas in the puffer chamber 15 is configured in relation to the shut-off operation. Become. The puffer cylinder 13 includes a movable main contact 16 that contacts the fixed main contact 9 in the charged state, and an insulating nozzle 17 that surrounds the contact portion between the fixed arc contact 10 and the movable arc contact 12. It is attached.

FIG. 4 is an enlarged sectional view showing the insulating nozzle 17.
The insulating nozzle 17 described above guides the arc extinguishing gas compressed by the compression device so as to be effectively blown against the arc generated between the fixed arc contact 10 and the movable arc contact 12. Is substantially cylindrical, and a blowing gas flow path 18 is formed therein. A throat portion 19 having a certain width and a minimum diameter is formed at an intermediate portion in the axial direction of the flow path 18 in the insulating nozzle 17. The throat portion 19 is almost closed by the fixed arc contact 10 in a normal charging state, and is appropriately set in relation to the outer diameter of the fixed arc contact 10. It has become an element that affects.

  A nozzle replacement guide groove 20 is formed in the throat portion 19 of the insulating nozzle 17 in the circumferential direction. The nozzle replacement guide groove 20 has a ring shape, a C shape, or the like that is continuous in the circumferential direction, has a width of about 2 to 3 mm in the axial direction of the insulating nozzle 17, and 2 to 3 mm from the inner surface. It is formed by cutting at a depth of. The width and depth of the nozzle replacement guide groove 20 can be determined empirically. However, the nozzle replacement guide groove 20 is not immediately indistinguishable due to arc damage, but should not be so large as to adversely affect the blowing gas flow. Yes.

Next, operation | movement of the gas circuit breaker mentioned above is demonstrated.
1 is in contact with the movable main contact 16 and the fixed arc contact 10 is inserted from the throat portion 19 of the insulating nozzle 17 to move the movable arc contact. 12 and the main circuit current flows through the central conductors 3a and 3b shown in FIG. 3 mainly through the former contact portion. When an accident occurs in the system and the main circuit current is interrupted, the movable shaft 11 and the movable arc contact 12 are driven rightward in the drawing by the operating device 7. At this time, since the fixed main contact 9 and the movable main contact 16 are first separated, the current to be interrupted flows through the fixed arc contact 10 and the movable arc contact 12. Thereafter, the fixed arc contact 10 and the movable arc contact 12 are separated from each other. In connection with this operation, the compression device compresses the arc extinguishing gas in the puffer chamber 15.

  When the breaking operation proceeds from the closing state shown in FIG. 1 to the halfway breaking state shown in FIG. 2, the fixed arc contact 10 and the movable arc contact 12 are separated to generate an arc. When the fixed arc contactor 10 comes out of the throat portion 19 of the insulating nozzle 17, the arc extinguishing gas in the puffer chamber 15 at that time flows into the gas flow flowing through the hollow portion of the movable shaft 11 and the throat portion 19 of the insulating nozzle 17. The arc generated between the fixed arc contact 10 and the movable arc contact 12 is effectively blown off while forming a gas flow that flows to the fixed arc contact 10 through the arc.

  2, the throat portion 19 is located between the opposite ends of the fixed arc contact 10 and the movable arc contact 12 and is therefore affected by the arc generated between the contacts. If the energy of the arc is large as in the case of a large current interruption or if the number of interruptions is increased, the throat portion 19 will be consumed and the diameter will increase and adversely affect the interruption performance. Therefore, it is necessary to replace the insulating nozzle 17.

  In view of this, the inspection of the interrupting part is performed after the period of periodic inspection or after a large current is interrupted, and the attached insulating nozzle 17 or the detached insulating nozzle 17 is observed if possible. At this time, the operator checks the state of the nozzle replacement guide groove 20 formed in the throat portion 19. If the nozzle replacement guide groove 20 is so damaged that the cut depth is lost, it is determined that the throat portion 19 is consumed as the insulating nozzle 17 is replaced, and the insulating nozzle 17 is replaced with a new one.

  The determination at this time is not made by measuring the inner diameter of the narrow throat portion 19 as in the conventional case, but by visually observing the state of the nozzle replacement guide groove 20 or by inserting the fingertip into the same portion. From this contact feeling, it can be determined by whether or not the nozzle replacement guide groove 20 still remains, so that it is easy and can be performed reliably even by a skilled operator. Moreover, since the nozzle replacement guide groove 20 is formed in the circumferential direction of the throat portion 19, the overall shape is a ring shape, a C shape, or the like, and is not a local observation but over the entire circumference. Since it can observe, the state of the throat part 19 can be judged more correctly.

  On the other hand, it is possible to check the state of the nozzle replacement guide groove 20 without disassembling and checking the blocking portion. For example, an X-ray imaging apparatus is disposed on the outer peripheral portion of the sealed container 1, the position corresponding to the insulating nozzle 17 is imaged, and the nozzle replacement guideline is obtained from the image displayed there as in the case of the previous embodiment. It can also be determined whether the working groove 20 is missing or still remaining.

FIG. 5 is a sectional view showing an insulating nozzle 17 of a gas circuit breaker according to another embodiment of the present invention.
In this embodiment, a plurality of nozzle replacement guide grooves 20 and 21 separated in the axial direction are formed in the throat portion 19 of the insulating nozzle 17. According to the plurality of nozzle replacement guide grooves 20 and 21 as described above, it is somewhat easier to see from the end side of the cylindrical insulating nozzle 17, and it is judged from the degree of the plurality of loss types, so that the consumption state can be judged correctly. Will be able to properly determine the time for replacement.

FIG. 6 is a sectional view showing an insulating nozzle 17 of a gas circuit breaker according to still another embodiment of the present invention.
In this embodiment, the cut shape of the nozzle replacement guide groove 22 formed in the throat portion 19 of the insulating nozzle 17 is changed. In the insulating nozzle 17 shown in FIG. 1, the nozzle replacement guide groove 20 having a rectangular bottom cross-sectional shape is used, but here the nozzle replacement guide groove 22 having a wedge-shaped cross section is used. In addition, a nozzle replacement guide groove having a semicircular bottom cross-sectional shape can be used, and substantially the same effect can be obtained.

  The gas circuit breaker according to the present invention is not limited to the structure of the interrupting portion shown in FIGS. 4 and 3 but can be applied to other structures.

It is sectional drawing which shows the interruption | blocking part injection state of the gas circuit breaker by one embodiment of this invention. It is sectional drawing which shows the interruption | blocking middle state of the interruption | blocking part shown in FIG. It is a fragmentary sectional view which shows the whole structure of the gas circuit breaker shown in FIG. It is an expanded sectional view which shows the insulation nozzle of the interruption | blocking part shown in FIG. It is sectional drawing which shows the insulation nozzle of the gas circuit breaker by other embodiment of this invention. It is sectional drawing which shows the insulation nozzle of the gas circuit breaker by further another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2a, 2b Bushing 3a, 3b Center conductor 4 Blocking part 5 Fixed side support conductor 6 Movable side support conductor 7 Actuator 8 Base 9 Fixed main contact 10 Fixed arc contact 11 Movable shaft 12 Movable arc contact 13 Pack Fur cylinder 14 Fixed piston 15 Puffer chamber 16 Movable main contact 17 Insulating nozzle 18 Gas flow path 19 Throat part 20-22 Nozzle replacement guide groove

Claims (1)

  A pair of separable arc contacts, a compression device for compressing the arc extinguishing gas in relation to the breaking operation between the arc contacts, and an arc generated between the arc contacts separated In the gas circuit breaker comprising an insulating nozzle for guiding the arc-extinguishing gas from the compression device to blow, the insulating nozzle has a throat portion having a minimum diameter in the arc-extinguishing gas blowing passage. A gas circuit breaker characterized in that a nozzle replacement guide groove is formed in the circumferential direction of the throat portion.

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