JPH0797464B2 - Buffer type gas circuit breaker - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a puffer type gas circuit breaker having a structure in which carbon nozzles are attached to the tips of a fixed contact portion and a movable contact portion, respectively.

[Technical background of the invention] Since the puffer type gas circuit breaker has a simple structure and is superior in breaking performance to other types of gas circuit breakers, it has become the mainstream as a circuit breaker for a high voltage transmission system of 60 kV or more. There is. In order to further improve the large current interruption performance of this puffer type gas circuit breaker, there is a plan to use carbon in the portion which will be the arc electrode.

In a gas circuit breaker using an arc electrode of normal arc-resistant metal <Cu (copper) -W (tungsten)>, when breaking a short-circuit large current, 80% or more of the composition in the arc is occupied by copper vapor. By reducing this copper vapor (or metal vapor), it is possible to improve the large current interruption performance (mainly in the case of short-range failure). It is an attempt to achieve such an object by using carbon for the arc electrode portion.

Conventionally, as a puffer-type gas circuit breaker using a carbon member for the arc electrode part, the structure shown in Fig. 4 was introduced in more detail in Siemens Reviw XL111,1976, No1, P33, and the carbon electrode (graphite There is a description of use.

In this structure, two fixed nozzles 1 and 2 are arranged coaxially with a predetermined spacing S, and fixed carbon nozzles 1a and 2a are attached near the narrowest part of the fixed contact to form nozzles.

On the opposite sides of the fixed carbon nozzles 1a and 2a, coupling flanges 1b and 2b are provided, and the insulating cylinder 3 is provided between them.
Are connected via. A movable cylinder 5 that supports the outer periphery of an axially slidable cylindrical movable contact 4 that is bridged between the fixed nozzles 1 and 2 and that can be separated, and an operation rod 6 of this movable cylinder 5. The movable contact 4 is connected via a drive device (not shown).
A compression chamber 8 is formed between the inner wall of the movable cylinder 5 and a fixed piston 7 slidably arranged on the inner wall, and the fixed piston 7 is flanged via a support rod 7a.
It is fixed at 2b.

[Problems of Background Art] In the puffer-type gas circuit breaker configured as described above, when a shutoff command is given, the tip of the fixed nozzle 1 and the tip of the fixed nozzle 1 are separated by the movement of the movable contactor 4 and the fixed nozzle 1. An arc 9 is generated between the tip of the movable contactor 4 and the movable contactor 4, and the compressed SF ₆ gas 10 is blown from the compression chamber 8 accordingly, and the foot of the arc 9 enters the fixed nozzle 1 and the carbon nozzle 1a, 2a becomes the arc electrode.

Therefore, generation of metal vapor is suppressed as much as possible, and a good state for interrupting a large current is secured.

The cab S is selected so that it is easy to interrupt a short-range fault in which the rise of the re-electromotive force is sharp.

As described above, in the example of the puffer type gas circuit breaker of FIG. 4, since the gap S for breaking is not so large and fixed, it is not possible to endure the breaking duty of high restart voltage.
In addition, it is difficult to insulate against a high lightning surge voltage.

Further, in the example of FIG. 4, after the cover portion 5a of the movable cylinder 5 reaches the position where the cover portion 5a overlaps with the fixed contactor 2, the gas 10 turns into the arc 9
The efficiency of gas utilization is very poor because it is wasted because it cannot be sprayed onto. Therefore, in the example of FIG. 4, it is difficult to develop an arc extinguishing chamber for high voltage and large current.

In order to solve such a drawback, in JP-A-58-186122, a fixed nozzle 2 on the movable side in FIG.
A plan to move is proposed.

However, when the link is used, the structure is complicated, and it is necessary to assemble the link part which is troublesome. It also requires a relatively large space for links.

[Object of the Invention] The present invention has been made based on the above circumstances, and an object of the present invention is to provide a puffer type gas circuit breaker having a simple structure suitable for high voltage and large current interruption.

[Summary of the Invention] In order to achieve the above object, the present invention has a fixed contact portion and a movable contact portion facing each other in a closed container filled with an arc extinguishing gas such as SF6 gas. A buffer-type gas that extinguishes the arc by extinguishing the arc-extinguishing gas compressed by the puffer piston in the puffer cylinder of the movable contactor during polar operation In the circuit breaker, a movable side nozzle having a contactor, a current-carrying contactor and a drive pipe to which the puffer cylinder is attached, and a force applied in the direction of the fixed contactor portion by a spring supported in the drive pipe. The movable-side nozzle has a movable pipe and a cylindrical carbon nozzle at the narrowest portion on one end side of the movable pipe. A first engaging portion that engages when closed to form a predetermined distance between the fixed contact portion and the carbon nozzle of the movable side nozzle is disposed on each of the other end sides of the movable pipe side and the drive pipe. On each side, at the time of the opening operation, the current-carrying contactor of the movable contact portion is separated from the fixed nozzle, and the tip of the current-carrying contactor engages from the position moved near the tip portion of the movable-side nozzle, Second movement of the movable nozzle together with the drive pipe
The engaging portion is formed.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. First, one embodiment will be described with reference to FIG.

FIG. 1 is a cross-sectional view showing a structure of an arc extinguishing chamber of a puffer type gas circuit breaker according to the present invention. The upper half shows a closed state and the lower half shows an open state.

The fixed nozzle 21 of the fixed contact portion is fitted so that the carbon nozzle 21a can energize the contact pipe 21b, and this contact pipe 21b is fixed to the pipe 21c by brazing or the like with the carbon nozzle 21a attached. There is.

Further, in the movable part, an insulating nozzle fixed to the flange part 34a of the drive pipe 34 connected to the operation rod 26 by the rib 26a by the puffer cylinder 25 and the nozzle retainer 33.
32, the energizing contact 24 is attached.

When the electrodes are closed, the energizing contact 24 contacts the outer peripheral portion of the contact pipe 21c of the fixed nozzle 21 to guide the current from the fixed contact portion to the movable contact portion. If the rated energizing current is large, a contact larger than the energizing contact 24 on the fixed side (not shown)
It is possible to introduce an electric current by providing a nozzle with the outer periphery of the nozzle retainer 33. A compression chamber 28 is constituted by the puffer cylinder 25 and the fixed puffer piston 27.

Further, a hollow nozzle of the drive pipe 34 is provided with a flexible nozzle 22 having a carbon nozzle 22a fitted at its tip. The contact pipe 22c and the pipe 22d are similar to the fixed nozzle 21.
It is fixed by brazing. Also, this movable side nozzle
The spring 22 supported by the drive pipe 34 applies a force to the nozzle 22 toward the fixed nozzle 21. The rear portion of the movable nozzle 22 is connected to the rod 36 via the rib 36a.

Further, as shown in the sectional view of FIG. 2, a slide plate 40 is attached to the rod 36 by a pin 36b, and the slide plate 40 is a cylinder attached to a movable part supporting member 38.
It is slidably fitted in a groove 37a provided in 37.

When the upper half of FIG. 1 is opened, the movable nozzle 22 is a spring.
Although the force is applied to the left by 35, the slide plate 40 is stopped by the tip projection of the groove 37a of the cylinder 37 (first engaging portion). As a result, the position of the movable nozzle 22 at the time of closing is determined, and the fixed nozzle 21 and the movable nozzle 22 are separated by a small gap S ₁ .

Further, at this time, the protrusion 24a formed on the energizing contact 24 inside the drive pipe 34 and the protrusion 22d _{1 on} the outer periphery of the movable nozzle 22.
A gap S ₂ is maintained between and.

The drive pipe 34 is slidably supported by the sliding contact portion 27a of the puffer piston 27 and the sliding contact portion 38a of the movable portion support member 38.

In the support part, the sliding part 38a by the movable part support member 38
Can also have a structure for supporting the operating rod 6 as shown in FIG.

As described above, in the structure shown in FIG. 1, when the driving force is transmitted from the driving mechanism (not shown) to the driving rod 26 and the opening operation is started, the puffer cylinder 25, the energizing contact 24, and the driving pipe 34 are formed in the same body. The insulating nozzle 32 and the like move to the right.

On the other hand, the movable nozzle 22 is kept in the closed position by the action of the spring 35, but when the drive pipe 34 moves by the stroke S ₂ , the protrusion 24a of the energizing contact 24 and the outer peripheral protrusion of the drive pipe 34 are moved. Since the portion 22d ₁ hits (the second engaging portion), after that,
It becomes the same body as the drive pipe 34 and moves to the right.

Therefore, unlike the conventional example of FIG. 4, the gap between the fixed nozzle 21 and the movable nozzle 22 can be increased during the opening operation. At the end of the contact opening operation, as shown in the lower half of FIG. 1, the gap between the fixed nozzle 21 and the movable nozzle 22 is set to a gap S ₃ of a length sufficient to enhance the insulating ability.

In the puffer type circuit breaker according to the embodiment of the present invention described above, when the current is interrupted, an arc is first generated between the tip of the fixed nozzle 21 and the tip of the movable contact 24. Arc 29 by gas flow 30 from compression chamber 28
Are moved inside the nozzle, and carbon nozzles 21a, 22a
It is made to exist in between. Therefore, the generation of metal vapor is minimized, and good blocking performance is secured.

As can be seen from the lower half of FIG. 1, the gas flow 30 from the compression chamber 28 is effectively blown onto the arc 29 until the end of the opening operation. Therefore, the utilization efficiency of the arc-extinguishing gas is much higher than that of the conventional example shown in FIG. As a result, the compression chamber 28 can be downsized.

FIG. 3 is a sectional view showing only a part of another embodiment of the present invention. The operating rod 26 is slidably supported by the sliding contact portion 38a of the movable portion supporting member 38 shown in FIG.
The right end portion of the figure is such that it is not supported by the movable portion support member 38. Even with this structure, the same effect as that of the embodiment shown in FIG. 1 can be obtained.

EFFECTS OF THE INVENTION As described above, according to the present invention, since carbon is used in the portion that becomes the arc electrode and the first and second engaging portions are provided, the carbon mounting is performed during the closing operation. Departments do not collide,
During the breaking operation, the gap between the arc electrodes can be made sufficiently long, and the gas utilization efficiency can be improved. Therefore, it is possible to provide a compact buffer type gas circuit breaker capable of breaking high voltage and large current. .

[Brief description of drawings]

FIG. 1 shows an embodiment of a puffer type gas circuit breaker according to the present invention, wherein an upper half part thereof is in a closed state and a lower half part is in a opened state. 1 is a sectional view showing a slide plate portion of FIG. 1, FIG. 3 is a sectional view showing a part of another embodiment of a puffer type circuit breaker according to the present invention, and FIG. 4 is a conventional one using carbon for electrodes. It is sectional drawing which shows an example of a puffer type gas circuit breaker. 21 …… Fixed nozzle, 24a …… Carbon nozzle, 22 …… Moveable nozzle, 24 …… Current contactor, 25 …… Puffer cylinder, 26 …… Operating rod, 27 …… Puffer piston, 28
...... Compression chamber, 29 …… Arc, 30 …… Gas flow, 32 …… Insulation nozzle, 33 …… Nozzle support, 34 …… Drive pipe, 35 ……
Spring, 36 ...... rods, 36a ...... ribs 37 ...... cylinder, 38 ...... movable support member, 22 d ₁ ...... drive pipe outer peripheral protrusions.

Claims (1)

[Claims] 1. A sealed container filled with an arc-extinguishing gas such as SF6 gas has a fixed contact portion and a movable contact portion facing each other, and inside the puffer cylinder of the movable contact portion at the time of opening operation. In the puffer type gas circuit breaker for extinguishing the arc-extinguishing gas compressed by the puffer piston of the arc generated by the tip of the fixed or movable contactor, The movable pipe has a drive pipe to which the puffer cylinder is attached, and a movable nozzle to which a force is applied in the direction of the fixed contact portion by a spring supported in the drive pipe. And a cylindrical carbon nozzle at the narrowest part on one end side of the movable pipe, and engages on the puffer piston side and the other end side of the movable pipe at the time of closing, A first engaging portion for forming a predetermined distance is arranged between the fixed contact portion and the carbon nozzle of the movable side nozzle, and the movable contact side of the movable contact side is provided on each of the movable pipe side and the drive pipe side during the opening operation. Secondly, the energizing contact is separated from the fixed nozzle, the tip of the energizing contact is engaged from a position moved to the vicinity of the tip of the movable side nozzle, and the movable side nozzle is moved together with the drive pipe.
A puffer-type gas circuit breaker, characterized in that an engaging portion of is formed.