JPH0548347Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention drives a movable contact that comes into contact with and separates from a fixed contact provided in an airtight container filled with arc-extinguishing gas to open and close it, and also drives a movable contact that connects and disconnects with a fixed contact provided in a sealed container filled with an arc-extinguishing gas. The present invention relates to measures for preventing insulation deterioration of an insulated operating rod disposed in a space from which the arc-extinguishing gas heated by the arc between both contacts is discharged.

[Prior art and its problems]

Currently, switching equipment, in which switching contacts such as fixed contacts and movable contacts are housed in a sealed container filled with an inert gas such as SF ₆ gas as an arc-extinguishing gas, is currently used in high-voltage switching equipment, especially high-voltage switching equipment. Buffer-type gas circuit breakers are the main type of circuit breaker, and for example, a buffer type gas circuit breaker having the structure shown in the example of FIG. 1 is known.

The figure shows the structure of a cut-off section that includes a fixed contact and a movable contact that is housed in a sealed container, and shows a bushing 2 that projects outward from the sealed container 1.
A fixed contact 4 connected to the conductor 2a, a movable contact 5 that approaches and separates from the fixed contact 4, a puffer cylinder 7 to which the movable contactor 5 is fixed, and a hollow shaft that is integrated with the puffer cylinder 7 at its axis. A fixed piston 8 defining a puffer chamber 10 between the exhaust pipe 7a and the puffer cylinder 7, and a fixed piston 8 surrounding the movable contact 5 and fixed to the puffer cylinder 7, move compressed gas in the puffer chamber with the fixed contact 4. An insulating nozzle 3 that leads to a separation gap with the contactor 3, a cylindrical current collector 6, a support base 9 that supports the fixed piston 8 and the current collector 6, and this support base 9.
a conductor 11b that leads to an external terminal 11a provided on the bushing 11, and the exhaust pipe 7a,
An insulated operating rod 12 that opens and closes the movable contact 5 via this exhaust pipe;
The blocking portion is formed mainly of a connecting rod 13 that connects the connecting rod 13 to a drive device (not shown).

When the movable part of the interrupting part is driven to the right in the figure via the connecting rod 13 when the current is interrupted, as shown in FIG. While an arc 14 is generated, the compressed gas in the puffer chamber 10 is guided to the insulating nozzle 3 and blown onto the arc 14. The gas blown onto the arc and heated is passed through the nozzle throat 3a.
through the direction of arrow E and inside 15 of exhaust pipe 7a.
is discharged from the discharge port 16 in the direction of arrow F. Therefore, the insulating portion 12 of the insulating operation rod 12
A will be exposed to hot gas heated by the arc.

By the way, the structure of the insulating part 12a of the insulating operation rod is made of glass fiber, for example, in order to increase the mechanical strength in the axial direction of the rod, as shown in the A-A sectional view of Fig. 2 shown in Fig. 3. The glass cloth 17 is wound as shown in the figure (the glass cloth is roughly wound in the figure for ease of understanding, but in reality it is wound tightly), placed in a mold, and then placed in a vacuum for example. It is impregnated with epoxy resin 18 and formed into a rod shape.

The insulating rod formed in this way, which forms the insulating part of the insulating operation rod, has extremely high mechanical strength, but when exposed to hot gas, it may deteriorate due to surface deterioration or carbonization. Insulation performance tends to deteriorate. On the other hand, highly heat-resistant insulating materials such as tetrafluoroethylene, which are resistant to deterioration or carbonization due to heat, are used in high-voltage circuit breakers, etc.
It has the disadvantage that it is not necessarily suitable for places that require light weight and high strength.

[Purpose of invention]

This idea provides heat resistance in terms of insulation performance in addition to mechanical strength to the insulated operating rod itself, without requiring structural changes such as moving hot gas heated by an arc away from the insulating operating rod. The purpose of this invention is to obtain an insulated operating rod.

[Key points of the idea]

This device drives a movable contact that comes into contact with and separates from a fixed contact provided in an airtight container filled with an arc-extinguishing gas to open and close the contact, and when the current is cut off, the contact is heated by the arc between the two contacts. In an insulated operating rod disposed in a space where arc-extinguishing gas is discharged, the insulating part of the insulating operating rod is separate from the insulating rod forming the insulating part, and only one end is bonded to the insulating operating rod. The strength member and the heat-resistant member are covered with a cylindrical heat-resistant insulating material, and the functions are shared by using appropriate insulating materials for the strength member and the heat-resistant member, thereby achieving the mechanical and The aim is to satisfy electrical performance at low cost.

[Example of idea]

FIG. 4 shows an embodiment of the present invention. Both ends of the insulating rod 12b forming the insulating portion 12a (FIGS. 1 and 2) of the insulating operating rod are connected to metal fittings 20 and 21, respectively, by a suitable method such as screw connection or riveting, and the metal fitting 20 has A connecting rod 13 is connected to the exhaust pipe 7a and the metal fitting 21, respectively. The insulating part 12a is formed into a cylindrical shape, and one end thereof is covered with a heat-resistant insulating material 23 bonded to the stepped ring 22 at the X surface, thereby protecting it from hot gas. The other end of the cylindrical heat-resistant insulating material 23 is
The insulating rod 12 is not fixed to the metal fitting 20 so as to cover it with a very small gap, and the insulating rod 12 is
The expansion and contraction of b is prevented from being transmitted to the heat-resistant insulating material 23. In this way, by forming a heat-resistant insulating material into a cylindrical shape and fixing only one end of the material to the insulating operation rod, a large amount of hot gas touches this insulating material when a large current is cut off, and the length of the insulating material increases. Even if it does stretch, it can stretch freely regardless of the insulating rod 12b inside, so it is not subject to mechanical stress, and this structure has the advantage of being applicable regardless of the magnitude of the breaking current. Note that if the thickness of this heat-resistant insulating material is, for example, about 2 mm, sufficient mechanical strength of the cylinder is usually obtained, so the increase in weight of the movable parts in the interrupting part can be almost ignored. Therefore, the influence on the opening/closing speed, that is, the breaking performance, can be substantially ignored.

[Effect of idea]

As described above, according to the present invention, it is possible to prevent the deterioration of the insulation performance of the insulating operating rod placed in the space where the arc-extinguishing gas heated by the arc at the time of current interruption is discharged. The insulation part of the insulated operating rod is covered with a heat-resistant insulating material, without making any structural changes such as moving the hot gas heated by the arc away from the insulated operating rod. By using appropriate insulating materials for each function, we have maintained the mechanical strength of the insulated operating rod and prevented the insulation performance of the insulated operating rod from deteriorating in hot gas. The effect is that deterioration of the insulation performance of the operating rod can be prevented at low cost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an example of the structure of the interrupting part of a puffer type gas circuit breaker, showing a closed circuit state;
Figure 2 is a diagram showing the discharge of arc-extinguishing gas heated by the arc at the time of current interruption at the interrupting part in Figure 1, and Figure 3 is the inside of the insulating rod forming the insulating part of the insulated operating rod. Diagram showing the structure in cross section,
FIG. 4 is a longitudinal sectional view of an embodiment of the present invention. 1... Sealed container, 4... Fixed contact, 5... Movable contact, 12... Insulated operation rod, 12a...
Insulating part, 12b... Insulating rod, 14... Arc, 15... Arc-extinguishing gas heated by arc, 16... Exhaust port, 23... Cylindrical heat-resistant insulating material, 24... Insulating sexual material.

Claims (1)

[Scope of utility model registration request] The arc-extinguishing gas is heated by the arc between the two contacts when the current is cut off, and the movable contact that comes into contact with and separates from the fixed contact provided in a sealed container filled with arc-extinguishing gas opens and closes. In an insulated operating rod disposed in a space from which gas is discharged, the insulating part of the insulating operating rod is separate from the insulating rod forming the insulating part and has a cylindrical shape with only one end glued to the insulating operating rod. An insulated operating rod for a contact in a closed container, characterized in that it is covered with a heat-resistant insulating material.