JPH0139377Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a mounting structure for a bushing internal conductor shield of a tank-type gas circuit breaker.

Conventionally, tank-type gas circuit breakers shown in FIGS. 1 to 4 have been used.

Namely, 1 is the inner conductor of the bushing, 2 is the shield, 3 is the set screw, 4 is the connection contact, 5 is the gas insulated tank, 6 is the bushing, 7 is the tank branch pipe, 8 is the movable contact, and 9 is the fixed part. Contact part, 10
11 is an insulating member, 11 is a support member, 12 is an insertion opening, 13 is a bushing current transformer, 14 is a bushing current transformer case, and inside the gas insulated tank 5,
A movable contact portion 8 and a fixed contact portion 9 are supported and fixed via an insulating member 10 on a support member 11, and a bushing current transformer 13 and a bushing current transformer case 14 are provided in the tank branch pipe portion 7. The bushing 6 and the bushing internal conductor 1 are connected to each other, and the movable contact portion 8 and the fixed contact portion 9 are connected to the bushing internal conductor 1 via the connection contact 4. A shield 2 is arranged around 4 to alleviate the electric field.

Regarding the arrangement of the shield 2, there is a method of fixing it on the side of the movable contact section 8 and the fixed contact section 9, but in most cases, the movable contact section 8 and the fixed contact section 9 are arranged on the side of the gas insulating tank 5. Since it is assembled and inserted outside the tank, the insertion opening 12 in the tank is enlarged. Furthermore, attaching the shield 2 from the outside of the tank branch pipe section 7 after insertion into the gas insulated tank 5 poses a problem in terms of assembly work since the shield 2 is located far away.

For this reason, it is advantageous for the shield 2 to be connected to the bushing inner conductor 1.

A conventional bushing internal conductor shield mounting structure is shown in FIGS. 2 to 4. this is,
FIG. 2 is an enlarged detailed view of the shield mounting structure of the connecting portion A between the movable contact portion 8 and the fixed contact portion 9 and the bushing internal conductor 1 shown in FIG. 1;

As is well known, the bushing 6 is usually installed vertically or in a nearly vertical position.
As a means of completely fixing the bushing internal conductor 1 and the shield 2, the bushing internal conductor 1 and the shield 2 are threaded, the shield 2 is attached, and an adhesive is applied to the threaded part to prevent loosening. As shown in FIG. 4, a means for further fixing is taken from the outer periphery of the shield using set screws 3.

However, the above-mentioned attachment means has the following drawbacks.

(1) In the bushing inner conductor 1 and shield 2,
The parts are expensive because they require threading.

(2) Extra length is required for the screw connection part.

(3) Assembly work becomes complicated, and care must be taken not to seize the threaded parts.

(4) In the one shown in Fig. 4, the set screw 3 part is unfavorable in terms of withstand voltage.

This invention was made in order to eliminate the above-mentioned drawbacks, and the bushing internal conductor and shield can be manufactured at low cost, and the assembly work can be performed reliably and easily. The main objective is to provide a shield mounting structure that can improve reliability in preventing falling off.

Hereinafter, this invention will be explained in detail with reference to the drawings showing an example of its implementation.

In FIG. 5, the shield 2 is abutted against the bushing inner conductor 1 by means of a shrink fit. That is, the fitting surface 15 of the shield is formed so that the shield 2 is smaller at the same temperature in order to ensure that the shield 2 and the bushing internal conductor 1 have the same potential and are in contact with each other. .
Furthermore, in order to prevent the shield 2 from falling off due to its own weight or vibrations during operation of the circuit breaker, a fixing C-shaped ring 16 is attached to the groove of the bushing internal conductor 1 on the inner circumference of the shield 2. Also,
In order to facilitate insertion of the bushing inner conductor 1 into the connection contact 4, a guide rod 17 is fixed to the conductor 18 of the movable contact part and the fixed contact part.

As described above, according to this invention, since the shield is attached to the bushing internal conductor by shrink fitting, the shield and the bushing internal conductor can be manufactured at low cost, and also reliably and easily. Excellent effects can be obtained, such as ease of assembly work and improved reliability in preventing the shield from falling off.

In addition, in the above examples, the shield mounting structure was explained for the connection part of the movable and fixed contact part of the tank-type gas circuit breaker and the internal conductor of the bushing, but this example is applied to the connection part of the internal conductor of a gas-insulated switchgear. However, the same effect as above can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the schematic structure of a tank-type gas circuit breaker, Figs. 2 to 4 are sectional views showing the mounting structure of a conventional bushing internal conductor shield, and Fig. 5 is an embodiment of this invention. FIG. 1... Bushing internal conductor, 2... Shield,
3... Set screw, 4... Connection contact, 5... Gas insulated tank, 6... Bushing, 7... Tank branch pipe section, 8... Movable contact section, 9... Fixed contact section, 10 ...Insulating member, 11...Supporting member, 12
...Insertion opening, 13...Bushing current transformer,
14... Bushing current transformer case, 15... Fitting surface, 16... C-shaped ring for fixing, 17... Guide rod, 18... Conductor. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A shield placed around the connecting contact between the movable contact part and the fixed contact part of the tank-type gas circuit breaker and the bushing internal conductor is brought into contact with the bushing internal conductor by shrink fitting, and A tank-type gas circuit breaker, characterized in that a fixing C-shaped ring for fixing the shield is attached to the conductor groove.