JPS5935488B2 - gas-filled butsing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bushing, in particular, a central conductor is supported by an insulator tube, and an annular ground sill bottom is arranged on the outer periphery of the insulator tube to reduce the potential gradient on the ground side of the lower part of the insulator tube. Regarding the gas filled bushing.

Conventionally, a gas-filled Yapsing is constructed as shown in FIG. 1, for example. That is, in a substantially cylindrical insulator tube 1 filled with gas, a central conductor 3 whose periphery is covered with an insulating coating 2 is arranged on its longitudinal central axis. In order to reduce the potential gradient between the central conductor 3 and the lower flange 4 of the insulator tube 1, a cylindrical internal grounding shield 5 is disposed concentrically between the insulator tube 1 and the central conductor 3, and the insulator tube 1
A cylindrical external air grounding shield 6 is supported by a support 7 and is arranged concentrically, that is, annularly, in the air outside of the air. Further, on the high-pressure side, a high-pressure side shield 8 is arranged concentrically in the air outside the insulator tube 1. As is clear from FIG. 2, the external air grounding shield 6 has a long
It is constructed by bending a metal pipe into a circular shape.

The potential gradient when the gas-filled yapsing with such a configuration is in a field state is shown by equipotential lines as shown by dotted lines in the figure.

As is clear from these equipotential lines, gas-filled pushers are usually designed so that the internal insulation is higher than the external insulation. In other words, the insulation of the bushing is determined by the external insulation. In other words, it is limited by the potential gradient of the surface of the grounding shield in the air and the potential gradient of the surface of the porcelain tube on the grounding side. By the way, in order to lower the potential gradient and improve the insulation in a gas-filled cupping constructed using a standard type insulator, it is necessary to It is necessary to reduce the ratio with the diameter of the shield 6 which is formed by bending it into a shape.

However, bending a large-diameter metal pipe into a small-diameter circular shape is extremely difficult considering the ductility of the metal. had the disadvantage of significantly increasing production costs.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide an inexpensive gas-filled bushing. Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows an embodiment of the invention.

That is, in a substantially cylindrical insulator tube 11 filled with gas, a central conductor 13 whose periphery is covered with an insulating coating 12 is disposed along its longitudinal central axis. A cylindrical internal grounding shield 14 is disposed concentrically between the insulator tube 11 and the central conductor 13, and an external air grounding shield 21 is disposed concentrically, that is, annularly, in the air outside the insulator tube 11. There is. The external air grounding shield 21 is fixed to a flange 17 at the bottom of the insulator tube by a support 16. By the way, as is clear from FIG. 4, the external air grounding shield 21 is constructed by annularly supporting a plurality of electrode units 22, each of which is a hollow cylindrical body, with an annular support 23. The electrode unit 22 is, for example, a fifth
As is clear from the figure, it is made up of two cylinders 25 made by drawing process, butted together and welded, and the welded part 26 is polished to a smooth finish.

Alternatively, a pair of semicircular structures 27 and 28 of substantially the same structure as shown in FIGS.
It can also be constructed by arranging a plurality of bolts on the lower side, inserting bolts into the holes 30 of the structure body 28, penetrating the support body 23, and tightening the bolts to the taps 32 of the structure body 27.

If a die casting is used as the electrode unit, that is, the boat-shaped structure, the work required for the processing process will be extremely simple, leading to a reduction in product cost.

Note that the small hole 33 provided in the side wall of the boat-shaped structure 28
is used for draining water. According to the embodiment described above, the ratio between the diameter of the annular external air grounding shield and the diameter of each electrode unit constituting this grounding shield can be made small, so that the insulation properties of the gas-filled b bushing can be reduced. can be increased.

As is clear from the above description, according to the present invention, the annular external air grounding shield has an annular structure in which a plurality of hollow electrode units are supported through the annular support. The ratio between the diameter of the grounding shield and the diameter of the electrode unit can be reduced, improving the insulation properties of the gas-filled shushing, improving workability, and allowing multiple annular external air grounding shields to be constructed from the same electrode unit. As a result, an inexpensive gas-filled shibbutsuing with reduced production costs is provided.

That is, according to the present invention, the ground shield is constructed by passing a plurality of electrode units through an annular support.

Therefore, by reducing the diameter of the annular support, the ratio between the diameter of the grounding shield and the diameter of the electrode unit can be set to a small value.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional gas-filled D bushing.
2 is a view of the bushing shown in FIG. 1 taken along line A-A, FIG. 3 is a longitudinal sectional view of the gas-filled bushing according to the present invention, and FIG. 4 is a view of the bushing shown in FIG. 5 is an external view of the electrode unit used in the gas-filled D bushing shown in FIG. 4, and FIG. 6 is a diagram showing another example of the electrode unit. A plan view of one of the pair of semicircular boat-shaped structures, FIG. 7 is a view of the structure shown in FIG. 6 taken along the X-X line, and FIG. 8 is a plan view of the structure shown in FIG. - A view taken along the X-line, FIG. 9 is a plan view of the other of the pair of semicircular boat-shaped structures, FIG. 10 is a view of the structure shown in FIG. 9 taken along the Y-Y line, and FIG. The figure is a view of the structure shown in FIG. 9 taken along the y-Y line. DESCRIPTION OF SYMBOLS 11... Insulator tube, 13... Center conductor, 14... Internal grounding shield, 21... External air grounding shield, 2
2... Electrode unit, 27, 28... Boat-shaped structure electrode unit.

Claims (1)

[Scope of Claims] 1. A hollow insulator tube filled with gas, a central conductor disposed on a central axis within the insulator tube, and a central conductor disposed concentrically between the insulator tube and the central conductor. and an external air grounding shield disposed outside the insulator tube concentrically with the central axis, the external air grounding shield each being connected to a hollow body. 1. A gas-filled bushing characterized by having an annular structure in which a plurality of electrode units are supported through an annular support. 2. The electrode unit is composed of a pipe having support through holes at both ends, and the external air grounding shield is formed into a ring shape by passing the annular support through the through holes of the pipes. The gas-filled bushing according to claim 1, which is a gas-filled bushing according to claim 1. 3. The electrode unit is composed of a pair of divided hollow semi-cylindrical boat-shaped members, and the external air grounding shield is constructed by tightening the pair of hollow semi-cylindrical members with the support body in between. Gas-filled bushings according to scope 1.