JP2519806Y2 - Tank cover for gas insulated transformer - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tank cover for a gas insulated transformer.

[0002]

2. Description of the Related Art As is well known, a gas-insulated transformer is constructed by housing a transformer body inside a tank, filling it with insulating gas, sealing it with a cover, and attaching a bushing to the upper surface of the cover. Composed.

FIG. 3 shows a cover of a conventional tank of a gas-insulated transformer. Reference numeral 1 denotes a cover body made of an iron plate. The bottom flange of the bushing is attached with bolts. However, in this conventional configuration,
The cylindrical base 2 is fixed to the cover body 1 by welding so as to be attached. Reference numeral 4 indicates the welding point.

When the cylindrical base 2 is attached by welding in this way, the insulating gas inside the tank may leak from the welded portion. Further, since there are many welding points, not only a long time is required for the mounting work, but also heat during welding may cause thermal distortion of the cover body 1.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to mount a bushing on the surface of a tank cover with a simple structure without welding.

[0006]

According to the present invention, a tap hole is formed around an insertion hole for a bushing conducting wire formed in a cover body so as not to penetrate the cover body, and the tap hole is utilized. , The bottom surface flange of the bushing is attached.

[0007]

The bushing can be directly attached to the cover body without the conventional cylindrical base. Since the mounting is performed by screwing, welding as in the conventional case is unnecessary. Therefore, there is no leakage of insulating gas from the welded part, the installation work is short, and heat distortion during welding does not occur.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. The cover body 1 is formed with a through hole 5 through which a bushing lead wire is inserted. This is the same as the conventional configuration. Then, a tap hole 6 is machined around the insertion hole 5 so as not to penetrate the cover body 1. FIG. 2 is an enlarged sectional view of the periphery of the insertion hole 5. Since the tap hole 6 is formed so as not to penetrate it, the insulating gas does not leak from the screwed portion.

A bushing is attached using the tap hole 6. This attachment is performed airtightly, for example, via packing, by the same method as that for attaching a bushing to the surface of the conventional cylindrical base 2. That is, the lower surface flange of the bushing is placed on the surface of the cover body 1, and the lower surface flange is fixed and attached by a bolt or the like screwed into the tap hole 6.

When mounted in this way,
Bushings can now be installed without the need for conventional welding, so leakage of insulating gas from the weld is eliminated. Since the tap holes 6 can be formed by simple machining, it is possible to manufacture the cover with the same quality in a large amount and in a short time. In addition, no thermal distortion occurs.

Even when other components are attached to the surface of the cover body 1, it is preferable to form the tap holes 6 and attach them directly to the surface of the cover body 1 as described above.

[0012]

As described above, according to the present invention, the bushing is attached to the surface of the cover that closes the tank of the gas insulated transformer without using conventional welding. It is possible to prevent the insulating gas from leaking from the welded portion and to easily manufacture it as compared with the conventional structure.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a part of FIG.

FIG. 3 is a perspective view of a conventional example.

[Explanation of symbols]

 1 Cover body 5 Insertion hole 6 Tap hole

Claims (1)

(57) [Scope of utility model registration request] 1. A transformer main body is housed inside, and
In a tank cover for a gas-insulated transformer that closes a tank that encloses an insulating gas, tap holes for screwing to attach the bottom flange of the bushing are formed around the insertion hole of the bushing conductor wire so as not to penetrate. Tank cover for gas insulated transformer.