JPS6023866Y2 - Dry butching - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a dry bushing.

In general, dry bushings are made of insulating paper 1 as shown in Figure 1.
A plurality of layers of intermediate electrodes 2 and 2 are laminated coaxially, and a through hole 5 is provided in the center of the core, which is impregnated and hardened with a synthetic resin 3, parallel to the lamination direction. A center conductor 6 having a smaller diameter is inserted through the inner diameter, and the center conductor 6 and the core 4 are connected to each other.
A so-called center clamp structure is known in which the two are fixed by the repulsive force of a spring.

However, this type of center clamp structure equipped with a spring not only has a large number of parts and a complicated structure and is expensive, but also requires holding all parts under the spring force, making it difficult to adjust the spring. The drawback was that it required considerable skill and was difficult to assemble accurately.

Moreover, since all the parts are supported under the elastic force of the spring, if a twisting force is applied to the center conductor, there is a risk that the spring or the metal parts that hold the spring will rotate and become misaligned with respect to the core 4. If a large compressive force is applied in the axial direction of the center conductor due to the repulsive force of the spring, the gasket that maintains airtightness with the core will float, causing a problem in that the airtightness of the bushing will be impaired.

Furthermore, if the spring were to break during use and its repulsive force was lost, it would not be able to maintain its structure as a bushing (and would become completely unusable), which had many drawbacks.

The dry type bushing of the present invention eliminates all of the above-mentioned drawbacks of conventional bushings, and is made by coaxially laminating multiple insulating papers and intermediate electrodes, and impregnating and curing them together with synthetic resin. In dry bushings using cores,
A through hole through which the center conductor is inserted is provided in the axis of the core, and a seal fitting is fixed to one end of the core with adhesive to maintain airtightness with a gasket interposed between it and the end surface of the core. A holding fitting having a sliding through hole in the center is fixed to the other end with adhesive, a center conductor is loosely inserted into the through hole of the core and the holding fitting, one of them is fixed to the sealing fitting, and the other is held. Supported slidably on the metal fitting side, electrically connecting the intermediate electrode of the innermost layer of the core to either the holding metal fitting or the sealing metal fitting, and connecting the center conductor and the holding metal fitting. It is constructed by electrically connecting.

The dry bushing of the present invention will be explained in more detail based on illustrated embodiments.

As shown in FIGS. 2 and 3, the dry type bushing of the present invention is made by laminating multiple layers of insulating paper 1 and intermediate electrodes 2 such as aluminum foil concentrically in a plurality of layers, similar to conventionally known ones, and using epoxy resin, etc. A through hole 5 is provided in the center of a core 4 impregnated with a hardened synthetic resin 3 in parallel to the stacking direction, and one end surface of the core 4 is cut to expose the innermost intermediate electrode 2'.

Then, on this exposed end surface, a short cylindrical crown part 8c having an inner diameter slightly larger than the end diameter of the core 4 is integrally connected and fixed to the periphery of a substrate 8b having a through hole 8a in the center. Then, a holding fitting 8 formed generally in the shape of a cap is fitted, and this is fixed with an adhesive 9 such as epoxy resin.

At this time, the innermost intermediate electrode 2 exposed on the end surface of the core 4
' and the holding fitting 8 are electrically connected.

Furthermore, a movable frame 10 having a smooth sliding surface on the inner surface is integrally fitted into the inner wall of the through hole 8a of the holding fitting 8, so that the center conductor 6 can be easily moved in the axial direction. It is.

The movable frame 10 may be integrally fitted into the center conductor 6 and slid on the inner wall of the through hole 8a of the holding fitting 8.

Further, at the other end of the core 4, a substantially cap-shaped sealing fitting 11 having a capping part 11a substantially similar to the capping part 8c of the holding fitting 8 is attached via a packing 12 using a material such as epoxy resin. It is fixed airtight using adhesive 9.

A center conductor 6 is inserted into the core 4 without contacting the inner wall of the through hole 5. In this state, one side of the center conductor 6 is fixedly supported by a seal fitting 11. The other side is supported by a movable frame 10 that is fitted into a holding fitting 8 as a two-piece so that it can freely slide in the axial direction, and the center conductor 6 and the holding fitting 8 are electrically connected. .

In the above embodiment, the innermost intermediate electrode 2' is exposed on the core end face on the holding metal fitting 8 side, and this intermediate electrode 2' and the holding fitting 8
Although the present invention is not limited to this, for example, the tip of the innermost layer intermediate electrode 2' may be exposed to the seal fitting 11 side, and this may be connected to the seal fitting 11. Of course, the present invention can also be implemented in this manner.

Note that various modifications can be made to the embodiments described in detail above within the scope of the present invention.

For example, as shown in FIG. 3, the center pipe 13 is inserted into the through hole 5 of the core 4, and both ends of the pipe are sealed! After fixing it to the sealing fitting 11 and the holding fitting 8, a separate conductor 14 for energization was loosely inserted into the center pipe 13, and one end of the conductor 14 was fixed airtight via the back packing 15 of the sealing fitting 11. Terminal fitting 16. It is also possible to use a so-called lead pull-up type structure in which the wire is connected to the wire.

Since the present invention is constructed as described above, it not only reduces the number of parts and simplifies the structure compared to conventional structures using springs, but also eliminates the need for difficult spring adjustment work. Moreover, the assembly work only requires fitting substantially cap-shaped holding fittings and sealing fittings to both ends of the core, which further simplifies the assembly and reduces costs.

Furthermore, the holding metal fittings and sealing metal fittings fitted to both ends of the core are fixed with adhesive, so even if a torsional force is applied to the center conductor, the holding metal fittings etc. will not rotate, and the center conductor Even if compressive force is applied in any direction, the seal will not float and the airtightness will not be broken, unlike with conventional spring structures.

In this way, the present invention not only has excellent characteristics despite its extremely simple structure, but also can provide a highly reliable dry bushing that can stably obtain a certain quality even during mass production, and is particularly suitable for high-voltage bushings. The present invention is industrially extremely useful as it sufficiently provides the required high reliability.

[Brief explanation of drawings]

Figure 1 is a sectional view of a conventional dry bushing, Figure 2 is a sectional view of a dry bushing according to an embodiment of the present invention, and Figure 3 is a sectional view of a dry bushing according to an embodiment of the present invention.
The figure is a sectional view showing a dry bushing according to another embodiment of the present invention. 1... Insulating paper, 2, 2'... Intermediate electrode, 3... Synthetic resin, 4... Core, 5...
...Through hole, 6...Center conductor, 7...
...Spring, 8...Holding metal fitting, 8a...
...Through hole, 8b... Board, 8C...
... Crown attachment part, 9... Adhesive, 10...
Movable frame, 11... Seal fitting, 11a...
・・Crown wearing part, 12・・・・Patsukin, 13・・・・
...Center pipe, 14...Conductor, 15...
...Packskin, 16...Terminal fitting.

Claims (1)

[Claims for Utility Model Registration] 1. In a dry bushing using a core 4 in which a plurality of insulating papers 1 and intermediate electrodes 2 are coaxially laminated and impregnated with a synthetic resin 3 and hardened, a center conductor is provided at the axis of the core 4. A through hole 5 is provided through which the core 4 is inserted, and a seal fitting 11 is fixed to one end of the core 4 with an adhesive 9 to ensure airtightness using a gasket 12 between the end surface of the core. A holding fitting 8 having a through hole 8a for movement is fixed with an adhesive 9, and a center conductor 6 is inserted into the core 4 and the through hole 5.8a of the holding fitting 8.
is inserted loosely, one of them is fixed to the seal fitting 11, and the other is slidably supported on the holding fitting 8 side, and the innermost layer intermediate electrode 2' is connected to either the sealing fitting 11 or the holding fitting 8. electrically connected to the center conductor 6
A dry type bushing characterized by electrically connecting a holding fitting 8 to the holding fitting 8. 2. The dry bushing according to claim 1, which is a registered utility model, in which a movable frame 10 is integrally attached to the inner surface of the through hole 8a of the holding fitting 8 so that the center conductor 6 can slide thereon.