JPS584174Y2 - molded coil - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a molded coil with improved main insulation interposed between high and low voltage coils.

Generally, for molded coils, a low-voltage coil is wound on an insulating cylinder, a film is wound and laminated several times to several tens of times as the main insulation part on this low-voltage coil, and then a high-voltage coil is further wound on this main insulation part. There is one in which the contents of the coil are molded in a vacuum using a synthetic resin.

By the way, even if such a molded coil is molded in a vacuum, a highly viscous synthetic resin will enter between the film layers of the main insulation part, and the molded synthetic resin and film will have poor adhesion, resulting in peeling. This shortens the creepage distance, making dielectric breakdown and partial discharge more likely to occur.

Therefore, in high voltage equipment, the main insulation section has become a major defective section.

For example, there is a structure in which synthetic resin is infiltrated between the duct pieces by interposing duct pieces at intervals in the circumferential direction between high and low voltage coils, but the infiltrated synthetic resin hardens and shrinks toward the center of the coil. In this case, the stress does not act on the duct piece portion, but acts between the duct pieces and is localized, resulting in the disadvantage that peeling occurs at the side boundaries of the duct pieces.

The present invention was developed to eliminate the above-mentioned drawbacks, and provides a molded coil with improved insulation strength of the main insulation portion of the molded coil.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a low-voltage coil 12 and a high-voltage coil 13' are wound around the outer periphery of an insulating cylinder 11.
．． A main insulating portion 14'' is interposed between the coils 13 to constitute the coil contents.

As shown in FIG. 2, the main insulating section 14 in the molded coil of the present invention is constructed by arranging wavy insulating plates 14C made of laminated films so that the traveling direction of the waves is in the circumferential direction of the coil.

Insulating plates 14a and 14b are provided on the outer periphery of the corrugated insulating plate 14C, which are formed by stacking a large number of insulating papers (for example, 7-Mex, etc.) and bonding or pressing them together.

The insulating plates 14a and 14b are integrally formed with the corrugated insulating plate 14C, making it easier to attach the coils to the high-voltage coil 1 wound around the outside of the main insulating section 14.
3 is provided to ensure uniform winding, and is not necessarily required.

Then, the contents of the coil thus constructed are housed in a mold (not shown), vacuum molded with synthetic resin, and molded insulation 15 is applied.

With this configuration, a gap is created along the axial direction of the coil on the inside and outside of the main insulating section 14, especially the corrugated insulating plate 14C, with both ends open. Even in this case, the synthetic resin easily penetrates into the main insulating portion 14, and the entire gap is filled with the synthetic resin.

Moreover, the corrugated insulating plate 14C has a long circumferential length,
Since the adhesive area with the synthetic resin increases, the adhesive strength increases.

In addition, when the synthetic resin hardens and contracts toward the center of the coil, the stress is applied uniformly to the entire circumference of the coil rather than locally because the synthetic resin is filled on the outside and inside of the corrugated insulating plate 14C. Become.

Furthermore, the curing shrinkage stress σ of the synthetic resin acting on the corrugated insulating plate 14C acts on the inclined surface of the corrugated insulating plate 14C, but it is dispersed into stress σ1 perpendicular to the inclined surface and stress σ2 along the inclined surface. The stress that causes peeling between the synthetic resin and the inclined surface of the corrugated insulating plate 14C is mainly the stress σ2 along the inclined surface, which is smaller than the curing shrinkage force σ.

Therefore, by combining these favorable conditions, no peeling occurs between the synthetic resin and the corrugated insulating plate 14C, and it is possible to obtain a molded coil with improved electrical properties such as an improvement in corona generation voltage and stable quality. .

As described above, according to the present invention, it is possible to provide a molded coil with improved insulation strength of the main insulating portion interposed between the high and low voltage coils and whose quality is stable.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a molded coil according to the present invention;
FIG. 2 is a sectional view showing the main part of the main insulation part of the molded coil according to the present invention. 11...Insulation tube, °12...Low voltage coil, 13...High voltage coil, 14...Main insulation part, 14 C... Corrugated insulation board, 15...
...Synthetic resin.

Claims (1)

[Claims for Utility Model Registration] A corrugated wire in which a main insulating part is interposed between high and low voltage coils, the whole being molded with synthetic resin, and the main insulating part is laminated with at least a film. This corrugated insulating plate is arranged so that the direction of wave propagation is in the circumferential direction, forming a gap along the inner and outer coil axial directions of the corrugated insulating plate, and the entire gap is A molded coil characterized in that the molded coil is filled with the synthetic resin.