JPH0673252B2 - Bushing - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement of a salt-resistant bushing used in a high-pressure oil-filled device such as a transformer.

(Constitution of the conventional example and its problems) In the bushing of the transformer in the area where salt damage is severe, it is generally impossible to use the exposed structure of the conductive part such as the pole bushing bushing. A power distribution lead-out wire is required. Even in this case, salt damage corrodes the coating of the lead wire for external power distribution and the portion between the core wires, or corrodes the coating due to the synergistic action of minute surface leakage current and salt content, and the salt content of the outside air enters the bushing. There is a problem that it goes in and goes inside the transformer. In order to solve these problems, bushings in salt-damaged areas are filled with synthetic resin in the porcelain tube along with a lead wire, which blocks the flow of air from the outside due to capillary phenomenon and completely embeds the conductive part, resulting in a short circuit accident. It is configured to solve such problems.

Conventionally, in order to form the above-mentioned structure, a lead wire previously connected with a sleeve or the like is adhered to a porcelain bushing and then filled and embedded with an epoxy-based or rubber-based resin in the integrated porcelain bushing. There is a crack in the synthetic resin due to the difference between the heat generated by the conductive part and the outside air temperature, or the temperature difference between the transformer internal temperature and the temperature of the porcelain tube exposed to the outside, or the porcelain tube itself is cracked due to the difference in cold fuel. It was In order to solve the above problems, the synthetic resin itself is a flexible material, and glass powder and quartz etc. are mixed as a filler material to prevent the occurrence of porcelain tube cracking, and the thermal expansion coefficient of the synthetic resin and the porcelain tube is integrated. I was trying to prevent cracking of the insulation insulator. However, at the time of heating and curing in the step after filling the synthetic resin, as shown in the half cross-sectional assembly view of the conventional bushing in FIG. 1, the synthetic resin 2 is sequentially heated from the outer peripheral portion of the porcelain bushing 1 to the inside. In itself, insulator 1
The fat outer peripheral portion 3 in contact with is cured first and gradually into the resin interior 4. In the case of the above conventional configuration, the diameter of the sheath 5a and the diameter of the core wire 5b of the lead wire 5 for high-voltage equipment are naturally different, so that the synthetic resin 2 filled in the porcelain tube 1 has a protruding layer with a different thickness. As described above, when the resin is heat-cured, the resin is sequentially hardened from the outer circumference, so that cracks are likely to occur in the resin at different thicknesses, and the adhesiveness may partially deteriorate, resulting in gaps. . The same is true at the end of the external power distribution lead-out wire 6, and cracks and gaps are caused by the greater the dimensional difference between the convex portions.

Also, in the cold heat test of the completion test, the resin expands when heated, but in this case as well, if there are parts with different thicknesses, the force exerted on the porcelain insulator due to resin expansion will be extremely different, and the porcelain cracks during the cold heat test. And the peeling occurs. Even when cold, it causes cracking and peeling due to contraction contrary to the above. These problems will eventually lead to transformer accidents.

(Object of the Invention) The present invention is intended to provide a bushing which solves the above-mentioned conventional drawbacks and particularly improves airtightness and adhesiveness.

(Structure of the Invention) The present invention relates to a bushing in which a lead wire for high-voltage equipment and a lead wire for external wiring are connected by a sleeve and arranged in a porcelain tube, and a synthetic resin for filling is filled in the porcelain tube. Connect each end of the lead wire for internal use of high-voltage equipment and the lead wire for external wiring with a sleeve with a partition, and bond the end near this connection portion with a quick-drying adhesive that has a lower viscosity than the synthetic resin for filling. It is configured such that it is cured and integrally cured by a filling synthetic resin.

(Description of Embodiments) FIG. 2 is a half sectional assembly view of an embodiment of the bushing according to the present invention, and the same members as those in the conventional example shown in FIG. Core wire 5b of leader wire 5 for high-voltage equipment
The core wire 6b of the lead wire 6 for external power distribution is a sleeve 7 with a partition wall.
The core wire 5b of the lead wire 5 for high voltage equipment and the core wire 6b of the lead wire 6 for external power distribution are bonded and hardened with a quick-drying adhesive 8 during the integrally connected process. The quick-drying adhesive 8 is a synthetic resin 2 for filling.
A material having a lower viscosity, for example, a monomer such as cyanoacrylic acid ester that penetrates into the core wires is selected, and the core wires are formed so as to eliminate the capillary phenomenon. Further, the porcelain bushing 1 and the mold cone portion 9 of the lead wire 6 for external power distribution are bonded and integrated with an adhesive agent 10, and the inside of the porcelain bushing 1 is completely filled and cured with a filling synthetic resin 2. 11 is a device case, 12 is a support ring, 13 is a stopper, and 14 is a tightening screw.

(Effects of the Invention) As described above, the bushing of the present invention has an adhesive applied to the end of the core wire even if a protruding layer is formed on the filling synthetic resin, and is more effective than when the core wire is a copper wire. Adhesion is improved, and since the core wire itself is a quick-drying adhesive to eliminate the capillary tube, airtight leakage does not occur even if peeling occurs, and each lead wire is connected by a sleeve with a partition wall. Therefore, the airtightness is excellent, and its practical effect is great.

[Brief description of drawings]

FIG. 1 is a half sectional assembly view of a conventional bushing, and FIG. 2 is a half sectional assembly view of an embodiment of a bushing according to the present invention. 1 ... Insulator, 2 ... Synthetic resin for filling, 5 ... Leader for high voltage equipment, 6 ... Leader for external power distribution, 7 ... Sleeve with partition, 8 ... Quick-drying adhesive, 9 ... Mold cone part, 10 …… adhesive, 11 …… equipment case.

Claims (1)

[Claims] 1. A bushing formed by connecting a lead wire for internal use of a high-voltage device and a lead wire for external wiring through a sleeve in a porcelain tube, and arranging the lead wire for filling a synthetic resin in the porcelain pipe. The respective ends of the lead wire for external use and the lead wire for external wiring are connected by a sleeve with a partition wall, and the ends near the connecting portion are bonded and cured with a quick-drying adhesive having a viscosity lower than that of the filling synthetic resin. ,
A bushing integrally formed by curing with the filling synthetic resin.