JPS60158513A - Bushing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a particularly resistant bushing used in high-pressure oil-filled equipment such as a transformer.

(Conventional configurations and their problems) Transformer bushings in areas with severe salt damage generally have a conductive part 1-exposed structure such as the bushing of a pole transformer. Requires good drawability for upper and external power distribution. In this case as well, salt damage may erode the area between the coating and core wire of the external power distribution lead wire, or the coating may be eroded by the synergistic effect of minute surface leakage current and salt, and salt from the outside air may leak into the bushing. There is a problem that the temperature inside the transformer may increase due to the infiltration. In order to solve these problems, bushings used in areas affected by salt damage are made by filling synthetic resin into the insulator tubes, cutting off the flow with the outside air due to capillarity, and completely embedding the conductive parts to prevent short circuits. The structure is designed to solve such problems.

Conventionally, in order to form the above structure, a leader wire connected in advance with a sleeve or the like was glued to the insulator tube, and the integrated insulator tube was filled with epoxy or rubber-based resin and embedded. Cracks were occurring in the synthetic resin due to the difference between the heat generated in the conductive parts and the outside temperature, and the temperature difference between the internal temperature of the transformer and the insulator tube itself exposed to the outside, and cracks were occurring in the insulator tube itself due to the difference between cold and flame. . In order to solve the above problems, the synthetic resin itself is made flexible, and to prevent the occurrence of cracks in the porcelain tube, glass powder, quartz, etc. are mixed as filler materials, and the thermal expansion coefficients of the synthetic resin and the porcelain tube are unified. Efforts were made to prevent insulator pipes from cracking. However, during heating and curing in the step after filling the synthetic resin, as shown in FIG. In itself, it is 1
The resin outer peripheral portion 3 that is in contact with the resin hardens first, and the resin interior 4 gradually hardens. ”1. In the case of the conventional configuration,
The diameter of the outer sheath 5a and the diameter of the core wire 5b of the lead wire 5 for internal use in high-voltage equipment are naturally different, and therefore, the synthetic resin 2 that can be filled into the insulator tube 1 has a protruding layer with a different thickness, and when it is heated and hardened, the diameter of the outer sheath 5a and the core wire 5b are different. As the resin hardens sequentially from the outer periphery, cracks are likely to occur in the resin in areas with different thicknesses, and adhesiveness may deteriorate locally, resulting in gaps. Furthermore, the same applies to the ends of the external power distribution lead wires 6, and the occurrence of cracks and gaps increases as the dimensional difference between the convex portions increases.

In addition, in the thermal test of the completion test, the resin expands when it is hot, but in this case too, if there is a difference in thickness, the force applied to the insulator tube due to resin expansion will be extremely different, and the insulator tube will crack during the thermal test. This causes peeling. Even when it is cold, shrinkage, which is the opposite of the above, causes cracking and peeling.

These problems ultimately lead to transformer accidents.

(Objective of the Invention) The present invention aims to provide a bushing that eliminates the drawbacks of the conventional bushings described in (1) and particularly improves airtightness and adhesion.

(Structure of the Invention) The present invention provides a bushing in which a lead wire for internal use in high-voltage equipment and a lead wire for external wiring are connected and penetrated through an insulating pipe using a sleeve, etc., and the insulating pipe is filled with a synthetic resin. The ends of each of the lead wires for internal use in high-voltage equipment and the lead wire for external wiring are bonded and cured with a quick-drying adhesive that has a lower viscosity than the filling synthetic resin, and are integrally cured with synthetic resin. It is.

(Description of Embodiment) FIG. 2 shows a half-sectional assembly view of an embodiment of the bushing according to the present invention, and the same members as those of the conventional example shown in FIG. 1 are given the same numbers. Core wire 5 of lead wire 5 for inside high voltage equipment
b and the core wire 6b of the external power distribution lead wire 6 are integrally connected by a sleeve 7, and during the integral connection process, the core wire 5b of the high voltage equipment internal lead wire 5 and the core wire 6b of the external power distribution lead wire 6 are connected together. Adhesively harden each end portion with a quick-drying adhesive 8. Similarly, this quick-drying adhesive 8 is made of a material with a lower viscosity than the synthetic resin 2, such as a monomer of cyanacrylic acid ester, which can penetrate into the inside of each core wire, and is applied to each core wire to prevent capillary action. It is designed to be lost. The insulator tube 1 and the molded cone portion 9 of the external power distribution lead wire 6 are integrally bonded together with an adhesive lO, and the inside of the insulator tube 1 is completely filled with synthetic resin 2 and hardened. 11 is the device case, 12
13 is a support ring, 13 is a stopper, and 14 is a tightening screw.

5- (Effects of the Invention) As explained above, even if a protruding layer is formed in the synthetic resin, the bushing of the present invention has adhesive applied to the end of the core wire, and the bushing has better performance than the case of copper wire, which is a single core wire. Adhesion is improved, and since the core wire itself is made of a quick-drying adhesive and has no capillary tubes, even if peeling occurs, airtight leakage often occurs, so the practical effects are great.

[Brief explanation of drawings]

FIG. 1 is a half-sectional assembly view of a conventional bushing, and FIG. 2 is a half-sectional assembly diagram of an embodiment of the bushing according to the present invention. 1......Insulator pipe, 2...Synthetic resin, 5......Leader wire for inside high-voltage equipment, 6......・External power distribution lead wire, 7
・・・・・・・・・Sleeve, 8...Song...Quick-drying adhesive, 9・・・・・・Moldco-78,
10・・・・・・Adhesive, 11・・・・・・・・・
・Equipment case. Patent applicant Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] Inside the insulated pipe, the high-voltage equipment internal lead-out wire and the external wiring lead-out wire are connected with sleeves, etc., and arranged through the bushing, and the high-voltage equipment internal lead-out wire and external wiring are inserted into the bushing, which is filled with synthetic resin. A bushing characterized in that each end of the lead-out line is adhesively cured with a quick-drying adhesive having a lower viscosity than the filling synthetic resin, and the bushing is integrally cured with a synthetic resin.