JPS6158931B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a resin molded insulating component with an insert, particularly a resin molded support insulator for high voltage equipment.

Generally, embedded metal fittings called inserts are embedded in resin molded support insulators for high voltage equipment to support and fix high voltage conductors and the like. Generally, it is desirable that the insert has a high mechanical strength and a shape that does not cause electric field concentration from the viewpoint of electrical insulation, and that the resin and the insert are in strong contact with each other.

Traditionally, materials such as iron, brass, and aluminum have been used for inserts, but because metals and resins have different coefficients of thermal expansion, thermal stress occurs especially during cooling and heating cycles, etc., and the interface between the insert and the resin Easy to cause peeling and cracking. To prevent this, as shown in Fig. 1, a stress relaxation layer 3 made of a rubber elastic material or the like is provided between the insert 1 with the bolt hole 4 and the resin mold body 2 to relieve the thermal stress, or As shown in Fig. 2, a wire mesh electrode 5 is provided around the insert 1, and due to its electric field shielding effect, even if peeling or cracking of the resin molded part 2 occurs around the insert 1, the peeled or cracked part will be removed. to prevent discharge from occurring. However, in the former case, since the mechanical strength of the stress relaxation layer itself is not very high, there is a drawback that the mechanical strength of the supporting insulator as a whole, such as bending strength, is reduced. Further, the latter has the disadvantage that the electric field tends to concentrate there because the electrode has a mesh structure, and the wire mesh electrode easily deforms and is difficult to maintain a shape in which electric field concentration does not occur.

The present invention eliminates the above-mentioned drawbacks, and provides a resin molded insulating component that is less likely to cause peeling or cracking even during thermal cycles, etc., and that does not cause a decrease in mechanical strength or an increase in local electric field. The purpose is to provide a manufacturing method.

The present invention is characterized by a double insert structure in which the metal insert portion is made small enough to support and fix a high-voltage conductor, etc., and a resin insert having a thin conductive layer on the surface is provided on the outside of the metal insert.

Next, examples of the resin mold supporting insulator according to the present invention will be described with reference to the drawings.

FIG. 3 shows a longitudinal section of a double insert inserted into the resin molded body of the support insulator. A double insert part is formed by the metal insert 1 and the resin insert 6 molded around it, and the surface of the resin insert 6 is made conductive by coating with metallicon such as copper or aluminum, carbon paint, silver powder paint, etc. A layer 61 is provided.

FIG. 4 shows a longitudinal section through a variant of the double insert. The metal insert 1 has protrusions on its surface, and the protrusions fix the resin insert 6 more firmly to improve mechanical strength. Of course, a recess may be provided instead of the protrusion.

FIG. 5 is a longitudinal sectional view of a resin mold supported insulator using a double insert.

In FIG. 5, a double insert consisting of a metal insert 1, a resin insert 6, and a conductive layer 61 is inserted into a resin mold body 2 of an insulator.

According to the present invention, (a) Since the main part of the insert is the same resin molded product as the supporting insulator body, the difference in thermal expansion coefficient between the resin insert and the resin molded body is small, so the insert and the supporting Because the thermal stress generated at the interface of the resin mold of the insulator body is significantly reduced,
Peeling and cracking are less likely to occur.

(b) The conductive layer made of metallicon or conductive paint applied to the insert surface has a smooth surface, so electric field concentration is less likely to occur than with conventional wire mesh electrodes.

H The resin molded part of the insert is completely electrically shielded by the conductive layer applied to the insert surface, and there is no need to consider electric field concentration due to the metal insert, so it is possible to use a small metal insert with a small radius of curvature of the head. Not only can it be used, but the reinforcing portion can be formed freely, saving metal materials and reducing weight.

For the same reason as 2), it is possible to provide unevenness on the metal insert, and the mechanical strength of the joint between the resin mold part and the metal insert can be improved.

(e) The metal insert and the conductive layer are molded in advance as an integral part, and this is embedded in the resin body when it is molded, resulting in excellent workability.

The present invention is not limited to the above resin molded supporting insulator, but also includes an insulating spacer used for gas insulated equipment, etc.
Can be applied to resin molded insulation parts such as insulation tubes and bushings.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional views of a conventional resin molded supporting insulator, FIGS. 3 and 4 are longitudinal sectional views of an embodiment of an insert according to the present invention, and FIG. 5 is a longitudinal sectional view of a conventional resin molded supporting insulator. FIG. 3 is a longitudinal cross-sectional view of an embodiment of the support insulator. 1... Metal insert, 2... Resin mold body, 6... Resin insert, 61... Conductive layer.

Claims (1)

[Claims] 1. A method for manufacturing a resin molded insulating component equipped with an insert, in which the insert is manufactured in advance by sequentially providing a resin insert surrounding a metal insert and a conductive layer covering the surface of the insert, and then molding the resin in which the insert is embedded. A method for manufacturing a resin molded insulating component, which comprises performing a molding process on the main body.