JPS61151909A - Bushing and manufacture thereof - 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] [Technical Field of the Invention] The present invention relates to a bushing used in a transformer or a switchgear, and in particular to a porcelain bushing used with an internal insulating oil or insulating gas sealed. Concerning improvement of insulator pipes.

[Technical background of the invention and its problems]

What is the structure of this type of bushing in general? The structure shown in Figure J3 is adopted. In other words, the spring 6 integrally tightens the support fitting 5, the air insulator tube la, and the oil extraction chamber lb. An insulating part or an insulating gas is sealed inside, and the entire structure is sealed, and a conductor is arranged inside.

When dielectric breakdown occurs inside the brush knob, abnormal pressure is generated inside and the air insulator tube 1a or oil insulator tube 1b, which is the weakest point in terms of strength, is destroyed.

Furthermore, if an excessive external force such as an earthquake causes the bushing to collapse, the 1 m insulator tube, which is the weakest point in terms of strength, will be destroyed. The 1m air insulator pipe and the oil insulator fib are made of porcelain, so when they break down as mentioned above, they instantly break into small pieces and scatter.
Peripheral equipment I: It is dangerous because it causes damage and may cause harm to people if there are people nearby.

[Purpose of the invention]

The present invention improves the drawbacks of the prior art described above, and provides a bushing and a porcelain insulator with a structure that increases the strength of the porcelain insulator and at the same time prevents fragments from scattering even if abnormal pressure that could lead to destruction occurs. The purpose is to provide a manufacturing method thereof.

[Summary of the invention]

According to the present invention, a resin layer is adhesively provided on the inside of the bushing insulator tube. According to an advantageous embodiment of the present invention, in forming the resin layer, the resin is spouted from a nozzle installed inside the insulator while rotating the insulator around its longitudinal direction (from two A resin is applied to the inner surface of the insulator tube to form a resin layer.According to another advantageous embodiment of the present invention, when the resin applied on the inner surface of the insulator tube is cured by the above method, the insulator tube is set with its longitudinal direction as an axis. Rotate.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention, in which a
Peeling tube inner surface I: In order to closely adhere and arrange, for example, polyester resin or epoxy resin alone, or a cured resin such as polyester resin or epoxy resin mixed with a filler such as glass fiber or silica. It is a layer. When the resin layer 8 is closely adhered and formed on the inner surface of the insulator tube 1 made by l:&fi, this resin 11m8 not only supplements the strength of the insulator tube 1, but also prevents abnormal dielectric breakdown accidents within the insulator tube. Even if the insulator 1 breaks due to an abnormal external force due to internal pressure or an earthquake, the inner resin Ill 8 will keep the pieces of the insulator glued to each other, so they will remain in their original shape and scatter. There's nothing to do.

FIG. 2 is a diagram showing an example of how to apply resin to the inner surface of the insulator tube 1 in order to adhere and form the resin layer 8 on the inner surface of the insulator tube l as shown in FIG. 8 is a resin layer, 9 is a resin spray nozzle, and 1o is a resin pressurizing device.

That is, in FIG. 2, the insulator tube 1 is rotated by an appropriate rotating device (not shown) about the longitudinal direction of the insulator tube 1 in the direction of the arrow in the figure, and the liquid in the resin pressurizing device 10 is sprayed through the resin spray nozzle 9L. resin or a mixture of resin and filler'#
11 and spray it onto the inner surface of the insulator tube 1. The resin spray nozzle 9 is moved back and forth in the longitudinal direction of the insulator until a resin layer of a predetermined thickness is obtained on the inner surface of the insulator, and the resin is sprayed over and over again. Since the insulator tube l is rotated around its long axis and direction, the thickness of the applied resin layer l is made uniform by the centrifugal force g2 acting in the radial direction of the insulator tube.

The resin-8 thus coated to a constant thickness on the inner surface of the insulator tube is cured by heating at a constant temperature as required for a certain period of time according to resin characteristic 1.

During this curing period, the two-phase resin layer applied to the inner surface of the insulator tube L is rotated by a rotating device around the longitudinal direction of the insulator tube L to maintain an even thickness of the resin layer and to prevent resin dripping. To prevent.

The resin layer 8 formed inside the insulator 1 in this way is bonded to the inner surface of the insulator 1, thereby reinforcing the mechanical strength of the insulator and reinforcing the abnormal internal pressure, which is considered to be a drawback of conventional insulators. Alternatively, external force 2: Since the scattering of fragments when the insulator tube is broken is prevented, damage to peripheral equipment and harm to the human body due to the scattering of insulator tube fragments is prevented, and safety can be ensured.

In addition, by appropriately designing the thickness of the resin layer, the mechanical strength can be further increased and leakage of the insulating oil or gas sealed inside can be prevented.

〔Effect of the invention〕

As explained above, according to the present invention, the bushing is bonded to the inside of the insulator tube to form a resin ttaw, which can prevent abnormal internal pressure caused by insulation breakdown inside the push knob or external force caused by earthquakes, etc. Since the insulator tube can be prevented from being destroyed and scattered, damage to peripheral equipment and the human body can be prevented, and safety is extremely high. Applying and curing the resin '5f while rotating the ITCl insulator tube around its longitudinal direction.

Inside of insulator tube I: Resin Il of uniform thickness! It is possible to glue and arrange the parts.

[Brief explanation of the drawing]

FIGS. 1 and 2 are views showing an embodiment of the insulator tube of the bushing according to the present invention; FIG. 1 is a sectional view of the insulator tube;
Fig. g2 is a cross-sectional view showing a manufacturing method for forming a resin layer in the outer tube, and Fig. 3 is a cross-sectional view showing an example of the structure of the bushing. ■...Insulator pipe 2...Tightening ring 3.
...Head expansion chamber 4...Core 5...Supporting metal fittings 6...Spring 7...Device body
8...Resin layer 9...Resin spray nozzle L
O...Resin circulation device 11...Tree name agent Patent attorney Noriyuki Chika (and 1 other person) Figure 1 Figure 2 Figure 3 □ 1/α/b

Claims (3)

[Claims] (1) In a bushing comprising a support fitting and a porcelain insulator tube arranged on both sides of the support fitting, which are integrally tightened by a spring and a conductor arranged inside, a resin layer is applied to the inner surface of the porcelain insulator tube. A bushing characterized by being adhesively arranged. (2) In a method for manufacturing a bushing in which porcelain insulators are placed on both sides of a support fitting, the bushings are integrally tightened by a spring, and a conductor is arranged inside, a resin layer is formed by spraying a fluid resin onto the inner surface of the insulators. A method of manufacturing a bushing, characterized in that the bushing is formed by forming a bushing. (3) The method for manufacturing a bushing according to claim 2, wherein the resin is sprayed while rotating the insulator tube.