JPS6032208A - Insulating cylinder - 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 an insulating cylinder made of glass fiber-reinforced plastic that is connected to two cylinders and used in a state where a vacuum or high-pressure gas is confined and a high voltage is applied.

[Technical background of the invention and its problems]

Glass fiber reinforced plastic (hereinafter referred to as GFRP).

) is being used in the high voltage field as an electrical insulator with high mechanical strength per unit weight. Demand for equipment to be lighter and smaller is increasing as it contributes to energy and resource conservation.

For this reason, improvements in both the electrical and military characteristics of GFRP, which is an electrical insulator, are strongly encouraged.

The mechanical properties of 0FFLP depend on the type, thickness, and weaving method of the JF class fibers used as the reinforcing material, or the method of twisting and folding the yarn.
It varies greatly depending on the type of binding resin and the degree of impregnation into the glass fiber. Of the currently used GFRP, the one with the highest bending strength and bending modulus is glass roving or glass yarn (1) a method of impregnating resin in advance and winding it around a rotating mandrel (2) while applying a 4N force; This method uses the winding method.

However, in order to apply the insulating cylinder manufactured by this method to high-voltage equipment, the design electric field must be lowered, which is a drawback. The reason for this is that during crow roving and winding the yarn around a mandrel in the atmosphere, air is trapped in the insulating layer and continues to remain as bubbles even after heating and curing (2). Bubbles are easily discharged, and if the discharge continues for a long period of time, the surrounding solid insulation will be eroded and deteriorated.

For this reason, it can only be used in low l,z electric fields to the extent that bubbles do not discharge. Therefore, the insulation thickness becomes relatively thick, which runs counter to the demand for miniaturization of hk devices. For this reason, a method of winding glass roving or yarn in a vacuum is considered, but in order to manufacture a long, large diameter insulating cylinder, a complete set including the rotating mechanism of a large mandrel must be placed directly under the head. , cannot be adopted due to both sealing technology and cost.

On the other hand, there is a known method for producing an insulating cylinder that does not contain air bubbles, in which a glass cloth that is not impregnated with resin is wrapped around a mandrel, and then resin is injected into the mold (with two people drawing a vacuum). There is a so-called vacuum impregnation method in which glass cloth is impregnated.According to this method, the air bubbles in the insulating layer are completely replaced with resin, so it has the advantage of being applicable to equipment designed for high electric fields.However, this method The manufactured insulating cylinder has a glass content of only 50% at most, and its mechanical properties are significantly inferior to that of an insulating cylinder manufactured by the filament winding method.For this reason, the mechanical stress that can be used is inevitably low. becomes smaller and the relative cross-sectional area becomes larger,
This has become a bottleneck in the demand for smaller equipment.

[Purpose of the invention]

In view of the above problems, the present invention aims to provide an insulating cylinder that does not contain air bubbles that are harmful to electrical insulation and has high mechanical strength.

[Summary of the invention]

When winding glass roving or yarn that is not impregnated with resin around a mandrel, even if multiple glass rovings are laid in the axial direction on the outer surface of the mandrel, they are lined along the length of the insulating cylinder to form a longitudinal impregnation path. I'll keep it. Then, wrap the glass roving and yarn at a predetermined wrapping angle. After the winding is completed, the mold (-) is impregnated with a thermosetting resin under vacuum pressure and cured to obtain an insulating cylinder. It facilitates impregnation and reduces air bubbles in the insulation cylinder inner layer, which is the most difficult to impregnate layer.

[Example of pimping]

Next, one embodiment of the present invention will be explained from rc with reference to the drawings. In FIG. 1, longitudinal impregnation paths 2 are formed by arranging 12 glass rovings on the outside of a mandrel 1 at intervals of 30° in the circumferential direction, slightly longer than the axial mandrel length. Thereafter, a plurality of glass rovings are arranged and wound at an angle of 70' to the axial direction while applying tension from one end of the mandrel. After reaching the opposite end, the filament winding layer 3 is formed by setting the winding angle to 110' again, facing each other, and continuing winding until a predetermined looseness is reached. At this time, glass rovings forming the innermost longitudinal impregnated path 3 and the filament winding layer 3 are both not impregnated with resin.

Next, as shown in Fig. 2, the impregnation t (with the first factor in y4) is composed of an inner cylinder slightly smaller than the diameter of the mandrel 1, an outer cylinder slightly larger than the outer diameter of the glass low pink layer 3, and a bottom plate. At this time, space is secured by placing spacers 5 intermittently in the circumferential direction between the bottom plate and the mandrel.A resin impregnation port 6 is previously provided in the lower part of the outer part of the impregnation tank 4 for introduction of the resin. The entire system connected to the seal 7 is placed in a vacuum chamber (not shown), and after evacuation, a low-viscosity epoxy resin 8 is gradually injected from the introduction path 7. Mandrel i
After the impregnation path 2 and the filament winding layer 3 are all bifurcated with the impregnated resin C, the vacuum in the vacuum chamber is broken, and after returning to atmospheric pressure (-), gas is injected into the vacuum chamber and Pressure is applied to the pressure.The subsequent steps follow the commonly known thermosetting (ζ) curing process. After heating and curing, take out the integrally cured resin from the impregnation 4F!4, remove the excess resin, and then 1 to obtain an insulating cylinder.In order to facilitate the resin removal work, it is recommended to wrap release tape around the inner and outer walls of the mandrel 1 and the outer surface of the filament winding layer 3.In an experiment, Layer glass cloth and apply epoxy resin
As a result of observing the resin impregnation state, it was found that the impregnation rate in the direction perpendicular to the blood was about 1/10 of the impregnation rate in the direction parallel to the surface. That is, impregnation along the threads that make up the glass cloth is easy, but penetration between the threads is difficult. Therefore, in the filament winding layer 3 of j6 in this example, glass threads are closely wound, and the winding angle is 70° with respect to the axial direction, so that the axial direction along the constituent threads is 70°. In contrast to the filament 1, which is almost impossible to impregnate in the filament winding layer 3, an axial resin impregnation path is formed to make the resin impregnation of the innermost layer easy. Since it is impregnated from the outside 1, the bottom, and the inside at the same time, a bubble-free insulating cylinder can be manufactured.

Moreover, since it is made by filament winding with a high glass content of 60 to 80%, the strength of the bending is 2 to 3 times that of ordinary glass cloth (wrapped with vacuum impregnated), and the bending elastic modulus is 3 to 3. You can get something 4 times thicker.

The longitudinal impregnation path 2, which played the role of the resin impregnation path, may be made of the same glass thread as that used in the filament winding layer 3, and since it is an insulator, there is no need to remove it after curing.

Even if the longitudinal impregnation channels 2 are formed with a glass roving cloth 5, a similar effect on impregnation can be obtained. In other words, the warp threads of the glass roving cloth form an impregnation path in the axial direction, making impregnation easier (=, the weft threads average the impregnation speed of each part and have the effect of suppressing extremely fast impregnation. If there is a part of the impregnated cylinder, the unimpregnated part will be left behind.
There is a high risk of creating a u+1 location with 7 gaps in the fully impregnated layer. This has the advantage of avoiding this risk.

〔Effect of the invention〕

As explained above, the insulating cylinder of the present invention is manufactured by impregnating the filament winding layer, which has a longitudinal impregnation path on the innermost side, with resin under vacuum pressure, thereby eliminating air bubbles that are harmful to electrical insulation, and allowing it to be used under electric fields. High strength insulation can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an insulating cylinder according to an embodiment of the present invention before being impregnated with resin, and FIG. 2 is a sectional view of the insulating cylinder in a state stored in an impregnating tank. 1... Mandrel 2... Vertical impregnation tank 3... Filament winding layer. Agent: Patent attorney Kensuke Chika (and 1 other person)

Claims (1)

[Claims] An insulating tube characterized in that a longitudinal impregnation path made of glass thread is provided along the outer peripheral surface of a mandrel in the longitudinal direction, and the glass thread is spirally wound back and forth on the outside of the path and impregnated with liquid resin and hardened.