JPS5812685B2 - insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-voltage electric wire, and more particularly, the present invention relates to a high-voltage electric wire having an insulating layer formed by providing a film layer on a conductor and winding a laminated mica prepreg tape thereon. The present invention relates to an insulated wire for high voltage use that has excellent processing resistance.

As this type of high-voltage electric wire, a mica-wound electric wire using a composite mica prepreg tape whose backing material is a film base material or a glass base material has been conventionally used.

Conventionally, a composite mica tape containing 20 to 30% of epoxy resin or the like as a prepreg resin is used, but this has the following drawbacks.

(1) When winding tape around a conductor to produce wires with predetermined specifications, it is necessary to maintain the winding speed at a level that does not reduce wire manufacturing efficiency, and to avoid wrinkles in the tape layer after winding. Conventionally, in the case of film base materials, a tape winding tension of 2 to 3 kg was applied in order to eliminate weak points in electrical characteristics and to make finished dimensions uniform.However, as shown in Figure 1, For example, electrical polyester film B has low tensile strength and low elongation under tension, so it is necessary to reduce the winding tension or slow the winding speed during winding, which eliminates the above-mentioned drawbacks. Difficult to improve.

(2) When manufacturing an insulated coil by hardening the windings with a specified number of wires and applying ground insulation, in the conventional method, due to the high resin content of the mica winding, the wire hardening During the press heat curing process when providing ground insulation, the resin hardens between the tape wraps due to resin flow and the adhesion between the tape layers is high, and the strength of the backing material against mechanical strain is low. The insulation layer of the strands may peel or crack, resulting in a decrease in breakdown voltage.
Reliability against surges such as high voltage or vacuum switches was low, and it was necessary to repair defective parts.

It is therefore an object of the invention to eliminate the above-mentioned drawbacks and to
An object of the present invention is to provide a mica-wound insulated electric wire which has good winding taping properties and is excellent in process resistance, high voltage resistance, and surge resistance.

The mica-wound insulated wire of the present invention is manufactured by providing a film layer on a conductor and winding a film or glass cloth-backed mica pre-preg tape assembly thereon.

In the above tape insulation configuration according to the invention, the conductor side film layer is applied by winding a tape of heat resistant film.

As the heat-resistant film tape, for example, a tape made of polyester, polyimide, polyamide, etc. is used.

In order to achieve the object of the present invention, the film used to form the film layer on the conductor side preferably has a tensile strength-elongation property of 1 to 5% elongation.
It has high strength and has a tensile strength of 6 kg/mm2 or more.

FIG. 1 is a graph illustrating the relationship between tensile strength and elongation properties of polyester film A, which is one of the preferred films used in the present invention, and polyester film B for general electrical use.

The thickness of the film layer can be selected arbitrarily to obtain the desired performance.

The laminated mica prepreg tape wound over the film layer applied as described above is a laminated mica prepreg tape backed with a film or glass cloth.

Such a tape is manufactured, for example, by applying a prepreg resin onto a film or glass cloth and laminating a mica layer thereon.

When a film substrate is used as a backing material in the production of laminated mica prepreg tape, the film substrate is
Preferably it is the same material as the film layer applied over the conductor.

Therefore, as the film base material, a high-strength film having a tensile strength of 16 kg/mm 2 or more at 5% elongation as described above is preferably used.

The aggregated mica used in the prepreg tape may be either a fired type or an unfired type, but it is preferably an unfired hard type that has been mechanically pulverized by a water jet method.

The particle size of the particles is preferably 200 to 800 microns.

Furthermore, a heat-resistant epoxy resin is used as the prepreg resin used for manufacturing the composite mica tape.

In order to cure this epoxy resin, a commonly used latent curing agent is used.

In order to achieve the desired effect, the prepreg resin must be
11-1 based on the weight of laminated mica prepreg tape
It is used in an amount of 3% by weight.

According to the present invention, the following effects can be obtained by using an insulating structure consisting of providing a film layer on the conductor side and winding an assembled mica prepreg tape thereon.

(1) Since the film layer is provided on the conductor side, there is less chance of the mechanical force of the assembled mica tape layer escaping at the corners of the conductor during processing, and this effect can be further improved by using unfired mechanical force. Ru.

(2) When wrapping a film layer around the conductor and applying laminated mica prepreg, the backing material of the laminated mica prepreg is the same as the film on the conductor side, and has high tensile strength with respect to elongation strength (with respect to 5% elongation). 16~17kg/m
m2) material, use an unfired type mica as the aggregated mica, and increase the content of the prepreg resin to 11
When using a tape manufactured by applying 13% to 13%, it has the same workability as the film on the conductor side, so it does not impair wire manufacturing efficiency, and the finished wire wound with it has a good finish. , a good electric wire without tape wrinkles or other weak points can be obtained.

(3) During the coil forming process after solidifying the wire or after ground insulation treatment, there is slippage between the film layers due to mechanical stress, and the amount of resin in the composite mica tape is 11 to 1.
3%, no peeling or cracking of the wire insulating layer due to resin pooling between the tapes due to resin flow during curing is observed.

Due to the above-mentioned effects, the insulation structure of the present invention improves the workability of electric wires, and is suitable for strand insulation for high-voltage rotating machines and static equipment (high-voltage transformers, induction electric furnaces, linear motor windings, etc.) In particular, it can greatly improve reliability against surges in items such as those that are subject to severe mechanical stress and high voltage is applied, and vacuum switches.

Examples of the present invention are shown below, but these are not intended to limit the invention in any way.

EXAMPLE As shown in FIG. 2b, a film tape is butted onto a conductor 1 with dimensions of 2 x 5 mm and wound one time to form a film layer 2, and then a 1/3 layer of assembled mica prepreg tape is formed. The assembled mica layer 3 was formed by winding it twice.

The above laminated mica pre-preg tape is made by applying epoxy resin (containing 25% solvent) to the backing material so that the resin amount is 13%, then drying at 80±5℃ for 1 minute, and then bonding the laminated mica layer. Created by.

Wire samples with several insulation configurations were prepared using film substrates, backing materials, and assembled wires as described below.

Changes in breakdown voltage retention due to bending after heating of these insulated wire samples ①, ② and ◯ were measured, and the results are shown in FIG.

Further, FIG. 3 also shows the results of electric wire sample O having a conventional insulation structure for comparison.

Electric wire sample ○ has a composite mica layer 3 formed by winding a composite mica prepreg tape around a conductor 1, as shown in a in FIG. A hard type (thickness: 30 μm) was used, and the resin content was 20%.

From the above results, it can be seen that the insulated wire of the present invention has a much more stable breakdown voltage value due to bending after heating than the conventional wire, and has significantly improved workability.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between tensile strength and elongation properties of a film base material. FIG. 2A is a schematic diagram showing an insulating structure of the prior art, and FIG. 2B is a schematic diagram showing a specific example of the insulating structure of the present invention. FIG. 3 is a graph showing the processing inferiority of various insulated wires. 1... Conductor, 2... Lylum layer, 3.
・・・・・・Laminated mica layer.

Claims (1)

[Claims] 1 A film layer is provided on a conductor, and a laminated mica prepreg tape lined with a film or glass cloth is wound on the film layer, and the film on the conductor has a tensile strength-elongation property of 16 kg at 5% elongation. /mm
An insulated wire comprising a heat-resistant film having a tensile strength of 2 or more, and wherein the film used as the backing material is the same material as the film on the conductor.