JPH07192539A - Insulated wire - Google Patents

Abstract

PURPOSE:To provide an insulated wire having excellent workability and excellent adhesion with an interlayer paper by winding an insulation tape into plural layers onto the outer periphery of a conductor to form an insulation layer to adopt the utmost outer layer of the insulation layer as a polyester tape layer. CONSTITUTION:An insulation tape having one or more kinds of insulation tapes such as kraft paper are wound on the outer periphery of a conductor 10 having a rectangular cross section shape to form an insulation layer 11, and a polyester tape layer 12 is formed on the outer periphery of the insulation layer 11. A resulting insulated wire is wound on a core with an interlayer paper interposed to form a coil. This can improve adhesion between the insulated wire and the interlayer paper to improve insulation and coiling workability, and increase the strength to be difficult to be broken and to prevent damage at the time of winding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated wire used in a coil for oil-filled electrical equipment such as an oil-filled transformer.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, an insulated electric wire 1 for a coil used in an oil-filled electric device is formed by winding a kraft paper on a periphery of a rectangular conductor 2 having a rectangular cross section to a specified thickness. Then, the insulating layer 3 was formed. The insulated wire 1 is wound around a winding core 4 as shown in FIG. 3, and a coil 6 is manufactured while sandwiching an adhesive-attached interlayer paper 5 after each winding of one layer. By interposing the adhesive-attached interlayer paper 5, the dielectric breakdown voltage between the layers can be increased.

[0003]

However, when a coil having a relatively small winding diameter is manufactured, the kraft paper may be cut during the winding operation due to the tight bending diameter. Therefore, the width of the kraft paper is reduced to prevent the kraft paper from being cut. However, when the width of the kraft paper is reduced, the productivity of the insulated wire is reduced. Further, in order to improve the insulating property, it is necessary to enhance the adhesiveness between the insulating layer 3 and the adhesive-attached interlayer paper 5, but the adhesiveness between the kraft paper and the adhesive-attached interlayer paper 5 was not sufficient. , The outermost kraft paper surface of the insulated wire 1 is previously coated with an adhesive, and then the adhesive-coated interlayer paper 5
However, there is a drawback that the work efficiency is low.

Therefore, an object of the present invention is to provide an insulated electric wire which improves the workability while making the best use of the characteristics of kraft paper and has a good adhesion with the interlayer paper.

[0005]

The insulated wire of the present invention is an insulated wire having an insulating layer formed by winding one or several kinds of insulating tape around the outer periphery of the conductor. The outermost layer is a polyester tape layer.

In the insulated wire of the present invention, examples of the insulating tape include kraft paper, polyamide paper, crepe paper, polyester tape, etc., but the one directly wound around the conductor of the coil for electric equipment containing oil is Kraft paper, which has a good impregnation property with insulating oil, is suitable.

The present inventors have found that the polyester tape has better adhesiveness to the adhesive-coated interlayer paper than the kraft paper, and the outermost layer of the insulating layer is the polyester tape layer. Since the polyester tape is not impregnated with insulating oil, it cannot have insulating properties even when wound on a conductor. Although polyester tape is used here,
Besides, a plastic tape having oil resistance and high tensile strength, such as a polyimide tape or a PEN tape, can also be used.

[0008]

According to the present invention, the outermost layer of the insulated electric wire is a polyester tape layer in order to improve the adhesiveness with the adhesive-attached interlayer paper inserted between the insulated electric wires when forming the coil and to improve the bending workability. It is what

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. Kraft paper was wound around the conductor 10 having a rectangular cross section to form the insulating layer 11, and a polyester tape was wound around the insulating layer 11 to form the polyester tape layer 12.
The insulated electric wire manufactured in this manner was wound around the core 4 while inserting the interlayer paper 5 with an adhesive according to a conventional method to form a coil.

In general, for the interlayer paper used for the coil, when the coil is impregnated with insulating oil in the oil-filled electrical equipment, the insulating tape wound around the insulated wire is insufficient in terms of the interlayer pressure resistance. It has come to be used. As the interlayer paper, kraft paper, which is excellent in oil impregnation and is inexpensive, is often used. The interlayer paper that maximizes the characteristics when a coil is formed by applying the present invention is an adhesive-coated interlayer paper made of kraft paper, the surface of which has diamond pattern-like irregularities in order to improve adhesion. However, it is not limited to this as long as it has the impregnation property and the adhesion property of the insulating oil.

Further, it is more preferable to wind a two-layer tape in which a polyester tape is adhered to one surface of kraft paper with the polyester tape surface as the outer periphery, in terms of simplifying the work of manufacturing the insulated wire.

[0012]

According to the present invention, since the polyester tape layer is provided as the outermost layer, the adhesion with the interlayer paper is improved, and the insulating property and the coil winding workability can be improved. In addition, since it is stronger than kraft paper and does not easily tear, it can prevent damage when winding the insulating tape or winding the coil, and furthermore, because it has good bendability, it can be used for forming small diameter coils. Also, the insulating layer is not cut, and therefore, it is not necessary to reduce the tape width, and the formation speed of the insulating layer can be increased.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional insulated wire.

FIG. 3 is a cross-sectional view of a coil with an interlayer paper interposed.

[Explanation of symbols]

 10 ... Conductor 11 ... Insulating layer 12 ... Polyester tape layer

Claims (1)

[Claims] 1. An insulated wire having an insulating layer formed by winding one or several kinds of insulating tape around a conductor, wherein the outermost layer of the insulating layer is a polyester tape layer. Characterized insulated wire.