JP2009245667A - Insulated wire and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulated wire and its manufacturing method capable of preventing generation of foams in a baking process when coating a wire with an enamel layer and superior in heat resistance and scratch resistance. <P>SOLUTION: The insulated wire W1 comprises a conductor 1 comprising a plurality of conducting wires 1a twisted one another, an extruded layer 2 coating the periphery of the conductor 1, and an enamel layer 3 coating the periphery of the extruded layer 2. The extruded layer 2 and the enamel layer 3 form an insulating coating. The extruded layer 2 is made of a thermoplastic resin having a heat resistance and/or amorphous property. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an insulated wire formed by coating an outer periphery of a conductor with an insulating film and a method for manufacturing the insulated wire.

  In recent years, in the fields of automobiles, various electric / electronic devices, etc., an insulated wire in which an outer periphery of a conductor is coated with an insulating film is used in accordance with demands for heat resistance and scratch resistance.

As a conventional insulated wire, what coat | covered the enamel layer by apply | coating a varnish to the outer periphery of a conductor, for example, and baking this is known (refer patent document 1).
Japanese Patent Laid-Open No. 9-237525

  In the conventional insulated wire, if the conductor surface is scratched in the baking process when coating the enamel layer, foaming may occur from the scratch when the varnish evaporates.

  In particular, in the case of a stranded wire obtained by twisting a plurality of conductive wires, the conductor surface is easily damaged in the twisting process. The coating state becomes non-uniform and foaming is likely to occur from that point.

  Due to the occurrence of such foaming, cavities remain in the insulating film, resulting in a problem that the quality of the product is remarkably lowered.

  The present invention has been made in order to solve the above-mentioned problems, an insulated wire that can prevent the occurrence of foaming in the baking process when coating the enamel layer, and has excellent heat resistance and scratch resistance, and a method for producing the same The purpose is to provide.

The insulated wire of the present invention is an insulated wire obtained by coating an outer periphery of a conductor with an insulating film
The conductor is a stranded wire obtained by twisting a plurality of conductive wires,
The insulating coating has an extruded layer coated on the outer periphery of the conductor, and an enamel layer coated on the outer periphery of the extruded layer.
It is characterized by having.

  The extruded layer is made of, for example, a thermoplastic resin.

  The extruded layer is preferably made of a resin having heat resistance and / or amorphous properties.

  The conductor may be made of metal, and a resin deterioration suppressing layer for preventing deterioration of the extruded layer due to the metal may be formed between the conductor and the extruded layer.

The method for producing an insulated wire according to the present invention includes:
Forming a conductor by twisting a plurality of conductive wires;
Coating the outer periphery of the conductor with an extruded layer;
Coating an enamel layer on the outer periphery of the extruded layer;
It is characterized by having.

  According to the first aspect of the present invention, since the extruded layer is directly coated on the outer periphery of the conductor, the occurrence of foaming can be prevented in the baking process when the enamel layer is coated, and the quality of the product can be improved. .

  Moreover, since the enamel layer is coat | covered on the outer periphery of the extrusion layer, heat resistance and scratch resistance can be improved.

  According to the invention which concerns on Claim 2, there can exist said effect reliably.

  According to the invention of claim 3, when the resin of the extruded layer has heat resistance characteristics, it is possible to prevent a part of the extruded layer from being decomposed and foamed during the baking process, thereby improving productivity. When improved and provided with amorphous characteristics, the vicinity of the surface of the extruded layer is dissolved by the solvent, so that the adhesion between the extruded layer and the enamel layer can be improved.

  According to the invention which concerns on Claim 4, deterioration of the resin by contact with a metal can be suppressed. This is because when the resin layer is directly coated on the metal conductor, the resin is oxidized by the catalytic action of the metal, and the deterioration of the resin layer may be accelerated. By providing this, deterioration of the resin can be suppressed.

  According to the invention which concerns on Claim 5, the insulated wire which has the said effect can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an insulated wire according to an embodiment of the present invention.

  The insulated wire W1 according to the embodiment of the present invention is covered with a conductor 1 made of a stranded wire obtained by twisting a plurality of conducting wires 1a, an extruded layer 2 coated on the outer periphery of the conductor 1, and an outer periphery of the extruded layer 2. And enamel layer 3. The extruded layer 2 and the enamel layer 3 constitute an insulating film.

  The conductor 1 is made of, for example, copper, copper alloy, aluminum, aluminum alloy, or a combination of these metals.

  The extruded layer 2 is made of a thermoplastic resin such as polyimide (PI) or polyamideimide (PAI).

  The enamel layer 3 is made of an enamel resin such as polyester.

  When the insulating coating is composed of an extruded layer and an enamel layer (Example (1)), when the insulating coating is composed only of an enamel layer (Comparative Example (1)), the present invention is composed only of an extruded layer. Experiments were conducted to compare the presence / absence of foaming, heat resistance (temperature rise softening), and scratch resistance in the case (Comparative Example (2)).

  In addition, the present inventors have a case where the properties of the resin of the extrusion layer 2 have heat resistance and amorphous properties such as thermoplastic polyimide (PI), thermoplastic polyamideimide (PAI) (Example ( 1)), such as polyether ether ketone (PEEK), polyphenylene sulfide (PPS), etc. (Example (2)), polycarbonate (PC), polysulfone (PSU), etc. In the case of having versatility / amorphous property (Example (3)), in the case of having versatility and crystallinity such as polyethylene terephthalate (PET) (Comparative Example (3)), the enamel layer Experiments were conducted on the adhesion and productivity between the extruded layer and the extruded layer. Table 1 shows the experimental results. Here, the heat resistance and general versatility are those having a 5% weight loss temperature, which is an index indicating the thermal decomposition temperature, of 500 ° C. or higher, and are high heat resistant engineering plastics, and those having a temperature less than 500 ° C. are general-purpose engineering plastics.

表１からわかるように、絶縁被覆が押出層とエナメル層で構成されている場合（実施例（１）、（２）、（３））は、発泡がなく、耐熱性・耐傷性が良好である。
一方、エナメル層だけで構成されている場合（比較例（１））は、耐熱性・耐傷性は良好であるが、発泡があり、押出層だけで構成されている場合（比較例（２））は、発泡はないが、耐熱性・耐傷性が悪い。

As can be seen from Table 1, when the insulating coating is composed of an extruded layer and an enamel layer (Examples (1), (2), (3)), there is no foaming and the heat resistance and scratch resistance are good. is there.
On the other hand, when it is composed only of the enamel layer (Comparative Example (1)), it has good heat resistance and scratch resistance, but there is foaming and it is composed only of the extruded layer (Comparative Example (2)). ) Is not foamed but has poor heat resistance and scratch resistance.

When the resin of the extruded layer 2 has heat resistance (Example (1), Example (2)), part of the extruded layer 2 is decomposed and foamed during the varnish baking step. Therefore, productivity is good.
In addition, when the resin of the extruded layer 2 is non-crystalline (Example (1), Example (3)), the adhesion of the varnish solvent to the varnish solvent is reduced during the step of applying the varnish solvent. Since it is favorable, the adhesion between the enamel layer 3 and the extruded layer 2 is improved.
When the resin of the extruded layer 2 has general versatility and crystallinity (Comparative Example (3)), the productivity is poor and the adhesion between the enamel layer and the extruded layer is also poor.
From the above, it is desirable that the insulating coating is composed of the extruded layer 2 and the enamel layer 3, and the resin of the extruded layer 2 has either or both of heat resistance and amorphous properties.

  In Table 1, the foaming in Example (1) and Comparative Example (1) means foaming in the enamel layer, and Examples (2) and (3) and Comparative Examples (2) and (3) ) Foaming means foaming in the extruded layer.

  2A to 2C are explanatory views for explaining a method of manufacturing the insulated wire W1 according to the embodiment of the present invention.

  First, the conductor 1 is formed by twisting a plurality of conducting wires 1a (see FIG. 2A).

  Next, the periphery of the conductor 1 is extruded with resin by an extruder (not shown) to cover the extruded layer 2 (see FIG. 2B).

  Next, the enamel layer 3 is coated by applying a varnish solvent to the outer periphery of the extruded layer 2 and baking it in a baking oven (see FIG. 2C). Thereby, the insulated wire W1 is completed.

  According to the insulated wire W1 according to the embodiment of the present invention, since the extruded layer 2 is directly coated on the outer periphery of the conductor 1, the occurrence of foaming can be prevented in the varnish baking process when the enamel layer 3 is coated. , Can improve product quality.

  Moreover, since the enamel layer 3 is coat | covered on the outer periphery of the extrusion layer 2, heat resistance and scratch resistance can be improved.

  According to the manufacturing method of the insulated wire W1 according to the embodiment of the present invention, an insulated wire that exhibits the above effects can be provided.

  When the insulated wire W1 according to the embodiment of the present invention is used to process a coil such as a motor or a transformer, the extruded layer 2 and the enamel layer 3 are made of a crystalline polymer material, and the crystallinity is low. Therefore, it is possible to suppress the stress due to bending or the like, and to prevent the insulation film from being peeled off or damaged.

  3A and 3B are cross-sectional views showing an insulated wire according to another embodiment of the present invention.

  As shown in FIG. 3A, in an insulated wire W2 according to another embodiment of the present invention, a metal is used between the conductor 1 and the extruded layer 2 in order to suppress deterioration of the resin due to contact with the metal. A resin deterioration suppressing layer 4 made of an oxide or a coding layer is formed.

  3B, in an insulated wire W3 according to still another embodiment of the present invention, the extruded layer 2 is formed in a square shape, and the enamel layer 3 is square along the outer periphery of the extruded layer 2. Is formed.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical matters described in the claims.

  The present invention is used in fields that require heat resistance and scratch resistance, such as automobiles and various electric and electronic devices.

It is sectional drawing which shows the insulated wire which concerns on the example of embodiment of this invention. (A)-(C) are explanatory drawings for demonstrating the manufacturing method of the insulated wire which concerns on the example of embodiment of this invention. (A) And (B) is sectional drawing which shows the insulated wire which concerns on the other embodiment of this invention.

Explanation of symbols

W1-W3: Insulated wire 1a: Conductor 1: Conductor 2: Extruded layer 3: Enamel layer 4: Resin degradation inhibiting layer

Claims (5)

In the insulated wire formed by coating the outer periphery of the conductor with an insulating film,
The conductor is a stranded wire obtained by twisting a plurality of conductive wires,
The insulating coating has an extruded layer coated on the outer periphery of the conductor, and an enamel layer coated on the outer periphery of the extruded layer.
An insulated wire characterized by that.   The insulated wire according to claim 1, wherein the extruded layer is made of a thermoplastic resin.   The insulated wire according to claim 2, wherein the extruded layer is made of a resin having heat resistance and / or amorphous properties.   The resin conductor is made of metal, and a resin deterioration suppressing layer for preventing deterioration of the extruded layer due to the metal is formed between the conductor and the extruded layer. The insulated wire according to any one of the items. In the method of manufacturing an insulated wire formed by coating an outer periphery of a conductor with an insulating film,
Forming a conductor by twisting a plurality of conductive wires;
Coating the outer periphery of the conductor with an extruded layer;
Coating the enamel layer on the outer periphery of the extruded layer;
The manufacturing method of the insulated wire characterized by having.

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