JPH0410168B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to an insulated wire, and in particular to a composite absolute conductor made by self-fusion or self-adhesion of conductors insulated from each other at rectangular cross sections in parallel. This invention relates to insulated wires for forming.

[Conventional technology]

Conventionally, insulated wires such as enamelled wires and fiber-wound wires were wound into a predetermined shape as coils for electric induction devices, motors, etc., and then impregnated with varnish and bonded between the wires to integrate them. Something was warm.

However, in recent years, in order to reduce the number of man-hours required for the varnish impregnation process and improve workability, self-fusion or self-adhesive techniques have been developed, in which the wires are bonded together by heating only, without varnish impregnation. Electric wires are increasingly being used.

Such self-fusing or self-adhesive wires are
Round wires used to be common, but recently thin rectangular self-fusing or self-adhesive wires have been used in electric induction equipment such as transformers and reactors to reduce eddy current loss in conductors. I've started using it.

Examples of applications using such rectangular wires include composite paper winding wires disclosed in Utility Model Publication No. 53-28475 and Utility Model Publication No. 57-17681, respectively;
There is a composite insulated wire etc. of Publication No. 47-43292.

In all of these application examples, as shown in FIG. 2, an enamel coating 2 is applied to a rectangular conductor 1.
Furthermore, a plurality of self-adhesive electric wires or self-adhesive electric wires A and B coated with adhesive 3 were combined and heated and cooled to obtain an integrated adhesive conductor.

[Problem that the invention seeks to solve]

When the cross-sectional shape of the conventional adhesive conductor formed as described above is schematically drawn as shown in Fig. 2, it has the following shape.
The self-fusion or self-adhesive electric wires A and B appear to be joined evenly.
However, the actual effective cross-sectional area is only about 30% for reasons described below. Therefore, conventional self-fusing or self-adhesive electric wires have a problem in that sufficient adhesive strength cannot be obtained.

When a rectangular wire has 90° corners, the electric field is too concentrated at the corners, so the corners are rounded.

As the rounded radius of the corner becomes smaller, the enamel coating tends to be thinner at the corner and thicker at the flat surface. Since adhesion is carried out between flat parts, if the situation is exaggerated a little, it will look like the one shown in Fig. 3, which shows that the effective cross-sectional area is extremely small.

In FIG. 3, 1 is a rectangular conductor, 2 is an enamel coating, and 3 is an adhesive.

This invention was made in view of the above-mentioned circumstances regarding conventional insulated wires for obtaining bonded conductors, and aims to improve the effective cross-sectional area and provide self-fusion or self-adhesive insulated wires that can be reliably bonded. The purpose is to provide

[Means for solving problems]

The insulated wire according to this invention has a corner radius of
It is characterized by forming an enamel coating by cutting the conductor surface on a rectangular conductor that is 0.4 mm or less and whose conductor plane dimension is smaller than the dimension between the corners, and then coated with an adhesive. .

[Effect]

In this invention, since the bonding surface becomes uniform, there is an effect that the effective bonding area increases dramatically.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

In FIG. 1, the portion of the conductor 11 where the enamel coating 12 is thickly applied is cut (t ₁ and t ₂ portions) to make the finished surface uniform.

From experience up to now, if the corner radius of the corner portion 11a is around 0.4 mm, if the radius is large, the corner portion will be coated thickly, and if the radius is small, the flat portion will be thickly coated. This tendency of uneven thickness is due to
Viscosity of enamel varnish, ratio of solvent to resin,
Depends on surface tension, baking temperature, etc. It is difficult to adjust these various conditions, and uneven thickness occurs when the corner radius mentioned above reaches around 0.4 mm. However, if you choose this corner radius,
Depending on the properties of the varnish and baking conditions, uneven thickness may occur.

Therefore, 0.4mm, which always has the same tendency of uneven thickness,
The present invention was completed based on the knowledge that a uniform finished surface could be obtained by selecting a corner radius of less than or equal to 1,000 yen, and cutting off the uneven thickness of the coating and the flat surface of the conductor.

Next, when adhesive 13 is applied to this enameled wire, the same tendency as that of the enamel coating is observed. However, the adhesive film thickness is 1/6 to 1/6 of the enamel film thickness.
The uneven thickness of the adhesive film is not a problem because the thickness is generally about 1/3, and when heated to bond the wires, the adhesive melts and the surfaces between the wires blend together. No.

Adhesives include linear polymer self-fusing agents such as phenoxy resin, butyral resin, polyamide, and polyester, and reactive reticular polymers such as epoxy resin, phenol resin, and a combination of phenoxy resin and melamine or isocyanate. A self-adhesive can be used.

〔Effect of the invention〕

As explained above, according to the present invention, since the conductor surface is cut to compensate for the uneven thickness of the enamel coating, the finished surface becomes uniform and the adhesion area between the wires is significantly improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the insulated wire according to the present invention, Fig. 2 is a sectional view showing an ideal adhesion state of a conventional adhesive conductor, and Fig. 3 is an actual adhesion of the adhesive conductor shown in Fig. 2. FIG. 3 is a cross-sectional view showing an exaggerated state. In the figure, 11 is a conductor, 12 is an enamel coating, and 13 is an adhesive. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A conductor surface is cut on a rectangular conductor whose corner radius is 0.4 mm or less and the dimension between the planes of the conductor is smaller than the dimension between the corners to form an enamel coating, and then bonded. An insulated wire characterized by being coated with a chemical agent. 2. The insulated wire according to claim 1, wherein the adhesive is a self-bonding adhesive that fuses by heating and solidifies by cooling. 3. The insulated wire according to claim 1, wherein the adhesive is a self-adhesive material that reacts and solidifies after being heated and melted.