JPH06119825A - Litz wire and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a novel litz wire excellent in space factor and capable of reducing partial electric discharge and electromagnetic vibration deterioration, and a method for manufacturing the same. CONSTITUTION:Seven enamel wires 3 each having an enamel insulated coating film 2 on a conductor 1 are twisted together, to pass through a circular die, followed by rolling to such an extent as not to exert any damage thereonto and reducing an outer diameter thereof, and then, a self-fusible layer 4 is applied and baked. Although not limited, a known enamel wire material is used for the enamel insulated coating film 2. Moreover, a known material is utilized for the self-fusible layer 4, although not limited. The number of element wires constituting a litz wire is not limited to seven, and numerous element wires may be twisted together according to a use purpose.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a litz wire which is capable of improving a high frequency gain in a high frequency electric device and the like and which has an excellent occupation ratio at the time of coil winding, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a litz wire obtained by twisting a plurality of enameled wires into a multi-conductor has been used for high-frequency electric equipment and the like.

[0003] This is because when the frequency of the applied current is high, the AC resistance increases due to the skin effect and the loss increases, so that the conductor is divided into a large number by using an enamel wire having an insulating film to increase the AC resistance. It is something to prevent. (For example, Japanese Utility Model Publication No. 61-28331, Japanese Patent Laid-Open No. 3-1842
(See Japanese Patent Publication No. 14) In recent years, with the miniaturization and high performance of electrical equipment, the frequency of inverter control has become higher and the deflection yoke coil of televisions has also become higher in frequency to improve the image. The demand is increasing.

As an example of a conventional litz wire, for example, as shown in FIG. 2, for example, seven enamel wires 3 in which the outside of a conductor 1 is covered with an enamel insulating coating are concentrically twisted.

[0005]

The litz wire is made by twisting a large number of enameled wires as described above. However, regardless of whether the twisting method is concentric twist, collective twist or composite twist, Further, as the number of enameled wires increases, the space between the enameled wires also increases, and there is a problem that when the coil is wound with the litz wire, the coil shape becomes larger than that of a coil wound with a single enameled wire.

Therefore, there has been a demand for a litz wire having an excellent occupation rate.

In the wound coil, the varnish is generally fixed by a treatment varnish in order to prevent deterioration of the enamel coating due to electromagnetic vibrations. In this case, the varnish penetrates into the inside of the coil. May not
It is liable to deteriorate due to partial discharge between lines and electromagnetic vibration.

In view of the above problems, an object of the present invention is to provide a new litz wire which has an excellent occupation ratio and can reduce partial discharge and electromagnetic vibration deterioration, and a method for manufacturing the same.

[0009]

SUMMARY OF THE INVENTION The gist of the present invention is to reduce the outer diameter by twisting a plurality of enameled wires and passing them through a circular die to reduce the outer diameter. By making a self-bonding layer on the outer periphery of the coil, it is possible to evenly fix the inside of the coil only by heating during coil winding, and the insulation reliability is greatly improved. .

That is, the above-mentioned object of the present invention is characterized in that a twisted wire made of a plurality of enameled wires is compressed into a circular shape from the outside so that the enameled wires are adhered to each other, and a self-bonding layer is provided on the outside. And the litz wire.

Alternatively, after twisting a plurality of enamel wires,
This is achieved by a method for producing a litz wire, characterized in that the twisted wire is passed through a circular die to be compressed, and a self-fusion layer is further provided on the outer circumference thereof.

In the present invention, a plurality of enameled wires can be considered in a wide range of, for example, 7 to 200, and in order to compress these twisted wires into a circular shape from the outside, a gap between the enameled wires is required. It can be carried out by passing the cross-sectional area of the litz wire from the total cross-sectional area of the plurality of enameled wires through a circular die having an inner diameter corresponding to the total cross-sectional area of the conductor portion of the enameled wire.

By doing so, useless voids between the enameled wires are expelled, and the enameled wires come into close contact with each other to form a single twisted wire having an excellent occupation ratio. By further applying a self-fusion layer, which is an insulator, on the outside thereof, it is possible to prevent the occurrence of interlayer short circuit of the coil.

[0014]

EXAMPLE FIG. 1 is a cross-sectional view showing an example of the litz wire according to the present invention, showing an example constituted by 7 strands. However, the present invention is not limited to this embodiment.

In the present embodiment, seven enameled wires 3 each having an enamel insulating coating 2 on a conductor 1 are twisted and passed through a circular die to be rolled so that the enameled wire is not damaged. FIG. 4 is a cross-sectional view of a litz wire after compression and application and baking of a self-bonding layer 4.

The enamel insulating coating 2 may be selected from conventionally known enamel wire materials and is not particularly limited. The self-fusing layer 4 is not limited as long as a conventionally known material is selected. The number of strands constituting the litz wire is not limited to the above-mentioned 7 strands, and the present invention can be sufficiently applied even when a larger number of strands are twisted according to the intended use.

[0017]

As described above, according to the litz wire of the present invention, the apparent outer diameter of the litz wire is reduced by the compression, and not only the coil occupation ratio is significantly improved, but also
It is industrially very useful because heat treatment is performed after the coil winding so that the inside of the coil can be fixed evenly and the insulation reliability is greatly improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a litz wire according to the present invention.

FIG. 2 is a cross-sectional view of an example in which seven conventional litz wire enameled wires are concentrically twisted.

[Explanation of symbols]

 1 conductor 2 enamel insulation film 3 enamel wire 4 self-bonding layer

Claims (2)

[Claims] 1. A litz characterized in that a self-bonding layer is provided on the outer periphery of a stranded wire made of a plurality of enameled wires compressed from the outside in a circular shape to bring the enameled wires into close contact with each other. line. 2. A method for producing a litz wire, which comprises twisting a plurality of enameled wires, compressing the twisted wires by passing through a circular die, and applying a self-bonding layer on the outer circumference thereof.