JPH0688012U - Insulated wire - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain an insulated wire which is used for a winding of a deflection yoke coil or a high frequency transformer and has a high withstand voltage when a high frequency voltage is applied. [Constitution] As a conductor of an insulated wire, chemical polishing or electrolytic polishing is applied, and the reduction amount of the conductor diameter due to this polishing is 0.5.
The conductor 1 having a range of ˜6 μm is used. The scratches on the surface of the conductor are repaired and become smooth, so that discharge and electric field concentration do not occur and the withstand voltage is improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an insulated wire used for a deflection yoke coil of a television picture tube, a coil used under a high frequency voltage such as a high frequency transformer, and an insulated wire used for a transformer, etc., and has improved high frequency voltage resistance.

[0002]

[Prior art]

 Conventionally, for insulated wires used under high-frequency voltage, measures have been taken to subdivide the conductor, such as litz wire, to suppress heat generation due to increased resistance, but from the viewpoint of withstand voltage. No measures were taken. Recently, in the field of color television receivers, the horizontal deflection scanning frequency exceeds 30 KHz in high-definition television, and high-frequency signals of approximately 60 KHz are scanned in high-resolution monitors. Therefore, the insulated wire constituting the deflection yoke coil of such a television receiver is required to have excellent high-frequency voltage resistance.

By the way, in such a conductor of an insulated wire, a predetermined conductor diameter is obtained through a plurality of drawing steps. However, during this drawing step, a drawing die is inevitably used as shown in FIG. Small scratches 2 are formed on the surface of the conductor 1. Even if an insulating layer is formed on the conductor 1 having such scratches 2, ... If a scratch is formed in a concave shape, a minute void is generated between the insulating layer and the conductor, and discharge easily occurs at this portion. Further, if the scratch is a convex and sharp protrusion, electric field concentration occurs at this portion, and the withstand voltage decreases.

Furthermore, since the withstand voltage of the insulated wire generally decreases with an increase in frequency, the scratches 2 on the conductors 1 ... Are extremely harmful in high frequency applications.

[0005]

[Problems to be solved by the device]

 Therefore, the problem in this invention is to obtain an insulated wire having high voltage resistance even in a high frequency region.

[0006]

[Means for Solving the Problems]

 This problem can be solved by electrolytically polishing or chemically polishing the conductor of the insulated wire, and using a conductor having a smooth surface with a reduction amount of the conductor diameter of 0.5 to 6 μm due to the polishing.

Hereinafter, the present invention will be described in detail. In the present invention, the surface of the conductor is electropolished or chemically polished before the insulating layer is formed on the conductor to make the surface smooth, and the surface scratches caused by the drawing process are repaired. As the electropolishing here, a usual method is used in which a conductor is used as an anode and an insoluble conductive material is used as a cathode, and electricity is applied in a electrolytic bath. For the electrolytic bath, for example, an aqueous solution of phosphoric acid, alcohol, an aqueous solution of phosphoric acid (pyrophosphoric acid), etc. is used. The electrolysis conditions are a bath temperature of 15 to 25 ° C. and a current density of 60 to 120 A / dm ^{2 with} respect to the conductor surface area. The voltage is 1 to 5 V and the time is about 5 to 20 minutes.

In this electropolishing, if the current density is less than 60 A / dm ² or more than 120 A / dm ² , the conductor surface becomes rough and the opposite effect occurs, so it is important to set this range. In addition, the polishing amount of the conductor at the time of this electrolytic polishing is reduced to 0. It is necessary to set it in the range of 5 to 6 μm. If the polishing amount is less than 0.5 μm, the conductor will have scratches and no smoothing effect will be obtained, and if the polishing amount exceeds 6 μm, the smoothing effect will reach the ceiling and the conductor material will be wasted. Becomes

Further, as the chemical polishing used in the present invention, a conventional method of immersing a conductor in a polishing bath of an acid aqueous solution such as phosphoric acid or nitric acid is used. As the polishing bath, for example, a mixed acid solution of nitric acid, sulfuric acid and hydrochloric acid, an aqueous solution of phosphoric acid, nitric acid and ammonium chloride, a mixed acid solution of phosphoric acid, nitric acid and acetic acid is used. As the dipping condition, the bath temperature is from room temperature to about 40 ° C. and the time is from several seconds to about 1 minute.

In this chemical polishing as well, it is necessary to reduce the conductor diameter similarly to the range of 0.5 to 6 μm by reducing the conductor diameter.

After polishing, the conductor is washed with water or the like to remove the polishing liquid or electrolytic solution, and then an insulating layer is formed on the surface thereof. The insulating layer is formed by a conventionally known method, for example, a method of applying and baking an insulating paint (enamel paint), a method of extrusion coating a thermoplastic resin, or a method of winding an insulating tape. As the insulating paint, those made of polyurethane, polyimide, polyester, polyesteramide, polyamide, polyesterimide, epoxy, polyvinyl formal, polyhydantoin, etc. are used, and as the thermoplastic resin, phenoxy resin, nylon resin, etc. are used. If necessary, a self-fusion layer, a self-lubricating layer or the like can be formed on the insulating layer.

In such an insulated wire, as shown in FIG. 1, fine scratches on the surface of the conductor 1 are repaired and the conductor surface is smooth, so that discharge or electric field concentration does not occur, Therefore, the dielectric strength (withstand voltage) under the application of high frequency voltage becomes high. In addition, the thickness of the insulating layer becomes uniform, and local dielectric breakdown can be prevented.

Hereinafter, the working effects of the present invention will be clarified by showing concrete examples. A copper wire with a diameter of 0.2 mm was used as a conductor, which was electrolytically or chemically polished under the various polishing conditions shown in Table 1 below, and then coated with polyester imide as an insulating layer to a thickness of about 20 μm and baked to insulate it. It was an electric wire. A high frequency voltage of 60 KHz and 600 V was applied to this insulated wire, and the time until dielectric breakdown was measured. The sample shape was a single wire with a length of 30 cm, and voltage application was performed in an electrolyte aqueous solution.

A mixed solution of 1 part of phosphoric acid, 2.5 parts of water and 1.5 parts of ethanol (weight ratio) is used in the electrolytic polishing bath, and 5 parts of phosphoric acid, 2 parts of nitric acid and acetic acid are used in the chemical polishing bath. A mixture of 3 parts (weight ratio) was used. The number of measurements (n) was 30, and the result was the minimum value. The results are shown in Table 1.

[0015]

[Table 1]

As is clear from the results in Table 1, it is understood that the withstand voltage of the insulated wire is improved and the life is extended when the polishing amount (reduction amount of the conductor diameter) is in the range of 0.5 to 6 μm.

[0017]

[Effect of device]

 As described above, according to the insulated wire of the present invention, since the conductor surface is smooth and there are no microscopic scratches, discharge, electric field concentration, etc. do not occur, and high withstand voltage is maintained even under high frequency voltage application. It becomes a thing. Therefore, this insulated wire is suitable for windings such as a high frequency transformer and a deflection yoke coil.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a polished conductor according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a conductor that is not polished.

[Explanation of symbols]

 1 ... conductor, 2 ... scratch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Mitsutaka Yata 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Ltd. (72) Creator Toshio Niwa 1-1-5, Kiba, Koto-ku, Tokyo Shareholders Inside Fujikura

Claims (1)

[Scope of utility model registration request] 1. An insulated wire comprising a conductor which has been electrolytically or chemically polished and whose diameter has been reduced by 0.5 to 6 μm.