JPH0430728Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a wire that is particularly suitable for a coil for an electromagnetic cooker.

[Conventional technology and problems]

Conventionally, insulated wires for coils of high-frequency devices such as electromagnetic cooker coils have been made using wires made by twisting multiple thin enamelled wires together to prevent AC resistance from increasing due to the skin effect in the high-frequency range. is used.

However, such wires have a problem in that the manufacturing cost increases as the wire diameter of the enameled wire becomes smaller, and the processing cost of twisting the enameled wires is added, increasing the cost.

Therefore, in recent years, copper oxide film insulated wires, in which a copper oxide film is provided on the surface of the copper wire, have come into use. Since this copper oxide film insulated wire is made by twisting a plurality of copper wires together and then applying copper oxide film insulation, it is possible to save cost by insulating the copper wires one by one.

However, the copper oxide film is thin and
There is a problem of low mechanical strength, especially when used as an electromagnetic cooker coil.
voltage is applied, so there is a drawback that sufficient dielectric strength cannot be ensured only by insulation using a copper oxide film. Additionally, the copper oxide film may be damaged due to mechanical deterioration during coil winding, resulting in a reduction in inter-turn insulation.

For this reason, there are methods such as winding glass thread horizontally around the outside of the copper oxide film insulated wire, impregnating and baking it with insulating varnish, or wrapping it with heat-resistant insulating tape, or using insulating tape as a separator between turns when winding the coil. Methods such as insertion are used.

However, each of these methods has advantages and disadvantages; the former method is effective in improving dielectric strength and mechanical strength against processing deterioration, but it involves a significant increase in production costs, and the latter method requires coil winding work. This results in a significant decrease in performance, and there remains dissatisfaction in terms of workability.

[Means for solving problems]

Therefore, in this invention, the above-mentioned disadvantages were solved by gap-wrapping an insulating tape around the outer periphery of the copper oxide film insulated wire.

〔Example〕

FIG. 1 shows an example of the Ritz wire of this invention, and the reference numeral 1 in the figure is the Ritz wire according to this invention.

This wire 1 is made by winding an insulating tape 3 around the outer periphery of a copper oxide film insulated wire 2 in a gap manner. The diameter of the copper oxide film insulated wire 2 is
Multiple strands of copper wire, copper alloy wire, etc. with a diameter of about 0.5 mm or less are twisted together to form a stranded wire, and this stranded wire is subjected to oxidation treatment to oxidize the surface of each strand 4 as shown in Figure 2. A copper film 5 is formed thereon. Examples of oxidation treatments include a method of immersing a stranded wire in a strongly oxidizing alkaline aqueous solution (see Japanese Patent Publication No. 59-5668, etc.), a method of immersing a stranded wire in a mixed aqueous solution of hydrogen peroxide, nitric acid, and copper nitrate (a method of immersing a stranded wire in a mixed aqueous solution of hydrogen peroxide, nitric acid, and copper nitrate) A well-known copper oxide forming method can be used, such as a method of immersing a twisted wire in a mixed aqueous solution of hydrogen peroxide and sulfuric acid (see Japanese Patent Publication No. 59-9639, etc.). The thickness of the copper oxide film 5 on the surface of the wire 4 is approximately 0.5 to 1.5 μm.

As the insulating tape 3, plastic tapes such as polyimide, polyamideimide, polyether ether ketone (PEEK), aromatic polyamide, polyester, polytetrafluoroethylene, polyfluoroethylene propylene, polyphenylene oxide, polyether sulfon, etc.
In addition to mica tape, glass fiber tape, polyester-reinforced mica tape, general insulating tape or these tapes are coated with B-stage resin of thermosetting resin such as polyimide resin, polyester resin, silicone resin, epoxy resin, phenol aralkyl resin, etc. prepreg tape, etc., is used. The width of this tape 3 varies depending on the outer diameter of the wire, and if the outer diameter is 3 to 5 mm,
It is said to be approximately 10 mm, and its thickness is approximately 25 to 100 μm.

Gap winding, as shown in Figure 1, involves winding the insulating tape 3 horizontally at a predetermined interval (gap) so that it does not overlap.In the case of this invention, the gap is 0 to 15 mm. ,Preferably
Selected in the range of 0.5 to 10 mm. If it is less than 0 mm, it will become a normal lap winding, which will increase the amount of insulating tape 3 required and have the disadvantage of reducing production speed. Furthermore, if the thickness exceeds 15 mm, the effect of improving insulation properties and the effect of improving mechanical strength against processing deterioration cannot be sufficiently obtained. Therefore, the gap width is 0~
By setting the range to 15 mm, it is possible to ensure inter-turn insulation and mechanical strength against processing deterioration when used as a coil, despite gap winding.

In the case of such a wire 1, the copper oxide film 5 is mechanically reinforced by the gap-wound insulating tape 3, so that the copper oxide film 5 is not damaged during coil winding, and the copper oxide film 5 is not damaged during coil winding. Processing deterioration resistance is improved. At the same time, the insulating tape 3 improves the insulation properties of the wire 1 as a whole, and when it is made into a coil, sufficient insulation properties between turns can be ensured. Furthermore, since the twisted wires are partially exposed, the surface coverage is small and heat dissipation is improved, resulting in good cooling when made into a coil.

[Experiment example]

A stranded wire was made by twisting 19 annealed copper wires with a diameter of 0.5 mm. The stranded wires were immersed in a mixed aqueous solution of hydrogen peroxide (35V01%), nitric acid (5VO1%), and copper nitrate (0.05Wt%) at 60°C for 2 minutes, and the surface of each copper wire was coated with a thickness of approximately
A copper oxide film of 1 μm was formed to form a copper oxide film insulated wire. Next, a polyimide insulating tape (25 μm thick) having a width of 6 mm was wrapped around the outer periphery of the wire with a gap interval of 2 mm to produce a wire of the present invention. This wire was wound to create an electromagnetic cooker coil. No damage to the copper oxide film was observed during winding, and the insulation voltage between turns of the coil was
It was able to secure 200V at 50Hz, and showed the same characteristics as conventional copper oxide film insulated wire wrapped with insulating tape.

[Effect of idea]

As explained in detail above, the invented Ritsutsu wire for electromagnetic cookers is made by gap-wrapping insulating tape around the outer periphery of the copper oxide film insulated Ritsutsu wire, so it can be produced quickly and eliminates the need for insulating tape. Since the amount is reduced, production costs can be reduced compared to conventional horizontal winding of glass thread or overlapping winding of tape. In addition, since there is no need to insert insulating tape for each turn during winding, the coil winding workability is also good, and the insulation is equivalent to that of conventional horizontally wound Ritsutsu wire made of glass thread or layered tape wrapped Ritsutsu wire. There are advantages such as being able to

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of the Ritsu wire of this invention, and FIG. 2 is a schematic sectional view showing the structure of each strand of the Ritsu wire of FIG. 1. 1... Ritsutsu wire for electromagnetic cooker, 2... Copper oxide film insulated Ritsutsu wire, 3... Insulating tape, 4... Element wire, 5... Copper oxide film.

Claims (1)

[Scope of utility model registration request] A wire for an electromagnetic cooker is made by wrapping insulating tape in a gap around the outer periphery of a stranded wire made by twisting together wires having a copper oxide insulating film.