JPH0656723B2 - Heat resistant wire - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat-resistant electric wire, such as a magnet wire, which is required to have heat resistance because it is used in a high temperature atmosphere.

[Problems to be Solved by Conventional Techniques and Inventions] The conventional electric wire insulatively coated with a general organic material such as enamel has a heat-resistant upper limit temperature of 300 ° C. or less, and is deteriorated with time, and when an abnormality occurs, the organic material However, it is not suitable for applications requiring heat resistance.

Japanese Patent Publication No. 61-3051 proposes coating of a mixture of a heat-resistant organic material such as a silicone resin and an inorganic material in order to solve such a problem. However, even with such a configuration, the improvement of the heat-resistant upper limit temperature at which the insulation is maintained is insufficient, and there is a problem that deterioration over time occurs and the heat dissipation property is poor.

Further, although coating of a ceramic having high heat resistance has been conventionally studied, this is inferior in flexibility, and the ceramic coating may be peeled off due to insufficient adhesion between the shellac coating and the metal. There was also. Further, it is not practically used in terms of heat dissipation.

Therefore, an object of the present invention is to provide a heat resistant electric wire excellent in heat resistance and heat dissipation.

[Means and Actions for Solving Problems] The heat resistant electric wire of the present invention is characterized in that a diamond coating is provided around the conductor as shown in FIG. In FIG. 1, 1 is a conductor and 2 is a diamond coating.

As the conductor, a general conductor such as an electric wire such as Cu or Al can be used. If the environment in which electric wires are used often exceeds 200 ° C, or the temperature becomes high during manufacturing, Cu-0.15% Ag alloy or Cu-0.6% C
A Cu alloy such as an r alloy or an Al alloy such as an Al-0.3% Zr alloy can be used as an alloy having excellent heat resistance.

The diamond coating used in the present invention includes not only one having a diamond structure but also a carbon coating having an amorphous structure which is generally called i-carbon. Since these diamond coatings have thermal conductivity several times higher than that of Cu, they have excellent thermal diffusivity, and at high temperatures, they have much better insulation than organic materials and high heat resistance.

Further, when the adhesion between the diamond coating and the conductor is not sufficient, an intermediate layer can be provided between the diamond coating and the conductor as shown in FIG. In FIG. 2, 3 indicates an intermediate layer. As the intermediate layer, Ti,
1 selected from the group consisting of Cr, Zr, Hf and Ta
It is preferable to use one kind or two or more kinds of metals as main components. By providing such an intermediate layer, it is possible to improve the bending resistance in the state of being coated with the diamond coating, the peeling resistance of the diamond coating, and the like.

Furthermore, in the present invention, an insulating coating made of an organic insulating material can be provided on the outside of the diamond coating. By providing the organic insulating film in this manner, the insulating property of the diamond film is complemented, and the diamond insulating film can be used in applications where higher voltage is applied. This state is shown in FIG.
In FIG. 3, reference numeral 4 denotes an insulating coating made of an organic material.

Although FIGS. 1 to 3 show a single wire as a conductor, the heat resistant electric wire of the present invention may be a stranded wire. For example, a single wire coated with diamond may be twisted and an organic insulating coating may be provided on the outside thereof.

Further, as shown in FIG. 5, a bare single-wire conductor not coated with diamond may be twisted, and after twisting, an intermediate layer or a diamond coating may be provided only on a portion corresponding to the outer circumference of the twisted wire.

Example 1 Example 1 Zr was formed on the surface of a tough pitch copper wire by a continuous sputtering method.
Was coated to a thickness of about 0.2 μm. Then, a high frequency (30 MHz or less) plasma CVD method is used to coat a diamond coating on the Zr coating layer with a mixed gas of CH ₄ and H ₂ to a thickness of about 1 μm.
An electric wire having a structure as shown in the figure was produced. A voice coil for a speaker was manufactured using this electric wire as a magnet wire. At this time, the electric wire had good adhesion between the diamond coating and the conductor, and the diamond coating was not peeled off by the winding process.

As a result, it was confirmed that the wire using the electric wire of this example can be designed with a large current and the sound quality is better than that of the conventional magnet wire coated with enamel.

Example 2 On the surface of an Al-0.3% Zr alloy wire excellent in heat resistance, C
₂ H ₂ was used as a source gas and a diamond coating (i.
-Carbon) was directly generated to prepare an electric wire having a structure as shown in FIG. When a lightweight high-power magnet was produced using this electric wire, high performance was exhibited as compared with a conventional magnet wire.

Example 3 In this example, a Cu-0.1% Ag alloy wire (0.5%) was used as a conductor in consideration of prevention of coarsening of crystallinity during high temperature use.
mmφ) was used. After coating the surface of this alloy wire with Ti to a thickness of 0.1 μm by the sputtering method,
A diamond coating of about 0.5 μm was formed by photo CVD using an excimer laser. Next, a polyamide imide resin coating having a thickness of about 1 μm was provided on the surface of the diamond coating by a conventional method to produce an electric wire having a structure as shown in FIG. A magnet was produced by winding this electric wire, and when a current twice as large as the permissible current of a magnet using a conventional winding having the same diameter was passed, it worked normally. On the other hand, the magnet using the conventional winding burned when a current twice the allowable current was passed.

Example 4 Cr was coated on the surface of an oxygen-free copper wire as a conductor to a thickness of 0.1 μm by a sputtering method, and then CH ₄ was used as a source gas by a high frequency (13.56 MHz) ioprating method to form a diamond film ( i-
A carbon film) was coated to a thickness of 0.2 μm. Next, a speaker cord having a structure as shown in FIG. 4 was manufactured in the same manner as the method for manufacturing a speaker cord having a normal Litz wire structure. In FIG. 4, 1 is oxygen-free copper as a conductor, 2
Is a diamond film, 3 is a Cr layer as an intermediate layer, 4 is a tetrafluoroethylene layer as an organic insulating film, 5 is a shield layer, and 6 is an outer tetrafluoroethylene film.

When an acoustic test was performed using the speaker cord thus manufactured, a good sound quality was obtained as compared with the conventional speaker cord using the litz wire structure.

[Effects of the Invention] As described above, the heat resistant electric wire of the present invention is superior in heat resistance to the conventional one, so that the allowable current of the magnet when wound to manufacture the magnet can be increased. The design can be more compact than before. Further, since the diamond coating and the intermediate layer of the present invention are thinner than the conventional coating made of an organic material, the diamond coating and the intermediate layer can be wound more compactly than the conventional winding and the current density can be increased. Furthermore, the insulating properties of diamond coatings at high temperatures are far superior to the insulating properties of conventional coatings made from organic materials, so that thermal degradation can be significantly reduced.

Further, since the diamond coating used in the present invention has excellent thermal conductivity, when it is wound around a magnet and used, the heat dissipation of the magnet itself is significantly improved.

Since the heat-resistant electric wire of the present invention has the above advantages as compared with the conventional one, it can be effectively used as a magnet wire or a litz wire for audio equipment.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of the second embodiment. FIG. 2 is a sectional view showing the structure of the first embodiment. FIG. 3 is a sectional view showing the structure of the third embodiment. FIG. 4 is a sectional view showing the structure of the fourth embodiment. FIG. 5 is a sectional view showing another embodiment of the present invention. In the figure, 1 is a conductor, 2 is a diamond coating, 3 is an intermediate layer, and 4 is an organic insulating coating.

Claims (4)

[Claims] 1. A heat-resistant electric wire, characterized in that a diamond coating is provided around a conductor. 2. Between the conductor and the diamond coating, T
The heat resistance according to claim 1, characterized in that an intermediate layer containing one or more metals selected from the group consisting of i, Cr, Zr, Hf and Ta as a main component is provided. Electrical wire. 3. An insulating coating made of an organic insulating material is further provided on the outside of the diamond coating.
The heat resistant electric wire according to claim 1 or 2. 4. The heat resistant electric wire according to claim 1, 2 or 3, wherein the conductor contains Cu or Al as a main component.