JP2749600B2 - Manufacturing method of heat-resistant insulated conductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a heat-resistant insulation used for coil windings, signal conductors, power conductors, etc., which is particularly suitable for use in vacuum and ultra-vacuum atmospheres. The present invention relates to a method for producing a coated conductor, and more particularly to a method for producing a heat-resistant insulated conductor capable of continuously producing a long product.

[Conventional technology]

2. Description of the Related Art In recent years, many scientific experiments such as production of industrial products such as semiconductors in an ultrahigh vacuum atmosphere or particle acceleration experiments have been conducted. Various improvements have been made to the equipment for obtaining the ultra-high vacuum atmosphere, and quite high-level equipment has been put into practical use. For small motors and signal cables and power cables necessary for automatic operation of robots, etc., gas is released from coil windings or enamel coatings used as insulating coatings for these cables, etc. Is no longer maintained.

Also, for a small motor, it is difficult to cool the coil in an ultra-high vacuum device because it is necessary to maintain the degree of vacuum. Therefore, when the coil temperature rises due to the conductor resistance during energization and the coil is burned out And the experimental constraints were great.

Therefore, in order to reduce the amount of gas released from these vacuum insulated conductors and to improve the heat resistance, Al ₂ which has a small amount of gas released and has heat resistance around copper as a conductive material. It has been proposed to coat a metal oxide ceramic such as O ₃ by a wet method (electrochemical method).

However, in a conductor in which the metal oxide-based ceramic is coated around the conductive material, the release of gas from the insulating film is suppressed, but there is a problem in terms of heat resistance and insulating properties.

That is, the metal oxide-based ceramics generally have poor bondability with a conductive material such as copper and cannot be directly coated with ceramics (oxide-based) outside the conductive material. After coating with metal, it is coated with ceramic (oxide type). However, when conducting electricity, heat diffusion occurs between the conductive material and the dissimilar metal and an alloy layer is formed. The heat resistance decreased.

Further, in these conventional ceramic-coated conductors, a phenomenon was observed in which the conductive material was thermally diffused on the ceramic surface even in a small amount, and a sufficient dielectric breakdown voltage was not obtained.

The present inventors have conducted intensive studies to solve such problems, and as a result, as a heat-resistant insulation-coated conductor having good heat resistance and insulation properties and extremely low gas emission, copper or copper as a conductive material. An alloy or silver or a silver alloy is coated with a carbon or boron nitride layer having a thickness of 0.05 μm or more composed of fine particles having an average particle size of 5 μm or less, and a thickness outside the carbon or boron nitride layer. Is a heat-resistant insulating coating in which an Al or Al alloy layer having a thickness of 1 μm or more is coated, and a metal oxide ceramic having a thickness in the range of 0.1 to 50 μm is coated outside the Al or Al alloy layer. He discovered conductors and filed a patent application earlier (Japanese Patent Application No. 63-1859).
No. 87 (see JP-A-2-37616).

Thus, in producing the heat-resistant insulated conductor,
The outer surface of the composite wire obtained by coating a carbon or boron nitride layer around copper or copper alloy or silver or silver alloy
Alternatively, as a method of coating the Al alloy layer, the composite wire is integrated with a predetermined length of Al or Al alloy hollow billet in a container, and an Al or Al alloy layer having a predetermined thickness is extruded outside the composite wire. After coating, a method of wire drawing to a desired size has conventionally been adopted.

[Problems to be solved by the invention]

However, the outside of the conventional composite wire has a predetermined thickness of Al.
Or in the method of extrusion coating the Al alloy layer, Al or Al
Since a hollow billet of a predetermined length was used by inserting it into the container as an alloy material, the length of the obtained extruded material was limited by the length of the hollow billet, and a long product could not be obtained. . In addition, each time it was pressed once, the extruding operation was interrupted due to billet exchange, and it was not possible to continuously extrude, so that the productivity was very poor.

[Means for solving the problem]

The present invention has been made as a result of intensive studies in view of the above points, and it is an object of the present invention to provide a method for manufacturing a heat-resistant insulated coated conductor capable of continuously manufacturing long products, and to improve the productivity. It is to improve.

That is, according to the present invention, after a copper or copper alloy or silver or silver alloy as a conductive material is coated with a carbon or boron nitride layer, the composite wire thus obtained has an inner diameter outside the composite wire. Continuously supply into the extruded Al or Al alloy pipe larger than the diameter and the inside is replaced with inert gas or reducing gas, then cool the Al or Al alloy pipe containing this composite wire to room temperature Thereafter, the outer surface of the composite wire and the inner surface of the Al or Al alloy pipe are brought into close contact with each other by performing surface reduction processing with a drawing die, and the Al or Al alloy coated conductor obtained in this manner is reduced to a predetermined wire diameter. The thickness of fine particles with an average particle size of 5 μm or less around copper or copper alloy or silver or silver alloy as a conductive material, characterized by being drawn and further coated with a metal oxide ceramic on the outside. With carbon or boron nitride of 0.05μm or more Layer is coated, carbon Motomata is Al or Al alloy layer thickness outside than 1μm boron nitride layer is coated, further said Al or Al
A method for producing a heat-resistant insulated conductor in which a metal oxide ceramic having a thickness in the range of 0.1 to 50 μm is coated on the outside of an alloy layer.

In the method of the present invention, as the extruder for extruding a long Al or Al alloy pipe, for example, a ram push extruder, a conform extruder, or the like can be used. The latter extruder extrudes a material by a frictional force between a rotating grooved wheel and a shoe block arranged and fixed on the groove, and is particularly suitable for extruding a small-sized long material. .

Thus, when extruding the Al or Al alloy pipe, when extruding such that the inner surface is in close contact with the outer surface of a composite wire obtained by coating a conductive material such as copper with carbon or the like, Al or Due to the frictional force acting between the Al alloy and the composite wire, the coating layer around the conductive material may peel off, so that Al or Al
It is necessary to extrude such that there is a predetermined clearance between the inner surface of the alloy pipe and the outer surface of the composite wire, and then apply a reduced surface area with a drawing die in a cold state to bring the two into close contact. The size of the clearance between the Al or Al alloy pipe and the composite wire required to prevent the peeling of the coating layer around the conductive material during the extrusion is determined by the degree of adhesion of the coating layer to the conductive material and the extrusion conditions. Although it differs depending on the like, it is usually desirable that the thickness is about 0.05 mm or more.

〔Example〕

 Next, the present invention will be described more specifically with reference to examples.

FIG. 1 is an explanatory view of an embodiment of a method for producing a heat-resistant insulated conductor of the present invention, and FIG. 2 is an explanatory view of a main part of a conform extruder used in the embodiment. In the figure, 1 is a carbon-coated copper wire, and 2 is an Al pipe. A carbon-coated copper wire 1 obtained by coating a copper wire having a wire diameter of 2.8 mmφ with a thickness of 0.5 μm of carbon is sent out from an uncoiler 3, and its surface is washed by a washing machine 4. The carbon-coated copper wire 1 is supplied into an Al pipe 2 having an inner diameter of 3.8 mmφ and an outer diameter of 5.0 mmφ extruded from a hollow mandrel 10 of No. 5 and Ar gas is passed through a gas pipe (not shown) inside the Al pipe 2. The carbon-coated copper wire 1 was enclosed by blowing and filling.
After cooling the Al pipe 2 in the cooling bath 6, the Al pipe 2 is reduced in surface area by the drawing die 7 until the outer diameter becomes 4.0 mmφ, and the inner surface of the Al pipe 2 is brought into close contact with the outer surface of the carbon-coated copper wire 1. Then, it was wound around a coiler 9 as an Al-coated conductor 8.

The thus obtained Al-coated conductor 8 is drawn and
A wire having a diameter of 0.5 mmφ and an Al layer having a thickness of 75 μm was used.
Thereafter, a 10 μm-thick Al ₂ O ₃ layer was wet-coated (electrochemical method) on the outside of the Al layer of the wire thus obtained.
To obtain a desired heat-resistant insulated conductor.

〔The invention's effect〕

According to the method of the present invention, it is possible to continuously manufacture long products of a heat-resistant insulation-coated conductor used for coil windings, signal conductors, power conductors, etc., thereby improving the productivity, etc. It has a remarkable industrial effect.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of a method for producing a heat-resistant insulated conductor of the present invention, and FIG. 2 is an explanatory view of a main part of a conform extruder used in the embodiment. 1 ... carbon coated copper wire, 2 ... Al pipe, 3 ... uncoiler, 4 ... washing machine, 5 ... extruder, 6 ... cooling tank, 7
… Drawing die, 8… Al-coated conductor, 9… coiler.

Claims (1)

(57) [Claims] (1) After coating a carbon or boron nitride layer around copper or a copper alloy or silver or a silver alloy as a conductive material, a composite wire obtained in this way has an inner diameter outside the composite wire. Continuously supply into the extruded Al or Al alloy pipe larger than the diameter and the inside is replaced with inert gas or reducing gas, then cool the Al or Al alloy pipe containing this composite wire to room temperature Thereafter, the outer surface of the composite wire and the inner surface of the Al or Al alloy pipe are brought into close contact with each other by performing surface reduction processing with a drawing die, and the Al or Al alloy coated conductor obtained in this manner is reduced to a predetermined wire diameter. The thickness of fine particles with an average particle size of 5 μm or less around copper or copper alloy or silver or silver alloy as a conductive material, characterized by being drawn and further coated with a metal oxide ceramic on the outside. Carbon or boron nitride having a particle size of 0.05 μm or more There are coated, carbon Motomata has more than 1μm thick on the outside of the boron nitride layer
A method for producing a heat-resistant insulated conductor in which an Al or Al alloy layer is coated, and a metal oxide ceramic having a thickness in the range of 0.1 to 50 μm is coated on the outside of the Al or Al alloy layer. .