JPS6348148B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric conductor, and particularly to an electric conductor suitable for use in high-voltage coils such as nuclear fusion devices and provided with insulation.

In general, when electrical conductors used in high-voltage coils such as nuclear fusion devices are subjected to large loads due to electromagnetic force, etc., copper or copper alloy materials (so-called hard copper) that have been work-hardened to have a high elastic limit are used. is used for conductors. Furthermore, since the length of large electrical conductors is usually limited by rolling equipment, it is necessary to divide the conductor into multiple parts and connect the divided parts metallurgically by welding or brazing to obtain the required length. A conductor is formed and then this conductor is covered with an insulator to make it an insulated electrical conductor.

When an electric conductor is metallurgically connected such as welding or brazing, the conductor near the metallurgical connection becomes soft. However, in the case of conventional electrical conductors, an insulator is also bonded to the conductor at this softened joint portion. However, in this structure, the elastic limit (0.2% yield strength) of the softened part due to welding or brazing of the conductor is as low as 3 to 4%, while the insulator made of epoxy resin mold used for high voltage coils etc. However, the dielectric strength deteriorates rapidly at a strain of a few tenths of a percent, resulting in a decrease in reliability. In other words, the stress between the hard copper part used in a normal conductor and the softened part (soft copper part) softened by metallurgical connection -
The strain curve is as shown in FIG.
In other words, the hard copper part 9 has a high stress against strain,
On the other hand, the annealed copper portion 10 has extremely low stress against strain. For example, when a load of σ ₁ is applied to a conductor, a large strain ε ₁ is generated in the annealed copper portion 10, and the dielectric strength of the insulator bonded thereto deteriorates, reducing reliability. Ta.

The present invention has been made in view of the above points, and its purpose is that even if conductors are connected by metallurgical connection, the dielectric strength of the insulator covering the conductors will not deteriorate. It is an object of the present invention to provide an electric conductor which has improved reliability without increasing the external dimensions of an insulator.

In the present invention, a conductor is divided into at least two parts, and the divided parts are metallurgically connected to form an integrated conductor, and a load due to electromagnetic force is applied to the conductor near the metallurgical connection part of the intermediate insulator. A sliding portion is formed that can slide against the conductor when strain occurs near the conductor, and each end of the insulator and the intermediate insulator is formed into a tapered shape. , the tapered ends are overlapped with each other, and the overlapped ends are formed to have the same thickness as the insulator and the intermediate insulator, thereby achieving the intended purpose. This was done to achieve this goal.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

FIG. 1 shows an embodiment of the electrical conductor of the present invention.

In the figure, 1 is a conductor that is divided into a plurality of parts and is usually work hardened, 2 is a welded part where the divided parts of the plurality of conductors 1 are successively welded as an example of metallurgical connection, and 3 is a welded part that has been softened by welding. a softened part of the conductor 1;
4 is an insulator that covers the part of the conductor 1 other than the softened part 3, that is, the vicinity of the metallurgical connection; 5 is an intermediate insulator that covers the softened part 3 of the conductor 1, that is, the vicinity of the metallurgical connection;
A sliding portion 6 is formed to cover the softened portion 3 in a slidable manner. Further, the boundary between the intermediate insulator 5 and the insulator 4, that is, the respective ends, is formed into a tapered shape, and the tapered ends are overlapped with each other at an overlapping portion 8, and the overlapping It is formed so that the thickness of the bent end portion is the same as that of the insulator 4 and the intermediate insulator 5.

By having the configuration of this embodiment as described above,
Even if a large load due to electromagnetic force is applied to the conductor 1 and a large strain occurs in the softened part 3, the sliding part 6 of the intermediate insulator 5 can slide against the conductor 1. No distortion occurs and therefore the dielectric strength does not deteriorate, and the reliability of the electrical conductor with this insulating structure is improved. Furthermore, in this embodiment, the overlapped ends of the intermediate insulator 5 covering the soft copper portion of the conductor 1 and the insulator 5 covering the hard copper portion are tapered to form the overlapped portion 8. The thickness is the same as that of the intermediate insulator 5 and the insulator 4, which has the effect of not increasing the outer dimensions of the overlapping insulator.

According to the electrical conductor of the present invention described above, the conductor is divided into at least two parts and the divided parts are metallurgically connected to form an integrated conductor. When a load due to electromagnetic force is applied to the conductor and strain occurs near the metallurgical connection, a sliding portion is formed that can slide against the conductor, and each end of the insulator and the intermediate insulator is The tapered ends are overlapped with each other, and the overlapped ends have the same thickness as the insulator and the intermediate insulator. Therefore, even if a large load is applied to the conductor due to electromagnetic force and strain occurs near the metallurgical connection, the insulator covering this area can slide, so no strain will occur in the insulator. Therefore, the dielectric strength is not deteriorated and the reliability is improved, and the external dimensions of the insulator are not increased, so it is very effective for this type of electrical conductor.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the electrical conductor of the present invention,
FIG. 2 is a partially cross-sectional perspective view of the conductor connection portion, and is a characteristic diagram showing stress-strain curves of the conductor work-hardened portion and the conductor softened portion. DESCRIPTION OF SYMBOLS 1...Conductor, 2...Welding part, 3...Conductor softening part, 4...Insulator, 5...Intermediate insulator, 6...Sliding part, 8...Overlapping part.

Claims (1)

[Claims] 1 A conductor that is divided into at least two parts and integrated by metallurgically connecting the divided parts, an insulator that covers the part of the conductor except for the vicinity of the metallurgical connection, and an intermediate that covers the vicinity of the metallurgical connection of the conductor. In an electrical conductor consisting of an insulator, on the conductor side of the intermediate insulator,
When a load due to electromagnetic force is applied to the conductor and strain occurs near the metallurgical connection part, a sliding part is formed that can slide on the conductor, and each of the insulator and intermediate insulator The ends of the tapered ends are overlapped with each other, and the overlapped ends have the same thickness as the insulator and the intermediate insulator. An electrical conductor characterized by being formed.