JPH04103105A - Superconducting coil - Google Patents

Abstract

PURPOSE:To prevent a superconducting strand from sustaining damage without squeezing out by a self-fusion film when the cross-section of a formed strand is compression-molded in square shape by a method wherein an insulated strand is formed into a self-fusion strand by covering it with a self-welded film consisting of soft thermosetting resin. CONSTITUTION:As a self-fusion film 17 is formed by thermosetting resin, a superconducting strand 18 is not squeezed by the self-fusion film 17 even when the cross-section of a formed strand 14 is compression-molded in square shape, and as a result, the super-conducting strand 18 is prevented from damage. Also, when a heat treatment is conducted on the self-fusion conductor 11 after a self-fusion conductor 11 has been multiple-wound, the self-fusion film 17 is hardened by heat. As a result, the rigidity of a super-conducting coil can be enhanced, and the quenching from a super-conducting state to a normal conducting state by the frictional heat can be prevented in the same manner as before. Besides, as the self-fusion film 17 before heat treated is in, a semihardened and soft state, the void formed between the adjacently positioned self-fusion strands 17 can be removed by vacuum evacuation when the heat treatment is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a superconducting coil, and particularly to a superconducting coil using a self-fusing conductor as a coil conductor.

(Prior art) Superconducting coils used in superconducting equipment such as superconducting generators and superconducting transformers are formed by multiple windings of superconducting conductors, but if frictional heat is generated within the coil, the superconducting state cannot be maintained. become unable to do so.

Therefore, in order to prevent the transition (quench) from a superconducting state to a normal conducting state due to frictional heat, a superconducting coil using a self-fusing conductor as a coil conductor was proposed.
This is disclosed in Publication No. 604 and the like.

FIG. 6 is a partial cross-sectional view of a superconducting coil using a self-fusing conductor as a coil conductor before heat treatment, and this superconducting coil is formed by winding the self-fusing conductor 1 in multiple layers.

The self-fusing conductor 1 consists of a conductor 2 and an insulating tape 3 wound around the surface of the conductor portion 2, and the conductor portion 2 is formed from a plurality of shaped stranded wires 4 as shown in FIG. There is. These formed strands 4 consist of a plurality of self-fused strands 5 (for example, 7
It is formed by twisting each strand together, and is compression molded to have a square cross section.

As shown in FIG. 8, the self-bonding wire 5 has a self-bonding coating 7 formed on the surface of an insulating wire 6, and the self-bonding coating 7 is made of a thermosetting resin such as an expository resin. has been done. The insulating wire 6 is a superconducting wire 8 with an insulating coating 9 formed on the surface thereof, as shown in FIG. 9, and the insulating coating 9 is made of the same material as the self-bonding coating 7.

Therefore, the superconducting coil configured as above is
After winding the self-bonding conductor 1 multiple times, when the self-bonding conductor 1 is subjected to heat treatment, the self-bonding coating 7 is melted. As a result, the self-fusion strand 5 is adhered to and integrated with the adjacent self-fusion strand 5 and the insulating tape 3. Therefore, by using the self-fusing conductor 1 as the coil conductor of the superconducting coil, friction within the coil is prevented, so that quenching from the superconducting state to the normal conducting state due to frictional heat can be prevented.

(Problem to be Solved by the Invention) However, in the self-bonding conductor 1 described above, the superconducting wire 8 is covered with an insulating coating 9 to form the insulating wire 6, and the insulating wire 6 is made of thermosetting resin. The cross section of the stranded wire obtained by twisting a plurality of self-fused strands 5 is compression-molded into a rectangular shape to form the formed stranded wire 4. Since it is formed by winding the insulating tape 3 around the stranded wire 4, there is a problem in that when the formed stranded wire 4 is compression molded, the superconducting element wire 8 is crushed by the self-bonding coating 7, and wire breakage is likely to occur. .

The present invention has been made in view of the above points, and its purpose is to prevent the superconducting strands from being crushed by the self-fusion coating when the cross section of the formed stranded wire is compressed into a rectangular shape. The object of the present invention is to provide a superconducting coil that can prevent damage.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides a superconducting coil formed by multiple windings of a self-fusion conductor, wherein the self-fusion conductor is a superconducting element. The wire is covered with an insulating film to make an insulated wire, this insulated wire is covered with a self-bonding film made of a soft thermosetting resin to make a self-bonding wire, and a plurality of these self-bonding wires are twisted. The cross section of the combined stranded wires is compressed into a rectangular shape to obtain a shaped stranded wire, and an insulating tape is wound around the shaped stranded wire.

(Function) In the present invention, by covering an insulated strand with a self-bonding coating made of a soft thermosetting resin to form a self-bonding strand, the cross section of the formed stranded wire can be compressed into a square shape. Since the superconducting strands are not crushed by the self-fusion coating, damage to the superconducting strands can be prevented.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

Figure 1 is a partial cross-sectional view of the superconducting coil before heat treatment.
This superconducting coil is formed by winding a self-fused conductor 11 in multiple turns. The self-fusion conductor 11 and the conductor 12,
An insulating tape 13 is wound around the surface of the conductor portion 12, and the conductor portion 12 is formed of a plurality of shaped twisted wires 14 as shown in FIG. These shaped strands 14 are formed by twisting together a plurality (for example, seven) of self-fused strands 15, and are compression-molded to have a rectangular cross section.

As shown in FIG.
A self-adhesive film 17 is formed on the surface of 6, and the self-adhesive film 17 is formed of a soft thermosetting resin (for example, an epoxy resin using dicyan diamide as a hardening agent). Further, the insulating wire 16 is a superconducting wire 18 with an insulating coating 19 formed on the surface thereof, as shown in FIG.

According to the above configuration, since the self-adhesive coating 17 is formed from a soft thermosetting resin as described above,
Even if the cross section of the formed stranded wire 14 is compression-molded into a rectangular cross section, the superconducting wire 18 is not crushed by the self-fusion coating 17, so damage to the superconducting wire 18 can be prevented. Further, when the self-fusion conductor 11 is subjected to heat treatment after winding it multiple times, the self-fusion coating 17 is thermosetted, so the rigidity of the superconducting coil can be increased, which is different from the conventional one. Similarly, quenching from a superconducting state to a normal conducting state due to frictional heat can be prevented. Furthermore, in the above embodiment, since the self-bonding coating 17 before heat treatment is a semi-hardened and soft coating, the voids formed between adjacent self-bonding strands 17 are vacuum degassed during the heat treatment. It can also be removed.

In the above embodiment, the formed stranded wire 14 was formed from a set of seven self-bonding strands 15, but as shown in FIG. [self-fusion strands] 5 and may be twisted together with the insulating strands 16 as the center. In this way, when compression molding is performed, the self-adhesive coating 1
7 can be prevented from concentrating around the insulated wire 16.

Further, in the above embodiment, the insulating coating 19 was formed on all the superconducting strands 18, but if a large insulation resistance between the strands is not required, some or all of the insulating coating 19 may be omitted. The occupancy rate of 18 can be increased.

[Effects of the Invention] As explained above, the present invention provides a superconducting coil formed by multiple windings of a self-fusing conductor, in which the self-fusing conductor is formed by covering a superconducting strand with an insulating coating and converting it into an insulated strand. This insulated strand is covered with a self-bonding film made of a soft thermosetting resin to form a self-bonding strand, and the cross-section of the stranded wire, which is made by twisting multiple strands of this self-bonding strand, is compression molded into a square shape. It is made by winding an insulating tape around the molded stranded wire. Therefore, it is possible to provide a superconducting coil in which the superconducting strands are not crushed by the self-fusion coating when the shaped strands are compression-molded into a rectangular cross section, and damage to the superconducting strands can be prevented.

[Brief explanation of the drawing]

Figures 1 to 4 are diagrams showing one embodiment of the present invention.
The figure is a partial cross-sectional view of a superconducting coil, FIG. A sectional view of a formed stranded wire showing another embodiment, FIGS. 6 to 9 are diagrams for explaining the prior art, FIG. 6 is a partial sectional view of a superconducting coil, and FIG. 7 is a self-fused conductor 8 is a cross-sectional view of the formed stranded wire,
FIG. 9 is a sectional view of the insulated wire. 11... Self-fusion conductor, 12... Conductor portion, 13...
- Insulating tape, 14... Molded stranded wire, 15... Self-bonding strand, 16... Insulating strand, 17... Self-bonding coating,
18... Superconducting wire, 19... Insulating coating. Figure 1 Applicant's agent Patent attorney Takehiko Suzue 1I2 Figure 1I3 Figure n1

Claims (1)

[Claims] In a superconducting coil formed by multiple windings of a self-fused conductor, the self-fused conductor covers a superconducting strand with an insulating film to form an insulated strand, and this insulated strand is made of a soft thermosetting resin. Covered with a self-bonding film to form a self-bonding strand,
A superconducting coil characterized in that a stranded wire made by twisting together a plurality of self-fused strands is compression-molded into a rectangular cross section to form a shaped stranded wire, and an insulating tape is wound around the shaped stranded wire.