JPH0551162B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement in a method for manufacturing a superconducting coil used in a pancake-type superconducting coil that generates a high magnetic field.

[Prior art and its problems] The superconducting conductor used in superconducting coils that generate high magnetic fields is a stabilized superconducting conductor in which multiple superconducting wires are arranged in a copper or aluminum matrix that has good electrical and thermal conductivity. used. When using this stabilized superconductor, it is essential to perform sufficient cooling in order to rapidly remove the generated heat. For this reason, in superconducting coils, an insulating spacer is inserted between the segments of the pancake coil to provide a coolant flow path in which a portion of the conductor surface is exposed. Such superconducting coils have conventionally been manufactured by the following method.

In other words, a segment obtained by winding a superconductor through a thin heat-resistant insulating tape coated with an epoxy adhesive with strong adhesive strength is compressed and heated to harden the adhesive. Stacked with insulating spacers between each segment,
This is a method of re-compressing.

However, in the case of this method, unreasonable force is applied to each segment due to re-compression, which causes the fixed cut angle to peel off and cause the conductor in the relevant part to move during practical use, causing various problems. There is fear;
Improvement was desired.

[Object of the Invention] An object of the present invention is to provide a method that does not apply excessive force to segments or conductors and can easily obtain superconducting coils with excellent strength.

[Summary of the Invention] In order to achieve the above object, in the present invention, each coil segment is heated after being stacked.

[Embodiments of the Invention] Examples of the present invention will be described with reference to the drawings.
In FIG. 1, numerals 1 indicate pancake coils each serving as a segment.

As shown in Fig. 2, each pancake coil 1 has Kapton tape (polyimide resin tape, trade name of DuPont, USA) on the wide side of a superconducting conductor 2 containing a plurality of superconducting wires. It is made by wrapping the tape 3 with epoxy adhesive applied on both sides while temporarily adhering it to the required number of turns.

Pancake coil 1 made in this way
In this example, a plurality of insulating spacers 4 are arranged radially on a substrate 5 of a holding device with good smoothness, one pancake coil 1 is placed on top of the insulating spacers 4, and an insulating spacer 4 is placed on top of the insulating spacer 4. Place it so that it is in the same position as.

As the insulating spacer 4, a fiber-reinforced resin having a predetermined thickness, such as a glass fiber cloth impregnated with an epoxy resin, was used.

After repeating the above stacking operation and placing the upper plate 6 of the presser on the uppermost insulating spacer 4, the gap between the substrate 5 and the upper plate 6 is set to a predetermined dimension using a tightening tool (not shown). to compress each coil 1 and insulating spacer 4. Since the epoxy adhesive in each coil 1 is still in an uncured state, each coil 1 fits well and deforms easily, with slight undulations and small irregularities on the sides caused by uneven winding. will be corrected.

When the entire coil is heated to a temperature of 100 to 150° C. in this compressed state, the epoxy adhesive of each coil 1 becomes slightly softened and promotes the aforementioned deformation. As the heat treatment progresses, curing begins, and curing is completed after a required period of time. As a result, strong and sufficient adhesion is achieved between the conductor 2 and the insulating tape 3 in each pancake coil 1, and the conductor 2 has excellent strength without fear of movement even when electromagnetic force is applied. This results in a highly reliable structure. Since a refrigerant flow path is formed between the pancake coils 1 by means of an insulating spacer 4 in which a short side, which is a part of the surface of the conductor 2, is exposed, it goes without saying that there is no problem in cooling with a refrigerant such as liquid helium.

Furthermore, according to this manufacturing method, heating treatment for each pancake coil 1 is not necessary, and the effort can be saved.

[Effects of the Invention] According to the method of the present invention, since the thermosetting adhesive is cured after the whole is compressed, heat treatment for each segment is not necessary, and a highly reliable superconductor with an excellent structure in terms of strength can be obtained. It has the advantage that the coil can be easily obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory view showing one embodiment of the method according to the present invention, and FIG. 2 is an enlarged vertical cross-sectional view thereof. 1: Coil segment, 2: Superconductor, 3:
Insulating tape, 4: Insulating spacer, 5: Substrate of presser, 6: Upper plate of presser.

Claims (1)

[Claims] 1 A plurality of coil segments are created by winding a superconductor into a pancake shape with an insulating tape coated with epoxy adhesive on the surface, stacked with insulating spacers in between, and then compressed from both end faces. A method for manufacturing a superconducting coil, comprising heating the entire coil under force to cure the adhesive in each coil segment.