JPS62229806A - Manufacture of superconducting coil - Google Patents

Abstract

PURPOSE:To obtain a superconducting coil having excellent mechanical strength by a method wherein the coil segment, formed by winding a superconducting conductor through an insulating tape on which an epoxy bonding agent is coated on the surface, is stacked through the intermediary of an insulating spacer, a heat treatment is performed thereon in the state wherein compressive force is added from both end faces of the superconducting conductor. CONSTITUTION:Each pancake coil 1 is formed by winding the material 3, obtained by coating an epoxy bonding agent on both surfaces of a polyimide resin tape, in the reguired number of turns on the wide-widthed surface of the superconducting conductor 2 having a plurality of built-in superconducting wires while the material 3 is being adhered temporarily. A plurality of insulated spacers 4 are radially arranged on the substrate 5 of a pressing jig, a pancake coil 1 is placed on one of the spacers 4, and stacking operation is repeated. After the upper plate 6 of the pressing jig has been placed on the insulated spacers 4 located on the top stage, the coil 1 and the insulated spacers 4 are compressed by tightening them until the interval between the substrate 5 and the upper plate 6 becomes the prescribed measurements. When they are heated up under the compressed state, they become hard after the lapse of the prescribed period of time, and the conductor 2 and the insulated tape 3, located in each pancake coil 1, can be adhered firmly and completely.

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 the superconducting coil that generates a high magnetic field is a stabilized superconducting four-body structure in which multiple superconducting wires are arranged in a matrix of copper or aluminum, which has good electrical and thermal conductivity. used. When using these four stabilized superconductors, it is essential to cool them sufficiently in order to rapidly remove the generated heat. For this reason, super? In the ft1j coil, an insulating spacer is inserted between the segments to provide a coolant flow path in which a portion of the conductor surface is exposed. Such superconducting coils are manufactured by conventional methods.

In other words, the segments obtained by winding four superconducting bodies through thin heat-resistant insulating tape coated with strong epoxy adhesive are compressed and heated to harden the adhesive. After that, they are stacked with insulating spacers placed between each segment and compressed again.

However, in the case of this method, unreasonable force is applied to each segment due to re-compression, and the fixed bevel may peel off, causing the conductor in the relevant part to move during actual use, causing various problems. There was a desire for improvement.

[Object of the Invention] An object of the present invention is to provide a method that does not apply unreasonable force to segments or conductors and can easily form a superconducting coil 1a with excellent strength.

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

[Embodiments of the Invention] The present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 1 denotes pancake coils each serving as a segment.

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

The pancake coil 1 made in this way is made by arranging a plurality of insulating spacers 4 radially on the substrate 5 of the holding tool with good smoothness, placing one pancake coil 1 on top of the insulating spacers 4, and then An insulating spacer 4 is placed above so as to be in the same position as the insulating spacer 4 of F.

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

Repeat the above stacking operation and remove the topmost insulating spacer 4.
The upper plate 6 of the presser is placed on top, and the tightening tool is used (not shown).
The coils 1 and the insulating spacers 4 are compressed by tightening them until the distance between the substrate 5 and the upper plate 6 reaches a predetermined dimension. Since the epoxy adhesive in each coil 1 is still in an uncured state, each coil 1 fits well and deforms easily, correcting slight waviness and small irregularities on the sides caused by uneven winding. be done.

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 with an exposed part of the surface of the conductor 2 by an insulating spacer 4, it goes without saying that there is no problem with cooling W using a refrigerant such as liquid helium. be.

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 entire body is compressed, heat treatment for each segment is not required, and the reliability of the structure with excellent strength is achieved. The advantage is that high superconducting coils 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: Superconducting conductor, 3: Insulating tape, 4: Insulating spacer, 5: Holder substrate, 6: Upper plate of presser.

Claims (1)

[Claims] (1) Coil segments are created by winding superconducting conductors with insulating tape coated with epoxy adhesive on the surface, stacked with insulating spacers in between, and compressive force is applied from both ends of the coil segments. A method for manufacturing a superconducting coil, characterized in that the entire body is heat-treated to cure the adhesive.