JPH0481284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a superconductor, and particularly to a superconductor suitable for manufacturing a highly rigid superconducting coil.

[Background of the invention]

Conventionally used superconducting conductors with a large cross section have a rectangular cross-sectional structure (hereinafter referred to as a solid conductor) in which twisted superconducting wires are embedded in a copper material with solder. The change in cross-sectional shape during bending of this solid conductor is almost the same as that of a solid copper rod.

In other words, when bending a solid rod or plate, it is known that warpage occurs in the direction perpendicular to the bending surface, and this is explained in "Bending Process of Thin Plate" (supervised by Moriharu Masuda, Seibundo Shinkosha p22). , published in 1952). The curvature of this warp is approximately 1/2R when the width of the bar is sufficiently smaller than the bending radius R, and both the inner and outer circumferential sides of the bend are in the same direction, that is, both are opposite to the center of curvature of the bend. Turn to the side.

On the other hand, superconducting conductors, which have recently come into use, consist of stranded wires housed in a rectangular tube.
The inventors' research has revealed that when this square tube is bent, each side of the square tube deforms so as to bulge outward in its cross section.

The solid conductor described above warps in the same direction on both the inner and outer sides of the bend, so when bending this solid conductor and winding it to make a superconducting coil, There were almost no gaps between the two.

However, as mentioned above, in a superconductor made of stranded wires housed in a rectangular tube, each side of the rectangular tube bulges outward, and the inner and outer circumferential sides of the bend warp in opposite directions. When manufacturing superconducting coils by winding these superconducting conductors, it is difficult to wind them densely so that the sides of the rectangular tube of the superconducting conductors touch each other, which may reduce the rigidity of the superconducting coil. Ta. If the rigidity of the superconducting coil is low, when a current is passed through it, the superconductor moves due to electromagnetic force, and the superconducting state is broken by frictional heat, making it impossible to obtain the desired performance as a superconducting coil. It disappears.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and it eliminates the bulge of the rectangular tube after bending of a superconducting conductor in which stranded wires are housed in a rectangular tube, thereby increasing the density of the winding of the superconducting coil. The object of the present invention is to provide a superconductor that enables the production of highly rigid superconducting coils.

[Summary of the invention]

The structure of the superconducting conductor according to the present invention is such that the superconducting conductor is made by bending a superconducting conductor made of stranded wires housed in a rectangular tube, and then winding the superconducting conductor in layers to produce a superconducting coil. The two opposite sides of the rectangular tube, which are the inner and outer circumferential sides of the bend, are both pre-formed to be concave inward, and the amount of concaveness is determined by the inner and outer diameters of the superconducting coil or The amount of depression corresponds to the amount of deflection deformation of the square tube during bending at the curvature corresponding to the average diameter of the inner and outer diameters.

In addition, the following is added.

A superconductor in which stranded wires are housed in a rectangular tube, in which the sides of the rectangular tube, which are the inner and outer circumferential sides of the bending process, are recessed inward in the cross section of the rectangular tube. By manufacturing a superconducting coil using this superconducting conductor, the bulge of the square tube due to the bending process is canceled out, and each side of the square tube is brought closer to a straight line, thereby making the superconducting coil This enables high-density winding of wires, making it possible to obtain superconducting coils with high rigidity.

[Embodiments of the Invention] Before entering into the description of the embodiments, basic matters related to the present invention will be explained using the drawings.

FIG. 2 is a cross-sectional view showing a superconducting conductor that is a subject of the present invention, and FIG. 3 is an example of a superconducting coil produced by bending the superconducting conductor shown in FIG. 2 and winding it overlappingly. 4 is a cross-sectional view showing the cross-sectional shape of the superconductor shown in FIG. 2 after bending, and FIG. 5 shows the relationship between the curvature of the bending process and the amount of deflection deformation in FIG. It is a curvature-deflection deformation amount diagram shown.

In FIG. 2, 1 is a superconducting wire, 2 is a stranded wire made by twisting a large number of these superconducting wires 1, and the superconducting body 4 is made by housing the stranded wire 2 in a square tube 3. be. Further, in FIG. 3, reference numeral 5 designates a circular superconducting coil manufactured by bending the superconducting conductor 4 and winding it overlappingly.

When manufacturing this superconducting coil 5, winding is performed while bending the superconducting conductor 4. At this time, the cross-sectional shape of the superconducting conductor 4 is changed as described above.
Each side of the square tube 3 is deformed so as to bulge outward.
That is, in FIG. 4, a bending amount of δ _a is generated on the side 3a of the square tube 3 that is on the inner side of the bend, and a bending amount of δ _b is generated on the side 3b of the square tube 3 that is on the outer side of the bend.

An example of the relationship between these deflection deformations δ _a and δ _b and the bending curvature 1/R (width B of superconductor 4 = 23
mm, height H = 23 mm, outer diameter d of superconducting wire 1 = 1 mm,
(in the case of 189 stranded wires) is shown in Figure 5,
As the curvature increases, the amount of deflection deformation also increases.

Therefore, in the present invention, the sides of the rectangular tube of the superconducting conductor, which are the inner and outer circumferential sides of the bending, are formed in advance to have a shape that is recessed inward of the rectangular tube. This is designed to cancel out the effects of swelling of the superconductor during processing.

Examples will be explained below.

FIG. 1 is a sectional view of a superconductor according to an embodiment of the present invention. In FIG. 1, the same numbers as in FIG. 2 indicate the same parts. 3a' is the side that becomes the inner circumferential side of the bend of the square tube 3A, and this side 3a' has a shape that is recessed inside the square tube 3A by δ _a ' (the amount of recess δ _a ', δ _b ' The method for determining this will be explained later). Moreover, 3b' facing this side 3a' is the side that becomes the outer circumferential side of the bending of the square tube 3A, and this side 3b' has a shape that is recessed by δ _b ' inside the square tube 3A. There is.

The sizes of the dents δ _a ′ and δ _b ′ are determined by using the curvatures corresponding to the average diameters of the inner and outer diameters of the superconducting coil to be manufactured using this superconductor 4A, respectively, as shown in FIG. This is determined from the solid line and broken line, and by determining it in this way, the influence of bulge during bending can be almost canceled out.

In the superconducting coil manufactured using this superconducting conductor 4A, after the bending process, the inner and outer circumferential sides 3a' and 3b' of the bending become almost straight, so that the superconducting 4A square tube 3A
The sides touch each other and can be wound densely.

According to the embodiment described above, since the superconducting body 4A has a shape in which the two opposing sides 3a' and 3b' of the square tube 3A are concave inward, the superconducting body 4A is formed into a superconducting coil by bending. The two sides 3a' and 3b' of the body 4A are substantially straight. This allows the superconductor 4A to be wrapped in a high density manner.
This has the effect that a highly rigid superconducting coil can be manufactured.

In this example, when determining the recess amounts δ _a ′ and δ _b ′, the curvature corresponding to the average diameter of the inner and outer diameters of the superconducting coil to be manufactured using this superconducting conductor 4A is used. Although the calculation was made from FIG. 5, if the inner and outer diameters of the superconducting coils are greatly different, the calculation may be made from FIG. 5 using the curvature corresponding to the curvature of each winding diameter. In this case, the recess amounts δ _a ′ and δ _b ′ change continuously or stepwise from the inner diameter to the outer diameter of the superconducting coil.

Furthermore, in this embodiment, the case where superconducting conductors are wound around a circular superconducting coil is explained.
The present invention is applicable not only to circular coils but also to superconducting conductors used to manufacture non-circular superconducting coils such as D-shaped toroidal coils for nuclear fusion devices. In this case, a superconducting conductor may be molded in which the amount of concavity is successively changed in accordance with the curvature of each part of the superconducting coil to be manufactured.

〔Effect of the invention〕

As explained in detail above, according to the present invention,
A superconducting conductor made by storing stranded wires in a rectangular tube, which eliminates the bulge of the rectangular tube after bending, enables high-density winding of superconducting coils, and makes it possible to manufacture highly rigid superconducting coils. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a superconducting conductor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a superconducting conductor to which the present invention is applied, and FIG. FIG. 4 is a front view showing an example of a superconducting coil manufactured by bending the body and winding the same, and FIG. 5 is a cross-sectional view showing the cross-sectional shape of the superconducting conductor shown in FIG. 4 is a curvature-deflection deformation diagram showing the relationship between the curvature of the bending process and the deformation amount in FIG. 4. FIG. 1...Superconducting wire, 2...Twisted wire, 3A...Square tube,
3a'...Side that is the inner periphery of the bend, 3b'...Side that is the outer periphery of the bend, 4A...Superconductor, 5...Superconducting coil, δ _a ', δ _b '... Amount of dent.

Claims (1)

[Scope of Claims] 1. In the superconducting conductor that is used to manufacture a superconducting coil by bending a superconducting conductor in which stranded wires are housed in a rectangular tube and winding the same, the rectangular tube includes: The two opposing sides, which are the inner and outer circumferential sides of the bend, are both pre-formed in a shape that is concave inward of the square tube, and the amount of concaveness is equal to the inner and outer diameters or the average of the inner and outer diameters of the superconducting coil. A superconducting conductor characterized in that the amount of concavity in the curvature corresponding to the diameter corresponds to the amount of deflection deformation of a square tube during bending.