JP2014165430A - Manufacturing method of superconducting coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a superconducting coil in which a superconducting wire and an electrode are surely joined in a superconducting coil using a thin film superconducting wire as the superconducting wire.SOLUTION: In a manufacturing method of a superconducting coil comprising a winding frame 1 formed from an electric insulation material, a superconducting wire 2 wound around the winding frame 1, and an electrode 3 extending in a winding frame axis direction, and formed by joining the superconducting wire 2 to the electrode 3, the superconducting wire 2 is formed from a thin film superconducting wire material of a multilayer structure in which one side becomes the superconducting layer side and the another side becomes the substrate side. While providing the electrode 3 at the outer peripheral side of the winding frame 1, an end portion of the superconducting wire 2 at the winding start side is fixed at a circumferential position different from the electrode 3 on an outer peripheral surface of the winding wire 1. Thereafter, the superconducting wire 2 is wound along a circumferential direction and in the state where a tensile force of winding is applied to the superconducting wire 2, the superconducting wire 2 and the electrode 3 are joined by soldering.

Description

  The present invention relates to a method for manufacturing a superconducting coil used in a superconducting transformer, a superconducting rotating machine, or the like.

  Applying superconducting technology to transformers and rotating machines has the advantage of reducing size and weight and increasing efficiency, and various researches are being conducted in Japan and overseas. Conventionally, it was an essential condition to use liquid helium as a refrigerant, but the discovery of a high-temperature superconductor made it possible to configure superconducting equipment near the liquid nitrogen temperature (77K), reducing the cooling load and insulating strength. Improvements have become possible, and the superiority of superconducting equipment has become greater than before.

  In recent years, thin film superconducting wires represented by yttrium-based superconducting wires are frequently used as high-temperature superconducting wires. The basic structure of this thin-film superconducting wire is to provide an intermediate layer to ensure the orientation of the superconductor on an alloy substrate typified by Hastelloy, and to form a superconducting layer on it to stabilize the conduction current. For this purpose, a low resistance metal layer such as silver or copper is formed. The thickness of the intermediate layer, superconducting layer and metal layer is about 1 μm, the substrate is about 100 μm, and the tensile strength is dominated by the substrate. More specifically, this thin film superconducting wire is disclosed in Non-Patent Document 1, for example.

  In order to form a superconducting coil as well as a high-temperature superconducting wire, it is generally performed to wind a superconducting wire around a winding frame, fix an electrode to the winding frame, and solder the superconducting wire and the electrode. (For example, see Patent Documents 1 to 3).

Yasunori Sudo, 4 others, “Yttrium-based oxide superconducting wire”, Fujikura Technical Report, No. 107, October 2004, p68-72, [0nline], [Search January 25, 2013], Internet <URL: HYPERLINK "http://www.fujikura.co.jp/rd/gihou/backnumber/pages/__icsFiles/afieldfile/2008/07/11/107_15.pdf">

JP 2001-291611 A JP 2008-140905 A JP 2010-267887 A

Among the technical problems in the superconducting coil configured as described above, the following two can be cited as related to the superconducting wire and the electrode.
A first problem is a manufacturing method in which a tension is applied to a superconducting wire and soldered to an electrode. If the superconducting wire and the electrode are solder-bonded and then wound by applying a tension, an excessive stress may be applied to the solder connection portion. If the tension at the start of winding is weakened to avoid this, there is a problem that the coil is weakened because the winding is not sufficiently fixed.

  A solution to this problem is described in Patent Document 1. In this method, first, a fixing plate is provided on the winding frame, a superconducting wire is fixed to the fixing plate, and then the superconducting wire and the electrode are soldered. Then, a superconducting coil is manufactured in the process of removing the fixing plate and the superconducting wire from the fixing plate to the electrode.

  The second problem is caused by the thin film superconducting wire that is a high-temperature superconducting wire, and occurs because the above-described superconducting layer and intermediate layer are easily peeled off from the substrate. When the superconducting wire and the electrode are soldered and winding is started, a shearing force acts on the soldered portion due to the tension. Superconducting layers or intermediate layers are vulnerable to this force and often peel off. Although measures against peeling as a coil after winding are described in Patent Documents 2 and 3, etc., there is no description about a manufacturing method at the time of winding.

  In the method described in Patent Document 1, when the superconducting wire from the fixing plate and the fixing plate to the electrode is removed, the winding tension acts on the solder joint between the electrode and the superconducting wire. When a thin-film superconducting wire is used as the superconducting wire, there is a high possibility that the substrate side and the superconducting layer side of the superconducting wire are peeled off at this solder connection portion, and there is a problem that a predetermined superconducting coil cannot be manufactured.

  Patent Document 1 describes a method of fixing a superconducting wire and a winding frame with an epoxy resin. However, when a thin film superconducting wire is used as the superconducting wire, the substrate of the thin film superconducting wire is an alloy. It is difficult to fix with an epoxy resin, and fixing may be insufficient.

  The present invention has been made in view of such a problem, and an object of the present invention is to reliably bond a superconducting wire and an electrode in a superconducting coil using a thin film superconducting wire as a superconducting wire. An object of the present invention is to provide a method of manufacturing a superconducting coil.

  In order to achieve such an object, the present invention comprises a winding frame made of an electrically insulating material, a superconducting wire wound around the winding frame, and an electrode extending in the axial direction of the winding frame, and the superconducting wire. The superconducting wire is made of a thin film superconducting wire having a multilayer structure in which one surface side is a superconducting layer side and the other surface side is a substrate side. Is provided on the outer peripheral side of the winding frame, and the end portion on the winding start side of the superconducting wire is fixed at a circumferential position different from the electrode on the outer peripheral surface of the winding frame, and then the superconducting wire is aligned along the circumferential direction. Then, the superconducting wire and the electrode are joined in a state where the winding tension is applied to the superconducting wire (invention of claim 1).

  Further, in the method of manufacturing a superconducting coil according to claim 1, the end of the superconducting wire on the winding start side can be fixed to the winding frame by bolting (the invention of claim 2). ).

  Further, in the method of manufacturing a superconducting coil according to claim 1, the fixing of the end portion on the winding start side of the superconducting wire to the winding frame can be constituted by an adhesive insulating tape (claim 3). Invention).

  In the method of manufacturing a superconducting coil according to claim 3, the superconducting coil is formed by winding a superconducting wire in a pancake shape for a plurality of turns, and is applied to the superconducting wire after the second turn. The adhesive insulating tape can be pressed against the winding frame side by winding tension (invention of claim 4).

Further, in the method of manufacturing a superconducting coil according to any one of claims 1 to 4, the joining may be a joining with solder (the invention of claim 5).
The method of manufacturing a superconducting coil according to any one of claims 1 to 5, wherein the thin film superconducting wire is a tape-shaped substrate made of metal, an intermediate layer, a superconducting layer, and a stable metal made of conductive metal. The metal-conducting metal layer is laminated, and the superconducting layer is located on the side where the superconducting layer is located via the stabilizing metal layer (invention of claim 6).

  Further, in the method of manufacturing a superconducting coil according to claim 6, the substrate of the thin film superconducting wire may be a tape-like substrate made of hastelloy or stainless steel (invention of claim 7).

  According to the present invention, the end portion on the winding start side of the superconducting wire made of the thin film superconducting wire is fixed at a circumferential position different from the electrode on the outer peripheral surface of the winding frame, and then the superconducting wire is wound along the circumferential direction. Then, by joining the superconducting wire and the electrode in a state where the winding tension is applied to the superconducting wire, the tension of the superconducting wire is held at the end on the winding start side. Accordingly, the tensile tension applied to the superconducting wire at the junction between the superconducting wire and the electrode is balanced between the direction toward the end of the winding start side and the direction of winding, so that the superconducting wire made of a thin film superconducting wire is used. It is possible to avoid the separation of the substrate side and the superconducting layer side.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the structural example of the manufacturing method of the superconducting coil by Example 1 of this invention, Comprising: Fig.1 (a) and FIG.1 (b) are respectively the winding frames of the edge part of the winding start side of a superconducting wire. It is the figure which showed typically the structure at the time of fixation to a structure, and the structure at the time of joining of a superconducting wire and an electrode. It is sectional drawing which shows the tension | tensile_strength applied to the superconducting wire of the electrode vicinity in FIG. It is a figure which shows typically the structural example of the thin film superconducting wire used by this invention. It is sectional drawing which shows the structural example of the manufacturing method of the superconducting coil by Example 2 of this invention. It is sectional drawing which shows the structural example of the manufacturing method of the superconducting coil by Example 3 of this invention. FIGS. 6A and 6B are cross-sectional views illustrating a configuration example of a method for manufacturing a superconducting coil according to Embodiment 4 of the present invention, in which FIG. 6A is a cross-sectional view seen from the reel axis direction, and FIG. It is sectional drawing seen from P arrow direction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, In the range which does not change the summary, it can implement suitably. In the following description, common parts or elements are denoted by common reference symbols throughout the drawings unless otherwise specified.
Embodiment of the present invention
(Structure of thin film superconducting wire)
FIG. 3 schematically shows a structural example of a thin film superconducting wire used as a superconducting wire in the present invention. FIG. 3A and FIG. 3B are a schematic cross-sectional view and a perspective view, respectively, of the thin film superconducting wire. The thin film superconducting wire shown in FIG. 3 has a laminated structure in which a tape-like substrate 201 made of metal, an intermediate layer 202, a superconducting layer 203, and a stabilizing metal layer 204 made of conductive metal are laminated. The structure corresponds to, for example, the thin film superconducting wire shown in Non-Patent Document 1 described above. Hereinafter, the side on which the superconducting layer 203 is located via the stabilizing metal layer 204 is also referred to as “superconducting layer side”. FIG. 3 schematically shows a laminated structure of thin-film superconducting wires, and the substrate 201 actually occupies most of the thickness ratio of each layer.

  Although the intermediate layer 202 may be composed of a plurality of layers, the present invention is not directly related to the composition and layer structure of the intermediate layer 202, and is therefore illustrated as a single layer. Since the bond between the intermediate layer 202 and the superconductor layer 203 is mainly based on intermolecular attractive force, it is easy to peel off at this portion.

  In the thin film superconducting wire shown in FIG. 3, a metal material having a relatively high electrical resistance such as Hastelloy or stainless steel is usually used as the substrate 201. The stabilizing metal layer 204 is made of a conductive metal, particularly a low-resistance metal material such as silver or copper, for the purpose of stabilizing the energization current. For this reason, it is not efficient to electrically connect on the substrate 201 side, and it is preferable to connect on the stabilized metal layer 204 side.

  The thin film superconducting wire used in the present invention is not limited to the configuration example of FIG. 3, but is a thin film superconducting wire having a multilayer structure in which one surface side is the superconductor layer side and the other surface side is the substrate side, The present invention is applicable as long as it has a metal layer that can be connected with solder on the surface on the superconducting layer side.

In addition, the superconducting wire includes a superconducting wire having a configuration in which a metal wire such as a copper wire is attached to both surfaces of a thin film superconducting wire as shown in FIG. 3, and such a superconducting wire is used. The present invention can also be applied to a superconducting coil.
(Configuration example of superconducting wire fixing method and joining method in superconducting coil)
A configuration example of a superconducting wire fixing method and a joining method applied to the superconducting coil manufacturing method according to the present invention will be described below.

  FIG. 1 is a cross-sectional view showing a configuration example of a method of manufacturing a superconducting coil according to Embodiment 1 of the present invention, and is a cross-sectional view of a method for fixing a superconducting wire winding start portion and a joining method as seen from the reel axis direction. This is shown schematically. 1 (a) and 1 (b) schematically show the structure when the superconducting wire is fixed to the winding frame at the end of the winding start side, and the structure when the superconducting wire and the electrode are joined, respectively. Yes.

  As shown in FIGS. 1A to 1B, a superconducting wire 2 is wound in a circumferential direction on a cylindrical winding frame 1 made of an electrically insulating material. As the superconducting wire 2, the above-described thin film superconducting wire is used. The winding frame 1 is provided with a winding start side electrode 3 extending in the winding axis direction so as to be embedded in a groove 10 formed on the outer peripheral surface of the winding frame 1.

  FIG. 1 (a) shows the first step, in which the winding-side end of the superconducting wire 2 is fixed to a circumferential position different from the electrode 3 on the outer peripheral surface of the winding frame 1, and the winding frame is several tens of degrees. 1 is rotated to wind the superconducting wire 2 around the winding frame 1 along the circumferential direction. The superconducting wire 2 is wound with the superconducting layer side, that is, the stabilizing metal layer 204 side, as the inner diameter side.

  As shown in FIG. 1B, at the stage where the superconducting wire 2 is wound up to the vicinity of the electrode 3, the superconducting layer side of the superconducting wire 2 and the electrode 3 are joined by soldering, for example. Thereafter, the winding frame 1 is further rotated to wind the superconducting 2 to produce a superconducting coil.

  FIG. 2 is a cross-sectional view showing the tension applied to superconducting wire 2 in the vicinity of electrode 3 in FIG. Superconducting wire 2 is fixed to winding frame 1 at fixing point 4. Until the tension F is applied in this state, the superconducting wire 2 is soldered to the electrode 3 at the soldering portion 5 on the superconducting layer side, and then further wound. Since the tensile tension F applied to the superconducting wire 2 is held at the fixed point 4, the tensile tension applied to the superconducting wire 2 at the soldering part 5 between the superconducting wire 2 and the electrode 3 is the end of the winding start side. There is a balance between the direction toward the part and the direction of winding. For this reason, a pulling force does not act on the soldering portion 5, and a pressing force acts on the winding frame 1. Accordingly, it is possible to avoid the separation of the substrate side and the superconducting layer side in the superconducting wire 2 made of a thin film superconducting wire.

  In addition, as a winding method in the superconducting coil, there are a cylinder winding method and a pancake winding method, but the present invention can be applied to either winding method.

  FIG. 4 is a cross-sectional view showing a configuration example of a method of manufacturing a superconducting coil according to Example 2 of the present invention, and schematically shows a method of fixing a superconducting wire to the winding frame as a cross-sectional view seen from the reel axis direction. Show. Example 2 shows a specific configuration example as a method of fixing the superconducting wire 2 to the winding frame 1 in Example 1, and the other configuration is the same as that of Example 1.

  As described above, the thin film superconducting wire is composed of a substrate of an alloy such as Hastelloy or stainless steel, and the strength of the substrate is sufficiently higher than that of copper or silver. Therefore, as shown in FIG. 4, a through hole is formed in the end portion on the winding start side of the superconducting wire 2, a bolt groove 6 is formed in the winding frame 1, and the superconducting wire 2 is attached to the winding frame 1 by the bolt 7. Secure to. Since the reel 1 is made of an electrically insulating material, the material of the bolt 7 may be conductive, and stainless steel is preferable from the viewpoint of strength.

  In the case of the cylinder winding method, the fixing method shown in FIG. 4 has no problem because the superconducting wire 2 moves in the axial direction when forming a turn. However, in the case of the pancake winding method, the superconducting wire If the winding process of winding 2 is advanced, the superconducting wire 2 overlaps the bolt 7, which causes inconvenience. Therefore, Example 3 shown in FIG. 5 can be considered.

  FIG. 5 is a cross-sectional view showing a configuration example of a method of manufacturing a superconducting coil according to Embodiment 3 of the present invention, and schematically shows a method of fixing a superconducting wire to a winding frame as a cross-sectional view seen from the axial direction of the winding frame. Show. The third embodiment shows a specific configuration example as a method for fixing the superconducting wire 2 to the winding frame 1 in the first embodiment, and other configurations are the same as the first embodiment.

  As shown in FIG. 5, the winding-side end of the superconducting wire 2 is fixed to the winding frame 1 with a sticky insulating tape 8 at a circumferential position different from the electrode 3 on the outer peripheral surface of the winding frame 1. In the subsequent steps, similarly to the manufacturing method described in the first and second embodiments, the superconducting wire 2 and the electrode 3 are soldered to perform winding.

  Further, in the subsequent process, especially in the case of the configuration of the pancake winding method, the superconducting wire 2 after the second turn is wound on the adhesive insulating tape 8, so that it is applied to the superconducting wire 2 by the winding. The adhesive insulating tape 8 is pressed against the winding frame 1 by the applied tension. As a result, the superconducting wire 2 can be firmly fixed to the winding frame 1.

The above description is about the winding start. However, in the case of a cylinder winding system and a single layer configuration, the winding end can be similarly performed.
Also, in the case of a multi-layer configuration or a pancake winding configuration in the cylinder winding method, the superconducting wire can be fixed by applying the manufacturing method of FIG. FIG. 65 shows the fourth embodiment.

  FIG. 6 is a cross-sectional view showing a configuration example of a method of manufacturing a superconducting coil according to Example 4 of the present invention, schematically showing a fixing method and a joining method of a winding end portion of a superconducting wire. 6A is a cross-sectional view as viewed from the reel axis direction, and FIG. 6B is a cross-sectional view as viewed from the reel radial direction (P arrow direction). Example 4 shows a specific configuration example, particularly at the winding end portion of the superconducting wire 2, and other configurations such as a fixing method and a joining method of the winding start portion of the superconducting wire 2 are the same as those of the first embodiment. .

  In FIG. 6, the superconducting winding portion 11 is omitted, and a specific winding structure is not shown. The superconducting wire 2 in the vicinity of the winding end is wound through the electrode 3b on the winding end side. The electrode 3b is fixed to the flange 9. At the end of the superconducting wire 2, it is fixed to the superconducting winding portion 11 with an adhesive insulating tape 8. Although simplified in FIG. 6, for example, the adhesive insulating tape 8 can be more firmly fixed by winding the adhesive insulating tape 8 in the circumferential direction a plurality of times.

  In the vicinity of the electrode 3b, a gap 12 is generated between the superconducting winding portion 11 and the superconducting wire 2. However, if the compensating piece 13 made of an electrically insulating material is placed in the gap 12, an adverse effect on the winding may be eliminated. it can. The compensation piece 13 can be formed of, for example, a flat plate member having flexibility.

  Although not shown, it is possible to reinforce mechanical strength and the like by winding a reinforcing tape made of an electrically insulating material around the entire outer periphery of the superconducting winding 11 including the adhesive insulating tape 8. It is.

1: winding frame 2: superconducting wires 3, 3a, 3b: electrode 4: fixing point 5: soldering part 6: bolt groove 7: bolt 8: adhesive insulating tape 9: flange 10: groove 11: superconducting winding part 12 : Air gap 13: Compensation piece 201: Substrate 202: Intermediate layer 203: Superconducting layer 204: Stabilized metal layer

Claims (7)

In a method of manufacturing a superconducting coil comprising a winding frame made of an electrically insulating material, a superconducting wire wound around the winding frame, and an electrode extending in the axial direction of the winding frame, and joining the superconducting wire to the electrode ,
The superconducting wire is composed of a thin film superconducting wire having a multilayer structure in which one surface side is a superconducting layer side and the other surface side is a substrate side,
The electrode is provided on the outer periphery side of the winding frame,
Fixing the end portion on the winding start side of the superconducting wire at a circumferential position different from the electrode on the outer peripheral surface of the winding frame;
Thereafter, the superconducting wire is wound along a circumferential direction, and the superconducting wire and the electrode are joined in a state where a winding tension is applied to the superconducting wire.   The method for manufacturing a superconducting coil according to claim 1, wherein the end of the superconducting wire on the winding start side is fixed to the winding frame by bolting.   The superconducting coil manufacturing method according to claim 1, wherein the end of the superconducting wire on the winding start side is fixed to the winding frame by an adhesive insulating tape. The superconducting coil is formed by winding a superconducting wire in a pancake shape a plurality of turns,
4. The method of manufacturing a superconducting coil according to claim 3, wherein the adhesive insulating tape is pressed against the winding frame side by winding tension applied to the superconducting wire after the second turn.   The method of manufacturing a superconducting coil according to claim 1, wherein the joining is joining with solder.   The thin-film superconducting wire has a tape-shaped substrate made of metal, an intermediate layer, a superconducting layer, and a stabilized metal layer made of a conductive metal, and the superconducting layer is located through the stabilizing metal layer. 6. The method of manufacturing a superconducting coil according to claim 1, wherein the side is the superconducting layer side.   7. The method of manufacturing a superconducting coil according to claim 6, wherein the substrate of the thin film superconducting wire is a tape-shaped substrate made of Hastelloy or stainless steel.