JP2021011375A - Reel wound body of oxide superconductive wire material - Google Patents

Abstract

To provide a reel wound body of oxide superconductive wire material that can reinforce the fixing strength of the wire that starts to be wound and furthermore, can suppress the degradation of the oxide superconductive wire even when the oxide superconductive wire is wound on a wound dummy wire.SOLUTION: The reel wound body of oxide superconductive wire material is formed by oxide superconductive wire material 11 wound on a winding core 21 of a reel 20. The oxide superconductive wire 11 has a dummy wire 12 connected to the end of the winding starting side onto the winding core 21, and the winding core 21 has a slit 21a for an end 12a of the dummy wire to be inserted into. The dummy wire 12 is engaged with the end 12a of the dummy wire inserted into the slit 21a by bending along an outer periphery 21b of the winding core. After the dummy wire 12 is wound on the winding core 21 in the range of 10 to 100 turns, the oxide superconductive wire material 11 is wound via the connection between the oxide superconductive wire material 11 and the dummy wire 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to a reel wound body of an oxide superconducting wire.

Oxide superconducting wire (hereinafter, also simply referred to as wire) is generally in the form of a tape wider than the thickness, and is wound on a reel having a winding core between a pair of side plates during transportation and storage (for example, patent). See Document 1). When manufacturing products such as coils and cables from wire rods, reels are attached to machines, and wire rods are sent out from the reels for processing. A machine that processes wire rods requires a pass line of a predetermined length from a reel. Therefore, in consideration of the case where the wire is passed through the pass line or the amount of wire remaining on the reel is reduced, a dummy wire may be connected to the end of the wire wound on the reel.

Japanese Unexamined Patent Publication No. 3-74012

When starting to wind a wire rod or a dummy wire around the reel core, it is generally fixed with adhesive tape or the like. However, if the fixing strength at the beginning of winding the reel is not sufficient, the fixing may come off when tension is applied to the wire. Further, if there is a step at the connection portion between the wire and the dummy wire, the wire may deteriorate when the wire is wound on the step.

The present invention has been made in view of the above circumstances, and the fixing strength at the beginning of reel winding can be increased, and even if an oxide superconducting wire is wound on the dummy wire, the oxide is formed. An object of the present invention is to provide a reel wound body of an oxide superconducting wire that can suppress deterioration of the superconducting wire.

In order to solve the above problems, the present invention is a reel winding body of an oxide superconducting wire material obtained by winding an oxide superconducting wire material around a winding core of a reel, and the oxide superconducting wire material is wound around the winding core. A dummy wire is connected to the end on the starting side, the winding core has a slit into which the end of the dummy wire is inserted, and the dummy wire is the end of the dummy wire inserted into the slit. The part is engaged with the winding core by bending along the outer circumference of the winding core, and the dummy wire is wound around the winding core in a range of 10 to 100 turns, and then the oxide superconducting wire and the dummy are used. Provided is a reel wound body of an oxide superconducting wire, characterized in that the oxide superconducting wire is wound through a connection portion with a wire.

The angle formed by the end of the dummy wire inserted into the slit and the dummy wire bent along the outer circumference of the winding core may be an acute angle.
The thickness at which the dummy wire is wound on the outer circumference of the winding core may be 0.1 to 10 mm.
At the connection portion between the oxide superconducting wire and the dummy wire, the oxide superconducting wire and the dummy wire are overlapped and connected to each other in the thickness direction, and a step generated in the connecting portion is formed on the oxide superconducting wire. And it may have a step relaxation portion in which the thickness of the end portion of the dummy wire is gradually reduced.
The step may be 20 to 100 μm.

According to the present invention, the fixing strength at the beginning of winding of the reel can be increased by engaging the dummy wire with the winding core. Further, when the dummy wire is wound under the oxide superconducting wire, the oxide superconducting wire is generated by the step of the bent portion of the dummy wire with respect to the slit or the step of the connection portion between the wire and the dummy wire. Deterioration can be suppressed.

It is sectional drawing which shows an example of the reel winding body of the oxide superconducting wire, (a) is the sectional drawing along the vertical plane in the axial direction, (b) is the sectional view along the axial direction. It is a partially enlarged sectional view which illustrates the part where the end part of the dummy wire was engaged with the winding core. It is a top view which shows an example of the connection part of the oxide superconducting wire material and a dummy wire. It is a partially enlarged sectional view which shows an example of the connection part of an oxide superconducting wire material and a dummy wire.

Hereinafter, the present invention will be described with reference to the drawings based on the preferred embodiments.

FIG. 1 shows an example of a reel wound body of an oxide superconducting wire. FIG. 1A is a cross-sectional view taken along a vertical plane in the axial direction of the reel winding body. FIG. 1B is a cross-sectional view taken along the axial direction of the reel winding body. The reel winding body of the oxide superconducting wire has a configuration in which the oxide superconducting wire 11 is wound around the reel 20. In FIG. 1, each layer corresponding to the thickness of the oxide superconducting wire 11 and the dummy wire 12 is not distinguished, and the illustration is simplified.

The reel 20 has a winding core 21 at the center of a portion around which the oxide superconducting wire 11 is wound. Side plates 22 are joined to both sides of the winding core 21 in the axial direction. The winding core 21 may have a hole 23 near the central shaft 24. The hole 23 can be used to insert the rotating shaft of the machine, for example, when attaching the reel 20 to the machine. The number of side plates 22 is not particularly limited, and side plates 22 may be provided at three or more locations on the winding core 21. In this case, another oxide superconducting wire 11 can be wound within the range of the interval L formed between the side plates 22.

The oxide superconducting wire 11 has a dummy wire 12 connected to an end on the winding start side with respect to the winding core 21. That is, the connecting body 10 having a configuration in which the dummy wire 12 is connected to one end of the oxide superconducting wire 11 is wound on the outer circumference 21b of the winding core 21 in the radial direction of the winding core 21. The dummy wire 12 has a first end portion 12a on the winding start side with respect to the winding core 21. The winding core 21 has a slit 21a into which the first end portion 12a of the dummy wire 12 is inserted. The winding procedure is not particularly limited, and the oxide superconducting wire 11 may be connected to the dummy wire 12 after the dummy wire 12 is wound around the winding core 21. Further, after connecting the dummy wire 12 to one end of the oxide superconducting wire material 11, the connecting body 10 may be wound around the winding core 21. The oxide superconducting wire 11 and the dummy wire 12 are wound in the radial direction of the winding core 21 so as to overlap each other in the thickness direction.

FIG. 2 shows a partially enlarged cross-sectional view of a portion where the end portion of the dummy wire 12 is engaged with the winding core 21. The slit 21a is open to the outer circumference 21b of the winding core 21. The dummy wire 12 is engaged with the first end portion 12a inserted into the slit 21a by bending along the outer circumference 21b of the winding core 21. As a result, the fixing strength between the winding core 21 and the dummy wire 12 at the beginning of winding can be increased. The angle θ formed by the first end portion 12a of the dummy wire 12 inserted into the slit 21a and the dummy wire 12 bent along the outer circumference 21b of the winding core 21 may be an acute angle or a substantially right angle. Examples of the angle θ include 45 to 90 °. If the angle θ is an acute angle (less than 90 °), the engagement between the winding core 21 and the dummy wire 12 becomes more difficult to loosen. Specific examples of the angle θ include values at 45 °, 60 °, 75 °, 90 °, and intermediate or near these. The length for inserting the first end portion 12a of the dummy wire 12 into the slit 21a is not particularly limited, and examples thereof include 10 to 20 mm. The slit 21a may reach the hole 23 on the inner peripheral side of the winding core 21.

The dummy wire 12 is wound around the outer circumference 21b of the winding core 21 in the radial direction of the winding core 21 in a range of 10 to 100 turns. The dummy wire 12 on the outer circumference 21b of the winding core 21 is bent with respect to the first end portion 12a of the dummy wire 12 inserted into the slit 21a, and a step S is generated. The height of the step S is, for example, 20 to 100 μm. Since this step S is relaxed as the dummy wire 12 is wound and the thickness increases, deterioration of the oxide superconducting wire 11 is suppressed even if the oxide superconducting wire 11 is wound on the dummy wire 12. be able to. The thickness D around which the dummy wire 12 is wound on the outer circumference 21b of the winding core 21 is preferably in the range of 0.1 to 10 mm. The length of the dummy wire 12 is preferably 10 m or more.

As shown in FIG. 1B, the distance L between the pair of side plates 22 provided on both sides of the winding core 21 in the axial direction is preferably larger than the width W1 of the oxide superconducting wire 11. As a result, even if the oxide superconducting wire 11 comes into contact with the side plate 22 when the oxide superconducting wire 11 is wound around the reel 20 or when the oxide superconducting wire 11 is sent out from the reel 20, the resistance of the side plate 22 Is reduced, and deterioration of the oxide superconducting wire 11 can be suppressed.

It is preferable that only one row of the oxide superconducting wire 11 is arranged between the side plates 22 in the width direction. As a result, the position of the oxide superconducting wire 11 wound between the side plates 22 is less likely to shift in the width direction. If the distance L between the side plates 22 is too wider than the width W1 of the oxide superconducting wire, when the oxide superconducting wire 11 is twisted, the oxide superconducting wire 11 wound on the winding core 21 and the side plate 22 In the meantime, the oxide superconducting wire 11 wound around the outer peripheral side may fall and deteriorate. The distance L between the side plates 22 is preferably, for example, about 1.1 to 1.5 times the width W1 of the oxide superconducting wire 11.

FIG. 3 shows an example of the connection portion 13 between the oxide superconducting wire 11 and the dummy wire 12. Further, FIG. 4 shows an example of a structure in which the thickness direction of the connecting portion 13 is partially enlarged. The oxide superconducting wire 11 has a tape shape having a width W1 larger than a thickness T1. Like the oxide superconducting wire material 11, the dummy wire 12 also preferably has a tape shape having a width W2 larger than a thickness T2. Examples of the material of the dummy wire 12 include a metal tape such as stainless steel.
The thickness T2 of the dummy wire 12 is, for example, 20 to 100 μm. The width W2 of the dummy wire 12 is not particularly limited, and examples thereof include 2 to 20 mm. The thickness T1 of the oxide superconducting wire 11 is not particularly limited, and examples thereof include 20 to 100 μm. The width W1 of the oxide superconducting wire 11 is not particularly limited, and examples thereof include 2 to 20 mm.
The thickness T1 of the oxide superconducting wire 11 and the thickness T2 of the dummy wire 12 are preferably about the same, for example, the value of T2 / T1 is preferably about 0.9 to 1.1. The width W1 of the oxide superconducting wire 11 and the width W2 of the dummy wire 12 are preferably about the same, for example, the value of W2 / W1 is preferably about 0.9 to 1.1.

In the connecting portion 13, the end portion 11a of the oxide superconducting wire 11 and the second end portion 12b of the dummy wire 12 are overlapped and connected to each other in the thickness direction. Here, the end portion 11a of the oxide superconducting wire 11 is the end portion on the winding start side. Further, the second end portion 12b of the dummy wire 12 is an end portion on the side opposite to the first end portion 12a in the longitudinal direction of the dummy wire 12. The length M on which the oxide superconducting wire 11 and the dummy wire 12 are overlapped in the connecting portion 13 is not particularly limited, but is preferably larger than the width W1 of the oxide superconducting wire 11, and examples thereof include 4 to 50 mm. ..

The method of connecting the oxide superconducting wire 11 and the dummy wire 12 in the connecting portion 13 is not particularly limited, and examples thereof include welding and soldering. In order to suppress the step generated in the connecting portion 13, it is preferable that the thickness of the connecting portion 13 does not exceed the total thickness of the oxide superconducting wire 11 and the dummy wire 12. For example, the welded portion 13a may be formed at, for example, about 2 to 100 points by spot welding or the like. Examples of the breaking strength of the connecting portion 13 with respect to the tensile force include 10 to 30 kgf (about 100 to 300 N).

The height of the step generated in the connecting portion 13 is, for example, 20 to 100 μm. This step is caused by the difference between the thickness of the connecting portion 13 and the thickness T1 of the oxide superconducting wire 11 alone or the thickness T2 of the dummy wire 12 alone before and after the connection portion 13. For example, when the connection portion 13 is arranged on the dummy wire 12 wound, if the second end portion 12b of the dummy wire 12 comes into contact with the outer surface around which the dummy wire 12 is wound, the second end portion of the dummy wire 12 A step S2 substantially corresponding to the thickness T2 of the dummy wire 12 is formed in the oxide superconducting wire 11 between the portion where the 12b is present and the portion where the dummy wire 12 is not present. Further, when the oxide superconducting wire 11 overlaps the dummy wire 12 from above the connecting portion 13, the oxide is formed between before reaching the end 11a of the oxide superconducting wire 11 and above the end 11a. A step S1 substantially corresponding to the thickness T1 of the superconducting wire 11 is generated. When the thickness of the connecting portion 13 is thicker than the total (T1 + T2) of the thickness T1 of the oxide superconducting wire 11 and the thickness T2 of the dummy wire 12, the step S1 is larger than the thickness T1 and the step S2 is the thickness. It tends to be larger than T2. Therefore, it is preferable that the connecting portion 13 has step relaxation portions 14 and 15 in which the thickness of the end portions of the oxide superconducting wire 11 and the dummy wire 12 is gradually reduced. That is, the end portion 11a of the oxide superconducting wire 11 connected to the connecting portion 13 has a step relaxation portion 14 whose thickness is gradually reduced toward the side in contact with the dummy wire 12. Further, the second end portion 12b of the dummy wire 12 connected to the connecting portion 13 has a step relaxation portion 15 whose thickness is gradually reduced toward the side in contact with the oxide superconducting wire member 11. As a result, it is possible to suppress a step generated in the connecting portion 13. The cross-sectional shape of the step relaxation portions 14 and 15 is not particularly limited, and examples thereof include roundness, inclination, and taper.

Although the present invention has been described above based on preferred embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

The oxide superconducting wire 11 may have, for example, a superconducting laminate having an oxide superconducting layer on one surface of the substrate and a stabilizing layer formed on the outer peripheral surface of the superconducting laminate. The superconducting laminate may have an intermediate layer between the substrate and the oxide superconducting layer. Further, the superconducting laminate may have a protective layer on the oxide superconducting layer on the opposite side of the substrate. For example, the superconducting laminate may have a structure in which an intermediate layer, an oxide superconducting layer, and a protective layer are laminated in this order on one side of a tape-shaped substrate.

The substrate of the oxide superconducting wire 11 is preferably a tape-shaped substrate made of, for example, a metal. Specific examples of the metal constituting the substrate include nickel alloys typified by Hastelloy (registered trademark), stainless steel, and oriented NiW alloys in which a texture is introduced into the nickel alloy. When an oriented substrate in which the arrangement of metal crystals is aligned and oriented is used as the substrate, the oxide superconducting layer can be formed directly on the substrate without forming an intermediate layer.

From the viewpoint of controlling the orientation of the oxide superconducting layer, it is preferable to provide an intermediate layer on one side of the substrate and to form an oxide superconducting layer on the intermediate layer. The intermediate layer may have a multi-layer structure, and may have a diffusion prevention layer, a bed layer, an alignment layer, a cap layer, and the like in the order from the substrate side to the oxide superconducting layer side, for example. These layers are not always provided one by one, and some layers may be omitted, or two or more layers of the same type may be repeatedly laminated. The intermediate layer is, for example, MgO, Al ₂ O ₃ , Y ₂ O ₃ , La ₂ O ₃ , CeO ₂ , Nd ₂ O ₃ , Eu ₂ O ₃ , Gd ₂ O ₃ , Dy ₂ O ₃ , Ho ₂ O ₃ , It can be composed of a metal oxide such as ZrO ₂ .

The oxide superconducting layer is composed of an oxide superconductor. The oxide superconductor is not particularly limited, for example, the general formula _{REBa 2 Cu 3 O x (RE123} ) with REBa-Cu-O based oxide superconductor represented (REBCO) and the like. Examples of the rare earth element RE include one or more of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Be done. The oxide superconducting wire 11 may be a superconducting wire using a Bi-based superconductor or the like as the oxide superconductor.

The protective layer of the oxide superconducting layer has functions such as bypassing an overcurrent generated at the time of an accident and suppressing a chemical reaction occurring between the oxide superconducting layer and the layer provided on the protective layer. .. Examples of the material of the protective layer include silver (Ag), copper (Cu), gold (Au), and alloys containing one or more of these. When an Ag layer or an Ag alloy layer is used as the protective layer, it preferably contains 50% or more of silver in terms of molar ratio or weight ratio. The protective layer preferably covers at least the surface of the oxide superconducting layer, and may further cover the back surface of the substrate or the like.

The stabilizing layer of the oxide superconducting wire 11 has a function as a bypass portion for commutating an overcurrent generated when the oxide superconducting layer is transferred to the normal conducting state. Examples of the constituent material of the stabilizing layer include metals such as copper, copper alloys (for example, Cu-Zn alloys, Cu-Ni alloys, etc.), aluminum, aluminum alloys, and silver. From the viewpoint of conductivity, economy, etc., it is preferable that the stabilizing layer is composed of copper plating, copper foil, or the like.

Hereinafter, the present invention will be specifically described with reference to Examples.

(Example 1)
A reel 20 having an outer diameter of the winding core 21 of 180 mm and a distance L of the side plates 22 of 5.0 mm was prepared. The first end portion 12a of the dummy wire 12 made of stainless steel tape having a thickness of 50 μm was inserted into the slit 21a of the winding core 21 and wound around the inner circumference side for 60 turns. Then, the second end portion 12b of the dummy wire 12 was welded to the end portion 11a of the oxide superconducting wire 11a using REBCO as the oxide superconductor with a width of 4.1 mm by spot welding. At the connecting portion 13, the length M at which the oxide superconducting wire 11 and the dummy wire 12 are overlapped is set to 10 mm, and at the end 11a of the oxide superconducting wire 11, a part of the stabilizing layer is removed to expose only the substrate. , The number of spot welds was 20 points. Using a rotary grindstone, both ends of the connecting portion 13 were rounded in a tapered shape to form the step reducing portions 14 and 15. The breaking strength of the connecting portion 13 was 20 kgf. After forming the connecting portion 13, the oxide superconducting wire 11 was wound 300 m with a tension of 5 kgf or 10 kgf to prepare a reel wound body. After that, when the oxide superconducting wire 11 was sent out from the reel wound body and the critical current characteristics were continuously measured in the longitudinal direction, no deterioration of the oxide superconducting wire 11 was observed. Further, even when the oxide superconducting wire 11 was wound with a tension of 10 kgf, the engagement of the dummy wire 12 with the slit 21a was not loosened.

(Example 2)
After forming the connecting portion 13, the formation of the step mitigation portions 14 and 15 using the rotary grindstone is omitted, and the tension when winding the oxide superconducting wire 11 is set to 1 kgf. In the same manner, a reel winding body was produced. After that, when the oxide superconducting wire 11 was sent out from the reel wound body and the critical current characteristics were continuously measured in the longitudinal direction, no deterioration of the oxide superconducting wire 11 was observed.

10 ... Connection body, 11 ... Oxide superconducting wire, 11a ... Oxide superconducting wire end, 12 ... Dummy wire, 12a ... 1st end, 12b ... 2nd end, 13 ... Connection, 13a ... Welded part , 14, 15 ... Step relaxation part, 20 ... Reel, 21 ... Wind core, 21a ... Slit, 21b ... Outer circumference of winding core, 22 ... Side plate, 23 ... Hole, 24 ... Central axis.

Claims (5)

It is a reel winding body of the oxide superconducting wire, which is formed by winding the oxide superconducting wire around the reel core.
The oxide superconducting wire is formed by connecting a dummy wire to the end on the winding start side with respect to the winding core.
The winding core has a slit into which the end portion of the dummy wire is inserted, and the dummy wire is bent along the outer circumference of the winding core with respect to the end portion of the dummy wire inserted into the slit. Being engaged by
The dummy wire is wound around the reel in a range of 10 to 100 turns, and the oxide superconducting wire is wound through the connection portion between the oxide superconducting wire and the dummy wire. A reel winding body of an oxide superconducting wire material characterized by. The oxide superconductivity according to claim 1, wherein the angle formed by the end portion of the dummy wire inserted into the slit and the dummy wire bent along the outer circumference of the reel is an acute angle. Reel winding body of wire rod. The reel winding body of the oxide superconducting wire according to claim 1 or 2, wherein the thickness at which the dummy wire is wound on the outer circumference of the winding core is 0.1 to 10 mm. At the connection portion between the oxide superconducting wire and the dummy wire, the oxide superconducting wire and the dummy wire are overlapped and connected to each other in the thickness direction, and a step generated in the connecting portion is formed on the oxide superconducting wire. The reel wound body of the oxide superconducting wire according to any one of claims 1 to 3, further comprising a step relaxation portion in which the thickness of the end portion of the dummy wire is gradually reduced. The reel wound body of the oxide superconducting wire according to claim 4, wherein the step is 20 to 100 μm.

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