JP5695772B1 - Superconducting wire connecting body manufacturing method, superconducting wire connecting body, and superconducting wire connecting apparatus - Google Patents

Abstract

A superconducting wire connecting body manufacturing method, a superconducting wire connecting body, and a superconducting wire connecting apparatus capable of suppressing the occurrence of burrs of low melting point metals are provided. A method of manufacturing a superconducting wire connecting body in which a plurality of tape-shaped superconducting wires 10 and 10 are connected via a low-melting point metal 16, wherein the superconducting wires 10 and 10 to be connected are connected to these superconducting wires. In a state where the low melting point metal 16 is interposed between the wires 10 and 10, the placement step of placing in the groove provided in the base, and the superconducting wires 10 and 10 and the low melting point metal 16 placed in the groove are pressurized and heated. Thus, there are a melting step for melting the low melting point metal 16 and a sucking step for sucking off the excessive molten low melting point metal 16. The sucking means is, for example, a metal mesh tape 17. [Selection] Figure 5

Description

  The present invention relates to a method for manufacturing a superconducting wire connecting body in which a plurality of tape-shaped superconducting wires are connected via a low melting point metal, a superconducting wire connecting body, and a superconducting wire connecting apparatus.

  Superconducting wires are used as conductors in superconducting coils and superconducting cables. When a relatively short superconducting wire is used, a wire having a length necessary for a coil or cable conductor can be obtained by connecting two or more superconducting wires in series. In Patent Documents 1 and 2, solder is disposed between the terminal portions of two superconducting wires, and the two superconducting wires are connected by heating the solder while these terminal portions are overlapped and pressed together. The technology to do is described.

International Publication No. 01/033580 JP 2011-003382 A

  When the superconducting wire is connected with a low melting point metal such as solder or brazing material, if the superconducting wire is not sufficiently pressurized, connection failure may occur due to displacement, separation, displacement, etc. of the superconducting wire. However, when the superconducting wires are superposed, when the low melting point metal between the superconducting wires is melted, excess low melting point metal leaks to the side in the width direction of the superconducting wire and the low melting point metal solidifies. This causes a problem of burrs.

  The present invention has been made in view of the above circumstances, and provides a superconducting wire connecting body manufacturing method, a superconducting wire connecting body, and a superconducting wire connecting apparatus capable of suppressing the occurrence of burrs due to low melting point metals. This is the issue.

In order to solve the above-mentioned problems, the present invention provides a method for manufacturing a superconducting wire connecting body in which a plurality of tape-shaped superconducting wires are connected via a low melting point metal, and the superconducting wires to be connected are connected to these superconducting wires. With the low melting point metal interposed between the wires, the placement step of placing in the groove provided on the base, and pressurizing and heating the superconducting wire and the low melting point metal placed in the groove a melting step of melting a refractory metal, wherein the extra melted possess a step blotter soak up low melting point metal, a, in the disposing step, by said melting step prior to melt the low melting point metal, said superconducting with wire and the low melting point metal, Hisage a method of manufacturing a superconducting wire connector characterized that you arranged by overlapping metal mesh tape or the superconducting wire is disposed inside the groove To.

After the sucking step, it is preferable to remove the metal mesh tape from which excess molten low melting point metal has been sucked in a state where the low melting point metal is melted .
The metal mesh tape may be a copper mesh tape containing a flux.
The present invention relates to a method of manufacturing a superconducting wire connecting body in which a plurality of tape-shaped superconducting wires are connected via a low melting point metal, and the superconducting wire connected is a low melting point metal between these superconducting wires. In a state where the metal is interposed in a groove provided in the base, and a melting step in which the superconducting wire and the low melting point metal placed in the groove are pressurized and heated to melt the low melting point metal. And a sucking step of sucking off the excessive molten low melting point metal, and the base has an exhaust port at least at one of the bottom surface or the side surface of the groove, and the exhaust port is connected to a pump. In the sucking step, a superconducting wire connecting body manufacturing method is provided in which excess molten low melting point metal is sucked from the exhaust port by suction of the pump.
When the superconducting wire has a stabilization layer joined by tin or a tin alloy, the low melting point metal is preferably lower than the melting point of the tin or the tin alloy joining the stabilization layer.

Further, the present invention is a superconducting wire connector manufactured by the method of manufacturing a superconducting wire connector of the present invention, wherein at least two superconducting wires overlap with each other with a low melting point metal interposed therebetween, and Provided is a connected superconducting wire, wherein the low-melting-point metal burrs are not present on the side surface of the superconducting wire connecting.

In order to solve the above-mentioned problem, the present invention is a superconducting wire connecting device for connecting a plurality of tape-shaped superconducting wires via a low melting point metal, and has a groove for arranging the superconducting wires to be connected. a base, means for arranged the superconducting wire of the pressure and heat to said groove, a blotter means sucks a low-melting-point metal that extra melted during melting of the low melting point metal, have a, the wicking means, A superconducting wire connecting device is provided , comprising an exhaust port provided in at least one position on a bottom surface or a side surface of the groove in the base, wherein the exhaust port is connected to a pump .

The wicking means may further comprise a metal mesh tape.
The metal mesh tape may be a copper mesh tape containing a flux .

  According to the present invention, the generation of burrs can be suppressed by sucking off the extra low melting point metal.

It is a perspective view which shows an example of the base provided with the groove | channel. It is a perspective view which shows an example of a means to pressurize and heat a superconducting wire. It is sectional drawing which shows an example which has arrange | positioned the low melting metal to the single side | surface of a superconducting wire. It is sectional drawing which shows an example of the state which the low melting-point metal intervened between the superconducting wires. It is sectional drawing which shows an example which piled up the metal mesh tape on the superconducting wire. 10 is a graph showing an example of a line width distribution in the connection result of Comparative Example 1. It is a top view which shows an example which the burr | flash produced on both sides of the connected superconducting wire. 6 is a graph showing an example of a line width distribution in the connection result of Example 1. It is a perspective view which shows an example of the base provided with the exhaust port.

Hereinafter, based on a preferred embodiment, the present invention will be described with reference to the drawings.
In FIG. 1, an example of the base 20 which has the groove | channel 21 which arrange | positions a superconducting wire is shown. FIG. 2 shows an example of a crimping jig 25 as means for crimping the superconducting wire by pressure and heating. In this specification, “pressurization and heating” is only necessary when there is a time when the superconducting wire is heated, and it is limited to when the pressurization and heating start timing and end timing are simultaneous. is not.

  The base 20 has a pair of side walls 22, 22 that form the side surfaces of the groove 21, and a bottom wall 23 that forms the lower surface of the groove 21. The bottom wall 23 is substantially rectangular in plan view, and the long side of the rectangle is parallel to the longitudinal direction of the groove 21. Both ends in the longitudinal direction of the groove 21 reach both ends of the base 20 without being closed. The depth of the groove 21 is preferably substantially the same as or greater than the sum of the thicknesses of the pair of superconducting wires and low melting point metal to be connected. The width W1 of the groove 21 is approximately the same as the width of the superconducting wire. In order to facilitate the operation of inserting and removing the superconducting wire from the groove 21, the width W1 of the groove 21 may be slightly larger than the width of the superconducting wire. It is preferable that the bottom surface of the groove 21 and the bottom surface of the bottom wall 23 are parallel because the superconducting wire disposed in the groove 21 can be easily maintained horizontally when the base 20 is disposed on a horizontal plane.

  The base 20 may include a clamping mechanism (not shown) that holds the superconducting wire disposed in the groove 21 in the vicinity of both ends in the longitudinal direction of the groove 21. It is preferable that the clamping mechanism can suppress the positional deviation of the superconducting wire in the longitudinal direction of the groove 21, and it is preferable that the positional deviation of the superconducting wire in the width direction of the groove 21 can be suppressed. The material constituting the base 20 preferably has a low thermal conductivity and a high heat insulating property. Thereby, the temperature rise of the base 20 is suppressed when the superconducting wire is heated, and the working efficiency can be improved without preventing the melting of the low melting point metal. Examples of the material of the base 20 include ceramics. The side walls 22 and 22 and the bottom wall 23 manufactured separately may be combined, but the side walls 22 and 22 and the bottom wall 23 may be integrally formed.

  The crimping jig 25 has a plate portion 27 and a convex portion 26 protruding from the plate portion 27. The plate portion 27 is substantially rectangular in plan view, and the long side of the rectangle is parallel to the longitudinal direction of the convex portion 26. The shape of the front end surface of the convex portion 26 is substantially rectangular, and is a single protrusion that is continuous in the long side direction of the plate portion 27. The dimension of the plate part 27 may be approximately the same as the planar dimension of the base 20 or may be slightly smaller. The upper surface of the plate part 27 is formed flat. The plate portion 27 of the crimping jig 25 preferably has a large area and a small thickness. Thereby, a surface area can be enlarged compared with a volume, and the heat dissipation after a heating can be improved.

  When a superconducting wire (not shown) disposed in the groove 21 is pressed by the crimping jig 25, the convex portion 26 of the crimping jig 25 is inserted into the groove 21 of the base 20. In order to facilitate the operation of inserting the convex portion 26 into the groove 21 and removing it from the groove 21, the width W1 of the groove 21 may be slightly larger than the width W2 of the convex portion 26. The crimping jig 25 has a heating means (not shown) inside or a structure capable of conducting heat obtained from an external heating means (not shown) to the tip surface of the convex portion 26. It is preferable.

  When an external heating means is used without providing a heating means inside the crimping jig 25, the external heating means is separated from the crimping jig 25 after heating, thereby suppressing further inflow of heat, and superconducting wire and low The melting point metal can be cooled efficiently. The external heating means may be configured such that heat flows from the heating body into the crimping jig 25 when the lower surface of the block-shaped heating body is pressed against the upper surface of the plate portion 27, for example. The heating method is not particularly limited as long as the low melting point metal can be heated to the melting point or higher, and a method using an electric heater can be mentioned.

  The material constituting the crimping jig 25 desirably has a strength capable of pressurizing the superconducting wire and a function of conducting heat from the heating means to the superconducting wire. In this respect, a metal material having a high thermal conductivity and a high heat transfer coefficient such as stainless steel, aluminum, copper, an aluminum alloy, and a copper alloy is preferable.

  For the vertical movement of the crimping jig 25, driving means (not shown) such as a cylinder or a motor may be used, or guide means (not shown) such as a ball screw or a slider may be used. The same applies to the case where an external heating body is moved up and down with respect to the crimping jig 25. In order to manage the temperature, a temperature measuring means for the crimping jig 25 and the heating body, a means for displaying the measured temperature (not shown), etc. (not shown) can also be provided in the connecting device.

  FIG. 3 shows an example of the superconducting wire 10. FIG. 3 also shows a low melting point metal 16 to be described later, but this low melting point metal 16 is not a part of the superconducting wire 10. The superconducting wire 10 has a tape substrate 11, an intermediate layer 12, a superconducting layer 13, a protective layer 14, a stabilizing layer 15, etc., and has a multilayer composite structure using yttrium (Y) based superconductor. The tape substrate 11 is a tape-like base material made of a metal such as a nickel alloy.

The intermediate layer 12 provided between the tape substrate 11 and the superconducting layer 13 may be composed of a plurality of layers such as a base layer, an orientation intermediate layer, and a cap layer. The underlayer is made of, for example, Y ₂ O ₃ and has high heat resistance and is provided to reduce interface reactivity. A diffusion prevention layer such as Al ₂ O ₃ may be interposed between the tape substrate and the base layer. The orientation intermediate layer is made of a metal oxide such as Gd ₂ Zr ₂ O ₇ , MgO, ZrO ₂ —Y ₂ O ₃ (YSZ), or SrTiO ₃ and is selected from materials that are biaxially oriented. The cap _{layer, CeO 2, Y 2 O 3} , Al 2 O 3, Gd 2 O 3, Zr 2 O 3, Ho 2 O 3, Nd 2 O 3 , etc., those crystal grains are selectively grown in the in-plane direction preferable.

The superconducting layer 13 is made of an oxide superconductor such as RE123 (REBa ₂ Cu ₃ O _7-δ ). RE in RE123 represents a rare earth element such as Y, La, Nd, Sm, Er, or Gd. Examples of RE123 include Y123 (YBa ₂ Cu ₃ O _7-δ ) and Gd123 (GdBa ₂ Cu ₃ O _7-δ ).

  The protective layer 14 is made of Ag, a noble metal, or the like. The stabilization layer 15 is preferably made of a highly conductive metal material such as copper or a copper alloy such as brass (Cu—Zn alloy). The stabilization layer 15 may be formed by joining a metal tape such as Cu on the protective layer 14 with solder such as Sn solder.

As another example of the superconducting wire 10, and a _{Bi2212 (Bi 2 Sr 2 CaCu 2} O 8 + δ), Bi2223 (Bi 2 Sr 2 Ca 2 Cu 3 O 10 + δ) bismuth using bismuth-based superconductors such as superconducting wires . The bismuth-based superconducting wire mainly has a structure in which an oxide superconducting layer is included in a sheath made of a tape-like stabilizing material such as Ag.

  The superconducting wire connecting method according to the present embodiment can be used as a method of manufacturing a superconducting wire connecting body in which a plurality of tape-like superconducting wires are connected via low-melting point metals. When connecting a plurality of superconducting wires 10, 10, as shown in FIG. 4, the end portions of the respective superconducting wires 10, 10 are overlapped, and the low melting point metal 16 is disposed therebetween. The low melting point metal 16 is a solder or a brazing material. The melting point of the low melting point metal 16 is preferably low enough to avoid deterioration of the superconductor even if the superconducting wire 10 is heated to a temperature higher than the melting point of the low melting point metal 16. When a part of the superconducting wire 10 includes a meltable joining material such as solder or brazing material, the melting point of the low melting point metal 16 is preferably lower than the melting point of the joining material of the superconducting wire 10. For example, when the superconducting wire has a stabilization layer joined by tin or a tin alloy, the melting point of the low melting point metal is preferably lower than the melting point of the tin or tin alloy joining the stabilization layer.

  The form before melting of the low melting point metal 16 is preferably a linear shape, a tape shape, a sheet shape, a paste shape, or the like so that the low melting point metal 16 can be easily maintained between the superconducting wires 10 and 10. A conventionally well-known thing can be used for a solder, for example, In solder which has In as a main component, Sn, Sn-Ag type alloy, Sn-Bi type alloy, Sn-Cu type alloy, Sn-Zn type alloy etc. Sn solder made of an alloy containing Sn as a main component, Pb—Sn alloy solder, eutectic solder, low-temperature solder, and the like. Moreover, only 1 type of solder may be used and it can also be used combining 2 or more types of solder. From the viewpoint of dealing with environmental problems, it is preferable not to use regulated substances such as Pb, and the content thereof is less than the regulated value.

  The connection method of the present embodiment includes a placement step of placing the superconducting wires 10 and 10 and the low melting point metal 16 to be connected in the groove 21 of the base 20 as a first step. The following (1) to (5) are exemplified as the order and method of arranging the superconducting wires 10 and 10 and the low melting point metal 16 in the groove 21, but the low melting point metal 16 is connected between the superconducting wires 10 and 10 to be connected. The arrangement process is not limited to the following.

(1) One (lower) superconducting wire 10 is disposed in the groove 21, then the low melting point metal 16 is disposed on the superconducting wire 10, and then the other (upper) superconducting wire 10 is disposed thereon. To do.
(2) The low melting point metal 16 is disposed on one superconducting wire 10 outside the groove 21, then these are disposed in the groove 21, and then the other superconducting wire 10 is disposed thereon.
(3) The low melting point metal 16 is disposed on one superconducting wire 10 outside the groove 21, then the other superconducting wire 10 is disposed thereon, and then these are collectively disposed in the groove 21.
(4) Arrange both superconducting wires 10 and 10 in the groove 21 and then place the low melting point metal 16 between the superconducting wires 10 and 10 in a state where the end of the upper superconducting wire 10 is lifted. To do.
(5) One superconducting wire 10 is disposed in the groove 21, and separately from this, the low melting point metal 16 is disposed on the other superconducting wire 10 outside the groove 21 (attached without heating as in solder paste) Next, the other superconducting wire 10 to which the low melting point metal 16 is attached is disposed on the one superconducting wire 10.

  In FIG. 4, the superconducting wire 10 is arranged so that the stabilization layer 15 of the superconducting wire 10 is in contact with the low melting point metal 16. When the stabilization layer 15 is made of Cu, if the stabilization layer 15 is disposed so as to contact the low melting point metal 16, the molten low melting point metal 16 tends to wet the surface of the stabilization layer 15, and the superconducting wire 10 is strengthened. Since it is easy to join, it is preferable.

  The connection method of the present embodiment includes a melting step of melting the low melting point metal 16 by pressurizing and heating the superconducting wires 10 and 10 and the low melting point metal 16 disposed in the groove 21 as the second step. In the melting step, the superconducting wires 10, 10 and the low melting point metal 16 are sandwiched between the groove 21 of the base 20 and the convex portion 26 of the crimping jig 25, thereby Pressurize so that does not separate. The pressure applied to the superconducting wire 10 is controlled to such an extent that the superconducting wire 10 is not damaged, particularly, the crystal structure of the superconductor is not changed. Examples of the heating method include a method of conducting heat from the heating means (not shown) provided inside or outside the crimping jig 25 to the superconducting wire 10 as described above.

  The connection method of the present embodiment includes a sucking step of sucking off the excessive molten low melting point metal 16 as a third step. FIG. 5 illustrates a case where a metal mesh tape 17 is used as a sucking means for sucking off an excessive molten low melting point metal. The metal mesh tape 17 is a mesh material formed by knitting metal thin wires into a tape shape. When the metal mesh tape 17 comes into contact with the molten low melting point metal, the low melting point metal can be sucked by a capillary phenomenon. Examples of the metal constituting the metal mesh tape 17 include copper (Cu) and alloys thereof.

  When the metal mesh tape 17 is used as the sucking means, when the groove 21 of the base 20 is arranged in the arranging step, the metal mesh tape 17 is placed inside the groove 21 or the superconducting wire 10 together with the superconducting wires 10 and 10 and the low melting point metal 16. It is preferable to arrange on top of. Further, when the metal mesh tape 17 is placed on the superconducting wire 10 in an overlapping manner, it is preferable to sandwich the metal mesh tape 17 between the superconducting wire 10 and the convex portion 26 of the crimping jig 25 in the melting step. . In this case, the metal mesh tape 17 as well as the superconducting wire 10 and the low melting point metal 16 are also pressurized and heated by the crimping jig 25.

  When the metal mesh tape 17 is arranged in the vicinity of the superconducting wire 10 before the low melting point metal 16 is melted, the excess low melting point metal 16 protruding from the side of the superconducting wire 10 can be immediately sucked by the metal mesh tape 17. it can. That is, during the melting process, the sucking process can be automatically started immediately after the low melting point metal 16 is melted. The generation of burrs can be suppressed by sucking off the extra low melting point metal.

  The metal mesh tape 17 preferably contains a flux in order to promote suction of the low melting point metal. When a copper mesh tape in which the metal of the metal mesh tape is copper is used, the thermal conductivity is excellent as well as the low melting point metal suction. For this reason, even when the metal mesh tape 17 is sandwiched between the superconducting wire 10 and the crimping jig 25, the heat of the crimping jig 25 can be conducted well to the superconducting wire 10.

  After the melting step and the sucking step are completed, it is preferable to remove the metal mesh tape 17 that has sucked off the excessive low melting point metal. In this removal, the crimping jig 25 is raised, and the metal mesh tape 17 is removed from the superconducting wire 10 with the pressurization stopped. The removal of the metal mesh tape 17 may be performed manually or automatically using a jig such as tweezers. Finally, the low-melting point metal 16 between the superconducting wires 10 and 10 is cooled and solidified to connect the superconducting wires 10 and 10. The following (A) to (C) are exemplified as procedures after the blotting process, but the connection method of the present embodiment using the metal mesh tape 17 is not limited to the following.

(A) The crimping jig 25 is raised in a state where the low melting point metal 16 is melted, and the metal mesh tape 17 that has absorbed excess low melting point metal is removed. Before the molten low melting point metal 16 between the superconducting wires 10 and 10 solidifies, the crimping jig 25 is lowered again to continue pressurization and heating on the superconducting wires 10 and 10. After that, the heating of the crimping jig 25 is finished, and it is cooled to below the melting point of the low melting point metal 16 while the crimped state is continued. After the low melting point metal 16 is solidified, the crimping jig 25 is raised, and the superconducting wires 10, 10 having been connected are taken out.

(B) The crimping jig 25 is raised in a state where the low melting point metal 16 is melted, and the metal mesh tape 17 that has absorbed excess low melting point metal is removed. After a part or all of the molten low melting point metal 16 between the superconducting wires 10 and 10 is solidified, the crimping jig 25 is lowered again, and the superconducting wires 10 and 10 are reheated while being pressurized. After the low melting point metal 16 between the superconducting wires 10 and 10 is melted, the heating of the crimping jig 25 is finished, and the melt is cooled to below the melting point of the low melting point metal 16 while continuing the crimped state. After the low melting point metal 16 is solidified, the crimping jig 25 is raised, and the superconducting wires 10, 10 having been connected are taken out.

(C) The heating of the crimping jig 25 is terminated while the superconducting wire 10 is pressed together with the metal mesh tape 17 that has absorbed excess low melting point metal, and the crimping jig 25 is raised after the low melting point metal 16 is solidified. After that, the metal mesh tape 17 that has absorbed excess low-melting point metal is removed, and the superconducting wires 10 that have been connected are taken out.

  The above procedure (A) or (B) is a state in which the low melting point metal is melted when the metal mesh tape 17 that has absorbed excess low melting point metal is removed, and the metal mesh tape 17 is unlikely to adhere to the superconducting wire 10. Therefore, it is preferable. Before the crimping jig 25 is lowered again, a buffer material can be disposed between the superconducting wire 10 and the convex portion 26 of the crimping jig 25. The cushioning material is a heat-resistant member that is compressed against pressure, such as a mesh or a sponge. By using the buffer material, the pressure applied by the crimping jig 25 is applied to the superconducting wire 10 evenly, and the balance (balance) can be obtained. The cushioning material may be a metal mesh tape that can absorb low melting point metal. By placing a new metal mesh tape that has not absorbed low melting point metal on the superconducting wire 10 again, even if the low melting point metal melted in the subsequent process is protruded, the protruding low melting point metal is removed from the metal mesh tape. Can be sucked out.

  As in (B) above, when the low melting point metal 16 solidifies while removing the metal mesh tape 17 that has absorbed excess low melting point metal, the superconducting wires 10 and 10 are once connected. However, since positional deviation in the width direction may occur, the first connection is set as a temporary connection process, and the low melting point metal 16 between the superconducting wires 10 and 10 is melted again by pressurizing and heating the superconducting wires 10 and 10 again. Then, after correcting the positional deviation in the width direction, it is possible to connect the superconducting wires 10 and 10 by cooling (this connection process).

  In order to confirm the effect of the connection method of the present embodiment, Comparative Example 1 in which the superconducting wires 10 and 10 are connected without using the metal mesh tape 17 and the superconducting wires 10 and 10 are connected using the metal mesh tape 17. Example 1 was carried out as follows.

  In Comparative Example 1 of the present embodiment, the base 20 in which the width W1 of the groove 21 in FIG. 1 is 5.2 mm and the crimping jig 25 in which the width W2 of the convex portion 26 in FIG. 2 is 5.0 mm are used. . The crimping jig 25 can be controlled by a heater. Superconducting wire 10 has a width of 5.02 mm and a length of 30 cm. Solder was applied over a length of 20 cm as a low melting point metal 16 as shown in FIG. In the groove 21 of the base 20, two superconducting wires 10, 10 were combined as shown in FIG. The solder was cooled to below the melting point using an air blow in the crimped state, and after the solder solidified, the superconducting wires 10, 10 having been connected were taken out from the groove 21.

  In FIG. 6, the graph which measured the width | variety of the superconducting wire 10 which completed the connection in the comparative example 1 is shown. This width was measured at intervals of 2 cm with respect to the length direction of the connecting portion of the superconducting wires 10 and 10. The average value of the width is about 5.3 mm. Compared to 5.02 mm which is the width of the original superconducting wire 10, the width deviation caused by connecting the two superconducting wires 10, 10 and the burrs caused by solder The width has increased due to the influence. FIG. 7 illustrates a state in which a large number of burrs 18 are generated on both sides in the width direction (vertical direction in FIG. 7) of the superconducting wire 10 that has been connected.

  In Example 1 of the present embodiment, the base 20, the crimping jig 25, and the superconducting wire 10 are the same as in Comparative Example 1, but the metal mesh tape 17 is attached to the superconducting wire 10 before crimping as shown in FIG. On top of each other and brought into close contact. The length of the metal mesh tape 17 was 29 cm, and the metal mesh tape 17 was protruded by about 2 cm from both ends of the groove 21 having a length of 25 cm. Further, after crimping at a temperature of 200 ° C., the metal mesh tape 17 that has absorbed the solder is removed before the solder solidifies, and a new metal mesh tape 17 that does not absorb the solder as a buffer material is placed on the superconducting wire 10. Placed and crimped again. After the solder was cooled to the melting point or lower in the crimped state and the solder solidified, the superconducting wires 10, 10 that had been connected were taken out from the groove 21.

  In FIG. 8, the graph which measured the width | variety of the superconducting wire 10 and 10 which completed connection in Example 1 is shown. This width was measured at intervals of 2 cm with respect to the length direction of the connecting portion of the superconducting wires 10 and 10. The average value of the width is about 5.09 mm. Compared with Comparative Example 1, it can be seen that the influence of burrs due to solder has been removed. Even when the superconducting wires 10 and 10 connected in Example 1 were observed, no burrs were found on the side surfaces. For this reason, the increase in the width compared with that before the connection is considered to be caused by the width shift.

  The superconducting wire connecting body of the present invention is a superconducting wire connecting body in which at least two superconducting wires overlap with each other with a low-melting point metal interposed therebetween and are connected to each other, and are connected to the side of the superconducting wire connecting body. It is characterized by the absence of refractory metal burrs. According to the present invention, it is possible to obtain a superconducting wire connecting body having no burr over the entire length of the connecting portion.

  As mentioned above, although this invention has been demonstrated based on suitable embodiment, this invention is not limited to the above-mentioned embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

  In the case where the metal mesh tape is used as the sucking means, in the above-described embodiment, the metal mesh tape is superposed on the superconducting wire from the stage of the arranging step, but the present invention is not particularly limited to this. For example, the metal mesh tape may be brought into contact with the superconducting wire after the low melting point metal is melted. It is also possible to provide an opening on the side surface or bottom surface of the groove, and to provide the sucking means so as to be able to appear and retract from the opening.

  As an example of the suction means other than the metal mesh tape 17, FIG. 9 shows a case where the exhaust port 24 is provided at least at one position on the bottom surface or side surface of the groove 21 of the base 20. In the illustrated example, a plurality of exhaust ports 24 are provided on the side surface of the groove 21 along the longitudinal direction thereof. The exhaust port 24 is connected to a pump (not shown), and excess molten low melting point metal can be sucked and removed from the exhaust port 24 by suction of the pump in the sucking process. In this way, the generation of burrs can be suppressed by sucking off the extra low melting point metal.

  The superconducting wire connection body obtained by the present invention is suitable as a conductor in a superconducting coil, a superconducting cable, or the like. The use of the superconducting coil is not particularly limited, and examples thereof include a magnetic resonance imaging diagnostic apparatus (MRI), a nuclear magnetic resonance spectroscopic apparatus (NMR), and a superconducting magnetic energy storage apparatus (SMES).

DESCRIPTION OF SYMBOLS 10 ... Superconducting wire, 11 ... Tape substrate, 12 ... Intermediate layer, 13 ... Superconducting layer, 14 ... Protective layer, 15 ... Stabilization layer, 16 ... Low melting point metal, 17 ... Metal mesh tape, 18 ... Burr, 20 ... Base 21: groove, 22: side wall, 23: bottom wall, 24: exhaust port, 25: crimping jig, 26: convex part, 27: plate part.

Claims (9)

A plurality of tape-shaped superconducting wires are manufacturing methods of a superconducting wire connecting body connected via a low melting point metal,
An arrangement step of arranging the superconducting wire to be connected in a groove provided in the base with a low melting point metal interposed between these superconducting wires,
A melting step of melting the low melting point metal by pressurizing and heating the superconducting wire and the low melting point metal disposed in the groove;
A blotting process for sucking off the excessive molten low melting point metal;
I have a,
In the placing step, before melting the low melting point metal in the melting step, a metal mesh tape is placed inside the groove or superposed on the superconducting wire together with the superconducting wire and the low melting point metal. method of manufacturing a superconducting wire connector characterized that you arranged Te. 2. The superconducting wire connector according to claim 1, wherein after the sucking step, the metal mesh tape that sucks off the excessive molten low melting point metal is removed in a state where the low melting point metal is melted. Manufacturing method. The said metal mesh tape is a copper mesh tape containing a flux, The manufacturing method of the superconducting wire connecting body of Claim 1 or 2 characterized by the above-mentioned. A plurality of tape-shaped superconducting wires are manufacturing methods of a superconducting wire connecting body connected via a low melting point metal,
An arrangement step of arranging the superconducting wire to be connected in a groove provided in the base with a low melting point metal interposed between these superconducting wires,
A melting step of melting the low melting point metal by pressurizing and heating the superconducting wire and the low melting point metal disposed in the groove;
A blotting process for sucking off the excessive molten low melting point metal;
Have
The base has an exhaust port in at least one of the bottom surface or the side surface of the groove, and the exhaust port is connected to a pump.
In the blotting step, by suction of the pump, the production method of extra molten said low melting point metal you characterized by blotting from the exhaust port superconducting wire connector. The superconducting wire has a stabilization layer joined by tin or tin alloy,
5. The method of manufacturing a superconducting wire connecting body according to claim 1, wherein the low melting point metal is lower than a melting point of the tin or the tin alloy to which the stabilization layer is joined. A superconducting wire connecting body manufactured by the method for manufacturing a superconducting wire connecting body according to any one of claims 1 to 5,
At least two superconducting wires overlap with each other with a low melting point metal interposed therebetween, and are connected to each other, and there is no burr of the low melting point metal on the side surface of the superconducting wire connecting member A superconducting wire connecting body characterized by that. A superconducting wire connecting device for connecting a plurality of tape-shaped superconducting wires via a low melting point metal,
A base having a groove for arranging a superconducting wire to be connected;
Means for pressurizing and heating the superconducting wire disposed in the groove;
A sucking means for sucking off an excessive molten low melting point metal when the low melting point metal is melted;
I have a,
The superconducting wire connecting device according to claim 1, wherein the suction means includes an exhaust port provided in at least one of a bottom surface or a side surface of the groove in the base, and the exhaust port is connected to a pump . The blotting means, superconducting wire connection device according to claim 7, further characterized by Rukoto comprises a metal mesh tape.   The superconducting wire connecting device according to claim 8, wherein the metal mesh tape is a copper mesh tape containing a flux.

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