JP2010098267A - Superconducting coil device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a superconducting coil device for suppressing heat generation at a connection between a superconducting coil and an electrode and for preventing the superconducting coil from producing a bending stress. <P>SOLUTION: The superconducting coil device includes: a superconducting coil wound with a tape-shaped superconducting wire material 5; a bobbin 3 having a body portion 3a disposed on the internal circumference of the superconducting coil and a flange portion 3b projecting from one end of the body portion in the axial direction; a first electrode 10 connected to an end portion of the superconducting wire material 5 of the superconducting coil; and a second electrode 11 integrated with the first electrode. The first electrode 10 is shaped to have a circular arc-shaped contact portion 20 extending in the circumferential direction along the end portion of the superconducting wire material of the superconducting coil and a fixing portion 21 for fixing to the flange portion 3b on one end side in the circumferential direction of the circular arc-shaped contact portion and projecting from the flange portion. The second electrode 11 is shaped to project outwardly from the flange 3b and have a connection with a power supply cable 6. The circular arc-shaped contact portion 20 of the first electrode is soldered to the end portion of the superconducting wire material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a superconducting coil device, and more specifically, in a superconducting coil device in which a tape-like superconducting wire is a pancake-type coil, the connection structure between the terminal of the superconducting wire of the coil and an electrode is improved.

As the superconducting wire forming the superconducting coil, there are a high-temperature oxide superconducting wire and a metal superconducting wire, and there are two types of wire shapes, a round wire shape and a tape shape (band shape).
Japanese Patent Laid-Open No. 3-237097 has been proposed as a superconducting coil in which a tape-like high-temperature oxide superconducting wire is wound.

As shown in FIG. 7, the superconducting coil is wound with the width direction surface 100a of the tape-shaped superconducting wire 100 parallel to the central axis L of the coil, and a flat plate width W and The electrodes 101 and 102 are connected.
The electrodes 101 and 102 are made of a flat copper plate, and the electrodes and the superconducting wire 100 are connected by soldering.

As described above, since the electrodes 101 and 102 have a flat plate shape, the contact area with the superconducting wire 100 is limited, and there is a limit to the reduction of contact resistance. Therefore, when a large current is passed through the superconducting wire 100, heat is generated between the electrodes 101, 102 and the superconducting wire 100, and the temperature of the superconducting wire 100 rises.
In particular, when the refrigerator cooling direct cooling system is adopted as a cooling mechanism for the superconducting coil, a large current of 300A level is caused to flow at 20K, so that it is necessary to suppress heat generation at the connection portion with the electrode as much as possible. Further, when the electrodes 101 and 102 are soldered to the superconducting wire 100, a force is applied to the electrodes 101 and 102, and a torsional force acts on the superconducting wire 100 in the region where the electrodes 101 and 102 are attached. In particular, bending stress works and there is a problem that the critical current is likely to deteriorate.

JP-A-3-237097

  The present invention has been made in view of the above problems, and in a superconducting coil device, it is possible to suppress generation of heat at a connection portion between a superconducting wire and an electrode and to prevent bending of the superconducting wire. It is an issue.

In order to solve the above problems, the present invention provides:
A superconducting coil wound with a tape-shaped superconducting wire,
A body part disposed on the inner periphery of the superconducting coil, and a bobbin provided with a flange projecting from one end of the body part in the axial direction;
A first electrode connected to a terminal portion of the superconducting wire of the superconducting coil;
A second electrode integrated with the first electrode;
The first electrode is fixed to the flange of the bobbin at one end side in the circumferential direction of the arc-shaped contact portion extending in the circumferential direction along the terminal portion of the superconducting wire of the superconducting coil. It has a shape with a fixed part protruding from the flange,
The second electrode protrudes outward from the flange and has a shape having a connection with a power supply cable,
A superconducting coil device is provided, wherein an arc-shaped contact portion of the first electrode is soldered to a terminal portion of the superconducting wire.

  The first electrode and the second electrode may be formed as a continuous body or as separate bodies. In the case of a separate body, the fixing portion of the first electrode is overlapped with the second electrode and fixed with screws.

The thickness of the first electrode is equal to the width of the superconducting wire, the arc-shaped contact portion is fixed by soldering in the entire width direction of the superconducting wire, and the arc-shaped contact portion of the first electrode to be soldered to the superconducting wire the circumferential length and 50 to 200 mm, an area of a 200mm ² ~800mm ^2, and it is the first electrode tip of the arc-shaped contact portion of the opposite side of the fixing part is provided with the tapered portion of the tapered shape Is preferred.
In the case of the first electrode and the second electrode and the separate body, the contact area is preferable that a 400mm ² ~2000mm ^2.

In the superconducting coil device having the above-described configuration, the first electrode to be soldered to the superconducting wire is provided with an arc-shaped contact portion having a curvature that follows the curvature of the terminal portion of the superconducting wire, and the superconducting wire and the first electrode are formed over a wide area. Can be connected by soldering. When the first electrode and the second electrode are separated from each other, the contact is made at a connecting portion between the superconducting wire and the electrode by contacting the second electrode with a power supply cable in a wide area. Resistance can be reduced, and the amount of heat generated can be reduced.
In addition, a fixing portion is provided on the first electrode and fixed to the flange of the bobbin with screws. In other words, unlike the conventional case where the electrode is fixed at the soldered portion with the superconducting wire, the soldered portion with the superconducting wire has only an electrical connection function, and the electrode is fixed by fixing the bobbin flange and screws. Yes. Thereby, the attachment strength of the first electrode can be increased without firmly fixing the first electrode to the superconducting wire by soldering. Therefore, it is possible to prevent the superconducting wire from being bent due to a torsional force acting on the superconducting wire when soldered to the first electrode, and deterioration of the critical current. In addition, since it is possible to prevent a load from being applied to the superconducting wire by the electrode at all times, even when the superconducting coil is energized, it can be stably energized without being deformed by the Lorentz force due to the interaction between the magnetic field and the current. .

  The connection part with the power supply cable provided on the second electrode is not a continuous side with the first electrode, but a bolt hole is provided on the back surface side opposite to the first electrode, and a bolt is attached to a bolt terminal that is crimped to the tip of the power supply cable. It is concluded. The power supply cable is preferably a flexible braided wire.

The superconducting coil is a double pancake type coil and a stack type in which a plurality of double pancake type coils are laminated,
The bobbin body is a stack body disposed on the inner periphery of the stacked double pancake coil, and the flange protrudes from the lower end of the body, and the superconductivity of the lower coil part of the bottom double pancake coil It is preferable that the first electrode is connected to a terminal on the outermost periphery of the wire by soldering.

As described above, when the double pancake type coil is used, the first coil portion and the second coil portion arranged on the upper and lower sides of the coil are bridged at the inner peripheral end to be continuous, and the double pancake type coil is connected. The end is the outermost terminal portion. In addition, in the stack type in which the double pancake type coils are laminated, the laminated double pancake type coils are sequentially connected by soldering with the outermost peripheral ends wrapped, and the lower side of the lowermost double pancake type coil The terminal part on the outermost periphery of the superconducting wire is connected to the power supply cable via an electrode.
Therefore, according to the present invention, in the stack type superconducting coil device, the first electrode is connected by soldering to the outermost terminal portion of the superconducting wire on the lower side of the lowermost double pancake coil, The electrode is connected to the second electrode, and the second electrode is connected to the power supply cable via the electrode.

Further, in the stack type superconducting coil device, the bobbin body is disposed on the inner periphery of the laminated double pancake type coil, the flange projects from the lower end of the body, and the lower end support material of the laminated double pancake type coil It becomes.
Since the bobbin is often formed of a metal material having strength such as stainless steel, it is necessary to insulate it from the first electrode fixed to the flange, and therefore the bobbin is fixed via an insulating liner.

  Note that the present invention is not limited to the stack type superconducting coil device in which the double pancake type coils are stacked, and can be applied to a single pancake type coil similar to that of Patent Document 1.

The superconducting wire used in the present invention is preferably a high-temperature oxide-based superconducting wire.
As the cooling means for cooling the high-temperature oxide-based superconducting wire to a superconducting temperature, it is preferable to employ a refrigerator cooling direct cooling system in which a cold conductive plate protruding from the refrigerator is brought into direct contact with the superconducting wire of the superconducting coil. .
When the refrigerator direct cooling method is adopted, a large current of 300A to 500A flows at 20K. Therefore, it is necessary to suppress heat generation at the connection portion between the superconducting wire and the electrode as much as possible. The first and second electrodes described above By connecting to the superconducting wire using, heat generation can be suppressed, and the superconducting wire can be cooled by the refrigerator cooling direct cooling method.

As described above, according to the superconducting coil device of the present invention, the first electrode that is solder-connected to the superconducting wire has a unique shape having an arc-shaped contact portion along the end of the superconducting wire. The soldering area with the superconducting wire can be increased. In addition, since the second electrode integrated with the first electrode and connected to the power supply cable has a wide area protruding from the flange, heat generation at the electrical connection portion between the superconducting wire and the electrode can be reduced.
Moreover, since the fixing portion is provided on the first electrode and is fixed to the flange of the bobbin, it is possible to suppress the bending load due to the electrode from being applied to the soldering fixing portion with the superconducting wire. As a result, bending of the superconducting coil can be prevented and deterioration of the critical current can be prevented during energization.

Hereinafter, embodiments of the superconducting coil device of the present invention will be described in detail with reference to the drawings.
1 to 3 show a first embodiment.

As schematically shown in FIG. 1, the superconducting coil device 1 is a stack type in which a plurality of double pancake type coils 2 are laminated in the axial direction. The coil 2 is formed by winding a high-temperature oxide-based superconducting wire 5.
The superconducting wire 5 is wound at a required rotational speed (number of turns) with the wide surface 5a parallel to the axial direction L of the coil 2 and the edge surface 5b orthogonal to the axial direction L.
In the double pancake-type coil 2, the lower first coil portion 2 a and the upper second coil portion 2 b are connected with a superconducting wire 5 on the inner peripheral side.

The laminated double pancake type coil 2 is attached to a bobbin 3 made of stainless steel. The bobbin 3 has a shape including a cylindrical body portion 3a disposed on the inner periphery of the laminated coil 2 and a flange 3b protruding from the outer periphery of the lower end of the body portion 3a.
The coils 2 to be stacked are connected by soldering by pulling out the terminal portions of the superconducting wire 5 at the outermost periphery.
As shown in FIG. 2, the lowermost coil 2-1 of the coil 2 to be laminated is disposed on the flange 3b. The outermost terminal portion 2 of the lowermost coil 2-1 is connected via the power supply cable 6, the first electrode 10, and the second electrode 11. The coils 2 to be laminated are connected by sequentially connecting the outermost terminal portions 2.
The first electrode 10 and the second electrode 11 are separated and formed by punching a copper plate.

As shown in FIGS. 2 and 3, the thickness t <b> 1 of the first electrode 10 is substantially equal to w of the wide portion of the tape-shaped superconducting wire 5.
The first electrode 10 has an arcuate contact portion 20 extending in the circumferential direction along the terminal portion of the superconducting wire 5 and a fixed portion protruding in the outer diameter direction on one end side in the circumferential direction of the arcuate contact portion 20. 21 is provided.
The arcuate contact portion 20 has an inner peripheral surface 20a as a contact surface that is soldered to the entire width direction of the wide surface 5a of the superconducting wire 5, and the outer peripheral surface 20b is located in the middle of the radial direction of the flange 3b of the bobbin. It is set as the magnitude | size mounted in the upper surface of 3b. The arcuate contact portion 20 is provided with a fixed portion 21 continuously at one end side in the circumferential direction, and the other end side is tapered by providing a tapered surface 20c on the outer peripheral surface 20b.

The inner peripheral surface 21 a of the fixing portion 21 of the first electrode 10 is provided at a slightly outer diameter position from the inner peripheral surface 20 a of the arcuate contact portion 20, and a gap C is formed between the inner peripheral surface 21 a and the superconducting wire 5. Is provided. The fixing portion 21 protrudes outward from the outer peripheral surface of the flange 3b of the bobbin, and one end side 21b in the radial direction is linear, while the other end side 21c is curved from the outer peripheral surface 20b of the arcuate contact portion 20. Let them continue.
The circumferential length of the arc-shaped contact portion 20 of the first electrode 10 is 50 to 200 mm, and the area of the inner peripheral surface 21 a to be soldered to the inner peripheral surface 21 a and the superconducting wire 5 is 200 to 800 mm ² .

  The inner peripheral side of the fixing portion 21 is arranged on the flange 3b via an insulating liner 13, and a screw hole 21d is provided in the arrangement portion, and is fixed with the flange 3b and the screw 25 via the insulating liner 13. A screw cylinder 21e for fixing to the second electrode 11 is provided on the outer peripheral side protruding outward from the flange 3b.

The second electrode 11 has a thickness t2 equal to the thickness of the flange 3b of the bobbin, and the inner peripheral surface 11a is disposed along the outer peripheral surface of the flange 3b. As shown in FIG. 2, the outer peripheral portion of the fixing portion 21 of the first electrode 10 is mounted on the upper surface of the second electrode 11, and the screw hole 11 b is positioned at a position corresponding to the fixing screw cylinder 21 e provided on the fixing portion 21. The first electrode 10 and the second electrode 11 are fixed by screws 26 with screws.
Furthermore, the second electrode 11 is provided with a bolt hole 11c for power connection, and is fastened with a bolt to the power supply terminal 28 that is crimped to the end of the power supply cable 6.

  The insulating liner 13 is interposed between the fixed portion 21 of the first electrode 10 and the upper surface of the flange 3b, and between the outer peripheral surface of the flange 3b and the inner peripheral surface of the second electrode 11, and the first and second electrodes 10 and 11 and the stainless steel flange 3b are insulated. The insulating liner is formed of an insulating fiber reinforced resin sheet using resin yarns as reinforcing fibers.

Next, a method for connecting the first electrode 10 and the second electrode 11 to the superconducting coil will be described.
A double pancake-type coil 2 formed by winding the superconducting wire 5 is externally fitted to the body portion 3a on the flange 3b of the bobbin 3 and stacked vertically to form a stack type superconducting coil device. An insulating material (not shown) is interposed between the lowermost layer coil 2-1 of the laminated coil 2 and the bobbin flange 3b.

The connection between the superconducting wire 5 and the first electrode 10 at the outermost end of the lowermost coil 2-1 is performed by connecting the arc-shaped contact portion 20 of the first electrode 10 with the inner peripheral surface 20a and the wide surface of the superconducting wire 5. 5a is fixed with solder H.
The fixing portion 21 of the first electrode 10 is disposed on the upper surface of the flange 3b with the insulating liner 13 interposed therebetween, and is fastened with a screw 25 to fix the first electrode 10 to the flange 3b.

The second electrode 11 is disposed on the outer peripheral surface of the flange 3b with the insulating liner 13 interposed therebetween, and the outer peripheral side portion of the fixing portion 21 of the first electrode 10 is disposed on the upper surface of the second electrode 11 and fixed with screws 26. To do.
Note that the first electrode 10 and the second electrode 11 may be fixed and integrated in advance with the screw 26 before being attached to the superconducting coil device. In that case, welding may be performed instead of screw fixing.

As described above, when the electrode composed of the first electrode 10 and the second electrode 11 is connected to the terminal portion on the outermost periphery of the coil 2, the contact area between the arc-shaped contact portion 20 of the first electrode 10 and the superconducting wire 5 is increased. In addition, the contact area between the first electrode 10 and the second electrode 11 can be increased.
Therefore, the contact resistance generated between the superconducting wire 5 and the electrode interposed in the connection portion between the superconducting wire 5 and the power supply cable can be reduced, and the amount of heat generated when a large current is passed through the superconducting wire 5 is greatly reduced. it can.
In addition, since the mounting strength of the first electrode 10 is maintained by screwing to the flange 3b, a load due to the fixing of the first electrode 10 to the superconducting wire 5 is not generated. As a result, the torsional force is not applied to the coil 2 made of the superconducting wire 5, the bending stress of the coil can be reduced, and the critical current is not deteriorated.

FIG. 4 shows a second embodiment.
The second embodiment is different from the first embodiment in that the first electrode and the second electrode are integrally provided.
That is, the electrode 30 continuously forms the first electrode portion 10A and the second electrode portion 11A with a step. Since the shape of the first electrode portion 10A and the second electrode portion 11A is the same as that of the first electrode 10 and the second electrode 11 of the first embodiment, the same reference numerals are given and the description thereof is omitted.

FIG. 5 shows a modification of the second embodiment.
The electrode 30A of the modified example continuously protrudes the second electrode portion 11B protruding from the first electrode portion 10B to the outside of the flange 3b with the same thickness.
Since other configurations are the same, the same reference numerals are given and description thereof is omitted.

6A and 6B show a third embodiment.
In the third embodiment, the superconducting coil device 1 of the first embodiment is provided with a refrigerator cooling direct cooling system.
In the third embodiment, a circular heat conduction plate 40 is interposed between the double pancake-type coils 2 to be laminated, and the entire superconducting wire 5 forming the coil 2 is cooled to the superconducting temperature. . The other end of the cooling plate 40 is connected to the cold head 42 of the refrigerator 41, and the superconducting wire is directly cooled by the cold heat conduction plate 40. The cold heat conductive plate 40 protrudes from the refrigerator 41 side in a case (not shown) for housing the superconducting coil device 1 and is interposed between the layers of the coils as described above.
Moreover, as shown in FIG. 6 (B), the lower heat conduction plate 40-1 of the cold heat conduction plate 40 connected to the refrigerator 41 has its tip 40-1a in an arcuate contact with the first electrode 10. The fixing unit 21 is in direct contact.
Since the connection form and other configurations of the coil 2 and the first and second electrodes are the same as those of the first embodiment, the same reference numerals are given and the description thereof is omitted.

As described above, when the coil 2 is formed of the high-temperature oxide-based superconducting wire 5 and the superconducting wire 5 is directly cooled by the cold / hot plate 40, a large current of 300A flows at 20K. It is necessary to suppress the heat generation of 5 as much as possible.
Therefore, the cooling mechanism of the refrigerator cooling direct cooling system can be employed by suppressing the heat generation at the connection portion between the superconducting wire 5 and the electrode as described above.
And since the 1st electrode 10 and the cooling-heat conduction board 40 are made to contact, even if a micro heat_generation | fever arises in the 1st electrode 10 and the 2nd electrode 11, it always contacts the cooling-heat conduction board 40 and is cooled. Therefore, an increase in electrode temperature can be prevented.
The cooling mechanism of the refrigerator cooling direct cooling system has an advantage that the apparatus can be simplified as compared with the cooling mechanism in which the superconducting coil is accommodated in a cooling container (cryo stud) filled with liquid nitrogen.

It is a schematic sectional drawing of the superconducting coil apparatus of 1st embodiment of this invention. It is a principal part perspective view of 1st embodiment. FIG. 3 is an exploded perspective view of FIG. 2. It is a perspective view of a second embodiment. It is a perspective view of the modification of 2nd embodiment. (A) is a schematic sectional drawing of 3rd embodiment, (B) is principal part explanatory drawing. It is a perspective view which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Superconducting coil apparatus 2 Double pancake type coil 3 Bobbin 3a Body 3b Flange 5 Superconducting wire 6 Power supply cable 10 1st electrode 11 2nd electrode 13 Insulating liner 20 Arc-shaped contact part 21 Fixed part

Claims (4)

A superconducting coil wound with a tape-shaped superconducting wire,
A body part disposed on the inner periphery of the superconducting coil, and a bobbin provided with a flange projecting from one end of the body part in the axial direction;
A first electrode connected to a terminal portion of the superconducting wire of the superconducting coil;
A second electrode integrated with the first electrode;
The first electrode is fixed to the flange of the bobbin at one end side in the circumferential direction of the arc-shaped contact portion extending in the circumferential direction along the terminal portion of the superconducting wire of the superconducting coil. It has a shape with a fixed part protruding from the flange,
The second electrode protrudes outward from the flange and has a shape having a connection with a power supply cable,
A superconducting coil device, wherein the arc-shaped contact portion of the first electrode is soldered to a terminal portion of the superconducting wire.   The superconducting coil device according to claim 1, wherein the first electrode and the second electrode are separated from each other, and a fixing portion of the first electrode is overlapped with the second electrode and fixed with screws. The superconducting coil is a double pancake type coil and a stack type in which a plurality of double pancake type coils are laminated,
The bobbin body is a stack body disposed on the inner periphery of the stacked double pancake coil, and the flange protrudes from the lower end of the body, and the superconductivity of the lower coil part of the bottom double pancake coil The superconducting coil device according to claim 1 or 2, wherein the first electrode is connected to a terminal on the outermost periphery of the wire by soldering.   4. The superconducting coil device according to claim 3, wherein a cooling heat conduction plate directly connected to a refrigerator is interposed between the laminated coils, and a cooling mechanism of a refrigerator cooling direct cooling system is attached.

Images