JP2014150223A - Superconducting coil and superconducting coil device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superconducting coil with an electrode capable of preventing damage to a superconducting wire rod, and a superconducting coil device with the superconducting coil.SOLUTION: A superconducting coil 1 comprises a coil part 10 formed by winding a superconducting wire rod and electrodes 12a and 12b connected to the coil part 10. The electrode 12a includes an extraction electrode 13a composed of a conductive material and a connection material 14a composed of a superconducting wire rod. The electrode 12b includes an extraction electrode 13b composed of a conductive material and a connection material 14b composed of a superconducting wire rod. The connection material 14a connects the superconducting wire rod of the coil part 10 and the extraction electrode 13a. The connection material 14b connects the superconducting wire rod of the coil part 10 and the extraction electrode 13b.

Description

  The present invention relates to a superconducting coil and a superconducting coil device.

  Japanese Patent Laying-Open No. 2010-98267 (Patent Document 1) discloses an electrode connected to a superconducting coil. This electrode includes a first electrode connected to the superconducting wire of the superconducting coil, and a second electrode integrated with the first electrode. The first electrode is fixed to the flange 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 and protruded from the flange. And a fixed portion. The second electrode protrudes outward from the flange and has a shape having a connection portion with the power supply cable. The arc-shaped contact portion of the first electrode is soldered to the terminal portion of the superconducting wire.

JP 2010-98267 A

  According to JP 2010-98267 A, the first electrode and the second electrode are formed of a copper plate. That is, the superconducting wire of the superconducting coil is connected to the copper electrode. The rigidity of the connecting portion between the copper electrode and the superconducting wire may change greatly.

  For example, cooling and heating of the superconducting coil are repeated. In this case, distortion resulting from the difference in the degree of thermal shrinkage between the copper electrode and the superconducting wire may occur at the connection portion between the copper electrode and the superconducting wire. Further, when a current flows through the coil, an electromagnetic force can be generated due to the interaction between the magnetic field and the current. The superconducting wire is subjected to stress by this electromagnetic force. On the other hand, when no current flows through the coil, the electromagnetic force is not generated. Therefore, stress is repeatedly applied to the connection portion between the copper electrode and the superconducting wire by repeatedly energizing and de-energizing the coil. These stresses may cause a problem that the portion of the superconducting wire connected to the copper electrode is damaged. And when a superconducting wire is comprised with an oxide superconductor, a superconducting wire is weak to a distortion. It is not preferable that stress is repeatedly applied to the connection portion between the copper electrode and the superconducting wire to the oxide superconducting wire which is weak against strain.

  Furthermore, although depending on the size of the electrode and / or the superconducting coil, the overall heat capacity of the electrode and the superconducting coil may increase. In such a case, in order to solder the electrode and the superconducting wire of the superconducting coil, a large amount of heat must be applied to the connecting portion between the electrode and the superconducting wire to melt the solder. However, since a large amount of heat is applied to a local portion such as the end portion of the superconducting coil, the superconducting wire may be damaged at the end portion of the superconducting coil. Similarly to the above, when the superconducting wire is made of an oxide superconductor, the superconducting wire is vulnerable to strain. Therefore, when a large amount of heat is applied to the local portion, the superconducting wire may be damaged.

Damage to the superconducting wire as described above results in an increase in electrical resistance of the superconducting wire.
Therefore, the electrode connected to the superconducting coil is required to have a configuration that prevents damage at the end of the superconducting coil. However, Japanese Patent Application Laid-Open No. 2010-98267 does not show the problem that the superconducting wire may be damaged at the connection portion between the electrode and the superconducting wire, and therefore there is a method for solving the problem. Not disclosed.

  The objective of this invention is providing the superconducting coil provided with the electrode which can prevent the damage of a superconducting wire, and the superconducting coil apparatus provided with the superconducting coil.

  A superconducting coil according to an aspect of the present invention includes a coil portion formed by winding a superconducting wire, and a first electrode member connected to the coil portion. The first electrode member includes a first extraction electrode made of a conductive material and a first connection member. The first connecting member is made of a superconducting wire. The first connection member connects the superconducting wire of the coil portion and the first extraction electrode.

  According to this configuration, the superconducting wire of the coil is connected to the first extraction electrode via the first connection member. The first connecting member is made of a superconducting wire. Therefore, the change in rigidity between the superconducting wire of the coil and the first connecting member can be reduced. Even when the rigidity differs greatly between the first lead electrode and the superconducting wire of the coil portion, the stress generated at the end of the coil portion (for example, the stress generated by cooling and raising the temperature of the superconducting coil) is reduced. Can do. Therefore, the possibility that the superconducting wire is damaged at the end of the coil portion can be reduced.

  “Rigidity” can be expressed as a force (load / deformation amount) required to cause unit deformation. “High rigidity (large)” means that the deformation is small relative to the force, and “low rigidity (small)” means that the deformation is large relative to the force.

  Preferably, the rigidity of the first extraction electrode is higher than the rigidity of the superconducting wire forming the coil portion. The rigidity of the first connecting member is lower than that of the first extraction electrode.

  According to this configuration, the rigidity of the first connecting member connected to the superconducting wire of the coil portion is smaller than the rigidity of the first extraction electrode. Therefore, it is possible to reduce the change in rigidity at the connection portion between the first electrode member (the first extraction electrode and the first connection member) and the superconducting wire at the end of the coil portion.

  Preferably, the superconducting wire forming the coil portion includes a first superconductor and a conductive first sheath covering the first superconductor. The first connecting member includes a second superconductor and a conductive second sheath. The second sheath includes the same material as the first sheath and covers the second superconductor.

  According to this configuration, the sheath (first sheath) of the superconducting wire forming the coil portion and the sheath (second sheath) of the first connecting member contain the same material. Therefore, a change in rigidity can be reduced between the superconducting wire forming the coil portion and the first connecting member.

  Preferably, the first connection member includes a first connection portion to which the coil portion is connected, a second connection portion to which the first extraction electrode is connected, and a first connection portion and a second connection portion. And an intermediate portion that is not connected to either the coil portion or the first extraction electrode.

  According to this configuration, for example, the intermediate portion of the first connection member functions as a buffer that relieves stress in the second connection portion. Therefore, it can avoid that the 1st connection part receives the influence of the stress in a 2nd connection part.

  Preferably, the superconducting coil further includes a second electrode member connected to the coil portion. The second electrode member includes a second extraction electrode made of a conductive material and a second connection member. The second connection member is made of a superconducting wire, and connects the coil portion and the second extraction electrode.

  According to this configuration, the superconducting coil includes the second connecting member in addition to the first connecting member. The first connecting member and the second connecting member can be used as one and the other of the input electrode and the output electrode of the coil portion. Even in the connection portion between the second connection member and the coil portion, the possibility of damage to the superconducting wire of the coil portion can be reduced.

  Preferably, the superconducting coil further includes an insulating member that insulates the first electrode member and the second electrode member. The first extraction electrode and the second extraction electrode are integrated with an insulating member interposed.

  According to this configuration, the first extraction electrode and the second extraction electrode can be brought close to each other. Therefore, it is possible to improve workability when connecting the first extraction electrode and the second extraction electrode of the superconducting coil device to another electrical component (for example, a current lead).

  Preferably, the rigidity of the first connecting member is at least the same as the rigidity of the superconducting wire forming the coil portion.

Preferably, the superconducting wire is made of an oxide superconductor.
In this case, the possibility that the superconducting wire is damaged at the end portion of the coil portion formed of the superconducting wire composed of the oxide superconductor can be reduced.

A superconducting coil device according to another aspect of the present invention includes the above-described superconducting coil.
According to this configuration, the possibility that the superconducting wire is damaged at the end of the coil portion can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the superconducting coil provided with the electrode which can prevent damage to a superconducting wire, and the superconducting coil apparatus provided with the superconducting coil are realizable.

It is a figure which shows roughly the structure of the superconducting coil which concerns on the 1st Embodiment of this invention. It is the figure which showed roughly the structure about the extraction electrode of the electrodes 12a and 12b shown in FIG. It is a top view for demonstrating the connection of the coil part 10 and electrode 12a, 12b. It is the figure which showed typically the cross section of the superconducting wire 31 with which the coil part 10 is provided, and the connection member 14a. It is typical sectional drawing which showed another structure of the connection member 14a. It is a figure for demonstrating the electric current which flows into the electrode 12a. It is the figure which showed the structure of the extraction electrode 13a. It is a figure for demonstrating the relationship between the thickness of the extraction electrode 13a, and the thickness of the connection member 14a. It is the figure which showed the example of the shape of the front-end | tip of the connection member 14a seen from the X direction shown in FIG. It is a figure for demonstrating the connection of the extraction electrode 13a and the connection member 14a, and the connection of the connection member 14a and the coil 11a. It is a figure for demonstrating another structural example of the electrode with which the superconducting coil 1 which concerns on the 1st Embodiment of this invention is provided. It is a figure for demonstrating another structural example of the electrode with which the superconducting coil 1 which concerns on the 1st Embodiment of this invention is provided. It is the figure which showed the 1st example of the direction of the connection of an electrode. It is the figure which showed the 2nd example of the direction of the connection of an electrode. It is a figure which shows roughly the structure of the superconducting coil which concerns on the 2nd Embodiment of this invention. It is the figure which showed the structure of the superconducting coil apparatus 101 which concerns on Embodiment 3 of this invention. It is the figure which showed the structure of the superconducting coil apparatus 201 which concerns on Embodiment 3 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a diagram schematically showing a configuration of a superconducting coil according to a first embodiment of the present invention. Referring to FIG. 1, superconducting coil 1 according to the first embodiment of the present invention has a coil portion 10. The coil portion 10 is formed by winding an oxide-based superconducting wire. In this embodiment, the coil unit 10 is a so-called double pancake type coil and includes coils 11a and 11b. The coils 11a and 11b are made of a superconducting wire on the inner peripheral side thereof and are continued.

  Superconducting coil 1 further includes electrodes 12 a and 12 b connected to coil unit 10. The electrode 12a is connected to the coil 11a. The electrode 12b is connected to the coil 11b. The electrodes 12a and 12b serve as one and the other of the input terminal and the output terminal of the superconducting coil 1.

  Each of the electrodes 12a and 12b has the same configuration. Specifically, the electrode 12a includes an extraction electrode 13a and a connection member 14a made of a superconducting wire. The electrode 12b includes an extraction electrode 13b and a connection member 14b made of a superconducting wire.

  The extraction electrodes 13a and 13b are electrodes made of a conductive material (typically a metal, for example, copper). The lead electrodes 13a and 13b are formed with holes 21a and 21b for connecting current leads (not shown) with screws, for example.

  The connection member 14a electrically connects the extraction electrode 13a and the superconducting wire forming the coil portion 10. The connection member 14b electrically connects the extraction electrode 13b and the superconducting wire forming the coil portion 10.

  Superconducting coil 1 further includes a fixed block 15 and heat transfer portions 16a and 16b. The fixed block 15 is formed of an insulating member such as FRP (Fiber Reinforced Plastics). The fixed block 15 is disposed between the extraction electrode 13a and the extraction electrode 13b.

  FIG. 2 is a diagram schematically showing the configuration of the extraction electrode among the electrodes 12a and 12b shown in FIG. With reference to FIG. 2, the extraction electrodes 13 a and 13 b are fixed to the fixed block 15 with the fixed block 15 interposed therebetween. Thereby, the extraction electrodes 13a and 13b are integrated. The Z direction shown in FIG. 2 is a direction in which the extraction electrodes 13a and 13b are overlapped. This direction corresponds to the thickness direction of the extraction electrodes 13a and 13b. The Y direction is a direction orthogonal to the Z direction and is a direction in which the extraction electrodes 13a and 13b extend. The X direction is a direction orthogonal to both the Z direction and the Y direction.

  Since the extraction electrodes 13a and 13b are arranged close to each other, workability when another electric component such as a current lead is connected to the extraction electrodes 13a and 13b can be improved. As a method for fixing the extraction electrodes 13a and 13b to the fixing block 15, a known method such as fixing with screws can be used.

  The extraction electrode 13a has a front end portion 22a, a curved portion 23a, and a rear end portion 24a. The extraction electrode 13b has a front end portion 22b, a curved portion 23b, and a rear end portion 24b. The leading end portion 22 a of the extraction electrode 13 a and the leading end portion 22 b of the extraction electrode 13 b are portions directed toward the coil portion 10.

  Returning to FIG. 1, the heat transfer section 16a contacts the coil 11a. Similarly, the heat transfer part 16b contacts the coil 11b. The heat transfer units 16a and 16b transmit heat to the coils 11a and 11b to cool or raise the temperature of the coils 11a and 11b, respectively. In addition, you may fix the fixing block 15 and the heat-transfer parts 16a and 16b with fixing members, such as a screw.

In the configuration shown in FIG. 1, superconducting coil 1 has both heat transfer portions 16 a and 16 b. However, the superconducting coil 1 may have only one of the heat transfer portions 16a and 16b. Further, when the superconducting coil 1 is directly immersed in a refrigerant such as LN ₂ or LHe, the heat transfer portions 16a and 16b can be omitted.

  FIG. 3 is a plan view for explaining the connection between the coil portion 10 and the electrodes 12a and 12b. Referring to FIG. 3, coil portion 10 (coil 11a is shown in FIG. 3) is formed by winding superconducting wire 31 using an oxide superconductor.

  In the electrode 12a, the extraction electrode 13a and the connection member 14a are mechanically and electrically connected by solder. The connecting member 14a is mechanically and electrically connected to the superconducting wire 31 of the coil 11a by solder.

  The connection member 14a has a first connection part, a second connection part, and an intermediate part. The connecting portion 19a is a portion of the connecting member 14a connected to the superconducting wire 31 of the coil 11a, and corresponds to the first connecting portion. The second connection portion is a portion of the connection member 14a connected to the extraction electrode 13a. A portion of the connection member 14a along the extraction electrode 13a corresponds to a second connection portion. The intermediate portion 20a is a portion between the first connection portion (connection portion 19a) of the connection member 14a and the second connection portion of the connection member 14a. The intermediate portion 20a of the connecting member 14a is not connected to either the coil portion (coil 11a) or the extraction electrode 13a.

  Similarly, in the electrode 12b, the extraction electrode 13b and the connection member 14b are mechanically and electrically connected by solder. The connecting member 14b is mechanically and electrically connected to the superconducting wire 31 of the coil 11a by solder.

  The connection member 14b has a first connection part, a second connection part, and an intermediate part. The connection portion 19b is a portion of the connection member 14b connected to the superconducting wire 31 of the coil 11b (see FIG. 1), and corresponds to a first connection portion. The second connection portion is a portion of the connection member 14b connected to the extraction electrode 13b. A portion of the connection member 14b along the extraction electrode 13b corresponds to a second connection portion. The intermediate portion 20b is a portion between the first connection portion (connection portion 19b) of the connection member 14b and the second connection portion of the connection member 14b. The intermediate portion 20b of the connection member 14b is not connected to either the coil portion (coil 11b) or the extraction electrode 13b.

  In the configuration shown in FIG. 3, a gap is provided between the extraction electrodes 13 a and 13 b and the coil portion 10. However, it is not necessary to be limited in this way. If the electrical insulation between the outer peripheral part of the coil part 10 and the extraction electrodes 13a and 13b can be ensured, the outer peripheral part of the coil part 10 and the extraction electrodes 13a and 13b may be in contact with each other.

  FIG. 4 is a diagram schematically showing a cross section of the superconducting wire 31 and the connecting member 14a included in the coil portion 10. As shown in FIG. Referring to FIG. 4, superconducting wire 31 has a plurality of superconductors 32a extending in the longitudinal direction and a sheath portion 32b covering the entire circumference of the plurality of superconductors 32a. The sheath portion 32b is in contact with the superconductor 32a. The material of the sheath part 32b is, for example, silver or a silver alloy. However, the material of the sheath portion 32b is not limited to silver or a silver alloy. The number of superconductors 32a may be single.

  The connection member 14 a that is a superconducting wire has the same structure as the superconducting wire 31. The connecting member 14a has a plurality of superconductors extending in the longitudinal direction and a sheath portion covering the entire circumference of the plurality of superconductors. The material of the sheath part of the connection member 14a is made of the same material as that of the sheath part of the superconducting wire 31, and specifically, for example, silver or a silver alloy.

  FIG. 5 is a schematic cross-sectional view showing another configuration of the connecting member 14a. 4 and 5, the connecting member 14a includes a plurality of superconductors 32a extending in the longitudinal direction, a sheath portion 32b covering the entire circumference of the plurality of superconductors 32a, and a sheath member 33a covering the sheath portion 32b. Have Examples of the material of the sheath member 33a include stainless steel and copper alloy. Further, the side surface of the sheath portion 32b is covered with solder 33b or the like as necessary.

  The configuration of the connecting member 14b is the same as that of the connecting member 14a, and has the configuration shown in FIG. 4 or FIG. Therefore, detailed description of the configuration of the connecting member 14b will not be repeated hereinafter.

  The characteristics of the configuration according to the present embodiment will be described representatively with respect to the electrode 12a. The extraction electrode 13a is formed of a copper plate. The rigidity of the superconducting wire 31 is smaller than the rigidity of the extraction electrode 13a. That is, the superconducting wire 31 is more susceptible to stress than the extraction electrode 13a. When the extraction electrode 13a is connected to the superconducting wire 31 of the coil portion 10 by soldering, the rigidity of the connecting portion between the superconducting wire 31 and the extraction electrode 13a changes greatly.

  However, in the present embodiment, a connecting member 14a made of a superconducting wire is connected to the superconducting wire 31 of the coil portion 10. Superconducting wire 31 and connecting member 14a have, for example, the configuration shown in FIG. The change in rigidity between the superconducting wire 31 of the coil and the connecting member 14a is small. Thereby, the stress which arises between the superconducting wire 31 and the extraction electrode 13a by the cooling and temperature rising of the superconducting coil 1 can be relieved. Or the stress which arises in the edge part of the coil part 10 can be made small also when the force which acts on the superconducting coil 1 by electromagnetic force acts.

  When a damaged part occurs in the superconducting wire 31, the electrical resistance of the damaged part increases. According to the present embodiment, the possibility that the portion of the superconducting wire 31 connected to the connecting member 14a is damaged can be reduced. Therefore, the possibility that the above problem occurs can be reduced. In particular, when the superconducting wire is composed of an oxide superconductor, the superconducting wire is vulnerable to strain. Therefore, it is preferable to reduce the stress generated at the end of the coil portion 10 as much as possible in order to prevent damage to the superconducting wire 31. Therefore, it is preferable to employ the electrode 12a according to the present embodiment.

  Further, when the lead electrode 13a and the superconducting wire 31 of the superconducting coil are directly connected by solder, it is necessary to apply a large amount of heat to the connecting portion between the electrode and the superconducting wire in order to melt the solder. However, since an excessive heat load is applied to a part of the superconducting wire 31, the possibility that the part will be damaged increases. According to the present embodiment, the electrode 12a can be formed in advance by connecting the connecting member 14a and the extraction electrode 13a with solder. Since the conventional electrode has a large heat capacity, soldering with a soldering iron is difficult unless the entire electrode is heated by a heater or a thermostat. On the other hand, according to this embodiment, if the tip of the connection member 14a, which is a superconducting wire, is warmed, the connection member 14a can be connected to the coil portion 10 with solder. Thereby, it can be made easy to connect an electrode to a coil using a soldering iron.

  Moreover, the superconducting wire 31 of the coil 11a and the superconducting wire that is the connecting member 14a may have the same configuration (see FIG. 4). Therefore, the material of the sheath part included in the superconducting wire 31 of the coil 11a may be the same as the material of the sheath part included in the superconducting wire that is the connection member 14a. In this case, the rigidity of the connecting member 14a and the rigidity of the superconducting wire 31 of the coil 11a are substantially the same. Therefore, the change in rigidity at the connection portion between the electrode 12a and the superconducting wire 31 of the coil portion 10 can be reduced. As described above, for example, the sheath part included in the superconducting wire 31 of the coil 11a and the sheath part included in the superconducting wire that is the connecting member 14a may be made of silver or a silver alloy.

  Alternatively, the rigidity of the connecting member 14a may be higher than the rigidity of the superconducting wire 31 of the coil 11a. However, the rigidity of the connection member 14a is lower than the rigidity of the extraction electrode 13a. Also in this case, by soldering the connecting member 14a to the superconducting wire 31 of the coil 11a, the change in rigidity can be made smaller than when the extraction electrode 13a is soldered directly to the superconducting wire 31 of the coil 11a.

  Furthermore, according to the present embodiment, the connection member 14a includes the first connection portion (connection portion 19a) to which the coil portion 10 is connected, the second connection portion to which the extraction electrode 13a is connected, and the first connection portion 14a. The intermediate part 20a located between a connection part and a 2nd connection part is included. The intermediate portion 20a of the connecting member 14a is not connected to either the coil portion 10 or the extraction electrode 13a. As the superconducting coil 1 is cooled and heated, each member contracts and expands. The intermediate portion 20a of the connecting member 14a functions as a buffer that absorbs stress generated in the second connecting portion when the corresponding member of the extraction electrode 13a contracts and expands. Thereby, it can prevent that the 1st connection part of the connection member 14a receives the influence of the stress which arises in a 2nd connection part.

  Furthermore, according to the present embodiment, the portion of the connection member 14a connected to the extraction electrode 13a (that is, the second connection portion of the connection member 14a) is along the extraction electrode 13a. Thereby, the electrical resistance of the whole electrode 12a can be made small.

  FIG. 6 is a diagram for explaining the current flowing through the electrode 12a. Referring to FIG. 6, current 35 output from superconducting wire 31 of coil 11a flows through connection member 14a. The current flows from the connecting member 14a to the extraction electrode 13a and is output from the rear end 24a of the extraction electrode 13a.

  Since the connecting member 14a is a superconducting wire, the electrical resistance value of the connecting member 14a is significantly smaller than the electrical resistance value of the extraction electrode 13a. When the current is extracted from the coil 11a, the current flows through the portion having a low electrical resistance, that is, the connection member 14a. Since the path of the current 35 in the extraction electrode 13a is shortened, the electrical resistance of the entire electrode 12a can be reduced. Note that the above description holds true even if the direction of the flow of the current 35 is opposite to the direction shown in FIG.

  Thus, the connection member 14a is preferably attached close to the rear end portion 24a of the extraction electrode 13a (that is, the portion to which the current lead is connected). Thereby, the current path in the extraction electrode 13a can be shortened. Therefore, the resistance of the electrode 12a can be reduced.

  Subsequently, the extraction electrode 13a and the connection member 14a will be described in more detail. FIG. 7 is a diagram showing the configuration of the extraction electrode 13a. Referring to FIG. 7, the extraction electrode 13a is formed so as to become thinner from the rear end portion 24a toward the front end portion 22a. The connection member 14a is connected to the extraction electrode 13a along the extraction electrode 13a (see FIG. 3). By making the extraction electrode 13a tapered, the change in rigidity between the extraction electrode 13a and the connection member 14a can be further reduced (relaxed). The tapered portion of the extraction electrode 13a is preferably as long as possible. Thereby, the effect which relieve | moderates the change of rigidity can be enlarged.

  Furthermore, the connection member 14a, which is a superconducting wire, is bent at the curved portion 23a of the extraction electrode 13a. Therefore, it is preferable that the curvature radius of the curved portion 23a is larger than 1/2 of the allowable bending diameter of the connection member 14a. The allowable double bending diameter of the connecting member 14a, that is, the superconducting wire is defined as, for example, the bending diameter when the critical current value of the superconducting wire is reduced to 95% with respect to the value before bending the superconducting wire.

  FIG. 8 is a diagram for explaining the relationship between the thickness of the extraction electrode 13a and the thickness of the connection member 14a. FIG. 8 shows the extraction electrode 13a and the connection member 14a when the electrode 12a is viewed along the Y direction shown in FIG.

  With reference to FIGS. 7 and 8, the thickness of the extraction electrode 13a is T1, and the thickness of the connection member 14a is T2. A relationship of T1 ≧ T2 is established between the thickness T1 of the extraction electrode 13a and the thickness T2 of the connection member 14a.

  If T2 ≧ T1, the connecting member 14a protrudes from the extraction electrode 13a in the Z direction. For this reason, for example, when a lead (not shown) is fixed to the hole 21a of the extraction electrode 13a with a screw, it may be difficult to screw. As shown in FIG. 8, by making the thickness T2 of the connection member 14a equal to or less than the thickness T1 of the extraction electrode 13a, various operations relating to the extraction electrode 13a (for example, fixing of leads as described above) can be facilitated. it can.

  FIG. 9 is a diagram showing an example of the shape of the tip of the connection member 14a viewed from the X direction shown in FIG. The X direction, Y direction, and Z direction shown in FIG. 9 are the same as the X direction, Y direction, and Z direction shown in FIGS. 7 and 8, respectively. As shown in FIGS. 9A to 9E, the distal end portion of the connection member 14a may have a tapered shape. For example, the shape shown in each of Drawing 9 (a)-(e) can be obtained by cutting the tip part of connecting member 14a. A change in rigidity in a state where the coil 11a and the connection member 14a are connected can be mitigated by the distal end portion (tapered portion) of the connection member 14a. It is preferable that the length L of the tapered portion is large. The effect of relaxing the change in rigidity can be further exhibited.

  Various shapes can be adopted as the tapered specific shape. For example, as shown in FIGS. 9A and 9B, the shape may have a linear inclination. Alternatively, as shown in FIG. 9C, the shape may be rounded. Alternatively, as shown in FIG. 9 (d), a shape in which a central portion in the thickness direction is removed may be used. Alternatively, as shown in FIG. 9 (e), a shape in which a corner portion is cut may be used.

  FIG. 10 is a diagram for explaining the connection between the extraction electrode 13a and the connection member 14a and the connection between the connection member 14a and the coil 11a. Referring to FIG. 10, it is preferable that connection member 14a is not connected to extraction electrode 13a and coil 11a in the vicinity of distal end portion 22a of extraction electrode 13a. Specifically, a portion of the connecting member 14a having a length L1 extending from the leading end of the extraction electrode 13a toward the extraction electrode 13a is not soldered to the extraction electrode 13a. Further, a portion of the connecting member 14a having a length L2 extending from the leading end of the extraction electrode 13a to the leading end side of the connecting member 14a is not soldered to the coil 11a.

  When the connection member 14a is soldered to the tip of the extraction electrode 13a, the difference in rigidity between the connection member 14a and the extraction electrode 13a becomes large. Therefore, there is a possibility that the connection member 14a is damaged (for example, the connection member 14a is broken) due to cooling and temperature rise of the superconducting coil 1. As shown in FIG. 10, since the connecting member 14a is not soldered to the tip of the extraction electrode 13a, the change in rigidity can be alleviated. Therefore, the above problem can be prevented from occurring.

  FIG. 11 is a diagram for explaining another configuration example of the electrodes provided in the superconducting coil 1 according to the first embodiment of the present invention. Referring to FIG. 11, electrode 42a is different from electrode 12a (see FIG. 3) in that connection member 14c is added. The connection member 14c is a superconducting wire similarly to the connection member 14a. The connecting member 14c has a configuration shown in FIG. 4 or FIG. 5, for example. When the current capacity or the rigidity is insufficient with only the connecting member 14a, an additional connecting member can be provided in this way. Note that the number of additional connecting members (superconducting wires) is not particularly limited.

  Furthermore, when there are a plurality of connection members, it is preferable to shift the positions of their tips. Thereby, a change in rigidity can be reduced in a state where the connecting member is soldered to the coil 11a. In FIG. 11, the tip of the connection member 14c is located farther from the extraction electrode 13a than the tip of the connection member 14a. According to this configuration, the redundancy of the connecting member can be expected. That is, even when a part of the connection member 14a or the connection member 14c is damaged, a current flows through the connection member 14c or the connection member 14a.

  FIG. 12 is a diagram for explaining still another configuration example of the electrodes provided in the superconducting coil 1 according to the first embodiment of the present invention. In the configuration shown in FIG. 11, the tip of the connection member 14a is located farther from the extraction electrode 13a than the tip of the connection member 14c. According to this configuration, the connection member 14a is connected to the coil 11a. Therefore, the operation | work at the time of soldering the electrode 12a to the coil 11a becomes easy.

  Furthermore, when an electric current flows through the coil portion 10, an electromagnetic force (Lorentz force) that follows Fleming's left-hand rule is generated in the coil portion 10. The connecting member connected to the coil unit 10 receives this electromagnetic force (Lorentz force). The direction of the electrode is preferably determined in consideration of the direction in which the electromagnetic force acts.

  FIG. 13 is a diagram showing a first example of the direction of electrode connection. FIG. 14 is a diagram showing a second example of the direction of electrode connection. Referring to FIGS. 13 and 14, the direction of the current flowing through coil 11a is the same. When the electrode 42a is attached as shown in FIG. 13, an electromagnetic force F toward the center of the coil 11a is generated on the connection members 14a and 14c. Therefore, it is possible to ensure a state in which the connection member 14a is connected to the coil 11a. On the other hand, when the electrode 42a is attached as shown in FIG. 14, an electromagnetic force F directed outward from the center of the coil 11a is generated on the connection members 14a and 14c. That is, the electromagnetic force F acts in the direction in which the connecting member 14a is peeled off from the coil 11a. Therefore, as shown in FIG. 13, it is preferable to determine the direction of the electrode 42a so that the electromagnetic force F toward the center of the coil 11a is generated with respect to the connection members 14a and 14c.

  Note that FIGS. 13 and 14 show the case where a current flows into the electrode 42a. Similarly, when current is output from the electrode 42a, it is preferable to determine the orientation of the electrode 42a so that the electromagnetic force F toward the center of the coil 11a is generated with respect to the connection members 14a and 14c. 13 and 14 show the case where the number of connecting members is plural, the number of connecting members may be singular.

[Embodiment 2]
FIG. 15 is a diagram schematically showing a configuration of a superconducting coil according to the second embodiment of the present invention. Referring to FIG. 15, superconducting coil 1 a according to the second embodiment of the present invention is a superconducting coil 1 according to the second embodiment of the present invention in that electrodes 12 a and 12 b are located at a distance. And different. In this configuration, the fixed block 15 is omitted.

  The configuration of the electrodes 12a and 12b is the same as that of the first embodiment, and has the extraction electrodes (13a and 13b) and the connection members (14a and 14b) made of superconducting wires. The extraction electrode and the coil portion are connected by a connection member. According to the second embodiment, as in the first embodiment, it is possible to reduce the change in rigidity at the connection portion between the electrode and the superconducting wire of the coil. Therefore, it is possible to reduce the possibility of damage to the superconducting wire at the time of attaching the electrode to the superconducting coil, or damage to the superconducting wire of the superconducting coil due to the thermal cycle of the superconducting coil.

[Embodiment 3]
In the third embodiment, a superconducting coil device including the superconducting coil according to the first or second embodiment is disclosed.

  FIG. 16 is a diagram showing a configuration of superconducting coil device 101 according to Embodiment 3 of the present invention. Referring to FIG. 16, superconducting coil device 101 has superconducting coil 1 and bobbin 102 for attaching superconducting coil 1. Superconducting coil 1 has a coil portion 10 and electrodes 12a and 12b. The coil unit 10 includes coils 11a to 11h. The axis Ax corresponds to the stacking direction of the coils 11a to 11h.

  The bobbin 102 includes a trunk portion 103 disposed inside the stacked coils 11 a to 11 h, a flange 104 a provided at the upper end of the trunk portion 103, and a flange 104 b provided at the lower end of the trunk portion 103. A cylindrical space (bore) 105 is formed in the body portion 103. As a direct current flows through the superconducting coil device 101, a static magnetic field is generated in the bore 105. When an alternating current flows through the superconducting coil device 101, a dynamic magnetic field is generated in the bore 105.

  The coils 11a to 11h are pancake type coils. An electrode 12a is connected to the uppermost coil 11a. On the other hand, the electrode 12b is connected to the lowermost coil 11h. The electrodes 12a and 12b are drawn from the same side of the coil unit 10 (left side of the paper surface in FIG. 16). The detailed configuration of superconducting coil 1 may be the same as the configuration of the superconducting coil according to Embodiment 1, or the same as the configuration of the superconducting coil according to Embodiment 2.

  FIG. 17 is a diagram showing a configuration of superconducting coil device 201 according to Embodiment 3 of the present invention. Referring to FIG. 17, superconducting coil device 201 is applied as a superconducting magnet. The superconducting coil device 201 includes a superconducting coil device 101, current leads 111 and 113, a high-temperature superconducting lead 112, a cryostat 120, a heat shield 121, a refrigerator 130, and a heater 133. The refrigerator 130 includes a first stage 131 and a second stage 132. When a current flows through the superconducting coil device 101, a static magnetic field is generated in the room temperature bore 141.

  Superconducting coil device 101 has a configuration similar to that shown in FIG. Therefore, detailed description of the configuration of superconducting coil device 101 will not be repeated. In addition, the heat-transfer part 16b is connected to each of the coils 11a-11h. The heat transfer section 16b connected to each coil is integrated at one place and is adjusted to a predetermined temperature by the second stage 132 and the heater 133, for example.

  The current lead 111 is connected to the electrodes 12 a and 12 b of the superconducting coil device 101 and to the high temperature superconducting lead 112. The current lead 113 is connected to an external power source (not shown). In order to suppress heat intrusion from the current lead 113 as much as possible, the high-temperature superconducting lead 112 having good heat insulation and generating no Joule heat is connected to the current lead 113.

  Superconducting coil 1 and heat shield 121 are housed inside cryostat 120. The heat shield 121 is cooled by the first stage 131 of the refrigerator 130. The superconducting coil device 101 is covered with a cooled heat shield 121. The inside of the cryostat 120 is evacuated.

  The heat transfer section 16b (cooling plate) to the second stage 132 are connected by a cooling path having a sufficient cross-sectional area so as to reduce the thermal resistance. (The cooling path is made of, for example, copper or aluminum.) The current leads 111 and 113 are adjusted to a predetermined temperature by the heater 133 and the second stage 132.

  As described above, according to the third embodiment, the superconducting coil according to the first or second embodiment is provided. Therefore, according to the third embodiment, it is possible to prevent the coil portion from being damaged at the connection portion between the coil portion and the electrode formed from the superconducting wire.

  In each of the embodiments described above, the electrodes 12a and 12b realize the “first electrode member” and the “second electrode member” included in the superconducting coil of the present invention. However, for example, the electrode 12a does not need to be limited to correspond to the “first electrode member” and the electrode 12b corresponds to the “second electrode member”. For example, the electrode 12a may correspond to the “second electrode member”, and the electrode 12b may correspond to the “first electrode member”.

  In each of the above embodiments, a superconducting coil having two electrodes (12a, 12b) is shown. However, any configuration including a coil portion formed by winding a superconducting wire and one electrode member connected to the coil portion is included in the scope of the present invention. Therefore, it is not necessary to limit the two electrodes to be essential.

  The embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1, 1a Superconducting coil, 10 coil part, 11a-11h coil, 12a, 12b, 42a electrode, 13a, 13b Extraction electrode, 14a-14c connection member, 15 fixing block, 16a, 16b heat transfer part, 19a, 19b connection part 20a, 20b Intermediate part, 21a, 21b hole, 22a, 22b tip part, 23a, 23b curved part, 24a, 24b rear end part, 31 superconducting wire, 32a superconductor, 32b sheath part, 33a sheath member, 33b solder, 35 current, 101, 201 superconducting coil device, 102 bobbin, 103 body, 104a, 104b flange, 105 bore, 111, 113 current lead, 112 high temperature superconducting lead, 120 cryostat, 121 heat shield, 130 refrigerator, 131 first Stage, 132 2nd Stage, 133 heater, Ax axis, F Electromagnetic force.

Claims (9)

A coil portion formed by winding a superconducting wire, and
A first electrode member connected to the coil portion,
The first electrode member is:
A first extraction electrode made of a conductive material;
A superconducting coil comprising a superconducting wire and including a first connecting member for connecting the superconducting wire of the coil portion and the first lead electrode. The rigidity of the first extraction electrode is higher than the rigidity of the superconducting wire forming the coil portion,
The superconducting coil according to claim 1, wherein the rigidity of the first connection member is lower than that of the first extraction electrode. The superconducting wire forming the coil portion is:
A first superconductor;
A conductive first sheath covering the first superconductor;
The first connecting member is
A second superconductor;
The superconducting coil according to claim 1, further comprising: a conductive second sheath that includes the same material as the first sheath and covers the second superconductor. The first connecting member is
A first connecting portion to which the coil portion is connected;
A second connection to which the first extraction electrode is connected;
The intermediate part which is located between the said 1st connection part and the said 2nd connection part, and is not connected to any of the said coil part and the said 1st extraction electrode of Claim 1 to 3 The superconducting coil according to any one of the above. The superconducting coil is
A second electrode member connected to the coil portion;
The second electrode member is
A second extraction electrode made of a conductive material;
The superconducting coil according to any one of claims 1 to 4, comprising a second connecting member made of a superconducting wire and connecting the coil section and the second lead electrode. The superconducting coil is
An insulating member that insulates the first electrode member from the second electrode member;
The superconducting coil according to claim 5, wherein the first extraction electrode and the second extraction electrode are integrated with the insulating member interposed therebetween.   The superconducting coil according to claim 2, wherein the rigidity of the first connecting member is at least the same as the rigidity of the superconducting wire forming the coil portion.   The superconducting coil according to any one of claims 1 to 7, wherein the superconducting wire is composed of an oxide superconductor. A superconducting coil device comprising the superconducting coil according to claim 1.

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