JPS6229081A - Connection for force-cooled type superconductor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a connection portion of a superconducting conductor used in a superconducting coil or the like.

"Prior Art" In recent years, a method has been developed that consists of a hollow jacket with a refrigerant flow path inside and a superconducting wire inserted into the refrigerant path, and a refrigerant such as supercritical helium is forced to circulate through the flow path. A superconducting conductor configured to cool a superconducting wire by cooling the superconducting wire is known.

By the way, when a superconducting coil is constructed using this type of superconducting conductor, the superconducting conductors may be connected to each other. Conventionally, as a connection structure for this type of superconducting conductor, superconducting wires extending from each end of a pair of superconducting conductors to be connected are overlapped and joined by soldering. The ends of the superconducting conductor on both sides are covered by a cylindrical joint cover that spans them, and both ends of the joint cover are attached to the outer cover.
I+++Shinyo beech? This joint cover also has the role of connecting the refrigerant flow paths of the joined pair of superconducting conductors and guiding the refrigerant to the connection part of the superconducting wire inside the joint cover. Fulfilling.

"Problems to be Solved by the Invention" Among the superconducting conductors described by Moe, particularly when joining superconducting conductors equipped with compound-based superconducting wires, the superconducting compound itself is extremely brittle and has poor workability. Conventionally,
A flat surface on which diffusion heat treatment is performed to generate a superconducting compound, and the superconducting conductor is processed to have a radius of curvature convenient for coil processing in a state of good workability, and then diffusion heat treatment is performed. Furthermore, the soldering work was carried out on the joint parts, and the soldering parts were covered with a cylindrical joint cover.

However, when forming the above-mentioned joining structure, when stacking the superconducting wires extending from each end of a pair of superconducting conductors to be joined, the superconducting wires are curved or solder is impregnated between the superconducting wires. If the thickness of the overlapping superconducting wires is made too large, the curvature will change, and the thicker superconducting wires will get in the way of the joint cover that covers the outside of the superconducting wires, causing joint cuts. If the inside of the joint cover is blocked by the superconducting wire, the refrigerant will not be able to pass through the inside of the joint cover, and there is a risk that the superconducting wire at the joint will not be sufficiently cooled. there were.

Note that even if the soldering work of superconducting wires is performed smoothly, the joint cover brazing that will be performed later may sometimes be difficult.
The heat associated with brazing loosens the soldered parts of the superconducting wire inside the joint cover, and in some cases, the solder melts and blocks the space inside the joint cover, closing the coolant flow path and preventing the soldering of the superconducting wire. There was a risk that the cooling of the parts would be insufficient.

``Object of the Invention'' The present invention was made in view of the above-mentioned circumstances, and it is possible to connect superconducting wires while securing a refrigerant flow path, and to connect the superconducting wires when brazing a joint cover to the superconducting wires. It is an object of the present invention to provide a connection part in which a joint part does not loosen or melt and a refrigerant flow path is not blocked.

"Means for Solving the Problems" In order to solve the above problems, the present invention provides a channel-shaped block body having a communication hole and a groove, and a lid body having a communication hole and closing the opening of the groove. It is composed of.

"Function" Connects the communication hole in the block body and the communication hole in the lid body or the refrigerant flow path of the superconducting conductor, allows the cooling medium to flow, and the groove accommodates the superconducting wires that are overlapped and joined, allowing the joint cover to be attached. It also functions as a stabilizing material for the joints of superconducting wires.

Embodiment FIGS. 1 to 3 show an embodiment of the present invention, in which a connecting portion J is composed of a block body 1 and a lid body 2. As shown in FIG.

Here, before explaining the connection part J, the connection part will be explained.

In this embodiment, the superconducting conductor connected by the connecting portion J has a structure as shown in detail in FIG. 4. This superconducting conductor includes a pair of superconducting wire aggregates 4 formed by twisting a plurality of superconducting wires 3,
A coolant flow path P is formed between the stabilizing base material 5, which is hollow and has a rectangular cross section and houses the superconducting wire assembly 4°4, and the stabilizing base material 5. It is mainly composed of a housed outer cover 6 having a rectangular cross section. Note that the superconducting wire 3 is made of Nb3Sn, V3Ga, Nb3G
The stabilizing base material 5 is made of a highly conductive material such as copper, copper alloy, high purity aluminum, or aluminum alloy. 6 is copper, copper alloy, stainless steel,
It is made of metal materials such as titanium and titanium alloys. Further, in the superconducting conductor, the stabilizing base material 5 is formed by fitting a channel material 7.8 having a U-shaped cross section,
Each channel full 0/N M demand) -? Kenfue, -
()4ν1■ri When the Q ratio is small, the protrusion 9 is formed so as to protrude outward from the stabilizing base material 5, and both channel materials 7.8
A plurality of slits 10 are formed in each side plate to facilitate the bending, and through holes 12 are formed at appropriate positions in the ceiling plate and bottom plate of the channel material 7.8. The stabilizing base material 5 is inserted into the outer sheath 6 with the protrusions 9 in contact with the inner surface of the outer sheath 6. The superconducting conductor is curved with a predetermined radius of curvature for convenience when forming a superconducting coil.

On the other hand, the connecting portion J consists of a block body 11 and a band-shaped lid 2 having the same radius of curvature as that of the superconducting conductor. As shown in FIG. 1, the block main body 1 includes a bottom wall 17 and side walls 18 and 18 standing on both sides of the bottom wall 17 at right angles to the bottom wall 17.
and a partition wall I9 that faces parallel to the bottom wall 17 and is integrated with the inner surface of the bottom side of the side wall 18.18, and is surrounded by and communicates with the bottom wall 17, the side wall 18.18, and the partition wall I9. In addition to forming the hole 20, a groove 21 is formed by dividing the side wall 1'8.18, the partition, and the wall 19, and the block body 1 has the outer surface of one of the side walls 18 concavely curved with the radius of curvature. It is curved. The depth and width of the groove section 21 are set to a size that allows superconducting wire assemblies 4.4 taken out from a pair of superconducting conductors to be connected by the connecting section J to be stacked and stored therein. Further, the lid body 2 has a hollow elongated band shape with a communication hole 22 formed therein, and its width is along the length direction of the block body l at the opening of the storage groove 21 of the block body l. It is set to a value that can close the opening 23. Then, the lid body 2
A plurality of through holes 24 are formed at a predetermined interval along the length direction of the lid body 2 on the bottom surface of the block body 1, and a plurality of through holes 25 are also formed at a predetermined interval in the partition wall 19 of the block body l. Note that these through holes 24 and 25 may be omitted.

The connecting portion J is constructed by closing the opening 23 of the block body I on one side of the lid 2 and integrating the block body I and the lid 2. In this state, the external dimensions of the connecting portion J are as follows. It is formed to have the same external dimensions as the cover 6. Further, the block body 1 and the lid body 2 are made of RR such as oxygen-free copper.
n (Residual Resistance Rat
It is preferable to use a steel material with a high io).

Next, the operation of connecting the superconducting conductors D using the connecting portion J configured as described above will be explained.

The superconducting conductor used here has already undergone coil processing and final heat treatment, and its ends are curved and terminal-treated at a predetermined radius of curvature.

This terminal treatment means that after coil processing and before final heat treatment, first, at the ends of a pair of superconducting conductors to be connected, the outer sheath 6 and the stabilizing base material 5 are made to a predetermined length longer than the length of the connecting part J. The outer sheath 6 is
This means that the superconducting wire assembly 4 is extended by a predetermined length from the end of the stabilizing base material 5 and is curved with a predetermined radius of curvature as shown in FIG. In order to connect the end of the superconducting conductor in this state to the end of another superconducting conductor, the superconducting wire assemblies 4 are stacked alternately in multiple layers (four layers in this example). This stacked superconducting wire assembly °4.
4 into the groove 21 of the block body l and soldered. This block body l has each superconducting conductor on both end faces in the length direction of the block body l.

It may be brought into contact with the end face of the outer cover 6 of D, or it may be made not to come into contact with it. Next, the groove portion 21 of the block body l
The opening surface of the block body 1 is closed with a lid body 2, and the lid body 2 is brazed to the block body 1. In this state, the lid 2 presses the superconducting wire assembly 4.4 in the groove 21.
Soldering step 4 secures the part and protects it.

After this, a superconducting conductor is attached to this part as shown in FIG.

Attach a rectangular cylindrical joint cover 30 to surround each end of D and the connection part J, attach the joint cover 30 to each superconducting conductor, and solder the end of D with silver solder, TAG.
The connection is completed by joining by welding such as welding or MrG welding, or soldering. During this brazing, the heat accompanying brazing is sometimes transmitted to the superconducting wire assembly 4.4, but since the superconducting wire assembly 4.4 is separated from the joint (joint) and cover 30 by the connection part J, the superconducting wire assembly 4.4 The soldering of assembly 4.4 prevents parts from loosening or melting. In addition, 1. Even if the soldered part of the superconducting wire assembly 4゜4 melts, the soldered part may become loose because it is fixed in the groove 21 of the connection part J. do not have. Note that when fitting the joint cover 30, since the external dimensions of the connecting portion J and the superconducting conductor are the same, the joint cover 30
It is also easy to fit.

In the superconducting conductor D connected as described above,
Since the communication hole 20.22 of the connection part J communicates with the refrigerant flow path P, the refrigerant can flow through this communication hole 20.22. Accordingly, the joint portion of the superconducting wire assembly 4.4 can be cooled. Note that in the past, the flow path in the joint cover was sometimes narrowed by soldering, but the communication hole 2
Since 0°22 is not narrowed by soldering the superconducting wire assemblies 4, 4, the flow 11 of the refrigerant is not obstructed. In addition, when the block body 1 and the lid body 2 have through holes 25 and 24, respectively, the refrigerant flowing through the communication holes 20 and 22 flows into the groove 21 through these holes, and directly causes superconducting. Cool the wire assembly 4.4.

Furthermore, the connecting portion J plays the role of a stabilizing base material in the joint portion of the superconducting wire assembly 4, and also has the effect of stabilizing the superconducting state of the joint portion.

In addition, in the embodiment, the bottom wall 1 of the block body l
Only one communication hole 20 was formed on the 7 side, but the block
Communication holes may also be formed on the side walls 18 and 18 of the body 1, so that in addition to the communication holes 20, the flow paths P of the superconducting conductor are communicated through the communication holes on the side wall 18 side. Furthermore, it goes without saying that the connecting portion J can also be applied to superconducting conductors having other configurations having a coolant flow path inside the jacket.

"Manufacturing Example" It has the same structure as the superconducting conductor shown in Fig. 4, the outer dimensions of the outer jacket are 23 x 13 mm, and the wire diameter of the superconducting wire is 1.
, 4 mmq The outer diameter of the stranded superconducting wire assembly 4 is 12 x 2.8 mm, and: A forced cooling type superconducting wire having two layers of superconducting wire assembly consisting of 15 superconducting wires is prepared, and these were joined using the connection section described below. This connection has a height of 23 mm and a width of 13 m.
The length of In5 is 100 mm, the depth of the groove in the block body is 12 mm, and the width of the groove is 11.8 mm.
The R(RttsK/R4,2K) value is.

200. The ends of the forcibly cooled superconducting conductor are bent by extending the superconducting wire assembly from the jacket and stabilizing base material to a predetermined length (slightly shorter than the length of the connection part), and after heat treatment, the superconducting wire assembly is The bodies were stacked to form a four-layer structure, and this part was inserted into the groove of the connection part and joined to the block main body by soldering. After that, the groove of the block body is closed with a lid body, and after the lid body is soldered to the block body, the inner diameter 2 which has been inserted into the superconducting conductor in advance
A joint cover in the shape of a square pipe of 4XI4 mm was slid to cover the connection portion and the ends of the superconducting conductor on both sides thereof, and the joint cover was brazed to the superconducting conductor.

The superconducting conductor bonded as described above is exposed to an external magnetic field of 8T.
When an OKA current was applied, no special heat generation phenomenon was observed at the junction, and a good superconducting state could be maintained.

"Effects of the Invention" As explained above, the connecting part of the present invention is composed of a channel-shaped block body having a communication hole and a groove, and a lid body having a communication hole and closing the opening of the groove. Insert the superconducting wire into the groove between the ends of the superconducting wires to be connected, close the groove with a lid, fix the lid to the block body by brazing or other fixing means, and connect it to the block body. The superconducting conductors can be connected by covering the lid and the ends of the superconducting conductors on both sides with a joint cover. At this time, since the communication holes in the block body and the communication holes in the lid body communicate with each other through the coolant flow path of the superconducting conductor, the coolant flowing through the superconducting conductor aligns the communication holes around the connection part of the superconducting wire. Since the joint portion is cooled, the superconducting conductors can be connected without causing problems in cooling the joint portion. Note that since the joint portion of the superconducting wire is housed in the groove, the joint portion does not come out of the connection portion, which has the effect of making it easier to attach the joint cover.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a cross-sectional perspective view showing a state of use, FIG. 2 is a longitudinal cross-sectional view showing a state of use, and FIG. 3 is a superconducting wire. FIG. 4 is a perspective view of a main part of the superconducting wire. J... Connection, D... Superconducting conductor!・
...Block body, 2 ... Lid body, 3
...Superconducting wire, 4...Superconducting wire assembly, 5...Stabilizing base material, 6...
...Outer covering, P...Flow path, 20.22...Communication hole, 23...Opening, Fig. 1, Fig. 2

Claims (1)

[Claims] A pair of superconducting conductors that are used to connect forced-cooled superconducting conductors, each of which includes an outer sheath in which a refrigerant flow path is formed, and a superconducting wire inserted into the flow path. A joint cover is interposed between the ends of the superconducting conductors, and a joint cover is applied outwardly over the ends of the superconducting conductors, the joint cover extending from each end of the pair of superconducting conductors and being overlapped. It consists of a channel-shaped block body having a groove for storing the bonded superconducting wires, and a long lid that closes the opening of the groove. 1. A forced cooling type superconducting conductor connection section, characterized in that a communication hole that opens is formed in the lid, and communication holes that open at both longitudinal end faces of the lid are formed respectively.