JPS5936807B2 - Superconducting coil connection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plurality of superconducting coils or a device for connecting a superconducting coil and a current lead thereto.

The structure of the coil connecting portion in a conventional device of this type is shown in FIG.

In the figure, 1 is a superconducting wire, 1a and Ib are drawn out from different coils for connection between the coils, are overlapped at the coil connection part 2, and after binding the outer periphery with copper wire 3, the outer periphery is further soldered. It is marked 4.
Note that the connection portion between the coil and the current lead also has a similar configuration.

In the connection part 2, in order to make good contact between the superconducting wires 1a and Ib and to stably pass a large current, they are bound together with a copper wire 3, and furthermore, the fern 4 is sufficiently melted into the superconducting wires 1a and Ib.

However, the conventional configuration shown above requires a space around the coil connection portion 2 for the work of tying the copper wire 3 together.

Since the lead-out portions 1a and Ib of each superconducting coil must ultimately be fixed due to the strong electromagnetic force and vibration, they are attached to the appropriate holding means (usually a coil frame) after the connection work is completed. I needed to bring it. At this time, there was a risk that stress such as bending would be applied to the superconducting wire 1. It is well known that applying force, such as bending, to a superconducting wire leads to deterioration of its superconducting properties (reduction in current capacity that allows stable current flow). In particular, in superconducting coil devices that use Nb3Sn superconducting wire as the superconducting wire, the allowable strain after heat treatment is 1% or less, and currently it is impossible to locally move the superconducting wire after heat treatment, and between the coils. It is difficult to make connections using conventional methods. Furthermore, in the conventional method, since the work of melting the solder 4 is carried out in space, it is not possible to apply enough solder to the superconducting wires 1a and Ib.
Another disadvantage is that there is insufficient contact with the This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it provides a groove in the holding means (winding frame, etc.) of the connecting part, and a conductor made of a copper plate placed in the groove. After arranging two superconducting wires or a superconducting wire and a current lead, we will melt the solder and connect the coils, thereby providing a method that can simultaneously fix the coil connection portion without tying the connection portion. That is.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, 5 is a connection groove provided in the coil winding frame 9, and 6 is formed by a U-shaped copper plate for connection that is placed in advance in this groove 5 via an insulator 7. It is a conductor. 8 melts into the conductor 6 after placing the superconducting wires 1a and 1b in it.

Reference numeral 11 denotes a holding plate for fixing the above-mentioned connection portion to the winding frame 9, and is fastened to the winding frame 9 with screws 12 with an insulator 10 interposed between it and the connection portion.

In the above structure, the superconducting coil connection part is formed by placing the two superconducting wires 1a and 1b in the connection part along the inside of the conductor 6 which has been arranged in advance, and then adding the first conductor 8. Ru. According to this configuration, by appropriately designing the groove 5, the insulator 7, and the conductor 6,
By simply placing the superconducting wires along them, a reasonably good contact can be expected, and furthermore, the solder 8 can be sufficiently melted to make the contact complete. The feature of the present invention is that the superconducting wire 1
It is not necessary to move a and 1b at all after connecting them, and there is no risk of damaging the superconducting properties of the connection part.1.The conductor 8 corresponds to the preset shape of the conductor 6 and ensures that a sufficient amount can be removed. This makes it possible to make sufficient electrical contact at the connection part, and by using the conductor 6 made of copper, the so-called copper ratio can be set to the required value, which is effective in stabilizing the superconducting coil. One example is to demonstrate.

In the example shown in FIG. 2, the holding plate 11 prevents the connection portion from popping out after the connection is completed, but this is effective in, for example, a superconducting coil device installed in a superconducting rotating machine. Note that when the superconducting wire 1 requires heat treatment after winding, such as Nb3Sn wire, the insulator 7 is made of a material that can withstand high temperatures, such as a glass table, since the heat treatment is performed at the stage where the wires 1a and 1b are placed along the relevant parts. Materials such as are preferred.

Incidentally, in the above embodiment, a rectangular wire was used as the superconducting wire 1, but a round wire may be used as shown in FIG. 3, and the same effect as in the above example can be obtained.

In addition, although the holding means for the connecting portion is set to the winding frame 9 in the above embodiment, depending on the coil device, it is possible that the same effect can be obtained by using other structures instead of the winding frame. It's obvious. As described above, in this invention, a groove for accommodating the connection part is formed in a holding means such as a winding frame, a conductor made of copper is placed in the groove, and a superconducting wire is placed in the groove. Since the superconducting wires can be connected and fixed at the same time, the superconducting wires do not need to be moved at all after connection, and the conductor can be fully immersed. Copper has characteristics such as the ability to set the so-called copper ratio appropriately, and stabilizes the superconducting coil connection device. In addition, in the Nb3Sn superconducting coil device, the superconducting wire is put into the connection part, heat treated, and then soldered, so the superconducting wire does not need to be moved at all after the heat treatment, which is extremely advantageous due to the characteristics of the Nb3Sn superconducting wire. It is.

[Brief explanation of drawings]

FIG. 1 shows a conventional superconducting coil connection device, with FIG. 1A being a perspective view and FIG. 1B being a sectional view. FIG. 2 is a sectional view showing one embodiment of the invention, and FIG. 3 is a sectional view showing another embodiment of the invention. Note that the same reference numerals in the figures indicate the same or equivalent parts. DESCRIPTION OF SYMBOLS 1... Superconducting wire, 2... Coil connection part, 4... Solder, 5... Groove, 6... Conductor, 7... Insulator, 8
...1.nda, 9.. winding frame, 10.. insulator.

Claims (1)

[Claims] 1. In a device having a connecting portion between two superconducting coils or a connecting portion between a superconducting coil and a current lead, a holding means for the connecting portion provided with a groove for accommodating the connecting portion, and the groove A superconducting coil comprising a conductor made of copper provided along the inside and interposed between the groove and the connection part, and a solder interposed between the conductor and the connection part. Connection device. 2. The superconducting coil connecting device according to claim 1, wherein the holding means comprises a winding frame for holding the superconducting coil. 3. The superconducting coil connection device according to claim 1 or 2, wherein the conductor is formed in a U shape. 4. The superconducting coil connection device according to any one of claims 1 to 3, wherein the superconducting coil is made of Nb_3Sn superconducting wire.