JPS6231805B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a superconducting electromagnet structure used in a superconducting magnetically levitated vehicle or the like.

For superconducting electromagnets, superconducting wires made of special alloys such as Nb and Ti and drawn into multi-core wires are generally used so that the electrical resistance becomes zero when cooled to an extremely low temperature. However, very careful attention is required to maintain the superconducting state of this superconducting wire. In other words, if the superconducting wire is not sufficiently cooled at extremely low temperatures, if it is exposed to a magnetic field higher than expected, or if the superconducting wire is held unstable and moves or vibrates, the superconducting state will be destroyed and it will return to the normal conducting state. The resulting resistance will be combined with the large current that has been flowing until now in a superconducting state, and unless this current is successfully led outside and consumed, the electromagnet will be damaged in an instant due to the heat generated at the bend. There is a danger of doing so. In particular, in the case of superconducting electromagnets used in superconducting magnetic levitation vehicles, the superconducting wire is excited by the strong magnetic field and the vehicle running, and the superconducting wire is bent or moved due to the interaction of the magnetic field and the strong current flowing through the superconducting wire. Therefore, there is a risk that the superconducting state cannot be maintained. However, when superconducting wire is formed into a coil, it is easy to fix it with a winding frame or coil mold, but the connection wire from the coil to the external power lead and the persistent current switch that opens and closes the closed loop circuit of the coil are difficult to fix. The connecting wires are difficult to secure and are very prone to problems.

An object of the present invention is to provide a superconducting electromagnet structure in which the superconducting state is prevented from being destroyed by stably holding the connecting wire portion drawn out from the coil of the superconducting wire.

An embodiment of the present invention will be described below with reference to the drawings. First, Figure 1 shows the schematic configuration of a superconducting electromagnet. In the figure, 1 is an inner tank built into an outer tank (not shown) whose interior is evacuated, and a superconducting coil (described later) is firmly fixed inside. It is constructed as a hollow truck-shaped container made of stainless steel. A liquid helium tank 2 is placed above the inner tank 1 and connected to the inner tank 1 by a connecting pipe 3. The inner tank 1 is also provided with a power lead lead-out part 4, through which a power lead 5 is led out from the inner tank 1, and its outer end protrudes outside the vacuum outer tank and is connected to an external power source. The inner tank 1 and power lead 5 are incorporated into the vacuum outer tank via various heat insulating materials and load supporting materials (not shown), and are thermally supported in a vacuum to maintain the extremely low temperature inside. I'm getting better at it. In this state, from the outer end of the power lead 5 to the inner tank 1
The necessary current is passed through the superconducting coil placed inside the
When a persistent current switch (not shown in this diagram) is closed, a persistent current flows in the superconducting coil, and even if the current from the power lead 5 is removed, the persistent current continues to flow in the superconducting coil, forming an extremely powerful magnet. It's becoming like that.

Here, the internal structure of the inner tank 1 near the power lead lead-out part 4 will be described in detail with reference to FIG.
It is firmly fixed and held. power lead 5
is composed of a conductor 5A made of copper and a pipe 5B serving as a gas passage for cooling with gas helium. Here, the power lead lead-out part 4 consists of a box body 4B that communicates internally with the inner tank 1 and a power lead penetration part 4A, and the inside thereof is always filled with liquid helium and kept at an extremely low temperature.

The pipe 5B end of the power lead 5 is welded and fixed to the outer peripheral end of the power lead penetration part 4A,
A pipe 16 is tightly fitted into the center hole by welding, and a connecting fitting part 14 is attached to this via an electrical insulator 15 such as ceramic, and the power lead conductor 5A passes through the center of the pipe 16. It penetrates through the insulator 15 and is electrically insulated from the inner tank 1 and maintained in electrical connection with the connecting fitting part 14 . Here, 11A is a connecting member formed in the shape of a groove from a copper material, etc., and has a member connected to the power lead 5A electrically connected to the connecting fitting part 14 at one end, and a circular shape facing inward of the inner tank 1 at the other end. Insulating materials 12A and 12B are attached to the washer 17 which is welded to the outside of the inner tank 1 and has a structure having a tongue-shaped support part 11B curved in an arc shape.
It is firmly fixed with bolts and nuts 13 through.
In addition, when the connecting member 11A is fixed with the insulating materials 12A, 12B and the bolt/nut 13, the connecting fitting part 14 is made to have some flexibility so that the insulating material 15, such as ceramic, is not strained due to dimensional irregularities. Incorporating a metal bellows (not shown) is also considered an effective means. Here, the superconducting wire 10 taken out from the superconducting coil 7 in the inner tank 1 is connected to the supporting part 1.
It is guided through the groove-shaped portion of the connecting member 11A so as to follow the connecting member 1B, and is fixed by soldering or the like to make an electrical connection.

The power lead conductor 5A as described above is provided through two pipes 5B for current input/output, and depending on the case, the number of intermediate terminals etc. provided in the superconducting coil 7 as necessary may be changed. However, since the connecting members 11A and the like do not require much dimension in the width direction, they can be easily arranged according to the number of power lead conductors 5A.

With the structure shown in FIG. 2 above, electrical insulation is provided for the inner tank 1 within the box body 4B of the power lead lead-out portion 4, which communicates with the inner tank 1 and maintains an airtight structure on the outside. Groove-shaped connection member 11A made of copper material
is firmly fixed, and the connection member 11A is connected to the inner tank 1.
Support part 11 that curves inward in an arc shape and protrudes
The superconducting wire 10 taken out from the superconducting coil 7 in the inner tank 1 is guided into the groove-shaped portion of the connecting member 11A and firmly fixed by soldering or the like, and the superconducting wire 10 is connected through the connecting member 11A. Since the superconducting wire 10 can be connected to the power lead conductor 5A, the superconducting wire 10 can be short and easily fixed and held firmly in its natural state. Therefore, in general, when a strong current flows through the superconducting coil 7 and the inner tank 1 is surrounded by a strong magnetic field, and when an excitation current is flowing through the superconducting wire 10, the vehicle When the superconducting wire 10 swings due to running or some kind of vibration, there is a risk that the superconducting wire 10 will be destroyed and the superconducting coil 7 will be quenched. Since it is extremely stably fixed by the groove-shaped connecting member 11A, inadvertent vibration is completely prevented, and there is no risk of superconductor breakdown or quenching. It is to be noted that it is more effective to fix the superconducting wire 10 with solder or a bind wire instead of just attaching the superconducting wire 10 to the tongue-shaped support portion 11B.

Next, Fig. 3 shows the internal structure of the one in Fig. 2 above, with the persistent current switch 18 incorporated.In this case, it is basically the same as Fig. 2, but the power lead The shape of the box 4C of section 4 has been changed, and a slightly larger space is provided inside, and the persistent current switch 1 is installed in that space.
8 is attached and fixed to the box body 4C by the fixing fittings 20, and the superconducting wire 19 from the persistent current switch 18 is integrated with the superconducting wire 10 from the superconducting coil 7 inside the groove of the connecting member 11 similar to that shown in FIG. It is fixed with soldering etc. By doing this, both the superconducting wires 10 and 19 can be shortened, and both can be stably fixed at the same time. Furthermore, since the portions of each wire that are loose in the space are extremely small, it is possible for the vehicle to run easily. There is no danger that the superconducting wires 10, 19 will vibrate and be quenched even when Further, the problem that the current flowing between the superconducting wires 10 and 19 causes the wires to repel each other and separate from each other is also eliminated. Although not shown in the figure, this persistent current switch 18 is constructed by non-inductively winding a superconducting wire and a heater wire, and the switch is opened by heating the superconducting wire with a heater and making it into a normal conductive state. The effect is obtained, but at that time some heater heat is released to the surrounding area. However, with the above-mentioned configuration, the persistent current switch 18 can be placed outside the end of the inner tank 1 and sufficiently far away from the superconducting coil 7, so that the effect of the heater heat on the superconducting coil 7 is extremely small. This allows for an advantageous equipment arrangement.

Since this invention has been made as described above, the superconducting wire that comes out from the superconducting coil in the inner tank and connects to the external power lead conductor, and the superconducting wire from the persistent current switch as necessary, are electrically insulated from the inner tank. It can be stably fixed and held, and there is no vibration even when the superconducting wire is vibrated in a strong magnetic field.This ensures that the vibration of the superconducting wire does not cause normal conductivity and induce quenching. This is an extremely advantageous structure that can prevent this.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention.
The figure is a conceptual diagram of the inner tank that is housed in the outer container of a superconducting electromagnet used in magnetic levitation vehicles, etc. Figure 2 is a cross-sectional view of the structure near the power lead lead-out part of the inner tank, and Figure 3 is the persistent current. FIG. 3 is a cross-sectional view of the configuration when a switch is provided. DESCRIPTION OF SYMBOLS 1... Superconducting electromagnet inner tank, 2... Liquid helium tank, 3... Connecting pipe, 4... Power lead lead-out part, 4A... Power lead penetration part, 4B, 4C...
...Power lead outlet box, 5...Power lead, 5A...Power lead conductor, 5B...Power lead tube, 7...Superconducting coil, 8...Insulating flange, 9...Spacer, 10...Superconducting wire ,1
1A...Groove-shaped connection member, 11B...Support part, 12
A, 12B... Insulating material, 13... Bolt nut,
14... Connection fitting, 15... Insulating material such as ceramic, 16... Pipe, 17... Washer, 18...
...Persistent current switch, 19...Superconducting wire, 20...
…securing bracket.

Claims (1)

[Claims] 1. In devices used in superconducting magnetic levitation vehicles, etc., a power lead lead-out part for supplying power to the superconducting coil from the outside is formed in a part of the inner tank storing the superconducting coil, and a power lead lead-out part is formed inside the power lead lead-out part. , a connecting member made of copper or the like is firmly fixed to the inner tank with electrical insulation, and is connected to the power lead conductor which is electrically insulated and conductive to the inner tank, and the inner tank is connected to the inner tank. A superconducting electromagnet structure characterized in that a superconducting wire taken out from a superconducting coil in a tank and, if necessary, a superconducting wire from a persistent current switch are connected and fixedly supported by soldering or the like.