JPH0353454Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a superconducting electromagnet with a circuit switching device.

<Prior Art> In a superconducting electromagnet, a winding made of a superconductor is housed in an insulated cryogenic container and cooled with liquid helium. The winding leads are led to the room temperature area through the evaporated helium gas exhaust pipe of the cryogenic container or separately provided lead wire piping, and then connected to the power supply wiring via the terminals provided there or directly. It is connected.

In this way, the winding leads have reached room temperature, so if there is no need to supply current to the windings from the power supply (when not using an electromagnet or when operating in persistent current mode), power wiring Even if the connection between the winding lead and the winding lead is broken, heat enters the cryogenic container from the end of the winding lead, promoting the evaporation of liquid helium, which is a cryogen.

<Problems to be solved by the invention> The invention proposes that the lead part of the superconducting electromagnet winding contributes to the introduction of heat into the cryogenic vessel even when it is not in use, and prevents the evaporation of liquid helium. The present invention solves the above-mentioned drawbacks of prior art superconducting electromagnets in promoting .

<Means for solving the problem> In order to solve the problem, in the superconducting electromagnet according to the present invention, an electrical circuit switching device that can be operated from the outside is installed in the insulation space of the dewar bottle-shaped cryogenic container that houses the electromagnet winding. If there is no need to supply current to the winding from the outside, the connection between the power supply wiring and the lead of the winding led into the heat insulation space to be connected to the circuit switching device is disconnected within the heat insulation space. It's starting to sag. In some cases, a radiant heat shielding plate is inserted between the disconnected winding lead and the power supply wiring.

<Function> As is clear from the installation location of the circuit switchgear,
When the device is in the open state, the tip of the winding lead is erected in the heat insulating space, so the heat insulating space insulates the lead from room temperature and prevents heat from entering. In addition, when using a radiant heat shield,
From the tip of the power supply wiring introduced into the insulation space,
Even the slightest amount of radiant heat transmitted to the tip of the winding lead is blocked by the radiant heat shielding plate, further increasing the heat insulation effect.

<Examples> Examples of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view orthogonal to the axial direction of a superconducting electromagnet, showing the overall configuration of an embodiment of the present invention. In the figure, a double cylindrical cryostat 13 is coaxially provided with a heat insulating space 12 interposed in a double cylindrical shell container having an outer wall 11 and an inner outer wall 11a. A liquid helium injection pipe 14 for injecting liquid helium as a cryogen from the upper part of the cryostat 13 extends upward around the cryostat 13 and reaches a liquid helium injection port 15 . Furthermore, a heat insulating plate 16 having a width sufficient to cover the longitudinal direction of the cryostat 13 is brazed to the outside of the liquid helium injection pipe 14 . This heat insulating plate 16 is cooled by evaporated helium gas from the cryostat 13 and
The insulation effect for 3 is enhanced. Low temperature chamber 13
A superconducting winding 17 is housed inside, and is kept at a low temperature below the superconducting transition point by liquid helium. The lead wire 18 of the superconducting winding 17 passes through a partial section of the liquid helium injection tube 14 and then penetrates the tube wall, and the power receiving terminal 1 at the tip is exposed to the heat insulating space 12. This power receiving terminal 1 forms an electric circuit switching device together with a power transmitting terminal 2 provided at the tip of a terminal moving mechanism 3 that penetrates the outer wall 11 of the outer shell container and is introduced into the heat insulating space. A current supply lead wire 4, which is also introduced through the outer wall 11, is connected to the power transmission terminal 2.

In the above configuration, the above-described power receiving terminal 1, power transmitting terminal 2, terminal moving mechanism 3, and current supply lead wire 4 included in the area surrounded by the chain line 19 in FIG. 1 constitute the main features of the present invention. The structure and operation details will be explained below based on FIG. 2.

FIG. 2 is an enlarged detailed view of the portion indicated by the chain line 19 in FIG. As is clear from FIG. 2, the lead 18 of the superconducting winding penetrates the pipe wall of the liquid helium injection pipe 14 connected to the cryostat, and the power receiving terminal at its tip is exposed to the heat insulating space. On the outer wall 11 of the outer shell container, a terminal moving mechanism 3 consisting of a so-called vacuum rotation introduction terminal (not related to a "terminal" in an electric circuit) is arranged toward the heat insulating space, and a terminal moving mechanism 3 is disposed toward the heat insulating space. An electrical circuit opening/closing driving piece 3a is fitted into the tip of the electrical circuit opening/closing driving piece 3a via a screw mechanism, and a power transmitting terminal 2 is provided on the tip surface of the electrical circuit opening/closing driving piece 3a in correspondence with the power receiving terminal 1. A current supply lead wire 4 is connected to the power transmission terminal 2,
The lead wire 4 is connected to a power source via an external terminal 5 passing through the outer wall 11. In the above configuration, by rotationally driving the terminal moving mechanism 3, the power receiving terminal 1 and the power transmitting terminal 2 are brought into contact with and separated from each other, and current is supplied to and cut off from the external power source to the superconducting winding. When the supply of current is cut off, the power receiving terminal 1 is isolated in the heat insulating space, and heat intrusion from the outside into the low temperature chamber through the lead wire is significantly suppressed.

Further, the present invention can also be implemented in an electrical circuit switching device as shown in FIG. 3 in order to further improve the effect of suppressing heat intrusion through the lead wires.

In FIG. 3, a power receiving terminal 1 and a power feeding terminal 2 are connected to each other by a wire 7 whose tip is fixed to a circuit opening/closing drive piece 3b provided at the tip of a terminal moving mechanism (which is different from the one in FIG. 2 as described later). When they are separated, a radiant heat shielding plate 6 is inserted into the space between them. This radiant heat shield plate 6
blocks heat radiation from the tip of the power supply terminal 2 toward the power reception terminal 1, further enhancing the effect of suppressing heat intrusion into the circuit switching device.

The terminal moving mechanism 3 in FIG. 3 is composed of a normal screw mechanism and a bellows 3c for preventing air from entering the heat insulating space through the threaded portion. Of course, as in the case of the embodiment shown in FIG. 2, a vacuum rotation introduction terminal can be used.

<Effects> As is clear from the above explanation, according to the present invention, a circuit breaker is mechanically provided within the heat insulating space of the cryogenic container, so that it is not necessary to supply current to the superconducting electromagnet. , heat entering the cryostat from the outside through the power supply circuit can be significantly suppressed, and the consumption of liquid helium, the cryogen for superconducting electromagnets, can be saved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the overall configuration of an embodiment of the present invention. FIG. 2 is a detailed diagram illustrating the main part of the above embodiment. FIG. 3 is a detailed diagram illustrating the main parts of another embodiment of the present invention. 1...Power receiving side terminal, 2...Power feeding side terminal, 3...
Terminal moving mechanism, 4...External connection lead wire, 11...
... Outer shell container, 12 ... Heat insulation space, 13 ... Low temperature chamber, 17 ... Superconducting winding.

Claims (1)

[Claims for Utility Model Registration] (1) A dewar bottle-type cryocontainer having a cryostat containing liquid helium and an outer shell container forming an insulating space around the cryochamber, A superconducting electromagnet formed by winding a conductive wire, with a power receiving terminal and a power feeding terminal configured to be able to contact and separate from each other within the above-mentioned adiabatic space, and a contact between the power receiving terminal and the power feeding terminal. In order to operate separation from the outside, there is provided an electric circuit opening/closing device consisting of a wall penetrating terminal moving mechanism disposed in the outer shell container, the superconducting winding is connected to the power receiving terminal, and the power supplying side A superconducting electromagnet with an electric circuit switching device, characterized in that a terminal is connected to a lead wire that penetrates the outer shell container and is drawn out to the outside. (2) The terminal moving mechanism has a radiant heat shielding plate interlocked therewith, and when the power receiving terminal and the power feeding side terminal are separated from each other by the terminal moving mechanism, the radiant heat shielding plate moves the power receiving side terminal and the power feeding side terminal away from each other. A superconducting electromagnet with an electric circuit switching device according to claim 1 of the utility model registration, characterized in that the superconducting electromagnet is configured to be interposed between terminals.