JP2856946B2 - Superconducting magnet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting magnet used for a superconducting magnetic levitation vehicle or the like.

[0003]

2. Description of the Related Art A superconducting magnet used in a magnetic levitation railway will be described with reference to FIGS.

A superconducting magnet used in a superconducting magnetic levitation vehicle is mounted on a bogie below the vehicle body and faces a ground coil.

The superconducting magnet comprises an inner tank 2 for cooling and storing the superconducting coil 1 with a medium such as liquid helium,
An outer tank 3 which is a vacuum container for storing the water, a heat shield plate 4 and the like provided between the inner tank 2 and the outer tank 3, and the like.
A thrust, a levitation force and a guide force are generated facing the ground coil 5.

The superconducting coil 1 wound with a superconducting wire is fixed to the inner tank 2 by a metal fitting 6 having a clear hole through which a coolant such as liquid helium passes. The inner tank 2 is usually made of stainless steel from the viewpoint of welding airtightness and strength against magnetic force.

[0007] The heat shield plate 4 is formed so as to surround the inner tank 2 in order to reduce radiant heat entering the inner tank 2, and as a cooler for the shield plate, a pipe 7 through which a coolant such as liquid nitrogen flows on the surface thereof. And the heat conduction keeps the shield plate in the liquid nitrogen temperature range.

The heat shield plate 4 is a good heat conductive material for keeping the whole at a uniform temperature.
Since it is necessary to shield an AC magnetic field from the material, a material having high conductivity, that is, a plate made of aluminum or steel is used.

By the way, in a superconducting magnetic levitation vehicle,
Since the thrust, the levitation force and the guide force are obtained by the electromagnetic action of the superconducting coil 1 and the ground coil 5, the distance between the coils is preferably as small as possible in order to levitate and travel efficiently. Therefore, the heat shield plate 4a on the side facing the ground coil 5 must be as thin as possible, and the interval between the inner tank 2a and the outer tank 3a must be as small as possible.

[0010]

As described above, the heat shield plate 4 causes the inner tank 2 integrated with the superconducting coil 1 to vibrate due to the electromagnetic disturbance received from the ground coil 5 while the vehicle is traveling, and the heat is transmitted to the heat shield plate 4. The vibration is received via the supporting load member 8. At this time, the heat shield plate 4 is displaced relative to the superconducting coil in the magnetic field of the superconducting coil 1 and receives a magnetic field fluctuation, and an eddy current is generated in the heat shield plate 4.

By the way, the heat shield plate 4a on the side facing the ground coil 5 is exposed to the place where the magnetic field of the superconducting coil 1 is strong because the space between the heat shield plate 4a and the inner tank 2a is made as small as possible. The eddy current increases, and a secondary eddy current is strongly induced in the inner tank 2a facing the heat shield plate 4a by the magnetic field generated by the eddy current. For this reason, excessive heat is generated in the heat shield plate 4a and the inner tank 2a due to the eddy current, and the heat load on the entire superconducting magnet tends to increase significantly.

In order to prevent this, a reinforcing member 9 for suppressing the vibration of the heat shield plate 4 is provided to increase the rigidity of the heat shield plate 4, but the heat shield plate 4a on the side facing the ground coil 5 is designed. Due to the dimensional restrictions described above, the reinforcing member 9 cannot be attached, and the effect is not sufficiently obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce an increase in thermal load due to an eddy current generated during running of such a superconducting magnet.

[Configuration of the Invention]

[0015]

According to the present invention, in order to solve this problem, the heat shield plate is made of a plate having a high rigidity honeycomb structure, and a refrigerant can flow through the honeycomb structure.

[0016]

When the heat shield plate has a honeycomb structure, the rigidity is sufficiently high even if the space is small, vibration of the heat shield plate, particularly film vibration, can be suppressed, and relative displacement with the superconducting coil can be reduced.

Further, by flowing the refrigerant through the honeycomb structure, the heat generated by the eddy current of the heat shield plate can be directly cooled, and the increase in heat input to the inner tank is reduced.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the embodiments shown in FIGS.

As the heat shield plate 4 of the superconducting magnet, a plate having a honeycomb structure having high rigidity is used, and a structure in which a refrigerant can flow through the honeycomb structure is used.

As the honeycomb structure, a general hexagonal honeycomb core 4b is used, and a vent hole 4c required for manufacturing the honeycomb core 4b is used as a refrigerant passage.

Alternatively, as shown in FIGS. 3 and 4, the honeycomb core 4b has a corrugated plate shape, and its space 4d is used as a refrigerant passage.

As described above, by forming the heat shield plate 4 into a honeycomb structure, the rigidity can be increased even in a portion having dimensional restrictions such as the side facing the ground coil 5 and the reinforcing member 9 is attached. The rigidity of the entire heat shield plate can be made higher than that of the heat shield plate.

Since the shield plate is configured as described above, vibration of the heat shield plate, particularly, film vibration can be suppressed, and relative displacement with respect to the superconducting coil 1 can be reduced. Furthermore, since the heat shield plate 4 that generates heat by flowing a coolant such as liquid nitrogen into the honeycomb structure can be directly cooled, the temperature rise due to the eddy current of the heat shield plate 4 is suppressed, and the radiant heat to the inner tank 2 and the load supporting material are reduced. 8 can reduce the heat of conduction.

Due to the high rigidity of the heat shield plate due to the honeycomb structure, the relative displacement between the heat shield plate 4 and the superconducting coil 1 can be reduced, the eddy current flowing through the heat shield plate 4 and the inner tank 2 can be reduced, and the heat generation can be reduced. . Furthermore, by flowing a coolant such as liquid nitrogen into the honeycomb structure, the amount of heat input to the inner tank 2 can be suppressed, and the increase in the heat load of the entire superconducting magnet during traveling can be significantly reduced.

A heat shield plate having a honeycomb structure is provided only at a portion having a dimensional restriction such as at least a side facing the ground coil 5, and the other surface where the dimensional restriction is not strict is provided with a reinforcing member 9 shown in FIG. 9. The same effect can be obtained.

Another embodiment of the present invention shown in FIGS. 5 to 7 will be described.

FIG. 5 shows an example in which the heat shield plate 4 has a honeycomb plate 10 made of reinforced plastic or stainless steel.
Are intermittently attached with a rivet or the like to increase the rigidity of the heat shield plate 4 and reduce the relative displacement to obtain the same effect. Further, by appropriately selecting the intermittent fixed pitch of the rivet or the like, the vibrations of the heat shield plate 4 and the honeycomb plate 10 cancel each other, the amplitude of the vibration is suppressed, and the relative displacement can be greatly reduced. You can have.

Further, as shown in FIG. 6, a high-strength anti-vibration member such as FRP having a low heat transfer coefficient is provided between the inner tank 2 and the heat shield plate 4 having the honeycomb structure or the rigidity for mounting the honeycomb plate. By mounting 11, the bending vibration of the heat shield plate as a whole determined by the load supporting member 8 can be suppressed, and the relative displacement can be greatly reduced.

In the case of a race track-shaped superconducting magnet as shown in FIG. 7, it is more effective to dispose the steady rest member 11 at a position away from the load supporting member 8 at the corner of the curved portion. Is obtained.

[0030]

According to the present invention, the rigidity can be increased without increasing the space for the heat shield plate of the superconducting magnet. Displacement can be reduced, eddy current flowing through the heat shield plate and the inner tank is reduced, and heat generation can be reduced. Furthermore, since the heat shield plate that generates heat by flowing a coolant such as liquid nitrogen into the honeycomb structure can be directly cooled, the temperature rise is suppressed, and radiant heat to the inner tank and conduction heat through the load supporting material can be reduced. The increase in the thermal load on the entire superconducting magnet during traveling can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a superconducting magnet according to the present invention.

FIG. 2 is a perspective view of a shield plate according to the present invention.

FIG. 3 is a perspective view of another shield plate according to the present invention.

FIG. 4 is a perspective view of still another shield plate according to the present invention.

FIG. 5 is a partial cross-sectional view of another embodiment of the present invention.

FIG. 6 is a partial sectional view of still another embodiment of the present invention.

FIG. 7 is a side view of FIG. 6;

FIG. 8 is a sectional perspective view of a conventional superconducting magnet.

FIG. 9 is a partial sectional view of FIG.

FIG. 10 is a view taken along line X-X of FIG. 9;

[Explanation of symbols]

 Reference Signs List 1 superconducting coil 2, 2a inner tank 3, 3a outer tank 4, 4a heat shield plate 4b honeycomb core 4d refrigerant passage 5 ground coil 10 honeycomb plate

Claims (1)

(57) [Claims] 1. A superconducting device comprising an inner tank for storing a superconducting coil, an outer tank as a vacuum container for storing the inner tank, and a heat shield plate with a cooler provided between the inner and outer tanks to cover the inner tank. A superconducting magnet, wherein the heat shield plate is formed of a plate having a honeycomb structure provided with a passage hole for a refrigerant.