JPS6141124B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support structure for an inner tank in a superconducting magnet used in a superconducting magnetic levitation vehicle or the like.

Currently, superconducting magnetic levitation vehicles are being developed as a means of transportation. The superconducting magnet used in this superconducting magnetic levitation vehicle has a structure in which an inner tank containing superconducting coils is supported within an outer tank, which is a vacuum container.The inner tank is kept at an extremely low temperature with liquid helium, etc. It receives a large acting force that causes the vehicle to float. For this reason, it is necessary to thermally insulate the vacuum outer tank and the inner tank, and at the same time, it is necessary to connect them with a strong support structure that can receive strong forces.

In other words, improving the thermal insulation between the inner tank and the outer tank is directly related to the consumption of internal liquid helium.
If the consumption of expensive liquid helium could be reduced, it would be very advantageous in terms of cost, and if this consumption was reduced, the capacity of the liquid helium reliquefaction refrigerator could be reduced, which would be extremely effective in reducing the overall weight of the vehicle. It's advantageous. However, the inner tank needs to be strongly connected and supported to the outer tank as described above, and for this reason, if the outer tank and the inner tank are connected with a thick structure,
This is a mutually contradictory requirement with the above-mentioned requirement for good thermal insulation, and thicker structures naturally have better thermal conductivity, leading to increased consumption of liquid helium. Furthermore, this support structure is subject to pulsations due to the repulsion from the ground and the thrust of the linear motor used to propel the vehicle.
Unless it has extremely high rigidity, there is a risk of damage to various parts due to resonance, etc.
The outer tank, which is a vacuum container, is at approximately atmospheric temperature, while the inner tank is at an extremely low temperature of 4 to 5 degrees. Conflicting demands arise.

Therefore, in the above-mentioned superconducting magnet, the inner tank must be supported in the outer tank, which is a vacuum container, by supporting the inner tank with high rigidity while having thermal insulation properties and allowing thermal contraction of the inner tank. There were many contradictory demands that the government had to meet, and it was extremely difficult to satisfy them.

Therefore, the present applicant has combined a plurality of support columns, for example, a multi-pipe type, which has thermal insulation properties and has high rigidity in a specific direction, but relatively soft rigidity in a direction perpendicular to the specific direction. By using this material, we devised a support structure that satisfies all of the above requirements and can support the inner tank with high rigidity while allowing thermal contraction.

The support structure is a structure in which an inner tank is supported within an outer tank as shown in FIG. 3 using a large number of support columns of the multi-pipe type shown as representative examples in FIGS. 1 and 2. However, with these support structures,
It is necessary to arrange a very large number of support columns,
There were problems such as the need for many adjusting and mounting parts to connect the inner tank and the outer tank.

In other words, to briefly explain the conventional support structure shown in Figs. 1 to 3 above, Fig. 1 is an example of a support column made of metal multiple tubes made of metals such as stainless steel, which have poor thermal conductivity in terms of strength. One end of a pipe 4 is connected via a spherical handle 3 to a seat 2 attached to the inside of an outer tank 1, which is a vacuum container, and a pipe 5 is attached from the other end of this pipe 4 so as to be folded around the outer circumference. Further, a pipe 6 is attached to one end of the pipe 5 so as to be folded back, and the other end of the pipe 6 is welded to an end fitting 7 to form a spherical handle 8.
It is connected to a seat 10 attached to the outer surface of the inner tank 9 via. According to the support column having such a configuration, it is possible to suppress heat intrusion from the outside to a low level due to the extremely long pipe, and at the same time, it is possible to maintain high rigidity in the axial direction between the outer tank 1 and the inner tank 9, and to provide a structure that is perpendicular to the axial direction. Since it becomes possible to connect even with low rigidity in the direction,
By appropriately selecting the mounting direction of a plurality of such support columns, it is possible to properly support the inner tank 9 even if it expands and contracts due to temperature changes.

FIG. 2 shows another example of support column structure, in which a central shaft 11 having flanges between both side plates 1A and 1B of an outer tank, which is a vacuum container, and a thin shaft portion 11A protruding from the end of the central shaft are fitted. A flanged hollow shaft 12 is fixed with screws 13, and one end of each is fitted into the flanges of the central shaft 11 and hollow shaft 12 to form a pipe made of FRP or the like with high strength and good thermal insulation. Materials 14A and 14B are installed,
At the other ends of the pipe forming materials 14A and 14B, a high-strength folding material 15 with poor heat conduction such as stainless steel is used.
A and 15B are fitted, and pipe forming materials 16A and 16B such as FRP are fitted and connected to the center ring 17, and this ring 17 is attached to the strength member 9A of the inner tank, and the side plates 1 of the outer tank are fitted.
The flange of the center shaft 10 and the fixing metal fittings 18 are attached to A and 1B.
It is attached and fixed by.

However, in the case of the support column shown in Fig. 2, initial pressure is applied in the axial direction by the screw 13, so even if the temperature drops in some parts, thermal contraction that causes play between each member will not occur. It has fairly high rigidity in the axial direction, and especially in the direction perpendicular to the axis.
Due to shear bending deformation of pipe forming materials such as FRP, the rigidity is considerably lower than that in the axial direction. For this reason, it is possible to connect and support the outer tank, which is a vacuum container as described above, and the inner tank cooled to a cryogenic temperature with high rigidity while avoiding thermal contraction of the inner tank.

Here, referring to FIG. 3, we will describe an example in which an inner tank is supported in an outer tank that is a vacuum container by using a large number of support columns of the method shown in FIG. Reference numeral 19 designates an inner tank having a racetrack shape that is also long in the front-rear direction and houses a superconducting coil (not shown). When the strong superconducting coil housed inside the inner tank 19 is energized, it receives a very strong repulsive force in the upper and lower parallel sections with a long straight line distance, and a deformation force is generated, but this deformation is prevented. For this reason, the inner tank 19 is reinforced with connecting beams 20A, 20B, and 20C arranged at intervals in the longitudinal direction, that is, in the front-back direction, between the upper and lower parallel parts. Connecting beam 2 near the front and rear ends
Support columns 21C, 21D, 21E, and 21F having the structure shown in FIG. The ring 1 in the center is connected to both sides of the outer tank 1C.
7C, 17D, 17E, and 17F are attached to the front and rear connecting beams 20A and 20C of the inner tank 19. Furthermore, support columns 21A and 21B are disposed so as to pass through the intermediate coupling beam 20B in a direction parallel to the longitudinal direction of the inner tank 19, and each center ring 17A and 17B is coupled to the coupling beam 20B, and both ends The support beams 23A, 23B, 23C, and 23D are connected to support beams 23A, 23B, 23C, and 23D supported on both side plates of the outer tank 1C, which is a vacuum container. Furthermore, connecting beams 20A, 20 are installed near both front and rear ends between the upper and lower parallel parts of the inner tank 19.
Support columns 21C and 21H are arranged in parallel with C, both ends of which are connected to the upper and lower parts of the inner tank 19, and central rings 17G and 17H are support columns from both side plates 1A and 1B of the outer tank, which is a vacuum container. It is attached to 22A and 22B in combination. However, according to this structure, the vertical direction of the inner tank 19 is connected to the support column 2.
1G and 21H, in the longitudinal direction, that is, in the front and back direction, are support columns 21A and 21B, and in the left and right direction, which is perpendicular to the longitudinal direction, are support columns 21C, 21D, 21E, and 21F.
The inner tank 19 is now supported by a plurality of support columns combined in three directions, which allows for rolling, pitching, and
Even against yawing, the inner tank 19 is supported with high rigidity by at least two support columns, so that the inner tank 19 is reliably supported and restrained. Moreover, the inner tank 19
In order to prevent longitudinal contraction of the
Since each of 1G and 21H is configured to be relatively flexible against displacement in a direction perpendicular to the central axis, rational support for the inner tank is possible because deformation is allowed freely.

However, in the support structures shown in FIGS. 1, 2, and 3 described above, there is a large difference between the axial rigidity and the axis-perpendicular rigidity of the support column.
In particular, since the rigidity in the direction perpendicular to the axis is weak, it is necessary to arrange a very large number of support columns in combination and install them between the outer tank and the inner tank, and for this reason, there are many adjustment and installation parts, which must be done with great care. There was a very troublesome problem.

This invention was made in view of the above circumstances, and its purpose is to provide a structure in which two pieces are connected to each of the outer tank side and the inner tank side, and the difference between the axial rigidity and the axis-perpendicular rigidity is It is an object of the present invention to provide a device that can easily and reliably support an inner tank in an outer tank with a very small number of support columns by using fewer support columns than conventional ones.

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. First, FIG. 4 is a sectional view showing one support column 24, which has coupling fittings 25 and 26 for fixing the inner tank at both ends and a pipe-shaped central shaft 27 passing through the center. A protrusion 27A is integrally provided at the longitudinally intermediate portion of the tube, and the inner ends are connected to both sides of the protrusion 27A, so that the folded members 29A, 29B and the pipe forming materials 30A, 30B are stacked on the pipe forming members 28A, 28B. They are assembled and attached, and outer cylinders 31A, 31B are attached to the outer ends of the pipe molded materials 30A, 30B.
The state of the multi-tube structure is somewhat similar to that shown in Fig. 2 above, but the central axis 27 is hollow and thick, resulting in a thick structure as a whole, and the wall thickness is slightly thinner accordingly. . Here, the outer cylinder 31A,
31B is a turnbuckle fitting 32 provided at the center which is screwed into one right-hand thread 33A and the other left-hand thread 33B of the outer cylinders 31A, 31B, so that they are tightened together, and the pipe forming members 28A, 28 are tightened together.
The outer cylinders 31A, 31B are provided with tapped holes 34A, 34B at positions spaced apart from each other toward the outer ends. Outer tank coupling portions 35A and 35B, such as seat surfaces, are provided, respectively.

Next, a support structure for supporting a racetrack-shaped inner tank 199A in an outer tank D, which is a vacuum container, using a plurality of support columns shown in FIG. 4 as shown in FIG. 5 will be explained. The inner tank 19A, which is cooled to an extremely low temperature, is connected to the connecting beams 20D, 2.
It has been strengthened in 0E. Support columns 24A, 24B and 24C, 24D, which are the same as those shown in FIG. and the outer tank coupling portions 35A, 35B of each case are connected to the tap holes 34A, 35B.
It is connected to the side wall of the outer tank 1D via 34B.

However, in this support structure, each support column 2
Since 4A to 24D have a thick structure, the bending rigidity generally increases in proportion to the cube of the diameter, so in order to reduce the increase in heat penetration, the cross-sectional area is decreased in inverse proportion to the increase in diameter. Also, the bending rigidity can increase in proportion to the square of the diameter, so the outer cylinder 31
The rigidity against lateral displacement of A, 31B and the pipe-shaped central shaft 27 is increased. Also, the bending rigidity is relatively weak.
Pipe forming materials 28A, 28B and 30 such as FRP
A, 30B also have a central axis 27 and folding members 29A, 2
9B and the outer cylinders 31A and 31B are both made of a rigid metal with good thermal insulation such as stainless steel, which allows them to be extremely rigidly supported, resulting in increased bending rigidity against shear bending like a beam fixed at both ends. The difference between the axial rigidity and the axially perpendicular rigidity of the support columns 24 to 24D is reduced. Moreover, tap holes 34A, 34
Since the outer tank coupling portions 35A and 35B with B are provided at separate positions, each of the support columns 24A to 24D can be relatively firmly connected between the inner and outer tanks due to this gap. However, in FIG. 5, by taking advantage of the improved lateral rigidity of each support column, four support columns 21C, 21D, 21E, 21 perpendicular to the connecting beams 20A, 20C from the case of FIG.
The structure is such that F can be omitted, and installation to the outer tank 1D is extremely easy, resulting in a support structure that is extremely rational and easy to install overall.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventionally commonly used support column, Figure 2 is a cross-sectional view of a newly developed support column, and Figure 3 is a cross-sectional view of an inner tank in a superconducting electromagnet using the support column shown in Figure 2. FIGS. 4 and 5 are explanatory diagrams showing an example of a support structure, and FIGS. 4 and 5 show an embodiment of the present invention. FIG. 4 is a cross-sectional view of a support column, and FIG. It is a schematic diagram of the support structure which supported the inner tank in the outer tank using a small number of pieces. 1, 1C, 1D...outer tank, 1A, 1B...outer tank side plates, 2,10...seat, 3,8...spherical joint, 4,5,
6... Pipe, 7... End fitting, 9, 19, 19A... Inner tank, 11... Center shaft, 12... Hollow shaft, 13... Screw,
14A, 14B, 16A, 16B... Pipe forming material, 15A, 15B... Turning material, 17, 17A,
17B, 17C, 17D, 17E, 17F, 17
G17H...Ring, 18...Fixing bracket, 20A, 2
0B, 20C, 20D, 20E...Connection beam, 21
A, 21B, 21C, 21D, 21E, 21F,
21G, 21H, 24, 24A, 24B, 24
C, 24D...Support column, 22A, 22B...Support beam from the outer tank, 23A, 23B, 23C, 23D
...Support beam from the outer tank, 25, 26...Joining metal fittings for fixing the inner tank, 27...Central shaft, 27A...Intermediate protrusion, 2
8A, 28B, 30A, 30B...pipe forming material,
29A, 29B...Folding material, 31A, 31B...Outer cylinder, 32...Turnbuckle fitting, 33A, 33B
...Screw, 34A, 34B...Tap hole, 35A, 3
5B...Outer tank connection part.

Claims (1)

[Claims] 1. In superconducting electromagnets used in superconducting magnetic levitation vehicles, etc., which support an inner tank containing superconducting coils in an outer tank, which is a vacuum container, by using an appropriate number of support columns with a multi-tube structure, the support columns A central shaft having inner tank support joints at both ends and penetrating through the center, pipe forming materials and folding materials combined in multiple ways by joining the inner ends to both sides of the intermediate protrusion of this central shaft, and a pair of outer shells which are connected to the outer ends of the pipe forming members on both sides and the folded members and are tightened together to apply a compressive force to the pipe forming members and the folding members on both sides thereof, each having an outer tank joint portion; An inner tank support structure in a superconducting magnet characterized by comprising a cylinder.