JPS6060703A - Supporting device of low temperature piping for superconductive magnet - Google Patents

Abstract

PURPOSE:To prevent the deterioration with aging of a supporting part by a method wherein a part of the supporting device which supports a low temperature piping is held by an elastic member which is bent in the axial direction of the low temperature piping. CONSTITUTION:The supporting part of the low temperature piping 5, with which a normal temperature part and a low temperature part or between each low temperature part are connected, is supported by an elastic member 14 in such a manner that the supporting part follows up to the expansion and contraction generating due to the temperature fluctuation in longitudinal direction of the piping 5 and that rigidity is given in the direction of gravity. As a result, the movement in axial direction by the thermal contraction or expansion of the piping 5 can be allowed by the continuous bending of the member 14. Accordingly, the piping can be held safely maintaing sufficient mechanical strength for vibrations and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a support structure for a low-temperature pipe that connects a normal temperature section and a low-temperature section or between low-temperature sections in a superconducting magnet used in a superconducting floating railway or the like.

Technical Background of the Invention and Problems thereof] FIG. 1 is a cross-sectional view of a superconducting magnet, and in particular, an example of low-temperature piping for supplying or recovering refrigerant to the superconducting magnet will be described. In Fig. 1, l is a superconducting coil, 2 is liquid helium for cooling the superconducting coil 1, 3 is an inner tank for storing the superconducting coil l and liquid helium 2, and 4 is for vacuum insulation between the inner tank 3 and the outside temperature. The interior is kept in a vacuum state with an outer tank provided. Reference numeral 5 designates a low-temperature pipe for leading helium gas generated in the inner tank 3 to the outside or injecting a refrigerant, and reference numeral 6 designates a support device for supporting the low-temperature pipe 5 insulated.

7 is a load support member that supports the inner tank 3 in a heat-insulating manner. others,
There are piping, leads, shields, etc., but they are omitted in the diagram for simplicity.

Here, in order to maintain the superconducting coil 1 in a superconducting state, it is necessary to maintain the liquid helium temperature at an extremely low temperature.

However, since liquid helium 2 evaporates due to heat intrusion from the outside, reducing the amount of heat intrusion requires extending the operating time of the superconducting coil 1 in the superconducting state, saving helium, and installing a refrigerator. In some cases, it leads to reducing the refrigeration function. The amount of heat infiltration can be roughly divided into two types: heat conduction from the low-temperature piping 5, load support material 7, etc., which connect the inner 4g13 directly to the outer M4, and heat radiation to the surface of the inner tank 3; The proportion of heat intrusion is large, and in particular, reducing the heat intrusion from the low-temperature pipe 5 greatly contributes to the functionality of the superconducting magnet. One way to reduce heat conduction from the low-temperature pipe 5 is to lengthen the pipe length or reduce the pipe diameter, but since the pipe diameter is determined by the amount of refrigerant injected per hour, the amount of gas discharged, and the pressure loss of the pipe, the length of the pipe should be determined by superconducting. Generally, the length is within the allowable range due to the structure of the magnet.

However, supporting the closed low-temperature pipe 5 at two points, the inner tank 3 and the outer tank 4, causes stress concentration in the support portion due to vibration.

Further, since the natural frequency is often low and disadvantageous due to resonance etc., a heat insulating support device 6 for the low temperature pipe 5 is provided in both containers 3 and 4 from the viewpoint of mechanical strength.

Conventionally, this type of support device has a support member 11 that is more rigid than a fixed base 8 fixed to an outer tank 4 and has mounting holes at both ends, as shown in FIGS. 2 and 3, for example. Several pieces of heat insulating material 9 are placed on the cryogenic tube 5 in advance using a band 10 at the end thereof, and the band 10 is supported as shown in FIG. 3 so as not to directly touch the cryogenic tube 5.

With the above configuration, external heat is conducted from the outer tank 4 → the fixing base 8 → the support member 11 → the band 10, but the heat insulating material 9
This is a structure that insulates heat from entering.

However, in this structure, when liquid helium 2 is stored in the inner tank 3, the low-temperature pipe 5 undergoes thermal contraction with a temperature difference of about 300'0 from room temperature, and when the inner tank 3 is heated,
On the other hand, thermal expansion occurs when viewed from a low temperature, and this thermal contraction or expansion causes the low-temperature pipe 5 to move in its longitudinal direction relative to the support device 6.

The movement of the low-temperature pipe 5 should be followed by the heat insulating material 9, but due to the frictional force between the low-temperature pipe 5 and the heat insulating material 9, the fourth
As shown in the figure, the heat insulating material 9 protrudes. In addition, the heat insulating material 9 has the disadvantage that it easily collapses and the collapse increases at an accelerated rate due to vibrations and the like. Further, even when the heat insulating material 9 follows, it cannot move continuously due to frictional force, so it is intermittent and has a disadvantage that it has a negative effect on the superconducting coil.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned drawbacks.
In particular, the object is to obtain a support structure for low-temperature piping that can follow changes in temperature, suppress heat conduction, and withstand vibrations.

SUMMARY OF THE INVENTION The present invention provides a superconducting magnet in which a supporting portion of a low-temperature pipe connecting a normal temperature part and a low-temperature part or between low-temperature parts or the like is expanded due to a temperature change in the longitudinal direction of the low-temperature pipe.

It is supported by an elastic member so as to follow contraction and have rigidity in the direction of gravity.

[Embodiments of the invention]

An embodiment of the present invention will be described below based on the drawings.

Figure 5 is a diagram equivalent to Figure 2, and as in Figure 1 and @2,
Superconducting coil 1, liquid helium 2, inner tank 3, outer tank 4, low-temperature pipe 5, load support 7, fixing table 8, and mounting screw 12a
, 12b, etc. are the same as those in the conventional method, and therefore their explanation will be partially omitted.

A low-temperature pipe 5 that is provided to penetrate from the inner tank to the outside +14,
In order to support it within the outer tank 4, as shown in FIG. A member 13a extending downward from the end is provided at approximately the same position as the horizontal direction of the low-temperature pipe 5, and a member 13a is provided horizontally on two sides of the low-temperature pipe 5 in a plane perpendicular to the longitudinal direction of the low-temperature pipe 5 (intersecting). An elastic member 14 made of metal, synthetic resin, ceramic, or the like is fixed directly or integrally to the outer diameter of the low-temperature pipe 5 as shown in FIG. It is supported so that it can bend freely in the direction of gravity and not bend in the direction of gravity.

Here, in order to finely adjust the mounting screws 12a and 12C in the front and back and left and right directions, it is free to provide elongated holes or the like in both or one of them.

However, the elastic member 14 that can freely follow the expansion and contraction of the low-temperature pipe 5 as a support member may be provided singly or in a plurality of layers, or the support member 13 and the elastic member 14 may be replaced. .

Incidentally, the reason why the support member 13 is provided in a long cantilevered manner is to reduce heat intrusion into the outer tank 4. Furthermore, it is even more effective if the supporting member 13 is made of a thin elastic member 14 or the like having a small cross section.

According to the low-temperature pipe support structure having the above configuration, axial movement due to thermal contraction or expansion of the low-temperature pipe can be tolerated by continuous deflection of the leaf spring, and furthermore, high rigidity can be achieved in other directions. Can be secured. Therefore, the support structure can be made sufficiently strong against mechanical strength such as vibration.

[Other Embodiments of the Invention] FIG. 6 shows an arrangement in which an elastic member 14a such as a leaf spring is provided directly between the outer tank 4 and the low-temperature pipe 5, and the ends of each are directly connected in the figure. However, it is also possible to indirectly attach an insert and secure it with a fastener.

In FIG. 7, the support member 13b fixed to the outer tank 4 is located below the low-temperature pipe 5, and the elastic member 14a is located above this.
, 1.4b. Similarly, the elastic members 14a and 14b are supported by changing the form as necessary, as in FIG. 6.

6 and 7 also provide the same effect as the first embodiment.

[Overall effect of the invention]

According to the present invention, even if the longitudinal support point, which expands and contracts with the temperature change of the low-temperature pipe, is formed in a fixed form, it can be freely followed by an elastic body such as a temporary spring. (Over time) No change occurs.

Furthermore, since it has flexibility in the direction of expansion and contraction, it is possible to suppress local stress such as thermal stress on each support part to a small level, and it is also possible to completely support vibrations in the two directions of gravity.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a cooling tank for a conventional superconducting magnet, Figure 2 is a perspective view of the low-temperature pipe support device shown in Figure 1, and Figure 3 is a
FIG. 4 is an explanatory diagram of the phenomenon in which the heat insulating material in FIG. 3 shifts due to the influence of heat, FIG. and FIG. 7 are perspective views showing other embodiments of the present invention. 1...Superconducting coil 2...Liquid helium 3.
...Inner 4!4...Outer Tank 5...Low temperature piping 14.14a, 14b...Elastic member (7317)
Agent Patent Attorney Kensuke Chika (and 1 other person) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a superconducting magnet equipped with a support device for a low-temperature pipe that connects a room temperature part and a low-temperature part or between low-temperature parts, etc., a part of the support device that supports the low-temperature pipe is made of an elastic member that bends in the axial direction of the low-temperature pipe. A support device for a low-temperature pipe for a superconducting magnet, characterized by supporting it.