JPH0469404B2 - - Google Patents

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 its problems]

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 Figure 1, 1 is a superconducting coil, 2 is liquid helium for cooling the superconducting coil 1, 3 is an inner tank for storing the superconducting coil 1 and liquid helium 2, and 4 is for vacuum insulating the inner tank 3 from the outside temperature. The interior is kept in a vacuum state with an outer tank provided. 5 is a low-temperature pipe for leading helium gas generated in the inner tank 3 to the outside and for injecting refrigerant;
Reference numeral 6 denotes a support device that supports the low-temperature pipe 5 in adiabatic manner.

7 is a load support member that supports the inner tank 3 in a heat-insulating manner.
In addition, 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 operation time of the superconducting coil 1 in the superconducting state, saving helium, and installing a refrigerator. If it is, it will lead to reducing the refrigeration function power. The amount of heat infiltration can be roughly divided into two types: heat conduction from things directly connected from the inner tank 3 to the outer tank 4, such as the low-temperature piping 5 and load support material 7, and heat radiation to the surface of the inner tank 3. Heat penetration by conduction accounts for a large proportion, and in particular, reducing heat penetration 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 elongated 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. A heat insulating material 9 is attached to the cryogenic tube 5 in advance by 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 transferred from outer tank 4 to fixed base 8 to
Although the heat is conducted from the support member 11 to the band 10, the heat insulating material 9 is designed to insulate heat from entering the low-temperature pipe 5. However, in this structure, when liquid helium 2 is stored in the inner tank 3, the low-temperature pipe 5 is about 300 m
Thermal contraction occurs due to a temperature difference of °C, and when the temperature of the inner tank 3 is raised, conversely, thermal expansion occurs when viewed from a low temperature.This thermal contraction or expansion causes the low temperature piping 5 to be supported. It will move relative to the device 6 in its longitudinal direction.

The heat insulating material 9 should just follow the movement of the low temperature pipe 5, but the heat insulating material 9 will protrude as shown in FIG. 4 due to the frictional force between the low temperature pipe 5 and the heat insulating material 9. 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 becomes intermittent and has a disadvantage in that it has a negative effect on the superconducting coil.

[Purpose of the invention]

The present invention has been made to eliminate the above-mentioned drawbacks, and in particular, to provide a support structure for low-temperature piping that can follow temperature changes, conduct heat, and withstand vibrations.

[Summary of the invention]

In a superconducting magnet, the present invention expands a supporting part of a low-temperature pipe that connects a normal temperature part and a low-temperature part or between low-temperature parts, etc. 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.

Fig. 5 is a diagram corresponding to Fig. 2, and as shown in Figs. Since the mounting screws 12a, 12b, etc. are the same as those in the conventional method, some explanations will be omitted.

In order to support the low-temperature piping 5, which is provided by penetrating the outer tank 4 from the inner tank, in the outer tank 4, a fixing base 8 is fixed in advance to the inner wall of the outer tank 4, as shown in FIG. protrude in a cantilever shape perpendicular to the upper part of the low-temperature pipe 5, and a member 13a extending below the end thereof is provided at approximately the same position as the horizontal direction of the low-temperature pipe 5, and a member 13a is provided horizontally along two sides of the member 13a. Made of metal, synthetic resin, ceramic, etc., which is fixed directly to the outer diameter of the low-temperature pipe 5 or integrally through a mounting member so as to be perpendicular to the longitudinal direction of the low-temperature pipe 5 (crossing plane). An elastic member 14 is provided to freely bend in the axial direction of the low-temperature pipe 5,
It is supported so that it does not bend in the direction of gravity.

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

Furthermore, 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.

By the way, the reason why the support member 13 is provided in a long cantilevered manner is to reduce heat infiltration from the outer tank 4. Further, it is more effective if the support member 13 is made of a thin elastic member 14 or the like having a small cross section.

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

[Other embodiments of the invention]

In Fig. 6, an elastic member 14a such as a leaf spring is provided directly between the outer tank 4 and the low-temperature pipe 5, and although the ends of each are directly connected in the figure, they are connected indirectly. It is also possible to attach an inclusion and secure it with a fastener.

FIG. 7 shows a case where the support member 13b fixed to the outer tank 4 is located below by the low-temperature pipe 5, and is supported above this by elastic members 14a and 14b. Similarly, the elastic members 14a, 1
Similarly to FIG. 6, 4b is supported by changing the form as necessary.

Similarly, FIGS. 6 and 7 have 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 as the temperature changes in the low-temperature pipe, is formed in a fixed form, it can be freely followed by an elastic body such as a leaf spring, and the support point expands and contracts over time. ) changes will no longer occur.

In addition, since it is flexible in the direction of expansion and contraction, local stress such as thermal stress can be suppressed to a small level in each support part, and it can also completely support vibrations and the direction 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 in Figure 1, Figure 3 is a cross-sectional view of Figure 1, and Figure 4 is a Figure 5 is a perspective view of the low-temperature pipe support device of the present invention, and Figures 6 and 7 show other embodiments of the present invention. FIG. 1...Superconducting coil, 2...Liquid helium, 3
...Inner tank, 4...Outer tank, 5...Low temperature piping, 14,
14a, 14b...Elastic members.

Claims (1)

[Claims] 1. In a superconducting magnet equipped with a support device for a low-temperature pipe that connects a normal 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
A support device for a low-temperature pipe for a superconducting magnet, characterized in that the low-temperature pipe is supported by an elastic member that bends in the axial direction of the low-temperature pipe.