JPH0738329B2 - Support structure for power supply line for superconducting conductor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a support structure of a power supply line for supplying power to a superconducting magnet in a cryostat, and when heat contraction of the power supply line occurs or when the superconducting magnet The present invention relates to a structure that enables stable power supply even when electromagnetic force is generated.

"Prior Art" Fig. 3 shows an example of a partial structure of a conventional cryostat A in which the superconducting magnet 1 is housed.

In FIG. 3, reference numeral 2 is a cryostat (low temperature container).
The upper flange plate (top flange) of A is shown, the power supply line 3 is provided through this upper flange plate 2, and the power supply line 3 is supported by the terminal part 4 fixed to the upper flange plate 2, The supply line 3 is connected to the superconducting magnet 1 housed inside the cryostat A, and
The power supply line 3 outside the upper flange plate 2 is connected to a terminal plate 6, and the terminal plate 6 is connected to a power source. The power supply line 3 and the superconducting magnet 1 are connected via a copper braided wire 7 having a flexible structure.
The reason why the copper braided wire 7 is provided is that the superconducting magnet 5 is cooled to an extremely low temperature by heat contraction of the power supply wire 3.
Alternatively, it is for absorbing the displacement of the magnet position and the like caused by the electromagnetic force generated by the superconducting magnet 5 during the excitation.

By the way, there is known a forced cooling type superconducting conductor in which a superconducting conductor is housed inside a tubular jacket and a cooling medium flow path is formed around the superconducting conductor. When a superconducting magnet is formed by using this main forced cooling type superconducting conductor and is housed in the cryostat shown in FIG. 3, a hollow power supply line in which a refrigerant flow passage is formed is prepared, and Since it is necessary to secure a cooling medium flow passage in the connection portion between the power supply line and the superconducting conductor, conventionally, instead of the braided wire 7, a pipe-shaped joint conductor is used to connect the power supply line and the superconducting conductor. ing.

"Problems to be Solved by the Invention" In the structure in which the forced cooling type superconducting conductor and the superconducting magnet are connected using the joint conductor as described above, the joint conductor portion is the weakest portion in terms of strength. In the joint conductor, the load due to the heat contraction of the power supply line that occurs when the cooling medium flows into the power supply line and the superconducting conductor, and the load due to the electromagnetic force that occurs when the superconducting magnet is excited are concentrated. There is a risk that the joint conductor may buckle or break. For this reason, in repeated experiments of superconducting magnet excitation, buckling and breakage of the joint conductor have become a major problem. A backup magnet may be attached around the superconducting magnet, but if the centers of both magnets are misaligned, the joint conductor may be loaded by the electromagnetic force acting in a misaligned manner. There was a risk of buckling or breakage of the conductor.

The present invention has been made in view of the above problems, when heat contraction of a power supply line occurs, or when an electromagnetic force of a superconducting magnet is generated, and further, when a backup magnet is attached to generate an electromagnetic force, etc. It is an object of the present invention to provide a support structure for a power supply line in which stable deformation of the power supply line can be absorbed by a bellows member and an elastic member.

"Means for Solving Problems" In the present invention, in order to solve the problems, a power supply line connected to a superconducting conductor of a superconducting magnet provided in a cryostat is formed on an upper flange plate of the cryostat. In the support structure of the power supply line for the superconducting conductor, which is provided by inserting the through hole and supporting the power supply line in the vicinity of the upper flange plate, the power supply line is provided by loosely inserting the through hole. A support plate is attached to the power supply line outside the flange plate, and an expandable bellows member is provided between the support plate and the upper flange plate to cover the power supply line.
The support plate and the upper flange plate are connected to each other, and the upper flange plate is provided with an elastic member that allows the support plate to move along the length direction of the power supply line.

[Operation] Since the support plate attached to the power supply line is movably supported by the bellows member and the elastic member provided on the upper flange plate, it is caused by the thermal deformation of the power supply line or the excitation of the superconducting magnet. The elastic member and the bellows member absorb the deformation of the power supply line that occurs as a result, and the load on the power supply line is reduced. Since the insertion hole of the upper flange plate in which the power supply line is loosely inserted can be covered with the bellows member, the airtightness of the cryostat can be maintained.

"Embodiment" FIG. 1 shows an embodiment of the present invention. In the figure, 10 shows a part of an upper flange plate (top flange) of a cryostat. A superconducting magnet is housed similarly to the cryostat A shown in FIG. 3, and a power supply line 11 is connected to the superconducting magnet inside the cryostat by penetrating the upper flange plate 10. This superconducting magnet has a known structure in which a forced cooling type superconducting conductor having a refrigerant passage through which a refrigerant such as liquid helium is formed is wound around a winding drum, and the superconducting magnet is connected via a required joint conductor. It is connected to the power supply line 11.

Then, the insertion hole 10a formed in the upper flange plate 10
A support plate 13 is provided above the above through a bellows member 12.

The bellows member 12 comprises an expandable bellows body 14 made of a stainless steel thin plate, a lower cylinder 15 joined to a lower opening of the bellows body 14, and an upper cylinder 16 joined to an upper opening of the bellows body 14. It has a cylindrical configuration. Then, the bellows member 12 fits the lower cylinder 15 into the upper opening of the insertion hole 10a of the upper flange plate 10, and the power supply line 11
It is provided to cover. A disc 17 made of a resin such as FRP (fiber reinforced plastic) is fitted into the insertion hole 10a of the upper flange plate 10, and the power supply line 11 is inserted into the passage hole 17a formed in the disc 17. The power supply line 11 is loosely inserted and is vertically movable along the insertion hole 17a.

Further, the support plate 13 is a plate body 18 made of resin such as FRP, an upper plate body 19 and a lower plate body 20 made of stainless steel sandwiching both upper and lower surfaces of the plate body 18 with bolts (not shown). A plurality of supporting pieces 21 are integrally projectingly provided on the outer peripheral portion of the lower plate body 20. And the upper flange plate below the support piece 21
In 10, the support bolt 22 is erected through the support piece 21,
Support springs (elastic members) 23, 23 are inserted into the support bolt 22 so as to sandwich the support piece 21 above and below, and a ring-shaped washer is further provided above the support spring 23 and above the support bolt 22. 24 is inserted and the nut 25 is screwed. Three or more supporting pieces 21 are formed on the outer periphery of the lower plate 20, and each supporting spring 23 is formed on the lower plate 20.
Are supported in parallel with the upper flange plate 10. by the way,
In the support plate 13, a support hole formed in the lower plate body 20.
The upper cylinder 16 of the bellows member 12 is joined to 20a, and the power supply line 11 is further provided through the lower plate body 20, the plate body 18, and the upper plate body 19, and the power supply line 11 is provided on the support plate 13. It is installed. With the above configuration, the upper flange plate 10
The insertion hole 10a of the disc 17 is provided with the disc 17, the power supply line 11, and the bellows member 1.
The bellows member 12 is closed by 2 and the upper opening of the bellows member 12 is closed by the lower plate body 20 and the plate body 18, so that the cryostat can maintain airtightness.

The power supply line 11 has a refrigerant flow passage (not shown) formed therein, and the refrigerant flow passage is connected to the power supply line 11 above the upper flange plate 10 ( (Not shown) is connected to the coolant supply source. The upper portion of the power supply line 11 shown in FIG. 1 is connected to a terminal plate having the same structure as the conventional structure shown in FIG. 3 so as to be connected to a required power source.

Next, the operation of the above structure will be described.

When the cryostat adopting the above structure is used, in order to energize the superconducting magnet, first, the power supply line
After cooling the superconducting magnet to a cryogenic temperature by flowing the refrigerant from the refrigerant flow passage 11 to the refrigerant flow passage of the superconducting conductor of the superconducting magnet, the power supply line 11 energizes the superconducting conductor.

In the above operation, when the refrigerant is passed through the power supply line 11 to flow the refrigerant through the superconducting conductor, the power supply line 11 thermally contracts, but the bellows member 12 contracts as the power supply line 11 contracts.
Is reduced and the support plate 13 is a lower support spring.
The power supply line 11 can be easily shrunk in order to move by compressing 23. Therefore, the load acting on the power supply line 11 can be reduced.

Further, when the superconducting magnet is excited and an electromagnetic force acts on the power supply line 11 to move the power supply line 11,
Since the support plate 20 can move against the biasing force of the support spring 23, the load acting on the power supply line 11 can be reduced. Further, when the power supply line 11 tries to move upward in FIG. 1 for some reason, the bellows member 12 expands and the upper spring 23 contracts to allow the support plate 13 to move. Also in this case, the load acting on the power supply line 11 can be reduced. As described above, when the bellows member 12 contracts and expands, the support spring 23 prevents the bellows member 12 from being crushed or fully expanded.

Further, since the bellows body 14 and the support spring 23 that absorb the deformation of the power supply line 11 are provided outside the cryostat, a refrigerant is introduced into the superconducting conductor inside the cryostat and the power supply line 11 to cool them. Even in such a case, since the bellows body 14 and the support spring 23 do not become as low as the temperature of the refrigerant, the bellows body 14 and the support spring 23 do not deteriorate in the elastic surface at a very low temperature, and the bellows does not occur. Body 14 and support spring
23 protects the power supply line 11 by exerting a required resilience.

By the way, since the insertion hole 10a of the upper flange plate 10 is closed by the bellows member 12 and the upper part of the bellows member 12 is closed by the support plate 13, the confidentiality of the cryostat can be secured. Therefore, the airtightness of the cryostat can be maintained even when the inside of the cryostat is evacuated, such as when a superconducting magnet using a forced cooling type superconducting conductor is provided in the cryostat.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, the bellows body 14 is composed of vertically split semi-cylindrical bellows sub-members 14 'and 14', and other configurations are shown. Is the same as in the above embodiment.

When assembling the structure of the present embodiment, when the support plate 13 is supported by the support springs 23 as shown in FIG.
Loosen the nut 25 and adjust the gap between the lower cylinder 15 and the upper cylinder 16 to be larger than the height of the bellows body 14,
14 'and 14' are abutted from both sides of the power supply line 11 so as to surround the power supply line 11, and the nut 25 is tightened to sandwich the bellows sub-members 14 'and 14' between the lower cylinder 15 and the upper cylinder 16,
Weld the bellows sub-members 14 'and 14' to each other to form the bellows sub-member 1
4'and 14 'can be assembled by welding the upper cylinder 16 and the lower cylinder 15 and the bellows sub-members 14', 14 '.

The structure of this embodiment has an effect that the assembling work can be facilitated as compared with the case where the cylindrical bellows body 14 is used as in the first embodiment. That is, the cylindrical bellows body
In the case of using the power supply line 14, it is necessary to pull out the power supply line 11 once and then insert the bellows body 14 into the power supply line 11, but in the structure of the present embodiment, the power supply line 11 is used.
Since the bellows sub-members 14 'and 14' can be assembled together from the state in which they are inserted into the upper flange plate 10, there is an effect that the power supply line 11 can be assembled without removing it from the support plate 13. .

[Advantages of the Invention] As described above, in the present invention, in the structure for supporting the power supply line connected to the superconducting conductor of the superconducting magnet in the cryostat, the power supply line on the outer side of the upper flange plate of the cryostat is bellows. Since the support plate, which is covered with the member and attached to the power supply line above the bellows member, is supported by the elastic member provided on the upper flange plate,
When the power supply line is cooled by the refrigerant and contracts, or when the superconducting magnet is excited and the electromagnetic force acts on the power supply line, the bellows member and the elastic member allow the deformation of the power supply line, There is an effect that the load acting on the power supply line can be reduced and the power can be stably supplied.

Further, since the insertion hole for inserting the power supply line formed in the upper flange plate can be closed by the bellows member, there is an effect that the airtightness of the cryostat can be maintained.

By the way, if the structure of the present application is adopted in a cryostat including a superconducting magnet having a refrigerant flow path inside and a power supply line connected by a pipe-shaped joint member, and including a superconducting magnet configured using the superconducting conductor, Since the deformation of the power supply line can be absorbed, the load is not applied to the joint member, buckling or breakage of the joint member can be prevented, and stable power can be supplied.

[Brief description of drawings]

1 is a sectional view showing a first embodiment of the present invention, FIG. 2 is a sectional view showing a second embodiment of the present invention, and FIG. 3 is a sectional view showing an example of a conventional power supply line supporting structure. It is a figure. A: Cryostat, 10 ... Flange plate, 11 ... Power supply line, 12 ... Bellows member, 13 ... Support plate, 14 ...
Bellows body, 15 …… Lower cylinder, 16 …… Upper cylinder, 18 …… Plate, 19 …… Upper plate, 20 …… Lower plate, 21 …… Supporting piece,
22 …… Support bolt, 23 …… Support spring.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Yoshimitsu Ikeno 7-2-5-605 Minamikasai, Edogawa-ku, Tokyo (72) Inventor Mikio Nakagawa 3-6-11 Tomihama, Ichikawa-shi, Chiba Examiner Shinji Uematsu

Claims (2)

[Claims] 1. A power supply line connected to a superconducting conductor of a superconducting magnet provided inside a cryostat,
In a support structure for a power supply line for a superconducting conductor, which is provided by inserting an insertion hole formed in an upper flange plate of a cryostat, and is supported in the vicinity of the upper flange plate, the power supply line includes the insertion hole. It is provided by loose insertion,
A support plate is attached to the power supply line outside the upper flange plate, and an expandable bellows member between the support plate and the upper flange plate covers the power supply line and is connected to the support plate and the upper flange plate. And the upper flange plate is provided with an elastic member that allows the support plate to move along the length direction of the power supply line. . 2. The support structure for a power supply line for a superconducting conductor according to claim 1, wherein the bellows member is composed of two bellows sub-members having a vertically split semi-cylindrical shape.