JPH054263Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The vertical position of an electromagnet disposed in a vacuum chamber can be easily aligned with the vertical position of an annular electromagnet disposed radially outward of the electromagnet. The present invention relates to a cryogenic device equipped with an electromagnetic centering mechanism.

(Prior Art) As is well known, superconductivity has been in the spotlight, and the technology has made great progress, with superconductors that exhibit superconductivity at higher temperatures being created and discovered one after another. However, in practice, liquid helium or the like is used as a coolant to cool the electromagnet. As a cooling means, a low temperature holding tank filled with liquid helium or the like is generally used. An example of a cryogenic apparatus including such a cryogenic tank will be described below with reference to FIG.

That is, a low temperature holding tank 23 in which liquid helium 21 is sealed is provided. The low temperature holding tank 2
A liquid nitrogen chamber into which liquid nitrogen 23 is injected is provided inside the magnet 2 in the thickness direction, and an annular electromagnet 24 is immersed in the liquid helium 21.
is supported at the lower part of a support rod 25 fixed to the inner upper surface of the low temperature holding tank 21. Also,
A plurality of heat shielding plates 2 are provided near the fixed side of the support rod 25.
6 is disposed at right angles to the support rod 25. The hole provided in the radial center of the upper surface of the low temperature holding tank 22 has an inside thereof in a sealed state.
Vacuum chamber 27 maintained at a vacuum level of about 10 ^-6 Torr
is inserted through the vacuum chamber 27, and the lower part of the vacuum chamber 27 is loosely fitted inside the annular electromagnet.
The upper surface of the vacuum chamber 27 is sealed by a sealing flange 27c provided on the outer periphery of the vacuum chamber 27. An electromagnet 29 is supported inside the vacuum chamber 27 at a position corresponding to the annular electromagnet 24 by a support rod 28 fixed to the lower surface of a support lid 27a that seals the top of the vacuum chamber 27. A plurality of heat shielding plates 30 are disposed near the fixed side of the support rod 25 at right angles to the support rod 28, and liquid nitrogen having a through hole in the support rod 28 is provided between the shielding plates 30 and the electromagnet 29. A tank 31 is provided.
Although not shown, the liquid nitrogen tank 31 is supported by the lower end of a support rod, one end of which is fixed to the lower surface of the support lid 27a. A strain gauge 35 is attached near the fixed portion of the support rod 28 that supports the electromagnet 29.

Therefore, in the assembled state of the low temperature holding tank 22 and the vacuum tank 27, if the vertical position of the electromagnet 29 is shifted with respect to the annular electromagnet 24, non-uniformity will occur in the electromagnetic force, and a predetermined amount of energy will be generated from the electromagnet 29. No electrical output is obtained. Therefore, it is desirable that the vertical positions of both the electromagnets 24 and 29 match. Therefore, in the design stage, the dimensions of each component of the cryogenic apparatus are determined in advance, taking into consideration the thermal contraction of each component. Finally, in the operating state of the cryogenic device, both the electromagnets 24, 2
The output of the strain gauge 35 is detected by utilizing the fact that tensile force or pressing force is applied to the support rod 28 supporting the electromagnet 29 in accordance with the amount of vertical deviation of the annular electromagnet 9. Detecting the degree to which the electromagnet 29 is shifted upward or downward with respect to the strain gauge 24, so that the output of the strain gauge 35, which takes into account shrinkage strain based on the temperature of the strain gauge 35 attached part, becomes approximately zero. Either a shim with a thickness equal to or less than the crushing margin of the seal provided between the upper surface of the low temperature holding tank 22 and the sealing flange 27c is interposed, or if only the shim is interposed, the electromagnets 24 and 29 cannot be moved in the vertical direction. If the position adjustment is insufficient, the electromagnet 29 may be adjusted in relation to the annular electromagnet by, for example, replacing the vacuum chamber 27 with another vacuum chamber 27 equipped with an electromagnet 29 supported by support rods 29 of different lengths. The vertical positions of are adjusted to match.

(Problems to be solved by the invention) The conventional cryogenic device explained based on FIG. 3 is widely used because of its simple structure. There are problems as described below in matching the vertical positions of the electromagnets disposed in both the tanks.

That is, in this conventional technique, both the electromagnets 24, 2
9, the support rods 25 and 28, the low temperature holding tank 22, the vacuum tank 27, etc. are designed and manufactured taking into account the amount of heat shrinkage, but as is well known, calculation errors and manufacturing errors may occur. , when the temperature is reduced to a level low enough to cause superconductivity, the positions of the two electromagnets 2 are misaligned to such an extent that the cryogenic device cannot exhibit its desired performance.
Occurs between April 4th and 29th. Therefore, the degree of positional deviation can be determined in advance by the support rod 2 that supports the electromagnet 29.
Liquid nitrogen 23 and liquid helium, which are injected or sealed into the low temperature holding tank 22, are detected by a strain gauge 35 attached near the fixed portion of the cryostat 8, and the positional deviation is adjusted based on the detection result. 21, not only must the cryogenic tank 22 and vacuum chamber 27 be disassembled, but in some cases, operations such as assembly, refrigerant supply and discharge, strain detection, and disassembly may be repeated. Sometimes you have to. That is, in this conventional technique, in order to operate the cryogenic device normally, not only is it necessary to adjust the position of the electromagnet 29 in the vertical direction with respect to the annular electromagnet 24 over a long period of time, but also it is necessary to adjust the position of the electromagnet 29 in the vertical direction with respect to the annular electromagnet 24. There are disadvantages such as the need to prepare spare parts.

In order to avoid the waste of preparing another vacuum chamber 27, for example, a structure may be considered in which the support rod 28 supporting the electromagnet 29 is supported via a turnbuckle so as to be movable in the vertical direction. However, the vacuum chamber 27
A heat shielding plate 30 is disposed inside, and when the vacuum chamber 27 is opened, the heat shielding plate 30 becomes contaminated by dirt, dust, etc. floating in the atmosphere. If it is re-assembled in a contaminated state, the heat shielding performance will deteriorate, and heat will be easily transmitted from the outside into the cryogenic holding tank 22 through the vacuum chamber 27, reducing the cooling capacity of the cryogenic equipment. The surface of the heat shield plate 30 must be cleaned. The cleaning takes a long time, and when comparing the cleaning cost with the cost of preparing another vacuum chamber 27 in advance, it is not necessarily uneconomical to prepare the vacuum chamber 27 in advance. .

Further, a structure may be considered in which the support rod 28 of the electromagnet 29 is made to penetrate the support lid 27a and protrude upward and outward, and is supported on the upper surface of the support lid 7a so as to be movable up and down. Such a structure is used in the low temperature holding tank 2.
It is desirable because the electromagnet 29 can be easily raised and lowered without disassembling the electromagnet 2 and the vacuum chamber 27, but as a practical matter, it is necessary to maintain a degree of vacuum of about 10 ^-6 Torr inside the vacuum chamber 27. However, with the structure in which the support body 28 protrudes from the support lid 27a, it is difficult to realize the required degree of vacuum.

Therefore, in the present invention, when adjusting the vertical position of the electromagnet with respect to the annular electromagnet, it is not necessary to detect the positional deviation of the two electromagnets using a strain gauge, and there is no need to disassemble the two tanks. The object of the present invention is to provide a cryogenic device equipped with an electromagnet centering mechanism that can easily align vertical positions.

(Means for Solving the Problems) The present invention aims to move the electromagnet supported in the vacuum chamber vertically by moving the support lid to which the support rod supporting the electromagnet is fixed. By moving the electromagnet up and down, the problem of the conventional technology, which arises because it is difficult to move the electromagnet up and down, has been solved. A low temperature holding tank is provided with a refrigerant chamber in which a refrigerant is sealed and an insertion hole communicating with the refrigerant chamber in the center of the upper surface thereof, and an annular electromagnet is supported in a state immersed in the refrigerant in the refrigerant chamber, and A vacuum chamber having a flange on its outer periphery that is placed on the top surface of the low temperature holding tank and seals the refrigerant chamber is inserted into the insertion hole, and a lower part of the vacuum chamber is loosely fitted inside the annular electromagnet, In a cryogenic apparatus, the support lid fixed to the opening of the vacuum chamber is raised and lowered in accordance with the position of the annular electromagnet. An adjusting means for freely supporting the support lid, moving it up and down, and fixing it is provided in the upper part of the low temperature holding tank.

(Function) The present invention has a structure in which the upper structure of the vacuum chamber is such that the support lid that supports the electromagnet via the support body can be raised and lowered on the upper opening side of the vacuum chamber, and a The support lid is supported in a vertically movable manner, and an adjustment means is provided for adjusting the vertical position of the electromagnet.

Therefore, when the adjusting means is actuated, the upper part of the vacuum chamber moves up and down in response to the actuation of the adjusting means. Further, since the electromagnet is supported by a support fixed to the lower surface of the support lid provided on the upper opening side of the vacuum chamber, the electromagnet also moves vertically in response to the operation of the adjustment means. It will be moved to That is, the electromagnet is easily moved to a corresponding position in the vertical direction of the annular electromagnet by operating the adjusting means, and when the electromagnet reaches the corresponding position, stopping the operation of the adjusting means causes the electromagnet to move to the corresponding position. The electromagnet will be maintained at .

Whether or not the corresponding position is present can be easily confirmed by measuring the electrical output from the electromagnet. That is, as the degree of vertical positional deviation of the electromagnet with respect to the annular electromagnet increases, the electrical output decreases, and as the degree of positional deviation decreases, the electrical output increases. This is because the vertical positions of both electromagnets correspond best. Therefore, the vertical position of the electromagnet relative to the annular electromagnet can be easily adjusted by simply operating the adjusting means.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

First Example The first example will be described below based on FIG.

That is, a low temperature holding tank 2 having a refrigerant chamber in which liquid helium 1 is sealed is provided. A liquid nitrogen chamber into which liquid nitrogen 3 is injected is provided inside the low temperature holding tank 2 in the thickness direction, and an annular electromagnet 4 is immersed in the liquid helium 1.
is supported at the lower part of a support rod 5 fixed on the inner upper surface of the refrigerant chamber. In addition, a plurality of hollow disc-shaped heat shielding plates 6 are provided near the fixed side of the support rod 5.
is arranged perpendicular to the support rod 5. A vacuum chamber 7 whose interior is maintained at a vacuum degree of about 10 ^-6 Torr in a sealed state is inserted into the insertion hole provided at the radial center of the upper surface of the low temperature holding chamber 2. The lower part of the annular electromagnet 4 is loosely fitted inside the annular electromagnet 4, and it is fixed in a sealing manner on the upper surface of the low temperature holding tank 2 by a sealing flange 7c provided on the outer periphery of the vacuum tank 7. Inside the vacuum chamber 7, at a position corresponding to the annular electromagnet 4, an electromagnet 9 is supported by a support rod 8 fixed to the lower surface of a support lid 7a provided on the upper opening side of the vacuum chamber 7. A plurality of heat shield plates 10 are disposed near the upper fixed part of the support rod 8 at right angles to the support rod 8, and a liquid nitrogen tank 11 is provided between the heat shield plates 10 and the electromagnet 9. will be placed. Although not shown, the liquid nitrogen tank 11 is supported by the lower part of a support rod, one end of which is fixed to the lower surface of the support lid 7a. A bellows 12 is formed on the outer periphery of the upper side of the vacuum chamber 7, the upper side of which is vertically expandable and retractable. Moreover, the support lid 7a and the flange 7
b and the sealing flange 7c are provided with the same number of through holes radially centered in the radial direction and at equal intervals, and the through holes are provided at positions corresponding to the through holes on the upper surface of the cryogenic tank 2. A threaded rod 13 is inserted into the threaded hole. A fixing nut 14a is screwed onto the threaded side of the threaded rod 13 and is tightened onto the upper surface of the sealing flange 7c. A pair of set nuts 14b screwed onto the opposite side of the threaded rod 13 are tightened while sandwiching the upper surface of the support lid 7a and the lower surface of the flange 7b.

Therefore, the low temperature holding tank 2 and the vacuum tank 7 are assembled, liquid nitrogen is injected into the liquid nitrogen chamber and the liquid nitrogen tank 11, and liquid helium 1 is injected into the refrigerant chamber.
is injected, and when the vacuum chamber 7 is degassed to a degree of vacuum of about 10 ^-6 Torr, the annular electromagnet 4 is cooled to an extremely low temperature and is wound around the annular electromagnet 4. The coil becomes superconducting.
When the coil is energized, an electrical output is obtained from one end of the coil wound around the electromagnet 9, as is well known. The electrical output is increased or decreased depending on the degree of vertical positional deviation between the electromagnets 4 and 9. That is, if the degree of positional deviation is large, the electrical output will be small, and conversely, if the degree of positional deviation is small, the electrical output will be large.
Therefore, the set nuts 14b are sequentially actuated to move the sealing lid 7a in the vertical direction, in other words, to move the electromagnet 9 in the vertical direction.
The support lid 7a was fixed by tightening the assembly nut 14b at a position where the maximum electrical output could be obtained. The fixed position of the support lid 7a indicates that the vertical positions of the two electromagnets 4 and 9 completely correspond to each other. Therefore, as in the conventional technique explained based on FIG. , assembly and disassembly of the low temperature holding tank 2 and vacuum chamber 7, insertion of shims or other vacuum chamber 7
The assembly nut 14b screwed onto the opposite side of the threaded rod 13 does not need to be reassembled with the threaded rod 13.
It is now possible to easily match the vertical position of the electromagnet 9 with respect to the annular electromagnet 4 by simply operating the annular electromagnet 4.

It should be noted that since the electromagnet 9 can be easily moved in the vertical direction in this way, the following effects have been derived. That is, in the conventional technology, since it takes time to adjust the positions of both electromagnets,
If the electrical output value from the electromagnet is within a set value having a certain range and the detection result by the strain gauge is within an allowable range, the two electromagnets are considered to correspond. In other words, the maximum capacity of the cryogenic equipment was not necessarily utilized, but with the present invention, the electromagnet can be easily moved, so the maximum output of the electromagnet can be easily determined. This has made it possible to reliably utilize the maximum capacity of cryogenic equipment.

Second example The second embodiment will be explained based on FIG. 2.

Since this embodiment differs from the first embodiment only in the structure of the upper part of the vacuum chamber, only this difference will be explained.

That is, a bellows 12 is provided inside the upper part of the vacuum chamber 7 and concentrically with the vacuum chamber 7, and a support rod 8 is provided at the bottom of the bellows 12.
A support lid 7a supporting the electromagnet 9 was sealed in a sealed manner. On the upper surface of the support lid 7,
The large diameter side of the threaded rod 13, which has a large diameter portion on one end side and a thread is threaded on the other end side, is connected to the threaded rod 13.
are connected so as to be rotatable about the radial center.
Further, a cross beam 15 passing through the radial center of the vacuum chamber 7
is fixed on the upper surface of the sealing flange 7c, and the threaded side of the threaded rod 13 is screwed into a threaded hole formed in the cross beam 15.

Therefore, when the threaded rod 13 is actuated, the support lid 7a is moved up and down in response to the actuation of the threaded rod 13. That is, since the electromagnet 9 supported by the support lid 7a via the support rod 8 also moves up and down, its operation and effect are exactly the same as in the first embodiment.

(Effect of the invention) The present invention has a structure on the upper side of the vacuum chamber in order to make the electromagnet supported in the vacuum chamber correspond to the position of the annular electromagnet that is immersed and supported in the refrigerant in the refrigerant chamber. is provided on the upper side of the vacuum chamber and supports the electromagnet through a support, and has a structure in which it can be raised and lowered freely, and the support lid is supported on the upper part of the cryogenic tank so that it can be raised and lowered. An adjustment means was provided.

Therefore, when the adjusting means is actuated, the electromagnet is supported via the support body in response to the actuation, without having to disassemble and reassemble the cryogenic device as in the prior art. As the supporting lid is raised and lowered, the electromagnet is also raised and lowered. When the adjustment means is deactivated, the electromagnet is maintained at the position when the adjustment means is deactivated. That is, since the electromagnet can be easily moved up and down and maintained by simply stopping the operation of the adjusting means, it has become possible to easily match the electromagnet to the annular electromagnet.

Furthermore, since the electromagnet can be easily raised and lowered, changes in electrical output corresponding to each position of the electromagnet can be easily detected. That is, since the position where the electrical output shows the maximum value means that the two electromagnets correspond best, it is no longer necessary to measure the degree of misalignment between the two electromagnets using a strain gauge.

Therefore, according to the present invention, when adjusting the positions of both electromagnets in the vertical direction, the electromagnets supported in the vacuum chamber can be raised and lowered relative to the annular electromagnet without disassembling the cryostat and vacuum chamber. As a result, we were able to realize a cryogenic device equipped with an electromagnet centering mechanism that can be easily adapted.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of the first embodiment, Fig. 2 is a side sectional view of the second embodiment.
FIG. 3 is a cross-sectional view of the main parts of the embodiment, and a side cross-sectional view of the conventional technology. 1...Liquid helium, 2...Low temperature holding tank, 3...
...Liquid nitrogen, 4...Annular electromagnet, 5, 8...Support rod, 6,10...Heat shield plate, 7...Vacuum chamber, 7a
... Support lid, 7b ... Flange, 7c ... Sealing flange, 9 ... Electromagnet, 11 ... Liquid nitrogen tank, 1
2... Bellows, 13... Threaded rod, 14a... Fixed nut, 14b... Set nut, 15... Cross beam.

Claims (1)

[Scope of utility model registration request] A cryostat is provided with a refrigerant chamber in which a refrigerant is sealed, and a low temperature holding tank having an insertion hole communicating with the refrigerant chamber in the center of the upper surface thereof, and supports an annular electromagnet immersed in the refrigerant in the refrigerant chamber. , a vacuum chamber having a flange on its outer periphery that is placed on the upper surface of the low temperature holding tank and seals the refrigerant chamber is inserted into the insertion hole, and a lower part of the vacuum chamber is loosely fitted inside the annular electromagnet. , an electromagnet vertically installed on the lower surface of the support lid fixed to the upper opening of the vacuum chamber in correspondence with the position of the annular electromagnet; A cryogenic apparatus equipped with an electromagnetic centering mechanism, characterized in that an adjusting means for vertically moving and fixing the supporting lid is provided on the upper part of the cryogenic holding tank.