JP3172024B2 - Cold bath support device for superconducting magnet and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of manufacturing the superconducting magnet for low temperature vessel supporting apparatus, a low-temperature layer supported through adiabatic support device in a vacuum chamber that particular housing the superconducting coil low temperature bath for it has a superconducting magnet support device and its manufacturing thereof
It is related to improvement of manufacturing method .

[0002]

2. Description of the Related Art A superconducting magnet apparatus includes a low-temperature tank enclosing a superconducting coil, and a vacuum tank accommodating and supporting the low-temperature tank, and heat of the vacuum tank is provided between the low-temperature tank and the vacuum tank. A supporting device having a heat insulating effect is provided so as not to be transmitted to the low temperature bath.

[0003] The supporting device employs a heat-insulating FRP rod which is generally strengthened in one direction, and this rod is fastened to metal fittings fixed to a low-temperature tank and a vacuum tank, respectively. In order to stably fasten the metal fitting on the low-temperature tank side and the FRP rod at a low temperature for a long time, a sufficient adhesive force or fastening force must be applied between them.

[0004] As a conventionally known general fastening structure of this kind, there is a document (JST LOOM: Insula).
to for High Voltages (19
88) Peter Peregrinus Ltd. 9
5 to 98).

FIG. 3 shows a cross section of the fastening portion of such a support device. In the figure, reference numeral 5 denotes a rod, and reference numeral 6 denotes its metal fitting. As is clear from the figure, the FRP rod 5 of a round bar is inserted into a metal fitting 6 having a tapered hole, and a resinous tapering 8 is interposed between the two to fasten them by an axial force. It is a method to do.

[0006]

However, this resinous tape
Although the use of the palling 8 has a certain degree of strength, a superconducting magnet device having a large capacity tends to be incapable of withstanding a high surface pressure due to insufficient strength, and has a large heat shrinkage compared to the rod FRP. Therefore, during long-time operation, there is a possibility that the fastening force may be reduced by cooling. Further, in this fastening method, a gap may be formed between the end face of the FRP rod 5 and the bottom face of the metal fitting 6 due to the tensile fastening, and there is a dislike that reliability is lacking in terms of resistance to a compressive force.

[0007] The present invention has been deemed ship thereto, it is an object of stable fastening force can be maintained low temperature vessel for this type of superconducting magnet over a long period of time even for compressive load at low temperatures An object of the present invention is to provide a supporting device and a method of manufacturing the supporting device.

[0008]

According to the present invention, a low-temperature tank supporting device is formed from the following. That is, it is arranged so as to extend in the direction bridging between the low-temperature tank and the inner wall of the vacuum tank,
And a rod made of a one-way fiber bundle, a low-temperature tank fitting fixed to a low-temperature tank having a tapered hole that expands outwardly into which one end of the rod is inserted, and the other end of the rod inserted. A vacuum vessel fitting having a tapered hole that expands outward , and fixed to the inner wall of the vacuum vessel, a conical core press-fitted from the rod end in the fiber direction of the rod, and provided in the low-temperature vessel fitting and the vacuum vessel fitting. and a pressing means for pressing said conical core
Wherein the low-temperature tank fitting and the vacuum tank fitting have tapered holes.
Surface pressure is applied between the surface and the fastening taper of the rod.
The rod is tapered by the pressing means.
The intended purpose is achieved without being elastically deformed in the radial direction in the hole .

[0009]

In other words, according to this structure, the fibrous rod and the metal fitting are fastened with a high surface pressure by the pressing action of the tapered hole and the conical core of the low-temperature tank metal fitting and the vacuum tank metal fitting. Can be sufficiently suppressed, and since the conical core is pressed and held by the pressing means, even when a compressive force is applied to the rod, the displacement with the inner surface of the metal fitting is prevented, and therefore, the compression load at low temperatures is suppressed. Thus, a stable fastening force can be maintained for a long time.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows a section of the superconducting magnet device.

The superconducting magnet device is mainly composed of a superconducting coil 1
And a low-temperature tank 2 enclosing the superconducting coil, a vacuum tank 3 accommodating the low-temperature tank, and a supporting device 4 for supporting the low-temperature tank in the vacuum tank 3. .

The supporting device 4 for supporting the low-temperature tank not only firmly supports the low-temperature tank in the vacuum tank 3 but also prevents the heat of the vacuum tank wall at room temperature from being transmitted to the low-temperature tank. It is formed to also have a heat insulating effect.

As shown in detail in FIG. 2, the supporting device 4 includes a one-way reinforced FRP rod 5, a vacuum tank fitting 7 connected to one end of the rod and maintained at an atmospheric temperature, and It is formed of a low-temperature bath fitting 6 connected to the other end of the rod and maintained at the liquid helium temperature. The rod 5 is formed by bundling alumina fibers 9,
The connection with the vacuum vessel fitting 7 is made by inserting a rod end into a tapered hole 10 provided in the vacuum vessel fitting. The connection with the low-temperature tank fitting 6 is made similarly.

In manufacturing the support device 4,
First, as shown in FIG. 4, the end of the alumina fiber 9 of the rod is inserted into the taper hole 10 which is widened toward the end of each metal fitting. Reference numeral 11 denotes a polyimide tube enclosing alumina fibers.

[0015] Then the unidirectional reinforcing FRP made conical core 12 is pushed from the end of the 9 bundles alumina fiber in the longitudinal direction, <br/> alumina fiber 9 to the wall surface of the tapered hole 10 of each bracket 6,7 Adhere.

In this state, the rod 5 and the low-temperature tank fitting 6,
The vacuum tank fitting 7 is placed in the mold tank 13 and the resin 14 is impregnated with the resin 14 by applying a high pressure 15. That is, each bracket 6,
The end taper portion 16 of the FRP rod is molded by using the mold 7 as a molding die.

The impregnated resin 14 used here has a small heat shrinkage due to cooling, and further has a glass transition temperature higher than normal temperature by about 100 ° C. or more in order to prevent stress relaxation of a fastening portion at a normal temperature. It is good to use.

Next, after this mold forming, as shown in FIG. 5, a solid lubricant 17 made of molybdenum disulfide is applied to the taper holes 10 of the metal fittings 6 and 7, and the metal fittings 6 and 7 at both ends are formed.
Are pulled in opposite directions to apply an axial force to the FRP rod 5 to apply a surface pressure between the taper holes 10 of the metal fittings 6 and 7 and the fastening taper portion 16 of the FRP rod 5.

In this state, the rod end is pressed in the axial direction by the pressing means 20. That is, the bolt 19 is screwed from the nut 18 formed in the metal fittings 6 and 7 to press the end of the rod 5 to further increase the surface pressure. The surface pressure is set so that the FRP rod 5 sufficiently shrinks more than the metal fitting in the radial direction when the load support is cooled to the liquid helium temperature.
The P rod 5 is largely elastically deformed in the radial direction.

Although the description has been given of the case of the screwing device using bolts and nuts as the pressing means, other devices may of course be used.

FIG. 6 shows the effect of the lubricant 17 applied to the tape surface. The outer diameter is 24 mm, the inner diameter is 10 mm, and
When the unidirectional reinforced alumina FRP rod 5 is fastened to the SUS304 fittings 6 and 7 having a par angle of 5 °, the liquid lubricant cannot sufficiently reduce the frictional force under a high surface pressure.
The case of 7 indicates that a relatively high tensile force can be obtained with a relatively small tensile force.

In the above-described supporting device, the ends of the FRP rod 5 are molded as the taper portion 16 using the metal fittings 6 and 7 as molding dies. The FRP rod 5 is in close contact with the surface pressure, and the alumina fibers 9 are arranged at a high density on the surface of the rod end of the FRP rod 5, so that it can withstand high pressure and have a high fastening force. In addition, the FRP conical core 12 not only increases the strength in order to reduce the resin content of this portion, but also suppresses heat shrinkage due to cooling and reduces a decrease in fastening force.

With this structure, the FRP rod 5 is built in the superconducting magnet even if the inside of the low-temperature tank 2 is cooled by liquid helium.
Rod end taper portion 16 and taper holes 10 of metal fittings 6 and 7
Since the surface pressure between them is maintained, even if a large load acts on the support device 4, the support device 4 can sufficiently withstand. In particular, even when a compressive force is applied in the axial direction, the end face of the FRP rod 5 is pressed by the bolt 19, so that the fastening portion is not loosened.

[0024]

As described above, according to the present invention, the fastening between the fibrous rod and these metal fittings can be performed with a high surface pressure by the pressing action of the tapered hole and the conical core of the low-temperature fitting and the vacuum fitting. Since the cooling contraction in the radial direction of the rod can be sufficiently suppressed, and since the conical core is pressed and held by the pressing means, even when a compressive force is applied to the rod, the displacement with the inner surface of the metal fitting is prevented, so that the low temperature is maintained. Thus, it is possible to obtain a superconducting magnet device having such a supporting device capable of maintaining a stable fastening force for a long time even with a compression load caused by the above.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing one embodiment of a superconducting magnet device of the present invention.

FIG. 2 is a longitudinal sectional side view showing an embodiment of the superconducting magnet support device of the present invention.

FIG. 3 is a vertical sectional side view showing a main part of a conventional superconducting magnet support device.

FIG. 4 is a longitudinal sectional side view showing another embodiment of the superconducting magnet support device of the present invention.

FIG. 5 is a vertical sectional side view showing another embodiment of the superconducting magnet support device of the present invention.

FIG. 6 is a comparison diagram of a fastening force by applying a lubricant to a fastening portion.

[Explanation of symbols]

5 ... Rod, 6 ... Low temperature bath fitting, 7 ... Vacuum bath fitting, 12 ...
Conical core, 17: solid lubricant, 18: metal fitting end nut, 1
9 ... bolts.

Continued on the front page (72) Inventor Hiroshi Aoyama 502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref.Hitachi, Ltd.Mechanical Research Laboratory Co., Ltd. (72) Inventor Toshio Ishitsuki 502-Kandate-cho, Tsuchiura-City, Ibaraki Pref. ) Inventor Tadashi Sonobe 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd.Hitachi Plant (72) Inventor Katsuto Fujimura 4-1-1, Higashi-cho, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd.Yamazaki Plant (72) Inventor Michiyuki Ichinose 4-3-1-1, Higashicho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Chemical Co., Ltd.Yamazaki Plant (72) Inventor Ryo Hoshi 3-1-1, Saimachi, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Hitachi Plant (56) References JP-A-63-36503 (JP, A) JP-A-62-187582 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01F 6/00 ZAA

Claims (4)

(57) [Claims] A low-temperature tank holding a superconducting coil;
A low-temperature tank supporting apparatus for a superconducting magnet, comprising: a vacuum tank covering the low-temperature tank; and a low-temperature tank supporting device disposed between an inner wall of the vacuum tank and the low-temperature tank. the outer wherein disposed to extend in a direction bridging between the cryostat and the vacuum chamber inner wall, and a rod made of unidirectional fiber bundle, which is one end of the rod is inserted
A low-temperature tank fitting fixed to the low-temperature tank, having a tapered hole that expands toward the outside, and an outside in which the other end of the rod is inserted.
A vacuum vessel fitting having the tapered hole to be enlarged and fixed to the inner wall of the vacuum vessel, a conical core press-fitted from a rod end in a fiber direction of the rod, and provided in the low-temperature vessel fitting and the vacuum vessel fitting; and Bei a pressing means for pressing said conical core
And the inner surface of the tapered hole of the low-temperature tank fitting and the vacuum tank fitting.
Surface pressure is applied between the rod and the fastening taper
The rod is moved into the tapered hole by the pressing means.
The low-temperature tank supporting device for a superconducting magnet is elastically deformed in the radial direction . 2. A low-temperature tank holding a superconducting coil,
A vacuum chamber covering the low-temperature chamber; and an inner wall of the vacuum chamber and the vacuum chamber.
A low-temperature tank support device disposed between the low-temperature tank and the low-temperature tank.
In the low-temperature tank support device for a superconducting magnet, the low-temperature tank support device, the low-temperature tank and the inner wall of the vacuum tank
Extending in the direction bridging between, and unidirectional fibers
A rod consisting of a bundle and one end of the rod
It has a tapered hole that expands toward
A low-temperature bath bracket and the outside where the other end of the rod is inserted
It has the tapered hole that expands and is fixed to the inner wall of the vacuum chamber.
And the rod end in the fiber direction of the rod.
Press-fitted conical core, the low-temperature tank fitting and the vacuum tank fitting
And a pressing means provided for pressing the conical core,
The connecting tapered portion of the rod, the low-temperature tank fitting and the vacuum
Lubricant present between the tapered hole of the tank fitting and
Cryostat supporting device for a superconducting magnet, characterized in that that. 3. A low-temperature tank holding a superconducting coil,
It is arranged between the vacuum chamber inner wall covering this low temperature chamber,
Rods with fittings fixed to each tank at both ends
In the method for manufacturing a low-temperature tank supporting device for a superconducting magnet, the rod is formed of a bundle of unidirectional fibers,
Each rod has an outwardly extending end into which the end of the rod is inserted.
The enlarged taper hole is provided, and the inserted rod is
Press the conical core into the end of the rod in the fiber direction,
The resin is pressure impregnated into the conical core and rod in
After the fat has hardened, apply a force in the direction to separate the metal fittings.
Tension is applied to the rod, and in this state, the conical core is further
A method for manufacturing a low-temperature tank supporting device for a superconducting magnet, characterized in that the device is pressed by a pressing means attached to a tool . 4. A low-temperature tank holding a superconducting coil.
Between the vacuum chamber inner wall covering the low temperature chamber of
At the end was provided a rod with a fitting fixed to each tank
In the method for manufacturing a low-temperature tank supporting device for a superconducting magnet, the rod is formed of a bundle of unidirectional fibers,
Each rod has an outwardly extending end into which the end of the rod is inserted.
The enlarged taper hole is provided, and the inserted rod is
Press the conical core into the end of the rod in the fiber direction,
The resin is pressure impregnated into the conical core and rod in
After the fat has hardened, apply a solid lubricant to the tapered surface of the bracket.
In this state, force is applied in the direction to separate the metal fittings.
Tension on the rod, and in this state, expose the conical core
A method for manufacturing a low-temperature tank supporting apparatus for a superconducting magnet, characterized in that the apparatus is pressed by a pressing means attached to a metal fitting .