JP2839698B2 - Superconducting coil device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a superconducting coil device used at a very low temperature.

(Conventional technology) A superconducting coil device is formed by winding a superconducting conductor around a bobbin and interposing a spacer between layers. In a superconducting coil device that mainly flows an alternating current or a pulse, an overcurrent is not generated in the bobbin. For this reason, glass fiber reinforced plastic (using an epoxy resin for the matrix) (hereinafter abbreviated as GFRP) is used.

(Problems to be Solved by the Invention) Since the superconducting coil undergoes normal conduction transition (quenching) due to the minute movement of the superconducting conductor, the superconducting conductor must be pressed and fixed to the bobbin by the tension caused by winding. However, when the superconducting coil is cooled as shown in FIGS. 12 (a) and 12 (b), the GFRP winding frame, including the spacer between the coil layers, shrinks due to cooling, and furthermore, the superconducting coil. When the coil is excited, the coil expands in the direction along the superconducting conductor, that is, in the direction of the vector A, and contracts in the vertical direction, that is, in the direction of the vector B, due to electromagnetic force. Therefore, in the excited state, the superconducting coil (1) rises from the bobbin (2). Quenching. At this time, if the winding frame (2) including the spacer expands in the direction along the superconducting conductor by cooling and can contract in the vertical direction, the superconducting conductor can be firmly held down on the winding frame even after excitation. It is possible to provide a superconducting coil device that is difficult to quench.

An object of the present invention is to provide a superconducting coil device which is difficult to quench and provided with a bobbin and a spacer which expands in a direction along a superconducting conductor by cooling and contracts in a vertical direction.

[Configuration of the invention]

(Means for Solving the Problems) In order to achieve the above object, as a first means in the present invention, in a superconducting coil device in which a superconducting conductor is wound around a cylindrical core in a solenoid shape and used at cryogenic temperature, The core is a fiber reinforced plastic in which polyethylene fibers and inorganic fibers such as glass fibers and ceramic fibers are mixed.

Further, as a second means, in a superconducting coil device in which a superconducting conductor is wound in a solenoid shape through a spacer between layers and used at cryogenic temperature, the spacer is made of a mixture of polyethylene fiber and inorganic fiber such as glass fiber and ceramic fiber. Fiber reinforced plastic.

(Operation) In this way, the winding frame and the spacer expand in the direction along the superconducting conductor by cooling, as indicated by the vector C of the solenoidal superconducting coil device shown in FIG. And shrink greatly in the vertical direction. For this reason, the superconducting conductor is pressed against the winding frame and the spacer with a stronger force than after the winding, and the superconducting coil expands in the direction of the superconducting conductor by excitation as shown by a vector A shown in FIG. Even if contracted, the superconducting conductor can be firmly pressed against the core and the spacer by the same force as after the winding. Therefore, the occurrence of quench can be completely eliminated.

Example 1 Example 1 Hereinafter, a first example of the present invention will be described with reference to FIG.

A GFRP laminated board made of polyethylene fiber and weft glass fiber, with the warp of the cloth being in the circumferential direction of the cylindrical winding core (2a), and using the epoxy resin as a matrix, and molding the cylinder by the hand lay-up method as the winding core. An adhesive is applied to both sides of the cylindrical core (2e) and screwed into the flange (2b) to form the reel (2). The superconducting coil (1) is formed by winding a plurality of superconducting conductors around the winding core (2a) of the winding frame (2) in a coil shape. The spacer (3) of the fiber reinforced plastic is interposed. Reel (2) and first
An insulating plate (4) between the superconducting coil (1) of the layer and the superconducting coil (1) is provided with a passage for helium, which is a cryogenic refrigerant (not shown). This helium passage is conventional.

 Next, the operation of the first embodiment will be described.

When the superconducting coil device thus formed is cooled, the bobbin and the spacer expand in the coil circumferential direction along the polyethylene fiber, and largely contract in the coil axis direction perpendicular to the polyethylene fiber. FIG. 3 shows the heat shrinkage of GFRP and polyethylene fiber reinforced plastic (matrix epoxy) by cooling. Polyethylene fiber reinforced plastic thermally expands in the direction along the fiber and thermally contracts in the direction perpendicular to the fiber, and has a much higher thermal contraction rate than GFRP. For this reason, the winding frame (2) and the spacer (3) that expand in the direction along the superconducting conductor and contract in the vertical direction by manufacturing the winding core and the spacer from plastic containing polyethylene fibers in the direction along the superconducting conductor. ) Can be obtained. (Fibers in the direction perpendicular to the conductor may be inorganic fibers such as glass fiber or ceramic fiber.) Therefore, when the superconducting coil is excited, it expands in the coil circumferential direction by electromagnetic force when excited, and the coil axial direction. Even if the superconducting coil shrinks, the superconducting coil does not rise from the bobbin.

For this reason, even in the excited state, the superconducting conductor is firmly pressed against the bobbin, so that the superconducting conductor cannot even move slightly, and when the flange (26) is made of GFRP, the strength of the bobbin (2) is reduced. Greater effects can be obtained. Accordingly, a highly reliable superconducting coil device in which the superconducting coil is not quenched at all is obtained.

Further, the superconductive coil device may have an oval cross section instead of a circular cross section.

Also, the flange (2b) of the bobbin (2) is
The same material as in a) may be integrally formed.

Embodiment 2 FIGS. 4 and 5 show the spacer (3) of the second embodiment.
Is shown. This is a winding (7) with polyethylene fibers (6) as the main component and glass fibers (5) as the main component on the fibers (that is, the vertical stripes) in the direction along the conductor, and vice versa in the direction perpendicular to the conductor. And a spacer (3) made of reinforced plastic using epoxy resin as a matrix, and in this case also, the superconducting coil can be more firmly restrained. Others are the same as the first embodiment.

Example 3 FIGS. 6 to 8 show spacers (3) each having a different weave.

FIG. 6 shows that the warp yarn and the weft yarn are woven with polyethylene fiber (6) and glass fiber (5) at a certain interval.
When the spacers (3) having a number of 35% are made, the superconducting coil is restrained as a constant external force due to the expansion of the polyethylene fiber (6) and the shrinkage of the glass fiber (5) at a low temperature for a large superconducting coil device. I can do it. FIG. 7 and FIG. 8 show that the warp yarn is mainly made of polyethylene fiber (6) and the weft yarn is made of glass fiber (5), and the cloth is woven. The woven material is wound between layers of the superconducting coil. Fiber-reinforced plastic.

Also in this case, by cooling, the polyethylene fiber (6) expands and the glass fiber (5) shrinks as shown in FIG. As a result, the coil acts as an external pressure, and the coil is restrained. In the large superconducting coil device, the size of the bobbin (2) is also large,
Since the length also tends to be longer, the amount of deformation increases when cooled. For this purpose, as shown in FIGS. 7 and 8, the warp yarn is mainly composed of polyethylene fiber (6) and the glass fiber (5).
It is also possible to adjust the expansion and contraction of the weft yarn in a similar combination to adjust the internal and external forces applied to the coil. For this reason, the compounding ratio of warp and weft is generally 50% in order to maintain the change in initial tension.
Should be held within tension.

Embodiment 4 FIG. 9 shows the embodiment of FIG.

This is the case where the first and second spacers (3a) and (3b) of the fiber reinforced plastic in which the material of the woven material is changed are overlapped in a double (or triple, etc.), and the reinforcing fibers are changed. The amount of deformation at a low temperature can be changed even in a combination with a woven fabric.

Example 5 A spacer (3) made of one piece of fiber-reinforced plastic
Can be formed by winding or butting fabrics as shown in FIGS. 6, 7, and 8, as shown in FIGS.

〔The invention's effect〕

As described above, according to the present invention, the deformation of the superconducting coil caused by cooling and excitation is performed by the winding core,
In the second aspect, the spacer is deformed so as to compensate by cooling, and in any case, the superconducting coil can be firmly pressed against the winding core and the spacer in the excited state, so that there is no quenching due to fine movement of the superconducting conductor. A coil device is obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention, FIGS. 2 (a) and 2 (b) are explanatory views for explaining the operation of FIG. 1,
FIG. 3 is a curve diagram showing the heat shrinkage in the fiber direction of glass and polyethylene fiber reinforced plastics. FIGS. 4 and 5 are longitudinal sectional views and essential part sectional perspective views showing the second embodiment, and FIG. FIG. 8 to FIG. 8 are plan views showing the main parts of a spacer obtained by weaving the third embodiment differently, FIG. 9 is a cross-sectional view of the spacer showing the fourth embodiment, FIG. 10 and FIG. FIG. 12 is a cross-sectional view showing different spacer shapes of the fifth embodiment, and FIGS. 12 (a) and 12 (b) are explanatory views showing a state where a gap is formed between the superconducting coil and the bobbin of the conventional example. is there. 1 ... superconducting coil, 2a ... core, 2b ... flange, 2 ... frame, 3 ... spacer, 4 ... insulator, 5 ... glass fiber, 6 ... polyethylene fiber.

────────────────────────────────────────────────── (5) References JP-A-63-20806 (JP, A) JP-A-62-108508 (JP, A) JP-A-60-173808 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) H01F 6/00

Claims (2)

(57) [Claims] 1. A superconducting coil device in which a superconducting conductor is wound around a cylindrical core in a solenoid shape and used at a very low temperature, wherein the core is a fiber reinforced fiber comprising a mixture of polyethylene fibers and inorganic fibers such as glass fibers and ceramic fibers. A superconducting coil device made of plastic. 2. A superconducting coil device in which a superconducting conductor is wound in a solenoid shape through a spacer between layers and used at a very low temperature, wherein the spacer is a fiber-reinforced plastic in which polyethylene fibers and inorganic fibers such as glass fibers and ceramic fibers are mixed. A superconducting coil device, characterized in that: