JP2001068331A - Method for manufacturing disc for superconducting coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a disc for a superconductor coil capable of remarkably reducing the number of disc machining steps. SOLUTION: This is a method of manufacturing a disc for a superconducting coil wherein the superconducting coil is formed by accommodating a superconductor in conductor grooves formed in a plate-shaped surface. In this case, a disc forming material is charged into a molding die 9 having an outer shell 10 and grooves 11. The shell 10 has an inner configuration close to the outer configuration of the above-mentioned disc and the grooves 11 swelling from the inner wall of the shell 10 and having a configuration analogous to the above- mentioned conductor grooves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a disk used for a large superconducting coil installed in a nuclear fusion experiment device or the like.

[0002]

2. Description of the Related Art A disk-type superconducting coil is used in a large superconducting coil used for a nuclear fusion device or the like (Journal of Plasma Fusion Society / Vol. 73, extra number ITER).
Special Issue on Design / P196-201). As shown in FIG. 6, a plurality of disk-shaped coils 2 formed by housing and winding superconducting conductors 1 in conductor grooves formed on both surfaces of a disk are stacked via an interlayer insulation 3 and surrounded by a ground insulation 4. The doughnut-shaped coil case 5 is provided on the outer periphery.
Is supported by the disk and the coil case.

[0003] Such a disk-type superconducting coil is shown in FIG.
Although it is manufactured by the procedure shown in
There is a need to efficiently manufacture large disks with high precision.
Conventionally, as shown in FIG. 8, a method is used in which the original shape of the disk 6 is shaped into a plate-like coil, and then the conductor grooves 7 are processed on both surfaces of the disk 6 by the side cutters 8. Yes (Journal of Plasma Fusion Society /
Volume 75 Special Issue Special Issue on ITER Engineering R & D / P14-16).

[0004]

In the conventional method of machining the conductor groove 7 of the disk 6 with the side cutter 8 as described above, since the conductor groove 7 is formed by cutting from the surface of the disk 6, a large amount of cutting is required. Further, in such a groove having a small radius of curvature, the amount of illegal processing increases. Although the diameter of the side cutter work may be reduced in order to reduce the amount of illegal machining, the number of blades to be attached is reduced, and machining accuracy is deteriorated and the life of the blades is shortened. Since such processing needs to be performed on both surfaces of the disk 6, the number of processing steps is increased.

The present invention has been made in view of such a problem, and it is an object of the present invention to provide a method of manufacturing a disk for a superconducting coil which can significantly reduce the number of disk processing steps.

[0006]

According to a first aspect of the present invention, there is provided a superconducting coil for forming a superconducting coil by accommodating a superconducting conductor in a conductor groove formed in a plate-like surface. In the method of manufacturing a disk, a disk material is injected into a mold having an outer shell having an inner shape close to the outer shape of the disk and a groove shape rising to the inner wall of the outer shell and having a shape similar to the conductor groove. Cast discs with conductor grooves.

According to the present invention, the groove processing by the side cutter can be performed only by performing the surface treatment after the disk is manufactured by casting, and the number of processing steps can be remarkably reduced. Therefore, the superconducting coil can be manufactured at a lower cost. it can.

According to a second aspect of the present invention, the disk material is made of stainless steel. According to the present invention, a mechanically strong disk for a superconducting coil can be obtained. The invention according to claim 3 is characterized in that a disk is cast for each predetermined portion in the circumferential direction of the superconducting coil, and thereafter, they are joined to form a disk around the entire coil. According to the present invention, a large superconducting coil disk can be obtained with a relatively small mold.

According to a fourth aspect of the present invention, after the upper and lower halves of the disk are manufactured by a casting method, a heat conductive layer such as copper or aluminum is inserted between the disks, and finally the HI
It is characterized in that an integrated disk is manufactured by P (hot isostatic pressing).

According to the present invention, by inserting a heat conducting layer of copper or aluminum between stainless steel discs, a disc made of stainless steel having poor heat conductivity can be made to have thermal conductivity. Can be easily cooled.

A fifth aspect of the present invention is characterized in that a portion having a heat conductive layer made of copper or aluminum and a portion not having the heat conductive layer are provided in the circumferential direction of one coil. According to the present invention, the disk can be easily cooled by a portion in which a heat conductive layer made of copper or aluminum is inserted between the stainless steel disks, and the mechanical strength can be ensured by the stainless steel only portion.

A sixth aspect of the present invention is characterized in that a cooling pipe is embedded in the disk. According to the present invention, the cooling performance of the stainless steel disk can be improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a mold used in the method for manufacturing a superconducting coil disk according to the first embodiment of the present invention. That is, the mold 9 comprises a box-shaped outer shell 10 and this outer shell
It is composed of a groove mold 11 which is raised inside the inside of the mold 10. shell
A gate 12 and a riser 13 are attached to the upper part of the top 10. The outer shell 10 and the groove mold 11 are made of molding sand.

When a molten metal made of stainless steel is poured from the gate 12 of the mold 9 having such a structure, the molten metal shown in FIG.
The original shape of the disk 6 as shown in FIG. FIG.
The mold 9 is removed, and the gate 12 and the feeder 13 are cut off. Conductor grooves 7 are formed on both sides of the disk 6 by groove molds 11. Since the surface of the disk 6 after casting has irregularities due to dimensional errors of the mold 9 and a rough surface due to molding sand, the processing margin 14 outside the dotted line is removed from the state of FIG. 2 to complete the disk 6.

According to the present embodiment as described above, the disk 6 is manufactured by casting using the mold 9 having the groove mold 11 corresponding to the conductor groove 7 of the superconducting coil. It is sufficient only to perform surface processing, and the number of disk processing steps can be significantly reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 shows that after the upper and lower half halves 15 are manufactured by the casting method described in the first embodiment, a copper or aluminum plate is interposed between the half halves 15 and HIP (hot hot). It is a configuration integrated by isotropic pressure bonding. A copper or aluminum plate forms the heat conducting layer 16.

FIG. 4 shows a structure in which a single coil (circumferential direction) is provided with a portion 17 sandwiching a heat conductive layer 16 made of copper or aluminum and a portion 18 consisting only of stainless steel not sandwiching. .

According to this embodiment, the heat conduction layer 16 made of copper or aluminum is interposed between the half-disc disks 15 made of stainless steel, so that the disk made of stainless steel having poor heat conductivity has heat conductivity. Thus, the cooling of the disk 6 can be facilitated. Further, by appropriately setting the ratio of the portion where the heat conductive layer 16 is interposed and the portion where the heat conductive layer 16 is not interposed, the two characteristics of the cooling property and the mechanical strength of the disk can be satisfied.

Next, a third embodiment of the present invention will be described with reference to FIG. This is a cooling pipe 19 near the outer periphery of the disk 6.
Embedded in the structure. The cooling pipe 19 may be provided on the inner peripheral side or both the inner and outer peripheral sides of the disk 6. According to this embodiment, by embedding the cooling pipe 19 in the stainless steel disk 6 having poor heat conductivity,
The disk 6 can be easily cooled.

[0020]

As described above, according to the method of manufacturing a disc for a superconducting coil of the present invention, a molten metal is poured into a mold having a groove shape in which a conductor groove is formed, and a disc is fabricated. Since the disk can be manufactured only by performing a certain amount of surface cutting, the number of manufacturing steps for the superconducting coil disk can be significantly reduced. Also,
Since a heat conductive layer made of copper or aluminum can be provided in the disk or a cooling pipe can be embedded, a disk for a superconducting coil having good heat conductivity can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of a mold according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a disc according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a disc according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a disc according to a second embodiment of the present invention.

FIG. 5 is a perspective view of a disk according to a third embodiment of the present invention.

FIG. 6 is a sectional view of a conventional disk-type superconducting coil.

FIG. 7 is a flowchart showing a method for manufacturing a conventional disk-type superconducting coil.

FIG. 8 is a perspective view showing a conventional method for processing a superconducting coil disk.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Superconducting conductor, 2 ... Disc-shaped coil, 3 ... Interlayer insulation, 4
... ground insulation, 5 ... coil case, 6 ... disk, 7 ... conductor groove, 8 ... side cutter, 9 ... mold, 10 ... outer shell, 11 ...
Groove type, 12 ... Gate, 13 ... Tender, 14 ... Processing, 15 ... Semi-disc, 16 ... Heat conductive layer, 17 ... Part sandwiching thermal conductive layer, 18 ... Part not sandwiching thermal conductive layer, 19 ... cooling pipe.

Claims (6)

[Claims] 1. A method for manufacturing a superconducting coil disk comprising a superconducting coil in which a superconducting conductor is accommodated in a conductor groove formed in a plate-like surface and comprising an outer shell having an inner shape close to the outer shape of the disk. Manufacturing a disc having a superconducting coil by injecting a disc material into a mold having a groove shape which rises to the inner wall of the outer shell and has a groove shape similar to the conductor groove, and casts a disk having a conductor groove. Method. 2. The method for manufacturing a superconducting coil disk according to claim 1, wherein the disk material is stainless steel. 3. The superconducting coil disc according to claim 1, wherein the disc is cast at predetermined portions in the circumferential direction of the superconducting coil, and then the discs are joined to form a disc around the entire coil. Method. 4. A disc to be cast is a half-split disc having a conductor groove on one surface of a plate, and a heat conducting layer is interposed between two half-split discs to be integrated by hot isostatic pressing. The method for manufacturing a disk for a superconducting coil according to claim 1, wherein: 5. A method for manufacturing a superconducting coil disk according to claim 4, wherein the portion having the heat conductive layer between the half-split disks is provided intermittently along the circumferential direction of the coil. 6. The method for manufacturing a disk for a superconducting coil according to claim 1, wherein a cooling tube is embedded in the disk by disposing a tube in a mold.