JPH03268409A - Superconductive coil and manufacture thereof - Google Patents

Abstract

PURPOSE:To enable to maintain a superconductive state more stably by forming a cooling path inward of the outer peripheral face of a coil spool at a position near to the innermost core of the wound layer of a superconductive wire rod. CONSTITUTION:A thin-walled pipe 10 and HIP capsule 12 are constituted of stainless steel and combined with each other. The combined material is subjected to diffusion bonding under HIP conditions of the temperature of 900-1050 deg.C, pressure of 50-300Kgf/cm<2> and processing time of 2-4 hours, then machined, wound by a superconductive wire rod 3 and impregnated with resin 8 for the purpose of obtaining a superconductive coil 20. A cooling path 17 is formed on the inside of the outer peripheral face of a coil spool 2 in a position near to the innermost core of the wound layer of this superconductive wire rod 3. Thus, it is possible to cool the superconductive wire rod 3 efficiently and to sustain a superconductive state stably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a superconducting coil and a method of manufacturing the same, and particularly to a superconducting coil with an improved cooling mechanism and a method of manufacturing the same.

[Prior Art] In general, superconducting coils require some important considerations in order to maintain a stable superconducting state. One of these considerations is to cool the superconducting coil in an upper position. Refer to Figure 15 and exit.

FIG. 15 is a vertical cross-sectional view of a conventional superconducting coil 1, and this superconducting coil 1 has a coil winding frame 2 and a superconducting wire 3 wound around the coil winding frame 2. Further, the superconducting coil 1 is housed in a helium container 4 and is cooled by a coolant 5 such as helium. Note that illustrations of a support mechanism, a heat insulation mechanism, etc. that further support the helium container rf4 are omitted.

In such a superconducting coil 1, frictional heat is generated between the superconducting wires 3 due to movement of the superconducting wire 3 due to the magnetic field in the superconducting state. this! ′! I! Conditions for raising the temperature of the xi conductive wire 3 due to heat friction and maintaining the superconducting state,
In other words, among the magnetic field, current value, and temperature, as the temperature rises, the resistance value increases and the current value decreases.
Or because the temperature of the superconducting wire 3 rises above the critical temperature.

It becomes impossible to maintain the superconducting state, that is, quenching occurs.

Therefore, in order to maintain the superconducting state, it is essential to cool the superconducting coil 1.

The location where this quench phenomenon occurs is the coil winding frame 2.
The part where the superconducting wire 3 and the superconducting wire 3 come into contact, that is, the superconducting wire 3
This is the innermost layer of the rolled layer. Therefore, in order to efficiently perform the cooling, it is necessary to sufficiently cool the coil winding frame 2 and the innermost layer or the portion between the innermost layer. It has also been found that such cooling treatment is effective in preventing the occurrence of the quench phenomenon.

Generally, it is considered to form an axial cooling central passage 6 (imaginary line) in the coil winding frame 2 as shown in the figure, but it is possible to If the thickness of the coil winding frame 2 in the radial direction is reduced in order to sufficiently cool the innermost layer or the portion between the innermost layer, the coil winding frame 2
There is a pressure at which the mechanical strength of the material decreases.

Therefore, in the past, a cooling groove 7 (imaginary line) was formed on the outer peripheral surface of the coil winding frame 2 using FRP (fiber reinforced plastic), and a coolant was passed through the groove to efficiently cool the superconducting coil 1. I was doing it.

However, as a method for preventing the above-mentioned quench phenomenon, after the superconducting wire 3 is wound around the coil winding frame 2, the superconducting wire 3 is impregnated with a resin 8 such as epoxy, thereby increasing the rigidity of the entire superconducting wire 3 or superconducting coil 1. There is also a method of increasing the superconducting wire 3 to prevent it from moving. However, in this method, there is a possibility that the cooling passage 7 is filled with the trees n8, and the refrigerant circulation efficiency decreases, making it impossible to perform cooling efficiently.

Therefore, the current situation is that either the cooling passage 7 is provided or the resin 8 is impregnated.

Therefore, if both can be performed at the same time, the possibility of occurrence of the quench phenomenon can be further reduced.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems, and includes forming a cooling passage or groove for cooling a superconducting coil, and a method to prevent clogging of the cooling passage or groove. The superconducting coil and its I would like to provide the manufacturing method! The title is II.

[Means for Solving the Problems] That is, the present invention provides a superconducting coil having a coil winding frame and a superconducting wire wound on the left side of the coil winding frame, wherein This is an M conductive coil characterized in that a cooling passage is formed inside the outer peripheral surface of the coil winding.

The first manufacturing method according to the present invention includes the steps of forming a notch for forming a cooling passage along the axial direction on the outer circumferential surface of the coil winding frame inner material, and converting the coil winding frame inner material into the coil winding frame outer material. a step of fitting together, a step of diffusion bonding the inner material of the coil winding frame and the outer material of the coil winding frame to form a coil winding frame, and a step of winding the superconducting wire around the coil winding frame and applying resin to the superconducting wire that has been wrapped once. 1. A method for manufacturing a superconducting coil, comprising the step of impregnating a superconducting coil with a superconducting coil.

Further, the second manufacturing method according to the present invention includes a step of arranging a rod for forming a cooling passage on the outer peripheral surface of the inner material of the coil winding frame along the axial direction thereof, and arranging the rod for forming the cooling passage. a step of fitting the coil winding frame inner material into the coil winding frame outer material; a step of filling a gap between the coil winding frame outer material and the coil winding frame inner material with metal powder; and a step of hot-heating the metal powder. A process of forming a metal layer through hydrostatic pressure treatment and integrating the inner material of the coil winding frame and the outer material of the coil winding frame, and eluting the above-mentioned bar material to form cooling passages to form the coil winding frame. In addition to winding the superconducting wire around this coil frame,
This method of manufacturing a superconducting coil is characterized by comprising a step of impregnating a wound G-conducting wire with a resin.

Next, the superconducting coil of the present invention and its first manufacturing method will be specifically explained based on FIGS. 1 to 6.

As shown in FIGS. 1 and 2, a thin-walled pipe 10 is prepared as the inner material of the coil winding frame, and a notch 11 for forming a cooling passage is formed on the outer peripheral surface of the thin-walled pipe 10 along its axial direction.
are formed in a predetermined number by machining. In addition, 8 meat pipe 1
0, the cooling central passage 6 is formed. Of course, this cooling central passage 6 is designed taking into consideration the overall mechanical strength.Next, as shown in FIGS. 3 and 4, the HIP capsule prepared as the outer material of the coil winding frame]-2 A thin-walled pipe 10 with a letter L is inserted therein, a lid 13 is placed on both the upper and lower ends of the pipe, and seal welding is performed in a vacuum by electron beam welding. code 1
4 shows this seal weld.

Next, HIP the thin-walled pipe 1o and the HIP capsule 12.
Diffusion bonding is performed by treatment (hot isostatic pressure treatment). At this time, the HIP pressure is selected so that the notch 11 for forming the cooling passage does not deform or disappear.

Next, as shown in FIG. 5, the HIP capsule 12 is machined to product dimensions, the lid 13 is removed 6, and flanges 15 are joined to both ends by welding, if necessary.

Further, a machined hole 16 similar to the notch 11 for forming a cooling passage is formed in this flange 15, and serves as a part of the cooling passage. That is, the cooling passage 17 is formed by the notch 11 for forming the cooling passage and the machined hole 16. Note that a center hole 18 (imaginary line) may be formed in the flange 15 so as to communicate with the cooling central passage 6.

The superconducting coil 20 is manufactured by winding the superconducting wire 3 around the coil winding frame 19 configured in this manner, impregnating a portion of the superconducting wire 3 with resin 8, and fixing the wound superconducting wire 3.

In the superconducting coil 20 manufactured in this way, cooling is carried out at a position as close as possible to the innermost shell of the winding layer of the superconducting wire 3 of the coil winding frame 19 of the superconducting coil 20 and inside the outer peripheral surface of the coil winding frame 19. Therefore, the superconducting coil 20 can be cooled sufficiently efficiently.

Furthermore, even if the superconducting wire 3 is impregnated with the resin 8, this resin can prevent the superconducting wire 3 from moving without clogging the cooling passage 17.
It is possible to maintain the cooling effect of the refrigerant passing through.

Therefore, the cooling function is strengthened, the superconducting coil 20 can maintain its superconducting state more stably than the conventional coil, and the occurrence of the quench phenomenon can be suppressed.

Next, the second manufacturing method according to the present invention will be explained based on FIGS. ff17 to 14.

The inner material 30 of the coil winding frame as shown in FIGS. 7 to 9 is used! RH, and an arbitrary number of drill holes 32 are formed on the surface of this flange 31.

As shown in FIG. 10, an arbitrary number of rods of arbitrary diameter, such as copper rods 33, are inserted into these drilled holes 32. As shown in FIG. 11, this is inserted into an HIP capsule 34 prepared as an outer material for a coil winding frame. A lower cover 35 is welded to this HIP capsule 34 in advance.

The bar material is selected from a material having a melting point lower than that of the coil winding frame inner material 3° and the coil winding frame outer material (HIP capsule 34).

The gap formed between the HIP capsule 34 and the coil winding frame inner material 3o is filled with the coil winding frame inner material 3o or metal powder 36 made of the same material as the HIP capsule 34, and the upper M37 is vacuum sealed by electron beam welding. do.

Next, perform HIP processing. Through this HIP process, the metal powder 36 is pressure sintered and becomes a 100% density metal layer 38 (bulk material), which forms the coil winding frame inner material 30 and the HIP capsule 3.
Fuse with 4 and become a body.

Next, as shown in FIG. 12, a drill hole 39 is drilled in the lower ff 135 and the upper lid 37 at the portions facing the copper rod 33, so that the copper can be eluted in the next step. That is, only the copper rod 33 is eluted at a temperature higher than the melting point of copper, for example 1100° C., in an atmospheric furnace or in a vacuum to form a cavity. This cavity becomes the cooling passage 4o.

Next, as shown in FIG. 13, the HIP capsule 34 is machined to product dimensions, and the lower lid 35 and upper lid 37 are removed. Then, if necessary, flanges 41 are joined to both ends by welding.

It should be noted that a drilled hole 42 similar to that of the cooling passage 40 is formed in this flange 41 to form a - section of the cooling passage 40. Note that a center hole 43 (imaginary line) may be formed in the flange 41 so as to communicate with the cooling central passage 6.

A superconducting coil 45 is obtained by winding the superconducting wire 3 around the thus configured coil winding frame 44 and impregnating a portion of the superconducting wire 3 with resin 8.

In the superconducting coil 45 manufactured in this way, the position is as close as possible to the innermost shell of the winding layer of the superconducting wire 3 of the coil winding frame 44 and on the outer circumferential surface of the coil winding frame 44, similarly to the above-mentioned superconducting coil 20. Cooling passage 40 inside
It becomes possible to arrange and form the superconducting coil 45, and the superconducting coil 45 can be cooled sufficiently efficiently.

Furthermore, even if the superconducting wire 3 is impregnated with the resin 8, this resin can prevent the superconducting wire 3 from moving without clogging the cooling passage 40.
It is possible to maintain the cooling effect of the refrigerant passing through.

Therefore, the cooling function is strengthened, and the superconducting coil 4-5
can maintain its superconducting state more stably than conventional ones, and can suppress the occurrence of the quench phenomenon.

[Function] In the GZ conductor coil and the manufacturing method thereof according to the present invention, since the cooling passage is formed inside the outer peripheral surface of the coil winding frame at a position close to the innermost shell of the winding layer of the superconducting wire, cooling of the superconducting wire is prevented. In addition, even if the part where the superconducting wire is wound is impregnated with resin, the cooling passage is not affected by the resin and will not become clogged, so each function, that is, cooling and superconducting wire, can be performed independently. can be fixed, and the superconducting state can be maintained stably.

Moreover, the method for manufacturing such superconducting coils is to use diffusion bonding using hot isostatic pressing (HIP treatment) or by using HIP capsules, so manufacturing using conventional machining is not required. It is possible to manufacture superconducting coils of any shape depending on the method.

[Example] Next, a first example of the method for manufacturing a superconducting coil according to the present invention will be described.

First, a thin-walled pipe 10 as shown in FIGS. 1 and 2,
and 11 I P as shown in FIGS. 3 and 4.
The capsule 12 is constructed from stainless steel chains and assembled together. Using this as HIP condition, the temperature is 900'C~1
050'u Pressure 50Kgf/crr (~300
Diffusion bonding was performed with K g f / cr d and a processing time of 2 to 4 hours.

Next, the machining process shown in FIG. 5 was performed, and the superconducting wire 3 was wound and impregnated with resin 8 as shown in FIG. 6, thereby manufacturing a superconducting coil 2o.

The thus manufactured superconducting coil 20 has the desired cooling function and fixing function.

Further, a second embodiment of the present invention will be described.

First, the coil winding frame inner material 3 as shown in FIGS. 7 to 9
0, and HIP as shown in Figures 10 and 11.
The capsule 34 is constructed from stainless steel and assembled together with the copper rod 33. Furthermore, coil winding frame inner material 30
and the HIP capsule 34 with stainless steel powder 3.
Fill 6.

This is then subjected to HIP treatment and pressure sintered.

HI P conditions, temperature 900'C ~ l O! ”)
0°C1 pressure 1000K g f/c n? ,
Processing time is 2 to 4 hours.

Next, the copper rod 33 is eluted at a temperature of 1100° C. to form a cooling passage 40 as shown in FIG.

Finally, as shown in Fig. 14, the superconducting wire 3 is wound,
A superconducting coil 45 was obtained by impregnating it with resin 8.

The superconducting coil 45 manufactured in this manner has the desired cooling function and fixing function.

[Effects of the Invention] As described above, according to the present invention, it is possible to enjoy both the conventionally contradictory functions of cooling and fixing a superconducting wire, and it is possible to maintain a stable superconducting state.

[Brief explanation of drawings]

FIG. 1 is a plan view of a coil winding frame (thin-walled pipe 10) in the first manufacturing method of a superconducting coil 20 according to the present invention, FIG. 2 is a longitudinal cross-sectional view of the thin-walled pipe 10, and FIG. same,
FIG. 4 is a plan view of the thin-walled pipe 10 and coil winding frame outer material (HTP capsule 12) combined; FIG. 5 is a vertical cross-sectional view of the state with the lid 13 attached; M2S is removed after diffusion bonding. FIG. 6 is a vertical cross-sectional view of the superconducting coil 20 with the flange 15 welded together, and FIG.
Fig. 8 is a cross-sectional view taken along the line ■-■ in Fig. 7, Fig. 9 is a TX-TXM cross-sectional view in Fig. 7, Fig. 10 is the same,
FIG. 3 is a cross-sectional view of a state in which a rod (#il rod 33) is inserted into a coil winding frame inner material 30; FIG. 11 shows the coil winding frame inner material 30 and the coil winding frame outer material (
TI I P capsule 34) is combined with metal powder 36
FIG. Fig. 12 is a longitudinal cross-sectional view of the same after HIP treatment, and Fig. 13 is the same, with the lower cover 35 and upper cover 37 removed, and the flange 41
FIG. 14 is a vertical cross-sectional view of the superconducting coil 45 in a welded state, and FIG. 15 is a vertical cross-sectional view of the conventional superconducting coil 1. 1 , superconducting coil 2 , coil winding frame 3 , superconducting wire 4 , helium container 5 , coolant such as helium 6 , , , , ,Central passage for cooling 7 , ,Cooling groove 8 , ,Resin 10 , ,F# meat pipe (coil winding frame inner material) 1
1. °Cut L for forming cooling passage 2.
, , , HI P capsule 13. , , Lid 14 , Seal welded part 'J-5, , Flange 16 , Machined hole 17 , Cooling passage 18. ...Central hole 19, . 00. , Coil winding frame 20 , Superconducting coil 30 , Coil winding frame inner material 31 , Flange 32 , Drill hole 33 , Copper Rod (bar material) 34 , , , , HIP capsule 35-0.60. Lower lid 36 , Metal powder 37 , Upper lid 38 , Metal layer 39 , Drill hole 40 , Cooling passage (stainless steel powder ) (Coil winding frame outer material) (Coil winding frame outer material) 41 , Flange 42 , Machined hole 43 , Central hole 44 , Coil winding frame 45 , , , , superconducting coil

Claims (3)

[Claims] (1) A superconducting coil having a coil winding frame and a superconducting wire wound around the coil winding frame, wherein the superconducting coil is cooled inward from the outer peripheral surface of the coil winding frame at a position close to the innermost shell of the winding layer of the superconducting wire. A superconducting coil characterized by having a passageway formed therein. (2) A step of forming a notch for forming a cooling passage along the axial direction on the outer peripheral surface of the inner material of the coil winding frame, and a step of fitting the inner material of the coil winding frame to the outer material of the coil winding frame. a step of diffusion-bonding the inner material of the coil winding frame and an outer material of the coil winding frame to form a coil winding frame, and a step of winding a superconducting wire around the coil winding frame and impregnating the wound superconducting wire with a resin. A method for manufacturing a superconducting coil characterized by the following. (3) A step of arranging a rod for forming a cooling passage on the outer peripheral surface of the coil winding frame inner material along its axial direction, and a step of arranging the coil winding frame inner material on which the cooling passage forming rod is arranged A step of fitting the outer material of the coil winding frame to the outer material of the coil winding frame, a step of filling the gap between the outer material of the coil winding frame and the inner material of the coil winding frame with metal powder, and a step of applying the metal powder to the metal layer by hot isostatic pressing. year,
a step of integrating the inner material of the coil winding frame and an outer material of the coil winding frame; a step of eluting the bar material to form a cooling passage to form a coil winding frame; and a step of attaching a superconducting wire to the coil winding frame. 1. A method for manufacturing a superconducting coil, comprising the steps of winding the coil and impregnating the wound superconducting wire with a resin.