Superconducting coil

Abstract

To provide a superconducting coil that can be manufactured in a short time.SOLUTION: A superconducting coil 10 includes a coil body 12 formed by winding a superconducting wire 18, and an impregnating material 16 containing a photocurable resin material that impregnates at least a portion of the coil body 12. The superconducting wire 18 includes a light-transmitting coating 18b that transmits at least a portion of light when irradiated with light that cures the photocurable resin material. Additionally or alternatively, the superconducting coil 10 includes a bobbin 14 around which the superconducting wire 18 is wound, at least a portion of which is made of a light-transmitting material that transmits at least a portion of light when irradiated with light that cures the photocurable resin material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a superconducting coil.

Background Art

[0002] A superconducting coil is formed by winding a superconducting wire. The wound superconducting wire is impregnated with a synthetic resin material for fixing the superconducting wire and also for improving the mechanical strength of the superconducting coil.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, a thermosetting resin is used for impregnating the wound superconducting wire. The process of thermosetting may require, for example, several hours to several tens of hours or more. Therefore, it takes a long time to manufacture a superconducting coil.

[0005] One exemplary object of an aspect of the present invention is to provide a superconducting coil that can be manufactured in a short time.

Means for Solving the Problems

[0006] According to an aspect of the present invention, a superconducting coil includes a coil body formed by winding a superconducting wire, and an impregnating material containing a photocurable resin material and impregnating at least a part of the coil body. The superconducting wire includes a light-transmissive coating that transmits at least a part of light when irradiated with light for curing the photocurable resin material.

[0007] According to an aspect of the present invention, a superconducting coil includes a coil body formed by winding a superconducting wire, an impregnating material containing a photocurable resin material and impregnating at least a part of the coil body, and a winding frame around which the superconducting wire is wound, at least a part of which is formed of a light-transmissive material that transmits at least a part of light when irradiated with light for curing the photocurable resin material.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a superconducting coil that can be manufactured in a short time.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description and the drawings, the same or equivalent components, members, and processes are denoted by the same reference numerals, and duplicate descriptions will be omitted as appropriate. The scales and shapes of the respective parts shown are set for convenience in order to facilitate the description, and are not to be construed in a limited sense unless otherwise specified. The embodiments are illustrative and do not limit the scope of the present invention in any way. Not all features and combinations thereof described in the embodiments are necessarily essential to the invention.

[0011] FIG. 1 is a diagram schematically showing a superconducting coil 10 according to a first embodiment. The superconducting coil 10 is configured to generate a strong magnetic field when energized in a state cooled to an extremely low temperature below the superconducting transition temperature. The superconducting coil 10 may be a known superconducting coil, for example, a low-temperature superconducting coil. Alternatively, the superconducting coil 10 may be a high-temperature superconducting coil. The superconducting coil 10 is mounted on a high magnetic field utilization device as a magnetic field source of, for example, an NMR system, an MRI system, an accelerator such as a cyclotron, a high-energy physics system such as a fusion system, or other high magnetic field utilization devices (not shown), and can generate the high magnetic field required for the device.

[0012] FIG. 1 schematically shows a cross-section of the superconducting coil 10 by a plane including the center line C of the superconducting coil 10. The superconducting coil 10 includes a coil body 12, a winding frame 14, and an impregnating material 16.

[0013] The coil body 12 is formed by winding a superconducting wire 18. In the illustrated example, the coil body 12 is a cylindrical coil formed by a stacked multilayer winding, but is not limited thereto. As another example, the coil body 12 may be a saddle-shaped coil. The coil body 12 may be formed by any other winding method and may have any other shape.

[0014] When the coil body 12 is a cylindrical coil, the winding frame 14 has a hollow cylindrical shape. The outer peripheral surface of the winding frame 14 is used as a winding surface 14a. The coil body 12 is formed by winding the superconducting wire 18 around the winding surface 14a. Further, the winding frame 14 may have a flange portion 14b. The flange portion 14b extends radially outward over the entire circumference from both ends of the winding frame 14 in the direction of the center line C. The flange portion 14b is adjacent to both ends of the coil body 12 in the direction of the center line C. Note that the winding frame 14 may have other shapes. When the coil body 12 has other winding methods and / or other shapes, the winding frame 14 may have a shape that conforms to the winding method and / or shape of the coil body 12.

[0015] The winding frame 14 may be formed of a non-magnetic metal material such as stainless steel or an aluminum alloy. Alternatively, the winding frame 14 may be formed of a fiber-reinforced plastic (FRP) such as glass fiber-reinforced plastic (GFRP) or other non-magnetic non-metallic materials. In this example, the winding frame 14 may be formed of an opaque material that does not transmit light.

[0016] The impregnating material 16 is impregnated into at least a part of the coil body 12. In the illustrated example, the impregnating material 16 is filled in the recess surrounded by the winding surface 14a of the winding frame 14 and the flange portion 14b, the entire coil body 12 is impregnated with the impregnating material 16, and the coil body 12 is fixed to the winding frame 14.

[0017] The impregnating material 16 contains a photocurable resin material and, in this example, consists of a photocurable resin material. The photocurable resin material may be a known ultraviolet-curable resin material such as an acrylic-based ultraviolet-curable resin material or an epoxy-based ultraviolet-curable resin material. Alternatively, the photocurable resin material may be a visible light-curable resin material.

[0018] The superconducting wire 18 includes a core material 18a having a superconductor and a light-transmissive coating 18b covering the core material 18a. When the superconducting coil 10 is a low-temperature superconducting coil, the core material 18a may include a superconductor formed of a superconducting material such as niobium titanium alloy (NbTi) or niobium tin alloy (Nb3Sn). When the superconducting coil 10 is a high-temperature superconducting coil, the core material 18a may include a superconductor formed of, for example, magnesium diboride, bismuth-based superconductor, copper oxide superconductor, or other high-temperature superconducting materials.

[0019] The light-transmissive coating 18b is formed of a material that transmits at least a part of light when irradiated with light for curing the photocurable resin material. When the impregnating material 16 is an ultraviolet-curable resin material, the light-transmissive coating 18b is permeable to ultraviolet light having a wavelength for curing the ultraviolet-curable resin material. When the impregnating material 16 is a visible-light-curable resin material, the light-transmissive coating 18b is permeable to visible light having a wavelength for curing the visible-light-curable resin material. The transmittance of the light-transmissive coating 18b with respect to the light for curing the photocurable resin material is adjusted so as to transmit the light in an amount sufficient to cure the photocurable resin material impregnated in the coil body 12. Further, in addition to the above-described light transmittance, the light-transmissive coating 18b has insulating properties for insulation between adjacent superconducting wires 18 in the wound coil body 12.

[0020] As an example, the light-transmissive coating 18b includes a glass braid, that is, a braided body of glass fibers. Generally, the glass braid is permeable to ultraviolet light and visible light. As another example, the light-transmissive coating 18b may include a braided body of synthetic fibers such as polyester. Alternatively, the light-transmissive coating 18b may include a thin layer of a synthetic resin material such as polyimide.

[0021] In order to enhance the light transmissibility of the superconducting wire 18, the thickness of the light-transmissive coating 18b may be at least 1% of the diameter of the superconducting wire 18. From a practical perspective in the superconducting coil 10 to avoid an excessive decrease in the area occupancy rate of the core material 18a in the cross-section of the superconducting wire 18, the thickness of the light-transmissive coating 18b may also be within 20% of the diameter of the superconducting wire 18. For example, when the superconducting wire 18 has a diameter of 1 mm, the thickness of the light-transmissive coating 18b may be not less than 0.01 mm and not more than 0.2 mm.

[0022] FIG. 2(a) is a diagram schematically showing the curing process of the impregnating material 116 in the superconducting coil 110 according to the comparative example, and FIG. 2(b) is a diagram schematically showing the curing process of the impregnating material 16 in the superconducting coil 10 according to the embodiment.

[0023] The superconducting coil 110 according to the comparative example includes a coil body 112 made of a superconducting wire 118, a winding frame 114, and an impregnating material 116 containing a photocurable resin material. The superconducting wire 118 is formed of an opaque material that does not transmit the light 22 for curing the photocurable resin material, not only for its core material but also for the insulating coating.

[0024] In the manufacturing process of the superconducting coil 110, the superconducting wire 118 is wound around the outer peripheral surface of the winding frame 114, and the coil body 112 is formed around the winding frame 114. The impregnating material 116 is filled or applied to the coil body 112, and the coil body 112 is impregnated with the impregnating material 116. Then, in the curing process, the light 22 for curing the photocurable resin material of the impregnating material 116 is irradiated from the light source 20. The light source 20 irradiates the light 22 onto the outer peripheral surface of the coil body 112 from the outside of the winding frame 114.

[0025] The impregnating material 116 on the outer peripheral surface of the coil body 112 directly irradiated with the light 22 from the light source 20 is cured by the light 22. However, since the superconducting wire 118 is opaque to the light 22, as understood from FIG. 2(a), the superconducting wire 118 becomes an obstacle to the light 22 reaching the impregnating material 116 in the portion of the coil body 112 hidden by the superconducting wire 118, making it difficult for the light 22 to reach from the light source 20. For example, the winding surface 114a of the winding frame 114 around which the coil body 112 is wound and the impregnating material 116 in the vicinity thereof are shielded by the superconducting wire 118, and the light 22 from the light source 20 is least likely to reach. Therefore, the impregnating material 116 in such a portion of the coil body 112 may be insufficiently cured.

[0026] In contrast, in the superconducting coil 10 according to the embodiment, the light-transmissive coating 18b of the superconducting wire 18 is formed of a material that transmits at least a part of the light 22 for curing the photo-curable resin material of the impregnating material 16. Therefore, as understood from FIG. 2(b), when the light 22 is irradiated from the light source 20 in the curing process, the light-transmissive coating 18b can be used as a transmission path for the light 22 to spread the light 22 to the impregnating material 16. Not only the incident surface of the light 22 to the coil body 12 and the portions in the vicinity thereof, such as the outer peripheral surface of the coil body 12, but also the inner portions of the coil body 12 away from the incident surface, such as the winding surface 14a of the winding frame 14 around which the coil body 12 is wound and the impregnating material 16 in the vicinity thereof, can receive the light 22 from the light source 20 through the light-transmissive coating 18b. Therefore, according to the embodiment, the impregnating material 16 can be cured over a wider range or entirely compared to the above-described comparative example.

[0027] When the coil body 12 is wound in multiple layers, the impregnating material 16 may be applied layer by layer so that the entire coil body 12 is impregnated with the impregnating material 16. The light 22 may be irradiated each time one layer is wound up, and the impregnating material 16 impregnated in that layer may be cured. Such winding up, irradiation, and curing may be repeated layer by layer to manufacture the coil body 12. Alternatively, the light 22 may be irradiated after all the layers are wound up, and the impregnating material 16 may be cured at once.

[0028] As described at the beginning of this book, in existing superconducting coils, generally, thermosetting resins are used as impregnating materials. Since the thermosetting process may require, for example, several hours to dozens of hours or more, the manufacture of superconducting coils takes a long time. In particular, in the impregnation method, also called "coating winding", in which a resin material is applied while winding a superconducting wire around a winding form, in order to avoid the thermal curing of the resin material from interfering with the operation of winding the superconducting wire around the winding form, among thermosetting resins, those with a relatively long curing time may be intentionally used. In that case, the thermosetting process requires even more time.

[0029] In contrast, in the superconducting coil 10 according to the embodiment, a photocurable resin material is used as the impregnating material 16. The photocurable resin material typically requires at most only a few minutes for the photocuring process. Therefore, the manufacture of the superconducting coil 10 according to the embodiment can achieve a dramatic reduction in time compared to existing superconducting coils.

[0030] Also, the irradiation of the light 22 can be easily applied selectively to a local area in the coil body 12. Also, it is easy to irradiate the light 22 at any timing while winding the superconducting wire 18 around the winding form 14. In contrast, in the thermosetting process, such freedom is small.

[0031] Due to the high degree of freedom in the irradiation location and irradiation timing, the photocuring process can be adapted to the manufacture of coils with more complex shapes, such as saddle-shaped coils. Different from circular coils, in coils with complex shapes, during the process of winding the wire around the winding form, the wires may shift due to the tension acting on the wires, and it may be difficult to wind them up while maintaining the desired coil shape, which may cause manufacturing difficulties. However, according to the embodiment, by curing the impregnating material at a specific local area at a desired timing in the wire winding process, spot-like temporary fixation of the wires during winding can be achieved, and it becomes possible to wind them up while maintaining the desired coil shape. Therefore, the superconducting coil 10 according to the embodiment is advantageous in winding coils with complex shapes.

[0032] In one embodiment, a portion of the superconducting wire 18 drawn out from the coil body 12 (for example, the lead wire 18c extending from the coil body 12 to the electrode of the superconducting coil 10 for connecting the superconducting coil 10 to a power source) may be fixed to the bobbin 14 with a photocurable resin material.

[0033] FIG. 3 is a diagram schematically showing a superconducting coil 10 according to another embodiment. FIG. 4 is a diagram schematically showing a curing process of the impregnating material 16 in the superconducting coil 10 according to another embodiment.

[0034] The superconducting coil 10 includes, as in the above-described embodiment, a coil body 12 of the superconducting wire 18, a bobbin 14 that supports the coil body 12, and an impregnating material 16 containing a photocurable resin material. The superconducting wire 18 includes a core material 18a including a superconductor and a light-transmissive coating 18b that coats the core material 18a. The light-transmissive coating 18b is formed of a material that transmits at least a part of the light 22 when the light 22 for curing the photocurable resin material of the impregnating material 16 is irradiated.

[0035] At least a part of the bobbin 14 is formed of a light-transmissive material that transmits at least a part of the light 22 when the light 22 for curing the photocurable resin material of the impregnating material 16 is irradiated. In this example, the entire bobbin 14 is formed of a light-transmissive material. The bobbin 14 may be formed of the same material as the light-transmissive coating 18b, or may be formed of a different material. The bobbin 14 may be formed of, for example, glass fiber reinforced plastic (GFRP). Alternatively, the bobbin 14 may be formed of other fiber reinforced plastics such as carbon fiber reinforced plastic (CFRP), or a synthetic resin material such as polyimide, for example.

[0036] In the manufacturing process of the superconducting coil 10, the superconducting wire 18 is wound around the winding surface 14a of the bobbin 14, and the coil body 12 is formed around the bobbin 14. The impregnating material 16 is filled or coated on the coil body 12, and the coil body 12 is impregnated with the impregnating material 16. Then, as shown in FIG. 4, in the curing process, light 22 for curing the photocurable resin material of the impregnating material 16 is irradiated from the light source 20. The light source 20 irradiates the inner peripheral surface of the bobbin 14 with light 22 from the inside of the bobbin 14. Since the bobbin 14 is formed of a light-transmissive material, the light 22 can pass through the bobbin 14 and reach the winding surface 14a and the impregnating material 16 in the vicinity thereof. Further, the light 22 can utilize the light-transmissive coating 18b of the superconducting wire 18 as a transmission path of the light 22 and reach the outer peripheral surface of the coil body 12 and the impregnating material 16 in the vicinity thereof. In this way, the impregnating material 16 can be cured by the light 22.

[0037] Further, the light source 20 may be disposed above or below the coil body 12, and irradiate the flange portion 14b of the bobbin 14 with light 22 therefrom. In this case, the light 22 can pass through the flange portion 14b and reach the impregnating material 16. Thus, the impregnating material 16 may be cured by the light 22. Further, as shown in FIGS. 2(a) and 2(b), the light source 20 may be disposed outside the bobbin 14 and irradiate the outer peripheral surface of the coil body 12 with light 22 therefrom, whereby the impregnating material 16 may be cured.

[0038] In addition, in the embodiment shown in FIG. 3, instead of the light-transmissive coating 18b, the superconducting wire 18 may be provided with an opaque coating formed of an opaque material that does not transmit the light 22 for curing the photocurable resin material. The opaque coating of the superconducting wire 18 may be, for example, a polyvinyl fluoride (PVF) coating or an enamel coating.

[0039] FIG. 5 is a diagram schematically showing a modified example of the superconducting coil 10 according to the embodiment of FIG. 3. As shown, a part of the bobbin 14 may be formed of a light-transmissive material that transmits at least a part of the light 22 when the light 22 for curing the photocurable resin material of the impregnating material 16 is irradiated. For example, the bobbin 14 may include a light-transmissive portion 14c formed of a light-transmissive material adjacent to the coil body 12.

[0040] The light transmission part 14c is formed on the outer peripheral surface of the winding frame 14 and is interposed between the coil body 12 and the winding frame 14. Therefore, the winding surface 14a of the winding frame 14 corresponds to the outer peripheral surface of the light transmission part 14c. The light transmission part 14c may be a sheet of a light transmissive material, and its thickness may be, for example, at least 0.1 mm. The thickness of the light transmission part 14c may be, for example, within 10 mm, or within 1 mm. The light transmissive material may be a synthetic resin material such as polyimide.

[0041] When the light 22 is irradiated, the light transmission part 14c can be used as a transmission path for the light 22. The light 22 can reach the winding surface 14a and the impregnating material 16 in the vicinity thereof while being reflected at the interface between the light transmission part 14c and the main body of the winding frame 14. In this way, the impregnating material 16 can be cured by the light 22.

[0042] As described above, the present invention has been described based on the embodiments. It is understood by those skilled in the art that the present invention is not limited to the above-described embodiments, various design changes are possible, various modifications are possible, and such modifications are also within the scope of the present invention. The various features described in connection with one embodiment are also applicable to other embodiments. The new embodiments resulting from the combination have the effects of the respective embodiments being combined.

[0043] In the above-described embodiment, the case where the impregnating material 16 is made of a photocurable resin material has been described as an example, but the impregnating material 16 may contain other materials together with the photocurable resin material. For example, the impregnating material 16 may be a mixture of a photocurable resin material and another synthetic resin material such as a thermosetting resin material or a thermoplastic resin material. In this case, the impregnating material 16 may be cured by using both the irradiation of the light 22 from the light source 20 to the coil body 12 and the heating of the coil body 12.

[0044] In the above-described embodiment, the case where the impregnated material 16 of the photocurable resin material is impregnated throughout the coil body 12 has been described as an example. However, the photocurable resin material may be impregnated into a part of the coil body 12. That is, the impregnated material 16 of the photocurable resin material may be locally applied to the coil body 12. Another part (for example, the remaining part) of the coil body 12 may be impregnated with an impregnated material of a thermosetting resin material or a thermoplastic resin material.

[0045] Based on the embodiment, the present invention has been described using specific terms. However, the embodiment only shows one aspect of the principle and application of the present invention. In the embodiment, many modifications and arrangement changes are recognized as long as they do not deviate from the idea of the present invention defined in the claims.

Explanation of Reference Numerals

[0046] 10 Superconducting coil, 12 Coil body, 14 Winding frame, 16 Impregnated material, 18 Superconducting wire, 18a Core material, 18b Light-transmitting coating, 22 Light.

Claims

1. A coil body formed by winding a superconducting wire, and An impregnating material containing a photocurable resin material and impregnating at least a part of the coil body, characterized in that The superconducting wire is provided with a light-transmitting coating that transmits at least a part of the light when the light for curing the photocurable resin material is irradiated, a superconducting coil.

2. The superconducting coil according to claim 1, wherein the light-transmitting coating includes a braided body.

3. The superconducting coil according to claim 1, wherein the impregnating material is made of the photocurable resin material.

4. The superconducting coil according to any one of claims 1 to 3, further comprising a winding frame around which the superconducting wire is wound, at least a part of which is formed of a light-transmitting material that transmits at least a part of the light when the light for curing the photocurable resin material is irradiated.

5. The superconducting coil according to claim 4, wherein the light-transmitting material includes glass fiber reinforced plastic.

6. A coil body formed by winding a superconducting wire, and An impregnating material containing a photocurable resin material and impregnating at least a part of the coil body, and A winding frame around which the superconducting wire is wound, at least a part of which is formed of a light-transmitting material that transmits at least a part of the light when the light for curing the photocurable resin material is irradiated, a superconducting coil characterized by comprising.

Images