A superconducting coil with a superconducting joint welding tool

Abstract

The application provides a superconducting coil with a superconducting joint welding tool, which comprises a basic coil winding framework, superconducting wires and two terminal cups. The cross section of the basic coil winding framework is in a "C" type structure, which comprises a closed loop body structure, a first loop protruding edge and a second loop protruding edge. Two first wire passing holes are arranged on the closed loop body structure along the circumferential direction. The superconducting wires are wound outside the closed loop body structure and two welding lead wires are drawn out. The two terminal cups are arranged on the inside of the closed loop body structure along the circumferential direction of the closed loop body structure. The bottom of each terminal cup is provided with a second wire passing hole. The two welding lead wires are sequentially passed through the corresponding first wire passing hole and second wire passing hole respectively and are wound with the wires to be welded. The two terminal cups are used for containing the welding material and the wires after being wound with each other, so as to realize the welding of the two welding lead wires and the wires to be welded.

Description

Technical Field

[0001] This invention relates to the field of superconducting coil technology, and in particular to a superconducting coil with a built-in superconducting connector welding fixture. Background Technology

[0002] Superconducting magnets, made from superconducting materials, can generate strong magnetic fields by applying large currents, and have been widely used in medical magnets, plasma confinement, and magnetic levitation. In superconducting magnets, superconducting wires are wound using specific designs to create superconducting coils capable of carrying large currents. Excitation of the coil is achieved by applying a large current (also known as excitation).

[0003] For a superconducting coil to stably carry current, it must form a closed superconducting circuit together with a superconducting switch (also known as a PCS): 1. The superconducting coil is used to carry current and form the designed magnetic field; 2. The superconducting switch is used to provide control over the closed and open states of the superconducting coil circuit.

[0004] When the superconducting switch is in the open state, the external excitation power supply can apply current to the coil for excitation. After the superconducting coil has completed excitation and reached the rated current, the superconducting switch closes, forming a closed circuit with the superconducting coil to store the excitation current.

[0005] The connection between the superconducting coil and the superconducting switch, two crucial components of a superconducting closed loop, involves the welding of superconducting joints. The low-resistivity superconductivity and low-temperature reliability of these joint welds are prerequisites for the stable operation of the entire superconducting loop. Currently, there are two main technical approaches for welding superconducting joints.

[0006] 1. Specific welding fixture: A specific welding fixture (also known as a junction cup fixture) is used to accommodate the superconducting connectors for welding. This welding method is generally used for dry-cooled superconducting magnets. The outer insulation layer of the two superconducting connectors is removed. After the two connectors are fully contacted for about 20cm through a special winding method, a certain length of connector is coiled and placed in the welding fixture. A special welding alloy is poured into the welding fixture to further promote full contact between the two connectors.

[0007] 2. Lap welding: Similar to direct welding of wires at room temperature, this method is generally used in wet-cooled superconducting magnets. After removing the outer insulation layer of the two joints, they are lapped together, ensuring a contact length of at least 20cm. Solder or other special welding materials are used to weld the two joints along the entire lap length to ensure full contact.

[0008] However, whether using specific welding fixtures or lap welding methods, there are the following drawbacks.

[0009] 1. High space occupation of joints: In order to ensure that the welded part has extremely low resistance and is infinitely close to the superconducting state, the welding work must ensure that the two joints are in full contact. This makes the joints have a large volume regardless of the welding method used, and the space layout requirements are high. This brings a large design burden and reduces the space utilization rate for superconducting magnets with extremely high space utilization.

[0010] 2. Difficulties in thermal design: Since superconducting joints also require cryogenic cooling to ensure they maintain a superconducting, low-resistivity state, specific welding fixtures in dry-cooled superconducting magnets require special thermal design; in wet-cooled superconducting magnets, lap welding needs to be fixed to the bottom of the container to ensure full contact with the refrigerant. These factors increase the difficulty of joint design and the complexity of thermal design.

[0011] 3. Lead wire damage: To achieve joint welding, two superconducting wires must be led out after the superconducting coil is wound for subsequent welding work. During production and welding, as well as during the fixing of the welded wires, the led-out superconducting wires will inevitably collide or rub against the surrounding mechanical structures, which can easily cause damage to the wires and render the entire superconducting coil unusable. Summary of the Invention

[0012] This invention provides a superconducting coil with a built-in superconducting connector welding fixture, which can solve the technical problems of high space occupation rate, difficulty in heat conduction design, and easy damage to welding leads in existing superconducting coils and superconducting switches.

[0013] This invention provides a superconducting coil with a built-in superconducting connector welding fixture, the superconducting coil comprising a basic coil winding frame, superconducting wire, and two terminal cups;

[0014] The cross-section of the basic coil winding skeleton is a "C" shaped structure, including a closed annular body structure, a first annular protrusion edge, and a second annular protrusion edge. One end of the closed annular body structure is connected to the first annular protrusion edge, and the other end is connected to the second annular protrusion edge. Two first wiring holes are provided at intervals along the circumference of the closed annular body structure.

[0015] The superconducting wire is wound around the outside of the closed annular body structure and two welding leads are drawn out.

[0016] Two terminal blocks are spaced apart circumferentially on the inner side of the closed annular body structure. Each terminal block has a second wiring hole at its bottom, and the positions of the two second wiring holes correspond to the positions of the two first wiring holes, so that the two welding leads pass through their respective first and second wiring holes in sequence and are intertwined with the wires to be welded. The two terminal blocks are used to hold the welding material and the intertwined wires to enable the welding of the two welding leads with the wires to be welded.

[0017] Preferably, the closed-loop body structure is a racetrack-shaped structure.

[0018] Preferably, the basic coil winding frame is an integral structure.

[0019] Preferably, the basic coil winding frame and the two terminal cups are an integral structure.

[0020] Preferably, the basic coil winding frame and the two terminal cups are both made of silicon nitride material.

[0021] Preferably, the diameters of both of the terminal cups are smaller than the width h of the closed annular body structure.

[0022] Preferably, the diameter of the two terminal cups is in the range of 50%h to 90%h.

[0023] Preferably, the height of the two junction cups is in the range of 15 to 20 mm.

[0024] Preferably, the welding material is Wood alloy.

[0025] By applying the technical solution of this invention, the two junction cups and the superconducting coil are integrated into one unit, improving space utilization; the superconducting connector can be cooled by the superconducting coil without the need for a special cooling structure design; the two junction cups protect the lead wires of the superconducting connector, improving the reliability of the lead wires of the superconducting coil; thus avoiding the problems of high space occupation, complex connector cooling design, and easy damage to the lead wires of the superconducting switch caused by traditional independent welded connectors, thereby improving the operability and welding reliability of the superconducting connector. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0027] Figure 1 A schematic diagram of a superconducting coil with a self-conducting joint welding fixture provided according to an embodiment of the present invention is shown;

[0028] Figure 2 It shows Figure 1 A schematic diagram of the basic coil winding frame in the diagram;

[0029] Figure 3 It shows Figure 1 A schematic diagram of the junction box structure;

[0030] Figure 4 It shows Figure 1 A schematic diagram of the basic coil winding frame and terminal block processing process.

[0031] The above figures include the following reference numerals:

[0032] 10. Basic coil winding frame; 11. Closed-loop ring-shaped body structure; 111. First wiring hole;

[0033] 12. First annular protrusion; 13. Second annular protrusion;

[0034] 20. Superconducting wire; 21. Welded lead wire; 30. Connecting cup. Detailed Implementation

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0038] like Figures 1-3 As shown, the present invention provides a superconducting coil with a built-in superconducting connector welding fixture. The superconducting coil includes a basic coil winding frame 10, a superconducting wire 20, and two terminal cups 30.

[0039] The cross-section of the basic coil winding skeleton 10 is a "C" shaped structure, including a closed annular body structure 11, a first annular protrusion 12, and a second annular protrusion 13. One end of the closed annular body structure 11 is connected to the first annular protrusion 12, and the other end is connected to the second annular protrusion 13. Two first wiring holes 111 are provided at intervals along the circumference of the closed annular body structure 11. The space formed by the closed annular body structure 11, the first annular protrusion 12, and the second annular protrusion 13 is used to accommodate the superconducting wire 20.

[0040] The superconducting wire 20 is wound around the outside of the closed annular body structure 11, and two welding leads 21 are led out.

[0041] Two terminal cups 30 are spaced apart circumferentially on the inner side of the closed annular body structure 11. Each of the two terminal cups 30 has a second wiring hole at its bottom. The positions of the two second wiring holes correspond to the positions of the two first wiring holes 111, so that the two welding leads 21 pass through their respective corresponding first wiring holes 111 and second wiring holes in sequence, and are respectively wrapped around the wires to be welded. The two terminal cups 30 are used to hold the welding material and the wrapped wires, so as to realize the welding of the two welding leads 21 with the wires to be welded.

[0042] The two junction cups 30 of this invention are integrated with the superconducting coil, improving space utilization; the superconducting connector can be cooled by the superconducting coil without the need for a special cooling structure design; the two junction cups 30 protect the lead wires of the superconducting connector, improving the reliability of the lead wires of the superconducting coil; thus avoiding the problems of high space occupation, complex joint cooling design, and easy damage to the lead wires of the superconducting switch caused by traditional independent welded connectors, thereby improving the operability and welding reliability of the superconducting connector.

[0043] In this invention, the structure of the superconducting coil can take various forms depending on the field shape design. This paper takes a racetrack-shaped design as an example: the inside of the racetrack-shaped coil is a basic coil winding frame 10, and the superconducting wire 20 is wound and fixed around the basic coil winding frame 10 in several passes. Based on the winding characteristics, generally two superconducting wires extend from the inner side of the basic coil winding frame 10 as welding joints, such as... Figure 1 As shown.

[0044] The basic coil winding frame 10 is an integral structure.

[0045] According to one embodiment of the present invention, the base coil winding frame 10 and the two terminal cups 30 are an integral structure, and the base coil winding frame 10 can provide sufficient cooling for the terminal cups 30.

[0046] According to one embodiment of the present invention, the basic coil winding frame 10 and the two terminal cups 30 are both integrally processed using non-metallic materials such as silicon nitride: using a block base material, integrally formed through machining methods such as cutting, shaving, grinding, and milling, for example... Figure 4 As shown. This material ensures that the structure has high hardness and can withstand the cold shock of the superconducting ultra-low temperature environment; it also ensures that the structure has good thermal conductivity and excellent insulation.

[0047] According to one embodiment of the present invention, the diameters of the two terminal cups 30 are both smaller than the width h of the closed annular body structure 11.

[0048] Specifically, the diameter range of the two terminal cups 30 is 50%h to 90%h. The diameter of the terminal cups 30 should not be too small to prevent reducing the cooling effect of the terminal cups 30; nor should it be too large to prevent the terminal cups 30 from exceeding the coil thickness.

[0049] According to one embodiment of the present invention, the height of the two terminal cups 30 is in the range of 15 to 20 mm. They should not be too high to avoid interference with other structures of the coil, nor too small to avoid reducing the contact surface of the two welding joints.

[0050] According to one embodiment of the present invention, the welding material is Wood's alloy. During the welding process, the welding lead 21 of the superconducting coil is directly led out from the two welding terminals 30. Therefore, after the insulation layer of the superconducting joint to be welded is removed, the two ends are intertwined and directly coiled into the terminals 30. The terminals 30 are then filled with a special welding alloy (generally Wood's alloy) to complete the welding.

[0051] In summary, the present invention provides a superconducting coil with a built-in superconducting joint welding fixture, which has the following beneficial effects:

[0052] 1. The basic coil winding frame 10 and the terminal cup 30 are integrated, eliminating the need for connection measures and improving the cooling efficiency;

[0053] 2. Both the junction cup 30 and the basic coil winding frame 10 are made of non-metallic materials, which have good insulation properties and ensure the insulation of the superconducting joint;

[0054] 3. The integrated design avoids the problem of secondary fixing of the terminal block 30 and the basic coil winding frame 10, improves the overall strength of the structural components and reduces the assembly difficulty.

[0055] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0056] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0057] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0058] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A superconducting coil with a superconducting joint welding tool, characterized by, The superconducting coil includes a basic coil winding frame, superconducting wire, and two terminal cups; The cross-section of the basic coil winding skeleton is a "C" shaped structure, including a closed annular body structure, a first annular protrusion edge, and a second annular protrusion edge. One end of the closed annular body structure is connected to the first annular protrusion edge, and the other end is connected to the second annular protrusion edge. Two first wiring holes are provided at intervals along the circumference of the closed annular body structure. The superconducting wire is wound around the outside of the closed annular body structure and two welding leads are drawn out. Two connectors are spaced apart circumferentially on the inner side of the closed annular body structure. Each connector has a second wiring hole at its bottom, and the positions of the two second wiring holes correspond to the positions of the two first wiring holes, so that the two welding leads pass through their respective first and second wiring holes in sequence and are intertwined with the wires to be welded. The two connectors are used to hold the welding material and the intertwined wires to enable welding of the two welding leads with the wires to be welded.

2. The superconducting coil of claim 1, wherein, The closed-loop body structure is a racetrack-shaped structure.

3. The superconducting coil of claim 1, wherein, The basic coil winding frame is an integral structure.

4. The superconducting coil of claim 1, wherein, The basic coil winding frame and the two terminal cups are an integral structure.

5. The superconducting coil according to claim 1, characterized in that, The basic coil winding frame and the two terminal blocks are both made of silicon nitride.

6. The superconducting coil according to claim 1, characterized in that, The diameters of both of the aforementioned terminal cups are smaller than the width h of the closed annular body structure.

7. The superconducting coil according to claim 1, characterized in that, The diameter range of the two said terminal cups is 50%h to 90%h.

8. The superconducting coil according to claim 1, characterized in that, The height range of the two described junction cups is 15-20mm.

9. The superconducting coil according to claim 1, characterized in that, The welding material used is Wood's alloy.

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