CN115117645A - Low-temperature superconducting wire welding packaging structure and method for cold conduction equipment - Google Patents

Abstract

The invention provides a low-temperature superconducting wire welding and packaging structure and a method for cold conduction equipment, wherein the packaging structure comprises an insulating base, an insulating cold conduction substrate, a metal top cover, an insulating top cover, a first superconducting wire, a second superconducting wire and a welding flux; the end surface of the insulating base is provided with a first through hole, and the upper end surface of the insulating base is provided with an annular groove; the insulating cold conduction substrate and the metal substrate are both arranged in the first through hole and are both connected with the insulating base; the metal top cover and the insulating top cover are covered in the annular groove; the first superconducting bare wire of the first superconducting wire and the second superconducting bare wire of the second superconducting wire are mutually wound and coiled into a plurality of turns of annular bare wires, and the annular bare wires are arranged in the annular container; the solder is used for soldering the first superconducting wire and the second superconducting wire. The invention can solve the technical problems of difficult processing of superconducting wires, difficult wiring of welding spots, large volume of welding spots, difficult packaging and insulation of welding spots and easy damage of cold-conducting insulating materials in the prior art.

Description

Low-temperature superconducting wire welding packaging structure and method for cold conduction equipment

Technical Field

The invention relates to the technical field of superconducting wire welding and packaging, in particular to a low-temperature superconducting wire welding and packaging structure and method for cold conduction equipment.

Background

Superconducting wires of low temperature metal materials have zero resistance properties at very low temperatures and play an important role in technical and engineering applications requiring high currents and strong magnetic fields. In the application of low-temperature superconducting technology, the problem of welding between superconducting wires is inevitable. Because of the extremely low temperature and zero resistance characteristic of the superconducting wire, the welding process of the wire is greatly different from the traditional common wire welding process. In order to ensure the welding quality, in the cooling-type superconducting equipment, three important points need to be considered for the welding of the superconducting wire: the solder joint has good cold effect of leading, avoids the inside hot spot that produces of solder joint and reinforcing solder joint steadiness.

The cold guiding type superconducting equipment realizes refrigeration completely through cold quantity conduction of the cold head, so that welding spots of all superconducting wires in the equipment are required to be in direct contact with an internal mechanical structure, external cold quantity during refrigeration of the equipment is ensured to rapidly enter the welding spots for cooling, and heat generated in the welding spots in the running state of the equipment is ensured to be timely led out. The over-low cold conduction effect can cause the overall refrigeration rate of the equipment to be reduced, the heat generated in the welding spot cannot be timely led out to cause the loss and the over-run, and the like, thereby influencing the steady-state work of the whole superconducting equipment.

At present, a superconducting wire welding process widely applied to a cooling guide type device mainly adopts an open metal container as a container for containing and receiving superconducting wires and welding fluxes, firstly two superconducting wires to be welded are led in from an inlet wire hole at the bottom of the open metal container, then a coating layer removing operation, a wire coiling operation and a welding operation are sequentially carried out on the two superconducting wires in the metal container, and finally cooling guide and insulation treatment of the metal container and the cooling guide type device are carried out.

However, the existing welding process has the following disadvantages:

(1) difficulty in handling superconducting wire

During welding, the metal container needs to be fixed in the equipment, and then subsequent operation is carried out, so that a stable welding platform is ensured. However, the superconducting equipment has a limited space, and thus, the work of removing the outer coating layer from the superconducting wire rod is difficult. In the operations of pickling, prewelding and the like of the wire rod, the welding efficiency and the welding quality are greatly influenced by the narrow operation space.

(2) Difficulty in solder joint wiring

In the process of welding the superconducting wire, 5-10 or even more superconducting bare wires are generally required to be welded together, too many superconducting bare wires have larger wire diameter and larger bending radius, all the superconducting bare wires are coiled into a metal container, the operation is difficult, and the risk of damaging the superconducting bare wires is caused.

(3) The volume of the welding spot is large

Under the conditions of more welding superconducting wires and longer bare wires, a metal container with larger volume is needed to ensure that all the bare wires are completely immersed into the container and ensure that a sufficient amount of welding materials completely wrap all the bare wires. This results in the metal container often having a large volume, placing great demands on the internal space of the apparatus, affecting the compactness of the apparatus; the whole refrigeration rate of the whole system is reduced while the equipment volume is increased.

(4) Solder joint packaging insulation difficulty

The metal container is used as welding outer packaging, so that the cold conduction effect is guaranteed, but the packaging is very easy to contact with an external mechanical structure to cause short circuit. The metal container has larger volume and irregular shape, which causes the problems of difficult insulation, easy occurrence of damage and the like.

(5) The cold conducting insulating material is easy to damage

The insulating material between the metal container base and the mechanical structure is generally aluminum nitride, and the like, and has high insulation and high cold conduction rate. The material is typically bolted between the metal container and the mechanical structure of the apparatus. However, the material has the characteristics of fragility and fragility, and during installation and equipment operation, the material can be cracked due to extrusion between hardware, friction of installation bolts and the like, and potential hazards are brought to insulation and stable operation of equipment.

Disclosure of Invention

The invention provides a low-temperature superconducting wire welding and packaging structure and method for cold conduction equipment, which can solve the technical problems that superconducting wires are difficult to process, welding spots are difficult to wire, welding spots are large in size, welding spots are difficult to package and insulate, and cold conduction insulating materials are easy to damage in the prior art.

According to an aspect of the present invention, there is provided a low-temperature superconducting wire soldering encapsulation structure for a cold conducting device, the encapsulation structure including an insulating base, an insulating cold conducting base, a metal cap, an insulating cap, a first superconducting wire, a second superconducting wire, and a solder;

a first through hole is formed in the end face of the insulating base, an annular groove is formed in the upper end face of the insulating base, and the axis of the first through hole is overlapped with the axis of the annular groove;

the insulating cold-conducting substrate and the metal substrate are arranged in the first through hole and are connected with the insulating base, the insulating cold-conducting substrate is arranged on the lower side of the metal substrate, and the lower end face of the insulating cold-conducting substrate and the lower end face of the insulating base are positioned on the same horizontal plane;

the metal top cover and the insulating top cover are covered in the annular groove, the insulating top cover is arranged on the outer side of the metal top cover, the metal top cover and the metal substrate form an annular container for containing the welding flux, a first wiring groove is formed in the bottom of the side wall of the metal top cover, the depth of the first wiring groove is larger than that of the annular groove, a second through hole for filling the welding flux is formed in the top of the metal top cover, a second wiring groove is formed in the bottom of the side wall of the insulating top cover, the depth of the second wiring groove is larger than that of the annular groove, and the first wiring groove and the second wiring groove are arranged oppositely;

one end of the first superconducting wire is a first superconducting bare wire with a coating layer removed, the other end of the first superconducting wire is a first superconducting bus without the coating layer removed, one end of the second superconducting wire is a second superconducting bare wire with the coating layer removed, the other end of the second superconducting wire is a second superconducting bus without the coating layer removed, the first superconducting bare wire and the second superconducting bare wire are mutually wound and coiled into a plurality of circles of annular bare wires, the diameter of each circle of the annular bare wire is smaller than the inner diameter of the metal top cover, the annular bare wires are arranged in the annular container, and the first superconducting bus and the second superconducting bus are arranged outside the annular container;

the solder is arranged in the annular container and used for welding the first superconducting wire and the second superconducting wire.

Preferably, a spiral groove is formed in the inner side wall of the metal top cover, the annular bare wire is embedded into the spiral groove, and the spiral groove is used for limiting the displacement of the annular bare wire in the vertical direction; the packaging structure further comprises a supporting component, wherein the supporting component is arranged inside the metal top cover and used for limiting the horizontal displacement of the annular bare wires.

Preferably, the inner diameter of the metal top cover is greater than or equal to 75 times of the outer diameter of the first superconducting bus and less than or equal to 80 times of the outer diameter of the first superconducting bus, wherein the outer diameter of the first superconducting bus is the same as the outer diameter of the second superconducting bus.

Preferably, the height of the metal top cover is greater than or equal to 8 times of the outer diameter of the first superconducting bus and less than or equal to 10 times of the outer diameter of the first superconducting bus.

Preferably, the thickness of the metal top cover is greater than or equal to the outer diameter of the first superconducting bus and less than or equal to 1.5 times the outer diameter of the first superconducting bus.

Preferably, the width of the annular groove is equal to the sum of the thickness of the side wall of the metal top cover and the thickness of the side wall of the insulating top cover, the inner diameter of the annular groove is the same as the inner diameter of the metal top cover, and the outer diameter of the annular groove is the same as the outer diameter of the insulating top cover.

Preferably, the diameter of the insulating cold-conducting substrate, the diameter of the metal substrate and the diameter of the first through hole are the same.

Preferably, the thickness of the insulating base is equal to the sum of the thickness of the insulating cold-conducting substrate and the thickness of the metal substrate.

According to another aspect of the present invention, there is provided a low temperature superconducting wire solder packaging method for a cold conducting device, the method for solder packaging using the packaging structure in the above embodiments, the method includes:

fixing the insulating base at a preset position, and placing the insulating cold conduction substrate in the first through hole to enable the lower end face of the insulating cold conduction substrate and the lower end face of the insulating base to be positioned on the same horizontal plane;

placing a metal substrate on the upper side of the insulating cold-conducting substrate;

removing the coating layers of one end of the first superconducting wire and one end of the second superconducting wire to obtain a first superconducting bare wire and a second superconducting bare wire with preset lengths;

the method comprises the steps of winding a first bare superconducting wire and a second bare superconducting wire, pre-welding to fixedly connect the first bare superconducting wire and the second bare superconducting wire, and winding the fixedly connected first bare superconducting wire and second bare superconducting wire into a multi-turn annular bare wire;

placing the annular bare wire on the metal substrate, and covering the metal top cover on the annular groove;

pouring the molten solder into an annular container formed by the metal top cover and the metal substrate from the second through hole, so that the solder is fully immersed in the annular bare wire, and cooling the solder;

and covering the insulating top cover on the annular groove to complete the welding of the first superconducting wire and the second superconducting wire.

According to another aspect of the present invention, there is provided a method for solder packaging of a low temperature superconducting wire for a cold conducting device, the method for solder packaging using the packaging structure in the above embodiments, the method comprising:

fixing an insulation base at a preset position, and placing an insulation cold conduction substrate in the first through hole to enable the lower end face of the insulation cold conduction substrate and the lower end face of the insulation base to be in the same horizontal plane;

placing a metal substrate on the upper side of the insulating cold-conducting substrate;

removing the wrapping layers of one end of the first superconducting wire and one end of the second superconducting wire to obtain a first superconducting bare wire and a second superconducting bare wire with preset lengths;

the method comprises the steps of winding a first bare superconducting wire and a second bare superconducting wire, pre-welding to fixedly connect the first bare superconducting wire and the second bare superconducting wire, and winding the fixedly connected first bare superconducting wire and second bare superconducting wire into a multi-turn annular bare wire;

embedding the annular bare wire into the spiral groove of the metal top cover, placing the supporting part in the metal top cover to fix the annular bare wire together with the spiral groove, and covering the metal top cover on the annular groove;

pouring molten solder into an annular container formed by the metal top cover and the metal substrate from the second through hole, so that the solder fully immerses the annular bare wire, and cooling the solder;

and covering the insulating top cover on the annular groove to complete the welding of the first superconducting wire and the second superconducting wire.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

(1) the superconducting wire is convenient to process.

Because the packaging structure is in an assembly form, the pretreatment (the work of removing a wrapping layer, pickling, prewelding and the like) of the superconducting wire is not limited by the installation position of the welding container. The wire may be pre-treated prior to placement on the metal substrate for solder infusion and subsequent packaging operations.

(2) Convenient wiring of welding spots

The packaging structure is in a flat form, has a larger diameter, provides a higher bending space for a wire coil, and enables the wiring of the superconducting bare wire in the welding spot to be easier.

(3) The packaging structure is compact

The packaging structure is in a flat form, has a larger diameter and a smaller height, so that welding spots are easier to install in gaps inside the equipment, and a larger welding spot space does not need to be reserved additionally.

(4) Perfect insulation package

The insulating base, the insulating cold-conducting substrate and the insulating top cover ensure that the whole packaging structure has complete insulating measures, and ensure that the whole welding spot can not be in short-circuit contact with any external mechanical structure.

(5) Cold conducting material keeping device

The insulating cold conduction substrate at the bottom of the packaging structure is only pressed and fixed through the metal substrate on the upper side of the packaging structure, the stress is uniform, and the problems of material fragmentation and the like caused by assembly and equipment operation vibration are avoided.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a schematic view illustrating a soldering package structure of a low temperature superconducting wire for a cold conducting apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic top view of the combination of the insulated base, insulated cold-conducting base and metal base of FIG. 1;

FIG. 3 is a schematic bottom view of the combination of the insulated base, the insulated cold-conducting base and the metal base of FIG. 1;

FIG. 4 shows a schematic view of the combination of the dielectric base, metal cap and dielectric cap of FIG. 1;

FIG. 5 illustrates a schematic view of a metal overcap having a helical groove provided in accordance with one embodiment of the present invention;

FIG. 6 shows a schematic view of the metal cap of FIG. 5 in combination with a support member;

FIG. 7 is a flow chart illustrating a method for solder encapsulation of a low temperature superconducting wire for a cold conducting apparatus according to an embodiment of the present invention;

FIG. 8 is a schematic diagram illustrating two superconducting bare wires wound into a multi-turn annular bare wire according to an embodiment of the invention;

FIG. 9 is a schematic diagram of a multi-turn wound bare wire loop placed on a metal substrate according to an embodiment of the present invention;

FIG. 10 illustrates a schematic view of a metal overcap cap provided in accordance with one embodiment of the present invention disposed over an annular groove;

FIG. 11 is a schematic diagram of a completed package structure provided in accordance with an embodiment of the present invention;

fig. 12 is a flowchart illustrating a low-temperature superconducting wire soldering and packaging method for a cold conducting device according to another embodiment of the invention.

Description of the reference numerals

10. An insulating base; 11. a first through hole; 12. an annular groove; 13. connecting holes;

20. an insulating cold conducting substrate;

30. a metal substrate;

40. a metal top cover; 41. a first wiring duct; 42. a second through hole; 43. a spiral groove;

50. an insulating top cover; 51. a second wiring duct;

60. a first superconducting wire; 61. a first superconducting bare wire; 62. a first superconducting bus;

70. a second superconducting wire; 71. a second superconducting bare wire; 72. a second superconducting bus;

80. welding flux;

90. a support member.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

As shown in fig. 1-4, the present invention provides a low-temperature superconducting wire soldering package structure for cold conducting equipment, which comprises an insulating base 10, an insulating cold conducting base 20, a metal base 30, a metal cap 40, an insulating cap 50, a first superconducting wire 60, a second superconducting wire 70 and a solder 80;

a first through hole 11 is formed in the end face of the insulating base 10, an annular groove 12 is formed in the upper end face of the insulating base 10, and the axis of the first through hole 11 is overlapped with the axis of the annular groove 12;

the insulating cold-conducting substrate 20 and the metal substrate 30 are both arranged in the first through hole 11 and are both connected with the insulating base 10, the insulating cold-conducting substrate 20 is arranged on the lower side of the metal substrate 30, and the lower end face of the insulating cold-conducting substrate 20 and the lower end face of the insulating base 10 are on the same horizontal plane;

the metal top cover 40 and the insulating top cover 50 are both covered in the annular groove 12, the insulating top cover 50 is arranged outside the metal top cover 40, the metal top cover 40 and the metal base 30 form an annular container for containing the solder 80, a first wiring groove 41 is formed in the bottom of the side wall of the metal top cover 40, the depth of the first wiring groove 41 is larger than that of the annular groove 12, a second through hole 42 for filling the solder 80 is formed in the top of the metal top cover 40, a second wiring groove 51 is formed in the bottom of the side wall of the insulating top cover 50, the depth of the second wiring groove 51 is larger than that of the annular groove 12, and the first wiring groove 41 and the second wiring groove 51 are arranged in opposite positions;

one end of the first superconducting wire 60 is a first superconducting bare wire 61 with a coating removed, the other end of the first superconducting wire is a first superconducting bus 62 without a coating removed, one end of the second superconducting wire 70 is a second superconducting bare wire 71 with a coating removed, the other end of the second superconducting wire is a second superconducting bus 72 without a coating removed, the first superconducting bare wire 61 and the second superconducting bare wire 71 are mutually wound and coiled into a plurality of turns of annular bare wires, the diameter of each turn of the annular bare wire is smaller than the inner diameter of the metal top cover 40, the annular bare wires are arranged in the annular container, and the first superconducting bus 62 and the second superconducting bus 72 are arranged outside the annular container;

the solder 80 is provided in the annular container for soldering the first superconducting wire 60 and the second superconducting wire 70.

Compared with the prior art, the invention has the following beneficial effects:

(1) the superconducting wire is convenient to process.

Because the packaging structure is in an assembly form, the pretreatment (the work of removing a wrapping layer, pickling, prewelding and the like) of the superconducting wire is not limited by the installation position of the welding container. The wire may be pre-processed before being placed on the metal substrate for solder filling and subsequent packaging operations.

(2) Convenient wiring of welding spots

The packaging structure is in a flat form, has a larger diameter, provides a higher bending space for a wire coil, and enables the wiring of the superconducting bare wire in the welding spot to be easier.

(3) The packaging structure is compact

The packaging structure is in a flat form, has a larger diameter and a smaller height, so that welding spots are easier to install in gaps inside the equipment, and a larger welding spot space does not need to be reserved additionally.

(4) Perfect insulation package

The insulating base, the insulating cold-conducting substrate and the insulating top cover ensure that the whole packaging structure has complete insulating measures, and ensure that the whole welding spot can not be in short-circuit contact with any external mechanical structure.

(5) Cold conducting material retention

The insulating cold conduction substrate at the bottom of the packaging structure is only pressed and fixed through the metal substrate on the upper side of the packaging structure, the stress is uniform, and the problems of material fragmentation and the like caused by assembly and equipment operation vibration are avoided.

According to an embodiment of the present invention, as shown in fig. 5 and 6, a spiral groove 43 is provided on an inner side wall of the metal top cover 40, the annular bare wire is embedded in the spiral groove 43, and the spiral groove 43 is used for limiting a vertical displacement of the annular bare wire; the package structure further includes a supporting member 90, wherein the supporting member 90 is disposed inside the metal top cover 40 and is used for limiting the horizontal displacement of the bare wires. The fixing of the ring-shaped bare wires is realized by the cooperation of the spiral groove 43 and the supporting member 90, so that each turn of the ring-shaped bare wires is fully immersed in the solder 80, the contact area with the solder 80 is increased, and the contact resistance is reduced.

For example, the support member 90 may have a cross-shaped structure adapted to the inner diameter of the metal top cover 40, or may have a star-shaped structure, a m-shaped structure, or other structures. The shape of the support member 90 is not limited in the present invention as long as the fixing effect of the bare wires in a loop shape can be achieved.

According to an embodiment of the present invention, the inner diameter of the metal top cover 40 is greater than or equal to 75 times the outer diameter of the first superconducting bus 62 and less than or equal to 80 times the outer diameter of the first superconducting bus 62, wherein the outer diameter of the first superconducting bus 62 is the same as the outer diameter of the second superconducting bus 72.

According to an embodiment of the present invention, the height of the metal cap 40 is greater than or equal to 8 times the outer diameter of the first superconducting bus 62 and less than or equal to 10 times the outer diameter of the first superconducting bus 62.

According to an embodiment of the present invention, the thickness of the metal cap 40 is greater than or equal to the outer diameter of the first superconducting bus 62 and less than or equal to 1.5 times the outer diameter of the first superconducting bus 62.

Through the arrangement, the packaging structure body is large in diameter and small in height, a flat structure is formed, a higher bending space is provided for a wire coil, the superconducting bare wire inside the welding spot is easier to wire, meanwhile, the welding spot is easier to install in a gap inside equipment, and a large welding spot space does not need to be reserved additionally.

According to an embodiment of the present invention, the width of the annular groove 12 is equal to the sum of the thickness of the sidewall of the metal cap 40 and the thickness of the sidewall of the insulating cap 50, the inner diameter of the annular groove 12 is the same as the inner diameter of the metal cap 40, and the outer diameter of the annular groove 12 is the same as the outer diameter of the insulating cap 50. Through the arrangement, the metal top cover 40 and the insulating top cover 50 can be just clamped in the annular groove 12, and the installation and the fixation are convenient.

The metal top cover 40 and the metal base 30 together form a metal container for containing the solder 80, and during the soldering process, the metal top cover 40, the metal base 30, the solder 80 and the annular bare wires form an integral structure, i.e. a solder joint. Therefore, the metal top cover 40 is only required to be covered in the annular groove 12, and no additional connecting operation is required. The insulating top cover 50, the insulating cold conducting substrate 20 and the insulating base 10 jointly form an insulating shell, and the insulating top cover 50 and the insulating base 10 can be assembled in a buckling, gluing or interference fit mode and the like.

According to an embodiment of the present invention, the diameter of the insulating and cold-conducting substrate 20, the diameter of the metal substrate 30 and the diameter of the first through hole 11 are all the same.

The insulating cold conducting substrate 20 and the metal substrate 30 can be assembled with the insulating base 10 by means of snap, adhesion, or interference fit.

According to an embodiment of the present invention, the thickness of the insulating base 10 is equal to the sum of the thickness of the insulating cold-conducting base 20 and the thickness of the metal base 30.

According to the actual wiring space requirement, the shape of the packaging structure can be a cylinder or a polygonal prism.

In the present invention, wood's alloy can be used as the solder 80.

Further, the insulating base 10 is further provided with a connecting hole 13, and the connecting hole 13 is used for fixing the packaging structure in the cold conducting device, so that a stable platform is provided for the subsequent welding process.

Fig. 7 is a flowchart illustrating a low temperature superconducting wire soldering encapsulation method for a cold conducting apparatus according to an embodiment of the present invention. As shown in fig. 7, the present invention provides a low temperature superconducting wire solder packaging method for cold conduction equipment, which uses the packaging structure in the above embodiment to perform solder packaging, and the method includes:

s11, fixing the insulation base 10 at a preset position, and placing the insulation cold conduction substrate 20 in the first through hole 11, so that the lower end face of the insulation cold conduction substrate 20 and the lower end face of the insulation base 10 are on the same horizontal plane;

s12, placing the metal substrate 30 on the upper side of the insulating cold-conducting substrate 20;

s13, removing the wrapping layers of the one end of the first superconducting wire 60 and the one end of the second superconducting wire 70 to obtain a first superconducting bare wire 61 and a second superconducting bare wire 71 with preset lengths;

s14, winding the first bare superconducting wire 61 and the second bare superconducting wire 71, and then pre-welding them, so that the first bare superconducting wire 61 and the second bare superconducting wire 71 are fixedly connected, and the fixedly connected first bare superconducting wire 61 and second bare superconducting wire 71 are coiled into a multi-turn annular bare wire, as shown in fig. 8;

s15, placing the bare wire on the metal base 30, as shown in fig. 9, and covering the metal top cover 40 on the annular groove 12, as shown in fig. 10;

s16, pouring the melted solder 80 into the annular container formed by the metal top cover 40 and the metal base 30 from the second through hole 42, so that the solder 80 is fully immersed in the annular bare wire, and cooling the solder 80;

s17, the insulating cap 50 is placed on the annular groove 12 to complete the welding of the first superconducting wire 60 and the second superconducting wire 70, as shown in fig. 11.

Compared with the prior art, the invention has the following beneficial effects:

(1) the superconducting wire is convenient to process.

Because the packaging structure is in an assembly form, the pretreatment (the work of removing a wrapping layer, pickling, prewelding and the like) of the superconducting wire is not limited by the installation position of the welding container. The wire may be pre-treated prior to placement on the metal substrate for solder infusion and subsequent packaging operations.

(2) Convenient wiring of welding spots

The packaging structure is in a flat form, has a larger diameter, provides a higher bending space for a wire coil, and enables the wiring of the superconducting bare wire in the welding spot to be easier.

(3) The packaging structure is compact

The packaging structure is in a flat form, has a larger diameter and a smaller height, so that welding spots are easier to install in gaps inside the equipment, and a larger welding spot space does not need to be reserved additionally.

(4) Perfect insulation package

The insulating base, the insulating cold-conducting substrate and the insulating top cover ensure that the whole packaging structure has complete insulating measures, and ensure that the whole welding spot can not be in short-circuit contact with any external mechanical structure.

(5) Cold conducting material retention

The insulating cold conduction substrate at the bottom of the packaging structure is only compressed and fixed through the metal substrate on the upper side of the packaging structure, the stress is uniform, and the problems of material fragmentation and the like caused by assembly and equipment operation vibration are avoided.

In S11 of the present invention, the insulated cold conduction substrate 20 is brought into contact with the cold conduction device by placing the lower end surface of the insulated cold conduction substrate 20 on the same level as the lower end surface of the insulated base 10; the insulating cold conducting substrate 20 and the insulating base 10 can be assembled by means of snap, gluing or interference fit.

In S12 of the present invention, the metal base 30 and the insulating base 10 may be assembled by means of snap, glue, or interference fit.

In S14 of the present invention, in order to increase the contact area of the solder joint, the first bare superconducting wire 61 and the second bare superconducting wire 71 are wound, and in order to ensure that the two wound bare superconducting wires do not loosen, the two wound bare superconducting wires may be pre-soldered with indium (solder) to fix the two bare superconducting wires together.

In S16 of the present invention, wood' S alloy may be used as the solder 80. The annular bare wire is fully immersed in the wood alloy, so that the wood alloy is fully contacted with the annular bare wire, and the contact resistance is reduced; meanwhile, the problems that the welding spot is internally provided with a gap and the wire rod is rubbed are avoided. The wood's alloy will solidify after cooling down, and realize the welding of annular bare wire, that is, the welding of first superconducting wire 60 and second superconducting wire 70.

In S17 of the present invention, the insulating cap 50 and the insulating base 10 may be assembled by means of snap-fitting, gluing, or interference fit.

Fig. 12 is a flowchart illustrating a method for solder encapsulation of a low temperature superconducting wire for a cold conducting apparatus according to another embodiment of the present invention. As shown in fig. 12, the present invention further provides a low temperature superconducting wire solder packaging method for a cold conducting device, in the case that the metal top cover 40 has a spiral groove 43, the solder packaging is performed by the following steps:

s21, fixing the insulation base 10 at a preset position, and placing the insulation cold conduction substrate 20 in the first through hole 11, so that the lower end face of the insulation cold conduction substrate 20 and the lower end face of the insulation base 10 are on the same horizontal plane;

s22, placing the metal substrate 30 on the upper side of the insulated cold conducting substrate 20;

s23, removing the wrapping layers of the one end of the first superconducting wire 60 and the one end of the second superconducting wire 70 to obtain a first superconducting bare wire 61 and a second superconducting bare wire 71 with preset lengths;

s24, winding the first bare superconducting wire 61 and the second bare superconducting wire 71, pre-welding to fixedly connect the first bare superconducting wire 61 and the second bare superconducting wire 71, and coiling the fixedly connected first bare superconducting wire 61 and second bare superconducting wire 71 into a multi-turn annular bare wire;

s25, embedding the annular bare wire into the spiral groove 43 of the metal top cover 40, placing the supporting component 90 in the metal top cover 40 to fix the annular bare wire together with the spiral groove 43, and covering the metal top cover 40 on the annular groove 12;

s26, pouring the melted solder 80 into the annular container formed by the metal top cover 40 and the metal base 30 from the second through hole 42, so that the solder 80 is fully immersed in the annular bare wire, and cooling the solder 80;

s27, the insulating cap 50 is placed on the annular groove 12 to complete the welding of the first superconducting wire 60 and the second superconducting wire 70.

By adopting the packaging structure or the packaging method, the contact area between the superconducting wires is increased as much as possible, the contact resistance is reduced, the wire friction can be avoided, and the stability between the welding spot and the wires nearby the welding spot is ensured, so that the welding spot is prevented from generating local hot spots, and the phenomena of the quenching of the whole superconducting circuit and the normal operation interruption of equipment caused by the temperature rise and quenching of the superconducting wires are avoided.

By adopting the packaging structure or the packaging method, the reinforcement of the welding spot is realized, the fracture of the welding spot caused by external mechanical tensile force or tangential force is prevented, meanwhile, the insulation and the fixation of the welding spot are realized, the welding spot is prevented from generating vibration in the operation of equipment and generating friction heat with other external parts or equipment, and the friction heat further causes the quenching of the superconducting wire in the welding spot.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A low-temperature superconducting wire welding packaging structure for cold conduction equipment is characterized by comprising an insulating base (10), an insulating cold conduction base (20), a metal base (30), a metal top cover (40), an insulating top cover (50), a first superconducting wire (60), a second superconducting wire (70) and a welding flux (80);

a first through hole (11) is formed in the end face of the insulating base (10), an annular groove (12) is formed in the upper end face of the insulating base (10), and the axis of the first through hole (11) is overlapped with the axis of the annular groove (12);

the insulation cold conduction substrate (20) and the metal substrate (30) are arranged in the first through hole (11) and are connected with the insulation base (10), the insulation cold conduction substrate (20) is arranged on the lower side of the metal substrate (30), and the lower end face of the insulation cold conduction substrate (20) and the lower end face of the insulation base (10) are on the same horizontal plane;

the metal top cover (40) and the insulating top cover (50) are covered in the annular groove (12), and the insulating top cover (50) is arranged on the outer side of the metal top cover (40), the metal top cover (40) and the metal base (30) form an annular container for containing the solder (80), a first wiring groove (41) is arranged at the bottom of the side wall of the metal top cover (40), the depth of the first wiring groove (41) is larger than that of the annular groove (12), the top of the metal top cover (40) is provided with a second through hole (42) for pouring the solder (80), a second wiring groove (51) is arranged on the bottom of the side wall of the insulating top cover (50), the depth of the second wiring groove (51) is larger than that of the annular groove (12), the first wiring groove (41) and the second wiring groove (51) are oppositely arranged;

one end of the first superconducting wire (60) is a first superconducting bare wire (61) with a coating removed, the other end of the first superconducting wire is a first superconducting bus (62) without a coating removed, one end of the second superconducting wire (70) is a second superconducting bare wire (71) with a coating removed, the other end of the second superconducting wire is a second superconducting bus (72) without a coating removed, the first superconducting bare wire (61) and the second superconducting bare wire (71) are mutually wound and coiled into a plurality of turns of annular bare wires, the diameter of each turn of the annular bare wire is smaller than the inner diameter of the metal top cover (40), the annular bare wires are arranged in the annular container, and the first superconducting bus (62) and the second superconducting bus (72) are arranged outside the annular container;

the solder (80) is disposed in the annular container for soldering the first superconducting wire (60) and the second superconducting wire (70).

2. The package structure according to claim 1, wherein a spiral groove (43) is formed on an inner side wall of the metal top cover (40), the bare wires are embedded in the spiral groove (43), and the spiral groove (43) is used for limiting vertical displacement of the bare wires; the packaging structure further comprises a supporting component (90), wherein the supporting component (90) is arranged inside the metal top cover (40) and used for limiting the horizontal displacement of the annular bare wires.

3. The encapsulation structure of claim 1, wherein the metal cap (40) has an inner diameter greater than or equal to 75 times an outer diameter of the first superconducting busbar (62) and less than or equal to 80 times an outer diameter of the first superconducting busbar (62), wherein the outer diameter of the first superconducting busbar (62) is the same as the outer diameter of the second superconducting busbar (72).

4. The encapsulation structure of claim 3, wherein the height of the metal cap (40) is greater than or equal to 8 times the outer diameter of the first superconducting busbar (62) and less than or equal to 10 times the outer diameter of the first superconducting busbar (62).

5. The encapsulation structure of claim 4, wherein the thickness of the metal cap (40) is greater than or equal to the outer diameter of the first superconducting busbar (62) and less than or equal to 1.5 times the outer diameter of the first superconducting busbar (62).

6. The encapsulation structure according to claim 1, wherein the width of the annular groove (12) is equal to the sum of the thickness of the side wall of the metal top cap (40) and the thickness of the side wall of the insulating top cap (50), the inner diameter of the annular groove (12) is the same as the inner diameter of the metal top cap (40), and the outer diameter of the annular groove (12) is the same as the outer diameter of the insulating top cap (50).

7. The package structure according to claim 1, wherein the diameter of the insulating and cold conducting base (20), the diameter of the metal base (30) and the diameter of the first through hole (11) are all the same.

8. The package structure according to claim 1, wherein the thickness of the insulating base (10) is equal to the sum of the thickness of the insulating cold conducting base (20) and the thickness of the metal base (30).

9. A low-temperature superconducting wire solder packaging method for cold conduction equipment, characterized in that the packaging structure of any one of claims 1 or 3 to 8 is adopted for solder packaging, and the method comprises the following steps:

fixing an insulating base (10) at a preset position, and placing an insulating cold-conducting substrate (20) in the first through hole (11) to enable the lower end face of the insulating cold-conducting substrate (20) and the lower end face of the insulating base (10) to be on the same horizontal plane;

placing a metal substrate (30) on the upper side of the insulated cold conduction substrate (20);

removing coating layers of one end of the first superconducting wire (60) and one end of the second superconducting wire (70) to obtain a first superconducting bare wire (61) and a second superconducting bare wire (71) which are preset in length;

winding a first bare superconducting wire (61) and a second bare superconducting wire (71) and then prewelding to fixedly connect the first bare superconducting wire (61) and the second bare superconducting wire (71), and coiling the fixedly connected first bare superconducting wire (61) and second bare superconducting wire (71) into a plurality of turns of annular bare wires;

placing the annular bare wire on the metal base (30), and covering the metal top cover (40) on the annular groove (12);

pouring molten solder (80) into an annular container formed by the metal top cover (40) and the metal base (30) from the second through hole (42), so that the solder (80) is fully immersed in the annular bare wire, and cooling the solder (80);

and covering an insulating top cover (50) on the annular groove (12) to complete the welding of the first superconducting wire (60) and the second superconducting wire (70).

10. A method for solder packaging of a low-temperature superconducting wire for a cold conducting device, wherein the package structure of claim 2 is used for solder packaging, and the method comprises the following steps:

fixing an insulating base (10) at a preset position, and placing an insulating cold-conducting substrate (20) in the first through hole (11) to enable the lower end face of the insulating cold-conducting substrate (20) and the lower end face of the insulating base (10) to be on the same horizontal plane;

placing a metal substrate (30) on the upper side of the insulated cold conduction substrate (20);

removing the coating layers of one end of the first superconducting wire (60) and one end of the second superconducting wire (70) to obtain a first superconducting bare wire (61) and a second superconducting bare wire (71) with preset lengths;

winding a first bare superconducting wire (61) and a second bare superconducting wire (71) and then prewelding to fixedly connect the first bare superconducting wire (61) and the second bare superconducting wire (71), and coiling the fixedly connected first bare superconducting wire (61) and second bare superconducting wire (71) into a plurality of turns of annular bare wires;

the annular bare wire is embedded into the spiral groove (43) of the metal top cover (40), the supporting part (90) is placed inside the metal top cover (40) and fixes the annular bare wire together with the spiral groove (43), and the metal top cover (40) is covered on the annular groove (12);

pouring the melted solder (80) into an annular container formed by the metal top cover (40) and the metal base (30) from the second through hole (42), so that the solder (80) is fully immersed in the annular bare wire, and cooling the solder (80);

and covering an insulating top cover (50) on the annular groove (12) to complete the welding of the first superconducting wire (60) and the second superconducting wire (70).

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