A superconducting tape joint welding test integrated device

Abstract

The present application relates to the technical field of superconducting tape, and discloses a superconducting tape joint welding test integrated device, which comprises a welding assembly comprising oppositely arranged upper and lower molds; a driving pressurizing mechanism for applying welding pressure to the upper and / or lower molds during welding; an electrical test assembly comprising at least four pairs of lead terminals, at least two pairs of lead terminals being arranged on each side of the lower mold, and the pairs of lead terminals being adapted to clamp the tapes arranged on two sides, respectively; and a test container mechanism comprising a lifting assembly and a container body. By arranging the driving pressurizing mechanism above the device and the liftable test container mechanism below the device, the pressure executing member can actively give way after welding, and the in-situ test of the tapes can be realized without secondary clamping after welding, so that the damage to the brittle superconducting layer caused by tape transfer and repeated clamping in the conventional technology is completely avoided.

Description

Technical Field

[0001] This invention relates to the field of superconducting tape technology, specifically to an integrated device for welding and testing superconducting tape joints. Background Technology

[0002] High-temperature superconducting tape technology, as a core development direction of second-generation superconducting materials, has shown enormous application potential in fields such as power transmission, magnetic confinement nuclear fusion, particle accelerators, nuclear magnetic resonance imaging, and superconducting energy storage. With the continuous maturation of industrial-scale fabrication processes for coated conductors such as yttrium barium copper oxide (YBCO), kilometer-long tapes have achieved mass production. However, limited by the complex multi-layer structure fabrication process of coated conductors and the precision of equipment tension control, the actual finished length of a single tape still cannot meet the requirements for continuous winding of large superconducting magnets—for example, a single-crystal silicon high-temperature superconducting magnet often requires a continuous conductor of several kilometers or even tens of kilometers. Therefore, reliable joint technology must be used to achieve segmented connections between tapes during the superconducting coil winding process. The critical current and contact resistance of the joints determine the current-carrying capacity and stability of the entire superconducting system.

[0003] Existing technologies include various low-melting-point metal brazing equipment for superconducting tapes, which typically possess heating, pressurizing, and cooling functions to control welding parameters such as temperature and pressure. However, after the welding equipment completes the joint welding of the superconducting tape, the tape and joint must be moved to a separate testing device for electrical performance measurement. This electrical performance measurement process requires disassembling, handling, and clamping the welded tape, which is not only cumbersome and inefficient but also prone to mechanical damage to the brittle superconducting tape due to improper stress or bending, affecting the reliability of the joint and even the overall device. Summary of the Invention

[0004] This invention provides an integrated device for welding and testing superconducting tape joints, which solves the problem that superconducting tapes are easily subject to mechanical damage during joint testing after welding in the prior art.

[0005] In a first aspect, the present invention provides an integrated testing device for superconducting tape joint welding, comprising: A welding assembly includes an upper mold and a lower mold arranged opposite each other, with a cavity formed between the upper mold and the lower mold for receiving the strip to be welded, and a heating element disposed in the upper mold and / or the lower mold; A drive pressurization mechanism is used to apply welding pressure to the upper and / or lower molds during the welding process; An electrical testing assembly includes at least four pairs of lead terminals, configured such that at least two pairs of lead terminals are provided on each side of the lower mold along the length of the strip, and the pairs of lead terminals are adapted to be clamped on both sides of the superconducting strip respectively, so as to perform joint electrical testing on both sides of the welded superconducting strip using the double-sided four-lead method. The test container mechanism includes a lifting assembly and a container body. The lifting assembly is adapted to drive the container body to move toward or away from the electrical test component. The container body has a test state in which the electrical test component is completely contained within the inner cavity of the container body, and a standby state in which it is completely separated from the container body.

[0006] The integrated welding and testing equipment for superconducting strip joints utilizes a spatially coupled design to sequentially execute welding and testing processes at the same workstation. Electrical testing components are always positioned on either side of the lower mold. During welding, the strip to be welded is placed within the cavity of the lower mold, while paired lead terminals in the electrical testing components on both sides of the lower mold clamp the strip to be welded and tested, providing auxiliary fixation. The upper mold is then placed above the lower mold, clamping the strip between them. A pressure-applying mechanism drives the pressure actuator downwards into the welding state, applying pressure to the upper mold so that both the upper and lower molds apply welding pressure to the strip. Simultaneously, heating elements provide heat to melt the brazing filler metal, forming a joint and completing the welding of the superconducting strip. After welding, the pressure actuator retracts upwards to a standby state, completely detaching from the upper mold and freeing up vertical operating space. The upper mold is then removed from the lower mold. Subsequently, the lifting assembly drives the container body upward to enter the testing state, completely enclosing the electrical testing components, including lead terminals and strip joints, within the container body's inner cavity. Liquid nitrogen is filled within the container body's cavity to maintain a cryogenic environment, allowing for simultaneous electrical testing of the joints on both sides of the double-sided superconducting strip under this cryogenic environment. After testing, the container body, driven by the lifting assembly, descends back to standby mode, completely separating from the electrical testing components, and the entire equipment returns to its initial ready state. By placing the driving pressurization mechanism at the top of the equipment and configuring the liftable testing container mechanism at the bottom, the pressure actuators can actively move aside after welding, providing uninterrupted vertical movement space for the testing container's ascent. This achieves longitudinal spatial coupling of welding and testing at the same station, reducing the equipment's footprint. Furthermore, in-situ testing of the strip can be performed without secondary clamping after welding, completely avoiding damage to the brittle superconducting layer that may be caused by strip transfer and repeated clamping in traditional technologies. During electrical testing, at least four pairs of leads are used to clamp both sides of the superconducting tape. This allows for simultaneous four-lead method testing of the electrical parameters of the joints on both sides of the double-sided superconducting tape. This enables in-situ testing of the resistance and critical current of the joints on each side of the double-sided superconducting tape without movement after welding, ensuring both the integrity of the superconducting tape and the accuracy of the test results. For single-sided superconducting tape testing, only the current leads on the superconducting side need to be energized, and the voltage on the superconducting side is collected to complete the single-sided tape joint test.

[0007] In one alternative implementation, the lifting assembly includes: The lifting drive component is fixedly installed. The transmission assembly includes a guide, a transmission screw, and a mating nut. The guide is fixedly installed, the transmission screw extends parallel to the guide and is driven on the output shaft of the lifting drive component. The mating nut is threadedly engaged with the transmission screw and slidably engaged with the guide. The container body is fixedly installed on the mating nut.

[0008] The lifting drive component is fixedly mounted on the equipment's support structure. When the output shaft of the lifting drive component rotates, it drives the transmission screw to rotate synchronously. The mating nut, due to its sliding engagement with the fixed guide component, cannot rotate; it can only move linearly along the axial direction of the transmission screw under its threaded drive. The container body is fixedly mounted on the mating nut and moves synchronously with its lifting motion, thus achieving vertical displacement of the container body. Through the threaded engagement between the transmission screw and the mating nut, combined with the guide component's restriction of the nut's rotation, the lifting motion of the container body achieves high positional accuracy and smooth movement. This prevents the container body from swaying or shifting during movement, ensuring that the container body accurately reaches the predetermined test position or standby position.

[0009] In one alternative embodiment, the output shaft of the lifting drive is coaxially connected to the transmission lead screw via a coupling.

[0010] The output shaft of the lifting drive component and the transmission lead screw are coaxially connected via a coupling. When the lifting drive component is running, the torque of the output shaft is directly transmitted to the transmission lead screw through the coupling, causing the transmission lead screw to rotate synchronously with the output shaft of the lifting drive component. By using a coupling, the concentricity of power transmission can be ensured, effectively reducing the additional stress and vibration caused by shaft misalignment, and improving transmission efficiency, the smoothness of operation of the entire lifting assembly, and its service life.

[0011] In one alternative implementation, the container body is a vacuum Dewar with an open top, and when the container body is in the test state, the container body rises so that its open end is not lower than the upper surface of the electrical test assembly.

[0012] The container body adopts a top-opening Dewar structure. When low-temperature testing is required, the lifting assembly drives the container body upward, raising the open end of the container body to a position no lower than the height of the upper surface of the electrical testing component, allowing the electrical testing component to fully enter the inner cavity of the container body. At this time, the open end of the container body completely surrounds the testing area of ​​the electrical testing component, forming a low-temperature testing environment. This enables the automated construction of the low-temperature environment during the testing process, as well as the automatic removal of the low-temperature environment during the welding process and after the test is completed.

[0013] In one alternative embodiment, a Dewar cap is movably provided at the open end of the container body. When the container body is in a test state, the Dewar cap cooperates with the open end of the container body to close the open end of the container body.

[0014] By installing a Dewar cover, the open Dewar can form a sealed space when in standby mode, preventing dust and debris from falling into the vacuum Dewar and ensuring the cleanliness of the vacuum Dewar's interior.

[0015] In one alternative embodiment, a drain hole is provided at the bottom of the container body, and an on / off control valve is installed at the drain hole.

[0016] After the test is completed, open the on / off control valve to allow the cooling medium in the inner cavity of the container to drain through the drain hole. Once the cooling medium has been drained, close the on / off control valve to complete the drainage operation. This achieves controlled discharge of the cooling medium, prevents its residue in the inner cavity of the container, and speeds up the equipment reset process.

[0017] In one alternative embodiment, the system further includes a support mounting assembly on which a workbench is suspended, and both the welding assembly and the electrical testing assembly are mounted on the workbench, with an insulating pad installed between the electrical testing assembly and the workbench.

[0018] The support mounting components are hoisted to the workbench, leaving ample space underneath to provide the necessary operating space for the lifting and lowering movement of the test container mechanism, achieving a compact longitudinal layout of the equipment structure. The insulating gaskets ensure reliable electrical insulation between the electrical test components and the workbench, preventing test current shunting or leakage through the workbench, ensuring the accuracy of the four-lead method test, and improving the reliability of the test data.

[0019] In one alternative embodiment, the driving pressure mechanism includes a driving assembly and a pressure actuator. The driving assembly is inverted and mounted on the support mounting assembly. The pressure actuator is arranged facing the upper mold. The driving assembly is adapted to drive the pressure actuator to move toward or away from the upper mold, so that the pressure actuator has a welding state in which it abuts against the upper mold to apply welding pressure to the upper mold, and a standby state in which it is completely separated from the upper mold.

[0020] In one alternative embodiment, the drive assembly is mounted upside down on the support mounting assembly, and the drive assembly includes: Welding drive components are fixedly mounted on the support mounting assembly; The linkage assembly includes a linkage screw, an auxiliary nut, and a guide. The guide is fixedly mounted on the support mounting assembly. The linkage screw extends parallel to the guide and is driven on the output shaft of the welding drive. The auxiliary nut is threadedly engaged with the linkage screw and slidably engaged with the guide. The pressure actuator is mounted on the end of the linkage screw away from the welding drive.

[0021] The inverted installation of the drive assembly places the welding drive unit on top of the equipment, fully freeing up the space below and providing ample operating space for the vertical lifting and lowering movement of the test container mechanism, avoiding mechanical interference. The guide is used to limit the movement direction of the auxiliary nut, preventing it from rotating and guiding it to slide vertically, ensuring that the pressure actuator only moves in a straight line, thus improving the accuracy and stability of pressure application.

[0022] In one alternative implementation, the pressure actuator is a universal floating pressure head, and a pressure sensor is installed between the pressure actuator and the linkage screw.

[0023] The omnidirectional floating pressure head can adaptively adjust its posture within a certain angle range to ensure that pressure is applied evenly to the surface of the upper mold, avoiding uneven pressure distribution caused by unevenness of the upper mold surface or installation errors. The pressure sensor can monitor the pressure applied by the omnidirectional floating pressure head to the upper mold in real time, realizing closed-loop control of welding pressure, making the pressure value precise and controllable, and improving the consistency of the welding process and the stability of joint quality.

[0024] In one optional embodiment, an insulating spacer is provided on one of the paired lead terminals. The insulating spacer has a test notch, and the tape is adapted to be installed within the test notch. The tape is installed within the test notch of the insulating spacer, which separates the paired lead terminals, ensuring that the lead terminals can only contact the tape surface through the test notch. This prevents short circuits or cross-currents between adjacent lead terminals and ensures the accuracy of data obtained from simultaneous electrical testing of both sides of the double-sided superconducting tape using the four-lead method.

[0025] In one alternative embodiment, at least two pairs of lead terminals located on the same side of the lower mold include at least one pair of voltage lead terminals and one pair of current lead terminals.

[0026] In one alternative embodiment, two current lead terminals located on both sides of the lower mold on the same side of the superconducting tape are connected to a current source so that current flows through a conductor into the upper and / or lower surface of the superconducting tape. Two voltage lead terminals located on both sides of the lower mold on the same side of the superconducting tape are respectively connected to the positive and negative terminals of a nanovoltmeter to record the voltage on the upper and / or lower surfaces of the superconducting tape. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of the integrated superconducting strip joint welding and testing equipment provided in an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the welding assembly provided in an embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the test container mechanism provided in an embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram of the structure of the support and installation assembly provided in an embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the driving pressurization mechanism provided in an embodiment of the present invention.

[0033] Figure 6 This is a schematic diagram of the structure of an electrical testing component provided in an embodiment of the present invention.

[0034] Figure 7 This is a schematic diagram of the structure for the mating installation of the upper current lead terminal and the lower current lead terminal provided in an embodiment of the present invention.

[0035] Figure 8 This is a schematic diagram of the structure for the mating installation of the upper voltage lead terminal and the lower voltage lead terminal provided in an embodiment of the present invention.

[0036] Figure 9 A schematic diagram of the circuit structure for testing the resistance of double-sided superconducting strip joints using an integrated superconducting strip joint welding and testing device provided in an embodiment of the present invention.

[0037] Figure 10 A schematic diagram of the circuit structure for single-sided superconducting strip joint resistance testing using an integrated superconducting strip joint welding and testing device provided in an embodiment of the present invention.

[0038] Explanation of reference numerals in the attached drawings: 1. Welding assembly; 101. Upper mold; 102. Lower mold; 103. Upper heating rod mounting hole; 104. Lower heating rod; 105. Temperature sensor mounting hole; 106. Heat insulation pad; 2. Drive pressurization mechanism; 201. Welded drive component; 202. Universal floating pressure head; 203. Pressure sensor; 204. Fixing plate; 3. Electrical test assembly; 301. Upper current lead terminal; 302. Lower current lead terminal; 303. Upper voltage lead terminal; 304. Lower voltage lead terminal; 305. Insulating spacer; 306. Insulating bolt; 307. Insulating nut; 308. Insulating gasket; 4. Test container mechanism; 401. Lifting drive component; 402. Guide component; 403. Coupling; 404. Container body; 405. Dewar cover; 406. On / off control valve; 5. Support and installation components; 501. Workbench; 502. Hanging rod; 503. Casters; 504. CNC screen; 505. Distribution box; 506. Lighting; 507. Fan; 6. Double-sided superconducting tape. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, not all embodiments. 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.

[0040] The following is combined Figures 1 to 10 The following describes embodiments of the present invention.

[0041] According to embodiments of the present invention, in one aspect, an integrated device for testing and welding of superconducting strip joints is provided, such as... Figure 1 As shown, it includes: welding assembly 1, driving pressurization mechanism 2, electrical testing assembly 3, testing container mechanism 4, and support mounting assembly 5.

[0042] Reference Figure 1 The welding assembly 1 is used to support and position the strip to be welded during the welding process of the double-sided superconducting strip 6, and to provide the heat required for welding. The welding assembly 1 includes an upper mold 101 and a lower mold 102, wherein the lower mold 102 is fixedly set, and the upper mold 101 is movably placed above the lower mold 102. The opposing surfaces of the upper mold 101 and the lower mold 102 together form a cavity that is closed at the top and bottom and front and back, and open at the left and right. The cavity is used to accommodate the high-temperature superconducting strip to be welded and the corresponding brazing filler metal. To achieve heating during the welding process, heating elements are integrated inside the upper mold 101, or integrated inside the lower mold 102, or heating elements are simultaneously set inside both the upper mold 101 and the lower mold 102, so as to uniformly heat the strip in the cavity.

[0043] The driving pressure mechanism 2 is used to provide and control the pressure required for welding during the welding process. The driving pressure mechanism 2 includes a driving assembly and a pressure actuator. The pressure actuator is positioned directly above the upper die 101 of the welding assembly 1. The driving assembly can drive the pressure actuator to move linearly in the vertical direction, thus allowing the pressure actuator to have a welding state and a standby state. In the welding state, the pressure actuator moves downward and abuts against the top surface of the upper die 101, thereby transmitting welding pressure to the strip to be welded through the upper die 101; in the standby state, the pressure actuator retracts upward, completely separating from the upper die 101, making room for subsequent electrical testing operations.

[0044] The electrical testing assembly 3 is used to measure the electrical performance parameters of the strip joint in situ after welding. The electrical testing assembly 3 includes at least four pairs of lead terminals. These lead terminals are divided into two groups, respectively located on both sides of the lower mold 102 of the welding assembly 1 along the length of the strip, i.e., the left and right sides of the lower mold 102. Each pair of lead terminals is clamped onto both the front and back surfaces of the strip, thus forming conductive contact with both surfaces. This allows the equipment to simultaneously test the joint resistance and critical current, among other electrical parameters, on both sides of the welded double-sided superconducting strip using a double-sided four-lead method.

[0045] The test container mechanism 4 provides a stable cryogenic environment for electrical testing. The test container mechanism 4 includes a lifting assembly and a container body 404. In this embodiment, the container body 404 is configured to provide a cryogenic environment of approximately 77K, and the container body 404 contains liquid nitrogen. The lifting assembly can drive the container body 404 to smoothly rise or fall vertically. The container body 404 has two working positions: a test state and a standby state. In the test state, the lifting assembly drives the container body 404 to rise until the inner cavity of the container body 404 completely accommodates the entire electrical test assembly 3 and the strip joint area it holds. In the standby state, the container body 404 descends, and its inner cavity is completely separated from the electrical test assembly 3 to facilitate welding operations or strip handling.

[0046] The workflow of the integrated welding and testing equipment for superconducting strip joints is as follows: First, the welding operation is performed. The prepared superconducting strip to be welded and the brazing filler metal are placed in the cavity of the lower mold 102. Simultaneously, the paired lead terminals in the electrical testing components 3 located on both sides of the lower mold 102 are used to clamp the two sides to be welded and tested for auxiliary fixation. Then, the upper mold 101 is placed on top of the lower mold 102. The driving pressure mechanism 2 is activated, and the driving component drives the pressure actuator downwards to enter the welding state, applying a preset welding pressure to the upper mold 101. Simultaneously, the heating element in the welding component 1 is activated to heat the strip and brazing filler metal in the cavity to the welding temperature and maintain this temperature. Under the combined action of pressure and heat, the brazing filler metal melts, flows, and fills the joint gap, forming a metallurgical bond. After the welding process is completed, the driving component drives the pressure actuator upwards to the standby state. At the same time, the operator can remove the upper mold 101.

[0047] Finally, the lead terminals are connected to external current sources and voltage measuring instruments for in-situ electrical testing. The lifting assembly of the test container mechanism 4 is activated, driving the container body 404 to rise smoothly to the testing position. Once the container body 404 is in position, a cryogenic medium such as liquid nitrogen is injected into the inner cavity of the container body 404 until the strip joint and lead terminals are completely submerged. Under stable cryogenic conditions, current is controlled to flow through the lead terminals using external instruments, and the voltage on the joint is measured and collected to calculate the joint's resistance and critical current. After the test is completed, the cryogenic medium is discharged, and the lifting assembly drives the container body 404 to descend to the standby state, allowing the tested strip joint to be removed.

[0048] By inverting the driving pressurization mechanism 2 above the equipment and configuring a liftable test container mechanism 4 below the equipment, the pressure actuator can actively move aside after welding, providing sufficient and mechanically interference-free vertical movement space for the test container to rise. This achieves longitudinal spatial coupling of welding and testing at the same station, reducing the equipment's footprint and improving space utilization. Simultaneously, the lead terminals of the electrical testing component 3 are directly integrated with the welding component 1, allowing for in-situ testing without secondary clamping of the strip after welding, avoiding damage to the brittle superconducting layer that may be caused by strip transfer and repeated clamping in traditional technologies. Furthermore, the configuration of at least four pairs of lead terminals clamping both sides of the superconducting strip enables simultaneous four-lead method testing of the joint electrical parameters on both sides of the double-sided superconducting strip 6, ensuring the accuracy of the resistance and critical current test results for the joints on each side of the double-sided superconducting strip 6 while maintaining the integrity of the superconducting strip.

[0049] In this embodiment, as Figure 2As shown, the upper mold 101 has a groove serving as a cavity, and the lower mold 102 has a corresponding protrusion aligned with the groove to ensure precise pressure on the strip during mold closing. A lower heating rod 104 is embedded in the lower mold 102. An upper heating rod mounting hole 103 is machined inside the upper mold 101 for inserting another set of heating rods, enabling simultaneous heating of the strip and brazing filler metal within the cavity from both above and below. This method results in faster heating and a more uniform temperature field. Furthermore, a temperature sensor mounting hole 105 is machined on the upper mold 101 for mounting a thermocouple or platinum resistance temperature sensor, thereby achieving real-time and accurate monitoring and feedback control of the mold's operating temperature, forming a closed-loop temperature control system.

[0050] In one embodiment, such as Figure 3 As shown, to ensure the smoothness of the lifting process and the accuracy of the lifting position of the container body 404, a stepper cylinder is selected as the lifting assembly, which includes a stepper motor as the lifting drive component 401 and a transmission assembly. The lifting drive component 401 is fixedly installed in the lower half of the support mounting assembly 5 by bolts or welding, and its position remains fixed throughout the entire operation. The transmission assembly includes a guide component 402, a transmission screw, and a mating nut. The guide component 402 is rigidly connected to the support mounting assembly 5 and is typically in the form of a linear guide or guide groove. The transmission screw and guide component 402 extend parallel to each other in spatial arrangement. The transmission screw is driven and installed on the output shaft of the lifting drive component 401, and can rotate synchronously with the output shaft of the lifting drive component 401. The internal thread of the mating nut and the external thread of the transmission screw form a threaded engagement pair, while the slider of the external structure of the mating nut forms a sliding engagement pair with the guide component 402, so that the mating nut cannot rotate when the transmission screw rotates and can only move linearly along the axial direction. Among them, the lifting drive component 401 adopts a stepper motor.

[0051] The container body 404 is fixedly mounted on the mating nut via a connecting bracket or clamp structure. The weight of the container body 404 is borne by the mating nut and moves synchronously with the lifting and lowering movement of the mating nut. Through the threaded transmission engagement between the transmission screw and the mating nut, combined with the rotation restriction of the mating nut by the guide 402, the lifting and lowering movement of the container body 404 has high positional accuracy and smooth movement, effectively preventing the container body 404 from shaking or deviating during movement, and ensuring that the container body 404 can accurately reach the predetermined test position or standby position.

[0052] Through the threaded transmission between the lead screw and the mating nut, combined with the rotation restriction of the mating nut by the guide 402, the lifting and lowering movement of the container body 404 has high positional accuracy and smooth movement. This prevents the container body 404 from shaking or deviating during movement, ensuring that the container body 404 can accurately reach the predetermined test position or standby position.

[0053] Specifically, when the lifting drive 401 receives a lifting command, its output shaft begins to rotate in the forward direction. The output shaft, through a rigid connection, drives the transmission screw to rotate at the same angular velocity. Because the mating nut is constrained circumferentially by the guide 402, it cannot rotate. The rotational motion of the transmission screw is converted into the linear upward motion of the mating nut through the threaded joint, causing the mating nut to smoothly lift the container body 404. When the lifting drive 401 receives a lowering command, its output shaft rotates in the reverse direction, and the transmission screw rotates in the reverse direction as well. The mating nut descends linearly under the threaded drive, causing the container body 404 to descend smoothly. Throughout the lifting process, the guide 402 provides continuous guiding support to the mating nut, preventing it from tilting or jamming due to uneven loading.

[0054] Furthermore, the output shaft of the lifting drive component 401 and the transmission lead screw are coaxially connected via a coupling 403. When the lifting drive component 401 is in operation, the torque of the output shaft is directly transmitted to the transmission lead screw through the coupling 403, causing the transmission lead screw to rotate synchronously with the output shaft of the lifting drive component 401.

[0055] By using coupling 403, the concentricity of power transmission can be ensured, effectively reducing additional stress and vibration caused by shaft misalignment, and improving transmission efficiency, operational stability, and service life of the entire lifting assembly. Coupling 403 can be a rigid coupling 403, a flexible coupling 403, or a diaphragm coupling 403. The rigid coupling 403 is suitable for applications requiring high shaft alignment accuracy, the flexible coupling 403 can compensate for certain shaft misalignment and buffer vibration, and the diaphragm coupling 403 combines high torque transmission with good flexibility. Both ends of coupling 403 are fixedly connected to the output shaft of lifting drive component 401 and the end of transmission screw via keyways or expansion sleeves, ensuring reliable torque transmission.

[0056] In one embodiment, the container body 404 employs a top-opening vacuum Dewar. When cryogenic testing is required, the lifting assembly drives the container body 404 upward, raising the open end of the container body 404 to a height no lower than the upper surface of the electrical testing component 3, allowing the electrical testing component 3 to fully enter the inner cavity of the container body 404. At this time, the open end of the container body 404 completely surrounds the testing area of ​​the electrical testing component 3, forming a cryogenic testing environment. This enables the construction of a cryogenic environment during testing, as well as the automatic removal of the cryogenic environment during the welding process and after testing.

[0057] The height position of the Dewar can be determined by setting a limit switch on the guide 402 or installing a position sensor on the mating nut. When the container body 404 rises to the preset height, the limit signal is triggered, and the lifting drive 401 stops operating, ensuring that the position of the open end is accurately not lower than the upper surface of the electrical test component 3.

[0058] In this embodiment, a Dewar cover 405 is movably disposed at the open end of the container body 404. By providing the Dewar cover 405, the open Dewar can form a sealed space in the standby state, preventing dust and debris from falling into the vacuum Dewar and ensuring the cleanliness of the internal space of the vacuum Dewar. The Dewar cover can be left unused during testing.

[0059] In some other embodiments, when the container body 404 is in the testing state, the Dewar cover 405 can also be used to close the open end of the container body 404 by engaging with it. The Dewar cover 405 is movably installed on the open end of the container body 404 and can be manually operated to open and close. At this time, the edge of the Dewar cover 405 needs to be grooved to allow the double-sided superconducting tape 6 to extend from the groove to the outside of the Dewar during the test. By setting the Dewar cover 405, the open Dewar can form a relatively closed space during the test, which improves the thermal insulation performance, reduces the evaporation and consumption of the cooling medium, and can prolong the low temperature maintenance time. It can also avoid the interference of external airflow and moisture on the testing process, prevent frost or ice formation in the test area, and ensure the accuracy of electrical testing. In the test preparation stage, the Dewar cover 405 is opened first, and after the container body 404 rises to the position and the electrical test component 3 is fully inserted into the inner cavity, the Dewar cover 405 is closed; after the test is completed, the Dewar cover 405 is opened first, and then the container body 404 is lowered.

[0060] As an alternative implementation, the Dewar Cover 405 can also be implemented with a sliding door structure or a rotating flip-top structure.

[0061] In this embodiment, a drain hole is provided at the bottom of the container body 404, and an on / off control valve 406 is installed at the drain hole. The drain hole is located at the lowest point of the bottom wall of the container body 404 or at the bottom of the side wall of the container body 404. The diameter of the hole is determined according to the flow rate and discharge time requirements of the cooling medium. The orifice of the drain hole is machined with an internal thread or flange connection structure to facilitate communication with external pipelines. The on / off control valve 406 can be a manual ball valve, a solenoid valve, or a pneumatic valve, and is fixedly installed at the drain hole by threads or flanges. After the test is completed, the on / off control valve 406 is opened to allow the cooling medium in the inner cavity of the container body 404 to be discharged through the drain hole. After the cooling medium is completely drained, the on / off control valve 406 is closed to complete the drainage operation. This achieves controllable discharge of the cooling medium, avoids the residue of the cooling medium in the inner cavity of the container body 404, and speeds up the equipment reset.

[0062] In one embodiment, such as Figure 4 As shown, for the stability of the overall equipment during operation, all components are mounted on the support mounting assembly 5. The support mounting assembly 5 is welded from metal sheets, forming a closed or semi-closed shell structure including a top plate, a bottom plate, and four side plates. Universal casters 503 with locking brakes are installed at the four corners of the bottom plate, allowing for easy movement and positioning of the entire equipment. A CNC screen 504 and a power distribution box 505 are integrated on the side of the support mounting assembly 5. The CNC screen 504 serves as a human-machine interface, used to set welding pressure, temperature curves, test parameters, and display real-time process data. The power distribution box 505 and its internal control assembly are responsible for the power distribution and logic control of the entire equipment. To improve the operator's visibility, a lighting lamp 506 can be installed at the bottom of the top plate. Furthermore, a fan 507 is installed near the welding station. The fan 507 is activated during the cooling phase after welding to accelerate the cooling of the upper mold 101, lower mold 102, and joint, thereby shortening the production cycle. During the welding process, the strip joints and bridging strips are cleaned with alcohol to remove impurities and oxide films. The double-sided superconducting strip 6 is placed in the mold with both ends aligned, and then the bridging strip, brazing filler metal sheet, and strip are stacked sequentially. Sheet brazing filler metal is used for ease of handling. Alternatively, paste or wire brazing filler metal can be used; paste brazing filler metal needs to be applied in advance, while wire brazing filler metal needs to be heated to melt onto the surface. The double-sided superconducting strip 6 and brazing filler metal are heated to the welding temperature range using heating elements, while pressure is applied and maintained for a period. Afterward, the heating program is turned off, and fan 507 is turned on to cool the strip. Once the temperature drops to the point where the brazing filler metal solidifies, the pressure is released, and the welding is complete.

[0063] A workbench 501 is mounted on the support assembly 5 via a hoisting structure. Welding assembly 1 and electrical testing assembly 3 are both fixedly mounted on the workbench 501. The lower mold 102 is fixedly connected to the workbench 501. To prevent heat conduction to the workbench 501 and ensure the heating rate of both the lower and upper molds 102 during heating, a heat-insulating gasket 106 is placed between the lower mold 102 and the workbench 501. To prevent electrical conductivity between the electrical testing assembly 3 and the workbench 501, an insulating gasket 308 is also installed between them. The hoisting structure uses multiple vertical suspension rods 502. The upper ends of the suspension rods 502 are connected to the top frame of the support assembly 5 via threads or welding, and the lower ends are connected to the edge of the workbench 501 via flanges or brackets, suspending the workbench 501 in the central space of the support assembly 5. The lower mold 102 of the welding assembly 1 is fixed to the central area of ​​the workbench 501 by bolts. The lead terminal mounting base of the electrical test assembly 3 is isolated from the surface of the workbench 501 by an insulating gasket 308. The insulating gasket 308 is made of polytetrafluoroethylene board, epoxy glass cloth board, ceramic insulator or rubber insulating gasket. The insulating gasket 308 has mounting holes. The insulating bolt 306 passes through the mounting holes to fasten the electrical test assembly 3 to the workbench 501.

[0064] The support mounting assembly 5 and the workbench 501 are hoisted together, leaving ample space underneath the workbench 501 to provide the necessary operating space for the lifting and lowering movement of the test container mechanism 4, thus achieving a compact longitudinal layout of the equipment structure. The use of insulating gaskets 308 ensures reliable electrical insulation between the electrical test assembly 3 and the workbench 501, preventing test current from being shunted through the workbench 501 or causing leakage, ensuring the accuracy of the four-lead method test, and improving the reliability of the test data.

[0065] If the Dewar cover needs to be used during the test, in order to avoid the Dewar cover and the rod 502 being restricted, the Dewar cover can be set as a splicing structure of two parts, the left cover and the right cover, and a long groove is set on the opposite side of the left cover and the right cover to accommodate the rod 502.

[0066] In one embodiment, such as Figure 5As shown, the drive assembly is inverted and mounted on the support mounting assembly 5. The drive assembly includes a welding drive component 201 and a linkage assembly. The drive assembly can adopt the same structure as the transmission assembly. In this embodiment, a stepper cylinder is used as the drive assembly, and the welding drive component 201 is a stepper motor. To ensure the stability of the drive assembly's movement in applying pressure to the upper mold 101, a mounting bracket consisting of at least two support columns is provided on the top of the support mounting assembly 5. A fixing plate 204 is fixedly mounted on the top of the mounting bracket, and the welding drive component 201 is fixedly mounted on the fixing plate 204, with the output shaft of the welding drive component facing upwards. A first mating wheel is mounted on the output shaft of the welding drive component on one side of the upper surface of the fixing plate 204. The linkage assembly includes a linkage screw, an auxiliary nut, and a guide component. One end of the linkage screw rotatably engages with the top plate of the support mounting assembly 5, and the other end passes through the fixing plate 204. A second mating wheel is provided at the end of the linkage screw that passes through the upper surface of the fixing plate 204. The first mating wheel and the second mating wheel are driven by a mating belt. Alternatively, both the first and second mating wheels can be gears, meshing and driving each other. A guide rod is used as the guide component, with one end fixed to the fixed plate 204 and the other end fixed to the top plate of the support mounting assembly 5. An auxiliary nut is threaded into the linkage screw, and a mating slider is fixedly mounted outside the auxiliary nut. The mating slider is also sleeved on the guide rod, slidingly engaging with it. An actuating rod is mounted on the mating slider. The actuating rod is located on one side of the linkage screw, or it is a hollow rod coaxially sleeved outside the linkage screw, extending downwards. A pressure actuator is fixedly mounted at the bottom of the actuating rod. A hole is pre-drilled in the top plate of the support mounting assembly 5 to allow the actuating rod to carry the pressure actuator up and down.

[0067] In this embodiment, the pressure actuator is a universal floating pressure head 202, and a pressure sensor 203 is installed between the pressure actuator and the linkage screw. The upper end of the universal floating pressure head 202 is connected to the pressure sensor 203 through a connecting plate to ensure the stability of vertical pressure transmission. The lower end of the universal floating pressure head 202 has a planar structure.

[0068] The universal floating pressure head 202 can adaptively adjust its posture within a certain angle range to ensure that the pressure is applied evenly to the surface of the upper mold 101, avoiding uneven pressure distribution caused by unevenness of the upper mold 101 surface or installation errors. The pressure sensor 203 is used to monitor the pressure applied to the upper mold 101 by the universal floating pressure head 202 in real time, realizing closed-loop control of welding pressure, making the pressure value precise and controllable, and improving the consistency of welding process and the stability of joint quality.

[0069] The pressure sensor 203 can be a strain gauge pressure sensor 203, a piezoelectric pressure sensor 203, or a hydraulic pressure sensor 203. The signal output line of the pressure sensor 203 is connected to the control system, and the control system adjusts the output torque or position of the welding drive component 201 in real time according to the pressure signal.

[0070] In some other embodiments, the pressure sensor 203 may be mounted on the lower end face of the pressure actuator, the upper end face of the upper mold 101, or on the connection structure between the auxiliary nut and the pressure actuator.

[0071] In one embodiment, such as Figures 6 to 8 As shown, the lead terminals are fixed to the left and right sides of the lower mold 102 by an assembly of insulating bolts 306 and insulating nuts 307. On the paired lead terminals, one lead terminal is provided with an insulating spacer 305, which has a test notch, and the strip is suitable for installation within the test notch. The insulating spacer 305 is made of epoxy glass cloth board or polyimide film, and is fixed to the contact surface of a lead terminal by adhesive or snap-fit.

[0072] A rectangular test notch is provided in the transverse middle position of the insulating spacer 305. The size of the test notch is slightly smaller than the width of the strip but larger than the contact point size of the lead terminal. The strip is installed within the test notch of the insulating spacer 305, which separates the paired lead terminals, ensuring that the lead terminals can only make contact with the strip surface through the test notch. This prevents short circuits or cross-currents between adjacent lead terminals and ensures the accuracy of data from simultaneous electrical tests on both sides of the double-sided superconducting strip 6 using the four-lead method. As an alternative implementation, the insulating spacer 305 can also be placed between two lead terminals to completely isolate the paired lead terminals, or partial insulation can be achieved by coating the lead terminal surface with an insulating coating. These alternative insulation methods can effectively prevent cross-currents and short circuits in the test current.

[0073] Specifically, the electrical testing component 3 in this embodiment includes four pairs of lead terminals. The paired lead terminals are divided into two groups based on their connection positions with the double-sided superconducting tape 6. One group of lead terminals is disposed on the upper surface of the double-sided superconducting tape 6, including two upper voltage lead terminals 303 respectively disposed on the left and right sides of the lower mold 102, and two upper current lead terminals 301 respectively disposed on the left and right sides of the lower mold 102. The other group of lead terminals is disposed on the lower surface of the double-sided superconducting tape 6, including two lower voltage lead terminals 304 respectively disposed on the left and right sides of the lower mold 102, and two lower current lead terminals 302 respectively disposed on the left and right sides of the lower mold 102. The upper current lead terminals 301 and lower current lead terminals 302 are connected to a current source via current leads, allowing current to flow through conductors into the upper and lower surfaces of the tape. The upper voltage lead terminals 303 and lower voltage lead terminals 304 are respectively connected to a nanovoltmeter via voltage leads to record voltage. Figure 9 As shown, the upper and lower surfaces of the double-sided superconducting tape 6 are each bridged with a superconducting tape bridge. During measurement, a set of four leads is arranged on the upper and lower surfaces of the tape to measure the resistance and critical current of the upper and lower surfaces respectively.

[0074] Similarly, the integrated welding and testing equipment for superconducting tape joints provided in this embodiment follows the same welding steps as for double-sided superconducting tapes when welding and testing single-sided superconducting tapes. During electrical testing, only the current lead terminals on the superconducting surface of the single-sided superconducting tape need to be energized, and the voltage on the superconducting surface is collected to complete the single-sided tape joint test. Figure 10 As shown.

[0075] Furthermore, to further improve the accuracy and automation level of equipment process control, the superconducting strip joint welding and testing integrated equipment in this embodiment integrates a complete computer control system. The core of the system is a programmable logic controller (PLC) or industrial computer, serving as the central control unit. The central control unit establishes bidirectional electrical connections and communication with the welding drive components and pressure sensors in the pressure-pressurizing mechanism, the heating elements and temperature sensors in the welding assembly, the lifting drive components in the testing container mechanism, and the human-machine interface CNC screen, thereby coordinating and directing the entire welding and testing process.

[0076] In terms of temperature control during the welding stage, the system implements high-precision closed-loop control. A temperature sensor is installed in the temperature sensor mounting hole of the upper mold to collect the temperature of the mold's working area in real time. This measured temperature value is continuously transmitted to the central control unit as a feedback signal. The central control unit stores a preset welding temperature curve, which includes parameters such as heating rate, target welding temperature, and holding time. The central control unit compares the measured temperature value fed back by the temperature sensor with the instantaneous target value of the preset curve to calculate the temperature deviation. Based on this deviation, the system performs real-time calculations using a built-in proportional-integral-derivative (PID) control algorithm. The PID algorithm dynamically calculates the optimal control output by linearly combining the proportional, integral, and derivative of the deviation. This control output is converted into a corresponding signal and sent to the power controller of the heating element, thereby precisely adjusting the power applied to both ends of the heating rod, achieving stepless control of the heating rate and stable maintenance of the holding temperature. This closed-loop control effectively overcomes interference from ambient temperature fluctuations and changes in heat dissipation conditions, ensuring that the temperature within the mold cavity strictly follows the preset process curve.

[0077] In terms of pressure control during the welding stage, the system also employs a closed-loop control strategy. Pressure sensors are connected in series along the force transmission path of the pressure actuator to monitor and provide feedback on the actual pressure applied to the upper mold in real time. The central control unit has a preset welding pressure curve, including stages such as pre-pressure, main welding pressure, and holding pressure, as well as corresponding target values. During pressurization, the central control unit continuously compares the actual pressure value fed back by the pressure sensors with the preset target value to obtain the pressure deviation. This deviation signal is also sent to the pressure control PID algorithm module for processing. The control signal output by the algorithm is transmitted to the driver of the welding actuator that drives the pressurization mechanism. The servo driver precisely adjusts the torque or speed of the motor based on this signal, and then adjusts the downward displacement or maintained force of the pressure actuator through transmission components such as the linkage screw, so that the actual applied pressure quickly and accurately tracks the preset pressure curve. At the instant the pressure actuator contacts the upper mold, the system can switch to force control mode to perform welding and holding pressure at a constant preset pressure, avoiding pressure overshoot or undershoot. Closed-loop precise pressure control, combined with precise temperature control, ensures that the process parameters are highly consistent for each weld, significantly improving the repeatability and reliability of the joint performance.

[0078] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An integrated testing and welding device for superconducting strip joints, characterized in that, include: Welding assembly (1) includes an upper mold (101) and a lower mold (102) disposed opposite to each other, wherein a cavity for receiving the strip to be welded is formed between the upper mold (101) and the lower mold (102), and the upper mold (101) and / or the lower mold (102) are provided with heating elements; A driving pressure mechanism (2) is used to apply welding pressure to the upper and / or lower molds during the welding process; Electrical testing assembly (3) includes at least four pairs of lead terminals, configured to provide at least two pairs of lead terminals on each side of the lower mold (102) along the length of the strip, the pairs of lead terminals being adapted to be clamped on both sides of the superconducting strip, so as to perform joint electrical testing on both sides of the welded superconducting strip using the double-sided four-lead method. The test container mechanism (4) includes a lifting assembly and a container body (404). The lifting assembly is adapted to drive the container body (404) to move toward or away from the electrical test assembly (3). The container body (404) has a test state in which the electrical test assembly (3) is completely housed in the cavity of the container body (404), and a standby state in which it is completely separated from the container body (404). A support mounting assembly (5) is provided, on which a workbench (501) is suspended and installed. The welding assembly (1) and the electrical testing assembly (3) are both installed on the workbench (501). An insulating gasket (308) is installed between the electrical testing assembly (3) and the workbench (501). The driving and pressurizing mechanism (2) includes a driving component and a pressure actuator. The driving component is inverted and mounted on the support mounting component (5). The pressure actuator is arranged toward the upper mold (101). The driving component is adapted to drive the pressure actuator toward or away from the upper mold (101) so that the pressure actuator has a welding state that abuts against the upper mold (101) to apply welding pressure to the upper mold (101), and a standby state that is completely separated from the upper mold (101).

2. The integrated equipment for welding and testing superconducting tape joints according to claim 1, characterized in that, The lifting assembly includes: The lifting drive component (401) is fixedly installed; The transmission assembly includes a guide (402), a transmission screw, and a mating nut. The guide (402) is fixedly installed, and the transmission screw extends parallel to the guide (402). The transmission screw is driven and installed on the output shaft of the lifting drive (401). The mating nut is threadedly engaged with the transmission screw and slidably engaged with the guide (402). The container body (404) is fixedly installed on the mating nut.

3. The integrated equipment for welding and testing superconducting tape joints according to claim 2, characterized in that, The output shaft of the lifting drive (401) is coaxially connected to the transmission screw via a coupling (403).

4. The integrated testing equipment for superconducting strip joint welding according to any one of claims 1 to 3, characterized in that, The container body (404) is a Dewar with an open top. When the container body (404) is in the test state, the container body (404) rises so that its open end is not lower than the upper surface of the electrical test assembly (3).

5. The integrated equipment for welding and testing superconducting tape joints according to claim 4, characterized in that, The container body (404) is movably provided with a Dewar cover (405) at its open end. When the container body (404) is in the test state, the Dewar cover (405) cooperates with the open end of the container body (404) to close the open end of the container body (404).

6. The integrated testing equipment for superconducting strip joint welding according to any one of claims 1 to 3, characterized in that, The bottom of the container body (404) is provided with a drain hole, and an on / off control valve (406) is installed at the drain hole.

7. The integrated testing equipment for superconducting strip joint welding according to any one of claims 1 to 3, characterized in that, The driving component includes: Welding drive component (201), which is fixedly mounted on the support mounting assembly (5); The linkage assembly includes a linkage screw, an auxiliary nut, and a guide. The guide is fixedly mounted on the support mounting assembly (5). The linkage screw extends parallel to the guide and is driven on the output shaft of the welding drive (201). The auxiliary nut is threadedly engaged with the linkage screw and slidably engaged with the guide. The pressure actuator is mounted on the end of the linkage screw away from the welding drive (201).

8. The integrated equipment for welding and testing superconducting tape joints according to claim 7, characterized in that, The pressure actuator is a universal floating pressure head (202), and a pressure sensor (203) is installed between the pressure actuator and the linkage screw.

9. The integrated testing equipment for superconducting strip joint welding according to any one of claims 1 to 3, characterized in that, On the paired lead terminals, one of the lead terminals is provided with an insulating spacer (305), the insulating spacer (305) has a test notch, and the strip is adapted to be installed in the test notch.

10. The integrated testing equipment for superconducting strip joint welding according to any one of claims 1 to 3, characterized in that, The at least two pairs of lead terminals located on the same side of the lower mold (102) include at least one pair of voltage lead terminals and one pair of current lead terminals.

11. The integrated equipment for welding and testing superconducting strip joints according to claim 10, characterized in that, Two current lead terminals located on both sides of the lower mold (102) on the same side of the superconducting tape are connected to a current source so that current flows through a conductor into the upper and / or lower surface of the superconducting tape; Two voltage lead terminals located on both sides of the lower mold (102) on the same side of the superconducting tape are respectively connected to the positive and negative terminals of a nanovoltmeter to record the voltage on the upper and / or lower surfaces of the superconducting tape.

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