A double-sided superconducting tape joint welding and testing integrated device and method

Abstract

The application relates to the technical field of superconducting tape processing equipment, and discloses a double-sided superconducting tape joint welding and testing integrated device and method. The integrated device comprises a hot-pressing welding assembly, a driving mechanism and a pressure applying mechanism. The pressure applying mechanism comprises first and second hot-pressing modules arranged oppositely, and the driving mechanism is suitable for driving the first hot-pressing module to move. An electrical testing assembly is detachably installed on the second hot-pressing module. The electrical testing assembly comprises at least two pairs of second electrical testing pieces arranged thereon. The second electrical testing pieces are suitable for extending into a welding station. The electrical testing assembly and the second hot-pressing module cooperate to test the joint resistance through a four-lead method. The double-sided superconducting tape joint welding and testing integrated device integrates the welding step and the testing step. After the double-sided superconducting tape joint is welded, the testing can be performed in situ, the movement and secondary fixation of the tape during the welding and testing process are reduced, and the risk of damage to the tape is reduced.

Description

Technical Field

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

[0002] High-temperature superconductivity (HTS) has shown great application potential in fields such as power transmission, magnetic levitation transportation, and medical imaging. As the technology matures, the production scale of HTS tapes is gradually expanding, placing higher demands on tape connection technology. In practical applications, due to the limitation of single tape length, multiple tapes often need to be interconnected to meet the needs of long-distance transmission or complex equipment.

[0003] Currently, there are two main methods for preparing joints for high-temperature superconducting tapes: low-melting-point metal brazing and diffusion welding mechanical joining. These methods are relatively mature for single-sided high-temperature superconducting tapes, but new challenges arise for double-sided tapes. Double-sided high-temperature superconducting tapes have a unique structure: a metal substrate in the middle, yttrium barium copper oxide (YBCO) high-temperature superconducting layers on both sides, and a metal stabilizing layer on the outermost layer. This structure makes traditional lap or single-sided bridging methods ineffective for current conduction and prevents the full utilization of the advantages of double-sided tapes. Furthermore, existing joint welding equipment typically only considers completing the welding process, without fully considering the potential damage caused by tape movement and secondary fixation during subsequent joint performance testing. In addition, existing joint resistance testing methods in the laboratory mainly use the four-wire method for short, cut samples. In actual production, due to the longer length of the welded tape, the two-wire method is mainly used for superconducting tape joint resistance testing to facilitate installation on the testing device. However, the two-wire method has a larger error for superconducting joints with lower resistance. Summary of the Invention

[0004] In view of this, the present invention provides an integrated device and method for welding and testing double-sided superconducting tape joints, in order to solve the problem that the existing high-temperature superconducting tape joint testing equipment will damage the superconducting tape products and have large testing errors.

[0005] In a first aspect, the present invention provides an integrated device for welding and testing double-sided superconducting strip joints, comprising: a hot-press welding assembly, which includes a driving mechanism and a pressure application mechanism. The pressure application mechanism includes a first hot-press module and a second hot-press module arranged opposite to each other. The driving mechanism is adapted to drive the first hot-press module to move toward or away from the second hot-press module. The second hot-press module is provided with a welding station, and at least two pairs of first electrical test pieces are installed on the second hot-press module. The first electrical test pieces all extend into the welding station. An electrical testing assembly is detachably mounted on a second hot-pressing module. The electrical testing assembly includes at least two pairs of second electrical test elements, which are adapted to extend into the welding station. The first electrical test piece is adapted to abut against the lower surface of the double-sided superconducting tape, and the second electrical test piece is adapted to be removed from the second thermo-pressing module in the welding state and abut against the upper surface of the double-sided superconducting tape in the testing state, so as to perform joint resistance testing on both sides of the double-sided superconducting tape using the four-lead method.

[0006] The integrated welding and testing device for double-sided superconducting tape joints provided by this invention performs welding first, followed by in-situ testing of the welded double-sided superconducting tape product. During welding, the electrical testing components are removed from the second thermopressing module, and the double-sided superconducting tape is placed on the welding station of the second thermopressing module. The drive mechanism is activated, moving the first thermopressing module toward the second thermopressing module, applying pressure and heating the tape to achieve joint welding. By controlling the welding pressure and temperature of the first thermopressing module during the welding process, welding quality can be ensured. After welding, the electrical testing assembly is placed on the second hot-pressing module, so that at least two pairs of first electrical test pieces on the second hot-pressing module are electrically connected to the lower surface of the welded double-sided superconducting tape, and at least two pairs of second electrical test pieces on the electrical testing assembly are electrically connected to the upper surface of the welded double-sided superconducting tape. Of the two pairs of first electrical test pieces and two pairs of second electrical test pieces, one first electrical test piece and one second electrical test piece are connected to a current source through current leads, and the other first electrical test piece and the other second electrical test piece are connected to a current source through another set of current leads; one first electrical test piece and one second electrical test piece are connected to a voltmeter through voltage leads, and the other first electrical test piece and the other second electrical test piece are connected to a voltmeter through another set of voltage leads, thus forming a four-lead method test circuit, and then the resistance of the double-sided connector is tested by the four-lead method. The drive mechanism moves the first hot-pressing module away from the second hot-pressing module, then installs the electrical testing components back onto the second hot-pressing module, ensuring that all second electrical test pieces have extended into the welding station. During testing, the drive mechanism can also move the first hot-pressing module downwards to apply pressure to the second electrical test pieces without heating them, allowing the first and second electrical test pieces to be clamped and fixed on both sides of the superconducting tape. Using multiple pairs of first and second electrical test pieces in conjunction, the voltage-current curves of the superconducting tape after welding are tested using the four-wire method, and the joint resistance and critical current are fitted. Testing of the superconducting tape can be completed within the welding station without moving the superconducting tape after welding. This integrates the welding and testing steps, allowing for in-situ testing after welding of the double-sided superconducting tape joint, reducing tape movement and secondary fixing during welding and testing, and lowering the risk of tape damage. Furthermore, the use of the four-wire method for electrical performance testing improves the accuracy of the test data.

[0007] In one alternative implementation, the electrical testing component further includes: The upper electrode mounting fixture and the second electrical test piece are both mounted on the upper electrode mounting fixture; An insulating pressure block is installed between the upper electrode mounting fixture and the second hot pressing module. A support is installed between the insulating pressure block and the upper electrode mounting fixture. The second electrical test piece extends toward the insulating pressure block and passes through the insulating pressure block.

[0008] The electrical testing assembly is configured as a separate upper electrode mounting fixture and insulating block, with a second electrical test piece passing through the insulating block. When the second electrical test piece extends into the welding station and contacts the superconducting tape for testing, the insulating block is pressed against the top surface of the second hot-pressing module to limit the length of the superconducting tape and prevent it from bending and contacting the first or second electrical test piece, thus avoiding incorrect test data.

[0009] In one optional embodiment, the support is an elastic element, and the support is parallel to the direction in which the second electrical test piece extends toward the insulating pressure block. By setting the support as an elastic element such as a spring or rubber pad, the distance by which the drive mechanism moves the first hot-pressing module downwards during the test can be adjusted to regulate the pressure between the second electrical test piece and the superconducting tape. At the same time, the elastic element can buffer the pressure exerted by the second electrical test piece on the superconducting tape, reducing the possibility of damage to the superconducting tape when the second electrical test piece comes into contact with the superconducting tape.

[0010] In one optional embodiment, the second electrical test piece includes a test lead and a test electrode. The test electrode is positioned perpendicular to the insulating pressure block, and the test lead extends from the side of the upper electrode mounting fixture to the outside of the upper electrode mounting fixture. By configuring the second electrical test piece into two electrically connected parts—a test lead and a test electrode—with the test electrode used to abut against the superconducting tape and the test lead used to connect to an external current testing device or voltage testing device, the connection position of the external device can be separated from and moved away from the superconducting tape device, facilitating the installation of the external device with the electrical test assembly.

[0011] In one optional embodiment, the second hot-pressing module is fixedly installed inside the test container, with the test container open on the side facing the first hot-pressing module. The test container is an open container, and during testing, a cryogenic fluid such as liquid nitrogen can be filled inside to expose the superconducting tape to a cryogenic environment to exhibit superconducting properties.

[0012] In one optional embodiment, a first limiting member is provided inside the test container, and a second limiting member is provided on the second hot-pressing module. The first limiting member and the second limiting member cooperate to limit the installation of the second hot-pressing module inside the test container, thereby ensuring the stability of the installation of the second hot-pressing module.

[0013] In one optional embodiment, the first hot-pressing module includes: a first heating plate, adapted to move toward or away from the second hot-pressing module under the drive of a driving mechanism; the first heating plate is provided with a heating element and a temperature sensor, the heating element being used to heat the first heating plate, and the temperature sensor being used to monitor the temperature of the first heating plate in real time; and a pressure sensor, which is connected in cooperation with the first heating plate and used to provide real-time feedback on the welding pressure. By heating the strip with the first heating plate and monitoring the welding pressure in real time with the pressure sensor, precise temperature and pressure control during the welding process is ensured, enabling the first hot-pressing module to accurately control welding parameters and improve welding quality.

[0014] In one optional embodiment, a base assembly is included, comprising: a base body, on which the second hot-pressing module is fixedly mounted; and a guide rail, fixedly mounted to the base body, on which the first hot-pressing module is slidably mounted. This allows the first hot-pressing module to slide stably on the guide rail, ensuring the smoothness and accuracy of the welding process.

[0015] In one optional embodiment, a guide rail slider is provided within the first hot-pressing module. The guide rail slider slides in engagement with a guide rail base, and a guide screw is mounted on the guide rail base. The guide screw passes through the guide rail slider, and the guide rail slider and the guide screw are threaded together. During operation, the guide screw rotates under the drive of the drive mechanism, driving the guide rail slider to slide along the guide rail base through the threaded engagement, thereby moving the first hot-pressing module. This makes the movement of the first hot-pressing module more precise and stable, improving the accuracy of welding pressure control. During testing, it can also provide precise and controllable pressure, ensuring good contact between the conductor and the strip surface.

[0016] In one optional embodiment, the drive mechanism is fixedly mounted on the base body and is driven by a transmission assembly and a guide screw. During operation, the drive mechanism drives the guide screw to rotate through the transmission assembly, thereby moving the first hot pressing module along the guide rail, making the movement of the first hot pressing module smoother and more reliable, and ensuring the smooth progress of the welding process.

[0017] Secondly, this application also provides a method for welding and testing double-sided superconducting strip joints, using the integrated device for welding and testing double-sided superconducting strip joints described in this application, including the following steps: Keeping the second electrical test piece in the welded state after it has been removed from the second thermopressing module, place the double-sided superconducting strip joint to be welded in the welding station on the second thermopressing module; The drive mechanism is activated, driving the first hot-pressing module to move toward the second hot-pressing module until the first hot-pressing module contacts the double-sided superconducting tape joint, so as to apply pressure and heat the double-sided superconducting tape joint to achieve joint welding; After welding is completed, the drive mechanism drives the first hot pressing module to move away from the second hot pressing module, places the electrical test component on the second hot pressing module, maintains the test state in which the second electrical test component is in contact with the upper surface of the double-sided superconducting tape, and uses the four-lead method to test the joint resistance of the two sides of the double-sided superconducting tape.

[0018] In the welding and testing method for double-sided superconducting tape joints, testing can be performed on the double-sided superconducting tape within the welding station without moving the welded tape. This integrates the welding and testing steps, allowing testing to be conducted in situ after the double-sided superconducting tape joint is welded, reducing tape movement and secondary fixation during welding and testing, and lowering the risk of tape damage. Furthermore, the use of the four-lead method for electrical performance testing improves the accuracy of test data. Attached Figure Description

[0019] 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.

[0020] Figure 1 A schematic diagram of the integrated welding and testing device for double-sided superconducting strip joints provided in an embodiment of the present invention.

[0021] Figure 2 A schematic diagram of the structure of a hot-press welding assembly provided for an embodiment of the present invention.

[0022] Figure 3 A schematic diagram of the transmission assembly provided for an embodiment of the present invention.

[0023] Figure 4 A schematic diagram of the structure of a liquid nitrogen Dewar provided for an embodiment of the present invention.

[0024] Figure 5 A schematic diagram of the structure of the second hot-pressing module provided for the implementation of the present invention.

[0025] Figure 6 A schematic diagram of the structure of an electrical testing component provided in an embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of the electrical testing assembly provided in an embodiment of the present invention from another angle.

[0027] Figure 8 A schematic diagram of the structure in which the electrical testing component and the second hot-pressing module are installed together, according to an embodiment of the present invention.

[0028] Figure 9 A schematic diagram of a double-sided superconducting tape joint resistance testing circuit provided for an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached drawings: 1. Worktable; 2. Hot pressing welding assembly; 201. Drive mechanism; 202. Base body; 203. Gear coupling; 204. Belt; 205. Transmission gear; 206. Guide screw; 207. Screw nut; 208. Slide table; 209. Guide rail slider; 210. Linear guide rail; 211. Guide rail seat; 212. Top plate; 213. Mounting bracket; 214. Pressure sensor; 215. Connecting column; 216. First heating plate; 217. Heating rod; 218. Temperature sensor; 219. Heating rod hole; 220. Temperature sensor hole 3. Electrical testing components; 301. Double-sided superconducting tape; 302. Second hot-pressing module; 303. First current lead interface; 304. First voltage lead interface; 305. First current conductor; 306. First voltage conductor; 307. Limiting hole; 308. Fixing bolt; 309. Upper electrode mounting fixture; 310. Insulating block; 311. Second current lead interface; 312. Second voltage lead interface; 313. Support component; 314. Second current conductor; 315. Second voltage conductor; 316. Limiting post; 317. Liquid nitrogen Dewar; 318. Limiting block. Detailed Implementation

[0030] 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.

[0031] The following is combined with Figures 1 to 9 The following describes embodiments of the present invention.

[0032] According to embodiments of the present invention, in one aspect, an integrated device for welding and testing double-sided superconducting strip joints is provided, such as... Figure 1 As shown, it includes a hot press welding assembly 2 and an electrical testing assembly 3 mounted on a workbench 1.

[0033] The hot-press welding assembly 2 includes a driving mechanism 201 and a pressure application mechanism. The pressure application mechanism includes a first hot-press module and a second hot-press module 302 arranged opposite to each other. The driving mechanism 201 is adapted to drive the first hot-press module to move toward or away from the second hot-press module 302, thereby achieving pressure control of the joint. A welding station is provided on the second hot-press module 302, and at least two pairs of first electrical test pieces are mounted on the second hot-press module 302, all of which extend into the welding station. An electrical testing assembly 3 is detachably mounted on the second hot-press module 302. The electrical testing assembly 3 includes at least two pairs of second electrical test pieces, which are adapted to extend into the welding station. The electrical testing component 3 is located on the upper side of the second hot-pressing module 302 and is used as an upper surface electrical testing component for electrical connection with the upper surface of the double-sided superconducting tape 301. Two pairs of second electrical testing pieces, which are used as lower surface electrical testing components, are formed on the second hot-pressing module 302 and form an integral component with the second hot-pressing module 302 for electrical connection with the lower surface of the double-sided superconducting tape 301.

[0034] The integrated welding and testing device for double-sided superconducting strip joints provided in this embodiment first places the double-sided superconducting strip 301 on the welding station of the second hot-pressing module 302. An external pneumatic clamping device can be used to temporarily fix the superconducting strip awaiting welding. Then, the drive mechanism 201 is activated, driving the first hot-pressing module towards the second hot-pressing module 302, applying pressure and heating the strip to achieve joint welding. During the welding process, welding quality can be ensured by controlling the welding pressure and temperature. After welding, the drive mechanism 201 moves the first hot-pressing module away from the second hot-pressing module 302, and then the electrical testing component 3 is installed back onto the second hot-pressing module 302, ensuring that all second electrical test pieces have extended into the welding station. During testing, the drive mechanism 201 can also move the first hot-pressing module downwards to apply pressure to the electrical testing component 3 without heating it, allowing the first and second electrical test pieces to be clamped and fixed on both sides of the double-sided superconducting tape 301. Using multiple pairs of first and second electrical test pieces in conjunction, the voltage-current curve of the superconducting tape after welding is tested using the four-wire method, and the joint resistance and critical current are fitted. Testing of the superconducting tape can be completed within the welding station without moving the superconducting tape during welding. This integration of welding and testing significantly improves the efficiency of superconducting tape welding and testing, reduces tape movement and secondary fixation during welding and testing, and lowers the risk of tape damage. Furthermore, by precisely controlling welding pressure and temperature and using the four-lead method for electrical performance testing, welding quality and the accuracy of test data can be improved.

[0035] For easy relocation of the integrated device, see [link / reference]. Figure 1The integrated device is fixedly mounted on the workbench 1, and casters are installed at the bottom of the workbench 1. To facilitate the formation of the testing environment required for the double-sided superconducting tape 301, a Dewar container is fixedly mounted on the base body 202, and the second hot-pressing module 302 is fixedly mounted inside the Dewar container. A fluid outlet is provided on the Dewar container near the bottom to facilitate the discharge of the cooling medium inside the Dewar container after the test. In this embodiment, liquid nitrogen is poured into the Dewar container during the test to provide a 77K environment, and the liquid nitrogen is discharged through the fluid outlet after the test.

[0036] In one embodiment, such as Figure 2 As shown, the first hot-pressing module includes a first heating plate 216 and a pressure sensor 214. The first heating plate 216 is connected to the drive mechanism 201 via a transmission assembly, enabling the drive mechanism 201 to move the first heating plate 216 up and down during operation. The first heating plate 216 is equipped with a heating rod 217 as a heating element and a temperature sensor 218. The heating element heats the first heating plate 216, and the temperature sensor 218 monitors the temperature of the first heating plate 216 in real time. The pressure sensor 214 is mounted on the first heating plate 216 and provides real-time feedback on the welding pressure. By heating the strip with the first heating plate 216 and monitoring the welding pressure in real time with the pressure sensor 214, precise temperature and pressure control during the welding process is ensured, enabling the first hot-pressing module to accurately control welding parameters and improve welding quality.

[0037] In this embodiment, a base assembly is also included, such as... Figure 1 and Figure 2 As shown, the base assembly includes a base body 202, a guide rail seat 211, and a top plate 212. The guide rail seat 211 is fixedly installed between the base body 202 and the top plate 212. The guide rail seat 211 is fixedly installed to the base body 202, and the first hot pressing module is slidably installed on the guide rail seat 211. This allows the first hot pressing module to slide stably on the guide rail seat 211, ensuring the smoothness and accuracy of the welding process. In this embodiment, the second hot pressing module 302 is fixedly installed on the base body 202.

[0038] Specifically, such as Figure 2As shown, the first hot-pressing module is equipped with a guide rail slider 209, and a linear guide rail 210 is provided on the guide rail base 211. The guide rail slider 209 slides in conjunction with the linear guide rail 210 on the guide rail base 211. A guide screw 206 is installed on the guide rail base 211, passing through the guide rail slider 209, and a screw nut 207 is fixedly installed on the guide rail slider 209. The screw nut 207 is sleeved on the guide screw 206 and threadedly engaged with the guide screw 206. During operation, the guide screw 206 rotates under the drive of the drive mechanism 201, driving the guide rail slider 209 to slide along the guide rail base 211 through the threaded engagement, thereby moving the first hot-pressing module. This makes the movement of the first hot-pressing module more precise and stable, improving the accuracy of welding pressure control.

[0039] Furthermore, such as Figure 2 As shown, a first mold is mounted on the first heating plate 216 of the first hot pressing module. During welding, the first mold cooperates with the welding tank to apply pressure to the double-sided superconducting strip 301 in the welding station. A connecting column 215 is fixedly mounted on the side of the first heating plate 216 away from the first mold, and a pressure sensor 214 is mounted on the first heating plate 216 through the connecting column 215. To avoid the high temperature of the first heating plate 216 affecting the detection accuracy of the pressure sensor 214, the pressure sensor 214 and the first heating plate 216 are respectively located at both ends of the connecting column 215. The pressure sensor 214 is fixedly mounted on the mounting bracket 213, which is mounted on the guide rail slider 209 through the slide table 208, so that the first heating plate 216 can carry the first mold and slide axially along the guide screw 206 under the drive of the guide slider.

[0040] In other embodiments, the pressure sensor 214 may also be disposed between the connecting post 215 and the first heating plate 216, or between the first heating plate 216 and the first mold.

[0041] In one embodiment, the drive mechanism 201 is fixedly mounted on the base body 202, and the drive mechanism 201 is in transmission cooperation with the guide screw 206 through a transmission assembly. During operation, the drive mechanism 201 drives the guide screw 206 to rotate through the transmission assembly, thereby driving the first hot pressing module to move along the guide rail seat 211, making the movement of the first hot pressing module more stable and reliable, and ensuring the smooth progress of the welding process.

[0042] Among them, such as Figure 3As shown, the transmission assembly includes a transmission gear 205 and a gear coupling 203 rotatably mounted on the bottom surface of the base body 202. The transmission gear 205 and the gear coupling 203 are connected by a belt 204. In this embodiment, the drive mechanism 201 is a servo motor. The output shaft of the servo motor is installed in conjunction with the transmission gear 205, and the guide screw 206 is installed in conjunction with the gear coupling 203. This allows the servo motor to drive the transmission gear 205 to rotate, which in turn drives the gear coupling 203 and the guide screw 206 to rotate together via the belt 204. Under the action of the thread between the guide rail slider 209 and the guide screw 206, the guide rail slides along the axial direction of the guide screw 206.

[0043] In some other embodiments, the transmission assembly may also employ a gear-meshing assembly. Specifically, the transmission assembly includes a drive gear, a linkage gear, and a mating gear mounted on the bottom surface of the base body 202, which mesh sequentially. A servo motor is selected as the drive mechanism, and the output shaft of the servo motor is mated with the drive gear, enabling the servo motor to drive the drive gear to rotate. The mating gear is coaxially mounted with a guide screw 206 penetrating the base body 202 via a coupling. One side of the linkage gear meshes with the drive gear, and the other side meshes with the mating gear. This ensures that when the servo motor, acting as the drive mechanism, drives the drive gear to rotate, it can synchronously drive the mating gear to rotate via the linkage gear, thereby causing the guide screw 206 to rotate together.

[0044] In another embodiment, a servo motor is selected as the driving mechanism. The servo motor is fixedly mounted upside down on the top plate 212 or fixedly mounted upwards on the bottom of the base body 202. The output shaft of the servo motor is directly connected to the end of the guide screw 206 through a coupling, so that the servo motor can directly drive the guide screw 206 to rotate.

[0045] In one embodiment, the second hot-pressing module 302 is fixedly installed inside the test container, with the test container open on the side facing the first hot-pressing module. The test container is an open container, and during testing, it can be filled with cryogenic fluids such as liquid nitrogen to expose the superconducting tape to a cryogenic environment and allow it to exhibit superconducting properties. In this embodiment, a cuboid-shaped liquid nitrogen Dewar 317 is selected as the test container, and liquid nitrogen is filled inside the liquid nitrogen Dewar 317 during testing.

[0046] In this embodiment, an open liquid nitrogen Dewar is used as the test container because it has good insulation properties and the joint test time is short with limited liquid nitrogen evaporation; therefore, no Dewar cover is required. In some other embodiments, to save liquid nitrogen and reduce surface evaporation, a Dewar cover can be added to the opening of the open liquid nitrogen Dewar during testing. The Dewar cover has slots on both sides at the strip entry point and at the center of the top surface where pressure needs to be applied during subsequent testing, ensuring that the double-sided superconducting strip can be properly introduced and properly pressed down by the second hot-pressing module 302.

[0047] Furthermore, such as Figure 4 and Figure 5 As shown, to ensure the stability of the second hot-pressing module 302 during installation within the test container, a limiting block 318, serving as a first limiting element, is provided inside the test container. The second hot-pressing module 302 is provided with a limiting groove, serving as a second limiting element. The limiting groove is engaged with the limiting block 318 to achieve a limiting fit between the first and second limiting elements. The first and second limiting elements work together to limit the installation of the second hot-pressing module 302 within the test container, ensuring its stability. To further secure the second hot-pressing module 302, a pair of fixing bolts 308 are installed through it. A pair of threaded holes are correspondingly provided on the limiting block 318. The second hot-pressing module 302 is fixedly installed on the limiting block 318 by the fixing bolts 308 engaging with the threaded holes.

[0048] In this embodiment, the second hot-pressing module 302 includes a second heating plate with a welding groove. The welding station is located within the welding groove. During operation, the first mold moves towards the second hot-pressing module 302 under the drive of the drive mechanism 201, cooperating with the welding groove to apply pressure to the strip, thereby achieving welding. This ensures uniform distribution of welding pressure and improves welding quality. In this embodiment, the second heating plate, like the first heating plate, is equipped with a second heating rod and a second temperature sensor (not shown in the figure). The second heating rod is used to heat the second heating plate, and the second temperature sensor is used to monitor the temperature of the second heating plate in real time.

[0049] In this embodiment, as Figure 5As shown, two pairs of first electrical test pieces and two pairs of second electrical test pieces are installed. The first electrical test piece includes a pair of first current leads and a pair of first voltage test pieces. The first current lead includes a first current lead interface 303 and a first current conductor 305 connected in sequence. The first current conductor 305 extends from the side of the second hot-pressing module 302 to a welding station located in the middle of the second hot-pressing module 302. The first current lead interface 303 is located on the side of the second hot-pressing module 302, and the first current lead interface 303 and the first current conductor 305 are arranged in an L-shape. The first voltage test piece includes a first voltage conductor 306 and a first voltage lead interface 304. The first voltage conductor 306 extends from the side of the second hot-pressing module 302 to a welding station located in the middle of the second hot-pressing module 302. The first voltage lead interface 304 is located on the side of the second hot-pressing module 302, and the first voltage lead interface 304 and the first voltage conductor 306 are arranged in a straight line. The second electrical test piece consists of test leads and test terminals. Its two pairs of test leads are a pair of second current lead interfaces 311 and a pair of second voltage lead interfaces 312, and the test terminals are a pair of second voltage conductors 315 and a pair of second current conductors 314.

[0050] In one embodiment, such as Figure 6 and Figure 7 As shown, the electrical testing assembly 3 also includes an upper electrode mounting fixture 309 and an insulating block 310. The second electrical test pieces are all mounted on the upper electrode mounting fixture 309. The insulating block 310 is installed between the upper electrode mounting fixture 309 and the second hot-pressing module 302. A support member 313 is installed between the insulating block 310 and the upper electrode mounting fixture 309. The second electrical test pieces extend towards and pass through the insulating block 310. To facilitate quick disassembly and removal of the electrical testing assembly 3 from the second hot-pressing module 302, four limiting holes 307 are provided on the top surface of the second hot-pressing module 302, and four limiting posts 316 are correspondingly provided on the bottom surface of the insulating block 310. The limiting posts 316 are engaged with the limiting holes 307.

[0051] like Figure 8 As shown, the electrical testing component 3 is configured as a separate upper electrode mounting fixture 309 and an insulating pressure block 310, with the second electrical testing piece passing through the insulating pressure block 310. When the second electrical testing piece extends into the welding station and contacts the superconducting tape for testing, the insulating pressure block 310 is pressed against the top surface of the second hot-pressing module 302 in cooperation with the upper surface of the second hot-pressing module 302 to limit the length of the double-sided superconducting tape 301, preventing the double-sided superconducting tape 301 from bending and contacting the first or second electrical testing piece, thus avoiding test data errors.

[0052] Furthermore, the support member 313 is an elastic member, and the support member 313 is parallel to the direction in which the second electrical test piece extends toward the insulating pressure block 310. By setting the support member 313 as an elastic member such as a spring or rubber pad, the distance by which the drive mechanism 201 drives the first hot-pressing module downward can be adjusted during the test to regulate the pressure between the second electrical test piece and the superconducting tape. At the same time, the elastic member can buffer the pressure applied by the second electrical test piece to the superconducting tape, reducing the possibility of damage to the superconducting tape when the second electrical test piece contacts the superconducting tape. In this embodiment, the support member 313 is a cylindrical compression spring.

[0053] Specifically, the second electrical test piece includes a test lead and a test electrode that are vertically arranged and connected in sequence. The test electrode is arranged perpendicular to the insulating pressure block 310, and a cylindrical compression spring, serving as a support member 313, is sleeved on the outside of the test electrode. The test lead extends from the side of the upper electrode mounting clamp 309 to the outside of the upper electrode mounting clamp 309. By setting the second electrical test piece into two conductively connected parts, the test electrode is used to abut against the superconducting tape, and the test lead is used to connect to an external current testing device or voltage testing device. This allows the connection position of the external device to be separated from the superconducting tape and moved away from the superconducting tape device, facilitating the installation of the external device with the electrical test assembly 3.

[0054] To ensure the accuracy of pressure, temperature, and other parameters during welding and testing, the integrated welding and testing device for double-sided superconducting strip joints also includes a controller (not shown in the figure). The controller can be a PLC controller, an industrial computer, or an embedded system. The controller is electrically connected to the drive mechanism 201, pressure sensor 214, first heating plate 216, and temperature sensor 218 and heating rod 217 on the second hot-pressing module 302 via signal lines. Specifically, the controller receives real-time pressure signals from pressure sensor 214 and real-time temperature signals from temperature sensor 218, and generates control commands based on a preset control algorithm. These commands are then output to the drive mechanism 201 to precisely control its output torque and speed, thereby achieving closed-loop control of the welding pressure. Simultaneously, the controller uses PWM pulse width modulation to adjust the output power of the heating rod 217, achieving closed-loop control of the temperatures of the first heating plate 216 and the second hot-pressing module 302. The controller can also integrate a human-machine interface for setting welding process parameters and test parameters such as pre-pressure, welding pressure, heating rate, welding temperature, and holding time, and display the dynamic curves of pressure and temperature and test data in real time.

[0055] The controller employs a closed-loop control strategy to achieve high-precision and high-stability automatic control of welding pressure and operating temperature. The specific method is as follows: The system employs a real-time feedback closed-loop control method to regulate the welding pressure. The controller continuously reads the actual pressure value detected by the pressure sensor 214 and compares it with the preset target pressure value in real time to calculate the pressure deviation. Subsequently, based on this deviation, the controller dynamically calculates control commands and sends them to the drive mechanism 201. This real-time closed-loop control enables the system to respond quickly and smoothly to pressure deviations: it can rapidly approach the target pressure while effectively preventing pressure overshoot, and it can completely eliminate steady-state errors during the pressure holding phase, thereby ensuring that the pressure remains stable within the process requirements throughout the entire welding process.

[0056] Similarly, a closed-loop control method is also used to control the welding temperature. The controller continuously monitors the actual temperature of the heating plate through temperature sensor 218 and compares it with the preset target temperature value or heating curve to obtain the temperature deviation. Based on this deviation, the controller calculates the heating power that should be supplied to the heating rod 217. This effectively overcomes the thermal inertia of the heating system itself, achieves stable heating, and can maintain a precise temperature at the welding temperature point for a long time, ensuring that the brazing filler metal melts and solidifies in the optimal thermal environment, thereby ensuring the uniformity and reliability of the joint quality.

[0057] The aforementioned closed-loop control parameters for pressure and temperature can be independently adjusted and optimized according to different superconducting tapes, brazing fillers, and process requirements, and stored in the controller as a mature process formula.

[0058] The integrated welding and testing device for double-sided superconducting tape joints provided in this embodiment is used for welding double-sided high-temperature superconducting tapes and performing in-situ measurements. The double-sided high-temperature superconducting tape can be considered as a five-layer structure, such as... Figure 9 As shown, the center is a metal baseband with high resistance. On either side of the baseband are two YBCO high-temperature superconducting layers, and the outermost layers are metal stabilizing layers. In related technologies, welding single-sided high-temperature superconducting tapes typically uses lap joints or single-sided bridging to connect the two superconducting surfaces. However, for double-sided high-temperature superconducting tapes, lap joints result in high resistance due to the central metal baseband, and single-sided bridging cannot utilize the superconducting layer on the other side of the tape. To fully utilize the advantages of double-sided superconducting tapes, both superconducting surfaces should be fully conductive; therefore, a double-sided bridging welding method is adopted. Measuring the resistance and critical current of single-sided high-temperature superconducting tape joints typically uses a four-lead method. However, when dealing with double-sided superconducting tape joints, a four-lead method cannot accurately measure the resistance of both joints regardless of the lead placement. Therefore, a double-sided four-lead method is needed. Figure 9As shown, a superconducting tape bridge is connected to the upper and lower surfaces of the double-sided high-temperature superconducting tape. During measurement, a set of four leads is arranged on both the upper and lower surfaces of the joint to measure the resistance and critical current of the upper and lower surfaces, respectively. The integrated welding and testing device for double-sided superconducting tape joints provided in this embodiment can meet the requirements for welding low-resistance double-sided superconducting tape joints and for resistance testing of the joints through two sets of four leads in a liquid nitrogen environment.

[0059] According to an embodiment of the present invention, in another aspect, a method for welding and testing double-sided superconducting strip joints is also provided, which utilizes the integrated device for welding and testing double-sided superconducting strip joints described in this application, and includes the following steps: First, perform the welding step, keeping the second electrical test piece in the welding state after it has been removed from the second thermopressing module, and place the double-sided superconducting tape joint to be welded in the welding station on the second thermopressing module; Next, the drive mechanism is activated, driving the first hot-pressing module to move toward the second hot-pressing module until the first hot-pressing module contacts the double-sided superconducting tape joint, so as to apply pressure and heat the double-sided superconducting tape joint to achieve joint welding; After welding is completed, the drive mechanism drives the first hot pressing module to move away from the second hot pressing module, places the electrical test component on the second hot pressing module, maintains the test state in which the second electrical test component is in contact with the upper surface of the double-sided superconducting tape, and uses the four-lead method to test the joint resistance of the two sides of the double-sided superconducting tape.

[0060] In the welding and testing method for double-sided superconducting tape joints, testing can be performed on the double-sided superconducting tape within the welding station without moving the welded tape. This integrates the welding and testing steps, allowing testing to be conducted in situ after the double-sided superconducting tape joint is welded, reducing tape movement and secondary fixation during welding and testing, and lowering the risk of tape damage. Furthermore, the use of the four-lead method for electrical performance testing improves the accuracy of test data.

[0061] This embodiment provides a welding and testing method for double-sided superconducting tape joints. During welding of the double-sided superconducting tape 301, a servo motor mounted on the base body 202 rotates, driving the guide screw 206 to rotate via a gear coupling 203, belt 204, and transmission gear 205. The screw nut 207 converts the rotation into linear motion, which is then linearly moved along the linear guide rail 210 via the guide rail slider 209. A mounting bracket 213 is bolted to the slide table 208. A pressure sensor 214 mounted on the mounting bracket 213 provides real-time feedback of the welding pressure, enabling precise control of the welding pressure by the system. Heating is provided by a first heating plate 216 and a second heating plate on the second hot-press module 302. Both the first and second heating plates have openings. Specifically, the first heating plate 216 has two openings: a heating rod hole and a temperature sensor hole. A first heating rod is installed in the heating rod hole, and a first temperature sensor is installed in the temperature sensor hole. The second heating plate of the second hot-pressing module 302 also has two openings: a heating rod hole 209 and a temperature sensor hole 220. A second heating rod is installed in the heating rod hole 209, and a second temperature sensor is installed in the temperature sensor hole 220. The first and second heating rods are used to heat the first heating plate 216 and the second heating plate, respectively. The first and second temperature sensors are used for precise temperature control of the first heating plate 216 and the second heating plate, respectively. The welding station on the first mold and the second heating plate under the first heating plate 216, where it contacts the strip, requires special processing to provide a high surface finish. The welding station will contact the brazing filler metal during use; therefore, using aluminum alloy or stainless steel materials that are not sensitive to brazing filler metal can prevent adhesion to the mold during welding.

[0062] To ensure precise temperature and pressure control during the welding process, enabling the first hot-press module to accurately control welding parameters and improve welding quality, during welding, a servo motor drives the slide 208 downwards via a lead screw nut until the protrusion on the first heating plate 216 matches the slot on the second hot-press module 302, pressing down the head to be welded. At this time, the pressure sensor 214 senses the pressure and feeds it back to the control system in real time. When the pressure reaches the preset pre-pressure, pressurization stops; the heating program is started, and the heating rods placed inside the first heating plate 216 and the second hot-press module 302 begin to work. A temperature sensor 218 installed inside the first heating plate 216 monitors the heating plate temperature in real time. When the heating plate temperature reaches the preset welding temperature, the central control system supplies power to the heating rods. When the heating plate temperature falls below the preset temperature, the heating rods are powered back on, allowing the first heating plate 216 and the second hot-press module 302 to maintain the preset temperature. Once the brazing filler metal melts, the servo motor of the drive mechanism 201 increases its output under preset pressure control, increasing the pressure on the joint and squeezing out excess brazing filler metal. When the pressure reaches the final welding pressure, the pressure is maintained for a period of time, and the heating rod is turned off. The first heating plate 216 and the second hot pressing module 302 begin to cool down. Once the joint temperature drops to the melting point of the brazing filler metal, the first heating plate 216 is raised to its original height, and the welding is completed.

[0063] The first current conductor 305 and the first current lead interface 303 are an integral structure, both made of copper. The contacts on the first current conductor 305 are in close contact with the surface of the strip. To facilitate the external current output, the first current conductor 305 is equipped with the first current lead interface 303. The first current lead interface 303 is connected to a current source through a current lead, allowing the current to flow through the conductor into the lower surface of the strip. The insulating pressure block 310 can restrict the movement of the double-sided superconducting strip 301 during testing, preventing cross-current between the upper and lower surfaces of the double-sided superconducting strip 301. An insulating gasket is located below the first current conductor 305. The fixing bolts 308 used in this embodiment are all made of insulating aluminum nitride material to prevent current from entering the heating plate and flowing across.

[0064] The second current conductor 314 is also made of copper. It has a cylindrical structure and passes through one end of the insulating block 310 as a second current contact for making contact with the upper surface of the strip to conduct electricity. In order to facilitate the external current output, the second current conductor 314 is also equipped with a second current lead interface 311. The second current lead interface 311 is connected to the current source through the current lead, so that the current flows into the upper surface of the strip through the conductor.

[0065] In this embodiment, the first voltage test piece and the first current test piece have similar structures and installation positions. The first voltage conductor 306 and the first voltage lead interface 304 in the first voltage test piece are an integral structure, both made of copper. The second voltage test piece and the second current test piece have similar structures and installation positions, and are also made of copper. In the second voltage test piece, the second voltage conductor 315 passes through the insulating pressure block 310. The second voltage lead interface 312 and the second voltage conductor 315 are an L-shaped integral structure, protruding from the side of the upper electrode mounting clamp 309. The first voltage lead interface 304 and the second voltage lead interface 312 are respectively connected to a nanovoltmeter via voltage leads to record voltage.

[0066] During welding and testing, the strip joint and bridging strip are cleaned with alcohol to remove impurities and oxide film. The strip ends are aligned and placed in the mold. The bridging strip and solder sheet strip are stacked sequentially. For ease of operation, sheet solder is used; paste solder is pre-applied, while wire solder needs to be heated to melt onto the strip surface. A small pre-compression pressure is applied, followed by heating to the welding temperature range, increasing the pressure to the welding pressure, holding the pressure for a period, and then cooling down to room temperature before releasing the pressure. Welding is then complete. The upper first hot-pressing module presses the mold tightly, ensuring close contact between the electrodes of the four leads and the strip surface. Liquid nitrogen is poured into a liquid nitrogen Dewar 317, and a nanovoltmeter and current source are connected to record data. After testing, the double-sided superconducting strip 301 joint is removed after welding and testing.

[0067] To prevent damage to the double-sided superconducting tape 301 during testing, during resistance testing, the upper electrode mounting fixture 309 and insulating pressure block 310 of the upper half of the electrical testing assembly 3 are inserted into the limiting hole 307 on the lower half of the second hot-pressing module 302 via the limiting post 316. This ensures precise contact between the first current conductor 305 and the second current conductor 314, and between the first voltage conductor 306 and the second voltage conductor 315, on the upper and lower surfaces of the double-sided superconducting tape 301. (Assembly diagram) Figure 8As shown. After assembly, the servo motor is started, and the slide 208 moves the first heating plate downwards. The pressure sensor 214 detects and provides feedback on the pressure on the first heating plate 216 in real time until the lower surface of the first heating plate 216 contacts the upper surface of the upper electrode mounting fixture 309. The compression spring ensures that the lower surface of the first heating plate and the upper surface of the upper electrical test assembly are completely in contact through spring deformation, ensuring that each current and voltage electrode applies the same pressure to the strip. At this time, the pressure value detected and fed back by the pressure sensor 214 is the pressure on the strip at each electrode contact point. When the pressure value reaches the preset pressure value of the test program, the pressurization stops, and the pressure is maintained until the end of the test. After the test, the servo motor drives the slide to reset the first heating plate 216, and the liquid nitrogen is discharged. After the test fixture is warmed to room temperature, the double-sided superconducting strip 301 can be taken out, and the welding test process of the double-sided superconducting strip 301 is completed. The contact points of the first current conductor 305, the second current conductor 314, the first voltage conductor 306, and the second voltage conductor 315 with the double-sided superconducting tape 301 are planar. The corners of the first current conductor 305 and the first voltage conductor 306 are chamfered or rounded to prevent scratching the double-sided superconducting tape 301. The contact surfaces can be silver-plated to reduce contact resistance.

[0068] This application proposes a welding method for YBCO double-sided superconducting tape joints based on the special structure of YBCO double-sided superconducting tape. It utilizes two sets of four-lead methods to test the resistance and critical current of the joints on both sides, and designs an integrated device for welding and testing double-sided superconducting tapes based on this method. This device uses a servo motor linear guide 210 to further improve the pressure accuracy and stability of the welding. Both the first and second hot-pressing modules 302 are equipped with thermocouples and temperature measurement systems, providing more precise temperature control for welding. Through precise control of welding pressure, temperature, and joint length, high-critical-current, low-resistance high-temperature double-sided superconducting tape joints are obtained. Using two sets of four-leads allows for more accurate measurement of the resistance and critical current of the joint on each side. The current and voltage conductors are pressed against the tape surface by the servo motor of the welding module, greatly improving pressure controllability. The testing waiting time can preheat the tape and solder on the next side to be welded, significantly shortening the welding-resistance testing time and reducing the possibility of damage to the tape caused by repeated movement and fixing. This device combines welding and testing fixtures, boasting a high degree of intelligence and integration. It completes welding and testing within a relatively small space, significantly improving the efficiency and success rate of joint welding. It can be used for welding and measuring the resistance of double-sided superconducting tape 301 joints. The width of the superconducting tape is not limited; tapes ranging from 2mm to 12mm can be welded and measured. It is also suitable for various types of superconducting tapes, including YBCO and Bi-based superconducting tape joints. This equipment is also applicable to single-sided tapes; the welding process remains largely unchanged. During testing, only the voltage and current leads on the superconducting side need to be connected.

[0069] 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 device for welding and testing double-sided superconducting strip joints, characterized in that, include: The hot press welding assembly (2) includes a driving mechanism (201) and a pressure application mechanism. The pressure application mechanism includes a first hot press module and a second hot press module (302) arranged opposite to each other. The driving mechanism (201) is adapted to drive the first hot press module to move toward or away from the second hot press module (302). The second hot press module (302) is provided with a welding station and at least two pairs of first electrical test pieces are installed on the second hot press module (302). The first electrical test pieces all extend into the welding station. An electrical testing assembly (3) is detachably mounted on the second hot-pressing module (302). The electrical testing assembly (3) includes at least two pairs of second electrical test pieces, which are adapted to extend into the welding station. The first electrical test piece is adapted to abut against the lower surface of the double-sided superconducting tape, and the second electrical test piece is adapted to be removed from the second hot-press module (302) in the welding state and abut against the upper surface of the double-sided superconducting tape in the test state, so as to perform joint resistance test on both sides of the double-sided superconducting tape using the four-lead method. The electrical testing component (3) also includes: Upper electrode mounting fixture (309), on which the second electrical test piece is mounted; An insulating pressure block (310) is installed between the upper electrode mounting fixture (309) and the second hot pressing module (302). A support member (313) is installed between the insulating pressure block (310) and the upper electrode mounting fixture (309). The second electrical test piece extends toward the insulating pressure block (310) and is disposed through the insulating pressure block (310).

2. The integrated device for welding and testing double-sided superconducting strip joints according to claim 1, characterized in that, The support member (313) is an elastic member, and the support member (313) is parallel to the direction in which the second electrical test piece extends toward the insulating pressure block (310).

3. The integrated device for welding and testing double-sided superconducting strip joints according to claim 2, characterized in that, The second electrical test piece includes a test lead and a test pole, the test pole being arranged perpendicular to the insulating block (310), and the test lead extending from the side of the upper electrode mounting fixture (309) to the outside of the upper electrode mounting fixture (309).

4. The integrated device for welding and testing double-sided superconducting strip joints according to claim 1 or 2, characterized in that, The second hot-press module (302) is fixedly installed inside the test container, and the test container is open on the side facing the first hot-press module.

5. The integrated device for welding and testing double-sided superconducting strip joints according to claim 4, characterized in that, The test container is provided with a first limiting member, and the second hot pressing module (302) is provided with a second limiting member. The first limiting member and the second limiting member cooperate to limit each other.

6. The integrated device for welding and testing double-sided superconducting strip joints according to claim 1 or 2, characterized in that, The first hot-press module includes: The first heating plate (216) is adapted to move toward or away from the second hot pressing module (302) under the drive of the driving mechanism (201). The first heating plate (216) is provided with a heating element and a temperature sensor (218). The heating element is used to heat the first heating plate (216), and the temperature sensor (218) is used to monitor the temperature of the first heating plate (216) in real time. A pressure sensor (214) is connected in conjunction with the first heating plate (216) to provide real-time feedback of welding pressure.

7. The integrated device for welding and testing double-sided superconducting strip joints according to claim 1 or 2, characterized in that, It also includes a base assembly, the base assembly comprising: The base body (202) is fixedly mounted on the second hot-pressing module (302); The guide rail base (211) is fixedly installed with the base body (202), and the first hot pressing module is slidably installed on the guide rail base (211).

8. The integrated device for welding and testing double-sided superconducting strip joints according to claim 7, characterized in that, The first hot-press module is provided with a guide rail slider (209), which is slidably engaged with the guide rail seat (211). A guide screw (206) is installed on the guide rail seat (211), which passes through the guide rail slider (209) and is threadedly engaged with the guide rail slider (209).

9. The integrated device for welding and testing double-sided superconducting strip joints according to claim 8, characterized in that, The drive mechanism (201) is fixedly installed on the base body (202), and the drive mechanism (201) is in transmission cooperation with the guide screw (206) through the transmission assembly.

10. A method for welding and testing double-sided superconducting tape joints, characterized in that, The integrated welding and testing apparatus for double-sided superconducting strip joints according to any one of claims 1 to 9 includes the following steps: Keeping the second electrical test piece in the welded state after it has been removed from the second thermopressing module, place the double-sided superconducting strip joint to be welded in the welding station on the second thermopressing module; The drive mechanism is activated, driving the first hot-pressing module to move toward the second hot-pressing module until the first hot-pressing module contacts the double-sided superconducting tape joint, so as to apply pressure and heat the double-sided superconducting tape joint to achieve joint welding; After welding is completed, the drive mechanism drives the first hot-pressing module to move away from the second hot-pressing module, installs the insulating pressure block in the electrical test assembly on the second hot-pressing module, and installs the electrode mounting fixture in the electrical test assembly on the insulating pressure block. A support is installed between the insulating pressure block and the upper electrode mounting fixture. The second electrical test piece is extended toward the insulating pressure block and passes through the insulating pressure block, maintaining the test state where the second electrical test piece is in contact with the upper surface of the double-sided superconducting tape. The joint resistance of the two sides of the double-sided superconducting tape is tested using the four-lead method.

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