A long superconducting joint welding device based on brazing technology

Abstract

The application discloses a long superconducting joint welding device based on brazing technology, which comprises a guide rail, a front support frame, a middle support frame, a tail end support seat, upper and lower nylon rollers, a rear support frame, a center support shaft, a joint framework, a fastening nut, a three-jaw chuck, an electric soldering iron welding head, a constant pressure spring and a welding head fixing seat. When welding the long superconducting joint, the superconducting bands with uniform tin hanging are fixed at the tail end support seat and the joint framework respectively. The power supply is started, the electric soldering iron welding head is heated to 180-280 DEG C, and the joint framework is driven by the center support shaft to rotate at a speed of 0.5-3 mm / s. With the increase of the welding length of the superconducting joint, the front support frame and the middle support frame move on the guide rail at a speed of 0.5-3 mm / s, the displacement of the movement is the same as the length of the superconducting band which has been welded into a joint, and the superconducting band maintains tension. With the increase of the layers of the superconducting joint wound into a coil shape, the constant pressure spring is contracted until the joint length is welded to the setting.

Description

Technical Field

[0001] This invention relates to a welding apparatus for long superconducting joints of superconducting magnets. Background Technology

[0002] With the development and maturation of superconducting technology, REBa2Cu3O 7-x High-temperature superconducting magnets composed of REBCO-coated conductors are receiving increasing attention in the research and application of nuclear magnetic resonance (NMR) instruments, high-field magnets, high-energy particle accelerators, and industrial equipment. Various applications require long REBCO-coated conductors. However, the current maximum length of REBCO-coated conductors is approximately 1 km, which is insufficient to meet application requirements. Therefore, it is necessary to connect REBCO-coated conductors. Especially when used as coils in continuous current mode, such as in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI), approximately 10 km is required. -12 Ω connector resistance.

[0003] Currently, the most common welding process for superconducting joints is brazing, which uses In or In-Sn as solder to weld REBCO tapes together. Brazing has advantages such as not requiring a special environment, ease of welding, and low cost; however, because brazing does not completely form a metallurgical bond at the interface, contact resistance exists, resulting in generally high resistance at the brazed joint. Therefore, it is necessary to increase the joint length to increase the contact area and reduce the joint resistance. Currently, the welding process for long superconducting joints involves first uniformly applying solder to the surface of the superconducting tape, then using a soldering iron for spot heating while simultaneously winding the superconducting tape into a coil shape. This welding process requires not only one person to use the soldering iron for spot heating but also another person to tighten the superconducting tape and apply pressure. Therefore, this process is not only extremely time-consuming and labor-intensive but also cannot guarantee uniform welding pressure at every point of the long superconducting joint, leading to a reduction in the effective contact area of ​​the joint. Summary of the Invention

[0004] The purpose of this invention is to overcome the imperfections of existing long superconducting joint welding methods and propose a welding device for long superconducting joints based on brazing technology. The superconducting strip used in the superconducting joint to be welded in this invention has a face surface and a back surface. During welding, the face surfaces of the two superconducting strips are welded together. A constant pressure spring is used to ensure that the welding pressure is the same at every point of the long superconducting joint. During the welding process, as the superconducting strip is welded into a joint and wound into a coil shape, the unwelded superconducting strip moves on a guide rail, with the displacement being the same as the length of the superconducting strip that has been welded into a joint, to ensure that the tension on the superconducting strip remains constant. Simultaneously, upper and lower nylon rollers are used to ensure close contact between the face surfaces of the upper and lower superconducting strips. Therefore, compared with current long superconducting joint welding methods, this invention has the characteristics of uniform forming and better metallurgical bonding, ensuring that the welding pressure is the same at every point of the long superconducting joint, thereby increasing the effective contact area of ​​the joint and producing superconducting joints with extremely low resistivity. Furthermore, this invention has high production efficiency, can be automated, and allows for precise control of process parameters and processes, resulting in stable process performance.

[0005] The superconducting joint welding device of the present invention includes a guide rail, a front support frame, a middle support frame, a tail support seat, an upper nylon roller, a lower nylon roller, a rear support frame, a central support shaft, a joint skeleton, a fastening nut, a three-jaw chuck, a soldering iron welding head, a constant pressure spring, and a welding head fixing seat.

[0006] The front support frame is fixed to the tail support seat. The upper and lower nylon rollers are fixed to the middle support frame, ensuring close contact between the faces of the upper and lower superconducting strips. The rear support frame is fixed to the three-jaw chuck. All three support frames are fixed to guide rails, but the front and middle support frames can move on the guide rails, while the rear support frame cannot. The constant pressure spring is fixed to the welding head holder. The soldering iron welding head is fixed to the constant pressure spring and is in close contact with the surface of the superconducting strip. During welding, the constant pressure spring contracts as the number of layers of the superconducting joint wound into a coil shape increases. The central support shaft is fixed to the three-jaw chuck, and the joint skeleton is fitted onto the central support shaft. The fastening nut is used to secure the joint skeleton.

[0007] The tail end of the superconducting tape used in the superconducting joint to be welded in this invention is fixed on the tail end support, and the head end of the superconducting tape is fixed to the joint skeleton with adhesive tape.

[0008] When welding long superconducting joints, the ends of the uniformly tinned superconducting strip are fixed to the joint frame and the tail support, respectively. The power is turned on, and the soldering iron tip heats to 180–280 degrees Celsius. The central support shaft drives the joint frame to rotate at a speed of 0.5–3 mm / s. As the welding length of the superconducting joint increases, the front and middle support frames move on the guide rails at a speed of 0.5–3 mm / s, with the displacement matching the length of the welded superconducting strip, maintaining tension on the superconducting strip. As the number of layers of the superconducting joint wound into a coil shape increases, the constant pressure spring contracts until the welded joint length is reached. Attached Figure Description

[0009] Figure 1 A schematic diagram of a welding device for long superconducting joints based on brazing technology proposed in this invention.

[0010] Figure 2 for Figure 1 Enlarged view of the structure of part A in the middle section.

[0011] Figure 3 Exploded view of the welded parts assembly.

[0012] In the diagram: 1 guide rail, 2 front support frame, 3 middle support frame, 4 tail end support seat, 5 upper nylon roller, 6 lower nylon roller, 7 superconducting belt, 8 rear support frame, 9 center support shaft, 10 joint skeleton, 11 fastening nut, 12 three-jaw chuck, 13 soldering iron tip, 14 constant pressure spring, 15 soldering tip fixing seat. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0014] like Figure 1 , 2 As shown in Figures 1 and 3, the superconducting joint welding device of the present invention includes a guide rail 1, a front support frame 2, a middle support frame 3, a tail end support seat 4, an upper nylon roller 5, a lower nylon roller 6, a rear support frame 8, a central support shaft 9, a joint skeleton 10, a fastening nut 11, a three-jaw chuck 12, a soldering iron welding head 13, a constant pressure spring 14, and a welding head fixing seat 15.

[0015] The front support frame is fixed to the tail support seat. The upper and lower nylon rollers are fixed to the middle support frame, ensuring close contact between the faces of the upper and lower superconducting strips. The rear support frame is fixed to the three-jaw chuck. All three support frames are fixed to guide rails, but the front and middle support frames can move on the guide rails, while the rear support frame cannot. The constant pressure spring is fixed to the welding head holder. The soldering iron welding head is fixed to the constant pressure spring and is in close contact with the surface of the superconducting strip. During welding, the constant pressure spring contracts as the number of layers of the superconducting joint wound into a coil shape increases. The central support shaft is fixed to the three-jaw chuck, and the joint skeleton is fitted onto the central support shaft. The fastening nut is used to secure the joint skeleton.

[0016] The superconducting strip used in the superconducting connector to be welded in this invention has a face surface and a back surface. During welding, the face surfaces are welded together. The tail end of the superconducting strip is fixed to the tail end support, and the head end of the superconducting strip is fixed to the connector frame with adhesive tape.

[0017] When welding long superconducting joints, the ends of the uniformly tinned superconducting strip are fixed to the joint frame and the tail support, respectively. The power is turned on, and the soldering iron tip heats to 180–280 degrees Celsius. The central support shaft drives the joint frame to rotate at a speed of 0.5–3 mm / s. As the welding length of the superconducting joint increases, the front and middle support frames move on the guide rails at a speed of 0.5–3 mm / s, with the displacement matching the length of the welded superconducting strip, maintaining tension on the superconducting strip. As the number of layers of the superconducting joint wound into a coil shape increases, the constant pressure spring contracts until the welded joint length is reached.

Claims

1. A welding device for long superconducting joints based on brazing technology, characterized in that... The superconducting joint welding device includes a guide rail (1), a front support frame (2), a middle support frame (3), a tail end support seat (4), an upper nylon roller (5), a lower nylon roller (6), a rear support frame (8), a central support shaft (9), a joint skeleton (10), a fastening nut (11), a three-jaw chuck (12), an electric soldering iron welding head (13), a constant pressure spring (14), and a welding head fixing seat (15). The front support frame (2) is fixed together with the tail support seat (4). The upper nylon roller (5) and the lower nylon roller (6) are fixed together with the middle support frame (3). The upper nylon roller (5) and the lower nylon roller (6) make the faces of the upper and lower superconducting strips in close contact. The rear support frame (8) is connected together with the three-jaw chuck (12). The front support frame (2), the middle support frame (3) and the rear support frame (8) are all fixed on the guide rail (1), but the front support frame (2) and the middle support frame (3) can move on the guide rail (1), while the rear support frame (8) cannot move on the guide rail (1). The constant pressure spring (14) is fixed on the welding head fixing seat (15), the soldering iron welding head (13) is fixed together with the constant pressure spring (14), and the soldering iron welding head (13) is in close contact with the surface of the superconducting strip (7); during the welding process, as the number of layers of the superconducting joint wound into a coil shape increases, the constant pressure spring (14) contracts; the central support shaft (9) is fixed on the three-jaw chuck (12), the joint skeleton (10) is sleeved on the central support shaft (9), and the fastening nut (11) is used to fix the joint skeleton (10).

2. The superconducting joint welding apparatus according to claim 1, characterized in that, The tail of the superconducting tape (7) used for the superconducting joint to be welded is fixed on the tail support (4), and the head of the superconducting tape is fixed on the intermediate joint skeleton (10) with tape.

3. The superconducting joint welding apparatus according to claim 1, characterized in that, When welding a long superconducting joint, the ends of the superconducting strip (7) that has been evenly tinned are fixed to the joint frame (10) and the tail support (4) respectively. The power is turned on and the soldering iron tip (13) is heated to 180-280 degrees Celsius. The central support shaft (9) drives the joint frame (10) to rotate at a speed of 0.5-3 mm / s. As the welding length of the superconducting joint increases, the front support frame (2) and the middle support frame (3) move on the guide rail (1) at a speed of 0.5-3 mm / s. The displacement of the movement is the same as the length of the superconducting strip that has been welded into a joint. Tension is maintained on the superconducting strip (7). As the number of layers of the superconducting joint wound into a coil shape increases, the constant pressure spring (14) contracts until the joint length is reached.

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