Tension device for electric plasticity rolling of rare earth magnesium alloy wire for electric arc additive

Abstract

The application discloses a rare earth magnesium alloy wire tension device for electric plasticity arc additive, which comprises a base frame, an electric plasticity roller drawing mechanism, a multi-stage tension detection and buffer mechanism, a driving servo tension mechanism, a servo drive unwinding mechanism and an integrated control system. Each functional component is sequentially installed on the base frame according to the wire feeding path, and the integrated control system realizes full-process collaborative control. The application solves the problems of the existing tension device and electric plasticity roller drawing process, such as the split, low tension control precision, response lag and easy wire breaking. Through the combination of multiple detection and composite control and the feed-forward tension prediction, the wire tension high-precision self-adaptive stable control is realized, the wire breaking rate is significantly reduced, and the forming quality and process reliability of the rare earth magnesium alloy electric arc additive are improved.

Description

Technical Field

[0001] This invention belongs to the field of metal additive manufacturing technology, specifically relating to a tensioning device for rare earth magnesium alloy wire electroplastic roller drawing of wire for electric arc additive manufacturing. Background Technology

[0002] Wire Arc Additive Manufacturing (WAAM) is a promising metal additive manufacturing technology. Its core technology uses an electric arc as a high-energy-density cladding heat source and metal wires as filler materials. Under the control of a CNC system, the wires are deposited layer by layer on a substrate according to a preset path to finally produce large parts.

[0003] In the materials sector, lightweighting has always been a relentless pursuit in aerospace, rail transportation, and high-end equipment manufacturing. Rare-earth magnesium alloys are a star material that has emerged under this trend. Magnesium, as the lightest metallic structural material, has a density only 2 / 3 that of aluminum and 1 / 4 that of steel. By adding rare-earth elements such as neodymium, yttrium, and gadolinium to magnesium, rare-earth magnesium alloys not only retain the inherent low-density advantage of pure magnesium, but also achieve a qualitative leap in their comprehensive mechanical properties: high specific strength, meaning that it can withstand greater loads for the same weight; excellent damping performance, effectively absorbing vibration and noise, improving the stability and comfort of equipment; in addition, it also has good heat resistance and creep resistance. These characteristics make rare-earth magnesium alloys an ideal choice for manufacturing lightweight, high-rigidity, and low-inertia structures, and their application in arc additive manufacturing is considered a key technological path to achieve integrated forming of large, complex, lightweight structures.

[0004] To overcome the first challenge of feeding magnesium alloy wire, the cutting-edge physical principle of "electroplastic effect" was introduced, leading to the development of an electroplastic roller drawing device. This device is typically integrated into the wire feeding path, and its core consists of one or more pairs of rollers made of highly conductive materials. As the magnesium alloy wire passes between the rollers, the device applies pressure or stretching to the wire via the rollers, performing online straightening and microstructure control. Simultaneously, a high-energy pulsed current is introduced to the rollers through brushes. This current instantaneously penetrates the wire's cross-section, utilizing the electroplastic effect to make the originally "hard and brittle" magnesium alloy exceptionally "soft" and easily deformable the moment it passes through the rollers. This significantly reduces the force required for straightening, effectively minimizing the risk of microcracks in the wire caused by forced straightening, and significantly improving the wire feeding performance.

[0005] However, existing electroplastic roller forming devices either lack an independent tensioning system entirely or are equipped with extremely rudimentary traditional tensioners. These tensioners mainly fall into two categories: the first is passive mechanical tensioning, such as spring tensioning or counterweight tensioning, which provides a fixed or extremely narrow adjustable tension range, cannot respond to dynamic disturbances, exhibits severe lag in response, and is prone to tension oscillations due to inertia; the second is simple pneumatic / electromagnetic braking, which, although able to change the braking force by adjusting air pressure or current, suffers from low control precision and poor linearity, essentially remaining a "passive response" lacking foresight and adaptive capabilities. Most importantly, these traditional tensioning devices are "disconnected" from the advanced electroplastic roller forming process, making collaborative intelligent control impossible.

[0006] Therefore, the current technological state urgently calls for an innovative solution. We urgently need a high-precision tensioning device that can work in deep collaboration with electroplastic rolling devices. It must have the ability to monitor minute changes in wire tension in real time; it must have the ability to respond quickly to counteract any tension disturbances; and more importantly, it must have the ability to adaptively adjust its control strategy and parameter settings according to the process conditions of electroplastic processing, thereby providing a relatively stable tension environment for rare earth magnesium alloy wires. Summary of the Invention

[0007] To address the aforementioned problems, this invention proposes a tensioning device for rare earth magnesium alloy wire electroplastic roller drawing of rare earth magnesium alloy wire for arc additive manufacturing.

[0008] The technical solution adopted in this invention is: a tensioning device for electroplastic roller drawing of rare earth magnesium alloy wire for electric arc additive manufacturing, characterized in that: it includes a base frame, an electroplastic roller drawing mechanism, a multi-stage tension detection and buffering mechanism, an active servo tensioning mechanism, a servo-driven unwinding mechanism, and an integrated control system;

[0009] The electroplastic roller stretching mechanism is fixedly connected to the middle of the front of the base frame through an insulating bracket, and applies a high-energy pulse current while stretching and straightening the filament.

[0010] The multi-stage tension detection and buffering mechanism is divided into two groups, which are fixedly connected to the base frames corresponding to the filament feeding side and the filament output side of the electroplastic roller pulling mechanism, respectively. It is used to detect the filament tension in real time and to perform preliminary flexible buffering and impact absorption of tension fluctuations.

[0011] The active servo tensioning mechanism is fixedly connected to the base frame on the back of the multi-stage tension detection and buffering mechanism on the yarn feeding side, and is used to achieve precise tension adjustment and high-frequency disturbance suppression according to the change of yarn tension.

[0012] The servo-driven unwinding mechanism is fixedly connected to the base frame at the front of the multi-stage tension detection and buffer mechanism on the wire feeding side of the electroplastic roller pulling mechanism. It is used to control the unwinding and rewinding of the filament spool and to provide adjustable braking torque.

[0013] The integrated control system is electrically connected to the electroplastic roller tensioning mechanism, the multi-stage tension detection and buffering mechanism, the active servo tensioning mechanism, and the servo-driven unwinding mechanism, respectively.

[0014] Furthermore, the electroplastic roller pulling mechanism includes two drive rollers, a precision servo motor that drives them to rotate, and a pulse power generator; the two horizontally arranged drive rollers are made of highly conductive material and are connected to the pulse power generator through brushes.

[0015] Furthermore, the multi-stage tension detection and buffering mechanism includes a first guide wheel group, a first tension sensor, and a first pneumatic buffer on the yarn feeding side, and a second guide wheel group, a second tension sensor, and a second pneumatic buffer on the yarn output side. The first tension sensor, the first pneumatic buffer, the second tension sensor, and the second pneumatic buffer are arranged on the back of the base frame along the yarn output direction, while the first guide wheel group and the second guide wheel group are arranged on the front of the base frame along the yarn output direction. The piston rod ends of the first tension sensor and the first pneumatic buffer are connected to the guide wheels in the first guide wheel group, and the piston rod ends of the second tension sensor and the second pneumatic buffer are connected to the guide wheels in the second guide wheel group. The yarn passes through the first guide wheel group and the second guide wheel group in an "S" shaped path. Both the first tension sensor and the second tension sensor are electrically connected to the integrated control system.

[0016] Furthermore, the active servo tensioning mechanism includes a Watt's linkage mechanism, a nonlinear spring-damping composite unit, and an absolute encoder; the rotating shaft end of the active rod of the Watt's linkage mechanism is connected to the absolute encoder, the driven rod end of the Watt's linkage mechanism is connected to the nonlinear spring-damping composite unit, and the end of the nonlinear spring-damping composite unit is connected to the guide wheel in the first guide wheel group; the absolute encoder is electrically connected to the integrated control system.

[0017] Furthermore, the servo-driven unwinding mechanism includes a servo motor, a precision drum, and a disc magnetic powder brake; the output shaft of the servo motor is coaxially and fixedly connected to the precision drum, and the disc magnetic powder brake is coaxially mounted to the precision drum; the wire spool is mounted on the precision drum, and both the servo motor and the disc magnetic powder brake are electrically connected to the integrated control system.

[0018] Furthermore, it also includes a vision sensor, which is fixed on the base frame directly above the electroplastic roller stretching mechanism to dynamically collect the degree of filament deformation; the vision sensor is electrically connected to the integrated control system.

[0019] Furthermore, the integrated control system employs a PLC controller. The PLC controller's program includes a feedforward tension prediction module, which collects pulse current parameters and filament deformation data from the electroplastic roller tensioning mechanism in real time, and dynamically collects the degree of filament deformation based on a visual sensor to establish a current-deformation-tension coupling model and predict the tension change trend. Based on the set target tension value, sensor feedback value, and feedforward tension prediction results, the PLC controller uses a fuzzy PID and feedforward compensation fusion control algorithm to dynamically adjust the torque and speed of the servo motor, the excitation current of the disc magnetic powder brake, and the damping coefficient of the nonlinear spring-damping composite unit, forming a multimodal intelligent tension control system.

[0020] Furthermore, the nonlinear spring-damping composite unit employs a magnetorheological fluid damper, and the control terminal of the magnetorheological fluid damper is electrically connected to the integrated control system.

[0021] Furthermore, the air paths of both the first and second pneumatic buffers are connected to a pressure reducing valve and an air storage tank, and the pressure reducing valve is electrically connected to the integrated control system.

[0022] The beneficial effects of this invention are:

[0023] 1. Multiple detection and composite control: By forming a dual detection mechanism through tension sensor and linkage mechanism encoder, and combining servo active winding and unwinding, magnetic powder braking, pneumatic buffering and nonlinear spring-damping adjustment composite control mode, ultra-precise and fast response adjustment of wire tension is achieved, effectively suppressing any form of tension fluctuation.

[0024] 2. Feedforward prediction and intelligent control: The introduction of a feedforward tension prediction module based on current-deformation coupling enables the control system to predict and compensate for tension fluctuations before they occur, achieving a leap from "passive response" to "active prediction" and significantly improving tension stability under high-frequency pulse current interference.

[0025] 3. Deep integration with electroplastic processing: The tensioning device is no longer an independent unit, but part of the electroplastic roller stretching process. The control system can coordinate the start and stop of the pulse power supply, current parameters and tension control logic. For example, at the moment when the pulse current is applied and the plasticity of the filament increases, the target tension is automatically adjusted according to the feedforward prediction results to achieve "flexible" treatment of the filament.

[0026] 4. High reliability and process adaptability: The entire device has a precise structure, high level of integration and automation, and is especially suitable for the arc additive manufacturing process of high-performance rare earth magnesium alloy wires that are extremely sensitive to tension. It can significantly reduce the wire breakage rate and improve the quality of formed parts. Attached Figure Description

[0027] Figure 1This is a front view of the present invention.

[0028] Figure 2 This is a schematic diagram of the rear structure of the present invention;

[0029] Figure 3 This is a schematic diagram of the electroplastic roller stretching mechanism;

[0030] In the diagram: 1-Base frame, 2-Wire reel, 3-Brake, 4-First guide wheel assembly, 5-First tension sensor, 6-First pneumatic damper, 7-Electroplated roller pulling mechanism, 701-Transmission roller, 702-Precision servo motor, 703-Pulse power generator, 8-Vision sensor, 9-Second pneumatic damper, 10-Second tension sensor, 11-Second guide wheel assembly, 12-Servo-driven take-up and unwinding mechanism, 121-Precision drum, 13-Servo motor, 14-Absolute encoder, 15-PLC controller, 16-Watt linkage mechanism, 17-Nonlinear spring-damping composite unit. Detailed Implementation

[0031] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort. To facilitate understanding of the present invention, the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 and Figure 2 As shown, the present invention is a wire tensioning device for rare earth magnesium alloy wire electroplastic roller drawing of electric arc additive manufacturing. The base frame 1 is used as the overall mounting base. The base frame 1 can be made of high-strength aluminum alloy profile to provide a stable mounting benchmark and structural support for all functional components. The device is laid out in a straight line along the wire feeding direction.

[0033] The servo-driven unwinding mechanism 12 is fixedly connected to the base frame 1 at the front of the multi-stage tension detection and buffer mechanism on the wire feeding side of the electroplastic roller pulling mechanism 7, which is the frontmost wire feeding end of the entire device. The servo-driven unwinding mechanism 12 includes a servo motor 13, a precision drum 121, and a disc magnetic powder brake 3. The servo motor 13 has a power of 400W and a rated speed of 3000rpm. The servo motor 13 drives the precision drum 121 through a 1:10 planetary reducer. The disc magnetic powder brake 3 is coaxially mounted with the precision drum 121 and has a rated torque of 12N·m. The wire spool 2 is fixedly mounted on the precision drum 121 through a quick-change clamp, which allows for quick disassembly and replacement of the wire spool 2. Both the servo motor 13 and the disc magnetic powder brake 3 are electrically connected to the PLC controller 15 of the integrated control system through control cables. The servo motor 13 can drive the precision drum 121 to rotate in both directions, actively unwinding or retracting a small amount of wire. The disc magnetic powder brake 3 can provide a continuous and precisely adjustable braking torque by adjusting the excitation current.

[0034] The multi-stage tension detection and buffer mechanism is divided into two groups: the infeed side and the outfeed side, which are fixedly connected to the base frame 1 corresponding to the infeed side and the outfeed side of the electroplastic roller pulling mechanism 7, respectively.

[0035] The yarn feeding side assembly includes a first guide wheel assembly 4, a first tension sensor 5, and a first pneumatic damper 6. The first guide wheel assembly 4 is located on the front of the base frame 1 along the yarn feeding direction and includes five vertically staggered guide wheels. The yarn passes around the guide wheels in an "S" shaped path to increase the wrap angle between the yarn and the guide wheels, ensuring reliable contact and no relative slippage. The first tension sensor 5 and the first pneumatic damper 6 are both fixedly installed on the back of the base frame 1, corresponding to the installation positions of the last two guide wheels in the first guide wheel assembly 4. The detection end of the first tension sensor 5 is fixedly connected to the axle of the corresponding guide wheel in the first guide wheel assembly 4, and can detect the yarn tension on the guide wheel in real time. The piston rod end of the first pneumatic damper 6 is fixedly connected to the axle of the corresponding guide wheel in the first guide wheel assembly 4, and provides flexible support for the guide wheel through the extension and retraction of the piston rod, realizing the initial buffering and impact absorption of tension fluctuations. The first tension sensor 5 is electrically connected to the PLC controller 15 of the integrated control system through a signal cable.

[0036] The filament exit group and the filament infeed group are arranged in a mirror image along the electroplastic roller stretching mechanism 7, including a second guide wheel group 11, a second tension sensor 10, and a second pneumatic buffer 9. The second guide wheel group 11 is set on the front of the base frame 1 along the filament exit direction and includes four guide wheels arranged vertically and horizontally. The filament after electroplastic roller stretching passes around the second guide wheel group 11 in an "S" shaped path. The second tension sensor 10 and the second pneumatic buffer 9 are both fixedly installed on the back of the base frame 1, corresponding to the installation positions of the first two guide wheels in the second guide wheel group 11. The detection end of the second tension sensor 10 is fixedly connected to the wheel axle of the corresponding guide wheel in the second guide wheel group 11 to detect the filament tension on the filament exit side in real time. The piston rod end of the second pneumatic buffer 9 is fixedly connected to the wheel axle of the corresponding guide wheel in the second guide wheel group 11 to buffer the high-frequency tension disturbances generated during the roller stretching process. The second tension sensor 10 is electrically connected to the PLC controller 15 of the integrated control system through a signal cable.

[0037] In a preferred embodiment, the first tension sensor 5 and the second tension sensor 10 described above are strain gauge type, with a range of 0-100N and an accuracy of ±0.1%FS.

[0038] In a preferred embodiment, the first pneumatic buffer 6 and the second pneumatic buffer 9 have cylinder diameters of 20mm and strokes of 50mm. Their air paths are both connected to a precision pressure reducing valve and a small air tank, providing a constant buffering force adjustable from approximately 10-30N to absorb sudden tension impacts from the unwinding of the wire reel 2. The control terminal of the precision pressure reducing valve is electrically connected to the PLC controller 15. The PLC controller 15 can adjust the internal pressure of the pneumatic buffer in real time and linearly according to the tension change rate and control requirements, achieving active buffering control and further improving the impact absorption and disturbance suppression effects.

[0039] The electroplastic roller tensioning mechanism 7 is fixedly connected to the center of the front of the base frame 1 via an insulating bracket, located between the multi-stage tension detection and buffering mechanism on the infeed side and the multi-stage tension detection and buffering mechanism on the outfeed side. For example... Figure 3As shown, the electroplastic roller pulling mechanism 7 includes two horizontally arranged drive rollers 701, precision servo motors 702 that drive the two drive rollers 701 to rotate respectively, and a pulse power generator 703. The two drive rollers 701 are made of high-conductivity, high-strength alloy materials such as chromium zirconium copper. The two drive rollers 701 are directly connected to the output shaft of the corresponding precision servo motor 702 through couplings. The precision servo motor 702 is fixed on an insulating bracket, with a rated torque of 5 N·m and a built-in 24-bit high-resolution encoder, which can achieve precise rotation speed of the two drive rollers. Synchronous control; the pulse power generator 703 adopts capacitor energy storage and is electrically connected to the transmission roller 701 through a silver graphite brush. It can deliver high-energy pulse current to the roller and output rectangular wave pulses with a peak current of up to 2000A and a frequency of 50-500Hz. The current is conducted through the transmission roller 701 to the filament passing through the gap between the two rollers, and the filament plasticity is instantly improved by utilizing the electroplastic effect; the precision servo motor 702 and the pulse power generator 703 are both electrically connected to the PLC controller 15 through control cables to realize the coordinated linkage of the roller drawing process and tension control.

[0040] Above the electroplastic roller stretching mechanism 7, a vision sensor 8 is fixedly installed on the base frame 1. The lens of the vision sensor 8 is facing the wire processing area between the two drive rollers 701, and can dynamically collect the degree of cross-sectional deformation and surface morphology features of the wire. The vision sensor 8 is electrically connected to the PLC controller 15 through a data cable, and the collected wire deformation data is transmitted to the integrated control system in real time.

[0041] The active servo tensioning mechanism is fixedly connected to the base frame 1 on the back of the multi-stage tension detection and buffer mechanism on the yarn feed side, and is arranged on the same side as the first tension sensor 5 and the first pneumatic buffer 6. The active servo tensioning mechanism includes a Watt's linkage mechanism 16, a nonlinear spring-damping composite unit 17, and an absolute encoder 14. The base of the Watt's linkage mechanism 16 is fixedly mounted on the back of the base frame 1. It possesses good kinematic characteristics and can produce significant deflection angle changes under small tension fluctuations, improving the system's sensitivity. The rotating shaft end of the active rod of the Watt's linkage mechanism 16 is coaxially fixedly connected to the rotating shaft of the absolute encoder 14. The housing of the absolute encoder 14 is fixed to the base frame 1, with a resolution of 17 bits, and can accurately detect the deflection angle of the active rod within the range of -30° to +30°. This angle has a nonlinear mapping relationship with the yarn tension and serves as an indirect feedback signal input to the control system for tension changes. The driven rod end of the Watt's linkage mechanism 16 is connected to the nonlinear spring-damping composite unit 17. One end of the composite unit 17 is connected to the nonlinear spring-damping composite unit 17, and the other end of the nonlinear spring-damping composite unit 17 is fixedly connected to the axle of the corresponding guide wheel in the first guide wheel group 4, and is arranged coaxially with the piston rod connection end of the first pneumatic buffer 6. When the tension of the wire changes, the guide wheel of the first guide wheel group 4 generates a corresponding displacement, which drives the nonlinear spring-damping composite unit 17 to move, thereby driving the active rod of the Watt linkage mechanism 16 to deflect. The nonlinear spring-damping composite unit 17 provides nonlinear stiffness and damping characteristics related to the amount of deformation when the tension changes, which can effectively suppress high-frequency disturbances and prevent resonance. The absolute encoder 14 is electrically connected to the PLC controller 15 through a signal cable. The detected deflection angle signal is transmitted to the PLC controller 15 in real time as an indirect feedback signal of the change in wire tension.

[0042] In a preferred embodiment, the nonlinear spring-damping composite unit 17 uses a magnetorheological fluid damper. The two ends of the magnetorheological fluid damper are connected to the driven rod of the Watt linkage mechanism 16 and the guide wheel axle of the first guide wheel group 4, respectively. The control end of the magnetorheological fluid damper is electrically connected to the PLC controller 15. The PLC controller 15 can dynamically adjust the damping coefficient of the magnetorheological fluid damper according to the real-time tension data and control requirements to achieve a wider range of nonlinear buffer adjustment.

[0043] The integrated control system uses a PLC controller 15 as the core control unit. The PLC controller 15 is fixedly installed on the side of the base frame 1, and its control program has a built-in feedforward tension prediction module. The signal input ports of the PLC controller 15 are electrically connected to the first tension sensor 5, the second tension sensor 10, the absolute encoder 14, and the vision sensor 8, respectively, to collect tension detection data, connecting rod deflection angle data, and filament deformation data in real time. The feedforward tension prediction module is based on a current-deformation coupling model, which can establish a mapping relationship between current-deformation-tension by combining the pulse current parameters output by the electroplastic roller pulling mechanism 7 and the filament deformation characteristics dynamically captured by the vision sensor 8. The PLC controller 15 predicts the tension change trend based on these data and fuses them with the feedback signals from the first tension sensor 5, the second tension sensor 10, and the absolute encoder 14 to achieve feedforward compensation of tension. The PLC controller 15 employs a fuzzy PID and feedforward compensation fusion control algorithm based on the set target tension value, real-time feedback values ​​from each sensor, and feedforward tension prediction results. The tension setpoint is the target tension from the second tension sensor 10. Simultaneously, the signal from the absolute encoder 14 is used as a fine-tuning quantity for feedback fusion, and the prediction result from the feedforward tension prediction module is used as a compensation term for early intervention control. Based on the tension deviation and feedforward information, the PLC dynamically calculates and outputs control quantities to the servo motor 13 for position or torque compensation, and adjusts the excitation current of the magnetic powder brake 3, achieving multi-modal intelligent control of the wire tension. Simultaneously, based on the electroplastic roller drawing process parameters, the PLC automatically reduces the target tension value temporarily by 10%-20% during pulse current conduction, achieving process linkage.

[0044] The complete workflow of the device described in this embodiment is as follows:

[0045] Step 1: The filament is drawn out from the filament reel 2 of the servo-driven unwinding mechanism 12 and enters the first guide wheel group 4 on the filament feeding side. After passing through the guide wheel in an "S" shaped path, it enters the gap between the two drive rollers 701 of the electroplastic roller pulling mechanism 7.

[0046] Step 2: The precision servo motor 702 of the electroplastic roller stretching mechanism 7 drives the transmission roller 701 to rotate synchronously, and straightens the filament by roller stretching. At the same time, the pulse power generator 703 applies a high-energy pulse current to the filament through the transmission roller, and uses the electroplastic effect to instantly improve the plasticity of the filament and reduce the deformation resistance of the filament. The vision sensor 8 collects the deformation data of the filament after roller stretching in real time and transmits it to the PLC controller 15.

[0047] Step 3: The filament after being treated by the electroplastic roller enters the second guide roller group 11 on the filament exit side, and after passing around the guide roller in an "S" shaped path, it is conveyed to the subsequent electric arc additive manufacturing filament feeding mechanism.

[0048] Step 4: During the wire feeding process, the first tension sensor 5 and the second tension sensor 10 detect the wire tension on the wire feeding side and the wire output side in real time, and the absolute encoder 14 detects the deflection angle of the active rod of the Watt linkage mechanism 16 in real time. All detection data are transmitted to the PLC controller 15 in real time. The first pneumatic buffer 6 and the second pneumatic buffer 9 provide preliminary flexible buffering for sudden tension impacts and high-frequency disturbances during the wire feeding process.

[0049] Step 5: The PLC controller 15 predicts the tension change trend by combining the pulse current parameters and wire deformation data through the feedforward tension prediction module. At the same time, it integrates the real-time feedback data of each sensor and outputs a control signal through the fuzzy PID and feedforward compensation fusion control algorithm. When the tension exceeds the preset range, the servo motor of the servo drive unwinding mechanism 12 is adjusted to rotate forward and backward to wind and unwind a small amount of wire for coarse adjustment. At the same time, the excitation current of the disc magnetic powder brake 3 is adjusted to change the braking torque for fine adjustment. The damping coefficient of the nonlinear spring-damping composite unit 17 is adjusted synchronously to suppress high-frequency tension oscillation and ensure that the wire tension is always stable within the preset target range.

[0050] Step 6: During the operation of the device, the PLC controller 15 synchronously coordinates the start and stop of the pulse power supply, the current parameters and the tension control logic. At the moment the pulse current is turned on, it automatically adapts to the corresponding target tension value, so as to realize the coordinated linkage between tension control and electroplastic roller stretching process, and avoid tension fluctuation, micro-cracks or wire breakage caused by sudden plasticity changes in the filament.

Claims

1. A tensioning device for electroplastic roller drawing of rare earth magnesium alloy wire for electric arc additive manufacturing, characterized in that: It includes a base frame (1), an electroplastic roller tensioning mechanism (7), a multi-stage tension detection and buffering mechanism, an active servo tensioning mechanism, a servo-driven unwinding mechanism (12), and an integrated control system; The electroplastic roller stretching mechanism (7) is fixedly connected to the middle of the front of the base frame (1) through an insulating bracket, and applies a high-energy pulse current while performing roller stretching and straightening on the filament. The multi-stage tension detection and buffering mechanism is divided into two groups, which are fixedly connected to the base frame (1) corresponding to the wire feeding side and the wire output side of the electroplastic roller pulling mechanism (7), respectively, for real-time detection of wire tension and preliminary flexible buffering and impact absorption of tension fluctuations; The active servo tensioning mechanism is fixedly connected to the base frame (1) on the back of the multi-stage tension detection and buffering mechanism on the wire feeding side, and is used to achieve precise tension adjustment and high-frequency disturbance suppression according to the change of wire tension. The servo-driven unwinding mechanism (12) is fixedly connected to the base frame (1) at the front of the multi-stage tension detection and buffer mechanism on the wire feeding side of the electroplastic roller pulling mechanism (7), and is used to control the unwinding and winding of the filament spool (2) and provide adjustable braking torque. The integrated control system is electrically connected to the electroplastic roller pulling mechanism (7), the multi-stage tension detection and buffering mechanism, the active servo tensioning mechanism, and the servo-driven unwinding mechanism (12), respectively.

2. The electroplastic roller tensioning device for rare earth magnesium alloy wire used in arc additive manufacturing according to claim 1, characterized in that: The electroplastic roller pulling mechanism (7) includes two drive rollers (701), a precision servo motor (702) that drives them to rotate, and a pulse power generator (703); the two horizontally arranged drive rollers (701) are made of highly conductive material and are connected to the pulse power generator through brushes.

3. The electroplastic roller tensioning device for rare earth magnesium alloy wire used in arc additive manufacturing according to claim 1, characterized in that: The multi-stage tension detection and buffering mechanism includes a first guide wheel group (4), a first tension sensor (5), and a first pneumatic buffer (6) on the infeed side, and a second guide wheel group (11), a second tension sensor (10), and a second pneumatic buffer (9) on the outfeed side. The first tension sensor (5), the first pneumatic buffer (6), the second tension sensor (10), and the second pneumatic buffer (9) are arranged on the back of the base frame (1) along the outfeed direction, and the first guide wheel group (4) and the second guide wheel group (11) are arranged on the front of the base frame (1) along the outfeed direction. The piston rod ends of the first tension sensor (5) and the first pneumatic buffer (6) are connected to the guide wheel in the first guide wheel group (4), and the piston rod ends of the second tension sensor (10) and the second pneumatic buffer (9) are connected to the guide wheel in the second guide wheel group (11). The filament passes around the first guide wheel group (4) and the second guide wheel group (11) in an "S" shaped path. The first tension sensor (5) and the second tension sensor (10) are both electrically connected to the integrated control system.

4. The electroplastic roller tensioning device for rare earth magnesium alloy wire used in arc additive manufacturing according to claim 1, characterized in that: The active servo tensioning mechanism includes a Watt's linkage mechanism (16), a nonlinear spring-damping composite unit (17), and an absolute encoder (14). The rotating shaft end of the active rod of the Watt's linkage mechanism (16) is connected to the absolute encoder (14), and the driven rod end of the Watt's linkage mechanism (16) is connected to the nonlinear spring-damping composite unit (17). The end of the nonlinear spring-damping composite unit (17) is connected to the guide wheel in the first guide wheel group (4). The absolute encoder (14) is electrically connected to the integrated control system.

5. The electroplastic roller tensioning device for rare earth magnesium alloy wire in arc additive manufacturing according to claim 1, characterized in that: The servo-driven unwinding mechanism (12) includes a servo motor (13), a precision drum (121), and a disc magnetic powder brake (3); the output shaft of the servo motor (13) is coaxially and fixedly connected to the precision drum (121), and the disc magnetic powder brake (3) is coaxially installed with the precision drum (121); the wire spool (2) is installed on the precision drum, and both the servo motor (13) and the disc magnetic powder brake (3) are electrically connected to the integrated control system.

6. The electroplastic roller tensioning device for rare earth magnesium alloy wire in arc additive manufacturing according to claim 1, characterized in that: It also includes a vision sensor (8), which is fixed on the base frame (1) directly above the electroplastic roller stretching mechanism (7) to dynamically collect the degree of filament deformation; the vision sensor (8) is electrically connected to the integrated control system.

7. The electroplastic roller tensioning device for rare earth magnesium alloy wire used in arc additive manufacturing according to claim 1, characterized in that: The integrated control system adopts a PLC controller (15); the program of the PLC controller (15) is equipped with a feedforward tension prediction module, which collects the pulse current parameters and filament deformation data of the electroplastic roller pulling mechanism (7) in real time, and establishes a current-deformation-tension coupling model based on the dynamic collection of filament deformation degree by the vision sensor (8) to predict the tension change trend. The PLC controller (15) dynamically adjusts the torque and speed of the servo motor (13), the excitation current of the disc magnetic powder brake (3), and the damping coefficient of the nonlinear spring-damping composite unit (17) based on the set target tension value, sensor feedback value, and feedforward tension prediction result using a fuzzy PID and feedforward compensation fusion control algorithm.

8. The electroplastic roller tensioning device for rare earth magnesium alloy wire in arc additive manufacturing according to claim 4, characterized in that: The nonlinear spring-damping composite unit (17) adopts a magnetorheological fluid damper, and the control end of the magnetorheological fluid damper is electrically connected to the integrated control system.

9. The electroplastic roller tensioning device for rare earth magnesium alloy wire in arc additive manufacturing according to claim 3, characterized in that: The air paths of the first pneumatic buffer (6) and the second pneumatic buffer (9) are both connected to a pressure reducing valve and an air storage tank, and the pressure reducing valve is electrically connected to the integrated control system.

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