A wire feeding system for non-consumable electrode arc welding in a low-temperature and low-pressure environment and a control method thereof

Abstract

The application discloses a kind of for low temperature low pressure environment under non-melting electrode arc welding wire feeding system and control method thereof, system includes: information perception unit is used to real-time acquisition welding arc area temperature distribution data and welding wire end position data;Central processing unit is used to calculate the offset of current arc highest temperature point relative to welding wire end according to temperature distribution data and welding wire end position data in real time, and then generate control instruction drive execution drive unit is converted from rotary motion to linear motion;Execution drive unit is used to drive wire feeding mechanism to adjust wire feeding position;Wire feeding mechanism changes the bending curvature of welding wire and reduces friction loss by variable pitch design during wire feeding process, controls welding wire end position and welding wire quality.The application combines real-time visual sensing and closed-loop control, designs a wire feeding mechanism based on variable-pitch wire feeding spring tube, and realizes real-time dynamic tracking and accurate adjustment of wire feeding position to high-temperature area of arc during welding wire straightening process.

Description

Technical Field

[0001] This invention belongs to the field of welding technology and relates to a wire feeding system and its control method for non-consumable electrode arc welding in low temperature and low pressure environments. Background Technology

[0002] Non-consumable electrode arc welding (NEA) offers advantages such as arc stability, concentrated heat, high weld quality, and a wide range of weldable materials, making it widely used in applications requiring high weld quality. Under normal atmospheric pressure, the arc morphology, temperature field distribution, and molten pool behavior are relatively stable and easily predictable, allowing for high-quality welding with a fixed-track wire feeding system. Related research indicates that under normal pressure, the temperature field distribution of the NEA arc is concentrated, with the highest temperature point stabilizing near the workpiece and the center of the tungsten electrode on the central axis of the arc column, and heat diffuses outwards in a gradient.

[0003] In special regions such as Antarctica and high-altitude plateaus, the environment is characterized by low temperatures and low air pressure. When performing welding operations in such environments, the influence of environmental parameters on the arc morphology must be considered. Under low temperature and low air pressure conditions, the arc morphology changes, its temperature field distribution alters, and the highest temperature point shifts towards the tungsten electrode. If a fixed wire feeding method is still used, the end of the welding wire cannot be accurately fed into the changed high-temperature arc zone, resulting in reduced wire melting efficiency, poor deposition, and a high likelihood of welding defects such as incomplete fusion and poor weld formation.

[0004] Therefore, in view of the problem that existing wire feeding systems cannot guarantee welding quality under low temperature and low pressure conditions, there is an urgent need to develop a new type of wire feeding system and its control method that can adapt to the dynamic changes of the arc shape and accurately feed the welding wire into the high temperature region. Summary of the Invention

[0005] Purpose of the invention: The present invention aims to solve the problems of low wire melting efficiency and poor weld formation caused by the displacement of the high temperature zone of the electric arc in the existing wire feeding system in low temperature and low pressure environment, and to provide a system and control method that can track the highest temperature point of the electric arc in real time and dynamically adjust the wire feeding position.

[0006] Technical Solution: The wire feeding system of the present invention includes: an information sensing unit, a central processing unit, an execution drive unit, and a wire feeding mechanism. The information sensing unit is used to collect temperature distribution data and wire end position data of the welding arc area in real time. The central processing unit is used to calculate the offset of the current highest arc temperature point relative to the wire end based on the temperature distribution data and wire end position data, and then generate control commands to drive the execution drive unit to convert rotational motion into linear motion. The execution drive unit is used to drive the wire feeding mechanism to adjust the wire feeding position. The wire feeding mechanism, through a variable pitch design, continuously changes the bending curvature of the welding wire and reduces friction loss during the wire feeding process, thereby controlling the wire end position and welding wire quality.

[0007] Optionally, the wire feeding mechanism includes a wire feeding spring tube connected to the execution drive unit. The wire feeding spring tube adopts a variable pitch design, with its pitch gradually increasing from top to bottom. The welding wire is passed through the wire feeding spring tube. When the execution drive unit drives the wire feeding mechanism to run, it applies axial pressure or releases pressure on the wire feeding spring tube, causing the wire feeding spring tube to undergo compression or elongation elastic deformation, thereby changing the height position of its end wire feeding port, so that the spatial position of the end of the welding wire is always aligned with the high-temperature core area of ​​the electric arc.

[0008] Optionally, the wire feeding mechanism also includes a control shim, which is connected to the actuation drive unit, and the wire feeding spring tube passes through the control shim and is clamped and fixed therein.

[0009] Optionally, the drive unit includes a motor, a coupling, a lead screw, and a lead screw nut. The motor drives the lead screw to rotate through the coupling. The lead screw and the lead screw nut that mate with it form a helical transmission pair, which converts the rotational motion of the motor into precise linear motion.

[0010] Optionally, the lead screw is rigidly connected to the welding gun via an upper fixed seat and a lower fixed seat.

[0011] Optionally, the information sensing unit is a temperature field acquisition camera, which is arranged on the side of the welding torch and flush with the arc area.

[0012] Optionally, the central processing unit has a built-in image processing and analysis algorithm to identify and calculate the position of the current highest arc temperature point, and compares the real-time position of the highest arc temperature point with the current position of the welding wire end to calculate the position deviation; based on the deviation value, it generates corresponding motor drive control commands based on a preset control algorithm.

[0013] The control method of the present invention includes the following steps:

[0014] Real-time acquisition of temperature distribution data and wire end position data in the welding arc area;

[0015] Based on temperature distribution data, the arc morphology is analyzed in real time using image processing algorithms to identify and calculate the spatial coordinates of the current arc's highest temperature point.

[0016] The real-time position of the highest temperature point of the electric arc is compared with the current position of the end of the welding wire to calculate the position deviation; based on the deviation value, corresponding drive control commands are generated based on the preset control algorithm.

[0017] The execution drive unit operates according to the control command and drives the wire feeding mechanism to continuously change the bending curvature of the welding wire during the wire feeding process, so that the end of the welding wire is aligned with the high-temperature core area of ​​the electric arc.

[0018] Repeat the above steps, monitor the changes in the arc shape in real time, and dynamically adjust the wire feeding position to form a closed-loop feedback control system until the welding process is completed.

[0019] The present invention also provides an electronic device, comprising:

[0020] Memory, used to store computer programs;

[0021] A processor for executing the computer program to implement the method.

[0022] The present invention also provides a computer program product, including a computer program / instructions that, when executed by a processor, implement the method described.

[0023] Beneficial effects: Compared with the prior art, the significant technical effects of this invention are as follows: By combining real-time visual sensing and closed-loop control, an innovative wire feeding mechanism with a variable pitch wire feeding spring tube is designed. Through the variable pitch design, the wire feeding mechanism continuously changes the bending curvature of the welding wire and reduces friction loss during the wire feeding process, controlling the position of the welding wire end and the quality of the welding wire, realizing real-time dynamic tracking and precise adjustment of the wire feeding position to the high-temperature zone of the electric arc; effectively overcoming the problem of unstable welding wire melting caused by the displacement of the high-temperature zone of the electric arc under low temperature and low pressure environments, significantly improving the weld formation quality and process reliability; the system has a compact structure, rapid control response, and can be integrated into existing welding equipment, and is particularly suitable for automated welding operations in special environments such as high altitudes and Antarctica. Attached Figure Description

[0024] Figure 1 A schematic diagram of the existing wire feeding method for non-consumable electrode arc welding (TIG);

[0025] Figure 2 This is a schematic diagram of the wire feeding system of the present invention;

[0026] Figure 3 This is a flowchart of the control method of the present invention;

[0027] The components are: 1-temperature field acquisition camera, 2-main unit, 3-cable, 4-welding gun, 5-motor, 6-coupling, 7-upper fixed seat, 8-lead screw, 9-control shim, 10-lead screw nut, 11-lower fixed seat, 12-wire feeding spring tube, 13-welding wire. Detailed Implementation

[0028] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0029] Existing non-consumable electrode arc welding typically uses a bypass wire feeding method, such as... Figure 1As shown, after the tungsten electrode ignites the arc, the welding wire is fed into the arc zone along a fixed path and with a fixed posture. This method can meet welding requirements under normal temperature and pressure conditions, but because it cannot sense the distribution of the arc temperature field and adjust the wire feeding position accordingly, it exhibits significant unsuitability in low-temperature and low-pressure environments. In such environments, the arc shape changes significantly, the high-temperature zone shifts, and the fixed wire feeding method cannot accurately guide the wire tip into the actual high-temperature zone, resulting in decreased wire melting efficiency, poor deposition effect, and a high risk of defects such as incomplete fusion and poor weld formation. This invention proposes a wire feeding system and control method for non-consumable electrode arc welding in low-temperature and low-pressure environments. By combining real-time visual sensing and closed-loop control, an innovative wire feeding mechanism with a variable pitch wire feeding spring tube is designed. By controlling the elastic deformation of the wire feeding spring tube through a control shim, the wire exit height is adjusted, achieving real-time dynamic tracking and precise adjustment of the wire feeding position to the high-temperature arc zone. This effectively ensures that the welding wire is always aligned with the high-temperature arc zone, thereby significantly improving welding quality in harsh environments.

[0030] Secondly, existing mechanical roller straightening techniques have inherent defects. Taking common steel straightening rollers and low-carbon steel welding wire as an example, the dry friction coefficient between them can reach 0.47-0.57, which easily leads to iron filings peeling off and contaminating the weld, as well as affecting mechanical transmission. The friction coefficients between common materials are shown in Table 1. This invention adopts a variable pitch non-forced straightening mechanism, replacing the forced contact deformation of traditional straightening rollers with the elastic deformation of the wire feeding spring tube, fundamentally avoiding scratches and wear on the surface of the welding wire. Traditional steel straightening rollers rely on the pressure of point or line contact to force the welding wire to bend in the opposite direction for straightening, which easily scratches the surface of the welding wire and causes debris to peel off. In contrast, the variable pitch spring tube of this invention gradually adjusts the curvature of the welding wire through its pipeline, allowing the welding wire to deform naturally under flexible constraints, transforming the concentrated point or line contact pressure into a uniformly distributed surface contact force, thereby eliminating surface damage caused by local high pressure.

[0031] Table 1. Friction coefficients between common materials

[0032]

[0033] It is important to note that traditional wire feeding position adjustment methods operate on the tail of the welding wire, forcibly twisting the wire to achieve a change in position. This forced adjustment introduces new residual stress into the welding wire, increasing feeding resistance. Essentially, it is a compromise that sacrifices the welding wire's posture to achieve a change in position.

[0034] This invention is entirely different; it directly positions the welding wire exit height through the elastic deformation of the wire feeding spring tube itself. This method achieves wire feeding position adjustment during the wire straightening process.

[0035] like Figure 2As shown, the present invention discloses a wire feeding system for non-consumable electrode arc welding in a low-temperature and low-pressure environment, comprising an information sensing unit, a central processing unit, an execution drive unit, and a wire feeding mechanism. The information sensing unit is a temperature field acquisition camera 1, the central processing unit is a host 2, and the execution drive unit includes a motor 5, a coupling 6, a lead screw 8, and a lead screw nut 10, used to drive the wire feeding mechanism to adjust the wire feeding position. The wire feeding mechanism includes an upper fixed seat 7, a lower fixed seat 11, a control shim 9, and a wire feeding spring tube 12, used to ensure that the welding wire 13 deforms and moves together with the wire feeding spring tube 12. The wire feeding mechanism, through a variable pitch design, continuously changes the bending curvature of the welding wire and reduces friction loss during the wire feeding process, thereby controlling the end position and quality of the welding wire.

[0036] The temperature field acquisition camera 1 is positioned to the side of the welding torch 4, flush with the arc area, to collect real-time temperature distribution data and wire end position data of the welding arc area. The host unit 2 is connected to the temperature field acquisition camera 1 and the motor 5 via cable 3, receiving the temperature distribution data and wire end position data. Its built-in image processing and analysis algorithm calculates and determines the position of the highest arc temperature point and its deviation from the wire end position in real time, driving the motor based on this deviation. The motor 5 receives control commands from the host unit 2 via cable 3 and drives the lead screw to rotate. The coupling 6 connects the output shaft of the motor 5 to the lead screw 8. The lead screw 8 and its mating lead screw nut 10 form a helical transmission pair, converting the rotational motion of the motor 5 into precise linear motion. The upper fixed seat 7 and the lower fixed seat 11 rigidly connect the lead screw 8 to the welding torch 4, forming an integral structure. The lead screw nut 10 is connected to the control pad 9. The wire feeding spring tube 12 passes through and is clamped and fixed by the control shim 9. This spring tube 12 employs a variable pitch design. This gradually changing pitch design provides a continuously varying bending curvature path for the welding wire during feeding. The curvature change from large to small from top to bottom achieves gradual straightening of the welding wire, effectively eliminating residual stress inside the wire, significantly suppressing springback and coiling at the wire exit, and ensuring stable wire stiffness and precise controllable end position. Its maximum and minimum pitches need to be optimized collaboratively based on the welding wire material, diameter, and the overall structure of the wire feeding system. Furthermore, the pitch change gradient should remain continuous and smooth to ensure that the spring tube maintains good structural stability while having sufficient deformation stroke.

[0037] Its core working principle is as follows: The host calculates the offset of the highest temperature point of the current electric arc relative to the end of the welding wire based on the information fed back by the temperature field acquisition camera, and then generates a control command to drive the motor to rotate. The motor drives the lead screw to rotate through the coupling, which in turn drives the lead screw nut and the control shim fixed to it to move along the lead screw axis (i.e., in the up and down direction). The control shim moves along the lead screw axis, applying axial pressure or releasing pressure to the wire feeding spring tube, causing the wire feeding spring tube to undergo compression or elongation elastic deformation, thereby changing the height of the welding wire exit and achieving precise adjustment of the spatial position of the welding wire end, so that it is always aligned with the high-temperature core area of ​​the electric arc.

[0038] The wire feeding system described above identifies the location of the high-temperature arc zone through real-time image processing and responds rapidly through a precision mechanical transmission mechanism, enabling dynamic adjustment of the wire feeding position during welding. This effectively overcomes the adverse effects of low-temperature and low-pressure environments on the welding process, thereby significantly improving the welding quality of TIG welding under low-temperature and low-pressure conditions.

[0039] like Figure 2 As shown, during the welding process, after the arc is ignited, the temperature field acquisition camera 1 collects real-time temperature distribution data of the welding arc area and the position data of the end of the welding wire 13. After receiving the temperature distribution data and the position data of the end of the welding wire, the host 2 calculates the deviation between the highest temperature point of the arc and the position of the end of the welding wire using a built-in algorithm. If the end of the welding wire is identified as being lower than the highest temperature point of the arc, the host sends a control command to the motor 5, driving the lead screw 8 to rotate and causing the lead screw nut 10 to move upward. The lead screw nut 10 pushes the control shim 9, applying axial pressure to the wire feeding spring tube 12, causing it to compress and deform, thereby raising the position of the end of the welding wire 13. If the end of the welding wire is higher than the highest temperature point, the control motor 5 rotates in the opposite direction, the lead screw nut 10 moves downward, and the control shim 9 releases the pressure on the wire feeding spring tube 12. The wire feeding spring tube 12 elastically recovers and extends, causing the end of the welding wire to move downward. Through this dynamic adjustment mechanism, the system can ensure that the welding wire is accurately and stably fed into the high-temperature core area of ​​the arc in real time.

[0040] like Figure 3 As shown, another aspect of the present invention provides a control method for a wire feeding system in a non-consumable electrode arc welding system under low temperature and low pressure conditions, the method comprising the following steps:

[0041] S1. Real-time acquisition of arc temperature field; The temperature distribution data and welding wire end position data of the welding arc area are acquired in real time by a temperature field acquisition camera, and the temperature distribution data and welding wire end position data are transmitted to the host via cable.

[0042] S2. High-temperature core area identification: The host receives the temperature distribution data, performs real-time analysis of the arc morphology using the built-in image processing algorithm, and identifies and calculates the spatial coordinates of the current arc's highest temperature point.

[0043] S3. Position deviation calculation and instruction generation: The host compares the highest arc temperature point obtained in step S2 with the position of the welding wire end and calculates the position deviation. Based on the deviation value, the host generates the corresponding motor drive control instruction based on the preset control algorithm (such as PID algorithm).

[0044] S4. Motor drive and wire feeding position adjustment: The host sends the control command to the motor through the cable, driving the motor to rotate; The motor transmits the rotational motion to the lead screw through the coupling, driving the lead screw nut and control shim to move along the lead screw axis; The control shim applies an axial force to the wire feeding spring tube, causing it to produce elastic deformation of compression or elongation, thereby accurately adjusting the height position of the end wire feeding port, so that the end of the welding wire is aligned with the high-temperature core area of ​​the electric arc.

[0045] S5. Repeat steps above until welding is finished: Repeat steps S1 to S4, monitor the changes in arc shape in real time, dynamically adjust the wire feeding position, and form a closed-loop feedback control system until the welding process is finished, ensuring that the welding wire can be accurately fed into the area with the highest arc temperature throughout the entire welding process.

[0046] The control method combines visual sensing and real-time feedback control. It identifies the high-temperature zone of the electric arc through image algorithms and uses the elastic deformation of the variable pitch wire feeding spring tube to achieve fine adjustment of the wire feeding position. It has a strong adaptability to changes in the shape of the electric arc under low temperature and low pressure environments.

[0047] In summary, this invention innovatively designs a wire feeding mechanism with a variable pitch wire feeding spring tube by combining real-time visual sensing and closed-loop control, achieving real-time dynamic tracking and precise adjustment of the wire feeding position within the high-temperature zone of the electric arc. This wire feeding structure not only effectively suppresses wire springback and coiling, improving wire stiffness and positional consistency, but also possesses strong adaptability to dynamic changes in the maximum arc temperature under various low-temperature and low-pressure environments. This significantly enhances the process stability and weld formation quality of non-consumable electrode arc welding in special environments such as high altitudes and Antarctica.

Claims

1. A wire feeding system for non-consumable electrode arc welding in low-temperature and low-pressure environments, characterized in that, include: The system includes an information sensing unit, a central processing unit, an execution drive unit, and a wire feeding mechanism. The information sensing unit is used to collect real-time temperature distribution data and wire end position data in the welding arc area. The central processing unit is used to calculate the offset of the current highest arc temperature point relative to the end of the welding wire in real time based on temperature distribution data and welding wire end position data, and then generate control commands to drive the execution unit to convert the rotary motion into linear motion. The drive unit is used to drive the wire feeding mechanism to adjust the wire feeding position; the wire feeding mechanism, through a variable pitch design, continuously changes the bending curvature of the welding wire and reduces friction loss during the wire feeding process, thereby controlling the end position and quality of the welding wire. The wire feeding mechanism includes a wire feeding spring tube, which is connected to the execution drive unit. The wire feeding spring tube adopts a variable pitch design, with its pitch gradually increasing from top to bottom. The welding wire is passed through the wire feeding spring tube. When the execution drive unit drives the wire feeding mechanism to run, it applies axial pressure or releases pressure on the wire feeding spring tube, causing the wire feeding spring tube to undergo compression or elongation elastic deformation, thereby changing the height position of its end wire feeding port, so that the spatial position of the end of the welding wire is always aligned with the high-temperature core area of ​​the electric arc. The wire feeding mechanism also includes a control shim, which is connected to the actuation drive unit. The wire feeding spring tube passes through the control shim and is clamped and fixed by it. The drive unit includes a motor, a coupling, a lead screw, and a lead screw nut. The motor drives the lead screw to rotate through the coupling. The lead screw and the lead screw nut that it mates with form a helical transmission pair. The helical transmission pair converts the rotational motion of the motor into precise linear motion. The lead screw is rigidly connected to the welding gun through the upper and lower fixed seats.

2. The system according to claim 1, characterized in that, The information sensing unit is a temperature field acquisition camera, which is arranged on the side of the welding torch, flush with the arc area.

3. The system according to claim 1, characterized in that, The central processing unit has built-in image processing and analysis algorithms to identify and calculate the current position of the highest arc temperature point, and compares the real-time position of the highest arc temperature point with the current position of the welding wire end to calculate the position deviation. Based on this deviation value, corresponding motor drive control commands are generated using a preset control algorithm.

4. A control method for the system according to any one of claims 1-3, characterized in that, Includes the following steps: Real-time acquisition of temperature distribution data and wire end position data in the welding arc area; Based on temperature distribution data, the arc morphology is analyzed in real time using image processing algorithms to identify and calculate the spatial coordinates of the current arc's highest temperature point. The position deviation is calculated by comparing the real-time position of the highest temperature point of the electric arc with the current position of the end of the welding wire. Based on the deviation value, corresponding drive control commands are generated using a preset control algorithm. The execution drive unit operates according to the control command and drives the wire feeding mechanism to continuously change the bending curvature of the welding wire during the wire feeding process, so that the end of the welding wire is aligned with the high-temperature core area of ​​the electric arc. Repeat the above steps, monitor the changes in the arc shape in real time, and dynamically adjust the wire feeding position to form a closed-loop feedback control system until the welding process is completed.

5. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the method as described in claim 4.

6. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the method of claim 4.

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