Welding power supply system and method for realizing high-frequency editable pulse current output

Abstract

The invention provides a welding power source system and method for achieving high-frequency editable pulse current output, and belongs to the field of welding power sources, the welding power source system comprises a TIG welding gun, an oscilloscope and a gas protection device, the TIG welding gun is connected with a high-frequency waveform editing module, the high-frequency waveform editing module is connected with an inductor and an FPGA control panel, the inductor is connected with a multi-output constant current source, and the multi-output constant current source is connected with the oscilloscope. The oscilloscope is connected with the TIG welding gun through a current clamp, and the gas protection device is connected with the TIG welding gun through a gas pipe. According to the welding power supply system and method for achieving high-frequency editable pulse current output, the high-frequency waveform editing module formed by sampling three paths of switching circuits in parallel can provide more waveform selections and more accurate current output on the premise of maintaining stable combustion of an electric arc; a special switch time sequence is matched with synchronous rectification, so that circuit heating can be reduced, the accuracy of current waveforms is improved, heat input can be accurately controlled, arc energy gradient distribution is optimized, and the welding seam quality is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of welding power supply, in particular to a welding power supply system and method for realizing high-frequency editable pulse current output. BACKGROUND

[0002] As the core power device of modern aviation industry, the key components of aero-engine need to withstand extreme working conditions of high temperature above 1000℃, high pressure and strong oxidative corrosion for a long time, which is easy to cause micro-cracks, wear and other damages. If such damages are not repaired in time, it will lead to blade failure and even catastrophic accidents, and greatly increase the operation and maintenance costs.

[0003] Currently, the aero-engine blade repair technology is facing great technical challenges. Nickel-based alloy is prone to microstructure segregation, grain coarsening and solidification cracks at high temperature. Although the traditional high-energy beam repair can realize in-situ processing, the control precision of heat input is insufficient, which easily leads to a large heat-affected zone and makes it difficult to match the performance of the repaired layer with the base material. The existing high-frequency pulse TIG power supply is limited by the switching frequency and waveform control ability, and cannot meet the needs of the ultra-high frequency pulse arc contraction effect, resulting in a lag in the response of arc energy and uneven heat input, which aggravates the risk of cracks and segregation. In addition, the power supply lacks a multi-parameter collaborative optimization mechanism based on the real-time state of the molten pool, making it difficult to adapt to the differentiated repair needs of complex cracks. Domestic existing technologies mainly focus on low-frequency pulse TIG process, and there is still a significant gap in grain refinement, defect suppression and repair efficiency compared with international technologies.

[0004] In recent years, high-frequency pulse arc technology has shown great potential in the field of material processing. Experimental studies have shown that by using ultra-high frequency pulse current, the arc size can be significantly shrunk, the grain size can be refined to 5-10 μm, and solidification cracks can be effectively suppressed. However, the existing power supply architecture and control strategy cannot fully utilize the advantages of high-frequency pulse, and breakthroughs are needed in key technologies such as power supply dynamic response, waveform editability and multi-parameter collaborative control to achieve the "shape control-property control" integration goal of aero-engine blade repair. SUMMARY

[0005] The present application aims to provide a welding power supply system and method for realizing high-frequency editable pulse current output. The power supply system can adjust the waveform editing circuit switching sequence in real time to output the required current waveform through the program. The design of three independent switching can output up to six different current platforms while maintaining the stable combustion of the arc, improving the freedom of current waveform editing. The use of MOS tubes with specific switching sequences in the later stage instead of Schottky diodes can improve the accuracy of the current waveform while greatly reducing the heat generated by the circuit, effectively prolonging the service life and continuous working time of the waveform editing circuit, and further accurately controlling the heat input, optimizing the arc energy gradient distribution, and improving the weld quality.

[0006] In order to achieve the above object, the application provides a welding power supply system for realizing high-frequency editable pulse current output, which comprises a TIG welding gun, a high-frequency waveform editing module, an inductor, a multi-output constant current source, an FPGA control board, an oscilloscope and a gas protection device, wherein the TIG welding gun is vertically arranged above a workpiece, the workpiece is arranged on a sliding table, the TIG welding gun is connected with the high-frequency waveform editing module, the high-frequency waveform editing module is connected with the inductor, the inductor is connected with the multi-output constant current source, the high-frequency waveform editing module is further connected with the FPGA control board, the oscilloscope is connected with the TIG welding gun through a current clamp, and the gas protection device is connected with the TIG welding gun through a gas pipe.

[0007] Preferably, the multi-output constant current source has three outputs, the positive electrode of the multi-output constant current source is connected with the high-frequency waveform editing module through the inductor, and the negative electrode of the multi-output constant current source is connected with the high-frequency waveform editing module through a cable.

[0008] Preferably, the positive electrode of the high-frequency waveform editing module is connected with the workpiece through a wire, and the negative electrode of the high-frequency waveform editing module is connected with the TIG welding gun through a wire.

[0009] Preferably, the system further comprises a sliding table control instrument, an upper computer and a high-speed camera, the sliding table control instrument is connected with the sliding table through a wire, and the high-frequency waveform editing module, the multi-output constant current source and the high-speed camera are all connected with the upper computer through signal lines.

[0010] Preferably, the high-frequency waveform editing module comprises a switching unit, and the switching unit comprises a left power switch tube, a right power switch tube, a diode and a switching unit inductor, wherein the left power switch tube and the right power switch tube are both N-type mos tubes.

[0011] A welding power supply method for realizing high-frequency editable pulse current output, comprising the following steps: S1, performing surface pretreatment on a metal workpiece to remove surface oxides and impurities and performing degreasing treatment; S2, positioning the pretreated metal workpiece to an arc welding system, starting an external water cooling device and an arc welding system power supply device, and completing welding preparation; S3, starting a gas protection device and setting current parameters of a multi-output constant current source; S4, exciting an electric arc in a short-circuit arc starting mode, switching the high-frequency waveform editing module to a high-frequency controllable square wave mode after the electric arc is stable; S5, monitoring metal workpiece topography features in real time, analyzing the influence effect of the high-frequency waveform editing module on the electric arc through a fusion width parameter, and controlling the multi-output constant current source output according to a fusion depth feature to optimize heat input parameters.

[0012] Therefore, the welding power supply system and method for realizing high-frequency editable pulse current output are adopted, and technical effects are as follows. 1. Precise heat transfer: the multi-output constant current source outputs three-way current through inductance, generates high-frequency variable polarity current through a high-frequency waveform editing module, and adopts a TIG welding gun to implement precise heat transfer on a workpiece.

[0013] 2. Reasonable circuit thermal design: through synchronous rectification and specific switch timing, the heat of the circuit is greatly reduced, the current accuracy is improved, and the continuous working time and service life of the circuit are prolonged.

[0014] 3. Optimizing arc energy gradient distribution and molten pool dynamic behavior: adjusting the current of the multi-output constant current source, accurately matching the heat input requirement of crack repair, optimizing the arc energy gradient distribution and molten pool dynamic behavior, and significantly improving the grain refinement degree and mechanical properties of the workpiece weld.

[0015] 3. Improving forming precision and microstructure uniformity: the frequency, phase and energy density of the welding current can be edited in real time according to the crack morphology, breaking through the limitations of traditional single-arc process thermal-mechanical coupling control, and significantly improving the forming precision and microstructure uniformity of nickel-based alloy crack repair. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a schematic diagram of the system connection structure of the present application; Figure 2 It is a schematic diagram of the system module connection of the present application; Figure 3 It is a schematic diagram of the circuit connection between the multi-output constant current source, high-frequency switching circuit and welding assembly of the present application; Figure 4 It is a schematic diagram of the circuit connection between the multi-output constant current source, high-frequency switching circuit and welding assembly of the present application; Figure 3 It is a current schematic diagram in one of the various states of the circuit diagram shown.

[0017] REFERENCE NUMERALS 1. Multi-output constant current source; 2. TIG welding gun; 3. Workpiece; 4. Slide table; 5. Inductance; 6. High-frequency waveform editing module; 7. Oscilloscope; 8. Gas protection device; 9. FPGA control board; 10. Slide table control instrument; 11. Upper computer; 12. High-speed camera. DETAILED DESCRIPTION

[0018] The technical solutions of the present application are further described below through the drawings and examples.

[0019] Unless otherwise defined, the technical terms or scientific terms used in the present application shall have the usual meanings understood by those skilled in the art to which the present application belongs.

[0020] Example 1 AsFigures 1-2 As shown, the present application provides a welding power supply system for realizing high-frequency editable pulse current output, comprising a TIG welding gun 2, a workpiece 3, a sliding table 4, a multi-output constant current source 1, an inductor 5, a high-frequency waveform editing module 6, an oscilloscope 7, a gas protection device 8, an FPGA control board 9, a sliding table controller 10, an upper computer 11, and a high-speed camera 12. The TIG welding gun 2 is vertically above the workpiece 3, and the workpiece 3 is installed on the sliding table 4 and can move with the sliding table 4. The sliding table controller 10 is connected to the sliding table 4 through wires to control the movement of the sliding table 4 and realize accurate adjustment of the welding position.

[0021] The multi-output constant current source 1 has three outputs, of which the positive electrode is connected to the high-frequency waveform editing module 6 through the inductor 5, and the negative electrode is directly connected to the high-frequency waveform editing module 6 through a cable. The FPGA control board 9 is connected to the high-frequency waveform editing module 6 to control it. The wires from the positive and negative electrodes of the high-frequency waveform editing module 6 are connected to the workpiece 3 and the TIG welding gun 2, respectively. The oscilloscope 7 is connected to the TIG welding gun 2 through a current clamp to detect the output current waveform. The gas protection device 8 provides protection gas to the TIG welding gun 2 through a gas pipe. The multi-output constant current source 1, the high-frequency waveform editing module 6, and the high-speed camera 12 are connected to the upper computer 11 through signal lines.

[0022] The power supply system adjusts the current flowing through the TIG welding gun 2 through the FPGA control board 9 to realize active regulation of the arc energy gradient distribution. The system uses high-frequency pulse current to cooperatively control the molten pool dynamic behavior and heat input parameters: the high-frequency waveform editing module 6 is used to adjust the arc to generate electromagnetic compression effect, generate micro-beam high-energy arc, accurately control the droplet temperature and deposition rate, and synchronously focus the penetration depth to break through the oxide film; the acoustic stirring effect generated by high-frequency pulse is used to optimize the molten pool flow path and promote gas escape, realize dynamic regulation of the molten pool temperature field and heat conduction path. The frequency, phase, and energy density of the welding current can be edited in real time according to the crack morphology, breaking through the limitations of traditional single-arc process thermal-mechanical coupling control, and significantly improving the forming precision and microstructure uniformity of nickel-based alloy crack repair.

[0023] The power supply system includes a multi-output constant current source 1 with three outputs. The high-frequency waveform editing module 6 comprises three switching units, each consisting of a left power switch, a right power switch, a diode, and a switching unit inductor. Both the left and right power switches are N-type MOSFETs. In the first switching unit, the positive terminal of the multi-output constant current source 1 is connected to the switching unit inductor. The first terminal of the left power switch is connected to the other end of the switching unit inductor, and the second terminal of the left power switch is connected to the negative terminal of the multi-output constant current source 1. The second terminal of the left power switch is also connected to the TIG welding torch 2. The switching unit inductor and diode are connected in parallel. The first terminal of the right power switch is connected to the other end of the switching unit inductor, and the second terminal of the right power switch is connected to the workpiece 3. The remaining two switching unit circuits are connected in the same way as the first switching unit. The output terminal of the gate switching drive circuit of the power switch is connected to input a PWM signal to the gate, and the PWM output waveform is controlled by the FPGA control board 9, causing the power switch to conduct according to the effective level of the PWM signal.

[0024] The high-frequency waveform editing module 6 and the FPGA control board 9 enable the current switching of the multi-output constant current source 1. The switching frequency of this circuit can reach 100kHz, thereby accurately matching the heat input requirements for crack repair, optimizing the arc energy gradient distribution and the dynamic behavior of the molten pool, and achieving precise repair of nickel-based alloys.

[0025] The host computer 11 communicates with the multi-output constant current source 1 and the high-frequency waveform editing module 6. The high-speed camera 12 captures images of the welding area in real time and transmits these images to the host computer 11 for analysis of the weld's appearance. The oscilloscope 7 simultaneously monitors current and voltage parameters. Based on the analysis of these data results, the multi-output constant current source 1 and the high-frequency waveform editing module 6 are adjusted to optimize the output current, effectively suppressing molten pool oscillation and hot cracking tendencies, and ensuring the simultaneous improvement of arc stability and forming quality during the welding of materials of different thicknesses.

[0026] like Figure 3 This diagram illustrates the circuit connections between the multi-output constant current source 1, the high-frequency switching circuit, and the welding components. The positive terminal of the multi-output constant current source 1 is connected to the switching unit inductor L1. The switching unit inductor L1 is connected in parallel with diode Q1. The other end of the switching unit inductor L1 is connected to the first terminal (drain) of power switch S1. The negative terminal of the multi-output constant current source 1 is connected to the second terminal (source) of power switch S1. The first terminal (drain) of power switch S2 is connected to the first terminal (drain) of power switch S1. The second terminal (source) of power switch S2 is connected to workpiece 3. The second terminal of power switch S1 is connected to TIG welding torch 2. The second terminal (source) of power switch S2 is connected to workpiece 3.

[0027] Assume the first output current of the multi-output constant current source 1 is I1, the second output current is I2, and the third output current is I3. Within one cycle, power switch S1 remains off and power switch S2 remains on. Different current waveforms are achieved by adjusting the switching on and off of power switching diodes S3, S4, S5, and S6. To prevent current backflow, there is a time interval between the switching on and off of the second power switch S3 and S4, and a time interval between the switching on and off of the third power switch S5 and S6. The current output waveform on the arc load has four possible values: I1, I1+I2, I1+I3, and I1+I2+I3. These current values ​​are determined by controlling the on and off times of the power switches. Figure 4 Several cases of pulse waveforms within one period T are shown.

[0028] The specific operating steps are as follows: start the gas protection device 8, input protective gas into the TIG welding torch 2, adjust the starting current of the multi-output constant current source 1 to 100A by controlling the host computer 11, set the frequency of the high-frequency waveform editing module 6 to 100kHz, start wire feeding, turn on the welding device, observe the high-speed camera 12 to know the welding quality during the welding process and the current and voltage detected by the oscilloscope 7, and adjust the parameters of the multi-output constant current source 1 and the high-frequency waveform editing module 6 to optimize the welding quality.

[0029] A welding power supply method for achieving high-frequency programmable pulse current output includes the following steps: S1. Perform surface pretreatment on the metal workpiece to remove surface oxides and impurities, and perform degreasing treatment. S2. Position the pre-treated metal workpiece onto the arc welding system, turn on the external water cooling device and the arc welding system power supply to complete the welding preparation. S3. Start the gas protection device and set the current parameters of the multi-output constant current source; S4. Use a short-circuit arc initiation method to start the electric arc. After the electric arc stabilizes, switch the high-frequency waveform editing module to the high-frequency controllable square wave mode. S5. Real-time monitoring of the morphological characteristics of metal workpieces, analysis of the effect of high-frequency waveform editing module on electric arc through melt width parameter analysis, and control of multi-output constant current source output based on melt depth characteristics to optimize heat input parameters.

[0030] Therefore, this invention employs a welding power supply system and method for achieving high-frequency programmable pulse current output. By coordinating high-frequency pulse current control with the dynamic behavior of the molten pool and thermal input parameters, and through a special switching sequence coupled with synchronous rectification, circuit heating is reduced while improving the accuracy of the current waveform, achieving high-precision repair of cracks in nickel-based alloy blades. The repaired weld exhibits high grain refinement and excellent mechanical properties, effectively suppressing molten pool oscillation and hot cracking tendency, ensuring simultaneous improvement in arc stability and forming quality during the welding of materials of different thicknesses.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A welding power supply system for realizing high-frequency programmable pulse current output, characterized in that, The system includes a TIG welding torch, a high-frequency waveform editing module, an inductor, a multi-output constant current source, an FPGA control board, an oscilloscope, and a gas protection device. The TIG welding torch is vertically positioned above the workpiece, which is placed on a slide table. The TIG welding torch is connected to the high-frequency waveform editing module, which is connected to the inductor. The inductor is connected to the multi-output constant current source. The high-frequency waveform editing module is also connected to the FPGA control board. The oscilloscope is connected to the TIG welding torch via a current clamp, and the gas protection device is connected to the TIG welding torch via a gas pipe.

2. The welding power supply system for realizing high-frequency programmable pulse current output according to claim 1, characterized in that, The multi-output constant current source has three outputs. The positive terminal of the multi-output constant current source is connected to the high-frequency waveform editing module through an inductor, and the negative terminal of the multi-output constant current source is connected to the high-frequency waveform editing module through a cable.

3. A welding power supply system for realizing high-frequency programmable pulse current output according to claim 1, characterized in that, The positive terminal of the high-frequency waveform editing module is connected to the workpiece via a wire, and the negative terminal of the high-frequency waveform editing module is connected to the TIG welding torch via a wire.

4. A welding power supply system for realizing high-frequency programmable pulse current output according to claim 1, characterized in that, The system also includes a slide controller, a host computer, and a high-speed camera. The slide controller is connected to the slide via wires, and the high-frequency waveform editing module, the multi-output constant current source, and the high-speed camera are all connected to the host computer via signal lines.

5. A welding power supply system for realizing high-frequency programmable pulse current output according to claim 1, characterized in that, The high-frequency waveform editing module includes a switching unit, which consists of a left power switch, a right power switch, a diode, and a switching unit inductor. Both the left and right power switches are N-type MOSFETs.

6. A welding power supply method for realizing high-frequency editable pulse current output, wherein the welding power supply system for realizing high-frequency editable pulse current output as described in claim 1 is applied to a power supply editing arc, characterized in that, Includes the following steps: S1. Perform surface pretreatment on the metal workpiece to remove surface oxides and impurities, and perform degreasing treatment. S2. Position the pre-treated metal workpiece onto the arc welding system, turn on the external water cooling device and the arc welding system power supply to complete the welding preparation. S3. Start the gas protection device and set the current parameters of the multi-output constant current source; S4. Use a short-circuit arc initiation method to start the electric arc. After the electric arc stabilizes, switch the high-frequency waveform editing module to the high-frequency controllable square wave mode. S5. Real-time monitoring of the morphological characteristics of metal workpieces, analysis of the effect of high-frequency waveform editing module on electric arc through melt width parameter analysis, and control of multi-output constant current source output based on melt depth characteristics to optimize heat input parameters.

Images