Inverter dc argon arc welding and welding method and welding device thereof

Abstract

The application discloses an inverter type direct current argon arc welding and a welding method and device thereof. The welding method comprises the following steps: obtaining a ratio coefficient of a welding constant current value, a peak-valley difference value and a ripple current peak value in a welding stage; determining a ripple current peak value and a ripple current valley value of the ripple current according to the welding constant current value and the ratio coefficient; wherein the ripple current valley value is greater than zero; controlling the ripple current to smoothly fluctuate at a preset frequency between the ripple current peak value and the ripple current valley value, and applying the ripple current to the inverter type direct current argon arc welding to realize a welding function. The technical scheme can improve the welding quality and effect of the inverter type direct current argon arc welding.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to an inverter-type DC argon arc welding method and welding apparatus. Background Technology

[0002] Inverter DC TIG welding uses a non-consumable tungsten electrode to generate an arc and performs welding under the protection of inert argon gas. It has a wide range of applications and materials, and can weld various metals such as carbon steel, stainless steel, and nickel alloys, enabling multi-point all-position welding of complex and irregular structural parts.

[0003] Inverter-type DC TIG welding uses a constant current output to ensure uniform heat input. However, this "static" current mode cannot actively push the liquid metal to the bottom of the molten pool, resulting in limited penetration depth. Furthermore, in gap conditions, it lacks the main force to squeeze the metal into the gap, resulting in poor bridging ability. When the molten pool solidifies, the gas cannot escape effectively, and the central part cannot be compensated for, which easily leads to the formation of shrinkage cavities in the center of the weld. Summary of the Invention

[0004] This invention provides an inverter-type DC argon arc welding method and welding apparatus to improve the welding quality and welding effect of inverter-type DC argon arc welding.

[0005] In a first aspect, the present invention provides a welding method for inverter-type DC argon arc welding, comprising: During the welding stage, the ratio of the constant welding current value, the peak-to-trough difference, and the peak value of the ripple current is obtained. Based on the welding constant current value and the proportional coefficient, the peak value and trough value of the ripple current are determined; wherein the trough value of the ripple current is greater than zero. The ripple current is controlled to fluctuate smoothly between the peak value and the trough value of the ripple current at a preset frequency, and the ripple current is applied to the inverter DC TIG welding to achieve the welding function.

[0006] Optionally, the preset frequency is F; Among them, 50Hz≤F≤1000Hz.

[0007] Optionally, the ratio of the peak-to-trough difference to the peak value of the ripple current is k; Among them, 10%≤k≤90%.

[0008] Optionally, the ripple current includes a sine wave with DC bias.

[0009] Optionally, the peak value and trough value of the ripple current are determined based on the welding constant current value and the proportional coefficient, including: According to the first calculation formula for the effective value of the ripple current, the peak value of the ripple current, and the trough value of the ripple current, and the second calculation formula for the difference between the peak and trough values ​​and the peak value of the ripple current, the welding constant current value is substituted into the first calculation formula as the effective value for calculation, and the proportional coefficient is substituted into the second calculation formula for calculation to determine the peak value of the ripple current and the trough value of the ripple current.

[0010] Optionally, the first calculation formula is: Ir = I2 + 1 / 2 (I1 - I2); the second calculation formula is: △I = I1 - I2 = k × I1; Wherein, Ir is the effective value of the ripple current, I1 is the peak value of the ripple current, I2 is the trough value of the ripple current, ΔI is the peak-to-trough difference, and k is the proportionality coefficient.

[0011] Optionally, obtaining the welding constant current value includes: Obtain the thickness of the plate material to be welded; The welding constant current value for the inverter-type DC argon arc welding is determined based on the thickness of the plate.

[0012] Optionally, the welding constant current value for the inverter-type DC TIG welding is determined based on the thickness of the plate, including: Based on the first mapping relationship between thickness and welding current, the welding current corresponding to the thickness of the plate is determined as the constant welding current value.

[0013] Secondly, the present invention provides a welding apparatus for inverter-type DC argon arc welding, comprising: The parameter acquisition module is used to acquire the welding constant current value, the peak-to-trough difference value and the ratio coefficient of the ripple current peak value during the welding stage. The ripple current peak value and trough value determination module is used to determine the ripple current peak value and ripple current trough value based on the welding constant current value and the proportional coefficient; wherein, the ripple current trough value is greater than zero. The waveform output module is used to control the ripple current to fluctuate smoothly between the peak current value and the trough current value at a preset frequency, and to apply the ripple current to the inverter DC TIG welding to achieve the welding function.

[0014] Thirdly, the present invention provides an inverter-type DC argon arc welding system, comprising: a control unit, a ripple waveform output unit, and a current feedback unit; The control unit is electrically connected to the ripple waveform output unit and the current feedback unit respectively; the control unit and the ripple waveform output unit are used to perform the inverter-type DC argon arc welding method described in the first aspect; The current feedback unit is used to acquire the output waveform provided by the ripple waveform output unit and transmit the output waveform to the control unit; the control unit adjusts the control parameters transmitted to the ripple waveform output unit according to the output waveform.

[0015] The technical solution provided by this invention obtains the welding constant current value, the peak-to-trough difference, and the proportional coefficient of the ripple current peak value during the welding stage. Based on the welding constant current value and the proportional coefficient, the peak and trough values ​​of the ripple current are determined, wherein the trough value is greater than zero. The ripple current is controlled to smoothly fluctuate between the peak and trough values ​​at a preset frequency, and this ripple current is applied to the inverter-type DC TIG welding to achieve the welding function. Thus, by replacing the welding constant current value applied to the inverter-type DC TIG welding with the ripple current, the inverter-type DC TIG welding can generate periodically changing arc pressure during the normal welding stage, producing a strong stirring effect on the molten pool. This results in welds with a smooth surface, no shrinkage cavities in the center, a denser microstructure, and superior physical properties, improving the welding quality and effect of the inverter-type DC TIG welding. Attached Figure Description

[0016] Figure 1 A flowchart of a welding method for inverter-type DC argon arc welding provided in an embodiment of the present invention; Figure 2 A waveform diagram of ripple current provided in an embodiment of the present invention; Figure 3 A schematic diagram of the structure of an inverter-type DC argon arc welding apparatus provided in an embodiment of the present invention; Figure 4 This is a partial structural schematic diagram of an inverter-type DC argon arc welding system provided in an embodiment of the present invention. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0018] Figure 1 A flowchart of an inverter-type DC argon arc welding method provided in an embodiment of the present invention is shown below. Figure 1 As shown, the welding method of this inverter-type DC argon arc welding includes: S101. During the welding stage, obtain the welding constant current value, the peak-to-trough difference value and the ratio coefficient of the ripple current peak value.

[0019] The welding constant current value can be fixed or non-fixed, and is related to the type of inverter DC TIG welding or the material to be welded, etc., and can be set according to actual needs. The ratio coefficient of the peak-to-trough difference to the peak value of the ripple current can be fixed or non-fixed, and is related to the weld depth of the welded material, etc., and can be set according to actual needs; no specific limitation is made here. The welding constant current value corresponds to the current value when the inverter DC TIG welding is performed with a constant current value.

[0020] Specifically, the value of the welding constant current can be manually input or obtained from the factory parameters of the inverter-type DC TIG welder. The ratio of the peak-to-trough difference to the peak value of the ripple current can be manually input or obtained from the setting parameters of the inverter-type DC TIG welder. Other methods can also be used to obtain the welding constant current value and the ratio, which are not specifically limited here.

[0021] S102. Determine the peak value and trough value of the ripple current based on the welding constant current value and the proportional coefficient.

[0022] The ripple current trough value is greater than zero. The ripple current peak value is greater than the ripple current trough value. The ripple current is a smoothly changing waveform, oscillating gently back and forth between the ripple current peak value and the ripple current trough value. The ripple current peak value represents the maximum current value during the ripple current oscillation process, and the ripple current trough value represents the minimum current value during the ripple current oscillation process.

[0023] Specifically, the welding constant current value is determined as the effective value of the ripple current. Then, based on the relationship between the peak value and trough value of the ripple current and the effective value of the current, as well as the ratio coefficient between the difference between the peak value and trough value of the ripple current and the peak value of the ripple current, the peak value and trough value of the ripple current corresponding to the welding constant current value and the ratio coefficient can be calculated.

[0024] S103. Control the ripple current to fluctuate smoothly between the peak value and the trough value of the ripple current at a preset frequency, and apply the ripple current to the inverter DC TIG welding to achieve the welding function.

[0025] The preset frequency can be a fixed value or a non-fixed value, and can be set according to actual needs. No specific limitation is made here.

[0026] Specifically, the time required for the ripple current to smoothly and monotonically fluctuate from its trough to its peak value, and then back to its trough, constitutes one cycle. The preset frequency can be achieved by adjusting the duration of this cycle, allowing a ripple current with the preset frequency to be applied to the welding head of the inverter-driven DC TIG welder during the welding stage. Compared to the constant welding current, the determined peak ripple current value is typically greater than the constant welding current value. This ensures that when the ripple current reaches its peak value, the instantaneous arc force generated by the inverter-driven DC TIG welder increases, significantly improving arc stiffness and energy density. This allows for rapid melting of the edges of the weld plates on both sides of the weld, increasing the weld penetration and facilitating good wetting and filling of the metal within the weld, thus achieving good fusion even in wide welds. Furthermore, when a smooth, fluctuating ripple current is applied to an inverter-type DC TIG welder, the periodic variation of the ripple current between its peak and trough values ​​causes the inverter-type DC TIG welder to generate periodically varying arc pressure during the normal welding phase. This generates a strong stirring effect on the molten pool, which can break up growing dendrites, promote grain refinement in the weld, and thus obtain welds with a smooth surface, no shrinkage cavities in the center, a denser structure, and superior physical properties.

[0027] The technical solution of this invention obtains the welding constant current value, the peak-to-trough difference, and the proportional coefficient of the ripple current peak value during the welding stage. Based on the welding constant current value and the proportional coefficient, the peak and trough values ​​of the ripple current are determined, wherein the trough value is greater than zero. The ripple current is controlled to smoothly fluctuate between the peak and trough values ​​at a preset frequency, and the ripple current is applied to the inverter DC TIG welder to achieve the welding function. Thus, by replacing the welding constant current value applied to the inverter DC TIG welder with the ripple current, the inverter DC TIG welder can generate periodically changing arc pressure during the normal welding stage, producing a strong stirring effect on the molten pool. This results in welds with a smooth surface, no shrinkage cavities in the center, a denser microstructure, and superior physical properties, improving the welding quality and effect of the inverter DC TIG welder.

[0028] Optionally, the preset frequency is F; where 50Hz≤F≤1000Hz.

[0029] In this embodiment, the preset frequency F is set to a value of 50Hz to 1000Hz. The specific value of the preset frequency F can be set according to actual needs. In an exemplary embodiment, the preset frequency F is 100Hz, but it can also be other values. No specific limitation is made here.

[0030] Specifically, if the preset frequency F is less than 50Hz, the fluctuation of the ripple current between its peak and trough values ​​is small, resulting in limited stirring of the molten pool and limited ability to fill gaps and remove pores, leading to poor weld joints. If the preset frequency F is greater than 1000Hz, the ripple current fluctuates too rapidly from its peak to its trough, or vice versa, preventing the molten metal from flowing smoothly into the weld and resulting in poor welding performance. Therefore, by setting the preset frequency F between 50Hz and 1000Hz, the ripple current applied to the inverter DC TIG welder can achieve a good stirring effect while maintaining good fluidity of the molten metal, thus improving welding quality and welding effect.

[0031] Optionally, the ratio of the peak-to-trough difference to the peak value of the ripple current is k; where 10%≤k≤90%.

[0032] In this embodiment, the proportional coefficient k is set to a value of 10% to 90%, and the specific value of the proportional coefficient k can be set according to actual needs. In an exemplary embodiment, the proportional coefficient k is 50%, but it can also be other values, which are not specifically limited here.

[0033] Specifically, if the ratio coefficient k between the peak-to-trough difference and the peak value of the ripple current is less than 10%, the difference between the peak and trough values ​​of the ripple current is small, resulting in minimal current fluctuation. This limits the stirring effect on the molten pool, restricts the ability to fill gaps and expel pores, and leads to poor weld joints. Conversely, if the ratio coefficient k is greater than 90%, the difference between the peak and trough values ​​is large, and the trough value is too small. In this case, the inverter DC TIG welder may experience arc extinction upon receiving the trough value, affecting welding continuity. Therefore, by setting the ratio coefficient k between the peak-to-trough difference and the peak value of the ripple current to between 10% and 90%, the ripple current applied to the inverter DC TIG welder can achieve a good fluctuation and stirring effect while ensuring welding continuity, thus improving welding quality and results.

[0034] Based on the premise that the ripple current smoothly fluctuates between its peak and trough values ​​at a preset frequency, the waveform of the ripple current can be set according to actual needs. For example, the ripple current includes a triangular wave with DC bias, etc. In an optional embodiment, Figure 2 A waveform diagram of ripple current provided in an embodiment of the present invention is shown below. Figure 2 As shown, the ripple current comprises a sine wave with DC bias.

[0035] Specifically, since the trough value of the ripple current is greater than zero and the peak value of the ripple current is greater than the peak value of the ripple current, the sine wave with DC bias here refers to the sine wave of the positive half-cycle. The sine wave is a smooth waveform without step changes, which can control the inverter DC TIG welding to generate a stable arc force, smoothly squeeze the liquid metal into the weld gap, and has a good spot welding bridging effect.

[0036] It should be noted that, Figure 2 The diagram only shows the waveform of the ripple current during the welding stage. The welding stage includes an arc-ignition stage before the welding stage and an arc-tering stage after the welding stage. This embodiment of the invention does not limit the waveforms of the arc-ignition and arc-tering stages. In an optional embodiment, the arc-ignition stage includes a sine wave with a positive half-cycle of one preset period corresponding to a preset frequency, and the peak value of the current wave during the arc-ignition stage is smaller than the peak value of the ripple current during the welding stage. The arc-tering stage includes a sine wave with two positive half-cycles of two preset periods corresponding to a preset frequency, and the peak value of the current wave during the arc-tering stage is also smaller than the peak value of the ripple current during the welding stage, with the peak value gradually decreasing during the arc-tering stage.

[0037] Optionally, the peak value and trough value of the ripple current are determined based on the welding constant current value and the proportional coefficient, including: according to the first calculation formula of the effective value of the ripple current and the peak value and trough value of the ripple current, and the second calculation formula of the peak-trough difference and the peak value of the ripple current, the welding constant current value is substituted into the first calculation formula as the effective value for calculation, and the proportional coefficient is substituted into the second calculation formula for calculation, so as to determine the peak value and trough value of the ripple current.

[0038] The first and second calculation formulas are related to the waveform of the ripple current, and can be determined based on the waveform of the ripple current.

[0039] Specifically, the first and second calculation formulas can be determined based on the waveform of the ripple current. The welding constant current value is then substituted into the first calculation formula as the effective value to obtain the first relationship between the welding constant current value and the peak and trough values ​​of the ripple current. The proportionality coefficient is then substituted into the second calculation formula to obtain the second relationship between the peak-to-trough difference and the peak value of the ripple current. The peak-to-trough difference represents the difference between the peak and trough values ​​of the ripple current. Solving the first and second relationships simultaneously determines the peak and trough values ​​of the ripple current.

[0040] Optionally, the first calculation formula is: Ir=I2+1 / 2(I1-I2); the second calculation formula is: △I=I1-I2=k×I1; where Ir is the effective value of the ripple current, I1 is the peak value of the ripple current, I2 is the trough value of the ripple current, △I is the peak-trough difference, and k is the proportionality coefficient.

[0041] For details, please refer to Figure 2 When the ripple current is a sinusoidal wave with a DC component, the effective value Ir in the first calculation formula consists of two parts: the trough value I2 of the ripple current and half (I1-I2) of the effective value of the ripple current. When the ripple current is a sinusoidal wave with a DC component, the peak-to-trough difference ΔI in the second calculation formula is K times the peak value I1 of the ripple current. Since the peak-to-trough difference ΔI = I1-I2, the second calculation formula can be calculated to obtain (1-k)I1 = I2. Substituting (1-k)I1 = I2 into the first calculation formula, we can obtain Ir = (1-k / 2)I1. Substituting the welding constant current value as the effective value Ir into Ir = (1-k / 2)I1, we can obtain the peak value I1 of the ripple current. Then, the trough value I2 of the ripple current can be calculated from (1-k)I1 = I2.

[0042] The above shows the calculation method for the peak value and trough value of the ripple current when the ripple current is a sine wave with a DC component. When the ripple current is other waveforms, the peak value and trough value of the ripple current can be calculated and determined according to the first calculation formula and the second calculation formula corresponding to the specific waveform of the ripple current. No specific limitation is made here.

[0043] Optionally, obtaining the welding constant current value includes: obtaining the thickness of the plate to be welded; and determining the welding constant current value of the inverter DC TIG welding based on the plate thickness.

[0044] The materials to be welded can include stainless steel, aluminum, magnesium, titanium, or copper, and can be selected according to actual needs. The thickness of the material to be welded indicates its dimension in the direction perpendicular to the welding surface.

[0045] Specifically, the thickness of the sheet material to be welded can be obtained using measuring devices such as vernier calipers or steel rulers. Then, based on the correspondence between the thickness and the welding current, the constant welding current value corresponding to the thickness of the sheet material to be welded can be determined. This improves the reliability of the waveform of the ripple current determined based on the constant welding current value and enhances the welding quality.

[0046] It should be noted that the plate thickness and welding current can be positively correlated; that is, the greater the plate thickness, the greater the required welding current, and the smaller the plate thickness, the smaller the required welding current. In other optional embodiments, the factors affecting the welding current are not limited to plate thickness, but may also include plate material, etc., which are not specifically limited here.

[0047] Optionally, the welding constant current value for inverter DC TIG welding is determined based on the plate thickness, including: determining the welding current corresponding to the plate thickness as the welding constant current value based on the first mapping relationship between thickness and welding current.

[0048] The first mapping relationship can be a curve of thickness versus welding current or a table of thickness versus welding current, which can be obtained through experiments or experience.

[0049] Specifically, when the first mapping relationship is a curve of thickness versus welding current, after obtaining the plate thickness, the welding current on the curve corresponding to the plate thickness can be directly determined as the constant welding current value by referring to the thickness-welding current curve. Alternatively, when the first mapping relationship is a correspondence table of thickness and welding current, after obtaining the plate thickness, the welding current corresponding to the plate thickness can be directly obtained from the table and determined as the constant welding current. It should be noted that other methods can also be used to determine the constant welding current value, which are not specifically limited here.

[0050] Figure 3 This is a schematic diagram of the structure of a welding apparatus for inverter-type DC argon arc welding provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the inverter-type DC argon arc welding apparatus includes: The parameter acquisition module 10 is used to acquire the welding constant current value, the peak-to-trough difference value and the ratio coefficient of the ripple current peak value during the welding stage. The ripple current peak value and trough value determination module 20 is used to determine the ripple current peak value and ripple current trough value based on the welding constant current value and the proportional coefficient; wherein, the ripple current trough value is greater than zero. The waveform output module 30 is used to control the ripple current to fluctuate smoothly between the peak current value and the trough current value at a preset frequency, and to apply the ripple current to the inverter DC TIG welding to achieve the welding function.

[0051] The inverter-type DC argon arc welding apparatus provided in this embodiment of the invention can perform the inverter-type DC argon arc welding method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for performing the method. The similarities can be referred to the above description.

[0052] Based on the same inventive concept, this invention also provides an inverter-type DC argon arc welding system. Figure 4 This is a partial structural schematic diagram of an inverter-type DC argon arc welding system provided in an embodiment of the present invention, as shown below. Figure 4As shown, the inverter-type DC TIG welding includes: a control unit 11, a ripple waveform output unit 12, and a current feedback unit 13; the control unit 11 is electrically connected to the ripple waveform output unit 12 and the current feedback unit 13 respectively; the current feedback unit 13 is used to acquire the output waveform provided by the ripple waveform output unit 12 and transmit the output waveform to the control unit 11; the control unit 11 adjusts the control parameters transmitted to the ripple waveform output unit 12 according to the output waveform.

[0053] The control unit 11 and the ripple waveform output unit 12 are used to execute the inverter-type DC argon arc welding method provided in any embodiment of the present invention. They have the corresponding functional modules and beneficial effects for executing the method, and the similarities can be referred to the above description.

[0054] Specifically, the control unit 11 includes a main control subunit and a PWM controller. The ripple waveform output unit 12 includes a first rectifier-filter subunit, an inverter subunit, and a second rectifier-filter subunit. The first rectifier-filter subunit converts the input AC signal into a DC signal. The PWM controller in the control unit 11 controls the switching transistors in the inverter subunit and the second rectifier-filter subunit to turn on and off, so that the second rectifier-filter subunit can output ripple current. The current feedback unit 13 acquires the output waveform provided by the second rectifier-filter subunit and feeds the output waveform back to the main control subunit of the control unit 11. The main control subunit adjusts the corresponding parameters according to the set value and the feedback waveform, and outputs the adjusted control signal value to the PWM controller. The PWM controller then adjusts the control parameters output to the ripple waveform output unit so that the final output ripple current meets expectations.

[0055] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A welding method for inverter-type DC argon arc welding, characterized in that, include: During the welding stage, the ratio of the constant welding current value, the peak-to-trough difference, and the peak value of the ripple current is obtained. Based on the welding constant current value and the proportional coefficient, the peak value and trough value of the ripple current are determined; wherein the trough value of the ripple current is greater than zero. The ripple current is controlled to fluctuate smoothly between the peak value and the trough value of the ripple current at a preset frequency, and the ripple current is applied to the inverter DC TIG welding to achieve the welding function.

2. The welding method for inverter-type DC argon arc welding according to claim 1, characterized in that, The preset frequency is F; Among them, 50Hz≤F≤1000Hz.

3. The welding method for inverter-type DC argon arc welding according to claim 1, characterized in that, The ratio of the peak-to-trough difference to the peak value of the ripple current is k; Among them, 10%≤k≤90%.

4. The welding method for inverter-type DC argon arc welding according to claim 1, characterized in that, The ripple current includes a sine wave with DC bias.

5. The inverter-type DC argon arc welding method according to claim 4, characterized in that, Based on the welding constant current value and the proportional coefficient, the peak value and trough value of the ripple current are determined, including: According to the first calculation formula for the effective value of the ripple current, the peak value of the ripple current, and the trough value of the ripple current, and the second calculation formula for the difference between the peak and trough values ​​and the peak value of the ripple current, the welding constant current value is substituted into the first calculation formula as the effective value for calculation, and the proportional coefficient is substituted into the second calculation formula for calculation to determine the peak value of the ripple current and the trough value of the ripple current.

6. The welding method for inverter-type DC argon arc welding according to claim 5, characterized in that, The first calculation formula is: Ir = I2 + 1 / 2 (I1 - I2); the second calculation formula is: ΔI = I1 - I2 = k × I1; Wherein, Ir is the effective value of the ripple current, I1 is the peak value of the ripple current, I2 is the trough value of the ripple current, ΔI is the peak-to-trough difference, and k is the proportionality coefficient.

7. The welding method for inverter-type DC argon arc welding according to claim 1, characterized in that, Obtaining the welding constant current value includes: Obtain the thickness of the plate material to be welded; The welding constant current value for the inverter-type DC argon arc welding is determined based on the thickness of the plate.

8. The welding method for inverter-type DC argon arc welding according to claim 7, characterized in that, Determining the constant welding current value for the inverter-type DC TIG welding based on the plate thickness includes: Based on the first mapping relationship between thickness and welding current, the welding current corresponding to the thickness of the plate is determined as the constant welding current value.

9. A welding apparatus for inverter-type DC argon arc welding, characterized in that, include: The parameter acquisition module is used to acquire the welding constant current value, the peak-to-trough difference value and the ratio coefficient of the ripple current peak value during the welding stage. The ripple current peak value and trough value determination module is used to determine the ripple current peak value and ripple current trough value based on the welding constant current value and the proportional coefficient; wherein, the ripple current trough value is greater than zero. The waveform output module is used to control the ripple current to fluctuate smoothly between the peak current value and the trough current value at a preset frequency, and to apply the ripple current to the inverter DC TIG welding to achieve the welding function.

10. An inverter-type DC argon arc welding machine, characterized in that, include: Control unit, ripple waveform output unit, and current feedback unit; The control unit is electrically connected to the ripple waveform output unit and the current feedback unit respectively; the control unit and the ripple waveform output unit are used to perform the welding method of inverter DC argon arc welding according to any one of claims 1 to 8; The current feedback unit is used to acquire the output waveform provided by the ripple waveform output unit and transmit the output waveform to the control unit; the control unit adjusts the control parameters transmitted to the ripple waveform output unit according to the output waveform.

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