A method of plasma gas gouging process control

Abstract

The application discloses a kind of plasma gas planing process control method, it is related to plasma processing technical field, including the following steps: release high-pressure plasma gas, for generating gas ionization arc;Wherein, according to the kind of material to be processed, the different gas medium and gas flow of high-pressure plasma gas are selected;Gas ionization arc is generated, and the metal material of the planed workpiece is melted;Multi-layer multi-pass plasma gas planing process is used to reach the planned planing depth;The present application is consistent for carbon steel material's root planing and forms, suitable for robot and other automation equipment;For the planing of the weld of stainless steel, titanium alloy, magnesium alloy material, release different medium high-pressure plasma gas by gas control unit, eliminate the carburizing of planed base material, using mixed gas plasma gas planing process, there is no oxidation layer on the planing surface, can be directly welded to seam, realize the efficient processing of different materials, greatly improve processing efficiency and quality.

Description

Technical Field

[0001] This invention relates to a plasma air gouging process control method, belonging to the field of plasma treatment technology. Background Technology

[0002] Plasma processing technology is a technique that uses high-temperature plasma to process materials and is widely used in the field of materials processing engineering. Plasma gouging, in particular, is a method that uses plasma to goug materials, and can be used to remove surface defects such as weld seams and oxide layers. At the same time, plasma gouging technology is also widely used in the field of precision machining.

[0003] As a traditional root removal process, the existing carbon arc gouging technology mainly uses a special carbon rod or graphite rod with copper foil as an electrode to generate a plasma arc between the electrode and the workpiece, melting the metal, and then using compressed air to blow away the molten metal. This method can meet the processing requirements of defects of different materials and shapes.

[0004] Existing carbon arc gouging technology still has some obvious shortcomings in practical applications, including:

[0005] First, carbon rods are non-metallic products. As an essential pre-welding cutting consumable in carbon arc gouging, they are made by extruding carbon and graphite with a suitable binder, baking at 2200℃, and then plating with a layer of copper. The manufacturing process pollutes the air and water environment.

[0006] Secondly, carbon arc gouging is currently operated manually. The high temperature and high pressure gas generated by the plasma arc between the carbon rod and the workpiece impacts and peels off the material, which generates a lot of noise and heat. This not only causes serious pollution to the workers' operating environment.

[0007] Third, manual planing with carbon rods results in inconsistent planing kerf formation, requires a lot of time for grinding, and is not suitable for subsequent automated welding processes.

[0008] Fourth, existing carbon arc gouging technology shows significant differences in effectiveness when processing different materials. For example, for carbon steel, existing carbon arc gouging technology can achieve efficient weld root cleaning and gouging shaping. However, for stainless steel, titanium alloys, and magnesium alloys, due to the high thermal conductivity and melting point of these materials, existing carbon arc gouging technology is less effective and cannot achieve efficient weld gouging.

[0009] Fifth, when processing materials such as medium and thick plates, the existing carbon arc gouging technology cannot meet the width and depth requirements due to the large thickness of the plates, requiring multiple processing steps. This not only increases processing time and cost but also affects processing accuracy and quality.

[0010] Currently, some research is dedicated to addressing the aforementioned shortcomings of carbon arc gouging technology. For example, Chinese patent CN110625233A discloses an automatic plasma gouging process for cleaning the root of submerged arc welds in medium-thickness steel plates. This process can automatically perform plasma gouging for cleaning the root of submerged arc welds (Y-type and I-type bevels) in steel plates with a thickness of 25mm or less. It effectively reduces gouging noise and dust pollution, lowers labor intensity, improves the stability of the gouging process, eliminates the risk of carburization at the gouged bevel, and reduces or avoids the work of grinding and finishing the gouged bevel. However, the drawback of this solution is that the applicable plate thickness for this gouging process is limited to within 25mm. For plates thicker than 25mm, the gouging depth and width increase, making it impossible to meet the gouging requirements for plates thicker than 25mm. Furthermore, in this method, compressed air is used as the gas medium for air gouging, which is only suitable for carbon steel plates. For non-ferrous metals such as stainless steel and magnesium alloys, air gouging can easily lead to severe oxidation of the gouging seam. The oxide layer changes the properties of the base material medium, and the oxide layer is difficult to clean and grind. Summary of the Invention

[0011] This invention addresses the shortcomings of existing technologies by providing a plasma air gouging process control method. This method controls the temperature and energy of the plasma by adjusting its parameters, thereby enabling air gouging of surface defects of different materials and shapes. It can efficiently process medium-thick plates with a thickness of up to 50mm and is applicable to plates of different metal materials such as stainless steel and non-ferrous metals, without the need for cleaning and grinding.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0013] A method for controlling plasma air gouging process includes the following steps:

[0014] High-pressure plasma gas is released to generate a gas ionization arc; the gas medium and flow rate of the high-pressure plasma gas are selected according to the type of material to be processed.

[0015] It generates a gas ionization arc, which melts the metal material of the workpiece being planed;

[0016] The predetermined kerf depth is achieved by using a multi-layer, multi-pass plasma air gouging process.

[0017] As a further technical solution, the gas medium and gas flow rate of the high-pressure plasma gas are selected according to the type of material to be processed, and the gas medium includes air and mixed gas.

[0018] As a further technical solution, the specific method of generating a gas ionization arc to melt the metal material of the workpiece being planed is to use a plasma air gouging unit to generate a gas ionization arc at a temperature of over 20,000°C to melt the metal material on the surface of the workpiece being planed; the plasma air gouging unit includes a plasma air gouging power supply and a plasma air gouging torch.

[0019] As a further technical solution, before generating the gas ionization arc, the travel trajectory of the air gouging motion is adjusted to determine the travel trajectory of the straight and circumferential welds for air gouging root cleaning.

[0020] As a further technical solution, before generating the gas ionization arc, the planing angle of the plasma gas planing torch is adjusted. Specifically, the relative angle between the plasma gas planing torch and the workpiece being planed is adjusted by controlling the planing current.

[0021] As a further technical solution, the method of adjusting the relative angle between the plasma air planing torch and the workpiece by controlling the planing current specifically includes:

[0022] When the planing current is less than 130A, the angle between the plasma planing torch and the workpiece being planed is 45°.

[0023] When the planing current is 130-160A, the angle between the plasma planing torch and the workpiece being planed is 40°.

[0024] When the planing current is 160-190A, the angle between the plasma planing torch and the workpiece being planed is 35°.

[0025] When the planing current is above 190A, the angle between the plasma planing torch and the workpiece being planed is 30°.

[0026] As a further technical solution, before generating the gas ionization arc, the position and motion parameters of the plasma gouging torch are adjusted to adjust the ratio of gouging width to depth, thereby improving the root cleaning effect.

[0027] As a further technical solution, the motion parameters include the swing amplitude, swing speed and travel speed of the plasma air planer torch, and the position parameters include the planing height and the relative angle between the plasma air planer torch and the workpiece being planed.

[0028] As a further technical solution, the planing current is 210A, the angle between the plasma air planer torch and the workpiece being planed is 30°, the distance is 3mm, the planing speed is 600mm / min, the oscillation amplitude is 5mm, the oscillation speed is 3000mm / min, the kerf width is 25mm, and the depth is 17mm, so as to achieve the optimal air planing root cleaning effect.

[0029] As a further technical solution, the method of using a multi-layer, multi-pass plasma air gouging process to achieve the predetermined kerf depth includes:

[0030] The first layer of plasma air gouging process is used to process the surface of the material to be processed to a certain depth;

[0031] A second-layer plasma gouging process is used to process the surface after the first-layer plasma gouging to a deeper depth. This process is repeated until the predetermined depth requirement is reached.

[0032] As a further technical solution, the first layer of plasma air gouging process has an air gouging current of 200A, an angle of 30° between the plasma air gouging torch and the workpiece being gouged, and a kerf depth of 10mm after processing.

[0033] The second-layer plasma air gouging process uses a gouging current of 150A, an angle of 30° between the plasma air gouging torch and the workpiece being gouged, and a kerf depth of 16mm after processing.

[0034] The beneficial effects of this invention are as follows:

[0035] 1. This invention provides consistent kerf shaping for carbon steel materials, making it suitable for automated equipment such as robots. For weld seam planing of stainless steel, titanium alloys, and magnesium alloys, the gas control unit can release high-pressure plasma gases of different media to adapt to different sheet materials, eliminating carburization of the base material. Employing a mixed gas plasma planing process using air-H35, air-F35, and air-nitrogen mixtures, the planed seam surface has no oxide layer, requiring no grinding and allowing for direct welding. This achieves highly efficient processing of different materials, significantly improving processing efficiency and quality.

[0036] 2. For plasma gouging of medium and thick plates and other materials, this invention uses a motion control unit and a plasma gouging torch control unit to adjust the motion and position parameters of the plasma gouging torch, increasing the kerf width. It employs a multi-layer, multi-pass plasma gouging process to achieve the required kerf depth. Compared with existing technologies, this expands the applicable range of processed materials, achieving efficient processing of medium and thick plates up to 50mm thick, meeting the processing requirements of medium and thick plates and other materials, further expanding the adaptability to processing different materials, and simultaneously improving processing efficiency and quality.

[0037] 3. This invention controls the temperature and energy of plasma by adjusting plasma parameters such as current, voltage, and gas flow rate, thereby meeting the processing requirements of defects of different materials and shapes. This not only reduces heat generation and improves the stability and service life of the equipment, but also reduces noise pollution in the operating environment and improves the production environment. Attached Figure Description

[0038] Figure 1 This is a block diagram of the plasma process control method provided by the present invention. Detailed Implementation

[0039] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0040] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0041] Similar to plasma cutting, plasma gouging removes metal using a plasma arc between a torch and the workpiece. The metal on the workpiece surface is melted, and the gas jet blows the molten metal away from the workpiece without penetrating or cutting it. During gouging, specially designed consumable parts generate a wider plasma arc, and the torch must be maintained at a certain angle so that only a portion of the metal is blown away.

[0042] A typical embodiment of the present invention mainly provides a plasma air gouging process control method, including the following steps:

[0043] Step 100 involves releasing high-pressure plasma gas to generate a gas ionization arc; wherein, the different gas medium and gas flow rate of the high-pressure plasma gas are selected according to the type of material to be processed.

[0044] Step 200 involves generating a gas ionization arc to melt the metal material of the workpiece being planed.

[0045] Step 300 involves using a multi-layer, multi-pass plasma air gouging process to achieve the predetermined kerf depth.

[0046] Specifically, in step 100, high-pressure plasma gas is released using a gas control unit to generate a gas ionization arc; the gas control unit is the gas supply device for the plasma gouging process. In actual production, the appropriate mixed-gas plasma gouging process is selected based on the material of the sheet to be processed, along with different gas media and flow rates corresponding to the high-pressure plasma gas, to achieve efficient processing of different materials and improve processing efficiency and quality. The gas media includes air and mixed gases. Specifically, for carbon steel, an air plasma gouging process is selected, with the gas control unit providing air as the gas medium at a flow rate of 150 L / min. For stainless steel, titanium alloys, and magnesium alloys, an air-H35 mixed-gas plasma gouging process is selected, with the gas control unit providing a mixture of air and H35 as the gas medium, and the flow rates of air and H35 being 16 L / min and 53 L / min, respectively.

[0047] In step 200, a gas ionization arc at a temperature exceeding 20,000°C is generated using a plasma air gouging unit to melt the metal material on the surface of the workpiece being gouged. The plasma air gouging unit employs a 500A plasma air gouging power supply and a 500A plasma air gouging torch, using an external high-frequency, high-voltage generator to produce a high-power, high-temperature plasma air gouging arc with compressed gas for metal material gouging.

[0048] Specifically, before generating the gas ionization arc, in order to meet the requirements for plasma gouging weld formation, the motion control unit is used to adjust the travel trajectory of the gouging motion and determine the motion trajectory of the straight plate weld and the circumferential weld for gouging root cleaning.

[0049] Before generating the gas ionization arc, steps 201 and 202 are included for adjusting the slit parameters.

[0050] Step 201 involves adjusting the planing angle of the plasma gouging torch. Specifically, this is achieved by adjusting the planing angle parameter of the plasma gouging torch using the plasma gouging torch control unit. The optimal kerf formation is achieved by adjusting the angle between the plasma gouging torch and the workpiece in conjunction with the planing current. Specifically, adjusting the relative angle between the plasma gouging torch and the workpiece by controlling the planing current includes:

[0051] When the planing current is less than 130A, the angle between the plasma planing torch and the workpiece being planed is 45°.

[0052] When the planing current is 130-160A, the angle between the plasma planing torch and the workpiece being planed is 40°.

[0053] When the planing current is 160-190A, the angle between the plasma planing torch and the workpiece being planed is 35°.

[0054] When the planing current is above 190A, the angle between the plasma planing torch and the workpiece being planed is 30°.

[0055] The control principle is as follows: the planing current and the angle between the plasma gas planing torch and the workpiece are the main factors affecting the amount of metal planed. As the planing current increases, the angle decreases, ensuring that the planed metal can be blown by high-pressure gas to the front of the plasma gas planing torch's travel direction and to both sides of the kerf, resulting in a smooth kerf formed in one pass. Conversely, if the angle increases or remains unchanged as the planing current increases, the amount of metal planed increases, the planing depth increases, and the planed metal cannot be blown by high-pressure gas to the front of the plasma gas planing torch's travel direction and to both sides of the kerf. Instead, the planed metal flows back into the kerf through the high-pressure gas backflow, resulting in an incomplete kerf formation.

[0056] Step 202 involves adjusting the position and motion parameters of the plasma air planer torch to optimize the kerf width-to-depth ratio and improve root clearing performance. Specifically, the plasma air planer torch control unit and motion control unit work together to adjust parameters such as the oscillation speed, oscillation amplitude, travel speed, and planing height of the plasma air planer torch, thereby achieving the optimal kerf width-to-depth ratio.

[0057] Specifically, the motion parameters include the swing amplitude, swing speed and travel speed of the plasma air planer torch, and the position parameters include the planing height and the relative angle between the plasma air planer torch and the workpiece being planed, wherein the relative angle between the plasma air planer torch and the workpiece being planed is adjusted in step 201.

[0058] Specifically, the oscillation amplitude, oscillation speed, and travel speed of the plasma gouging torch primarily affect the kerf width and surface quality. Within a certain range, a larger oscillation amplitude, faster oscillation speed, and faster travel speed result in a wider kerf; conversely, a narrower kerf results in a narrower kerf. However, excessively large oscillation amplitudes can cause serrated textures on the kerf surface, affecting surface smoothness. Furthermore, the kerf surface will exhibit a U-shaped kerf with perpendicular sides, impacting the welding quality and requiring manual re-grinding and finishing.

[0059] Specifically, the planing height, planing current, and the relative angle between the plasma planing torch and the workpiece mainly affect the kerf depth. Within a certain range, a lower planing height, higher current, and a larger angle between the plasma planing torch and the workpiece result in a deeper kerf. However, if the planing height is too low, the current is too high, and the angle is too large, the planed metal may flow into the kerf through the backflow of high-pressure gas, preventing the kerf from being properly formed.

[0060] In this embodiment, the adjustment of the swing amplitude and swing speed of the plasma air gouging torch is mainly achieved by controlling the connecting rod. Specifically, the servo motor and the connecting rod are connected by a gear and rack. By adjusting the speed of the servo motor, the swing amplitude of the connecting rod can be controlled. The lower end of the connecting rod is connected and fixed to the air gouging torch clamping mechanism. The clamping mechanism clamps the plasma air gouging torch, and the relative position between the plasma air gouging torch and the connecting rod remains fixed. Therefore, the swing amplitude of the connecting rod is the swing amplitude of the plasma air gouging torch.

[0061] In a preferred embodiment, the swing amplitude of the control linkage is 5mm, the swing speed is 3000mm / min, the travel speed is 600mm / min, the planing height is 3mm, the planing current is above 210A, and the angle between the plasma gas planing torch and the workpiece being planed is 30°, thereby achieving a kerf width of 25mm, a depth of 17mm, a smooth kerf surface, and a trumpet-shaped arc on both sides of the kerf surface. Under these parameter conditions, the planing effect is optimal.

[0062] In step 300, for materials such as medium and thick plates, a multi-layer, multi-pass plasma air gouging process is used to achieve the required depth of the gouging seam.

[0063] Specifically, the operation steps of the multi-layer, multi-pass plasma gouging process are as follows:

[0064] The first layer of plasma air gouging process is used to process the surface of the material to be processed to a certain depth;

[0065] A second-layer plasma air gouging process is used to process the surface after the first-layer plasma air gouging to a deeper depth. This process is repeated until the preset kerf depth requirement is reached.

[0066] In the first layer of plasma air gouging, the air gouging current is 200A, the angle between the plasma air gouging torch and the workpiece being gouged is 30°, and the width of the kerf after processing reaches 15mm and the depth reaches 10mm.

[0067] On the plasma gouging kerf created by the first layer of plasma gouging, the second layer of plasma gouging uses a gouging current of 150A, with the angle between the plasma gouging torch and the workpiece at 30°. The resulting kerf width reaches 15mm and the depth reaches 16mm. This process is repeated in subsequent steps until the predetermined kerf depth is achieved. This method is applicable to various sheet materials and meets the root cleaning needs of medium-thick plates up to 50mm in thickness.

[0068] This embodiment can be widely applied in fields such as materials processing engineering, precision machining technology, and automated equipment such as robots.

[0069] In the field of materials processing engineering, the plasma air gouging process control method proposed in this technical solution can effectively solve the problems of serious environmental pollution, low efficiency, and serious noise pollution of workers' operating environment in the existing carbon arc air gouging process.

[0070] Meanwhile, the application of the plasma gouging gas medium control unit and the swing motion control unit can meet the processing requirements of defects of different materials and shapes, thereby improving the processing accuracy and quality.

[0071] Furthermore, since the plasma air gouging process used in this technical solution does not require grinding, it can directly weld the gouging seam, which greatly improves processing efficiency and reduces processing costs, and has broad market demand and application prospects.

[0072] In the field of precision machining technology, the plasma air gouging process control method proposed in this technical solution can achieve high-precision machining requirements, and is particularly suitable for automated equipment such as robots, with broad market demand and application prospects. In summary, this technical solution has broad application prospects, large market demand, and good commercial value and social benefits.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of controlling a plasma gas-scrubbing process, characterized by, The method comprises the following steps: Releasing high-pressure plasma gas for generating gas ionization arc; wherein, according to the type of the material to be processed, different gas media and gas flow of the high-pressure plasma gas are selected; Generating gas ionization arc to melt the metal material of the workpiece to be planed; Using multi-layer multi-pass plasma gas planing process to reach the predetermined planing depth; In the step of selecting different gas media and gas flow of the high-pressure plasma gas according to the type of the material to be processed, for carbon steel material, air plasma gas planing process is selected; for stainless steel, titanium alloy and magnesium alloy material, air-H35, air-F35 and air-nitrogen mixed gas plasma gas planing process is selected; Before generating the gas ionization arc, the planing angle of the plasma gas planing torch is adjusted, specifically, the relative angle between the plasma gas planing torch and the workpiece to be planed is adjusted by controlling the planing current; The step of adjusting the relative angle between the plasma gas planing torch and the workpiece to be planed by controlling the planing current specifically comprises: When the planing current is less than 130A, the angle between the plasma gas planing torch and the workpiece to be planed is 45°; When the planing current is 130-160A, the angle between the plasma gas planing torch and the workpiece to be planed is 40°; When the planing current is 160-190A, the angle between the plasma gas planing torch and the workpiece to be planed is 35°; When the planing current is above 190A, the angle between the plasma gas planing torch and the workpiece to be planed is 30°; Before generating the gas ionization arc, the position parameters and motion parameters of the plasma gas planing torch are adjusted to adjust the ratio of the planing width and the planing depth; The motion parameters comprise the swing amplitude, swing speed and walking speed of the plasma gas planing torch, and the position parameters comprise the planing height and the relative angle between the plasma gas planing torch and the workpiece to be planed.

2. A method of controlling a plasma gasdabing process as recited in claim 1, wherein, The step of generating the gas ionization arc to melt the metal material of the workpiece to be planed specifically comprises generating the gas ionization arc with a temperature above 20000℃ by using the plasma gas planing generating unit to melt the metal material on the surface of the workpiece to be planed.

3. The method of claim 1, wherein the process gas is selected from the group consisting of argon, helium, hydrogen, nitrogen, oxygen, and mixtures thereof. Before generating the gas ionization arc, the walking track of the gas planing motion is adjusted to determine the motion track of the straight seam and the circular seam of the gas planing root.

4. The method of claim 1, wherein the process is a plasma gouging process. The step of using the multi-layer multi-pass plasma gas planing process to reach the predetermined planing depth comprises: Using the first layer plasma gas planing process to process the surface of the material to be processed to a certain depth; Using the second layer plasma gas planing process to process the surface after the first layer plasma gas planing to a deeper depth, and sequentially repeating the process until the predetermined depth requirement is reached.

5. A method of controlling a plasma gasdabing process as defined in claim 4, wherein The planing current of the first layer plasma gas planing process is 200A, the angle between the plasma gas planing torch and the workpiece to be planed is 30°, and the planing depth after processing is 10mm; The planing current of the second layer plasma gas planing process is 150A, the angle between the plasma gas planing torch and the workpiece to be planed is 30°, and the planing depth after processing is 16mm.

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