Plasma gouging process control method

Abstract

The invention discloses a plasma gouging process control method, which relates to the technical field of plasma processing, and comprises the following steps: releasing high-pressure plasma gas for generating gas ionization arc; wherein different gas media and gas flows of the high-pressure plasma gas are selected according to the types of materials to be processed; generating a gas ionization arc to melt a metal material of the planed workpiece; adopting a multi-layer and multi-channel plasma gouging process to reach a preset gouging seam depth; the back gouging and seam planing forming of the carbon steel material is consistent, and the device is suitable for automatic equipment such as robots; for welding seam planing of stainless steel, titanium alloy and magnesium alloy materials, high-pressure plasma gas of different media is released through a gas control unit, carburization of planed base metal is eliminated, a mixed gas plasma gouging process is adopted, no oxide layer exists on the surface of a planed seam, direct butt seam welding can be achieved, efficient treatment of different materials is achieved, and the welding quality is improved. And the processing efficiency and quality are greatly improved.

Description

Technical Field

[0001] The invention relates to a plasma gouging process control method and belongs to the technical field of plasma processing. Background Art

[0002] Plasma processing technology is a technology that uses high-temperature plasma to process materials. It is widely used in the field of material processing engineering. Among them, plasma gouging is a method of using plasma to gouge materials. It can be used to remove defects on the surface of materials, such as welds, oxide layers, etc. At the same time, plasma gouging technology is also widely used in the field of precision processing technology.

[0003] As a traditional root cleaning process, the existing carbon arc gouging technology mainly uses a special carbon rod or graphite rod with a copper coating as an electrode to generate a plasma arc between the workpiece, melt the metal, and use compressed air to blow away the molten metal. This is a metal root cleaning method, thereby achieving the processing requirements of defects of different materials and different shapes.

[0004] The existing carbon arc gouging technology still has some obvious defects in practical application, including:

[0005] First, carbon rods are non-metallic products. As a necessary cutting consumable before welding in the carbon arc gouging cutting process, they are made of carbon, graphite and appropriate adhesives, extruded, baked at 2200℃ and then plated with a layer of copper. The production process causes pollution to the air, water and other environments.

[0006] Second, carbon arc gouging is currently done manually. Since 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, it will generate a lot of noise and heat, which not only causes serious pollution to the workers' operating environment.

[0007] Third, manual planing with a carbon rod results in poor consistency in the seam formation, requires a lot of man-hours for polishing, and is not suitable for subsequent automated equipment welding process requirements.

[0008] Fourth, the existing carbon arc gouging technology has different effects when processing different materials. For example, for carbon steel materials, the existing carbon arc gouging technology can achieve efficient weld root cleaning and gouging seam shaping, but for stainless steel, titanium alloy, and magnesium alloy materials, due to the high thermal conductivity and melting point of these materials, the existing carbon arc gouging technology has poor effect and cannot achieve efficient weld gouging.

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

[0010] At present, some research is devoted to solving the above-mentioned defects of carbon arc gouging technology. For example, Chinese patent CN110625233A discloses an automatic plasma gouging root cleaning process for submerged arc welds of medium-thickness steel plates. It can realize automatic plasma gouging root cleaning of submerged arc welds (Y-type grooves, I-type grooves) of steel plates with a thickness of 25 mm or less, and can effectively reduce gouging noise and smoke pollution, reduce labor intensity, improve the stability of the gouging process, eliminate the risk of carburization of gouging grooves, and reduce or avoid the work of gouging groove grinding and trimming. However, the defect of this solution is that the thickness of the plate to which the gouging root cleaning process of this solution is applicable is limited to within 25 mm, and the gouging depth and width of the welds of plates with a thickness of more than 25 mm increase, which cannot meet the gouging root cleaning requirements of plates with a thickness of more than 25 mm. In addition, in this solution, compressed air is used as the gas medium for air planing and root cleaning, which is only suitable for carbon steel plates. For non-ferrous metals such as stainless steel and magnesium alloys, air planing and root cleaning can easily lead to severe oxidation of the planing seams. The oxide layer changes the medium properties of the parent material, and the oxide layer is difficult to clean and polish. Summary of the invention

[0011] In view of the deficiencies in the prior art, the present invention provides a plasma gouging process control method, which can control the temperature and energy of the plasma through the parameters of the plasma, thereby achieving gouging treatment of surface defects of different materials and shapes, and can achieve efficient treatment of medium and thick plates with a thickness of less than 50 mm, and can be applicable to plates of different metal materials such as stainless steel and non-ferrous metals, without the need for cleaning and polishing.

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

[0013] A plasma gouging process control method comprises the following steps:

[0014] Releasing high-pressure plasma gas to generate a gas ionization arc; wherein different gas media and gas flow rates of the high-pressure plasma gas are selected according to the type of material to be processed;

[0015] Generate a gas ionization arc to melt the metal material of the workpiece being planed;

[0016] A multi-layer and multi-pass plasma gouging process is used to achieve the predetermined gouging depth.

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

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

[0019] As a further technical solution, before generating the gas ionization arc, the moving trajectory of the gouging movement is adjusted to determine the moving trajectory of the straight plate weld and the circular weld for gouging root cleaning.

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

[0021] As a further technical solution, the relative angle between the plasma gouging torch and the gouged workpiece is adjusted by controlling the gouging current, specifically including:

[0022] When the gouging current is less than 130A, the angle between the plasma gouging torch and the workpiece being gouged is 45°;

[0023] When the gouging current is 130-160A, the angle between the plasma gouging torch and the workpiece being gouged is 40°;

[0024] When the gouging current is 160-190A, the angle between the plasma gouging torch and the workpiece being gouged is 35°;

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

[0026] As a further technical solution, before generating the gas ionization arc, the position parameters and movement parameters of the plasma gouging torch are adjusted to adjust the ratio of the gouging seam width to depth and improve 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 gouging torch, and the position parameters include the gouging height and the relative angle between the plasma gouging torch and the workpiece being gouged.

[0028] As a further technical solution, the planing current is 210A, the angle between the plasma air planing torch and the workpiece being planed is 30°, the distance is 3mm, the planing speed is 600mm / min, the swing amplitude is 5mm, the swing speed is 3000mm / min, the planing seam 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 multi-layer and multi-pass plasma gouging process is used to achieve a predetermined gouging depth, including:

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

[0031] The second layer of plasma gouging process is used to process the surface after the first layer of plasma gouging to a deeper depth, and the process is repeated in sequence until the predetermined depth requirement is reached.

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

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

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

[0035] 1. The present invention has consistent root cleaning and planing for carbon steel materials and is suitable for automated equipment such as robots; for weld planing of stainless steel, titanium alloy, and magnesium alloy materials, the gas control unit can release high-pressure plasma gases of different media to adapt to different plate materials, eliminate carburization of the planed parent material, and adopt mixed gas plasma planing processes such as air-H35, air-F35, and air-nitrogen. There is no oxide layer on the planed seam surface, no grinding is required, and the seam can be directly welded, thereby achieving efficient processing of different materials and greatly improving processing efficiency and quality.

[0036] 2. For plasma gouging processing of medium and thick plates and other materials, the present invention adopts a motion control unit and a plasma gouging torch control unit to adjust the motion parameters and position parameters of the plasma gouging torch, increase the gouging seam width, and adopts a multi-layer and multi-pass plasma gouging process to meet the gouging seam depth requirement. Compared with the prior art, the application scope of the processed plate is expanded, and efficient processing of medium and thick plates with a thickness of less than 50 mm is achieved, which meets the processing requirements of medium and thick plates and other materials, further expands the adaptability to the processing of different materials, and at the same time improves the processing efficiency and quality.

[0037] 3. The present invention controls the temperature and energy of plasma by adjusting the parameters of plasma, such as current, voltage, gas flow, etc., so as to meet the processing requirements of defects of different materials and shapes. It not only reduces the heat generation and improves the stability and service life of the equipment, but also reduces the noise pollution of the operating environment and improves the production environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A block diagram of the plasma process control method provided by the present invention. DETAILED DESCRIPTION

[0039] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the present invention explicitly states otherwise, singular forms are also intended to include plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0041] Plasma gouging is similar to plasma cutting. It uses a plasma arc between the torch and the workpiece to remove metal. The metal on the surface of the workpiece is melted, and the gas jet blows the molten metal away from the workpiece without penetrating or cutting through it. When gouging, specially designed consumables produce a wider plasma arc, and the torch needs to be held at a certain angle so that only part of the metal material is blown away.

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

[0043] Step 100 is to release high-pressure plasma gas to generate a gas ionization arc; wherein different gas media and gas flow rates of the high-pressure plasma gas are selected according to the type of material to be processed;

[0044] Step 200 is to generate a gas ionization arc to melt the metal material of the workpiece being planed;

[0045] Step 300 is to use a multi-layer and multi-pass plasma gouging process to reach a predetermined gouging depth.

[0046] Specifically, in step 100, a gas control unit is used to release high-pressure plasma gas to generate a gas ionization arc; the gas control unit is a gas supply device for the plasma gouging process. In actual production, according to the material of the plate to be processed, the corresponding mixed gas plasma gouging process is selected, corresponding to different gas media and gas flow rates of high-pressure plasma gas, so as to achieve efficient processing of different materials and improve processing efficiency and quality. The gas medium includes air and mixed gas. Specifically, for carbon steel materials, the air plasma gouging process is selected, and the gas control unit provides air as the gas medium, and the air flow rate is 150L / min. For stainless steel, titanium alloy, and magnesium alloy materials, the air-H35 mixed gas plasma gouging process is selected, and the gas control unit provides a mixed gas of air and H35 as the gas medium, and the flow rates of air and H35 are 16L / min and 53L / min, respectively.

[0047] In step 200, a plasma gouging generating unit is used to generate a gas ionization arc of more than 20,000°C to melt the metal material on the surface of the workpiece being gouged. The plasma gouging generating unit uses a 500A plasma gouging power supply and a 500A plasma gouging torch to gouge metal materials by generating a high-power, gas-compressed high-temperature plasma gouging arc through external high-frequency high voltage.

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

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

[0050] Step 201 is to adjust the planing angle of the plasma gouging torch, specifically, to use the plasma gouging torch control unit to adjust the planing angle parameters of the plasma gouging torch, and to achieve the best planing seam formation by adjusting the angle between the plasma gouging torch and the workpiece being planed in conjunction with the planing current. The relative angle between the plasma gouging torch and the workpiece being planed is adjusted by controlling the planing current, specifically including:

[0051] When the gouging current is less than 130A, the angle between the plasma gouging torch and the workpiece being gouged is 45°;

[0052] When the gouging current is 130-160A, the angle between the plasma gouging torch and the workpiece being gouged is 40°;

[0053] When the gouging current is 160-190A, the angle between the plasma gouging torch and the workpiece being gouged is 35°;

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

[0055] The control principle is that the planing current and the angle between the plasma gouging torch and the workpiece being planed are the main factors affecting the amount of metal being planed. As the planing current increases, the angle decreases, ensuring that the planed metal can be blown to the front of the plasma gouging torch in the direction of travel and on both sides of the planing seam through high-pressure gas, so that the planed seam is smooth and formed in one go. On the contrary, as the planing current increases, if the angle increases or does not change, the amount of metal being planed increases, the planing depth increases, and the planed metal cannot be blown to the front of the plasma gouging torch in the direction of travel and on both sides of the planing seam through high-pressure gas. Instead, the planed metal flows into the planing seam through the backblowing of high-pressure gas, which will cause the planing seam to be unable to be formed.

[0056] Step 202 is to adjust the position parameters and motion parameters of the plasma gouging torch to adjust the ratio of the gouging width to the depth and improve the root cleaning effect. Specifically, the plasma gouging torch control unit cooperates with the motion control unit to adjust the parameters such as the swing speed, swing amplitude, travel speed, and gouging height of the plasma gouging torch so that the ratio of the gouging width to the depth is optimal.

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

[0058] Specifically, the swing amplitude, swing speed and travel speed of the plasma gouging torch mainly affect the gouging seam width and the gouging seam surface quality. Among them, within a certain range, the larger the swing amplitude, the faster the swing speed, and the faster the travel speed, the wider the gouging seam; conversely, the narrower the gouging seam. However, if the swing amplitude is too large, it will cause a jagged texture track to appear on the gouging seam surface, affecting the surface smoothness, and the U-shaped gouging seam with both sides of the gouging seam in a vertical state, which affects the welding quality of the welding process and requires manual grinding and trimming.

[0059] Specifically, the planing height, planing current, and the relative angle between the plasma gouging torch and the workpiece being planed mainly affect the planing seam depth. Among them, within a certain range, the planing height is low, the current is large, and the angle between the plasma gouging torch and the workpiece being planed is large, then the planing seam depth is deep. However, if the planing height is too low, the current is too large, and the angle is too large, the planed metal will flow into the planed seam through the backblowing of the high-pressure gas, resulting in the planed seam being unable to be formed.

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

[0061] In a preferred embodiment, the swing amplitude of the control connecting rod 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 air planing torch and the workpiece being planed is 30°, so as to achieve a planing seam width of 25mm and a depth of 17mm. The planing seam surface is smooth and the two sides of the planing seam surface are trumpet-shaped. Under this set of parameters, the planing seam achieves the optimal effect.

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

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

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

[0065] The second layer of plasma gouging process is used to process the surface after the first layer of plasma gouging to a deeper depth, and the process is repeated in sequence until the preset gouging depth requirement is reached.

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

[0067] On the plasma gouging seam formed by the first layer of plasma gouging process, the gouging current of the second layer of plasma gouging process is 150A, the angle between the plasma gouging torch and the workpiece being gouged is 30°, and the processed gouging seam width reaches 15mm and the depth reaches 16mm. In the subsequent steps, the process is circulated in sequence until the predetermined gouging seam depth requirement is reached; it can be applied to plates of different materials and meet the root cleaning requirements of medium and thick plates with a thickness of less than 50mm.

[0068] This embodiment can be widely used in application fields such as material processing engineering, precision processing technology, and automation equipment such as robots.

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

[0070] At the same time, through the application of plasma gouging gas medium control unit and swing motion control unit, the processing requirements for defects of different materials and shapes can be achieved, and the processing accuracy and quality are improved.

[0071] In addition, since the plasma gouging process adopted in this technical solution does not require grinding, the gouging seams can be directly welded, which greatly improves the processing efficiency and reduces the processing cost, and has broad market demand and application prospects.

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

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A plasma gouging process control method, characterized in that: The steps include: Releasing high-pressure plasma gas to generate a gas ionization arc; wherein different gas media and gas flow rates of the high-pressure plasma gas are selected according to the type of material to be processed; Generate a gas ionization arc to melt the metal material of the workpiece being planed; A multi-layer and multi-pass plasma gouging process is used to achieve the predetermined gouging depth.

2. A plasma gouging process control method according to claim 1, characterized in that: According to the type of the material to be processed, different gas media and gas flow rates of the high pressure plasma gas are selected, and the gas medium includes air and mixed gas.

3. A plasma gouging process control method as claimed in claim 1, characterized in that: The method of generating a gas ionization arc to melt the metal material of the planed workpiece specifically comprises using a plasma gouging generating unit to generate a gas ionization arc above 20000° C. to melt the metal material on the surface of the planed workpiece.

4. A plasma gouging process control method as claimed in claim 1, characterized in that: Before generating the gas ionization arc, adjust the trajectory of the gouging movement and determine the movement trajectory of the straight plate weld and the circular weld for gouging root cleaning.

5. A plasma gouging process control method as claimed in claim 1, characterized in that: Before the gas ionization arc is generated, the planing angle of the plasma gouging torch is adjusted. Specifically, the relative angle between the plasma gouging torch and the workpiece being planed is adjusted by controlling the planing current.

6. A plasma gouging process control method as claimed in claim 5, characterized in that: The method of adjusting the relative angle between the plasma gouging torch and the gouged workpiece by controlling the gouging current specifically includes: When the gouging current is less than 130A, the angle between the plasma gouging torch and the workpiece being gouged is 45°; When the gouging current is 130-160A, the angle between the plasma gouging torch and the workpiece being gouged is 40°; When the gouging current is 160-190A, the angle between the plasma gouging torch and the workpiece being gouged is 35°; When the gouging current is above 190A, the angle between the plasma gouging torch and the workpiece being gouged is 30°.

7. A plasma gouging process control method as claimed in claim 1, characterized in that: Before generating the gas ionization arc, the position parameters and movement parameters of the plasma gouging torch are adjusted to adjust the ratio of the gouging seam width to the depth.

8. A plasma gouging process control method as claimed in claim 7, characterized in that: The motion parameters include the swing amplitude, swing speed and travel speed of the plasma gouging torch, and the position parameters include the gouging height and the relative angle between the plasma gouging torch and the workpiece being gouged.

9. A plasma gouging process control method as claimed in claim 1, characterized in that: The method of using a multi-layer and multi-pass plasma gouging process to achieve a predetermined gouging depth includes: The first layer of plasma gouging is used to process the surface of the material to be processed to a certain depth; The second layer plasma gouging process is used to process the surface after the first layer plasma gouging to a deeper depth, and the process is repeated in sequence until the predetermined depth requirement is reached.

10. A plasma gouging process control method according to claim 9, characterized in that: The gouging current of the first layer of plasma gouging process is 200A, the angle between the plasma gouging torch and the workpiece being gouged is 30°, and the gouging depth after processing is 10mm; The gouging current of the second layer plasma gouging process is 150A, the angle between the plasma gouging torch and the workpiece being gouged is 30°, and the gouging depth after processing is 16mm.

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