Electric arc fuse additive manufacturing fine rod structure forming method and system

Abstract

The application provides an arc fuse additive manufacturing thin rod structure forming method and system, which comprises the following steps: step 1, determining raw material wire for forming and corresponding process parameters used, using a preset wire feeding speed, and performing base forming through unit welding; step 2, adjusting the position of a welding gun by using a six-axis robot, so that the center position of the end of the welding gun is 10mm to 12mm away from the workpiece; step 3, adjusting the attitude angle coordinates of the welding gun, and making the attitude angle coordinates parallel to the thin rod forming direction; step 4, using an infrared camera to monitor the surface temperature of the rod in real time, and performing step 5 when the average temperature of the thin rod surface is lower than 70 DEG C; and step 5, forming the thin rod structure in the forming direction, and repeatedly performing steps 2 to 5 until the thin rod is formed. The application can realize the forming of large-angle inclined thin rod structures in a primary way, the appearance is smooth and complete, and the forming quality is good.

Description

Technical Field

[0001] This invention relates to the field of metal additive manufacturing technology, specifically to a method and system for forming thin rod structures using electric arc wire additive manufacturing. Background Technology

[0002] Additive manufacturing is a novel forming technology that uses digital model files as a basis and materials such as metals or polymers to construct objects layer by layer through printing. Wire and Arc Additive Manufacturing (WAAM) is a typical example of metal additive manufacturing technology, derived from welding. WAAM technology uses CNC machine tools or robotic arms to control the movement of a welding torch, using welding techniques such as tungsten inert gas welding, metal inert gas welding, and plasma arc welding as the heat source. Following a pre-defined trajectory, a molten pool is formed on the substrate, and metal wire is fed into the molten pool to melt, ultimately stacking to form the final shape.

[0003] Compared to other existing metal additive manufacturing technologies, WAAM technology has advantages such as high deposition efficiency, unlimited forming size, and low cost. However, it also has limitations such as low forming accuracy, large melt pool, and large heat-affected zone. Domestic and international scholars have conducted extensive research on forming path planning for WAAM technology. The main path planning algorithms are for forming paths in a plane. There is still no mature research on vertical forming of thin rods using WAAM technology. For structures with large outward tilt angles, a common approach is to use a rotatable turntable to change the stacking direction to a vertical direction, which is complex and requires high-end equipment. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for forming thin rod structures using arc-fused wire additive manufacturing.

[0005] The method for forming a thin rod structure by arc-fused wire additive manufacturing according to the present invention includes:

[0006] Step 1: Determine the raw material wire for forming and the corresponding process parameters, use the preset wire feeding speed, and form the base through one-piece welding;

[0007] Step 2: Use a six-axis robot to adjust the position of the welding torch so that the distance between the center of the welding torch tip and the workpiece is 10mm to 12mm;

[0008] Step 3: Adjust the welding torch's attitude angle coordinates to be parallel to the forming direction of the thin rod;

[0009] Step 4: Use an infrared camera to monitor the surface temperature of the rod in real time. When the average surface temperature of the thin rod is below 70°C, proceed to step 5.

[0010] Step 5: Form the thin rod structure along the forming direction, and repeat steps 2 to 5 until the thin rod is formed.

[0011] Preferably, in step 1, the diameter of the raw material wire is 1.2mm, the coil diameter ranges from 800mm to 1000mm, and the warp distance ranges from 0 to 2mm; the wire feeding speed for base forming is 8m / min, the wire feeding speed for rod forming is 6m / min, and the welding current and voltage are adjusted according to the wire feeding speed.

[0012] Preferably, in step 2, a 2319 high-strength aluminum alloy substrate is used. After polishing and polishing, it is sandblasted. Then, the substrate is fixed on the work platform, and a six-axis robot is used as the motion unit. The welding gun is perpendicular to the substrate, and the distance between the gun and the substrate is 10-12mm. The welding gun position is kept fixed, the welding machine supplies gas 4s in advance, the welding machine starts the arc and prints, the wire feeding speed is 8m / min, the arc duration is 5s, and the gas supply is maintained for 8s after the arc is extinguished.

[0013] Preferably, in step 4, the vertical direction is set as the z-axis, so the rotation angle C = 0, and the initial orientation of the welding torch T0 is the vertical direction, so T0 = (0,0,1); the normalized components T of the forming direction vector of the thin rod in the xoz plane and yoz plane in the tool coordinate system are... xz With T yz Decompose the parts and calculate the required rotation angles A and B. The calculation formulas are as follows:

[0014]

[0015] Fix the center position of the welding torch tip, and use a six-axis robot to adjust the welding torch posture to the target angular coordinates (A,B,C), so that the welding torch posture angular coordinates are parallel to the forming direction vector of the thin rod.

[0016] Preferably, in step 5, after the welding machine supplies gas 4 seconds in advance, it starts arc printing at a wire feeding speed of 6 m / min, prints for 5 seconds, and then extinguishes the arc, followed by a gas supply delay of 8 seconds after the arc is extinguished.

[0017] The arc-wire additive manufacturing system for forming thin rod structures according to the present invention includes:

[0018] Module M1: Determines the raw material wire for forming and the corresponding process parameters, uses a preset wire feeding speed, and forms the base through unified welding;

[0019] Module M2: Use a six-axis robot to adjust the position of the welding torch so that the distance between the center of the welding torch tip and the workpiece is 10mm to 12mm;

[0020] Module M3: Adjust the welding torch's attitude angle coordinates to be parallel to the forming direction of the thin rod;

[0021] Module M4: Uses an infrared camera to monitor the surface temperature of the rod in real time. Module M5 is triggered when the average surface temperature of the rod is below 70°C.

[0022] Module M5: Forms a thin rod structure along the forming direction, repeatedly triggering modules M2 to M5 until the thin rod is formed.

[0023] Preferably, in module M1, the diameter of the raw material wire is 1.2mm, the coil diameter ranges from 800mm to 1000mm, and the warp distance ranges from 0 to 2mm; the wire feeding speed for base forming is 8m / min, the wire feeding speed for rod forming is 6m / min, and the welding current and voltage are adjusted according to the wire feeding speed.

[0024] Preferably, in module M2, a 2319 high-strength aluminum alloy substrate is used. After polishing and polishing, it is sandblasted. Then, the substrate is fixed on the work platform, and a six-axis robot is used as the motion unit. The welding gun is perpendicular to the substrate, and the distance between the gun and the substrate is 10-12mm. The position of the welding gun is kept fixed, the welding machine supplies gas 4s in advance, the welding machine starts the arc and prints, the wire feeding speed is 8m / min, the arc duration is 5s, and the gas supply is maintained for 8s after the arc is extinguished.

[0025] Preferably, in module M4, the vertical direction is set as the z-axis, so the rotation angle C = 0, and the initial orientation of the welding torch T0 is the vertical direction, so T0 = (0,0,1); the normalized components T of the thin rod forming direction vector in the xoz plane and yoz plane in the tool coordinate system are... xz With T yz Decompose the parts and calculate the required rotation angles A and B. The calculation formulas are as follows:

[0026]

[0027] Fix the center position of the welding torch tip, and use a six-axis robot to adjust the welding torch posture to the target angular coordinates (A,B,C), so that the welding torch posture angular coordinates are parallel to the forming direction vector of the thin rod.

[0028] Preferably, in module M5, the welding machine supplies gas 4 seconds in advance, starts arc printing at a wire feeding speed of 6 m / min, prints for 5 seconds and then extinguishes the arc, followed by a gas supply delay of 8 seconds after the arc is extinguished.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) By adjusting the welding torch posture, the present invention stabilizes the molten pool by using the thrust of the electric arc and the thrust of the shielding gas, effectively preventing the molten pool from flowing due to gravity in the tilted part, thus ensuring the forming quality of the large-angle inclined structure.

[0031] (2) The present invention can achieve high-quality forming of large-angle tilted structures by using a six-axis robot. Compared with the method of forming tilted structures by using a rotating platform, the present invention has higher degree of freedom, lower cost, and lower trajectory planning difficulty.

[0032] (3) The present invention proposes a segmented thin rod forming method. First, a vertical forming base is formed to provide support for the subsequent inclined rod forming. Then, the thin rod is formed in segments to control the interlayer temperature, effectively reduce residual stress and heat accumulation, and avoid defects such as collapse, porosity and oxidation of the thin rod structure, so as to realize the forming of thin rod structure by arc wire additive manufacturing. Attached Figure Description

[0033] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0034] Figure 1 A schematic diagram of the deflection of a welding torch in a Cartesian coordinate system;

[0035] Figure 2 This is a schematic diagram showing the positional relationship between the welding torch and the thin rod. Detailed Implementation

[0036] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0037] Example 1:

[0038] This invention provides a method for forming a vertical thin rod structure using arc-fused wire additive manufacturing, comprising the following steps:

[0039] Step 1: Raw materials and process parameters

[0040] This embodiment uses 1.2mm diameter 2319 high-strength aluminum alloy wire as raw material and employs integrated welding for forming. Integrated welding is a welding mode convenient for engineering applications. The welding machine pre-stores process data packages based on material type, wire diameter, and welding mode, and the current and voltage can be automatically changed simply by adjusting the wire feed speed. In this embodiment, the base forming wire feed speed V... fd The wire feeding speed for rod forming is 8 m / min. f The speed is 6 m / min.

[0041] Step 2: Base forming

[0042] Using a 2319 high-strength aluminum alloy substrate, after polishing to a shine, it undergoes sandblasting. The substrate is then fixed on the work platform. A six-axis robot is used as the motion unit, with the welding torch perpendicular to the substrate and a torch-to-substrate distance of 10-12mm. The welding torch position is kept fixed, and the welding machine is pre-filled with gas for 4 seconds to ensure a suitable atmosphere at the arc ignition point to prevent oxidation. The welding machine then initiates the arc, with a wire feed speed of V. fd The speed is 8m / min, the arc initiation duration is 5s, and the air supply is maintained for 8s after the arc is extinguished to prevent the surface of the rod from being oxidized.

[0043] Step 3: Welding torch positioning and deflection

[0044] A six-axis robot is used to adjust the position of the welding torch, ensuring that the distance between the center position (TCP) of the torch tip and the workpiece is 10mm to 12mm. The vertical forming rod does not involve torch deflection, and the torch posture remains vertical.

[0045] Step 4: Interlayer temperature monitoring

[0046] The surface temperature of the thin rod is monitored using a thermal imager. Once the average surface temperature of the thin rod is below 70°C, proceed to step 5.

[0047] Step 5: Rod forming

[0048] The welding machine supplies gas 4 seconds in advance to ensure an optimal atmosphere at the arc ignition point to prevent oxidation. Arc ignition printing is then performed, with wire feed speed V. f The speed is 6m / min. The arc is extinguished after printing for 3 seconds, and the air supply is delayed for 8 seconds after the arc is extinguished to avoid oxidation of the rod surface.

[0049] Step 6: Repeat steps 3 to 5 until the target rod length is reached.

[0050] Step 7: Polish until glossy

[0051] After the workpiece has cooled sufficiently, remove it from the worktable and use an angle grinder to polish the surface of the rod to a smooth finish, thus completing the forming of the thin rod.

[0052] Example 2:

[0053] This invention provides a method for forming an inclined thin rod structure using arc-fused wire additive manufacturing, comprising the following steps:

[0054] (1) Raw materials and process parameters

[0055] This embodiment uses 1.2mm diameter 2319 high-strength aluminum alloy wire as raw material and employs integrated welding for forming. Integrated welding is a welding mode convenient for engineering applications. The welding machine pre-stores process data packages based on material type, wire diameter, and welding mode, and the current and voltage can be automatically changed simply by adjusting the wire feed speed. In this embodiment, the base forming wire feed speed V... fdThe wire feeding speed for rod forming is 6 m / min. f It is 4 m / min.

[0056] (2) Base forming

[0057] Using a 2319 high-strength aluminum alloy substrate, after polishing to a shine, it undergoes sandblasting. The substrate is then fixed on the work platform. A six-axis robot is used as the motion unit, with the welding torch perpendicular to the substrate and a torch-to-substrate distance of 10-12mm. The welding torch position is kept fixed, and the welding machine is pre-filled with gas for 4 seconds to ensure a suitable atmosphere at the arc ignition point to prevent oxidation. The welding machine then initiates the arc, with a wire feed speed of V. fd The speed is 6m / min, the arc initiation duration is 5s, and the air supply is maintained for 8s after the arc is extinguished to prevent the surface of the rod from being oxidized.

[0058] (3) Welding torch positioning and deflection

[0059] A six-axis robot is used to adjust the welding torch position so that the distance between the center position (TCP) of the torch tip and the workpiece is 10mm to 12mm. For ease of calculation, this embodiment sets the vertical direction as the z-axis, so the rotation angle C does not affect the welding torch posture, i.e., C = 0. The initial orientation of the welding torch T0 is vertical, therefore T0 = (0, 0, 1). Figure 1 The normalized components T of the forming direction vector of the thin rod in the xoz and yoz planes in the tool coordinate system. xz With T yz Decompose the parts and calculate the required rotation angles A and B. The calculation formulas are as follows:

[0060]

[0061] With the TCP point fixed, a six-axis robot is used to adjust the welding torch posture to the target angular coordinates (A, B, C), ensuring that the welding torch posture angular coordinates are parallel to the forming direction vector of the thin rod. Figure 2 .

[0062] (4) Interlayer temperature monitoring

[0063] The surface temperature of the thin rod is monitored using a thermal imager. When the average surface temperature of the thin rod is below 70°C, proceed to step (5).

[0064] (5) Rod forming

[0065] The welding machine supplies gas 3 seconds in advance to ensure an optimal atmosphere at the arc ignition point to prevent oxidation. Arc ignition printing is then performed, with wire feed speed V. f The speed is 4m / min. The printing continues for 3 seconds and then the arc is extinguished. After the arc is extinguished, the air supply is delayed for 6 seconds to avoid oxidation of the rod surface.

[0066] (6) Repeat steps (3) to (5) until the target rod length is reached.

[0067] (7) Polish until shiny

[0068] After the workpiece has cooled sufficiently, remove it from the worktable and use an angle grinder to polish the surface of the rod to a smooth finish, thus completing the forming of the thin rod.

[0069] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0070] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for forming a thin rod structure using arc-fused wire additive manufacturing, characterized in that, include: Step 1: Determine the raw material wire for forming and the corresponding process parameters, use the preset wire feeding speed, and form the base through one-piece welding; Step 2: Use a six-axis robot to adjust the position of the welding torch so that the distance between the center of the welding torch tip and the workpiece is 10mm~12mm; Step 3: Adjust the welding torch's attitude angle coordinates to be parallel to the forming direction of the thin rod; Step 4: Use an infrared camera to monitor the surface temperature of the rod in real time. When the average surface temperature of the thin rod is below 70°C, proceed to step 5. Step 5: Form the thin rod structure along the forming direction, and repeat steps 2 to 5 until the thin rod is formed; In step 1, a 2319 high-strength aluminum alloy substrate is used. After polishing and polishing, it is sandblasted. Then, the substrate is fixed on the work platform. A six-axis robot is used as the motion unit. The welding gun is perpendicular to the substrate, and the gun-to-plate distance is 10-12mm. The welding gun position is kept fixed. The welding machine supplies gas 4s in advance. The welding machine starts the arc and prints. The wire feeding speed is 8m / min. The arc duration is 5s. After the arc is extinguished, the gas supply is maintained for 8s. In step 5, the welding machine supplies gas 4 seconds in advance, then starts the arc printing at a wire feeding speed of 6 m / min. The printing lasts for 5 seconds, then the arc is extinguished, followed by a gas supply delay of 8 seconds after the arc is extinguished.

2. The method for forming a thin rod structure by arc-fused wire additive manufacturing according to claim 1, characterized in that, In step 1, the diameter of the raw material wire is 1.2mm, the coil diameter ranges from 800mm to 1000mm, and the warp distance ranges from 0 to 2mm; the wire feeding speed for base forming is 8m / min, the wire feeding speed for rod forming is 6m / min, and the welding current and voltage are adjusted according to the wire feeding speed.

3. The method for forming a thin rod structure by arc-fused wire additive manufacturing according to claim 1, characterized in that, In step 4, the vertical direction is set as the z-axis, therefore the rotation angle C=0, and the welding torch is initially oriented... Since it is in the vertical direction, therefore Normalized components of the forming direction vector of the thin rod in the xoz and yoz planes of the tool coordinate system. and Decompose the parts and calculate the required rotation angles A and B. The calculation formulas are as follows: Fix the center position of the welding torch tip, and use a six-axis robot to adjust the welding torch posture to the target angular coordinates (A,B,C), so that the welding torch posture angular coordinates are parallel to the forming direction vector of the thin rod.

4. A system for forming thin rod structures using electric arc wire additive manufacturing, characterized in that, include: Module M1: Determines the raw material wire for forming and the corresponding process parameters, uses a preset wire feeding speed, and forms the base through unified welding; Module M2: Use a six-axis robot to adjust the position of the welding torch so that the distance between the center of the welding torch tip and the workpiece is 10mm~12mm; Module M3: Adjust the welding torch's attitude angle coordinates to be parallel to the forming direction of the thin rod; Module M4: Uses an infrared camera to monitor the surface temperature of the rod in real time. Module M5 is triggered when the average surface temperature of the rod is below 70°C. Module M5: Forms a thin rod structure along the forming direction, repeatedly triggering modules M2 to M5 until the thin rod is formed; In module M1, a 2319 high-strength aluminum alloy substrate is used. After polishing and polishing, it is sandblasted. Then, the substrate is fixed on the work platform, and a six-axis robot is used as the motion unit. The welding gun is perpendicular to the substrate, and the gun-to-plate distance is 10~12mm. The welding gun position is kept fixed, the welding machine supplies gas 4s in advance, the welding machine starts the arc and prints, the wire feed speed is 8m / min, the arc duration is 5s, and the gas supply is maintained for 8s after the arc is extinguished. In module M5, the welding machine supplies gas 4 seconds in advance, starts arc printing at a wire feeding speed of 6 m / min, prints for 5 seconds and then extinguishes the arc, followed by a gas supply delay of 8 seconds after the arc is extinguished.

5. The arc-wire additive manufacturing system for forming thin rod structures according to claim 4, characterized in that, In module M1, the diameter of the raw material wire is 1.2mm, the coil diameter ranges from 800mm to 1000mm, and the warp distance ranges from 0 to 2mm; the wire feeding speed for base forming is 8m / min, the wire feeding speed for rod forming is 6m / min, and the welding current and voltage are adjusted according to the wire feeding speed.

6. The arc-wire additive manufacturing system for forming thin rod structures according to claim 4, characterized in that, In module M4, the vertical direction is set as the z-axis, therefore the rotation angle C=0, and the welding torch initially faces the z-axis. Since it is in the vertical direction, therefore Normalized components of the forming direction vector of the thin rod in the xoz and yoz planes of the tool coordinate system. and Decompose the parts and calculate the required rotation angles A and B. The calculation formulas are as follows: Fix the center position of the welding torch tip, and use a six-axis robot to adjust the welding torch posture to the target angular coordinates (A,B,C), so that the welding torch posture angular coordinates are parallel to the forming direction vector of the thin rod.

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