Arc fuse additive manufacturing slender rod structure forming method and system

Abstract

The invention provides an electric arc fuse additive manufacturing slender rod structure forming method and system, and the method comprises the steps: 1, determining a raw material wire for forming and used corresponding process parameters, and carrying out base forming through unified welding by using a preset wire feeding speed; 2, the position of a welding gun is adjusted through a six-axis robot, and the distance between the center position of the tail end of the welding gun and the workpiece is 10-12 mm; 3, the attitude angle coordinate of a welding gun is adjusted to be parallel to the slender rod forming direction; 4, the surface temperature of the rod body is monitored in real time through an infrared camera, and when the average surface temperature of the slender rod is lower than 70 DEG C, the step 5 is executed; and 5, the slender rod structure is formed in the forming direction, and the step 2 to the step 5 are executed repeatedly till the slender rod is formed. According to the method, large-angle inclined slender rod structure forming can be achieved originally, the appearance is smooth and complete, and the forming quality is good.

Description

Technical Field

[0001] The present invention relates to the technical field of metal additive manufacturing, and in particular to a method and system for forming a thin rod structure by using arc fuse additive manufacturing. Background Art

[0002] Additive manufacturing is a new forming technology that uses digital model files as the basis, and uses materials such as metals or polymers to construct objects by printing layer by layer. Wire and Arc Additive Manufacturing (WAAM) is a typical representative of metal additive technology and is an additive manufacturing technology derived from welding. WAAM technology controls the movement of the welding gun through CNC machine tools or robotic arms, uses tungsten inert gas welding, metal inert gas shielded welding, plasma arc welding and other welding technologies as heat sources, forms a molten pool on the substrate according to the set trajectory planning path, transports the metal wire to the molten pool for melting, and finally stacks it into shape.

[0003] Compared with other existing metal additive manufacturing technologies, WAAM technology has advantages such as high deposition efficiency, unlimited forming size, and low cost, but it also has limitations such as low forming accuracy, large molten pool, and large heat-affected zone. Domestic and foreign scholars have done a lot of research on the forming path planning of WAAM technology. The main path planning algorithm is for the forming path in the plane. There is no mature research on the vertical forming of thin rods with WAAM technology. For structures with large camber angles, the common solution is to use a rotatable turntable to change the stacking direction to a vertical direction. The process is complex and the equipment requirements are high. Summary of the invention

[0004] In view of the defects in the prior art, an object of the present invention is to provide a method and system for forming a thin rod structure by additive manufacturing of arc fuses.

[0005] The method for forming a thin rod structure by additive manufacturing of an arc fuse provided by the present invention comprises:

[0006] Step 1: Determine the raw material wire for forming and the corresponding process parameters to be used, use the preset wire feeding speed, and perform base forming through unified welding;

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

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

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

[0010] Step 5: Form a thin rod structure in the extending 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 range is 800mm-1000mm, and the warp range is 0-2mm; the base forming wire feeding speed is 8m / min, the rod forming wire feeding speed is 6m / min, and the welding current and voltage are adjusted with the wire feeding speed.

[0012] Preferably, in step 2, a 2319 high-strength aluminum alloy substrate is used, which is sandblasted after being polished to light, and then the substrate is fixed on a work platform, a six-axis robot is used as a motion unit, the welding gun is perpendicular to the substrate, and the gun-plate distance is 10 to 12 mm; the welding gun position is kept fixed, the welder supplies gas 4 seconds in advance, the welder starts arcing, the wire feeding speed is 8 m / min, the arcing duration is 5 seconds, and the gas supply is maintained for 8 seconds 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, the initial direction T0 of the welding gun 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 the yoz plane in the tool coordinate system are xz With T yz Decompose and calculate the angles A and B that need to be rotated. The calculation formula is as follows:

[0014]

[0015] The center position point of the end of the welding gun is fixed, and a six-axis robot is used to adjust the welding gun posture to the target angular coordinates (A, B, C) so that the welding gun posture angular coordinates are parallel to the thin rod forming direction vector.

[0016] Preferably, in step 5, the welding machine supplies gas in advance for 4 seconds, starts arc printing using a wire feeding speed of 6 m / min, extinguishes the arc after printing continues for 5 seconds, and delays gas supply for 8 seconds after arc extinguishing.

[0017] The arc fuse additive manufacturing thin rod structure forming system provided by the present invention comprises:

[0018] Module M1: Determine the raw material wire for forming and the corresponding process parameters to be used, use the preset wire feeding speed, and perform base forming through unified welding;

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

[0020] Module M3: adjust the posture angle coordinates of the welding gun to be parallel to the thin rod forming direction;

[0021] Module M4: Use an infrared camera to monitor the rod surface temperature in real time. When the average surface temperature of the thin rod is lower than 70°C, module M5 is triggered.

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

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

[0024] Preferably, in module M2, a 2319 high-strength aluminum alloy substrate is used, which is sandblasted after being polished to light, and then the substrate is fixed on the work platform, and a six-axis robot is used as a motion unit. The welding gun is perpendicular to the substrate, and the gun-plate distance is 10 to 12 mm; the welding gun position is kept fixed, the welder supplies gas 4 seconds in advance, the welder starts the arc, the wire feeding speed is 8 m / min, the arc duration is 5 seconds, and the gas supply is maintained for 8 seconds 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, the initial direction T0 of the welding gun 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 the yoz plane in the tool coordinate system are xz With T yz Decompose and calculate the angles A and B that need to be rotated. The calculation formula is as follows:

[0026]

[0027] The center position point of the end of the welding gun is fixed, and a six-axis robot is used to adjust the welding gun posture to the target angular coordinates (A, B, C) so that the welding gun posture angular coordinates are parallel to the thin rod forming direction vector.

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

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

[0030] (1) The present invention adjusts the welding gun posture and utilizes arc thrust and shielding gas thrust to stabilize the molten pool, effectively preventing the molten pool from flowing due to gravity, thereby ensuring the forming quality of the large-angle inclined structure;

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

[0032] (3) The present invention proposes a segmented thin rod forming method, which first forms a base vertically to provide support for the subsequent inclined rod forming, and then forms the thin rod in segments to control the interlayer temperature, effectively reduce residual stress and heat accumulation, avoid defects such as thin rod structure collapse, pores, and oxidation, and realize the formation of arc fuse additive manufacturing thin rod structure. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 1 It is a schematic diagram of the deflection decomposition of the welding gun in the Cartesian coordinate system;

[0035] Figure 2 Schematic diagram of the position relationship between the welding gun and the thin rod. DETAILED DESCRIPTION

[0036] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0037] Embodiment 1:

[0038] The present invention provides a method for forming a vertical thin rod structure by arc fuse additive manufacturing, comprising the following steps:

[0039] Step 1: Raw materials and process parameters

[0040] This embodiment uses 2319 high-strength aluminum alloy wire with a diameter of 1.2 mm as the raw material and uses synergetic welding for forming. Synergetic welding is a welding mode that is convenient for engineering applications. The welding machine pre-stores process data packets according to the material type, wire diameter and welding mode. The current and voltage can be automatically changed by adjusting the wire feeding speed. In this embodiment, the base forming wire feeding speed V fd The wire feeding speed V is 8m / min. f It is 6m / min.

[0041] Step 2: Shaping the Base

[0042] Use 2319 high-strength aluminum alloy substrate, polish it to light, then sandblast it, and fix the substrate on the work platform. Use a six-axis robot as the motion unit, the welding gun is perpendicular to the substrate, and the gun-plate distance is 10-12mm. Keep the welding gun in a fixed position, and the welder will supply gas 4s in advance to ensure that the atmosphere at the arc starting position avoids oxidation. The welder starts the arc and prints, and the wire feeding speed is V fd The speed is 8m / min, the arcing duration is 5s, and the gas supply is maintained for 8s after the arc is extinguished to prevent oxidation of the rod surface.

[0043] Step 3: Welding gun positioning and deflection

[0044] Use a six-axis robot to adjust the welding gun position so that the distance between the welding gun end center position (TCP) and the workpiece is 10mm to 12mm. The vertical forming rod does not involve welding gun deflection, and the welding gun posture remains vertical.

[0045] Step 4: Interlayer Temperature Monitoring

[0046] Use a thermal imager to monitor the surface temperature of the thin rod. When the average surface temperature of the thin rod is lower than 70°C, proceed to step 5.

[0047] Step 5: Shaping the rod

[0048] The welding machine supplies gas 4s in advance to ensure that the atmosphere at the arc starting position avoids oxidation, arc starting print, wire feeding speed V f The speed is 6m / min, the arc is extinguished after printing for 3s, and the gas is supplied 8s after the arc is extinguished to avoid oxidation of the rod surface.

[0049] Step 6: Repeat steps 3 to 5 until you reach your target rod length.

[0050] Step 7: Polish to a shine

[0051] After the workpiece has cooled sufficiently, remove it from the workbench and use an angle grinder to polish the surface of the rod to complete the thin rod forming.

[0052] Embodiment 2:

[0053] The present invention provides a method for forming an inclined thin rod structure by arc fuse additive manufacturing, comprising the following steps:

[0054] (1) Raw materials and process parameters

[0055] This embodiment uses 2319 high-strength aluminum alloy wire with a diameter of 1.2 mm as the raw material and uses synergetic welding for forming. Synergetic welding is a welding mode that is convenient for engineering applications. The welding machine pre-stores process data packets according to the material type, wire diameter and welding mode. The current and voltage can be automatically changed by adjusting the wire feeding speed. In this embodiment, the base forming wire feeding speed V fdThe wire feeding speed V is 6m / min. f 4m / min.

[0056] (2) Base forming

[0057] Use 2319 high-strength aluminum alloy substrate, polish it to light, then sandblast it, and fix the substrate on the work platform. Use a six-axis robot as the motion unit, the welding gun is perpendicular to the substrate, and the gun-plate distance is 10-12mm. Keep the welding gun in a fixed position, and the welder will supply gas 4s in advance to ensure that the atmosphere at the arc starting position avoids oxidation. The welder starts the arc and prints, and the wire feeding speed is V fd The speed is 6m / min, the arcing duration is 5s, and the gas supply is maintained for 8s after the arc is extinguished to prevent oxidation of the rod surface.

[0058] (3) Welding gun positioning and deflection

[0059] Use a six-axis robot to adjust the welding gun position so that the distance between the welding gun end center position (TCP) 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 gun posture, that is, C = 0. The initial direction T0 of the welding gun is the vertical direction, so T0 = (0,0,1). Figure 1 , the normalized components T of the thin rod forming direction vector in the xoz plane and the yoz plane in the tool coordinate system xz With T yz Decompose and calculate the angles A and B that need to be rotated. The calculation formula is as follows:

[0060]

[0061] Fix the TCP point and use a six-axis robot to adjust the welding gun posture to the target angular coordinates (A, B, C) so that the welding gun posture angular coordinates are parallel to the thin rod forming direction vector, such as Figure 2 .

[0062] (4) Interlayer temperature monitoring

[0063] Use a thermal imager to monitor the surface temperature of the thin rod, and proceed to step (5) when the average surface temperature of the thin rod is lower than 70°C.

[0064] (5) Rod forming

[0065] The welding machine supplies gas 3s in advance to ensure that the atmosphere at the arc starting position avoids oxidation, arc starting print, wire feeding speed V f The speed is 4m / min, the arc is extinguished after printing for 3s, and the gas is supplied 6s after the arc is extinguished to avoid oxidation of the rod surface.

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

[0067] (7) Polishing to a shine

[0068] After the workpiece has cooled sufficiently, remove it from the workbench and use an angle grinder to polish the surface of the rod to complete the thin rod forming.

[0069] Those skilled in the art know that, in addition to implementing the system, device and its various modules provided by the present invention in a purely computer-readable program code, it is entirely possible to implement the same program 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, device and its various modules provided by the present invention can be considered as a hardware component, and the modules included therein for implementing various programs can also be considered as structures within the hardware component; the modules for implementing various functions can also be considered as both software programs for implementing the method and structures within the hardware component.

[0070] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for forming a thin rod structure by additive manufacturing of an arc fuse, characterized in that: include: Step 1: Determine the raw material wire for forming and the corresponding process parameters to be used, use the preset wire feeding speed, and perform base forming through unified welding; Step 2: Use the six-axis robot to adjust the welding gun position so that the distance between the center position of the welding gun end and the workpiece is 10mm to 12mm; Step 3: Adjust the welding gun's posture angle coordinates to be parallel to the thin rod forming direction; Step 4: Use an infrared camera to monitor the rod surface temperature in real time. When the average surface temperature of the thin rod is lower than 70°C, proceed to step 5. Step 5: Form a thin rod structure in the extending direction, and repeat steps 2 to 5 until the thin rod is formed.

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

3. The arc fuse additive manufacturing thin rod structure forming method according to claim 1, characterized in that: In step 2, a 2319 high-strength aluminum alloy substrate is used, which is sandblasted after being polished to light. 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-plate distance is 10 to 12 mm. The welding gun is kept in a fixed position, the welder supplies gas 4 seconds in advance, the welder starts the arc, the wire feeding speed is 8 m / min, the arc duration is 5 seconds, and the gas supply is maintained for 8 seconds after the arc is extinguished.

4. The arc fuse additive manufacturing thin rod structure forming method according to claim 1, characterized in that: In step 4, the vertical direction is set as the z-axis, so the rotation angle C = 0, and the initial direction T0 of the welding gun 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 the yoz plane in the tool coordinate system are xz With T yz Decompose and calculate the angles A and B that need to be rotated. The calculation formula is as follows: The center position point of the end of the welding gun is fixed, and a six-axis robot is used to adjust the welding gun posture to the target angular coordinates (A, B, C) so that the welding gun posture angular coordinates are parallel to the thin rod forming direction vector.

5. The arc fuse additive manufacturing thin rod structure forming method according to claim 1, characterized in that: In step 5, the welding machine supplies gas 4s in advance, starts the arc and prints at a wire feeding speed of 6m / min, and the arc is extinguished after printing for 5s. Gas is then supplied 8s later after the arc is extinguished.

6. An arc fuse additive manufacturing thin rod structure forming system, characterized in that: include: Module M1: Determine the raw material wire for forming and the corresponding process parameters to be used, use the preset wire feeding speed, and perform base forming through unified welding; Module M2: Use a six-axis robot to adjust the welding gun position so that the distance between the center of the welding gun end and the workpiece is 10mm to 12mm; Module M3: Adjust the posture angle coordinates of the welding gun to be parallel to the thin rod forming direction; Module M4: Use an infrared camera to monitor the rod surface temperature in real time. When the average surface temperature of the thin rod is lower than 70°C, module M5 is triggered. Module M5: forming a thin rod structure in the extending direction, repeatedly triggering modules M2 to M5 until the thin rod is formed.

7. The arc fuse additive manufacturing thin rod structure forming system according to claim 6, characterized in that: In module M1, the raw material wire diameter is 1.2mm, the coil diameter range is 800mm-1000mm, and the warp distance range is 0-2mm; the base forming wire feeding speed is 8m / min, and the rod forming wire feeding speed is 6m / min. The welding current and voltage are adjusted with the wire feeding speed.

8. The arc fuse additive manufacturing thin rod structure forming system according to claim 6, characterized in that: In module M2, a 2319 high-strength aluminum alloy substrate is used. After being polished to light, 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-plate distance is 10 to 12 mm. The welding gun is kept in a fixed position, the welder supplies gas 4 seconds in advance, the welder starts the arc, the wire feeding speed is 8 m / min, the arc duration is 5 seconds, and the gas supply is maintained for 8 seconds after the arc is extinguished.

9. The arc fuse additive manufacturing thin rod structure forming system according to claim 6, characterized in that: In module M4, the vertical direction is set as the z axis, so the rotation angle C = 0, and the initial direction T0 of the welding gun 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 the yoz plane in the tool coordinate system are xz With T yz Decompose and calculate the angles A and B that need to be rotated. The calculation formula is as follows: The center position point of the end of the welding gun is fixed, and a six-axis robot is used to adjust the welding gun posture to the target angular coordinates (A, B, C) so that the welding gun posture angular coordinates are parallel to the thin rod forming direction vector.

10. The arc fuse additive manufacturing thin rod structure forming system according to claim 6, characterized in that: In module M5, the welding machine supplies gas 4s in advance, starts the arc and prints at a wire feeding speed of 6m / min, and the arc is extinguished after printing for 5s. Gas is then supplied 8s later after the arc is extinguished.

Images