A method and apparatus for additive manufacturing by electric arc on a free surface
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TSC LASER TECH DEV BEIJING CO LTD
- Filing Date
- 2023-12-27
- Publication Date
- 2026-07-03
AI Technical Summary
Existing electric arc additive manufacturing equipment cannot achieve additive manufacturing of parts with protruding surfaces, and existing heat preservation methods cannot guarantee the temperature uniformity of large parts, resulting in poor printing quality.
By constructing a shaped enclosure around the substrate and filling it with insulating sand, combined with the use of conductive plates and heating plates, protruding surface parts are manufactured through arc printing, and the insulation effect is improved by multi-layer heating of ceramic and coating with insulating sand.
It enables efficient arc printing of parts with protruding surfaces, improves forming accuracy and temperature uniformity, reduces equipment requirements and additive manufacturing costs, avoids cracks and deformation of parts, and is suitable for high-quality printing of large parts.
Smart Images
Figure CN117773278B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of additive manufacturing technology, and in particular to a method and apparatus for surface arc additive manufacturing. Background Technology
[0002] Arc additive manufacturing is an additive manufacturing process that uses fused wire deposition welding to form parts. It employs an electric arc as a heat source and completes the manufacturing of parts through path planning and process control. Due to its advantages of high forming efficiency, low cost, variety of forming materials, and ability to add large and complex parts, it can be used to add large and complex parts.
[0003] Currently, due to limitations in the size of the arc additive manufacturing equipment and the structure of the parts, arc additive manufacturing equipment cannot achieve additive manufacturing of parts with protruding surface structures. Furthermore, the heat preservation of parts in arc additive manufacturing mainly relies on bottom substrate heating and external electromagnetic heating. Bottom substrate heating suffers from significant heat loss through air transfer, making it difficult to ensure temperature uniformity across the entire part, resulting in poor heat preservation. Large parts dissipate heat quickly, and uneven temperature distribution and drastic temperature changes during the forming process increase the tendency for crack formation, leading to poor quality of printed large parts. Electromagnetic heating, with its exposed heating element, poses a high risk and is only suitable for specific structures, making it unsuitable for heat preservation of irregularly shaped large parts. Summary of the Invention
[0004] The purpose of this invention is to provide a method and apparatus for arc additive manufacturing of protruding surfaces, which solves the problems that existing arc additive manufacturing cannot print parts with protruding surfaces, and that existing heat preservation methods have poor heat preservation effects and are not suitable for printing large parts.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] On one hand, the present invention provides a method for surface arc additive manufacturing, comprising:
[0007] Obtain basic data of the protruding surface of the part to be printed and a conductive plate; the basic data includes the size and height of the protruding surface and the target position of the protruding surface in the part to be printed; the upper surface of the conductive plate has the same size as the protruding surface.
[0008] A shaped enclosure is constructed around the substrate, and insulating sand is filled between the shaped enclosure and the substrate; the height of the shaped enclosure is greater than or equal to the height of the substrate, and the height of the insulating sand is less than or equal to the height of the substrate.
[0009] The heating plate on the substrate is controlled to heat the substrate, and the part to be printed is printed on the substrate using an electric arc.
[0010] The height of the part to be printed is determined during the printing process. When the height of the part to be printed reaches the height of the protruding surface, the conductive plate is welded to the target position of the printed part and filled with insulating sand to obtain a welded part. The upper surface of the conductive plate of the welded part coincides with the protruding surface. The height of the filled insulating sand is the same as the height of the protruding surface.
[0011] Continue printing on the welded part to complete the printing of the part to be printed.
[0012] Compared with the prior art, the present invention provides a method for arc additive manufacturing of protruding surfaces, comprising: acquiring basic data of the protruding surface of the part to be printed and a conductive plate; constructing a forming enclosure around the substrate and filling the space between the forming enclosure and the substrate with insulating sand; controlling the heating plate on the substrate to heat the part to be printed using an arc to print the part to be printed on the substrate; determining the height of the part to be printed during the printing process; when the height of the part to be printed reaches the height of the protruding surface during the printing process, welding the conductive plate to the target position of the printed part to be printed and filling with insulating sand to obtain a welded part; continuing printing on the welded part to complete the printing of the part to be printed. This solution enables arc printing of parts with protruding surfaces, achieving high forming efficiency and reducing process difficulty, equipment requirements, and additive manufacturing costs. The insulating sand provides support, effectively reducing deformation of printed parts and improving forming accuracy. The combined use of the heating plate and insulating sand enhances the insulation effect, resulting in strong temperature uniformity and slow heat dissipation in the printed parts, thus preventing cracks and enabling high-quality arc printing of large parts. The forming enclosure also provides insulation. Due to the conductive plate, arc printing can be used on protruding surfaces of parts, whether they are inside or outside the part, or inside a closed structure.
[0013] On the other hand, the present invention also provides a protruding surface arc additive manufacturing apparatus, applied to the above-mentioned protruding surface arc additive manufacturing method, wherein the protruding surface arc additive manufacturing apparatus includes at least a conductive plate, a substrate, a forming enclosure, insulating sand, a heating plate, and an arc additive manufacturing device; the upper surface dimension of the conductive plate is the same as the protruding surface dimension of the part to be printed;
[0014] A forming barrier is constructed around the substrate, and the space between the substrate and the forming barrier is filled with insulating sand. A heating plate is fixed to the upper surface of the substrate. The heating plate is used for heating. The height of the forming barrier increases with the height of the part to be printed during the printing process. The insulating sand is used to fill the space enclosed by the forming barrier during the printing process and to keep the printed part warm. A conductive plate is welded to the protruding surface of the printed part. The protruding surface is formed on the upper surface of the conductive plate. The arc additive manufacturing equipment is used to print the part to be printed on the substrate.
[0015] Compared with the prior art, the beneficial effects of the protruding surface arc additive manufacturing apparatus provided by the present invention are the same as the beneficial effects of the protruding surface arc additive manufacturing method described in the above technical solution, and will not be repeated here. Attached Figure Description
[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:
[0017] Figure 1 This is a schematic diagram of the structure of an arc additive manufacturing apparatus for protruding surfaces provided by the present invention;
[0018] Figure 2 A flowchart of a surface arc additive manufacturing method provided by the present invention;
[0019] Figure 3 Structural diagram of a 304 stainless steel part with two protruding surfaces provided for the present invention;
[0020] Figure 4 A schematic diagram of the forming direction and additive manufacturing parameters of the 304 stainless steel part provided by the present invention;
[0021] Figure 5 A schematic diagram of the upper surface of the conductive plate corresponding to the external protrusion provided by the present invention;
[0022] Figure 6 A schematic diagram of the upper surface of the conductive plate corresponding to the inner protruding surface provided by the present invention;
[0023] Figure 7 This is a schematic diagram of the additive manufacturing structure for externally protruding surfaces provided by the present invention;
[0024] Figure 8 This is a top view of the conformal welding of the conductive plate corresponding to the external protrusion provided by the present invention.
[0025] Figure label:
[0026] 1- Bolt, 2- Spacer, 3- Forming enclosure, 4- Insulating sand, 5- Insulating brick, 6- Conductive plate, 7- Printed part to be printed, 8- Pressure plate, 9- Substrate, 10- Heating plate, 101- Heating hole, 11- Welding platform, 12- Welding gun, 13- Raised surface, 14- Area to be added, 15- Underlay, 16- Insulating sand plane, 17- Inner raised surface, 18- Outer raised surface, 19- Conductive plate corresponding to outer raised surface, 20- Position of outer raised surface, 21- Added 304 stainless steel part. Detailed Implementation
[0027] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.
[0028] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.
[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.
[0030] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0032] Currently, arc additive manufacturing for small parts mainly uses a positioner to dynamically change the additive angle. Multi-axis servo additive manufacturing path planning is difficult, and special internal protrusions require separate additive manufacturing. Internal additive manufacturing cannot be fully realized due to gun size limitations. For large parts, servo additive manufacturing, due to their larger size and weight, places high demands on equipment. The overall forming process is complex, and the secondary additive manufacturing process makes local dimensional control difficult, resulting in long production cycles and high costs. Therefore, existing arc additive manufacturing cannot process parts with protrusions. Furthermore, the existing heating plates and external electromagnetic heating insulation measures cannot guarantee the overall temperature uniformity of large parts, resulting in poor insulation and a tendency for cracks to appear in the printed parts.
[0033] To address the aforementioned problems, this invention provides a method and apparatus for protruding surface electric arc additive manufacturing, which realizes protruding surface additive manufacturing in the electric arc additive process, improves forming efficiency, enhances forming accuracy, and adapts to multi-structure parts. At the same time, the use of multi-layer ceramic heating and heat-insulating sand coating improves the heat preservation effect for printing large parts. The following description is in conjunction with the accompanying drawings.
[0034] See Figure 1 The present invention provides an arc additive manufacturing apparatus for protruding surfaces, comprising: bolt 1, pad 2, forming enclosure 3, insulating sand 4, conductive plate 6, pressure plate 8, substrate 9, heating plate 10, welding platform 11, and arc additive manufacturing equipment; the upper surface dimension of the conductive plate 6 is the same as the protruding surface dimension of the part to be printed.
[0035] A substrate 9 is positioned between a pressure plate 8 and a welding platform 11. A pad 2 is embedded between the end of the pressure plate 8 furthest from the substrate and the welding platform 11. Bolts 1 are used to tighten the pressure plate 8, substrate 9, pad 2, and welding platform 11. A forming enclosure 3 is constructed around the substrate 9. The forming enclosure 3 is composed of insulating bricks 5, which can be lightweight clay insulating bricks. Insulating sand 4 is filled between the substrate 9 and the forming enclosure 3. A heating plate 10 is fixed to the upper surface of the substrate 9. The heating plate 10 is used for heating. The height of the forming enclosure 3 increases with the height of the part to be printed during the printing process. The insulating sand 4 is used to fill the space enclosed by the forming enclosure 3 during the printing process and to keep the printed part 7 warm. The height of the insulating sand 4 increases with the height of the part to be printed during the printing process. A conductive plate 6 is welded to the protruding surface of the printed part 7.
[0036] The protruding surface 13 of the part to be printed is formed on the upper surface of the conductive plate 6. After the conductive plate 6 is welded onto the printed part, the insulating sand plane 16, the upper surface of the conductive plate 6 and the protruding surface 13 are on the same horizontal plane. The conductive plate 6 and the printed part 7 form a welded part. The data of the slice layer where the protruding surface is located is called to print the bottom layer 15 on the welded part, and then the printing of the additive area 14 continues on the bottom layer 15.
[0037] The arc additive manufacturing equipment is used to print the part to be printed on the substrate. The wire is fed to the welding position of the welding gun 12 by the wire feeder of the arc additive manufacturing equipment. The welding gun 12 can swing the additive angle α in the range of 0-40°. When no protruding surface appears, the continuous additive process can be performed.
[0038] The insulating sand 4 in the above device includes quartz sand and silica sand, with a ratio of 3:7. The insulating sand 4 is mechanically mixed and dried at a temperature of 100-200℃ for 4-8 hours.
[0039] The heating element of the heating plate 10 in the above-mentioned device is an electric heating tube, such as... Figure 1 As shown, the heating hole diameter of the heating plate 10 is d, the diameter of the electric heating tube is 0.8d, the heat preservation temperature of the heating plate 10 is 200-400℃ and is adjusted by a temperature controller, and the heating plate 10 can be a ceramic heating plate.
[0040] The thickness D of the conductive plate 6 in the above device is greater than or equal to 1 mm, and the material of the conductive plate 6 is the same as that of the welding wire.
[0041] As an alternative, a positioner is installed at the bottom of the welding platform. The positioner is used to change the tilt angle of the welding platform to control the forming angle of the part. The positioner enables triaxial additive manufacturing in arc additive manufacturing equipment.
[0042] See Figure 2 This invention provides a method for surface arc additive manufacturing, applied to the aforementioned surface arc additive manufacturing apparatus. The method includes the following steps:
[0043] Step 201: Obtain the basic data of the protruding surface of the part to be printed and the conductive plate; the basic data includes the size and height of the protruding surface and the target position of the protruding surface in the part to be printed;
[0044] Before obtaining the basic data of the protruding surfaces of the part to be printed and the conductive plate, the additive manufacturing direction should be determined according to the part structure. The main principles for determining the manufacturing direction should be high manufacturing efficiency, a small number of protruding surfaces, and strong structural stability, while also meeting the manufacturing angle requirements of arc additive manufacturing.
[0045] The conductive plate is manufactured based on data such as the size, position, and contour characteristics of the protruding surface. The upper surface size of the conductive plate is the same as that of the protruding surface. The thickness of the conductive plate is greater than or equal to 1 mm, with the principle of non-melting. The material of the conductive plate is consistent with the material of the wire used in arc additive manufacturing.
[0046] Before constructing the shaped enclosure, the protruding surface electric arc additive manufacturing device is installed. After the substrate is polished by a grinding wheel, a pressure plate is used to fix the substrate on the welding platform. The substrate is located between the pressure plate and the welding platform, and the connection method is to tighten the bolts by using bolts, pressure plates and spacers.
[0047] Step 202: Construct a ring of shaped enclosure around the substrate and fill the space between the shaped enclosure and the substrate with insulating sand;
[0048] The forming enclosure is constructed of insulating bricks and can be increased in height as the additive height of the part to be printed increases during the printing process; the height of the forming enclosure installed before arc printing is greater than or equal to the height of the substrate, and the height of the insulating sand is less than or equal to the height of the substrate; for example, such as Figure 1 As shown, the height of the substrate is M. Before printing, the forming barrier is raised to 1 to 1.2 times the height of the substrate M, and the height of the insulating sand added is 0.8 to 1 times the height of the substrate M. The length of the forming barrier is greater than the length of the substrate, and the width of the forming barrier is greater than the width of the substrate.
[0049] Step 203: Control the heating plate on the substrate to heat up, and use an electric arc to print the part to be printed on the substrate; the height of the forming enclosure increases with the increase of the height of the part to be printed during the printing process; during the printing process, insulating sand is filled into the space enclosed by the forming enclosure, and the height of the insulating sand in the space enclosed by the forming enclosure increases with the increase of the height of the part to be printed during the printing process.
[0050] The heating plate is installed when the additive height is greater than or equal to the heating plate height. The heating plate is arranged laterally on the upper surface of the substrate, and the number of heating plates can be increased according to the increase in additive height.
[0051] Step 204: Determine the height of the part to be printed during the printing process. When the height of the part to be printed reaches the height of the protruding surface during the printing process, weld the conductive plate to the target position of the printed part and fill it with insulating sand to obtain a welded part. The upper surface of the conductive plate of the welded part coincides with the protruding surface. The height of the filled insulating sand is the same as the height of the protruding surface.
[0052] like Figure 1As shown, for additive manufacturing of protruding surfaces, the forming barrier lifting height h = protruding surface height H + substrate height M is determined based on the height of the protruding surface. The insulating sand plane 16 is aligned with the protruding surface 13. After grinding, the conductive plate plane coincides with the protruding surface. Based on the position of the protruding surface in the part to be printed and the conformal welding of the additive manufacturing contour, the height of the upper surface of the conductive plate is the same as the height of the protruding surface.
[0053] Step 205: Continue printing on the welded part to complete the printing of the part to be printed.
[0054] When the number of protruding surfaces on the part to be printed is greater than or equal to two, the additive manufacturing program for the protruding surface layer is invoked, and the underlayer is printed on the welded part based on the data of the slice layer where the current protruding surface is located, such as... Figure 1 The layer 15 shown represents the structure of the slice layer containing the current protruding surface of the part to be printed. Printing continues on layer 15 until the height of the part to be printed reaches the height of the next protruding surface. A conductive plate corresponding to the next protruding surface is then soldered into the printed part and filled with insulating sand. Printing continues for the next protruding surface, and so on. This additive manufacturing process is repeated until step 204 is reached for the next protruding surface, and the printing cycle continues until the part is completely printed. After additive manufacturing is complete, the silica sand covering the part is removed, and the additive manufacturing process is finished.
[0055] This method of arc additive manufacturing for protruding surfaces enables continuous arc additive manufacturing of parts with protruding surfaces. It can be performed using triaxial additive manufacturing equipment, resulting in high forming efficiency and reducing process difficulty, equipment requirements, and additive manufacturing costs. The insulating sand provides support, effectively reducing deformation of the printed parts and improving forming accuracy. The combined use of the heating plate and insulating sand enhances the insulation effect, ensuring strong temperature uniformity and slow heat dissipation in the printed parts, thereby preventing cracks, improving the surface appearance quality of the parts, reducing weld spatter, and enabling high-quality arc printing of large parts. The forming enclosure also provides insulation. Due to the conductive plate, the protruding surfaces of the parts can be printed using an arc, whether inside or outside the part, or inside a closed structure.
[0056] As an alternative approach, since the protruding surface of the part is not perpendicular to the plane containing the forming direction, additive manufacturing cannot be performed in this case, and the part angle needs to be adjusted. Therefore, when determining the height of the part to be printed during the printing process, and when the height of the part to be printed reaches the height of the protruding surface, the conductive plate is welded to the target position of the printed part and filled with insulating sand. Before obtaining the welded part, the following steps are also included:
[0057] Determine whether the protruding surface is parallel to the horizontal plane. If the protruding surface is not parallel to the horizontal plane, adjust the angle of the substrate and fill with insulating sand so that the protruding surface to be printed coincides with the insulating sand plane and is parallel to the horizontal plane. If the protruding surface is parallel to the horizontal plane, proceed directly to the next step to determine the height of the part to be printed during the printing process. When the height of the part to be printed reaches the height of the protruding surface during the printing process, weld the conductive plate to the target position of the printed part and fill with insulating sand.
[0058] The tilt angle of the positioner can be used to adjust the protruding surface of parts that are not parallel to the horizontal plane. The adjustment efficiency can be improved by filling the insulation sand while adjusting the angle. Alternatively, the angle of the substrate can be adjusted to make the protruding surface parallel to the horizontal plane before filling the insulation sand to make the insulation sand plane parallel to the horizontal plane.
[0059] Next Figure 3 The above-mentioned surface arc additive manufacturing method is illustrated using a 304 stainless steel part as an example:
[0060] like Figure 3 As shown, the 304 stainless steel part has two protruding surfaces: an inner protruding surface 17 and an outer protruding surface 18. Both the inner protruding surface 17 and the outer protruding surface 18 are non-closed, suspended protruding surfaces with a forming angle of 90°, which does not meet the conditions for continuous additive manufacturing. Therefore, the protruding surface arc additive manufacturing method is selected. The forming direction of the part is as follows. Figure 4 As shown, the height of the outer protruding surface 18 is determined to be 100mm according to the forming direction. From the first layer, 33 layers are needed to reach the height of the outer protruding surface 18. The height of the inner protruding surface 17 is 150mm, and 50 layers are needed to reach the height of the inner protruding surface 17. Both protruding surfaces are parallel to the horizontal plane. The steps for printing 304 stainless steel parts are as follows:
[0061] S1: Determine the dimensions of the upper surface of the conductive plate based on the dimensions of the protruding surface. The conductive plate thickness is 1mm, and it is made of 304 stainless steel cold-rolled sheet. The outer protruding surface corresponds to the upper surface of the conductive plate as follows: Figure 5 As shown, the upper surface of the conductive plate corresponding to the inner protruding surface is as follows: Figure 6 As shown.
[0062] S2: Thermal insulation sand drying and mixing. Quartz sand and alumina sand are mechanically mixed in a high-temperature drum drying and mixing equipment at a ratio of 3:7. The drying temperature is 150℃ and the mixing time is 6 hours.
[0063] S3: The substrate is made of 20mm thick 304 stainless steel plate. The substrate and the welding platform are fixed by pressure plate and bolts. The surface of the substrate is polished with a grinding wheel.
[0064] S4: Install the formed enclosure. Use lightweight clay insulating bricks to build the enclosure. The enclosure size is 100mm larger than the base plate envelope size. The enclosure height is 20mm and the insulating sand height is 18mm.
[0065] S5: Select a heating hole diameter of 15mm, a height of 20mm, an electric heating tube specification of ф12mm, and select an intelligent temperature controller to control the heat preservation temperature at 200±5℃.
[0066] S6: For 304 stainless steel parts manufactured using arc additive manufacturing, CMT arc additive manufacturing equipment is used, with the welding torch oscillation angle set to 0°. Figure 7 As shown, arc additive manufacturing is performed on substrate 9, which is equipped with a heating plate 10. The heating plate 10 includes multiple heating holes 101. During the additive manufacturing process, as the additive height of the part increases, insulating sand 4 is added and the forming barrier height is increased. The continuous additive manufacturing process continues until the height of the outer protruding surface 18 reaches 100mm or 33 layers. After adding insulating sand 4, the insulating sand 4 is scraped flat so that the insulating sand plane is parallel to the horizontal plane and the outer protruding surface 18 and is on the same horizontal plane. Then, conformal welding of the conductive plate is performed. See [link to documentation]. Figure 7 and 8 The outer protruding surface is connected to the conductive plate 19 and the additively made 304 stainless steel part 21 by conformal welding. The conformal welding position is the outer protruding surface position 20, which is the position of the outer protruding surface in the 304 stainless steel part. The additively made 304 stainless steel part 21 is the first 33 layers of the 304 stainless steel part. After completion, the bottom layer 34 program is called to reduce the welding voltage and use a low current and low penetration method to carry out the bottom layer additive manufacturing. After the bottom layer additive manufacturing is completed, the additive forming parameters are called to continuously add material to the inner protruding surface of 150mm or 50 layers. The above conductive plate additive manufacturing steps are repeated.
[0067] S7: Post-processing. After additive manufacturing is completed, keep the material at 200℃ for 1 hour, cool it to 50℃, remove the insulating sand and dismantle the enclosure. The arc additive manufacturing process is now complete.
[0068] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.
[0069] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method of flash front arc additive manufacturing, characterized in that, include: Obtain basic data of the protruding surface of the part to be printed and a conductive plate; the basic data includes the size and height of the protruding surface and the target position of the protruding surface in the part to be printed; the upper surface size of the conductive plate is the same as the size of the protruding surface; A shaped enclosure is constructed around the substrate, and insulating sand is filled between the shaped enclosure and the substrate; the height of the shaped enclosure is greater than or equal to the height of the substrate, and the height of the insulating sand is less than or equal to the height of the substrate. The heating plate on the substrate is controlled to heat the substrate, and the part to be printed is printed on the substrate using an electric arc. The height of the part to be printed is determined during the printing process. When the height of the part to be printed reaches the height of the protruding surface, the conductive plate is welded to the target position of the printed part and filled with insulating sand to obtain a welded part. The upper surface of the conductive plate of the welded part coincides with the protruding surface. The height of the filled insulating sand is the same as the height of the protruding surface. Continue printing on the welded part to complete the printing of the part to be printed.
2. The method for additive manufacturing of protruding surface arcs according to claim 1, characterized in that, The process of determining the height of the part to be printed during the printing process, and when the height of the part to be printed reaches the height of the protruding surface, involves welding the conductive plate to the target position of the printed part and filling it with insulating sand. Before obtaining the welded part, the process further includes: Determine whether the protruding surface is parallel to the horizontal plane. If the protruding surface is not parallel to the horizontal plane, adjust the angle of the substrate and fill it with insulating sand so that the protruding surface to be printed coincides with the plane of the insulating sand and is parallel to the horizontal plane.
3. The method for additive manufacturing of protruding surface arcs according to claim 1, characterized in that, The number of protruding surfaces is at least two, and the process of continuing printing on the welded part to complete the printing of the part to be printed includes: Print the underlayer onto the weldment based on the data of the slice layer where the current protruding surface is located; Continue printing on the base layer until the height of the part to be printed reaches the height of the next protruding surface. Then, weld the conductive plate corresponding to the next protruding surface into the printed part and fill it with insulating sand. Continue printing the next protruding surface and repeat the printing process until the part to be printed is completed.
4. The method for additive manufacturing of protruding surface arcs according to claim 1, characterized in that, The process of constructing a shaped enclosure around the substrate also includes: After the substrate is polished with a grinding wheel, a pressure plate is used to fix the substrate on the welding platform; the substrate is located between the pressure plate and the welding platform.
5. A protruding surface electric arc additive manufacturing apparatus, characterized in that, The method for protruding surface arc additive manufacturing according to any one of claims 1-4 is provided, wherein the protruding surface arc additive manufacturing apparatus includes at least a conductive plate, a substrate, a forming enclosure, insulating sand, a heating plate, and an arc additive manufacturing device; the upper surface dimension of the conductive plate is the same as the protruding surface dimension of the part to be printed; A forming barrier is constructed around the substrate, and the space between the substrate and the forming barrier is filled with insulating sand. The heating plate is fixed to the upper surface of the substrate. The heating plate is used for heating. The height of the forming barrier increases with the height of the part to be printed during the printing process. The insulating sand is used to fill the space enclosed by the forming barrier during the printing process and to keep the printed part warm. The conductive plate is welded to the protruding surface of the printed part. The protruding surface is formed on the upper surface of the conductive plate; The electric arc additive manufacturing equipment is used to print the part to be printed on the substrate.
6. The protruding surface arc additive manufacturing apparatus according to claim 5, characterized in that, The protruding surface also includes a pressure plate, a welding platform, a pad, and bolts; the substrate is disposed between the pressure plate and the welding platform, and the pad is embedded between the end of the pressure plate away from the substrate and the welding platform; the bolts are used to press the pressure plate, substrate, pad, and welding platform together.
7. The protruding surface arc additive manufacturing apparatus according to claim 5, characterized in that, The insulating sand includes quartz sand and silica sand, with a ratio of 3:7 between the quartz sand and the silica sand, and the formed enclosure is composed of insulating bricks.
8. The protruding surface arc additive manufacturing apparatus according to claim 5, characterized in that, The heating element of the heating plate is an electric heating tube, the diameter of which is 0.8 times the diameter of the heating hole of the heating plate. The heat preservation temperature of the heating plate is adjusted by a temperature controller. The number of heating plates increases as the height of the part to be printed increases during the printing process.
9. The protruding surface arc additive manufacturing apparatus according to claim 5, characterized in that, The thickness of the conductive plate is greater than or equal to 1 mm, and the material of the conductive plate is the same as that of the wire.
10. The protruding surface arc additive manufacturing apparatus according to claim 5, characterized in that, A positioner is installed at the bottom of the welding platform. The positioner is used to change the tilt angle of the welding platform in order to control the forming angle of the part to be printed.