A method of forming a location for a part

Abstract

The application discloses a part forming positioning method and relates to the technical field of additive manufacturing, to solve the problem that traditional positioning methods are prone to causing damage to special parts during clamping. The positioning method comprises the following steps: obtaining a three-dimensional model of a part; determining a part forming direction; constructing an auxiliary clamping structure for clamping the part to obtain a part machining model, wherein the auxiliary clamping structure comprises a connected structure, an auxiliary structure and a dot matrix structure, the connected structure is connected around the outer wall of the part, the auxiliary structure is connected with one side edge of the connected structure, the auxiliary structure and the connected structure form a filling cavity with the dot matrix structure between the parts, and the outer wall of the part is connected with the inner wall of the inner wall of the annular plate close to the part; additive printing based on the machining model to obtain a printed part; separating the printed part and the substrate; clamping the auxiliary clamping structure, and machining the printed part to obtain the part. Through clamping the auxiliary clamping structure to machine and position the part, the machining equipment is prevented from directly contacting the part, and damage to the surface of the part during clamping is reduced.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and more specifically to a method for forming and positioning parts. Background Technology

[0002] Selective laser melting (SLM, also known as additive manufacturing or 3D printing) is a metal additive manufacturing technology used for high-precision, high-efficiency and repeatable processing on metal materials. It is suitable for complex components made of metal materials such as stainless steel, titanium alloys, high-temperature alloys and aluminum alloys, and for irregularly shaped structures that are usually difficult to complete using traditional processing methods.

[0003] When clamping is required for some thin-walled, complex, or other special parts, direct clamping can cause damage to the parts, and it is difficult to determine the correct position and locate them. Typically, custom-made tooling is used, and a rough reference block is formed by gluing the tooling and the part together to assist in machining. However, removing the glue usually involves localized heating with a high-temperature gun, which can easily cause deformation or even cracking of the part. Therefore, traditional positioning methods all suffer from the problems of difficulty in directly clamping thin-walled, complex, or other special structural parts, as well as the difficulty in positioning and the risk of clamping damage. Summary of the Invention

[0004] The purpose of this invention is to provide a forming and positioning method for parts, which facilitates the positioning and clamping of parts with special structures and protects the outer wall of the parts with special structures.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for forming and positioning a part, comprising:

[0006] Obtain the 3D model of the part;

[0007] The forming direction of the part is determined based on the three-dimensional model, so that the axis of the part is perpendicular to the substrate.

[0008] An auxiliary clamping structure for clamping during machining is constructed in a 3D model to obtain a machining model of the part. The auxiliary clamping structure includes a connecting structure, an auxiliary structure, and a lattice structure. The connecting structure is connected around the outer wall of the part and is inclined relative to the forming direction. The auxiliary structure is connected to the edge of the connecting structure away from the part. The auxiliary structure is an annular plate. The extension direction of the annular plate is parallel to the forming direction, so that the auxiliary structure and the connecting structure form a filling cavity between the outer wall of the part. The opening direction of the filling cavity is facing the forming direction. The lattice structure is located in the filling cavity. The outer wall of the part is connected to the inner wall of the annular plate near the part through the lattice structure. The lattice structure is composed of multiple interconnected cell arrays. The cell is formed by at least two sets of overlapping cross rods. The cross rods are interconnected by two support rods.

[0009] Additive printing is performed based on the fabrication model to obtain the printed part;

[0010] Separate the printed parts and the substrate;

[0011] The clamping auxiliary clamping structure is used to machine the printed parts to obtain the finished product.

[0012] Optionally, in the forming and positioning method of the above-mentioned part, the connecting structure is an annular cone, and multiple through holes are opened on the surface of the annular cone, with the multiple through holes arranged at intervals around the outer wall of the part.

[0013] Optionally, in the forming and positioning method of the above-mentioned parts, the diameter d2 of the through hole satisfies the condition: 1mm≤d2≤3mm.

[0014] Optionally, in the above-mentioned forming and positioning method for the part, the clamping auxiliary clamping structure and the machining of the printed part include:

[0015] Remove connected structures, retaining auxiliary structures and lattice structures;

[0016] Clamping the auxiliary structure and machining the printed parts;

[0017] Remove auxiliary structures and lattice structures.

[0018] Optionally, in the above-mentioned forming and positioning method for parts, after clamping the auxiliary clamping structure, the forming and positioning method further includes: using a tool to detect the clamping surface provided by the auxiliary structure to confirm whether the placement of the printed part meets the processing standards.

[0019] Optionally, in the above-mentioned forming and positioning method for parts, after machining the printed part to obtain the part, the forming and positioning method further includes: grinding the non-machined surface of the part.

[0020] Optionally, in the forming and positioning method of the above parts, the diameter d1 of the support rod satisfies the condition: 0.5mm≤d1≤2mm;

[0021] And / or, the angle α1 between the axial direction of the support rod and the horizontal plane satisfies the condition: α1≥45°.

[0022] Optionally, in the above-mentioned forming and positioning method for the part, the material thickness N1 of the connected structure is less than the material thickness N2 of the auxiliary structure;

[0023] And / or, the material thickness N1 of the connected structure satisfies the condition: N1≥1mm.

[0024] Optionally, in the above-mentioned forming and positioning method for the part, the included angle β between the side surface of the connected structure near the outer wall of the part and the horizontal plane satisfies the condition: 45°≤β<90°.

[0025] Optionally, in the above-mentioned forming and positioning method for the part, the corner of the connecting structure connected to the outer wall of the part is rounded, and the radius α2 of the corner of the connecting structure connected to the outer wall of the part satisfies the condition: α2≥1mm.

[0026] Compared with existing technologies, the above technical solution involves first obtaining a three-dimensional model of the part, determining the forming direction of the part based on the three-dimensional model, and then constructing an auxiliary clamping structure in the three-dimensional model to obtain a processing model of the part. The processing model is then additively printed, and the printed part is separated from the substrate. The printed part is then machined using the auxiliary clamping structure to obtain the final part. Compared with traditional methods of clamping directly to the surface of a special part, this application constructs an auxiliary clamping structure on the surface of the part, ensuring that the processing equipment does not directly contact the surface of the special part during machining, thus avoiding clamping damage to the part surface. Furthermore, the lattice structure, while meeting the clamping force requirements, also has a certain energy absorption effect, reducing the squeezing deformation caused to the part during machining. Additionally, the lattice structure and the connected structures have small contact areas with the part surface, making them easy to remove and reducing the risk of damage to the part during removal. Attached Figure Description

[0027] 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:

[0028] Figure 1 This is a process flow diagram of a part forming and positioning method provided in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of a printed part according to a part forming and positioning method provided in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of an auxiliary clamping structure in a part forming and positioning method provided in an embodiment of the present invention;

[0031] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure;

[0032] Figure 5 for Figure 3 A schematic diagram of the cross-sectional structure after setting a lattice structure inside the filling cavity;

[0033] Figure 6 for Figure 5 Top view;

[0034] Figure 7 for Figure 3 A schematic diagram of the structure after removing the connected structures;

[0035] Figure 8 for Figure 7 The front view;

[0036] Figure 9 for Figure 7 A schematic diagram of the cross-sectional structure;

[0037] Figure 10 This is a schematic diagram of the cell structure in the lattice structure of a part forming and positioning method provided in an embodiment of the present invention;

[0038] Figure 11 for Figure 10 A schematic diagram of the crossbar structure in a cell.

[0039] Figure label:

[0040] 1-Substrate; 2-Printed part; 3-Auxiliary clamping structure; 31-Connecting structure; 32-Auxiliary structure; 33-Lattice structure; 4-Filling cavity; 5-Cell; 51-Support rod; 6-Through hole. Detailed Implementation

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] like Figures 1-11 As shown in the figure, an embodiment of the present invention provides a method for forming and positioning a part, the steps of which include:

[0047] Step S100: Obtain the 3D model of the part;

[0048] The 3D model of the part is constructed in 3D software based on the actual dimensions of the part. The 3D software can be selected according to actual needs, without specific limitations.

[0049] Step S200: Determine the forming direction A of the part based on the three-dimensional model, so that the axis of the part is perpendicular to the substrate 1.

[0050] Export the part in STL format from the 3D software, set the triangular tolerance and adjacent tolerance to 0.0025, open the STL format part in the 3D software, use the repair wizard function to repair and slice the part model, and import it into the equipment to print the 3D model according to the forming direction A.

[0051] Step S300: Construct an auxiliary clamping structure 3 for clamping during machining in a 3D model to obtain a machining model of the part. The auxiliary clamping structure 3 includes a connecting structure 31, an auxiliary structure 32, and a lattice structure 33. The connecting structure 31 is connected around the outer wall of the part and is inclined relative to the forming direction A. The auxiliary structure 32 is connected to the edge of the connecting structure 31 away from the part. The auxiliary structure 32 is an annular plate. The extension direction of the annular plate is parallel to the forming direction A, so that the auxiliary structure 32 and the connecting structure 31 form a filling cavity 4 between the outer wall of the part. The opening direction of the filling cavity 4 faces the forming direction. The lattice structure 33 is located in the filling cavity 4. The outer wall of the part is connected to the inner wall of the annular plate near the part through the lattice structure 33. The lattice structure 33 is composed of an array of multiple interconnected cells 5. The cells 5 are formed by at least two sets of overlapping cross rods. The cross rods are interconnected by two support rods 51.

[0052] Specifically, the part described above is a hollow cylinder with a diameter of 200mm, a height of 300mm, and a wall thickness of 2mm. The parts processed using this method are not limited to those listed in this embodiment. In step S300, the optimal forming direction A of the part's machining model during processing is as follows: Figure 2 As shown, the auxiliary structure 32 can be annular or block-shaped, etc. The shape of the auxiliary structure 32 is not limited to the cases listed in this embodiment, as long as the auxiliary structure 32 meets the clamping requirements. When the part is a hollow cylinder, the auxiliary structure 32 is preferably an annular plate, which improves the processing efficiency and processing quality of the part.

[0053] Step S400: Perform additive printing based on the processing model to obtain printed part 2;

[0054] Step S500: Separate the printed part 2 and the substrate 1;

[0055] Specifically, before step S500, the surface metal powder of the printed part 2 is cleaned using a vibration platform and compressed air. Then, the structure of the printed part 2 and the substrate 1 is heat-treated. The printed part 2 and the substrate 1 are separated using wire cutting. The cutting method between the printed part 2 and the substrate 1 is not limited to the cases listed in this embodiment, which facilitates the machining of the printed part 2.

[0056] In step S600, the auxiliary clamping structure 3 is used to machine the printed part 2 to obtain the part.

[0057] Specifically, such as Figure 3As shown, firstly, the 3D software scanning data is compared and the deformation trend and amount of the part are determined. Corresponding adjustments are made during programming and operation. The printed part 2 obtained by additive printing based on the processing model has an auxiliary clamping structure 3. The auxiliary clamping structure 3 is used as the clamping position for machining using equipment such as a three-axis or five-axis CNC milling machine. This means that in step S600, there is no need to customize special tooling. The fixture can directly clamp the auxiliary clamping structure 3 without directly contacting the outer wall of the part, which reduces structural damage to the surface of the part. The machining of the printed part 2 is completed to obtain the part, which reduces the production cost of the part and shortens the manufacturing cycle.

[0058] In specific implementation, such as Figure 1 As shown, a three-dimensional model of the part is first obtained, and the forming direction A of the part is determined based on the three-dimensional model. Then, an auxiliary clamping structure 3 for clamping the part is constructed in the three-dimensional model to obtain a processing model of the part. The processing model is additively printed, and the resulting printed part 2 and substrate 1 are separated. The printed part 2 is machined by clamping the auxiliary clamping structure 3 to obtain the part. Compared with the traditional method of clamping directly in contact with the surface of the special part, this application constructs an auxiliary clamping structure 3 on the surface of the part, so that the processing equipment does not directly contact the surface of the special part during the machining process, avoiding clamping damage to the surface of the part. In addition, the lattice structure 33 has a certain energy absorption effect while meeting the clamping force, which can reduce the squeezing deformation of the part caused by clamping during the machining process. Moreover, the lattice structure 33 and the connected structure 31 have a small contact area with the surface of the part, which is easy to remove and reduces the risk of damaging the part during the removal process.

[0059] like Figure 3 As shown, in some embodiments, the connecting structure 31 is an annular cone, and multiple through holes 6 are formed on the surface of the annular cone. The multiple through holes 6 are arranged at intervals around the outer wall of the part. The through holes 6 can be circular, polygonal, or other shapes. The through holes 6 are not limited to those listed in this embodiment. Forming multiple through holes 6 on the surface of the annular cone saves printing costs and facilitates the removal of the connecting area. Preferably, the through holes 6 are circular.

[0060] like Figure 3As shown, specifically, in this embodiment, the diameter d2 of the through hole 6 satisfies the condition: 1mm ≤ d2 ≤ 3mm. The diameter d2 of the through hole 6 can be 1mm, 1.2mm, 2mm, 2.5mm, 3mm, etc. The diameter d2 of the through hole 6 is not limited to the cases listed in this embodiment. When the diameter d2 of the through hole 6 is ≥ 1mm, the area of ​​the hollow region on the connected structure 31 increases, reducing the required processing material and thus lowering the processing cost of the auxiliary clamping structure 3. When the diameter d2 of the through hole 6 is ≤ 3mm, the connected structure 31 has sufficient support strength after the through hole 6 is opened.

[0061] like Figure 3 and Figure 7 As shown, specifically, in this embodiment, the mechanical processing of the printed part 2 by clamping the auxiliary clamping structure 3 in step S600 specifically includes:

[0062] Step S601: Remove the connected structure 31, and retain the auxiliary structure 32 and the lattice structure 33;

[0063] Step S602: Clamp the auxiliary structure 32 and perform machining on the printed part 2;

[0064] Step S603: Remove the auxiliary structure 32 and the dot matrix structure 33. When removing the connected structure 31, the auxiliary structure 32 and the dot matrix structure 33, a pneumatic shovel or other tools can be used. The method for removing the connected structure 31, the auxiliary structure 32 and the dot matrix structure 33 is not limited to the cases listed in this embodiment. Any method that facilitates the removal of the auxiliary clamping structure 3 is acceptable.

[0065] During operation, the operator can first remove the connecting structure 31 in the auxiliary clamping structure 3, and then clamp the remaining auxiliary structure 32 and dot matrix structure 33. After the machining of the printed part 2 is completed, the auxiliary structure 32 and dot matrix structure 33 on the surface of the part are then removed. Before clamping the auxiliary structure 32 and dot matrix structure 33, the connecting structure 31 is removed first to reduce the residual stress in the area between the connecting structure 31 and the outer wall of the part during machining, avoid the generation of local deformation, improve the machining quality, and facilitate the structural stability when clamping the part through the auxiliary structure 32. At the same time, the dot matrix structure 33, while meeting the clamping force, has a certain energy absorption effect, which can reduce the squeezing deformation of the part caused by clamping during machining. In addition, the connection contact area between the dot matrix structure 33 and the surface of the part is small, making it easy to remove and reducing the risk of damaging the part during the removal process.

[0066] In this embodiment, after the clamping auxiliary clamping structure 3 in step S600, the forming and positioning method further includes: using a tool to detect the clamping surface provided by the auxiliary structure 32 to confirm whether the placement of the printed part 2 meets the processing standards.

[0067] The clamping surface of the auxiliary structure 32 needs to be a regular horizontal plane and side surface to meet the clamping and positioning requirements, facilitate the judgment of whether the condition of the part meets the processing standards, and improve the quality of machining by stable clamping and accurate positioning, and facilitate operation.

[0068] In this embodiment, after machining the printed part 2 to obtain the part in step S600, the forming and positioning method further includes: grinding the non-machined surface of the part.

[0069] In the above steps, grinding tools are used to grind the non-machined surfaces of the parts, and adjustments are made according to the shape of the parts to ensure the quality of the machining.

[0070] like Figure 10 and Figure 11 As shown, specifically in this embodiment, in step S300, the diameter d1 of the support rod 51 satisfies the condition: 0.5mm ≤ d1 ≤ 2mm; and / or, the angle α1 between the axial direction of the support rod 51 and the horizontal plane satisfies the condition: α1 ≥ 45°. The diameter d1 of the support rod 51 can be 0.5mm, 0.6mm, 0.7mm, 1.2mm, 2mm, etc., and the angle α1 between the axial direction of the support rod 51 and the horizontal plane can be 45°, 50°, 55°, 60°, 75°, 80°, etc. The diameter d1 and angle α1 of the support rod 51 are not limited to the cases listed in this embodiment. This allows each cell 5 in the lattice structure 33 to achieve forming stability and provide energy absorption during the clamping process, while also forming a small contact area between the lattice structure 33 and the outer wall of the part. This facilitates the removal of the lattice structure 33, simplifies the process flow, and improves production efficiency.

[0071] In this embodiment, in step S300, the material thickness N1 of the connecting structure 31 is less than the material thickness N2 of the auxiliary structure 32; and / or, the material thickness N1 of the connecting structure 31 satisfies the condition: N1 ≥ 1 mm. The material thickness N1 of the connecting structure 31 can be 1 mm, 1.5 mm, 2 mm, etc., and is not limited to the cases listed in this embodiment. As long as the material thickness N1 of the connecting structure 31 is less than the material thickness N2 of the auxiliary structure 32, printing costs are saved while ensuring the connection strength between the connecting structure 31 and the outer wall of the part.

[0072] like Figure 4 and Figure 5As shown, in this embodiment, in step S300, the included angle β between the surface of the connected structure 31 near the outer wall of the part and the horizontal plane satisfies the condition: 45°≤β<90°. The included angle β can be 45°, 50°, 55°, 60°, 75°, 80°, etc., and is not limited to the cases listed in this embodiment, in order to ensure the stability of the forming between the connected structure 31 and the outer wall of the part, and improve the forming efficiency of the part.

[0073] like Figure 4 and Figure 5 As shown, in this embodiment, in step S300, the corner of the connecting structure 31 connected to the outer wall of the part is rounded. The radius α2 of the rounded corner on the side of the connecting structure connected to the outer wall of the part satisfies the condition: α2 ≥ 1 mm. The radius α2 can be 1 mm, 1.5 mm, 2 mm, etc., and is not limited to the cases listed in this embodiment. The larger the structure of the part, the larger the radius α2, which reduces the risk of cracking during the forming of the printed part 2 and improves the forming efficiency of the part.

[0074] 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.

[0075] 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 forming a location of a part, characterized by, The method comprises the following steps: acquiring a three-dimensional model of a part; determining a forming direction of the part according to the three-dimensional model, so that an axis of the part is perpendicular to a substrate; constructing an auxiliary clamping structure for clamping during machining in the three-dimensional model, to obtain a machining model of the part, wherein the auxiliary clamping structure comprises a connecting structure, an auxiliary structure and a dot matrix structure, the connecting structure is connected around an outer wall of the part, and the connecting structure is arranged obliquely relative to the forming direction, the auxiliary structure is connected with a side of the connecting structure away from the part, the auxiliary structure is an annular plate, a plate surface of the annular plate extends in a direction parallel to the forming direction, so that the auxiliary structure and the connecting structure form a filling cavity between the outer wall of the part, an opening direction of the filling cavity is towards the forming direction, the dot matrix structure is arranged in the filling cavity, the outer wall of the part and an inner wall of the annular plate close to the part are connected through the dot matrix structure, the dot matrix structure is composed of a plurality of cell arrays connected with each other, the cell is formed by at least two groups of intersecting rods intersecting and overlapping, and the intersecting rods are connected with each other by two supporting rods intersecting each other; based on the machining model, additive printing is performed to obtain a printed part; the printed part and the substrate are separated; the auxiliary clamping structure is clamped, and the printed part is machined to obtain the part.

2. The method of claim 1, wherein The connecting structure is an annular cone, a plurality of through holes are formed in a surface of the annular cone, and the plurality of through holes are arranged at intervals around the outer wall of the part.

3. The method of claim 2, wherein A diameter d2 of the through hole satisfies a condition: 1mm≤d2≤3mm.

4. The method of claim 1, wherein The clamping of the auxiliary clamping structure and the machining of the printed part comprise the following steps: the connecting structure is removed, and the auxiliary structure and the dot matrix structure are retained; the auxiliary structure is clamped, and the printed part is machined; the auxiliary structure and the dot matrix structure are removed.

5. The method of claim 1, wherein After the auxiliary clamping structure is clamped, the forming positioning method further comprises: using a tool to detect a clamping surface provided by the auxiliary structure to confirm whether the placement of the printed part meets a machining standard.

6. The method of claim 1, wherein After the printed part is machined to obtain the part, the forming positioning method further comprises: polishing a non-machining surface of the part.

7. The method of claim 1-6, wherein A diameter d1 of the supporting rod satisfies a condition: 0.5mm≤d1≤2mm. And / or, an included angle α1 between an axial direction of the supporting rod and a horizontal plane satisfies a condition: α1≥45°.

8. The method of claim 1-6, wherein A material thickness N1 of the connecting structure is less than a material thickness N2 of the auxiliary structure. And / or, the material thickness N1 of the connecting structure satisfies a condition: N1≥1mm.

9. The method of claim 1-6, wherein, An included angle β between a side surface of the connecting structure close to the outer wall of the part and a horizontal plane satisfies a condition: 45°≤β<90°.

10. The method of claim 1-6, wherein, A side of the connecting structure connected with the outer wall of the part is rounded, and a rounding radius α2 of the side of the connecting structure connected with the outer wall of the part satisfies a condition: α2≥1mm.

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