A method and device for forming an opening structure part

Abstract

The present invention discloses a method and device for forming an open structure part, which relates to the field of additive manufacturing technology, in order to solve the problem that the forming of open structure parts is difficult and the forming accuracy cannot be guaranteed. A method for forming an open structure part includes: obtaining a three-dimensional model of the part; determining the forming direction of the part according to the three-dimensional model; copying the part in the three-dimensional model to obtain multiple parts, and arranging the multiple parts along the opening direction; constructing a first connecting structure connecting the open end of the part and its adjacent parts in the three-dimensional model; at the same time, constructing a second connecting structure connecting the two open ends of the terminal part in the three-dimensional model to obtain a processing model of the part; according to the processing model and the forming direction, forming and printing the part; processing the print to obtain multiple parts. The method for forming an open structure part provided by the present invention is used for the forming of an open structure part, and the forming method is simple and the forming accuracy is high.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a method and device for forming an open structure part. Background Art

[0002] Special-shaped parts are complex and irregular in shape, such as a large number of thin-walled and special-shaped parts in the aerospace field. Due to their harsh use environment, they require not only high dimensional accuracy and surface roughness, but also high performance requirements. The most common special-shaped parts in additive manufacturing are open structures with non-closed structures, and the parts themselves have large stresses.

[0003] The existing technology generally uses traditional machining methods or casting methods to process parts with open structures. However, when using traditional machining methods to manufacture parts with open structures, not only is the surface processing difficult, which wastes raw materials, but also because the non-closed ports of the parts expand outward, the forming accuracy is difficult to ensure, and it takes manpower and material resources to calibrate the parts in the later stage to ensure the size requirements. The performance of parts cast by casting is often lower than that of forgings. Summary of the invention

[0004] The object of the present invention is to provide a method and device for forming an open structure part, which is used to solve the problem that the existing forming method of the open structure part is difficult to process and the forming accuracy is difficult to ensure.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] In one aspect, the present invention provides a method for forming an open structure part, comprising:

[0007] Obtain a 3D model of the part;

[0008] Determining a forming direction of the part according to the three-dimensional model;

[0009] Copying the part in the three-dimensional model to obtain a plurality of the parts, and arranging the plurality of the parts along the opening direction;

[0010] A first connection structure connecting the open end of the part and its adjacent part is constructed in the three-dimensional model; and a second connection structure connecting two open ends of the terminal part is constructed in the three-dimensional model to obtain a processing model of the part; the first connection structure and the second connection structure form a closed structure;

[0011] Performing forming printing on the part according to the processing model and the forming direction;

[0012] The printed part is processed to obtain a plurality of the parts.

[0013] Compared with the prior art, the present invention provides a method for forming an open structure part, including obtaining a three-dimensional model of a part; determining the forming direction of the part according to the three-dimensional model; duplicating the part in the three-dimensional model to obtain a plurality of the parts, and arranging the plurality of the parts along the opening direction; constructing a first connection structure connecting the open end of the part and its adjacent parts in the three-dimensional model; at the same time, constructing a second connection structure connecting the two open ends of the end parts in the three-dimensional model to obtain a processing model of the part; the first connection structure and the second connection structure form a closed structure; according to the processing model and the forming direction, the part is formed and printed; and the print is processed to obtain a plurality of the parts. The method for forming an open structure part has strong versatility. Through this method, a plurality of parts can be obtained by printing at one time, which improves the forming efficiency, shortens the cycle, reduces the cost, and has a more obvious effect on mass production of parts; at the same time, the first connection structure and the second connection structure constructed in the three-dimensional model form a closed structure between adjacent parts and the end parts, which can make the parts stably formed, and the structure is simple, which minimizes the deformation, ensures the forming accuracy of the parts, avoids post-forming correction, and reduces the processing cost. In addition, the constructed closed structure also avoids the problem of non-closed ports expanding outward during the printing process.

[0014] On the other hand, the present invention also provides a forming device for an open structure part, comprising:

[0015] A three-dimensional model acquisition module is used to acquire a three-dimensional model of a part;

[0016] A forming direction determination module, used to determine the forming direction of the part according to the three-dimensional model;

[0017] A parts arrangement module, used for copying the parts in the three-dimensional model to obtain a plurality of the parts and arranging the plurality of the parts along the opening direction;

[0018] A first connection structure and a second connection structure construction module, for constructing a first connection structure connecting the open end of the part and its adjacent part in the three-dimensional model; and at the same time constructing a second connection structure connecting the two open ends of the terminal part in the three-dimensional model to obtain a processing model of the part; the first connection structure and the second connection structure form a closed structure;

[0019] A part printing module, used for printing the part according to the processing model and the forming direction;

[0020] The print processing module is used to process the print to obtain a plurality of the parts.

[0021] Compared with the prior art, the beneficial effects of the forming device for an open structural part provided by the present invention are the same as the beneficial effects of the forming method for an open structural part described in the above technical solution, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 A flow chart of a method for forming an opening structure part provided by the present invention;

[0024] Figure 2 A schematic diagram of the parts structure after the first connection structure and the second connection structure are constructed provided by the present invention;

[0025] Figure 3 A schematic structural diagram of an opening structure part forming device provided by the present invention.

[0026] Reference numerals:

[0027] 1-opening structural part, 11-first opening structural part, 12-second opening structural part, 13-third opening structural part, 2-first connecting structure, 21-rounded corner structure, 3-second connecting structure. DETAILED DESCRIPTION

[0028] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0029] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0030] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0031] Before introducing the embodiments of the present invention, the following definitions are given for the relevant terms involved in the embodiments of the present invention:

[0032] Selective laser melting (SLM) is a widely used and mature process. This method is based on the basic idea of ​​rapid prototyping and adopts a layer-by-layer cladding additive manufacturing method. According to the three-dimensional model of the part, the model is sliced ​​and layered according to a certain thickness. Then, under the control of the CNC system, the laser is used to control the molten metal powder through the galvanometer to directly form parts with specific geometric shapes. During the SLM forming process, the metal powder is completely melted to produce a metallurgical bond. The formed parts have good density and high organizational performance, and can form high-precision complex special-shaped metal parts.

[0033] As laser selective melting forming technology becomes more and more mature, more and more special-shaped parts are manufactured using laser selective melting forming technology. The existing forming method for parts with open structures is generally to ensure the forming of parts by adding a large amount of support, which not only increases the use of raw materials, but also faces the problem of increased stress and deformation of parts, and cannot guarantee the forming accuracy of the printing of open structure parts.

[0034] Based on the above problems, the present invention provides a method and device for forming an open structure part, which is suitable for a laser selective melting forming system. The laser selective melting forming system includes a forming device. The open structure part generally includes a U-shaped or C-shaped structure. Figure 2 The opening structure part 1 in the figure is taken as an example to describe in detail the opening structure part forming method provided by the present invention.

[0035] Figure 1 It is a flow chart of a method for forming an opening structure part, such as Figure 1 As shown, the method comprises the following steps:

[0036] Step 101: Obtain a three-dimensional model of the part.

[0037] The 3D model of the component can be constructed in 3D software according to the actual size information of the component. The 3D software can be UG, ProE, 3dmax, Maya and other software that can build the 3D model of the component. The 3D software can be selected according to the actual needs. This is just an example and is not specifically limited.

[0038] Step 102: Determine a forming direction of the part according to the three-dimensional model.

[0039] The forming direction of the part is the direction of increasing height during the forming process. The forming direction of the part is determined according to the structural characteristics of the part. The selection of the forming direction is based on the basic principles of stability, less support and short forming time. Figure 2 The determined forming direction of the opening structure part 1 does not require any support during the forming process.

[0040] Step 103: copying the part in the three-dimensional model to obtain a plurality of the parts, and arranging the plurality of parts along the opening direction.

[0041] The number of parts obtained after duplication is two or more, and the number can be selected according to the demand, the size of the part or the size of the printing device. Duplicating multiple parts can not only improve the efficiency of part manufacturing, but also enhance the stability of the part structure. When the parts are arranged, the distance between adjacent parts is selected based on the principle of saving raw materials. The parts can be between the two open ends of the adjacent parts, or outside the two open ends of the adjacent parts.

[0042] Step 104: construct a first connection structure connecting the open end of the part and its adjacent parts in the three-dimensional model; and simultaneously construct a second connection structure connecting the two open ends of the terminal part in the three-dimensional model to obtain a processing model of the part.

[0043] Specifically, Figure 2 As shown, a first connecting structure 2 is constructed between the two open ends of the first opening structure part 11 and the second opening structure part 12, a first connecting structure 2 is constructed between the two open ends of the second opening structure part 12 and the third opening structure part 13, and a second connecting structure 3 is constructed between the two open ends of the third opening structure part 13. The first connecting structure 2 and the second connecting structure 3 form a closed structure between the first opening structure part 11, the second opening structure part 12 and the third opening structure part 13; it should be understood that the first connecting structure 2 and the second connecting structure 3 need to connect the entire opening end, that is, the heights of the first connecting structure 2, the second connecting structure 3 and the opening end are the same.

[0044] Furthermore, before obtaining the processing model of the part, a first connection structure connecting the open end of the part and its adjacent part is constructed in the three-dimensional model; and a second connection structure connecting the two open ends of the terminal part is constructed in the three-dimensional model, the process further includes:

[0045] Obtain the wall thickness value of the opening end of the part and determine whether the wall thickness value is greater than 1 mm.

[0046] Specifically, if the wall thickness value is greater than 1 mm, the thickness of the first connection structure and the second connection structure constructed is greater than or equal to 1 mm; if the wall thickness value is less than or equal to 1 mm, the thickness of the first connection structure and the second connection structure constructed is the same as the wall thickness value.

[0047] The thickness of the first connecting structure and the second connecting structure set by the above principle can provide a stable support for the open end of the part. If the thickness is too small and the strength is insufficient, the accuracy of the part during the forming process is difficult to guarantee.

[0048] As an alternative, Figure 2 As shown, the connection between the first connection structure 2 and the adjacent parts can be set as a fillet structure 21. Adding fillets at the connection position between the first connection structure 2 and the adjacent parts can reduce stress concentration.

[0049] As an optional manner, the first connection structure and the second connection structure have hollow parts. The hollow parts can reduce weight and stress concentration.

[0050] Specifically, Figure 2 As shown in the example, the hollow portion of the first connection structure 2 can be made into a plurality of uniformly arranged elliptical hollow structures, and an elliptical structure with (diameter: short diameter)>2:1 can be selected; a plurality of uniformly arranged arched hollow portions can be added to the second connection structure 3. The setting of the elliptical and arched hollow portions can effectively reduce the support consumables, and the support structure is stable, high in strength, and reduces the printing time. It is understandable that the hollow portion can also be selected from a variety of other forms according to needs, such as circular, diamond, rectangular, etc., which are only examples here and are not specifically limited.

[0051] Step 105: Perform forming printing on the part according to the processing model and the forming direction.

[0052] As an optional method, the forming and printing method selects the laser selective melting forming technology, and exports the above-constructed processing model as an STL format file. When exporting the file, the triangular tolerance and adjacent tolerance are set to 0.0025. Then use Magics software to open the processing model of the STL format file, use the repair guide function to repair the processing model, and add auxiliary supports as needed. Finally, the repaired processing model is sliced, imported into the forming equipment, and printed in the forming direction to obtain a print. The obtained print includes multiple parts, a first connecting structure 2 and a second connecting structure 3. It should be noted that the first connecting structure 2 and the second connecting structure 3 constructed during the forming process are formed together with the multiple opening structure parts 1.

[0053] Step 106: Process the printed part to obtain a plurality of the parts.

[0054] As an optional method, the printed part is processed to obtain a plurality of the parts, including:

[0055] The first connecting structure 2 and the second connecting structure 3 in the printed part are cut, and the three parts can be obtained by removing the first connecting structure 2 and the second connecting structure 3.

[0056] As an optional manner, before cutting the first connection structure and the second connection structure in the printed part to obtain the plurality of parts, the method further includes:

[0057] Cleaning the surface and internal metal powder of the printed part;

[0058] Performing heat treatment on the printed part and the substrate;

[0059] Separating the printed part from the substrate by wire cutting;

[0060] The outer surface of the printed part is subjected to overall grinding, polishing and sandblasting.

[0061] Optionally, if the number of parts obtained by copying the parts in the three-dimensional model is N, the N parts are arranged in sequence along the opening direction, and a first connecting structure is constructed between the opening end of the first part and the second part, and a first connecting structure is constructed between the opening end of the second part and the third part, and so on, a first connecting structure is constructed between the opening end of the N-1th part and the Nth part, and a second connecting structure is constructed between the two opening ends of the Nth part.

[0062] Optionally, if only one part needs to be manufactured, it is only necessary to construct the second connection structure in the three-dimensional model of the part, and there is no need to copy it in the three-dimensional model of the part. Since there are no adjacent parts, there is no need to construct the first connection structure.

[0063] The method for forming an open structure part provided by the present invention is applied to a laser selective melting forming device with a forming device. When it is implemented specifically, during the part forming process, a three-dimensional model of the part is first obtained, and then a forming direction of the part is determined according to the three-dimensional model, the part is copied in the three-dimensional model to obtain a plurality of the parts, and the plurality of parts are arranged along the opening direction; then a first connecting structure 2 connecting the opening end of the part and its adjacent parts is constructed in the three-dimensional model; at the same time, a second connecting structure 3 connecting the two opening ends of the terminal part is constructed in the three-dimensional model to obtain a processing model of the part; secondly, the processing model of the part is imported into the forming device, and according to the processing model and the forming direction, the forming device is controlled to perform forming and printing on the part, and finally the print is processed to obtain a plurality of parts. This method for forming open structure parts has strong versatility. Through this method, multiple parts can be obtained by printing at one time, which improves the forming efficiency, shortens the cycle, reduces the cost, and has a more obvious effect on mass production of parts. At the same time, the first connection structure 2 and the second connection structure 3 constructed in the three-dimensional model form a closed structure between adjacent parts and the end parts, which can make the parts stably formed, and the structure is simple, which minimizes the deformation, ensures the forming accuracy of the parts, avoids post-forming correction, and reduces the processing cost. In addition, the constructed closed structure also avoids the problem of non-closed ports expanding outward during the printing process of the parts.

[0064] The present invention can divide the functional modules according to the above method examples. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present invention is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0065] In the case of dividing each functional module into corresponding functional modules, Figure 3 FIG. 1 is a schematic diagram showing a structural diagram of a forming device for an open structure part provided by an embodiment of the present invention. Figure 3 As shown, the forming device of the opening structure part includes:

[0066] A three-dimensional model acquisition module 301 is used to acquire a three-dimensional model of a part;

[0067] A forming direction determination module 302, used to determine the forming direction of the part according to the three-dimensional model;

[0068] A parts arrangement module 303, used for copying the parts in the three-dimensional model to obtain a plurality of the parts and arranging the plurality of the parts along the opening direction;

[0069] The first connection structure and the second connection structure construction module 304 is used to construct a first connection structure connecting the open end of the part and its adjacent part in the three-dimensional model; and at the same time, construct a second connection structure connecting the two open ends of the terminal part in the three-dimensional model to obtain a processing model of the part; the first connection structure and the second connection structure form a closed structure;

[0070] A part printing module 305, used for printing the part according to the processing model and the forming direction;

[0071] The print processing module 306 is used to process the print to obtain a plurality of the parts.

[0072] Optionally, the connection between the first connecting structure and the adjacent parts is a rounded structure.

[0073] Optionally, the first connecting structure and the second connecting structure have a hollow portion.

[0074] Optionally, the hollow portion of the first connecting structure is a plurality of evenly arranged elliptical structures; and the hollow portion of the second connecting structure is a plurality of evenly arranged arch structures.

[0075] Optionally, the print processing module 306 further includes:

[0076] A printing and cutting unit is used to cut the first connecting structure and the second connecting structure in the printed part to obtain a plurality of the parts.

[0077] Optionally, the print processing module 306 further includes:

[0078] A cleaning unit, used for cleaning the surface and internal metal powder of the printed part;

[0079] A heat treatment unit, used for heat treating the printed part and the substrate;

[0080] A separation unit, used for separating the printed part and the substrate by using wire cutting;

[0081] The processing unit is used for overall grinding, polishing and sandblasting of the outer surface of the printed part.

[0082] Optionally, the device also includes a processing model processing module, which can be specifically used for

[0083] Exporting the STL format file of the processing model;

[0084] Repairing the processing model in the STL format file;

[0085] The part is formed and printed according to the repaired processing model and the forming direction.

[0086] The above-mentioned forming device for an open structure part is a virtual device, including a virtual unit and a virtual functional module. This device is built on a forming device for use. At the same time, the forming device for an open structure part provided by the present invention corresponds to a forming method for an open structure part and acts on the forming device.

[0087] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0088] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the claims of the present invention and their equivalents.

Claims

1. A method for forming an open structure part, characterized in that: include: Obtain a 3D model of the part; Determining a forming direction of the part according to the three-dimensional model; The forming direction of the part is the direction of increasing height when deposited during the forming process; Copying the part in the three-dimensional model to obtain a plurality of the parts, and arranging the plurality of the parts along the opening direction; A first connection structure connecting the open end of the part and its adjacent part is constructed in the three-dimensional model; and a second connection structure connecting the two open ends of the terminal part is constructed in the three-dimensional model to obtain a processing model of the part; the first connection structure and the second connection structure form a closed structure; the first connection structure, the second connection structure and the open end of the part have the same height; According to the processing model and the forming direction, the part is formed and printed to obtain a printed part; Processing the printout to obtain a plurality of the parts; said constructing in said three-dimensional model a first connection structure connecting said part opening end and its adjacent part; At the same time, a second connecting structure connecting the two open ends of the terminal part is constructed in the three-dimensional model, and before obtaining the processing model of the part, it also includes: obtaining the wall thickness value of the open end of the part and judging whether the wall thickness value is greater than 1mm; if the wall thickness value is greater than 1mm, the thickness of the constructed first connecting structure and the second connecting structure is greater than or equal to 1mm; if the wall thickness value is less than or equal to 1mm, the thickness of the constructed first connecting structure and the second connecting structure is the same as the wall thickness value.

2. The method for forming an opening structure part according to claim 1, characterized in that: The connection between the first connection structure and the adjacent parts is a rounded structure.

3. The method for forming an opening structure part according to claim 1, characterized in that: The first connection structure and the second connection structure have hollow parts.

4. The method for forming an opening structure part according to claim 3, characterized in that: The hollowed-out portion of the first connection structure is a plurality of evenly arranged elliptical structures; the hollowed-out portion of the second connection structure is a plurality of evenly arranged arched structures.

5. The method for forming an open structure part according to claim 1, characterized in that: The process of processing the printed part to obtain a plurality of the parts comprises: The first connection structure and the second connection structure in the printed part are cut to obtain a plurality of the parts.

6. The method for forming an open structure part according to claim 5, characterized in that: Before the first connecting structure and the second connecting structure in the printed part are cut to obtain a plurality of the parts, the method further includes: Cleaning the surface and internal metal powder of the printed part; Performing heat treatment on the printed part and the substrate; Separating the printed part from the substrate by wire cutting; The outer surface of the printed part is subjected to overall grinding, polishing and sandblasting.

7. The method for forming an open structure part according to claim 1, characterized in that: Before forming and printing the part according to the processing model and the forming direction, the method further comprises: Exporting the STL format file of the processing model; Repairing the processing model in the STL format file; The part is formed and printed according to the repaired processing model and the forming direction.

8. A forming device for an open structure part, used to implement the forming method for an open structure part according to any one of claims 1 to 7, characterized in that: The device comprises: A three-dimensional model acquisition module is used to acquire a three-dimensional model of a part; A forming direction determination module, used to determine the forming direction of the part according to the three-dimensional model; the forming direction of the part is the increasing direction when deposited during the forming process; A parts arrangement module, used for copying the parts in the three-dimensional model to obtain a plurality of the parts and arranging the plurality of the parts along the opening direction; A first connection structure and a second connection structure construction module are used to construct a first connection structure connecting the open end of the part and its adjacent parts in the three-dimensional model; and at the same time, a second connection structure connecting the two open ends of the terminal part is constructed in the three-dimensional model to obtain a processing model of the part; the first connection structure and the second connection structure form a closed structure; the first connection structure, the second connection structure and the open end of the part have the same height; A part printing module, used for forming and printing the part to obtain a printed part according to the processing model and the forming direction; A print processing module is used to process the print to obtain a plurality of the parts; a first connection structure is constructed in the three-dimensional model to connect the open end of the part and its adjacent parts; and a second connection structure is constructed in the three-dimensional model to connect the two open ends of the terminal part. Before obtaining the processing model of the part, the following steps are also included: obtaining the wall thickness value of the open end of the part and determining whether the wall thickness value is greater than 1 mm; if the wall thickness value is greater than 1 mm, the thickness of the first connection structure and the second connection structure constructed is greater than or equal to 1 mm; if the wall thickness value is less than or equal to 1 mm, the thickness of the first connection structure and the second connection structure constructed is the same as the wall thickness value.

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