Support design method for 3D printing and 3D printing method

Abstract

A support design method and a 3D printing method for 3D printing, wherein the support design method comprises: selecting a structure with a texture pattern and a lower surface less than 45°; forming a curved surface or a plane consistent with the outer surface shape of the structure to be supported according to the outer surface shape of the structure to be supported; or, when the structure with the texture pattern in the workpiece to be printed is generated by three-dimensional software on the basis of the original smooth structure surface, selecting the curved surface or the plane corresponding to the structure to be supported from the original smooth structure surface; translating the curved surface or the plane so that the distance between the root of the highest convex surface of the texture pattern in the structure to be supported and the curved surface or the plane is one-third to one-half of the maximum convex length; and designing the support below the translated curved surface or plane. The application can improve the support design efficiency of the workpiece with the texture feature, improve the workpiece forming capacity, and improve the appearance quality of the texture structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of additive manufacturing, in particular to a support design method for 3D printing and a 3D printing method. BACKGROUND

[0002] Additive manufacturing technology (also known as 3D printing technology) is a rapid manufacturing technology that forms a three-dimensional object by controlling a laser to scan layer by layer. The process flow is as follows: firstly, the three-dimensional model of the workpiece is sliced to obtain the cross-section information of each layer of the workpiece; the powder material is uniformly spread on the surface of the work platform, and the laser selectively melts the powder according to the system instruction; after one cross-section is completed, a new layer of material is spread, and selective scanning is continued according to the corresponding cross-section information of the three-dimensional object; the next cross-section is spread and scanned according to this method, and finally a three-dimensional object is obtained.

[0003] With the increasing maturity of the 3D printing industry, the market for 3D printing is now also getting bigger and bigger, from the initial high-end manufacturing such as aerospace, aviation, medical, scientific research, jewelry field to the civilian, so more and more people directly or indirectly start to consume 3D printing products, but there are often some small structure features but large number of texture structures in civilian products, which are usually called pattern structures, especially some molds have high requirements for the appearance of patterns, which will increase the design and process requirements. As we all know, in the process of metal 3D printing, structures with small overhanging angles cannot be directly printed, and 45° is usually regarded as the critical angle. If the overhanging angle is greater than 45°, no support is needed, and if the overhanging angle is less than 45°, support needs to be set on the lower surface of the structure to assist the workpiece forming. Since there are many patterns in the current civilian workpieces, and the patterns are mainly concentrated on the internal surface of the workpiece, there are many patterns with large area, small features, large number and small inclination angle, and even overhanging surface, which greatly increases the difficulty of printing. Therefore, support needs to be added on the lower surface of these pattern features to assist printing success. However, this greatly increases the workload and difficulty of our support design, because the workpiece format applied in the current support design software is stl, which is composed of a large number of small triangular facets. When we design or edit the support of the workpiece, we actually process the countless triangular facets on the surface of the model. Since the concave-convex ways of these pattern surfaces that need to be supported are inconsistent and the pattern surfaces are discontinuous, it greatly increases the difficulty of selecting the support surface when we design the support, and even some small pattern surfaces are easily missed, which leads to no support in the position of the missed selected surface, and further leads to poor printing quality of these lower surfaces, and even causes local warping and makes the workpiece printing fail. SUMMARY

[0004] In order to solve the above problems existing in the prior art, the application provides a support design method for 3D printing and a 3D printing method. The support design method can greatly improve the support design efficiency of a workpiece with a pattern feature, and the part with the pattern on the lower surface of the workpiece can be completely supported, which can greatly improve the forming capacity of the workpiece and the appearance quality of the pattern structure.

[0005] In order to achieve the above-mentioned purpose, the application provides a support design method for 3D printing, which is applied to a structure with a texture pattern and a lower surface less than 45° in a workpiece to be printed, and the method comprises the following steps:

[0006] Step S1, selecting a structure with a texture pattern and a lower surface less than 45°, denoted as a structure to be supported and designed;

[0007] Step S2, forming a curved surface or a plane consistent with the outer surface shape of the structure to be supported and designed according to the outer surface shape of the structure to be supported and designed, and the curved surface or the plane does not have a texture pattern; or when the structure with the texture pattern in the workpiece to be printed is generated by three-dimensional software on the basis of an original smooth structure surface, selecting a curved surface or a plane corresponding to the structure to be supported and designed from the original smooth structure surface;

[0008] Step S3, translating the curved surface or the plane so that the distance between the curved surface or the plane and the root of the highest convex surface of the texture pattern in the structure to be supported and designed is one-third to one-half of the maximum convex length;

[0009] Step S4, supporting and designing below the translated curved surface or plane.

[0010] As a further preferred scheme of the application, forming a curved surface or a plane consistent with the outer surface shape of the structure to be supported and designed according to the outer surface shape of the structure to be supported and designed specifically comprises the following steps:

[0011] selecting all convex surfaces in the structure to be supported and designed, and randomly finding points on all convex surfaces along the extension trend of the texture pattern, determining a new curved surface or plane according to the positions of all randomly found points, and the curved surface or plane is consistent with the outer surface shape of the structure to be supported and designed.

[0012] As a further preferred scheme of the application, forming a curved surface or a plane consistent with the outer surface shape of the structure to be supported and designed according to the outer surface shape of the structure to be supported and designed specifically comprises the following steps:

[0013] Select all the surfaces between the convex surface and the concave surface in the design structure to be supported, and randomly find points on all the surfaces along the extension trend of the texture pattern, and determine a new curved surface or plane according to the positions of all the randomly found points, and the curved surface or plane is consistent with the shape of the outer surface of the design structure to be supported.

[0014] As a further preferred scheme of the present application, the curved surface or plane has the same length and width as the design structure to be supported.

[0015] As a further preferred scheme of the present application, the curved surface or plane has a distance from the root of the highest convex surface in the design structure to be supported, which is one-half of the length of the highest convex surface.

[0016] As a further preferred scheme of the present application, the curved surface or plane has a distance from the root of the highest convex surface in the design structure to be supported, which is -0.02-0.15 mm of the length of the highest convex surface.

[0017] As a further preferred scheme of the present application, the convex or concave length and width of the convex surface and the concave surface of the texture pattern are less than or equal to 2 mm.

[0018] As a further preferred scheme of the present application, the specific parameters of the support design are as follows: the Z-axis offset is 0-0.1 mm, the offset without support is 0, and the offset of the vertical support wall is 0.

[0019] As a further preferred scheme of the present application, when the workpiece to be printed has two or more than two discontinuous design structures to be supported, the support design method described above is used for each design structure to be supported.

[0020] The present application also provides a 3D printing method, comprising the following steps:

[0021] All the design structures to be supported are selected from the workpiece to be printed, and the support design method for 3D printing described in any one of the above is used to support design each design structure to be supported to obtain a first support structure; the design structure to be supported is a structure with a texture pattern and a lower surface less than 45°;

[0022] All the structures in the workpiece to be printed except the design structure to be supported are supported and designed according to the prior art to obtain a second support structure; and the first support structure and the second support structure and the workpiece to be printed are formed by 3D printing together.

[0023] The support design method for 3D printing and the 3D printing method of the present application can greatly improve the support design efficiency of the workpiece to be printed with a pattern feature, and the part of the lower surface of the workpiece with a pattern can be completely supported, which can not only improve the forming ability of the workpiece, but also greatly improve the appearance quality of the pattern structure. In addition, the support structure formed by the method has complete tooth shape and continuity, and the support teeth do not extend into the position where the texture pattern is recessed, which does not bring trouble to post-processing, and ensures the printing effect, so that the workpiece is successfully printed. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The method flowchart of an embodiment of the support design method for 3D printing provided by the present application;

[0025] Figure 2 The local structure diagram of the workpiece to be printed in the present application;

[0026] Figure 3 The working state diagram of an embodiment of the support design method for 3D printing provided by the present application;

[0027] Figure 4 The working state diagram of another embodiment of the support design method for 3D printing provided by the present application;

[0028] Figure 5 The working state diagram of another embodiment of the support design method for 3D printing provided by the present application;

[0029] Markings in the figure:

[0030] 1, workpiece to be printed, 2, intermediate surface, 3, first support structure. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0032] As shown in Figure 1 The support design method for 3D printing of the present application is applied to a structure with a texture pattern and a lower surface less than 45° in the workpiece to be printed, and the method comprises the following steps:

[0033] Step S1, selecting a structure with a texture pattern and a lower surface less than 45°, denoted as a support design structure; as shown in Figure 2 Figure 2 ​The middle orange and orange-red color represents different degrees of inclination of the design structure to be supported, and the smaller the angle, the closer the color to red.

[0034] In step S2, a curved surface or a plane is formed according to the shape of the outer surface of the design structure to be supported, and the curved surface or the plane is consistent with the shape of the outer surface of the design structure to be supported. The curved surface or the plane does not have a texture pattern. Alternatively, when the structure with a texture pattern in the workpiece 1 to be printed is generated by three-dimensional software on the basis of an original smooth structure surface, a curved surface or a plane corresponding to the design structure to be supported is selected from the original smooth structure surface. The curved surface or the plane can be referred to as an intermediate surface 2. Preferably, the intermediate surface 2 has the same length and width as the design structure to be supported. Of course, the length and width of the intermediate surface 2 can also be slightly larger than the length and width of the design structure to be supported. As shown in FIG. 2, the blue part represents the original smooth structure surface, and the intermediate surface 2 is newly created. Figure 3 As shown in FIG. 3, the blue part represents the original smooth structure surface, and the intermediate surface 2 is newly created. Figure 3 As shown in FIG. 3, the blue part represents the original smooth structure surface, and the intermediate surface 2 is newly created. Figure 4 As shown in FIG. 3, the blue part represents the original smooth structure surface, and the intermediate surface 2 is newly created. Figure 4 As shown in FIG. 3, the blue part represents the original smooth structure surface, and the intermediate surface 2 is newly created.

[0035] In step S3, the curved surface or the plane is translated so that the distance between the curved surface or the plane and the root of the highest convex surface in the design structure to be supported is one-third to one-half of the maximum convex length. Preferably, the distance between the curved surface or the plane and the root of the highest convex surface in the design structure to be supported is one-half of the maximum convex length, or the distance between the curved surface or the plane and the root of the highest convex surface in the design structure to be supported is -0.02-0.15 mm. This can further ensure that the generated support has complete tooth shape and continuity, and further ensure the printing effect. The maximum convex length here is the convex length of the highest convex surface.

[0036] In step S4, the support is designed below the translated curved surface or plane.

[0037] As an embodiment of the present application, the step of forming a curved surface or a plane according to the shape of the outer surface of the design structure to be supported specifically includes the following steps:

[0038] All convex surfaces in the design structure to be supported are selected, and points are randomly found on all convex surfaces along the extension trend of the texture pattern. A new curved surface or plane is determined according to the positions of all randomly found points, and the curved surface or plane is consistent with the shape of the outer surface of the design structure to be supported.

[0039] As another embodiment of the present application, the step of forming a curved surface or a plane according to the shape of the outer surface of the design structure to be supported specifically includes the following steps:

[0040] Select all the surfaces between the convex surface and the concave surface in the to-be-supported design structure, and randomly find points on all the surfaces along the extension trend of the texture pattern. A new curved surface or plane is determined according to the positions of all the randomly found points, and the curved surface or plane is consistent with the shape of the outer surface of the to-be-supported design structure.

[0041] It should be noted that the random point finding refers to randomly finding one or more points for all the convex surfaces or all the surfaces. It is not necessary to uniformly find points for each convex surface or surface. The points are mainly randomly found along the extension trend of the texture pattern, which can be automatically implemented by existing software, and belongs to the prior art. Therefore, it is not specifically described.

[0042] In order to better support the lower surface of the texture pattern, preferably, the specific parameters of the support design are that the Z-axis offset is 0-0.1mm, the support offset is 0, and the vertical support wall offset is 0.

[0043] It should be noted that the technical solution of the present application is preferably applied to the convex or concave length and width of the convex surface and the concave surface of the texture pattern, which are less than or equal to 2mm. The specific meaning of this sentence is that the convex length and width of all the convex surfaces are less than or equal to 2mm; and the concave length and width of all the concave surfaces are less than or equal to 2mm. If the convex length and width of the convex surface and the concave surface of the texture pattern exceed this size, in order to better ensure the support effect of the texture pattern, the texture needs to be individually supported according to the size of the area.

[0044] Specifically, when the to-be-printed workpiece 1 has two or more than two discontinuous to-be-supported design structures, the support design method of any one of the above is used for support design for each to-be-supported design structure; of course, if it is several continuous to-be-supported design structures, it only needs to be combined into one to-be-supported design structure, and the support design method is referred to for support design.

[0045] The present application also provides a 3D printing method, comprising the following steps:

[0046] All to-be-supported design structures are selected from the to-be-printed workpiece 1, and the support design method for 3D printing of any one of the above is used for support design of each to-be-supported design structure to obtain a first support structure 3, as shown in Figure 5 The to-be-supported design structure is a structure with a texture pattern and a lower surface less than 45°;

[0047] All structures except the to-be-supported design structure in the to-be-printed workpiece 1 are support designed according to the prior art to obtain a second support structure; and the first support structure 3 and the second support structure are combined with the to-be-printed workpiece 1 to form a 3D printing.

[0048] It should be noted that the core of the present application is to support the structure with texture patterns and a lower surface less than 45° in the workpiece 1 to be printed according to the above technical solution of the present application to obtain the first support structure 3, so the specific method of the design of the second support structure and the overall printing of the first and second support structures and the workpiece 1 to be printed is not described in detail, which belongs to the conventional technology in the art.

[0049] In order for those skilled in the art to better understand and implement the technical solutions of the present application, the technical solutions of the present application are specifically described in the form of examples as follows.

[0050] Example 1

[0051] After the workpiece is well positioned by the support design software, the position with texture patterns and less than 45° that needs to be supported is found, which is referred to as a design structure to be supported, all convex surfaces in the design structure to be supported are selected, and points are randomly found on all convex surfaces along the extension trend of the texture patterns. According to the positions of all the randomly found points, a new curved surface or plane (also referred to as an intermediate surface 2) is determined, and the curved surface or plane is consistent with the shape of the outer surface of the design structure to be supported. Since the position of the intermediate surface 2 is at the outermost end of the texture, the position contacted with the entire texture is less, so the support made in this way cannot well contact with the texture, and therefore the newly established surface needs to be offset. The offset distance is half the size of the convexity of the texture, and the offset direction is to move along the direction of the root of the texture. For example, the size of the convexity of the texture on the texture is 0.2 mm, a new surface is generated by drawing at the outermost end of the texture, and then the new surface is offset inward, so that the distance between the outermost end of the texture and the new surface is 0.2÷2=0.1 mm. Then the new surface is imported together with the workpiece that needs to be supported on the platform, and the relative position with the workpiece is kept unchanged. When supporting, the surface at the texture can directly select the newly established surface to generate support (as shown in Figure 3 After the design of the support to be supported, the support generated on the newly established surface is exported separately, and the export mode of the workpiece is unchanged, so that the support design of the small triangular patches at the texture can be quickly completed. Moreover, this design method can not only ensure that the generated support has complete tooth shape and continuity, but also the teeth of the support will not stretch into the position where the texture is recessed, which will not bring trouble to the post-processing, and can ensure the printing effect, so that the workpiece can be successfully printed.

[0052] Example 2

[0053] The structure with large-area pattern texture is generally designed and generated in three-dimensional software, and is generated on the basis of the original smooth structure surface, so when designing the support at the lower surface with an angle of <45° in the large-area pattern texture structure, we can first confirm the pattern surface that needs to be supported in the support design software, then export the original drawing before generating the pattern from the three-dimensional software in STL format, and align it with the drawing for generating the pattern and place it in the support design software. In the original drawing without pattern (denoted as B), the surface that needs to be supported in the original drawing with pattern (denoted as A) is copied, and then B is hidden or deleted, only A drawing and the copied smooth surface are left as a newly created surface (also referred to as intermediate surface 2). Before formal support design, the new surface is offset, the offset distance is (pattern protrusion height-0.02~0.15mm), and the offset surface is marked with color, in order to facilitate the differentiation when supporting. When designing the support, the first step is to select the surface that needs to be supported on the entire merged workpiece, and the original smooth surface on the workpiece is still selected according to the conventional method. The new surface (the size of a single pattern is limited to ≤2mm in length and width, if the size exceeds this, the pattern needs to be supported individually according to the size of the area) that has been merged with the workpiece in the previous step is selected, and then the support is designed according to the conventional method. After the support is designed, the support file is exported, and the support file is saved in the folder of the workpiece drawing that has been exported before. It is worth noting that during the support design process, the support parameters need to be adjusted for those supports generated on the new surface, because these supports will eventually come into contact with the concave-convex surface of the pattern. In order to better support the lower surface of the concave-convex surface of the pattern, the "Z-axis offset" in the support parameters of these positions is set to 0~0.1mm, the "no support offset" is set to 0, and the "vertical support wall offset" is set to 0.

[0054] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0055] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A support design method for 3D printing, applied to a structure having a textured pattern in a workpiece to be printed and a lower surface of less than 45°, characterized in that, The method comprises the following steps: Step S1, selecting a structure with a texture pattern and a lower surface less than 45°, denoted as a to-be-supported design structure; Step S2, forming a curved surface or a plane consistent with the outer surface shape of the to-be-supported design structure according to the outer surface shape of the to-be-supported design structure, the curved surface or the plane not having a texture pattern; or, when the structure with the texture pattern in the to-be-printed workpiece is generated by three-dimensional software on the basis of an original smooth structure surface, selecting the curved surface or the plane corresponding to the to-be-supported design structure from the original smooth structure surface; Step S3, translating the curved surface or the plane so that the distance between the curved surface or the plane and the root of the highest convex surface of the texture pattern in the to-be-supported design structure is one third to one half of the maximum convex length; Step S4, supporting the design below the translated curved surface or plane.

2. The support design method for 3D printing according to claim 1, wherein, Forming a curved surface or a plane consistent with the outer surface shape of the to-be-supported design structure according to the outer surface shape of the to-be-supported design structure specifically comprises the following steps: selecting all convex surfaces in the to-be-supported design structure, and randomly finding points on all the convex surfaces along the extension trend of the texture pattern, determining a new curved surface or plane according to the positions of all the randomly found points, and the curved surface or plane being consistent with the outer surface shape of the to-be-supported design structure.

3. The support design method for 3D printing according to claim 1, wherein, Forming a curved surface or a plane consistent with the outer surface shape of the to-be-supported design structure according to the outer surface shape of the to-be-supported design structure specifically comprises the following steps: selecting all surfaces between the convex surfaces and the concave surfaces in the to-be-supported design structure, and randomly finding points on all the surfaces along the extension trend of the texture pattern, determining a new curved surface or plane according to the positions of all the randomly found points, and the curved surface or plane being consistent with the outer surface shape of the to-be-supported design structure.

4. Support design method for 3D printing according to any one of claims 1 to 3, characterized in that, The curved surface or plane has the same length as the to-be-supported design structure and also has the same width.

5. The support design method for 3D printing according to claim 4, characterized in that, The curved surface or plane has a distance of one half of the maximum convex length from the root of the highest convex surface in the to-be-supported design structure.

6. The support design method for 3D printing according to claim 4, wherein, The curved surface or plane has a distance of -0.02-0.15 mm from the root of the highest convex surface in the to-be-supported design structure.

7. The support design method for 3D printing according to claim 1, wherein, The convex or concave length and width of the convex surface and the concave surface of the texture pattern are less than or equal to 2 mm.

8. The support design method for 3D printing according to claim 1, wherein, The specific parameters of the support design are that the Z-axis offset is 0-0.1 mm, the support offset is 0, and the vertical support wall offset is 0.

9. A support design method for 3D printing, characterized by, When the to-be-printed workpiece has two or more than two discontinuous to-be-supported design structures, the support design method of any one of claims 1-8 is used for support design for each to-be-supported design structure.

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