An additive manufacturing support structure for an elliptical thin-walled cabin section

Abstract

This invention relates to a support structure for additive manufacturing of elliptical thin-walled compartment sections, belonging to the field of additive manufacturing technology for thin-walled compartment sections. Addressing the challenges of shape control in additive manufacturing and post-processing of elliptical thin-walled compartment sections, this invention proposes a multi-layered support structure design. This support structure employs a combination of a cylindrical internal support structure, ribs, and thin-plate supports, providing layered internal support and shaping for the elliptical thin-walled compartment section. This transforms the unstable elliptical cross-sectional structure into a stable approximately circular, triangular, or rhomboid cross-sectional structure, ensuring the support structure's stability and enabling effective control of deformation during additive manufacturing and post-processing of the elliptical thin-walled compartment, thereby improving the overall efficiency of additive manufacturing.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology for thin-walled compartments, and more particularly to an additive manufacturing support structure for elliptical thin-walled compartments. Background Technology

[0002] With the development of high-end manufacturing, in fields such as aerospace and transportation, the structural forms of cabin components are constantly breaking through the limits of traditional manufacturing processes, continuously evolving towards irregular shapes and thin walls. Typically, cabin structures have a circular cross-section, with an overall three-dimensional cylindrical shape, exhibiting symmetry and uniformity, thus ensuring good structural stability and easy deformation control. However, with the evolution of component structures, the traditional circular cross-section has gradually evolved into irregular, non-circular elliptical cross-sections, accompanied by thinner walls, more features, and higher requirements for surface precision. Compared to standard cylindrical cabin sections, these irregularly shaped elliptical cross-section cabin sections face challenges in additive manufacturing, including uneven internal stress distribution, greater deformation tendencies, and highly complex shape control.

[0003] In existing technologies, internally supported dimensional structures are typically introduced to address the support and stability issues in additive manufacturing of thin-walled parts. For elliptical thin-walled sections, the internal stress distribution is uneven, deformation is significant, and structural stability is low. Traditional methods, such as using ribs and lattice dimensional structures, while applicable to deformation control in additively manufactured sections, are ineffective for elliptical thin-walled sections. While denser internally supported dimensional structures, such as those with dense mesh filling, provide better support, they also lead to material waste and increased printing time, hindering cost control and manufacturing efficiency.

[0004] Therefore, for elliptical thin-walled compartments, it is necessary to develop an additive manufacturing support structure that can effectively control deformation, has a simple structure, and is low in cost. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide an additive manufacturing support structure for elliptical thin-walled compartments to solve at least one of the following problems in existing additive manufacturing of elliptical thin-walled compartments: difficulty in controlling deformation, poor surface accuracy, and waste of internal support material.

[0006] This invention provides an additive manufacturing support structure for an elliptical thin-walled compartment section, the support structure comprising a support body and support members;

[0007] The support body consists of two cylindrical internal support structures symmetrically arranged on both sides of the center line of the short axis of the inner surface of the elliptical thin-walled section.

[0008] The support includes a rib plate arranged along the minor axis between two cylindrical internal support structures. The rib plate is parallel to the minor axis and penetrates the interior of the elliptical thin-walled section. Its two ends are respectively connected to the inner side of the straight section sidewall on both sides of the minor axis of the elliptical thin-walled section.

[0009] The support also includes a thin plate support, which is disposed in the area between the inner surface of the elliptical thin-walled section, the support body, and the ribs. The support body and the support divide the elliptical section into circular, triangular, and / or rhomboid sections.

[0010] Furthermore, the centers of the two cylindrical internal support structures are respectively located at two eccentric points on the major axis diameter of the elliptical thin-walled compartment, and the outer surface of the cylindrical internal support structure does not directly contact the inner surface of the elliptical thin-walled compartment.

[0011] Furthermore, the outer radius of the cylindrical inner support structure is set as the shortest distance between the center of the cylindrical inner support structure and the inner surface of the elliptical thin-walled section minus the minimum processing spacing.

[0012] Furthermore, the ribs may be one or more, the minimum distance between the ribs and the inner support structure of the cylinder is set as the minimum processing spacing, and / or the spacing between the plurality of ribs is the minimum processing spacing.

[0013] Furthermore, one end of the thin plate support located between the support body and the rib is connected to the outer surface of the cylindrical inner support structure, and the other end is connected to the rib, with the orientation pointing towards the center of the cylindrical inner support structure.

[0014] Furthermore, the thin plate support located in the arc segment of the elliptical thin-walled compartment is configured such that one end is connected to the inner wall of the arc segment of the elliptical thin-walled compartment, and the other end is connected to the outer surface of the cylindrical inner support structure, with the direction pointing towards the center of the arc segment of the elliptical thin-walled compartment.

[0015] Furthermore, the thin plate support located on the straight section of the elliptical thin-walled compartment is configured such that one end is connected to the inner wall of the straight section of the elliptical thin-walled compartment, the connection point is the point where the deformation curvature is the maximum when the straight section is unsupported, the thin plate support passes through the center of the circle of deformation curvature when unsupported at the connection point, and the other end is connected to the cylindrical inner support structure, rib plate or other thin plate support.

[0016] Furthermore, the internal support structure of the cylinder is a multi-layered cylindrical structure, and the multi-layered cylinders are connected by a lattice, truss, or thin plate.

[0017] Furthermore, each of the ribs is a multi-layered plate, and the multi-layered plates are connected by a lattice, truss or thin plate, forming triangles and / or rhombuses between the multi-layered plates.

[0018] On the other hand, the present invention discloses an additive manufacturing method for an elliptical thin-walled compartment, comprising: constructing the aforementioned support structure.

[0019] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0020] 1. This invention employs support bodies and support components to internally support and shape the elliptical thin-walled cabin section in layers, transforming the unstable elliptical cross-sectional structure into a stable approximately circular, triangular, or rhomboid cross-sectional structure, thereby achieving effective control over the surface accuracy of the additive manufacturing of the elliptical thin-walled cabin structure.

[0021] 2. This invention utilizes simulation analysis to simulate the thin plate support component, obtains the model deformation results, and adds the thin plate support component at the center of the deformation curvature circle passing through the deformation point. This solves the problem of difficulty in determining the thin plate support component and makes it easy to determine the position and set up the thin plate support component.

[0022] 3. The present invention adopts a combination of cylindrical internal support structure, rib plate and thin plate support component. With a simple structure, it maximizes the expansion of the internal space of the internal support structure while ensuring the support strength, saving the amount of material used in the internal support structure and improving the efficiency of additive manufacturing.

[0023] 4. This invention achieves easy removal of the internal support structure after additive manufacturing by thinning the part connecting the internal surface of the internal support structure and the elliptical thin-walled compartment; and saves the overall printing time of the model by setting a lower additive manufacturing energy density for the internal support structure model.

[0024] 5. This invention utilizes a support structure as a tooling fit structure in the post-processing process, extending the control of the internal support structure used in additive manufacturing to the post-processing process. This facilitates the assembly and clamping of the elliptical thin-walled compartment body and its internal support structure during post-processing, achieving full-process shape control from additive manufacturing to post-processing, and saving overall product manufacturing time and costs.

[0025] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0027] Figure 1a This is a schematic diagram of the elliptical thin-walled compartment body model;

[0028] Figure 1b This is a cross-sectional view of the AA section of the elliptical thin-walled compartment model.

[0029] Figure 2 This is a schematic diagram of the cross-section of the additive manufacturing support structure of the present invention;

[0030] Figure 3 This is a schematic diagram of the deformation of the straight section of the elliptical thin-walled compartment.

[0031] Figure 4 This is a schematic diagram of the cross-section of the elliptical thin-walled section and its supporting structure in Example 1;

[0032] Figure 5 This is a schematic diagram of the cross-section of the elliptical thin-walled section and its supporting structure in Example 2;

[0033] Figure 6 This is a schematic diagram of the elliptical thin-walled compartment body in Embodiment 3;

[0034] Figure 7 This is a schematic diagram of the elliptical thin-walled section and its supporting structure in Example 3;

[0035] Figure 8 This is a schematic diagram of the thin-plate support and the component in Embodiment 3;

[0036] Figure 9 This is a diagram showing the deformation effect of a part manufactured using direct additive manufacturing in Example 3;

[0037] Figure 10 This is a diagram illustrating the deformation effect of the part after the support structure according to the present invention has been controlled in Example 3.

[0038] Figure 11 This is a schematic diagram of the internal support structure and fitting tooling in Example 3.

[0039] Figure label:

[0040] 1-Elliptical thin-walled section; 2-Cylindrical internal support structure; 3-Rib plate; 4-Thin plate support; First thin plate support 401; Second thin plate support 402; Third thin plate support 403; 5-Matching tooling. Detailed Implementation

[0041] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0042] One specific embodiment of the present invention discloses an additive manufacturing support structure for an elliptical thin-walled compartment.

[0043] like Figures 1a-1b As shown, the elliptical thin-walled section 1 has a flattened elliptical cross-section with a major axis and a minor axis, corresponding to a major axis centerline and a minor axis centerline. The middle section is a straight line segment, and the two sides are circular arc segments. For example, the ratio of the major axis diameter X to the minor axis diameter Y is greater than 1.2.

[0044] like Figure 2 As shown in the cross-sectional view, the supporting structure is an internally supported dimensional structure of the elliptical thin-walled section 1, including the supporting body and supporting components;

[0045] Among them, the support body consists of two cylindrical internal support structures 2 symmetrically arranged on both sides of the center line of the short axis of the inner surface of the elliptical thin-walled section 1;

[0046] The support includes a rib 3 located between the two cylindrical inner support structures 2 along the short axis direction. The rib 3 is parallel to the short axis direction and penetrates the interior of the elliptical thin-walled section 1. Its two ends are respectively connected to the inner side of the straight section sidewall on both sides of the short axis direction of the elliptical thin-walled section 1, supporting the inner surface of the elliptical thin-walled section 1 along the short axis direction.

[0047] The support also includes a thin plate support 4, which is disposed in the area between the inner surface of the elliptical thin-walled section 1, the support body, and the rib plate 3. The support body and the support divide the elliptical cross-section structure into circular, triangular, and / or rhomboid cross-section structures.

[0048] In the support structure of the present invention, the elliptical thin-walled cabin section is internally supported and shaped in layers through the design of the internal support structure of the support members and the support body, so as to transform the unstable elliptical cross-section structure into a stable cross-section structure such as an approximate circle, triangle or rhombus, thereby achieving effective control of the surface accuracy of the additive manufacturing of the elliptical thin-walled cabin structure.

[0049] Preferably, the outer surface of the cylindrical internal support structure 2 is set to be as close as possible to the inner surface of the elliptical thin-walled section 1, and the outer radius of the cylindrical internal support structure 2 is set as the shortest distance between the center of the cylindrical internal support structure 2 and the inner surface of the elliptical thin-walled section 1 minus the minimum machining spacing. The minimum machining spacing is the distance between the outer surface of the cylindrical internal support structure 2 and the inner surface of the cylindrical section where they are closest, and is set according to the machining requirements after removing the internal support structure in additive manufacturing. The value of the minimum machining spacing is 5 to 50 mm.

[0050] Specifically, when half of the major axis diameter of the inner surface of the elliptical thin-walled compartment 1 is greater than the minor axis diameter, the shortest distance between the center of the cylindrical internal support structure 2 and the inner surface of the elliptical thin-walled compartment 1 is in the minor axis direction, and the closest point is on the straight section wall. The outer radius of the cylindrical internal support structure 2 is set to half of the minor axis diameter minus the minimum machining spacing. When half of the major axis diameter of the inner surface of the elliptical thin-walled compartment 1 is less than the minor axis diameter, the shortest distance between the center of the cylindrical internal support structure 2 and the inner surface of the elliptical thin-walled compartment 1 is in the major axis direction, and the closest point is on the arc section wall. The outer radius of the cylindrical internal support structure 2 is set to one-quarter of the major axis diameter minus the minimum machining spacing.

[0051] For example, multiple ribs 3 are provided, and the thickness of each rib 3 is 1 to 3 times the minimum wall thickness of the elliptical thin-walled section 1. The closest distance to the cylindrical inner support structure 2 on both sides of the short axis centerline is set as the minimum processing spacing, and the spacing between the multiple ribs 3 is the minimum processing spacing.

[0052] Specifically, when half of the major axis diameter of the inner surface of the elliptical thin-walled section 1 is greater than the minor axis diameter, the distance between the two cylindrical internal support structures 2 is relatively large, and multiple ribs 3 are used for support. The rib 3 adjacent to the cylindrical internal support structure 2 is closest to the arc vertex of the cylindrical internal support structure 2, and this distance is set as the minimum processing spacing. When half of the major axis diameter of the inner surface of the elliptical thin-walled section 1 is less than the minor axis diameter, the distance between the two cylindrical internal support structures 2 is relatively small, and one rib 3 is used for support. In this case, the distance between the rib 3 and the arc vertex of the two cylindrical internal support structures 2 is set as the minimum processing spacing.

[0053] For example, the thin plate support 4 located between the support body and the rib 3 is configured such that one end is connected to the outer surface of the cylindrical inner support structure 2, and the other end is connected to the nearest rib 3, with its setting direction pointing towards the center of the cylindrical inner support structure 2.

[0054] Specifically, such as Figure 2 As shown, the thin plate support members 4 located between the support body and the rib plate 3 are symmetrically arranged about the short axis, with 5 on each side, for a total of 10. Among them, the 5 thin plate support members 4 located on the same side of the short axis are symmetrically arranged about the long axis. Specifically, each of them has one end connected to the outer surface of the cylindrical inner support structure 2 and the other end connected to the rib plate 3.

[0055] Specifically, such as Figure 4 As shown, the thin plate support members 4 located between the support body and the rib plate 3 are symmetrically arranged about the short axis, with 3 on each side, for a total of 6. Among them, the 3 thin plate support members 4 located on the same side of the short axis are symmetrically arranged about the long axis. Specifically, each of them has one end connected to the outer surface of the cylindrical inner support structure 2 and the other end connected to the rib plate 3.

[0056] For example, the thin plate support 4 located in the arc segment of the elliptical thin-walled compartment 1 is configured such that one end is connected to the inner wall of the arc segment of the elliptical thin-walled compartment 1, and the other end is connected to the outer surface of the cylindrical inner support structure 2, with the direction pointing towards the center of the arc segment of the elliptical thin-walled compartment 1.

[0057] Specifically, such as Figure 2 As shown, the thin plate support 4 located in the arc segment of the elliptical thin-walled compartment 1 is symmetrically arranged about the short axis, with 16 on each side. Two of them are located at the intersection of the arc segment and the straight segment. All of them are configured to have one end connected to the inner wall of the arc segment of the elliptical thin-walled compartment 1, and the other end connected to the outer surface of the cylindrical inner support structure 2, pointing towards the center of the arc segment of the elliptical thin-walled compartment 1.

[0058] Specifically, such as Figure 4 As shown, the thin plate support 4 located on the arc segment of the elliptical thin-walled compartment 1 is symmetrically arranged about the short axis, with 13 on each side. Two of them are located at the intersection of the arc segment and the straight segment. All of them are configured to have one end connected to the inner wall of the arc segment of the elliptical thin-walled compartment 1, and the other end connected to the outer surface of the cylindrical inner support structure 2, pointing towards the center of the arc segment of the elliptical thin-walled compartment 1.

[0059] For example, the thin-plate support 4 located on the straight section of the elliptical thin-walled compartment 1 is configured such that one end is connected to the inner wall of the straight section of the elliptical thin-walled compartment 1, with the connection point being the point of maximum deformation curvature when the straight section is unsupported. The thin-plate support 4 passes through the center of the circle of deformation curvature when unsupported at this connection point. The other end is connected to the cylindrical inner support structure 2, rib plate 3, or other thin-plate support 4. Specifically, such as... Figure 3 As shown in the figure, the dashed line represents the simulated deformation of the straight segment of the elliptical thin-walled section. The location where the supporting plate is added is the point where the curvature of the straight segment of the elliptical thin-walled section is at its maximum, and the direction of the added supporting plate is the center of the circle of curvature at that point. It should be noted that the deformation direction is not necessarily perpendicular to the straight segment.

[0060] Specifically, such as Figure 2 As shown, the thin-plate support members 4 located on the straight section of the elliptical thin-walled compartment 1 are symmetrical about the minor axis, with 12 on each side. Among them, 2 on each side are located at the intersection of the arc segment and the straight segment, with one end connected to the inner wall of the straight section of the elliptical thin-walled compartment 1 and the other end connected to the outer surface of the cylindrical internal support structure 2, pointing towards the center of the arc segment of the elliptical thin-walled compartment 1; 8 on each side are configured with one end connected to the inner wall of the straight section of the elliptical thin-walled compartment 1 and the other end connected to the outer surface of the cylindrical internal support structure 2, with the direction passing through the center of the circle of curvature when there is no support at the connection point with the elliptical thin-walled compartment 1; and 2 on each side are configured with one end connected to the inner wall of the straight section of the elliptical thin-walled compartment 1 and the other end connected to the rib plate 3, with the direction passing through the center of the circle of curvature when there is no support at the connection point with the elliptical thin-walled compartment 1.

[0061] Specifically, such as Figure 4 As shown, the thin plate support 4 located on the straight section of the elliptical thin-walled compartment 1 is symmetrically arranged about the short axis, with two on each side. It is located at the junction of the arc segment and the straight segment. One end is connected to the inner wall of the straight section of the elliptical thin-walled compartment 1, and the other end is connected to the outer surface of the cylindrical inner support structure 2. The direction is towards the center of the arc segment of the elliptical thin-walled compartment 1.

[0062] For example, the internal support structure 2 of the cylinder is set as a multi-layer cylinder structure. The multi-layer cylinders can be connected by means of lattice, truss, thin plate, etc. The multi-layer cylinders form a support structure with triangular or rhomboid cross sections. The total thickness of the internal support structure 2 of the cylinder is 1 to 3 times the minimum wall thickness of the elliptical thin-walled section 1.

[0063] Specifically, the thin plate support 4 includes a first thin plate support 401, a second thin plate support 40102, and a third thin plate support 403. The first thin plate support 401, the second thin plate support 402, and the third thin plate support 403 are disposed in the area between the inner surface of the elliptical thin-walled section, the support body, and the ribs. The support body and the support members divide the elliptical section into circular, triangular, and / or rhomboid sections.

[0064] For example, the rib plate 3 is set as a multi-layer plate, and the multi-layer plates can be connected by means of lattice, truss, thin plate, etc., forming a support structure with triangular or rhomboid cross sections between the multi-layer plates.

[0065] For example, the thickness of the thin plate support 4 is set to 1 to 3 times the minimum wall thickness of the elliptical thin-walled section 1.

[0066] For example, the thin plate support 4 is thinned near the inner surface of the elliptical thin-walled compartment 1, and the thinning thickness is 0.5 to 1 times the minimum wall thickness of the compartment.

[0067] For example, the additive manufacturing parameters for the elliptical thin-walled section 1 body are set to those of a general part with high fusion strength, such as a laser power of 250–400 W and a scanning speed of 950–1400 mm / s, scanning the border; while the solid support parameters with lower fusion strength are set to those of the inner support structure, such as a laser power of 250–320 W and a scanning speed of 1100–1600 mm / s, not scanning the border. Specifically, the additive manufacturing energy density of the elliptical thin-walled section 1 body model is set to 1.5–2 times that of the inner support structure model.

[0068] During implementation, the elliptical thin-walled section 1 body model, together with the cylindrical internal support structure 2, ribs 3, and thin-plate support components 4, are designed and additively manufactured as a whole to obtain the integral component. Post-processing is then performed on the integral component, including heat treatment and necessary machining of the external surfaces. After post-processing, the internal support structure is removed using wire cutting, machining, and fitter work.

[0069] For example, the additive manufacturing material in this invention is a titanium alloy, an aluminum alloy, or a high-temperature alloy.

[0070] For example, the support structure of the present invention can be used as a tooling fit structure in the post-processing stage. Post-processing includes heat treatment and machining of the elliptical thin-walled section 1. Figure 11 As shown, the support structure is connected to the mating fixture to facilitate clamping the integral component during post-processing. Specifically, the mating fixture is a cover plate with two cylindrical protrusions. The outer diameter of the protrusions is the same as the inner diameter of the cylindrical inner support structure 2, and the protrusions can be engaged with the cylindrical inner support structure 2.

[0071] On the other hand, the present invention discloses an additive manufacturing method for an elliptical thin-walled compartment segment, comprising: constructing the above-mentioned support structure by additive manufacturing of the elliptical thin-walled compartment segment.

[0072] The additive manufacturing model design method specifically includes the following steps:

[0073] Step 1. Construct a model of the elliptical thin-walled section 1;

[0074] Step 2. Determine the center and outer radius of the cylindrical internal support structure 2 based on the major axis dimension and minimum machining spacing of the elliptical thin-walled section 1, and symmetrically set two cylindrical internal support structures 2 on both sides of the minor axis centerline of the inner surface of the elliptical thin-walled section 1.

[0075] Step 3. Determine the location of the rib plate 3 based on the major axis dimension of the elliptical thin-walled section 1 and the outer diameter dimension of the cylindrical internal support structure, and set the rib plate 3 along the minor axis direction between the two cylindrical internal support structures 2;

[0076] Step 4. Determine the setting direction of the first thin plate support 401 according to the center position of the cylindrical internal support structure 2. The first thin plate support 401 is connected to the outer surface of the cylindrical internal support structure 2 at one end and to the nearest rib 3 at the other end.

[0077] Step 5. Determine the setting direction of the second thin plate support 402 according to the center position of the arc segment of the elliptical thin-walled compartment 1. One end of the second thin plate support 402 is connected to the inner wall of the arc segment of the elliptical thin-walled compartment 1, and the other end is connected to the outer surface of the cylindrical inner support structure 2.

[0078] Step 6. Perform additive manufacturing simulation on the elliptical thin-walled compartment 1 model equipped with ribs 3, cylindrical internal support structure 2, first thin plate support 401, and second thin plate support 402 to obtain the model deformation results;

[0079] Step 7. Determine whether a thin-plate support needs to be added based on the deformation results. If the model deformation results do not meet the target deformation requirements in the design documents, then a thin-plate support needs to be added; if the model deformation results meet the target deformation requirements in the design documents, then it is determined to be an elliptical thin-walled compartment additive manufacturing model.

[0080] Step 8. Repeat steps 6 and 7 until the deformation of the simulated model meets the target deformation requirements in the design document.

[0081] like Figure 2 As shown in the cross-sectional view, the supporting structure is an internal support structure of the elliptical thin-walled section 1, including a cylindrical internal support structure 2, a rib plate 3, a first thin plate support member 401, a second thin plate support member 402, and a third thin plate support member 403.

[0082] In this invention, the elliptical thin-walled cabin segment is internally supported and shaped in layers through the design of an internally supported dimensional structure. This transforms the unstable elliptical cross-section structure into a stable cross-section structure, such as an approximate circle, triangle, or quadrilateral, thereby achieving effective control over the surface accuracy of the elliptical thin-walled cabin structure in additive manufacturing. Furthermore, based on the construction of the basic support structure model, this invention further introduces simulation analysis. The number and angle of the thin-plate supports are adjusted according to the simulation results, improving the efficiency of the additive manufacturing model design.

[0083] For example, in step 2, the centers of the two cylindrical internal support structures 2 are respectively set at two eccentric points on the major axis diameter of the inner surface of the elliptical thin-walled compartment, and the outer surface of the cylindrical internal support structure 2 does not directly contact the inner surface of the elliptical thin-walled compartment.

[0084] For example, in step 2, the outer surface of the cylindrical internal support structure 2 is set to be as close as possible to the inner surface of the elliptical thin-walled section 1, and the outer radius of the cylindrical internal support structure 2 is set as the shortest distance between the center of the cylindrical internal support structure 2 and the inner surface of the elliptical thin-walled section 1 minus the minimum processing spacing. The minimum processing spacing is the distance between the outer surface of the cylindrical internal support structure 2 and the inner surface of the cylindrical section where they are closest, and is set according to the processing requirements of removing the internal support structure after additive manufacturing. The value of the minimum processing spacing is 5 to 50 mm.

[0085] Specifically, when half of the major axis diameter of the inner surface of the elliptical thin-walled compartment 1 is greater than the minor axis diameter, the shortest distance between the center of the cylindrical internal support structure 2 and the inner surface of the elliptical thin-walled compartment 1 is in the minor axis direction, and the closest point is on the straight section wall. The outer radius of the cylindrical internal support structure 2 is set to half of the minor axis diameter minus the minimum machining spacing. When half of the major axis diameter of the inner surface of the elliptical thin-walled compartment 1 is less than the minor axis diameter, the shortest distance between the center of the cylindrical internal support structure 2 and the inner surface of the elliptical thin-walled compartment 1 is in the major axis direction, and the closest point is on the arc section wall. The outer radius of the cylindrical internal support structure 2 is set to one-quarter of the major axis diameter minus the minimum machining spacing.

[0086] For example, in step 2, the inner support structure 2 of the cylinder is set as a multi-layer cylinder structure. The multi-layer cylinders can be connected by means of lattice, truss, thin plate, etc. The multi-layer cylinders form a support structure with triangular or quadrilateral cross sections. The total thickness of the inner support structure 2 of the cylinder is 1 to 3 times the minimum wall thickness of the elliptical thin-walled section 1.

[0087] For example, in step 3, the rib 3 is set as one, which is set along the center line of the short axis. The thickness of the rib 3 is 1 to 3 times the minimum wall thickness of the elliptical thin-walled section 1. The closest distance between the rib 3 and the cylindrical inner support structure 2 on both sides of the center line of the short axis is set as the minimum processing spacing.

[0088] For example, in step 3, there are multiple ribs 3, and the thickness of each rib 3 is 1 to 3 times the minimum wall thickness of the elliptical thin-walled section 1. The closest distance to the cylindrical inner support structure 2 on both sides of the short axis centerline is set as the minimum processing spacing, and the spacing between the multiple ribs 3 is the minimum processing spacing.

[0089] Specifically, when half of the major axis diameter of the inner surface of the elliptical thin-walled section 1 is greater than the minor axis diameter, the distance between the two cylindrical internal support structures 2 is relatively large, and multiple ribs 3 are used for support. The rib 3 located adjacent to the cylindrical internal support structure 2 is closest to the arc vertex of the cylindrical internal support structure 2, and this distance is set as the minimum processing spacing. When half of the major axis diameter of the inner surface of the elliptical thin-walled section 1 is less than the minor axis diameter, the distance between the two cylindrical internal support structures 2 is relatively small, and one rib 3 is used for support. In this case, the distance between the rib 3 and the arc vertex of the two cylindrical internal support structures 2 is set as the minimum processing spacing.

[0090] For example, in step 3, the rib plate 3 is set as a multi-layer plate, and the multi-layer plates can be connected by means of lattice, truss, thin plate, etc., forming a support structure with triangular or quadrilateral cross sections between the multi-layer plates.

[0091] For example, in step 4, the first thin plate support 401 is positioned in the direction of the center of the cylindrical inner support structure; the thickness of the first thin plate support 401 is set to 1 to 3 times the minimum wall thickness of the elliptical thin-walled section 1.

[0092] Specifically, such as Figure 2 As shown, the first thin plate support member 401 located between the cylindrical inner support structure 2 and the rib plate 3 is symmetrically arranged about the short axis, with 5 on each side, for a total of 10. Among them, the 5 first thin plate support members 401 located on the same side of the short axis are symmetrically arranged about the long axis. Specifically, each of them has one end connected to the outer surface of the cylindrical inner support structure 2 and the other end connected to the rib plate 3.

[0093] Specifically, such as Figure 4 As shown, the first thin plate support member 401 located between the cylindrical inner support structure 2 and the rib plate 3 is symmetrically arranged about the short axis, with 3 on each side, for a total of 6. Among them, the 3 first thin plate support members 401 located on the same side of the short axis are symmetrically arranged about the long axis. Specifically, each of them has one end connected to the outer surface of the cylindrical inner support structure 2 and the other end connected to the rib plate 3.

[0094] For example, in step 5, the setting direction of the second thin plate support 402 is directed towards the center of the arc segment of the elliptical thin-walled compartment 1; the thickness of the second thin plate support 402 is set to 1 to 3 times the minimum wall thickness of the elliptical thin-walled compartment.

[0095] Specifically, such as Figure 2 As shown, the second thin plate support 402 located in the arc segment of the elliptical thin-walled compartment 1 is symmetrically arranged about the short axis, with 16 on each side. Two of them are located at the intersection of the arc segment and the straight segment. All of them are configured to have one end connected to the inner wall of the arc segment of the elliptical thin-walled compartment 1, and the other end connected to the outer surface of the cylindrical inner support structure 2, pointing towards the center of the arc segment of the elliptical thin-walled compartment 1.

[0096] Specifically, such as Figure 4 As shown, the second thin plate support member 402 located in the arc segment of the elliptical thin-walled compartment 1 is symmetrically arranged about the short axis, with 13 on each side. Two of them are located at the intersection of the arc segment and the straight segment. All of them are configured to have one end connected to the inner wall of the arc segment of the elliptical thin-walled compartment 1, and the other end connected to the outer surface of the cylindrical inner support structure 2, pointing towards the center of the arc segment of the elliptical thin-walled compartment 1.

[0097] For example, in step 7, the direction of the added thin plate support is determined according to the deformation curvature of the straight section of the elliptical thin-walled compartment when it is unsupported; the added thin plate support is the third thin plate support 403, one end of the third thin plate support 403 is connected to the inner wall of the straight section of the elliptical thin-walled compartment, the connection point is the place where the deformation curvature is the maximum when the straight section is unsupported, the third thin plate support 403 passes through the center of the circle of deformation curvature when it is unsupported at the connection point, and the other end is connected to the cylindrical inner support structure, rib plate or the first thin plate support 401.

[0098] Specifically, such as Figure 3As shown in the figure, the dashed line portion represents the simulated deformation of the straight segment of the elliptical thin-walled compartment 1. The location where the third thin-plate support 403 is added is the point where the curvature of the straight segment of the elliptical thin-walled compartment 1 is at its maximum, and the direction of the third thin-plate support 403 is the center of the circle passing through the curvature of that point. It should be noted that the deformation direction of the straight segment of the elliptical thin-walled compartment 1 is not necessarily perpendicular to the straight segment.

[0099] Specifically, such as Figure 2 As shown, the third thin plate support 403 located on the straight section of the elliptical thin-walled compartment 1 is symmetrical about the minor axis, with 10 on each side. Among them, 8 on each side are configured to connect one end to the inner wall of the straight section of the elliptical thin-walled compartment 1 and the other end to the outer surface of the cylindrical inner support structure 2, with the direction passing through the center of the circle of curvature of deformation when there is no support at the connection point with the elliptical thin-walled compartment 1; and 2 on each side are configured to connect one end to the inner wall of the straight section of the elliptical thin-walled compartment 1 and the other end to the rib plate 3, with the direction passing through the center of the circle of curvature of deformation when there is no support at the connection point with the elliptical thin-walled compartment 1.

[0100] Specifically, such as Figure 5 As shown, the third thin plate support 403 located on the straight section of the elliptical thin-walled compartment 1 is symmetrically arranged about the short axis, with 6 on each side. It is configured such that one end is connected to the inner wall of the straight section of the elliptical thin-walled compartment 1, and the other end is connected to the outer surface of the cylindrical inner support structure 2. The direction passes through the center of the circle of curvature of the deformation when there is no support at the connection point with the elliptical thin-walled compartment 1.

[0101] For example, the second thin plate support 402 and the third thin plate support 403 are thinned near the part that connects with the inner surface of the elliptical thin-walled compartment 1, and the thinning thickness is 0.5 to 1 times the minimum wall thickness of the compartment.

[0102] Example 1

[0103] This embodiment provides an additive manufacturing support structure for an elliptical thin-walled section 1. For example... Figure 4 The schematic diagram of the cross-section of the parts and supporting structure is shown. The target part of the additive manufacturing is an elliptical thin-walled compartment 1 with a major axis diameter of 240mm, a minor axis diameter of 200mm, a minimum wall thickness of 2.5mm, and an aluminum alloy material.

[0104] Cylindrical internal support structures 2 are symmetrically arranged on both sides of the center line of the minor axis of the inner surface of the elliptical thin-walled section 1. The centers of the two cylindrical internal support structures 2 are respectively set at the points that are eccentrically divided into four parts (cross-shaped points in the figure) on the major axis diameter of the inner surface of the elliptical thin-walled section 1. The outer radius of the cylindrical internal support structure 2 is set as 1 / 4 of the major axis diameter of the elliptical thin-walled section 1 minus the minimum machining spacing of 15mm, which equals 45mm. The cylindrical internal support structure 2 is a concentric double-layer cylindrical structure. The thickness of each layer of the cylinder is 1.5mm, the distance between the two layers of cylinder is 2mm, and the total thickness of the cylindrical internal support structure 2 is 5mm. The two layers of cylinder are connected by thin plates.

[0105] A rib 3 is set between the two cylindrical internal support structures 2. The rib 3 is set perpendicular to the cross section along the short axis. The rib 3 penetrates the interior of the elliptical thin-walled section 1. Its two ends are respectively connected to the inner side of the straight section sidewall on both sides of the short axis of the elliptical thin-walled section 1. The rib 3 is composed of parallel double-layer plates. The thickness of each plate is 1.5mm. The distance between the double-layer plates is 3mm. The total thickness of the rib 3 is 6mm. The double-layer plates are connected by a dot matrix. The shortest distance between the rib 3 and the outer surface of the cylindrical internal support structures 2 on both sides is 12mm.

[0106] Multiple thin-plate supports 4, each 3mm thick, are installed perpendicular to the cross-section in the area between the inner surface of the elliptical thin-walled section 1, the cylindrical internal support structure, and the rib 3. The thin-plate supports 4 located between the support and the rib 3 are configured such that one end is connected to the outer surface of the cylindrical internal support structure 2, and the other end is connected to the rib 3, with their orientation pointing towards the center of the cylindrical internal support structure 2. The thin-plate supports 4 located in the arc segment of the elliptical thin-walled section 1 are configured such that one end is connected to the outer surface of the elliptical thin-walled section 1. The inner wall of the arc segment is connected, and the other end is connected to the outer surface of the cylindrical inner support structure 2, pointing towards the center of the arc segment of the elliptical thin-walled compartment 1 (X-shaped point in the figure); the thin plate support 4 located on the straight segment of the elliptical thin-walled compartment 1 is configured such that one end is connected to the inner wall of the straight segment of the elliptical thin-walled compartment 1, the connection point is the point where the deformation curvature is the maximum when the straight segment is unsupported, and the thin plate support 4 passes through the center of the circle of deformation curvature when unsupported at the connection point, and the other end is connected to the cylindrical inner support structure 2, rib plate 3 or other thin plate support 4.

[0107] Example 2

[0108] This embodiment provides an additive manufacturing support structure for an elliptical thin-walled section 1. For example... Figure 5 The schematic diagram of the cross-section of the parts and supporting structure is shown. The target part of the additive manufacturing is an elliptical thin-walled compartment 1 with a major axis diameter of 500 mm, a minor axis diameter of 200 mm, a minimum wall thickness of 3.5 mm, and a material of titanium alloy.

[0109] Cylindrical internal support structures 2 are symmetrically arranged on both sides of the center line of the minor axis of the inner surface of the elliptical thin-walled section 1. The centers of the two cylindrical internal support structures 2 are respectively set at the points that are off-center from the major axis diameter of the inner surface of the elliptical thin-walled section 1 (cross-shaped points in the figure). The outer radius of the cylindrical internal support structure 2 is set as 1 / 2 of the minor axis diameter of the elliptical thin-walled section 1 minus the minimum processing distance of 45mm, which equals 55mm. The cylindrical internal support structure 2 is a concentric double-layer cylindrical structure. The thickness of each layer of the cylinder is 2mm, the distance between the two layers of cylinder is 1mm, and the total thickness of the cylindrical internal support structure 2 is 5mm. The two layers of cylinder are connected by a truss.

[0110] Three ribs 3 are arranged between the two cylindrical internal support structures 2. The ribs 3 are perpendicular to the cross-section along the minor axis and penetrate the interior of the elliptical thin-walled section 1. Their two ends are connected to the inner sidewalls of the straight sections on both sides of the minor axis of the elliptical thin-walled section 1. Each rib 3 consists of parallel double-layer plates, each with a thickness of 2 mm. The distance between the double-layer plates is 4 mm, and the total thickness of each rib 3 is 8 mm. The double-layer plates are connected by trusses. The spacing between each rib 3 is 18 mm. The shortest distance between the rib 3 on the same side and the outer surface of the cylindrical internal support structure 2 is 35 mm.

[0111] Multiple thin-plate supports 4, each 4mm thick, are provided perpendicular to the cross-section in the area between the inner surface of the elliptical thin-walled section 1, the cylindrical internal support structure, and the rib 3. The thin-plate supports 4 located between the support and the rib 3 are configured such that one end is connected to the outer surface of the cylindrical internal support structure 2, and the other end is connected to the rib 3, with their orientation pointing towards the center of the cylindrical internal support structure 2. The thin-plate supports 4 located in the arc segment of the elliptical thin-walled section 1 are configured such that one end is connected to the outer surface of the elliptical thin-walled section 1. The inner wall of the arc segment is connected, and the other end is connected to the outer surface of the cylindrical inner support structure 2, pointing towards the center of the arc segment of the elliptical thin-walled compartment 1 (X-shaped point in the figure); the thin plate support 4 located on the straight segment of the elliptical thin-walled compartment 1 is configured such that one end is connected to the inner wall of the straight segment of the elliptical thin-walled compartment 1, the connection point is the point where the deformation curvature is the maximum when the straight segment is unsupported, and the thin plate support 4 passes through the center of the circle of deformation curvature when unsupported at the connection point, and the other end is connected to the cylindrical inner support structure 2, rib plate 3 or other thin plate support 4.

[0112] Example 3

[0113] This embodiment provides an additive manufacturing support structure for an elliptical thin-walled section 1. For example... Figure 6 As shown, the target part for additive manufacturing is an elliptical thin-walled compartment 1, with a major axis diameter of 400mm, a minor axis diameter of 200mm, a height of 200mm, a minimum wall thickness of 3mm, a major axis dimension of 400mm, and a material of titanium alloy.

[0114] The fitting is a cover plate with two cylindrical protrusions. The outer diameter of the protrusions is the same as the inner diameter of the cylindrical inner support structure 2. The protrusions can be engaged with the cylindrical inner support structure 2.

[0115] like Figure 7 As shown in the diagram of the elliptical thin-walled section 1 and its supporting structure, cylindrical internal support structures 2 are symmetrically arranged on both sides of the center line of the minor axis of the inner surface of the elliptical thin-walled section 1. The centers of the two cylindrical internal support structures 2 are respectively located at the points that are eccentrically divided by the major axis diameter of the inner surface of the elliptical thin-walled section 1. The outer radius of the cylindrical internal support structure 2 is set to 1 / 4 of the major axis diameter of the elliptical thin-walled section 1 minus the minimum machining spacing of 10mm, which equals 90mm. The cylindrical internal support structure 2 is a concentric double-layer cylindrical structure, with each layer of cylinder having a thickness of 2mm and a distance of 1mm between the two layers of cylinders. The total thickness of the cylindrical internal support structure 2 is 5mm, and the two layers of cylinders are connected by a dot matrix.

[0116] A rib 3 is set between the two cylindrical internal support structures 2. The rib 3 is set perpendicular to the cross section along the short axis. The rib 3 penetrates the interior of the elliptical thin-walled section 1, and its two ends are respectively connected to the inner side of the straight section sidewall on both sides of the short axis of the elliptical thin-walled section 1. The rib 3 is composed of parallel double-layer plates, each layer of which is 2.5 mm thick. The distance between the double-layer plates is 1 mm, and the total thickness of the rib 3 is 6 mm. The double-layer plates are connected by multiple thin plates. The two ends of the thin plates are respectively connected to the side of the double-layer plates at an angle. The thin plates are staggered in pairs to form an X shape. Several pairs of thin plates are distributed between the double-layer plates, so that the space between the double-layer plates forms a support structure with triangular and rhomboid cross sections. The shortest distance between the rib 3 and the outer surface of the two cylindrical internal support structures 2 is 7 mm.

[0117] Multiple thin-plate supports 4, each 3mm thick, are installed perpendicular to the cross-section in the area between the inner surface of the elliptical thin-walled section 1, the cylindrical internal support structure, and the rib 3. The thin-plate supports 4 located between the support and the rib 3 are configured such that one end is connected to the outer surface of the cylindrical internal support structure 2, and the other end is connected to the rib 3, with their orientation pointing towards the center of the cylindrical internal support structure 2. The thin-plate supports 4 located in the arc segment of the elliptical thin-walled section 1 are configured such that one end is connected to the elliptical thin-walled section 1. The inner wall of the arc segment of compartment 1 is connected to the outer surface of the cylindrical internal support structure 2, with the direction pointing towards the center of the arc segment of the elliptical thin-walled compartment 1; the thin plate support 4 located on the straight segment of the elliptical thin-walled compartment 1 is configured such that one end is connected to the inner wall of the straight segment of the elliptical thin-walled compartment 1, the connection point is the point where the deformation curvature is the maximum when the straight segment is unsupported, and the thin plate support 4 passes through the center of the circle of deformation curvature when unsupported at the connection point, and the other end is connected to the cylindrical internal support structure 2, rib plate 3 or other thin plate support 4.

[0118] The portion where the thin-plate support 4 connects to the inner surface of the elliptical thin-walled section 1 is thinned, such as... Figure 8 As shown, the thickness reduction is 2mm.

[0119] After simulating the deformation results of direct additive manufacturing of the elliptical thin-walled section 1 and additive manufacturing using the support structure of this invention, the results are shown in the following figures: Figure 9 and Figure 10 As shown in the figure, after adopting the support structure of the present invention, the large deformation of the original compartment was completely eliminated, and the maximum local deformation was reduced from 2.56 mm to 0.67 mm. This result indicates that the support structure of the present invention improves the stability and surface accuracy of the additive manufacturing of the elliptical thin-walled compartment 1, and effectively controls the deformation problem.

[0120] The elliptical thin-walled section 1 and its supporting structure are integrally additively manufactured. The energy density of the additive manufacturing of the elliptical thin-walled section 1 is set to twice that of the internal support structure to obtain the integral component.

[0121] After additive manufacturing is completed, using, for example Figure 11 The fixture shown, which can be connected to the internal support structure, clamps the entire component, and then the outer surface of the elliptical thin-walled section 1 is machined. After the outer surface is machined, the internal support structure is removed by wire cutting combined with fitter work. No subsequent straightening or other processes are required, thus achieving good surface accuracy control directly.

[0122] Example 4

[0123] This embodiment provides an additive manufacturing method for an elliptical thin-walled compartment segment, used for additive manufacturing of the elliptical thin-walled compartment segment with a support structure in Embodiment 3. The elliptical thin-walled compartment segment includes the elliptical thin-walled compartment segment part body and the support structure.

[0124] like Figure 6 As shown, the target part for additive manufacturing is an elliptical thin-walled compartment 1 with a major axis diameter of 400mm, a minor axis diameter of 200mm, a height of 200mm, a minimum wall thickness of 3mm, a major axis dimension of 400mm, and a material of titanium alloy. The design documents specify that the deformation for additive manufacturing should be less than ±0.8mm.

[0125] The additive manufacturing method specifically includes the following steps:

[0126] Step 1. Construct the model of the elliptical thin-walled section 1.

[0127] Step 2. Determine the center and outer radius of the cylindrical internal support structure 2 based on the major axis dimension and minimum machining spacing of the elliptical thin-walled section 1, and symmetrically set two cylindrical internal support structures 2 on both sides of the minor axis centerline of the inner surface of the elliptical thin-walled section 1.

[0128] Specifically, cylindrical internal support structures 2 are symmetrically arranged on both sides of the center line of the minor axis of the inner surface of the elliptical thin-walled section 1. The centers of the two cylindrical internal support structures 2 are respectively set at the points that are off-center from the quarter points of the major axis diameter of the inner surface of the elliptical thin-walled section 1. The outer radius of the cylindrical internal support structure 2 is set as 1 / 4 of the major axis diameter of the elliptical thin-walled section 1 minus the minimum machining spacing of 10mm, which equals 90mm. The cylindrical internal support structure 2 is a concentric double-layer cylindrical structure, with each layer of cylinder having a thickness of 2mm and a distance of 1mm between the two layers of cylinders. The total thickness of the cylindrical internal support structure 2 is 5mm, and the two layers of cylinders are connected by a dot matrix.

[0129] Step 3. Determine the location of the rib plate 3 based on the major axis dimension of the elliptical thin-walled section 1 and the outer diameter dimension of the cylindrical internal support structure, and set the rib plate 3 along the minor axis direction between the two cylindrical internal support structures 2;

[0130] Specifically, a rib plate 3 is set between the two cylindrical internal support structures 2. The rib plate 3 is set perpendicular to the cross section along the short axis direction. The rib plate 3 penetrates the interior of the elliptical thin-walled section 1, and its two ends are respectively connected to the inner side of the straight section sidewall on both sides of the short axis direction of the elliptical thin-walled section 1. The rib plate 3 is composed of parallel double-layer plates, each layer of which is 2.5mm thick. The distance between the double-layer plates is 1mm, and the total thickness of the rib plate 3 is 6mm. Multiple thin plates are used to connect the double-layer plates. The two ends of the thin plates are respectively connected to the side of the double-layer plates at an angle. The thin plates are staggered in pairs to form an X shape. Several pairs of thin plates are distributed between the double-layer plates, so that the space between the double-layer plates forms a support structure with triangular and quadrilateral cross sections. The shortest distance between the rib plate 3 and the outer surface of the two cylindrical internal support structures 2 is 7mm.

[0131] Step 4. Determine the setting direction of the first thin plate support 401 according to the center position of the cylindrical internal support structure 2. The first thin plate support 401 is connected to the outer surface of the cylindrical internal support structure 2 at one end and to the nearest rib 3 at the other end.

[0132] Specifically, the thickness of the first thin plate support 401 is 3mm. The first thin plate support 401 is symmetrically arranged about the short axis, with 3 on each side, for a total of 6. Among them, the 3 first thin plate support 401 located on the same side of the short axis are symmetrically arranged about the long axis. Specifically, each of them has one end connected to the outer surface of the cylindrical inner support structure 2 and the other end connected to the rib plate 3, pointing towards the center of the cylindrical inner support structure 2.

[0133] Step 5. Determine the setting direction of the second thin plate support 402 according to the center position of the arc segment of the elliptical thin-walled compartment 1. One end of the second thin plate support 402 is connected to the inner wall of the arc segment of the elliptical thin-walled compartment 1, and the other end is connected to the outer surface of the cylindrical inner support structure 2.

[0134] Specifically, the thickness of the second thin plate support 402 is 3mm. The second thin plate support 402 is symmetrically arranged about the short axis, with 10 on each side. Two of them are located at the intersection of the arc segment and the straight segment. All of them are configured to connect one end to the inner wall of the arc segment of the elliptical thin-walled compartment 1 and the other end to the outer surface of the cylindrical inner support structure 2, pointing towards the center of the arc segment of the elliptical thin-walled compartment 1.

[0135] Step 6. Perform additive manufacturing simulation on the elliptical thin-walled compartment 1 model, which is equipped with ribs 3, cylindrical internal support structure 2, first thin plate support 401, and second thin plate support 402, and obtain the model deformation results.

[0136] Step 7. Determine whether a thin plate support needs to be added based on the deformation results; if the model deformation results do not meet the target deformation requirements in the design documents, then add a third thin plate support 403; one end of the third thin plate support 403 is connected to the inner wall of the straight section of the elliptical thin-walled compartment, and the connection point is the point where the deformation curvature is the maximum when the straight section is unsupported. The third thin plate support 403 passes through the center of the circle of deformation curvature when the connection point is unsupported, and the other end is connected to the cylindrical inner support structure, rib plate or the first thin plate support 401.

[0137] Step 8. Repeat steps 6 and 7 until the maximum deformation of the simulated elliptical thin-walled section 1 model is less than ±0.8 mm, meeting the target deformation requirements in the design documents. In this embodiment, steps 6 and 7 are repeated four times to obtain the following result. Figure 7 The part body and its supporting structure are shown. The added third thin-plate support members are symmetrical about the short axis, with 6 on each side; 4 on each side are configured such that one end connects to the inner wall of the straight section of the elliptical thin-walled compartment 1, and the other end connects to the outer surface of the cylindrical inner support structure 2, with the direction passing through the center of the circle of curvature of the deformation when there is no support at the connection point with the elliptical thin-walled compartment 1; 2 on each side are configured such that one end connects to the inner wall of the straight section of the elliptical thin-walled compartment 1, and the other end connects to the rib plate 3, with the direction passing through the center of the circle of curvature of the deformation when there is no support at the connection point with the elliptical thin-walled compartment 1.

[0138] After simulating the deformation results of direct additive manufacturing of the elliptical thin-walled section 1 and additive manufacturing using the support structure of this invention, the results are shown in the following figures: Figure 9 and Figure 10 As shown in the figure, after adopting the support structure of the present invention, the large deformation of the original compartment was completely eliminated, and the maximum local deformation was reduced from 2.56 mm to 0.67 mm. This result indicates that the support structure of the present invention improves the stability and surface accuracy of the additive manufacturing of the elliptical thin-walled compartment 1, and effectively controls the deformation problem.

[0139] Specifically, during the model design phase, the portions connecting the second thin-plate support 402 and the third thin-plate support 403 to the inner surface of the elliptical thin-walled section 1 are thinned, such as... Figure 8 As shown, the thickness reduction is 2mm.

[0140] Elliptical thin-walled section 1 and its supporting structure are integrally additively manufactured. The volume energy density of the elliptical thin-walled section 1 is set to twice that of the internal support structure to obtain the integral component.

[0141] After additive manufacturing is completed, using, for example Figure 11 The fitting fixture 5, which connects to the internal support structure, clamps the integral component, and then the outer surface of the elliptical thin-walled section 1 is machined. The fitting fixture 5 is a cover plate with two cylindrical protrusions. The outer diameter of the protrusions is the same as the inner diameter of the cylindrical internal support structure 2, and the protrusions can engage with the cylindrical internal support structure 2. After the outer surface is machined, the internal support structure is removed by wire cutting and fitter work. No subsequent straightening or other processes are required, achieving good surface accuracy control directly.

[0142] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for additive manufacturing of an elliptical thin-walled compartment section, characterized in that, This includes constructing the following support structure and performing additive manufacturing based on the constructed support structure; the cross-sectional shape of the elliptical thin-walled section is a flat ellipse, with a major axis and a minor axis, a major axis centerline and a minor axis centerline, a straight section in the middle, and circular arc sections on both sides; the ratio of the major axis diameter X to the minor axis diameter Y of the elliptical thin-walled section is greater than 1.2; The support structure includes a support body and support components; The support body consists of two cylindrical internal support structures symmetrically arranged on both sides of the center line of the short axis of the inner surface of the elliptical thin-walled section. The support includes a rib plate arranged along the minor axis between two cylindrical internal support structures. The rib plate is parallel to the minor axis and penetrates the interior of the elliptical thin-walled section. Its two ends are respectively connected to the inner side of the straight section sidewall on both sides of the minor axis of the elliptical thin-walled section. The support also includes a thin plate support, which is disposed in the area between the inner surface of the elliptical thin-walled section, the support body, and the ribs. The support body and the support divide the elliptical section into circular, triangular, and / or rhomboid sections. The method for constructing the support structure includes: Step 1. Construct an elliptical thin-walled section model; Step 2. Determine the center and outer radius of the cylindrical internal support structure based on the major axis diameter and minimum machining spacing of the elliptical thin-walled section. Set two cylindrical internal support structures symmetrically on both sides of the minor axis centerline of the inner surface of the elliptical thin-walled section. Step 3. Determine the rib placement position based on the major axis diameter of the elliptical thin-walled section and the outer diameter of the cylindrical internal support structure, and place the rib along the minor axis between the two cylindrical internal support structures; Step 4. Determine the setting direction of the first thin plate support member according to the center position of the cylindrical internal support structure. The first thin plate support member is connected to the outer surface of the cylindrical internal support structure at one end and to the nearest rib at the other end. Step 5. Determine the setting direction of the second thin plate support according to the center position of the arc segment of the elliptical thin-walled compartment. The second thin plate support is connected to the inner wall of the arc segment of the elliptical thin-walled compartment at one end and to the outer surface of the cylindrical inner support structure at the other end. Step 6. Perform additive manufacturing simulation on the elliptical thin-walled compartment model equipped with ribs, cylindrical internal support structure, first thin plate support, and second thin plate support to obtain the model deformation results; Step 7. Determine whether a thin-plate support needs to be added based on the deformation results. If the model deformation results do not meet the target deformation requirements in the design documents, then a thin-plate support needs to be added; if the model deformation results meet the target deformation requirements in the design documents, then it is determined to be an elliptical thin-walled compartment additive manufacturing model. Step 8. Repeat steps 6 and 7 until the deformation of the simulated model meets the target deformation requirements in the design document; In step 2, the outer surface of the cylindrical internal support structure is set to be close to the inner surface of the elliptical thin-walled section, and the outer radius of the cylindrical internal support structure is set to the shortest distance between the center of the cylindrical internal support structure and the inner surface of the elliptical thin-walled section minus the minimum processing distance; the minimum processing distance is the distance between the outer surface of the cylindrical internal support structure and the inner surface of the elliptical thin-walled section at the closest point; The support structure is connected to the matching tooling to facilitate clamping the integral component during post-processing.

2. The additive manufacturing method for the elliptical thin-walled compartment section according to claim 1, characterized in that, The centers of the two cylindrical internal support structures are respectively located at two eccentric points on the major axis diameter of the elliptical thin-walled compartment. The outer surface of the cylindrical internal support structure does not directly contact the inner surface of the elliptical thin-walled compartment.

3. The additive manufacturing method for the elliptical thin-walled compartment section according to claim 2, characterized in that, The ribs may be one or more, and the minimum distance between the ribs and the inner support structure of the cylinder is set as the minimum processing spacing, and / or the spacing between the multiple ribs is the minimum processing spacing.

4. The additive manufacturing method for the elliptical thin-walled compartment section according to claim 3, characterized in that, One end of the thin plate support located between the support body and the rib is connected to the outer surface of the cylindrical inner support structure, and the other end is connected to the rib, with the orientation pointing towards the center of the cylindrical inner support structure.

5. The additive manufacturing method for the elliptical thin-walled compartment section according to claim 4, characterized in that, One end of the thin plate support located in the arc segment of the elliptical thin-walled compartment is connected to the inner wall of the arc segment of the elliptical thin-walled compartment, and the other end is connected to the outer surface of the cylindrical inner support structure, with the direction pointing towards the center of the arc segment of the elliptical thin-walled compartment.

6. The additive manufacturing method for the elliptical thin-walled compartment section according to claim 5, characterized in that, One end of the thin plate support located on the straight section of the elliptical thin-walled compartment is connected to the inner wall of the straight section of the elliptical thin-walled compartment. The connection point is the point where the deformation curvature is the maximum when the straight section is unsupported. The thin plate support passes through the center of the circle of deformation curvature when the connection point is unsupported. The other end is connected to the cylindrical inner support structure, the rib plate, or other thin plate support.

7. The additive manufacturing method for the elliptical thin-walled compartment section according to any one of claims 1-6, characterized in that, The internal support structure of the cylinder is a multi-layered cylindrical structure, and the multi-layered cylinders are connected by a lattice, truss or thin plate.

8. The additive manufacturing method for an elliptical thin-walled compartment section according to any one of claims 1-6, characterized in that, Each of the ribs is a multi-layered plate, which is connected by a lattice, truss or thin plate, and the multi-layered plates form triangles and / or rhombuses.

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