Light-weight low-expansion connecting ring structure for 3D printing and manufacturing method

Abstract

The invention discloses a light-weight low-expansion connecting ring structure for 3D printing and a manufacturing method, and the structure comprises a glue joint section which is used for being connected with an antenna housing; the base and the glue joint section are integrally formed, and the base is located below the glue joint section and used for being connected with a cabin body; wherein the glue joint section is a hollow conical ring body; the taper of the conical ring body is 2-5 degrees; the wall thickness of the conical ring body is gradually increased from one end far away from the base to one end connected with the base; the base is of an annular skin lattice structure. The skin lattice structure comprises a hollow lattice structure and two layers of skins arranged at the top end and the bottom end of the lattice structure respectively. By changing the production and manufacturing method, material selection and structural design of the connecting ring, the connecting ring with the comprehensive performance of light weight, low expansion, easiness in manufacturing and the like is obtained.

Description

Technical Field

[0001] The invention relates to the field of lightweight low expansion connecting ring manufacturing, and in particular to a lightweight low expansion connecting ring structure and a manufacturing method for 3D printing. Background Art

[0002] The connecting ring is a key component for connecting the radome to the cabin. In order to avoid damage to the connecting ring due to thermal stress of the hard and brittle radome under high temperature conditions, the connecting ring is generally made of low-expansion alloy steel materials that match the thermal expansion of the radome material and have higher strength, such as 4J32, 4J36, 4J40, etc. In the prior art, there are also cases where composite materials are used to manufacture connecting rings, but their structural strength is still somewhat different from that of connecting rings made of low-expansion alloy materials, and due to space size constraints, it is difficult for composite connecting rings to increase their strength by thickening, resulting in problems such as low strength and easy deformation. In the prior art, the lightweighting of low-expansion alloy steel connecting rings is also achieved through structural design, but during mechanical processing, the complexity of the structure will cause greater processing difficulty and manufacturing cost.

[0003] In summary, the existing connecting rings are generally manufactured by forging the blank and then performing mechanical processing, which has the following problems: First, the structural strength problem of the connecting ring; second, the high production cost and long processing cycle, which makes it difficult to respond to the needs of rapid research and development; third, due to the limitations of processing methods, a solid structure is generally adopted, which makes it difficult to achieve lightweight design, and the connecting ring after manufacturing is heavy; fourth, after the operating temperature exceeds the Curie point, the thermal expansion system of the low expansion alloy steel material increases sharply, and there is a risk of bursting the cover body.

[0004] Therefore, the present invention is aimed at the above-mentioned technical status and proposes a connection ring design and manufacturing method that meets certain comprehensive requirements such as structural strength, light weight, and low expansion. Summary of the invention

[0005] The purpose of the present invention is to provide a lightweight, low-expansion connecting ring structure and manufacturing method for 3D printing. By changing the production and manufacturing method, material selection and structural design of the connecting ring, the problems of the connecting ring made by traditional mechanical processing, such as long manufacturing cycle, high cost, inability to combine structural strength and lightness, and easy bursting of the cover after connection with the antenna cover, are overcome.

[0006] To achieve the above object, the present invention provides a lightweight low expansion connection ring structure for 3D printing, comprising:

[0007] A bonding section, used for connection with the radome;

[0008] A base, which is integrally formed with the bonding section and is located below the bonding section and is used to be connected to the cabin body;

[0009] The adhesive section is a hollow conical ring; the conical ring has a taper of 2° to 5°; the wall thickness of the conical ring gradually increases from the end away from the base to the end connected to the base;

[0010] The base adopts an annular skin lattice structure; the skin lattice structure comprises a hollow lattice structure and two layers of skin respectively arranged at the top and bottom of the lattice structure.

[0011] Optionally, the connection between the bonding section and the radome is achieved by bonding the outer wall of the conical ring body to the inner wall of the radome.

[0012] Optionally, the inner wall of the conical ring body is provided with inner supporting ribs distributed in a diamond grid shape.

[0013] Optionally, the internal support ribs include a plurality of first ribs and a plurality of second ribs; adjacent first ribs are arranged in parallel at a certain distance; adjacent second ribs are arranged in parallel at a certain distance; the first ribs and the second ribs are cross-arranged to form a plurality of regularly arranged rhombuses.

[0014] Optionally, a plurality of buffer holes are provided on the conical ring body, and the buffer holes are provided at positions corresponding to the center points of the respective rhombuses.

[0015] Optionally, the outer wall of the skin lattice structure is provided with a plurality of external weight-reducing grooves; and the inner wall thereof is provided with a plurality of internal weight-reducing grooves.

[0016] Optionally, the bottom of the skin lattice structure is provided with:

[0017] Connecting threaded holes are arranged around the bottom of the skin lattice structure at certain angles and can be connected to the cabin by installing studs;

[0018] The pin holes are symmetrically arranged in a radial direction with the center of the bottom as the center of the circle, and are used for circumferential positioning of the cabin body.

[0019] Optionally, the height of the bonding section is set to 60mm-80mm; the wall thickness of the conical ring body gradually increases from 0.3mm to 3mm from the end away from the base to the end connected to the base; the distance between the buffer holes is set to 20mm-40mm.

[0020] Optionally, the lightweight low expansion connecting ring structure is made of 4J36 or 4J40 low expansion alloy steel material.

[0021] The present invention also provides a method for manufacturing a lightweight low expansion connecting ring for 3D printing, comprising the following steps:

[0022] Step S1, constructing a theoretical design model of the lightweight low expansion connecting ring;

[0023] Step S2, based on the theoretical design model, preset the machining allowance on the surface to be machined, perform solid filling at the connection threaded holes and pin holes, and reserve an auxiliary positioning structure on the base to build a blank process model;

[0024] Step S3, 3D printing the above-mentioned blank process model by using selective laser melting technology;

[0025] Step S4, after removing the printing support, the initially formed connecting ring after 3D printing is subjected to stress relief heat treatment in air;

[0026] Step S5, placing the connecting ring on a milling tool, and finishing the bottom plane of the base and the connecting threaded holes and pin holes;

[0027] Step S6, placing the connecting ring obtained in step S5 on a turning tool, and then fine-machining the outer surface of the connecting ring;

[0028] Step S7, placing the connecting ring obtained in step S6 in a vacuum or nitrogen protection environment for aging treatment.

[0029] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention provides a lightweight, low-expansion connecting ring structure for 3D printing. On the basis of meeting the requirements of mechanical strength, low expansion, and bonding, the overall weight is reduced by more than 30% compared with the conventional connecting ring structure for mechanical processing, which is of great significance to the lightweighting of the connecting ring.

[0031] 2. The present invention provides a lightweight, low-expansion connecting ring structure for 3D printing, which reduces the stress and strain caused by the mismatch of thermal expansion coefficients at high temperatures by setting a buffer groove; when 4J36 or 4J40 materials are used, the overall operating temperature can reach above 300°C, and the buffer groove can also improve the bonding reliability between the connecting ring and the antenna cover.

[0032] 3. The present invention provides a manufacturing method for a lightweight, low-expansion connecting ring for 3D printing, which is not only convenient for 3D printing of the blank, but also easy to achieve fine processing of the blank. The manufacturing difficulty and manufacturing cost are low. Compared with conventional mechanical processing methods, the manufacturing cycle can be shortened by more than 50%, and the manufacturing cost can be reduced by 10% to 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a connection diagram of a lightweight, low-expansion connection ring for 3D printing of the present invention;

[0034] Figure 2It is a front view of the lightweight low expansion connecting ring structure for 3D printing of the present invention;

[0035] Figure 3 A cross-sectional view of a lightweight, low-expansion connecting ring structure for 3D printing according to the present invention;

[0036] Figure 4 A bottom view of the lightweight, low-expansion connecting ring structure for 3D printing of the present invention;

[0037] Figure 5 A schematic diagram of the milling process of the lightweight low expansion connecting ring for 3D printing of the present invention;

[0038] Figure 6 It is a schematic diagram of the turning process of the lightweight and low expansion connecting ring for 3D printing of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the attached Figures 1 to 6 , the technical content, structural features, objectives achieved and effects of the present invention are described in detail through preferred embodiments.

[0040] It should be noted that the drawings are in a very simplified form and use non-precise proportions. They are only used to conveniently and clearly assist in explaining the embodiments of the present invention, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0041] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] The present invention provides a lightweight low expansion connection ring structure and a manufacturing method for 3D printing, such as Figure 1 and Figure 2 As shown, the lightweight low expansion connecting ring is used to achieve the transition connection between the antenna cover 2 and the cabin body, and the lightweight low expansion connecting ring includes two main bodies: a bonding section 11, which refers to the upper section of the connecting ring, and the bonding section 11 is connected to the antenna cover 2 by bonding; a base 12, which refers to the lower section of the connecting ring, is integrally formed with the bonding section 11, and is located below the bonding section 11, and the base 12 is connected to the cabin body by a stud 3.

[0044] Among them, Figure 3 As shown, the adhesive section 11 is a hollow conical ring body 11a, and its taper is set to 2° to 5°; the inner wall of the conical ring body 11a is provided with inner support ribs 11b distributed in a rhombus grid; and the conical ring body 11a is also provided with a plurality of buffer holes 11c. By providing the inner support ribs 11b distributed in a rhombus grid on the inner wall, the adhesive section 11, which is one of the main bodies of the connecting ring, is effectively reduced in weight without reducing the wall thickness, while its structural strength is well guaranteed.

[0045] Furthermore, the bonding section 11 is bonded to the inner wall of the radome, that is, the outer wall of the conical ring body 11a is bonded to the inner wall of the radome. A bonding gap of 0.4 mm to 0.6 mm is reserved between the outer wall of the conical ring body 11a and the inner wall of the radome; the height of the outer wall of the conical ring body 11a for bonding (that is, the height of the bonding section 11) is set to 60 mm to 80 mm.

[0046] The wall thickness of the conical ring body 11a of the bonding section 11 gradually increases from the end away from the base 12 to the end connected to the base 12 (i.e., from Figure 3 Further, the wall thickness of the conical ring body 11a gradually thickens in a gradual manner from 0.3 mm to 3 mm, that is, at the end with a smaller inner diameter away from the base, the wall thickness of the conical ring body 11a is 0.3 mm, and after gradually thickening, at the end with a larger inner diameter connected to the base, the wall thickness of the conical ring body 11a reaches 3 mm.

[0047] The inner support rib 11b includes a plurality of first ribs 11b1 and a plurality of second ribs 11b2, adjacent first ribs 11b1 are arranged in parallel at intervals of 20mm to 40mm, adjacent second ribs 11b2 are also arranged in parallel at intervals of 20mm to 40mm, and the first ribs 11b1 and the second ribs 11b2 are arranged crosswise to form a plurality of regularly arranged rhombuses. The horizontal angle ɑ of the first rib 11b1 is 120° to 150°, and the horizontal angle β of the second rib 11b2 is 30° to 60°. The rib widths of the first rib 11b1 and the second rib 11b2 are both 0.5mm to 0.8mm, and the protruding heights of the first rib 11b1 and the second rib 11b2 on the inner wall of the conical ring body 11a are both 0.3mm to 0.5mm.

[0048] Furthermore, the buffer hole 11c opened on the conical ring body 11a has an opening position corresponding to the center point of each rhombus area surrounded by the first rib 11b1 and the second rib 11b2; the buffer hole 11c is used to regulate the thermal expansion characteristics of the connecting ring and ensure the reliability of bonding with the antenna cover 2.

[0049] Specifically, due to the large difference in deformation between the connecting ring and the antenna cover at high temperatures, the connecting ring will produce outward deformation and extrusion force, which will cause the antenna cover to have the risk of cracking. The purpose of the buffer hole 11c is to absorb thermal stress and thermal deformation at high temperatures. After the buffer hole 11c is provided on the connecting ring, a part of the thermal stress and thermal deformation can be absorbed, thereby reducing the overall outward stress and strain of the connecting ring, and effectively reducing the risk of cracking of the antenna cover caused by the outward expansion of the connecting ring. In addition, there are air bubbles inside the adhesive used for gluing, and the buffer hole 11c can also discharge these air bubbles during gluing, which is conducive to ensuring the reliability of gluing.

[0050] Furthermore, the transverse width of the buffer hole 11c is 1mm to 3mm, the longitudinal length is 10mm to 20mm, and the spacing between two adjacent buffer holes 11c is 20mm to 40mm; under the aforementioned boundary conditions, the shape of the buffer hole 11c can be rectangular, waist-shaped, T-shaped or X-shaped.

[0051] Among them, Figure 3 As shown, the base 12 adopts an annular skin lattice structure 12c with a certain wall thickness, and the skin lattice structure 12c has high strength and rigidity and is a hollow structure. By designing the base 12 as a hollow skin lattice structure 12c, the base 12 as another main body of the connecting ring can be effectively reduced in weight.

[0052] Among them, the skin lattice structure 12c includes a lattice structure and two layers of skin respectively arranged at the top and bottom of the lattice structure. The lattice structure can have a variety of hollow structural forms, including lattice type, pyramid type, diamond arrangement type, Kagome type, etc.

[0053] The relative density of the lattice structure is 30% to 60%.

[0054] Among them, Figure 3 As shown, the outer wall of the skin lattice structure 12c is provided with a plurality of external weight-reducing grooves 12b, which are 25mm to 45mm in length, 10mm to 15mm in width, and 8mm to 10mm in depth; the inner wall of the skin lattice structure 12c is provided with a plurality of internal weight-reducing grooves 12a, which are 40mm to 60mm in length, 4mm to 8mm in width, and 15mm to 20mm in depth. By adding the external weight-reducing grooves 12b and the internal weight-reducing grooves 12a to the skin lattice structure 12c, the weight of the connecting ring is further reduced.

[0055] Preferably, in order to ensure the strength of the skin lattice structure 12c, the inner weight-reducing grooves 12a and the outer weight-reducing grooves 12b are arranged alternately.

[0056] Further, if Figure 4 As shown, a plurality of connecting threaded holes 12d and pin holes 12e are provided at the bottom of the skin lattice structure 12c; the specification of the connecting threaded hole 12d is M5~M6, and can be connected to the cabin body by installing the stud 3; the diameter of the pin hole 12e is 4mm~5mm, which is used for circumferential positioning when connecting to the cabin body.

[0057] The connecting threaded holes 12d are arranged at a certain angle around the bottom of the skin lattice structure 12c; the pin holes 12e are symmetrically arranged in the radial direction with the center of the bottom as the center of the circle. Preferably, the connecting threaded holes 12d are arranged in 4 groups, and the 4 groups of connecting threaded holes 12d are evenly distributed around the bottom of the skin lattice structure 12c, that is, the threaded connection holes 12d of two adjacent groups are arranged at 90° intervals; and each group of threaded connection holes 12d is provided with 2. For two groups of connecting threaded holes 12d in any relative direction, the pin holes 12e are arranged between the two threaded connection holes 12d of each group.

[0058] The usability of the lightweight low expansion connection ring is mainly affected by the mechanical strength and thermal expansion performance, and the mechanical strength and thermal expansion performance can be regulated by some structural parameters of the connection ring. Therefore, the structural parameters of the connection ring can be regulated by simulation analysis to optimize the mechanical strength and thermal expansion performance of the connection ring.

[0059] Furthermore, in order to determine the lightweight structural parameters of the connecting ring, the structural parameters of the conical ring body 11a, the inner support ribs 11b, the inner weight-reducing grooves 12a, the outer weight-reducing grooves 12b and the skin lattice structure 12c of the base 12 can be set through mechanical simulation analysis. Specifically, by inputting material parameters including elastic modulus, Poisson's ratio, yield strength, tensile strength, density and other load conditions and bending moment, axial force and other load conditions, the stress and strain of the above different structural parameters under given load conditions are calculated, and the above weight-reducing structural parameters under boundary conditions such as maximum allowable stress and maximum allowable strain are obtained.

[0060] Furthermore, in order to ensure that the connecting ring has good low expansion performance at high temperature, the structural parameters of the conical ring body 11a, the inner support rib 11b and the buffer groove 11c can be adjusted through thermal simulation analysis. Specifically, by inputting parameters including the maximum working temperature condition of the connecting ring and the thermal expansion coefficient of the material, the thermal expansion amount of the above different structural parameters under given temperature conditions is calculated, and the optimal structural parameters under the condition of minimum thermal expansion amount are obtained.

[0061] In a specific embodiment of the present invention, based on the analysis of the thermal expansion characteristics of the connection ring material and the radome material, as shown in Table 1, in order to ensure the low expansion characteristics of the connection ring and reduce the risk of the radome bursting, the lightweight low expansion connection ring is made of 4J36 or 4J40 low expansion alloy steel. The radome is made of quartz ceramics.

[0062] Table 1 Thermal expansion coefficients of the connecting ring material and the radome material

[0063]

[0064] The lightweight low expansion connection ring designed by the present invention can be manufactured by 3D printing technology. When the connection ring is 3D printed, a flange 12f (such as Figure 5 As shown), to facilitate clamping and positioning during milling; wherein the thickness of the flange 12f is 4mm to 6mm, and the length protruding outward from the outer wall of the skin lattice structure 12c is 6mm to 8mm.

[0065] The present invention also provides a method for manufacturing a lightweight low expansion connecting ring for 3D printing, comprising the following steps:

[0066] Step S1, constructing a theoretical design model of the lightweight low expansion connecting ring based on the simulation design;

[0067] Step S2, based on the theoretical design model, the thickness of the outer contour to be processed is increased by 0.3mm to 0.5mm as a processing allowance, and the connection threaded hole 12d and the pin hole 12e are filled with solids, and a flange 12f is added to the base 12 to construct a blank process model for 3D printing;

[0068] Step S3, when the above preparation work is completed, the above blank process model is 3D printed by selective laser melting technology; the laser power is 100W to 250W, the printing speed is 500mm / s to 800mm / s, and the printing layer thickness is 0.03mm to 0.05mm;

[0069] Step S4, after removing the printing support, the initially formed connecting ring after 3D printing is subjected to stress relief heat treatment in air; the heat treatment temperature is 300° C. to 500° C., and the heat treatment time is 4 h to 6 h;

[0070] Step S5, using the flange 12f as a clamping and positioning block, placing the connecting ring on the milling tool 5 (such as Figure 5 As shown), the pressing plate device 4 is used to press, and the bottom plane of the base 12 and the connecting threaded hole 12d and the pin hole 12e are precisely processed in place under one clamping condition;

[0071] Step S6, using the bottom plane of the base 12 as the clamping and positioning surface, the connecting ring is placed axially on the turning tool 9 (such as Figure 6 As shown in the figure, the turning tool 9 is fixed by a three-jaw chuck 6; the connecting ring is circumferentially positioned by a positioning pin 8 matched with the pin hole 12e, and is axially locked by a fastening screw 7 screwed into the connecting threaded hole 12d, and the outer profile is finely machined in place under a single clamping condition to obtain a finely machined lightweight low expansion connecting ring;

[0072] Step S7, finally placing the above-mentioned finely processed connecting ring in a vacuum or nitrogen protection environment for aging treatment to ensure the stability of the thermal expansion coefficient; the heating temperature is 315±10°C, the insulation time is 3h~6h, and it is cooled with the furnace.

[0073] In summary, the lightweight, low-expansion connecting ring structure and manufacturing method for 3D printing provided by the present invention effectively meet the comprehensive requirements of lightweight, low expansion, easy manufacturing and stable performance. A good lightweight design is achieved while ensuring overall strength through multiple weight-reducing structures; by pre-setting a buffer groove in the connection part with the antenna cover, the thermal expansion characteristics of the connecting ring are controlled, avoiding the problem of the cover body bursting due to the mismatch of thermal expansion coefficients between the connecting ring and the antenna cover at high temperature; by pre-setting a clamping structure on the 3D printed blank, the precision machining of the thin-walled complex structure blank is guaranteed; by heat treatment after printing and precision machining, the internal stress is effectively eliminated and the stability of the thermal expansion characteristics is guaranteed.

[0074] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the invention. After reading the above content, it will be obvious to those skilled in the art for various modifications and substitutions of the present invention. Therefore, the protection scope of the present invention should be limited by the attached claims.

Claims

1. A lightweight, low-expansion connecting ring structure for 3D printing, characterized in that: Include: A bonding section (11), used for connecting with the radome (2); A base (12) is formed integrally with the bonding section (11) and is located below the bonding section (11) and is used for connection with the cabin body; The adhesive section (11) is a hollow conical ring (11a); the conical ring (11a) has a taper of 2° to 5°; the wall thickness of the conical ring (11a) gradually increases from the end away from the base (12) to the end connected to the base (12); The base (12) adopts an annular skin lattice structure (12c); the skin lattice structure (12c) comprises a hollow lattice structure and two layers of skin respectively arranged at the top and bottom of the lattice structure.

2. The lightweight low expansion connecting ring structure according to claim 1, characterized in that: The connection between the bonding section (11) and the radome (2) is achieved by bonding the outer wall of the conical ring body (11a) and the inner wall of the radome (2).

3. The lightweight low expansion connecting ring structure according to claim 1, characterized in that: The inner wall of the conical ring body (11a) is provided with inner supporting ribs (11b) distributed in a rhombus grid shape.

4. The lightweight low expansion connecting ring structure according to claim 3, characterized in that: The inner support ribs (11b) include a plurality of first ribs (11b1) and a plurality of second ribs (11b2); adjacent first ribs (11b1) are arranged in parallel at a certain distance; adjacent second ribs (11b2) are arranged in parallel at a certain distance; the first ribs (11b1) and the second ribs (11b2) are arranged crosswise to form a plurality of regularly arranged rhombuses.

5. The lightweight low expansion connecting ring structure according to claim 4, characterized in that: A plurality of buffer holes (11c) are provided on the conical ring body (11a), and the opening positions of the buffer holes (11c) correspond to the center points of the respective rhombuses.

6. The lightweight low expansion connecting ring structure according to claim 1, characterized in that: The outer wall of the skin lattice structure (12c) is provided with a plurality of outer weight-reducing grooves (12b); and the inner wall thereof is provided with a plurality of inner weight-reducing grooves (12a).

7. The lightweight low expansion connecting ring structure according to claim 1, characterized in that: The bottom of the skin lattice structure (12c) is provided with: Connecting threaded holes (12d) are arranged at a certain angle around the bottom of the skin lattice structure (12c), and can be connected to the cabin by installing studs (3); The pin holes (12e) are symmetrically arranged in a radial direction with the center of the bottom as the center of the circle, and are used for circumferential positioning of the cabin body.

8. The lightweight low expansion connecting ring structure according to claim 4, characterized in that: The height of the adhesive section (11) is set to 60 mm to 80 mm; the wall thickness of the conical ring body (11a) gradually increases from 0.3 mm to 3 mm from the end away from the base to the end connected to the base; and the distance between the buffer holes (11c) is set to 20 mm to 40 mm.

9. The lightweight low expansion connecting ring structure according to claim 1, characterized in that: Made of 4J36 or 4J40 low expansion alloy steel.

10. A method for manufacturing a lightweight low expansion connection ring for 3D printing, which is implemented by using the lightweight low expansion connection ring structure as described in any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, constructing a theoretical design model of the lightweight low expansion connecting ring; Step S2, based on the theoretical design model, preset the machining allowance on the surface to be machined, perform solid filling at the connection threaded hole (12d) and the pin hole (12e), and reserve an auxiliary positioning structure on the base (12) to construct a blank process model; Step S3, 3D printing the above-mentioned blank process model by using selective laser melting technology; Step S4, after removing the printing support, the initially formed connecting ring after 3D printing is subjected to stress relief heat treatment in air; Step S5, placing the connecting ring on a milling tool, and fine-machining the bottom plane of the base (12) and the connecting threaded hole (12d) and the pin hole (12e); Step S6, placing the connecting ring obtained in step S5 on a turning tool, and then fine-machining the outer surface of the connecting ring; Step S7, placing the connecting ring obtained in step S6 in a vacuum or nitrogen protection environment for aging treatment.

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