Double-sided co-bulk silicon carbide reflector structure and preparation method thereof

Abstract

The invention relates to a double-sided co-bulk silicon carbide reflector structure and a preparation method thereof. The double-sided co-bulk silicon carbide reflector structure comprises a primary mirror surface and a fourth mirror surface which are provided with central holes, and a silicon carbide topological structure lightweight mirror body which is used for connecting the primary mirror surface and the fourth mirror surface to two sides in a back-to-back manner; the silicon carbide topological structure lightweight mirror body comprises a peripheral rib located on the periphery, a center hole peripheral rib located in the middle and corresponding to a center opening hole, and a lightweight rib connected between the inner side of the peripheral rib and the outer side of the center hole peripheral rib. The peripheral ribs are provided with peripheral rib light-weight holes, the central hole peripheral ribs are provided with central hole peripheral rib light-weight holes, and the light-weight ribs are provided with light-weight holes. According to the invention, the lightweight rate of the primary mirror and four-mirror double-sided integrated silicon carbide reflecting mirror in the coaxial four-mirror optical system can be improved, the structural damping of the reflecting mirror is improved, and the processing efficiency of the reflecting mirror is improved.

Description

Technical Field

[0001] The invention relates to the technical field of space optical remote sensing, in particular to a double-sided co-body silicon carbide reflector structure and a preparation method thereof. Background Art

[0002] In optical remote sensing instruments, the coaxial quadruple mirror is widely used for its symmetrical structure, compactness, multiple optical design variables, no chromatic aberration, and large field of view. Among them, the main mirror and the four mirrors of the coaxial quadruple mirror optical system are arranged back to back in the layout structure, and its structure and implementation form have an important influence on the system structure size, weight, mechanical properties, processing cycle, and assembly.

[0003] At present, in the coaxial four-mirror system, the main mirror and the fourth mirror are used separately. The specification of the Chinese invention patent application (publication number: CN115826186A) discloses a two-reflecting-surface integrated reflector and a coaxial reflector optical system using the reflector. It proposes an integrated solution for the main mirror and the fourth mirror of the coaxial four-mirror optical system, wherein: the back of the main mirror adopts a regular fan-shaped lightweight hole, and does not mention the lightweight solution for the mirror body between the main mirror and the fourth mirror. Lightweighting can only be carried out in the non-overlapping area on the back of the main mirror and the fourth mirror, and the lightweight rate of the entire mirror is not high. The document does not mention how to improve the rigidity of the reflector in design, nor does it mention the reflector material and the reflector manufacturing method. In addition, the specification of the Chinese utility model patent (authorization announcement number: CN213903925U, that is, the applicant's own technology) discloses an integrated double-sided mirror. It proposes that the main mirror and the fourth mirror of the coaxial four-mirror system adopt a silicon carbide integrated reflector. The implementation method is to first lightweight the A reflector and the B reflector respectively using a triangular lightweight structure, and then weld the A reflector and the B reflector back to back to one another by welding, sharing a common support structure. This method still uses two independently designed reflectors, and cannot be collaboratively designed. In terms of lightweighting, it is impossible to process on the reflector ribs, and it is impossible to achieve a higher lightweighting rate. Reflector A and reflector B are formed by two-body welding, and there is a certain welding stress. Under the influence of later processing and the environment, the welding stress distribution may change, resulting in a decrease in the accuracy of the main mirror and the four mirror surfaces. The processing technology is complex and the cycle is long. The welding method has certain difficulties in ensuring the coaxiality of the A reflector and the B reflector, which requires high-precision welding tooling or more processing allowances to ensure. The technical difficulty and cost of manufacturing are increased. Summary of the invention

[0004] The purpose of the present invention is to provide a double-sided co-body silicon carbide reflector structure and a preparation method thereof, which mainly solves the problems existing in the above-mentioned prior art. It improves the lightweight rate of the main mirror and the four-mirror double-sided co-body silicon carbide reflector in the coaxial four-mirror optical system, improves the damping of the reflector structure, and improves the reflector processing efficiency.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A double-sided co-body silicon carbide reflector structure, characterized in that: it comprises a primary mirror surface and a fourth mirror surface with a central opening, and a silicon carbide topological structure lightweight mirror body that connects the primary mirror surface and the fourth mirror surface back to back on both sides;

[0007] The silicon carbide topological structure lightweight mirror body includes peripheral ribs located on the periphery, central hole peripheral ribs located in the middle corresponding to the central opening, and lightweight ribs connected between the inner side of the peripheral ribs and the outer side of the central hole peripheral ribs; the peripheral ribs are provided with peripheral rib lightweight holes, the central hole peripheral ribs are provided with central hole peripheral rib lightweight holes, and the lightweight ribs have lightweight holes.

[0008] The double-sided co-body silicon carbide reflector structure is characterized in that the peripheral rib lightweight hole, the central hole peripheral rib lightweight hole, and the lightweight hole are through holes and / or blind holes.

[0009] The double-sided co-body silicon carbide reflector structure is characterized in that a negative Poisson's ratio structure is arranged on the lightweight mirror body of the silicon carbide topological structure.

[0010] The double-sided co-body silicon carbide reflector structure is characterized in that the negative Poisson's ratio structure is arranged on the lightweight ribs.

[0011] The double-sided co-body silicon carbide reflector structure is characterized in that an external mounting interface for bonding the reflector support structure bushing is provided on the lightweight mirror body of the silicon carbide topological structure.

[0012] A method for preparing a double-sided co-body silicon carbide reflector structure as described above, characterized in that the lightweight mirror body of the silicon carbide topological structure is manufactured by means of silicon carbide 3D printing additive manufacturing technology.

[0013] The method for preparing the double-sided co-body silicon carbide reflector structure is characterized in that a negative Poisson's ratio structure is arranged on the lightweight mirror body of the silicon carbide topological structure and is also manufactured by means of silicon carbide 3D printing additive manufacturing technology.

[0014] In view of the above technical features, the present invention has the following advantages:

[0015] 1. The present invention adopts topology optimization technology to perform lightweight design on the mirror body between the two mirror surfaces of the silicon carbide double-sided co-body reflector, which increases the lightweight design space and improves the lightweight rate of the reflector compared with the traditional silicon carbide double-sided co-body reflector.

[0016] 2. The present invention can design lightweight holes on lightweight ribs, peripheral ribs, and central hole peripheral ribs without affecting the surface accuracy of the reflector, thereby further improving the lightweight rate of the reflector.

[0017] 3. The present invention designs a negative Poisson's ratio structure on the lightweight rib, which can increase the damping ratio of the reflector in structure.

[0018] 4. The present invention adopts silicon carbide 3D printing technology to process and realize the complex lightweight structure of the reflector formed by topological optimization, lightweight rib opening, negative Poisson's ratio structure, etc. It breaks through the limitations of traditional subtractive machining technology on structural space and structural size. It can process more complex structures and smaller structural sizes. It increases the structural design space and further reduces the weight of the reflector.

[0019] 5. Through means including but not limited to ultrasound, industrial CT, fluorescence detection, etc., we can check whether there are defects inside and on the surface of silicon carbide, and find defects in the internal structure manufacturing process of double-sided co-body silicon carbide double-sided reflector in advance, thus reducing product development risks.

[0020] 6. After the double-sided co-body silicon carbide double-sided reflector is polished and finished, mechanical, temperature and other environmental tests can verify the structural stability and environmental load adaptability of the double-sided co-body silicon carbide reflector.

[0021] 7. The present invention adopts silicon carbide 3D printing technology, and can print one or more sets of integrated double-sided co-body silicon carbide reflectors at a time. It improves the processing efficiency of double-sided reflectors and reduces the processing cost of double-sided co-body silicon carbide reflector blanks. It is particularly suitable for large-scale satellite optical payloads. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a three-dimensional double-sided co-body silicon carbide reflector structure Figure 1 .

[0023] Figure 2 The present invention is a three-dimensional double-sided co-body silicon carbide reflector structure Figure 2 .

[0024] Figure 3 It is a radial cross-sectional view of the double-sided co-body silicon carbide reflector structure of the present invention.

[0025] Figure 4 It is a cross-sectional view of a lightweight mirror body of a silicon carbide topological structure in a double-sided co-body silicon carbide reflector structure of the present invention.

[0026] Figure 5 It is a structural schematic diagram of a coaxial four-mirror system having a double-sided co-body silicon carbide reflector structure according to the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0028] See also Figure 1-4 The present invention discloses a double-sided co-body silicon carbide reflector structure. As shown in the figure: it includes a primary mirror surface 1 and a fourth mirror surface 4 with a central opening 6, and a silicon carbide topological structure lightweight mirror body 12 that connects the primary mirror surface 1 and the fourth mirror surface 4 back to back on both sides.

[0029] In the present invention, the parameter constraints such as the reflection surface accuracy, weight, mirror aperture, and the distance between the two mirror surfaces of the primary mirror surface 1 and the fourth mirror surface 4 are all within a reasonable range and are not limited.

[0030] In the present invention, the silicon carbide topological structure lightweight mirror body 12 includes a peripheral rib 8 located on the periphery, a center hole peripheral rib 9 located in the middle corresponding to the center opening 6, and a lightweight rib 10 connected between the inner side of the peripheral rib 8 and the outer side of the center hole peripheral rib 9; the peripheral rib 8 is provided with a peripheral rib lightweight hole 81, the center hole peripheral rib 9 is provided with a center hole peripheral rib lightweight hole 91, and the lightweight rib 10 has a lightweight hole 101.

[0031] See also Figure 4 This is a structure of the silicon carbide topological structure of the present invention, in which the lightweight ribs 10 include a plurality of circular structures connected to each other and to the peripheral ribs 8 or the central hole peripheral ribs 9. Of course, the corresponding lightweight structures can also be designed as triangles, quadrilaterals, hexagons, and hybrid lightweight structures of various shapes above.

[0032] In the present invention, the peripheral rib lightweight hole 81, the central hole peripheral rib lightweight hole 91, and the lightweight hole 101 are through holes and / or blind holes.

[0033] In the present invention, a negative Poisson's ratio structure 11 is provided on the silicon carbide topological structure lightweight mirror body 12. Preferably, the negative Poisson's ratio structure 11 is provided on the lightweight rib 10. The characteristics of the negative Poisson's ratio structure 11 are utilized to improve the structural damping of the silicon carbide double-sided reflector itself and reduce the vibration response size during the mechanical test of the reflector.

[0034] In the present invention, the silicon carbide topological structure lightweight mirror body 12 is provided with an external mounting interface 7 for bonding the reflector support structure bushing. The interface position is not limited to being close to the main mirror surface 1, but can also be close to the fourth mirror surface 4. The interface direction can be in the direction of the mirror optical axis, or in the radial direction of the mirror surface. The number of mounting interfaces is not limited to 3, and multiple interfaces can be designed as needed.

[0035] In the preparation method of the structure of the present invention, the silicon carbide topological structure lightweight mirror body 12 (including the main mirror surface 1 and the four-mirror mirror surface 4) is manufactured by means of silicon carbide 3D printing additive manufacturing technology.

[0036] In the preparation method of the structure of the present invention, the negative Poisson's ratio structure 11 is arranged on the lightweight mirror body 12 of the silicon carbide topological structure and is also manufactured by means of silicon carbide 3D printing additive manufacturing technology.

[0037] After completing the processing of the double-sided common silicon carbide reflector blank using silicon carbide 3D printing technology, the internal and surface defects of the silicon carbide are inspected through means including but not limited to ultrasound, industrial CT, and fluorescence detection.

[0038] After the double-sided co-body silicon carbide mirror is polished, it is subjected to tests including but not limited to high and low temperature and vibration dynamics tests to check whether the design of the silicon carbide double-sided mirror meets the environmental mechanical test assessment.

[0039] Please see again Figure 5 The present invention also discloses a coaxial four-mirror system, which includes the double-sided co-body silicon carbide reflector structure as described above; a second mirror surface 2 is coaxially arranged on one side of a main mirror surface 1 of the double-sided co-body silicon carbide reflector structure, and a third mirror surface 3 and an image surface 5 are coaxially arranged in sequence on one side of a fourth mirror surface 4 of the double-sided co-body silicon carbide reflector structure.

[0040] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A double-sided co-existing silicon carbide reflector structure, characterized in that: It comprises a primary mirror surface (1) and a quad mirror surface (4) having a central opening (6), and a lightweight mirror body (12) of a silicon carbide topological structure which respectively connects the primary mirror surface (1) and the quad mirror surface (4) back to back on both sides; The silicon carbide topological structure lightweight mirror body (12) comprises a peripheral rib (8) located at the periphery, a central hole peripheral rib (9) located in the middle corresponding to the central opening (6), and a lightweight rib (10) connected between the inner side of the peripheral rib (8) and the outer side of the central hole peripheral rib (9); the peripheral rib (8) is provided with a peripheral rib lightweight hole (81), the central hole peripheral rib (9) is provided with a central hole peripheral rib lightweight hole (91), and the lightweight rib (10) has a lightweight hole (101).

2. The double-sided co-existing silicon carbide reflector structure according to claim 1, characterized in that: The peripheral rib lightweight hole (81), the central hole peripheral rib lightweight hole (91), and the lightweight hole (101) are through holes and / or blind holes.

3. The double-sided co-existing silicon carbide reflector structure according to claim 1, characterized in that: A negative Poisson's ratio structure (11) is provided on the lightweight mirror body (12) of the silicon carbide topological structure.

4. The double-sided co-existing silicon carbide reflector structure according to claim 3, characterized in that: The negative Poisson's ratio structure (11) is arranged on the lightweight rib (10).

5. The double-sided co-existing silicon carbide reflector structure according to claim 1, characterized in that: The silicon carbide topological structure lightweight mirror body (12) is provided with an external mounting interface (7) for bonding a reflector support structure bushing.

6. A method for preparing a double-sided co-existing silicon carbide reflector structure as claimed in claim 1, 2, 3, 4 or 5, characterized in that: The silicon carbide topological structure lightweight mirror body (12) is manufactured by means of silicon carbide 3D printing additive manufacturing technology.

7. The method for preparing a double-sided co-existing silicon carbide reflector structure according to claim 6, characterized in that: The silicon carbide topological structure lightweight mirror body (12) is provided with a negative Poisson's ratio structure (11) and is also manufactured by means of silicon carbide 3D printing additive manufacturing technology.

Images