Silicon carbide sub-mirror flexible support device
By integrating the mirror body and connecting end face into a flexible support structure with screw connections, the problems of difficult assembly and easily affected surface accuracy of silicon carbide secondary mirrors are solved. This results in a high-precision, reliable, and safe silicon carbide secondary mirror support device, which simplifies the assembly process and reduces costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JILIN TEACHERS INST OF ENG & TECH
- Filing Date
- 2025-10-17
- Publication Date
- 2026-07-21
AI Technical Summary
The existing center support method for silicon carbide secondary mirrors leads to high assembly difficulty, surface accuracy is easily affected by adhesive shrinkage stress, and the assembly cycle is long, requiring high technical skills from workers.
The mirror body and connecting end face are integrated into one design. Flexible support is achieved through screw connection. The flexible hinge absorbs external stress and changes the force transmission path. The use of materials with the same coefficient of thermal expansion achieves a heatless design.
It improves the stability of the secondary mirror surface accuracy, simplifies the assembly process, shortens the development cycle, reduces costs, and meets the space camera's requirements for high surface accuracy and high stability.
Smart Images
Figure CN224536261U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of flexible support technology for silicon carbide mirrors, and specifically relates to a flexible support device for silicon carbide secondary mirrors. Background Technology
[0002] Due to size and weight limitations, micro- and nano-satellite space cameras often employ coaxial three-mirror optical systems with multiple optical path folds to achieve the technical requirements of small size and light weight. The secondary mirror, used to reflect imaging light, plays a crucial role in image quality due to its surface accuracy and stability. Furthermore, the secondary mirror is located at the forefront of the optical path, exposed to harsh space environments with significant temperature variations, which greatly affects its surface accuracy. Additionally, because the secondary mirror is in a cantilever beam configuration, it is most susceptible to deformation under impact and vibration, making it difficult to maintain surface accuracy. Due to the small aperture of the secondary mirror, a central support method is often used, where a conical sleeve is glued to the back hole of the secondary mirror, with one end of a flexible hinge connected to a screw on the conical sleeve and the other end connected to a screw on the secondary mirror mount. However, the glue bonding of the conical sleeve and the back hole of the secondary mirror generates shrinkage stress, which, when transferred to the mirror surface, can easily cause deformation and compromise its surface accuracy. The surface accuracy before and after assembly can sometimes show significant aberrations, requiring rework and re-gluing. Rework involves soaking the mirror in glue for approximately half a month, making assembly difficult, extending the development cycle, and demanding high levels of gluing skills from the workers.
[0003] To address the challenges of assembly difficulties in existing silicon carbide secondary mirror center supports, and the susceptibility to surface shape accuracy issues caused by adhesive shrinkage stress, a novel flexible support structure for silicon carbide secondary mirrors is proposed. Utility Model Content
[0004] The purpose of this invention is to provide a flexible support device for a silicon carbide secondary mirror. This device avoids adhesive bonding and instead uses a safer screw connection. The secondary mirror adopts an integrated structure of the mirror body and the connecting end face. The connecting end face is fixedly connected to the adjusting shim and the secondary mirror mount by screws. One end of the flexible support is screwed to the secondary mirror mount, and the other end is screwed to the main support plate. This transforms the traditional flexible support directly supporting the secondary mirror into a flexible support supporting the secondary mirror mount, with the secondary mirror and the mount fixedly connected together. When subjected to external loads, the flexible hinge can effectively absorb external stress, thereby ensuring the surface accuracy of the secondary mirror. Since all connections are screwed, compared to adhesive bonding, it reduces the damage to the mirror surface caused by adhesive shrinkage stress, improves the stability of the secondary mirror's surface accuracy, and simplifies assembly, saving a significant amount of assembly and adjustment time, ensuring the production cycle, reducing development costs, and meeting the high surface accuracy and high stability requirements of space cameras for secondary mirrors.
[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by this utility model is as follows: A flexible support device for a silicon carbide secondary mirror includes: The secondary mirror is a small-diameter silicon carbide reflector, which adopts an integrated design of the mirror body and the connecting end face; Secondary mirror mount, connected to the secondary mirror; An adjustment shim is placed between the secondary mirror and the secondary mirror mount; A flexible hinge, one end of which is connected to the secondary mirror mount, and the other end of which is connected to the main support plate; The main support plate, with a sheet-like structure, is connected to a flexible hinge and is used to support the entire device.
[0006] The connecting end face of the secondary mirror is designed with a boss structure, and the connecting end face is fixedly connected to the adjusting pad and the secondary mirror mount by at least three screws.
[0007] The flexible hinge employs two sets of mutually perpendicular slots to achieve six degrees of freedom of movement.
[0008] The secondary mirror mount is designed as a triangular or circular structure, and two flexible hinges are installed on each side of the secondary mirror mount.
[0009] The secondary mirror and the adjustment pad are fixedly connected to the secondary mirror mount by screws.
[0010] Compared with existing center support technologies, this utility model has a flexible structure with high surface accuracy, high reliability, and high safety.
[0011] This invention changes the transmission path of external forces, reducing the sensitivity of the sub-mirror surface accuracy to environmental loads.
[0012] This invention employs a threaded connection, which reduces the impact of shrinkage stress during adhesive bonding, simplifies the assembly process, shortens the development cycle, and improves the stability and environmental adaptability of the structure.
[0013] The entire device of this utility model adopts the same coefficient of thermal expansion, achieving a heatless design, reducing deformation caused by thermal load, and improving wide temperature adaptability. Attached Figure Description
[0014] This utility model can be further illustrated by the non-limiting embodiments given in the accompanying drawings.
[0015] Figure 1 An exploded view of the assembly relationship of a novel flexible support device for silicon carbide secondary mirrors. Figure 2 This is an assembly diagram of a novel flexible support device for a silicon carbide secondary mirror. Figure 3 This is a three-dimensional model diagram of the secondary mirror; Figure 4 This is a three-dimensional model diagram of the secondary mirror mount; Figure 5 This is a 3D model of a flexible hinge.
[0016] The symbols for the main components are explained below: Secondary mirror 1, Adjustment pad 2, Secondary mirror mount 3, Flexible hinge 4, Main support plate 5. Detailed Implementation
[0017] To enable those skilled in the art to better understand this utility model, the technical solution of this utility model will be further described below in conjunction with the accompanying drawings and embodiments.
[0018] like Figure 1-5 As shown, the secondary mirror 1 of this utility model belongs to a small-diameter silicon carbide reflector. Traditionally, it adopts a central support technology and is usually composed of a mirror body, a conical sleeve and a flexible hinge. The conical sleeve is glued to the central hole on the back of the secondary mirror, and one end of the flexible hinge is connected to the conical sleeve and the other end is connected to the secondary mirror base.
[0019] Because the adhesive shrinks during bonding in the central support technology, generating shrinkage stress, it can easily deform the mirror surface. Furthermore, assembly requires precise control over adhesive thickness and quantity, demanding high levels of experience and skill from the workers. Severe mirror deformation often necessitates rework and re-adhesion, extending the development cycle. To overcome these difficulties, the secondary mirror body and secondary mirror mount 3 are designed as a single unit, with a weight-reducing hole in the center of the back of the secondary mirror. The interface locations of the secondary mirror mount 3 are designed with boss structures to reduce the contact area with the adjustment pads and improve installation stability. Each connection point is secured with three screws to enhance installation firmness and ensure structural safety during dynamic experiments or launches.
[0020] The secondary mirror mount 3 can be either triangular or circular, and its shape is consistent with that of the adjustment pad and the secondary mirror mount.
[0021] The adjustment shim 2 is made of Invar 4J32 steel to ensure it has the same coefficient of thermal expansion as silicon carbide, thus reducing the impact of temperature load. The distance accuracy between the secondary mirror 1 and the primary mirror is adjusted by grinding the adjustment shim, thereby achieving clear imaging.
[0022] The main support plate 5 adopts a sheet-like structure and can be made of silicon carbide or aluminum-based silicon carbide, etc. This application uses silicon carbide. To facilitate the installation of the main support plate 5, the secondary mirror mount 3 adopts a triangular structure, and the main support plate 5 is mounted on the flexible hinge 4 of the secondary mirror mount 3.
[0023] The main support plate 5 adopts a circular carbon fiber truss structure. The secondary mirror base 3 can be designed as a circular structure as needed. The secondary mirror base 3, the adjustment pad 2 and the connecting plate of the secondary mirror should also be designed as circular.
[0024] The secondary mirror mount 3 is made of silicon carbide.
[0025] The secondary mirror 1 is adjusted by grinding the thickness of the adjustment shim to adjust the distance between the primary and secondary mirrors. When the measured wavelet aberration meets the system requirements, the secondary mirror 1 and the adjustment shim 2 are connected to the secondary mirror mount 3 by screws. Therefore, the secondary mirror 1 and the secondary mirror mount 3 are fixed together.
[0026] Each side of the secondary mirror mount 3 is equipped with two flexible hinges that are fixed to the main support plate 5 with screws, so that the connection of the main support plate is more stable.
[0027] When environmental changes such as vibration, temperature changes, and transportation occur, the external load is transmitted to the flexible hinge 4 through the main support plate 5. The flexible hinge 4 absorbs part of the external force and transmits part of the external force to the secondary mirror mount 3. The secondary mirror mount 3 then transmits the external force to the connecting end face of the secondary mirror. Finally, the external load reaching the surface of the secondary mirror is basically consumed, which changes the force transmission path when the central support is in place, and can better maintain the surface accuracy of the secondary mirror and the positional accuracy of the main and secondary mirrors.
[0028] The flexible hinge 4 uses Invar 4J32 steel, which matches the thermal expansion coefficient of silicon carbide. All components of the device use materials with the same thermal expansion coefficient, realizing the heatless design of the secondary mirror flexible support device.
[0029] The flexible hinge 4 uses two sets of mutually perpendicular slots to achieve six degrees of freedom of movement, which can effectively reduce the influence of external forces. The end face of the flexible hinge 4 is threaded to the secondary mirror mount 3, and the other end is connected to the main support plate 5.
[0030] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A flexible support device for a silicon carbide secondary mirror, characterized in that, include: The secondary mirror is a small-diameter silicon carbide reflector, which adopts an integrated design of the mirror body and the connecting end face; Secondary mirror mount, connected to the secondary mirror; An adjustment shim is placed between the secondary mirror and the secondary mirror mount; A flexible hinge, one end of which is connected to the secondary mirror mount, and the other end of which is connected to the main support plate; The main support plate, with a sheet-like structure, is connected to a flexible hinge and is used to support the entire device.
2. The flexible support device for a silicon carbide secondary mirror according to claim 1, characterized in that, The connecting end face of the secondary mirror is designed with a boss structure, and the connecting end face is fixedly connected to the adjusting pad and the secondary mirror mount by at least three screws.
3. The flexible support device for a silicon carbide secondary mirror according to claim 2, characterized in that, The flexible hinge employs two sets of mutually perpendicular slots to achieve six degrees of freedom of movement.
4. The flexible support device for a silicon carbide secondary mirror according to claim 3, characterized in that, The secondary mirror mount is designed as a triangular or circular structure, and two flexible hinges are installed on each side of the secondary mirror mount.
5. The flexible support device for a silicon carbide secondary mirror according to claim 4, characterized in that, The secondary mirror and the adjustment pad are fixedly connected to the secondary mirror mount by screws.