分块式同步折展主镜保护机构设计及验证

Design and verification of multi-block synchronous folding primary mirror protection mechanism

主镜是望远镜的核心部分,需要设计保护机构以维持其性能、延长主镜膜层的使用寿命。在此背景上,针对某2.5m大口径光学望远镜结构特点及项目需求,设计了分块式同步折展主镜保护机构。重点对复合夹层材料的保护盖板进行了铺层优化设计,使其在满足轻量化需求的同时,刚度强度达到相关要求(盖板质量<2.5kg,一阶模态约>20Hz,在八级风载和1kg物块冲击下Tsai-Wu<1)。同时通过对机构折展运动的驱动设计及控制方式试验,可在规定时间内实现多扇同步驱动,单向折展运动时间约为52s。此设计对主镜甚至整个主镜筒内部结构都产生了良好的保护效果。该设计为国内大口径望远镜的主镜保护机构提供了新的思路及验证,对其余主镜保护结构的研究具有一定的参考意义。

The primary mirror is the core part of the telescope, and the protection mechanism needs to be designed to maintain its performance and extend the service life of the main mirror film.On this background, according to the structural characteristics and project requirements of a 2.5-meter large aperture optical telescope, a segmented synchronous folding primary mirror protection mechanism is designed.The optimization design of the protective cover plate of composite sandwich material is emphasized, so that the stiffness and strength can meet the relevant requirements while meeting the requirements of lightweight.(Cover plate mass <2.5kg, first-order mode about >20Hz, encountered eight-level wind load and 1kg block impact Tsai-Wu <1).At the same time, through the driving design and control mode test of the folding movement of the mechanism, the multi-fan synchronous driving can be realized in the specified time, and the unidirectional folding movement time is about 52s.This design has a good protection effect on the main mirror and even the entire internal structure of the main mirror tube.This design provides a new idea and validation for the main mirror protection mechanism of large aperture telescopes in China, and has a certain reference significance for the research of other main mirror protection structures.