Expandable curved surface truss mechanism based on rigid shear fork mechanism

Abstract

The invention provides an expandable curved surface truss mechanism based on a rigid shear fork mechanism. The expandable curved surface truss mechanism comprises an I-level hexagonal prism frustum unit and six II-level hexagonal prism frustum units, each hexagonal prism frustum unit comprises a central splined disc, and six double-4R mechanisms are arranged in the circumferential direction of each central splined disc and are of a closed plane symmetric structure; and each double-4R mechanism comprises two identical first longitudinal rods, two identical first shear fork rods and two identical first connecting rods, wherein the two first shear fork rods are connected with each other through a rotating pair R1 to form a shear fork mechanism, the starting ends of the two first shear fork rods are correspondingly connected to the lower ends of the two first longitudinal rods through a rotating pair R2, the starting ends of the two first connecting rods are correspondingly connected to the upper ends of the two first longitudinal rods through a rotating pair R3, and the tail ends of the two first connecting rods are connected to the tail ends of the two first shear fork rods correspondingly through a rotating pair R4. The expandable curved surface truss mechanism has the advantages of single degree of freedom, easy engineering manufacturing, good folding and unfolding performance,large folding and unfolding ratio, light weight, high strength, high curved surface precision and the like.

Description

technical field [0001] The invention relates to an expandable curved surface truss mechanism based on a rigid scissor mechanism. Background technique [0002] Due to the limited load space of the launch vehicle, the space antenna is usually designed as a foldable mechanism, and is in a fully folded state during the launch to obtain the smallest volume. When it reaches the predetermined orbit, it will be stably unfolded to the working state according to relevant instructions. Today, a variety of deployable mechanisms have been developed that are applicable to space antennas. [0003] Chinese patent document CN106450647A discloses a scissor-type hexagonal prism expandable unit and a space expandable mechanism composed of it. A faceplate, six sets of scissor folding links and twelve sets of folding links, one set of folding links depends on the length of the link to limit the expansion of the basic expandable unit, and the remaining eleven sets of folding links are all over-co...

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