Trajectory Designing and Realizing for the Variable Structure Motorcycle Helmet

摘要

A new type of variable structure motorcycle helmet is proposed in this paper, in which that the helmet's chin-guard can be transformed between the full-helmet status and the half-helmet status as needed. The helmet creatively adopts double movement nails and double track grooves to constraint the chin-guard movement according to the predetermined trajectory, and thus smoothly accomplishing the chin-guard's lifting, climbing, passing zenith, falling and closing in the helmet shell. The paper introduces the chin-guard's trajectory planning principles, realizing methods and designing steps, and then gives a design case for the constraint slot tracks in detail. The results show that the new type helmet can reliably realize helmet structure conversion between full-helmet and half-helmet and fully meets the design requirements.