Innovative Design and Evaluation of Folding Mechanisms for Two-Section and Three-Section Folding Umbrellas

Autor: Yu-Cheng Hong, 洪育昌
Rok vydání: 2008
Druh dokumentu: 學位論文 ; thesis
Popis: 96
Due to the advantages of easy to fold and carry, folding umbrella has become very popular. However, it is very common to see a folding umbrella destroyed by strong wind. Though there are some improvements on the material used for folding mechanisms in order to strengthen the ability to stand against wind force, we haven’t seen any research on reducing folding volume and the rib structure to stand against wind force in the literature. Therefore, the purpose of this study is to systematically obtain innovative designs and evaluate all potential folding mechanisms, and then pick up the best designs from them. Based on the method of Creative Design of Mechanical Devices, this study carries the creative design of mechanisms for two-section and three-section of folding umbrella, and presents all possible structures of folding umbrella mechanisms. This study also analyzes and evaluates those mechanisms. Firstly, this study reviewed the related literature and patents to obtain the design requirements and constraints of folding umbrella. Secondly, by following the procedure of Creative Design of Mechanical Devices, we obtained one new type of specialized kinematic chain for six-link-seven-joint, and nine new types of specialized kinematic chains for eight- link-ten-joint available for the rib structures of folding umbrella. Based on the results from synthesizing the potential folding mechanisms for the umbrella using six-link seven-joint, eight-link ten-joint, all those potential folding mechanisms are particularized. Then, the feasibilities of those mechanisms are examined by ADAMS software. Thereafter, the evaluation is performed under the conditions of same horizontal projected area and same wind force. The criteria for the comparison between those mechanisms are the folding length and the maximum reaction force at joint of each mechanism. The results of better designs are presented by applying the criteria. The results show that, except the best design of the two-section folding umbrella of eight-link–ten-joint with two sliders is innovative, all the other best designs from evaluations could be found in the existed patents.
Databáze: Networked Digital Library of Theses & Dissertations
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