Summary: | 碩士 === 國立中山大學 === 機械工程研究所 === 85 ===
A Parallel index cam mechanism is made up of two conjugate, parallel plate cams in conjunction with a follower wheel that has cylindrical rollers mounted on it. The input and output shafts of the device are parallel to each other. When on of the cams rotates the follower through a path dictated by the shape of the cam, the other prevents the roller from leaving the cam surface. The rigidity of the mechanism can be increased by the preload between the cam and follower wheel. From its special geometry, stable and smooth outputs with high indexing accuracy can be generated. As a result, the indexer has wildly been used in industry for varioius applications.
The major goal of this study is to develop a computer integrated manufacturing procedure to synthesize, analyze, and machining the parallel index cams. To meet the application requirements, the study includes four main parts. The first part is the design of the timing schemes. Type Ⅱ (1/2 revolution) is added to the type of the indexing cam mechanism, and therefore it can be used mroe wildly. The second part is the synthesis of the motion curve. Including the common curves, it also adds the rational B-spline curve as a synthesis tool to refine the motion function of the follower. The third part is based on the rigid body transformation to analytically determine the conjugate cam profiles. The last part is the analysis of the kinematic characteristics of the mechanism, and more importantly these results are utilized as the basis for adjusting the cam profiles and their modified tool cutting paths.
To illustrate the application of the procedure, a serice of examples is given.
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