Experimental tolerance design of a six-bar toggle-linkage mechanism using near-singularity characteristics

Abstract

Tolerance analysis is very important for the mass production of mechanism parts to guarantee satisfactory performance at a low production cost. The tolerance analysis of linkage mechanisms is important because linkage mechanisms are very sensitive to tolerance owing to many shaft–hole connections. Typically, tolerance is determined by intuition and experiences, but it can lead to low performance or high production cost. In particular, the tolerance of a linkage has a significant effect on near-singularity operation as even a very small dimension difference can change the performance dramatically. In this paper, we present an experimental tolerance design of a six-bar toggle-linkage mechanism for clamping application. The tolerance design is very important to the six-bar toggle-linkage mechanism as the clamping operation is performed with a near-singularity configuration. Based on a design of experiment, the tolerances are determined by optimal criteria with performance and cost deviations. We determine the positions with high tolerance and low tolerance empirically. The final tolerances can be used for mass production of the toggle clamping device.