A simple approach for the tolerance design of watt-i type six-bar hinge mechanism using taguchi method

This paper uses the Taguchi method on the tolerance design of a hinge mechanism with the aim of obtaining a design that is insensitive to variations in manufacturing tolerance and joint clearance. The contribution of each control factor in the mechanism to the variations was also quantified. From the analysis of the response table and diagram, it was concluded that the dimension r ₁, r ₂, r ₄ and β had a significant effect on the quality of the mechanism, contributing a total of 82.36% to product variation and were consequently named the key dimensions. The tolerance of these factors must therefore be tightened to improve the quality of the mechanism. Through a series of confirmation experiments, it was revealed that tightening the tolerance resulted in an increase in the S/N (signal to noise) ratio by 1.851 db and a reduction in product variation by 19.25% from the original 80.75%. The proposed method does not require complex mathematical derivatives, but simply the input and output relationship of the system. The method proposed in this study can be applied to all types of mechanism.