Optimization of Resilient Tolerance Allocation Based on Dynamic Process Capability Index

Tolerance allocation is a critical aspect of product design. It connects both design and manufacturing processes and bridge the gap between machine processing Accuracy and assembly reliability. Effective tolerance analysis technology and allocation models play a pivotal role in providing precise data to enhance product design efficiency, reduce costs, and elevate product quality. This study proposed a novel tolerance allocation model that formulates a mathematical framework by considering the structural significance of tolerance nodes, tolerance-cost model, resilience evaluation parameters based on dynamic process capability index, and quality loss cost function. Moreover, it accounts for machining tool degradation disturbances during the manufacturing process to imbue the tolerance allocation scheme with greater system resilience. The proposed model is exemplified through a case study on the assembly size chain of a specific engine, juxtaposed against two conventional tolerance allocation methods, namely the equal tolerance method and equal precision method. The findings reveal that the proposed tolerance allocation scheme in this study minimizes the overall cost effectively.