Xiaodong Wang
Dalian University of Technology, China
Title: Quality estimation of interference fits assembly based on press-fit curve
Biography
Biography: Xiaodong Wang
Abstract
Statement of the Problem: Press-fit assembly is one of the traditional methods for assembly of interference fitting parts, and its assembly quality has attracted the attention of many researchers. Generally, the strength of assemblies depends on various parameters such as interference value, physical dimensions, form error of contact surfaces, etc. Furthermore, the connection quality cannot be obtained directly by the press-fit method. Hence, many studies have been performed to investigate the effect of various parameters on the load bearing ability of interference fits based on finite element method (FEM) and theoretical method. But most of the researches focus on the contact status of finished interference fits. Since the press-fit curve can be used for real-time monitoring and evaluate the assembly quality, the purpose of this study is to obtain standard press-fit curves as an evaluation criterion to estimate the assembly quality.
Methodology: A theoretical model and simplified FE model were used to predict the standard press-fit curves. To verify the accuracy of the prediction results, assembly experiments were carried out using an automatic press-fit instrument which consists of binocular vision device, upper and lower fixtures, XY precision stages, and force-displacement measurement module, etc. Finally, the reasonable growth tendency and a reasonable range of maximum press-mounting force are obtained and used for quality estimation.
Results: The prediction results of the press-fit curve have sufficient accuracy, and the evaluation strategy proposed in this study can give a reasonable assessment of assembly quality whether the failure is caused by form error or alignment error, etc.
Conclusion & Significance: The theoretical model is more efficient than FEM in press-fit curve prediction. The evaluation strategy can be used to predict the assembly quality, which is of great significance to improve the reliability of interference fits.