Transactions of Materials and Heat Treatment

Title：Analysis and improvement on local deformation of punching for piston pin

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ClassificationCode：TG316.1+5

year,vol(issue):pagenumber：2022,47(7):13-19

Abstract：

For a piston pin of an internal combustion engine, the result of excessive local upsetting deformation at the bottom of piston pin punching was analyzed and corrected. Firstly, 20CrH steel samples for piston pin materials were subjected to tensile and compression tests at room temperature, the tensile process was numerically simulated by software DEFORM, and the Normalized Cockcroft & Latham (NCL) ductile fracture criterion was used as a model to solve the critical value of 0.22. Secondly, the NCL model was used to numerically simulate the punching process for piston pin, and the reasons for the local upsetting deformation of piston pin punching were analyzed. The outside of the cylinder wall was in state of no radial constraint, during the punching process, the axial and radial composite metal flow occurred at the cylinder wall corresponding to the connecting skin. Finally, on the basis of not changing the original mold, a solution method was proposed to reduce the local upsetting deformation at the bottom by reducing the thickness of connecting skin. The results of numerical simulation and process test show that this method can ensure that the size of the outer cylindrical surface of piston pin after punching will not be out of tolerance due to excessive local upsetting deformation.

Funds：

乐山市科技局重点研究项目（21GZD029）

作者简介：袁磊（1986-），男，硕士，讲师 E-mail：yuanlei11@163.com

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