斜轧穿孔机顶杆弯曲挠度及临界失稳力计算分析

By analyzing the force and movement constraints of the mandrel during rotary piercing process, the calculation model of the distribution of critical bending unstable force and bending deflection of the mandrel was established based on the relevant mechanics theory. The stability resistance of the mandrel increases rapidly with the increase of mandrel diameter and the number of centering device sets, and decreases with the increase of the mandrel length. The maximum bending deflection of mandrel increases with the increase of the resistance and the mandrel length, and decreases with the increase of the mandrel diameter. The compression mandrel bending experiment was conducted on pressure machine, and the bending deflection deformation was confirmed to be asymmetric. The maximum bending deflection appears was one third of the mandrel length when none of the centering device is installed. A new method to install a centering device at the position where the maximum bending deflection appears was proposed which can satisfy the purpose of saving the number of centering device sets and improving the ability of unstable resistance. The research results can provide credit help for predicting mandrel instability and determining the number of centering device sets and the installation positions.