双锥冲头半积极摩擦反挤压力与实验研究

Derivation and Experimental Research on the Pressure for Backward Extrusion With Biconical Punch Under Conditions of Semi-active Friction

通过分析双锥冲头反挤杯形件的主应力导出了双锥冲头半积极摩擦反挤压的主应力解表达式。设计了可用于实验和生产的半积极摩擦反挤压的实验装置。在实验装置上验证了轴承钢半积极摩擦反挤杯形件降低挤压力的效果。指出半积极摩擦反挤压适用于深杯、薄壁、外形尺寸大、变形抗力高和毛坯润滑不良的挤压件。

The expression for the principal stress of backward extrusion with biconical punch under conditions of semi-active friction can be derived from the solution of primary stress of cup-like piece backward extruding with biconical punch. The set-up is designed for experiments of backward extrusion under conditions of semi-active friction and can be used in practical production as well. The experiments prove the effectiveness of semi-active friction in lowering the pressure of backward extrusion for cup-like pieces of rolling bearing steel. It is pointed out that backward extrusion under conditions of semi-active friction is suitable for workpieces which are deep cup-like, and also for those workblanks with one of following features: large-sized, thin wall, high resistance force to deformation as well as ill lubrication.