挤压凹模变形区变形力新解法

A new solution of force in the deformation zone of extrusion die

在柱坐标系下,建立连续速度场,利用上界定理求解变形区内部的纯塑性变形功率、速度不连续面上的剪切功率及摩擦功率,推导出了凹模正挤压时其锥形变形区变形力的理论计算公式。经国产16.3NM卧式挤压机生产实验反复对比验证,发现实测值略小于计算值,相对误差为(-8.36)%。推导的挤压力计算公式具有一定的工程实用性,为挤压类模具设计和挤压工艺的制定提供了理论依据。

In the cylinderical coordinate,building the continuity velocity field,the pure plastic deformation power in the deformation zone,the shear power and the friction power of the uncontinual surface were resolved by upper bound theory,and the formula of force in the deformation zone was developed when the die is extruded.The formula was validated repeatedly on 16.3NM horizontal extruding press in the course of production.It is found that the test value is lower than the count value.The relative error is（8.36）%.The formula given has certain utility in the engineering and affords a theoretical basis for designing cone die and setting down the process of extrusion.