基于流函数法的铝型材挤压导流模合理设计

RATIONAL DESIGN OF THE FLOW- GUIDE DIE OF ALUMINUM SHAPE EXTRUSION BASED ON THE FLOW FUNCTION METHOD

采用模拟试验法和理论分析法研究了导流模内型材挤压的流动机理;提出了确定导流腔最小深度的理论依据;用基于流函数的上限分析法确定了实心薄壁铝型材挤压变形的流线方程、动可容速度场、应变速率场及上限功率;讨论了变形程度等参数对导流模最小理论深度的影响,得出实心薄壁铝型材导流腔深度的理论最小值为导流腔半宽的0.7～0.8倍。理论结果得到了试验证实,为导流模合理设计提供了可靠的依据。

The flow characteristics in aluminum shape extrusion with the flow-guide die added are analyzed by both the simulating experiment method and the theoretical method. The theoretical basis for minimum height of flow-guide die cavity is provided. The flow line equation, the kinematically admissible velocity field , the strain rate field and the deformation power of solid aluminum shape with thin wall extrusion are obtained by the upper bound method based on the flow function . The effects of the parameters , such as deformation ratio, on minimum height of flow-guide die cavity are discussed. The minimum height when aluminum shape with thin wall is extruded can be expressed by 0.7-0.8 b0, where b0 is the half-width of the entrance of the flow-quide die cavity. The theoretical result is confirmed by experiment. The useful knowledeges for die design can be obtained.