带枝桠筒形件挤压成形工艺研究

Research on extrusion forming process of cylindrical parts with branches

为了获得综合性能优良的某铝合金带枝桠筒形挤压件,结合其形状特点,首先提出了一次整体挤压成形工艺方案。通过有限元模拟对成形工艺方案进行验证,结合一次整体成形中所产生缺陷进行工艺改进。并提出两种改进方案,通过有限元模拟验证,方案1为下料热处理预成形热处理终成形(冲盂成形)机械加工,获得的挤压件金属填充不饱满;方案2为下料热处理反挤压成形热处理终成形(翻边成形)机械加工,获得了合格的挤压件。对方案2的载荷位移曲线变化规律及曲线上特殊节点产生原因进行了分析,初步确定了方案2的可行性;对方案2进行模具设计并进行工艺试验。试验结果表明,采用方案2的挤压成形工艺最终得到了填充效果良好、符合生产要求的带枝桠筒形挤压件。

To obtain cylindrical parts with branches who possess excellent overall performance, one-step integral extrusion forming process considering its shape characteristics was proposed. The process, analyzing the defects generated during forming, was improved and verified by the finite dement simulation. Two kinds of improved processes were proposed and verified by finite element simulation. Plan one is cutting → heat treatment → preforming → heat treatment → final forming （cupping） → machining, and the extrusion parts could not be filled completely. Plan two is cutting → heat treatment → backward extrusion forming → heat treatment → final forming （flanging） machining, and the qualitied extrusion parts were obtained. In addition, the variation of load-stroke curve and the cause of the particular nodes on the curve were analyzed, and the feasibility of plan two was identified. Then, the mold was designed and the process experiment was conducted for plan two. The experiment results show that the cylindrical extrusion parts with branches are well filled and their requirements are met.