基于数值模拟的内螺纹冷挤压成形过程工艺参数优化

Optimization of processing parameters for cold extrusion of internal thread based on numerical simulation

在内螺纹冷挤压数值模拟的基础上,获得了对其成形过程内螺纹质量及丝锥寿命有关键影响的工艺分析数据——挤压扭矩及挤压温度,并基于这两个指标,分别选取了不同工艺参数及水平进行了正交试验设计,分析了工件底孔直径、挤压速度及冷却润滑液的选择对它们的影响规律,获得了最优的工艺参数。验证试验结果表明,数值模拟及正交试验优化结果准确有效,成形之后内螺纹牙高率满足连接强度要求,螺纹表面平整性及成形质量较好。

The analysis data during the forming process including extrusion torque and extrusion temperature which made great difference to the thread quality and tap life were derived based on the numerical simulation on the process of internal thread formed by cold extrusion using Deform-3D. Different processing parameters and factor level were select- ed to carry the orthogonal experiment out based on these two indicators to analyze the influence law of workpiece diam- eter, extrusion speed and coolant on them and to obtain the optimal processing parameters. A validation experiment was also carried out to show that the numerical simulation results and optimization result of orthogonal experiment are accurate and effective; the rate of internal thread tooth can well meet the joint strength requirements after forming, the surface smoothness and the thread after forming are also of good quality.