薄壁阀壳冲压成型工艺参数的优化

Optimization for the Forming Process Parameters of Thin-Walled Valve Shell

工业生产中广泛应用的球阀,其中一个关键部分就是阀壳,一般通过铸造和锻造制成。一项关于管件液压成型的新技术,可以克服传统方法中的局限性。为了获得液压中的最佳成型参数,提出一种结合遗传算法和有限元模拟的新方法。基于塑性理论,内部压力和轴向进给量分别表示为一个应力比率函数,然后,采用有限元方法对目标函数求解,遗传算法用来搜索最优应力比。最后,计算出最优的内部压力和轴向进给量,并在工厂里进行了验证性试验。试验结果表明,所提出的方法可以有效地获得管件液压成型中的最佳加载路径,并显著改善球阀壳面的质量。

Ball valves are widely used in industry, and the valve shell, a key component, is conventionally produced by casting and forging. A new technique, tube hydroforming, is introduced to overcome limitation of the conventional techniques. In order to obtain the optimal forming parameters of hydroforming, a new method combining genetic algorithm with finite element simulation is proposed in this paper. On the basis of plastic theory, the internal pressure and axial feed are expressed as a function of the stress ratios, respectively. Then, finite element method is used as a solver of the objective function, and genetic algorithm is employed to search the optimal stress ratios. Finally, the optimal internal pressure and axial feed are calculated by using their computation expressions. Verified experiments are carried out in the plant. The experiment results show that the proposed method can effectively obtain the optimal loading paths of tube hydroforming and remarkably improve quality of the ball valve shell.