采用ProCAST软件对液压阀体铸造的流动和凝固过程进行数值模拟,预测铸造过程中出现缩孔的位置;在此基础上建立含有缩孔缺陷的阀体几何模型,利用Workbench计算带有缩孔的阀体在不同压力下的强度并改进阀体结构。结果表明:缩孔出现在阀体沉割槽靠出油口侧的两棱边附近,即最后凝固的部位,最大孔隙率为91.8%;与理想阀体相比,缩孔使得阀体局部有效壁厚大为减小,削弱阀体强度,导致阀体最大应力增大且随压力变化的梯度增大;与改进前的阀体相比,改进后的阀体缩孔缺陷减少且孔隙率降低了2.9倍;改进后带有缩孔的阀体承载能力较改进前带有缩孔的阀体承载能力强。
Casting flow and solidification process of hydraulic valve body were calculated by using Pro CAST, the location of shrinkage cavity was predicted. Valve body model with shrinkage cavity defects was set up, valve body strength under different pressure was calculated by using Workbench and the structure of valve body was improved. The results show that Shrinkage cavity appears in the parts of final solidification. The maximum porosity is 91.8%. Compared with the valve body without defects, shrinkage cavity decreases greatly effective wall thickness, which weakens the valve body strength, resulted in maximum stress and the change gradient of it with pressure increasing. Compared with the unimproved valve body, shrinkage cavity defects of the improved valve body is reduced and the porosity is decreased by 2.9times. The carrying capacity of improved valve body with shrinkage cavity is higher than unimproved valve body with shrinkage cavity.