一种板材小圆角胀压复合成形工艺解析

针对薄壁板材零件小圆角特征成形制造难的问题,提出了一种新型胀压复合成形工艺.其关键工艺参数为:预成形高度、预成形凹圆角大小和终成形胀形压力与背压凸模运行速度匹配关系.预成形高度决定了终成形小圆角的材料储备,预成形凹圆角的最佳值为充液拉深时凸模圆角可取的最小值,通过理论分析给出了预成形高度和预成形凹圆角的计算方法.建立了胀压复合成形过程力学模型,通过应力状态分析给出了不同胀形压力与背压凸模运行速度匹配关系下坯料圆角区变形状况.同时基于有限元模拟和工艺试验,研究了预成形高度和终成形胀形压力与背压匹配路径对试验件成形质量的影响,验证了理论分析的准确性,并证明了该新工艺的适用性.

Analysis of a bulging-pressing compound-forming process for the sheet metal part with a small round corner feature

This study presented a new bulging-pressing compound-forming process to solve the manufacturing problem of a thin-wall specimen with a small round corner radius.Its key process parameters were the pre-forming depth, pre-forming concave round corner, and matching relation between the liquid bulging pressure and the backpressure punch velocity in the final forming process.The pre-forming depth determines the material reserves of the small round corner area in final forming.The best pre-forming concave round corner is the minimum punch corner in hydro-mechanical deep drawing.The calculating methods for the pre-forming depth and the pre-forming concave round corner were provided by a theoretical analysis.The mechanical model of the bulging-pressing compound forming process was built.Moreover, the deformation situation in the round corner area with different matching relations between the liquid bulging pressure and the backpressure punch velocity was provided by the stress state analysis.Meanwhile, the influences of the pre-forming depth and the matching relation between the liquid bulging pressure and the backpressure in final forming on the quality of the part were researched based on the finite element simulations and experiments.The accuracy of the theoretical analysis was verified.In addition, the applicability of the new process was proven.