小半径薄壁管内胀推弯成形模拟与实验分析

Simulation and experiment analysis of inner bulging and push bending process for thin-wall tubes with small radius

通过拉弯、滚弯及数控弯曲等传统方法对Φ10 mm×1 mm、Φ20 mm×1 mm、Φ30 mm×1 mm三种规格管件进行弯曲加工实验。针对传统方法加工中出现的断裂、内侧壁厚增厚、外侧壁厚减薄、起皱和椭圆度差等问题设计了推弯模具,利用Deform软件建立了内胀推弯成形模型并进行仿真分析。在模拟过程中,对不同内压下的每一类型的管件采集数据绘制壁厚变化曲线,选取3条波动较小的曲线进行对比,最后确定模拟效果最好的内压值。依据模拟结果,通过实验对3种规格的弯管进行内胀推弯成形实验,结果表明,该方法很好地解决了小半径弯管内外壁厚度不均匀、起皱、断裂等问题。

For three kinds of specification pipes of 410 mm× 1 mm, φ420 mm × 1 mm, 430 mm× 1 mm, bending experiments were conducted by the traditional methods of bending, roll bending and CNC bending. In view of the fracture, inside wall thickening, outside wall thinning, wrinkling and poor ovality etc. existed in the traditional methods processing, push bending die was designed. The inner bulging and push bending model was establish and simulated by the Deform software. During the simulation, the thickness change curves were obtained through data collection for three kinds of specification pipes with different inner pressures, then three curves with small fluc- tuation were selected to compare. Finally, the inner pressure of the best simulation effect was determined. Based on the simulation re- suhs, experiments of inner bulging and push bending process based on three kinds of specification pipes were carried out. The results show that the problems of uneven thickness of inside and outside wall, wrinkling and fracture for bending tubes with small radius are well solved by the above method.