小半径弯管弯胀复合成形研究

Research on Bending-Bulging Compound Forming Technology of Small Radius Tube

为解决小半径弯管内侧起皱、外侧减薄的成形缺陷,提出了一种弯胀复合成形的方法。通过几何关系解析了初始弯曲半径和初始管坯直径与最终管径和最终弯曲半径之间的关系,确定了初始弯曲半径的取值范围。采用有限元与实验相结合的方式研究了不同初始弯曲半径对零件壁厚分布的影响,分析了胀形过程中零件弯曲处及直壁处的变形规律。最终发现:初始弯曲半径越大,零件的最终减薄越小,胀形过程中弯曲处内外侧发生均匀减薄,直壁处内侧减薄明显大于外侧减薄。

To solve the forming defects of the inside wall of small-radius tube wrinkling and the outside thinning,a bending-bulging compo und forming has been put forward.The range of the initial bending radius is determined by analyzing the geometrical relationship among the initia l bending radius,the initial tube diameter,the final pipe diameter and the fin al bending radius.The influence of different initial bending radius on the wall thickness distribution and bulging on the straight and deformation wall are st udied by FEM simulations and experiments.Finally,the results show that the lar ger initial bending radius is,the smaller thinning of the parts is.At the same ti me,the uniform thinning appears at bend,and thinning at the inside of the straight wall is obviously larger than that at the outside during the bulging process.