摘要
带长直管的小弯曲半径（R=1D）薄壁弯头推弯成形极易产生成形不足、失稳起皱等缺陷。通过改变摩擦系数和成形内压两种工艺参数,研究带长直管的小弯曲半径弯头推弯成形。结果表明：管材内部压力的大小对弯头成形效果影响显著,压力太小会造成管材弯曲段产生失稳起皱的现象,压力太大则易造成弯管成形不足和弯管头部破裂等缺陷;管坯外壁与模具型腔摩擦力的大小对弯头成形亦有重要影响,摩擦力过大将阻碍管坯材料沿轴向的流动,降低弯头长度。实验采用聚氨酯填料作弹性介质,二硫化钼作润滑剂,内胀推弯成形带长直管的小弯曲半径薄壁弯头,其外侧壁厚减薄量控制在安全范围之内。
Defects such as insufficient forming,instability and wrinkling seriously emerge in the push-bending for thin-walled and small bending radius(R = 1D） elbow with long straight tube. The push-bending of thin-walled and small bending radius(R = 1D） elbow with long straight tube was studied by changing friction coefficient and forming internal pressure. The results show that the internal pressure of tube has a significant influence on the forming of elbow,the instability wrinkling in the bending section of tube emerges because of too small pressure,and the defects such as insufficient forming and head fracture of elbow are prone to occur due to large pressure. Moreover,the friction between the outer wall of tube and the mold cavity also has an important influence on the forming of elbow,and the material flow of tube along the axial direction is hindered and the length of elbow is reduced due to excessive friction. In the experiment,polyurethane filler and supramoly were respectively used as elastic medium and lubricant,and the thin-walled and small bending radius elbow with long straight tube were formed by push-bending with internal bulging. And the thickness reduction of its outer wall is controlled within the scope of security.
作者
刘琪
徐雪峰
付春林
王高潮
华如雨
Liu Qi;Xu Xuefeng;Fu Chunlin;Wang Gaochao;Hua Ruyu(School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, Chin)
出处
《锻压技术》
CAS
CSCD
北大核心
2018年第5期62-67,共6页
Forging & Stamping Technology
基金
国家自然科学基金资助项目(51405219)
中航工业产学研项目(BA2013063219)
关键词
内胀成形
失稳起皱
小弯曲半径
薄壁管材
弯头破裂
internal bulging
instability and wrinkling
small bending radius
thin-walled tube
elbow fracture
