摘要
介绍了小型汽车桥壳的液压胀形工艺,提出了初始胀形内压的表达式,预测了初始胀形内压与轴向推力的匹配关系(即经向应力比的大小)对预胀形时各部分变形顺序的影响。在普通液压机上进行了两种加载路径下的液压胀形试验,在初始经向应力比小于零并保持恒内压的条件下,预胀形管坯先变形成两侧高、中部低的双鼓形,经增压后将中部胀起;在初始经向应力比大于零且内压恒定的条件下,预胀形管坯中部沿轴向胀裂;两种加载路径下,管坯扁锥体凸起与胀形区之间均产生了明显内凹缺陷。理论分析与试验结果均表明,初始变形条件对小型桥壳的预胀形有重要影响。
The hydroforming technology of light axle housing was introduced.The formula of initial internal pressure was deduced, and the influences of the relation of the internal pressure and axial thrust （axial stress ratio）in the pre-bulging process on the deformation sequence was predicted. The hydroforming experiments were done on general hydraulic machine under two different load paths.Under the first load path, the initial axial stress ratio was negative and the pressure was constant throughout the feeding process,the pre-bulging tube was first deformed to a double-drum type with the diameter of two sides larger than the central, and the central part was finally bulged by increasing the internal pressure. Under the second load path, the initial axial stress ratio was positive and the pressure was constant throughout the feeding process, the central of the tube cracked axially. The common concave defects of the samples of two load paths were observed at the transition region between flat cone and bulging area, and it will not disappear after the final bulging.Both of the theoretical analyses and experiments demonstrate that the initial deformation conditions have an important influence on the pre-bulging process of light axle housing.
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2016年第3期398-402,共5页
China Mechanical Engineering
基金
河北省自然科学基金资助项目(E2012203022)
关键词
汽车桥壳
液压胀形
初始胀形内压
经向应力比
预胀形管坯
automobile axle housing
hydroforming
initial pressure
axial stress ratio
pre-bulging tube
