小型自调式J-T制冷机波纹管刚度特性分析

摘要

自调式节流制冷器具有结构简单、响应速度快、稳定工作时间长等突出优势,在红外制导领域具有广泛的应用.镍基封闭充压波纹管作为自调式J-T节流制冷机的自调节机构的主要组成部分,其刚度特性对于实现稳定可靠自调过程非常重要.首先建立了自调式有限元模型,求解了波纹管刚度,进而将刚度的有限元求解结果与现有算法进行了对比分析.在此基础上,深入分析了环境温度、波纹管壁厚、波拱高度、倒角、波距等参数变化对波纹管刚度的影响,深入剖析了不同参数影响下,波纹管刚度变化规律.结果显示,有限元计算的刚度值与现有算法比起来更加准确.温度和波拱高度与刚度负相关,壁厚与刚度正相关,波纹倒角变化的影响可忽略.波距对刚度的影响并不稳定,波距在一定范围内变化时,刚度呈现先下降后上升的趋势.%The self-regulated J-T cryocooler is widely applied in the field of infrared guidance because of simple structure,fast response and stable long working hours.As the main part of self-regulating mechanism of J-T cryocooler,the stiffness of nickel-based closed bellow is very important to achieve stable and reliable self-adjusting process.A model based on finite element was modified to calculate the stiffness.And the values were compared with other methods.Some parameters affected the stiffness,such as temperature,wall thickness,wave height,fillet and wave pitch.The change regulation of stiffness was analyzed.The results show that finite element method is more accurate than other methods.The wall thickness is positive but the temperature and wave height is negative.The effect of fillet radius change can be ignored.And the influence of the wave pitch is not stable,the stiffness trend decreases and then increases.