超高压缸体机械自紧芯棒结构研究  

Research on the Mechanical Autofrettage Core Rod Structure of Ultra High Pressure Cylinder Block

作　　者：孙立华 孙言博 白金石 赵帅 张宝庆[2] SUN Lihua;SUN Yanbo;BAI Jinshi;ZHAO Shuai;ZHANG Baoqing(Engineering Training Center,Changchun University of Technology,Changchun Jilin 130012,China;School of Mechanical and Electrical Engineering,Changchun University of Science and Technology,Changchun Jilin 130022,China)

机构地区：[1]长春工业大学工程训练中心,吉林长春130012 [2]长春理工大学机电工程学院,吉林长春130022

出　　处：《机床与液压》2025年第6期148-156,共9页Machine Tool & Hydraulics

基　　金：吉林省自然科学基金(YDZJ202201ZYTS537)。

摘　　要：掌握机械自紧芯棒结构是提升超高压缸体承载能力的关键,但是循环工作内压导致缸体内壁有效残余应力出现松弛,使得缸体使用寿命缩短。针对此问题,利用二次自紧延缓残余应力衰减的原理,对芯棒进行优化设计,以达到更好的自紧效果;以芯棒最佳过盈量为基础,分析阶梯形芯棒对缸体残余应力分布影响,利用Abaqus有限元软件模拟机械自紧挤压过程。结果表明:当阶梯形芯棒后半段为最佳过盈半径且前后过盈半径比为1时,工作载荷下弹塑性分界面最接近内壁且周向残余应力最小;阶梯型芯棒相较于橄榄形芯棒可使缸体的疲劳寿命最低位置向内壁移动,残余应力分布更加均匀,降低了缸体外壁疲劳破坏的风险;超高压缸体可承受更大的工作载荷,与后续芯棒机械挤压试验相符。Mastering the mechanical autofrettage core rod structure is the key to improve the load bearing capacity of ultra high pressure cylinder block.However,the circulating internal pressure leads to the relaxation of the effective residual stress on the inner wall of the cylinder block,resulting in short service life of the cylinder.In view of this problem,the principle of secondary autofrettage to delay the residual stress attenuation was used to optimize the design of the core rod to achieve a better autofrettage effect.Based on the optimum interference quantity of core rod,a method was proposed to study the influence of stepped core rod on the residual stress distribution of cylinder block.Abaqus finite element software was used to simulate the mechanical autofrettage extrusion process.The results show that when the second half of the stepped core rod is the best interference radius and the front to back interference radius ratio is 1,the elastic-plastic interface is closest to the inner wall and the circumferential residual stress is minimum under working load.Compared with the olive core rod,the stepped core rod can make the lowest position of the fatigue life of the cylinder move to the inner wall,and the residual stress distribution is more uniform,which reduces the risk of fatigue damage of the outer wall of the cylinder.The ultra high pressure cylinder block can withstand greater working load,which is consistent with the subsequent mechanical extrusion test of core rod.

关 键 词：超高压缸体 机械自紧 芯棒结构优化 残余应力 

分 类 号：TH49[机械工程—机械制造及自动化] TH123