摘要
扭转强度是评价装配式凸轮轴的重要指标,为了解决液压胀接装配式凸轮轴扭转强度较低的问题,提出了通过改善微观组织提高扭转强度的方法。基于芯轴退火、拉伸实验,建立了退火工艺参数与晶粒尺寸关系的数学模型,分析了不同退火工艺参数对力学性能参数的影响规律,基于液压胀接仿真结果,研究了不同退火工艺参数对液压胀接装配式凸轮轴接触面积和扭转强度的影响规律,探究了晶粒尺寸对其扭转强度的影响规律。研究表明:退火温度、保温时间与芯轴晶粒尺寸满足奥氏体晶粒长大模型,随着退火温度以及保温时间的提高,芯轴屈服强度、抗拉强度和显微硬度逐渐降低,断后伸长率逐渐提高,塑性提高使胀接后凸轮与芯轴间的接触面积增加,相较于未退火芯轴,液压胀接装配式凸轮轴的扭转强度提高。结果证明改善芯轴微观组织可以提高液压胀接装配式凸轮轴的扭转强度,该方法对液压胀接装配式凸轮轴生产加工具有重要的指导意义。
Torsional strength is an important indicator for evaluating assembled camshafts.In order to solve the problem of low torsional strength of assembled camshafts,a method is proposed to improve the torsional strength by improving the microstructure.A mathematical model of the relation between the annealing process parameters and grain size is established through core axis annealing and tensile experiments.The influence of different annealing processes on the mechanical performance parameters is analyzed.Based on the simulation results of hydraulic expansion,the influence of different annealing processes on the contact area and torsional strength of the assembled camshafts is studied,and the influence of grain size on the connection strength of the assembled camshafts is explored.The research has shown that the annealing temperature,holding time and core grain size meet the austenite grain growth model.As the annealing temperature and holding time increase,the yield strength,tensile strength and microhardness of the core gradually decrease,and the elongation after fracture gradually increases.The increase in plasticity leads to an increase in the contact area between the cam and the core after expansion.Compared to the unannealed core,the torsional strength of the assembled camshaft is improved.The results show that improving the microstructure of the core shaft can improve the torsional strength of the assembled camshaft,and this method has important guiding significance for the production and processing of the assembled camshafts.
作者
徐虎
马建平
何玉林
XU Hu;MA Jianping;HE Yulin(School of Mechanical&Electrical Engineering,Guilin University of Electronic Technology,Guilin Guangxi 541004,China;School of Electronic Engineering&Automation,Guilin University of Electronic Technology,Guilin Guangxi 541004,China;Guangxi Key Laboratory of Manufacturing System&Advanced Manufacturing Technology,Guilin University of Electronic Technology,Guilin Guangxi 541004,China)
出处
《机械设计与研究》
CSCD
北大核心
2024年第1期184-189,共6页
Machine Design And Research
基金
国家自然科学基金(52065014)
广西自然科学基金(2023GXNSFBA026121)资助项目
广西制造系统与先进制造技术重点实验室主任基金项目(22-35-4-S013)
广西高校中青年教师科研基础能力提升项目(2023KY0220)。
关键词
退火
微观组织
晶粒尺寸
力学性能
扭转强度
annealing
microstructure
grain size
mechanical properties
torsional strength
