材料力学性能对装配式凸轮轴球体扩径连接性能的影响

Influence of material mechanical properties on ball expanding and connection performance for assembled camshaft

为给球体扩径连接装配式凸轮轴在结构设计和材料优化匹配阶段提供相应的理论依据,应用弹塑性力学分析了弹性模量和屈服强度对球体扩径连接的影响,并根据不同材料匹配下相应的应力-应变曲线分析了球体扩径连接过程,给出了不同材料对应凸轮和轴体的连接条件,最后完成了扩径连接试验。结果表明：凸轮和轴体材料的弹性模量和屈服强度是球体扩径连接的关键,直接决定着扩径后凸轮和轴体弹性回复量的大小;在凸轮弹性模量小于轴体弹性模量情况下,可以不考虑凸轮和轴体材料的屈服强度;对于凸轮和轴体材料弹性模量相接近的情况,只有轴体屈服强度小于凸轮屈服强度才能够实现扩径连接。

In order to provide corresponding theoretical basis for structure design and material optimal matching of assembled camshaft on ball expanding and connection,the influences of Young＇s modulus and yield strength on ball expanding and connection were analyzed by elastic-plastic mechanics,and the ball expanding and connection process was analyzed according to the corresponding stress-strain curve of different material matching. Then,the connection conditions of corresponding cam and shaft for different materials were given,and the expanding and connection experiment was completed. The results show that the key factors in ball expanding and connection process are Young＇s modulus and yield strength of cam and shaft,which decide the elastic recovery values of cam and shaft after expanding process.Furthermore,the yield strength of cam and shaft may not be considered when the Young＇ s modulus of cam is smaller than that of shaft.However,when the Young＇s modulus of cam and shaft are approximate,the expanding and connection process can be realized as long as the yield strength of shaft is smaller than that of cam.