中空装配式凸轮轴扩径联接强度影响因素分析

Analysis of Influencing Factors on Assembled Camshaft Connection Strength of Tube Expanding Connection

针对某汽车发动机装配式凸轮轴,对机械扩径联接强度的主要影响因素进行了数值模拟研究,并进行了钢球扩径联接装配及静扭强度试验对比。研究结果表明:对GCr15钢凸轮和35钢轴管可进行机械扩径联接,材料匹配性能良好,完全满足产品联接强度要求;凸轮与轴管的初始装配间隙值、球体过盈量、轴管厚度和球体加载速度等工艺参数对联接区压配力和静力扭转力矩有很大影响;对工艺参数进行合理选择与匹配,可提高静扭强度35%,且高于凸轮轴产品要求的三倍以上,具有很高的联接可靠性。

For a certain type assembled camshaft of automobile engine,the main factors which influence mechanical expanding tube connection strength were studied by numerical simulation. The tube expanding connection and static torque strength experiments were conducted and the simulation result was compared with the experiment values. The results show that GCr15 steel cam and 35 steel tube can be assembled well with each other by the mechanical tube expanding connection and the connection strength meets the requirement of the products＇ the process parameters including initial assembled clearance values between cam and tube, ball interference, shaft tube thickness and-loading speed obviously impact the connected area pressure-fit stress the and static torque strength ; with the reasonable selection of the above parameters, the camshaft static torque strength increases by 35% which is three times more than the requirement of camshaft products, providing high connection reliability.