关键词: 组合式凸轮轴, 径向滚花装配机理, 压装力, 静扭强度, 凸轮外轮廓精度, 残余应力

Abstract:  A finite element predictive approach involving severe plastic deformation of the materials and including three subsequent models（knurling， press-fit and torsion strength） were established  based on the coupled Euler-Lagrangian mesh and Johnson-Cook material model. The sub models were connected in series by transferring the residual stress and strain fields of the shaft tubes to ensure the continuity of the physical fields. The whole process of radial knurling assembly was systematically simulated by connecting each working step model in series； the press-fit force， static torsional strength and the variation characteristics of the cam profiles were predicted and analyzed. The influence law of knurling tool parameters and feed rate on the press-fit force and static torsional strength was revealed. It is shown that numerical results of morphological characteristics of shaft tubes in knurling and assembly area as well as temperature field are in good agreement with the experimental work. The torque strength of the joint is 90% higher than that of a typical passenger vehicle requirement. The torque strength is significantly positive correlated to the press-fit loads. The max displacement of outline of cam is not less than 0.0425 mm. The predicted press-fit and joining strength using the subsequent modeling are validated by the experimental measurement with maximum errors less than 11%. The subsequent models may partly take a place of knurling assembly tests， which is instrumental in shorten development cycles. 

Key words: assembled camshaft, mechanism of radial knurling joint, press-fit force, static torsional strength, cam contour accuracy, residual stress