某汽车旋锻轴毛坯尺寸要求研究

Investigation on workblank size requirements of rotary-swaging shafts of an automobile

以某汽车等速万向传动中间旋锻轴为对象,提出耦合旋锻成形工艺特性以及材料加工硬化特性、毛坯力学特性、毛坯旋锻前后的壁厚和内外径之间的关系进行毛坯尺寸要求设计。首先根据芯棒与坯料之间的最大间隙要求,保证旋锻成形质量,确定毛坯的最大内径要求;其次根据旋锻成形工艺、材料加工硬化特性以及旋锻后无芯棒两端渐开线花键成形工艺要求确定毛坯最大硬度;最后根据毛坯力学特性试验获得的硬度强度转换关系、材料拉伸试验拟合得到的加工硬化特性曲线、毛坯旋锻前后的壁厚和内外径之间的关系以及毛坯最大内径要求确定毛坯最大外径要求。

Taking the middle rotary-swaging shafts of constant velocity and universal drive in an automobile as the case,the size requirements of rotary-swaging shafts workblank were designed considering the swaging forming process,the work hardening characteristics of the material,the mechanical properties of the workblank and the relationship between wall thickness and inner and outer diameters before and after rotary-swaging.First of all,in order to guarantee the quality of the shafts,the maximum inner diameter requirement of the workblank was determined according to the maximum clearance between the mandrel bar and the workblank.Secondly,the maximum hardness of the workblank was determined according to the rotary-swaging forming process,the work hardening characteristics of the material and the involute spline forming process by rotary-swaging without mandrel at both ends of the shafts.Finally,combining the hardness-strength conversion relationship obtained by the mechanical property test of the workblank,the work hardening characteristic curve obtained by the material tensile testing,the relationship between wall thickness and inner and outer diameters before and after rotary-swaging and the maximum inner diameter requirement of the workblank,the maximum outer diameter requirement of the workblank was determined.