曲轴NTR弯曲镦锻物理模拟系统相似性分析

Similarity Analysis of Crankshaft NTR Upset-bending Physical Simulation System

分析了曲轴NTR弯曲镦锻物理模拟系统与原型系统的几何相似性、运动学相似性与动力学相似性。根据相似定理,两系统几何条件与运动学条件可以实现精确相似,并能在相关性水平α=0.05的情况下实现动力学近似相似。基于此物理模拟系统,以42CrMo钢6G32曲轴为原型,采用铅轴坯进行NTR弯曲镦锻物理模拟试验,所得锻件出现了曲轴原型系统模锻工艺中容易产生的塌角与飞边现象,且主体结构尺寸与原型锻件设计尺寸之间符合系统几何相似常数,系统传感器记录的模具成形载荷数据与预期变化趋势吻合。

The geometric,kinematics and dynamics similarity of crankshaft NTR upset-bending physical simulation system to the prototype system were studied.Based on the similarity theorem this simulation system met the geometric and the kinematics similarity conditions to the prototype system and when the relative coefficient a=0.05 they met the approximate dynamics similarity conditions.A NTR upset-bending experiment for one lead crankshaft billet was carried out on this physical simula-tion system,taking the 42CrMo steel 6G32 crankshaft as the prototype.The small crankshaft forming in this trial had sunks and flashes similar to the large forgings obtained in actual forming process.The dimension scale between the design size of the prototype and the main structure dimensions of the lead forging is as the same as the geometric similarity coefficient of two systems.The change of the force data recorded in the sensors in forming process is consistent with the expected trend.