144型高性能转向节预锻件优化设计与精锻工艺研究

Optimized design of preforging and precision forging process of 144-type high-performance steering knuckle

144型转向节是中重型高端商用车转向部件中的核心零件,其对延伸率和断面收缩率均有严格要求,根据传统锻造工艺理论设计的预锻方案不能满足断面收缩率要求,研究其预锻件的优化设计与精锻终成形工艺对于获得合格锻件具有重要意义。首先采用经典塑性成形理论分析了基于传统方法设计的预锻件存在的问题,然后基于损伤理论提出了其预锻件结构的优化设计方法,同时提出了基于平面薄飞边的精锻终成形工艺。应用结果表明,生产的144型转向节精密锻件阶梯杆部的关键技术指标延伸率A≥12.5%,断面收缩率Z≥50%,超过了国外客户所提技术指标的要求。

The 144-type steering knuckle is a key part of the steering components of medium and heavy commercial vehicles.It has strict requirements for both elongation and area reduction.How⁃ever,the preforging scheme designed based on traditional forging process theory cannot meet the requirements of section reduction rate.Therefore,studying the structural optimization of preforg⁃ings and the final precision forging forming process is of great significance to obtain qualified prod⁃ucts.First,the classical plastic forming theory was used to analyze the existing problems of pre⁃forgings designed based on traditional methods.Then,an optimal design method for the preforging structure was proposed based on the damage theory.Meanwhile,the final forging process with small flash,that is,flat thin flash,was proposed.The application results showed that the elonga⁃tion and area reduction of the stepped rod part of the produced 144 steering knuckle precision forg⁃ings were A≥12.5%and Z≥50%,respectively,exceeding the technical index requirements of foreign customers and creating significant technical and economic benefits.