大型柴油发动机油底壳预成形工艺设计及优化

Design and optimization on preforming process for high-capacity diesel engine oil pan

由于新型大容量柴油发动机油底壳具有薄壁、大尺寸和非对称深腔的外观特征,传统的油底壳成形工艺已不适用。采用充液拉深成形工艺来成形最终胀形所用的坯料,工艺分为两步,先局部拉深,再整体拉深。借助有限元模拟软件建立计算模型,结合响应面法和正交试验法,探究凹模圆角半径、板/凸模间摩擦因数、板/凹模间摩擦因数、压边力和液压力等关键工艺参数对油底壳充液拉深的影响,并以最大减薄率和最大增厚率作为优化目标,得到最佳工艺参数组合。对最佳工艺参数组合进行试验验证,最终成功制成符合质量要求的新型龙门口式预成形件,最大减薄率与模拟结果基本吻合,验证了工艺方案的正确性和模拟仿真的可靠性。

Due to the appearance features of thin wall, large size and asymmetric deep cavity for the new type large-capacity diesel engine oil pan, the traditional forming process of oil pan is no longer applicable. Therefore, the billet used in final bulging was formed by hydro-mechanical deep drawing process, and the hydro-mechanical deep drawing process was developed into two steps, that is first partial deep drawing, and then overall deep drawing. With the help of finite element simulation software, the calculation model was established, and combined with the response surface method and orthogonal test method, the influences of the crucial process parameters such as die fillet radius, friction factor between blank and punch, friction factor between blank and die, blank holder force and hydraulic pressure on the hydro-mechanical deep drawing for oil pan were investigated. Furthermore, taking the maximum thinning rate and the maximum thickening rate as the optimization goals, the best combination of process parameters was obtained and verified, and a new type of gantry-type preformed part that met the quality requirements was successfully manufactured, and the maximum thinning rate was basically consistent with the simulation results, which verified the correctness of the process plan and the reliability of the simulation.