本文就水箱盖零件的特点说明了其周壁凸缘台肩的成形采用镦压胀形工艺的必要性和优越性。以K>3.5～4的平砧圆环失稳镦粗和中等柔度压杆失稳问题的有关理论为指导,探讨了水箱盖周壁凸缘台肩镦压胀形的工艺计算及其模具设计。通过工艺的实施,论证了镦压胀形工艺的适用条件和该工艺冲压力的估算方法的合理性。 In this paper, the characteristics of the water tank cover parts illustrate the necessity and superiority of the forming of the flange of the peripheral wall by the upsetting and bulging bulging process. Guided by the theory of instability upsetting of flat anvil ring with K> 3.5 ~ 4 and instability of medium pressure bar, the calculation of the process of upsetting and bulging of the shoulder of the tank cap and its mold design . Through the implementation of the process, the applicable conditions of the upsetting bulging process and the reasonableness of the estimating method of the process stamping force are demonstrated.