小孔护圈拉伸模设计吉林省柳河石棉制品厂（１３５３００）华中奭１引言在生产汽车汽缸垫（材料Ｈ６２，厚０．Ｚｍｍ）过程中，经常碰到直径在４ｇｍｍ以下的小护圈，如图１。拉伸系数一般都接近最小值，成形难度大。经过多年实践，把原来单层顶杆护圈模改成双层顶杆，收... Jilin Province Liuhe asbestos Products Factory (135300) Huazhong Wan 1 Introduction In the production of automotive cylinder pad (material H62, thickness 0.Zmm) process, often encounter small diameter of 4gmm below the small ring, Figure 1 Tensile coefficients are generally close to the minimum, forming a large difficulty. After many years of practice, the original single-layer ram retainer into a double-layer ram, closing ...