我们曾用如图1所示的模具在空气锤上镦锻长螺栓头部,因圆钢(?)料在炉中加热的长度难以控制准确,镦头时变形区太大,常使坏料卡在模具里拿不出来,造成工件或模具报废。后来改用如图2所示的模具。新模具分内、外两层,内层由左、右两半 We have used the mold shown in Figure 1 upsetting the head of long bolts on the air hammer, because the round steel (?) Material in the furnace heating the length of the control is not accurate, the deformation zone is too large when heading, often bad cards Can not get out in the mold, resulting in scrapped parts or molds. Later switched to the mold shown in Figure 2. New mold points, the outer two layers, the inner left and right halves