枪弹弹壳挤盂组合模新型设计与研究

New Design and Research of Bullet Casings Extrusion Combined Die

为保证弹壳挤盂成形中模具的较高使用寿命,以冷挤压工艺理论为基础,结合有限元仿真技术对枪弹弹壳挤盂组合模进行新型设计。利用拉美优化公式计算得到组合模各层直径及径向过盈量,并通过DEFORM-3D软件对枪弹弹壳挤盂成形过程进行数值模拟。仿真结果表明:组合模内壁可以完全不受切向拉应力的作用,模具强度和承载能力是整体模的1.75倍左右。预应力组合模的合理设计能有效降低模具破裂的风险,使弹壳挤盂成形得到保证。

To ensure long service life of dies in the cartridge case extrusion forming, the combined extrusion die for cartridge cases was newly designed by finite element simulation based on cold extrusion process theory. Diameters of each layer of the combined die and shrink ranges between neighboring layers were calculated using lame optimal formula, and extrusion forming process for cartridge cases was simulated with DEFORM-3D software. It was proved that the inner wall of combined die can be completely free from tangential tensile stress, and the corresponding structural strength and bearable load was 1.75 times of integral die. So, the fracture risk would be reduced effectively and the cartridge case extrusion forming was achieved with the suitable design of pre-stressed combined die.