某埋头弹机枪弹膛驱动螺旋槽优化设计

Optimization Design of the Driving Spiral Groove of the Chamber of a Cased Telescoped Ammunition Machine Gun

某埋头弹机枪采用了弹膛与枪管分离的结构,其弹膛在整个自动循环中存在两个工作位置,即供弹位与发射位.该埋头弹机枪通过枪机框上的导柱与弹膛上的螺旋槽相互作用,带动弹膛摆动,以实现弹膛在两个工作位之间的相互转换.最初在设计弹膛螺旋槽时选用了规则的螺旋线,然后在试验中发现,枪机框导柱在进入弹膛螺旋槽时螺旋槽对其的冲击力很大,冲击不仅使得枪机框动能损失严重,而且会降低导柱寿命.现以枪机框导柱与弹膛螺旋槽之间的最大冲击力为目标函数,选用5次函数曲线为弹膛螺旋槽理论轮廓线展开线的形式,运用遗传算法对弹膛螺旋槽理论轮廓线进行优化,使得枪机框导柱与弹膛螺旋槽之间的最大冲击力降低为原来的42.27%.试验验证表明枪机框导柱与优化后的弹膛螺旋槽相互作用时速度损失由优化前的30.3%降低到25.6%.研究结果为该枪的改进提供了可靠的理论依据.

A cased telescoped ammunition machine gun adopts the structure of separated chamber and barrel,and its chamber has two working positions in the whole automatic cycle,namely the ammunition supply position and the firing position.The interaction between the guide pillar on the bolt carrier and the spiral groove on the chamber outside drives the chamber to swing to and fro,so as to realize the mutual conversion between the two working positions of the chamber.Preliminarily,the regular spiral line was selected when the spiral groove in the chamber was designed.Later,in the actual test,it was found that the impact force on the spiral groove from the guide pillar of the bolt carrier when the guide pillar entered the spiral groove in the chamber outside was very large.The impact not only caused significant kinetic energy loss of the bolt carrier,but also reduced the life of the guide pillar.The maximum impact force between the guide pillar of bolt carrier and the spiral groove in the chamber outside was taken as the objective function,and the quintic function curve was selected as the theoretical contour curve of the spiral groove in the chamber outside,and the genetic algorithm was used to optimize the theoretical contour curve of the spiral groove in the chamber outside,so that the maximum impact force between the bolt carrier guide pillar and the spiral groove in the chamber was reduced to 42.27%of the original value before optimization.It is concluded by firing test that the velocity loss due to the interaction between the bolt carrier guide pillar and the chamber spiral groove was reduced from 30.3%to 25.6%.The research results provide a reliable theoretical basis for the improvement of the gun.