全射弹寿命过程中的大口径机枪自动机磨损和性能衰减趋势研究

大口径机枪在全射弹寿命过程中的自动机关键部位磨损和性能衰减情况对机构功能和动作可靠性将产生影响，从而影响武器的使用性能和作战效能。以某型大口径机枪作为试验对象，测量全射弹寿命过程中自动机关键部位磨损情况和自动机性能衰减情况，统计自动机故障。研究结果与分析表明：全射弹寿命过程中的枪机闭锁支撑面磨损量和开闭锁曲线磨损量不大，枪机框导轨磨损量较大；随着射弹量的增加，自动机闭锁力逐渐变小，复进簧逐渐变短，后坐到位速度的均方差变大，自动机动作故障变多；自动机后坐到位速度的均方差增大，自动机动作故障增多与自动机关键部位磨损正相关。建立了闭锁力衰减经验公式、复进簧自由长度衰减经验公式、枪机框导轨磨损经验公式、枪机框后坐到位与复进到位撞击面的磨损经验公式，经验公式计算结果与试验数据吻合较好，可以用于推断该大口径机枪自动机部分性能衰减和磨损情况。

Research on Wear and Performance Degradation of a Large-caliber Machine Gun Automatic Mechanism in Firing Life-span

The wear of key portion and performance degradation of automatic mechanism have an impact on the mechanism function and action reliability in firing life-span, which leads to an influence on the performance and operational effectiveness of the large-caliber machine gun. A large-caliber machine gun is used as the experimental object. The wear of key portion and performance degradation of automatic mechanism during firing life-span are measured in detail, and the failure statistics of automatic mechanism are completed. Experimental results show that the wear losses of bolt locking supporting surface and locking curve groove during firing are low, but the wear loss of bolt carrier guiderail is high. With the increase in fired shot quantity, the locking force decreases, the length of recoil spring is shortened, the standard deviation of recoil velocity increases, and the moving fault of automatic mechanism increases. There is a positive correlation among the moving fault and standard deviation of recoil velocity and the wear of key portion of automatic mechanism. The empirical models of locking force attenuation and the free length attenuation of recoil spring, and a wear model of bolt carrier guiderail and impact surface when bolt carrier recoils to position and returns to original position are established, respectively. The empirical models are good agreement with the experimental data. These models can be used to estimate the wear and performance degradation of automatic mechanisms.