一种双腔射击式气动冲击锤的设计与性能分析

The Design and Characteristics Analysis of a Dual-chamber Shooting Pneumatic Hammer

设计了一种结构紧凑的双腔射击式气动冲击锤,建立了该冲击锤工作过程的动力学模型,通过数值求解得到了气动冲击锤冲击速度、位移随时间的变化规律,以及气动冲击锤结构和气动参数对芯锤运动特性的影响。结果表明:芯锤冲击速度随通气小孔的直径增大而增大,当直径增大到一定值后,冲击速度增大不再明显;背压腔排气孔直径的大小在一定范围内会改变芯锤速度的变化趋势,当排气孔直径较小时,芯锤速度先增后减,当排气孔直径增大到一定值后,芯锤速度始终增加;预压气腔的初始体积对芯锤的冲击速度没有影响。同时,采用有限元方法对冲击锤冲击碰撞过程进行了仿真,得到了冲击时间及冲击力的大小。研究表明,所设计的双腔射击式气动冲击锤具有结构轻、冲击力大的特点。

This paper presents a compact dual-chamber shooting pneumatic hammer, establishes a dynamic model for its working process. The pneumatic hammer impact velocity, displacement variation with time and the effects of structural and aerodynamic parameters on motion characteristics of the hammer core are obtained through numerical solutions. The simulation results indicate that impact velocity of the core increases with the diameter of the ventilation holes, the trend of the core＇s velocity changes by the exhaust hole of back pressure gas chamber within a certain size, when the exhaust hole＇s diameter is smaller, the core＇s velocity decrease after an initial increase; but when the exhaust hole＇s diameter increases to a certain value, the core＇s velocity always increases. The initial volume of preloading gas chamber has no effect on the impact velocity of the core. Moreover, after using the finite element method to simulate the impact collision process of the hammer, the time of impact process and the size of the impact force are obtained. The study shows that this dual-chamber shooting pneumatic hammer has a light structure and large impact force.