大直径气动潜孔锤冲击器动力学过程分析

Kinetic Process of Large Diameter Pneumatic DTH Hammer Impactor

大直径气动潜孔锤是一种以压缩空气作为动力的冲击破岩工具。建立了大直径气动潜孔锤的数学模型,采用有限差分法,模拟了活塞在气室内稳定运动状态下的动力学过程,得到了特性的规律以及各结构参数对工作过程的影响。活塞低速运动时,后气室会出现压力波动现象,采取合适的时间步长可以减小数值仿真中出现的压力波动。

The large diameter pneumatic Down-the-hole hammer is an entering-rock drilling tool powered by com- pressed air. The mathematical model is built and the kinetic process of impactor is analyzed by using finite differ- ence algorithm. The change rule of parameters is obtained. The overlarge input pressure leads to the unnecessary en- ergy consumption and too low input pressure can＇t generate the drilling required impact power and frequency. The phenomenon of pressure oscillation happening in the inlet chamber is theoretically analysed. The research results show that the pressure oscillation can be decreased by taking the appropriate time step.