露天矿用潜孔钻机钻进破岩模型

Rock breaking model of downhole drilling rig used in open-pit mine

针对潜孔钻机工作过程中存在的冲击力过大导致主体结构变形破裂、冲击破岩过程设备振动不稳定等问题,以露天矿用潜孔钻机为研究对象,分析钻进工况下的破岩特征。首先,分析潜孔钻机冲击破岩机制,获得冲击载荷下岩石破坏的主要模式;然后,对比模型屈服与破坏准则,采用Drucker-Prager模型分析钻头冲击作用下的岩石面破碎效果;最后,利用ABAQUS软件分析不同钻进参数下的冲击破岩特征。结果显示:当冲击力过小且转速过大时,钻头对岩石的作用力不够,钻进效率低;当转速过小且冲击力过大时,岩石未完全破坏,碎屑排出困难,导致破碎效果较差;随着转速的增大,钻进速度呈现先增加后减小的规律;随着冲击力的增加,钻头侵入岩石的能量增加,钻进速度得到提升,但推进力过大会造成钻杆钻进不稳定,导致破岩效果不理想,影响钻进效率。

In response to the problems of deformation and rupture of the main structure caused by excessive impact force and the unstable vibration of equipment in the process of rock breaking by impact force during the operation of the downhole drilling rig,the downhole drilling rig for open-pit mines was taken as the research object to analyze the rock breaking characteristics under drilling conditions.Firstly,the rock breaking mechanism of the downhole drilling rig by impact force was analyzed to obtain the main modes of rock breaking under impact load.Secondly,by comparing the yield and breaking criteria of the model,the Drucker-Prager model was used to analyze the rock fragmentation effect under the impact of the drill bit.Finally,ABAQUS software was used to analyze the rock breaking characteristics by impact force under different drilling parameters.The results show that when the impact force is too small,and the rotation speed is too high,the force of the drill bit on the rock is not enough,leading to low drilling efficiency.When the rotation speed is too small,and the impact force is too large,the rock is not completely destroyed,and it is difficult to discharge debris,resulting in a poor crushing effect.As the rotation speed increases,the drilling speed first increases and then decreases.As the impact force increases,the energy of the drill bit invading the rock increases,resulting in an increase in drilling speed.However,excessive pushing force can cause unstable drilling of the drill rod,leading to an unsatisfactory rock breaking effect and affecting the drilling efficiency.