Abstract: Hydraulic drilling machine will produce blast-hole deflection in the drilling process;it will seriously hamper the drilling efficiency.The engineering practice shows that the drilling force is mainly caused by the uneven drilling-hole deviation.Therefore,to promote the design of a pressure control valve is applied for controlling the drill propulsion mechanism of propulsion.The boost pressure control valve system by theoretical analysis and mathematical modeling and simulation analysis,the simulation results show that the boost pressure control valve system can automatically adjust the outlet pressure of work,to achieve its desired effect.In order to control the drill drilling thrust propulsion mechanism to improve the effect of rock drilling provides a feasible technical ideas.

Key words: advance pressure control valve, hydraulic drilling process, deflection, digital simulation