Design And Experiment Of Anti-jamming System For Medium-length Hole Hydraulic Rock Drill

As the key point in the construction of hydraulic rock drill,anti-jamming system's significance is to reduce the jamming frequency of the hydraulic rock drill during its work time.Because of the small impact energy and low drilling speed,the pneumatic rock drill can avoid the occurrence of jamming conditions.On the one hand,although anti-jamming systems on the market have a certain anti-jamming effect,its anti-jamming efficiency is not high because jamming conditions can divide into?jamming condition,?jamming condition and ? jamming condition.They are cave jamming,slow change jamming and crack jamming,anti-jamming effect is not comprehensive because of three jamming conditions.On the other hand,the change of rock hardness has a great influence on the anti-jamming efficiency.Introduced the development history of the rock drill and anti-jamming system and analyzed the design principle of the anti-jamming system.Introduced all kinds of anti-jamming systems of the domestic and foreign,the advantages and disadvantages of anti-jamming systems in three jamming conditions are obtained through the comparison and analysis.Taking the rotary pressure,the advance pressure and the anti-jamming pressure of hydraulic rock drill system as research objects,their mechanical models is established.The effects of different rock physical properties on three kinds of pressure are studied.Through the Simulink simulation analysis,the influence of the physical characteristics of rock on the anti-jamming pressure and the anti-jamming efficiency is obtained,the design direction of the anti-jamming system is pointed out.An anti-jamming system for?jamming condition is designed.It can prevent the?jamming condition through the switching between heavy shock and light impact.an anti-jamming system for?jamming condition or ? jamming condition is designed.It can prevent the?jamming condition or ? jamming condition by reducing the propulsion pressure and reversing the propulsion mechanism.Select the system components according to the working parameters of hydraulic rock drill system and the structural parameters of anti-jamming valves are designed according to the working parameters of the drilling system,the pressure spring is designed.The action pressures of these valves are set,the motion equation of two anti-jamming valves is carried out through the simulation and analysis.The parameters of anti-jamming valves are optimized.The AMESim software is used to improve the equivalent diameter of the orifice to keep the stable working condition of two anti-jamming valves.Through simulation and analysis of different equivalent diameter of throttle valves,the working state of light impact and heavy impact of hydraulic rock drill is optimized and the optimal speed is obtained.Two anti-jamming systems are simulated and analyzed,responses of the anti-jamming system under three jamming conditions are obtained.It is proved that the designed anti-jamming system has a good anti-jamming efficiency.The anti-jamming system is built and the test system is designed.Through the analysis of the collected experimental data,it is concluded that the designed anti-jamming system has a good anti-jamming effect.