Study On Crushing Energy Consumption Of Drill Under Coupling Of Impact Frequency And Rotational Speed

Based on the National Natural Science Fund Project "The collaborative rock-breaking mechanism of unloading induced by drilling and multiple cutting tooth for hard rock under high geostresses" as the basis,this paper studies the low efficiency problem of the commonly used construction method about mine roadway and tunnel construction in our country.In the light of the low rock breaking efficiency of rock drilling and the excessive loss of equipment due to mechanical tunneling,the drilling of hard rock under the coupling of impact frequency and rotary speed is studied under different confining pressure conditions.The research results provide a reference for improving drilling efficiency and improving drilling method.At the same time,to lay a foundation for the drilling and cutting together to break rock or to break rock directly with impact bit lay on the basis.In this paper,impact rotary bit is taken as the research object,and the finite element analysis software ABAQUS/Explicit is used to simulate the rock breaking process.According to the results of rock breaking under different impact frequency,rotary speed and rock confining pressure,from the perspective of energy consumption analysis,and obtains the energy consumption per unit depth on the different performance parameters.Combined with the rock breaking speed,the matching relation between the impact frequency and the rotary speed is optimized,which provides an important reference for improving rock breaking efficiency.On this basis,numerical simulation of rock breaking under no confining pressure is carried out for granite,and mainly focused on double bit synchronous and asynchronous drilling methods,different drilling spacing is studied,and from the point of energy consumption,analyzes the influence of different drilling spacing and drilling mode on bit rock breaking.Research shows that:for the granite material,unconfined,impact frequency in 70Hz,rotary speed of around 310r/min;IOMPa confining pressure,performance parameters in 65Hz,280r/min;25MPa confining pressure,in 55Hz,320r/min;40MPa under confining pressure,in 54Hz,370r/min,with low energy consumption and high bit the rock breaking speed,and rock breaking efficiency optimization.According to the study of porous rock breaking for granite with 10MPa confining pressure,the rotary speed is 300r/min and the bit synchronous drilling,one to four times the diameter of the drill bit under the depth of the unit energy consumption values are 194.95J/mm,199.44J/mm,195.98J/mm,196.34J/mm.In the double diameter of the drill bit when the depth of the unit energy consumption is significantly the largest,broken rock effect is poor;when the drill bit is in asynchronous drilling,the energy consumption values of the bit and the bit in the double spacing are 192.87J/mm and 195.35J/mm respectively,and when it is twice spacing,the energy consumption are 200.88J/mm,195.86J/mm,while three times,four times the gap,the energy consumption is very close.Change the speed of rotation,the results are similar.The results show that compared with the first drill bit,the bit has the characteristics of low energy consumption and high speed,the rock breaking effect is better.However,when the distance is two times;the energy consumption is large and speed is low.Comparison of two drilling methods,in one and double times of the spacing,asynchronous than synchronous rock breaking energy consumption is low,and the effect is good;when the spacing value reaches three times and four times,drilling distance has no effect on rock breaking.The results of this study in order to improve the efficiency of rock breaking and rock drilling of rock breaking mechanism of drilling,which has important reference value,to provide new ideas and research for mechanical hard rock tunneling method;at the same time,it has important practical significance to save the economic cost,improve the mining efficiency and ensure the safety of the construction.