Mechanism And Key Technology Of Vibration Reduction Of Drill Pipe For Roof Cutting In Coal Mine Roadway

In the production process of coal mines,drilling technology has been rapidly developed and widely used.Especially in the process of roof cutting,the drilling efficiency of the drilling hole has an important impact on the process.In order to improve the drilling efficiency,according to the geological conditions of Longtan mine,small drilling equipment is used to drill hole.During the drilling process,the vibration characteristics of the drill pipe were significant,the drilling efficiency was low,and the quality of the drill hole was poor.The thesis takes Longtan Coal Mine as the research background.In order to improve the drilling efficiency of roof cutting holes,comprehensive research methods such as theoretical analysis,numerical simulation and laboratory tests are used.The vibration characteristics of the drill pipe during the drilling of the roof cutting hole were studied,and the key technology for vibration reduction of the drill pipe was proposed.The following results were achieved:(1)Through experiments,it is found that the violent vibration of the drill pipe is the internal reason for the low efficiency and poor quality of the large diameter hole drilling of the lightweight drill pipe.Research reveals the vibration characteristics of the drill pipe during drilling.As the drilling depth increases,the vibration acceleration and amplitude of the drill pipe also increase.The greater the drilling depth,the more serious violent the drill rod vibration.It may cause drilling deflection,which seriously affects the efficiency and quality of drill pipe drilling.(2)Based on the structure of traditional drill pipe and its accessories,a vibration damping device for coal mine roadway roof cutting drilling drill pipe was developed.The device is mainly composed of an embedded drill pipe connector,a bearing structure,a lock washer and a support base.The device has the functions of vibration reduction and drill pipe connection.The device is easy to operate and does not affect the normal drilling construction process.(3)Taking the limitation of the vibration of the drill pipe as the main line,a method for reducing the vibration of the drill pipe for large diameter drilling is proposed.It reveals the mechanism of vibration reduction of drill pipe.When the drilling depth reaches 4m,the vibration acceleration of the drill pipe can be reduced by23% and the amplitude can be reduced by 70%.It can effectively improve drilling efficiency and improve drilling quality.