Study on drilling mechanism and optimization of percussion-extruding DTH hammer bit  

作　　者：LUO Chunhong ZHENG Zhichuan CAO Pinlu 

机构地区：[1]College of Construction Engineering, Jilin University, Changchun 130026, China

出　　处：《Global Geology》2009年第1期36-39,共4页世界地质（英文版）

摘　　要：The authors tested the percussion-extruding Down-the-hole(DTH)hammer bit with five different structures and mainly analyzed the drilling mechanism between conical bit and stepped bit.In addition,aiming at "the pile effect" in combination with the advantage of stepped bit,we design a new cam spinning bit and test it outdoors.The result shows that using cam spinning bit can solve the problem of "the pile effect",which can also obtain higher drilling efficiency than using conical bit in high confining pressure strata.It is characterized by novel structure and high drilling speed as well as good guiding,and it is significant for improving efficiency in percussion-extruding drilling technique.The authors tested the percussion-extruding Down-the-hole （DTH）hammer bit with five different structures and mainly analyzed the drilling mechanism between conical bit and stepped bit. In addition, aiming at ＂the pile effect＂ in combination with the advantage＇ of stepped bit, we design a new cam spinning bit and test it outdoors. The result shows that using cam spinning bit can solve the problem of ＂the pile effect＂, which can also obtain higher drilling efficiency than using conical bit in high confining pressure strata. It is characterized by novel structure and high drilling speed as well as good guiding, and it is significant for improving efficiency in percussion-extruding drilling technique.

关 键 词：percussive-extruding drilling DTH hammer bit cam spinning bit 

分 类 号：P634.5[天文地球—地质矿产勘探] TE242[天文地球—地质学]