仿生耦合PDC单齿的设计及其仿真

Design and Simulation of Bionic Coupling PDC Cutter

针对现有PDC钻头存在的工作效率低、金刚石与硬质合金易分层、由于岩石碎屑排出不及时所形成的泥包等问题,设计了一种破岩效率更高、更耐磨、切削平稳性更好的仿生耦合PDC切削齿。仿生耦合PDC切削齿通过改变刀具自身的结构和破岩方式,更容易破入地层,而且阶梯形的齿结构使岩石更容易剥离,大大提高了破岩效率。对仿生耦合PDC切削齿与常规PDC切削齿进行单齿仿真对比,仿真结果表明:在相同的吃深下,当切削角度在6°~26°范围变化时,仿生耦合PDC切削齿的破岩体积大于常规PDC切削齿,前者破岩效率高于后者,但两种切削齿的破岩效率总体上呈下降趋势;在相同切削角度18°下,随着仿真时间的延长,两种切削齿的破岩体积都增加,且仿生耦合PDC切削齿的破岩体积大于常规PDC切削齿,前者破岩效率高于后者,但两种切削齿的破岩效率都在逐渐下降;仿生耦合PDC切削齿最大剪应力的平均值和标准差均比常规PDC切削齿小。研究结果可为PDC钻头的优化设计提供一定的指导。

In order to solve the problems of PDC bit such as low working efficiency,easy stratification of diamond and hard alloy and bit balling formed by delayed discharge of rock fragment,the structure of polycrystalline diamond-hard alloy interface and the surface shape of polycrystalline diamond,a bionic coupling PDC cutter with higher rock breaking efficiency,better wear resistance and better cutting stability was designed.The bionic coupling PDC cutter is easier to break into the formation by changing the cutter structure itself and the rock breaking mode,and the stepped cutter structure makes the rock easier to peel off,which greatly improves the rock breaking efficiency.Single cutter simulation comparison was carried out for the bionic coupling PDC cutter and the conventional PDC cutter,with results showing that under the same cutting depth,when the cutting angle changes from 6°to 26°,the rock breaking volume of the bionic coupling PDC cutter is larger than that of the conventional PDC cutter,and the rock breaking efficiency of the former is higher than that of the latter,but the rock breaking efficiency of them exhibits a decrease trend on the whole;at the same cutting angle of 18°,as the simulation time prolongs,the rock breaking volume of the two kinds of cutters both increases,the rock breaking volume of the bionic coupling PDC cutter is larger than that of the conventional PDC cutter,and the rock breaking efficiency of the former is higher than that of the latter,but the rock breaking efficiency of them gradually falls;and the average and standard deviation of maximum shear stress of the bionic coupling PDC cutter are smaller than that of the conventional PDC cutter.The study results provide some guidance for the optimum design of PDC bits.