【摘要】 文章通过对钻头边齿的力学分析,找出了危险点。明确了牙齿最可能的破坏不是受压或受拉破坏,而是剪切破坏。分析了危险点的应力与钻头边齿倾角的关系,确定了合理的边齿倾角设计范围是30°～45°。在冲击力较小的情况下可放宽到20°～50°;在冲击力较大的情况下可缩小到35°～40°,为科学设计冲旋钻头边齿倾角提供了理论依据。初步实验结果表明,按照上述准则设计的冲旋钻头寿命得到了有效地提高。更多还原

【Abstract】 The paper found out the dangerous spots by mechanic analysis of drill-bit’s side teeth,clarified that the most possible wreck of teeth is not stress or strength wreckages,but shear wreckage.The paper also analyzed the relation between the incline angle of the side teeth and the stress of the dangerous spot,ascertained that the reasonable range of designed side-teeth’s incline angle is 30°~45°.The range can be extended to 20°~50°when the impact is less fierce and reduced to 35°~40°when the impact is fiercer,which provided a foundation for scientific design of the incline angle of percussion-rotary drill-bit side teeth.Preliminary tests showed that the life of percussion-rotary drill bit designed according to abovementioned criterion has been effectively improved.更多还原