空气钻井潜孔钻头本体与钻齿的过盈分析

ANALYSISES OF AIR DRILLING DOWN-THE-HOLE BITS' INTERFERENCE BETWEEN BITS' BODY AND TEETH

潜孔钻头是空气钻井中一种重要的破岩工具,钻齿镶嵌过程中的过盈量直接影响钻齿与钻头本体的接触强度。文章以φ311.1mm潜孔钻头用φ19mm钻齿为研究对象,建立了钻头本体与钻齿过盈配合的力学模型,并进行计算机模拟仿真。通过对过盈量分别为0.01、0.02、0.04、0.06、0.07、0.08、0.09、0.1mm时钻齿与钻头本体的接触分析可知,过盈量小于等于0.07mm时,钻头本体均为弹性变形;当过盈量为0.08mm时,钻头本体接触区域局部开始发生塑性变形;当过盈量达到0.1mm时,钻头本体沿齿眼的应力值接近材料的强度极限。根据分析结果并考虑塑形强化的影响,推荐φ311.1mm潜孔钻头φ19mm钻齿的安装过盈量为0.07～0.08mm。论文的研究工作为空气钻头钻齿的科学装配提供了理论依据。

DTH(down-the-hole) bit is a very important equipment used to break rocks in air drilling,when drilling teeth inlay into bit's body,the wring can directly effect theirs contact strength.In this paper,taking 311.1mm DTH bit and 19mm drilling tooth as the research target,a mechanical model of interference fit between bit's body and tooth was established,and the analog simulation with computer was carried out.Through the contact analysis between bit's body and tooth with the wring at 0.01、0.02、0.04、0.06、0.07、0.08、0.09、0.1mm,the results showed that while the wring was less than or equal to 0.07mm,the bit's body was elastic deformation;while the wring was 0.08mm,part of contact area on bit started to occur plastic deformation;while the wring was 0.1mm,the stress value along bit's body hole was close to this material's strength limit.According to the analysis results and considering the effect of shaping enhanced,the assemble wring of 0.07mm～0.08mm about 311.1mm DTH bit and 19mm drilling tooth was recommended.The research results provided theoretical criteria for reasonable assemble air drilling DTH bit's tooth into its body.