自形成同心径向环齿金刚石钻头设计与制造

通过钻头胎体配方的分区设计，钻头在钻进过程中，其唇面会自动形成同心径向环齿，该类钻头具有钻进时效高，使用寿命相对延长，破碎岩石时的稳定性好，钻进质量明显改善等优点。其碎岩机理是：由于自形成同心径向环齿金刚石钻头胎体工作面各区的耐磨能力不同，导致切削破碎岩石的效率不一样。工作过程中，金刚石在轴向作用下产生破碎槽，并在周向力作用下切削岩石，由于胎体的强耐磨区和弱耐磨区破碎岩石能力的差异，使孔底岩体上留下一条条岩脊。由于破碎槽效应，岩脊内的微裂纹十分发达，强度大大降低，在钻进过程的振动作用下被双向剪切，稍有挤压，岩脊顶部的剪应力即达抗剪强度，很容易以体积方式被破碎。研究表明，设计的自形成同心径向环齿钻头，使钻头在碎岩机理方面有所突破；与普通钻头相比，自形成同心径向环齿钻头在时效方面提高了45％，寿命方面延长了20～25％。

RESEARCH ON CONCENTRICAL SEGMENTED DIAMOND BIT

In this paper, the working principle, design and manufacturing method for a new type of drilling bit are discussed. Each segment of the drilling bit is constituted by several concentrically segmanted layers, which consist of two type of matrix, namely the main work matrix and the subsidiary work matrix, having different working and resistance wear performance, and being distributed alternately. In drilling, the subsidiary work matrix layers are wore faster, and on the working surface of drilling bit the main work matrix layers are projected and form the circular annular teeth as wave shape automatically. At the same time, on the rock drilled form a coupled wave also. When drilling bit vibrates, rock split by mechanical extrusion and clip.In the meantime, because of increase of free faces of the waves on rock, it is useful for rock split, the drilling rate will be added. The result of research by author shows that, the new type of drilling bit has changed the principle of split rock operation with the diamond drilling bit; and the working life and efficiency of the drilling bit have been improved.