选择水口形状,是确定钢粒钻头结构的关键性问题.以前所用三角形与直角形水口,钢粒很难进入孔底,而多消耗在钻头与孔壁或与岩心之间,不仅效率低、质量差,且消耗管材、钢砂多,容易造成孔斜.采用直弧形水口(如图右示)时,回次钻进时间短, Select the shape of the nozzle is to determine the key issue of the structure of steel drill bits.Previously used triangular and right angle nozzle, the steel is difficult to enter the bottom of the hole, and more consumption in the drill bit and hole wall or between the core, not only inefficient, Poor, and consumption of pipe, grit and more likely to cause hole oblique .Used straight arc nozzle (shown right), the time back to drilling time is short,