The mechanical characteristics of the three wing back reamer used in guided boring in difficult formation is examined.
分析了导向钻进法用三翼回拉扩孔钻头在复杂地层条件下的力学性质 ,推导了计算不同岩石的最优切削角公式 ,并得出常见岩石的最优切削角值 ,进一步对回拉扩孔钻头的结构形式提出了优化 ,为导向钻进法回拉扩孔施工达到最优钻进 ,提供了必要的力学计算依
When wind force cutting pick-up drilling is applyed in coal seam if dedusting equipment is installed in the opening of the bore,it should enlarge drilling bore with ream bit so that dedusting equipment can be installed,and then retreat drilling and replace bit of drill.
在煤层采用风力排渣打钻时,如果在钻孔孔口处安装除尘设备,在打钻前要采用扩孔钻头打一个能够安装除尘器的钻孔,然后退钻更换钻头钻进。
The improved cylindrical wing-form bit has 18 diamond tungsten carbide composite button bits and 3 button bits more than the original drilling bit,with drilling cutters arranged according to the force on bit.
改进型筒形翼状钻头比原先使用的平底滚刀钻头增加了18个孕镶金刚石-针状硬质合金复合式钻齿和3个钎头,并按受力特点进行了合理分布。
Application of Bit Water Way in HDD
水平定向钻进扩孔钻头水口应用分析
a bit for enlarging the upper part of a hole.
用来扩大凿孔上部的一种钻头。
A hole with the top part enlarged so that the head of a screw or bolt will lie flush with or below the surface.
埋头孔顶部扩大的孔，为使钻或螺栓的头与地面相平或在地面以下
A tool used for drilling.
钻头用于钻孔的工具
counterbore with guide
有导柱的平底扩充孔钻
A pointed and threaded tool for drilling and boring that is secured in a brace, bitstock, or drill press.
钻头曲柄、钻柄或钻床之上用于钻孔的尖头工具
Using a drill, he bore a hole through the wood.
他用钻孔机在木头上钻了一个孔。
Drilling is cutting a hole with a drill.
钻削就是用钻头钻一个孔。
To form, shape, taper, or enlarge(a hole) with or as if with a reamer.
扩，整用扩孔钻或仿佛是用扩张钻去造出、成形出、整出或扩大（某个孔）
A selfmade apparatus called" fish scalelike grinding head" is employed to solve the problem, and its operation and structure are introduced.
介绍该厂用自制鱼鳞磨头解决轴孔在钻床上扩孔120μ的具体操作方法及鱼鳞磨头的结构。
A needle-shaped drill for boring holes in rock or masonry.
钻头，钻石器，钻孔器用于在岩石或砖石上钻孔的针形钻
Many of the stones have holes drilled through them.
许多石头钱都钻有孔。
To drive(a screw or bolt)into a countersink.
将钻或螺栓置入埋头孔
bolt or cotter-pin drill
螺栓或开尾销孔钻头
To make a hole in (a hard material) with a drill
用钻头在(硬材料)上打孔.
A tapered, serrated tool used to shape or enlarge a hole.
手钻用来钻孔，或扩大孔的尖细带齿的工具
three point neat-bit reamer
三点式近钻头扩眼器
To shape or enlarge(a hole)with a tapered, serrated tool.
凿孔扩大用带齿的尖的工具钻或扩大（孔）