钻头与螺旋外管连接，螺旋外管的后端内侧切有直槽，外管端部外侧切有与之配合的花健。花健的配合非常松旷，即使螺旋外管的轴与外管的回转轴弯曲一定角度亦能回转。内接头插入钻头内部，其后部是弯接头。弯接头后端呈楔形向后突出。内接头与弯接 The drill bit is connected with the spiral outer pipe, the inner side of the spiral outer pipe is cut with a straight slot, and the outer side of the outer pipe end is cut with the corresponding Huazhuo. Hua Jian is very loose with the Kuang Kuang, even if the spiral axis of the outer tube and the axis of rotation of the tube can also be a certain angle of rotation. The inner fitting is inserted into the drill bit, and the rear part is the bent fitting. Bending back joints were wedge-shaped protruding backwards. Internal joints and bending