| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a drilling unit capable of efficiently crushing a hard layer, and capable of reducing a size and weight of the unit, for crushing hard ground such as a base rock up to a range of exceeding an inner diameter of a casing.SOLUTION: A drilling unit comprising a drilling casing 1, a whole periphery rotary driving device 2 and a crushing unit 3 inserted into the casing 1. The crushing unit 3 includes a unit base frame 4 suspended in a supported manner in the casing 1 by a crane, fixing means 5 for fixing the unit base frame 4 to a required position in the casing 1, a leader 6 and a crusher 8 composed of a down-the-hole hammer 9 drivable in an elevating/lowering manner along the leader 6. The leader 6 of the crusher 8 is pivoted by the unit base frame 4, and the down-the-hole hammer 9 can be changed in an attitude parallel to an axial direction of the casing 1 and an inclined attitude, and the down-the-hole hammer 9 is held in a required attitude by an attitude holding cylinder 11 interposed between a loose end side required part of the leader 1 and the unit base frame 4.</p> |
