| 摘要 |
PROBLEM TO BE SOLVED: To detect a rotation angle of an end-inclined plate of a drilling rod by a simple constitution.SOLUTION: An induction implement 60 is fixed to a tip of a probe 50 which has a position detecting function and a rotation-angle detecting function, and inserted into the drilling rod 12 for free boring. An end unit 20 is attached to a tip 12A of the drilling rod 12, and the end inclined plate 40 for determining a drilling direction is attached to a tip of a cylindrical pipe 21 of the end unit 20. A movable guide member 70 which can freely protrude from and recede to an outer peripheral surface of a cylindrical housing 61 is mounted to the outer peripheral portion of the induction implement 60. The movable guide member 70 is guided by guide means 30 (all-round release groove 32, an induction groove 33, and a positioning groove 34) which are provided at the inner wall surface 22 of the cylindrical pipe 21, so that the induction implement 60 can be rotated while being inserted. Finally, the movable guide member 70 is fitted into the positioning groove 34, so that the probe 50 can be circumferentially fixed to the end inclined plate 40. Thus, the rotation angle of the end inclined plate 40 is detected by the probe 50. |
