| 摘要 |
PROBLEM TO BE SOLVED: To provide a drilling head capable of reducing a burden occurring in a drilling machine when forming an enlarged bottom part in a pile hole, and reducing the occurrence of failure.SOLUTION: A drilling head 1 includes: a rotary shaft 10 and a head body 20 rotating around a vertical shaft core; a fixing rod 30 fixed to a holding part 130 and having an annular fixing gear 34 formed; a conversion part 40 having a conversion shaft 41 rotatably held on an outer periphery of the rotary shaft 10 and a conversion gear 42 engaging with the fixing gear 34; a sending shaft 50 with a screw thread formed and held in the head body 20 rotatably around another horizontal shaft core extending in parallel with a horizontal shaft core; a bit 60 with a screw thread engaging with the screw thread of the sending shaft 50 formed and held in the head body 20 slidably and movably along the other horizontal shaft core; and a transmission part 70 engaging with the conversion part 40 and the sending shaft 50. |
