Expansion drilling jig for foundation pile construction

摘要

PROBLEM TO BE SOLVED: To provide an excavating tool for constructing a foundation pile, capable of setting a diametrally expanding quantity large, while preventing reception of sudden resistance from the ground, when expanding a diameter.;SOLUTION: An excavating shaft 3 is joined to a driving shaft 2 by a spline, so as to be relatively displaceable in the vertical direction. An upper end part of an expanded blade 4 is rotatably connected in the vertical direction to the driving shaft 2. A lower end part of the expanded blade 4 is rotatably connected in the vertical direction to an upper end part of auxiliary links 12, and a lower end part of the auxiliary links 12 is rotatably connected in the vertical direction to the excavating shaft 3. An expansively excavating cutter 8 is installed on the expanded blade 4. The expanded blade 4 is arranged, so as to be vertically movable on a virtual plane F passing through a rotary shaft. The two auxiliary links 12 connected to the expanded blade 4 are arranged in plane symmetry to the virtual plane F.;COPYRIGHT: (C)2005,JPO&NCIPI