| 摘要 |
PROBLEM TO BE SOLVED: To provide an excavating bit where an excavating rod is a single pipe, only the excavating bit is double bits and an inner bit can be pulled out, and an anchor construction method using the excavating bit. SOLUTION: This excavating bit is composed of a bit sub 2 detachably installed by threadedly arranging a screw on inner/outer peripheral surfaces on one end side and an inner peripheral surface on the other end side, and coaxially and threadedly engaging the screw threadedly arranged on the outer peripheral surface on one end side with an excavating rod 1, an outer bit 3 detachably installed by being coaxially and threadedly engaged with the screw threadedly arranged on the inner peripheral surface on the other end side of this bit sub 2 and an inner bit 4 coaxially positioned inside the bit sub 2 and the outer bit 3 and detachable installed by being threadedly engaged with the screw threadedly arranged on the inner peripheral surface on one end side of the bit sub 2, and a screw hole 7 is arranged in the axial direction from the end surface center in the inner bit 4.
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