HORIZONTAL HOLE EXCAVATOR

摘要

PROBLEM TO BE SOLVED: To provide a horizontal hole excavator enabling long-boring in soil with compressive strength not more than that of a soft rock. SOLUTION: In this horizontal hole excavator for excavating by rotating a cutter head 3 provided at the front part, at least one part of the cutter head 3 is provided with a center cutter 28 protruded in an advancing direction, and a plurality of cutter bits 29-1-29-28 disposed at the cutter head 3 in the radial positions of the cutter head 3 from the center cutter 28 so as to be successively positioned on the axially rear side off the horizontal hole excavator. These cutter bits 29-1-29-28 are shaped to enlarge the radial dimension of the cutter head 3 from the tip parts 26 provided at both circumferential side ends of the cutter head 3, to an intermediate part 25 so that an excavated face is cut wide in the radial direction of the cutter head 3 following the rotation of the cutter head 3.