TUNNEL EXCAVATOR

摘要

PROBLEM TO BE SOLVED: To enable a tunnel excavator to secure a sufficient tunnel driving force and to surely withstand a excavating reaction at the time of excavating a tunnel. SOLUTION: The thrust of a thrust jack 17 of a parallel link mechanism 20 installed between a front drum 11 and rear drum 12 is detected by pressure detectors 22a and 22b and the position and attitude of a cutter head 13 attached to the front drum 11 are detected by a stroke detect 21. The force vector of the radial force generated from the mechanism 20 is calculated from the detected values of the thrust of the jack 17 and the position and attitude of the head 13. The drive of a front gripper 15 which holds the front drum 11 by pressing the drum 11 against the internal surface of an already existing tunnel is controlled to that the force vector can become smaller that a preset precribed value.