CONTROL METHOD OF AND CONTROL CIRCUIT OF DRIVING JACK, AND CUTTER DRIVING METHOD OF AND CUTTER DRIVING DEVICE FOR UNDERGROUND EXCAVATOR

摘要

PROBLEM TO BE SOLVED: To efficiently obtain cutter torque by controlling pressure of a hydraulic fluid supplied to the piston head chamber side and the piston rod chamber side in a cylinder so that pushing-out force and pulling-in force of a piston rod become almost the same. ;SOLUTION: A directional control valve 18 is switched to an upside-down Y-shape position (a letter corresponding to the first square form of the Japanese alphabet) to be controlled under pressure P2 and a flow rate Q1, a piston 3 is pushed by a hydraulic fluid supplied to the piston head chamber side in a cylinder 2, and a piston rod 4 is pushed out by pushing-out force F and a pushing-out speed V according to this. Next, the directional control valve 18 is switched to a square-shape position (a letter corresponding to the second square form of the Japanese alphabet) to be controlled under pressure P1 and a flow rate Q2, the piston 3 is pushed by a hydraulic fluid supplied to the piston rod chamber side in the cylinder 2, and the piston rod 4 is pulled in by pulling-in force F' and a pulling-in speed V' to thereby reduce a fluctuation in torque generated by a driving jack 1 as well as to efficiently obtain cutter torque.;COPYRIGHT: (C)2001,JPO