| 摘要 |
PROBLEM TO BE SOLVED: To provide a tunnel excavator which can perform overbreak with an inner periphery cutter and easily cope with a failure of a driving system for the inner periphery cutter, thus actualizing suitable excavation of a large-section tunnel with high excavating efficiency and convenience.SOLUTION: In the tunnel excavator having a cutter head 12 rotatably supported on the front part of an excavator body 10, the cutter head is provided which is divided into an inner periphery cutter 12B and an outer periphery cutter 12A to be rotated by independent driving motors 22, 37, the inner periphery cutter is provided slidably in the longitudinal direction, and a copy cutter 31 extendable in the radial direction of the tunnel is provided on the inner periphery cutter. The inner periphery cutter can be connected at its predetermined slide position via the copy cutter to the outer periphery cutter. |
