| 摘要 |
PURPOSE:To enable the execution of long-distance excavation without changing cutter bits even if the propulsion speed of a shield excavator main body is fast. CONSTITUTION:When sediment in front of a shield excavator main body is excavated while rotating a cutter head 1 and simultaneously propelling the shield excavator main body, sediment is at first excavated by each cutter bit 6 fixed to each cutter spoke 4. When each cutter bit 6 wears, a hydraulic jack 9 is operated in the elongated direction to move each sub-frame 8 forward, and each cutter bit 6 fitted to the sub-frame 8 is pushed out more forward than each worn cutter bit 6 to excavate sediment. |
