| 摘要 |
PROBLEM TO BE SOLVED: To provide a shield machine constituted by assembling an excavation unit 2 on a shield cylinder 1, forming the excavation unit to have a bulkhead 21 fitted internally in a ring body 16 fixed at the inner periphery of a front part of the shield cylinder, supporting a cutter head 22 on the bulkhead, and removing a stopper 23 for fixation of the bulkhead 21 to let the bulkhead leave toward the back of the ring body in order to recover the excavation unit and improve workability in the work for recovering the excavation unit. SOLUTION: In this shield machine, a driving source 25 for letting the cutter head 22 advance and retreat in the forward and backward directions is mounted on the bulkhead 21. A step part 16a in the radial direction on which a rear face of an outer end part in the radial direction of the cutter head 22 is abutted when storing the cutter head 22 in a front end part of the ring body 16 while diameter of the cutter head 22 is contracted is formed at the inner periphery of the ring body 16. COPYRIGHT: (C)2009,JPO&INPIT |
