| 摘要 |
PURPOSE:To cut down a construction cost of shaft construction and to reduce a construction period by mounting loading and unloading type cutter bits to an external cylinder provided to the peripheral surface of cutter spokes of a shield machine, and changing the bits in a slide box provided to a partition wall. CONSTITUTION:A shield machine is stopped in the midst of excavation to retreat the whole cutter spokes 9 in the direction of approaching a partition wall 5 and, at the same time, one of the cutter spokes 9 is opposed to a window 30 to stop. After that, a motor 25 is driven to rotate an external cylinder 22, and cutter bits 10 which are going to replace are directed to the window 30 side. Then, jacks 40... are driven, a slide box 36 is moved forward to make the pressure-welding thereof to the external cylinder 22, and an exhaust pressure valve 32 is opened. After the inside pressure of the slide box 36 is sufficiently lowered, a cover 31 is removed to change the cutter bits 10. According to the constitution, the cutter bits 10 can be changed at a position in the midst of excavation. |
