| 摘要 |
PURPOSE: To enhance safety as well as excavation work efficiency by reducing a burden on a worker through the easy replacement of a cutter bit. CONSTITUTION: When a cutter bit 15 mounted on a cutter head 14 is abraded during a tunnel excavation work, the cutter head 14 is made to stop advancing, and radially vibrated under rotation with a parallel link mechanism 29. A tunnel inner wall is thereby excavated and a cavity is formed between the forward end of the cutter bit 15 and the tunnel inner wall. The abraded cutter bit 15 is, then, demounted and a new cutter bit is mounted via the cavity. |
