| 摘要 |
PROBLEM TO BE SOLVED: To improve the safety and efficiency of an boring work in a tunnel boring machine by certainly carrying out the replacing work of a cutter bit in a short time to reduce a load acting on a worker. SOLUTION: A cutter spoke 13 attached to a cutter head 12 is composed of a support cylinder and a rotary cylinder 22, and a cutter bit 14 is fixed to the surface part of the rotary cylinder 22, and a replacing cutter bit is fixed to a back side, and the rotary cylinder 22 is rotated by a main rotation mechanism 20 to make them replaceable. The rotary cylinder 22 is then auxiliary rotated by an auxiliary rotary jack 40 to make it replaceable. |
