| 摘要 |
PROBLEM TO BE SOLVED: To replace a bit in a shield machine by making a rotating shaft in a drive portion and the rotating shaft of a cuter plate freely detachable and by providing a partition wall freely rotatable in the middle between the drive portion and the cutter plate and arranging the rotating shaft of the cuter plate slidably to the partition wall. SOLUTION: When a excavating capacity is lowered, the operation of a driving portion 4 is stopped, an expandable spoke 21 is retracted, a partition wall 41 at the driving portion is retreated and the rotating shaft 4a of the driving portion and a rotating shaft 2a of the cutter plate are separated. Next, using a butterfly partition wall 5 as a reaction receiver, a jack 22 united in one body with the rotating shaft 2a of the cutter plate is extended, and the cutter plate 2 is retreated to the inside of rotation locus of the butterfly partition wall 5. Next, by using the rotation shafts 5a, 5b of the butterfly partition wall as the center, the butterfly partition wall 5 is rotated. Then, the front face of the cutter plate 2 is directed toward the inside of the shield machine 3, a bit is replaced, thereafter, the cutter plate 2 is directed to the side of facing in a reverse order, and excavation work is continued. By doing this, a shaft becomes unnecessary and bit replacement can be performed even for a small aperture shield machine 3. |
