| 摘要 |
PURPOSE:To swiftly control the direction for bending operation, by jointing a shield body through a spherical joint so as to be able to bend at the middle and extending or contracting the bending cylinder to the radial direction of the shield body. CONSTITUTION:A slide hood 14 is protruded from the front shell 10F by forwarding an excavating jack 20 while rotating the cutter head 12 to receive soil and sand into a chamber. Next, when a propulsive jack 24 is extended, the rear shell 10R is moved forward by serving the segment 30 as a support face and then the front shell 10F is stretched forward as a unit therewith. A pair of upper and lower or right and left bending jacks 34 are simultaneously operated on the way of excavation to contract the inside of the bending direction and extend the out side thereof. Then the front shell 10F is slit to turn at the spherical joint 32 and bent together with the cutter head 12. |
