| 摘要 |
PROBLEM TO BE SOLVED: To allow easily following the movement of a shield main body by fitting a joint inner cylinder and a joint outer cylinder together in such a way that they can move relative to each other along the direction of an axis, fixing a sludge feeding pipe and a sludge discharge pipe respectively to front and rear shells, and connecting the sludge feeding pipe to the sludge discharge pipe. SOLUTION: Front and rear shells which constitute a shield main body are expanded and contracted in the direction of an axis to expand and contract a first expansion pipe joint 20a. In this case, the expansion pipe joint device 20a connects together a sludge feeding pipe 11 and a sludge discharge pipe 12 which are fixed respectively to the front and rear shells. Also, a joint inner cylinder 27 smoothly expands within a joint outer cylinder 28 along the direction of the axis until a connecting plate 32, guided by a guide rod by means of a guide hole, abuts to an expansion stopper. Similarly, the joint inner cylinder 27 smoothly contracts within the joint outer cylinder 28 until the connecting plate 32 abuts to a contraction stopper 31b secured to the rear end of the guide rod. Thus because of a double pipe structure in which the joint inner cylinder 27 and the joint outer cylinder 28 are fitted together in such a way as to be movable relative to each other in the direction of the axis, the pipe joint device can follow the relative movements of the front and rear shells when installed in the shield main body. |
