| 摘要 |
PROBLEM TO BE SOLVED: To provide a concrete placing device which facilitates washing of a concrete placing line, contributes to shortening of a washing time, and achieves setup of re-excavation in a short period of time, and also to provide a tunnel excavator equipped with the concrete placing device. SOLUTION: The concrete placing device is comprised of: an inner form S for covering a peripheral wall of the excavated natural ground G so as to be spaced a predetermined interval away from the same; and an end form 46 for securing a concrete placement space E between the inner form and the peripheral wall of the natural ground. The end form has a front end of a straight pipe portion of a concrete placing pipe 50 inserted therein and fixed thereto. Then a branch pipe portion branched from a proximal end of the straight pipe portion has a concrete placing pipe arrangement 51 detachably connected thereto, which communicates with a concrete feed source. Further the proximal end of the straight pipe portion has connected thereto a block valve device 60 having a jack 62 and a rod piston 63 attached to the rod tip od the jack. When the jack is contracted, the rod piston recedes, and then the branch pipe portion of the placing pipe communicates with the straight pipe portion. On the other hand when the jack is extended, due to advancement of the rod piston, communication between the branch pipe portion and the straight pipe portion is interrupted, and concrete remaining in the straight pie portion is pushed into a placement space. COPYRIGHT: (C)2007,JPO&INPIT
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