| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-bore pipe jacking machine, in which a vacuum earth-removal type and a screw earth-removal type can be changed over by simple changeover operation by utilizing the structure of a lead pipe in the normal screw earth-removal type small-bore pipe jacking machine. SOLUTION: In a lead pipe having screw conveyors for discharging soil and sand in a shield case, screw driving units 20 for vacuum earth removal, which can be mounted and demounted to and from the screw conveyors respectively and have the screw conveyors, in which screw hydraulic motors 21 are fixed at rear ends, and in which vacuum earth-removal pipes 23 are set up to parts of the cases 22 of the screw conveyors, are fitted, and small-bore pipe jacking by screw type earth removal and vacuum type earth removal can be changed over easily by installing and removing the units 20 and from the lead pipe. |
