| 摘要 |
PROBLEM TO BE SOLVED: To provide a backfill material injection device in which the risk of closing of an injection pipe is eliminated and also provide a shield machine. SOLUTION: The backfill material injection device comprises the injection pipe 15. The injection pipe is formed by connecting, in series, a plurality of double tube units 13 each having an inner pipe 11 through which a backfill material flows and an outer pipe 9 into which the inner pipe 11 is inserted. Each double pipe unit 13 is so formed that both the inner pipe 11 and the outer pipe 9 are connected airtight to each other to pressurize the outer surface of the inner pipe 11 by a flow supplied between the inner pipe 11 and the outer pipe 9 and that the cross sectional area of a flow passage for the backfill material can be changed by the pressurization of the outer surface of the inner pipe by the fluid. COPYRIGHT: (C)2009,JPO&INPIT
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