EARTH DISCHARGING DEVICE FOR UPWARD-FACING SHIELD MACHINE

摘要

The present invention is an earth discharging device comprising: an earth discharging pipe which is disposed in a longitudinal direction in order to discharge downward earth and sand that have been excavated by an upward-facing shield machine which advances upward an elastic film-type valve which is provided in this earth discharging pipe, and which expands and contracts diametrically by means of fluid pressure to open and close the interior of the earth discharging pipe and a gate mechanism which is provided further toward the outlet side of the earth discharging pipe tha n the elastic film-type valve, and which adjusts the sectional area of the spa ce through which earth and sand pass inside the earth discharging pipe through which earth and sand pass. By using the gate mechanism to narrow the sectional area of the space inside the earth discharging pipe at the outlet side of the elastic film-type valve, the earth and sand at the outlet side of the elastic film-type valve become slightly blocked, thereby raising the earth pressure of the earth and sand such that the earth pressure at the outlet side of the elastic film-type valve can be made substantially equal t o the earth pressure at the inlet side. Thus, a substantially uniform earth pressure acts upon the entire elastic film-type valve, wherebythe elastic film-type valve expands substantially uniformly so as to narrow the entire interior of the earth discharging pipe substantially uniformly. As a result, blockages and eruptions of the earth and sand can be avoided, and earth pressure control at the work face can be performed reliably regardless of depth or soil type.