JPS6117113Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an earth removal device for a shield excavator.

As shown in Fig. 1, a shield excavator that excavates with a pressurized face is equipped with a screw between a face pressurizing chamber 1 and an earth removing chamber 2 under atmospheric pressure as its earth removal device. Some are equipped with a conveyor 3.
In such cases, no measures have been taken to deal with sudden changes in the condition of the ground during excavation. Therefore, for example, in the case of encountering a humid layer, there is a possibility that groundwater flows through the casing 4 of the screw conveyor 3 and flows out from the soil discharge port 5.

The present invention has been devised in view of the above, and embodiments thereof will be described below with reference to FIGS. 2 to 5.

6 is a shield, 7 is a cutter head, 8 is a cutter head drive device, and 9 is a partition wall.The front part of this partition wall 9 is a face pressurizing chamber 10, and the rear part is an earth removal chamber 11 under atmospheric pressure. An earth removal device consisting of a screw conveyor 12 is provided between the face pressurizing chamber 10 and the earth removal chamber 11. Screw conveyor 12
The casing 13 has an excavated soil receiving port 14 at the end of the pressure chamber, and a soil discharge port 15 at the end of the soil discharge chamber.
are formed respectively. Here, the soil discharge port 15 is formed at the lower part of the casing 13, and this soil discharge port 1
5 is provided with an opening/closing gate (not shown). A space S in which the screw conveyor blade 17 does not exist is formed in the middle part of the earth and sand transfer path 16 inside the screw conveyor casing 13 (in the illustrated example, on the side closer to the receiving port 14). Inside this space S, an earth and sand transfer path changing plate 18 is provided to block a part of the space S and change the direction of earth and sand transfer. Second
As is clear from FIG. 5, the earth and sand transfer path changing plate 18 is composed of a pair of upper member 19 and lower member 20. These upper member 19 and lower member 2
0 has arcuate plates 19A, 20A having a chevron-shaped cross section and flanges 19B, 20B that are integral with the arcuate plates 19A, 20A. As clearly shown in FIG. 5, the arc-shaped plate 19
A, 20A are inserted from the outside of the casing 13, and the flanges 19B, 20B are fixed to the casing 13. At this time, a pair of arcuate plates 19A, 20
A is arranged so that it is opposed to each other with the screw conveyor rotating shaft 21 interposed therebetween, and its chevron-shaped portion is spirally twisted along the outer periphery of the screw conveyor rotating shaft 21. A rotating blade 22 is fixed to the tip of the screw conveyor rotating shaft 21 (the end of the face pressurizing chamber) so as to be concentric with the rotating shaft 21 . This rotating blade 22 is a hollow truncated conical drum 2.
2A, and linear or volute curved blades 22B provided at equal angles on the circumferential surface of the drum 22A. Furthermore, a piston body 23 is fitted onto the tip of the screw conveyor rotating shaft 21 so as to be slidable in a liquid-tight manner between a retracted position within the drum 22A and a position protruded from the drum 22A. Reference numeral 24 denotes a plug (opening/closing member) provided on the piston body 23, which opens and closes the excavated earth receiving port 14 of the casing 13 as the piston body 23 moves into or out of the drum 22A. The retraction or protrusion movement of the piston body 23 with respect to the drum 22A is achieved by constantly biasing the piston body 23 in the direction of retraction from the drum 22A, for example, by a spring or the like, and in this state, by passing the screw conveyor rotating shaft 21 By supplying hydraulic pressure into the drum 22A, the piston body 23 is made to protrude from the drum 22A against the bias of the spring, and by releasing the biased state by the hydraulic pressure, the piston body 23 is caused to protrude from the drum 22A by supplying hydraulic pressure into the drum 22A. This is done by moving the drum into and out of the drum 22A. 25 is a viscous agent injection pipe leading into the face pressurizing chamber 10, and 26 is a screw conveyor casing 13 in front of the earth and sand transfer path change plate 18.
This is a viscous agent injection pipe that leads to the inside.

The excavated earth and sand are taken into the face pressurizing chamber 10 by ground excavation, and at the same time, the screw conveyor 12 is operated. In this case, if the excavated earth and sand receiving port 14 of the screw conveyor casing 13 is opened, the earth and sand in the face pressurizing chamber 10 will be stirred by the action of the rotary blades 22 and then flowed from the receiving port 14 into the screw conveyor casing 13. sent. Thereafter, the earth and sand are transferred to the earth removal chamber 11 side through the transfer path 16 along the axis of the screw conveyor casing 13, but in the meantime, the earth and sand transfer path change plate 1
8 inhibits its movement. That is, the excavated soil is consolidated to some extent within the soil transfer path 16A between the excavated soil receiving port 14 and the soil transfer path change plate 18, and exhibits water-stopping properties. The consolidated earth and sand collides with the soil transfer path change plate 18 due to the continuous transfer action of the screw conveyor 12, and then moves along the change plate 18 as indicated by the dotted line arrow in FIG. It is pushed out to the soil transfer path 16 behind it and discharged from the soil discharge port 15. Therefore, even during continuous discharge of excavated earth and sand, the face holding pressure in the face pressurizing chamber 10 is maintained appropriately by the earth and sand that exhibits the water-stopping property. However, this compaction of the excavated soil will only provide water-stopping properties when excavating stable ground that has a certain degree of viscosity. Therefore, if the condition of the ground changes during excavation and the ground turns into a humid layer, it is necessary to prevent situations such as outflow of groundwater. In such a case, a viscosity agent (clay, silt, bentonite, CMC, organic thickener, etc.) is injected into the face pressurizing chamber 10 through the viscosity agent injection pipe 25. In this way, the humid earth and sand and the viscous agent are stirred and mixed in the face pressurizing chamber 10 by the action of the rotary blades 22 and are fed into the earth and sand transfer path 16A. Therefore, it is consolidated in front of the earth and sand transfer path change plate 18 and exhibits water-stopping properties. If necessary, the viscous agent injection pipe 2 is also inserted into the earth and sand transfer path 16.
A viscous agent is injected through 6, and a stirring and mixing action by a screw conveyor blade 17 is also added to this part. With the above, excavation of humid ground can be carried out in a stable state. In addition, if good water-tightness is still not secured even after taking such measures, the piston body 23 is made to protrude from the drum 22A, and the excavated earth and sand reception port 14 is temporarily closed by the plug 24, and at this time, the screw The rotation of the conveyor rotating shaft 21 and the injection of the viscous agent into the face pressurizing chamber 10 are continued. In this way, the earth and sand and the viscous agent are sufficiently stirred and mixed in the face pressurizing chamber 10, and the viscous agent permeates into the ground, thereby stabilizing the ground. After the ground is stabilized, the piston body 23 is moved back into the drum 22A and the excavated earth and sand receiving port 14 is opened, and safe operation is performed in the same state as described above.

As is clear from the above explanation, according to the present invention, even if the rock properties suddenly change during operation, appropriate countermeasures can be taken immediately without stopping continuous operation. Therefore, the adaptability of the shield excavator to soil conditions is improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional example, FIGS. 2 to 5 show an embodiment of the present invention, FIG. 2 is an overall longitudinal sectional view, and FIG. 3 is an enlarged longitudinal sectional view of main parts. 4 is an enlarged cross-sectional view taken along the line XX in FIG. 3, and FIG. 5 is an enlarged cross-sectional view taken along the line Y-Y in FIG. 2. 10... Face pressurization chamber, 11... Earth removal chamber, 12...
... Screw conveyor, 13 ... Screw conveyor casing, 14 ... Excavation earth and sand receiving port, 15
...Earth discharge port, 16, 16A...Earth transfer path, 17
... Screw conveyor blade, 18 ... Sediment transfer path change plate, 21 ... Screw conveyor rotating shaft, 22 ... Rotating vane, 22A ... Drum, 22
B...Blade, 23...Piston body, 24...
Plug (opening/closing member), 25, 26...viscous agent injection pipe.

Claims (1)

[Scope of utility model registration request] A screw conveyor is provided between the face pressurization chamber and the soil removal chamber under atmospheric pressure, and an excavated soil receiving port is provided at the end of the pressure chamber of the screw conveyor casing, and a soil discharge port is provided at the end of the soil discharge chamber. A space in which no screw conveyor blade exists is formed in the middle part of the soil movement path inside the casing, and the soil is transferred by the screw conveyor blade to the inner surface of the casing of the screw conveyor corresponding to this space. An earth and sand transfer path changing plate having an arcuate plate twisted to guide the earth and sand in a direction opposite to the rotational direction of the screw conveyor blade is provided, and An earth removal device for a shield excavator, characterized in that a rotating blade concentric therewith and an opening/closing member for the receiving port are provided, and a viscous agent injection pipe communicating with the face pressurizing chamber is provided.