JPH026157Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a shield propulsion machine.

Figure 1 shows a conventional shield propulsion machine. 1 is the shield body, 2 is a cutter, and the support part has a structure in which both pressure chambers A and B are fully connected, and a bolt is attached to the outer circumferential rotation side of the cutter bearing 3. It has been concluded. A power transmission section such as a gear or a chain is provided on the outer circumferential rotation side of the cutter bearing 3, which meshes with a pinion attached to the drive shaft of several cutter rotation drive sources 4 and drives the same. The cutter 2 is rotated by a source 4. A bulkhead 5 is fastened to the fixed side of the cutter bearing 3 with bolts, and is also fixed to the shield body 1 by bolting or welding.

In the figure, 6 is a shield jack, and 7 and 8 are earth and sand seals.

9 is a screw conveyor device for discharge, the tip of which communicates with chamber A or chamber B, and its outer cylinder 10.
is fixed to the bulkhead 8 by bolting or welding. Further, 11 is a screw blade, 12 is a drive source for the screw blade, and 13 is a gate of the soil discharge port, which is opened and closed by a hydraulic jack or the like.

Therefore, if the screw blades 11 of the screw conveyor 9 are ribbon screws as shown in FIG. There is a high risk that water will gush out or earth and sand will flow out from 13, causing a sudden drop in the pressure inside the chamber, which could lead to the collapse of the ground. In addition, water and soil flowing into the mine are dangerous, as they may cause damage to workers and equipment inside the mine.

Therefore, a shield tunneling machine as shown in Fig. 1,
Rocks with high hydraulic conductivity such as sand and gravel layers, and many springs,
There are many construction difficulties when mining in collapsible ground with low soil pressure and high water pressure.

Therefore, as an improvement plan, a method of injecting mud into the chamber has been devised, but the above-mentioned outflow phenomenon at the soil discharge port has not been completely eliminated. The reality is that there is no suitable water-stopping method during continuous soil removal, especially when using ribbon screws.

In addition, as shown in Fig. 2, a hollow section without screw blades is provided at the rear of the screw conveyor 9, and water is retained and compacted in this section to form an impermeable layer, and a water-stopping wall is continuously formed. It is proposed that something be maintained. In this case, by changing the distance of the hollow section depending on the properties of the discharged sediment,
Furthermore, the degree of compaction and retention can be varied.

In FIG. 2, the screw 11 is fixed to a ring 14 in the screw conveyor section, and the turning force is transmitted through a gear 15 and the like attached to the outer periphery of the ring 14. Further behind that, the inner cylinder 16 and the outer cylinder 17 are connected to a hydraulic jack 18.
It is designed to be able to slide using a turnbuckle or the like.

However, even in the above-mentioned improvement plan, there is a drawback that, depending on the soil quality, the hollow section must be made considerably long to allow the accumulation and consolidation of the soil, and water and soil may flow into the mine.

The present invention was proposed to solve these problems, and includes a bulkhead, a screw conveyor is disposed on the face side so as to communicate through the bulkhead, and the screw conveyor is A compressed chamber consisting of an inner and outer cylinder is arranged in a row at the rear discharge port of the pump, a hollow resistor is provided in the compressed chamber, and a fluid supply source is connected to the hollow resistor. This relates to a shield propulsion machine.

In the shield propulsion device according to the present invention, as described above, an expandable compression chamber consisting of both inner and outer cylinders is connected to the rear discharge port of the screw conveyor, which is arranged to communicate with the face side via the bulkhead. A retractable hollow resistance body was installed in the consolidation chamber, and a fluid supply source was connected to the hollow resistance body, so that 〓 was retained and consolidated in the consolidation chamber, and during continuous earth removal by the screw conveyor. The earth pressure and water pressure inside the chamber are blocked by the impermeable layer in the consolidation chamber described above. The length of the compaction chamber is adjusted by expanding and contracting both the inner and outer cylinders constituting the hollow chamber according to the soil quality, and the amount or pressure of the fluid injected into the hollow part of the hollow resistor is adjusted. By adjusting the shape of the resistor and the number of mounting stages, reliable interrupting performance can be achieved.
In addition, by using physical means to retain and compact the water to form a water stop layer,
The amount of mud injected into the chamber can be suppressed to the necessary minimum.

Further, as described above, by providing a hollow resistor and expanding and contracting it, the entire length of the compaction chamber can be shortened in advance, so that the effective space inside the mine can be widened.

In this way, the shield propulsion device according to the present invention prevents natural outflow and spouting of soil and water from the gate of the screw conveyor into the mine, and continuously reduces the amount of expensive mud injected into the chamber. It forms a water stop layer and prevents the collapse of the ground, making construction safer and more economical.

The present invention will be described below with reference to the illustrated embodiments.

21 is a shield body, 22 is a cutter, and the supporting portion has a structure in which both pressure chambers A and B are sufficiently communicated with each other, and is fastened to the outer peripheral rotating side of the cutter bearing 23 with bolts. A power transmission unit such as a gear is integrally attached to the outer circumferential rotation side of the cutter bearing 23, and is attached to the drive shaft of a cutter rotation drive source 25, which is composed of several oil motors, electric motors, etc. attached to the bulkhead 24. The drive source 2 engages with the pinion etc.
It is designed to be rotated by 5. The bulkhead 24 is fixed to the shield body 21 by bolts or welding, and is further fastened to the fixed side of the cutter bearing 23 with bolts.

In the figure, reference numeral 26 is a shield jack, and 27 and 28 are earth and sand seals, which prevent earth, sand and water from entering the cutter bearings, etc.

29 is a screw conveyor device for discharge,
The tip thereof communicates with chamber B or chamber A as in the illustrated embodiment, and the outer cylinder 30 is fixed to the bulkhead 24 by bolts or welding. Reference numeral 31 denotes a screw blade, in addition to a normal screw, there are also ribbon screws and paddle screws as shown in the figure, which are driven and rotated by a rotary drive source 32 to discharge the water inside the chamber to the rear.

The space behind the screw end in the screw conveyor device 29 is a consolidation zone and is connected to the outer cylinder 30.

FIG. 4 shows details of the consolidation zone, in which an outer cylinder 34 is slidably fitted into an inner cylinder 33 connected to an outer cylinder 30 along the same axis, and is arranged, for example, on the outer periphery of the inner cylinder 33. The inner and outer cylinders are sealed by a sealing material such as an O-ring. The inner and outer cylinders 33,
An expansion and contraction device using a hydraulic jack 35 or a screw such as a turnbuckle is interposed between 34.

A gate 36 is pivotally supported at the rearmost end of the outer cylinder 34, and is opened and closed by a hydraulic jack 37 interposed between the gate 36 and the outer cylinder 34.

A hollow resistor 38 made of a stretchable elastic material such as rubber is fixed inside the inner cylinder 33 in one or more stages, facing toward the center over the entire circumference or a part thereof. The resistor 38 is equipped with a device that allows gas or liquid to enter and exit the hollow portion from a fluid supply source (not shown). Usually, an easily handled air source (compressor) is used to inject air into the hollow part by opening and closing a valve. The hollow resistor 38 may be made of a material with relatively low physical strength, such as elastic rubber, and in order to protect it, an elastic material made of resin, thin steel plate, steel wire, etc. may be used. The protective material 39 is fixed by bolting or welding. However, if the hollow resistor 38 is made of rubber with high strength, the protective material 39 may be omitted.

Since the illustrated embodiment is constructed as described above, the 〓 cut by the cutter 22 is taken into the A chamber or the B chamber, and the screw blade 31 facing into the B chamber is rotated. Transport the 〓 to the rear.

The 〓 thus transported rearward remains in the hollow chamber formed by the inner cylinder 33 and the outer cylinder 34 in which no screw blades are present. Since the earth and sand are continuously conveyed by the screw blades 31, the accumulated dirt is gradually consolidated, and the further consolidated dirt slides from the inner cylinder 33 to the outer cylinder 34 and enters the mine through the gate 36. be discharged.

In this way, when the soil is discharged from the gate 36, it changes from the state in which it was in the chamber, that is, the state in which the soil, groundwater, and even the injected mud are stirred, to the state in which it is consolidated and dehydrated.

Furthermore, in the consolidation zone, the formation of an impermeable layer of earth and sand is promoted. Frictional resistance between the inner and outer cylinders is an element that consolidates the earth and sand in the consolidation zone, and is expressed by the following equation.

The frictional force can be expressed as a general formula as shown in equation (1) below.

F=μ・N...(1) where μ: coefficient of friction, N: axial force, F: frictional force. Now, a circular pipe is filled with earth and sand, and the earth and sand are pressed against the pipe wall with uniform pressure. The force F ₁ that allows the soil to move is expressed by the following equation (2).

F ₁ : Moving force, μ: Friction coefficient, Np: Average axial force exerted by the earth and sand on the pipe wall, D: Pipe diameter, L: Consolidation zone length, P: Pressure of earth and sand, then Np=π・D・Assuming L・P, from equation (1), F ₁ = μ・π・D・L・P …(2) Also, in a state where the earth and sand are not completely filled, A:
Equivalent contact area (area of earth and sand in contact with pipe wall),
If P: equivalent average contact pressure (average value of the load applied to the pipe wall of earth and sand), the moving force F ₂ at the time of incomplete filling is expressed by the following equation (3).

F ₂ =μ・A・P (3) Note that equation (2) is considered to be a special case of equation (3) (consolidated state).

Now, if the conveyance force due to the rotation of the screw blade 31 is Fs, then in order to discharge the consolidated earth and sand, it is necessary that Fs>F ₁ (4).

Furthermore, when the compacted state has not been reached (incomplete filling), it is necessary to increase the value of _F2 .

If earth and sand are continuously carried out of the machine from the screw conveyor without being filled with earth and sand, water and earth and sand may blow out due to the earth pressure and water pressure from the face, which is dangerous. Therefore, it is important as a safety measure to increase the value of F ₂ to promote sediment retention.

That is, by increasing the value of A or μ in formula (3),
Increase the value of F ₂ to bring it closer to the value of F ₁ to create a state of sediment retention and consolidation.

Specifically, the hydraulic jack 35 is extended and the inner cylinder 3
There is a method of increasing the value of A in equation (3) by increasing the total length L of the compaction chamber formed by the cylinder 3 and the outer cylinder 34. If only this method is used, L may become very long, but air or water is injected into the hollow part of the hollow resistor 38, which is formed of a hollow elastic rubber or the like on the inner surface of the inner cylinder 33. It is effective to greatly expand the resistor 38 by injecting it, and thereby extremely increase the coefficient of friction μ. Since the hollow resistor 38 does not need to be attached all around the circumference, but can be attached only to a portion such as the inside of the lower half circumference, the flow of earth and sand can be inhibited, so various methods can be considered for attaching it. In order to increase the degree of compaction, it is conceivable to increase the amount of air or water injected to increase the overall height of the hollow resistor 38 inward, or to arrange a plurality of resistors.

The carrying force Fs of the screw blade 31 can be changed by varying the torque of the screw shaft. In reality, the shaft torque varies depending on the load due to the characteristics of the drive source. Therefore, as the values of F ₁ and F ₂ become larger, the load becomes larger and the motor is operated up to the maximum torque obtained from the drive source.

Therefore, it is essential that the maximum value Fsmax of the carrying force satisfies Fsmax>F ₁ (5).

When the _F1 value is large, that is, when Fsmax< _F1 , the hydraulic jack 35 is retracted to move the outer cylinder 34 backward, thereby reducing L (the length of the consolidation chamber) in equation (2). Therefore, by reducing the moving force F ₁ to reach the state of equation (5), the consolidated 〓 can be continuously discharged as it is.

In this way, according to the illustrated embodiment, a water stop layer with a low permeability coefficient can be created by retaining and compacting water in the consolidation chamber formed between the inner and outer cylinders, and the water stop layer has a low permeability coefficient. It prevents underground water etc. from flowing into the mine, enables continuous soil removal, and provides a water-stopping effect even in an earth-draining device such as a ribbon screw, which has almost no water-stopping effect. In addition, the degree of compaction can be determined by changing the overall length of the compaction chamber between the inner and outer cylinders, changing the amount or pressure of the fluid injected into the hollow part of the hollow resistor, and changing the shape and number of mounting stages of the hollow resistor. This adjustment function prevents the creation of a water stop layer that makes it impossible to drain soil, or the change in soil quality that makes it impossible to consolidate.

Further, by providing a hollow resistor and expanding and contracting it, the length of the entire compaction chamber can be made short in advance, so that the effective space in the underground space can be widened.

[Brief explanation of the drawing]

Figure 1 is a vertical side view of a conventional shield propulsion machine.
Fig. 2 is a longitudinal side view of the rear end of the screw conveyor device, Fig. 3 is a longitudinal side view showing an embodiment of the shield propulsion device according to the present invention, and Fig. 4 is the rear end of the screw conveyor device. FIG. 29... Screw conveyor device, 33... Inner cylinder, 34... Outer cylinder, 35... Hydraulic jack, 38
...Hollow resistor.

Claims (1)

[Scope of utility model registration request] A screw conveyor is disposed on the face side so as to communicate through the bulk head, and an expandable compression chamber consisting of an inner and outer cylinder is connected to the rear discharge port of the screw conveyor. A shield propulsion device characterized in that a retractable hollow resistor is provided in a chamber and a fluid supply source is connected to the hollow resistor.