JPH026156Y2 - - 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 part such as a gear or a chain is provided on the outer peripheral rotation side of the cutter bearing 3, and it 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 bolted to the fixed side of the cutter bearing 3 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 difficulties in construction when it is applied to ground that has a low value and has high water pressure and collapsibility.

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 consolidated 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 connected to the face side through the bulkhead. An expandable compression chamber consisting of an inner and outer cylinder is installed at the rear discharge port of the conveyor, and the cells are bundled into a brush shape in the same compression chamber.
This relates to a shield propulsion device characterized by being provided with an elastic resistor whose free end is directed toward the center of the cylinder.

In the shield propulsion device according to the present invention, as described above, an expandable compression chamber consisting of both an inner and outer cylinder is connected to the rear discharge port of the screw conveyor, which is arranged to communicate with the face side via the bulkhead. Since the elastic resistor is bundled like a brush in the same consolidation chamber and has its free end directed toward the center of the cylinder, the dirt is retained and consolidated in the consolidation chamber, and the soil is continuously discharged by the screw conveyor. The earth pressure and water pressure inside the chamber at this time are blocked by the impermeable layer in the consolidation chamber described above. Therefore, by adjusting the length of the compaction chamber by expanding and contracting both the inner and outer cylinders that make up the compaction chamber according to the soil quality, and by adjusting the number of mounting stages of the resistor, reliable breaking performance can be achieved. be able to. Furthermore, by using physical means to retain and compact mud to form a water stop layer, the amount of mud injected into the chamber can be suppressed to the necessary minimum.

Furthermore, as mentioned above, by providing a resistor, the entire length of the consolidation chamber can be shortened in advance.
The effective space inside the shaft can be widened.

As described above, the shield propulsion device of the present invention prevents the 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 as in the illustrated embodiment, or with chamber A, 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.

Inside the inner tube 33, elastic and restorable materials such as rubber, resin, thin steel plates, and steel wires are bundled into strips or brushes, and the free ends are oriented toward the center of the tube. The resistors 36 are fixed in one row or in several rows around the entire circumference of the inner cylinder or partially to constitute a resistor against the flow of earth and sand.

In the illustrated embodiment, a wire brush is used as the resistor 36. Also, the resistor 36 is connected to the inner cylinder 3.
3, or an inner cylinder part may be further provided inside the inner cylinder 33 and fixed to the same part. Further, as for the fixing method, in either case, bolting, welding, etc. are used to fix directly or indirectly via bundled pedestals.

Since the illustrated embodiment is constructed as described above, the material excavated by the cutter 22 is taken into chamber A or chamber B, and the material is taken into chamber A or chamber B by the rotation of the screw blade 31 facing into chamber B. to the rear.

The 〓 thus transported rearward stays in a compaction 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 transported continuously by the screw blades 31, the accumulated dirt is gradually consolidated, and the further compacted dirt slides from the inner cylinder 33 to the outer cylinder 34 and enters the mine through the gate 37. be discharged. 38 in the figure is a hydraulic jack for opening and closing the gate 37.

In this way, when the soil is discharged from the gate 37, 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 chamber, 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 of pipe wall, Np: Average axial force exerted by earth and sand on pipe wall, D: Pipe diameter, L: Consolidation zone length, P: Pressure of earth and sand, then Np=π・Assuming D・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 state of F ₁ to create a state of sediment retention and consolidation.

Specifically, the hydraulic jack 35 is extended and the inner cylinder 3
3 and the outer cylinder 34, the value of A in equation (3) is increased. Further, by providing the resistor 36, the coefficient of friction μ between the earth and sand and the pipe wall can be dramatically increased. Since the resistor 36 can inhibit the flow of earth and sand even if it is disposed in the lower half section of the consolidation chamber, various methods can be considered for attaching it. For example, it is conceivable to increase the number of stages of strips or brushes in order to increase the degree of compaction.

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 F ₁ value is large, that is, when Fsmax<F ₁ , 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 adjusted arbitrarily by changing the overall length of the compaction chamber between the inner and outer cylinders and the mounting method of the resistor. It is possible to prevent the soil from becoming incapable of forming, or from changes in soil quality that result in changes in consolidation and the inability to form a water stop layer.

Furthermore, by attaching the resistor, the overall length of the compaction chamber can be shortened in advance, so that the effective space inside the mine can be widened.

[Brief explanation of drawings]

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, 36
...Resistance body.

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 machine characterized by having an elastic resistor bundled in a chamber in the shape of a brush and with its free end directed toward the center of the cylinder.