JPS6126471Y2 - - Google Patents

Description

[Detailed description of the invention] The invention relates to a shield tunneling machine,
The purpose of this is to maintain an appropriate pressure on the entire face of the face to prevent its collapse even when excavating a face of large diameter, and to obtain an effective excavation condition.

Usually, shield excavators such as mud water pressure shields and pressure holding shields (earth pressure shields) are provided with a cutter head, and this cutter head is supported on the shield body by a drum-type support structure. That is, a cylindrical body having approximately the same diameter as the shield body is provided rearwardly projecting from the cutter head, and this cylindrical body is rotatably supported by the shield body via a bearing. By the way, when the diameter of the tunnel becomes large, the cutter head naturally becomes large in diameter, and the drum portion for supporting it also becomes large in diameter. As a result, machining accuracy deteriorates, distortion occurs in the drum section, and unreasonable force is applied to the bearing section. Furthermore, when the diameter of the cutting head increases, the volume of the pressure chamber also increases, causing pressure unevenness, making it difficult to support the cutting face in a good condition.

The present invention has been devised in view of the above, and examples thereof will be described below with reference to FIGS. 1 and 2. 1 is the shield body, inside and outside 2
It has two concentric supports 2A, 2B, and a cutter head 3 is arranged in front thereof. Thus, a muddy water pressurizing chamber 4 is constructed at the back of the cutter head 3. 5 is a cylindrical partition wall, which is connected to the supporting material 2
It is rotatably supported by A and 2B via bearings 6 and 7 and sealing materials 8 and 9, and its front end is concentrically fixed to the back surface of the cutter head 3. Cylindrical bulkhead 5
A gear mechanism 10 is connected to the rear end of the shield body 1, and an input gear 10A of this gear mechanism 10 is connected to a drive motor M installed in the shield body 1. When performing excavation operation, the output of this drive motor M is connected to the gear mechanism 10.
It is transmitted to the cylindrical partition wall 5 through the cylindrical partition wall 5, and the cutter head 3 rotates in the forward or reverse direction together with the cylindrical partition wall 5. The muddy water pressurizing chamber 4 formed at the back of the cutter head 3 described above is connected to a central pressure chamber 4 by a cylindrical partition wall 5.
The pressure chamber A and the outer peripheral pressure chamber 4B are divided into two sections, and these are communicated through pressure regulating openings 11 formed at a plurality of locations in the circumferential direction of the cylindrical partition wall 5. Central pressure chamber 4
Mud water pipes 12 are connected to A and outer pressure chamber 4B, respectively.
A, 12B are connected, and agitators 13A, 13B are installed at the bottom of each chamber, and a drainage pipe 14 is connected from the vicinity of the agitators 13A, 13B.
A and 14B are extended. Furthermore, a plurality of slits 1 are formed in the center and outer circumference of the cutter head 3, facing the center pressure chamber 4A and the outer circumference pressure chamber 4B, respectively.
5A, 15B are formed at required pitches in the circumferential direction, and the excavated earth and sand flow into these slits 15A, 1.
5B into the central pressure chamber 4A and the outer peripheral pressure chamber 4B. These slits 15A, 15B are provided with gates 16A, 16B which can be opened and closed as appropriate. Reference numeral 17 indicates a mud water specific gravity adjustment tank, which is usually installed outside the mine. Mud water specific gravity adjustment tank 17 and the aforementioned mud water pipe 1
A pipe group 18 for feeding and draining slurry is provided between 2A and 12B and the draining water pipes 14A and 14B. As is clear from the illustration, the piping group 18 includes the following systems.

A Mud water system: A system that runs from the mud water specific gravity adjustment tank 17 to the mud water pipe 12A that goes to the central pressure chamber 4A via pipes a, b, and c. A mud pump is installed in this system.
P ₁ and valves V ₁ and V ₂ are interposed.

B. In-machine circulation system: A system that runs from the sludge water pipe 14A from the central pressure chamber 4A to the sludge water pipe 12B to the outer peripheral pressure chamber 4B via pipes d, e, and f. In this system there is a circulation pump P ₀ and valves V ₃ , V ₄ , V ₅
is intervened.

C. First mud drainage system: A system leading from the mud drainage pipe 14B from the outer peripheral pressure chamber 4B to the treatment tank outside the mine via piping g, h, and i. A pump P ₂ and valves V ₆ and V ₇ are interposed in this system.

D Second mud drainage system: A system that extends from the mud drainage pipe 14A from the central pressure chamber 4A to the outside of the mine via pipes d, e, j, k, and i. In this system, the above-mentioned circulation pump P ₀ , sludge pump P ₂ and valves V ₃ , V ₈ ,
V ₉ is mediated.

E. First sweep circulation system: A system that extends from the mud water specific gravity adjustment tank 17 through pipes a, b, d, e, f, l, and c to the mud feeding water pipe 12A to the central pressure chamber 4A. A mud pump P ₁ , a circulation pump P ₀ , and valves V ₁ , V ₁₀ , V ₄ , V ₁₁ , and V ₂ are interposed in this system.

F Second sweep circulation system: From the muddy water specific gravity adjustment tank 17 to the outer peripheral pressure chamber 4 via piping a, b, d, e, f
The system leading to the mud water pipe 12B to B. In this system, the aforementioned slurry pump P ₁ , circulation pump P ₀ and valves V ₁ , V ₁₀ , V ₄ and V ₅ are interposed.

G Other systems: Piping m, n, valves V ₁₂ , V ₁₃
etc.

When excavating a ground with a large face area, the mud water is sent to the central pressure chamber 4A through the mud water system described above, and the mud in the central pressure chamber 4A is further sent to the outer pressure chamber 4B through the in-machine circulation system. . In this case, a part of the mud water may be directly fed into the outer circumferential pressure chamber 4B, and such changes in operating conditions are made as appropriate depending on the nature of the ground and the like. In addition, mud water is discharged through the first mud drainage system or a part thereof through the second mud drainage system. In this way, the main mud water is mainly sent to the central pressure chamber 4A, and the main mud water is adjusted within this central pressure chamber 4A by the stirring action of the agitator 13A etc. [Those sent from the mud water specific gravity adjustment tank 17]
By circulating muddy water of higher density into the outer pressure chamber 4B inside the machine and applying the pressure of this muddy water to the face, the face ground, which tends to loosen due to its large area, can be stabilized relatively easily. becomes. In addition, by the action of the pressure regulating opening 11 formed in the cylindrical partition wall 5, whether or not the above-described muddy water is circulated in the machine, the central pressure chamber 4A and the outer peripheral pressure chamber 4
Since the difference in mud water pressure with B is small or maintained at the same time, a situation where the face collapses due to a local pressure difference acting on the face is prevented, and at the same time, the difference between the cutter head 3 and the shield is prevented. Unreasonable external pressure is not applied to the support structure between the support structure and the main body 1, and the support structure is stabilized.

When the face ground is made of clay (clay, silt), excavated soil is particularly likely to adhere to the back of the cutter head 3, slits 15A, 15B, agitators 13A, 13B, and other parts due to its adhesive strength, making it difficult to maintain continuity. This can easily become a factor that hinders driving. If these adhere, it is necessary to remove them, and in order to continue continuous operation, it is necessary to prevent such adhesion. In such a case, the central pressure chamber 4 is supplied through the first sweep circulation system and the second sweep circulation system.
A. Mud water is sent under increased pressure to the outer peripheral pressure chamber 4B to generate a jet water flow in these pressure chambers 4A and 4B to prevent or remove the excavated earth and clay from adhering to it.

As is clear from the above explanation, according to the present invention, the cutter head is supported by the cylindrical bulkhead, so if the cylindrical bulkhead is made smaller in diameter than the shield diameter, the machining accuracy of the support structure can be improved. Therefore, no unreasonable force is generated on the bearing part. In addition, since pressure chambers are formed separately inside and outside of this cylindrical partition, the faces corresponding to the inside and outside of the cylindrical partition can be maintained in good condition, and a pressure regulating opening is provided in the cylindrical partition to communicate both pressure chambers. This structure prevents the pressure difference between the two pressure chambers from increasing, and therefore prevents the face from collapsing, which occurs when earth and sand in the pressure chamber moves through the face when a pressure difference occurs. Further, if the structure is configured such that muddy water can be circulated or swept in the machine as in the embodiment, a stable state during excavation can be maintained even better.

In the embodiment, the case of a muddy water pressure shield has been described, but the present invention can be similarly applied to other earth pressure type shields.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of an embodiment of the present invention, and FIG. 2 is a front view thereof. 1... Shield body, 2A, 2B... Support body,
3... Cut head, 4... Mud water pressurization chamber, 4A...
...Central pressure chamber, 4B...Outer pressure chamber, 5...
Cylindrical bulkhead, 6, 7...Bearing, 8, 9...Sealing material, 11...Pressure adjustment opening, 12A, 12B...Mud water pipe, 13A, 13B...Agitator, 14A,
14B...Sludge water pipe, 15A, 15B...Slit.

Claims (1)

[Scope of utility model registration request] In a shield excavator in which a pressure chamber for holding a face is formed in the back of a cutter head that is pivotally supported on a shield body, a cylindrical bulkhead for supporting the cutter head is provided in the pressure chamber concentrically with the cutter head; A shield excavator characterized in that a pressure regulating opening is formed that communicates a central pressure chamber and an outer peripheral pressure chamber that are divided into sections.