JPH0380239B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a shield excavator for excavating a tunnel having a cocoon-shaped cross section.

BACKGROUND ART Conventionally, when excavating a tunnel with a wide cross section, for example, a two-lane subway tunnel, as shown in FIG. As shown in Figure 4, two small-diameter tunnels 52 were excavated in parallel. By the way, in the former case, the tunnel diameter becomes large, the face becomes easy to collapse, the cost of the excavator itself increases, and there is a lot of wasted space inside the tunnel. As a method of resolving these drawbacks, the cross-sectional shape of the tunnel was changed to a cylindrical tunnel, which had the disadvantages of increasing running costs and prolonging the construction period due to the need for a shield tunneling machine. It is conceivable to arrange two of them on the left and right, and to make them overlap each other with a predetermined width on opposite sides, that is, form a cocoon shape. By the way, as a shield excavator for excavating a tunnel in a cocoon shape, as shown in FIG. It is necessary to form them into spokes so that they do not interfere with each other.

Problems to be Solved by the Invention As mentioned above, when the face plate of the cutter head is spoke-shaped, there is a problem in that it cannot sufficiently support the face when the ground is soft and highly collapsible.

Therefore, an object of the present invention is to provide a shield tunneling machine that can solve the above problems.

Means for Solving the Problem In order to solve the above problem, the shield excavator of the present invention connects two cylindrical shield main bodies in parallel with each other so that their opposing sides partially overlap. A shield main body having a cocoon-shaped cross section is configured, and the rotation axes of cutter heads rotatably provided at the front ends of both shield main bodies are arranged to intersect in the same horizontal plane so that the respective face plates face each other outward, and Each of the face plates is formed into a circular shape having a size that does not interfere with each other, and a movable cutter is provided for excavating the upper and lower gaps between the opposing edges of the double-sided plates.

Operation In the above configuration, when each cutter head and the movable cutter are operated to move the shield body forward, a tunnel having a cocoon-shaped cross section is excavated.
According to this configuration, the cutter head is arranged at the front end of each shield body so as to face outward, so the face plate of the cutter head can be made circular, so even if the ground is soft and highly collapsible, the face can be sufficiently covered. It can be supported, and since both cutter heads are arranged symmetrically on the left and right, excavation is stable and has excellent directionality.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the drawings. In FIGS. 1 and 2, 1 has a cocoon-shaped cross-section formed by connecting two cylindrical shield main bodies 2 and 3 in left and right parallel to each other so that their opposing sides partially overlap. This is the main body of the shield. That is, when the radius of each cylindrical shield main body part 2, 3 is R, and the distance between the centers of both shield main parts 2, 3 is L, R and L are selected so as to satisfy the relationship R<L<2R. be done. Reference numerals 4 and 5 designate cutter heads rotatably provided at the front ends of the shield main bodies 2 and 3, respectively, and the respective face plates 6 and 7 are circular and directed outward. That is, each shield main body 2,
3. In the vicinity of the front end, partition walls 8 and 9 for forming pressure chambers are provided so as to face outward and laterally, and a rotary shaft body 10 is provided protruding from the rear of the face plates 6 and 7 of each cutter head 4 and 5. , 11 are held via bearings 39 in holding cylinders 14 and 15 which are disposed slidably in the axial direction within support cylinders 12 and 13 attached to the partition walls 8 and 9, and are further rotated in both directions. The rotational axes of the shaft bodies 10 and 11 are arranged so as to intersect with each other (for example, at about 120 degrees) in the same horizontal plane. Further, each of the face plates 6 and 7 is formed into a circular shape having a diameter as large as possible within a range that does not interfere with each other.
In addition, on the front and peripheral parts of each of the face plates 6 and 7,
Multiple slits (8 in a row) for taking in soil 1
6 and 17 are formed radially, and a large number of cuttlefish 18 (only some of which are shown in the figure) are provided on the edges thereof. Further, pressure chambers 19, 20 are provided between the face plates 6, 7 and the partition walls 8, 9.
will be formed. Reference numerals 21 and 22 denote motors for rotating the cutter heads 4 and 5, which are attached to support brackets 23 and 24 protruding from each holding cylinder 14 and 15, and are attached to each output shaft 21.
The pinions 25, 26 attached to the shafts 10, 11 are meshed with ring gears 27, 28 attached to the rear ends of the rotating shafts 10, 11. This is a first cylinder device that moves forward and backward in the direction of the rotation axis, and is provided in pairs, for example, between the partition walls 8 and 9 and the holding cylinders 14 and 15. 31 and 32 are a pair of left and right movable cutters for excavating the triangular gap between the upper and lower parts of the double-sided plates 6 and 7;
A pair of left and right triangular cutter bodies 33 and 34 are arranged in the front end portions of the shield body parts 2 and 3 so as to be movable in the front and rear directions, and these cutter bodies 3
and a second cylinder device 35 for moving the cylinders 3 and 34 in and out. Further, a plurality of cutter bits 36 are provided at the upper edge of each upper cutter body 33 and at the lower edge of each lower cutter body 34, respectively. Although not shown,
A water pipe and a mud drainage pipe are connected to each of the partition walls 8 and 9. Also, 37 is Shield Jack, 38
is a vertical segment pushing jack.

In the above configuration, when excavating a tunnel with a cocoon-shaped cross section, each motor 21, 22
Excavation can be carried out by rotating each cutter head 4, 5 and moving the movable cutters 31, 32 in and out. At this time, slurry is injected into each pressure chamber 19, 20 from a water pipe (not shown) to support the face, and the excavated earth and sand is discharged from a mud drainage pipe (not shown). Ru. When performing half-way excavation, the predetermined cutter head 4 may be projected as shown by the imaginary line in FIG. 1 to perform the excavation.

Effects of the Invention According to the above configuration of the present invention, it is possible to excavate a tunnel with a cocoon-shaped cross section, so the overall tunnel width is narrower than in the case of excavating two circular tunnels. At the same time, the amount of excavation is reduced, which is advantageous in terms of economy. In addition, since the cutter head is placed at the front end of each shield body so that it faces outward, the face plate of the cutter head can be made circular, unlike conventional spoke-shaped ones, which can be used on soft ground with high collapsibility. Even if there is a problem, the cutting face can be sufficiently supported, and since both cutter heads are arranged symmetrically on the left and right, excavation is stable and has excellent directionality. Furthermore, since the movable cutter is arranged in the triangular gap between the upper and lower parts of both cutter heads, it is possible to excavate a tunnel in a cocoon-like shape.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention, FIG. 1 is a horizontal sectional view, FIG. 2 is a view taken along the - arrow in FIG. 1, and FIGS. 3 to 5 are conventional examples. Figures 3 and 4 are cross-sectional views of the tunnel, and Figure 5 is a cross-sectional view of the tunnel.
The figure is a front view of the cocoon-shaped shield tunneling machine. DESCRIPTION OF SYMBOLS 1... Shield body, 2, 3... Cylindrical shield main body part, 4, 5... Cut head, 6, 7... Face plate,
8, 9...Partition wall, 10,11...Rotating shaft body, 12,1
3... Support cylinder, 14, 15... Holding cylinder, 19, 20...
Pressure chamber, 21, 22...Motor, 23, 24...Support bracket, 31, 32...Movable cutter, 3
3, 34... cutter body, 35... second cylinder device.

Claims (1)

[Claims] 1. Two cylindrical shield main bodies are connected in parallel with each other so that their opposing sides partially overlap to form a shield main body having a cocoon-shaped cross-section,
The rotation axes of the cutter heads rotatably provided at the front ends of both shield bodies are intersected in the same horizontal plane so that the face plates face each other outward, and the face plates are formed into a circular shape large enough not to interfere with each other. A shield excavator characterized in that a movable cutter is provided for excavating the upper and lower gaps between the opposing edges of the double-sided plate.