JPH0426398B2 - - 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. Since it requires a standalone shield excavator, it has disadvantages such as increased running costs and a longer construction period. As a method to eliminate such drawbacks, it is conceivable to make the cross-sectional shape of the tunnel into a shape in which two cylindrical tunnels are arranged on the left and right, and the opposing sides overlap each other with a predetermined width, that is, 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 in the shape of a spoke, 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 has two cylindrical shield main bodies connected in parallel with each other so that their opposing sides partially overlap. The shield body has a cocoon-shaped cross section, and a partition wall is provided in the front part of the shield body.
Left and right cutter heads are rotatably supported at the center of each shield body of the bulkhead, and the face plates of each of the cutter heads are arranged in the same vertical plane,
Each of these face plates is configured in a circular shape with a size that does not interfere with each other, and an excavation arm is provided protruding from the outer periphery of each of the face plates to excavate an annular space formed between the face plate and the outer peripheral surface of the shield main body. , a rocking device for rocking each cutter head within a predetermined angle range is provided, and a retaining plate that can move in and out toward each annular space is arranged in the upper half of the partition wall, and each of the annular spaces A front wall is placed at a position behind the excavation arm so as to close the lower half of the excavation arm, and an earth and sand intake hole is formed in this front wall, and the excavated earth and sand taken in through this earth and sand intake hole are carried out. A screw conveyor-type earth removal device for this purpose is provided in the lower half of the partition wall.

Operation In the above configuration, when each cutter head is operated to move the shield body forward, a tunnel having a cocoon-shaped cross section is excavated. According to the above structure, the face plate of each cutter head rotatably provided at the front end of each shield body is made circular in size so as not to interfere with each other, so that a considerable part of the face can be supported, and the annular space around the outer periphery of the face plate can be supported. Since the pile retaining plate, front wall, and screw conveyor-type earth removal device are provided, pile retaining can be performed even when the operation is stopped.

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 numeral 4 denotes a partition wall for forming an earth and sand intake chamber, which is provided in the vicinity of the front ends of both the shield main bodies 2 and 3 and across both. Reference numerals 5 and 6 denote left and right cutter heads rotatably supported by the partition wall 4 at the center of each shield body 2, 3. The face plates 7 and 8 of the cutter heads 5 and 6 are arranged on the left and right in the same vertical plane position (same position in the front and back direction), and are configured in a circular shape with a size that does not interfere with each other. A holding cylinder 12 is provided with rotary shaft bodies 9 and 10 provided on the partition wall 4 and a support wall 11 behind the partition wall 4, respectively, with rotating shaft bodies 9 and 10 respectively protruding from the rear surface.
13 through a bearing (not shown). At appropriate positions on the outer circumference of each of the face plates 7, 8, a substantially trapezoidal shape is provided for excavating annular spaces 14, 15 formed between the outer circumferential surfaces of the face plates 7, 8 and the outer circumferential surfaces of the shield main bodies 2, 3. One excavation arm 16, 17 is provided in a protruding manner. A large number of cutters 18 are attached to both end edges of each excavation arm 16, 17, and each face plate 7, 8 has a plurality of slits 19 for taking in soil.
20 It is formed in a radial pattern and there are many cuttlefish on the edge (only some are shown in the figure) 21
is installed. 22 is the annular space part 14,1
The front wall is disposed so as to close the lower half of the excavating arms 16, 17, and is provided at the rear end positions of the face plates 7, 8 so as not to support the rocking motion of the excavating arms 16, 17. A soil intake chamber 2 is provided between the front wall 22 and the partition wall 4.
3 is formed. 24 is a drive motor attached to the support wall 11 that supports the holding cylinders 12 and 13;
The face plates 7, 8 and the excavating arms 16, 17 are oscillated and rotated in conjunction with each other. That is, ring gears 25 and 26 that mesh with each other are fixed to the rear ends of each rotating shaft body 9 and 10, and a pinion 27 fixed to the output shaft of the motor 24 is connected to one of the ring gears. It is meshed with 25. Note that the motor 24, pinion 27, and ring gears 25 and 26 constitute a swinging device. By the motor 24, the excavating arm 16,
17 is oscillated and rotated between an upper position (solid line position in Figure 2) and a lower position (phantom line position in Figure 2).
Of course, at this time, the face plates 7 and 8 also swing and rotate. Also,
The swinging angle of the excavating arms 16, 17 is such that both the annular spaces 14, 1 are different from each other.
The angular range is such that all 5 are moved, and the mutual end shapes are made to be the same shape so that they do not interfere with each other. In order to automatically perform the above-mentioned swinging, a pair of upper and lower limit switches (not shown) are arranged on the support wall 11 to determine the range of swinging, and a pair of upper and lower limit switches (not shown) are arranged on the side of the ring gears 25 and 26 facing the limit switches. is equipped with a kicker (not shown) that operates the limit switch. Reference numeral 28 indicates the upper half position of each of the annular spaces 14 and 15, and a plurality of them in the circumferential direction (for example, 4
The cylinder device 29 is supported by the bulkhead 4 and the shield body parts 2 and 3, and the cylinder device 2
It consists of a retaining plate 30 attached to the tip of the rod 9. 31 is each annular space part 14,1
A screw conveyor-type earth removal device is a screw conveyor-type soil removal device that is arranged in a plurality of pieces (for example, 5 pieces) in the lower half position of 5 and along the circumferential direction. A sediment intake opening 3 is connected to the intake hole 32 and is located in the sediment intake chamber 23.
It is composed of a cylindrical casing 33 in which a number 3a is formed, a screw blade 34 rotatably disposed within the cylindrical casing 33, and a motor 35 that rotates the screw blade 34. 36
38 is a water pipe connected to the upper part of the partition wall 4. Reference numeral 38 indicates a mud discharge pipe that communicates with a dirt discharge port 33b formed at the lower rear of the cylindrical casing 33 via a communication box 37.

In the above configuration, when excavating a tunnel with a cocoon-shaped cross section, the face plates 7 and 8 are driven by the motor 24.
Excavation may be carried out by rotating the excavation arms 16 and 17 in a reciprocating manner as shown by arrow A in FIG.
The earth and sand excavated by the excavation arms 16 and 17 is discharged from the earth and sand intake hole 32 in the lower half by the earth removal device 31 through the mud removal pipe 36, and the face plate 7,
The earth and sand taken into the earth and sand intake chamber 23 through the slits 19 and 20 of 8 falls downward, enters the earth removal device 31 through the earth and sand intake opening 33a, and is discharged from the mud removal pipe 36. . Note that during excavation, water is constantly supplied into the earth and sand intake chamber 23 from the water pipe 38.

Incidentally, during excavation, the retaining plate 30 is retracted to the rear position (solid line position in Figure 1), but the face plate 7,
By adjusting the gap between 8 and the mountain retaining plate 30, the amount of soil taken in can be adjusted. Also,
When the operation is stopped, the ridge retaining plate 30 is projected to the front position where it is flush with the face plates 7 and 8 (the imaginary line position in FIG. 1), and the crest retaining is accomplished. For the lower half, the front wall 22 and the screw blades 34 of the earth removal device 31 perform the same function.

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, the face plate of each cutter head, which is rotatably provided at the front end of each shield main body, is circular in size so that it does not interfere with each other, so it can support a considerable part of the face compared to conventional spoke-shaped ones, and the face plate Since a pile retaining plate, a front wall, and a screw conveyor-type soil removal device are provided in the annular space on the outer periphery, pile retaining can be performed even when the operation is stopped.

[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... Partition wall, 5, 6... Cut head, 7, 8... Face plate, 14, 15... Annular space part, 16, 17... Excavation arm, 22... front wall,
23...Sediment intake chamber, 24...Motor, 25,2
6...Ring gear, 27...Pinion, 28...
Mountain retaining device, 29... Cylinder device, 30... Mountain retaining plate, 31... Earth removal device, 32... Soil disposal hole, 33... Cylindrical casing, 34... Screw blade.

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 with a cocoon-shaped cross section, and a partition is provided in the front part of the shield main body. , the left and right cutter heads are rotatably supported at the center of each shield body of the bulkhead, the face plates of each of the cutter heads are arranged in the same vertical plane, and the face plates are arranged in a circular shape of a size that does not interfere with each other. A digging arm is provided on the outer periphery of each face plate to excavate an annular space formed between the face plate and the outer circumferential surface of the shield main body, and each of the cutter heads is oscillated within a predetermined angle range. A rocking device is provided, and a retaining plate that can move in and out toward each annular space is arranged in the upper half of the partition wall so as to close the lower half of each annular space and from the excavation arm. A front wall is arranged at the rear position, an earth and sand intake hole is formed in this front wall, and a screw conveyor type earth removal device for carrying out the excavated earth and sand taken in from this earth and sand intake hole is installed as described above. A shield excavator characterized by being installed in the lower half of the bulkhead.