JP2542050Y2 - Tail sealing device for tunnel excavator - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tail seal device for stopping water between a tail shield provided at the rear of a tunnel excavator and an existing segment mounted in an excavated tunnel.

[0002]

2. Description of the Related Art As a tunnel excavation method using a tunnel excavator, there is a method in which segments are sequentially mounted in an excavated tunnel. In this case, ground water intrudes into the tunnel from between the tunnel excavator and an existing segment. For this reason, a tail seal device is used in which a tail shield is attached to a rear portion of a tunnel excavator and a seal member is sealed between the tail shield and an existing segment to stop water. For example, as shown in FIG. 1, a wire brush type tail seal device in which a plurality of wire brushes 2 are attached to a tail shield 1 and grease 4 is sealed between an adjacent wire brush 2 and an existing segment 3. A plurality of L-shaped rubber seals 5 are attached to the tail shield 1 as shown in FIG.
A rubber seal type tail seal device in which the tip of the rubber seal 5 is pressed against the existing segment 3. Etc. are known.

[0003]

[Problems to be Solved by the Invention] The former tail seal device stops water by opposing the pressurized grease pressure and the ground water pressure (earth pressure), and the pressurized grease pressure exceeds a certain value. Therefore, it is necessary to increase the number of the wire brushes 2 and the number of stages of the grease 4 to counter the high water pressure as the ground water pressure becomes higher. For this reason, in the case of a tunnel excavator that operates in the ground under high water pressure, as shown in FIG. 3, the number of wire brushes 2 increases, the total length L of the tail seal device increases, If the existing segment 3 and the tunnel excavator 6 undergo a large curved displacement at the time of a correction operation or the like, the existing segment 3 and the tail shield 1 interfere with each other, resulting in poor tunnel construction and operation controllability. The latter tail seal device stops water by the repulsive force of the rubber seal 5. If the repulsive force of the rubber seal 5 is increased, it is possible to withstand high water pressure without increasing the number of rubber seals 5, so that the overall length can be shortened. As described above, even when the existing segment 3 and the tunnel excavator 6 are greatly displaced in a curved manner, the interference between the existing segment 3 and the tail shield 1 can be prevented. However, when the repulsive force of the rubber seal 5 is increased, the rubber seal 5 slides on the outer peripheral surface of the existing segment 3 in a state where the outer peripheral surface of the existing segment 3 is tightened by a large kinking force, so that the rubber seal 5 is damaged early and deteriorates in durability. If the number of the rubber seals 5 is increased without increasing the repulsive force of the rubber seal 5,
Although the durability of the tail seal device can be improved, the total length of the tail seal device becomes longer like the former tail seal device, and even if the existing segment and the tunnel excavator are greatly displaced, the existing segment and the tail shield interfere and the workability, Operation controllability will be inferior.

Accordingly, an object of the present invention is to provide a tail seal device for a tunnel excavator capable of solving the above-mentioned problem.

[0005]

A movable cylinder is provided in a tail shield so as to be movable back and forth, a slide seal is attached to an outer peripheral surface of the movable cylinder, and an inner peripheral surface of the movable cylinder and a rear of the tail shield are provided. The front and rear expansion / contraction seals are attached to the ends.

[0006]

[Operation] When installing a new segment, expand the rear expansion / contraction type seal and stop the high water pressure by pressing against the outer peripheral surface of the existing segment. When moving the tail shield, stop the high water pressure with the front expansion / contraction type seal. Water can be prevented, and the rear expandable / contractible seal can be prevented from being damaged by contracting and separating from the outer peripheral surface of the existing segment.

[0007]

As shown in FIG. 4, a front main body 11 having a cutter head 10 and an intermediate main body 12 are swingably connected by a front thrust cylinder 13, and a rear main body 14 is connected to the intermediate main body 12. A tail shield 16 is provided behind the rear main body 14 so as to be swingable by an intermediate thrust cylinder 15, and a flexible cover 17 is provided between the main bodies and between the rear main body 14 and the tail shield 16. A tail shield thrust cylinder 19 is provided between the rear body 14 and the tail shield 16 to form a tunnel excavator capable of sharply excavating. The tail shield 1
5, a cylindrical recess 20 is formed in the longitudinal direction, that is, in the middle portion in the front-rear direction, to form a large-diameter seal sliding inner peripheral surface 21. The rear end of the tail shield 16 The inner diameter of the annular recess 20 is smaller than the inner diameter of the seal sliding inner surface 21 and is smaller than the inner diameter of the seal mounting inner surface 22.
A front expansion / contraction type seal 25 and a rear expansion / contraction type seal 26 are respectively attached to the inner peripheral surface 24 of the movable cylindrical body 23 disposed at The sliding seal 2 is provided on the outer peripheral surface 27 of the movable cylinder 23.
A cable 29 is attached to the movable cylinder 23 and pulled and loosened by a winch or the like (not shown). The front / rear expansion / contraction type seals 25 and 26 are band-shaped and ring-shaped as shown in FIGS. The other end in the width direction is attached to the inner peripheral surface 24 of the movable cylindrical body 23 and the seal mounting inner peripheral surface 22 of the tail shield 16 via the retaining plate 32 via the retaining plate 32. 33, the inner peripheral surface 24 of the movable cylindrical body 23, the seal attaching inner peripheral surface 22 of the tail shield 16
The space 34 communicates with the movable cylinder 23 and the hole 35 of the tail shield 16, and contracts when the air or water in the space 34 is sucked and reduced to a negative pressure. When air or water is pressure-fed into the space 34 while being separated from the outer peripheral surface of the segment 36, it expands as shown by the solid line in FIG. As shown in FIG. 8, the sliding seal 28 has a ring shape with a substantially mountain-shaped cross section and a small sliding resistance so that it does not break when sliding. 21 is sealed.

Next, the operation will be described. As shown in FIG. 9, when the new segment 40 is mounted on the end face 36 a of the existing segment 36 after the excavation of the predetermined stroke, air or water is supplied into the space of the rear expansion / contraction type seal 26 to expand the outer periphery of the existing segment 36. At the same time, the air or water in the space of the front expansion / contraction type seal 25 is discharged and contracted. When the installation of the new segment 40 is completed, the front expandable / contractible seal 25 is expanded and pressed against the outer peripheral surface of the new segment 40 as shown in FIG. 10, and the rear expandable / contractible seal 26 is contracted to be separated from the outer peripheral surface of the existing segment 36. In this state, the tail shield 16 is advanced by the excavation stroke while the cable 29 is extended. At this time, as shown in FIG. 11, the rear expanding / contracting seal 26 is separated from the outer peripheral surface of the existing segment 36, and the tail shield 16 slides with respect to the movable cylinder 23, so that the front expanding / contracting seal 25 is moved to the existing segment 36. Since it does not slide along the outer peripheral surface, there is no breakage. The sliding seal 28 is a seal sliding inner peripheral surface 2 of the tail shield 16.
1, but the seal sliding inner peripheral surface 21 is not damaged because the surface accuracy is good. When the tail shield 16 advances by the excavation stroke, as shown in FIG. 12, the rear expandable seal 26 is expanded to press against the outer peripheral surface of the existing segment 36 to stop water, and the front expandable seal 25 is contracted to make a cable. By pulling the ridge 29, the front expansion / contraction type seal 25 is moved together with the movable cylinder 23 to the position shown in FIG. Since the inner peripheral surface 24 of the movable cylinder 23 sliding along the seal sliding inner peripheral surface 21 of the tail shield 16 and the seal mounting inner peripheral surface 22 of the tail shield 16 have substantially the same inner diameter, The rear expansion / contraction type seals 25 and 26 can be formed in the same shape, and parts can be shared. The movable cylinder 23 has a shape in which a plurality of unit arc-shaped pieces are connected, and the sliding seal 28 can be replaced by dividing the unit arc-shaped piece.

[0009]

When the new segment is attached, the rear expansion / contraction seal 26 is expanded to press against the outer peripheral surface of the existing segment 36 to stop water. In addition, the pressure contact force of the rear expansion / contraction seal 26 is increased to increase the water pressure. When the tail shield 16 moves forward with the tunnel excavator, the movable cylinder 2
3 is moved forward to expand the front expandable / contractible seal 25 and press-contact the outer peripheral surface of the existing segment 36, and press-contact the sliding contact 28 of the movable cylindrical body 23 with the inner peripheral surface of the tail shield 16. The rear seal 26 is contracted by separating the rear expandable seal 26 from the outer peripheral surface of the existing segment 36, so that it is not damaged. Further, the sliding seal 28 has a good surface accuracy and the flat inner peripheral surface of the tail shield 16. It does not break at an early stage because it comes into sliding contact. Therefore, the overall length of the tail seal device can be shortened, high water pressure can be countered, and durability can be improved without breakage of each seal.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a conventional tail seal device.

FIG. 2 is an explanatory view of another conventional tail seal device.

FIG. 3 is an explanatory view of a problem with a conventional tail seal device.

FIG. 4 is an overall view of a tunnel excavator equipped with the tail seal device of the present invention.

FIG. 5 is a sectional view of a tail seal device portion.

FIG. 6 is an enlarged detailed cross-sectional view of the expansion / contraction type seal mounting portion.

FIG. 7 is a cross-sectional view of the expansion and contraction type seal.

FIG. 8 is a sectional view of a sliding seal.

FIG. 9 is an operation explanatory diagram.

FIG. 10 is an operation explanatory diagram.

FIG. 11 is an operation explanatory diagram.

FIG. 12 is an operation explanatory diagram.

[Explanation of symbols]

16: tail shield, 23: movable cylinder, 25: front expansion / contraction type seal, 26 ... rear expansion / contraction type seal, 28: sliding seal, 36: existing segment.

Claims (1)

(57) [Scope of request for utility model registration] A tail shield having a cylindrical shape is provided at a rear portion of a tunnel excavator, and a rear expanding / contracting seal is attached to a rear end of the tail shield.
The movable cylinder 23 is disposed in the movable cylinder 23 so as to be movable back and forth, and a sliding seal 28 is attached to the outer peripheral surface of the movable cylinder 23 to press the inner peripheral surface of the tail shield 16. A tail seal device for a tunnel excavator, characterized in that a front expanding / contracting seal 25 facing an outer peripheral surface of an existing segment is attached to a surface thereof.