JP2817013B2 - 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 shield 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 enters the tunnel from between the tunnel excavator and an existing segment. For this reason, a tail shield 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 shield device in which a plurality of wire brushes 2 are attached to a tail shield 1 and a grease 4 is sealed between an adjacent wire brush 2 and an existing segment 3. As shown in FIG. 2, a rubber seal type tail shield device in which a plurality of L-shaped rubber seals 5 are attached to the tail shield 1, and the distal ends of the rubber seals 5 are pressed against the existing segments 3. Etc. are known.

[0003]

The former tail seal device stops water by opposing the pressurized grease pressure and the ground water pressure (earth pressure). The higher the water pressure of the ground, the higher the water pressure of the ground. It is necessary to increase the number of wire brushes 2 and the number of stages of the grease 4 to counter high water pressure. 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 the 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 the rubber seals 5. As described above, even when the existing segment 3 and the tunnel excavator 6 are greatly bent and displaced, the interference between the existing segment 3 and the tail shield 1 can be prevented. However, if the repulsive force of the rubber seal 5 is increased,
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 amount of force, so that it is damaged early and the durability is deteriorated. The durability of the rubber seal 5 can be improved by increasing the number of the rubber seals 5 without increasing the repulsive force of the rubber seal 5, but the overall length of the tail seal device becomes longer like the former tail seal device, and the existing segment has If the tunnel excavator is significantly displaced, the existing segment and the tail shield interfere with each other, resulting in poor workability and operation controllability.

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

Means for Solving the Problems A pressure ring is provided in a tail shield so as to be movable back and forth, a slide seal and an end face seal are mounted on the pressure ring, and an expansion / contraction type seal is mounted on a rear end of the tail shield. .

[Operation] When installing a new segment, the expansion / contraction seal is expanded and pressed against the outer peripheral surface of the existing segment to stop high water pressure. When moving the tail shield, high water pressure is stopped by the slide seal and end face seal. I can do it
Breakage can be prevented by contracting the expandable / contractible seal and separating it from the outer peripheral surface of the existing segment.

[0005]

[Embodiment] 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. An intermediate thrust cylinder 15 swingably connects, a tail shield 16 is provided behind the rear main body 14, and a flexible cover 17 is provided between the main bodies and between the rear main body 14 and the tail shield 16. A gripper 18 is attached so as to be able to enter and exit to form a tunnel excavator capable of sharply excavating. The tail shield 16 has a cylindrical shape, and has an expansion / contraction seal 20 at its rear end.
Are mounted inward, a pressure ring 21 is provided in the tail shield 16, a slide seal 22 is mounted on the outer peripheral surface of the pressure ring 21, and an end face seal 23 is mounted rearward on the rear surface. A pressure ring cylinder 24 is swingably connected to the rear main body 14 and the pressure ring 21, and the pressure ring cylinder 24 is extended and contracted by the pressure ring cylinder 24 via a slide seal 22. The end seal 23 slides along the inner peripheral surface of the tail shield 16 so that the end face seal 23 is pressed against the end face 26 of the existing segment 25. As shown in FIG. 5, the expandable / contractible seal 20 has a band shape and a ring shape, and one end in the width direction is attached to the inner peripheral surface of the tail shield 16 with a bolt 28 via a holding plate 27, and the other end in the width direction. An annular space 31 is attached to the inner peripheral surface of the tail shield 16 with a bolt 30 via a holding plate 29 via a holding plate 29 and forms an annular space 31 between the tail shield 16 and the hole 32 of the tail shield 16. When the air or water in the space 31 is suctioned to make a negative pressure, the air or water contracts and separates from the outer peripheral surface of the existing segment 25, and the space 3
When air or water is pressure-fed into the inside 1, it expands as shown by the imaginary line in FIG. As shown in FIG. 6, the slide seal 22 is formed by attaching a ring-shaped rubber 34 to a mounting plate 33, and the outer peripheral surface of the rubber 34 is formed with irregularities 35, and a scraper blade 36 Is attached so that when the slide seal 22 slides rearward, soil and the like adhering to the inner peripheral surface of the tail shield 16 can be scraped off. As shown in FIG. 7, the end face seal 23 has a ring shape with a cross-sectional shape including a thick base 37 and a pointed tip 38. When the end seal 23 is pressed against the end face 26 of the existing segment 25, the tip 38 is indicated by an imaginary line. To be deformed.

Next, the operation will be described. As shown in FIG. 8, when the new segment 40 is attached to the end surface 26 of the existing segment 25, the expansion / contraction type seal 20 is expanded and pressed against the outer peripheral surface of the existing segment 25 to stop water. New segment 4
When the mounting of the end segment seal 25 has been completed, the pressure ring 21 is moved backward, as shown in FIG.
10, the expansion / contraction type seal 20 is contracted to separate from the outer peripheral surface of the existing segment 25 as shown in FIG. , The tail shield 16 is advanced by the excavation stroke. At this time, since the expansion / contraction type seal 20 is separated from the outer peripheral surface of the existing segment 25, there is no breakage. The slide seal 22 slides along the inner peripheral surface of the tail shield 16, but the inner peripheral surface is not damaged because of its high surface accuracy. FIG.
As shown in FIG. 1, the expandable / contractible seal 20 is expanded and pressed against the outer peripheral surface of the existing segment 25, and the new segment 40 is carried inside and attached to the end surface of the existing segment 25.

[0007]

According to the present invention, when the new segment is attached, the expansion / contraction seal 20 is expanded to press against the outer peripheral surface of the existing segment 25 to stop the water, and the pressure of the expansion / contraction seal 20 is increased to withstand high water pressure. When the tail shield 16 is moved forward together with the tunnel excavator, the pressure ring 21 is moved rearward to press the end face seal 23 against the end face 26 of the existing segment 25, and the press contact portion and the slide seal 22 and the inner peripheral surface of the tail shield 16 are provided. At the pressure contact portion of the tail seal 16, and can be separated from the outer peripheral surface of the existing segment 25 by contracting the expandable / contractible seal 20, so that the slide seal 22 has good surface accuracy and the inner peripheral surface of the flat tail shield 16 has good surface accuracy. Since it comes into sliding contact with the surface, there is no early damage. 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 provided with the tail seal device of the present invention.

FIG. 5 is a cross-sectional view of the expansion and contraction type seal.

FIG. 6 is a sectional view of a slide seal.

FIG. 7 is a sectional view of an end face seal.

FIG. 8 is an operation explanatory diagram.

FIG. 9 is an operation explanatory diagram.

FIG. 10 is an operation explanatory diagram.

FIG. 11 is an operation explanatory diagram.

[Explanation of symbols]

16 tail shield, 20 expansion and contraction type seal, 21 pressure ring, 22 slide seal, 23 end face seal,
25 Existing segment, 26 End face.

Claims (1)

(57) [Claims] 1. A tubular tail shield 16 is provided at a rear portion of a tunnel excavator. An expansion / contraction type seal 20 is attached to a rear end portion of the tail shield 16. A pressure ring 21 is movable in the tail shield 16 back and forth. Characterized in that a slide seal 22 for pressing against the inner peripheral surface of the tail shield 16 and an end face seal 23 facing the end face 26 of the existing segment 25 are attached to the pressure ring 21. Sealing device.