JP2000328887A - Tail seal structure of shield machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable welding of a tail seal to easily and securely fix it by using a noncombustible sheet instead of combustible filter cloth to be caught by a wire brush when the tail seal is constituted of the wire brush. SOLUTION: A shield machine 10 is moved forward at the front end thereof while circularly excavating ground G and a segment 20 is assembled at the inner periphery of the rear end part and a backfill material 26 is charged between the segment 20 and the inner periphery of the excavation hole. The basal end part 28a of the tail seal 28 is fitted to the rear end of the shield machine 10 and the front end part 28b is brought into slidable contact with the outer periphery of the segment 20 to cut the backfill material off not to intrude in the shield machine 10. The tail seal 28 is chiefly constituted of a wire brush 30 and a noncombustible sheet 34 is put into the wire brush 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tail seal structure for a shield machine, and more particularly, to a tail seal having a main body formed of a wire brush for preventing leakage of a lubricant sealed inside. The present invention relates to a tail seal structure of a shield machine capable of using welding to attach a tail seal using a non-combustible sheet.

[0002]

2. Description of the Related Art A shield excavator advances while excavating an underground ground in a circular shape with a cutter disk provided at a front end thereof, and a segment at a rear end of a cylindrical skin plate connected to the rear of the cutter disk. While assembling in a ring shape, the gap between this segment and the inner periphery of the excavation hole is filled with a backfilling agent. And, when such a shield excavator is filled with a backfill, in order to prevent the backfill and groundwater or muddy water from entering the shield excavator through a gap between the cutter disc and the segment. A tail seal is attached to the rear end of the skin plate.

The above-mentioned tail seal is made of a brush or plate made of a piano wire, stainless steel, spring steel, filter cloth, rubber, resin, or the like, and is formed in a ring shape. At the same time, the front end is slid on the outer periphery of the segment. At this time, the segment is formed by joining arc-shaped blocks divided into a plurality of pieces in the circumferential direction and assembling into an annular shape. At this time, a stepped portion occurs at a joint portion due to an error in forming or assembling the arc-shaped block. In this case, in order to absorb the step and maintain the close contact, it is desirable to form the tail seal with a wire brush.

However, when the tail seal is formed of a wire brush as described above, the backfill agent easily penetrates from the brush portion. For this reason, in the related art, a plurality of tail seals are arranged in a plurality of rows in the front-rear direction at appropriate intervals, and a gelled lubricant such as grease is sealed between each of the tail seals to prevent the backfill agent from entering. Some are marked. Also, when the lubricant is sealed in this way,
In order to prevent the lubricant from leaking from the wire brush and to enhance the function of blocking the backfill from entering, the filter cloth is sandwiched between the wire brushes.

[0005]

However, in such a conventional tail seal structure of a shield machine,
Since the filter cloth sandwiched between the wire brushes constituting the tail seal is flammable, it is necessary to use a fixing method that does not involve heat generation as a means for attaching the tail seal to the skin plate. It has become. For this reason, it is necessary to tighten a large number of bolts arranged in the circumferential direction one by one to attach the tail seal, and it takes a lot of time for the attachment work, and the bolts are loosened during the operation of the shield machine. There was a problem that it could fall.

Accordingly, the present invention has been made in view of such a conventional problem, and when a tail seal is constituted by a wire brush, a non-combustible sheet is used instead of a combustible filter cloth sandwiched between the wire brushes. By using
An object of the present invention is to provide a tail seal structure of a shield machine that can be easily and reliably fixed by welding.

[0007]

In order to achieve the above object, a tail seal structure for a shield machine according to a first aspect of the present invention moves forward while excavating the ground and has a segment formed on an inner periphery of a rear end portion. In the shield machine where the backfilling agent is filled between the segment and the inner periphery of the excavation hole while assembling, the base end portion is attached to the rear end portion, and the front end portion slides on the segment outer periphery. An annular tail seal is provided, and a main body of the tail seal is formed of a wire brush, and a non-combustible sheet is sandwiched between the wire brushes.

According to this construction, the tail seal of the tail seal mainly composed of the wire brush has the base end portion attached to the rear end portion of the shield machine and the front end portion slides on the outer periphery of the segment. It closes the gap between the hole inner circumference and blocks the backfill agent, groundwater, muddy water and the like from entering the shield machine. At this time, since the tail seal is mainly composed of a wire brush, the tip portion moves while resiliently sliding on the outer periphery of the segment, so that the sealing property between the tail seal and the segment can be improved.

On the other hand, since the non-combustible sheet is sandwiched between the wire brushes, the hermeticity of the wire brush itself can be ensured. At this time, when the tail seal is attached to the shield machine, the non-combustible sheet sandwiched between the wire brushes can withstand high heat, so that the tail seal can be attached by welding. Therefore, by attaching the tail seal by welding in this manner, the work of attaching the tail seal is facilitated, and since the tail seal is integrated at the welded portion, the tail seal can be securely fixed. Can be eliminated.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of a tail seal structure of a shield machine according to the present invention.
FIG. 1 is a sectional view showing the entire structure of the shield machine, and FIG. 2 is an enlarged sectional view of a tail seal.

The basic structure of the tail seal structure of the shield machine according to the present invention is as follows. The ground G is excavated in a circular shape at the front end while moving forward, and the segment 20 is assembled on the inner periphery of the rear end. In the shield machine 10 in which the backfilling agent 26 is filled between the hole and the inner periphery of the excavation hole 24, the base end portion 28 a is attached to the rear end portion and the tip end portion 28 b slides on the outer periphery of the segment 20. An annular tail seal 28 is provided in contact with the main body of the tail seal 28, and a non-combustible sheet 34 is sandwiched between the wire brush 30.

FIG. 1 shows a shield machine 10 to which the tail seal structure of the present embodiment is applied. The shield machine 10 excavates an underground ground G while traveling leftward in FIG. Part is to be built.
At the front end (left end in the figure) of the shield machine 10, a cutter disk 12 for cutting the ground G is provided.
A cylindrical skin plate 14 is connected to the rear of the cutter disk 12. A compartment 18 for filling the excavated earth and sand is provided in the front part of the work space 16 inside the skin plate 14, and a drive device and a control device of the cutter disk 12 and a device for discharging the excavated earth and sand, which are not shown, are provided. Provided. An assembly facility for the segment 20 and a shield jack 22 are provided in a rear portion of the work space 16. The segment 20 is formed by assembling an arc-shaped block 20 a divided into a plurality of pieces in the circumferential direction into an annular shape, and the assembling is performed inside the rear portion of the skin plate 14.

Then, the shield jack 22 is pressed against the front end face of the segment 20, and the skin jack 14 is pushed out by extending the shield jack 22 to advance the cutter disk 12. by the way,
Since the segment 20 is assembled inside the skin plate 14, the outer periphery of the segment 20 and the excavation hole 2
4, a clearance δ is provided between the backing agent 26 and the backing agent 26 behind the skin plate 14.
And the segment 20 is fixed. For this reason, a tail seal 28 is provided at the rear end of the skin plate 14 in order to prevent the backfill agent 26 and groundwater or muddy water generated by excavation from entering the shield machine 10.

As shown in FIG. 2, the tail seal 28 has a wire brush 30 as a main body and is formed in an annular shape along the inside of the skin plate 14. The tail seal 28 has spring plates 32 disposed on both sides thereof. The wire brush 30 is attached between the spring plates 32 so as to form a plurality of layers with the wire mesh. Sheet 34 is sandwiched. The distal end of the wire brush 30 protrudes from the spring plates 32 on both sides, and a U-shaped bracket 36 is provided at the base end 28a of the tail seal 28, and the spring plate 32 is inserted into the U-shaped bracket 36. Further, the wire brush 30, the wire mesh, and the noncombustible sheet 34 are bundled and fixed.

The tail seal 28 is provided at the base end 2.
When the tail seal 28 is attached, the base end 28a is abutted against a guard ring 38 having a circular cross section fixed to the inside of the rear end of the skin plate 14 when the tail seal 28 is attached. The outer peripheral surface of the base end portion 28a is fixed to the inner peripheral surface of the skin plate 14 by welding. The distal end portion 28 b has a distal end portion of the wire brush 30 protruding from the spring plate 32, and the protruding wire brush 30 is slidably contacted with the outer periphery of the segment 20 with a resilient force. Furthermore, in the present embodiment, the tail seals 28 are arranged in two rows in the front-rear direction (there may be one row or three or more rows).
A gelled lubricant 40 such as grease is filled between 8, 28.

The non-combustible sheet 34 sandwiched between the wire brushes 30 is formed by knitting a material obtained by firing and carbonizing carbonized fiber or special acrylic fiber, a material obtained by embedding ceramic felt with carbon glass, A fiber and a glass fiber are mixed, and the fiber is finished in a felt shape and subjected to pure needle processing. The fiber is sufficiently durable even at a high temperature during welding.

With the above configuration, in the tail seal 28 of the shield machine according to the present embodiment, the shield machine 1
With the advance of zero, the back end of the skin plate 14 is sequentially filled with the backfill agent 26 between the segment 20 and the inner periphery of the excavation hole 24 while assembling the segment 20. When the backfill agent 26 is filled, the tail seal 28 mainly composed of the wire brush 30 is attached to the rear end of the shield machine, and the distal end 28b is attached to the segment 20. And slides against the outer periphery to close the gap δ between the segment 20 and the inner periphery of the excavation hole 24, and blocks the backfill agent 26 and groundwater or muddy water flowing out during excavation from entering the shield machine 10. .

At this time, since the tail seal 28 is mainly composed of the wire brush 30, the tip portion 28b moves while resiliently slidingly contacting the outer periphery of the segment 20, so that the space between the tail seal 28 and the segment 20 is formed. Hermeticity can be improved. Further, since the tail seals 28 are provided in two rows in the front-rear direction, and a lubricant 38 is filled between the tail seals 28, the lubricant 38 fills a gap between the steel wires of the wire brush 30, 3
Since the non-combustible sheet 34 is sandwiched between 0, the non-combustible sheet 34 can prevent the lubricant 38 from flowing out, and can further improve the airtightness.

By the way, as described above, the wire brush 30
A non-combustible sheet 34 is sandwiched between the non-combustible sheets 34. Since the non-combustible sheet 34 can withstand high heat, it can be fixed by welding when the tail seal 28 is attached to the skin plate 14. Therefore, by attaching the tail seal 28 by welding in this manner, the work of attaching the tail seal 28 is facilitated, and since the tail seal 28 is integrated at the welded portion, it can be securely fixed, and there is a possibility that the tail seal 28 may fall off during operation. Can be eliminated. Further, since the tail seal 28 has the guard ring 38 in front of the base end portion 28a, when rocks or the like protrude from the excavated surface,
The tail seal 28 can be protected by the guard ring 38.

[0020]

As described above, in the tail seal structure of the shield machine according to the present invention, a tail seal is constituted mainly by a wire brush, and a non-combustible sheet is provided on the wire brush in order to enhance hermeticity. When the tail seal is attached to the shield machine, the non-combustible sheet sandwiched between the wire brushes can withstand high heat, so that the tail seal can be attached by welding. Therefore, by attaching the tail seal by welding in this manner, the work of attaching the tail seal becomes easy, and the tail seal is integrated at the welded portion, so that it can be securely fixed, and the possibility of falling off during operation is eliminated. An excellent effect is achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an overall structure showing an embodiment of a shield machine according to the present invention.

FIG. 2 is an enlarged sectional view of a tail seal showing one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Shield machine 20 segment 24 excavation hole 26 backfill 28 tail seal 28a base end 28b tip 30 wire brush 34 nonflammable sheet G ground

Claims (1)

[Claims] 1. A shield excavator that advances while excavating the ground, assembles a segment on the inner periphery of a rear end portion, and fills a backfill agent between the segment and the inner periphery of the excavation hole. A base end is attached to the rear end, and a tail end is provided with an annular tail seal slidably contacting the outer periphery of the segment. The main body of the tail seal is constituted by a wire brush, and a non-combustible sheet is attached to the wire brush. The tail seal structure of the shield machine characterized by being sandwiched.