JPS6124635Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tail seal device for a shield excavator, and particularly to a tail seal device for a shield excavator that is suitable for use when the water pressure is high.

Currently, infrastructure is being actively developed not only in large cities but also in small and medium-sized cities. Particularly in large cities, underground underground structures, which make up a large portion of infrastructure, are nearing saturation, and future expansion requires urban tunnels (for subways, water and sewage systems, power, communication lines, etc.) built deep underground. The development of a shield excavator that can cope with this situation is desired.

By the way, conventional tail seal devices for shield excavators are often equipped with two or three rows of rubber ring-shaped seal members to prevent groundwater from entering between the segments and the shield excavator.

However, in conventional tail seal devices of this type, the amount of water pressure is usually 0.5 to 2.0 kg/
^cm2 , and there are some decimal examples that can withstand up to 3.0Kg/ ^cm2 , but tail seal devices that can withstand water pressures of this magnitude are not suitable for tunnel excavation where underground depth increases and water pressure increases. I can't deal with it.

One possible way to deal with this is to apply pressure from inside the tail seal to counteract the high external pressure, but this is mechanically complex.

The present invention attempts to seal by utilizing the external pressure as it is, and by using the external pressure, that is, the water pressure, as the pressing force of the tail seal itself.

That is, a bag-shaped sealing member is provided on the inner peripheral surface of the skin plate of the shield excavator, and a hole communicating with the inside of the bag-shaped sealing member is formed in the skin plate. The bag-shaped seal member is made of an elastic material such as rubber, and the number of holes is within a range that does not pose a problem in terms of the strength of the skin plate. Also, a sandproof net or filter membrane is placed inside the skin plate to prevent dirt from entering. External pressure is introduced into the inside of the bag-shaped seal member through the hole formed in the skin plate, and sealing is achieved by this external pressure, that is, the water pressure, and the pressing force of the tail seal itself.

Furthermore, if the tail clearance is reduced, the internal water flowing in due to the pressing force from the segment will flow out, so the holes in the skin plate will not become clogged. In addition, in the case of several stages of tail seals, high pressure is directly applied to the one closest to the front, so it is likely to be damaged, but this can be overcome by making it convertible.

1 and 2 show an embodiment of the present invention,
In Figure 1, 1 is the shield excavator main body, 2 is the skin plate of the shield excavator, 3 is the shield jack, 4 is the segment, and the skin plate 2
A tail seal device is provided between the rear end of the segment 4 and the tip of the segment 4.

FIG. 2 shows the details of the skin plate 20.
An elastic bag-shaped seal member 5 is removably attached to the inner circumferential surface with bolts 6. In the illustrated example, the bag-shaped seal members 5 are provided in three stages, and the side where the seal members 5 come into contact with the segments 4 is thinned 5a so as to come into close contact with the segments 4. The skin plate 2 is provided with a hole 7 that communicates with the interior of the bag-shaped seal member 5. The number of holes 7 is determined by the skin plate 2 as described above.
This should be within a range that does not pose a problem in terms of strength. An anti-sand net or a filter membrane 8 is placed inside the skin plate 2 to prevent dirt from entering. A dust seal 9 is attached to the end of the skin plate 2.
is attached.

As such, external pressure is introduced into the inside of the bag-shaped sealing member 5 through the hole 7 formed in the skin plate 2, and sealing is achieved by this external pressure, that is, the water pressure and the pressing force of the tail seal itself. The higher the pressure, the stronger the pressing force against the segments 4, and the better the seal. Further, no pressurizing device such as a pressurizing pump is required.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic vertical sectional view of a shield excavator equipped with a tail seal device of the present invention. FIG. 2 is a detailed longitudinal sectional view of the tail seal device portion. 2...Skin plate, 4...Segment, 5
... Bag-shaped seal member, 7 ... Hole, 8 ... Sand prevention net, 9 ... Dust seal.

Claims (1)

[Claims for Utility Model Registration] (1) An elastic bag-like seal member is provided on the inner peripheral surface of the skin plate of a shield excavator, and a hole is formed in the skin plate that communicates with the inside of the bag-like seal member. A tail seal device for a shield excavator, characterized in that external pressure is introduced into a bag-shaped seal member through a hole, and a seal is created between a segment and a skin plate using this external pressure and the pressing force of the bag-shaped seal member itself. (2) A tail seal device for a shield excavator according to claim 1, which is characterized by comprising a bag-shaped seal member whose side that contacts the segment is thinned.