JPH06108777A - Seal device for intermediate fold part of shield excavator - Google Patents

Abstract

PURPOSE:To prevent a seal from projecting from a seal holder inside of a curve of an excavating line in a seal device for an intermediate fold part of a shield excavator, and to maintain the water tight function. CONSTITUTION:A lump-like resilient member 3 is charged in a space surrounded by a working face side end face of a seal holder 2A provided at the rear end of a shield front barrel 1A, for holding a seal 2, the inner surface of the seal front barrel 1A and a shield slide surface 1C of a shield rear barrel 1B so that the lump-like resilient member 3 is expandable in the shield-axial direction and the shield-radial direction. Further, a pressing mechanism (4, 5, 6, 7A, 7B, 8) for pressing the working face side end surface of the shield holder 2A positioned inside of the curve of the excavating line, and the seal slide surface 1C, against the lump-like resilient member 3, so as to adjust the contact surface pressure between the lump-like resilient member 3 and the seal slide surface 1C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device for a middle broken portion for preventing muddy water or earth and sand from entering the inside of the shield excavator through the middle broken portion.

[0002]

2. Description of the Related Art In a shield machine having a center bending function, as shown in FIG. 5, a shield front body 1A, which is the front half of a shield body 1, and a shield rear body 1B, which is the rear half, are connected to each other via a seal 2. A middle bent portion is formed so as to be slidable, and a seal 2 prevents muddy water and earth and sand from entering the machine through the middle bent portion. Conventionally, as shown in FIG. 6, this middle bent portion seal device has a seal holder 2A provided at the rear end of the shield front body 1A in which a plurality of seals 2 each having a bending margin Q are mounted in plural stages as necessary, and When the body 1A and the shield rear body 1B are folded in the middle, the seal 2 is indicated by an arrow A along the seal sliding surface 1C (formed on a spherical surface centered on one point on the shield axis) of the shield rear body 1B. It is usually configured to slide in the direction of arrow B and for preventing interference between the seal sliding surface 1C and the face end and the tail end of the seal holder 2A. A gap a and a gap b are provided.

[0003]

In the above-mentioned prior art, as shown in FIG. 7, when the shield front body 1A and the shield rear body 1B are folded in the middle, the curve outer side portion and the curve inner side portion of the excavation route are As shown in FIGS. 8 and 9, the gap a and the gap b between the seal sliding surface 1C and the seal holder 2A change. In particular, the gap a inside the curve is larger than that in the state where no bending is performed (FIG. 6). Therefore, the seal 2 on the face side (the left side in the drawing) of the seals 2 provided in a plurality of stages is the shield front body 1A and the seal holder 2
While A moves in the direction of arrow B with respect to the seal sliding surface 1C, it tries to jump out in the direction of arrow A through the gap a due to the sliding resistance received from the seal sliding surface 1C. In the prior art, since no means is provided to prevent the seal 2 from popping out in such a state of being bent, as shown in FIG. 9, the seal 2 pops out of the seal holder 2A through the gap a, and the water stoppage occurs. There was a risk that the performance could not be maintained.

An object of the present invention is to provide a device for sealing the middle broken portion of a shield machine, which is provided with a means effective for preventing the above-mentioned middle broken portion seal from protruding from the seal holder and maintaining the water stopping performance. To provide.

[0005]

In order to achieve the above object, the present invention provides a shield digging method in which a shield front body and a shield rear body are superposed so as to be slidable with each other through a seal to form a middle bent portion. In the device for sealing the broken part in the machine,
A massive elastic body is provided in the shield axial direction in a space provided at the rear end of the shield front body, which is surrounded by the end face of the seal holder for holding the seal, the inner surface of the shield front body, and the seal sliding surface of the shield rear body. And the shield is loaded so that it can expand and contract in the radial direction, and when the front shield and rear shield are bent in the middle, the block elastic end face and seal sliding face of the seal holder located inside the curve of the excavation route A pressing mechanism for pressing the body and adjusting the contact surface pressure of the bulk elastic body with the seal sliding surface is provided.

[0006]

[Function] When the front shield body and the rear shield body are folded in the middle, the pressing mechanism is operated to cause a massive elastic body on the face of the seal holder located inside the curve of the excavation route and the seal sliding surface of the rear shield body. Even if the gap between the face of the seal holder on the face side and the seal sliding surface on the inside of the curve is increased by pressing, the movement of the seal that tries to jump out from the seal holder through the gap is Blocked by the body. Also, by adjusting the contact surface pressure with the seal sliding surface of the massive elastic body by the pressing mechanism,
The water-blocking effect of the massive elastic body itself can also be obtained.

[0007]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a side cross-sectional view showing a state in which a center bent portion sealing device according to the present invention is not broken, and FIG. 2 is a section II of FIG.
-A cross-sectional view of the entire shield along the line II, and Fig. 3 is III of Fig. 1.
-III is a partial cross-sectional view taken along the line III, and FIG. 4 is a side cross-sectional view showing a state of intermediate bending at the inside of the curve of the intermediate-folding portion sealing device according to the present invention.

1 to 3, a shield front body 1A which is the front half of the shield body 1 and a shield rear body 1B which is the rear half of the shield body 1 are superposed with a seal 2 therebetween to form a middle bent portion. This is the same as the conventional example shown in FIGS. In this example, the seal 2 having the deflection margin Q is the shield front body 1
The seal holders 2A provided at the rear end of A are mounted at two positions on the face side and the tail side, and when the front shield body 1A and the rear shield body 1B are folded inward, each seal 2 is a spherical surface of the rear shield body 1B. It slides along the seal sliding surface 1C formed in the shape of a circle.

At this time, in order to prevent the seal 2 from jumping out of the seal holder 2A through the gap a between the seal sliding surface 1C and the seal holder 2A inside the curve of the excavation route, as shown in FIG. In the space surrounded by the face end on the face of the face, the inner surface of the shield front body 1A and the seal sliding surface 1C of the shield rear body 1B, a massive elastic body 3 such as rubber can be expanded and contracted in the shield axial direction and the shield radial direction. 1A of front shield and 1 rear shield
When B is bent in the middle, the block elastic body 3 is pressed against the face end surface of the seal holder 2A and the seal sliding surface 1C located inside the curve of the excavation line, and the seal sliding surface 1C of the block elastic body 3 is pressed. A pressing mechanism is provided for adjusting the contact surface pressure with.

In FIGS. 1 to 3, the massive elastic body 3 is divided into a plurality of pieces on the circumference, and they are arranged adjacent to each other without a gap. In the state where the shield front body 1A and the shield rear body 1B are not bent in the middle, the massive elastic body 3 is the seal sliding surface 1
There is no need to be in contact with C, and there may be a gap with the seal sliding surface 1C. As the pressing mechanism, the block elastic body 3 is used.
A plurality of pressing plates 4 in contact with the end face on the face of the blade are arranged on the circumference, and a pressing rod 5 extending in the shield axial direction through the rod holder 6 provided in the shield front body 1A and the center hole of the guide 8. An example is shown in which one end is attached to each pressing plate 4, and the pressing rod 5 is held by a nut 7A and a nut 7B that are attached to the threaded portion 5a at the other end of the pressing rod 5 with the rod holder 6 interposed therebetween.

An example of the operation of this device will be described with reference to FIG. When folding the front shield body 1A and the shield rear body 1B in the middle,
Inside the curve of the excavation route, as shown in FIG. 4, the shield front body 1A and the seal holder 2A move in the direction of arrow B with respect to the seal sliding surface 1C. Then, as the center bending angle between the front shield body 1A and the rear shield body 1B increases, the gap a between the face end of the seal holder 2A and the seal sliding surface 1C increases. Therefore, the seal 2 mounted on the face of the seal holder 2A tends to pop out in the direction of arrow A from the seal holder 2A through the gap a due to the sliding resistance received from the seal sliding surface 1C. In order to stop this movement, the massive elastic body loaded in the space formed by the face on the face side of the seal holder 2A, the inner surface of the front shield body 1A and the seal sliding surface 1C of the rear shield body 1B inside the curve of the excavation route. 3 is pressed in the direction of arrow C toward the end face of the seal holder 2A on the face side. The block elastic body 3 has its two surfaces constrained by the seal holder 2A and the shield front body 1A. Therefore, when pressed in the direction of arrow C, the block elastic body 3 contracts in the shield axial direction and extends in the shield radial direction by the amount of the other elastic body 3. The surface is pressed against the seal sliding surface 1C. As a result, even if the gap a between the seal holder 2A and the seal sliding surface 1C becomes large, it is possible to prevent the seal 2 from protruding from the gap a. To press the massive elastic body 3, loosen the nut 7A
This is done by rotating B to move the pressing rod 6 in the direction of arrow C, and after setting the center bending, tighten the nuts 7A and 7B to move the pressing rod 5 to a predetermined position according to the center bending angle. Hold it.

Similarly, by moving the pressing rod 5 and expanding and contracting the bulk elastic body 3, the contact surface pressure of the bulk elastic body 3 with the seal sliding surface 1C can be adjusted.

As the pressing mechanism, instead of the above-mentioned screw feed type, the pressing rod 5 is a hydraulic jack.
May be moved.

[0015]

As described above, according to the present invention, as the center bending angle of the shield front body and the shield rear body increases, the gap a between the face end of the seal holder and the seal sliding surface increases. In particular, by pushing the block-like elastic body against the end face of the seal holder and the sliding face of the seal, the seal can be prevented from jumping out of the gap a, and the waterproof performance of the seal can be maintained.

Further, by expanding and contracting the block elastic body to adjust the contact surface pressure with the sliding surface of the seal, the block elastic body itself has a water blocking effect and enhances the water blocking effect at the middle bent portion. You can

[Brief description of drawings]

FIG. 1 is a side cross-sectional view showing a state in which a center-folded portion sealing device according to the present invention is not center-folded.

FIG. 2 is an overall cross-sectional view of the shield taken along the line II-II of FIG.

FIG. 3 is a partial cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a side cross-sectional view showing a state of a center-folded portion inside the curved line of the center-folded portion sealing device according to the present invention.

FIG. 5 is a side cross-sectional view of the shield body in a state where the conventional shield is not folded.

6 is a detailed view of part A of FIG.

FIG. 7 is a side sectional view of a conventional shield main body in a state of being bent.

FIG. 8 is a detailed view of part A in FIG.

FIG. 9 is a detailed view of a portion of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... shield main body, 1A ... shield front body, 1B ... shield back body, 1C ... seal sliding surface, 2 ... seal, 2A ... seal holder, 3 ... block elastic body, 4 ... pressing plate, 5 ...
Pressing rod, 5a ... Threaded portion of rod 5, 6 ... Rod holder, 7A, 7B ... Nut, 8 ... Guide, a, b ... Gap.

Claims (1)

[Claims] 1. A rear end of a front shield body in a middle break portion sealing device of a shield machine, wherein a front shield body and a rear shield body are overlapped so as to be slidable with each other through a seal to form a middle bend portion. The elastic body expands and contracts in the shield axial direction and the shield radial direction in a space surrounded by the face of the seal holder that holds the seal, the end face of the seal holder, the inner surface of the front shield case, and the seal sliding surface of the rear shield case. When loading as much as possible, when folding the shield front body and the shield rear body in the middle, press the massive elastic body against the face end surface and the seal sliding surface of the seal holder located inside the curve of the excavation line, and A device for sealing a middle portion of a shield machine, comprising a pressing mechanism for adjusting a contact surface pressure of a massive elastic body with a seal sliding surface.