JP7092569B2 - Tail seal structure of shield excavator - Google Patents

Description

The present invention relates to a tail seal structure of a shield excavator.

There is a shield excavator that assembles a segment ring by digging while assembling the segment into a cylindrical wall inside the body.
From the annular gap between the inner peripheral surface of the skin plate on the body of the shield excavator and the outer peripheral surface of the segment, the earth and sand or water of the ground, or the back filled between the outer peripheral surface of the segment and the ground. A tail seal that closes the gap is provided on the inner peripheral surface of the skin plate to prevent the filling material from entering the inside of the body.
Conventionally, a tail seal is composed of a wire brush composed of a large number of wires and grease (shielded putty grease) filled between the large number of wires.
However, since such grease has fluidity, it gradually flows out from the wire brush as the shield excavator digs, so that the sealing property deteriorates or the grease flows out. There is a disadvantage that the sealing property is further deteriorated because the backfill material invades into the generated gap of the wire brush and solidifies.

Therefore, Patent Document 1 discloses a technique of filling a foamed resin such as urethane foam between a large number of wires instead of grease.
According to this technique, the foamed resin does not flow out like grease, which is advantageous in maintaining the sealing property.

Patent No. 3158019

However, in the above-mentioned conventional technique, the foamed resin is easily damaged and its volume decreases with use.
In addition, since the gas (air) in the foamed resin is released by applying stress, it becomes difficult to restore the original shape with use.
Therefore, the durability of the tail seal is low, and there is room for improvement in maintaining the sealing property for a long period of time.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a tail seal structure of a shield excavator which is advantageous for maintaining a sealing property for a long period of time.

In order to achieve the above object, the present invention has a front body portion provided with a cutter for excavating the ground at the front end thereof, and a rear body portion flexibly coupled to the rear end of the front body portion. The outer circumference of the segment ring assembled inside the body is provided with a body, and a plurality of tail seals are provided on the inner peripheral surface of the rear end of the rear body at intervals in the axial direction of the rear body. A shield excavator in which the annular gap between the surface and the inner peripheral surface of the rear end is closed by the tail seal, and between the tail seals adjacent to each other in the axial direction of the rear body portion. An annular and hollow elastic body formed of an elastic material, which is in contact with the outer peripheral surface of the segment ring and the inner peripheral surface of the rear end and extends all around the circumferential direction and is filled with an incompressible fluid. The tail seal is provided so as to extend from the inner peripheral surface of the rear end in a direction intersecting the axial center of the body portion, and the tip portion thereof comes into contact with the outer peripheral surface of the segment ring to contact the outer peripheral surface of the segment ring. It has a brush portion that can tilt in response to the expansion and contraction of the gap between the inner peripheral surface of the rear end, and the radial shape of the segment ring of the elastic body is the outer peripheral surface of the segment ring and the rear surface. The shape of the segment ring, which is constrained by the inner peripheral surface of the end and along the axial direction of the segment ring, is constrained by the brush portion of the tail seal adjacent to each other in the axial direction of the rear body portion, and the shield excavator is dug. The direction is curved and the axes of the front body portion and the rear body portion are displaced, and the size of the gap between the inner peripheral surface of the rear end and the outer peripheral surface of the segment ring is one side in the radial direction of the segment ring. The elastic body is in constant contact with the outer peripheral surface of the segment ring, the inner peripheral surface of the rear end, and the brush portion of the adjacent tail seal, even when the elastic body is enlarged in the above direction and reduced in the portion on the opposite side thereof. It is characterized by that.

According to the present invention, between the tail seals adjacent to each other in the axial direction of the body portion, the outer peripheral surface of the segment ring and the inner peripheral surface of the rear end of the segment ring are elastically contacted and extended all around the circumferential direction. An existing annular and hollow elastic body is provided.
Therefore, it is no longer necessary to fill the wire portion of the tail seal with grease or foamed resin as in the conventional case, the sealing property is not deteriorated due to the outflow of grease, and the inner peripheral surface of the rear end of the body portion and the outer peripheral surface of the segment are eliminated for a long period of time. It is advantageous in maintaining the sealing property between the and, and is advantageous in preventing the intrusion of earth and sand, water, or the backfill material into the inside of the body.

It is explanatory drawing of the shield excavator which concerns on embodiment. It is sectional drawing of the elastic body of the tail seal structure of the shield excavator which concerns on embodiment. It is sectional drawing which shows the tail seal structure of the shield excavator which concerns on embodiment, and shows the state where the axis of the front body part and the axis of the rear body part coincide with each other. It is sectional drawing which shows the tail seal structure of the shield excavator which concerns on embodiment, and shows the state which the axis of the front body part and the axis of the rear body part are deviated from each other.

Next, an embodiment of the present invention will be described with reference to the drawings.
First, the shield excavator will be described.
As shown in FIG. 1, the body of the shield excavator 10 includes a front body 12, a rear body (tail) 14 flexibly coupled to the rear end of the front body 12, and a rear portion (not shown). The front body portion 12 includes an excavation portion 16 and a rear chamber 18 provided behind the excavation portion 16.

The front body portion 12 includes a cylindrical front skin plate 1202, and the excavation portion 16 includes a disk-shaped cutter 1602 provided at the front portion of the front skin plate 1202.
The cutter 1602 is configured to excavate the ground by rotating around an axis parallel to the excavation direction.
A conveyor device (earth removal device), a jack device, and the like (not shown) are arranged in the rear chamber 18 behind the cutter 1602 inside the front skin plate 1202.
The conveyor device is configured to carry the earth and sand discharged by excavation of the ground by the cutter 1602 to the rear.
The jack device propels the cutter 1602 and the conveyor device in the excavation direction by pressing the end face portion of the segment 22 assembled in the shape of a cylindrical wall into the excavation hole 20 excavated by the cutter 1602 toward the rear in the excavation direction. It is configured in.

The rear body portion 14 includes a cylindrical rear skin plate 1402, and the rear skin plate 1402 has a cylindrical shape, and has an outer peripheral surface 1404 facing the inner wall 2002 of the drilling hole 20 and a segment facing the outer peripheral surface 1404, which will be described later. It has an inner peripheral surface 1406 facing the outer peripheral surface 2102 of the ring 21.
A rear end inner peripheral surface 1406A having a larger inner diameter than other places is provided at the rear portion of the inner peripheral surface 1406 of the rear skin plate 1402, and a tail seal 24 is provided on the rear end inner peripheral surface 1406A.
The plurality of segments 22 are assembled into a cylindrical wall-shaped segment ring 21 within the rear body portion 14.
The segment ring 21 assembled in a cylindrical wall shape has a cylindrical outer peripheral surface 2102 facing the inner wall 2002 of the excavation hole 20 and a cylindrical inner peripheral surface 2104 located inside the segment ring 21. ing.

Next, the tail seal 24 will be described.
A plurality of tail seals 24 are provided on the inner peripheral surface 1406A of the rear end of the rear body portion 14 at intervals in the axial direction of the rear body portion 14, and two tail seals 24 are provided in the present embodiment.
The tail seal 24 closes the annular gap between the outer peripheral surface 2202 of the segment ring 21 assembled inside the rear body portion 14 and the rear end inner peripheral surface 1406A.
The tail seal 24 is composed of a large number of wires, and the tail seal 24 includes a mounting portion 2402 and a brush portion 2404.
The mounting portion 2402 is a place where a large number of wires are attached to the rear end inner peripheral surface 1406A of the rear skin plate 1402 via bolts and nuts, and extends in a cylindrical shape all around the rear end inner peripheral surface 1406A in the circumferential direction. It exists.
The brush portion 2404 extends from the mounting portion 2402 attached to the rear end inner peripheral surface 1406A in a direction in which a large number of wires intersect the axial center of the segment ring 21, and the tip thereof extends all around the outer peripheral surface 2102 of the segment ring 21. Contact.

Between the tail seals 24 adjacent to each other in the axial direction of the rear body portion 14, the outer peripheral surface 2102 of the segment ring 21 and the inner peripheral surface 1406A of the rear end are in contact with each other and extend all around them in the circumferential direction. An existing annular and hollow elastic body 26 is provided.
As the elastic material constituting such an elastic body 26, various conventionally known materials such as rubber and silicon can be used.
In the present embodiment, the incompressible fluid 28 is filled inside the elastic body 26.
As the incompressible fluid 28, various conventionally known incompressible fluids such as water, oil, and grease can be used.
In the present embodiment, water 28 is used as the incompressible fluid 28, and when water 28 is used as the incompressible fluid 28, it is not necessary to form the elastic body 26 with an expensive material having oil resistance. Therefore, it is advantageous in reducing the cost.
The elastic body 26 has, for example, a cylindrical cross section.
In the present embodiment, as shown in FIG. 2, in the elastic body 26, one elongated elastic plate having a constant width is wound in a circle in the width direction, and both ends of the elastic plate in the width direction are overlapped as flanges 2602. It is configured by being joined together.
Then, the entire circumference of the elastic body 26 is rearranged by screwing bolts B inserted at a plurality of locations spaced in the circumferential direction over the entire circumference of the overlapped flanges 2602 into a plurality of female threads on the inner peripheral surface 1406A of the rear end. It is immovably attached to the inner peripheral surface of the end 1406A in the axial direction of the body.
The fluid supply port 27 is provided at a location near the elastic body 26 near the flange 2602, that is, at a location near the location where the elastic body 26 is attached to the inner peripheral surface 1406A at the rear end, and the fluid supply port 27 has the elasticity of water 28. A one-way valve 2702 that enables filling inside the body 26 is provided.

As shown in FIG. 1, a fluid supply path 30 for filling water 28 is provided inside the elastic body 26.
The fluid supply path 30 includes a water tank 32, a pump 34, and a flow path 36 arranged inside the rear body portion 14.
The flow path 36 includes a flow passage 3602 provided inside the wall portion of the rear skin plate 1402 constituting the rear body portion 14, and a pipe 3604 connecting one end of the flow passage 3602 and the pump 34. Has been done.
The other end of the flow passage 3602 is opened to the inner peripheral surface 1406A at the rear end, and the fluid supply port 27 of the elastic body 26 is connected to this opening.
Therefore, by driving the pump 34, the water 28 in the water tank 32 is supplied to the fluid supply port 27 from the inside of the rear body portion 14 via the flow path 36, and is filled inside the elastic body 26.

The radial shape of the segment ring 21 of the elastic body 26 is constrained by the outer peripheral surface 2102 of the segment ring 21 and the rear end inner peripheral surface 1406A, and the shape along the axial direction of the segment ring 21 is the rear body portion. It is constrained by the brush portions 2404 of the tail seals 24 adjacent to each other in the axial direction of 14.

Next, the operation and effect of the tail seal structure of the shield excavator 10 will be described.
A plurality of tail seals 24 are provided in advance over the entire circumference of the rear end inner peripheral surface 1406A of the rear skin plate 1402 in the circumferential direction and at intervals in the axial direction of the rear body portion 14.
The elastic body 26 is attached between the adjacent tail seals 24, but the inside of the elastic body 26 is not yet filled with water 28.

The ground is dug by the shield excavator 10, several segment rings 21 are assembled, and the elastic body 26 is between the inner peripheral surface 1406A at the rear end of the rear skin plate 1402 and the outer peripheral surface 2102 of the segment ring 21. When the position is reached, the elastic body 26 is filled with water 28 via the fluid supply path 30, and the pressure (water pressure) of the water 28 filled inside the elastic body 26 is measured by the pressure gauge 38. ..
The pressure of the water 28 to be filled in the elastic body 26 is, for example, about 0.05 to 0.1 MPa, and is filled between the earth and sand or water of the ground or between the outer peripheral surface 2102 of the segment ring 21 and the ground. It is preferable that the pressure is sufficient to withstand the backfill material.
By filling the elastic body 26 with water 28 in this way, the elastic body is formed between the adjacent tail seals 24 with respect to both the rear end inner peripheral surface 1406A of the rear skin plate 1402 and the outer peripheral surface 2102 of the segment ring 21. By the 26s in close contact with each other and closing the gap, it is possible to prevent the earth and sand and water of the ground or the backfilling material from invading the inside of the rear body portion 14.
Further, in the process of excavation of the shield excavator 10, when the excavation direction is linear, the axes of the front body portion 12 and the rear body portion 14 are substantially aligned with each other. The size of the gap between the inner peripheral surface 1406A at the rear end of the skin plate 1402 and the outer peripheral surface 2102 of the segment ring 21 is substantially uniform over the circumferential direction.
On the other hand, when the digging direction is curved, the axial centers of the front body portion 12 and the rear body portion 14 are deviated. Therefore, as shown in FIG. 4, the rear end inner peripheral surface 1406A and the segment ring of the rear skin plate 1402 are used. The size of the gap between the outer peripheral surface 2102 of 21 and the outer peripheral surface 2102 is not uniform over the circumferential direction, the gap expands on one side in the radial direction, and the gap shrinks on the opposite side.
In this case, since one side of the elastic body 26 in the radial direction is compressed, the water 28 moves instantaneously toward the opposite side in the radial direction of the elastic body 26. That is, since the water 28 is an incompressible fluid, it moves rapidly without changing its volume.
Therefore, regardless of the fluctuation of the gap between the rear end inner peripheral surface 1406A of the rear skin plate 1402 and the outer peripheral surface 2102 of the segment ring 21, the gap is always closed by the elastic body 26 over the entire circumference thereof.
Therefore, it is possible to prevent the earth and sand and water of the ground or the backfill material from invading the inside of the rear body portion 14.

According to the present embodiment, the elastic body 26 follows the fluctuation of the gap between the rear end inner peripheral surface 1406A of the rear skin plate 1402 and the outer peripheral surface 2102 of the segment ring 21 between the adjacent tail seals 24. However, the elastic body 26 is always in close contact with both the rear end inner peripheral surface 1406A of the rear skin plate 1402 and the outer peripheral surface 2102 of the segment ring 21.
Therefore, it is no longer necessary to fill the wire portion 2404 of the tail seal 24 with grease or foamed resin as in the conventional case, the sealing property is not deteriorated due to the outflow of grease, and the rear end inner peripheral surface 1406A of the rear skin plate 1402 is eliminated. It is advantageous in maintaining the sealing property between the segment ring 21 and the outer peripheral surface 2102, and prevents the earth and sand or water of the ground or the backfilling material from invading the inside of the rear body portion 14.

In the present embodiment, the case where the incompressible water 28 is used as the fluid 28 to be filled in the elastic body 26 has been described, but a gas such as air may be used as the fluid 28.
However, since the volume of the gas changes according to the pressure, the incompressible fluid 28 has the effect of ensuring the adhesion between the rear end inner peripheral surface 1406A of the rear skin plate 1402 and the outer peripheral surface 2102 of the segment ring 21. It is lower than the case.
Therefore, when a gas is used, the pressure of the gas filled in the elastic body 26 is set to about 0.3 MPa, and the elastic body 26 is moved by the pressure of the gas to the rear end inner peripheral surface 1406A of the rear skin plate 1402 and the outer peripheral surface of the segment ring 21. It is preferable to make strong contact with 2102.

Further, in the present embodiment, the radial shape of the segment ring 21 of the elastic body 26 is constrained by the outer peripheral surface 2102 of the segment ring 21 and the rear end inner peripheral surface 1406A of the rear skin plate 1402, and the segment ring 21 The shape along the axial direction of the rear body portion 14 is constrained by the brush portions 2404 of the tail seals 24 adjacent to each other in the axial direction of the rear body portion 14.
Therefore, the elastic body 26 is securely held in the space between the rear end inner peripheral surface 1406A of the rear skin plate 1402, the outer peripheral surface 2102 of the segment ring 21, and the brush portion 2404 of the adjacent tail seal 24, and is shielded. With the excavation of the excavator 10, the elastic body 26 does not fall out from the shield excavator 10, and the sealing property between the rear end inner peripheral surface 1406A of the rear skin plate 1402 and the outer peripheral surface 2102 of the segment ring 21 is maintained for a long period of time. It is advantageous to maintain.

Further, in the present embodiment, since the portion of the elastic body 26 near the portion of the elastic body 26 that comes into contact with the rear end inner peripheral surface 1406A is attached to the rear end inner peripheral surface 1406A, the rear skin plate 1402 is provided for a long period of time. It is advantageous in maintaining the sealing property between the inner peripheral surface 1406A at the rear end and the outer peripheral surface 2102 of the segment ring 21.

Further, in the present embodiment, the location of the elastic body 26 in the vicinity of the portion where the elastic body 26 is attached to the inner peripheral surface 1406A at the rear end is unidirectionally enabled to fill the inside of the elastic body 26 with water 28. Since the fluid supply port 27 provided with the valve 2702 is provided, it is possible to suppress the force applied to the elastic body 26 during excavation from acting on the fluid supply port 27, prevent the water 28 from leaking from the elastic body 26, and lengthen the length. It is advantageous in maintaining the sealing property between the rear end inner peripheral surface 1406A and the outer peripheral surface 2102 of the segment ring 21 over a period of time.

Further, the opening of the rear end inner peripheral surface 1406A and the fluid supply port 27 may be connected by a rubber hose, but as in the present embodiment, the fluid supply port 27 is connected to the rear end inner peripheral surface 1406A. Directly coupling to the opening of the road 3602 is advantageous in reducing the number of parts, prevents water 28 from leaking from the elastic body 26, and forms the rear end inner peripheral surface 1406A of the rear skin plate 1402 for a long period of time. It is advantageous in maintaining the sealing property between the segment ring 21 and the outer peripheral surface 2102.

In the present embodiment, the case where the flow passage 3602 constituting the flow path 36 is provided inside the wall portion of the rear skin plate 1402 constituting the rear body portion 14 has been described, but the flow passage 3602 is rearward. It may be provided on the outer peripheral surface 1404 or the inner peripheral surface 1406 of the body portion 14.
Further, when three or more tail seals 24 are provided at intervals in the axial direction of the rear body portion 14, the elastic bodies 26 may be provided between the adjacent tail seals 24, or may be arbitrarily provided. It is optional, such as providing one between adjacent tail seals 24.

10 Shield excavator 12 Front body (body)
14 Rear torso (torso)
1406A Rear end inner peripheral surface 21 Segment ring 2102 Outer peripheral surface 24 Tail seal 26 Elastic body 27 Fluid supply port 2702 One-way valve 28 Water (fluid)
3602 flow passage

Claims (5)

It comprises a torso having a front torso provided at its front end with a cutter for excavating the ground and a rear torso flexibly coupled to the rear end of the anterior torso.
A plurality of tail seals are provided on the inner peripheral surface of the rear end of the rear body portion at intervals in the axial direction of the rear body portion.
A shield excavator in which the annular gap between the outer peripheral surface of the segment ring assembled inside the body and the inner peripheral surface of the rear end is closed by the tail seal.
It is formed of an elastic material between the tail seals adjacent to each other in the axial direction of the rear body portion, and extends all around the outer peripheral surface of the segment ring and the inner peripheral surface of the rear end while colliding with each other. An annular, hollow elastic body filled with an incompressible fluid is provided.
The tail seal extends from the inner peripheral surface of the rear end in a direction intersecting the axial center of the body portion, and the tip thereof contacts the outer peripheral surface of the segment ring to contact the outer peripheral surface of the segment ring and the inside of the rear end. It has a brush part that can be tilted according to the expansion and contraction of the gap between it and the peripheral surface.
The radial shape of the segment ring of the elastic body is constrained by the outer peripheral surface of the segment ring and the inner peripheral surface of the rear end, and the shape along the axial direction of the segment ring is the rear body portion. It is restrained by the brush portion of the tail seal adjacent to each other in the axial direction of the shield, and the excavation direction of the shield excavator is curved, and the axial centers of the front body portion and the rear body portion are displaced from each other to the inner peripheral surface of the rear end. Even if the size of the gap between the outer peripheral surface of the segment ring and the outer peripheral surface of the segment ring expands on one side in the radial direction of the segment ring and decreases on the other side thereof, the elastic body of the segment ring is formed. Always in contact with the outer peripheral surface, the inner peripheral surface of the rear end, and the brush portion of the adjacent tail seal.
The tail seal structure of the shield excavator is characterized by that. The incompressible fluid is water,
The tail seal structure of the shield excavator according to claim 1 . A portion near the portion where the elastic body comes into contact with the inner peripheral surface of the rear end is attached to the inner peripheral surface of the rear end.
The tail seal structure of the shield excavator according to claim 1 or 2 . A fluid supply port provided with a one-way valve capable of filling the inside of the elastic body with the fluid is provided at the location of the elastic body near the portion where the elastic body is attached to the inner peripheral surface of the rear end. Has been
The tail seal structure of the shield excavator according to claim 3 . The flow passage for supplying the fluid opens on the inner peripheral surface of the rear end, and the flow passage is opened.
The fluid supply port is coupled to the opening.
The tail seal structure of the shield excavator according to claim 4 .

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