JP2930577B1 - Two-stage shield machine - Google Patents

Abstract

An object of the present invention is to enable a simple mechanism to support a load caused by soil pressure acting on a front end of an excavator when switching from a large-diameter shield excavation to a small-diameter shield excavation, thereby improving the switching work efficiency. A shield machine 1 includes a cutter disk 2 (including a disk body 3, an outer ring portion 4, and a coupling mechanism 20), a cutter driving mechanism 10, and a large-diameter body 5 (a large-diameter front body 6).
And the large-diameter rear body 7), the small-diameter front body 8, the plurality of shield jacks 11, the plurality of connection fittings 14 for connecting the large-diameter body 5 to the rear end of the small-diameter front body 8 and the small-diameter shield machine.
An outer ring bearing mechanism 13 for supporting a load caused by soil pressure acting on a front end of the excavator via an outer ring portion 4,
5 and an erector device 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-stage shield machine, and more particularly, to excavating shield tunnels for transmission lines and communication cables, shield tunnels for sewage systems, etc., following a large-diameter shield tunnel. The present invention relates to a two-stage shield machine capable of excavating a small-diameter shield shaft.

[0002]

2. Description of the Related Art In many cases, tunnel diameters of shield tunnels for sewerage and the like gradually increase from upstream to downstream. When constructing shield tunnels (tunnels) in which the tunnel diameter changes in this manner, conventionally, A shaft is provided at each point where the diameter of the tunnel changes, and a tunnel excavator having a diameter approximately equal to the diameter of the tunnel to be excavated is inserted from the shaft to excavate the tunnel. In this case, it is necessary to provide a shaft at each junction point of a tunnel having a different diameter, and the provision of the shaft requires a great deal of cost and labor. Moreover, in urban areas, it is often impossible to form shafts because they interfere with existing structures such as buildings, but in such cases, tunnel excavation is required to unify the tunnels to a larger diameter than necessary. Costs will increase.

Therefore, various two-stage shield machines capable of excavating a small-diameter tunnel following a large-diameter tunnel without using a shaft have been proposed. JP-A-3-59292
The shield excavator described in Japanese Patent Publication No.
Outer cylinder, inner cylinder, inner and outer cylinder fixing pins that connect the outer cylinder to the inner cylinder so that torque and force can be transmitted, cutter driving means, multiple shield jacks inside the outer cylinder, multiple shield jacks inside the inner cylinder, etc. The cutter spoke of the cutter disk is provided with a telescopic piece for excavating the outer periphery of the large-diameter shield well. When switching to the excavation of a small-diameter shield pit, shrink the expansion and contraction pieces, install a reaction force receiver on the reinforced segment, and apply a reaction force to the reaction force receiver and the segment built inside the inner cylinder, and shield the inner cylinder The jack can generate the excavating thrust, remove the inner and outer cylinder fixing pins, and operate the shield excavator for small diameter shield.

In the two-stage shield machine described in JP-A-5-10086, a small-diameter shield machine is installed inside a large-diameter trunk member, and a plurality of shield jacks are provided inside the small-diameter shield machine. When excavating the diameter shield,
Each shield jack generates a digging thrust while applying a reaction force to the large-diameter segment via the transmission stand. When switching to the small-diameter shield, disconnect the large-diameter trunk member and the small-diameter trunk member, cut off the outer ring on the outer peripheral side of the cutter disk,
The small-diameter segment is lined in a stepped manner at the front end of the large-diameter segment. When the small-diameter shield is excavated, a reaction force is applied to the small-diameter segment with a shield jack without using a transmission stand, so that the excavation thrust can be generated.

[0005] Japanese Patent Application Laid-Open No. Hei 7-145699 describes
The step-type shield excavator is a small-diameter shield cutter disk, an annular cutter disk on its outer peripheral side, a large-diameter fuselage (skin plate), a small-diameter fuselage, and an annular disk-shaped fixing for fixing the large-diameter fuselage to the rear end of the small-diameter fuselage. It has a member, a shield jack inside the large-diameter fuselage, a shield jack inside the small-diameter fuselage, and the like.

[0006]

[Problems to be Solved by the Invention]
The shield excavator disclosed in Japanese Patent Publication No. 2 is configured to transmit torque and force between the outer cylinder and the inner cylinder by the inner and outer cylinder fixing pins. It is necessary to provide a plurality (for example, about eight) of the inner and outer cylinder fixing pins, and it is necessary to provide a plurality of the inner and outer cylinder fixing pins so that all of the plurality of inner and outer cylinder fixing pins operate in unison. It is difficult in terms of processing accuracy, and the production cost is high.

In the shield machine described in Japanese Patent Application Laid-Open No. Hei 5-10086, a plurality of shield jacks inside the small-diameter shield machine generate excavation thrust even when a large-diameter shield machine is excavated. No measures are taken to support the cutter disc on which soil pressure acts so that it does not recede when switching from a small shield to a small diameter shield. Further, when switching to the small-diameter shield, when the outer ring portion of the cutter disk is divided, there is no means for supporting the outer ring portion, so that the outer ring portion may fall and interfere with the small-diameter shield cutter disk.

In the shield machine described in Japanese Patent Application Laid-Open No. 7-145699, a driving means for rotating and driving a small-diameter shielding cutter disk, and a driving means for rotating and driving an annular cutter disk on the outer peripheral side of the small-diameter shielding cutter disk. Are provided independently of each other, which complicates the configuration and increases the production cost. SUMMARY OF THE INVENTION It is an object of the present invention to provide a two-stage shield machine capable of supporting a load caused by soil pressure acting on a front end portion of a shield machine when switching from a large-diameter shield to a small-diameter shield with a simple mechanism. The purpose is to be able to regulate the position of the outer ring portion of the disk, and to increase the work efficiency when switching to the small diameter shield.

[0009]

A two-stage shield machine according to claim 1, further comprising a cutter disk, a large-diameter body, a small-diameter front body concentrically located inside a front portion of the large-diameter body, and a cutter. A two-stage shield excavator comprising a cutter drive mechanism for rotating and driving a disk, and a plurality of shield jacks for applying excavation thrust to the large-diameter fuselage, and capable of excavating a small-diameter shield pit following a large-diameter shield pit, The cutter disk has a disk body located on the front side of the small-diameter front body, an outer ring portion located separately from the disk body and located on the outer peripheral side thereof, and the disk body connected to the outer ring portion so as to be able to transmit force and to be separable. A coupling mechanism, and provided with a plurality of connection fittings for releasably connecting the large-diameter body to the rear end of the small-diameter front body in order to transmit the excavating thrust acting on the large-diameter body to the small-diameter front body, Of the large-diameter fuselage A bearing capable of outer ring support mechanism outer ring portion against the soil pressure acting on the cutter disc and a small-diameter front cylinder to the inner surface near the portion near the front end portion, after the rear of the outer ring portion
One or more grooves formed in the shape of an end opening, a large-diameter body and a small
The outer ring part is engaged from the groove provided between
Multiple pin members that can be supported, between the large-diameter body and the small-diameter front body
A plurality of pins for driving a plurality of pin members provided in the front-rear direction.
And an outer ring bearing mechanism provided with the hydraulic cylinder described above.

In a state where the large-diameter shield shaft is dug, the disk body of the cutter disk and the outer ring portion are connected by a connecting mechanism, and the cutter disk is rotated by the cutter driving mechanism. Excavation thrust generated by the plurality of shield jacks is transmitted to the large-diameter fuselage, transmitted from the large-diameter fuselage to the small-diameter front body via a plurality of connection fittings, and the large-diameter shield pit is excavated. A segment is attached to the inner surface of the large shield tunnel.

When switching to a state in which the small-diameter shield pit is excavated following the large-diameter shield pit, the outer ring portion is supported by the outer ring support mechanism, and the load caused by the soil water pressure acting on the cutter disk and the small-diameter front body is reduced. The outer ring part, outer ring bearing mechanism, and large-diameter fuselage are used to support the inner diameter segment of the large-diameter shield pit, so that the load does not act on the small-diameter front body. The body and the small-diameter front body are separated from each other, and the plurality of shield jacks provided on the inner surface of the small-diameter front body take a reaction force on the segment to generate a digging thrust. Then, the coupling mechanism of the cutter disk is released. In this state, when the cutter disk is rotationally driven by the cutter driving mechanism and excavation thrust is generated by the plurality of shield jacks on the inner surface of the small-diameter front body, the small-diameter shield well can be excavated. Outer ring
A bearing mechanism is formed at the rear portion of the outer ring portion in the shape of a rear end opening.
Are a plurality of grooves, the grooves provided between the large-diameter body and the small-diameter front body.
A plurality of pin members capable of supporting the outer ring portion from behind by engaging with
And a plurality of pin members provided between the large-diameter body and the small-diameter front body.
With multiple hydraulic cylinders for driving in the front-back direction
Because of the configuration, when operating the outer ring bearing mechanism,
Regardless of the rotation phase of the cutter disk,
The fitting member is securely fitted into the one or more grooves.
No need to adjust the rotation phase of the cutter disk.
No.

According to a second aspect of the present invention, in the two-stage shield excavator according to the first aspect of the present invention, during excavation of the large-diameter shield tunnel, the excavation thrust by the shield jack is reduced from the large-diameter body to the small-diameter front via the connection fitting. It is characterized by transmitting to the torso. During excavation of the large-diameter shield tunnel, most of the load due to the soil pressure acting on the front end of the shield excavator acts on the small-diameter front body. Therefore, the excavating thrust generated by the shield jack is transmitted from the large-diameter body to the small-diameter front body via a plurality of connection fittings.

The two-stage shield excavator according to the third aspect of the present invention acts on the cutter disk and the small-diameter front body when switching from excavation of the large-diameter shield tunnel to excavation of the small-diameter shield tunnel in the invention of the first or second aspect. The load caused by the soil water pressure is supported via an outer ring support mechanism. As described in the section of claim 1, since the load caused by the soil water pressure can be supported by the large-diameter body or the inner surface segment of the large-diameter shield pit or the like via the outer ring bearing mechanism, the load is transmitted to the small-diameter front body. Since there is no need to support the connection jacks, it is possible to easily disassemble a plurality of connection fittings and mount a shield jack near the inner surface of the small-diameter front body.

According to a fourth aspect of the present invention, there is provided a two-stage shield machine according to any one of the first to third aspects, wherein the cutter drive mechanism is provided inside a small-diameter front body. is there. If the disk main body and the outer ring are connected by a connecting mechanism, the entire cutter disk can be rotationally driven by the cutter driving mechanism.

According to a second aspect of the present invention, in the two-stage shield machine according to any one of the first to fourth aspects, the connection mechanism is connected via a plurality of radially oriented pin members of the shield shaft. It is characterized by having such a configuration. Therefore, the coupling mechanism can transmit torque and force between the disk body and the outer ring portion.

According to a sixth aspect of the present invention, in the two-stage shield machine according to any one of the first to fifth aspects, the outer ring support mechanism has a function of restricting the outer ring portion from moving in the radial direction. It is characterized by the following. When the disk main body and the outer ring portion are separated during excavation of the small-diameter shield shaft, the outer ring portion may move in a radial direction (for example, downward) and interfere with the disk main body. Since it has a function to regulate so that it does not move in the direction,
There is no interference between the outer ring and the disk body.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. The two-stage shield excavator 1 according to the present embodiment can excavate a small-diameter shield tunnel following a large-diameter shield tunnel, and FIG. 1 is a longitudinal sectional side view of the two-stage shield excavator 1. Hereinafter, the front, rear, left and right in the excavation direction will be described as front, rear, left and right. As shown in FIG. 1, this two-stage shield excavator 1 (hereinafter referred to as a shield excavator at an end) includes a cutter disk 2, a large-diameter body 5, a small-diameter front body 8, and an inside of the small-diameter front body 8. , A cutter driving mechanism 10 for rotatingly driving the cutter disk 2, a plurality of shield jacks 11 for a large-diameter shield, and a plurality of shield jacks 12 for a small-diameter shield.
, An outer ring bearing mechanism 13, a plurality of connection fittings 14, a sludge exhaust system 15, an erector device 16, and the like.

The cutter disk 2 includes a disk main body 3 corresponding to the front side of the small-diameter front body 8, an outer ring portion 4 that is separate from the disk main body 3 and located on the outer peripheral side of the disk main body 3,
And a coupling mechanism (20) for coupling the disk body (3) and the outer race (4) so that torque and force can be transmitted and separable. The cutter disk 2 is rotatably supported by a partition 9 a of the main body frame 9. The coupling mechanism 20 includes a hydraulic cylinder 21 mounted in each cutter spoke, and a radially oriented pin member 2 integrally formed at the tip of the cylinder body.
The piston rod 23 of the hydraulic cylinder 21 is connected to the disk main body 3, and the pin member 22 is configured to be freely disengageable from the engagement hole 24 of the outer race 4 by the hydraulic cylinder 21.

When excavating a large-diameter shield tunnel, the disc body 3 and the outer ring section 4 are held in a connected state by the connecting mechanism 20. When excavating a small-diameter shield tunnel, the disc body 3 and the outer ring section 4 are connected to each other. Is cut off, and excavation is performed only with the disk body 3. An annular groove 25 for engaging a plurality of flanged pins 31 of the outer ring support mechanism 13 is formed on the rear end surface of the outer ring portion 4. The cutter drive mechanism 10 has a plurality of cutter drive motors 10a mounted on the partition 9a, and the cutter drive motor 10a allows the cutter disk 2
Are driven forward and reverse. A hydraulic supply system swivel joint 17 is also provided.

The large-diameter body 5 has a large-diameter front body 6 and a large-diameter rear body 7 (having the same diameter as the large-diameter front body 6) which is concentrically and integrally connected to the rear end and extends rearward. Consists of By bolt-joining the ring web 6a at the rear end of the large-diameter front barrel 6 and the ring web 7a at the front end of the large-diameter rear barrel 7, the large-diameter front barrel 6 and the large-diameter rear barrel 7 are integrally connected. ing. Small diameter front trunk 8
Are arranged concentrically inside the large-diameter front body 6 with a smaller diameter than the large-diameter front body 6, and a ring web 8 a at the rear end of the small-diameter front body 8 is a ring web 7 a at the front end of the large-diameter rear body 7. And the same plane. An annular frame 9b having a groove-shaped cross section is welded to the inner surface near the front end of the large-diameter front body 6, and the annular frame 9b
The partition 9a of the main body frame 9 is provided inside the small-diameter front body 8 at a position corresponding to the inside of the small-diameter front body 8, the partition 9a is welded to the small-diameter front body 8, and a chamber 18 is provided between the cutter disk 2 and the partition 9a. Is formed.

A plurality of shield jacks 11 arranged near the inner surface of the large-diameter front barrel 6 are arranged at appropriate intervals in the circumferential direction and with the piston rods facing rearward. Part is ring web 6
The spreader 26 is fixed to the hemispherical convex portion at the tip of the piston of each shield jack 11 loosely and pin-connected. When excavating a large diameter shield shaft,
These shield jacks 11 generate a digging thrust by taking a reaction force at the front end of the segment 27 lining the inner surface of the large-diameter shield shaft T.

A plurality of shield jacks 12 arranged near the inner surface of the small-diameter front body 8 are arranged at appropriate intervals in the circumferential direction and with the piston rods facing rearward. Is ring web 8
The spreader 28 is loosely pin-connected to the hemispherical convex portion at the tip of the piston of each shield jack 12. When excavating a small-diameter shield tunnel, these shield jacks 12 are used to reduce a small-diameter shield tunnel Ta (FIG. 2).
(See FIG. 2), a reaction force is applied to the front end of the segment 29 lining the inner surface to generate a digging thrust.

At the time of excavating the large-diameter shield shaft T, the large-diameter fuselage 5
The large-diameter fuselage 5
The rear end of the small-diameter front body 8 is connected to, for example, eight connection fittings 14 so that the connection can be released. These connecting fittings 14 are arranged at approximately eight equally-circumferential positions on the rear surfaces of the ring webs 7a, 8a so as to be in contact with each other.
a, 8a are bolted together with a plurality of bolts. Each connection fitting 14 has a flange and a web, and is excellent in rigidity and strength.

The outer ring bearing mechanism 13 will be described. The outer ring bearing mechanism 13 supports the outer ring portion 4 against soil water pressure acting on the cutter disk 2 and the small diameter front body 8 when switching from excavating the large diameter shield tunnel T to excavating the small diameter shield tunnel Ta. It is. In the vicinity of the inside of the front half of the large-diameter front trunk 6, for example, six sets of outer ring bearing devices 30 constituting the outer ring bearing mechanism 13 are provided at appropriate circumferential intervals. Each outer ring bearing device 30 has a flanged pin 31 facing the annular groove 25 of the outer ring portion 4 from behind and a hydraulic cylinder 32 capable of driving the flanged pin 31 forward. Connected to the source.

The flanged pin 31 is formed with a pin portion 31a that can be fitted into the annular groove 25 and a flange portion 31b that can support the rear end surface of the outer ring portion 4. The rear end of the flanged pin 31 is hydraulically driven. Pin connected to the front end of the piston rod of the cylinder 32,
The cylinder body of the hydraulic cylinder 32 is connected to the large-diameter front body 6. The flanged pin 31 is guided by passing through the front wall portion of the annular frame 9 b, and the inserted portion is sealed by a seal member 33.

A wide and shallow annular groove 34 is formed in the inner peripheral surface of the annular frame 9b, and a waterproof seal 35 is mounted in the annular groove 34. The waterproof seal 35 allows the small-diameter front body 8 and the annular frame 9b to be formed. Water can be stopped between the rooms. Describing the sludge drainage facility 15, the sludge drainage facility 15 includes a water pipe 36, a valve 36a, a sludge pipe 37, and a valve 37a. The water supply pipe 36 is connected to a water supply source on the ground and connected to a water supply system introduced into the shield well, and the chamber 1
Send water into 8. The sludge pipe 37 is for discharging the muddy water in the chamber 18 and is connected to a sludge system extending backward in the shield well, and the sludge system extends to a sludge tank on the ground. The shield machine 1 employs a muddy water shield, but may employ an earth pressure shield. In such a case, a soil discharging facility is provided instead of the mud discharging facility 15.

The erector device 16 for lining the segment (27 or 29) on the inner surface of the shield shaft (T or Ta) has a general configuration, and the erector device 16 is attached to the rear end of the small-diameter front body 8. ing. The erector device 16 includes: a rotating frame 38 rotatably supported by a plurality of rollers attached to the annular portion 8b at the rear end of the small-diameter front body 8; an erector body 39 provided on the rotating frame 38; A rotation drive mechanism 40 for rotating the rotation frame 38 is provided.

When the shield excavator 1 described above excavates the large-diameter shield tunnel T, the coupling mechanism 20 of the cutter disk 2 is held in the coupled state, and the outer ring support mechanism 13 is connected to the outer ring section 4 as shown in the figure. Is not supported. When the cutter disk 2 is rotationally driven by the cutter driving mechanism 10 and the plurality of shield jacks 11 take a reaction force on the segment 27 to generate a digging thrust, the cutting face is excavated by the cutter disk 2, and the sediment is deposited in the chamber 18. The slurry flows into and is stirred by the stirring blades 19 of the cutter disk 2 to become muddy water.
7 to the outside. Each time the shield jack 11 excavates for one stroke, a concrete segment 27, for example, is assembled in a ring shape by the erector device 16, and this is repeated thereafter to excavate the large-diameter shield pit T.

FIG. 2 shows a small-diameter shield excavator 1A included in the shield excavator 1, in which only the small-diameter rear trunk 42 is attached by retrofitting, and is the same as that shown in FIG. The same components are denoted by the same reference numerals and description thereof is omitted.
Next, in order to excavate the large-diameter shield tunnel T by the shield excavator 1 shown in FIG. 1 and excavate the small-diameter shield tunnel Ta from the end of the large-diameter shield tunnel T, the shield excavator 1 is replaced with the small-diameter shield excavator 1A. Will be described with reference to FIGS. 3 to 8.

As shown in FIG. 3, first, the erector body 39 of the erector device 16 is removed. Next, as shown in FIG. 4, in order to support the shield machine 1 so as not to retreat against the soil water pressure acting on the shield machine 1, for example, a reaction force composed of, for example, 8 to 10 H-shaped steels is used. Receiving member 4
3 are mounted between the front ends of the segments 27 and the ring webs 6a, 7a as shown in the figure at appropriate intervals in the circumferential direction.

Thereafter, in each outer ring bearing device 30 of the outer ring bearing mechanism 13, the hydraulic cylinder 32 is operated to drive the flanged pin 31 forward, and the pin portion 31a of the flanged pin 31 is driven.
Is fitted into the annular groove 25 and the flange 31b is brought into contact with the rear end face of the outer race 4. At this time, since the connecting mechanism 20 remains in the connected state, the outer ring supporting mechanism 13 supports the outer ring portion 4 against the load caused by the soil water pressure acting on the cutter disc 2 and the small-diameter front body 8, and The outer ring 4 is restricted from moving in the radial direction. The chamber 18
The soil pressure acting on the inside acts on the partition wall 9b, and the load acts on the small-diameter front body 8, but can be supported by the outer ring support mechanism 13 via the cutter disk 2, the coupling mechanism 20, and the outer ring portion 4.

Thus, the reaction force receiving member 43 is attached,
When the outer ring support mechanism 13 is operated, the load caused by the soil pressure acting on the cutter disk 2 and the small-diameter front body 8 causes the outer ring support mechanism 13, the large-diameter front body 6, and the reaction force receiving member 43.
Since the load is not supported through the small-diameter front body 8 since the load is supported by the segment 27 through the first and second members, the load hardly acts on all the connection fittings 14. Therefore, all the connection fittings 14 are to be removed, but the connection fittings 14 can be easily and efficiently removed. An annular groove 25 formed in the outer ring portion 4 has a flanged pin 3
No. 1 pin portion 31a is fitted, so that the rotational phase of the cutter disc 2 can be set at any phase.
a can be reliably fitted into the annular groove 25, and there is no need to adjust the rotational phase of the cutter disk 2.

Next, as shown in FIG. 5, the small-diameter rear body 42 is carried in from the outside, is attached concentrically to the rear end of the small-diameter front body 8, and the erector body 39 is attached. Next, as shown in FIG. 6, the reaction force receiving ring 44 is fixed to the inner surface of the segment 27 lining the inner surface of the large-diameter shield shaft T, and the reaction force receiving ring 44 takes a reaction force. The segment 29 corresponding to the small-diameter shield shaft Ta is assembled on the inner surface of the small-diameter rear trunk 42. While the reaction force is being taken at the front end of the segment 29, the plurality of shield jacks 12 inside the small-diameter front trunk 8 are set to be able to generate the excavating thrust. Next, as shown in FIG. 7, the connection of the connecting mechanism 20 in the cutter disk 2 is separated, and only the disk main body 3 can be driven to rotate while the outer ring portion 4 is kept fixed by the outer ring support mechanism 13. The outer ring portion 4 is restricted by the outer ring support mechanism 13 so as not to move in the radial direction, and keeps the stationary state.

Next, as shown in FIG. 8, the pressurized water is supplied to the water-stop seal 35 to exert a water-stop function, and then the disk body 3 is driven to rotate by the cutter driving mechanism 10 and the plurality of shield jacks 12 are used. The excavation thrust is generated to start the small-diameter shield excavator 1A, and the excavation of the small-diameter shield tunnel Tb connected to the large-diameter shield tunnel T is started. Then, the segment 27,
A mortar 46 as a backfill agent is filled and solidified in the rear end portion of the annular gap between the 29 to be sealed.

Next, in the two-stage shield machine 1 described above, a plurality of connection fittings 14 for connecting the large-diameter body 5 to the rear end of the small-diameter front body 8 are provided so as to be disconnectable.
Excavation thrust generated by the shield jack 11 and acting on the large-diameter body 5 can be reliably transmitted from the large-diameter body 5 to the small-diameter front body 8. An outer ring support mechanism 13 capable of supporting the outer ring portion 4 against the soil water pressure acting on the cutter disc 2 and the small diameter front body 8 is provided near the inner surface near the front end of the large diameter body 5, so that the small diameter shield shaft is When switching to excavation, the cutter disk 2
And the load caused by the soil pressure acting on the small-diameter front body 8 is supported by the large-diameter body 5 and the segment 27 on the inner surface of the large-diameter shield pit via the outer ring bearing mechanism 13, and the load is supported by the small-diameter front body 8. It is possible to make it unnecessary, and it is possible to easily and efficiently switch to a state where the shield jack 12 on the inner surface side of the small-diameter front body 8 can generate a digging thrust by removing the plurality of connection fittings 14.

The cutter disk 22 includes a disk main body 3 located on the front side of the small-diameter front body 8, an outer ring portion 4 that is separate from the disk main body 3 and located on the outer peripheral side, and the disk main body 3 is attached to the outer ring portion 4. Since the coupling mechanism 20 has a coupling mechanism 20 capable of transmitting and separating torque and force, the disk main body 3 and the outer ring 4 are coupled by the coupling mechanism 20 when the large-diameter shield digging is performed. When it can be driven to rotate by the mechanism 10 and switches to excavation of a small diameter shield shaft,
By releasing the connection of the connecting mechanism 20, the disc body 3 is released.
And the outer ring portion 4 can be easily separated.

Since one cutter driving mechanism 10 is disposed inside the small-diameter front barrel 8, the small-diameter shield excavator 1A
After that, the disk drive 3 can be driven to rotate by the cutter driving mechanism 10. An annular groove 25 is formed at the rear end of the outer ring portion 4 and the pin portion 31a of the flanged pin 31 is fitted into the annular groove 25. Therefore, when the pin portion 31a is fitted, the cutter disc 2 There is no need to adjust the rotational phase of the pin portion 31a, and the pin portion 31a can be easily fitted.

Here, a description will be given of an example in which the above-described embodiment is partially changed. The case where the shield jack 12 is provided in addition to the shield jack 11 has been described as an example, but when switching to the small-diameter shield excavator 1A, The shield jack 11 can be moved to the position of the shield jack 12. Also, a plurality of arc-shaped long holes are formed instead of the annular groove 25 formed at the rear end of the outer ring portion 4, and the pin portions 31 a of the pin 31 with a flange are fitted into these long holes. May be. The difference in diameter between the large-diameter front body 6 and the small-diameter front body 8 is not limited to the illustrated one, but may be various diameter differences. It should be noted that the present invention is not limited to those shown in the drawings, and can be implemented in a form in which various changes are added to the above-described embodiment without departing from the spirit of the present invention.

[0039]

According to the first aspect of the present invention, a plurality of connection fittings for connecting the large-diameter body to the rear end of the small-diameter front body are detachably provided. The acting excavating thrust can be reliably transmitted from the large-diameter body to the small-diameter front body. In addition, an outer ring support mechanism that can support the outer ring part against the soil pressure acting on the cutter disk and the small diameter front body is provided near the inner surface near the front end of the large diameter body, so switching to excavation of the small diameter shield shaft At this time, the load caused by the soil pressure acting on the cutter disk and the small-diameter front body is supported on the large-diameter body or the inner surface segment of the large-diameter shield shaft via the outer ring bearing mechanism, and the load is supported by the small-diameter front body. An unnecessary state can be achieved, and a plurality of connection fittings can be removed to easily and efficiently switch to a state where a digging thrust can be generated by the shield jack on the inner surface side of the small-diameter front body. Outer ring support mechanism is formed at the rear end of the outer ring to form a rear end opening
One or more grooves and between the large-diameter body and the small-diameter front body
And a plurality of outer rings can be supported from behind by engaging with the grooves.
A plurality of pin members, provided between the large-diameter body and the small-diameter front body.
Multiple hydraulic cylinders for driving the pin member in the front-back direction
The outer ring bearing mechanism is
The rotation phase of the cutter disk
Also, securely insert a plurality of pin members into the one or more grooves.
Can adjust the rotation phase of the cutter disk
No need to do.

A cutter disk is located on the front side of the small-diameter front body, an outer ring portion separate from the disk body and located on the outer peripheral side, and the disk body is capable of transmitting force to the outer ring portion and is separable. When the large-diameter shield digging is performed, the disk body and the outer ring portion are connected by the coupling mechanism, and can be rotationally driven by one cutter driving mechanism. By releasing the connection of the connecting mechanism, the disk main body and the outer ring portion can be easily separated.

According to the second aspect of the present invention, during excavation of the large-diameter shield shaft, the excavation thrust by the shield jack is transmitted from the large-diameter body to the small-diameter front body via the connection fitting. The input excavation thrust can be reliably transmitted to the small-diameter front body via the plurality of connection fittings. The other effects are the same as those of the first aspect.

According to the third aspect of the present invention, when the excavation of the large-diameter shield pit is switched to the excavation of the small-diameter shield pit, the load caused by the soil water pressure acting on the cutter disk and the small-diameter front body is transferred to the outer ring support mechanism. Since the load can be supported by the large-diameter fuselage or the inner surface segment of the large-diameter shield shaft via the outer ring support mechanism, the load does not need to be supported by the small-diameter front body. Disassembly of metal fittings and assembly of shield jacks near the inner surface of the small-diameter front body are simplified. The other effects are the same as those of the first or second aspect.

According to the fourth aspect of the present invention, since the cutter driving mechanism is provided inside the small-diameter front body, if the disk main body and the outer ring portion are connected by the connecting mechanism, the cutter driving mechanism allows the cutter disk to be driven. The whole can be rotationally driven. In addition, the same effect as any one of the first to third aspects is obtained.

According to the fifth aspect of the present invention, since the connecting mechanism is configured to be connected via a plurality of radially oriented pin members of the shield shaft, the connecting mechanism connects the disk body to the outer ring portion. Transmission of torque and force between them is possible. In addition, the same effects as in any one of the first to fourth aspects are exhibited.

According to the sixth aspect of the present invention, since the outer ring support mechanism has a function of restricting the outer ring portion from moving in the radial direction, the disk main body and the outer ring portion are separated when the small diameter shield tunnel is dug. In this case, no interference occurs between the outer ring portion and the disk body. In addition, the same effects as in any one of the first to fifth aspects are provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a shield machine according to an embodiment of the present invention.

FIG. 2 is a vertical side view of the small-diameter shield machine.

FIG. 3 is an explanatory diagram showing a first stage of a switching process for switching a shield machine to a small-diameter shield machine.

FIG. 4 is an explanatory diagram showing a second stage of the switching procedure.

FIG. 5 is an explanatory diagram showing a third stage of the switching procedure.

FIG. 6 is an explanatory diagram showing a fourth stage of the switching procedure.

FIG. 7 is an explanatory diagram showing a fifth stage of the switching procedure.

FIG. 8 is an explanatory diagram showing a sixth stage of the switching procedure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shield machine 1A Small-diameter shield machine 2 Cutter disk 3 Disk body 4 Outer ring part 5 Large-diameter body 6 Large-diameter front trunk 7 Large-diameter rear trunk 8 Small-diameter front trunk 10 Cutter drive mechanism 11 Shield jack 13 Outer ring support mechanism 14 Connection metal fitting 20 connecting mechanism 22 pin member

Claims (6)

(57) [Claims] 1. A cutter disk, a large-diameter body, a small-diameter front body concentrically located inside a front portion of the large-diameter body, a cutter driving mechanism for rotating and driving the cutter disk, and a digging thrust on the large-diameter body. In a two-stage shield excavator comprising a plurality of shield jacks to add a, a small-diameter shield pit following the large-diameter shield pit, the cutter disk, a disk body located on the front side of the small-diameter front body, An outer ring portion that is separate from the disk body and is located on the outer peripheral side thereof; and a coupling mechanism that couples the disk body to the outer ring portion so as to be able to transmit power and to be separable, wherein a digging thrust acting on the large diameter body In order to transmit the large-diameter body to the small-diameter front body, a plurality of connection fittings are connected to the rear end of the small-diameter front body so that the large-diameter body can be disconnected. Disk and A bearing capable of outer ring support mechanism outer ring portion against the soil pressure acting on the small diameter front cylinder, a rear end to the rear of the outer ring portion
One or more grooves formed in an opening shape, a large-diameter body and a small-diameter
The outer ring portion is supported from behind by engaging with the groove provided between the front bodies.
Multiple pin members that can be supported, and between the large-diameter body and the small-diameter front body
Multiple pin members for driving the
A two-stage shield machine comprising an outer ring bearing mechanism having a hydraulic cylinder . 2. The two-stage structure according to claim 1, wherein, during excavation of the large-diameter shield shaft, excavation thrust by the shield jack is transmitted from the large-diameter body to the small-diameter front body via the connection fitting. Type shield machine. 3. When switching from excavation of a large-diameter shield pit to excavation of a small-diameter shield pit, a load caused by soil pressure acting on the cutter disk and the small-diameter forebody is supported via an outer ring bearing mechanism. The two-stage shield machine according to claim 1. 4. The cutter driving mechanism according to claim 1, wherein the cutter driving mechanism is provided inside a small-diameter front body.
Item 2. A two-stage shield machine described in the item. 5. The method according to claim 1, wherein the connecting mechanism is configured to connect via a plurality of radially oriented pin members of the shield shaft.
Step type shield machine. 6. The two-stage shield machine according to claim 1, wherein the outer ring support mechanism has a function of restricting the outer ring portion from moving in a radial direction. .