JP3039921B2 - Two-stage shield machine - Google Patents

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 tunnel.

[0002]

2. Description of the Related Art In many cases, shield tunnels for sewerage have a tunnel diameter gradually increasing from an upstream side to a downstream side. In the case of constructing a shield tunnel (tunnel) 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. And in urban areas,
In many cases, shafts cannot be formed because they interfere with existing structures such as buildings, but in such a case, tunnels are excavated unified into tunnels having a diameter larger than the required diameter, so that tunnel excavation costs increase.

Therefore, recently, various two-stage shield machines capable of excavating a small-diameter tunnel following a large-diameter tunnel without using a shaft have been proposed. For example,
In the two-stage shield machine described in JP-A-5-10086, a small-diameter shield machine is installed inside one cylindrical large-diameter trunk member, and a plurality of shield jacks are provided inside the small-diameter shield machine. When excavating large-diameter shields, the shield jacks generate excavating thrust while applying reaction force to the segments via the transmission table, and when switching to small-diameter shields, connecting large-diameter trunk members to small-diameter trunk members. The cutter disk is remodeled to a small diameter, the small-diameter segment is lining stepwise at the front end of the large-diameter segment, and when excavating the small-diameter shield, the large-diameter trunk member is left in the ground and shielded without using a transmission stand. A jack produces a reaction force on the small-diameter segment to generate a thrust. In addition, this two-stage shield machine does not have a bent part.

On the other hand, in a two-stage shield machine described in Japanese Patent Application Laid-Open No. 8-82187, a small-diameter shield machine is installed inside a large-diameter trunk member, and a plurality of outer surface-side portions of the small-diameter trunk member are recessed inward. A plurality of shield jacks for large-diameter shield are provided between the large-diameter trunk member and the small-diameter trunk member so as to be located in the recessed portions, and a plurality of small-diameter shield shield jacks are also provided inside the small-diameter trunk member. The cutter disk is provided with a parent cutter on the outer peripheral side, a child cutter on the inner side, and a torque transmission mechanism for transmitting torque from the child cutter to the parent cutter.

When excavating a large diameter shield, a thrust is generated by a shield jack for a large diameter shield. When excavating a small diameter shield, a parent cutter is removed to reduce the diameter of a cutter disk, and a plurality of small diameter shield jacks are used to reduce the thrust. Dig while generating. In addition, this two-stage shield machine does not have a bent part.

[0006]

In the two-stage shield excavator disclosed in the former publication, a reaction force is applied to the segments via a large-diameter and heavy-weight transmission table when excavating a large-diameter shield. Therefore, it is necessary to move the transmission table having a large weight every time the segments are assembled, which requires a great deal of labor and time, and it is difficult to improve the work efficiency of excavation. In addition, since there is no center bent portion, a straight tunnel excavation cannot be performed, and the application target is restricted, and versatility is lacking.

In the two-stage shield machine described in the latter publication, a plurality of recesses are formed in the small-diameter trunk member in order to dispose the large-diameter shield jack between the large-diameter trunk member and the small-diameter trunk member. Due to the formation, the small-diameter trunk member cannot be formed into a cylindrical body, which is structurally unreasonable. In other words, when the difference between the diameter of the large-diameter shield and the diameter of the small-diameter shield is small, this method cannot be applied and lacks versatility or the size of the concave portion becomes large. Although the cross section of the tunnel excavated with the cutter disk is circular, if there are multiple recesses on the outer surface of the small diameter trunk member, the ground will become unstable, and the consumption of mortar injected into the outside of the segment will be large. Problems remain.
In addition, since there is no middle bent portion, a straight tunnel excavation cannot be performed, and the application target is restricted, and versatility is lacking.

In a conventional two-stage shield excavator, if a center bend portion that connects the front body and the rear body so that the front body and the rear body can be bent is provided, the thrust generated by the shield jack cannot be transmitted to the front body. The bend is omitted, but in that case,
The versatility of the shield machine will be significantly reduced. An object of the present invention is to make it possible to excavate in a curved shape in a two-stage shield excavator, to enhance the excavation work efficiency, to easily and efficiently switch from a large-diameter shield to a small-diameter shield, The purpose is to increase the versatility of the excavator.

[0009]

According to a first aspect of the present invention, there is provided a two-stage shield machine, wherein a cutter disk, a large-diameter front body, a large-diameter rear body, a large-diameter front body and a large-diameter rear body are bent. A two-stage shield having a large-diameter bent part connected as possible, a small-diameter front body concentrically positioned inside the large-diameter front body, and a small-diameter bent part connected to the rear end of the small-diameter front body. An excavator, provided with a cutter driving means for rotating and driving a cutter disk inside the small-diameter front body, providing a plurality of middle folding jacks for connecting the small-diameter front body and the small-diameter middle bending body of the small-diameter middle bending part, A plurality of shield jacks fixed to the small-diameter center bend cylinder are provided near the inside of the small-diameter center bend cylinder. Is transmitted to the small-diameter front body.

With this shield excavator, when excavating a large-diameter tunnel, the large-diameter front trunk, large-diameter center bend portion, and large-diameter rear trunk are located at the outermost periphery. A small-diameter rear trunk is connected to the rear end of the small-diameter middle bend, and the large-diameter front trunk, the large-diameter middle bend and the large-diameter rear trunk are excavated while remaining in the ground.
Since the small-diameter middle bent portion and the large-diameter middle bent portion are provided, it is possible to excavate in a curved shape when excavating a large-diameter tunnel or a small-diameter tunnel.

The cutter disk is rotated by cutter driving means, and the small-diameter front body is connected to the small-diameter middle bending cylinder of the small-diameter middle bending part by a plurality of middle bending jacks. A plurality of shield jacks are provided, which are fixed to each other.When excavating shields, multiple shield jacks take a reaction force on the large diameter shield segment, and the excavation thrust is applied to the small diameter front body via multiple middle bent jacks. introduce.

In a two-stage shield machine according to a second aspect of the present invention, in the first aspect of the present invention, the small-diameter front body is provided with a front-body fixing device for fixing the large-diameter front body to the small-diameter front body so that the large-diameter front body can be released. It is characterized by the following. When excavating large diameter tunnels,
The large-diameter front body is fixed to the small-diameter front body by the front-body fixing device, and the excavating thrust acting on the small-diameter front body is transmitted through the front-body fixing device. Before the excavation of the small-diameter tunnel, the fixing of the front fuselage fixing device is released, and the large-diameter front fuselage is left underground when excavating the small-diameter tunnel.

According to a third aspect of the present invention, in the invention of the first aspect, the large-diameter rear body is releasably fixed to the small-diameter center bending cylinder by a fixing mechanism including a plurality of bolts. It is characterized by the following. Therefore, when switching from the large-diameter tunnel excavation to the small-diameter tunnel excavation, the fixing mechanism is released, and the fixing of the large-diameter rear trunk to the small-diameter middle folding cylinder can be easily released.

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 spokes correspond to a part of the cutter spokes and the cutter spokes correspond to a large-diameter front body. An expansion mechanism capable of switching from a large-diameter state to a small-diameter state corresponding to the small-diameter front body is provided, and a mud discharge port is provided in the remaining cutter spokes of the cutter disk in the constantly small-diameter state. . When excavating a large-diameter tunnel, some cutter spokes of the cutter disk are held in a large-diameter state, and when excavating a small-diameter tunnel, those cutter spokes are switched to a small-diameter state by a telescopic mechanism. Since the remaining cutter spokes in the always small diameter state are provided with the humidifier discharge port, there is no need to provide a telescopic mechanism, and there is no interference between the humidifier supply system and the telescopic mechanism.

In a two-stage shield excavator according to a fifth aspect of the present invention, in the invention of the fourth aspect, an eccentric metal fitting for a large diameter shield is detachably connected to a tip portion of a piston rod of each of the shield jacks when excavating a large diameter shield. When the small-diameter shield is excavated, the large-diameter shield eccentric bracket is replaced with a small-diameter shield eccentric bracket. Therefore, when switching from large-diameter tunnel excavation to small-diameter tunnel excavation,
The large-diameter shield eccentric can be easily and efficiently replaced with the small-diameter shield eccentric.

A two-stage shield machine according to a sixth aspect of the present invention further includes an erector device for lining the segment, wherein the length of the erector body of the erector device in the tunnel radial direction is increased. A diameter switching mechanism for switching from the shield length to the small-diameter shield length is provided. Therefore, the length of the erector body in the tunnel radial direction can be switched according to the tunnel diameter.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment relates to a two-stage shield excavator capable of continuously excavating a large-diameter shield tunnel (large-diameter tunnel) and a small-diameter shield tunnel (small-diameter tunnel) connected thereto. The description will be made with the front as the left and right as the left and the right toward the front. In the following description, a large-diameter shield is synonymous with a large-diameter tunnel, and a small-diameter shield is synonymous with a small-diameter tunnel.

As shown in FIG. 1, a two-stage shield machine 1 comprises a cutter disk 2 for excavating a face, a large-diameter front body 3, a large-diameter rear body 5, a large-diameter front body 3 and a large-diameter rear body 5 A large-diameter central bend portion 4, which is connected so as to be able to be folded in the middle, a small-diameter front body 6, which is concentrically located inside the large-diameter front body 3, a small-diameter central bend part 7, which is connected to the rear end of the small-diameter front body 6, It has an erector device 8 arranged inside the large-diameter rear trunk 5, a plurality of shield jacks 9 for generating excavating thrust, and an earth discharging mechanism 10 for discharging excavated earth and sand to the outside.

The shield machine 1 excavates a large diameter tunnel Ta by the shield machine 1 shown in FIG.
When excavating the small-diameter tunnel after the excavation of the large-diameter tunnel Ta is completed, the small-diameter rear trunk 45 is welded to the small-diameter rear trunk front end 45a on the outer periphery of the rear end of the small-diameter middle bend part 7 to form the large-diameter front trunk 3 and the large-diameter trunk. The middle bend portion 4 and the large-diameter rear trunk 5 are left in the ground, and the small-diameter front trunk 6, the small-diameter middle bend portion 7, the small-diameter rear trunk 45, and the excavating internal device excavate.

First, the cutter disk 2 will be described. As shown in FIGS. 1 and 2, a cutter disk 2 for excavating a face is provided at a front end of the shield machine 1. The cutter disk 2 is provided on a partition wall 23 inside a front end portion of the small-diameter front body 6. It is rotatably supported. The cutter disk 2 is provided with four cutter spokes 11a of variable diameter extending in the radial direction in a cross shape from the center, and two cutter spokes 11b of always small diameter. Each cutter spoke 11a, 11b is provided with a number of cutter bits 12. The cutter spoke 11 a is provided with a telescopic mechanism 13 that can switch from a large-diameter state corresponding to the large-diameter front barrel 3 to a small-diameter state corresponding to the small-diameter front barrel 6.

The telescopic mechanism 13 is configured to switch the movable spoke 13a to a smaller diameter state by driving the movable spoke 13a to a smaller diameter side by a hydraulic cylinder in the cutter spoke 11a. The cutter spoke 11b is provided with a mud discharge port 14 for discharging the mud supplied from the swivel joint 26 to the pipe in the cutter spoke 11b, and excavation is performed between the cutter disk 2 and the partition wall 23. A chamber 15 for accommodating earth and sand is formed, and the excavated earth and sand is stirred with a mudifying agent in the chamber and discharged to the outside by an earth discharging mechanism 10 including a screw conveyor 10a and a belt conveyor (not shown).

Next, the large-diameter front body 3 will be described. FIG.
As shown in the figure, the large-diameter front body 3 is formed of a steel cylindrical body, and in order to prevent water and earth and sand from flowing into the large-diameter front body 3, the inner peripheral surface of the ring member 18 and the small-diameter front body are formed. A ring-shaped water seal 19 and earth and sand seal 20 are provided between them.

As shown in FIG. 11, the water stop seal 19 is
A plurality of plate members arranged in the circumferential direction are covered with a synthetic resin or a synthetic rubber, and the rear end portion is fixed to the concave groove 18b on the inner peripheral side of the ring member 18 via the ring-shaped metal member 19a, and is attached.
The pressurized water of the pressurized water supply pipe 18a is injected from the pressurized water supply port 18c to the outer surface side of the water seal 19, and the water seal 19 is opened inward by the pressurized water. It is configured to stop water by making contact with the outer peripheral surface. A ring-shaped earth and sand seal 20 is provided on the front side of the water stop seal 19.

The large-diameter middle bend portion 4 for connecting the rear end of the large-diameter front trunk 3 and the front end of the large-diameter rear trunk 5 so as to be able to be bent has a ring-shaped large-diameter central bend cylinder 21. A partial spherical portion is formed on the outer peripheral surface of the large-diameter center folding cylinder 21, and this partial spherical portion is engaged with a partial spherical surface on the inner surface of the rear end of the large-diameter front barrel 3 via a seal. The rear end of the large-diameter middle folding cylinder 21 is fixed to the front end of the large-diameter rear trunk 5 so as to be fitted inside.

The large-diameter rear body 5 will be described. The large-diameter rear body 5 is a steel cylinder having the same diameter as the large-diameter front body 3, and the front end of the large-diameter rear body 5 includes a plurality of bolts. The fixing mechanism 32 is fixed to the small-diameter center-folding cylinder 28 so that the fixing can be released. The fixing mechanism 32 includes, for example, ten brackets 32a (having flange portions on the outer surface and the front surface) located at equal positions on the circumference of a circle and a flange portion of the brackets 32a. A plurality of bolts are connected to the rear end of the body 28 by bolts.

When excavating in the large-diameter tunnel Ta, the large-diameter rear trunk 5 is fixed to the small-diameter middle folding cylinder 28 by a fixing mechanism 32. Before starting the excavation of the small-diameter tunnel Tb, the fixing mechanism 32 is removed, and the small-diameter center bending cylinder 28 of the large-diameter rear trunk 5 is removed.
The small-diameter rear trunk 45 divided into two or three parts is carried into the shield machine 1 and welded to the rear end of the small-diameter rear trunk front end 45a fixed to the outer surface of the small-diameter middle folding cylinder 28. Into a cylindrical body coaxial with the small-diameter front body 3. still,
A tail seal 22 is provided at the rear end of the large-diameter rear trunk 5.

The small-diameter front body 6 will be described. The small-diameter front body 6 is a steel cylinder. The small-diameter front body 6 is provided concentrically inside the large-diameter front body 3, and the rear end of the small-diameter front body 6. In the state where the small-diameter middle bend portion 7 is connected to the small-diameter rear body 45 and the small-diameter rear body 45 is connected, the small-diameter front body 6 and the small-diameter rear body 45 are connected via the small-diameter middle bend portion 7 so as to be able to be folded. A partial spherical portion is formed on the outer peripheral surface of the ring-shaped small-diameter middle folding cylinder 28 of the small-diameter middle folding portion 7, and the partial spherical portion is engaged with a partial spherical surface on the inner surface of the rear end of the small-diameter front barrel 6. . An annular partition wall 23 is provided inside the front end side portion of the small-diameter front body 6. A ring web 29 is fixed to the inside of the rear end of the small-diameter middle folding cylinder 28, and a small-diameter rear trunk front end 45a is fixed to the outer surface of the rear end of the small-diameter middle folding cylinder 28.

A plurality of (for example, six) cutter driving motors 25 for driving the cutter disk 2 to rotate in the forward and reverse directions are fixedly provided on the partition wall 23, and are fixed to the tips of the output shafts of the respective cutter driving motors 25. The pinion is meshed with the ring gear on the outer peripheral surface of the cutter disk support 16,
The cutter disk 2 is rotationally driven by a plurality of cutter drive motors 25 via a ring gear. A swivel joint 26 for supplying a muddy agent to the cutter disk 2 is provided at a rear end of the cutter disk support 16.

The front body fixing device 27 for fixing the large-diameter front body 3 to the small-diameter front body 6 in a releasable manner will be described. As shown in FIG. 1, eight guide square cylinders 27 a are fixed to the small-diameter front body 6 near the rear side of the partition wall 23, for example, at eight equally-circumferential positions. Eight engagement hole forming tools 27b corresponding to the guide square tubes 27a are fixed, and each guide square tube 2
An engagement tool 27c is mounted movably in the radial direction inside 7a,
Hydraulic cylinders 27d are provided for driving the respective engaging members 27c forward and backward. When each hydraulic cylinder 27d drives the engaging members 27c outward to partially engage with the engaging holes of the engaging hole forming member 27b, it is large. The diameter front body 3 is fixed so as not to move relative to the small diameter front body 6, and each hydraulic cylinder 27 d engages with an engagement member 27 c
Is driven inward to disengage from the engagement hole, the small-diameter front body 6
And the large-diameter front body 3 and the small-diameter front body 6 can move relative to each other.

Next, a description will be given of the center-folding jack 30 for bending the shield machine 1. Ten center bending jacks 30 are provided near the outer periphery of the inside of the small diameter front trunk 6, five center bending jacks 30 are provided on the left half side, and five center bending jacks 30 are provided on the right half side. I have. The jack main body of each of the middle bending jacks 30 is pin-connected to a bracket fixed to the small-diameter center bending cylinder 28 and the ring web 29 by a vertical pin, and the piston rod is connected to the small-diameter front barrel 6 and the partition 23.
The pin is connected to the fixed bracket by a vertical pin. Therefore, when bending and digging in the right direction, the left half-side middle bent jack 30 is extended and the right half-side middle bent jack 30 is reduced. When the vehicle is to bend leftward, the middle half-jack 30 on the right half is extended and the middle half-jack 30 on the left half is reduced.

Each half-folding jack 30 is formed of a double-acting hydraulic cylinder, and becomes rigid when the oil pressure in the oil chamber is blocked on both sides of the piston. Since it is impossible to transmit the excavating thrust generated by the plurality of shield jacks 9 to the small-diameter front body 3 via the small-diameter middle bend portion 4, the shield excavator 1 uses the ten middle-fold jacks 30. In such a state that the hydraulic block is applied, the excavating thrust is transmitted to the small-diameter front body 6 via the middle bending jack 30 and transmitted from the small-diameter front body 6 to the large-diameter front body 3 via the front body fixing device 27. It is composed. Therefore, even if the middle bent portions 4 and 7 are provided, the excavation thrust can be reliably transmitted to the small-diameter front body 6.

Next, the shield jack 9 for generating the excavating thrust will be described. A plurality of (for example, 16) shield jacks 9 (comprising a double-acting hydraulic cylinder) are disposed rearward at 16 equally-spaced positions near the inside of the small-diameter center bending cylinder 28, and the jack body of each shield jack 9 is provided. Is fixed to the ring web 29 in a penetrating manner, and a large-diameter shield eccentric fitting 33 is detachably fixed to the tip of the piston rod of each shield jack 9.

When switching from excavation of the large diameter tunnel Ta to excavation of the small diameter tunnel Tb, the eccentric metal fitting 3 for the large diameter shield is used.
As shown in FIG. 10, a spigot hole 9b is formed in the piston rod 9a of each shield jack 9 so that the small-diameter eccentric fitting 34 can be quickly replaced with the small-diameter shield eccentric fitting 34. 33 fitting part 3
3a and a plurality of bolts 33b
Is fixed to the piston rod 9a. At the outer end of the large-diameter shield eccentric bracket 33, a hemispherical convex portion 36 is formed. The hemispherical convex portion 36 is engaged with the hemispherical concave portion of the spreader 35.
Is pin-connected.

The large-diameter shield eccentric fitting 33 is formed to have a length sufficient to allow the spreader 35 to abut on the segment 37 lining the inner surface of the large-diameter tunnel Ta to take the reaction force of excavation. The small-diameter shield eccentric fitting 34 has the same hemispherical convex portion as described above, but has a large-diameter shield so that a spreader 35 can be brought into contact with a segment 38 lining the inner surface of the small-diameter tunnel Tb so as to take a reaction force of excavation. It is formed shorter than the eccentric fitting 33. When excavating the small-diameter tunnel Tb, the large-diameter shield eccentric bracket 33 is replaced with a small-diameter shield eccentric bracket 34.

The erector device 8 for mounting the segments 37, 38 on the inner peripheral surface of the tunnel pit wall is mounted on the ring web 29. The erector device 8 includes a ring-shaped erector frame, a plurality of support rollers for rotatably supporting the erector frame, a drive motor (electrically or hydraulically) for rotating and driving the erector frame, and the erector frame. This is a general configuration having an erector main body 39.

A description will be given of the diameter switching mechanism 40 for switching the length of the erector body 39 in the radial direction from the length for the large diameter shield to the length for the small diameter shield. This diameter switching mechanism 40
Is a distance piece that is releasably bolted to the middle part in the length direction of the erector body 39 with a plurality of bolts. The length of the distance piece is set equal to the difference between the large diameter tunnel radius and the small diameter tunnel radius. ing. At the time of excavation of the large diameter tunnel Ta, the length of the erector body 39 is increased by the distance piece so that the large diameter tunnel T
a, the distance piece is removed when the small-diameter tunnel Tb is excavated to shorten the length of the erector body 39, and the segment 38 can be wrapped on the inner surface of the small-diameter tunnel Tb. .

Next, the operation of the above-described two-stage shield machine 1 will be described with reference to FIGS. When excavating the large-diameter tunnel Ta, the variable spokes 13a are held in the large-diameter state corresponding to the large-diameter front body 3 by the expansion and contraction mechanism 13 of the cutter disk 2, and the front-body fixing device 27
The small-diameter front body 3 and the large-diameter front body 6 are held in a fixed state, the large-diameter shield eccentric fitting 33 is fixed to the piston rod 9a of each shield jack 9, and the erector main body 3 of the electaku device 8 is fixed.
In the state of FIG. 1 in which the distance piece is fixed to 9,
Excavate the large diameter tunnel Ta.

At this time, the cutter disk 2 is driven to rotate by the cutter drive motor 25 and the shield jack 9 is rotated.
The large-diameter shield segment 37 takes a reaction force to generate excavation thrust with the shield jack 9, and the erector device 8 excavates while excavating the large-diameter shield segment 37 while lining the inner surface of the large-diameter tunnel Ta. The excavated soil is discharged by the discharging mechanism 10 to the outside of the shield machine 1 for excavation.

As shown in FIG. 4, when the shield machine 1 reaches the point where the excavation of the small diameter tunnel Tb is started,
The shield machine 1 is stopped, and the shield machine 1 is switched to small tunnel excavation. In this case, first, in order to attach the front body connection fitting 42 to the inner peripheral surface of the large-diameter front body 3,
A plurality (for example, eight) of notches 41 are formed near the front of the small-diameter center bending cylinder 28 of the small-diameter front trunk 6.

As shown in FIG. 5, a front body connecting fitting 42 is welded from each notch 41 to the inner surface of the large-diameter front body 3, and the large-diameter front body 3 and the large-diameter center bending cylinder 21 are cut out from the notch 41. The front end of is welded. Thereafter, the notches 41 of the small-diameter front body 6 are closed with a cover 43. Next, the fixing mechanism 32 that fixes the large-diameter rear trunk 5 to the small-diameter center folding cylinder 28 is removed, and the fixing of the large-diameter rear trunk 5 to the small-diameter central folding cylinder 28 is released. On the inner surface side of the large-diameter rear body 5, the large-diameter shield segment 3
A plurality (for example, eight) of rear body connection fittings 44 are assembled in a ring shape on the front end side of the unit 7. Also, the large-diameter shield eccentric fitting 33 of each shield jack 9 is replaced with the small-diameter shield eccentric fitting 3.
4 and the spreader 35 is connected to the small-diameter shield eccentric fitting 34.

As shown in FIG. 6, the cylindrical small-diameter rear trunk 45 divided into two or three parts is carried into the shield machine 1, and the small-diameter rear folding drum 28 has a small-diameter rear trunk front end on the outer surface at the rear end. 4
5a is welded and assembled into a cylindrical small-diameter rear body 45. In the elector device 8, the distance piece of the diameter switching mechanism 40 is removed and then bolted again to switch the radial length of the elector body 39 to the small-diameter shielding length.

As shown in FIG. 7, a ring-shaped reaction force receiving bracket for receiving a reaction force of the shield jack 9 at the time of excavation of the small diameter shield is provided on the inner peripheral surface behind the front end of the large diameter shield segment 37 by a predetermined distance. 47 is fixed by bolt connection. Then, the erector device 8 is operated, and the small-diameter shield segment 3
8 is assembled.

As shown in FIG. 8, the engagement member 27c of the front body fixing device 27 is switched inward to release the fixing of the large diameter front body 3 to the small diameter front body 6. In the cutter spoke 11 a of the cutter disk 2, the movable spoke 13 a is contracted by the hydraulic cylinder of the extension mechanism 13, and the four cutter spokes 11 a are switched to the small-diameter state corresponding to the small-diameter front body 3.

As shown in FIG. 11, pressurized water is supplied from a pressurized water supply source to a pressurized water supply pipe 18a.
c, pressurized water is injected outside the water stop seal 19 to urge the water stop seal 19, and the lip portion 19 a of the water stop seal 19 is brought into contact with the outer peripheral surface of the small diameter front body 6, and the large diameter front body 3 Prevents water from entering inside.

As shown in FIG. 9, while the segment 38 attached to the inner surface of the small-diameter rear body 45 takes a reaction force, the shield jack 9 generates a digging thrust, and the cutter disk 2 excavates the face to cut the small-diameter tunnel. The excavation of Tb is started. When the excavation has advanced a little, stop the excavation once,
A backing material (for example, mortar) is injected into the inter-segment gap 49 between the large-diameter shield segment 37 and the small-diameter shield segment 38 from the backing material injection hole 48 formed in the small-diameter shield segment 38, and the large-diameter shield is formed. The small segment 37 and the small-diameter shield segment 38 are connected by a backing material, and after the connection, excavation of the small-diameter tunnel Tb is started again. Then, while leaving the large-diameter front trunk 3, the large-diameter middle bend part 4, and the large-diameter rear trunk 5 in the ground, the small-diameter front trunk 6, the small-diameter middle bend part 7, the small-diameter rear trunk 45, the excavator internal equipment, and the like. The excavation of the small-diameter tunnel Tb is executed by the shield excavator composed of.

According to the two-stage shield excavating machine 1 described above, after excavating the large diameter tunnel, the small diameter tunnel can be excavated following the large tunnel, and the large diameter middle bent portion 4 and the small diameter middle bent portion 7 are excavated. Thus, the large-diameter tunnel can be dug in a curved shape via the small-diameter middle bent portion 7, and thus the small-diameter tunnel can be dug in a curved shape. Since the excavation thrust generated by the plurality of shield jacks 9 is transmitted to the small-diameter front body 6 via the plurality of middle bending jacks 30, the small-diameter middle bending portion 7 and the large-diameter middle bending portion 4 are provided. Nevertheless, the excavation thrust can be transmitted reliably, in other words, the shield excavator 1 can be formed into a center-fold type structure. Therefore, the versatility of the shield machine 1 is significantly improved.

Further, since a plurality of shield jacks 9 are provided inside the small-diameter middle bent portion 7 so that excavation thrust can be generated by the shield jacks 9 when excavating a large-diameter tunnel or a small-diameter tunnel, a shield for a large-diameter shield is provided. The required number of the shield jacks 9 can be reduced and the equipment cost can be reduced as compared with a case where a jack and a shield jack for a small-diameter shield are provided. Further, since a plurality of shield jacks 9 can be provided irrespective of the difference between the large-diameter shield diameter and the small-diameter shield diameter, design flexibility is increased.

Further, since the small-diameter front body 3 is provided with the front-body fixing device 27 for fixing the large-diameter front body 3 to the small-diameter front body 6 so that the large-diameter front body 3 can be released, the small-diameter front body 3 is provided with the small-diameter front body fixing device 27 when excavating the large-diameter tunnel. The large-diameter front body 3 is fixed to the front body 6 and the small-diameter front body 6 is fixed.
Can be transmitted via the front fuselage fixing device 27, and the fixing of the front fuselage fixing device 27 can be released before the small-diameter tunnel excavation starts, and the large-diameter front trunk remains in the ground during the small-diameter tunnel excavation. Can be. In addition, since the fixing of the front trunk fixing device 27 can be easily released, the work load for switching from the large-diameter tunnel excavation to the small-diameter tunnel excavation can be reduced.

Further, since the large-diameter rear body 5 is fixed to the small-diameter center bending cylinder 28 so as to be releasable by the fixing mechanism 32 including a plurality of bolts, the large-diameter rear body 5 is excavated when excavating the large-diameter tunnel.
Can be fixed to the small-diameter center bending cylinder 28, and when switching from the large-diameter tunnel excavation to the small-diameter tunnel excavation, the fixing mechanism 32 is released and the fixing of the large-diameter rear trunk 5 to the small-diameter center bending cylinder 28 can be easily released.

A telescopic mechanism 13 is provided on some of the cutter spokes 11a of the cutter disk 2 to switch the cutter spokes 11a from a large-diameter state corresponding to the large-diameter front barrel 3 to a small-diameter state corresponding to the small-diameter front barrel 6. , And the remaining small diameter of the cutter spoke 1 of the cutter disk 2
Since the mud material discharge port 14 is provided in 1b, a part of the cutter spokes 11a can be switched from the large diameter state to the small diameter state when excavating the small diameter tunnel, so that the preparation work is simplified. Since the mud discharge outlet 14 is provided in the cutter spoke 11b which is always in a small diameter state, there is no need to provide the expansion and contraction mechanism 13 and there is no interference between the mud supply system and the expansion and contraction mechanism.

Further, the large-diameter shield eccentric fitting 33 is detachably connected to the tip end of the piston rod 9a of each shield jack 9 when the large-diameter shield is excavated. Since the eccentric metal fitting for small diameter shield excavation 34 is replaced, a common plurality of shield jacks 9 can be used to generate excavation thrust at the time of large diameter shield excavation and small diameter shield excavation, which is advantageous in terms of equipment cost. Also, the preparation work for switching from the large diameter shield excavation to the small diameter tunnel excavation is simplified.

The erector device 8 for lining the segments 37 and 38 has a diameter for switching the length of the erector main body 39 in the tunnel radial direction from the length for the large-diameter shield to the length for the small-diameter shield. Since the switching mechanism 40 is provided, it is possible to easily and reliably switch from the large-diameter shield length to the small-diameter shield length using the same erector device 8, which is advantageous in terms of equipment cost. It should be noted that the above embodiment is merely an example, and it goes without saying that the present invention can be carried out in a mode in which each part of the shield machine 1 is appropriately modified without departing from the spirit of the present invention.

[0053]

According to the two-stage shield excavator of the present invention, after excavating in a large-diameter tunnel, a small-diameter tunnel can be excavated following the large-diameter tunnel. It is possible to excavate a large-diameter tunnel in a curved manner through the small-diameter middle bent portion, and it is excellent in versatility because the small-diameter tunnel can be excavated through a small-diameter middle bent portion. And, because the excavation thrust generated by the multiple shield jacks is transmitted to the small-diameter front body via the multiple middle-bent jacks, the excavation thrust is provided despite the provision of the small-diameter middle bend and the large-diameter middle bend. That is, the shield excavator can be made to have a folding-type structure. As a result, the versatility of the shield machine is significantly improved.

Further, since a plurality of shield jacks are provided inside the small-diameter middle bend portion and the shield jacks can generate a thrust when excavating the large-diameter tunnel and the small-diameter tunnel, the shield jack for the large-diameter shield and the small-diameter shield jack can be formed. The required number of shield jacks can be reduced and the equipment cost can be reduced as compared with the case where a shield jack for shielding is provided. Further, since a plurality of shield jacks can be provided regardless of the difference between the large-diameter shield diameter and the small-diameter shield diameter, the degree of freedom in design is increased.

According to the two-stage shield excavator of the present invention, the small-diameter front body is provided with the front-body fixing device for fixing the large-diameter front body to the small-diameter front body so that the large-diameter front body can be released. The large-diameter front body is fixed to the small-diameter front body by the front-body fixing device, and the excavating thrust acting on the small-diameter front body can be transmitted through the front-body fixing device. It is possible to release the fixation and leave the large-diameter forebody in the ground when excavating the small-diameter tunnel. Further, since the fixing of the front fuselage fixing device can be easily released, the work load for switching from large-diameter tunnel excavation to small-diameter tunnel excavation can be reduced. The other effects are the same as those of the first aspect.

According to the two-stage shield excavator of the third aspect, since the large-diameter rear body is fixed to the small-diameter center-folding body so as to be releasable by the fixing mechanism including a plurality of bolts, the large-diameter tunnel is excavated. The large-diameter rear trunk can be fixed to the small-diameter middle-bend trunk,
When switching from large-diameter tunnel excavation to small-diameter tunnel excavation, the fixing mechanism can be released to easily release the fixing of the large-diameter rear trunk to the small-diameter middle folding cylinder. The other effects are the same as those of the first aspect.

According to the two-stage shield excavator of the fourth aspect, the cutter spokes are partially provided on the cutter spokes from the large-diameter state corresponding to the large-diameter front body to the small-diameter state corresponding to the small-diameter front body. A switchable telescopic mechanism is provided, and a mud discharge port is provided for the remaining cutter spokes of the cutter disc that are always in a small diameter state, so that some cutter spokes are switched from a large diameter state to a small diameter state when excavating a small diameter tunnel. Preparation work is simplified. Since the humidifier discharge port is always provided in the cutter spoke having a small diameter, there is no interference between the humidifier supply system and the expansion / contraction mechanism. In addition, the same effect as any one of the first to third aspects is obtained.

According to the two-stage shield excavator of the fifth aspect, the distal end of the piston rod of each shield jack is provided with:
When excavating large-diameter shields, the large-diameter shield eccentric bracket is detachably connected, and when excavating small-diameter shields, the large-diameter shield excavation bracket is replaced with small-diameter shield excavation eccentric brackets. Since it is possible to generate a thrust when excavating a large-diameter shield and when excavating a small-diameter shield, it is advantageous in terms of equipment cost, and the preparation work for switching from excavating a large-diameter shield to excavating a small-diameter tunnel is simplified. The other effects are the same as those of the fourth aspect.

According to the two-stage shield excavator of the sixth aspect, there is provided an erector device for lining the segment, and the length of the erector body of the erector device in the tunnel radial direction is reduced from the length for the large-diameter shield to the small-diameter shield. Since a diameter switching mechanism is provided to switch the length from the large-diameter shield to the small-diameter shield using the same erector device, the equipment cost is advantageous. It is. The other effects are the same as those of the fourth aspect.

[Brief description of the drawings]

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

FIG. 2 is a view of the cutter disk as viewed from the front side.

3 is a cross-sectional view taken along the line AA-A in the left half and FIG. 1B in the right half.
It is a B-line end elevation.

Fig. 4 Shield excavator (while switching to small diameter shield excavation)
FIG.

Fig. 5 Shield excavator (while switching to small diameter shield excavation)
FIG.

Fig. 6 Shield excavator (while switching to small diameter shield excavation)
FIG.

Fig. 7 Shield excavator (while switching to small diameter shield excavation)
FIG.

Fig. 8 Shield excavator (while switching to small diameter shield excavation)
FIG.

FIG. 9 is a longitudinal sectional view of a shield excavator (after starting small-diameter shield excavation).

FIG. 10 is a partially cutaway longitudinal side view of the shield jack.

FIG. 11 is an enlarged cross-sectional view of a main part of the water stop seal and the earth and sand seal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Two-stage shield machine 2 Cutter disk 3 Large-diameter front trunk 4 Large-diameter center bent part 5 Large-diameter rear trunk 6 Small-diameter front trunk 7 Small-diameter center bent part 8 Electa device 9 Shield jack 10 Discharge mechanism 11a, 11b Cutter spoke DESCRIPTION OF SYMBOLS 13 Expansion-contraction mechanism 14 Mud discharge outlet 27 Front body fixing device 30 Center bending jack 32 Fixing mechanism 33 Eccentric metal fitting for large-diameter shield 34 Eccentric metal fitting for small-diameter shield 40 Diameter switching mechanism

Claims (6)

(57) [Claims] 1. A large-diameter middle bend portion for connecting a cutter disk, a large-diameter front body, a large-diameter rear body, a large-diameter front body and a large-diameter rear body so as to be able to be folded, and a large-diameter front body. A two-stage shield machine including a small-diameter front body concentrically located inside and a small-diameter middle bend portion connected to a rear end of the small-diameter front body, wherein a cutter disc is provided inside the small-diameter front body. Providing a cutter driving means for rotating and providing a plurality of middle bending jacks connecting the small diameter front body and the small diameter center bending body of the small diameter center bending part,
Providing multiple shield jacks fixed to the small-diameter folded body near the inside of the small-diameter folded body, taking the reaction force to the large-diameter shield segment using the multiple shield jacks, and excavating thrust through multiple folded-jacks A two-stage shield excavator, which is configured to transmit to the small-diameter front body. 2. The two-stage shield excavator according to claim 1, wherein a front body fixing device for fixing the large diameter front body to the small diameter front body so that the large diameter front body can be released is provided on the small diameter front body. . 3. The two-stage shield machine according to claim 1, wherein the large-diameter rear body is releasably fixed to the small-diameter center bending cylinder by a fixing mechanism including a plurality of bolts. 4. A cutter disk, wherein a part of the cutter spokes is provided with a telescopic mechanism capable of switching the cutter spokes from a large-diameter state corresponding to the large-diameter front body to a small-diameter state corresponding to the small-diameter front body. The two-stage shield excavator according to any one of claims 1 to 3, wherein a mud discharge outlet is provided in the remaining cutter spoke in a constantly small diameter state. 5. A large-diameter shield eccentric fitting is detachably connected to a tip end of a piston rod of each of the shield jacks when a large-diameter shield is excavated, and a large-diameter shield eccentric metal fitting is used for a small-diameter shield excavation. The two-stage shield machine according to claim 4, wherein the machine is replaced with a metal fitting. 6. An erector device for lining a segment, further comprising a diameter switching mechanism for switching the length of the erector body in the tunnel radial direction from the length for the large-diameter shield to the length for the small-diameter shield. The two-stage shield machine according to claim 4, characterized in that: