JPH03197790A - Shield excavator - Google Patents

Abstract

PURPOSE:To enable the shield of a steep curve by coupling the front cylindrical pat and rear cylindrical part with each other by a jack so that they are capable of bending and, at the same time, bending the front cylindrical part in accordance with curvature of a tunnel. CONSTITUTION:A shield frame 22 is constituted of the rear cylindrical part 23 and front cylindrical part 24 and, at the same time, the rear cylindrical part 23 is coupled with the front cylindrical part 24 by a center bent jack 28 at a center bent angle gamma so that they are capable of bending. The front bending piece 24b bent small to a specific angle alpha in accordance with curvature of a tunnel is provided to the end of the front cylindrical part 24 and, at the same time, a cutter 31 is held by the bending piece 24b. In the event of execution, after the frame 22 is set to a specific center bent angle gamma, the jack 28 is locked hydraulically, a center bent angle of a center bent section 30 is fixed and, at the same time, the frame 22 if fixed to a bedrock with grippers 52. In addition, a cutter motor 44 is driven, and the cutter 31 is rotated to excavate the bedrock.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a shield tunneling machine, and particularly to a shield tunneling machine that can construct tunnels with sharp curvature.

[Prior Art] In recent years, there has been an increasing demand for sharp curve enforcement under narrow roads in urban areas with heavy traffic volume, where standing techniques are not provided.

Generally, a folding type shield tunneling machine as shown in FIG. 7 is known as a tunneling machine for constructing curved tunnels.

The illustrated example shows a mud-water type excavator 1, and this excavator 1 has a cylindrical shield frame 2. This shield frame 2 is mainly composed of a rear body part 3 and a front body part 4, which are divided into front and rear parts in the excavation direction, and the divided parts are overlapped and connected to each other.

A shield jack 5 that generates a propulsive force is disposed in the circumferential direction inside the rear body 3, and this shield jack 5 engages with a segment 6 that provides a propulsive reaction force to push the excavator 1 in the excavation direction. It looks like this.

Further, a cutter 7 constituting an excavation part is rotatably provided at the front part of the front body part 4 in the digging direction, and a copy cutter 7a for extra digging is provided on the outer periphery of this cutter so as to be freely retractable. . A cutter drive device 8 and a mud feeding pipe 9 are located behind the cutter. A mud removal pipe 10 is connected.

Further, a bent jack 11 is provided, one end of which is connected to the rear body part 3 and the other end of which is connected to the front body part 4, and this bent jack 11 is arranged alternately with the shield jack 5 in the circumferential direction. has been done. Therefore, the shield frame 2 is formed with a folded part 12 for bending it, and by expanding and contracting the folding jack 11 at the folded part 12, the shield frame 2 can be bent at any angle from the folded part 12. become.

[Problem to be solved by the invention] By the way, in the conventional excavator 1, the axis A of the front body 4
is formed in a straight line, and the shield frame 2 is formed by a single center fold (a single center fold 12). Therefore, when constructing a tunnel with a sharp curve, bending the shield frame 2 along the sharp curve requires a large bending angle, and there is a limit to the bending angle. Therefore, tunnel construction is limited to shields with relatively gentle curves, and the bend angle is large, resulting in a large amount of over-excavation.

Furthermore, when the bending angle becomes large, it is necessary to provide a large tail clearance, which increases the tail void between the ground and the tunnel, which causes the problem of ground subsidence.

In addition, in order to cope with sharp curves, it is effective to divide the shield frame into three parts in the excavation direction and connect each divided part with center-folding jacks to form a two-section shield frame 2, but in this case. has the disadvantage of having a long pilot. It is also conceivable to connect the front body part 4 and the rear body part 3 with a bellows, but this has the drawback of requiring a complicated mechanism to counter the tonosho.

The present invention has been devised to effectively solve the above problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide a shield excavator that enables shielding of sharp curves.

[Means for Solving the Problems] The present invention provides a shield excavator for excavating a tunnel with a curvature in one direction, in which the shield frame is positioned forward in the excavation direction and has a front body section having an excavation section for excavating the ground. , and a rear body part that engages with a segment formed rearward in the digging direction to allow digging in the digging direction, and the front body part and the rear body part are connected to each other with a jack so as to be flexible, The portion is bent to correspond to the above curvature.

[Function] As described above, since the front body part is bent in advance in accordance with the curvature in one direction, the bending angle of the connecting portion between the front body part and the rear body part can be reduced by the bending angle. Therefore, it is possible to form a small bending angle and a large bending angle of the entire shield frame. Therefore, it is possible to deal with sharp curves, and the tail void between the ground and the tunnel can be reduced.

[Example code] Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a shield excavator for excavating hard ground, such as a soft rock layer.

As shown in the figure, this excavator 21 has a cylindrical shield frame 22, and this shield frame 22 is divided into two parts in the front and back of the excavation direction, and a rear body part 23 and a front body part 24 are overlapped and connected. It is mainly composed of.

A plurality of shield jacks 25 that generate propulsive force are disposed in the circumferential direction inside the rear body section 23, and the shield jacks 2
5 is a segment 27 whose one end is connected to the girder part 26 of the rear body part 23 and whose other end is formed rearward in the excavation direction.
It is designed to be removably engaged with.

The rear body part 23 and the front body part 24 are connected by a bent jack 28, one end of which is connected to the girder part 26 of the rear body part 23, and the other end connected to the front body part 24. It is connected to the girder part 29 of. In other words, the middle bending portion 3 where the shield frame 22 is bent
0 will be formed. The bent jack 28 has substantially the same propulsion force as the shield jack 25.

On the other hand, a cutter 3 constituting an excavation part for excavating the face ground is provided at the tip of the front body part 24 located forward in the excavation direction.
As shown in FIG. 2, the front face of the cutter 31 is provided with a tooth bit 32 and a roller cutter 33, and an overcutter 33 is provided so as to be freely retractable. At the rear of the cutter 31, as shown in FIG. ) is now connected.

Further, the cutter 31 is rotatably driven in one direction concentrically with the front body portion 24 and is supported so as to be movable forward and backward in the digging direction.

Specifically, a center shaft 41 inserted through the bulkhead 35 is integrally extended behind the cutter 31, and a spline shaft 42 is attached to the rear end of the center shaft 41.
is formed. A cutter gear 43 is meshed with the spline shaft 42, and a binion 45 of a cutter motor 44 is meshed with the cutter gear 43. Further, a sleeve 46 is engaged with an intermediate portion of the center shaft 41, and this sleeve 46 is adapted to engage with a journal portion 47 formed in the bulkhead 35 so as to be slidable in the excavation direction. A fixed arm 48 extends from the rear end of the sleeve 46.
8 is connected to a slide jack 49 fixedly supported by the bulkhead 35.

Therefore, the cutter 31 including the center shaft 41 is rotationally driven by the cutter motor 44 with the bulkhead 35 and the sleeve 46 fixed, and the cutter gear 4
3 and the journal portion 47 as fixed sides, it is moved forward and backward to slide integrally with the sleeve 46 by a slide jack 49.

In particular, the front torso 24 is designed to form a tunnel with curvature in one direction.
is formed by being bent in advance according to its curvature. In this embodiment, the straight portion 24a has a straight intermediate portion.
A front body portion 24 is formed, and a front bent portion 24b that is slightly bent at a predetermined angle α (5 degrees) corresponding to the curvature of the tunnel is formed at the tip thereof, and a predetermined bent portion 24b is formed at the rear end. Rear bent portion 24 that is largely bent at an angle β (15 degrees)
c is formed. The rear bent portion 24c is provided with a folded seal 51, into which the tip of the rear body portion 23 is inserted and engaged. That is, at the tip of the rear body part 23, there is a spherical sliding part 2 which is inscribed in the rear end bending part 24c of the front body part 24 and whose diameter is gradually reduced to allow bending in the middle.
3a is formed.

Therefore, since the cutter 31 is held at the tip of the front body portion 24 bent at a predetermined angle, the cutter 31 is held with its rotational axis inclined inward at the same angle.

In addition, a gripper 52 for preventing rolling of the shield frame 22 is provided in the front body portion 24 and is attached to the bulkhead 35.
is supported by This gripper 52 is designed to be inserted into and removed from the ground. Furthermore, an erector 53 for assembling the segments 27 is provided within the rear body portion 23.

Next, the operation of the above embodiment will be explained.

As shown in FIG. 1, first, the center bending jack 28 is expanded and contracted along the bending direction to bend the center bend portion 3o at a predetermined angle. In this case, the rear end bent portion 2 of the front body portion 24
4c is bent in advance at a predetermined angle β, the bending angle of the center bending portion 30 can be reduced by the bending angle β.

As a result, the tail void can also be made smaller.

In the illustrated example, the axis C of the rear body part 23 is bent at a maximum angle of ±10° with respect to the axis B of the rear bending part 24c of the front body part 24, at an intermediate bending angle γ. Therefore, the shield frame 22 is bent within the range of this bending angle γ.

In this way, the shield frame 22 is bent at a predetermined center bend angle γ.
After this is determined, the center bending jack 28 is hydraulically locked,
The folding angle of the folding part 30 is fixed. After fixing the bending angle, push out the gripper 52 and insert it into the ground,
The shield frame 22 is fixed to prevent rolling.

Next, the rotational force of the cutter motor 44 is transmitted from the cutter gear 43 to the cutter 31 to rotate it in one direction, and the cutter 31 is slid toward the front face side to excavate the ground. That is, by shortening the slide jack 49 with the cutter gear 43 and journal portion 47 fixed, the cutter 31 moves integrally with the sleeve 46.

At this time, since the tip of the front body portion 24 is bent inward at a predetermined angle α, the cutter 31 also slides while rotating inward along the axis of the inward bend. Therefore, the remaining amount can be reduced compared to when the cutter 31 slides along the axis of the straight portion 24a.

After excavating the amount of slide movement of cutter 31, cutter 3
1 and pull it back, pull out the gripper 52 from the ground, and release the lock. Therefore, a space is formed in front of the cutter 31, but the face ground is held by the mud water pressure.

Next, the excavator 21 is propelled and moved. For this purpose, the shield jack 25 is extended. shield jacket 2
5 causes the excavator 21 to propel itself using the segment 27 as a reaction force. The excavator 21 is a bent jack 28 having approximately the same propulsion force as the shield jack 25.
Since it is hydraulically locked, the center bending angle is maintained while it is propelled. In this case, since the tip of the front trunk section 24 is bent, there is little propulsion resistance.

In addition, the front body part 2 generated by pushing from the rear body part 23
The warping effect of the ground of 4 rpJ can be used for the rotational moment of the excavator 21.

After the propulsion movement, the segments 27 are assembled by the erector 53.

Therefore, prior to the propulsion movement of the excavator 21, the cutter 3
By rotating and sliding the shield to excavate the ground, it is possible to create a shield along a curve.

Furthermore, if the curvature of the curve changes, the bend angle will be adjusted.

FIG. 3 shows the turning attitude when the radius of curvature is small (7 mR), and FIG. 4 shows the turning attitude when the radius of curvature is large (25 mR).

As shown in FIG. 3, in the case of a relatively sharp curve, the bend angle γ (10°) is the maximum angle. In this case, the tail void is reduced by the bending angle of the rear end portion 24C of the front body portion 24. Further, in the case of a gentle curve as shown in FIG. 4, the bending angle γ (7 degrees) is small.

Therefore, it is possible to construct tunnels with a wide range of curvatures, from sharp curves to gentle curves, and to continuously construct tunnels that do not curve in one direction. Because of this, it is possible to construct tunnels in a spiral or loop shape.

As shown in FIG. 5, the front end portion of the front body portion 24 is formed by folding the front end bent portion 24b to the opposite side to form a straight axis, and the center bent portion 30 is formed at the rear end portion of the front body portion 24. The same angle (β-γ
), the axis of the shield frame 22 becomes approximately straight. Therefore, in this case, straight excavation is also possible.

In this way, the present invention connects the front body part 24 and the rear body part 23 in a flexible manner, and also forms the front body part 24 bent in accordance with the curvature in one direction, thereby preventing the shield frame 22 from folding in the middle. Since the angle can be made smaller, the amount of excess excavation can be reduced. In addition, it is possible to accommodate curve radii of various sizes by simply changing the bend angle, allowing the tunnel construction range to be expanded.

Furthermore, since the tail clearance can be reduced, the tail void between the tunnel and the ground is also reduced.

Therefore, the amount of ground subsidence after the tunnel is completed can be reduced, and the amount of backfilling material injected into the tail void can be reduced.

In addition, although the said Example demonstrated the excavation machine for excavating hard ground, it is not limited to this. Therefore, it can also be applied to conventional excavators that excavate soft soil layers. Therefore, it is highly versatile.

Further, the front body portion 24 may be formed as shown in FIG.
That is, the front body portion 24 may be formed to have a gentle curve so that its axis coincides with the axis of the curved tunnel.

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are achieved.

(1) Connecting the front body part and the rear body part in a flexible manner,
By bending the front body to correspond to the curvature in one direction, the bending angle of the shield frame becomes smaller, reducing the amount of excess excavation, and it is possible to accommodate curve radii of various sizes by simply changing the bending angle. , the scope of tunnel construction can be expanded.

(2) Since the tail clearance can be reduced, the tail void between the tunnel and the ground becomes smaller, and the amount of ground subsidence after the tunnel is completed can be reduced, as well as the amount of backfilling material injected into the tail void.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an excavator according to the present invention, FIG. 2 is a view taken along the line ■-■ in FIG. 1, and FIGS. 3 and 4 are schematic diagrams showing the excavator in a curved position. 5 and 6 are schematic views showing other embodiments, and FIG. 7 is a sectional view showing a conventional example. In the figure, 23 is a rear body part, 24 is a front body part, and 28 is a jack.

Claims (1)

[Claims] 1. In a shield excavator that excavates a tunnel with a curvature in one direction, the shield frame is divided into a front body part located at the front in the excavation direction and having an excavation part for excavating the ground, and a segment formed at the rear in the excavation direction. The front body part and the rear body part are connected to each other with a jack so as to be flexible, and the front body part is bent in accordance with the curvature. A shield excavator characterized by: