JP2020094440A - Boring machine - Google Patents

Abstract

To provide a boring machine capable of increasing or reducing a boring diameter at any ratio without largely changing arrangements.SOLUTION: A shield machine 1 is provided with: a cutter head 20 which serves as a rotational body for cutting provided with a plurality of bits 21 cutting the natural ground, and is configured to allow a boring diameter to be increased or reduced at any ratio; a barrier wall 30 configured to allow its outer diameter to be increased or reduced at any ratio; and a steel shell 40 configured to allow its outer diameter to be increased or reduced at any ratio. Such configuration of the shield machine 1 allows the boring diameter to be increased or reduced at any ratio without largely changing arrangements.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an excavator capable of enlarging or reducing an excavation diameter at an arbitrary ratio.

Conventionally, excavators including shield machines and propulsion machines have been used for excavating sewers, power cables, road tunnels, and the like. An excavator generally excavates while rotating a cutter head having a bit. Therefore, the excavated cross section is basically circular, and its outer diameter (excavation diameter) is also constant.

By the way, for example, it may be necessary to enlarge or reduce the cross section in the middle of a power cable cave or branch/junction of a water and sewer tunnel, a railway tunnel station, or an emergency parking zone of a road tunnel. In order to enlarge/reduce the cross section on the way, there are a method of installing a vertical shaft and replacing the excavator on the way, and a method of enlarging the cross section while continuously using one excavator. However, in the former method of installing a shaft and exchanging excavators, there is a problem in that in addition to excavating the shaft, it is necessary to prepare two excavators and replace excavators. It was

As the excavator capable of enlarging the cross section of the latter excavator, the following construction methods are specifically known. That is, there is known a construction method in which a part of an outer cylinder portion of an excavator is lapped and the lap portion is expanded/contracted during excavation to expand an excavation cross-section simultaneously with excavation (see Patent Document 1).

In addition, there is also known a method of constructing an enlarged space from the inside of the tunnel by excavating the outer periphery of the shield tunnel constructed in advance in a ring shape in the tunnel axial direction using an enlarged shield (Patent Document 2). reference).

On the other hand, as a shield excavator that can reduce the cross section, for example, a child shield machine with a smaller diameter than the parent shield machine is built in the parent shield machine, and the child shield machine is started from the parent shield machine on the way. A construction method adapted to do so is known (see Patent Document 3).

JP 2004-270356 A JP-A-58-98595 JP, 2003-82978, A

However, each of the above-mentioned construction methods is configured so that the work is interrupted and the setup is changed, and then the work is enlarged or reduced only to a predetermined excavation shape or excavation diameter. It was not possible to expand or reduce the excavation diameter at any ratio.

Therefore, an object of the present invention is to provide an excavator capable of enlarging or reducing the excavation diameter at an arbitrary ratio without largely changing the setup.

In order to solve such a problem, an excavator according to a first aspect of the present invention is a rotating body for cutting having a plurality of bits for cutting a natural ground, so that an excavation diameter can be enlarged or reduced at an arbitrary ratio. A configured rotating body for cutting, a partition wall configured to expand or reduce the outer diameter at an arbitrary ratio, and a steel shell configured to expand or reduce the outer diameter at an arbitrary ratio. I have it.

Further, the cutting rotating body of the excavator of the second invention is a drive shaft installed at a rotation center and a plurality of spokes radially attached to a tip of the drive shaft. A plurality of spokes that are rotatably attached and a plurality of jacks that change the rotation angle of the plurality of spokes are provided.

Further, each of the plurality of spokes of the cutting rotary body of the excavator of the third invention has a plurality of spoke pieces having the bit, and a spoke rod inserted into the plurality of spoke pieces, The plurality of spoke pieces are configured so that an angle with respect to the spoke rod can be changed.

Further, the partition wall of the excavator of the fourth invention is composed of a plurality of substantially fan-shaped partition wall flaps and is rotated in the tunnel longitudinal direction while overlapping the adjacent partition wall flaps, or the adjacent partition walls. By rotating the flap in the tunnel longitudinal direction while folding the flap, the outer diameter can be enlarged or reduced at an arbitrary ratio.

Further, the steel shell of the excavator according to the fifth invention is composed of a plurality of cylindrical shell pieces and a plurality of support jacks supporting the plurality of cylindrical shell pieces, and the adjacent cylindrical shell pieces are centered. The outer diameter can be expanded or contracted at an arbitrary ratio by expanding and contracting the support jack while tilting and superposing them.

The excavator according to a sixth aspect of the present invention is a lining or a load-supporting shaft disposed substantially at the center of a lining or segment installed on the pit side of the excavator, and the lining or the segment from the load-supporting shaft. At least three grippers overhanging the load supporting shaft are further provided so that the load supporting shaft can support its own weight.

Further, the excavator according to the seventh aspect of the present invention further includes a supporting means that is inserted into the natural ground so that the supporting means supports its own weight.

Further, an excavation method of the eighth invention is an excavation method for enlarging an excavation diameter by using any of the excavators described above, which comprises enlarging an outer diameter of the cutting rotor and It comprises a step of excavating the ground for the captain of the excavator in a state where the rotating body is enlarged, a step of enlarging the outer diameter of the steel shell, and a step of enlarging the outer diameter of the partition wall. ..

The excavation method of the ninth invention is an excavation method for enlarging the excavation diameter by using any one of the excavators described above, which comprises enlarging the outer diameter of the cutting rotary body, and The method includes the steps of excavating the ground for one segment in a state where the rotating body is expanded, expanding the outer diameter of the steel shell, and expanding the outer diameter of the partition wall.

The excavation method of the tenth invention is an excavation method of enlarging the excavation diameter by using any of the excavators described above, which comprises enlarging the outer diameter of the cutting rotary body, and The step of excavating the natural ground while enlarging the outer diameter of the rotating body, the step of enlarging the outer diameter of the face end of the steel shell, and the step of enlarging the outer diameter of the partition wall are continuously tuned. Let me repeat it.

Further, an excavation method of the eleventh invention is an excavation method of reducing an excavation diameter by using any one of the excavators described above, wherein the cutting rotor has a length corresponding to a length of the excavator before being reduced. The step of excavating the natural ground, the step of reducing the outer diameter of the cutting rotary body, the step of reducing the outer diameter of the partition wall, and the step of reducing the outer diameter of the steel shell. ..

The excavation method of the twelfth invention is an excavation method of reducing the excavation diameter by using one of the excavators described above, wherein the cutting rotary body is in a state before reduction in size for one segment. A step of excavating, a step of reducing the outer diameter of the rotating body for cutting, a step of reducing the outer diameter of the partition wall, and a step of reducing the outer diameter of the steel shell.

The excavation method of the thirteenth invention is an excavation method of reducing the excavation diameter by using any one of the excavators described above, and excavates the natural ground while reducing the outer diameter of the cutting rotary body. A step, and a step of reducing the outer diameter of the partition wall,
The step of reducing the outer diameter of the face end of the steel shell is continuously synchronized and repeated.

In the present invention, the phrase "outer diameter can be enlarged or reduced at an arbitrary ratio" means mainly from a first state (for example, a small diameter state) to a second state (for example, a large diameter state). It is intended that the size can be continuously changed to a similar shape while maintaining a predetermined shape. However, the case where the shape changes from the first state to the second state is not excluded, and it is of course possible to change the shape on the way. As a matter of course, the deformation from the first state to the second state may be an expansion deformation that widens the cross-sectional area or a reduction deformation that narrows the cross-sectional area.

Thus, the excavator according to the first aspect of the present invention is a rotating body for cutting having a plurality of bits for cutting the ground, and is configured to be capable of enlarging or reducing the excavation diameter at an arbitrary ratio. The rotating body, the partition wall configured to expand or reduce the outer diameter at an arbitrary ratio, and the steel shell configured to expand or reduce the outer diameter at an arbitrary ratio are provided. With such a configuration, the excavator is capable of enlarging or reducing the excavation diameter at an arbitrary ratio without largely changing the setup.

In other words, in the case of the excavator of the first invention, the work is interrupted by using the three main elements that are also used during the normal excavation of the rotating body for cutting, the partition wall, and the steel shell as they are. It is possible to continuously expand or reduce the drilling diameter. Further, since all three elements are configured to be able to be expanded or contracted at any ratio, the excavation diameter can be expanded or contracted at any ratio.

Further, since the excavator of the first invention can expand or reduce the excavation diameter at any time, even if the diameter is different depending on the section such as a long-distance sewer main line, the diameter can be enlarged or reduced at any time. It becomes possible to excavate. Therefore, since it is possible to excavate by one shield machine 1 without preparing different excavators for each section, it is possible to reduce costs. Furthermore, the cost is reduced compared to excavation according to the maximum diameter, and the environmental load is also reduced by reducing the amount of soil generated.

Furthermore, with the excavator of the first aspect of the present invention, it is possible to achieve an expansion ratio of about 2 times from the minimum diameter and a reduction ratio of about 1/2 from the maximum diameter. Therefore, in the sewerage field, it can be applied to the widened part only at the joint part when connecting the merge main line to two upstream main lines having almost the same flow rate. Furthermore, it can be applied to emergency parking zones and branch sections of road tunnels. If construction can be performed during the main excavation, it is expected that construction period will be shortened, cost will be reduced, workability will be improved, and safety will be improved.

The cutting rotating body of the excavator of the second invention is a drive shaft installed at the center of rotation and a plurality of spokes radially attached to the tip of the drive shaft, and is rotatable with respect to the drive shaft. , And a plurality of jacks for changing the rotation angle of the plurality of spokes. With such a configuration, the excavation diameter can be easily changed (enlarged/reduced) at an arbitrary ratio simply by expanding and contracting the jack.

Further, each of the plurality of spokes of the rotating body for cutting of the excavator of the third invention has a plurality of spoke pieces having a bit and a spoke rod inserted through the plurality of spoke pieces, and a plurality of spokes. The piece is configured so that the angle with respect to the spoke rod can be changed. Therefore, even if the excavation diameter changes due to the rotation of the spoke rod, the tooth bit can always face the face, so that the excavation efficiency does not decrease.

Further, the partition wall of the excavator of the fourth invention is composed of a plurality of substantially fan-shaped partition wall flaps and is rotated in the tunnel longitudinal direction while overlapping the adjacent partition wall flaps, or the adjacent partition wall flaps are folded. While rotating in the tunnel longitudinal direction, the outer diameter can be enlarged or reduced at an arbitrary ratio. Therefore, only by rotating the partition wall in the longitudinal direction of the tunnel, it is possible to easily enlarge or reduce the outer diameter of the partition wall at an arbitrary ratio without making a large setup change.

Further, the steel shell of the excavator of the fifth invention is composed of a plurality of cylindrical shell pieces and a plurality of support jacks supporting the respective cylindrical shell pieces, and the adjacent cylindrical shell pieces are tilted with respect to the center. By expanding and contracting the support jacks while overlapping them, the outer diameter can be enlarged or reduced at an arbitrary ratio. Therefore, the outer diameter of the steel shell can be easily expanded or contracted at an arbitrary ratio by simply expanding and contracting the support jack without a large setup change.

The excavator according to a sixth aspect of the invention is a load supporting shaft disposed substantially at the center of a lining or segment installed at the rear, and at least three grippers extended from the load supporting shaft to the lining or segment. Further, the load supporting shaft is adapted to support its own weight. With this configuration, the lining or the segment can be mainly borne by the weight of the rear portion of the excavator.

The excavator according to the seventh aspect of the present invention further includes a support means that is inserted into the ground from the cutting rotary body, and has the support means support its own weight. With this configuration, it is possible to mainly bear the own weight of the front portion of the excavator on the ground.

In addition, the excavation method for enlarging the excavation diameter of the eighth to tenth inventions is a method of enlarging the diameter at a time, discontinuously enlarging the diameter little by little, or by continuously enlarging the diameter. It is possible to increase the outer diameters of the rotating body, partition wall, and steel shell. Therefore, with this excavation method, the excavation diameter can be easily enlarged at an arbitrary ratio without a large setup change.

Further, the excavation method for reducing the excavation diameter according to the eleventh to thirteenth aspects of the invention is to reduce the diameter at a time, reduce the diameter discontinuously little by little, or reduce the diameter continuously to perform cutting. It is possible to reduce the outer diameters of the rotating body, partition wall, and steel shell. Therefore, according to this excavation method, the excavation diameter can be easily reduced at an arbitrary ratio without a large setup change.

It is a longitudinal cross-sectional view of the excavator in a state in which the excavation diameter is reduced. It is a cross-sectional view of the excavator with the excavation diameter reduced. It is a longitudinal cross-sectional view of the excavator with the excavation diameter enlarged. It is a cross-sectional view of the excavator with the excavation diameter enlarged. FIG. 5 is an explanatory diagram illustrating a state of transformation of the rotating body for cutting according to the first embodiment. (A) is the state of the minimum diameter, (b) is the state of the intermediate diameter, and (c) is the state of the maximum diameter. It is an explanatory view explaining a spoke piece and a spoke rod in detail. (A) shows the state of the maximum diameter, and (b) shows the state of the intermediate diameter. FIG. 5 is an explanatory diagram of a state where the partition wall of Example 1 has a minimum diameter. (A) is a front view and (b) is a side view. FIG. 6 is an explanatory diagram of a state where the partition wall of Example 1 has a maximum diameter. (A) is a front view and (b) is a side view. It is explanatory drawing explaining the drive cylinder of a partition. It is explanatory drawing of the state of the minimum diameter of the steel shell of Example 1. (A) is a front view, (b) is a side view, and (c) is a partially enlarged view. It is explanatory drawing of the state of the maximum diameter of the steel shell of Example 1. (A) is a front view, (b) is a side view, and (c) is a partially enlarged view. It is explanatory drawing of the first half of the excavation construction method which expands an excavation diameter. It is explanatory drawing of the latter half of the excavation method of enlarging the excavation diameter. It is explanatory drawing of the first half of the excavation construction method which reduces an excavation diameter. It is explanatory drawing of the latter half of the excavation construction method which reduces an excavation diameter. 5 is a side view of a cutting rotary body of Example 2. FIG. (A) shows the state of the minimum diameter, and (b) shows the state of the maximum diameter. It is explanatory drawing which illustrates the spoke piece and spoke rod of Example 2 in detail. (A) shows the state of the maximum diameter, and (b) shows the state of the intermediate diameter. It is explanatory drawing of the state of the minimum diameter of the partition of Example 3. (A) is a front view and (b) is a side view. It is explanatory drawing of the state of the maximum diameter of the partition wall of Example 3. (A) is a front view and (b) is a side view. It is explanatory drawing explaining the drive motor of a partition. It is explanatory drawing explaining an edge part flap. (A) is a perspective view of the state of the maximum diameter seen from the face side, and (b) is a perspective view of the state of the maximum diameter seen from the wellhead side. (C) is a perspective view of the state of the intermediate diameter as seen from the face side, and (d) is a perspective view of the state of the intermediate diameter as seen from the wellhead side. (E) is a perspective view of the state of the minimum diameter seen from the face side, and (f) is a perspective view of the state of the minimum diameter seen from the wellhead side. It is explanatory drawing of the state of the minimum diameter of the steel shell of Example 4. (A) is a front view and (b) is a side view. It is explanatory drawing of the state of the maximum diameter of the steel shell of Example 4. (A) is a front view and (b) is a side view.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, a shield construction method including the shield machine 1 as an excavator will be described as an example, but the present invention is not limited to this.

In each of Examples 1 to 4, the basic configuration of the excavator (shielding machine 1) and the excavation method will be described in Example 1, and the rotating body for cutting (cutter head 20) of another form will be described in Example 2. Then, the partition 30B of another form will be described in Example 3, and the steel shell 40 of another form will be described in Example 4.

<Structure>
(Overall structure of shield machine)
First, the overall configuration of the shield machine 1 as an excavator of this embodiment will be described with reference to FIGS. 1 to 4. The shield machine 1 is composed of a generally cylindrical face-side front body portion 1A (hood portion and girder portion) and a wellhead-side rear body portion 1B (tail portion). The shield machine 1 according to the present embodiment is configured so that the excavation diameter can be enlarged or reduced at an arbitrary ratio, and the cutter head 20 as a cutting rotating body can be enlarged or reduced at an arbitrary ratio. And the steel shell 40 (40A, 40B) configured so that the outer diameter can be enlarged or reduced at an arbitrary ratio.

The cutter head 20 as a cutting rotary body is supported by the center shaft 11, and is configured to rotate by rotationally driving the center shaft 11 by the cutter motor 12 (center support system). A mechanism for enlarging or reducing the excavation diameter of the cutter head 20 will be described later. Although not shown, the annular bearing may be configured to be driven to rotate (intermediate support system).

The partition wall 30 is installed between the hood portion (tip portion of the shield body) and the girder portion (intermediate portion of the shield body) in order to maintain the pressure of mud or muddy water for stabilizing the face. A mechanism for enlarging or reducing the outer diameter of the partition wall 30 will be described later.

The steel shell 40 constitutes the outer plate portion of the main body of the shield machine 1, prevents the inflow of soil and groundwater from the outside of the shield machine 1, and protects the internal device group and working space. The steel shell 40 is composed of a front steel shell 40A corresponding to the front body portion 1A and a rear steel shell 40B corresponding to the rear body portion 1B. A mechanism for enlarging or reducing the outer diameter of the steel shell 40 will be described later.

In addition to this, the shield machine 1 is, as shown in FIGS. 1 and 3, for carrying out the shield jack 13 for propelling the shield machine 1 in the cutting face direction, the erector 14 for assembling the segment into a predetermined shape, the curve construction and the posture control. It is equipped with a group of devices such as a center folding jack 15 and a screw conveyor 16 which is an earth discharging device. Here, the center-breaking jack 15 is not necessary when making a straight line. Further, as the soil discharging device, the screw conveyor 16 is used in the case of the earth pressure type and the mud pressure type, but it is not limited to this, and in the case of the muddy type, a mud pipe (drain pipe) is used. You can also

As described above, the shield machine 1 constructs a tunnel structure by excavating the natural ground using the device group. For example, in the case of the earth pressure type shield construction method, the earth and sand excavated by the cutter head 20 is filled between the face and the partition wall 30, an additive is injected if necessary, and the ground face is excavated while stabilizing the face face, and the partition wall. The soil is discharged by the screw conveyer 16 which is installed penetrating 30.

Then, the segment is assembled into a ring shape by the erector 14 while partially releasing the shield jack 13 (primary lining). Further, backfilling injection and secondary lining as required are performed to complete the tunnel structure.

As will be described below, the shield machine 1 as the excavator of the present embodiment is a main element constituting the shield machine 1, that is, the cutter head 20 as a cutting rotating body, the partition wall 30, and the steel shell 40. , 3 are configured so that they can be enlarged or reduced at any ratio.

(Structure of cutting rotor)
Next, with reference to FIGS. 5A to 5C, 6A and 6B, the configuration of the cutter head 20 as the cutting rotary member of the present embodiment will be described. The cutter head 20 of the present embodiment has a plurality of bits 21 for cutting the natural ground and is configured so that the excavation diameter can be enlarged or reduced at an arbitrary ratio.

That is, when expanding, the cutter head 20 has a plurality of spokes 23,... (Refer to FIG. 4) rotatably attached to the boss portion 22 connected to the center shaft 11, in the face direction (spoke 23). By rotating the center shaft 11 such that the angle formed by the center shaft 11 and the center shaft 11 becomes large, the entire V-shaped state is reduced from the closed state (FIG. 5A) to the open V-shaped state (FIG. 5A). After the process of FIG. 5(b), the process can be expanded at an arbitrary ratio up to the most expanded linear state (FIG. 5(c)).

On the contrary, when shrinking, the cutter head 20 has a plurality of spokes 23,..., Which are rotatably attached to the boss portion 22 connected to the center shaft 11, in the direction of the wellhead (the spoke 23 and the center shaft 11). By being rotated so that the angle formed by () becomes smaller), from the most expanded linear state (FIG. 5(c)) to the opened V-shaped state (FIG. 5(b)), It is possible to reduce the V-shaped state which is the most reduced and closed (FIG. 5A) at an arbitrary ratio.

In the present embodiment, the plurality of spokes 23,... Are configured such that the base end side (inner side) attached to the center shaft 11 is the face side and the tip end side (outer side) is the wellhead side. As a whole, the center is formed in a V shape projecting to the face of the face. That is, in this embodiment, the spokes 23 are inclined so that the inner peripheral side is excavated first.

Specifically, the cutter head 20 includes a center shaft 11 as a drive shaft installed at the center of rotation and four spokes 23 radially attached to a boss portion 22 at the tip of the center shaft 11. There are four spokes 23,... Which are rotatably attached to the boss portion 22, and four jacks 24, which change the rotation angle of the four spokes 23,. , Are provided. The number of spokes 23,... Is not limited to four, and may be six or eight, for example.

More specifically, the spokes 23 are rotatably attached to the boss portion 22 at their base ends, and rotatably attached to the rod side of the jack 24 at their tip ends. Further, the head side of the jack 24 is attached to a ring member 25 arranged near the center of rotation. Then, the opposing jacks 24 are uniformly expanded and contracted to rotate the spokes 23 while canceling out the reaction forces.

(Bit configuration)
Next, the configuration of the bit 21 of this embodiment will be described with reference to FIGS. 5A to 5C, 6A, and 6B. The bit 21 of this embodiment includes a fish tail bit 21F installed on the boss 22 and a plurality of tooth bits 21T installed on the spokes 23. That is, each of the plurality of spokes 23,... Of the cutter head 20 is common to the plurality of spoke pieces 23P,. The spoke rod 23R is inserted through the spoke rod 23R.

The plurality of spoke pieces 23P of this embodiment are configured so that the angle with respect to the spoke rod 23R can be changed. Specifically, as shown in FIG. 6A, each spoke piece 23P is formed to have a parallelogram cross section, and the spoke rod 23R is inserted into the through hole 23H. The side surface of the spoke piece 23P is obliquely divided with respect to the axial direction of the spoke rod 23R, and adjacent spoke pieces 23P are in contact with each other obliquely. More specifically, the angle of the side surface of the spoke piece 23P of the present embodiment is configured to incline from the outside (the side close to the face) toward the rear, from the outside to the inside.

Further, a semi-cylindrical cushioning material 23G is sandwiched between each spoke piece 23P and the spoke rod 23R. That is, the spoke piece 23P is provided with a semicylindrical notch 23N continuous with the through hole 23H, and the semicylindrical cushioning material 23G is provided in the notch 23N. As a result, as shown in FIG. 6B, when the spoke rod 23R is pulled in obliquely, the cushioning member 23G rotates (rolls), so that the spoke piece 23P does not follow the inclination of the spoke rod 23R. In addition, the teeth bit 21T always faces the face. Therefore, even if the spokes 23 change the angle when the diameter is expanded or reduced, the tooth bit 21T always faces the face, so that the cutting efficiency is maintained.

(Structure of partition wall)
Next, a mechanism for enlarging or reducing the outer diameter of the partition wall 30 of this embodiment will be described with reference to FIGS. 7 to 9. Although the drive cylinder 62 is shown in FIGS. 7 to 9 as the drive means for convenience of description, it may be the drive motor 61 as described later (see FIG. 20).

As shown in FIGS. 7 and 8, the partition wall 30A is composed of a disk-shaped center plate 35 arranged in the center and a plurality of partition wall flaps 32 divided at equal circumferential angles. It is assembled in a substantially conical shape or a substantially truncated conical shape (mortar shape) protruding rearward. Then, by adjoining the partition wall flaps 32, 32 that are adjacent to each other in the circumferential direction and rotating in the longitudinal direction of the tunnel, the outer diameter can be enlarged or reduced at an arbitrary ratio without leaving a gap. ing.

The partition flap 32 is formed as a substantially fan-shaped flat plate, and has a flap ring 32 a rotatably connected to the center end thereof via a center plate 35 and a center ring 31. Here, the term “substantially fan-shaped” is intended to mean a shape in which the center side of the fan is cut into an arc shape. In addition to the substantially fan-shaped flat plate shape, each partition flap 32 is preferably formed as a curved surface (conical divided curved surface, conical piece) obtained by dividing a conical curved surface in the circumferential direction.

As shown in FIG. 9, a drive cylinder 62 for rotationally driving the partition flap 32 is attached to the flap ring 32a. That is, a link arm 63 is rotatably attached to the drive cylinder 62 through a long hole, and the link arm 63 is fixed to the flap ring 32 a of the partition flap 32. The center ring 31 is an axis for rotating the partition flap 32, and if it functions as an axis, it does not need to be continuous 360 degrees.

Therefore, when the drive cylinder 62 expands and contracts, the link arm 63 rotates up and down, and the partition flap 32 fixed to the link arm 63 rotates. Specifically, when the drive cylinder 62 is contracted, the partition flap 32 is rotated so as to open outward, and when the drive cylinder 62 is extended, the partition flap 32 is rotated so as to be closed inward.

Here, the case where 24 partition wall flaps 32 divided by 15 degrees are provided has been described, but the invention is not limited to this. The number of partition wall flaps 32 and the division angle may be arbitrary.

More specifically, the partition flap 32 of the present embodiment is divided into two parts, left and right, into an inner piece protruding inward and an outer piece protruding outward by a dividing line extending in the radial direction. The inner side piece and the outer side piece of the partition flap 32 are connected by the hinge 32b so that they can be bent in the circumferential direction. Therefore, in the present embodiment, the partition flap 32 is divided into 48 in the circumferential direction in order to further divide 24 sheets into two. As a result, it is easy to enter the gap (groove) of the flap cap 33 (described later) of the adjacent partition flap 32.

The partition wall 30A is assumed to have a maximum expansion ratio of 2 times in the radial direction, but the partition wall flap 32 is ½ of the side positioned inside when the partition wall flap 32 is contracted. With respect to the width, a flap cap 33 folded back in a U shape is formed at the outer end in the radial direction so that the adjacent partition flaps 32 (overlapping on the outer side) are wound. In other words, the vicinity of the outer edge portion of the inner piece protruding toward the inside of each of the two divided partition flaps 32 is bent in a U shape so as to wrap the adjacent partition flaps 32.

In the state of the minimum diameter shown in FIGS. 7(a) and 7(b), the partition wall 30A rotates by tilting toward the face while the adjacent partition flaps 32 partially overlap each other in the circumferential direction. The outer diameter is minimized. More specifically, in this state, the adjacent partition wall flaps 32 overlap each other at the maximum, and the outer piece of the partition wall flap 32 divided into two parts overlaps with the inner partition piece of the adjacent partition wall flap 32 and is almost from the face side. It is not visible (Fig. 7(a)).

On the other hand, in the state where the partition wall 30A has the maximum diameter shown in FIGS. 8A and 8B, the partition wall flaps 32 stand up substantially vertically and form the same plane with almost no overlap between the adjacent partition wall flaps 32. Is maximized. More specifically, in this state, the overlapping of the adjacent partition wall flaps 32 is minimal, and the outer piece of the partition wall flap 32 divided into two is aligned with the inner piece of the adjacent partition wall flap 32 when viewed from the face side. (FIG. 8(a)).

Then, in the state of this maximum diameter, the outer edge of the partition flap 32 comes into contact with the inner surface of the steel shell 40 substantially perpendicularly, so that the reaction force cannot be taken from the steel shell 40. Therefore, a projection 45 is provided on the inner surface of the steel shell 40 to support the outer edge of the partition flap 32 against the earth pressure from the back side, that is, the wellhead side. The protrusion 45 allows the outer edge of the partition flap 32 to receive a reaction force against the earth pressure from the rear side, that is, the wellhead side even in the state of the maximum diameter, and prevents the partition flap 32 from falling to the rear side. Is done. In this way, the partition wall 30A can expand or contract the outer diameter from the minimum diameter to the maximum diameter at an arbitrary ratio.

(Structure of steel shell)
Next, a mechanism for enlarging or reducing the outer diameter of the steel shell 40 of this embodiment will be described with reference to FIGS. 10 and 11. The steel shell 40 (40A, 40B) supports an annular center ring 41 arranged in the center, a plate piece 42 which is a plurality of cylindrical shell pieces divided at equal circumferential angles, and the plate piece 42. And a plurality of support jacks 43. A plate piece 42, which is a cylindrical shell piece formed by dividing a cylinder into equal circumferential angles, has a reinforcing ridge protruding inward in the circumferential direction at a position where a support jack 43 is connected. Are formed. Therefore, a recess is formed on the back side of the plate piece 42. Then, the convex stripe of the plate piece 42 adjacent to the concave groove on the back side is inserted.

In the transverse direction, adjacent plate pieces 42 are supported by the post jacks 43 in a state of being overlapped with each other in the circumferential direction. That is, one end of the post jack 43 is rotatably supported by the plate piece 42, and the other end is rotatably supported by the center ring 41. Further, the plate piece 42 is inclined from the direction directly facing the center of the cross section and overlaps with the adjacent plate piece 42. More specifically, the plate pieces 42 are overlapped with each other while being inclined in the same direction with respect to the center of the cross section. For example, in FIG. 10 and FIG. 11, each plate piece 42 is oriented in such a direction that a vortex is swirled (clockwise) in the same direction as a whole.

Then, in the state where the steel shell 40 has the minimum diameter shown in FIG. 10, the support jacks 43 are contracted to maximize the overlap between the adjacent plate pieces 42, thereby minimizing the outer diameter. On the other hand, in the steel shell 40, in the state of the maximum diameter shown in FIG. 11, the support jacks 43 are extended, and the overlap between the adjacent plate pieces 42 is minimized (or zero, that is, the state of forming the same cylindrical surface). Therefore, the outer diameter is maximized. In this way, the outer diameter of the steel shell 40 can be increased or decreased from the minimum diameter to the maximum diameter at an arbitrary ratio.

<Excavation method>
Next, a method of excavating the shield machine 1 as the excavator of this embodiment will be described with reference to FIGS. 12 to 15. First, the excavation method for increasing the excavation diameter will be described with reference to FIGS. 12 and 13, and then the excavation method for reducing the excavation diameter will be described with reference to FIGS. 14 and 15.

(Excavation method to increase the excavation diameter)
When enlarging the excavation diameter, as shown in FIG. 12(a), the ground around the planned cross-section change (enlargement) position is previously improved by the chemical injection method, ground improvement method, freezing method, etc. Keep it independent.

Next, as shown in FIG. 12B, the outer diameter of the cutter head 20 is enlarged while excavating the natural ground by rotating the cutter head 20 up to the planned cross-section change position. That is, by extending the jack 24, the spoke 23 is rotated in a direction in which the angle formed with the center shaft 11 is increased. At this time, the partition wall 30 and the steel shell 40 maintain the outer diameter before expansion.

Subsequently, as shown in FIG. 12C, the shield head 1 is dug by the length of the shield head 1 with the outer diameter of the cutter head 20 being enlarged. That is, while the cutter head 20 is rotated to excavate the natural ground, the shield jack 13 (and the erector 14) is driven to push the shield machine 1 forward. At this time, the partition wall 30 and the steel shell 40 maintain the outer diameter before expansion.

Further, as shown in FIG. 13(a), the shield machine 1 is forwardly excavated to a position where it can be expanded, and the load supporting shaft 51 is arranged at substantially the center of the lining or segment installed on the wellhead side. It is supported by grippers 52 that project in at least three directions. Then, the load supporting shaft 51 is made to support the dead weight of the shield machine 1 (mainly the dead weight of the rear body portion 1B).

In addition, a support rod 53 as a support means is inserted into the ground on the face side, and the weight of the shield machine 1 (mainly the weight of the front body portion 1A) is supported by the support rod 53. That is, the support rod 53 is fixed to the boss portion 22 of the shield machine 1 and prevents the cutter head 20 from rotating so as to tilt backward due to the weight of the shield machine 1.

Furthermore, the ground around the exposed segment of the shield machine 1 which is disturbed by the excavation is improved so that it does not flow into the shield machine 1 when removing the sand (see FIG. 13B described later). .. In addition, it is also possible to remove the ground in this portion and then expand the diameter before filling.

Next, as shown in FIG. 13(b), suction removal of the surrounding ground corresponding to the captain of the shield machine 1 with a hose extended from inside the chamber or a hose extended from the inboard side and the inboard side Thus, a space in which the steel shell 40 can expand is secured around the shield machine 1. Then, the dead weight of the shield machine 1 is in a state in which both ends thereof are supported by the support rod 53, the load supporting shaft 51, and the gripper 52 in the space.

Finally, as shown in FIG. 13( c ), the outer diameter of the steel shell 40 is enlarged, and the outer diameter of the partition wall 30 is enlarged in synchronization with this. That is, while the support jack 43 is extended little by little, the plate piece 42 is pushed outwards little by little, and the drive jack (or drive motor) is gradually reduced in conjunction with this, whereby the partition flap 32 is gradually increased. In the case of (c), it is raised toward the face. After that, the load supporting shaft 51, the gripper 52, and the support rod 53 are housed, and the forward excavation is restarted in the state of the enlarged diameter.

Here, the case where the diameter is increased while the cutter head 20 is being excavated has been described, but the present invention is not limited to this, and the diameter can be increased while the excavation is stopped. In that case, it is preferable to attach a bit also to the side surface (outward surface) of the spoke piece 23P of the cutter head 20. If the diameter can be expanded while the excavation is stopped in this way, there is an advantage that the ground improvement of the ground around the exposed segment of the shield machine 1 can be omitted.

Further, although the example in which the cross-section is greatly changed has been described here, the present invention is not limited to this, and the cross-section can be continuously changed as described below, or the cross-section can be changed discontinuously in small steps. You can also

When changing the cross-section continuously, the diameter of the face end of the steel shell 40 of the shield machine 1 is increased by one machine length compared to the end of the wellhead side, and the shield machine 1 uses the same. It is possible to continuously excavate the cutter head 20, the partition wall 30, and the steel shell 40 while expanding the diameter at the same rate. When the expansion/contraction ratio is large, the diameter of the steel shell may be greatly changed after the excavation at the expansion start point and the expansion end point, and therefore ground improvement may be necessary.

When changing the cross section in small increments, the shaft of the cutter head 20 of the shield machine 1 is expanded by a diameter corresponding to the length of one machine to be larger than the diameter of the steel shell 40, and the excavated earth and sand are pushed every time one segment is drilled. While expanding, the diameter of the steel shell 40 is expanded. In this case, the earth and sand on the back surface of the steel shell 40 must be removed by suction from the side surface of the steel shell 40 with a vacuum or the like unless it is pushed and spread during diameter expansion. Further, since the steel shell 40 and the segment are separated from each other at the portion in contact with the ground at the rear end of the shield machine 1, it is necessary to improve the ground if the earth pressure cannot be suppressed by the tail seal.

(Excavation method to reduce the excavation diameter)
When reducing the excavation diameter, as shown in Fig. 14(a), the ground around the planned cross-section change (reduction) position is improved in advance by the chemical injection method, the ground improvement method, the freezing method, etc. Keep it independent.

Next, as shown in FIG. 14(b), the cutter head 20 is excavated by the length of the shield machine 1 while the outer diameter of the cutter head 20 is in a state before the reduction.

Subsequently, as shown in FIG. 14C, the shield machine 1 is advanced to a position where it can be reduced, the load supporting shaft 51 and the gripper 52 are installed on the wellhead side, and the support rod 53 is projected on the face side. By inserting the shield machine 1, the weight of the shield machine 1 can be supported when the cross section is reduced.

Further, as shown in FIG. 15A, the cutter head 20 is rotationally excavated in a state where the weight of the shield machine 1 is supported by the support rod 53 on the face of the face, the load supporting shaft 51 and the gripper 52 on the wellhead side. However, the partition wall 30 and the steel shell 40 are reduced while supporting the earth pressure and water pressure on the face side.

Next, as shown in FIG. 15( b ), the voids formed by reducing the steel shell 40 are filled with mud, fluidized soil, foamed mortar, etc. A lubricant or the like is injected so that the shield machine 1 can perform forward excavation.

Finally, as shown in FIG. 15C, the support rod 53 on the face of the face, the load supporting shaft 51 and the gripper 52 on the wellhead side are removed, and the forward excavation is restarted in the reduced diameter state.

Further, although the example in which the cross-section is greatly changed has been described here, the present invention is not limited to this, and the cross-section can be continuously changed as described below, or the cross-section can be changed discontinuously in small steps. You can also

In the case of continuously changing the cross section, the diameter of the face end of the steel shell 40 of the shield machine 1 is reduced by one machine length compared to the end of the wellhead side, and the shield machine 1 uses the same. The cutter head 20, the partition wall 30, and the steel shell 40 can be continuously excavated while reducing the diameter at the same rate. When the diameter reduction ratio is large, the diameter of the steel shell is greatly changed after excavation at the diameter reduction start point and the diameter reduction end point, so it may be necessary to improve the ground.

When the cross-section is changed in small steps, the diameter of the steel shell 40 is reduced every time one segment is drilled, and the voids in the natural ground generated during the diameter reduction are filled with excavated soil or backfill material. In this case, it is necessary to improve the ground depending on the ground strength.

<Another form of cutting rotor>
Next, with reference to FIGS. 16 and 17, a cutter head 20 as a cutting rotating body having a different form from that of the first embodiment will be described. It should be noted that the description of the same or equivalent portions as the contents described in the first embodiment will be given the same reference numerals.

First, the configuration of the cutter head 20 as the cutting rotary member of the present embodiment will be described with reference to FIGS. 16(a) and 16(b). The cutter head 20 of the present embodiment has a plurality of bits 21 (21T, 21F) for cutting the natural ground, and is configured so that the excavation diameter can be enlarged or reduced at an arbitrary ratio.

That is, the cutter head 20 is at an arbitrary ratio from the most contracted closed inverted V-shaped state (FIG. 16A) to the most expanded linear state (FIG. 16B). It is expandable. On the contrary, the cutter head 20 is reduced at an arbitrary ratio from the most expanded linear state (FIG. 16(b)) to the most reduced closed V-shaped state (FIG. 16(a)). It is possible.

Then, in the present embodiment, the plurality of spokes 23,... Are configured such that the base end side (inner side) attached to the center shaft 11 is the wellhead side and the tip end side (outer side) is the face face side. As a whole, the center is formed in an inverted V shape protruding toward the wellhead side. That is, in this embodiment, the spokes 23 are inclined so that the outer peripheral side is excavated first.

Specifically, the cutter head 20 is attached to a center shaft 11 as a drive shaft installed at the center of rotation, a boss portion 22 fixed to the tip of the center shaft 11, and a cross shape penetrating the boss portion 22. Two sets (4) of spokes 23,..., Which are slidably attached to the boss portion 22, and two sets (4) of spokes 23. , Two sets (4) of jacks 24,..., Which change the rotation angle of the spokes 23,. The number of spokes 23,..., Jacks 24,... is not limited to two sets (four), but may be three sets (six) or four sets (eight), for example. Good.

More specifically, as shown in FIG. 16B (A-A), the boss 22 has a cross-shaped cut for allowing two pairs of spokes 23 (spoke rods 23R),. A notch is formed. Two notches through which the two sets of spokes 23 pass through are formed so as to be offset in the front-rear direction so that the vertical and horizontal spokes 23 do not interfere with each other. Further, the spoke 23 has a free end at its distal end and a base end extending through the boss 22 to the wellhead side. A pair of facing spokes 23 intersect in the boss portion 22, and a cross section of the intersecting portion is divided into a plurality of portions so as to cross each other in an alternating manner.

The rear end side (center side) of the spoke 23 is bent in an L shape so as to prevent interference with the spokes 23 facing each other. That is, the end of the spoke 23 on the wellhead side is rotatably connected to the link 26, and the ends of the pair of facing links 26, 26 are connected to each other via the central link 27. That is, the pentagonal link mechanism is formed by the spokes 23, 23, the links 26, 26, and the center link 27, and the width in the tunnel longitudinal direction is suppressed to prevent interference.

Then, the rod sides of the two jacks 24 are connected to the boss portion 22 so that the boss portion 22 is pushed out toward the face. On the other hand, the cylinder side of the two jacks 24 is attached to a ring member 25 arranged near the center of rotation. Therefore, by extending the jack 24, the angle formed by the two spokes 23, 23 is opened and the outer diameter of the cutter head 20 is increased, and by contracting the jack 24, the angle formed by the two spokes 23, 23 is closed and the cutter head 20 is closed. The outer diameter of 20 becomes smaller.

Next, the configuration of the bit 21 of this embodiment will be described with reference to FIGS. 17(a) and 17(b). The plurality of spoke pieces 23P of the present embodiment are configured so that the angle with respect to the spoke rod 23R can be changed. Specifically, each spoke piece 23P is formed to have a parallelogram cross section, and the spoke rod 23R is inserted into the through hole 23H. The side surface of the spoke piece 23P is obliquely divided with respect to the axial direction of the spoke rod 23R, and adjacent spoke pieces 23P are in contact with each other obliquely. More specifically, the angle of the side surface of the spoke piece 23P of the present embodiment is configured to incline from the inner side to the outer side from the front (the side close to the face) to the rear.

Note that the other configurations are substantially the same as those in the first embodiment, and thus the description thereof will be omitted.

<Different form of partition wall>
Next, a partition 30B having a different form from that of the first embodiment will be described with reference to FIGS. It should be noted that the description of the same or equivalent portions as the contents described in the first embodiment will be given the same reference numerals.

As shown in FIGS. 18 and 19, the U-shaped partition wall 30B includes a disk-shaped center plate 35 arranged at the center, a fixed flap 36 that is a plurality of partition flaps divided at equal circumferential angles, and It is composed of a plurality of folding flaps 37, and has a substantially conical shape or a substantially frustoconical shape (mortar shape) with its center protruding toward the wellhead side as a whole. Then, the folding flap 37 is folded and the folding flap 37 and the fixed flap 36 are rotated in the tunnel longitudinal direction, so that the outer diameter can be enlarged or reduced at an arbitrary ratio.

That is, the partition wall 30B is provided with the fixed flaps 36 and the folding flaps 37 alternately in the circumferential direction. Among them, the fixed flap 36 is formed in a substantially fan shape, and has a flap ring 32a rotatably connected to the center plate 35 at the end portion on the center side. Here, the term “substantially fan-shaped” is intended to mean a shape in which the center side of the fan is cut into an arc shape. The fixed flaps 36 and the folding flaps 37 are preferably formed into a curved surface (conical divided curved surface, conical piece) obtained by dividing a conical curved surface in the circumferential direction, in addition to the substantially fan-shaped flat plate shape.

A drive motor 61 for rotationally driving the fixed flap 36 and the folding flap 37 is attached to the center plate 35. Specifically, as shown in FIG. 20, a worm gear 61a is attached to the drive motor 61, and a (wheel) gear 36b is attached to an orthogonal shaft (a staggered shaft) on the outer periphery of the flap ring 32a. Has been.

Then, by rotating the drive motor 61, the worm gear 61a rotates together with the drive motor 61, so that the flap ring 32a and the fixed flap 36 rotate together with the gear 36b. For example, when the drive motor 61 is normally rotated, the fixed flap 36 is rotated to open outward, and when the drive motor 61 is reversely rotated, the fixed flap 36 is rotated to be closed inward. ..

On the other hand, the folding flap 37 is configured to be further folded in two near the center along the fold line in the radial direction. Further, the bent line portion in the radial direction and the connection portion between the fixed flaps 36, 36 on both sides are rotatably connected by a hinge. Therefore, the folding flap 37 is rotated in the tunnel longitudinal direction together with the fixed flap 36 by rotating the fixed flap 36 in the tunnel longitudinal direction. In this way, the fixed flap 36 and the folding flap 37 can be rotated in the tunnel longitudinal direction while being folded. Further, the folding flap 37 has an end flap 38 attached to the outermost edge near the steel shell 40 in order to close the gap in the folded state, as described later.

In the present embodiment, the case where the fixing flaps 36 and the folding flaps 37, which are divided by 15 degrees each by 24 sheets, are provided has been described, but the present invention is not limited to this. The number of the fixed flaps 36 and the folding flaps 37 and the division angle may be arbitrary.

In the state of the minimum diameter shown in FIGS. 18(a) and 18(b), the partition wall 30B is configured such that the folding flaps 37 and the fixed flaps 36 rotate forward while the adjacent folding flaps 37 are folded in two. The outer diameter is minimized. More specifically, in this state, the folding flap 37 is completely folded in half, and the angle formed with the center plate 35 is close to 90 degrees (see also FIG. 21E).

On the other hand, in the state where the partition wall 30B has the maximum diameter shown in FIGS. 19(a) and 19(b), the folding flap 37 is not folded and constitutes the same surface as the fixed flap 36, thereby maximizing the outer diameter. There is. More specifically, in this state, the folding flap 37 is completely flattened out, and the angle formed with the center plate 35 is close to 0 degrees, and the folding flaps 37 are substantially flush with each other. In this way, the U-shaped partition wall 30B can expand or contract the outer diameter from the minimum diameter to the maximum diameter at an arbitrary ratio (see also FIG. 21A).

Here, the manner in which the partition wall 30B changes from the state of the maximum diameter to the state of the minimum diameter will be described with reference to FIGS. The partition wall 30B is shown in FIGS. 21(e) and 21(f) through the state of the maximum diameter shown in FIGS. 21(a) and 21(b) through the state of the intermediate diameter shown in FIGS. 21(c) and 21(d). It changes to the state of the minimum diameter. 21(a)(b)-(c)(d)-(e)(f), the outer diameter becomes smaller, and the fixed flap 36 and the folding flap 37 fall inward to form an angle with the center plate 35. You can see that is getting bigger.

Then, it is understood that in the state of the intermediate diameter, a triangular gap is formed at the outermost edge of the folding flap 37 (see FIG. 21(d)). When such a gap is created, the earth and sand will flow into the shield machine 1 from the face side. Therefore, in order to close this triangular gap, an end flap 38 is attached to the outermost edge of the folding flap 37 at a substantially right angle to the folding flap 37. The end flap 38 is a pentagonal plate in which the vicinity of the base angle of an isosceles right triangle is cut off. It is preferable that a fitting groove into which a protrusion protruding from the outermost edge of the folding flap 37 is fitted is formed on the inner surface of the end flap 38 so that both are connected. In addition, the end flap 38 can be fixed to the fixed flap 36.

Note that the other configurations are substantially the same as those in the first embodiment, and thus the description thereof will be omitted.

<Another form of steel shell>
Hereinafter, a steel shell 40 having a different form from that of the first embodiment will be described with reference to FIGS. 22 and 23. It should be noted that the description of the same or equivalent portions as the contents described in the first embodiment will be given the same reference numerals.

First, the configuration of the steel shell 40 of this embodiment will be described with reference to FIGS. 22 and 23. 22(a) and 23(a), the overlapping of the steel shells 40 is omitted. Since the configuration in the transverse direction is substantially the same as that of the first embodiment, the description thereof will be omitted, and only the configuration in the longitudinal direction will be described.

In this embodiment, as shown in FIGS. 22 and 23, the plate piece 42 as a cylindrical shell piece supports the first support jack 431 that supports the face of the face and the wellhead side, as in the first embodiment. The second support jacks 432. Further, in the present embodiment, unlike the first embodiment, the first support jack 431 and the second support jack 432 are connected to each other by the third support jack 433 in the longitudinal direction. That is, the face ring side center ring 41F and the wellhead side center ring 41R are connected by the third support jack 433 arranged along the tunnel longitudinal direction.

More specifically, one end of the first strut jack 431 is connected to the face side of the plate piece 42, and the other end is connected to the face-side center ring 41F. Similarly, one end of the second support jack 432 is connected to the wellhead side of the plate piece 42, and the other end is connected to the wellhead side center ring 41R. Then, the face ring side center ring 41F and the wellhead side center ring 41R are connected to each other by a third support jack 433.

Then, in the state where the steel shell 40 has the minimum diameter shown in FIG. 22, the first support jack 431, the second support jack 432, and the third support jack 433 are contracted, and the overlap between the adjacent plate pieces 42 is maximum. Therefore, the outer diameter is minimized. That is, the diameter is reduced in the radial direction by the first support jack 431 and the second support jack 432, and is further reduced in the radial direction by being deformed in the longitudinal direction by the third support jack 433.

On the other hand, in the steel shell 40, in the state of the maximum diameter shown in FIG. 23, the first support jack 431, the second support jack 432, and the third support jack 433 are extended, and the overlap between the adjacent plate pieces 42 is minimum. Therefore, the outer diameter is maximized (or zero, that is, the same cylindrical surface is formed). That is, the diameter is increased in the radial direction by the first support jack 431 and the second support jack 432, and is also increased in the vertical direction by the third support jack 433. In this way, the outer diameter of the steel shell 40 can be increased or decreased from the minimum diameter to the maximum diameter at an arbitrary ratio.

In addition, although the case where the third support jack 433 is provided has been described in the present embodiment, the present invention is not limited to this, and the third support jack 433 may be omitted. In that case, three or more jack groups are connected. It is possible to Further, even when the third support jack 433 is provided, it is possible to connect three or more by electrically controlling each jack.

Note that the other configurations are substantially the same as those in the first embodiment, and thus the description thereof will be omitted.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and any design change that does not depart from the gist of the present invention is not limited to included.

For example, in the embodiment, the case where the outer edge portion of the partition wall 30 has a mortar shape in which the outer edge portion is on the face side and the central portion is on the wellhead side to reduce the projected area has been described, but the present invention is not limited to this, and the partition wall has an outer edge portion. May have a cone shape in which the rear portion is at the rear and the central portion is at the front.

Further, in the embodiment, the case where the support rod 53 as the supporting means that is inserted into the natural ground is inserted into the natural ground in front of the boss portion 22 has been described, but the present invention is not limited to this, and the steel shell It may be inserted into the surrounding ground through a hole provided in 40. In that case, the supporting means may be a rod-shaped or plate-shaped one, or a sled-shaped one.

Further, in the embodiment, the example in which the excavation diameter is discontinuously enlarged or reduced in one step in the excavation method has been described, but the excavation diameter is not limited to this, and the excavation diameter is gradually increased step by step such as 5 steps. It is also preferable to enlarge or reduce (increase/decrease). Furthermore, it is also possible to reduce the excavation diameter and then reduce it.

In addition, the tunnel structure constructed by the shield machine 1 as the excavator of the present embodiment may be of any type. For example, pass vehicles, pedestrians, trains, electric wires, gas pipes, tap water, rainwater, sewage, etc. safely and appropriately according to the purpose of use such as roads, railways, electric power, communications, gas, water and sewerage, underground rivers, etc. be able to.

1: Shield machine (excavator)
1A: Front body part 1B: Rear body part 11: Center shaft 12: Cutter motor 13: Shield jack 14: Electa 15: Middle folding jack 16: Screw conveyor 20: Cutter head (rotating body for cutting)
21: Bit 21F: Fish tail bit 21T: Teeth bit 22: Boss 23: Spoke 23G: Buffer material 23H: Through hole 23N: Notch 23P: Spoke piece 23R: Spoke rod 24: Jack 25: Ring member 26: Link 27 : Central link 28: Telescopic rod 30: Partition wall 30A: Partition wall 30B: Partition wall 31: Center ring 32: Partition flap 32a: Flap ring 32b: Hinge 33: Flap cap 35: Center plate 36: Fixed flap 36b: Gear 37: Folding flap 38: End flap 40: Steel shell 40A: Front steel shell 40B: Rear steel shell 41: Center ring 41F: Face side center ring 41R: Wellhead side center ring 42: Plate piece (cylindrical shell piece)
43: Strut jack 431: First strut jack 432: Second strut jack 433: Third strut jack 45: Protrusion 51: Load supporting shaft 52: Gripper 53: Support rod 61: Driving motor 61a: Worm gear 62: Driving cylinder 63 : Link arm

Claims (13)

A rotating body for cutting having a plurality of bits for cutting a natural ground, which is configured so that the excavation diameter can be enlarged or reduced at an arbitrary ratio, and a rotating body for cutting,
A partition configured to be able to expand or contract the outer diameter at an arbitrary ratio,
An excavator, comprising: a steel shell configured so that the outer diameter can be expanded or reduced at an arbitrary ratio. The cutting rotating body,
A drive shaft installed at the center of rotation,
A plurality of spokes radially attached to the tip of the drive shaft, the plurality of spokes being rotatably attached to the drive shaft,
The excavator according to claim 1, further comprising: a plurality of jacks that change a rotation angle of the plurality of spokes. Each of the plurality of spokes of the cutting rotator has a plurality of spoke pieces having the bit, and a spoke rod inserted into the plurality of spoke pieces, and the plurality of spoke pieces are the spoke rods. The excavator according to claim 2, wherein the excavator is configured so that an angle with respect to can be changed. The partition wall is composed of a plurality of substantially fan-shaped partition wall flaps and is rotated in the tunnel longitudinal direction while overlapping the adjacent partition wall flaps or is rotated in the tunnel vertical direction while folding the adjacent partition wall flaps. The excavator according to any one of claims 1 to 3, wherein the outer diameter can be enlarged or reduced at an arbitrary ratio by performing the above. The steel shell is composed of a plurality of cylindrical shell pieces and a plurality of support jacks supporting the plurality of cylindrical shell pieces, and the support jacks are arranged while the adjacent cylindrical shell pieces are stacked while being inclined with respect to the center. The excavator according to any one of claims 1 to 4, which is configured to expand or contract the outer diameter at an arbitrary ratio by expanding and contracting. A lining or a load-supporting shaft arranged substantially at the center of the segment installed on the pit side of the excavator, and at least three grippers protruding from the load-supporting shaft to the lining or the segment. The excavator according to any one of claims 1 to 5, further comprising: a load supporting shaft configured to support its own weight. The excavator according to any one of claims 1 to 6, further comprising a support means that is inserted into the ground from the cutting rotary body so that the support means supports its own weight. . A drilling method for expanding a drilling diameter by using the drilling machine according to any one of claims 1 to 7,
Expanding the outer diameter of the cutting rotor,
A step of excavating a rock mass for a captain of the excavator in a state where the rotating body for cutting is expanded;
Expanding the outer diameter of the steel shell,
A step of enlarging the outer diameter of the partition wall. A drilling method for expanding a drilling diameter by using the drilling machine according to any one of claims 1 to 7,
Expanding the outer diameter of the cutting rotor,
Excavating the ground for one segment in a state where the rotating body for cutting is expanded,
Expanding the outer diameter of the steel shell,
A step of enlarging the outer diameter of the partition wall. A drilling method for expanding a drilling diameter by using the drilling machine according to any one of claims 1 to 7,
Expanding the outer diameter of the cutting rotor,
A step of excavating the ground while expanding the outer diameter of the cutting rotary body;
Enlarging the outer diameter of the face end of the steel shell,
An excavation method in which the step of enlarging the outer diameter of the partition wall is continuously synchronized and repeated. An excavation method for reducing the excavation diameter using the excavator according to any one of claims 1 to 7.
A step of excavating the rock mass for the captain of the excavator in a state where the rotating body for cutting is not yet reduced,
Reducing the outer diameter of the cutting rotor,
Reducing the outer diameter of the partition wall,
And a step of reducing the outer diameter of the steel shell. An excavation method for reducing the excavation diameter using the excavator according to any one of claims 1 to 7.
Excavating the ground for one segment in a state in which the cutting rotor has not been reduced,
Reducing the outer diameter of the cutting rotor,
Reducing the outer diameter of the partition wall,
And a step of reducing the outer diameter of the steel shell. An excavation method for reducing the excavation diameter using the excavator according to any one of claims 1 to 7.
Excavating the ground while reducing the outer diameter of the cutting rotor,
Reducing the outer diameter of the partition wall,
A method of excavating, wherein the step of reducing the outer diameter of the face end of the steel shell is continuously synchronized and repeated.