JP7159029B2 - Rotary body for cutting and excavator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cutting rotator for an excavator capable of increasing or decreasing the excavation diameter at any ratio.

Conventionally, excavators including shield machines and propellers are used to excavate 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 expand/reduce the cross section in the middle of a power cable tunnel, a branch/joint of a water supply and sewage tunnel, a railway station station, an emergency parking zone of a road tunnel, or the like.

As a technique for enlarging a cross section, for example, a shield excavator disclosed in Patent Document 1 discloses a spoke that can be freely opened and closed with respect to a drive shaft. Further, Patent Document 2 discloses a shield machine in which a bit can be replaced by folding and retreating the spokes.

JP-A-1-310093 JP-A-2002-194994

However, in the above-described conventional shield machine, if the rotation angle of the spoke is changed, the angle of the bit with respect to the face also changes, so there is a problem that the cutting efficiency is lowered.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an excavating rotary body and an excavator in which the angle of the bit with respect to the face is almost unchanged.

In order to achieve the above object, a cutting rotator of a first invention is a cutting rotator for an excavator, comprising: a drive shaft installed at the center of rotation; A plurality of spokes that are rotatably attached to the drive shaft; spoke pieces, and spoke rods that are commonly inserted through through holes formed in the plurality of spoke pieces, and the side surfaces of the plurality of spoke pieces are arranged with respect to the axial direction of the spoke rods. It is formed so as to incline obliquely.

In addition, the plurality of spoke pieces of the cutting rotor of the second invention are provided with semi-cylindrical notches facing the through holes, and semi-cylindrical cushioning materials are provided in the notches. and the plurality of spoke pieces are brought into contact with the spoke rod via the cushioning material.

In addition, one end of the jack of the rotating body for cutting of the third invention is attached to the tip side of the spoke rod away from the drive shaft, and the other end of the jack is attached to the vicinity of the center of rotation. attached to a ring member installed in the

Further, the side surfaces of the plurality of spoke pieces of the cutting rotary body of the fourth invention are inclined from the outside toward the inside from the face side toward the wellhead side, and the spoke rods are attached to the drive shaft. The base end side where it is applied is the face side, and the tip side is turned so that it is the wellhead side.

Further, the side surfaces of the plurality of spoke pieces of the cutting rotor of the fifth invention are inclined from the inside to the outside from the face side toward the wellhead side, and the spoke rods are attached to the drive shaft. The shaft is rotated so that the proximal end side of the shaft is on the wellhead side and the distal end side is on the face side.

An excavator according to a sixth aspect of the invention includes any one of the cutting rotating bodies described above, a partition wall configured so that the outer diameter can be enlarged or reduced at an arbitrary ratio, and the outer diameter can be enlarged or reduced at an arbitrary ratio. a steel shell configured to be collapsible.

In the present invention, "the outer diameter can be expanded or reduced at any ratio" mainly means that the first state (for example, small diameter state) to the second state (for example, large diameter state) , is intended to be continuously variable in size 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 in the middle. Of course, the deformation from the first state to the second state may be expansion deformation such that the cross-sectional area is widened, or may be reduction deformation such that the cross-sectional area is narrowed.

Thus, the cutting rotator of the present invention is a cutting rotator for an excavator, which includes a drive shaft installed at the center of rotation and a plurality of spokes radially attached to the drive shaft. a plurality of spokes pivotably mounted to the spokes and a plurality of jacks for changing the pivoting angle of the plurality of spokes, the spokes formed in a plurality of spoke pieces having bits and a plurality of spoke pieces; and spoke rods that are commonly inserted through the through-holes, and the side surfaces of the plurality of spoke pieces are formed so as to be inclined with respect to the axial direction of the spoke rods. With such a configuration, even when the spoke rod is rotated, the spoke piece slides obliquely so that the bit comes to substantially face the face, so cutting efficiency can be maintained.

In addition, the plurality of spoke pieces of the cutting rotor of the second invention are provided with semi-cylindrical cutouts facing the through holes, and the cutouts are provided with semi-cylindrical cushioning materials. spoke pieces are brought into contact with the spoke rods through cushioning materials. With this configuration, the spoke piece rotates smoothly, so that the direction of the bit can be stabilized and oriented so as to substantially face the face.

In addition, one end of the jack of the rotating body for cutting of the third invention is attached to the tip side of the spoke rod away from the drive shaft, and the other end of the jack is installed near the center of rotation. attached to the ring member. According to this structure, forces in opposite directions acting by extending and contracting the jack cancel each other out through the ring member.

In addition, the side surfaces of the spoke pieces of the cutting rotary body of the fourth invention are inclined from the outside to the inside from the face side toward the wellhead side, and the spoke rods have the base end side attached to the drive shaft. It rotates on the face side so that the tip side is on the pit side. With this configuration, the natural ground can be excavated in a conical shape while changing the excavation diameter at an arbitrary ratio.

In addition, the side surfaces of the spoke pieces of the cutting rotor of the fifth invention are inclined from the inside toward the wellhead side from the face side toward the wellhead side, and the base end side of the spoke rod attached to the drive shaft is inclined toward the wellhead side. It rotates so that the tip side becomes the face side. With this construction, the natural ground can be excavated in an inverted conical shape while changing the excavation diameter at an arbitrary ratio.

An excavator according to a sixth aspect of the invention includes any one of the cutting rotating bodies described above, a partition wall configured so that the outer diameter can be enlarged or reduced at an arbitrary ratio, and the outer diameter can be enlarged or reduced at an arbitrary ratio. a steel shell configured to be collapsible. With this configuration, even if the outer diameter is enlarged or reduced, the bit will substantially face the face, so that the cutting efficiency can be maintained. Furthermore, the excavator can expand or reduce the excavation diameter at an arbitrary ratio without a large setup change.

In other words, in the case of the excavator of this embodiment, the work can be interrupted by using the three major elements that are also used during normal excavation of the cutting rotor, the bulkhead, and the steel shell. It is possible to continuously expand or reduce the excavation diameter. Furthermore, since each of the three elements is configured to be able to expand or contract at any ratio, the excavation diameter can be expanded or reduced at any ratio.

In this manner, the excavator of this embodiment can enlarge or reduce the excavation diameter at any time. , it becomes possible to excavate by reducing it. Therefore, since excavation can be performed with one excavator without preparing a different excavator for each section, cost reduction is possible. Furthermore, the cost is lower than excavating according to the maximum diameter, and the reduction in the amount of generated soil reduces the environmental load.

1 is a longitudinal sectional view of an excavator with a reduced excavation diameter; FIG. 1 is a cross-sectional view of an excavator with a reduced excavation diameter; FIG. 1 is a longitudinal sectional view of an excavator with an enlarged excavation diameter; FIG. FIG. 3 is a cross-sectional view of the excavator with an enlarged excavation diameter; FIG. 4 is an explanatory diagram illustrating how the cutting rotating body of Example 1 transforms; (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. FIG. 4 is an explanatory diagram for explaining spoke pieces and spoke rods in detail; (a) is the state of the maximum diameter, and (b) is the state of the intermediate diameter. FIG. 4 is an explanatory diagram of the state of the minimum diameter of the partition of Example 1; (a) is a front view, and (b) is a side view. FIG. 4 is an explanatory diagram of the state of the maximum diameter of the partition walls of Example 1; (a) is a front view, and (b) is a side view. It is an explanatory view explaining a drive cylinder of a partition. FIG. 2 is an explanatory diagram 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. FIG. 2 is an explanatory diagram 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 construction method which expands an 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. FIG. 11 is a side view of the cutting rotating body of Example 2; (a) is the state of the minimum diameter, and (b) is the state of the maximum diameter. FIG. 11 is an explanatory diagram illustrating in detail the spoke pieces and spoke rods of the second embodiment; (a) is the state of the maximum diameter, and (b) is the state of the intermediate diameter. FIG. 11 is an explanatory diagram of a state of a minimum diameter of partition walls in Example 3; (a) is a front view, and (b) is a side view. FIG. 10 is an explanatory diagram of the state of the maximum diameter of the partition walls of Example 3; (a) is a front view, and (b) is a side view. It is an explanatory view explaining a drive motor of a partition. It is an explanatory view explaining an end flap. (a) is a perspective view of the maximum diameter state viewed from the face side, and (b) is a perspective view of the maximum diameter state viewed 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 minimum diameter state viewed from the face side, and (f) is a perspective view of the minimum diameter state viewed from the wellhead side. FIG. 10 is an explanatory diagram 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. FIG. 10 is an explanatory diagram 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.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In the following embodiments, a shield construction method including a shield machine 1 as an excavator will be described as an example, but the invention is not limited to this.

In each of Examples 1 to 4, Example 1 describes the basic configuration of the excavator (shield machine 1) and an excavation method, and Example 2 describes a different cutting rotor (cutter head 20). In the third embodiment, a partition wall 30B of another form will be explained, and in the fourth embodiment, a steel shell 40 of another form will be explained.

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

A cutter head 20 as a rotary body for cutting is supported by a center shaft 11, and is configured to rotate when the center shaft 11 is rotationally driven by a 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, it is also possible to rotate the annular bearing (intermediate support system).

The partition wall 30 is installed between the hood portion (the tip portion of the shield body) and the girder portion (the intermediate portion of the shield body) in order to hold 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 devices and working space. The steel shell 40 is composed of a front steel shell 40A corresponding to the front body 1A and a rear steel shell 40B corresponding to the rear body 1B. A mechanism for enlarging or reducing the outer diameter of the steel shell 40 will be described later.

In addition, as shown in FIGS. 1 and 3, the shield machine 1 includes a shield jack 13 for propelling the shield machine 1 in the face direction, an erector 14 for assembling segments into a predetermined shape, and a It is equipped with a group of devices such as a center-folding jack 15 and a screw conveyor 16 as an earth removal device. Here, the folding jack 15 is not necessary when excavating in a straight line. Furthermore, as the soil removal device, the screw conveyor 16 is used in the case of the soil pressure type or the mud pressure type, but it is not limited to this, and in the case of the slurry type, a sludge transfer pipe (sludge discharge pipe) may be used. can also

As described above, the shield machine 1 constructs a tunnel structure by excavating natural ground using a group of devices. For example, in the case of the earth pressure shield construction method, the space between the face and the partition wall 30 is filled with earth and sand excavated by the cutter head 20, an additive is injected as necessary, the face is stabilized by earth pressure, and the partition wall is excavated. The soil is discharged by a screw conveyor 16 installed to penetrate through 30.

Thereafter, while partially releasing the shield jacks 13, the segments are assembled into a ring shape by the erector 14 (primary lining). Further, backfilling is performed, and secondary lining is applied as necessary to complete the tunnel structure.

As will be described below, the shield machine 1 as an excavator of the present embodiment includes a cutter head 20 as a rotary body for cutting, a partition wall 30, and a steel shell 40, which are main elements constituting the shield machine 1. , can be scaled up or down at any ratio.

(Structure of rotary body for cutting)
Next, the configuration of the cutter head 20 as the cutting rotor of this embodiment will be described with reference to FIGS. The cutter head 20 of this 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 any ratio.

That is, when the cutter head 20 is enlarged, a plurality of spokes 23 (see FIG. 4) rotatably attached to a boss portion 22 connected to the center shaft 11 move in the face direction (spokes 23 and the center shaft 11), the closed V-shaped state (Fig. 5(a)), which is the most contracted as a whole, changes to an open V-shaped state ( 5(b)) to the most enlarged linear state (FIG. 5(c)) can be enlarged at any ratio.

Conversely, when the cutter head 20 is contracted, the plurality of spokes 23, which are rotatably attached to the boss portion 22 connected to the center shaft 11, move in the tunnel direction (spokes 23 and center shaft 11). By rotating so that the angle formed by the It can be reduced at any ratio up to the most contracted closed V-shaped state (FIG. 5(a)).

In this 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 distal end side (outer side) is the pit side. As a whole, the center is formed in a V shape protruding toward the face side. 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, four spokes 23 radially attached to a boss portion 22 at the tip of the center shaft 11, and so on. 4 spokes 23, . , is equipped with The number of spokes 23, . . . is not limited to four, and may be, for example, six or eight.

More specifically, the spokes 23 have their base ends rotatably attached to the boss 22 and their tip ends rotatably attached to the rod side of the jacks 24 . Furthermore, the head side of the jack 24 is attached to a ring member 25 arranged near the center of rotation. By uniformly extending and contracting the opposing jacks 24, the spokes 23 are rotated while canceling out the reaction forces.

(Configuration of bits)
Next, the configuration of the bit 21 of this embodiment will be described with reference to FIGS. 5(a) to 5(c) and FIGS. The bit 21 of this embodiment includes a fishtail bit 21F installed on the boss portion 22, and a plurality of tooth bits 21T installed on the spoke 23, . . . That is, each of the plurality of spokes 23, ... of the cutter head 20 has a plurality of spoke pieces 23P, ... each having one tooth bit 21T, and a plurality of spoke pieces 23P, ... in common. and a spoke rod 23R to be inserted.

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 a spoke rod 23R is inserted through a through hole 23H. The side surfaces of the spoke pieces 23P are divided obliquely with respect to the axial direction of the spoke rods 23R, and the adjacent spoke pieces 23P are in oblique contact with each other. More specifically, the angle of the side surface of the spoke piece 23P of this embodiment is configured to be inclined from the outside to the inside from the front (the side close to the face) toward the rear.

Furthermore, 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 semi-cylindrical notch 23N that continues to the through hole 23H, and a semi-cylindrical cushioning material 23G is installed in the notch 23N. As a result, as shown in FIG. 6B, when the spoke rod 23R is pulled diagonally, the cushioning material 23G rotates (rolls), and the spoke piece 23P does not follow the inclination of the spoke rod 23R. In addition, the tooth bit 21T always faces the face. Therefore, even if the angle of the spokes 23 is changed when the diameter is expanded or contracted, the tooth bit 21T always faces the face face, so 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. FIG. For convenience of explanation, the drive cylinder 62 is shown as the drive means in FIGS. 7 to 9, but a drive motor 61 may be used as described later (see FIG. 20).

As shown in FIGS. 7 and 8, the partition 30A is composed of a disk-shaped center plate 35 arranged in the center and a plurality of partition flaps 32 divided at equal circumferential angles. It is assembled in a substantially conical or substantially truncated conical shape (mortar shape) projecting backward. By overlapping the adjacent partition wall flaps 32 in the circumferential direction and rotating them in the longitudinal direction of the tunnel, the outer diameter can be enlarged or reduced at an arbitrary ratio without creating a gap. ing.

The partition wall flap 32 is formed as a substantially fan-shaped flat plate, and has a flap ring 32a rotatably connected to the center plate 35 and the center ring 31 at the end on the center side. Here, the term "substantially fan-shaped" refers to a shape obtained by cutting an arc from the center side of the fan. The shape of each partition wall flap 32 is preferably formed as a curved surface obtained by dividing a conical curved surface in the circumferential direction (divided conical curved surface, conical piece) instead of a substantially fan-shaped flat plate shape.

As shown in FIG. 9, the flap ring 32a is provided with a drive cylinder 62 for rotating the partition wall flap 32. As shown in FIG. That is, a link arm 63 is rotatably attached to the driving cylinder 62 through a long hole, and the link arm 63 is fixed to the flap ring 32a of the partition wall flap 32. As shown in FIG. Note that the center ring 31 is a shaft for rotating the partition wall flap 32, and if it functions as a shaft, 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 wall flap 32 fixed to the link arm 63 rotates. Specifically, when the drive cylinder 62 is contracted, the partition wall flap 32 rotates to open outward, and when the drive cylinder 62 is extended, the partition wall flap 32 rotates to close inward.

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

More specifically, the partition wall flap 32 of the present embodiment is divided by a radially extending parting line into an inner piece that protrudes inward and an outer piece that protrudes outward. The inner piece and the outer piece of the partition wall flap 32 are connected by a hinge 32b so that they can be folded in the circumferential direction. Therefore, in this embodiment, the partition wall flaps 32 are divided into 48 in the circumferential direction in order to further divide the 24 partition flaps 32 into two. This facilitates entry into gaps (grooves) of flap caps 33 (described later) of adjacent partition wall flaps 32 .

Bulkhead 30A, as shown, assumes a maximum expansion rate of two times in the radial direction. width, a U-folded flap cap 33 is formed at the radially outer end to enclose the adjacent bulkhead flap 32 (outwardly overlapping). In other words, the vicinity of the outer edge of the inner piece protruding inward of each partition flap 32 divided into two is bent in a U shape so as to involve the adjacent partition flap 32 .

In the minimum diameter state shown in FIGS. 7(a) and 7(b), the partition wall 30A rotates so that the adjacent partition wall flaps 32 partially overlap each other in the circumferential direction and fall toward the face side. Minimize outer diameter. More specifically, in this state, the overlap of the adjacent bulkhead flaps 32 is maximum, and the outer piece of the halved bulkhead flap 32 overlaps the inner piece of the adjacent bulkhead flap 32, and is almost slanted from the face side. invisible (Fig. 7(a)).

On the other hand, when the partition wall 30A has the maximum diameter shown in FIGS. 8(a) and 8(b), the adjacent partition wall flaps 32 hardly overlap each other, and stand substantially vertically to form the same plane, thereby increasing the outer diameter. is maximized. More specifically, in this state, the overlap of adjacent bulkhead flaps 32 is minimal, and the outer piece of the bisected bulkhead flap 32 is aligned with the inner piece of the adjacent bulkhead flap 32 when viewed from the face side. (Fig. 8(a)).

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

(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. FIG. The steel shell 40 (40A, 40B) includes an annular center ring 41 arranged in the center, plate pieces 42 which are a plurality of cylindrical shell pieces divided into equal circumferential angles, and supports the plate pieces 42. It is composed of 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 reinforcing ridges protruding inward along the circumferential direction at locations where support jacks 43 are connected. is formed. Accordingly, grooves are formed on the back side of the plate piece 42 . Then, the ridges of the plate piece 42 adjacent to the ridges on the back side enter.

In the transverse direction, adjacent plate pieces 42 are supported by support jacks 43 while being superimposed on 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 overlapped with the adjacent plate piece 42 . More specifically, the plate pieces 42 are superimposed while being inclined in the same direction with respect to the cross-sectional center. For example, in FIGS. 10 and 11, each plate piece 42 is oriented in a spiraling (clockwise) direction generally in the same direction.

In the minimum diameter state shown in FIG. 10, the steel shell 40 minimizes the outer diameter by contracting the strut jacks 43 and maximizing the overlap between the adjacent plate pieces 42 . On the other hand, when the steel shell 40 has the maximum diameter shown in FIG. 11, the strut jacks 43 are extended, and the overlap between the adjacent plate pieces 42 is minimized (or zero, that is, the same cylindrical surface is formed). This maximizes the outer diameter. In this way, the steel shell 40 can be expanded or contracted in any ratio from the minimum diameter to the maximum diameter.

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

(Excavation method for enlarging the excavation diameter)
When expanding the excavation diameter, as shown in FIG. to stand on its own.

Next, as shown in FIG. 12(b), the outer diameter of the cutter head 20 is enlarged while rotating the cutter head 20 and excavating the natural ground before reaching the planned cross-section change position. That is, by extending the jack 24, the spokes 23 are rotated in a direction in which the angle between the spokes 23 and the center shaft 11 is increased. At this time, the partition wall 30 and the steel shell 40 maintain their outer diameters before being enlarged.

Subsequently, as shown in FIG. 12(c), excavation is carried out by the machine length of the shield machine 1 while keeping the outer diameter of the cutter head 20 enlarged. That is, while rotating the cutter head 20 to excavate the 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 their outer diameters before being enlarged.

Further, as shown in FIG. 13(a), the shield machine 1 is moved forward to excavate to a position where it can be expanded, and the load-bearing shaft 51 is arranged substantially at the center of the lining or segment installed on the side of the wellhead. Support is provided by grippers 52 that extend in at least three directions. Then, the weight of the shield machine 1 (mainly the weight of the rear trunk portion 1B) is supported by the load supporting shaft 51 .

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 shielding machine 1 and prevents the cutter head 20 from rotating backward due to the weight of the shielding machine 1 .

Furthermore, the ground around the exposed segment behind the shield machine 1 disturbed by excavation is improved to prevent it from flowing into the shield machine 1 during removal of earth and sand (see FIG. 13(b) described later). . In addition, it is also possible to remove the natural ground of this portion and fill it after expanding the diameter.

Next, as shown in FIG. 13(b), the surrounding ground corresponding to the length of the shield machine 1 is sucked and removed by a hose extended from the inside of the chamber, or a hose extended from the inside of the machine and the inside of the machine. , a space in which the steel shell 40 can expand is secured around the shield machine 1. - 特許庁Then, the weight of the shield machine 1 is supported at both ends by the support rod 53, the load-supporting shaft 51, and the gripper 52 in the space.

Finally, as shown in FIG. 13(c), while enlarging the outer diameter of the steel shell 40, the outer diameter of the partition wall 30 is enlarged in synchronization therewith. That is, the support jack 43 is gradually extended to push the plate piece 42 outward little by little, and in conjunction with this, the drive jack (or drive motor) is gradually contracted to gradually open the partition wall flap 32 as shown in FIG. In the case of (c), it is raised toward the face side. After that, the load-bearing shaft 51, the gripper 52, and the support rod 53 are housed, and forward excavation is restarted with the enlarged diameter.

Although the case where the diameter is expanded while the cutter head 20 is digging has been described here, it is not limited to this, and it is also possible to expand the diameter while digging is stopped. In that case, it is preferable to attach a bit to the side surface (outward surface) of the spoke piece 23P of the cutter head 20 as well. If the diameter can be expanded while the excavation is stopped in this way, there is an advantage that ground improvement of the natural ground around the exposed segment portion behind the shield machine 1 can be omitted.

Furthermore, although an 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 changed continuously as described below, or the cross section can be changed discontinuously in small increments. can also

When the cross section is changed continuously, the diameter of the face side end of the steel shell 40 of the shield machine 1 is made larger than the hole mouth side end by the amount corresponding to the length of one machine, and the shield machine 1 The cutter head 20, the partition wall 30, and the steel shell 40 can be excavated while expanding their diameters continuously at the same rate. If the expansion/reduction ratio is large, ground improvement may be required because the diameter of the steel shell changes greatly after excavation at the diameter expansion start point and the diameter expansion end point.

In the case of changing the cross section in small increments, the shaft of the cutter head 20 of the shield machine 1 is stretched larger than the diameter of the steel shell 40 by the amount of diameter expansion for one machine length, and the cut earth and sand is pushed every time one segment is excavated. While expanding, the diameter of the steel shell 40 is increased. 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 spread out during diameter expansion. In addition, since the steel shell 40 and the segment are separated from each other at the rear end of the shield machine 1 in contact with the ground, ground improvement is required if the tail seal cannot suppress the ground pressure.

(Excavation method for reducing excavation diameter)
When reducing the excavation diameter, as shown in FIG. to stand on its own.

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

Subsequently, as shown in FIG. 14(c), the shield machine 1 is moved forward to a position where it can be contracted, and a load-bearing shaft 51 and a gripper 52 are installed on the tunnel mouth side, and a support rod 53 is pushed on the face side. By inserting it, it is made possible to support the own weight of the shielding machine 1 when the cross section is reduced.

Further, as shown in FIG. 15(a), the cutter head 20 is rotated and excavated while the dead weight of the shield machine 1 is supported by the supporting rod 53 on the face side and the load supporting shaft 51 and the gripper 52 on the wellhead side. After that, 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 shrinking the steel shell 40 are filled with mud, fluidized soil, foam mortar, etc., and if necessary, the surroundings of the steel shell 40 are: A lubricant or the like is injected to enable the shield machine 1 to excavate forward.

Finally, as shown in FIG. 15(c), the support rod 53 on the face side and the load bearing shaft 51 and gripper 52 on the wellhead side are removed, and forward excavation is resumed with the reduced diameter.

Furthermore, although an 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 changed continuously as described below, or the cross section can be changed discontinuously in small increments. can also

When the cross section is changed continuously, the diameter of the steel shell 40 of the shield machine 1 is made smaller than the diameter of the face side end by the amount corresponding to the length of one machine compared to the hole mouth side end. The cutter head 20, the partition wall 30, and the steel shell 40 can be excavated while their diameters are continuously reduced at the same rate. If the diameter reduction ratio is large, the diameter of the steel shell changes greatly after excavation at the diameter reduction start point and the diameter reduction end point, so ground improvement may be required.

In the case of changing the cross section in small increments, the diameter of the steel shell 40 is reduced each time one segment is excavated, and the gaps in the ground generated during the diameter reduction are filled with excavated soil, backfill material, or the like. In this case, ground improvement is required depending on ground strength.

<Different form of rotary body for cutting>
16 and 17, a cutter head 20 as a cutting rotator having a form different from that of the first embodiment will be described. The same or equivalent parts as those described in the first embodiment will be described with the same reference numerals.

First, the configuration of the cutter head 20 as the rotary body for cutting of this embodiment will be described with reference to FIGS. The cutter head 20 of this 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 any ratio.

That is, the cutter head 20 can be adjusted at any ratio from the most contracted closed inverted V-shaped state (FIG. 16(a)) to the most enlarged linear state (FIG. 16(b)). It is expandable. Conversely, the cutter head 20 can be contracted at any rate from the most expanded linear state (FIG. 16(b)) to the most contracted closed inverted V-shaped state (FIG. 16(a)). It is possible.

In this 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 distal end side (outer side) is the face side. As a whole, it is formed in an inverted V shape with the center protruding toward the wellhead. That is, in the present embodiment, the spokes 23 are inclined so that the outer 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, a boss portion 22 fixed to the tip of the center shaft 11, and a cruciform shape passing through the boss portion 22. two sets (four) of spokes 23, ... and two sets (four) of spokes 23, ... which are slidably attached to the boss portion 22, and two sets (four) of spokes 23 are provided with two sets (four jacks) of jacks 24 for changing the rotation angles of the spokes 23, . The number of spokes 23, ... and jacks 24, ... is not limited to two sets (four), but may be, for example, three sets (six) or four sets (eight). good too.

More specifically, as shown in FIG. 16(b)(AA), the boss portion 22 has cross-shaped cuts for two sets of spokes 23 (spoke rods 23R) to pass through. A defect is formed. The two cutouts through which the two sets of spokes 23, . Further, the spoke 23 has a free end at the tip and a base end extending through the boss 22 to the pit side thereof. A pair of opposing spokes 23 intersect within the boss portion 22, and the cross section of the intersecting portion is divided into a plurality of parts so that the spokes intersect alternately.

The rear end sides (center sides) of the spokes 23 are bent in an L shape to prevent interference with the spokes 23 facing each other. That is, the ends of the spokes 23 on the wellhead side are rotatably connected to links 26 , and the ends of a pair of opposing links 26 , 26 are connected to each other via a central link 27 . That is, the spokes 23, 23, the links 26, 26, and the center link 27 form a pentagonal link mechanism, which suppresses the width in the longitudinal direction of the tunnel to prevent interference.

The rod sides of two jacks 24 are connected to the boss portion 22 so as to push the boss portion 22 toward the face side. On the other hand, the cylinder sides of the two jacks 24 are 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 widened and the outer diameter of the cutter head 20 is increased. 20 becomes smaller.

Next, the configuration of bit 21 of this embodiment will be described with reference to FIGS. 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, each spoke piece 23P is formed to have a parallelogram cross section, and a spoke rod 23R is inserted through a through hole 23H. The side surfaces of the spoke pieces 23P are divided obliquely with respect to the axial direction of the spoke rods 23R, and the adjacent spoke pieces 23P are in oblique contact with each other. More specifically, the side surfaces of the spoke pieces 23P of this embodiment are angled from the inside to the outside from the front (the side close to the face) toward the rear.

Note that the rest of the configuration is substantially the same as that of the first embodiment, so description thereof will be omitted.

<Different form of partition wall>
Next, a partition wall 30B having a form different from that of the first embodiment will be described with reference to FIGS. 18 to 21. FIG. The same or equivalent parts as those described in the first embodiment will be described with the same reference numerals.

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

That is, the partition wall 30B includes fixed flaps 36 and folding flaps 37 alternately in the circumferential direction. Among them, the fixed flap 36 is formed in a substantially sector shape, and has a flap ring 32a rotatably connected to the center plate 35 at the end on the center side. Here, the term "substantially fan-shaped" refers to a shape obtained by cutting an arc from the center side of the fan. The fixed flaps 36 and the folding flaps 37 may preferably be formed as curved surfaces obtained by dividing a conical curved surface in the circumferential direction (divided conical curved surface, conical piece), in addition to the substantially fan-shaped flat plate shape.

A drive motor 61 is attached to the center plate 35 to rotate the fixed flap 36 and the folding flap 37 . Specifically, as shown in FIG. 20, a worm gear 61a is attached to the drive motor 61, while a (wheel) gear 36b is attached to the outer periphery of the flap ring 32a on orthogonal axes (interleaved axes). It is

By rotating the driving motor 61, the worm gear 61a rotates together with the driving motor 61, thereby rotating the flap ring 32a and the fixed flap 36 together with the gear 36b. For example, when the drive motor 61 is rotated forward, the fixed flap 36 rotates to open outward, and when the drive motor 61 is rotated in the reverse direction, the fixed flap 36 rotates to close inward. .

On the other hand, the folding flap 37 is further folded in two near the center along the radial folding line. Connection points between the radial fold line and the fixed flaps 36, 36 on both sides are rotatably connected by hinges. Therefore, the folding flap 37 rotates in the tunnel longitudinal direction together with the fixed flap 36 by rotating the fixed flap 36 in the tunnel longitudinal direction. In this manner, the fixed flap 36 and the folding flap 37 can be rotated in the longitudinal direction of the tunnel while being folded. In addition, the folding flaps 37 have end flaps 38 attached to their outermost edges near the steel shell 40 to close the gaps in the folded state, as will be described later.

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

18(a) and 18(b), the partition wall 30B is formed by rotating the folding flap 37 and the fixed flap 36 forward while the adjacent folding flap 37 is folded in half. Minimize outer diameter. More specifically, in this state, the folding flap 37 is completely folded in two, and the angle between it and the center plate 35 is close to 90 degrees (see also FIG. 21(e)).

On the other hand, in the state of the maximum diameter shown in FIGS. 19(a) and 19(b), the partition wall 30B forms the same surface as the fixed flap 36 without folding the folding flap 37, thereby maximizing the outer diameter. there is More specifically, in this state, the folding flaps 37 are completely flattened, form an angle close to 0 degrees with the center plate 35, and form substantially the same plane. In this manner, the U-shaped partition wall 30B can expand or contract the outer diameter at any ratio from the minimum diameter to the maximum diameter (see also FIG. 21(a)).

Here, with reference to FIGS. 21(a) to 21(f), how the partition wall 30B changes from the maximum diameter state to the minimum diameter state will be described using perspective views. The partition wall 30B changes from the state of the maximum diameter shown in FIGS. 21(a) and 21(b) to the state of the intermediate diameter shown in FIGS. It changes to the state of the minimum diameter. 21(a)(b)-(c)(d)-(e)(f), as the outer diameter decreases, the fixed flap 36 and the folding flap 37 fall inward, forming an angle with the center plate 35. becomes larger.

In the state of the intermediate diameter, it can be seen that a triangular gap is generated at the outermost edge of the folding flap 37 (see FIG. 21(d)). If such a gap occurs, 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 obtained by cutting off the vicinity of the base angle of an isosceles right triangle. It is preferable that the inner surface of the end flap 38 is formed with a fitting groove into which a projection protruding from the outermost edge of the folding flap 37 is fitted so that the two are connected. Alternatively, the end flaps 38 can be secured to the fixed flaps 36 .

Note that the rest of the configuration is substantially the same as that of the first embodiment, so description thereof will be omitted.

<Another form of steel shell>
A steel shell 40 having a form different from that of the first embodiment will be described below with reference to FIGS. 22 and 23. FIG. The same or equivalent parts as those described in the first embodiment will be described with the same reference numerals.

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

In this embodiment, as shown in FIGS. 22 and 23, a plate piece 42 as a cylindrical shell piece has a first support jack 431 that supports the face side and a pit side that supports the face side, in substantially the same manner as in the first embodiment. It is supported by the second stanchion jacks 432 and . In this embodiment, unlike the first embodiment, the first pillar jack 431 and the second pillar jack 432 are connected to each other by a third pillar jack 433 in the vertical direction. That is, the face-side center ring 41F and the wellhead-side center ring 41R are connected by a third support jack 433 arranged along the longitudinal direction of the tunnel.

More specifically, one end of the first support 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 post 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. The face-side center ring 41F and the wellhead-side center ring 41R are connected to each other by a third post jack 433. As shown in FIG.

When the steel shell 40 has the minimum diameter shown in FIG. By being said, the outer diameter is minimized. That is, the first support jack 431 and the second support jack 432 reduce the diameter in the radial direction, and the third support jack 433 deforms the support in the longitudinal direction, thereby further reducing the diameter in the radial direction.

On the other hand, when the steel shell 40 has the maximum diameter shown in FIG. , the outer diameter is maximized (or zero, that is, the state of forming the same cylindrical surface). That is, the diameter is expanded in the radial direction by the first support jack 431 and the second support jack 432 , and the diameter is expanded in the longitudinal direction by the third support jack 433 . In this way, the steel shell 40 can be expanded or contracted in any ratio from the minimum diameter to the maximum diameter.

Also, in this embodiment, the case where the third support jacks 433 are provided has been described, but the present invention is not limited to this, and the third support jacks 433 may be omitted, in which case three or more jack groups are connected. It is possible to Furthermore, even when the third support jack 433 is provided, it is possible to connect three or more jacks by electronically controlling each jack.

Note that the rest of the configuration is substantially the same as that of the first embodiment, so description thereof will be omitted.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes to the extent that they do not depart from the gist of the present invention can be applied to the present invention. included.

For example, in the embodiment, the outer edge of the partition wall 30 is on the face side and the center portion is on the pit side to reduce the projection area. It may have a cone shape in which the center is forward and the rear is the rear.

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

Furthermore, in the embodiment, in the excavation method, an example in which the excavation diameter is discontinuously increased or decreased in one step has been described, but the excavation diameter is not limited to this, and the excavation diameter is gradually increased step by step, for example, in five steps. Expanding or contracting (increasing/decreasing) is also preferred. Furthermore, it is also possible to reduce the excavation diameter after enlarging it.

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

1: shield machine (excavator)
1A: front body 1B: rear body 11: center shaft 12: cutter motor 13: shield jack 14: erector 15: folding jack 16: screw conveyor 20: cutter head (rotating body for cutting)
21 : Bit 21F : Fishtail bit 21T : Teeth bit 22 : Boss portion 23 : Spoke 23G : Cushioning material 23H : Through hole 23N : Notch 23P : Spoke piece 23R : Spoke rod 24 : Jack 25 : Ring member 26 : Link 27 : Center link 28 : Telescopic rod 30 : Partition 30A : Partition 30B : Partition 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: Portal 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 : Drive motor 61a : Worm gear 62 : Drive cylinder 63 : Link arm

Claims (6)

A cutting rotating body for an excavator,
a drive shaft installed at the center of rotation;
a plurality of spokes radially attached to the drive shaft, the spokes being rotatably attached to the drive shaft;
and a plurality of jacks that change the rotation angles of the plurality of spokes,
The spokes are composed of a plurality of spoke pieces having bits, and spoke rods commonly inserted through through-holes formed in the plurality of spoke pieces, and the side surfaces of the plurality of spoke pieces are A rotary body for cutting formed so as to be inclined with respect to the axial direction of the spoke rod. The plurality of spoke pieces are provided with semi-cylindrical cutouts facing the through holes, semi-cylindrical cushioning materials are installed in the cutouts, and the plurality of spoke pieces cover the cushioning materials. 2. An excavator cutting wheel according to claim 1, adapted to contact said spoke rods through. One end of the jack is attached to the tip side of the spoke rod away from the drive shaft, and the other end of the jack is attached to a ring member installed near the center of rotation. A cutting rotor for an excavator according to claim 2. The side surfaces of the spoke pieces are slanted from the outside to the inside from the face side toward the wellhead side, and the spoke rods are arranged such that the base end side attached to the drive shaft is the face side and the tip end side is the wellhead side. 4. A cutting wheel for an excavator according to claim 2 or 3, which is adapted to rotate in the direction of . The side surfaces of the spoke pieces are slanted from the inner side to the outer side from the face side toward the wellhead side, and the spoke rods are arranged such that the proximal end side attached to the drive shaft is the wellhead side and the distal end side is the face side. 4. A cutting wheel for an excavator according to claim 2 or 3, which is adapted to rotate in the direction of . a rotating body for cutting according to any one of claims 1 to 5;
a partition configured so that the outer diameter can be enlarged or reduced at any ratio;
an excavator comprising a steel shell configured such that the outer diameter can be increased or decreased by any ratio.

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