JP2001311388A - Tunnel boring machine and tunnel boring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously excavate a long-distance tunnel without reducing boring efficiency by a tunnel boring machine and a tunnel boring method. SOLUTION: A plurality of second cutter bits 21 are provided along the radial direction at inner storage positions separately from first cutter bits 18 invariably protruded forward on a cutter head 12. When the first cutter bits are abraded, or when the bulkhead section of a vertical shaft formed with a strong concrete wall is to be ruptured, the second cutter bits 21 are extruded forward by extruding jacks 22, and boring is conducted by using the new and sharp second cutter bits 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel excavator and a tunnel excavation method applied to a shield excavator or a tunnel boring machine for constructing a tunnel by excavating the ground.

[0002]

2. Description of the Related Art For example, in a shield excavator, a cutter head is rotatably mounted on a front portion of a cylindrical excavator body, and a large number of cutter bits are mounted on the cutter head, while a plurality of cutter bits are mounted on a rear portion. Shield jacks are juxtaposed and an electr device is mounted. Therefore, when the shield jack is extended while rotating the cutter head, the excavator body advances due to the reaction force against the existing segment, and the cutter bit excavates the ground in front. Then, the excavated earth and sand are discharged to the outside, and a segment having a predetermined length is constructed by assembling the segments on the tunnel wall surface by the erector device.

[0003] In recent years, tunnels have tended to be long-hauled, and a cutter bit mounted on a cutter head may be worn during tunnel excavation work. If the cutter bit is worn, the excavation efficiency of the ground is reduced, so the excavation operation must be stopped and the worn cutter bit must be replaced. Conventionally, cutter bit replacement work involves solidifying and improving the front ground by injecting or freezing chemicals, excavating to this ground improvement point, retreating, and discharging all excavated earth and sand in the chamber. I was going inside to replace the cutter bit.

[Problems to be solved by the invention]

[0004] However, such replacement work of the cutter bit is expensive and uneconomical due to the use of a chemical solution for improving the ground, and the work time is long and the workability is high. Not good. In addition, since the worker works in a narrow space in the chamber, there is a problem that the work becomes inconvenient and the burden on the worker increases.

[0005] When constructing a tunnel, a shaft is generally formed in advance at a predetermined distance, and an excavator is inserted from one shaft to excavate and penetrate the tunnel toward the other shaft. ing. However, when the excavator causes the other shaft to penetrate the tunnel, it is necessary to break the partition wall (vertical wall) of the shaft using a cutter bit. However, since the excavator has excavated a long distance before reaching the shaft, the cutter bit has already been worn or damaged, making it difficult to break the strong concrete wall, and the work is prolonged. is there.

[0006] By the way, the work of exchanging the cutter bit is performed from within the excavator main body.
Although this is disclosed in Japanese Patent Application Laid-Open No. 291791, the "Cutter Bit Replacement Device" disclosed in this publication requires a large-scale device to increase the mounting cost, and has only a part of the cutter head. However, there is a problem that the excavation efficiency is reduced.

An object of the present invention is to provide a tunnel excavator and a tunnel excavation method capable of continuously excavating a long-distance tunnel without lowering the excavation efficiency. I do.

[0008]

According to a first aspect of the present invention, there is provided a tunnel excavator, comprising: a tubular excavator body; a propulsion jack for advancing the excavator body; A cutter head rotatably provided at a front portion of the main body, a plurality of first cutter bits fixed to the cutter head and capable of excavating a ground in front of the cutter head; and an internal storage position along a radial direction of the cutter head. And a moving mechanism for projecting the second cutter bit forward from the storage position to move the second cutter bit to a ground excavation position.

In the tunnel excavator according to the second aspect of the present invention, the cutter head is provided with a plurality of radially extending spokes, and a plurality of the first cutter bits are arranged on both sides of the radially extending spoke. A plurality of the second cutter bits are arranged at the center of the cut spokes, and the second cutter bits are provided at different positions in the radial direction for each of the cut spokes.

[0010] In the tunnel excavator according to the third aspect of the present invention, the cutter head has a box shape and the second cutter bit is housed therein, and the cutter head is provided in front of the second cutter bit. A projecting opening is formed, and a detachable first earth and sand intrusion prevention lid is attached to the projecting opening, while the second cutter bit closes the projecting opening when the second cutter bit projects forward. It is characterized by a lid for preventing intrusion of earth and sand.

Further, in the tunnel excavator according to the invention of claim 4, the base end of the second cutter bit is rotatably supported by the cutter head, and the moving mechanism causes the plurality of second cutter bits to move forward. It is characterized in that it can be rotated and protruded.

Further, in the tunnel excavator according to the fifth aspect of the present invention, a circular chain link that can be circulated and moved is supported in the cutter head, and a plurality of sets of the second cutter bit group are mounted on the chain link. When one set of the second cutter bits is located at the front position, the second cutter bit group can be moved to the excavation position of the ground by the moving mechanism.

[0013] In the tunnel excavator of the invention according to claim 6, the moving mechanism is provided with the plurality of second excavators at the storage position.
The cutter bit can be selectively moved to the excavation position of the ground.

In the tunnel excavator according to the present invention, a plurality of sets of second cutter bits are mounted in the cutter head so as to be movable along a radial direction of the cutter head.
When one set of the second cutter bit group is located at a predetermined position, the second cutter bit group can be moved to the excavation position of the ground by the moving mechanism.

The tunnel excavation method of the invention according to claim 8 is a tunnel excavation method for excavating a tunnel communicating between a pair of shafts formed at a predetermined position, wherein the excavator body is driven while rotating a cutter head. By moving forward
The ground in front is excavated by a plurality of first cutter bits fixed to the cutter head, and a predetermined distance before the shaft, a second cutter bit housed in the cutter head is projected forward to remove the wall surface of the shaft. It is characterized by breaking.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a front view of a tunnel excavator according to a first embodiment of the present invention, FIG. 2 is a II-II section of FIG. 1, FIG. 3 is a III-III section of FIG. 1, and FIG. 4 shows an IV-IV cross section.

In the tunnel excavator of the present embodiment, as shown in FIGS. 1 and 2, the excavator body 11 has a cylindrical shape, and a cutter head 12 is provided in front of the excavator body 11.
Are rotatably supported, and the cutter head 12 can be driven and rotated by a drive motor 13. The cutter head 12 is provided with a cut-spoke 15
Are provided, and the outer end of each cut spoke 15 is connected by a ring portion 16. The leading cutter bit 17 is fixed to the center portion 14, and a plurality of first cutter bits 18 are fixed to both sides of each cut spoke 15. Further, a cut-spoke 19 is provided between the cut-spokes 15, and a plurality of cutter bits 20 are fixed to both sides of the cut-spoke 19.

In the present embodiment, three second cutter bits 21 are mounted radially in the center of each cutter spoke 15, and the second cutter bits 21 are attached to the cutter head 12. It can protrude forward from the internal storage position by an extrusion jack 22 as a moving device when necessary. In addition, in three Katas pork 15,
The mounting positions of the second cutter bits 21 are different from each other in the radial direction.
By the rotation, the entire area of the cutter head 12 can be excavated by each second cutter bit.

That is, the cut-spoke 15 has three radially
One support cylinder 23 is formed, and the second
A cutter bit 21 is movably supported. Each of the second cutter bits 21 has a blade 21b at the tip of the main body 21a.
Are fixed, and the three second cutter bits 21 are connected by a connecting lever 24. A push jack 22 is attached to the cut spoke 15, and a distal end of the drive rod 25 is connected to a connection lever 24 via a connection joint 26 by a connection pin 27. A protruding opening 28 is formed in the cut-spoke 15 facing the blade portion 21b of each second cutter bit 21, and this protruding opening 28 is formed from the outside with a first earth and sand made of hard rubber (or made of aluminum or hard resin). While a cover 29 for preventing intrusion is attached, a second cover 30 for preventing intrusion of hard rubber, which is capable of closing the projecting opening 28 from the outside, is fixed to the main body 21a of the second cutter bit 21. Further, each support cylinder 2
When the second cutter bit 21 protrudes from the projecting opening 28, a non-return jack 31 for preventing the second cutter bit 21 from retreating is attached to 3, and the non-return pin 32 can protrude.

Therefore, when the main body 11 of the excavator is advanced by a propulsion jack (not shown) while the cutter head 12 is driven and rotated by the drive motor 13, each of the cutter bits 17 and 18 attached to the rotating cutter head 12 is rotated. , Cutter bit 20 excavates the ground in front to form a tunnel. The excavated earth and sand is discharged to the outside by a discharge device (not shown). At this time, the second cutter bit 21 is stored in the cutter head 12 and the first
The projecting opening 28 is closed by the cover 29 for preventing earth and sand from entering, so that the excavated earth and sand does not enter the inside of the cutter head 12.

At the time of excavating a long-distance tunnel, the cutter bits 18 and 20 are worn or damaged to lower the excavation efficiency. At this time, each of the second cutter bits 21 at the storage position in the cutter head 12 is removed. Protrude forward. That is, the drive rod 25 is driven by driving the extrusion jack 22.
And push each second cutter bit 21 forward through the connecting lever 24. Then, each second cutter bit 2
In 1, the blade portion 21 b penetrates through each first earth and sand intrusion prevention lid 29 and projects forward from the cutter head 12, and the second earth and sand intrusion prevention lid 30 closes the projecting opening 28 from the inside. Then, the second check bit 21 is prevented from retreating by projecting the check pin 32 by the check jack 31.

Therefore, by rotating the cutter head 12 with each second cutter bit 21 protruding forward from the first cutter bit 18, the ground can be continuously excavated by the second cutter bit 21. Therefore, it is not necessary to replace the first cutter bit 18, and it is possible to suppress a decrease in excavation efficiency and to ensure the safety of the operator.

When a tunnel is excavated, the tunnel is excavated from a preformed shaft to the next shaft, and penetrates. When the tunnel to the shaft is penetrated, the partition wall (vertical wall) of the shaft is broken. There is a need to. When the tunnel excavator reaches the shaft, there is a high possibility that the cutter bits 18, 20 have already been worn or broken. Therefore, as described above, by pushing each second cutter bit 21 forward by the extrusion jack 22, the partition wall portion of the shaft is broken by using the new and sharp second cutter bit 21, A strong concrete wall can be easily broken in a short time. At this time, each of the second cutter bits 21 is mounted on each of the cutter spokes 15 at different positions in the radial direction, and each rotation of the cutter head 12 causes each of the second cutter bits to sequentially contact the partition wall to excavate the entire area. it can.

As described above, in the tunnel excavator of the present embodiment, apart from the first cutter bit 18 always protruding forward from the cutter head 12, the second cutter bit 21 at the internal storage position is provided with a diameter. A plurality is provided along the direction, the first
When the cutter bit 18 is worn or breaks the partition wall of the shaft made of a strong concrete wall, the second cutter bit 21 is pushed forward by the extrusion jack 22, and the new and sharp second cutter bit 21 is used. To excavate. Therefore, a long-distance tunnel can be continuously excavated without lowering the excavation efficiency.

FIG. 5 is a front view of a main part of a cutter head in a tunnel excavator according to a second embodiment of the present invention, and FIGS. 6 and 7 are front views of a main part of a cutter head in a modified example thereof. In the embodiments described below, members having the same functions as those described in the above-described embodiments are denoted by the same reference numerals, and redundant description will be omitted.

In the tunnel excavator of the present embodiment, as shown in FIG. 5, three second cutter bits 21 are mounted on each cutter spoke 15 provided on the cutter head 12 in two rows in the radial direction. It can protrude forward from a storage position in the cutter head 12 by an extrusion jack (not shown). As a modified example, as shown in FIG. 6, three second cutter bits 21 are staggered in three rows along the radial direction on each of the cutter spokes 15 provided on the cutter head 12. From the storage position in the cutter head 12 by an extrusion jack (not shown). Further, as a modified example, as shown in FIG.
Each of the cut-spokes 15 provided with three cutter bits 21A and 21B is mounted along the radial direction, and two second cutter bits 21B are mounted on both sides thereof. It has a larger diameter than 21B, and can protrude forward from a storage position in the cutter head 12 by an extrusion jack (not shown).

As described above, in the tunnel excavator of the present embodiment, since the second cutter bits 21 at the storage position of the cutter head 12 are provided in a plurality of rows along the radial direction, the rock is hard rock. Can be reliably broken. By providing the second cutter bits 21 in a staggered manner, a large number of second cutter bits 21 can be disposed without gaps, and a large-diameter cutter bit 21A is provided outside the cutter head 12 having a large excavation stress.
By arranging the rock can be surely broken,
Long-distance tunnels can be continuously excavated without lowering the excavation efficiency.

FIG. 8 shows a cross section of a main part of a cutter head in a tunnel excavator according to a third embodiment of the present invention, and FIG. 9 shows a cross section of a main part of a cutter head in a modified example thereof.

In the tunnel excavator of this embodiment, as shown in FIG. 8, a pair of left and right vertical walls 41 is formed in the cut spoke 15 and a pair of left and right vertical The base end of the second cutter bit 43 is rotatably supported. A push jack 44 is attached to the cut-spoke 15, and a connection joint 45 attached to the tip of the drive rod is connected to each second cutter bit 43 via a pair of left and right link levers 46. And, the projection opening 47
Is provided with a lid 48 for preventing earth and sand from entering from outside.
Further, when the second cutter bit 43 protrudes from the protruding opening 47 on each vertical wall 41, a non-return jack 49 for preventing retraction is mounted, and the non-return pin 50 can protrude.

Accordingly, when the drive rod is extended by the pushing jack 44, the connecting joint 45 and each link lever 46 are extended.
Each of the second cutter bits 43 is rotated to open and is pushed forward through. Then, each second cutter bit 43 can pierce the earth and sand intrusion prevention lid 48 and protrude from the projecting opening 47 to the front of the cutter head 12. And
By projecting the non-return pin 50 by the non-return jack 49, the retraction of the second cutter bit 43 is prevented.

As described above, in the present embodiment, the pair of left and right second cutter bits 43 is rotatable, and is rotated by the pushing jack 44 so as to open left and right and project forward. The protrusion amount and the protrusion position of the second cutter bit 43 can be changed according to the amount of expansion and contraction of the extrusion jack 44.

As a modified example, as shown in FIG. 9, at the front portion of each vertical wall 41 of the cut-spoke 15, a base end of a pair of left and right second cutter bits 52 is rotatably mounted on a bracket 51. Supported. Also, Katas Spoke 15
The tip of the drive rod of the extrusion jack 44 attached to the second cutter bit 52 is connected to each second cutter bit 52 via a connection joint 45 and a link lever 53. Accordingly, when the drive rod is extended by the push-out jack 44, the second cutter bit 52 is rotated via the coupling joint 45 and the link lever 53 so as to close and is pushed forward. Then, each second
The cutter bit 52 can penetrate the earth and sand intrusion prevention lid 48 and protrude forward from the cutter head 12 through the protruding opening 47. Then, the second check bit 43 is prevented from retreating by projecting the check pin 50 with the check jack 49.

As described above, in the present embodiment, the pair of left and right second cutter bits 52 is rotatable, and is rotated by the pushing jack 44 so as to close to the center and protrude forward. In addition, the protrusion amount and the protrusion position of the second cutter bit 52 can be changed in accordance with the amount of expansion and contraction of the extrusion jack 44, and the excavation strength can be improved by making the protrusion position substantially near the center.

FIG. 10 is a sectional view of a main part of a cutter head in a tunnel excavator according to a fourth embodiment of the present invention, and FIG. 11 is a sectional view taken along line XI-XI of FIG.

In the tunnel excavator of this embodiment, as shown in FIGS. 10 and 11, a mounting bracket 61 is fixed to the cutter spoke 15 along the radial direction, and one end of the mounting bracket 61 has a drive motor. A drive sprocket 63 that can be driven and rotated by 62 is mounted, and a rotatable driven sprocket 64 is mounted at the other end. A double chain link 65 is looped around each of the sprockets 63 and 64, and four second cutter bits 66 are attached to the front side of the double chain link 65 on the cutter spoke 15 in the radial direction. On the other hand, four third cutter bits 67 are mounted on the rear side. An extruding jack 68 is attached to the center of the mounting bracket 61, and a tip of a driving rod 69 is connected to an extruding plate 70. A protruding opening 71 is formed in each of the cut spokes 15 facing each of the second cutter bits 66, and a hard rubber first earth and sand intrusion prevention lid 72 that closes each of the protruding openings 71 from the outside is attached. Each cutter bit 66, 67 is provided with a second earth / sand intrusion prevention lid 73 that closes the respective projecting openings 71 from the inside.

Therefore, when the first cutter bit (not shown) fixed to both sides of the cut-spoke 15 is worn, when the driving rod is extended by the pushing jack 68, the pushing plate 7 is pushed.
0 pushes out each second cutter bit 66 forward, and each second cutter bit 66 breaks through the first earth and sand intrusion prevention lid 71 and projects forward of the cutter head 12 from the projecting opening 70, so that the second cutter bit 66 is pushed out. The ground can be excavated by the cutter bit 66. Thereafter, when the second cutter bit 66 is worn out, the extrusion plate 68 is used by the extrusion jack 68.
, The second cutter bit 66 is moved backward by driving the drive motor 62 and the double chain link 65 is circulated to move the second cutter bit 66 to the rear side, while moving the third cutter bit 67 to the front side. Go to Then, in the same manner as described above, the ground can be excavated by the third cutter bits 67 by pushing each third cutter bit 67 forward by the extrusion jack 68 through the extrusion plate 70.

As described above, in this embodiment, a double chain link 65 is provided in the cutter head 12 around the sprockets 63 and 64, and the double chain link 65 is provided with the second cutter bit 67 and the third cutter When the first cutter bit is worn out when the first cutter bit is worn, the second cutter bit 66 can be pushed out by the extrusion jack 68 to excavate the ground in front of the first cutter bit. Is worn out,
By circulating the double chain link 65, the third cutter bit 67 is moved forward, and the third cutter bit 67 is
The cutter bit 67 can be pushed out to excavate the ground in front, and a long-distance tunnel can be excavated continuously without lowering the excavation efficiency. In this embodiment, by making the shapes of the second cutter bit 66 and the third cutter bit 67 different, the respective cutter bits 66 and 67 can be selectively projected as necessary.

FIG. 12 is a sectional view of a main part of a cutter head in a tunnel excavator according to a fifth embodiment of the present invention, and FIG. 13 is a sectional view taken along line XIII-XIII of FIG.

In the tunnel excavator of the present embodiment, as shown in FIGS. 12 and 13, a mounting bracket 81 is fixed to the cut-spoke 15 in a radial direction, and a driving motor is attached to one end of the mounting bracket 81. A driving sprocket 83 that can be driven and rotated by 82 is mounted, and a rotatable driven sprocket 84 is mounted at the other end. A double chain link 85 is looped around each of the sprockets 83 and 84. Four push protrusions 86 are mounted on the front side of the double chain link 85, and two push protrusions 87 are mounted on the rear side. Is installed. At the center of the mounting bracket 81 is an extrusion jack 8
8 is attached, the tip of the drive rod 89 is connected to the pushing plate 90, and the pushing protrusions 86 and 87 can be pressed. Further, four second cutter bits 91 are mounted on the cut-spoke 15 so as to be movable back and forth along the radial direction, and are biased and supported by a compression spring 92 in a direction in which the cut-spoke 15 is stored in the cut-spoke 15. And each second
Each of the cut spokes 15 facing the cutter bit 91 is formed with a projecting opening 93, and the hard rubber first earth and sand prevention cover 9 for closing each projecting opening 93 from the outside.
The second cutter bit 91 is provided with a second sediment intrusion prevention lid 95 for closing each projecting opening 93 from the inside.

Accordingly, when the drive rod 89 is extended by the push-out jack 88, the push-out plate 90 becomes four push-out protrusions 86.
All the second cutter bits 91 are pushed forward, and the respective second cutter bits 91 pierce the first earth and sand intrusion prevention lid 94 and come out of the projection opening 93 through the cutter head 12.
Can protrude forward. The drive motor 82
Is driven to circulate the double chain link 95 to move the extrusion protrusion 87 to the front side.
As a result, the pushing plate 90 can push the two second cutter bits 91 forward through the four pushing protrusions 87.

As described above, in the present embodiment, the double chain link 85 is provided in the cutter head 12 so as to be able to move in a circulating manner. Two extrusion protrusions can be mounted, and the necessary number of the second cutter bits 94 can be pushed out by the extrusion jack 88 to excavate the ground in front, if necessary.

FIG. 14 shows a cross section of a main part of a cutter head in a tunnel excavator according to a sixth embodiment of the present invention.

In the tunnel excavator of the present embodiment, as shown in FIG. 14, a pair of mounting brackets 101 and 102 are movably supported on the cut-spoke 15 along the radial direction. While three second cutter bits 103 are mounted, three third cutter bits 104 are mounted on the other mounting bracket 102. A moving jack 105 is attached to the cut spoke 15, one of the drive rods 106 is connected to a mounting bracket 101 by a lever joint 107, and the other is connected to a mounting bracket 102 by a lever joint 108. Further, an extrusion jack 109 is attached to the cutout spoke 15.
The distal end of the drive rod 110 can push out the second cutter bit 103 or the third cutter bit 104 via the pushing protrusion 111. A protruding opening 112 is formed in each of the cut spokes 15 facing each of the second cutter bits 103, and a hard rubber first earth and sand intrusion prevention lid 113 for closing each protruding opening 112 from the outside is attached. The cutter bits 103 and 104 are provided with second earth and sand intrusion prevention covers 114 and 115 for closing the respective projecting openings 112 from inside.

Therefore, when the first cutter bits (not shown) fixed to both sides of the cut-spoke 15 are worn, the pushing jack 109 is driven, and the pushing projections 111 push the respective second cutter bits 103 forward, thereby causing the second cutter bits 103 to move forward. The ground can be excavated by the cutter bit 103. Thereafter, when the second cutter bit 103 is worn, each second cutter bit 103 is retracted, and the second cutter bit 103 is moved by the moving jack 105.
Is moved to the storage position, and each third cutter bit 104 is moved to the protrudable position. Then, as described above, the ground can be excavated by the third cutter bits 104 by pushing each third cutter bit 104 forward by the extrusion jack 109.

As described above, in this embodiment, when the first cutter bit is worn, when the second cutter bit 103 is worn.
Alternatively, the third ground can be excavated by pushing out the third cutter bit 104, and a long-distance tunnel can be excavated continuously without reducing the excavation efficiency.

[0047]

As described in detail in the above embodiment, according to the tunnel excavator of the first aspect of the present invention, a plurality of first cutter bits capable of excavating the ground in front of the cutter head are fixed to the cutter head. A plurality of second cutter bits are provided at an internal storage position along the radial direction of the head, and the second cutter bit is protruded forward from the storage position by a moving mechanism and can be moved to a ground excavation position. When the bit wears or breaks the partition wall of the shaft made of strong concrete wall, the second cutter bit 21
Extruded forward, and it is possible to excavate using this new and sharp second cutter bit, and it is possible to excavate a long-distance tunnel continuously without reducing the excavation efficiency.

According to the tunnel excavator of the second aspect of the present invention, the cutter head is provided with a plurality of radially extending spokes, and a plurality of first cutter bits are arranged on both sides of the radially opposite side of the spokes, while a plurality of radially extending first and second cutter bits are provided at the center. Since a plurality of two cutter bits are arranged in parallel and the second cutter bits are provided at different positions in the radial direction for each cutter spoke, most areas of the cutter head can be efficiently excavated by the second cutter bits.

According to the third aspect of the present invention, the cutter head is box-shaped to house the second cutter bit therein, and the cutter head in front of the second cutter bit has a projecting opening. Since the detachable first earth and sand intrusion prevention lid is attached to the projecting opening, the second earth and sand intrusion preventing lid that closes the projecting opening when the second cutter bit projects forward is attached to the second cutter bit. Even when the second cutter bit is in the storage position or in the protruding storage position, the intrusion of excavated earth and sand into the inside can be reliably prevented by the earth and sand intrusion prevention lid.

Further, according to the tunnel excavator of the present invention, the base end of the second cutter bit is rotatably supported by the cutter head, and the moving mechanism rotates the plurality of second cutter bits forward. Since the second cutter bit can move and project, the projecting amount and projecting position of the second cutter bit can be changed according to the moving amount of the moving mechanism.

According to the tunnel excavator of the fifth aspect of the present invention, a circular chain link that can move in a circulating manner is supported in the cutter head, and a plurality of sets of the second chain link are supported on the chain link.
Since the cutter bit group is mounted and the second cutter bit group of one set can be moved to the excavation position on the ground by the moving mechanism when the second set of cutter bits is located at the front position, the cutter bit group is sequentially moved to the excavation position on the ground. Thus, even a hard rock can be reliably broken.

According to the tunnel excavator of the present invention, the moving mechanism can selectively move the plurality of second cutter bits at the storage position to the excavation position on the ground.
By moving the required number of second cutter bits to the excavation position depending on the wear frequency of the first cutter bits, the hardness of the ground, and the like, the second cutter bits can be used efficiently.

According to the tunnel excavator of the present invention, a plurality of sets of second cutter bits are movably mounted in the cutter head along the radial direction of the cutter head.
When the second cutter bit group of the set is located at a predetermined position, it is possible to move to the ground excavation position by the moving mechanism, so by sequentially moving the cutter bit group to the ground excavation position,
Even hard rock can be reliably broken.

According to the tunnel excavation method of the present invention, when excavating a tunnel communicating between a pair of shafts formed at a predetermined position, the excavator body is advanced while driving and rotating the cutter head. By this, the ground in front is excavated by the plurality of first cutter bits fixed to the cutter head, and a predetermined distance before the shaft, the second cutter bit housed in the cutter head is projected forward to break the wall surface of the shaft. When breaking the partition wall of a shaft made of a strong concrete wall, the second cutter bit 21 is pushed forward, and it is possible to excavate using the new and sharp second cutter bit. Long-distance tunnels can be continuously excavated without lowering the excavation efficiency.

[Brief description of the drawings]

FIG. 1 is a front view of a tunnel excavator according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a front view of a main part of a cutter head in a tunnel excavator according to a second embodiment of the present invention.

FIG. 6 is a front view of a main part of a cutter head according to a modification of the second embodiment.

FIG. 7 is a front view of a main part of a cutter head according to a modification of the second embodiment.

FIG. 8 is a sectional view of a main part of a cutter head in a tunnel excavator according to a third embodiment of the present invention.

FIG. 9 is a sectional view of a main part of a cutter head according to a modification of the third embodiment.

FIG. 10 is a sectional view of a main part of a cutter head in a tunnel excavator according to a fourth embodiment of the present invention.

11 is a sectional view taken along line XI-XI of FIG.

FIG. 12 is a sectional view of a main part of a cutter head in a tunnel excavator according to a fifth embodiment of the present invention.

FIG. 13 is a sectional view taken along line XIII-XIII of FIG.

FIG. 14 is a sectional view of a main part of a cutter head in a tunnel excavator according to a sixth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Excavator main body 12 Cutter head 15 Cutter spoke 18 1st cutter bit 21, 21A, 21B, 43, 52, 66, 91, 103
Second cutter bit 22, 44, 68, 88, 109 Extrusion jack 28, 47, 70, 93, 112 Projection opening 29, 48, 71, 94, 113 First earth and sand intrusion prevention lid 30, 72, 73, 95, 114 Second earth and sand intrusion prevention lid 65,85 Double chain link 67,104 Third cutter bit 86,87 Extrusion protrusion 92 Compression spring 105 Moving jack

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Katsumi Munemi 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo F-term in Mitsubishi Heavy Industries, Ltd. Kobe Shipyard 2D054 AC01 BA02 BB05

Claims (8)

[Claims] 1. An excavator body having a cylindrical shape, a propulsion jack for advancing the excavator body, a cutter head rotatably provided at a front portion of the excavator body, and a plurality of cutter heads fixed to the cutter head. A first cutter bit capable of excavating the ground in front of the cutter head, a plurality of second cutter bits provided at an internal storage position along a radial direction of the cutter head, and A tunnel excavator, comprising: a moving mechanism that projects to a ground excavation position. 2. The tunnel excavator according to claim 1, wherein the cutter head is provided with a plurality of cut-spokes radially, and a plurality of the first cutter bits are arranged in parallel on both sides of the cut-spoke. A tunnel excavator, wherein a plurality of the second cutter bits are arranged in the center of a cutter spoke, and the second cutter bits are provided at radially different positions for each of the cutter spokes. 3. The tunnel excavator according to claim 1, wherein the cutter head has a box shape and the second cutter bit is housed therein, and the cutter head protrudes from the cutter head in front of the second cutter bit. An opening is formed, and a detachable first earth and sand intrusion prevention lid is attached to the projecting opening, while the second cutter bit closes the projecting opening when the second cutter bit projects forward. A tunnel excavator equipped with an intrusion prevention lid. 4. The tunnel excavator according to claim 1, wherein a base end of the second cutter bit is rotatably supported by the cutter head, and a plurality of the second cutter bits are moved forward by the moving mechanism. A tunnel excavator characterized by being rotatable and protrudable. 5. The tunnel excavator according to claim 1, wherein a circular chain link that can be circulated is supported in the cutter head, and a plurality of sets of the second cutter bits are mounted on the chain link. A tunnel excavator, which is movable to the excavation position on the ground by the moving mechanism when the set of second cutter bits is located at a forward position. 6. The tunnel excavator according to claim 1, wherein the moving mechanism is configured to move the plurality of second excavators in the storage position.
A tunnel excavator wherein a cutter bit can be selectively moved to an excavation position on the ground. 7. The tunnel excavator according to claim 1, wherein a plurality of sets of second cutter bits are movably mounted in the cutter head along a radial direction of the cutter head.
A tunnel excavator, wherein the set of second cutter bits is movable to a ground excavation position by the moving mechanism when the second cutter bit group is located at a predetermined position. 8. A tunnel excavation method for excavating a tunnel communicating between a pair of shafts formed at a predetermined position,
By moving the excavator body forward while driving and rotating the cutter head, the ground in front is excavated by the plurality of first cutter bits fixed to the cutter head, and stored in the cutter head a predetermined distance before the shaft. A tunnel excavation method characterized in that the second cutter bit is projected forward to break the wall surface of the shaft.