JPH09158680A - Cutter head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent lowering in excavating efficiency even if cutter bits are abraded, and enhance the safety and the working efficiency in a tunnel excavator. SOLUTION: A drivable-rotatable cutter head 31 is arranged in a front part of an excavator main body, and freely rotatable rotary bodies 36a and 36b of the cutter head 31 are arranged with a support shaft 35 in the direction almost orthogonal to the rotational direction of this cutter head 31, and cutter bits 39a and 39b to which tips 40a, 40b, 41a and 41b are brazed in a multilayer shape, are installed on these rotary bodies 36a and 36b, on the one hand, a plug 43 which checks rotation of the rotary bodies 36a and 36b and allows rotation of the rotary bodies 36a and 36b according to an abraded condition of a cemented carbide tip is provided, and locking pins 47a and 47b and locking holes 48a and 48b are arranged to hold them in its rotary position when the rotary bodies 36a and 36b rotate by a specified angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutter head having a plurality of cutter bits attached to a front portion of an excavator body for excavating the ground, a tunnel excavator having the cutter heads, and the cutter. The present invention relates to a tunnel excavation method using a head.

[0002]

2. Description of the Related Art FIG. 6 is a cross section of a general shield excavator,
FIG. 7 is a front view of this shield excavator, FIG. 8 is a cross-sectional view of a conventional cutter head showing a mounted state of a cutter bit, and FIG. 9 is a side view of the conventional cutter head.

As shown in FIGS. 6 and 7, in a shield excavator for excavating the ground, a cutter head 1 is provided at the front of a cylindrical skin plate 11 as the excavator body.
2 is rotatably mounted, and this cutter head 12
The spokes 13 are radially fixed to the front surface of the, and a large number of cutter bits 14 are fixed to the spokes 13. A ring gear 15 is fixed to the rear portion of the cutter head 12, while a hydraulic motor 16 is attached to the skin plate 11, and a drive gear 17 of the hydraulic motor 16 meshes with the ring gear 15. Therefore,
When the hydraulic motor 16 is driven to drive the drive gear 17 to rotate, the cutter head 12 can be rotated via the ring gear 15.

[0004] A bulkhead 18 is attached to the skin plate 11 behind the cutter head 12, and a chamber 19 is formed between the cutter head 12 and the bulkhead 18. In the chamber 19, one end of a mud feeding pipe 20 and the other end of a mud discharging pipe 21 that are extended outside the shield excavator are open,
An agitator 22 that stirs and mixes excavated soil and mud is installed near the opening of the mud discharge pipe 21.

[0005] Further, a plurality of shield jacks 23 are arranged in the circumferential direction around the rear outer periphery of the skin plate 11, and the shield jacks 23 extend rearward in the excavation direction of the shield excavator and excavate in a tunnel. By pressing against an existing segment S (not shown) constructed on the peripheral surface, the skin plate 11, that is, the entire shield excavator can be advanced by the reaction force. On the other hand, a segment elector 24 is provided at the rear center of the skin plate 11, and the segment elector 24 is provided in a space between the skin plate 11 advanced by the shield jack 23 and the existing segment S.
You can install and build a tunnel.

By the way, the above-mentioned cutter bit 14 is swingably provided on both sides of the spoke 13. That is,
As shown in FIGS. 8 and 9, ears 25a and 25b as cutter bit mounting portions are integrally formed on both sides of the spoke 13, and the ears 25a and 25b are provided with the cutter bits 14a and 14b. It is swingably mounted by mounting pins 26a and 26b. Then, tips 27a and 27b made of a material such as cemented carbide having excellent abrasion resistance against earth and sand are fixed to the tip ends of the cutter bits 14a and 14b.

Therefore, as shown in FIG. 6, in order to excavate and form a tunnel, a plurality of shield jacks 23 are first extended, and the skin plate 11 is advanced by a reaction force against the existing segment S, while the hydraulic pressure is increased. Motor 16
, The cutter head 12 is rotated, and the ground in front is excavated by the multiple cutter bits 14. At this time, FIG.
As shown in FIG. 4, when the cutter head 12 rotates in the direction of the arrow, the cutter bit 14a on the front side in the rotation direction rotates and projects in the counterclockwise direction by the reaction force of the excavation ground, and the cutter bit 14b on the rear side in the rotation direction rotates in the clockwise direction. Turn around and retract. Therefore, the plurality of cutter bits 14a excavates the ground in front. And the cutter bit 14
The earth and sand excavated by is taken into the chamber 19, is supplied with water from the mud pipe 20, the agitator 22 stirs and mixes the excavated earth and water, and is discharged to the outside by the mud pipe 21. Next, one of the shield jacks 23 is operated in the contracting direction to form a space between the shield jack 23 and the existing segment S, and a new segment S is mounted in the space by the segment elector 24. By repeating this operation, a tunnel of a predetermined length is excavated and formed.

[0008]

In recent years, tunnels formed by excavation have a tendency to have a long distance, and the cutter bits 14 (14a, 14b) mounted on the cutter head 12 are worn during excavation work by a shield excavator. It may happen. When the cutter bit 14 is worn, the tip 27
The tips of a and 27b are not sharpened, and the excavation resistance of the earth and sand increases, the excavation efficiency decreases, and excavation becomes impossible. Further, the protruding amount of the cutter bit 14 (chips 27a, 27b) from the cutter head 12 forward in the excavation direction is reduced, and the face plate and the spokes 13 of the cutter head 12 made of a material softer than the chips 27a, 27b. Will contact the earth and sand radically, and there is a possibility that the contact portion will be worn and the function will be impaired.

Therefore, when the cutter bit 14 is worn, it is necessary to stop the excavation work and replace the worn cutter bit. In the above-described conventional shield excavator, first, the ground at a point in front of the shield excavator for exchanging the cutter bit 14 is solidified and improved by injecting a chemical solution or freezing, and completely stopping the water. A tunnel excavator is excavated to this ground improvement point. Here, the shield excavator is stopped to discharge all the excavated earth and sand in the chamber 16 so that the operator can enter the chamber 19 and can move the cutter head 12 forward of the cutter head 12 to replace the cutter bit 14. Work, that is, the worn cutter bit 14 is removed and a new cutter bit is attached.

However, the work of replacing the cutter bit in this shield excavator is costly and uneconomical in order to improve the ground and requires a chemical solution, and requires a long working time, resulting in good workability. Absent. In addition, the operator may use a narrow space in the chamber 19 or the cutter head 12
Therefore, there is a problem that the work is performed in the space in front of the operator, which is inconvenient and dangerous, and the burden on the operator increases.

The present invention solves such a problem, and prevents the excavation efficiency from being lowered even if the cutter bit is worn, and improves the safety and the working efficiency of the cutter head and the tunnel excavation. The purpose is to provide a machine and tunnel excavation method.

[0012]

A cutter head according to the present invention for achieving the above-mentioned object is a cutter head mounted on a front part of an excavator main body and having a plurality of cutter bits for excavating the ground, A support shaft provided along the direction substantially orthogonal to the excavation direction in the cutter head body,
A rotating body mounted on the support shaft so as to be rotatable by a predetermined angle only at the rear side in the excavation direction, a cutter bit mounted on the rotating body and brazed in multiple layers with a cemented carbide tip, and the rotating body Of the rotation blocking member for blocking the rotation of the rotation blocking member, a regulation member for regulating the rotation blocking member to a predetermined position, and the regulation of the rotation blocking member is released by removing the regulation member. Holding means for holding the rotating body at the rotating position when the rotating body rotates by a predetermined angle.

Therefore, the cutter head operates as the excavator body moves forward, and the plurality of cutter bits attached to the cutter head excavate the ground. At this time, the rotating body to which the cutter bit is attached is prevented from rotating by the rotation preventing member, and the cutter bit is held at the original position. After that, due to long-term use, abrasion occurs on the surface of the cemented carbide tip mounted on the cutter bit, and the cemented carbide tip falls off to reveal the next new cemented carbide tip. Further, due to the wear of the tip due to the wear of the tip, the regulation of the rotation prevention member is released and the rotation prevention member falls off, and the rotation body whose rotation is prevented by the rotation prevention member moves backward by a predetermined angle. The rotating body is rotated, and the rotating body is held at this rotating position by the holding means. In this way, the cutter bit is replaced with a new sharp carbide tip, and the rotating body rotates so that the cutter bit projects forward, and the excavation position of the ground by the cutter bit does not change, and the cutter bit The ground can be excavated as before wear.

Further, the tunnel excavator of the present invention comprises a tubular excavator body, a propulsion means for advancing the excavator body,
A cutter head rotatably mounted on the front part of the excavator body, a cutter head driving means for driving and rotating the cutter head, and a radial spoke fixed on the front surface of the cutter head. In a tunnel excavator equipped with a large number of cutter bits, a rotary body is provided on the spokes with a support shaft extending along a direction substantially orthogonal to the rotation direction of the cutter head, the rotatable body being rotatable only behind the rotation direction of the cutter head. While mounting the cutter bit in which a plurality of cemented carbide tips projecting forward are brazed to the rotating body, the rotating body is prevented from rotating and the rotating body is responsive to the wear state of the cemented carbide tip. And a holding means for holding the rotating body at the rotating position when the rotating body rotates by a predetermined angle. It is.

Therefore, while the cutter head is driven and rotated by the cutter head driving means, the propulsion means advances the excavator main body, whereby a large number of cutter bits mounted on the front surface of the cutter head crushes the ground in front. Excavate the tunnel. At this time, the rotation member to which the cutter bit is attached is prevented from rotating by the blocking member, and the cutter bit is held at its original position. After that, due to long-term use, abrasion occurs on the surface of the cemented carbide tip mounted on the cutter bit, and the cemented carbide tip falls off to reveal the next new cemented carbide tip. Further, as the tip wears, blocking of the rotating body by the blocking member is permitted, and the rotating body rotates backward by a predetermined angle in the excavating direction and is held at this rotating position by the holding means. In this way, the cutter bit is replaced with a new sharp carbide tip, and the rotating body rotates so that the cutter bit projects forward, and the excavation position of the ground by the cutter bit does not change, and the cutter bit The ground can be excavated as before wear.

Further, in the tunnel excavation method of the present invention, the cutter head mounted on the front portion of the excavator body is driven and rotated to move the excavator body forward so that a large number of blades are mounted on the front surface of the cutter head. In the tunnel excavation method of excavating a tunnel by crushing the ground in front of the cutter bit, a rotating shaft having the cutter bit mounted on the cutter head is provided with a support shaft along a direction substantially orthogonal to the rotation direction of the cutter head. Is rotatably mounted only on the rear side in the rotation direction of the cutter head, and the cutter head is driven and rotated at the original position of the cutter bit that prevents the rotation of the rotating body, thereby crushing the ground by the cutter bit. When the wear of the cutter bit progresses by excavating the tunnel, the blocking of the rotating body is released, and the cutter bit is rotated by a predetermined angle to project the cutter bit. By crushing ground by the cutter bit which projects by rotationally driving the cutter head location is characterized in that so as to excavate the tunnel.

Therefore, when the wear of the cutter bit progresses during excavation of the tunnel, the rotating body rotates by a predetermined angle to hold the cutter bit at the protruding position, and the excavation position of the ground by the cutter bit changes. Instead, the tunnel can be excavated as before the wear of the cutter bit.

[0018]

Embodiments of the present invention will be described below.

The cutter head of the present invention has a plurality of cutter bits attached to the front portion of the excavator body for excavating the ground. That is, the cutter head body is provided with a support shaft along a direction substantially orthogonal to the excavation direction,
A rotary body is mounted on the support shaft so as to be rotatable by a predetermined angle only at the rear of the excavation direction. A cutter bit protruding forward in the excavating direction is attached to the rotating body, and the cutter bit is formed by brazing a plurality of cemented carbide chips in multiple layers. Further, the rotating body to which the cutter bit is attached is prevented from rotating by a rotation preventing member interposed between the rotating body and the cutter head main body, and is positioned at the original position where the rotating body can rotate only in the rear side in the excavating direction. The position of the rotation preventing member is regulated by the regulating member so that it cannot fall off.

Therefore, the rotating body is prevented from rotating by the rotation preventing member, and the cutter bit mounted on the rotating body is held at the original position. In this state, as the excavator body advances, When the cutter head operates, a plurality of cutter bits attached to the cutter head excavate the ground.

After that, when the cutter head is used for a long period of time and wear occurs on the cemented carbide tip on the surface mounted on the cutter bit, the excavation efficiency decreases. Therefore, when the tip is worn by a predetermined amount, the tip on the worn surface falls off, and the next new cemented carbide tip appears. Further, the regulation member is also worn along with the wear of the tip, and the regulation of the rotation preventing member is released by the abrasion and the fall of the regulation member. Then, the rotating body, which has been prevented from rotating by the rotation preventing member, rotates backward by the excavation reaction force by a predetermined angle. The cutter head main body is provided with a holding unit that holds the rotating body at a rotating position when the rotating body, to which the cutter bit is attached, rotates backward by a predetermined angle in the excavating direction. Therefore, the rotating body rotated by a predetermined angle is held at the rotating position by this holding means, and the cutter bit mounted on the rotating body is held at the protruding position.

When the tip of the cutter bit wears as described above for a long period of time, the worn tip falls off and is exposed to a new sharp tip, and the rotary body supporting the cutter bit rotates to rotate the new cutter bit. As a result, the excavation position of the ground by the cutter bit does not change, and the cutter head can excavate the ground in the same manner as before the wear of the cutter bit.

Further, the tunnel excavator of the present invention is the one in which the above-mentioned cutter head is applied to the front face of the tunnel excavator so as to be freely rotatable. This tunnel excavator has a cylindrical excavator body that can be moved forward by propulsion means such as a hydraulic jack, a rotatable cutter head is attached to the front part, and can be driven and rotated by cutter head drive means such as a motor. ing. The spokes are radially fixed to the front surface of the cutter head, and a large number of cutter bits are attached to the spokes. That is, the cutter bit is formed by brazing a plurality of cemented carbide chips that protrude forward in the tunnel excavation direction in multiple layers. On the other hand, the spoke is provided with a support shaft along a direction substantially orthogonal to the rotation direction of the cutter head,
A rotating body is attached to the support shaft so as to be rotatable only rearward in the rotation direction of the cutter head, and a cutter bit is attached to the rotating body. Further, the rotating body is prevented from rotating by a blocking member interposed between the rotating body and the spoke, and is positioned at an original position in which the rotating body can only rotate backward in the excavating direction. The position of the rotation preventing member is regulated by the regulating member so that it cannot fall off.

Therefore, the turning member is prevented from turning by the blocking member, and the cutter bit mounted on the turning member is held at the original position. In this state, the cutter head is driven and rotated to excavator body. By moving forward, a large number of cutter bits mounted on the front surface of the cutter head crush the ground in front and excavate the tunnel.

Thereafter, when the excavator is used for a long period of time and the cemented carbide tip mounted on the cutter bit is worn away, the worn cemented carbide tip falls off, and the next new cemented carbide tip appears. Further, as the tip wears, blocking of the rotating body by the blocking member is allowed, and the rotating body rotates a predetermined angle rearward in the tunnel excavation direction. Holding means is provided between the spoke and the rotating body for holding the rotating body at the rotating position when the rotating body, to which the cutter bit is attached, rotates backward by a predetermined angle in the excavating direction. Therefore, the rotating body rotated by a predetermined angle is held at the rotating position by this holding means, and the cutter bit mounted on the rotating body is held at the protruding position.

When the tip of the cutter bit wears as described above for a long period of time, the worn tip falls off and is exposed to a new sharp tip, and the rotary body supporting the cutter bit rotates to rotate the new cutter bit. As the excavation position of the cutter bit does not change, the excavation position of the ground by the cutter bit does not change, and the cutter head can excavate the ground in the same way as before the wear of the cutter bit, and the tunnel is continuously excavated without lowering the excavation efficiency. it can.

Further, the tunnel excavation method of the present invention is a method for excavating a tunnel using the above-mentioned tunnel excavator, and the excavator main body is driven and rotated while the cutter head mounted on the front portion of the excavator main body is driven and rotated. By moving forward, a large number of cutter bits mounted on the front surface of the cutter head crush the ground in front and excavate the tunnel. At this time,
The rotating body that supports the cutter bit is located at the original position of the cutter bit, which prevents the cutter head from rotating rearward in the direction of rotation. When the cutter head is driven and rotated, the cutter bit crushes the ground and excavates the tunnel. To do. After that, as the wear of the cutter bit progresses, the blocking of the rotating body is released and the cutter bit is rotated by a predetermined angle, and the cutter bit is held in the protruding position.In this state, the cutter head is driven and rotated. The ground is crushed by the cutter bit that protrudes at and the tunnel is excavated.

As described above, even if the tip of the cutter bit is worn due to long-term use, the rotating body is rotated by a predetermined angle to hold the cutter bit at the protruding position, and the excavation position of the ground by the cutter bit is changed. Without excavating the cutter bit, the tunnel can be excavated, and the tunnel can be continuously excavated without lowering the excavation efficiency.

[0029]

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

FIG. 1 is a sectional view of a main part of a cutter head mounted on a shield excavator according to an embodiment of the present invention (I- in FIG. 2).
2), FIG. 2 is a plan view of a main part of the cutter head of this embodiment, FIG. 3 is a side view of the main part of the cutter head, FIG. 4 is a cross section of the main part of the cutter head in which the mounting position of the cutter bit is changed, and FIG. Fig. 3 shows a plan view of the main parts of the cutter head with the mounting position of the cutter bit changed.

In the cutter head mounted on the shield excavator of this embodiment, as shown in FIGS. 1 to 3, a step portion 33a facing the spoke 32 of the cutter head 31,
A notch 34 having a reference numeral 33b is formed, and a support shaft 35 extending along the direction substantially orthogonal to the rotation direction of the cutter head 31 is formed on the spoke 32 so as to bridge the notch 34.
Is installed. A forward spoke rotating body 36a and a reverse spoke rotating body 36b are rotatably attached to the support shaft 31, and the respective spoke rotating bodies 36a, 36b.
Cutter bits 39a and 39b are attached to the earpieces 37a and 37b formed integrally with b by attaching pins 38a and 38b. And each of these cutter bits 39
Carbide tip 40 protruding forward at the tip of a, 39b
While a and 40b are fixed, this carbide tip 40
Surface layer chips 41a and 41b are brazed on a and 40b.

By the way, the forward spoke rotating body 36a and the reverse spoke rotating body 36b mounted on the support shaft 31 have step portions 33a, 33 of the spoke 32 at the end portions 42a, 42b, respectively.
The rotation allowable angle θ is regulated by contacting b. Then, normally, a rod-shaped plug 43 as a rotation blocking member for blocking the rotation of each of the spoke rotating bodies 36a and 36b is inserted in the gap between the upper portion of the normal spoke rotating body 36a and the reverse spoke rotating body 36b. A lid 44 is provided as a regulating member on the positive spoke turning body 36a and is fixed to the positive spoke turning body 36a by welding to prevent the plug 43 from falling out of the gap. Therefore, the normal spoke rotating body 36a having the cutter bit 39a mounted thereon is held at the original position rotated clockwise in FIG. 1, and the reverse spoke rotating body 36b having the cutter bit 39b mounted thereon is opposite to that shown in FIG. It is held in its original position rotated clockwise.

Further, the spoke 32 and each of the spoke turning bodies 3
The spoke rotating bodies 36a, 3 are provided between the spoke rotating bodies 36a, 36b.
A holding mechanism is provided for holding each of the spoke turning bodies 36a and 36b at the turning position when the 6b turns by a predetermined angle θ. That is, the notch 3 is formed in the spoke 32.
4, a pair of left and right storage holes 45a, 45b are formed, and locking pins 47a, 47b urged outward by the compression springs 46a, 46b are formed in the respective storage holes 45a, 45b. It is provided. On the other hand, the locking pins 47a, 4 are provided on both side surfaces of the spoke turning bodies 36a, 36b.
Locking holes 48a and 48b are formed corresponding to 7b. The respective locking pins 47a and 47b have their plugs 43 removed from the gaps between the normal spoke rotating body 36a and the reverse spoke rotating body 36b so that the normal spoke rotating body 36a rotates counterclockwise by an angle θ in FIG. 1 and the reverse spoke rotating body 36b is inserted into the locking holes 48a and 48b, respectively, at the rotating position rotated by the angle θ in the clockwise direction in FIG.

Here, the operation of the cutter head 31 mounted on the shield excavator of this embodiment described above will be described.

When excavating and forming a tunnel, usually, while a plurality of shield jacks are extended to advance the skin plate, the cutter head 31 is rotated by a hydraulic motor, and the front ground is excavated by a large number of cutter bits 39a, 39b. To do. It should be noted that, as shown in FIGS. 1 and 2, the positive spoke rotating body 36a to which the cutter bit 39a is attached.
The reverse spoke turning body 36b to which the cutter bit 39b is attached is held in the original position by inserting the plug 43 between them and fixing them by the lid 44. Therefore, at this time, as shown by the chain double-dashed line in FIG.
When the cutter head 31 rotates in the direction of the arrow, the cutter bit 39a on the front side in the rotation direction rotates and projects in the counterclockwise direction by the reaction force of the excavation ground, and the cutter bit 39b on the rear side in the rotation direction rotates in the clockwise direction. The cutter bits 39a excavate the ground in front.

The earth and sand excavated by the cutter bit 31 is discharged to the outside by an earth discharging device (not shown). On the other hand, one of the shield jacks is operated in the contraction direction to form a space between the existing segment and a new segment is attached to this space by the segment erector, and a tunnel of a predetermined length is formed by excavation. I will do it.

When the tunnel is excavated in this way for a long period of time, each cutter bit 3 is cut in the cutter head 31.
9a (39B) mounted surface chip 41a (41
The abrasion is generated in b), the tip is not sharp, the excavation resistance of earth and sand increases, and the excavation efficiency decreases. Therefore,
In this embodiment, when the surface bits 41a (41b) are worn together with the cutter bits 39a (39B), the brazing is removed and the surface chips 41a, 41b drop off. Then, the cemented carbide chips 40a, 40b under the surface chips 41a, 41b are exposed.

Further, as the surface tip 41a (41b) is worn, the welded portion of the lid 44 that holds down the plug 43 is worn away, and the lid comes off, leaving a gap between the normal spoke rotating body 36a and the reverse spoke rotating body 36b. The plug 43 is removed from the plug and falls off. Then, the restriction of each of the spoke turning bodies 36a and 36b is released, the normal spoke turning body 36a is turned counterclockwise by an angle θ in FIG. 1, and the end portions 42a are brought into contact with the stepped portion 33a. The spoke rotating body 36b is rotated by an angle θ in the clockwise direction in FIG. 1 so that the end portion 42b abuts against the stepped portion 33b, and as shown in FIGS. 4 and 5, at each rotating position, each locking pin 47a. And 47b are locking holes 48a and 48b, respectively.
Insert into. In this way, each spoke turning body 36a, 36
Since b is held at a position rotated by a predetermined angle θ, the cutter bit 39a attached to the normal spoke rotating body 36a and the cutter bit 39b attached to the reverse spoke rotating body 36b are held at the protruding positions. It will be.

Therefore, in the cutter head 31, the cemented carbide tip 40 is attached as the surface layer tips 41a and 41b are worn.
a and 40b are exposed, and each spoke rotating body 36
The cutter bits 39a, 39b are projected forward by rotating the a, 36b.
The excavation position of the ground by 39b does not change, and the surface chip 4
Carbide chips 40a, 40 as before wear of 1a, 41b
The ground can be continuously excavated by b.

In the present embodiment, the cutter bit 3
The normal spoke rotation body 36a with the 9a attached and the reverse spoke rotation body 36b with the cutter bit 39b held in the original position by inserting the plug 43 between them and fixing them with the lid 44, By removing the lid 44 and dropping the plug 43, the spoke rotating bodies 36a, 3
Although 6b is rotatable, the holding method and the releasing method are not limited to this.

[0041]

As described above in detail with reference to the embodiments, according to the cutter head of the present invention, the supporting shaft provided on the cutter head main body along the direction substantially orthogonal to the excavating direction is rearward in the excavating direction. A rotating body that can be rotated by a predetermined angle is attached only to this, and a cutter bit in which a carbide tip protruding forward is brazed in multiple layers is attached to this rotating body, while a rotation blocking that blocks the rotation of the rotating body A member and a regulating member for regulating the rotation preventing member to a predetermined position are provided, and when the regulating member is removed, the regulation of the rotation preventing member is released and the rotating body is rotated by a predetermined angle. Since the holding means for holding the chip in the rotating position is provided, the lower layer chip is exposed due to wear of the chip, and the rotating body is rotated so that the cutter bit is held at the position projecting forward. Same as before wear Continuously by another chip by drilling a ground, it is possible to prevent a reduction of drilling efficiency.

Further, according to the tunnel excavator of the present invention,
The excavator body can be moved forward by the propulsion means, and the cutter head mounted on the front part of the excavator body can be driven and rotated by the cutter head drive means, along a direction substantially orthogonal to the rotation direction of the cutter head. With a support shaft, a spoke is provided with a rotating body that is rotatable only behind the cutter head in the direction of rotation, and a cutter bit brazed in multiple layers with carbide chips protruding forward is attached to this rotating body while the rotating body is rotated. A holding member that prevents the rotation of the rotating body and that allows the rotating body to rotate according to the wear state of the carbide tip, and holds the rotating body at the rotating position when the rotating body rotates by a predetermined angle. Since the chip is worn, the lower layer chip is exposed and the rotating body is rotated to hold the cutter bit at the position where it is projected forward. Similarly, by continuously excavating the ground with another chip, it is possible to prevent a decrease in excavation efficiency, and it is no longer necessary to replace the cutter bit in a narrow space as in the past, so that safety and It is possible to improve work efficiency.

Further, according to the tunnel excavation method of the present invention, when a large number of cutter bits mounted on the cutter head that is driven and rotated crush the ground in front to excavate the tunnel, the wear of the cutter bits progresses. In this case, since the rotation of the rotating body to which the cutter bit is attached is released and the cutter bit is rotated by a predetermined angle to project the cutter bit, it is possible to continuously excavate the ground without exchanging the cutter bit. It is possible to prevent a decrease in excavation efficiency and improve safety and work efficiency.

[Brief description of the drawings]

FIG. 1 is a sectional view (sectional view taken along line I-I of FIG. 2) of a cutter head mounted on a shield excavator according to an embodiment of the present invention.

FIG. 2 is a plan view of a main part of a cutter head according to this embodiment.

FIG. 3 is a side view of a main part of a cutter head.

FIG. 4 is a sectional view of a main part of a cutter head in which a mounting position of a cutter bit is changed.

FIG. 5 is a plan view of a main part of a cutter head in which a mounting position of a cutter bit is changed.

FIG. 6 is a cross-sectional view of a general shield excavator.

FIG. 7 is a front view of a general shield excavator.

FIG. 8 is a sectional view of a main part of a conventional cutter head showing a mounted state of a cutter bit.

FIG. 9 is a side view of a main part of a conventional cutter head.

[Explanation of symbols]

 31 Cutter Head 32 Spoke 35 Support Shaft 36a Forward Spoke Rotating Body 36b Reverse Spoke Rotating Body 39a, 39b Cutter Bit 40a, 40b Carbide Tip 41a, 41b Surface Layer Tip 43 Plug (Rotation Blocking Member) 44 Lid (Regulating Member) 47a, 47b Locking pin (holding means) 48a, 48b Locking hole (holding means)

Claims (3)

[Claims] 1. A cutter head mounted on a front portion of an excavator main body, to which a plurality of cutter bits for excavating the ground are attached, the support being provided on the cutter head main body along a direction substantially orthogonal to the excavating direction. A shaft, a rotating body mounted on the supporting shaft so as to be rotatable only by a predetermined angle rearward in the excavating direction, and a cutter bit mounted on the rotating body and brazing a cemented carbide tip protruding forward in multiple layers, A rotation blocking member that blocks the rotation of the rotating body, a regulation member that regulates the rotation blocking member to a predetermined position, and the regulation of the rotation blocking member is released by removing the regulation member. A cutter head, comprising: holding means for holding the rotating body at a rotating position when the rotating body rotates by a predetermined angle. 2. A tubular excavator main body, a propulsion means for advancing the excavator main body, a cutter head rotatably mounted on the front portion of the excavator main body, and a drive rotation of the cutter head. In a tunnel excavator equipped with a cutter head driving means and a large number of cutter bits mounted on radial spokes fixed to the front surface of the cutter head, in a direction substantially orthogonal to the rotating direction of the cutter head. With the support shaft provided on the spoke, a rotating body that is rotatable only behind the cutter head in the rotation direction is provided, and the cutter bit on which the carbide tip protruding forward is brazed in multiple layers is attached to the rotating body. A blocking member that blocks the rotation of the rotating body and allows the rotation of the rotating body according to the wear state of the cemented carbide tip, and the rotating body rotates by a predetermined angle. A tunnel excavator characterized in that holding means for holding the rotating body at a rotating position is provided at times. 3. A large number of cutter bits mounted on the front surface of the cutter head advance the ground while driving the cutter head mounted on the front portion of the excavator main body while driving and rotating the cutter head. In a tunnel excavation method for crushing a tunnel to excavate a tunnel, a rotating body in which the cutter bit is attached to the cutter head is attached to a rear side in a rotation direction of the cutter head with a support shaft along a direction substantially orthogonal to a rotation direction of the cutter head. Rotatably attached to the cutter bit only, and the cutter head is driven and rotated at the original position of the cutter bit that blocks the rotation of the rotating body to crush the ground by the cutter bit to excavate a tunnel, When the wear of the bit progresses, the blocking of the rotary body is released, the rotary body is rotated by a predetermined angle, and the cutter head is driven and rotated at the protruding position of the cutter bit. A method for excavating a tunnel, characterized in that the ground is crushed by the protruding cutter bit to excavate a tunnel.