JPH07259488A - Shield excavator - Google Patents

Abstract

PURPOSE:To facilitate exchange work of a cutter bit, to lighten a burden applied on a worker, to improve safety and working performance of digging work and to exchange the cutter bit at proper time in accordance with an abrasion state of the cutter bit. CONSTITUTION:A fixed cutter bit 15 is fixed on a cutter head 12 which is free to drive to rotate, and a cutter bit 31 for exchange is installed free to appear and disappear adjacent to this fixed cutter bit 15. When the fixed cutter bit is abrased and its diggingcapacity is lowered, the cutter bit 31 is projected forward in the digging direction rather than the fixed cutter bit 15 by an actuation control mechanism 32, and digging work is carried out by this cutter bit 31 for exchange.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator for excavating rock or the like, and more particularly to a cutter bit mounted on a cutter head in front of the shield excavator.

[0002]

2. Description of the Related Art FIG. 6 is a schematic side view showing a conventional shield excavator, and FIG. 7 is a front view of the shield excavator.

As shown in FIGS. 6 and 7, in a shield excavator for excavating the ground, a cutter head 12 is rotatably mounted on the front part of a cylindrical excavator body 11.
The cutter head 12 has spokes 13 on the front surface, and a large number of leading cutter bits 14 and fixed cutter bits 15 for excavating the natural ground are fixed to the spokes 13. A ring gear 16 is fixed to the rear portion of the cutter head 12, and a drive gear of a cutter turning drive device 17 attached to the excavator body 11 meshes with the ring gear 16. A copy cutter 18 is attached to the cutter head 12.

In addition, the excavator body 11 has a cutter head 1
2 and the bulkhead 19, a chamber chamber 20 is formed, and one end of the chamber chamber 20 is opened at the other end of the mud pipe 21 and the mud pipe 22 which extend to the outside of the excavator body 11. In the vicinity of the opening of the mud discharge pipe 22, an agitator 23 that stirs and mixes excavated soil and mud is installed. Further, a plurality of shield jacks 24 are arranged side by side in the circumferential direction on the rear part of the excavator body 11, and the shield jacks 24 extend to the rear in the excavating direction of the shield excavator and are constructed on the inner peripheral surface of the excavated tunnel. The shield excavator main body 11 can be moved forward by its reaction force by pressing it against the existing segment 10a (not shown). On the other hand, 25 is a segment erector device, which is the shield excavator body 11 advanced by the shield jack 24.
A new segment 10b is attached to a space between the existing segment 10a and the existing segment 10a to build a tunnel.

Therefore, in order to excavate and form a tunnel, first, a plurality of shield jacks 24 are actuated to move the shield excavator main body 11 forward by the reaction force against the existing segment 10a, while the cutter turning drive device 17 is used. Rotate the cutter head 12 to move the leading cutter bit 1
The ground is excavated by 4 and the fixed cutter bit 15. Then, the earth and sand excavated by the cutter bits 14 and 15 are taken into the chamber 20, the mud water is fed from the mud pipe 21, the agitator 23 mixes the excavated mud and the mud water, and the mud pipe 22 It is discharged to the outside. Next, one of the shield jacks 24 is operated in the contracting direction to form a space between the shield jack 24 and the existing segment 10a, and a new segment 10b is attached to this space by the segment erector device. By repeating this operation, a tunnel of a predetermined length is excavated and formed.

[0006]

In recent years, tunnels for excavation and construction tend to have a long distance, and the fixed cutter bit 15 mounted on the cutter head 12 may be worn during excavation work by a shield excavator. is there. In this case, the excavation work must be stopped and the fixed cutter bit 15 must be replaced. In the conventional shield excavator described above, first, the ground at a point in front of the shield excavator for exchanging the cutter bit 15 is solidified and improved by injecting a chemical solution or freezing, and the shield excavator is reached to this ground improvement point. Dig in. Here, the shield excavator is stopped and the chamber 2
All the excavated earth and sand in 0 are discharged, and an operator enters the chamber chamber 20 to replace the cutter bit 15, that is, the worn cutter bit 15 is removed and a new cutter bit is attached.

However, in the work of exchanging the cutter bit in the conventional shield excavator, there is a problem that the burden on the operator is large, the time required for the exchanging work is long, and the cost is large. there were.
That is, in the conventional shield excavator, the ground must be improved when the cutter bit 15 is replaced, quality control of the ground improvement is difficult, and a lot of construction period and cost are required for that. At the same time, excavation work is temporarily interrupted during exchanging the cutter bit, which reduces work efficiency. In addition, the worker enters the chamber room 20 to perform replacement work, but the inside of the chamber room 20 is under a high water pressure of 3 kg / cm ² or more due to the supply of mud water from the mud pipe 21. Work is difficult and dangerous, and all replacement work is done manually by the worker, resulting in reduced work efficiency. Further, it is difficult to predict the wear state of the fixed cutter bit 15, and it is difficult to grasp the life and properly adjust the replacement timing.

The present invention is intended to solve such a problem. The cutter bit can be replaced easily, the burden on the operator is reduced, the safety and the work efficiency of excavation work are improved, and the cutter bit is improved. It is an object of the present invention to provide a shield excavator that can be replaced at an appropriate time according to the wear state of the shield excavator.

[0009]

A shield excavator unit according to the present invention for achieving the above object is a shield excavator in which a fixed cutter bit is mounted on a freely rotatable cutter head. A replacement cutter bit is closely mounted so as to be retractable, and the replacement cutter bit is set to a retracted position with respect to the fixed cutter bit by an operation control mechanism based on a state of loss or wear of the fixed cutter bit. It is something.

[0010]

[Operation] When wear of the fixed cutter bit progresses during excavation work using the shield excavator, the operation control mechanism detects the position of the replacement cutter bit with respect to the fixed cutter bit based on the missing or worn state of the fixed cutter bit. By setting, if the fixed cutter bit is lost or the wear is severe and the excavation capacity is extremely reduced during long-term excavation work, the replacement cutter bit protrudes forward from the fixed cutter bit and becomes a fixed cutter bit. Instead, excavation work is performed by the replacement cutter bit, so that the replacement work of the cutter bit can be performed easily and in a short time, and the replacement time is appropriate.

[0011]

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

FIG. 1 is a schematic side view showing a shield excavator according to an embodiment of the present invention, FIG. 2 is a front view of the shield excavator, and FIG. 3 is an enlarged sectional view showing a replacement cutter bit and its operation control mechanism. 4 shows a cross section of the operation control mechanism of the replacement cutter bit, and FIG. 5 shows a cross section of the fixed cutter bit. It should be noted that the members having the same functions as those of the related art are designated by the same reference numerals, and the duplicate description will be omitted.

As shown in FIGS. 1 and 2, in the shield excavator of this embodiment, a cylindrical excavator body 11 having a cylindrical shape is used.
A cutter head 12 is rotatably mounted on the front part of the cutter head 12, and a front cutter bit 14 for excavating the ground is fixed to the spokes 13 of the cutter head 12 and a plurality of fixed cutter bits 15 are arranged side by side. ing. The cutter head 12 can be driven to rotate by a cutter rotation drive device 17.

The excavator main body 11 has a chamber 20
The chamber chamber 20 is provided with an agitator 23 for connecting the ends of the mud pipe 21 and the mud pipe 22 and stirring and mixing the excavated soil and mud. Furthermore,
A plurality of shield jacks 24 are provided at the rear of the excavator body 11.
And a segment erector device 25 for mounting a new segment 10b between the excavator body 11 and the existing segment 10a.

In the shield excavator of this embodiment, a plurality of fixed cutter bits 1 arranged in parallel on the cutter head 12 are provided.
5, a replacement cutter bit 31 is attached and the replacement cutter bit 31 is fixed to the fixed cutter bit 15.
When the blade is damaged or worn, the operation control mechanism 32 projects the fixed cutter bit 15 forward. That is, as shown in FIG. 3, the cutter head 12
The replacement cutter bits 31 are respectively located in the spokes 13 at positions adjacent to the fixed cutter bits 15 fixed to the spokes 13.
Are movably supported by guides 33 attached to the spokes 13. Also, each replacement cutter bit 3
1, the drive jack 34 is located corresponding to the position 1, and the base end of the drive jack 34 is attached to the spoke 13 by the support pin 35.
On the other hand, the tip end is connected to the replacement cutter bit 31 by a connecting pin 36.

The drive jack 34, as shown in FIG.
The cylinder 37, the piston 38 movable in the cylinder 37, and the piston rod 39 connected to the piston 38 are provided, and the piston rod 39 is provided as described above.
One end of the cylinder 37 is connected to the spoke 13 by the support pin 35, and one end of the cylinder 37 is connected to the replacement cutter bit 31 by the connection pin 36. Then, in the drive jack 34, the piston 38 and the cylinder 37
A compression spring 40 is interposed between the compression spring 40 and the inner wall thereof, and the compression spring 40 urges the drive jack 34 in the extending direction. A lock piece 41 is fixedly connected to the piston rod 39, a fitting groove 42 is formed at the end of the cylinder 37, and a ratchet mechanism (not shown) is provided between the piston rod 39 and the cylinder 37. Intervenes. Therefore, when the drive jack 34 is extended, the piston rod 39 and the cylinder 37 are allowed to move relative to each other only in one direction, and the lock piece 41 is fitted into the fitting groove 42 so that the extended state of the drive jack 34 is maintained. It is supposed to be done.

Further, the inside of the cylinder 37 is partitioned into two chambers 43 and 44 by a piston 38, and one chamber 44, that is, the one in which the lock piece 41 is located, supplies and discharges a fluid to and from a fluid supply port 45. Is formed, and one end of a fluid supply / discharge pipe 47 is connected to the supply / discharge port 45 via a joint 46. The cylinder 37 and the piston 3
An O-ring 48 is attached to the sliding portion with respect to 8. On the other hand, as shown in FIG. 5, the fixed cutter bit 15 is fixed to the spoke 13 by a fixing bolt 49, and the fixed cutter bit 15 has a tip 50 welded to its tip.
A hollow portion 51 is formed so as to communicate with each other. The other end of a supply / discharge pipe 47 connected to the drive jack 34 via a joint 52 is connected to the hollow portion 51.

Therefore, in order to excavate and form a tunnel with the shield excavator of the present embodiment, as shown in FIGS. 1 and 2, a plurality of shield jacks 24 are actuated and the reaction force against the existing segment 10a is applied. While the shield excavator body 11 is moved forward, the cutter turning drive device 17
The cutter head 12 is swung by and the ground is excavated by the fixed cutter bit 15. The excavated earth and sand is taken into the chamber 20, and this earth and sand is stirred and mixed by the agitator 23 with the muddy water sent from the mud sending pipe 21, and is discharged to the outside by the mud discharging pipe 22. Then, one of the shield jacks 24 is actuated in the contracting direction to mount a new segment 10b in the space formed between the existing segment 10a and the segment erector device. The tunnel is excavated and formed by repeating this work.

The fixed cutter bit 1 mounted on the cutter head 12 during excavation work by such a shield excavator.
When the 5 wears and needs to be replaced, the operation control mechanism 3
2 operates each drive jack 34 based on the wear (loss) state of the fixed cutter bit 15, and the replacement cutter bit 3
1 is pushed out to cause the replacement cutter bit 31 to project forward of the worn fixed cutter bit 15. Then, the protruding replacement cutter bit 31 is held at the protruding position, and excavation work is performed by the replacement cutter bit 31.

In the operation control mechanism 32, as shown in FIGS. 3 (a), 4 (a) and 5, when the excavation work is being carried out by the fixed cutter bit 15, the drive jack 34 contracts and the replacement cutter 34 is retracted. The bit 31 is held in a state of being stored in the cutter head 12 (spoke 13). That is, the chamber 44 of the cylinder 37 in the drive jack 34
In addition, a supply / discharge pipe 47 and a hollow portion 51 communicating with this room 44
A fluid is filled therein and is pressurized, the compression spring 40 is compressed, the drive jack 34 is contracted, and the replacement cutter bit 31 is held in the retracted position.

In this state, when the fixed cutter bit 15 is used for long-term excavation work, the fixed cutter bit 1
As the wear of the tip 50 of No. 5 progresses, the hollow portion 51 is exposed to the outside, and the internal fluid is ejected from there, and the fluid pressure of the hollow portion 51, the supply / discharge pipe 47, and the chamber 44 of the cylinder 37. Is reduced. Then, as shown in FIG. 3 (b) and FIG. 4 (b), the compression spring 4 which has been compressed by the pressure of the fluid.
0 extends due to its elastic force and pushes the cylinder 37 against the piston 38 to move the drive jack 34.
Is extended and the replacement cutter bit 31 is projected. Then, when the cylinder 37 moves relative to the piston 38, the lock piece 41 is fitted into the fitting groove 42, whereby the extended state of the drive jack 34 is maintained, and the replacement cutter bit 31 wears the fixed cutter bit 15. It is fixed at a position that protrudes more forward than.

As described above, in the shield excavator of this embodiment, when the fixed cutter bit 15 is worn, the hollow portion 5 is removed.
The internal pressure from which the internal fluid is jetted from 1 decreases, and each drive jack 34 is activated to cause the replacement cutter bit 31 to project forward of the worn fixed cutter bit 15 and hold it at this position. Therefore, the protruding replacement cutter bit 3
1, the excavation work can be continuously performed in place of the fixed cutter bit 31.

[0023]

As described above in detail with reference to the embodiments, according to the shield excavator of the present invention, the replacement cutter bit is provided in the vicinity of the fixed cutter bit mounted on the freely rotatable cutter head. It is mounted so that it can be retracted freely, and the replacement cutter bit is set to the retracted position with respect to the fixed cutter bit by the operation control mechanism based on the defect or wear state of the fixed cutter bit. Alternatively, if the excavation capacity is extremely reduced due to wear, the operation control mechanism causes the replacement cutter bit to project forward in the excavation direction with respect to the fixed cutter bit, so that the replacement cutter bit automatically replaces the fixed cutter bit and excavates with the replacement cutter bit. Since the work is done, the exchange work of the cutter bit can be done easily and in a short time, so that the burden on the operator is lightened. It can be replaced at an appropriate time in accordance with cutter bits on the wear situation with to improve the safety and working efficiency of excavation work.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a shield excavator according to an embodiment of the present invention.

FIG. 2 is a front view of the shield excavator of this embodiment.

FIG. 3 is an enlarged sectional view showing a replacement cutter bit and its operation control mechanism.

FIG. 4 is a sectional view of an operation control mechanism of a replacement cutter bit.

FIG. 5 is a cross-sectional view of a fixed cutter bit.

FIG. 6 is a schematic side view showing a conventional shield excavator.

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

[Explanation of symbols]

 11 shield excavator main body 12 cutter head 13 spoke 15 fixed cutter bit 17 cutter turning drive device 20 chamber chamber 31 replacement cutter bit 32 operation control mechanism 34 drive jack 37 cylinder 38 piston 39 piston rod 40 compression spring 47 supply / discharge pipe 50 tip 51 hollow

Claims (1)

[Claims] 1. In a shield excavator in which a fixed cutter bit is mounted on a freely rotatable cutter head, a replacement cutter bit is mounted in a retractable manner close to the fixed cutter bit, and the replacement cutter bit is A shield excavator characterized in that an operation control mechanism sets a projecting / retracting position with respect to the fixed cutter bit based on a state of loss or wear of the fixed cutter bit.