JP2000087691A - Tunnel boring machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boring machine capable of surely suppressing the fluctuation in the earth pressure on a facing by advancing/retracting a cylindrical body provided on a bulkhead according to the elongation/contraction of an overbreak device for facing excavation to change the volume of a part to communicate with a chamber. SOLUTION: A skin plate 2 of approximately rectangular section is provided on a tunnel boring machine 1, and a cutter head 3 is fitted in an oscillating manner. A chamber 7 is demarcated behind the cutter bead 3 between a bulkhead 6 and the cutter head. A cutter head oscillating mechanism 5 turns the cutter head 3 reciprocally in the forward/reverse direction by a specified angle. An overbreak device 15 is built in the cutter head 3, and the natural ground of an outer circumferential part is excavated by projecting an over cutter 15a. Cylindrical bodies 16, 16 are advanced/retracted to/from the bulkhead 6 by a hydraulic jack in the direction of an arrow A, and operated in the projecting/ retreading direction respectively when the overbreak device 15 is contracted/ elongated. The volume in the chamber 7 is increased/decreased to suppress the fluctuation in the earth pressure on the cutting face for stable excavation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting head which is excavated by rotation or reciprocating swing of a cutter head and expansion and contraction of an excavating device provided in the cutter head, and the excavated earth and sand is taken into a chamber behind the cutter head. This is related to a tunnel excavator that is to be carried out by a tunnel.

[0002]

2. Description of the Related Art Generally, in the construction work of a tunnel using a shield machine, while excavating the ground by a disk-shaped cutter head provided in front of a cylindrical skin plate, segments are assembled in the machine, and the segments are assembled. The tunnel is excavated with substantially the same diameter as the skin plate by extending the shield jack by taking a reaction force to the tunnel.

[0003] Recently, with the expansion of the use range of tunnels, there has been an increasing demand for a shield machine capable of excavating a tunnel having an irregular cross section such as a rectangular cross section. As a shield excavator responding to such a demand, the present applicant has disclosed in Japanese Patent Application Laid-Open No. 10-14079 and the like that a cutter head can be made to swing, and the cutter head can be extended and contracted in the radial direction of the cutter head. A shield machine capable of excavating a tunnel with an irregular cross section has been already proposed by providing a plurality of extra excavating devices and extending the extra excavating devices at required positions.

[0004]

However, as described above, when excavation of the ground is performed by expanding and contracting the excavation device, the internal volume of the chamber for taking the excavated earth and sand decreases when the excavation device is extended. There is a problem that the earth pressure in the chamber fluctuates due to the increase during shrinkage, which causes fluctuations in cutter head torque, shield jack thrust, and excavation speed.

As related prior arts for adjusting the earth pressure in a chamber or the like, there are those disclosed in JP-A-61-211499 and JP-A-62-248798. Among them, the one is provided so as to provide an earth pressure adjusting chamber communicating with the inside of the chamber, and to provide an earth pressure jack for changing the volume of the earth pressure adjusting chamber by moving in and out of the earth pressure adjusting chamber. Is configured to form a pressure adjustment chamber in which a fluid pressurized from the outside is supplied to a part of the chamber.

However, in the related art, since the volume of the control chamber is changed after the earth pressure in the chamber fluctuates, a control response delay is likely to occur or a large earth pressure is generated. There is a problem such as incompatibility with the one with the fluctuation, and it cannot be applied to the one for the purpose of suppressing the earth pressure fluctuation due to the expansion and contraction of the overground equipment as in the present invention.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to prevent a change in the empty volume in a chamber due to the expansion and contraction of an excavation device, and to reliably prevent a change in face pressure. It is an object of the present invention to provide a tunnel excavator capable of performing a tunnel excavation.

[0008]

In order to achieve the above object, a tunnel machine according to the present invention comprises:
In a tunnel excavator in which a face is excavated by rotation or reciprocating swing of the cutter head and expansion and contraction of an extra excavation device provided in the cutter head, the excavated earth and sand is taken into a chamber behind the cutter head and carried out, It is characterized in that earth pressure fluctuation suppressing means for changing the volume of the chamber or a portion communicating with the chamber in accordance with the amount of expansion and contraction of the excavation device to suppress earth pressure fluctuation in the chamber is provided. .

In the present invention, the cutter head is rotated or reciprocally oscillated, and the cutting face is excavated by the extension and retraction of the extra-digging device provided on the cutter head. Excavation such as a tunnel with a rectangular cross section is performed by being extended at the corner.
The earth and sand generated by the excavation is taken into a chamber provided behind the cutter head, and is carried out from inside the chamber toward the rear of the tunnel. At this time, at the time of the expansion and contraction operation of the excavation device, the volume of the chamber or a portion communicating with the chamber is changed by the earth pressure fluctuation suppression means according to the expansion and contraction amount of the excavation device to suppress the earth pressure fluctuation in the chamber. Is done. In this way, it is possible to prevent the fluctuation of the earth pressure in the chamber due to the expansion and contraction operation of the excavator, thereby preventing the fluctuation of the cutter head torque, the shield jack thrust and the excavation speed, and the ground is disturbed. It is possible to perform stable excavation without any trouble.

Here, the earth pressure fluctuation suppressing means includes:
Either one having power or one not having power can be employed. As a means for changing the volume of the chamber or the like, there is a means for moving a cylindrical body into and out of the chamber, and a means for moving a cylindrical body into and out of a casing of a screw conveyor as earth and sand carrying means.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of a tunnel machine according to the present invention will be described with reference to the drawings.

(First Embodiment) FIGS. 1 (a) and 1 (b) are front views of a tunnel excavator of a first embodiment applied to a shield excavator having a modified cross section, and FIG. 2 shows the tunnel excavator. A longitudinal sectional view of the machine is shown. FIG. 1A shows a state in which the overground equipment is contracted, and FIG. 1B shows a state in which the overground equipment is extended.

In the tunnel machine 1 of this embodiment,
A skin plate 2 having a substantially rectangular cross section is provided, and a cutter head 3 is mounted in front of the skin plate 2 so as to be swingable by a cutter head swinging mechanism 5. Behind the cutter head 3, a chamber 7 is defined between the cutter head 3 and the bulkhead 6, and a screw conveyer 8 for carrying out earth and sand is provided in the chamber 7 so as to open a front end portion. A ring girder 9 is fixed to the inner wall surface of the skin plate 2, and a number of shield jacks 10 are fixed to a flange mounted on the ring girder 9. In FIG. 2, reference numeral 11 denotes an erector for winding up the segment 13, and reference numeral 12 denotes a segment expansion device.

The cutter head 3 is a spoke type cutter head, and has four spokes 14, 14, 14, 1.
4 are arranged so that the angle between the spokes adjacent to each other is a right angle. Each of the spokes 14 has a built-in excavation device 15, and an overcutter 15 a provided at the tip of the extra-drilling device 15 projects outward from the tip of the spoke 14, thereby excavating the ground at the outer peripheral portion. Have been able to. Although not explicitly shown in the figure,
The outer surface of each spoke 14 has a leading bit in the center,
Tool bits are mounted on both sides, and the cutting face is excavated by these bits.

The cutter head swinging mechanism 5 is constituted by two pairs of swinging jacks. The cutter head swinging mechanism 5 operates a pair of swinging jacks in the extending direction and operates the other pair of swinging jacks in the contracting direction. The head 3 is configured to reciprocate a predetermined angle in the forward and reverse directions. The swing mechanism is not limited to such a mechanism, and various other means such as a method of rotating a motor forward and backward can be used.

As shown in FIG. 1B, the overdigging device 15 protrudes outward from the tip end of the spoke 14 in a region near the corner of the rectangular cross section which is the region outside the swing radius of the spoke 14. Thus, a rectangular cross section is excavated.

In this embodiment, in order to change the volume of the chamber 7 in accordance with the expansion and contraction of the excavator 15, as shown schematically in FIG. The cylindrical bodies 16 can be moved in and out of the bulkhead 6 in the direction of arrow A. These cylinders 16 are operated by hydraulic jacks (or pneumatic jacks) (not shown), and are operated in the projecting direction when the excavating device 15 is contracted to reduce the volume of the chamber 7 and conversely, the excavating device 15 is extended. When operated, it is operated in the backward direction to increase the volume of the chamber 7. In this manner, the fluctuation of the face earth pressure which is caused by the expansion and contraction of the over-cutting measure 15 is suppressed, thereby enabling stable excavation. Since the swing cycle of the cutter head 3 and the expansion and contraction time and amount of expansion and contraction of the excavator 15 are known in advance, the expansion and contraction time and amount of expansion and contraction of the cylindrical body 16 can be obtained in advance based on these information. Therefore, by performing the projecting / retracting control of the cylindrical bodies 16 based on the calculation result, it is possible to effectively suppress the fluctuation of the face pressure without causing a control response delay.

(Second Embodiment) FIG. 4 schematically shows a second embodiment of the earth pressure fluctuation suppressing means. In the first embodiment, the case where the cylindrical body 16 is made to protrude and retract from the bulkhead 6 has been described. However, in the second embodiment, the cylindrical body 17 (4 in this embodiment) is radiated from the center of the cutter head 3 ′. ) Appear and disappear. Note that these cylinders 17 are also driven by hydraulic jacks (or pneumatic jacks), and their protrusion / retreat control is performed based on a result calculated in advance, as in the first embodiment.

(Third Embodiment) FIG. 5 shows a third embodiment of the earth pressure fluctuation suppressing means. In each of the above embodiments, the earth pressure fluctuation is suppressed by changing the volume in the chamber 7, but in this embodiment, the screw conveyor 8 connected to the chamber 7 is changed.
The cylindrical body 18 is moved in and out of the housing 8a. That is, in the screw conveyor 8 including the ribbon-type screw blades 8b, the cylindrical body 18 is mounted so as to penetrate the center cavity of the screw blade 8b, and the cylindrical body 18 is provided at the rear end of the housing 8a. The jack 19 is operated to appear and disappear in the direction of arrow B. In this case, the appearance control is performed in the same manner as in the above-described embodiments. In this embodiment, a ribbon screw is used.
The same configuration can be adopted by using a screw with a shaft.

(Fourth Embodiment) FIG. 6 schematically shows a fourth embodiment of the earth pressure fluctuation suppressing means. In each of the above embodiments, the cylindrical body is made to protrude and retract using the power of a hydraulic jack or the like. In this embodiment, the cylinder is made to protrude and retract without using power. That is, in the present embodiment, the inside of each spoke 14 of the cutter head 3 ″ is defined as the closed space 20,
Numeral 0 communicates with the internal space of a piston-type cylindrical body 25 protruding into the chamber 7 through an air passage 22 and a rotary joint 23 formed in the main shaft 21, and further through an air pipe 24. . With such a configuration, when the excavator 15 is operated in the contracting direction, the compressed air from the closed space 20 is supplied to the internal space of the cylindrical body 25, and the cylindrical body 25 is operated in the projecting direction. Thus, the volume of the chamber 7 is reduced. Conversely, when the excavating device 15 is operated in the extension direction, the cylinder 25 is operated in the retreating direction due to a negative pressure in the closed space 20, and the volume of the chamber 7 is increased. In this way, it is possible to suppress the fluctuation of the cutting face pressure caused by the expansion and contraction of the extra excavation device 15 without requiring the power for operating the cylindrical body 25.

As described above, according to each of the above-described embodiments, when excavating a tunnel having an irregular cross section such as a rectangular cross section, the excavation device 1
5 is expanded or contracted, the volume of the chamber 7 or a portion communicating with the chamber 7 (for example, the internal space of the screw conveyor 8) is changed to the cylindrical bodies 16, 17, 18,
Since the fluctuation of the cutting face earth pressure can be suppressed by changing by the emergence of the 25, the fluctuation of the cutter head torque, the fluctuation of the shield jack thrust and the fluctuation of the excavation speed can be prevented beforehand. Therefore, stable excavation can be performed without disturbing the ground.

In each of the above embodiments, the reciprocating swing type cutter head has been described. However, it goes without saying that the present invention can be applied to a rotary type cutter head.

In each of the embodiments described above, the tunnel excavator for excavating a tunnel with an irregular cross section has been described. It can also be applied to machines.

[Brief description of the drawings]

FIGS. 1A and 1B are front views of a tunnel machine according to a first embodiment, wherein FIG. 1A is a view showing a state where an over-digging apparatus is contracted, and FIG.

FIG. 2 is a longitudinal sectional view of the tunnel machine according to the first embodiment.

FIG. 3 is a diagram illustrating an earth pressure fluctuation suppressing unit according to the first embodiment.

FIG. 4 is a diagram illustrating an earth pressure fluctuation suppressing unit according to a second embodiment.

FIG. 5 is a diagram illustrating an earth pressure fluctuation suppressing unit according to a third embodiment.

FIG. 6 is a diagram illustrating an earth pressure fluctuation suppressing unit according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tunnel machine 2 Skin plate 3, 3 ', 3 "Cutter head 6 Bulk head 7 Chamber 8 Screw conveyor 14 Spoke 15 Excavation device 16, 17, 18, 25 Cylindrical body 20 Sealed space 22 Air passage 24 Air piping

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Junkichi Onoe 3-12-10 Hakata-ekimae, Hakata-ku, Fukuoka City Kashima Construction Co., Ltd.Kyushu Branch (72) Inventor Hiroshi Matsuo Hakata-ekimae, Hakata-ku, Fukuoka City, Fukuoka Prefecture 3-12-10 Kashima Corporation Kyushu Branch (72) Inventor Takashi Minami 5 Yokaichi Town, Komatsu City, Ishikawa Prefecture Inside Komatsu Plant, Komatsu Plant (72) Inventor Hideo Kambayashi Yokaichi Town, Komatsu City, Ishikawa Prefecture 5 Komatsu Manufacturing Co., Ltd. Komatsu Factory (72) Inventor Kazunari Kawai Yokaichi-cho, Komatsu City, Ishikawa Prefecture 5 Komatsu Manufacturing Co., Ltd. Komatsu Factory F-term (reference) 2D054 AA05 AB05 AC04 BA25 CA08 DA03 GA10 GA34 GA52 GA58 GA58

Claims (1)

[Claims] A cutting face is excavated by rotation or reciprocating swing of a cutter head and expansion and contraction of an extra-digging device provided on the cutter head, and excavated earth and sand is taken into a chamber behind the cutter head and carried out. In the tunnel machine, earth pressure fluctuation suppressing means for changing the volume of the chamber or a portion communicating with the chamber according to the amount of expansion and contraction of the extra excavation device to suppress the earth pressure fluctuation in the chamber is provided. And a tunnel machine.