JPH11173074A - Cutter head for tightly closed type shield boring machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the central portion of a cutter head from being stuck with cohesive soil. SOLUTION: In an ordinary drive, the central cutter 12 is positioned at the center of a cutter head 11, and the excavating work is performed by rotating both the center cutter 12 and an outer peripheral ring cutter 13 in one united body. If cohesive soil sticks to the surfaces of the central cutter 12 and the thrust of a shield boring machine or the torque of the cutter head 11 rises during excavation work, then the central cutter 12 is positioned to the outer side of the radial direction and the excavation work is performed. The central cutter 12 rotates at a peripheral velocity higher than that at the center position when it is located at a position deviated from the center of the cutter head 11, so that cohesive soil stuck can be removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a cutter head mounted on a front end of a sealed shield machine.

[0002]

2. Description of the Related Art As shown in FIG. 4, a cutter head of a sealed shield machine generally comprises a central small circular portion 2 and an outer peripheral ring portion 3 thereof. Central small circle portion 2 and its outer peripheral ring portion 3
Is excavated by the cutter bits 4, 4... Attached to both sides.

The excavated earth and sand is taken into the rear chamber through a slit 6 provided along the longitudinal direction of the spoke portion 5 of the outer peripheral ring portion 3. Cannot widen the intake port such as the slit 6. Further, since the peripheral speed becomes slower toward the center of the cutter head 1, viscous soil easily adheres to the surface of the central small circle portion 2, and the thrust and the cutter torque of the shield excavator increase, which hinders stable excavation. It has become.

According to Japanese Utility Model Publication No. Sho 62-14229, there is also known a shield machine in which an opening is provided in the center of a cutter head and a screw excavator is provided in the opening. According to the shield excavator, it is possible to prevent the adhesion and growth of sediment on the wall surface of the sediment intake portion in the aircraft, but it requires two driving means and effectively uses the internal space of the shield excavator. Can not. Also,
There are many places around the rotation axis that require water stoppage, which makes the waterstop measures complicated.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to prevent the adhesion of viscous soil to the central portion of a cutter head and to secure the stability of the excavating performance of a shield machine. .

[0006]

According to the present invention, a cutter head of a sealed shield machine according to the present invention is a cutter head comprising at least two members, a central cutter and an outer peripheral ring cutter, wherein the outer peripheral ring cutter is a cutter. The object is achieved by having an opening which is deviated from the center of the head in the outer peripheral direction and in which the center cutter is movable in the radial direction.

It is preferable that the central cutter is moved by a hydraulic jack provided on the back of the cutter head.

[0008]

In the tunnel excavation work, viscous soil easily adheres to the surface of the central cutter, but excavation is performed by moving the central cutter outward in the radial direction.
Adhered soil is removed. In addition, no cohesive soil is newly attached during excavation in this state.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention applied to a muddy shield machine will be described below in detail with reference to the drawings.

FIG. 1 is a front view of a cutter head 11 of a sealed shield machine. The cutter head 11 comprises a central cutter 12 having a small area and an outer peripheral ring cutter 13 having a large area. In the present embodiment, the front shape of the central cutter 12 is a shape in which square portions are connected to both ends with a substantially circular intermediate portion interposed therebetween, but the present invention is not limited to such a shape. Multiple cutter bits 14, 14
・ ・ There is no particular limitation as long as the shape can be attached. In the present embodiment, the cutter bits 14, 14,... Are arranged in a cross shape in the substantially circular intermediate portion, and are arranged on two opposing sides in the square portion.

On the other hand, the outer peripheral shape of the outer circumferential ring cutter 13 constituting the cutter head 11 is circular, and it is slightly deviated radially outward from the center to form a substantially rectangular opening 1.
7 are provided. The opening 17 accommodates the central cutter 12, and the central cutter 12 can be moved in the radial direction from the central position shown in FIG. 1 to the outer part shown in FIG. .

The opening 17 is an iron plate or the like (not shown) from the chamber side except for the portion where the central cutter 12 is located.
It is desirable to be able to close by.

In the spoke portion 15 of the outer peripheral ring cutter 13, a large number of cutter bits 14, 14,... Are radially arranged and attached, and a slit 16 is provided along the longitudinal edge of the spoke portion 15. Have been. Therefore, the earth and sand excavated by the cutter bits 14 are taken into the chamber on the back side of the cutter head 11 through the slit 16.

FIG. 3 is a side view showing a longitudinal section of a main part of a sealed shield machine 20 provided with a cutter head 11. The shield machine 20 includes a cutter head 11 provided on a front end face of a shield 21. Is rotated by a drive motor 23 via a rotary shaft 22 to excavate a face, and mud is supplied from a mud feed pipe 24 to fill a chamber 26 between the partition wall 25 and the face with pressurized mud. In addition to stabilizing the face, the excavated earth and sand is taken into muddy water, and fluid is transported as muddy water through a mud pipe 27.
In FIG. 3, reference numeral 28 indicates a shield jack, and reference numeral 29 indicates a lining body of the constructed tunnel.

A hydraulic jack 30 is mounted on the back surface of the outer peripheral ring cutter 13 constituting the cutter head 11.
The center cutter 12 connected to the free end of the hydraulic jack 30 can be moved.

In this embodiment, during normal excavation, as shown in FIG. 1, the central cutter 12 is positioned at the center of the cutter head 11, and the outer peripheral ring cutter 13 and the central cutter 12 are integrally rotated. Excavation work.

During the excavation work, when the viscous soil adheres to the surface of the central cutter 12 and the thrust of the shield machine 20 and the torque of the cutter head 11 increase, as shown in FIG. The excavation work is performed by positioning the to the outside in the radial direction. At this time, the central portion 12 rotates at a peripheral speed higher than the peripheral speed at the central position at a position deviated from the center of the cutter head 11, so that the adhered clayey soil is easily removed.

While the embodiment of the muddy shield excavator has been described above, the present invention can be applied to any type of hermetic shield excavator as long as it is a shield type excavator. It is applicable to any of the machines.

In the present invention, an obstruction removing device may be exposed to the opening 17 from the side of the chamber 26 to remove obstructions appearing in front of the shield machine, particularly at the central portion. is there.

[0020]

According to the cutter head of the shielded shield machine according to the present invention, the excavation work can be performed on the viscous soil adhering to the central part of the cutter head without interruption.
Removal work can be performed. Therefore, there is an excellent effect that the stability of the excavation performance of the sealed shield machine can be ensured.

[Brief description of the drawings]

FIG. 1 is a front view of a cutter head of a sealed shield machine during steady state excavation.

FIG. 2 is a front view of the cutter head at the time of earth and sand removal work.

FIG. 3 is a side view showing a main part of the sealed shield machine in a longitudinal section.

FIG. 4 is a front view of a cutter head of a conventional sealed shield machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Cutter head 12 Central cutter 13 Outer ring cutter 14 Cutter bit 17 Opening of outer ring cutter 20 Shield excavator 30 Hydraulic jack

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Yakata 2-1 Tsukudo-cho, Shinjuku-ku, Tokyo Kumagaya Gumi Tokyo Head Office (72) Inventor Kazuhiro Naozuka 2-1 Tsukudo-cho, Shinjuku-ku, Tokyo No. Kumagai Gumi Tokyo Head Office

Claims (1)

[Claims] 1. A cutter head comprising at least two members, a central cutter and an outer peripheral ring cutter, wherein the outer peripheral ring cutter has an opening extending from the center of the cutter head toward the outer peripheral direction. A cutter head for a hermetically sealed shield machine, wherein the central cutter is movable in a radial direction at an opening.