JPS61274090A - Expansion shielding machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a shield machine for tunnel excavation, and more particularly to an expanding shield machine used when constructing an enlarged diameter tunnel around the outer periphery of an excavated tunnel.

(Prior Art) As is well known, when constructing a subway tunnel, for example, platforms and the like are provided at appropriate locations by excavating the tunnel to a diameter larger than that of a typical tunnel.

The shield machine used in such cases is usually called an enlarged shield machine, and for example, one disclosed in Japanese Patent Laid-Open No. 102082/1982 is provided.

The expansion shield machine described in the same issue receives reaction force from a cylindrical shield that is placed around the outside of the primary segment and excavates an expansion tunnel around the primary segment, and a secondary segment that is provided on the inner surface of the expansion tunnel. The shield is equipped with a jack that propels the shield machine, and a drive device for reciprocating the shield in the circumferential direction is installed on the shield transport vehicle, which rotates the shield in addition to the propulsive force of the jack. This reduces the resistance at the face and allows for more efficient excavation work.

(Problems to be Solved by the Invention) The expanding shield machine disclosed in the above publication not only requires extremely large power to rotate the large-diameter shield, but also has the following problems.

That is, although the expanding shield machine rotates around the outer periphery of the primary segment, the primary segment itself is not necessarily a perfect circle on the same axis due to eccentricity and meandering during construction.

Therefore, the distance between the shield machine and the outer periphery of the primary segment is uneven, and there is usually a seal backing interposed between them to prevent muddy water from entering, making it difficult to rotate the shield smoothly. This made it difficult to improve efficiency as much as expected.

The present invention has been made in view of the conventional problems as described above, and its purpose is to improve excavation efficiency with a relatively simple configuration without requiring large power consumption. Our goal is to provide an expanding shield machine.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an expanding shield machine that is installed on the outer periphery of a primary segment and propelled by obtaining a reaction force from a secondary segment, etc. The cutter bit is characterized in that a plurality of cutter bits are provided at intervals in the circumferential direction and are rotatably driven on a ring-shaped partition wall provided at the tip end of the ring-shaped partition wall defining a partition chamber.

(Function) By rotating the cutter bit to excavate the face and propel the entire unit, excavation and pushing into the face are performed simultaneously, making efficient excavation work possible.

A plurality of cutter bits are provided, each having a relatively small diameter, and large power is not required to rotate the cutter bits.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of an expanding shield machine according to the present invention.

The expansion shield machine shown in the figure is installed on the outer periphery of a small-diameter primary segment 10 constructed in advance.
It is propelled by obtaining a reaction force from the secondary segment 12 with a larger diameter than that of the surrounding ground, etc., and the installation of the shield machine is as shown in, for example, Japanese Patent Laid-Open No. 58-98595. It is done in various ways.

The expanding shield machine includes an outer skin plate 14 that is open at both ends and has an inner diameter approximately equal to the outer diameter of the secondary segment 12.
and an inner skin plate 16 having a cylindrical portion 16a having an inner diameter approximately equal to the outer diameter of the primary segment 10, and a flange portion 16b connected to the cylindrical portion 16a is provided at one end of the inner skin plate 16. By fixing the flange portion 16b to the inner peripheral surface of the outer skin plate 14, an annular center B1 is formed between these skin plates 14 and 16.
8 is formed.

The tips of the inner and outer skin plates 14 and 16 on the face side (right side in FIG. 1) are sharp cutting edges that are inclined into the annular space 18, and the flange portions of the secondary segment 12 and the inner skin plate 16 A plurality of propulsion jacks 18 are interposed in 16blIl at intervals in the circumferential direction.

Although not shown, the outer skin plate 14, the secondary segment 12, and the cylindrical portion 16 of the inner skin plate 16
A backing is interposed between a and the primary segment 10 to prevent muddy water and dirt from entering the shield machine.

On the other hand, the annular space 18 is divided into front and rear sections by a ring-shaped partition wall 20, and a concave front chamber 22, which serves as an earth pressure to prevent collapse of the face, is provided with spaces spaced apart in the circumferential direction. A plurality of cutter bits 26, 26, .
The motor 30 is connected to the motor 30 shown in FIG.

In the shielding machine of the present invention, the jack 18 is extended to propel the entire body while supplying muddy water to the face surface, and each cutter bit 26 is rotationally driven by a motor 30 to excavate earth and sand. The excavated earth and sand are filled in the front chamber 22 and the excavated earth and sand are discharged from the discharge ports provided at appropriate locations on the partition wall 20 while maintaining the face pressure.

Excavation is the best! This is done efficiently by propelling the stick 18 and rotating the cutter bit 26, and since each cutter bit 26 is individually driven by the motor 30, each motor 30 does not require much power.

FIG. 3 shows another embodiment of the invention, and only its features will be explained below.

In the enlarged shield machine shown in the figure, the cutter bits 26 protruding from the partition wall 20 are made to have different protruding heights so that the rotation radii of adjacent bits partially overlap.

With this configuration, the holes excavated by the cutter bit 26 are connected, allowing more efficient excavation.

(Effects of the Invention) As described above in detail in the embodiments, in the expanding shield machine according to the present invention, efficient excavation work is performed by the rotationally driven cutter hit and propulsion, and the rotation of the cutter bit The power can also be smaller than when rotating the entire shield machine.

Further, even if there is eccentricity or meandering in the primary shield, it is possible to excavate an enlarged tunnel without being affected by this.

[Brief explanation of the drawing]

Figure 1 is a front view of the shield machine of the present invention, Figure 2 is a sectional view of the machine in its installed state, Figure 3 (A> is a plan view of the main part of another embodiment, and Figure (B) is Figure 3). It is a side view of (A).

Claims (2)

[Claims] (1) In an expanding shield machine that is installed on the outer periphery of a primary segment and propelled by obtaining a reaction force from a secondary segment, etc., the ring-shaped partition wall that is provided at the tip of the expanding shield machine and defines a compartment rotates. An expanding shield machine characterized by a plurality of driven cutter bits protruding at intervals in the circumferential direction. (2) The expanding shield machine according to claim 1, wherein the cutter bits are spaced apart so that rotation radii of adjacent bits partially overlap.