JPH0532557B2 - - Google Patents

Description

[Detailed description of the invention] ≪Industrial application fields≫ The present invention relates to an oval shield digging machine.

<<Prior Art>> As is well known, there is a shield construction method as a method for constructing subway tunnels, and in this construction method, a shield excavator is used to excavate the tunnel.

There are various types of shield tunneling machines, but those with a circular cross section are generally widely used.

By the way, subway tunnels usually require two rails, one for the upper and one for the upper and lower lines.

In this case, excavating each tunnel individually would be wasteful in terms of land, construction time, and construction costs.

Therefore, it may be possible to excavate a large circular section at once, but although this method is slightly more advantageous in terms of construction time than excavating each section individually, it does not improve the efficiency of the section.

For this reason, for example, as seen in Japanese Patent Application Laid-Open No. 47-44931, a cider excavator has been proposed that excavates with two overlapping circular sections, but this excavator has the following features: There were flaws.

<<Problems to be Solved by the Invention>> In other words, in the shield excavator disclosed in the above publication, the cross section has circular cross sections that overlap, so although its cross-sectional efficiency is improved, the segments installed after excavation also overlap the circular cross sections. Since the shape is curved, there is a problem that the assembly and manufacturing method are complicated.

In addition, in the overlapping area where the circular cross sections intersect, the ground is likely to collapse, and the ground above the area may become loose, leading to the risk of ground subsidence.

This invention was made in view of these conventional problems, and its purpose is to simplify the assembly and manufacturing method of segments, suppress the loosened areas of the surrounding ground, and improve the stability of the ground. An object of the present invention is to provide an oval shield excavator capable of preventing subsidence.

<<Means for Solving the Problem>> In order to achieve the above object, the present invention provides an oval shield excavator with a skin plate having a substantially oval cross section, and a skin plate having a substantially oval cross section on the tip side of the skin plate. It consists of a pair of main cutters rotatably arranged on the long axis of the center of the circular arc portion, and an annular chain cutter attached to the tip of the skin plate on the outer periphery of the main cutters.

<<Operation>> According to the shield tunneling machine having the above configuration, the tunnel to be formed has an elliptical cross-section, and a cross-sectional efficiency intermediate between a circular cross-section and a cross-section obtained by overlapping two circular cross-sections is obtained, and the segment Since it is oval in shape, it is relatively easy to manufacture and install.

Furthermore, since the annular chain cutter defines the outer shell with an oval cross section, loosening of the ground can be prevented.

<<Example>> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 4 show an embodiment of an oblong shield tunneling machine according to the present invention.

The shield tunneling machine shown in the figure is an example of an earth pressure type shield tunneling machine in which the present invention is applied.
0, and a pair of circular main cutters 12, 1 rotatably disposed on the tip side of the skin plate 10.
2, a pair of sub-cutters 14, 14 arranged around the outer periphery of the main cutter 12, and an annular chain cutter 16 attached to the tip of the skin plate 10.

A partition wall 18 is fixed on the front side of the skin plate 10 to separate an earth pressure chamber that is filled with excavated earth and sand and opposes the face. A screw conveyor and the like for discharging are installed, and a propulsion jack for propelling the skin plate forward is installed inside the skin plate 10.

The main cutter 12 is equipped with a cutter disk 12a and a rotating shaft 12b that extends rearward through the partition wall 18, as in the conventional circular shield excavator. A slit hole is provided.

The rotation centers of the main cutters 12, 12 are located on the long axis l1 of the ellipse of the skin plate 10, and are set at the centers of the semicircular portions at both ends of the ellipse, and in this embodiment, They are starting to overlap partially.

In the case of overlapping in this manner, mutual interference may be avoided by shifting the cutter disks 12a back and forth or by forming the outer shape into a gear-like shape.

The sub-cutters 14, 14 are equipped with a cutter disk 14a and a rotating shaft 14b, and a cutter bit 14c is fixed to the front surface of the cutter disk 14a. It is set on axis l2.

The main cutter 12 and the sub cutter 14 are each rotated by a drive motor (not shown) to excavate earth and sand.
The part remaining in the moat between 2 and 14 is a cone cone 20
excavated by.

In this embodiment, the cone cone 20 is arranged between the main cutter 12 and the sub cutter 14.
When the shield excavator is moved forward by the propulsion jack, it excavates this area by pushing the earth and sand left in the trench back and forth and left and right along the slope. do.

Details of the chain cutter 16 are shown in FIG. 4.

The chain cutter 16 includes a bendable chain main body 16a connected in an annular shape, and a chain main body 16a that is connected in a ring.
It is composed of cutter blocks 16b and excavated soil guide blocks 16c, which are attached alternately to the cutter disks 12a and 14a, and protrude forward from the front surfaces of the cutter disks 12a and 14a.

The chain body 16a has a substantially U-shaped cross section, is fitted to the tip of the skin plate 10 with a plurality of sealing materials 22 interposed therebetween, and has a protrusion 24 protruding from its lower surface.

A slope 16d that slopes inward is formed on the guide block 16c, and the earth and sand excavated by the cutter block 16b is transferred to the slope 16d.
along the inside of the skin plate 10.

Chain cutter 16 configured as above
is rotated along the cross-sectional shape of the skin plate 10 from the cutter block 16b toward the guide block 16c when the protrusion 24 meshes with the rotary gear 26 that protrudes through the partition wall 18. The earth and sand excavated by the block 16b is guided into the earth pressure chamber of the skin plate 10 by the guide block 16c and taken into it, thereby clarifying the cross-sectional shape of the tunnel to be excavated by the shield tunneling machine.

In order to prevent excavated soil from entering the meshing part between the rotary gear 26 and the protrusion 24 for rotating the chain cutter 16, it is necessary to install a water jet pipe 28 and inject high-pressure water, or
Alternatively, it is desirable to install a cover 30 that covers the engaging portion.

In the shield excavator having the above configuration, if the skin plate 10 is advanced by the propulsion jack while the main and auxiliary cutters 12 and 14 and the chain cutter 16 are each rotationally driven, the skin plate 1
An oval cross section corresponding to the cross section of 0 is excavated.

Then, as the excavation progresses, skin plate 1
A tunnel is constructed by sequentially assembling segments with an oval cross section on the rear end side of 0.

Now, in a tunnel with an oval cross section that is excavated as described above, a cross-sectional efficiency intermediate between a conventional circular cross section and a combination of two circular cross sections can be obtained, and the segments also have an oval cross section. Therefore, its assembly and production become easy.

Also, when excavating, first use the chain cutter 16.
After the outer shell with an oval cross section is excavated, the main and sub-cutters 12 and 14 excavate the inside thereof, so that loosening of the upper ground is reliably prevented when excavating with the cutters 12 and 14.

In the above embodiment, the present invention is applied to an earth pressure type shield excavator, but the present invention is not limited to this and can be applied to other types of shield excavators.

Furthermore, if the distance between the main cutters 12, 12 is made closer than that shown in FIG.
0 is not necessarily required.

<<Effects of the Invention>> As explained in the embodiments above, according to the oval shield excavator according to the present invention, the tunnel formed has an oval cross section, and a circular cross section overlaps two circular cross sections. A cross-sectional efficiency that is intermediate to the cross-sectional area is obtained, preventing a significant drop in the cross-sectional efficiency, and the segment shape is also oval, making manufacturing and construction relatively easy, and preventing the loosening of the ground. .

[Brief explanation of drawings]

Fig. 1 is a front view showing an example of the shield tunneling machine of the present invention, Fig. 2 is a sectional view taken in the direction of Fig. 1, Fig. 3 is a sectional view taken in the direction of the - sectional arrow in Fig. FIG. 10... Skin plate, 12... Main cutter, 14... Sub cutter, 16... Chain cutter, l1... Long axis, l2... Short axis.

Claims (1)

[Claims] 1. A skin plate with a substantially elliptical cross section, a pair of main cutters located on the distal end side of the skin plate and rotatably arranged on the long axis of the center of the arcuate portions at both ends of the ellipse, and a pair of main cutters of the main cutter. An oval shield excavator characterized by comprising an annular chain cutter attached to the tip of the skin plate on the outer periphery.