JPH0525996B2 - - Google Patents

Description

[Detailed description of the invention] ≪Industrial application fields≫ The present invention relates to a shield tunneling 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, one idea is to excavate a large circular section at once, but although this method has a slight advantage in terms of construction time compared to excavating tunnels 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 shield 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-mentioned publication, the cross-section is made by overlapping the circular cross-sections, so although the cross-sectional efficiency is improved, The cutter disks are arranged to be shifted in the front and back direction, so the cutter disk located at the rear always excavates the overlapped part with the cutter disk located at the front, so it is necessary to efficiently excavate that cross section. There was a problem that I couldn't do it.

In addition, the segments installed after excavation also have a shape with overlapping circles, making assembly and manufacturing complicated.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to eliminate the need to excavate a cross section using a cutter disc even when excavating a tunnel with two rails. It is an object of the present invention to provide a shield excavator that can efficiently assemble and manufacture segments.

<<Means for Solving the Problems>> In order to achieve the above object, the shield excavator of the present invention includes a skin plate having a substantially elliptical cross section, a skin plate rotatably disposed at the tip of the skin plate, and a portion of the elliptical cross section. a spoke having a length that is approximately the same as the short axis length; a pair of circular cutter disks that are rotatably supported at both ends of the spoke and have a diameter that is approximately 1/2 the short axis length of the ellipse; a moving device that moves each cutter disk along the inner periphery of the skin plate while maintaining a predetermined distance between the center of these cutter disks and the skin plate; and a moving device that is fixed to the front surface of the spoke. It is characterized in that it consists of a katsukubitsu.

<<Operation>> According to the shield excavator having the above configuration, the pair of cutter disks are moved along the inner periphery of the skin plate while maintaining a predetermined distance between the center and the skin plate by the moving device. The diameter is approximately 1/2 of the minor axis length of the skin plate with an elliptical cross section.
Therefore, the reason why these overlap with each other is
This occurs only when the cutter disk is located near the short axis of the elliptical cross section of the skin plate, and thereby the cutter disk can efficiently excavate the elliptical cross section.

In addition, the tunnel that is formed has a substantially elliptical cross-section, which provides a cross-sectional efficiency intermediate between a circular cross-section and a cross-section that overlaps two circular cross-sections, and the shape of the segments is also elliptical, making it easy to manufacture and construct them. can be done relatively easily.

<<Example>> 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 a shield excavator 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, a spoke 12 rotatably arranged on the tip side of this skin plate 10, and this spoke 1.
A pair of circular cutter disks 14, 14 are rotatably supported at both ends of the skin plate 10. The cutter disk 14 is generally constructed of a moving device 15 that revolves and moves while maintaining a predetermined interval, that is, an interval of approximately 1/2 the diameter of the cutter disk 14.

A partition wall 1 is provided on the distal end side of the skin plate 10.
6 is fixedly installed, and the earth pressure chamber 18 is filled with excavated earth and sand.
are separated from each other, and the skin plate 10
Inside, a propulsion jack for advancing the excavator, a screw conveyor for discharging excavated earth and sand from the earth pressure chamber 18, etc. are installed.

The spokes 12 are formed in a rectangular shape (see FIG. 2), and have cutter bits 12a on the front surface.
is fixed thereto, and is supported by a rotating shaft 20 that passes through the partition wall 16 and is located on the central axis of the ellipse of the skin plate 10 and extends rearward along the axial direction of the skin plate 10. Also, spoke 1
The length in the longitudinal direction of the spokes 2 is slightly shorter than the short axis l ₁ of the ellipse of the skin plate 12, and the spokes 12 are rotationally driven by a drive motor (not shown) attached to the rotating shaft 20.

The pair of circular cutter disks 14 have substantially the same configuration, and the skin plate 1
A disk-shaped cutter face 14a having a length of approximately 1/2 of the short axis _l of the ellipse 0, and a cutter face 14a.
It consists of a cutter bit 14b fixed to the front side of the cutter face 14a, and a rotating shaft 14c fixed to the back side of the cutter face 14a, and a drive motor 22 for rotationally driving the cutter face 14a is installed at the rear end of each rotating shaft 14c. It is set up. Further, the cutter faces 14a, 14a are arranged slightly shifted in the front-rear direction to prevent mutual interference.

In this embodiment, the moving device 15 is composed of a hydraulic jack 24 built into the spoke 12, and a telescopic plunger 24a of the hydraulic jack 24 has a rotating shaft 14 of the cutter disk 14 at its tip.
c is locked.

Furthermore, guide grooves 12b are provided at both ends of the spokes 12, each extending linearly from the central axis l in the longitudinal direction toward the corner. It moves along this guide groove 12b by expansion and contraction.

In the shield excavator with the above configuration, each cutter disk 1 is
By rotating the spokes 12 and 4, 14, excavation is performed by driving the propulsion jack while taking earth and sand from the face into the earth pressure chamber 18, and a tunnel with an elliptical cross section is formed.

FIG. 2 is an explanatory diagram schematically showing the excavation state of the shield excavator having the above configuration.

Now, the rotation center of one cutter disk 14 is O ₁ and the other is O ₂ , and these are connected to the drive motor 22.
While rotating the spoke 12, the spoke 12 is rotated clockwise.

_{Here ,} as _shown in FIG.
5 is contracted to position O ₁ and O ₂ on the central axis l of the spoke 12 in the longitudinal direction. Then, as the spokes 12 rotate, the hydraulic jacks 24 are gradually extended, and the guide grooves 1
2b, and when the spokes 12 are rotated approximately 90 degrees as shown in FIG. 2b,
The center of each cutter disk 14, 14 is controlled to be located at the corner of the spoke 12.

Then, while the spokes 12 rotate from 90 degrees to 180 degrees, the centers O ₁ and O ₂ of each cutter disk 14 and 14 are located on the short axis l ₁ of the ellipse, and the center axis l
Retract the hydraulic jack 24 so that it returns to the top again. If such control is repeated sequentially thereafter, the cutter disk 14 will rotate by itself, and its center will be located inside the ellipse of the skin plate 10, as shown by the imaginary line in FIG. The cutter disk 14 revolves along an elliptical orbit with an interval of approximately 1/2 the diameter of the cutter disk 14.

The portion left unexcavated by the cutter disk 14 is excavated by the rotation of the spokes 12, so if the cutter disk 14 and the spokes 12 are rotationally driven as described above, the skin plate 10
An elliptical cross-section of approximately the same size as is excavated. A tunnel is constructed by sequentially assembling segments of elliptical cross section on the rear end side of the skin plate 10.

Note that the length and direction of the guide groove 12b and the control of the amount of expansion and contraction of the hydraulic jack 24 are not limited to those described above.
2b may be set on the central axis l in the longitudinal direction of the spokes 12 so that the amount of rotation of the spokes 12 and the revolution angle of the cutter disk 14 are synchronized,
By selecting these appropriately, it is possible to excavate various elliptical cross sections such as oval and gourd shapes.
Especially when there is a limit to the occupied width, it becomes possible to select a cross section that matches the width.

A tunnel with an elliptical cross section excavated as described above has a cross-sectional efficiency intermediate between that of a conventional circular cross-section and that of a combination of two circular cross-sections.

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

<<Effects of the Invention>> As explained in the embodiments above, according to the shield excavator according to the present invention, the pair of cutter disks that rotate by themselves and are moved around the inner circumference of the skin plate by the moving device are ,
Since the length of the diameter is approximately 1/2 of the short axis length of the skin plate with an elliptical cross section, they overlap each other only when the cutter disk is located near the short axis of the ellipse. As a result, the cutter disc can efficiently excavate an elliptical cross section.

In addition, the tunnel that is formed has an elliptical cross-section, which provides a cross-sectional efficiency intermediate between a circular cross-section and a cross-section that overlaps two circular cross-sections, and the shape of the segments is also elliptical. can be easily carried out.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of the shield tunneling machine seen from above, showing an example of the shield tunneling machine of the present invention;
FIG. 2 is an explanatory diagram of the orbit of the cutter disk of the shield tunneling machine. 10...skin plate, 12...spoke,
14...Circular cutter disk, 15...Movement device.

Claims (1)

[Claims] 1. A skin plate having a substantially elliptical cross section, a spoke that is rotatably disposed at the tip of the skin plate and has a length that is approximately the same as the short axis length of the ellipse, and is rotatably supported at both ends of the spoke, and a pair of circular cutter disks having a diameter of approximately 1/2 of the short axis length of the ellipse, and each cutter disk while maintaining a predetermined distance between the centers of these cutter disks and the skin plate. A shield excavator comprising: a moving device for moving a disk along the inner periphery of the skin plate; and a cutter bit fixed to the front surface of the spoke.