JPH0566479B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application Field>> The present invention relates to a shield tunneling machine, and particularly to a shield tunneling machine capable of excavating an oblong cross section.

<<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 upper and lower, but in this case, excavating and constructing two tunnels separately would be wasteful in terms of land, construction period, and construction cost.

Therefore, it may be possible to excavate a large circular cross section that can accommodate two rails at once, but although this method is slightly advantageous in terms of construction period than excavating them individually, the cross section efficiency is On the contrary, it gets worse.

For this reason, for example, as disclosed in Japanese Patent Application Laid-Open No. 47-44931, a shield excavator has been proposed that excavates a cross section in which two circular cross sections overlap each other at once. The structural excavator had problems as explained below.

<Problems to be Solved by the Invention> In other words, in the shield tunneling machine disclosed in the above publication, a cross section obtained by overlapping two circular cross sections can be obtained at once, so the cross section efficiency is improved. However, since the segments installed at the rear of the shield excavator after excavation also have overlapping circles, there is a problem in that their assembly and production are complicated.

The present invention has been made in view of these problems, and its purpose is to provide a shield excavator capable of excavating an oval cross section, which facilitates the assembly and manufacture of segments.

<<Means for Solving the Problems>> In order to achieve the above object, the present invention provides a cylindrical skin plate with an oval cross section that is open at both ends, and a cutter rotatably installed on the front end side of the skin plate. The cutter device is rotatably driven around the center long axis of the ellipse, and the cutter device includes a plurality of sets adjacent to each other in the center long axis direction of the ellipse. The cutter bit is characterized in that the cutter bit is provided so as to be swingable in the longitudinal direction of the center of the oval.

Preferably, each of the cutter bits is configured to be expandable and contractible.

<<Operation>> According to the shield excavator having the above configuration, by moving the skin plate forward while rotating the plurality of cutter bits, a tunnel having an oval cross section corresponding to the skin plate is excavated.

In this case, if each cutter bit is configured to be expandable and retractable, and the cutter bit is rotated while being extended only in front of the skin plate, an excavation hole larger than the cross section of the skin plate can be formed, making curved construction easier. .

<<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 a shield excavator according to the present invention.

The shield tunneling machine shown in the same figure exemplifies the case where the present invention is applied to an earth pressure type machine, and includes a cylindrical skin plate 10 that is open at both ends, and a rotatably installed on the front end side of this skin plate 10. A cutter device 12 is provided.

In this embodiment, the skin plate 10 has an oval cross-sectional shape, and a partition wall 14 is fixedly installed on the front side of the skin plate 10, and the front side of the partition wall 14 serves as an earth pressure chamber 16 filled with excavated earth and sand. There is.

The cutter device 12 is installed in an earth pressure chamber 16 separated by a partition wall 14, and rotatably supported on the long axis of the skin plate 10 via a bearing 18.
and a rotating shaft 20 as the central long axis of the ellipse, which is installed on a line connecting the tips of the skin plate 10.
It is composed of hollow cylindrical arms 22, 22, . has been done.

In this embodiment, six arms 22 are arranged in one set, and a total of five sets of arms 22 are arranged at predetermined intervals along the axial direction of the rotating shaft 20. Three sets of arms 22 located
The length of the arm 22 is set to be approximately the same as the short axis of the skin plate 10, that is, the central short axis of the ellipse, and the two sets located at both ends of the long axis are longer than the other three sets. The length of is getting shorter.

Further, each cutter bit 26 has a cutter rod 24 fixed thereto inserted into the arm 22, and a jack 2 at the rear end of the cutter rod 24.
8 is attached to the cutter bit 26, and the cutter bit 26 is configured to be extendable and retractable by driving the jack 28.

Further, each cutter bit 26 has a rotary shaft 20
The skin plate 10 is configured to be swingable in the radial direction of the skin plate 10 by driving a swinging jack 27 attached to the outer periphery of the arm 22 with a pin.

Note that the member designated by the reference numeral 29 in FIG. 4 is a support member to which both ends of the swinging jack 27 are connected with pins.

The rotational drive mechanism of the rotating shaft 20 includes a pair of driven gears 30, 3 on both sides of an arm 22 located at the center.
0 is fixedly installed, and this driven gear 30 is connected to a pair of driving gears 34, 34 driven by a motor 32 installed behind the partition wall 14 by chains 36, 36, respectively.

On both sides of the chain 36, one end is connected to the partition wall 1.
A cover 38 supported by 4 is attached.

Incidentally, a plurality of screw conveyors 40 for discharging excavated earth and sand, whose tips partially enter the earth pressure chamber 16, are arranged in the partition wall 14.

In the shield excavator configured as above,
Driving the motor 32 to rotate each cutter bit 26 in the axial direction of the skin plate 10 to excavate the ground and sequentially take in the excavated earth and sand into the earth pressure chamber 16, while extending a shield jack (not shown). The earth and sand taken into the earth pressure chamber 16 are transported to the screw conveyor 40 while stabilizing the face.
is discharged to the outside.

In this case, the cutter bit 26 of the cutter device 12 for excavating the earth is oscillated by the oscillating jack 27, but at this time, the oscillating angle is set within a range where radially adjacent sets do not interfere with each other, and ,
If the swing angles are set to gradually deviate within each group, excavation with an elliptical cross section can be performed simply by rotationally driving the cutter bit 26.

In this case, the cutter bit 26 swings only in the section where it protrudes forward from the tip of the skin plate 10, and the section where the cutter bit 26 rotates inside the skin plate 10 is rotated by the rotation axis 2.
It may also be controlled to be orthogonal to 0.

In addition, when excavating the ground, the above-mentioned jack 28
If excavation is performed with the cutter bit 26 extended only on the front side of the tip of the skin plate 10, excess excavation will occur on the outer periphery of the skin plate 10, making it easier to perform curved construction.

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.

<<Effects of the Invention>> As explained above in the embodiments, according to the shield excavator according to the present invention, the cross-sectional shape to be excavated is oval, and the cross-sectional efficiency is slightly higher than that of two circular cross-sections overlapped. Although it decreases,
Since the segment has an oval cross-section, assembly and production are facilitated.

In addition, if the cutter bit is configured to be telescopic and extends only in front of the skin plate,
Easily secure the extra excavation required for curved construction.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of the shield tunneling machine of the present invention, FIG. 2 is a front view of the same shield tunneling machine,
FIG. 3 is a sectional view of the main part of the cutter bit, and FIG. 4 is an explanatory diagram of the main part showing the attachment part of the cutter bit. 10... skin plate, 12... cutter device, 26... cutter bit, 27... rocking jack.

Claims (1)

[Scope of Claims] 1. A shield excavator comprising a cylindrical skin plate with an oval cross section open at both ends, and a cutter device rotatably installed on the front end side of the skin plate, wherein the cutter device The cutter bit is rotatably driven around the center long axis of the ellipse, and has a plurality of sets of cutter bits adjacent to each other in the direction of the center long axis of the ellipse, and each cutter bit is connected to the center long axis of the ellipse. A shield excavator characterized by being installed so that it can swing freely in the direction of the central long axis. 2. The shield excavator according to claim 1, wherein each of the cutter bits is configured to be extendable and retractable.