JPH04285295A - Shield excavator - Google Patents

Abstract

PURPOSE:To excavate a tunnel which is so formed as to have an almost flat lower portion by deciding most part of a tunnel opening using a first cutter face, and surely drilling a front working face with a second cutter face. CONSTITUTION:A first cutter face 10 is installed the outer form of which when seen from the front side is like a fan including a circular portion extending along the upper portion of a tunnel and which has drilling blades 11 and earth inlets 12 radially disposed therein and which oscillates about the center O of curvature of the circular portion. A tunnel opening which is so formed as to have a circular upper portion and a rectilinear lower portion is almost determined by the first cutter face 10. A second cutter face 20 which has drilling edges 21 and earth inlets 22 disposed therein and which rotates or oscillates within an angle range larger than the angle S of oscillation of the first cutter face 10 is installed near the center of the radial arrangement of the first cutter face 10. A front working face is surely drilled by the second cutter face 20.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator for excavating a tunnel having a cylindrical upper part and a nearly flat lower part, which is suitable for constructing, for example, many rows of railway lines.

0002

[Prior Art] A shield excavator consists of a tube called a shield that prevents the earth wall from collapsing, a shield jack that allows it to move forward, and various cutters that cut the face (ground) at the front of the shield. (excavation tool) as the main part, and generally excavates a tunnel with a circular cross section that follows the outer shape of the shield.

However, when laying tracks (or roads) in multiple rows to allow several vehicles to pass in parallel,
It is preferable that the opening cross-section of the tunnel is horizontally long, and preferably flat at the bottom, rather than circular.

[0004] A shield tunneling machine for tunnels having an elliptical or flat opening cross-section at the bottom is disclosed in Japanese Patent Laid-Open No. 2-9
1395 and Japanese Unexamined Patent Publication No. 1-295992. The excavator described in the former publication has a cutter face (an excavating tool with a excavating blade on the face plate) that rotates at the front of the shield, and a sliding excavating blade that expands and contracts in the radial direction using a hydraulic cylinder on the outside. It is equipped with a digging blade that expands and contracts during rotation to dig a tunnel with a horizontally long oval cross section. On the other hand, the excavator in the latter publication uses a rotating (autorotating) excavation head that is considerably smaller than the tunnel opening cross section, and is equipped with a rotating (self-rotating) excavation head that is extendable and retractable using a hydraulic cylinder.
This is a device that uses the so-called NATM construction method, which is installed at the tip of a revolving (revolving) arm and forms an opening in a desired shape while moving the excavation location by extending, contracting and rotating the arm.

[0005]

[Problems to be Solved by the Invention] The excavators described in each of the above-mentioned publications have the following disadvantages.

First, the former (Japanese Patent Application Laid-Open No. 2-91395) requires a complicated mechanism to extend and retract the sliding excavation blade (if the mechanism is complicated, the cost and maintenance burden of the device will increase). It is difficult to stably excavate the long axis side of the ellipse, that is, the part where the excavation blade is extended and used. A shield excavator with a cutter face can stably excavate sand and gravel layers based on the earth retaining effect (supporting the face to prevent it from collapsing) due to the face facing the face, but the long oval shape This is because, on the shaft side, excavation must be performed in a state in which the excavation blade protrudes outward from the cutter face, in other words, in a state in which the earth retaining effect of the cutter face cannot be obtained. Therefore, the digging machine disclosed in this publication can be effectively used only on relatively stable ground. Furthermore, the cross-sectional shape of the tunnel is limited to an ellipse or something close to it, and it is difficult to excavate a tunnel with a flat bottom.

Although the latter device (Japanese Unexamined Patent Publication No. 1-295992) has a fairly wide range of applicability for the cross-sectional shape of tunnels, the extension/contraction/swivel mechanism of the swing arm is complicated, and it is difficult to perform stable excavation. The ground is more limited than in the example above. The drilling head at the front of the shield is
This is because it is only a fraction of the size of the tunnel opening, so it cannot be expected to have any earth retaining effect on the face.

An object of the present invention is to provide a shield excavator with a simple structure that can stably excavate a tunnel with a cross-sectional shape suitable for laying a double-track railway line in various types of ground. It is to be.

[0009]

[Means for Solving the Problems] In order to excavate a tunnel whose upper part is cylindrical and whose lower part is nearly flat, the shield excavator of the present invention includes: ■ an arcuate portion whose outer shape when viewed from the front follows the upper part of the tunnel; a first cutter face having a fan shape, with excavation blades and earth and sand intake ports arranged radially up to the arc-shaped portion, and swinging around the center of curvature of the arc-shaped portion;
■It is arranged near the center of the above-mentioned radial arrangement in the first cutter face and is equipped with an excavation blade and an earth and sand intake port,
A second cutter face that rotates or swings over a larger angular range than the first cutter face and ■ are provided at the front.

0010

[Operation] When excavating a tunnel with the shield excavator of the present invention, its opening cross section is roughly determined by the first cutter face shown in (■) above, with an arcuate portion at the top and a straight section at the bottom. It becomes a shape with parts. The reason is as follows. In other words, if you first rotate a fan shape with an opening angle of around 180 degrees by an appropriate angle around the center of curvature of the arc, the arc part that is an extension of the arc of the fan shape will be in the upper part and the lower part will be in the lower part as a geometric trajectory. can obtain a relatively flat figure. In this respect, the first cutter face has a fan-shaped external shape when viewed from the front, and swings around the center of curvature of its arcuate portion, so it draws a geometric trajectory as described above, but Since the intake ports are arranged radially on the front, if the swing angle is greater than the angle between each radial arrangement (excavation blade), the face within the trajectory is completely excavated and the shape described above is created. It is possible to form an opening of

[0011] When the first cutter face is oscillated as described above, most of the excavated face, including the upper part (that is, the arc-shaped part), is always facing the cutter face and is earth-retained. Therefore, various types of ground, including sand and gravel layers, can be excavated stably. However, while the upper part is perfectly supported to the outer periphery by the cutter face with the same curvature as the opening, the lower part of the face, that is, near both ends of the fan, has an area equal to the total swing angle of the cutter face on the left and right sides. Some parts are not supported. Although this part is inevitably a little more unstable (easier to collapse) than other parts, it is located at a lower position where the influence of instability is not serious, and the above radial arrangement is densely arranged (with narrow angular intervals). ), the swing angle (and therefore the area of the unsupported portion) can be reduced, so this does not pose a major problem.

[0012] When the swing angle of the first cutter face is made small, the radial arrangement must also be dense (the angular interval is narrow), but in this case, the excavation blade and the earth and sand intake port are arranged in the same radial direction near the center. Since it is difficult to arrange the cutter face according to the arrangement, the second cutter face (2) above is arranged near the center of the excavator of the invention. This second cutter face can be rotated or oscillated over a relatively large angular range, even if the arrangement of cutting edges and intake ports is sparser than that of the first cutter face. Make sure to excavate the face. Therefore, when the second cutter face is arranged so that there is no gap when viewed from the front with respect to the first cutter face, the excavator of the present invention can be stabilized while exerting a heap retaining effect on almost the entire surface of the face. excavation.

The excavator of the present invention has a simple structure because it does not require a telescoping mechanism for moving the excavation blade, and it also has advantages in terms of strength and service life because it does not need to support the excavation load through such a complicated mechanism. be.

[0014]

Embodiment FIGS. 1 and 2 respectively show a front view and a side sectional view (A-A in FIG. 1) of a shield tunneling machine 1 which is a first embodiment of the present invention. This excavator 1 excavates a tunnel suitable for laying three sets of tracks in parallel as a subway vehicle parking line.

As shown in FIG. 2, the excavator 1 has two cutter faces 10 and 20 on the front of the shield 2, and two cutter faces 10 and 20 on the inside rear of the shield 2, which is partitioned from the front chamber 4 by a partition wall 3. Drive source 16 for faces 10 and 20
・In addition to 25, although not shown, it is equipped with a shield jack, earth and sand discharge equipment (sludge pipe, screw conveyor, belt conveyor, etc.), segment erector, etc. Line the inner surface of the excavated earthen wall a with a segment using an erector, press the shield jack against the segment, and while obtaining propulsion force face 10 and 20.
By excavating face b at , the excavator 1 excavates the tunnel to the left in FIG.

The two cutter faces 10 and 20 are arranged in the same plane at the front of the excavator 1 with almost no gap between them, and are visible from the front as shown in FIG. That is,
First, regarding the first cutter face 10, its outer shape is generally fan-shaped, with an arcuate portion at the top, and the center of curvature O at the bottom. Needless to say, this face 10 is a means for excavating a face, so it is equipped with a large number of cutting blades (cutter bits) 11 on the front surface of the face plate 11a, and also has an intake port 12 for introducing the scraped earth and sand into the chamber 4. ing. A large number of digging blades 11 (19 in this example) are arranged radially toward the outer edge of the face 10 including the arc portion.
The earth and sand intake ports 12 are also formed radially between the face plates 11a having such excavation blades 11. In the radial arrangement of the excavating blade 11 and the intake port 12, the center point of extending them is the above-mentioned center of curvature O.
, with a uniform angle R (15° in this example) between each array.
is provided. In this example, in addition to the radial portion, the excavating blade 11 is also arranged at the lower edge of the cutter face 10 (excluding the arcuate portion).

On the other hand, the second cutter face 20 has an outer shape having a circle centered at the same center O as above, and whose outer shape is a circle centered at the center O.
A cutting blade (cutter bit) 2 is placed on the face plate extending from to the outer edge.
1, and has an earth and sand intake port 22 between them. Since the center O is also the center of the radial arrangement of the excavation blades 11 and intake ports 12 in the cutter face 10, it is natural that the face 20 is arranged at a place where the radial arrangement of the face 10 is densely arranged. Become.

While the cutter face 20 rotates around the center O, the fan-shaped cutter face 10 swings around the same center O in both forward and reverse directions. In order to prevent uncut parts from being left uncut by the radially arranged excavation blades 11, the swing angle S (in this example, approximately 17
°) is larger than the angle R between each arrangement.

Due to such swinging of the cutter face 10 (excavation blade 11) and rotation of the cutter face 20 (excavation blade 21), the cross-sectional shape of the earth wall a to be excavated becomes as shown in the imaginary line in FIG. . In other words, there is a cylindrical portion a1 at the top and a nearly flat portion a2 at the bottom. For that purpose, the shield 2 (see Figure 2) also
It is formed to have an external shape that follows the cross-sectional shape of this earthen wall a. This shape of the earthen wall a has no unnecessary openings at the bottom even if the radius of the cylindrical part a1 is large, so it is considered to be a convenient and rational shape for use as the vehicle parking line mentioned above. I can say that.

As is clear from FIG. 1, the cutter faces 10 and 20 cannot always face the face b during excavation, as is clear from FIG. It's just a part. This is because the soil retaining effect of Faces 10 and 20 is exerted over a wide area, making stable excavation possible.

The mechanism for supporting and operating the cutter faces 10 and 20 is as shown in FIG. That is, first, the support shaft 23 of the face 20 is supported by a bearing box 24 that is fixed to the excavator 1 together with the partition wall 3 and the like, and is rotationally driven by a drive source (such as a motor) 25. One face 10 has an annular frame 14 rotatably disposed on a circular frame around the bearing box 24 via a bearing 15.
4 using a bracket 13. Further, a plurality of thrust receiving rollers 18 and the like are provided on the face plate 11a as auxiliary support means. and,
The face 10 swings as described above by expanding and contracting the hydraulic cylinder 16 provided at the rear of the partition wall 3 and moving the annular frame 14 in a direction perpendicular to the plane of FIG. 2 (tangential direction on the circumference).

[0022] As a means of stabilizing the excavation of the face, the main excavation machine 1 may pressurize the inside of the chamber 4 with muddy water (muddy water type excavation machine) or fill it with excavated soil or additives (earth pressure type excavation machine). ) can be applied without any problems. Also, bulkhead 3
If not provided, it can be used as a so-called open shield excavator for excavating relatively stable ground.

Next, FIG. 3 shows a front view of a shield tunneling machine 6 which is a second embodiment of the present invention. This excavator 6 is also used to excavate tunnels for multiple rows of railway lines, and has a first cutter face 30 having a fan-shaped outer shape and a circular second cutter face 40 on the front side. and face 3
0, a face plate 31 with a digging blade (not shown) and a sand intake port 32 are arranged radially up to the edge of the circular arc. Ports 42 are provided at every 90° as shown in the figure. Including these points, the present excavator 6 has the same configuration as the excavator 1 of the first embodiment, but differs from the excavator 1 described above in the following points.

a) In order to excavate a tunnel having a lower surface that is even closer to a flat surface than the above embodiment, the cutter face 30 has both ends (lower part) straight and the angle between them is, for example, 150 mm. It is formed to have a strong angle of 30° (±15°) and swings within an angular range of 30° (±15°).

b) The cutter face 40 does not rotate, but oscillates, for example, over an angular range of about 100°, which exceeds 90° (the abovementioned spacing). As a drive source for rocking, a hydraulic cylinder that expands and contracts may be used, but a motor that can rotate in forward and reverse directions may also be used (this point also applies to the drive sources of the face 30 and the face 10 of the above embodiments). applicable).

c) Inside the earthen wall c that will become the tunnel,
In addition to the cylindrical surface portion c1 and the flat surface portion c2, it is configured to form upper and lower protruding portions c3 and c4 that serve as construction spaces for lighting equipment, wiring, piping, etc. That is, the three face plates 31 at the top of the cutter face 30 (in the center of the arcuate portion) protrude slightly outward compared to other parts, and a portion of the cutter face 40 extends downward from the outer edge of the face 30. It's sticking out.

d) Although the cutter face 30 and the cutter face 40 are arranged without any gap when viewed from the front, they are not on the same plane, and the face 40 is provided slightly forward.

e) The center of swing P of the cutter face 30 is the center of curvature of its arcuate portion and the center of the radial arrangement, but it does not coincide with the center (center of external shape and rotation) Q of the cutter face 40. Not yet.

f) The cutter face 30 is the excavator 6
It is supported so as to be able to swing while sliding on an arc-shaped guide rail 33 fixed to the guide rail 33, and is driven in this state by a hydraulic cylinder (not shown).

Although two embodiments have been introduced above, the technical idea of the present invention can be realized in many other embodiments in addition to these embodiments. An excavator similar to the excavator 1 of the first embodiment and having only some of the features (a) to f)) of the excavator 6 of the second embodiment can also be easily manufactured according to the present invention. Needless to say, it can be configured.

[0031]

[Effects of the Invention] The shield tunneling machine of the present invention has the following effects.

1) It is possible to excavate a tunnel whose lower part is nearly flat and which has a cross-sectional shape suitable for, for example, running a plurality of railway cars, automobiles, etc. in parallel (that is, a streamlined and rational cross-sectional shape).

2) The tunnel described in 1) above can be stably excavated in various types of ground.

3) Since the structure is simple, it is advantageous in terms of equipment cost and maintenance burden, as well as mechanical strength and life.

[Brief explanation of the drawing]

[Fig. 1] Shield excavator 1 as a first embodiment of the present invention
FIG.

2 is a side cross-sectional view showing an outline of the excavator 1 of FIG. 1, and is a cross-sectional view taken along line A-A in FIG. 1. FIG.

FIG. 3 is a schematic front view of a shield excavator 6 which is a second embodiment of the present invention.

[Explanation of symbols]

1.6 Excavation machine

Claims (1)

[Claims] Claim 1: A shield excavator for excavating a tunnel with a cylindrical upper part and a nearly flat lower part, the external shape when viewed from the front is fan-shaped including an arc-shaped part along the upper part of the tunnel, and the arc-shaped A first cutter face in which the excavation blades and the earth and sand intake ports are arranged radially up to the first cutter face and swings around the center of curvature of the arcuate part, and the first cutter face is arranged near the center of the radial arrangement in the first cutter face. A shield excavator equipped with a second cutter face that rotates or swings in a larger angular range than the first cutter face, which is equipped with an excavation blade and an earth and sand inlet.