JPH09170399A - Rectangular shield machine - Google Patents

Abstract

(57) Abstract: A rectangular shield machine capable of excavating a tunnel having a desired size and a rectangular cross section close to the final use state. SOLUTION: A plurality of main cutter disks 2A, 2B arranged side by side on the front surface of the excavator 1 and adjacent main cutter disks 2A, 2B on the outer side of the front surface of the excavator are on a substantially common tangent line and on the tangent line. A plurality of cutter drums 13 respectively arranged on vertical tangent lines, and auxiliary cutter disks 20 arranged at the four corners of the rectangle on the front surface of the excavator 1.
The main cutter disks 2A and 2B and the cutter drum 13
The front surface of the excavator is formed in a substantially rectangular shape as described above, and the body element 3a having a rectangular cross section is arranged for each of the main cutter disks 2A and 2B, and each main cutter disk 2A, 2B and the body element 3a are formed. The excavator elements 1a are detachably connected to each other.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a rectangular shield machine. More specifically, the present invention relates to a rectangular shield excavator that enables excavation of a tunnel having a rectangular cross section by excavating unevenness of an excavation peripheral edge with an additional cutter while using a circular main cutter disk.

[0002]

2. Description of the Related Art Conventionally, a shield excavator has been used as a machine for forming a tunnel in the ground, and a circular shield excavator for excavating a tunnel having a circular cross section is often used.

On the other hand, there is also a demand for forming a widened tunnel for laying a road having a plurality of lanes, for example. In order to meet such a demand, when excavating with the circular shield machine, it is necessary to excavate into a large-diameter circular cross section, and usually wasteful work such as backfilling is required for forming a tunnel having a horizontally long rectangular cross section. Alternatively, a plurality of tunnels each having a circular cross section may be excavated so as to be overlapped with each other and arranged side by side. However, in order to excavate a desired widened tunnel by superimposing circles, it is necessary to take a large margin of superimposition, so a shield excavator with a larger diameter than necessary is required and it becomes inefficient work. .

Therefore, for example, there is a conventional technique for excavating a special cross section other than the circular cross section as described in Japanese Utility Model Publication No. 4-14552. This technique attempts to excavate a horizontal shaft having a rectangular cross section, for example, by moving a single circular cross section excavating cutter along a cutter guide. That is, as shown in FIG. 12, a single cutter disk 51 is swung in all directions using a spherical bearing 53 that extends the cutter shaft 52 and supports the cutter shaft 52 (so-called pivoting). It is intended to excavate a widened tunnel by swinging it in a lateral direction (conventional example 1).

Still another conventional technique is Japanese Patent Laid-Open No. 62-2.
There is a technique described in Japanese Patent No. 25694. In order to excavate a tunnel with a wide excavation cross section such as a highway (four lanes), this technique uses a plurality of large-diameter cutters 60 as shown in FIG. 13 (a front view showing the front of the shield machine). A cutter 61 of small diameter is provided between the cutters 60 of large diameter, which are rotatably arranged side by side. An attempt is made to excavate a tunnel having an enlarged cross-sectional shape such that excavation areas by the cutters 60 and 61 overlap with each other (conventional example 2).

[0006]

In the prior art example 1 shown in FIG.
As is clear from 2, it is necessary to lengthen the cutter shaft 52 in order to widen the tunnel. When the cutter shaft 52 is lengthened in this way, the moment due to the excavation reaction force becomes large, and the mechanism for supporting this moment becomes large, so that the body 54 must be enlarged in the height direction. Therefore, the aspect ratio of the rectangular tunnel is limited. Moreover, the excavated surface in the ground is inevitably partly spherical, and the ground is unstable and easily collapses. Moreover, since a single cutter disk 51 is used to excavate a rectangular cross section, if the cutter disk 51 is made too large, it becomes difficult to excavate the tunnel corner into a rectangular shape. As a result, it becomes necessary to make the cutter disk 51 relatively small. However, if the cutter disk 51 is made smaller, the ratio of the cutter disk 51 in the rectangular cross section becomes smaller, and the mountain clasp at the front face of the shield excavator cannot be achieved.
It is not suitable for excavating collapsible ground such as soft ground where there is a risk of collapse of the ground at the time of excavation.For example, it will not be used in a mud pressure shield excavator. It will not be possible.

On the other hand, in the conventional example 2, as shown in FIG. 13, the large-diameter cutter 60 and the small-diameter cutter 61 can excavate a rectangular shape to some extent, but the large-diameter cutter 60 and the small-diameter cutter 61 are used. An uneven unexcavated portion 62 remains between the unexcavated portions 62 and it is necessary to forcibly excavate the unexcavated portion 62 in the machine outer shell portion 63 (hood plate portion) when the shield excavator advances, so the ground is hard. If it is the ground, the excavation resistance increases and the excavation becomes difficult. Even if the machine outer casing 63 is forcibly excavated, the machine outer casing 63 is prematurely worn and the shield excavator itself needs to be replaced early, which is a very inefficient operation that requires cost and time. Therefore,
This conventional example 2 also has difficulty in excavation unless the ground is soft.

In order to reduce the excavation resistance, it is assumed that the machine shell 63 of the shield machine according to Conventional Example 2 has an uneven shape which is substantially the same as the shape in which the outer circumferences of the large diameter cutter and the small diameter cutter are continuous. In that case, it takes time and cost in manufacturing, and the uneven unexcavated portion 62 remains after excavation by the shield machine.

Therefore, it is conceivable to install another rectangular tunnel in parallel with the rectangular tunnel previously formed by such a shield machine. In that case, usually when excavating the previous tunnel, the concrete backing material is injected between the segment and the ground to form the tunnel, so when excavating the latter tunnel, The backfill material is excavated while excavating, and the backfill material of the later tunnel is installed side by side so as to be combined with the backfill material of the previous tunnel, and both tunnels are firmly arranged side by side.

However, as described above, the unexcavated portion 6 having the uneven shape is formed.
If 2 remains, there will be a portion that cannot be excavated unless a large margin of overlap with the previous tunnel is left when excavating a later tunnel, so this excavation work becomes an inefficient operation with a large margin of overlap.

Further, when it is attempted to form a road tunnel by arranging rectangular tunnels side by side, the road tunnel is usually excavated up and down with a gradient of about 5%. When the uneven unexcavated portion 62 remains, the unevenness of the leading tunnel and the unevenness of the trailing tunnel may deviate when excavating the trailing tunnel, and the unexcavated portion 62 may further increase. is there. Therefore, in such a case, an inefficient excavation operation with a larger polymerization margin is required. Further, at this time, if the overlap allowance is too large, there is a possibility that the subsequent shield machine may excavate the segment of the preceding tunnel, so that the excavation operation requires advanced technology.

When such rectangular tunnels are juxtaposed, a shield excavator having a large excavation section capable of excavating both sections at once may be manufactured. In this case, for example, the width of the machine is 20 m. Because it becomes a shield excavator with more than
Its production is technically difficult,
Alternatively, there is a problem in assembling, and it is very difficult to realize it uneconomically.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a rectangular shield machine capable of excavating in a rectangular cross section which is extremely close to the cross section of a tunnel finally required. There is.

[0014]

SUMMARY OF THE INVENTION A rectangular shield machine according to the present invention comprises a plurality of main cutter disks arranged side by side on a front surface of the shield machine with a predetermined distance from each other so as not to interfere with each other in an axial direction, and a front surface of the shield machine. A substantially cylindrical shape for excavating the unexcavated portion of the main cutter discs, which are respectively disposed on substantially common tangent lines of adjacent main cutter discs that are the outer edges of the main cutter discs and tangent lines perpendicular to the tangent lines. It is provided with a plurality of cutter drums, and a cylinder having a rectangular cross section substantially the same as the front surface of the shield machine formed in a substantially rectangular shape by the main cutter disk and the cutter drum.

With such a construction, the rectangular shield machine of the present invention can excavate its front surface by a plurality of main cutter disks, and the plurality of cutter drums can be used by the main cutter disk at the outer peripheral portion of the front surface of the shield machine. The unexcavated part can be excavated. By doing so, a rectangular tunnel can be excavated.

In such a rectangular shield machine, an auxiliary cutter disk having a diameter smaller than that of the main cutter disk for excavating an unexcavated portion of the main cutter disk is disposed at the four corners of the front surface having the substantially rectangular shape. It is possible to excavate the unexcavated parts at the both end corners of the main cutter disc so that the disc surface is substantially parallel to the surface of the main cutter disc. can do. Furthermore, since the surface of the auxiliary cutter disk is substantially parallel to the surface of the main cutter disk, the surface of the ground excavated by the auxiliary cutter disk is also stable and difficult to collapse.

The cylinder having the substantially rectangular cross section is formed by detachably connecting the cylinder elements of the rectangular cross section arranged behind each main cutter disk to each other so as to be excavated. This is preferable in that the number of radixes can be appropriately connected according to the width and height of the tunnel to be formed. Further, when the excavator is conveyed, it is preferable in that it can be divided into pairs of main cutter disks and barrel elements and then conveyed.

Further, the cutter drum is constructed so as to be swingable so as to be able to advance and retreat outward from the tangent line of the main cutter disc, so that so-called over-digging is performed on the side that has advanced outward. Therefore, it is preferable that the excavation can be performed while curving, that is, the curved excavation can be performed. In addition, it is possible to perform a wide widening excavation.

Further, the auxiliary cutter disk is constructed so that it can be rockably driven so as to be movable in a substantially tangential direction of the main cutter disk. Since the excavation allowance can be expanded outward, a plurality of tunnels, for example, can be used. When excavating adjacent to each other, tunnels can be easily communicated with each other, which is preferable. In addition, it is possible to perform a wide widening excavation.

In addition, each of the body elements having the substantially rectangular cross section is configured to be capable of being center-folded from a front body and a rear body connected by center folding pins, and the rear bodies are detachably fixedly connected to each other. It is preferable that each of the front cylinders be configured to be swingably driven around the center bending pin in terms of enabling the curved excavation, and the excavation can be performed by bending each of the cylinder elements in opposite directions as appropriate. Since the machine can be rotated around its axis, it is preferable in that the attitude of the machine can be adjusted.

Further, an excavator element is constituted by each of the main cutter disks and a trunk element behind the main cutter disk, and each excavator element is provided with the cutter in each of four orthogonal tangential directions of the main cutter disk. It is preferable to configure the drum so that the excavator elements can be connected in a suitable radix according to the width and height of the tunnel to be excavated, and a tunnel having a rectangular cross section can be used regardless of the connection radix. Can be drilled.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION A rectangular shield machine (hereinafter, simply referred to as a machine) of the present invention will be described below with reference to the embodiments shown in the accompanying drawings.

FIG. 1 is a perspective view showing an embodiment of the excavator of the present invention, FIG. 2 is a front view showing the front of the excavator of FIG. 1, and FIG.
2 is a side sectional view showing a section taken along line A1-A2-A3-A4 of FIG. 2, and FIG. 4 is a partial plan sectional view showing a section taken along line BB of FIG.
5 is a perspective view showing an auxiliary cutter disk in the excavator in FIG. 1, FIG. 6 is an explanatory view showing a cutter drum in the excavator in FIG. 1, and FIG. 7 is a perspective view showing a configuration of a connecting pin in the excavator in FIG. 8, FIG. 8 is an explanatory view showing a broken state of the excavator of FIG. 1, FIG. 9 is an explanatory view showing an example of tunnel excavation by the excavator of FIG. 1, and FIG. 10 is another example of tunnel excavation by the excavator of FIG. 11 is an explanatory diagram showing yet another example of tunnel excavation by the excavator of FIG. 1.

As shown in FIG. 1, three main cutter disks 2 having substantially the same diameter are arranged side by side in a row at the front of the excavator 1. In this embodiment, the main cutter disks 2A in the central portion are arranged so that the main cutter disks 2 do not interfere with each other.
Are arranged so as to project forward by a predetermined distance D (FIG. 3) from the main cutter disks 2B on both sides. Adjacent main cutter disks are disposed such that the centers thereof are separated by a distance E (FIG. 2) equal to or larger than the radius of the main cutter disk and equal to or smaller than the diameter.

The main cutter disks 2A, 2B are
As shown in FIGS. 3 and 4, the drive shaft 6 is rotated by a rotary drive device 5 provided behind the bulkhead 4 in the body 3 of the excavator 1.
The drive shaft 6 is supported by a seal box 7 and a bearing 8.

Further, in this embodiment, a mud-water type using the mud pipe 9 and the mud pipe 10 for discharging the drilling waste is illustrated. Of course, in the present invention, a well-known excavation method such as a mud pressure type using a screw conveyor or an open mechanical type using a conveyor or the like may be used in addition to the muddy water type.

Incidentally, S is a segment forming a tunnel shell, and 11 is an erector for assembling the segment S. Reference numeral 12 denotes a propulsion jack that pushes the segment S and advances the excavator 1 by the reaction force.

As is apparent from FIGS. 1 and 2, one barrel element 3a is arranged behind one main cutter disk 2. Body element 3a as described below
The parts are removably connected to each other. Hereinafter, one body element 3a corresponding to this one main cutter disc 2
An element consisting of and is called an excavator element 1a.

Then, the adjacent main cutter disk 2
A cutter drum 13 is provided on a substantially common tangent of A and 2B and on a tangent perpendicular to the tangent. In other words, the cutter drums 13 are provided at both corners of the main cutter disc 2B at both ends and at an outer edge corresponding to a substantially central portion of the center distance E between the adjacent main cutter discs 2A and 2B. I have. Thereby, the front surface of the excavator 1 has a substantially rectangular shape. The cutter drum 13 has a plurality of cutter bits 13b arranged on the surface of a cylindrical drum 13a. The cutter drums 13 at both corners of the main cutter discs 2B at both ends are formed by connecting two drums 13a by an intermediate member 13c (hereinafter referred to as a cutter drum pair). The ground portion corresponding to the position of the intermediate member 13c has already been excavated by the main cutter discs 2B at both ends, and the ground portion does not become an obstacle for the intermediate member 13c when the excavator 1 excavates. In addition, the driving mechanism is economical because one driving mechanism is provided for two cutter drums 13. On the other hand, the cutter drums 13 between the adjacent main cutter disks 2A, 2B are arranged one by one. Of course, it may be configured such that one cutter drum 13 or one cutter drum pair 13 can be disposed on each of four orthogonal sides of the main cutter disc 2 for one excavator element 1a. By doing so, it is possible to select on which side of the front surface of each excavator element 1a the cutter drum or the pair of cutter drums should be disposed according to the radix of the excavator elements 1a to be connected.

As shown in FIG. 2, this cutter drum 1
3 is an arrow F direction and an arrow G perpendicular to each side of the excavator.
You can move back and forth in the direction. That is, each cutter drum 1
Numeral 3 is configured to be advanced outward from the long sides and short sides of the rectangle on the front surface of the excavator 1 and to be retracted. FIG. 4 shows a reciprocating drive mechanism 14 for moving the cutter drum 13 back and forth. That is, the bulkhead 4
Is equipped with a bearing 14b for swingably supporting the support member 14a of the cutter drum 13.
A drive jack 14c for swinging and driving a in the direction of the arrow HJ is provided behind the bulkhead 4. FIG.
Although only the reciprocating drive mechanism 14 of the cutter drum 13 on the rectangular short side on the front side of the excavator is shown in the above, a similar reciprocating drive mechanism is also used on the cutter drum 13 on the long side. In this way, by making the cutter drum 13 advance outward and digging, so-called extra digging on the side where the cutter drum 13 has advanced becomes possible. In addition, since a known so-called copy cut mechanism is provided on the main cutter disk, it is possible to perform extra cutting by such a copy cut mechanism. Therefore, the excavator 1 can be easily curved and advanced in the direction in which the excavation has been performed.

The rotary drive mechanism for the cutter drum and the pair of cutter drums are the same, and have the structure shown in FIG. That is, the drive device 15 behind the bulkhead 4 rotates the drive shaft 16 penetrating the bulkhead 4, and the bevel gear mechanism 1 disposed on the tip side of the drive shaft 16.
The drum shaft 13d is rotated via 7 to rotate the drum 13a. Here, in the case of the cutter drum pair 13, the bevel gear mechanism 17 and the drum shaft 13d are incorporated in the intermediate member 13c. Reference numeral 18 denotes a taper roller bearing provided to receive the pressing reaction force of the bevel gear mechanism 17, and 19 denotes a cylindrical roller bearing. 14b is the bearing (FIG. 4). Illustration of the support member 14a (FIG. 4) is omitted.

Returning to FIGS. 1 and 2, an auxiliary cutter disk 20 having a diameter smaller than that of the main cutter disk 2 is provided at each of the four corners of the front face of the excavator 1. The outer peripheral portion of each of the auxiliary cutter disks 20 is disposed in such a manner that the tangent line of all the main cutter disks 2 protrudes slightly outward from a rectangle surrounding the entire main cutter disks 2. And as shown in FIG. 2, it is comprised so that it can reciprocate in the arrow KL direction along the long side of the rectangle of the excavator 1 front surface.

The structure is apparent from FIGS. 3 and 6. In both figures, a first member 21 and a second member 22 that support the auxiliary cutter disk 20 are fixedly connected in a crank shape by an arm member 23. The second member 22 penetrates the bulkhead 4 through the bearing member 24. A driving device 25 for rotating the auxiliary cutter disc 20 is disposed behind the bulkhead 4, and the rotational driving force is applied to the first member 21, the second member 22, and the arm member 2.
3 through a known mechanism (not shown) such as a chain drive or a shaft drive. The drive cylinder 26 is used as a reciprocating mechanism of the auxiliary cutter disk 20. The drive cylinder 26 pushes and pulls a bracket 22 a formed on the rear part of the bulkhead 4 of the second member 22, thereby rotating the arm member 23 about the axis of the second member 22 to remove the auxiliary cutter disk 20. It can be rotated in the direction of arrow MN. By doing so, the auxiliary cutter disk 20 can be reciprocated in the arrow KL direction (FIG. 2) substantially along the long side of the rectangle on the front surface of the excavator 1, although the auxiliary cutter disk 20 is not a complete linear movement. Therefore, by advancing these auxiliary cutter disks 20 outward along the long sides of the rectangle on the front of the excavator 1, the unexcavated portions of the main cutter disks 2A, 2B are excavated to excavate a tunnel having a substantially rectangular cross section. it can.

In this embodiment, the auxiliary cutter disk 20 is reciprocated along the long side of the rectangle on the front surface of the excavator 1. However, it is not limited to the long side of the rectangle, and may be configured to be able to reciprocate along the short side. Further, since it has the configuration shown in FIG. 6, it is possible to configure the same auxiliary cutter disk 20 so as to be movable in both the long side direction and the short side direction via the corners of the rectangle.

Further, by allowing the cutter drum 13 to move outward and the auxiliary cutter disk 20 to move outward at the same time, a slight tunnel widening is possible.

The present invention is not particularly limited to the excavator equipped with the auxiliary cutter disk 20, and the auxiliary cutter disk 20 may be omitted and the main cutter disk and the cutter drum may be provided. . Even such an excavator can easily excavate a rectangular cross-section tunnel.

Next, as described above, in this embodiment, three excavator elements 1a are connected (see FIG. 1). As shown in FIG. 4, each excavator element 1a is composed of a front body 27 and a rear body 28, and the front body 27 is connected by a center bending pin 29 so that the front body 27 can be bent at a slight angle with respect to the rear body 28. Has been done. A front body 27 and a rear body 28 are connected to each of the machine elements 1a at the same axial position. The rear trunks 28 of the excavator elements 1a are fixedly connected to each other by bolts 31 via their own flanges 30. As shown in FIG. 7, the front torso 27 is bendable by inserting the connecting pin 34 into the connecting hole formed by the round hole 32 on one side and the elongated hole 33 on the other side, and the excavator element 1a can be bent. They are connected so that they cannot move relative to each other in the axial direction. In addition, in FIG. 4, illustration of the excavator element 1a at one end is omitted.

With this configuration, the three excavator elements 1a can swing their front bodies 27 individually in different directions, for example, as shown in FIG. 8A, 8B, and 8C, the upper stage is a plan view and the lower stage is a front view. FIG. 8A shows a state in which the front trunk 27 is swung in the same direction (rightward in the drawing) in all the three excavator elements 1a. If the excavation is performed in that state, the excavator 1 curves in the direction of the arrow P due to the excavation reaction force. Therefore, it is convenient when bending the excavation direction. When combined with the advance of the cutter drum 13 described above, it becomes easier to change the excavation direction.

In FIG. 8 (b), the excavator element 1a at the center does not swing the front body 27 (axial direction coincides with the rear body 28), and the excavator elements 1a at both ends have the front body 27. Are oscillated in opposite directions. If the digging machine 1 is advanced in this state, the excavator 1 rotates while moving in the direction of arrow Q due to the digging reaction force.
Therefore, it is convenient because correction can be made when there is a sign that the excavator 1 rotates around the axis for some reason during excavation.

FIG. 8C shows a state in which the front body 27 of the excavator element 1a at both ends is swung in the opposite direction to that of FIG. 8B, and the excavator 1 is rotated around its axis as shown in FIG. In contrast to that of b), it can be rotated in the R direction.

In FIG. 8, the excavator 1 is vertically connected long, but the same effect can be obtained even if it is horizontally connected long.

In the above embodiment, three excavator elements 1a were connected, but the present invention is not limited to three, and two or four or more may be connected.

According to the excavator 1 configured as described above, a tunnel having a rectangular cross section can be excavated as follows.

That is, 3 provided on the front surface of the excavator 1
The front ground is excavated by the main cutter disks 2A, 2B without interfering with each other, and the unexcavated portion by the main cutter disks 2A, 2B is provided by the auxiliary cutter disk 20 and the cutter drum 13 provided at the rear. Excavate. The auxiliary cutter disc 20 excavates the unexcavated portion of the main cutter disc 2 while reciprocating by the swing drive of the arm member 23 by the drive cylinder 26.

An outline of a tunnel which can be excavated by the above-mentioned excavator 1 is shown in FIGS.

As shown in FIG. 9, the excavator 1 can excavate a tunnel having a rectangular cross section with only one unit by the above-mentioned configuration. The excavated tunnel in FIG. 9 is shown by a chain double-dashed line, and the laid segment S is shown by a solid line. According to the present excavator 1, by selecting the connecting direction of the excavator elements 1a, not only the horizontally long rectangular tunnel but also the vertically long rectangular tunnel can be excavated.

On the other hand, it is also possible to excavate a rectangular cross-section tunnel having a larger cross-sectional area by excavating different parts of the ground several times with this single excavator 1. That is, as shown in FIG. 10, first the excavator 1 excavates the first tunnel T (indicated by a chain double-dashed line on the right side in FIG. 10), and then the excavator 1 is returned to the excavation start point. Then, next to the first tunnel T, the second tunnel U
Excavation (shown by the solid line on the left side in FIG. 10). The segment S is indicated by hatching in the figure. Further, in this case, the auxiliary cutter is moved while moving along the long side of the rectangle in front of the excavator. Then, the first tunnel T and the second tunnel U are communicated with each other by the excavated portions of the auxiliary cutter. Then, the excavated portion outside the segment S in FIG. 10 is filled with the segment backing material and solidified. Finally, the first tunnel T and the second tunnel U are communicated by cutting the segment backing material between them to complete a tunnel having a rectangular cross section with a large width dimension.

FIG. 11 shows a method of excavating a tunnel having a larger cross section. This tunnel is shown in Figure 10.
It is formed by repeating the method shown in (1) to connect a plurality of tunnels. The hatching indicates the segment S, and the chain double-dashed line indicates the outer edge of the excavation portion to be filled with the segment backing material. In the figure, the inside V surrounded by six tunnels is excavated within a range where there is no collapse of the ground from the front side of the excavation, or if the so-called mountain retaining method for preventing collapse is used, It is not necessary to use a shield machine, and can be easily excavated by an ordinary excavator such as a backhoe.

In this way, a large-sized rectangular section tunnel can be excavated by a single machine.

When excavating a plurality of tunnels by one excavator, the excavator is transported to the excavation start point again after the completion of excavation of one tunnel. Since the machine element can be divided, it can be easily transported. Furthermore, after the excavator is transported to the excavation start point, it can be easily re-connected by bolts or connecting pins.

[0051]

The excavator according to the present invention can excavate its front surface by a plurality of main cutter disks, and the unexcavated portion by the main cutter disk on the outer peripheral portion of the front surface of the shield excavator by a plurality of cutter drums. Can be drilled. By doing so, a rectangular tunnel can be excavated.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the excavator of the present invention.

FIG. 2 is a front view showing a front surface of the machine shown in FIG. 1;

FIG. 3 is a side sectional view showing a section taken along line A1-A2-A3-A4 of FIG.

FIG. 4 is a partial plan cross-sectional view showing a cross section taken along the line BB of FIG.

5 is a perspective view showing an auxiliary cutter disk in the excavator of FIG. 1. FIG.

FIG. 6 is an explanatory diagram showing a cutter drum in the excavator of FIG. 1.

FIG. 7 is a perspective view showing a configuration of a connecting pin in the excavator of FIG.

FIG. 8 is an explanatory diagram showing a state in which the excavator of FIG. 1 is broken.

FIG. 9 is an explanatory diagram showing an example of tunnel excavation by the excavator of FIG. 1.

FIG. 10 is an explanatory diagram showing another example of tunnel excavation by the excavator of FIG. 1.

FIG. 11 is an explanatory diagram showing still another example of tunnel excavation by the excavator of FIG. 1.

FIG. 12 is an explanatory view showing an example of a conventional excavator,
(A) is a schematic front view and (b) is a side view.

FIG. 13 is an explanatory view showing another example of a conventional excavator.

[Explanation of symbols]

 1 ... Excavator 1a ... Excavator element 2 ... Main cutter disk 3 ... Trunk 4 ... Bulkhead 13 ... Cutter drum 20 ... Auxiliary cutter disk 27 ... Front trunk 28・ ・ ・ Rear body 29 ・ ・ ・ Center bent pin 33 ・ ・ ・ Connecting pin T ・ ・ ・ First tunnel U ・ ・ ・ Second tunnel

Claims (7)

[Claims] 1. A plurality of main cutter disks, which are arranged side by side by a predetermined distance so as not to mutually interfere in the axial direction with each other on the front surface of the shield machine, and adjacent main cutter disks, which are the outer edges of the front surface of the shield machine, are substantially common to each other. A plurality of substantially cylindrical cutter drums for digging the unexcavated portion of the main cutter disc, which are respectively disposed on a tangent line and a tangent line perpendicular to the tangent line, the main cutter disc and the cutter A rectangular shield machine having a drum and a shield machine formed in a substantially rectangular shape with a drum and a barrel having a substantially rectangular cross section. 2. An auxiliary cutter disc having a diameter smaller than that of the main cutter disc for excavating at least the unexcavated portion of the main cutter disc is provided at four corners of the front face having the substantially rectangular shape, and the face of the auxiliary cutter disc is provided. 2. The rectangular shield machine according to claim 1, wherein is made substantially parallel to the surface of the main cutter disk. 3. The cylinder having a substantially rectangular cross section is formed by detachably connecting the cylinder elements having a rectangular cross section arranged for each main cutter disk to each other. Rectangular shield machine. 4. The rectangular shield machine according to claim 1, wherein the cutter drum is configured to be swingably driven so as to be able to advance and retreat outward from a tangent line of the main cutter disk. 5. The rectangular shield machine according to claim 2, wherein the auxiliary cutter disk is configured to be swingable so as to be movable in a substantially tangential direction of the main cutter disk. 6. A body element having the substantially rectangular cross section is configured to be capable of being center-folded from a front body and a rear body connected by center-folding pins, and the rear bodies are detachably fixedly connected to each other. 4. The rectangular shield machine according to claim 3, wherein each of the front barrels is configured to be swingably driven around the center bending pin. 7. An excavator element is formed from each of the main cutter discs and a trunk element behind the main cutter discs, and each excavator element is provided in each of four orthogonal tangential directions of the main cutter disc. The rectangular shield machine according to claim 1, wherein the cutter drum is arranged so that the cutter drum can be arranged.