JPH0711877A - Rectangular shield excavator - Google Patents

Abstract

PURPOSE:To excavate a tunnel having a square-shaped cross section. CONSTITUTION:A rotary partition wall 3 is borne rotatably to a fixed partition wall 12 fixed inside a skin plate 1 having a square-shaped cross section and a bearing plate 2. A shaft 15 is fitted rotatably at a position eccentric to the center of the rotary partition wall 3. A cutter head 20 is fixed at one end of the front ends of the shaft 15. A fixed parting plate 16 is fastened inside the skin plate 1 between the cutter head 20 and the rotary partition wall 3. A circular soil discharge opening 17 centering around the center of the fixed parting plate 16 is installed. An external tooth gear 31 is fixed at the other end of the shaft 15, and the external tooth gear 31 is engaged with an internal tooth gear 32. The shaft 15 and the cutter head 20 are planetary-moved by the revolution of the rotary partition wall 3, and an excavating section constituting the equilateral triangle of the cutter head 20 can excavate a tunnel having a square-shaped cross section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectangular shield excavator for excavating a horizontal hole having a square cross section.

[0002]

2. Description of the Related Art Conventionally, there is the following shield excavator (Japanese Patent Laid-Open No. 63-247497). In this shield excavator, a funnel-shaped hood is fixed to the front end of a cylindrical skin plate, and a partition wall is fixed to the skin plate so as to be located behind the hood, and a space between the rear end of the hood and the partition wall is fixed. The chamber is formed in the. A rotary shaft is rotatably fitted in the center of the partition wall, and a cutter head is fixed to the tip of the rotary shaft. This cutter head consists of a cone fixed to the tip of the rotating shaft and an excavation part such as a cutter arm fixed to the tip of this cone.
A crushing chamber is formed between the cone and the hood. Then, mud water is supplied to this crushing chamber by a mud pipe, the ground is excavated by the excavation section, the excavated gravel is crushed in the crushing chamber, and the crushed gravel, earth and sand, etc. are guided from the crushing chamber to the chamber, Further, the sludge pipe communicating with the chamber is used to discharge the gas to the outside.

[0003]

By the way, recently, when excavating a lateral hole for a conduit having a square cross section, there is a demand for excavating a lateral hole having a square cross section according to the shape of the conduit. is there.

However, in the conventional shield excavator, the rotary shaft is arranged at the center of the partition wall fixed to the cylindrical skin plate, that is, the center of the cylindrical skin plate, and the cutter head fixed to this rotary shaft is rotated. Since the excavation is performed, the excavated lateral hole is necessarily circular, and there is a problem that the lateral hole having a square cross section cannot be excavated.

Therefore, an object of the present invention is to provide a rectangular shield excavator capable of excavating a horizontal hole having a square cross section.

[0006]

In order to achieve the above object, a rectangular shield excavator according to the invention of claim 1 is provided with a skin plate having a substantially square cross section and is arranged inside the skin plate. A fixed partition wall having a circular hole centered on the center, a circular rotary partition wall fitted in the circular hole and rotatably supported by the fixed partition wall, and a position eccentric to the center of the rotary partition wall. A rotary shaft that is rotatably supported, a cutter head that is fixed to the tip of the rotary shaft, and has an excavation portion that forms a substantially equilateral triangle, and the cutter head that is disposed between the rotary partition wall and the cutter head. And a fixed partition plate which forms an earth pressure chamber between the front surface and a chamber between the rotary partition wall and the rear surface, and the fixed partition plate, which is provided on the fixed partition plate and excavates from the earth pressure chamber to the chamber. Passed through A soil discharge port, an external gear fixed to the other end of the rotary shaft, fixed to the skin plate so that its center coincides with the center of the skin plate, and the diameter of the pitch circle is the external teeth. An inner toothed gear having a diameter of a pitch circle of 4/3 times and meshing with the outer toothed gear; a drive device for revolving the rotating shaft about the center of the skin plate; A rectangular shield excavator, comprising a mud pipe for feeding mud from the outside and a drain pipe for discharging the excavated material and mud in the chamber to the outside.

A rectangular shield excavator according to a second aspect of the present invention is the rectangular shield excavator according to the first aspect, further comprising a sludge injection pipe for injecting a sludge from the outside into the earth pressure chamber. It has a feature.

A rectangular shield excavator according to a third aspect of the present invention is characterized in that, in the rectangular shield excavator according to the first or second aspect, a stirring blade is fixed to a back surface of the cutter head.

[0009]

In the rectangular shield excavator according to claim 1, when the drive device is driven, the rotating shaft supported at a position eccentric with respect to the center of the skin plate of the rotary partition revolves around the center of the skin plate. Then, the rotary partition wall rotatably supported by the fixed partition wall rotates. Therefore, the external gear fixed to the other end of the rotary shaft meshes with the internal gear, and revolves while revolving. Therefore, the rotating shaft also rotates while revolving around the center of the skin plate.
That is, the rotating shaft performs a planetary motion that revolves around its axis while being rotated while being eccentrically supported by the skin plate through the rotating rotating partition wall.
Then, the excavating portion which constitutes the substantially equilateral triangle of the cutter head fixed to the tip of the rotating shaft excavates earth and sand and gravel. At this time, in the excavated portion of the cutter head, the diameter of the pitch circle of the external gear and the diameter of the pitch circle of the internal gear are 3
Since the ratio is 4: 4, the rotating shaft makes a planetary motion, and the envelope of the locus of this excavation portion becomes substantially square. Therefore, in combination with the fact that the skin plate has a substantially square cross section, a substantially square lateral hole can be excavated. Further, the earth and sand excavated by the cutter head is accumulated in the earth pressure chamber between the cutter head and the rotary partition wall, and the earth and sand and the gravel accumulated in the earth pressure chamber are discharged from the fixed partition plate. Pass through the mouth and enter the chamber. The sediment and gravel in this chamber are agitated with the muddy water sent from the mud pipe. Then, the muddy water containing the stirred earth and sand and gravel is discharged to the outside from the mud discharge pipe.

Further, since the rotating shaft revolves by a drive device, whereby the external gear and the internal gear mesh with the internal gear to make a planetary motion, so that this rectangular shield excavator uses, for example, a crank mechanism. The structure can be simplified and the length of the machine can be shortened compared to the one. Further, since the length of this rectangular shield excavator is shortened, the angle at which the excavation portion advances can be changed to a larger angle than before, and it becomes easier to implement a curve.

Further, the sand face and the gravel accumulated in the earth pressure chamber between the upper fixed partition plate and the cutter head press the face of the ground faced by the cutter head so that the face face of the ground does not collapse. it can.

Since the rotary shaft is in a planetary motion, it is generally considered difficult to partition the inside of the skin plate into the cutter head side and the drive unit side at this location. However, in the present invention, since the rotary shaft is rotatably supported at an eccentric position of the rotary partition wall, and the rotary partition wall is rotatably supported by the fixed partition wall, while allowing the planetary motion of the rotary shaft, The chamber side and the drive device side in the skin plate can be tightly partitioned.

The rectangular shield excavator according to claim 2 is
The rectangular shield excavator according to claim 1, further comprising a sludge injection pipe for injecting a sludge from the outside into the earth pressure chamber,
The mud additive is injected from the mud additive injection pipe into the earth pressure chamber where soil and gravel, which is the object of excavation, has accumulated. Then, the earth and sand and the gravel in the earth pressure chamber are stirred together with the mud additive.

Therefore, since the earth and sand and the gravel are mixed with the mud additive in the earth pressure chamber to be in a plastic flow state, the earth and sand and gravel in the plastic flow state support the face of the ground faced by the cutter head, It is possible to prevent the face part of the ground from collapsing.
Moreover, a film containing a mudifying agent can be formed on the surface of the ground face to prevent the face part of the ground from collapsing due to this film.

According to the rectangular shield excavator of claim 3, in the rectangular shield excavator of claim 1 or 2, the stirring blade is fixed to the back surface of the cutter head. The stirring blade on the back surface of the cutter head makes one rotation in the opposite rotation direction while the rotary partition wall makes three rotations.

Therefore, the sand and gravel in the earth pressure chamber can be efficiently stirred.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rectangular shield excavator according to the present invention will be described in detail below with reference to an embodiment.

FIG. 1 is a sectional view of a rectangular shield excavator according to an embodiment of the present invention, in which 1 is a skin plate having a substantially square cross section, and 2 is a support plate fixed inside the skin plate 1. Reference numeral 3 denotes a rotary partition wall rotatably supported by the fixed partition wall 12 and the support plate 2 via a bearing 11 with the center of the skin plate 1 as the center of rotation.
The first cylindrical portion 5 is fixed at a position eccentric with respect to the center of the skin plate 1 of the rotary partition wall 3, and the rotary shaft 1 is provided inside thereof.
5 is inserted and is rotatably supported via a bush (not shown). A cutter head 20 is fixed to one front end of the rotary shaft 15. Then, the fixed partition plate 16 is fixed inside the skin plate 1 between the rotary partition wall 3 and the cutter head 20, and the rotary shaft 1 is fixed to the fixed partition plate 16.
A circular earth discharge port 17 through which 5 passes is formed. An earth pressure chamber 45 is formed between the front surface of the fixed partition plate 16 and the cutter head 20, and a chamber 46 is formed between the rear surface of the fixed partition plate 16 and the rotary partition wall 3. on the other hand,
At the other end of the rotary shaft 15 on the support plate 2 side, an external gear 31
Is fixed. The external gear 31 meshes with an internal gear 32 fixed to the inner periphery of the skin plate 1, and the external gear 31 and the internal gear 32 constitute an eccentric ring gear device 30.

The rotary partition wall 3 has a disc portion 4, the first cylindrical portion 5 fixed to the disc portion 4, and a second cylindrical portion extending from the outer periphery of the disc portion 4 to the support plate 2 side. 4a, and a third cylindrical portion 4b extending from the second cylindrical portion 4a to the support plate 2 side and having an inner circumference having the same diameter as the inner circumference of the second cylindrical portion 4a and an outer circumference smaller than the second cylindrical portion 4a. ing. A bearing 11 is arranged between the step portion of the second cylindrical portion 4a and the third cylindrical portion 4b and the fixed partition wall 12 and the support plate 2, and the bearing 11
The rotary partition wall 3 is rotatably supported by the fixed partition wall 12 and the support plate 2 via the. By the bearing 11,
Both the radial load and the thrust load acting on the rotary partition wall 3 can be supported. Further, as shown in FIG. 4, on the wall surface of the rotary partition wall 3 which faces the front of the disk portion 4, three first stirring blades are radially arranged at every 90 degrees of the rotation angle of the rotary partition wall 3. 7 and functions to stir gravel, earth and sand, etc. in the chamber 46 between the rotary partition wall 3 and the fixed partition plate 17. The third cylindrical portion 4b passes through the inner periphery of the support plate 2, and the outer tooth gear 6 shown in FIG. 5 is formed on the outer periphery of the third cylindrical portion 4b on the eccentric ring gear device 30 side. The third cylindrical portion 4b, that is, the rotary partition wall 3 is rotated by an electric motor 42 as a drive device via a drive gear 41 that meshes with the external gear 6.

The cutter head 20 is shown in FIGS.
As shown in FIG. 4, a cylindrical portion 26 fixed to the tip of the rotary shaft 15, three cutter arms 21 fixed to the cylindrical portion 26 at equal intervals in the circumferential direction and extending in the radial direction, and the cutter arm 21. It is composed of a cutter ring 22 having a small curvature that connects substantially the distal end portions of 21. The second stirring blade 2 shown in FIG. 1 is provided on the back surface of the cutter arm 21.
3 is fixed. On the front surface of the cutter arm 21,
One or two cutter teeth 24 are respectively arranged at different positions in the radial direction, while one outer peripheral bit 25 is arranged at the center of the front surface of the cutter ring 22. The apex A of each cutter arm 21 is located substantially outside the skin plate 1 having a substantially square cross section, and the apex A of the cutter arm 21 is connected to form an equilateral triangle.

Further, as shown in FIGS. 1 and 3, the fixed partition plate 16 is provided with a circular earth discharge port 17 at a position centered on the center of the skin plate 1. Then, by the revolution of the rotary shaft 15 penetrating the soil discharge port 17 to be described later, the soil discharge is performed so that the outer peripheral surface of the cylindrical portion 26 fixed to the rotary shaft 15 does not contact the inner peripheral surface of the soil discharge port 17. The diameter of the mouth 17 is set. It should be noted that the shape of the soil discharge port 17 does not have to be circular. Further, the cylindrical portion 26 is not provided at a position where the rotary shaft 15 penetrates the soil discharge port 17, so that the soil discharge port 1
7 may be further reduced.

On the other hand, in the eccentric ring gear device 30, the radius of the pitch circle of the internal gear 32 and the external gear 31 shown in FIG.
The ratio of the radii of the pitch circles is 4 to 3. The center of the internal gear 32 is located at the center of the skin plate 1. For example, the radius R1 of the pitch circle of the internal gear 32 is
4. If the radius R2 of the pitch circle of the external gear 31 is R2 = 3,
The rotary shaft 15 and the external gear 31 are the skin plate 1
This means that the center is eccentric by an eccentric amount e = 1.
Further, this eccentricity e = 1, radius R1 = 4, radius R2 = 3
At this time, as shown in FIG. 2, the length S of one side of the skin plate 1 is set to S = 14, and the length S of one side of an equilateral triangle connecting the apex A of the cutter arm is set to S = 14. The electric motor 42 drives the external gear 6 and the drive gear 41 of the third cylindrical portion 4b.
When the rotary partition wall 3 is rotated via the, the external gear 31 of the eccentric ring gear device 30 meshes with the internal gear 32,
The external gear 31 can revolve while rotating around the inner circumference of the internal gear 32.

In FIGS. 1 and 4, 51 is a direction correction jack for correcting the excavation direction of the rectangular shield excavator, and 52 is the internal gear 32 and the fixed partition wall 12.
3 and the opening 52 shown in FIG. 3 provided in a wide area near the corner of the skin plate 1 of the fixed partition plate 16.
Through a, a mud additive injection pipe for injecting bentonite as a mud additive into the earth pressure chamber 45, 53 is the fixed partition wall 1
No. 2 of the skin plate 1 through the opening 53a provided in a wide area near one corner of the lower side of the skin plate 1, a mud pipe for guiding the muddy water into the chamber 46, and 54 is the bottom side of the skin plate 1 of the fixed partition wall 12. It is a mud pipe for discharging the earth and sand and the gravel as the object to be excavated in the chamber 46 to the outside through an opening 54a provided in a wide area near the other corner portion.

The rectangular shield excavator having the above structure operates as follows. First, this rectangular shield excavator is propelled forward through a buried pipe by a jack (not shown) provided at the bottom of the vertical hole.

While propelling the rectangular shield excavator forward, the external gear 6 of the third cylindrical portion 4b is driven by the electric motor 42.
When the rotary partition wall 3 is rotated via the drive gear 41 and
A rotary shaft 15 rotatably supported at a position eccentric to the rotary partition wall 3 rotates around the center of the skin plate 1. Therefore, the external gear 31 fixed to one end of the rotary shaft 15 is
Rotates in mesh with the internal gear 32 and makes one rotation while the rotary partition wall 3 makes three revolutions, and makes three revolutions in the opposite direction to the rotation while rotating. By the planetary motion of the external gear 31, the rotary shaft 15 and the cutter head 20 also perform one rotation while the rotary partition wall 3 makes three revolutions, and the revolution in the opposite direction three times to perform the planetary motion.

On the other hand, the radius R1 of the pitch circle of the internal gear 32 of the eccentric ring gear device 30 is R1 = 4, the radius of the pitch circle of the external gear 31 is R2 = 3, the eccentricity e of the rotary partition wall 3 is 1, and the cutter arm 21. Length of one side of an equilateral triangle connecting the vertices A of
14, and since the length S of one side of the skin plate 1 is 14, the locus of the tip A of the cutter arm 21 of the cutter head 20 is as shown in FIG.
It will be a substantially square that fits the outer shape of. Therefore, the excavating portion such as the cutter arm 21 excavates a substantially square lateral hole conforming to the outer shape of the skin plate 1.

Then, the excavated earth and sand and gravel are transferred to the earth pressure chamber 45.
The bentonite is collected in the soil pressure chamber 45, and bentonite is injected into the earth pressure chamber 45 through the opening 52a. Then, the earth and sand and the gravel in the earth pressure chamber 45 are agitated by the second agitating blade 23 of the cutter head 20 to be in a plastic flow state. The earth and sand and the gravel in the plastic flow state enter the chamber 46 from the earth pressure chamber 45 through the earth discharge port 17 of the fixed partition plate 16. Then, the earth and sand and the gravel in the chamber 46 are stirred by the first stirring blade 7 of the rotary partition wall 3 together with the muddy water guided from the opening 53 a of the mud feeding pipe 53, and the opening 54
It is discharged from a through the sludge pipe 54 to the outside.

As described above, since the tip of the cutter arm 21 of the cutter head 20 excavates the ground in front while drawing a locus of a substantially square shape, the outer shape of the skin plate 1 is combined with a substantially square shape. It is possible to drill a substantially square lateral hole.

Further, since the electric motor 42 rotates the rotary partition wall 3 via the external gear 6 of the third cylindrical portion 4b and the drive gear 41, the external gear 31 is planetary-moved, for example, of a crank mechanism. Such a long transmission mechanism is not necessary. Therefore, the structure of this rectangular shield excavator can be simplified and the machine length can be shortened. Further, by shortening the length of this rectangular shield excavator, the angle at which the excavation section advances by the direction correcting jack 51 can be greatly changed, and the curve of the lateral hole can be easily implemented.

The earth and sand and gravel in the earth pressure chamber 45 between the fixed partition plate 16 and the cutter head 20 are fixed to the fixed partition plate 1.
A part of the material moves sequentially into the chamber 46 through the soil discharge port 17 of No. 6, but the earth pressure chamber 45 is always in a state where a sufficient amount of earth and sand or gravel is filled therein. Therefore,
The earth and sand and the gravel in the earth pressure chamber 45 can press the surface of the face of the ground facing the cutter head 20 so that the face of the ground does not collapse. Further, the bentonite in the earth pressure chamber 45 and the agitated earth and sand or gravel are in a plastic flow state, and the entire surface pressure can press the face surface of the ground. On the other hand, a film containing bentonite can be formed on the surface of the ground face to prevent the face part of the ground from collapsing.

Further, since the second stirring blade 23 of the cutter head 20 makes one revolution while the rotary partition wall 3 makes three revolutions,
The earth and sand and gravel in the earth pressure chamber 45 can be efficiently stirred. Further, the first stirring blade 7 of the rotary partition wall 3 moves in the reverse rotation direction while the cutter head 20 makes one rotation.
Since it rotates, the earth and sand and gravel in the chamber 46 can be efficiently stirred with muddy water.

Further, when excavating the ground, a large bending moment acting on the rotating shaft 15 which makes a planetary motion is supported by the rotating partition wall 3 which rotates while supporting the rotating shaft 15 at an eccentric position in a freely rotatable manner. From this rotating shaft 1
5 can rotate smoothly without bending.

Further, since the rotary shaft 15 is rotatably supported at an eccentric position of the rotary partition wall 3, and the rotary partition wall 3 is rotatably supported by the fixed partition wall 12, the planetary motion of the rotary shaft 15 is performed. While allowing, the cutter head 20 side and the eccentric ring gear device 30 side in the skin plate 1 can be tightly partitioned. Therefore, it is possible to prevent dirt and sand and gravel that are mixed with muddy water in the chamber 46 from entering the eccentric ring gear device 30 side in the skin plate 1.

In the above-described embodiment, the rotary partition wall 3 is rotated by the electric motor 42 via the external gear 6 of the third cylindrical portion 4b and the drive gear 41. However, the rotary partition wall is rotated by a drive device such as an electric motor. Of course, the transmission mechanism for transmitting force is not limited to this. The drive device does not necessarily drive the rotary partition wall, and the crankshaft may directly drive the rotary shaft.

In the above embodiment, the eccentricity e of the rotary partition wall 3 is 1, and the radius R1 of the pitch circle of the internal gear 32 is R1.
4, the radius R2 of the pitch circle of the external gear 31 was set to R2 = 3, and the length S of one side of an equilateral triangle connecting the apex A of the cutter arm 21 was set to S = 14. By changing the ratio with respect to e, it is possible to excavate a lateral hole having a substantially square cross-section with one side curved inward or outward and slightly deformed.

Although bentonite was used as the mudizing agent in the above-mentioned examples, the mudifying agent is not limited to this, and it is a film that prevents the collapse of the face surface of the ground while making the sand and gravel into a plastic flow state. Any mudifying agent that forms Further, depending on the nature of the ground, a mud additive is not required, and in that case, the mud additive may not be injected or the mud injection pipe may not be provided.

[0037]

As is apparent from the above, the rectangular shield excavator according to the first aspect of the invention has the fixed partition wall having a circular hole centered on the center of the skin plate disposed inside the skin plate having a substantially square cross section. Then, a circular rotary partition wall is fitted into the circular hole of the fixed partition wall to rotatably support the rotary partition wall on the fixed partition wall, and the rotary shaft is rotatable at a position eccentric to the center of the rotary partition wall. The cutter head having an excavation portion forming a substantially equilateral triangle is fixed to the tip of the rotary shaft, and a fixed partition plate is arranged inside the skin plate between the rotary partition wall and the cutter head. An earth pressure chamber is formed between the head and the front surface of the fixed partition plate, a chamber is formed between the rotary partition wall and the rear surface of the fixed partition plate, and the earth pressure chamber is excavated from the earth pressure chamber to the chamber on the fixed partition plate. Let things pass A mouth is provided, an external gear is fixed to the other end of the rotary shaft, an internal gear having a pitch circle diameter of 4/3 times the pitch circle diameter of the external gear is meshed with the external gear, The internal gear is fixed to the skin plate so that the center thereof coincides with the skin plate, the rotary shaft is revolved with respect to the center of the skin plate by a driving device, and muddy water is fed from the mud pipe into the chamber, The excavated material and muddy water in the chamber are discharged to the outside from the mud discharge pipe.

Therefore, according to the rectangular shield excavator of the first aspect of the invention, when the rotating shaft is revolved by the drive device, the rotary partition wall rotatably supported by the fixed partition wall rotates. The rotation of the rotary partition wall causes the external gear to rotate while meshing with the internal gear, and causes the rotor to revolve in the opposite direction, so that the rotating shaft fixed to the external gear and the cutter head revolve. Therefore, the excavation portion forming the approximately equilateral triangle of the cutter head makes a planetary motion, and the locus of the excavation portion of the approximately equilateral triangle becomes approximately square, so that the skin plate has an approximately square cross-section. It is possible to drill a substantially square lateral hole.

The drive device revolves the rotary shaft,
Since a long transmission mechanism that drives an external gear using a crankshaft or the like is not necessary, the structure of this rectangular shield excavator can be simplified and the machine length can be shortened. Also,
When the length of this rectangular shield excavator is shortened, the angle of advance of the excavation portion can be changed more greatly, and it becomes easier to implement the curve of the lateral hole.

Further, part of the earth and sand and gravel in the earth pressure chamber between the fixed partition plate and the cutter head move into the chamber in order from the earth discharge port provided in the fixed partition plate, and in the earth pressure chamber. The amount of earth and sand and gravel that almost fills the inside is always accumulated. Therefore, it is possible to prevent the cutting face of the ground from collapsing by pressing the cutting face of the ground facing the cutter head with the sand and gravel filled in the earth pressure chamber.

Further, at the time of excavation, a large bending moment acting on the rotating shaft that is in planetary motion is supported by the rotating partition wall, so that this rotating shaft can rotate smoothly without bending.

Further, since the rotary shaft is rotatably supported at an eccentric position of the rotary partition wall and the rotary partition wall is rotatably supported by the fixed partition wall, while permitting the planetary motion of the rotary shaft, The cutter head side and the drive device side in the skin plate can be tightly partitioned.

A rectangular shield excavator according to a second aspect of the present invention is the rectangular shield excavator according to the first aspect, further comprising a sludge injection pipe for injecting a sludge from the outside into the earth pressure chamber. is there.

Therefore, according to the rectangular shield excavator of the second aspect of the present invention, since the earth and sand and the gravel are mixed with the mud additive in the earth pressure chamber to be in a plastic fluidized state, the sand and gravel in the plastic fluidized state are brought into a state. It is possible to support the pressure due to the cutter head substantially evenly on the surface of the face of the ground facing the cutter head, and to prevent the face of the ground from collapsing. Furthermore, a film containing a mud additive is formed on the surface of the face of this ground, and this film also prevents the face of the ground from collapsing into the earth pressure chamber.

A rectangular shield excavator according to a third aspect of the present invention is the rectangular shield excavator according to the first or second aspect, in which a stirring blade is fixed to the back surface of the cutter head.

Therefore, according to the rectangular shield excavator of the third aspect of the present invention, the stirring blade on the back surface of the cutter head makes one rotation in the opposite rotation direction while the rotary partition wall makes three rotations. The sand and gravel in the pressure chamber can be stirred efficiently.

[Brief description of drawings]

FIG. 1 is a sectional view of a rectangular shield excavator according to an embodiment of the present invention.

FIG. 2 is a view seen from a line II-II in FIG.

FIG. 3 is a view seen from a line III-III in FIG. 1.

FIG. 4 is a view seen from line IV-IV in FIG. 1.

5 is a view seen from the line VV in FIG. 1. FIG.

6 is a view as seen from the line VI-VI in FIG. 1.

FIG. 7 is an explanatory view showing excavation of a square lateral hole by the excavation portion forming an equilateral triangle performing a planetary motion.

[Explanation of symbols]

1 ... Skin plate, 2 ... Support plate, 3 ... Rotating partition wall, 4 ...
Disc portion, 4a ... Second cylindrical portion, 4b ... Third cylindrical portion, 5 ... First cylindrical portion, 6 ... External gear, 7 ... First stirring blade, 11 ... Bearing, 12 ... Fixed partition wall, 15 ... Rotation Shaft, 16 ... Fixed partition plate, 17 ... Soil discharge port, 20 ... Cutter head, 21 ... Cutter arm, 22 ... Cutter ring, 23 ... Second stirring blade, 30 ... Eccentric ring gear device, 31 ... External gear, 32
... internal gear, 41 ... drive gear, 42 ... electric motor, 51 ... direction correction jack, 52 ... mud additive injection pipe, 53 ... mud feed pipe,
54 ... Mud pipe.

Claims (3)

[Claims] 1. A skin plate having a substantially square cross section, a fixed partition wall disposed inside the skin plate and having a circular hole centered on the center of the skin plate, and fitted into the circular hole, A circular rotary partition wall rotatably supported by a fixed partition wall, a rotary shaft rotatably supported at a position eccentric to the center of the rotary partition wall, and a rotary shaft fixed to the tip of the rotary shaft to form a substantially equilateral triangle. A cutter head having an excavating portion to be configured, and arranged between the rotary partition wall and the cutter head to form an earth pressure chamber between the cutter head and the front surface, and a chamber between the rotary partition wall and the rear surface. A fixed partition plate formed with, a soil discharge port provided on the fixed partition plate for passing the material to be excavated from the earth pressure chamber to the chamber, and an external gear fixed to the other end of the rotary shaft, Centered above The inner diameter of the pitch circle is 4/3 times the diameter of the pitch circle of the external gear, and is fixed to the skin plate so as to match the center of the outer gear. A tooth gear, a drive device for revolving the rotary shaft with respect to the center of the skin plate, a mud pipe for feeding mud from the outside into the chamber, and discharge of excavated material and mud in the chamber to the outside. A rectangular shield excavator, which is provided with a sludge discharge pipe. 2. The rectangular shield excavator according to claim 1, further comprising a sludge injection pipe for injecting a sludge from the outside into the earth pressure chamber. 3. The rectangular shield excavator according to claim 1, wherein a stirring blade is fixed to the back surface of the cutter head.