JP2000104486A - Shield boring machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately cut an underground obstruction by supporting a cutter head with a bulkhead of a skin plate, and integrally providing a ring body with the periphery of the bulkhead so as to be fitted in an opening of the plate. SOLUTION: An advancing jack 6 is extended so as to bond a bracket piece 5b to a connecting piece 5a, and they are connected to each other for fixation so as to unify a skin plate 1 and a bulkhead 2. A broken type fixed bolt 17 for connecting opposite projecting pieces 18, 19 of a front and a rear barrel parts 1a, 1b of the skin plate 1 is removed. The front and the rear barrel parts 1a, 1b are formed so that they can be bent, and obstruction cutting bits 11, 11' arranged in inclining arms 3a of a cutter head are put into the barrels 1a, 1b. Continuously, a tip is moved backward than a tip of a ground excavating bit 10' so as to excavate the ground, and a tunnel is constructed. With this structure, the only cutter head is moved forward with the bulkhead 2 so as to cut the obstruction for elimination, and the cutter head is smoothly rotated so as to prevent the generation of breakdown and damage of the cutting bits 11. 11'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator capable of excavating while excavating an underground obstacle such as a retaining wall such as a sheet pile or a pile existing on the way of excavation.

[0002]

2. Description of the Related Art When an obstacle such as a foundation pile is reached while a tunnel is being excavated by a shield excavator, the obstacle cannot be cut or removed with a drill bit protruding from a cutter plate. After stopping the operation, digging a shaft from the ground to remove obstacles and removing workers by hand from the inside of the aircraft to the face side are performed, but in the former method to excavate the shaft from the ground In addition to adversely affecting the surrounding environment and traffic, as well as buried pipes, if the obstacle is a foundation pile for a structure, excavation of a horizontal shaft from the vertical shaft to the foundation pile is required, and a long construction period is required. And the cost increases. On the other hand, the latter method requires auxiliary methods for ground stability such as ground freezing method and jet grout method so that safe work on the face is possible. There is a problem in that the use of fire for cutting piles is extremely dangerous work, and furthermore, the working environment at the face is poor and the efficiency is reduced.

For this reason, the applicant of the present invention has disclosed in
As described in Japanese Patent No. 8778, a partition is integrally provided at the front end of the opening of the skin plate, and an arm on which a ground excavation bit is protruded and an obstacle cutting bit are protrudingly provided on the partition. We have developed a shield excavator in which a cutter head, which is provided with alternately radiating arms, is rotatably supported.

According to this shield excavator, when excavating the ground, the shield excavator is propelled while rotating the cutter head with the obstacle cutting bit immersed in the arm, so that the ground is excavated with the excavation bit. On the other hand, when the shield excavator reaches the underground obstacle while excavating, the obstacle cutting bit is made to protrude forward from the ground excavation bit from the arm provided with the obstacle cutting bit, and the cutter head is set in this state. By rotating the shield excavator while rotating the drill, the underground obstacle can be cut by the cutting bit.

[0005]

However, according to the above-mentioned shield excavator, a plurality of partition walls which rotatably support the cutter head are integrally fixed to the skin plate and mounted on the inner peripheral surface of the skin plate. By operating the propulsion jack, the skin plate is configured to be propelled integrally with the partition supporting the cutter head.For example, when cutting underground obstacles existing in soft ground or sand layers, When the support of the skin plate becomes unstable and the entire skin plate is propelled by the propulsion jack, the skin plate swings back and forth, left and right, or moves discontinuously with respect to the propulsion direction. Is transmitted to the cutter head as it is, not only is it not possible to cut underground obstacles smoothly and efficiently, but also Parts there was a shocking fear of or damaged deficient abuts pressed into.

Further, since the whole shield excavator, that is, the underground obstacle is cut while the skin plate and the cutter head on which various equipments are arranged are integrally propelled, In addition to the need for propulsion, the skin plate has its outer peripheral surface in sliding contact with the tunnel excavation ground, so that it is difficult to finely adjust the cutting speed by the cutting bit via the skin plate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and makes it possible to independently propel a cutter head when cutting an underground obstacle so that an obstacle cutting bit provided on the cutter head can be provided. An object of the present invention is to provide a shield excavator capable of smoothly and accurately cutting an underground obstacle without causing unstable movement such as run-out.

[0008]

That is, claim 1 of the present invention.
The shield excavator according to the present invention, a cutter head comprising a plurality of ground excavation bits and a plurality of obstacle cutting bits capable of appearing and retracting with respect to the ground excavation bit is provided on the partition wall at the opening front end of the skin plate. It is rotatably supported, and a ring body is provided integrally on the outer periphery of this partition wall. This ring body is fitted inside the front end of the skin plate so as to be slidable back and forth, and the skin plate and the ring body are detachably fixed. A lock mechanism is provided, and a propulsion mechanism for a partition is provided on the inner peripheral surface of the skin plate on the rear side of the lock means.

In the shield excavator constructed as described above, the invention according to claim 2 is a structure of a lock means for detachably fixing the skin plate and the partition wall,
The locking means for detachably fixing the skin plate and the partition is fixed to a connection piece protruding from the inner peripheral surface of the skin plate and a propulsion mechanism connected to the rear end of the ring body of the partition on the front side of the connection piece. It is characterized in that it comprises a bracket piece that is connected and a bolt that removably connects the connection piece and the bracket piece.

[0010] Further, the invention according to claim 3 is the shield excavator according to claim 1 or 2, wherein the skin plate is formed by a front body and a rear body connected to bendable with each other, While the locking means is provided on the front body part side, a plurality of middle bending jacks are arranged at regular intervals in the circumferential direction between the inner circumferential surfaces of the connecting parts of the front and rear body parts, and the partition wall is propelled by these middle bending jacks. It is characterized by constituting a mechanism.

According to a fourth aspect of the present invention, in the shield excavator according to the third aspect, a protruding piece is fixed to an inner peripheral surface of the front trunk portion and the rear trunk portion connected to bend freely. It is characterized in that the protruding pieces are removably connected to each other by a center bending fixing bolt.

[0012]

[Operation] When excavating the ground on the planned tunnel line with a shield excavator, the obstacle cutting bit is immersed backward from the ground excavation bit, and the shield excavator is rotated while rotating the cutter head in this state. The tunnel is constructed while excavating the ground with a drill bit by propelling. When hitting an obstacle such as a sheet pile or a pile during the excavation, the shield excavator is temporarily stopped, and the locking means between the outer peripheral ring body of the bulkhead supporting the cutter head and the skin plate is released to isolate the skin. Cut off by cutting the obstruction cutting bit forward from the ground excavation bit while separating from the plate, turning the cutter head while propelling the partition wall forward along the inner peripheral surface of the front end of the skin plate by the propulsion mechanism in this state The bit is used to cut and remove obstacles.

If the obstacle cannot be completely removed by a single propulsion length of the cutter head by the propulsion mechanism because the diameter or thickness of the obstacle is large, the skin plate is advanced by a predetermined length by the propulsion jack, and then again. By moving the partition supporting the cutter head by the propulsion mechanism along the inner peripheral surface of the skin plate and rotating the cutter head, the cutting excavator cuts and removes obstacles with the cutting bit and the shield excavator removes obstacles. A circular hole that can pass through is formed.

Thus, when a circular hole through which the shield excavator can pass is formed in the obstacle, the outer peripheral ring body of the partition wall is connected and fixed to the skin plate via the lock means, and the obstacle cutting bit is retracted to thereby remove the ground. The tunnel is excavated in the ground by immersing the drill bit backward and propelling the shield excavator while rotating the cutter head. In addition, excavated earth and sand and cut pieces of obstacles,
It is taken into the machine through the space behind the cutter head and discharged through the tunnel.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, a specific embodiment of the present invention will now be described. In FIG. 1, a shield excavator includes a skin plate 1 and a skin plate 1 provided at an opening front end of the skin plate 1. , A cutter head 3 rotatably supported by the partition 2, a propulsion mechanism 4 for propelling the partition 2, a skin plate 1 and a partition 2 And a locking means 5 for detachably connecting and fixing the propulsion jack and a plurality of propulsion jacks 6 on the inner peripheral surface of the skin plate 1 and for discharging the excavated earth and sand. 7 and an erector 8 for assembling the segment S on the tunnel excavation wall surface.

As shown in FIG. 2, the cutter head 3 has a center shaft 9 disposed in the center thereof and a circular outer peripheral frame having substantially the same diameter as the skin plate 1 on the outer peripheral side.
3b, a fixed width in which the front end of the center shaft 9 protrudes forward from the outer peripheral frame 3b and the front end and the outer peripheral frame 3b are radially arranged radially obliquely rearward with the center shaft 9 as a center. Are integrally connected by a plurality of oblique arms 3a each having a front rectangular shape having a front and rear side, and a sediment intake opening 3c is provided between adjacent inclined arms 3a, 3a, The end is rotatably inserted into and supported by the center of the partition 2 so as to rotate in front of the open end of the skin plate 1.

The plurality of inclined arms 3a are disposed at equal intervals in the circumferential direction, and the inner and outer ends thereof are fixedly fixed to the front end of the center shaft 9 and the outer peripheral frame 3b, respectively. The arm 3a is formed in a hollow rectangular cross section as shown in FIG. 3, and is fixed to the long edge of both sides of the front end face thereof with the ground excavation bits 10 projecting forward at small intervals in the length direction. ing. In addition, a long hole 12 communicating with the hollow inside is formed in the center of the front end face of each inclined arm 3a between the inner and outer ends, and a plurality of obstacle cutting bits 11 protrude freely through the long hole 12. Let me.

As means for causing the obstacle cutting bit 11 to protrude and retract through the elongated hole 12, the obstacle cutting bit 11 is attached to the front half of a rectangular rod-shaped mounting member 13 long in the length direction of the inclined arm 3a. A jack 14 having the rear part of the mounting member 13 protruding into the inclined arm 3a through the long hole 12 and being attached to the inner and outer ends of the hollow interior of the inclined arm 3a. , 14 are connected to the rod ends, and the jacks 14, 14 are configured to extend and contract. When the jacks 14 and 14 are extended, the tip of the obstacle cutting bit 11 is
It protrudes forward from the front end of the ground excavation bit 10 and, when contracted, sinks backward from the front end of the ground excavation bit 10.

The plurality of inclined arms 3a, 3a
An inclined arm 3a having an obstacle cutting bit 11 capable of cutting in the direction when the cutter head 3 is rotated to the right, and an obstruction capable of cutting in the direction when the cutter head 3 is rotated to the left. Inclined arm with object cutting bit 11
3a are arranged alternately, and the obstacle cutting bit 11 of the inclined arm 3a that does not perform cutting is configured to be immersed.

Further, the front end of the center shaft 9 is formed in a hollow cylindrical portion 9a having a diameter larger than the shaft diameter, and a pair of mountain-shaped ground excavation bits is formed at the front end of the hollow cylindrical portion 9a.
10 ', 10' are fixed. The hollow cylindrical portion 9a forms a front end portion of the center shaft 9 by integrally fixing the hollow cylindrical portion 9a to the center shaft 9 separately. A jack 15 is mounted in the hollow cylindrical portion 9a, and the jack 15 cuts a mountain-shaped obstacle cutting bit 11 'interposed between the pair of mountain-shaped ground excavation bits 10', 10 '. Ground excavation bit 10 '
From the haunting.

The center shaft 9 of the cutter head 3
A ring 2A constituting an outer peripheral portion of the partition 2 is integrally fixed to an outer peripheral end face of the partition 2 rotatably supported. This ring body 2A is formed in a U-shaped cross section formed by integrally fixing a short tubular outer tubular portion 22 and an inner tubular portion 23 to the inner and outer peripheral edges of the annular plate 21 toward the front. The outer peripheral surface of the outer cylindrical portion 22 is fitted inside the inner peripheral surface of the front end opening of the skin plate 1 so as to be slidable back and forth.
Is integrally fixed to the outer peripheral end surface of the partition wall 2.
Bent jack 4A to be described later, which constitutes the propulsion mechanism 4
Are integrally connected, and the partition wall 2 is propelled forward by the extension of the middle fold jack 4A.

On the other hand, the skin plate 1 comprises a front body 1a and a rear body 1b having a front end connected to the rear end of the front body 1a so that the front end can be freely bent. The propulsion mechanism 4 is constituted by a bending jack 4A that controls the direction by refracting 1a vertically and horizontally. Folded jack 4A
As shown in FIG. 4, a plurality of pieces are provided on the inner peripheral surface of the skin plate 1 at regular intervals in the circumferential direction, and the rear end thereof is the inner peripheral surface of the front end of the rear trunk 1b as shown in FIG. And a front end thereof is integrally connected to a rear surface of the annular plate 21 of the ring 2A of the partition wall 2.

Further, a plurality of connecting pieces 5a are fixed to the inner peripheral surface of the front body portion 1a behind the partition wall 2 at small intervals in the circumferential direction so as to correspond to the above-mentioned middle bending jacks 4A. Piece
The bracket piece 5b is fixed to the outer peripheral surface of the front half part of the middle bent jack 4A inserted through the insertion hole 16 and the front half of the middle bent jack 4A inserted through the insertion hole 16 through the insertion hole 16 drilled in 5a. The locking means 5 is constituted by joining the rear surface of the bracket piece 5b to the front surface of the connection piece 5a so as to be detachable and detachably connecting the connection piece 5a and the bracket piece 5b with a removable bolt 5c. I have. Further, projecting pieces 18 and 19 which are detachably connected to each other at a plurality of positions on the inner peripheral surface of the rear end of the front body portion 1a of the skin plate 1 and the inner peripheral surface of the front end of the rear body portion 1b are fixed by fixing bolts 17 at the plural positions. ing.

The cutter head 3 has a plurality of horizontal support members 31 integrally projecting rearward from the outer peripheral portion thereof, and a ring member 32 integrally attached to the rear end surfaces of these horizontal support members 31. Are rotatably supported via bearings on the opposing surfaces of the inner and outer cylindrical portions 22 and 23 of the ring body 2A in the ring body 2A of the partition 2 and an internal gear 33 is integrally fixed to the rear surface of the ring member 32. And a ring body on this internal gear 33
The cutter head 3 is rotated by the drive motor 20 by meshing a gear 20a fixed to the rotation shaft of the drive motor 20 mounted on the rear surface of the 2A annular plate 21.

The space between the cutter head 3 and the partition 2 is formed in a sediment take-in chamber 34, and the screw conveyor 7 as a means for carrying out the sediment has its front opening opened to the lower end of the partition 2. It penetrates and faces the lower end of the earth and sand intake chamber 34. Further, the screw conveyor 7 is supported by the partition 2 via a support rod 35, and is configured to move back and forth with respect to the skin plate 1 integrally with the partition 2. The propulsion jack 6 is a skin plate 1
Are provided on the inner peripheral surface of the front end portion of the rear trunk portion 1b at a predetermined interval in the circumferential direction.

In the shield excavator thus constructed, when excavating the ground, the bracket piece 5b fixed to the front half outer peripheral portion of the center bending jack 4A is fixed to the inner peripheral surface of the front body of the skin plate 1. The skin plate 1 and the partition 2 are integrated into a locked state by being joined to the connecting piece 5a and connected and fixed by bolts 5c, and the opposing projections 18 of the skin plate 1 with the front and rear body portions 1a and 1b. , 19, remove the middle bending fixing bolt 17 and remove the front and rear torso 1a, 1b
Are refractible to each other. Further, all the obstacle cutting bits 11, 11 'disposed on the inclined arm 3a of the cutter head 3 are immersed in the inclined arm 3a, and the tips thereof are retracted from the tips of the ground excavation bits 10, 10'. Keep it.

In this state, the spreader at the rod end of the propulsion jack 6 is brought into contact with the front end surface of the segment S assembled in the tail portion of the rear body 1b of the skin plate 1 so that the segment S supports the reaction force. By extending the propulsion jack 6, the entire shield excavator is propelled, and the drive motor 20 is operated to rotate the cutter head 3, thereby constructing a tunnel while excavating the ground with the ground excavation bits 10, 10. Go. The excavated earth and sand is taken into the intake chamber 34 from the earth and sand intake opening 3c, carried out into the machine by the screw conveyor 7, and discharged through the tunnel by a toro or the like.

Further, when excavating a curved tunnel portion or when it is desired to correct the direction, for example, when turning the shield excavator 1 to the right side, the center bending jack 4A provided on the left side is extended while the right side is extended to the right side. If the middle bending jack 4A provided is contracted, the front trunk 1a bends rightward with respect to the rear trunk 1b, and digging may be performed in that state.

Next, the shield excavator 1 moves forward while excavating the tunnel as described above and applying segment lining to the excavated wall surface, and in the course of the excavation, such as a sheet pile or a pile driven into the ground. When the vehicle hits an obstacle, the excavation of the shield excavator 1 and the driving of the cutter head 3 are temporarily stopped. The oblique cutting arm 11a of the cutter head 3 and the jacks 14 and 15 disposed in the hollow cylindrical portion 9a of the center shaft 9 are extended, whereby the obstacle cutting bit 11 is extended.
Is projected forward from the ground excavation bit 10. On this occasion,
The obstruction cutting bit 11 that can be cut is projected in the rotation direction of the cutter head 3.

Further, the bolt 5c connecting the bracket piece 5b fixed to the outer peripheral part of the front half of the center bending jack 4A and the connecting piece 5a fixed to the inner peripheral surface of the front body part of the skin plate 1 is removed. , The partition 2 connected to the front body 1a of the skin plate 1 via the bracket piece 5b is separated from the skin plate 1, and the front and rear body parts 1a, 1b of the skin plate 1 face each other. The front and rear body portions 1a and 1b are locked so that they cannot be bent by integrally connecting the pieces 18 and 19 with the center bending fixing bolts 17.

In this state, when the cutter head 3 is rotated by the drive motor 20 and all of the center bending jacks 4A are extended, the skin plate 1 is connected to the tip of the center bending jack 4A in a stopped state. As shown in FIG. 5, the ring body 2A of the partition wall 2 is propelled forward from the opening end of the front body 1a while sliding along the inner peripheral surface of the front body 1a of the skin plate 1, and The obstacle is cut by the obstacle cutting bit 11 while moving forward with the partition 2, the cutting waste is taken into the intake chamber 34 from the earth and sand intake opening 3 c, and is carried out and removed by the screw conveyor 7. is there. The extension of the middle folding jack 4A causes the bracket piece 5b, which is a component of the lock mechanism 5 fixed to the middle folding jack 4A, to move forward from the connecting piece 5a fixed to the skin plate 1.

At this time, if the obstacle cannot be completely removed by the extension amount of the center-bending jack 4A due to the large diameter or thickness of the obstacle, the propulsion jack 6 is extended and the center-bending jack is adjusted according to the extension amount. By contracting 4A, the whole skin plate is advanced toward the partition 2 side by a fixed length, and the connecting piece 5a fixed to the front body 1a is connected to the partition 2 side. The bracket piece 5b fixed to the outer peripheral surface is brought into proximity or in contact with the bracket piece 5b.

In this state, the cutter head 3 is rotated again and the center bending jack 4A is extended, so that the partition 2 is advanced with the skin plate 1 stopped and the obstacle is cut by the obstacle cutting bit 11. This operation is repeated as necessary to form a circular hole in the obstacle through which the shield excavator can pass.

The bent jack as the propulsion mechanism 4
4A is a connecting piece 5a fixed to the front body of the skin plate 1.
And the front end thereof is connected to the outer peripheral ring body 2A of the partition wall 2, so that even if the partition wall 2 tries to rotate together when the cutter head 3 rotates, the middle bent jack 4A
Can be blocked by the skin plate 1 through the connection piece 5a. However, between the inner peripheral surface of the front body part 1a of the skin plate 1 and the outer peripheral ring body 2A of the partition wall 2 so that an excessive force in the torsional direction does not act on the center bending jack 4A due to the rotation of the cutter head 3. May be provided with a spline or other appropriate rotation stopping means.

Thus, when a circular hole through which the shield excavator can pass is formed in the obstacle, the propulsion jack 6 is extended and the center bend jack 4A is contracted.
The bracket piece 5b fixed to the front half outer peripheral portion of the center bent jack 4A is joined to the connecting piece 5a fixed to the front body inner peripheral surface of the skin plate 1 and connected and fixed by bolts 5c to connect with the skin plate 1. The partition wall 2 is integrated into a locked state, and the center bending fixing bolt 17 connecting the opposed protruding pieces 18 and 19 with the front and rear body parts 1a and 1b of the skin plate 1 is removed to remove the front and rear body parts 1a and 1b. The cutting bits 11 and 11 'arranged on the inclined arm 3a of the cutter head 3 are immersed, and their tips are retracted from the tips of the ground excavation bits 10 and 10'. In this state, the tunnel is constructed by performing the usual ground excavation as described above. In the above embodiment, the center bending jack 4A is used as a mechanism for propelling the partition wall 2 with respect to the skin plate 1, but the propulsion mechanism may be constituted by another jack.

[0036]

As described above, according to the first aspect of the present invention, a plurality of ground excavation bits and a plurality of obstacle cutting bits which can be protruded and retracted from the ground excavation bit are arranged. The cutter head is rotatably supported by the partition at the front end of the opening of the skin plate, and a ring body is integrally provided on the outer periphery of the partition, and the ring body is fitted inside the front end of the opening of the skin plate so as to be slidable back and forth. In addition, a lock means for detachably fixing the skin plate and the ring body is provided, and furthermore, a propulsion mechanism of the partition wall is provided on the inner peripheral surface of the skin plate on the rear side of the lock means,
By integrally connecting the skin plate and the outer peripheral ring body of the partition wall by the lock means, it is possible to construct a tunnel while excavating the ground with a ground excavation bit arranged on the cutter head as usual. Of course, if there is an obstacle such as a concrete pile, H steel, or wooden pile during the excavation, the cutter head is set by the propulsion mechanism with the obstacle cutting bit protruding forward with respect to the ground excavation bit. The obstacle can be reliably cut off by the obstacle cutting bit while moving the robot forward.

Further, at the time of cutting an obstacle, the partitioning means is released from the lock by releasing the lock means, and the partition is advanced by the propulsion mechanism. It is possible to cut and remove obstacles while advancing only the cutter head together with the partition wall in a fixed state at a fixed position in the tunnel without propelling, so that the cutter head rotates smoothly without swinging and obstacles It can be used for a long time without losing or damaging the cutting bit.In addition, since the partition wall with the cutter head is propelled by the propulsion mechanism without propelling the skin plate, comparison It can efficiently remove obstacles with a small propulsion force, and can be used as an obstacle cutting bit for the cutter head. The cutting speed can be accurately adjusted according to various obstacles, and efficient cutting of obstacles is possible, and the cutter head can be easily moved back and forth by the propulsion mechanism. It is possible to adjust the cutting depth and the like.

Further, the lock means for detachably fixing the skin plate and the partition wall includes a connecting piece projecting from an inner peripheral surface of the skin plate.
It is composed of a bracket piece fixed to the propulsion mechanism connected to the rear end of the ring body of the partition on the front side of the connection piece, and a bolt removably connected to the connection piece and the bracket piece. The lock (connection) between the skin plate and the partition can be reliably and firmly performed, and when the skin plate is separated from the skin plate, the partition can be smoothly advanced by the propulsion mechanism.

According to a third aspect of the present invention, in the shield excavator according to the first or second aspect, the skin plate is formed by a front body and a rear body which are connected to each other so as to be freely bent. While the locking means is provided on the side of the section, a plurality of middle-fold jacks are arranged at regular intervals in the circumferential direction between the inner peripheral surfaces of the connecting portions of the front and rear body parts, and the propulsion mechanism of the partition wall by these middle-fold jacks With this construction, it is possible to simplify the structure by providing a propulsion mechanism for the bulkhead, and a curved bend jack used for curved tunnels and direction correction without arranging a new propulsion jack. The partition wall can be smoothly and accurately propelled by the center bending jack.

Further, according to the fourth aspect of the present invention, the projecting pieces are fixed to the inner peripheral surfaces of the front body and the rear body which are connected to bend freely, and the space between these projecting pieces is fixed by the center bending fixing bolt. Since it is detachably connected, it can be integrally connected to the front and rear torso of the skin plate with a middle bending fixing bolt at the time of cutting an obstacle to form a single skin plate structure. When moving forward, the obstacle can be cut while the partition wall is supported on the skin plate in a stable state.

[Brief description of the drawings]

FIG. 1 is a simplified longitudinal side view of a shield excavator,

FIG. 2 is a front view of the cutter head,

FIG. 3 is an enlarged vertical sectional view of an inclined arm,

FIG. 4 is a vertical cross-sectional view of a portion where the center-bending jack is provided.

FIG. 5 is a simplified vertical sectional side view of the shield excavator with the partition wall advanced.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Skin plate 1a Front torso 1b Rear torso 2 Partition wall 2A Ring body 3 Cutter head 4 Propulsion mechanism 4A Folding jack 5 Locking means 5a Connecting piece 5b Bracket 5c Bolt 6 Propulsion jack 10 Ground drill bit 11 Obstacle cutting bit 17 Medium Bend fixing bolt

Claims (4)

[Claims] 1. A cutter head having a plurality of ground excavation bits and a plurality of obstacle cutting bits capable of protruding and retracting with respect to the ground excavation bits is rotatable on a partition wall at an opening front end of a skin plate. And a ring body is integrally provided on the outer periphery of the partition wall, and the ring body is fitted inside the opening front end of the skin plate so as to be slidable back and forth, and the skin plate and the ring body are detachably fixed. A shield excavator, comprising: means for arranging a partition wall; and a propulsion mechanism for a partition wall on an inner peripheral surface of the skin plate on a rear side of the locking means. 2. A locking means for detachably fixing the skin plate and the partition wall is connected to a connecting piece protruding from an inner peripheral surface of the skin plate and a rear end of the ring body of the partition wall on the front side of the connecting piece. The shield excavator according to claim 1, comprising a bracket piece fixed to the propulsion mechanism, and a bolt connecting the connection piece and the bracket piece in a detachable manner. 3. The skin plate comprises a front body and a rear body connected to bendable with each other, and a locking means is provided on the front body side, while a circumferential direction is provided between inner peripheral surfaces of the connection parts of the front and rear body. The shield excavator according to claim 1 or 2, wherein a plurality of middle-bent jacks are disposed at regular intervals, and the middle-bent jacks constitute a partition wall propulsion mechanism. 4. A protruding piece is fixed to an inner peripheral surface of a front body part and a rear body part which are flexibly connected, and these protruding pieces are detachably connected to each other by a center bending fixing bolt. The shield excavator according to claim 3, wherein