JP2008231846A - Processing method of unretreatable copy cutter in shield machine and copy cutter cutting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To safely remove an unretreatable-unstorable copy cutter at small cost in a short construction period. <P>SOLUTION: After finishing outbreak excavation, a cutting head part 31 is approached to a copy cutter 15 from a shield body 1 to the unretreatable-unstorabe copy cutter 15, and is cut by injecting super-high pressure high speed water into a projection part of the copy cutter 15 from water jet nozzles 35a to 35c arranged in the cutting head part 31, and is separated from the copy cutter. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of processing a non-retractable copy cutter for processing a protruding portion of a non-retractable copy cutter and a process of the copy cutter when the copy cutter used for overexcavation cannot be retracted during tunnel excavation. The present invention relates to a copy cutter cutting device for carrying out the method.

  Conventionally, when a tunnel is excavated by a shield machine, a copy cutter shown in Patent Document 1 is projected from the cutter head to the outer peripheral side by an extra excavation device at a curved portion or a widened portion of the tunnel, and the excavation cross section of the cutter head Excessive excavation for excavating a wide cross section extended to the outer peripheral side is widely performed.

  By the way, in recent years, a large amount of extra excavation is required, such as excavation of a tunnel with an irregular cross section or excavation of a widening tunnel, and the protruding amount of a copy cutter is increasing. As a result, there is an increasing number of troubles in which the protruding copy cutter cannot be retracted for some reason.

In such a case, conventionally, the soil quality of the Mt.Kiwachiyama is improved and solidified, and the excavated soil is discharged from the chamber and the worker enters the chamber, forcibly retracting and storing the copy cutter, Alternatively, the protruding part of the copy cutter is gas-melted and separated from the cutter head. It is also conceivable that excavation is continued while the copy cutter is in a protruding state, and a filler is injected into the overexcavated portion and backfilled.
JP-A-10-169376

  However, when the excavation tunnel has a large diameter or a deep groundwater level, it takes a lot of cost and work time for workers to enter the chamber, and there is a problem that the danger is high. It was. Further, if excavation is performed with the copy cutter protruding, there is a problem that the face is collapsed, the direction of the shield machine is difficult to control, and unnecessary injection work is costly.

  The present invention solves the above-mentioned problems, and a method of processing a non-retractable copy cutter in a shield machine capable of safely processing a copy cutter which has become impossible to be retracted at a low cost, with a short construction period, and the non-retractable copy cutter. An object of the present invention is to provide a copy cutter cutting apparatus for carrying out the processing method.

  According to a first aspect of the present invention, there is provided a method for processing a non-retractable copy cutter in a shield machine, which excavates a tunnel by rotationally driving a cutter head provided at a front portion of a shield body, and from a storage position in the cutter head. Excessive excavation that extends the tunnel by projecting the copy cutter to the outer peripheral side, and when the copy cutter cannot be retracted and stored after completion of the excavation excavation, the water jet nozzle from the shield body side to the protruding part of the copy cutter The high pressure and high speed water is jetted from the water jet nozzle to cut the protruding portion of the copy cutter and separate it from the cutter head.

  According to a second aspect of the present invention, there is provided a method for processing a non-retractable copy cutter in a shield machine, wherein the high pressure high speed water containing the abrasive is jetted from the water jet nozzle.

  The copy cutter cutting device in the shield machine according to claim 3 is for carrying out the processing method of the non-retractable copy cutter in the shield machine according to claim 1 or 2, wherein the shield body includes the shield body. A cutting head portion that is arranged so as to be able to move forward and backward and is accessible to the protruding portion of the copy cutter, and a water jet nozzle provided in the cutting head portion.

  The copy cutter cutting device in the shield machine according to claim 4 is the configuration according to claim 3, wherein the cutting head portion is accommodated in a storage space formed at a predetermined position on the outer periphery of the front portion of the shield body. Is cut out from the storage space to the outside of the outer periphery of the shield body, and then a cutting head moving device that protrudes forward and is accessible to the copy cutter is provided.

  The copy cutter cutting device in the shield machine according to claim 5 is the configuration according to claim 3 or 4, wherein the cutting head portion has a notch portion formed so as to be able to be externally fitted to the protruding portion of the copy cutter, and the cut portion. And a nozzle moving device that changes the injection direction by moving the water jet nozzle along the periphery of the notch.

  According to the first aspect of the present invention, the projection of the copy cutter is caused by the ultra-high pressure high-speed water jetted from the water jet nozzle by bringing the water jet nozzle from the shield body close to the projection of the copy cutter that has become unretractable. Is cut off and separated from the cutter head, the protruding portion of the copy cutter can be safely cut and separated at a low cost and with a short construction period, and the excavation of the tunnel can be resumed in a short period of time.

  According to the invention of claim 2, the water jet nozzle is an abrasive type that injects the ultra-high pressure and high-speed water containing the abrasive, so that it is shorter in time than the hydro-type only of ultra-high pressure and high-speed water. Can cut the copy cutter efficiently.

  According to the third aspect of the present invention, the cutting head portion is approached from the shield main body to the base end portion of the copy cutter that has become unable to be retracted, and the ultra high pressure high speed water is copied from the water jet nozzle of the cutting head portion. The projection of the copy cutter can be safely cut and separated from the cutter head at a low cost and with a short construction period, and the excavation of the tunnel can be resumed in a short period of time. . In addition, by providing the shield body with a cutting head part that is accessible to the copy cutter, by changing the position of the copy cutter by rotating the cutter head, the protruding parts of a plurality of copy cutters with one cutting head part Can be cut respectively.

According to the fourth aspect of the present invention, at the time of excavation, the cutting head portion is accommodated in the accommodating space of the shield body, so that the copy cutter cutting device does not become an obstacle to tunnel excavation.
According to the fifth aspect of the present invention, by providing the nozzle moving device in the cutting head portion and changing the jet direction of the water jet nozzle, the protruding portion of the copy cutter having a large cross section or a deformed cross section can be cut efficiently. It can be separated from the cutter head.

Embodiments of a non-retractable copy cutter processing method according to the present invention and a copy cutter cutting apparatus for carrying out the non-retractable copy cutter processing method will be described below with reference to the drawings.
[Embodiment 1]
In this shield machine, as shown in FIG. 1, a pressure bulkhead 2 that holds the face collapsed earth pressure is provided at the front part of the shield body 1, and a pressure chamber (chamber) that takes excavated earth and sand into the front part of the pressure bulkhead 2. ) 3 is formed. A cutter head 4 for excavating natural ground is rotatably disposed around the shield axis O at the front portion of the shield body 1, and the cutter head 4 is rotatably supported by the pressure bulkhead 2 via the cutter shaft 5. Has been. Further, a cutter driving device 7 that rotationally drives the cutter head 4 via the cutter pivot shaft 5 is provided on the pressure chamber 2 on the atmosphere chamber 6 side. The pressure bulkhead 2 is provided with a screw-type soil removal device 8 that penetrates the excavated earth and sand taken into the pressure chamber 3 to the atmosphere chamber 6 side.

  The cutter head 4 includes a plurality of radial frames 12 extending radially from the center member 11, and a cutter face plate (not shown) connecting the radial frames 12, and is attached to the radial frame 12. A plurality of cutter bits 12 a for excavation (FIG. 2) and a sand intake (not shown) that is formed on the cutter face plate and takes the excavated earth into the pressure chamber 3 are provided. A storage chamber 13 opened at the tip is formed on the outer peripheral side of the predetermined radial frame 12, and an overburden device 14 is provided in these storage chambers 13. The extra digging device 14 includes a copy cutter 15 that is retractably retracted from the storage chamber 13 to the outer peripheral side through an opening, and a cutter retracting drive device (hydraulic cylinder) that drives the copy cutter 15 to exit and retract. Or a jack) 16.

  As shown in FIG. 2, the copy cutter 15 has a main body portion 15b formed in a columnar shape, and the protruding portion 15a protruding from the opening of the radial frame 12 to the outer peripheral side has a semicircular cross section on the rear side and the front side on the front side. Are formed in a trapezoidal cross section consisting of left and right inclined surfaces, and excavation bits 15c are attached to the front and left and right inclined surfaces, respectively.

  When the copy cutter 15 cannot be retracted from the protruding position and cannot be stored in the storage chamber 13 due to some cause such as deformation or damage due to a large impact force or applied pressure, the protruding portion 15a of the copy cutter 15 is cut and the cutter head 4 is cut. The shield body 1 is provided with a copy cutter cutting device 21 according to the present invention that is separated from the shield body 1.

  As shown in FIGS. 2 and 3, the copy cutter cutting device 21 has a bottom plate 22b, a left and right side plate 22c, and a front and rear side at a predetermined position on the outer periphery of the front portion of the shield body 1 at the connecting portion between the pressure bulkhead 2 and the skin plate 1a. A box-shaped accommodation space 22 is formed by the plate 22 d, and an opening 22 a of the accommodation space 22 is opened in the skin plate 1 a of the shield body 1. And in this accommodation space 22, the main body frame 23 which can be moved in and out of the radial direction outer periphery side from the opening part 22a, and the several main body withdrawal / retraction apparatus which are standingly arranged by the baseplate 22b and can drive the main body frame 23 back and forth. (Hydraulic cylinder or jack) 24 is arranged. The main body retracting device 24 projects the main body frame 23 in a parallel posture, and the upper surface of the main body frame 23 is flush with the outer surface of the skin plate 1a as shown in FIG. It is withdrawn between the protruding positions in FIG. The storage space 22 is formed in a watertight structure with seal members (not shown) disposed between the left and right side plates 22c and the front and rear plates 22d and the main body frame 23, respectively.

  In the main body frame 23, a guide passage 25 opened on the front surface is formed in the direction of the shield axis O, and a slide frame 26 having a cutting head portion 31 at the front is slidable in the guide passage 25. Has been placed. On the bottom side of the main body frame 23, a head retracting device (hydraulic cylinder or jack) 27 in which the tube main body is supported by the main body frame 23 and the output rod is connected to the slide frame 26 is provided. With the head retracting device 27, the slide frame 26 can be driven back and forth between the storage position in the guide passage 25 and the cutting position where the cutting head unit 31 approaches the copy cutter 15. The head retracting device 27 is long, and the rear part extends into the rear machine chamber 28 through the through part 22e of the rear plate 22d. As described above, the cutting head moving device that moves the cutting head portion 31 from the storage space 22 to the cutting position includes the main body retracting device 24 and the head retracting device 27.

  The slide frame 26 is formed in a box-like hollow shape, and is provided with a cutting head portion 31 at the front portion. The cutting head portion 31 includes a notch portion 32 that can be externally fitted to the copy cutter 15, and the cutting head portion 31. There are provided a plurality of water jet nozzles 35a to 35c arranged on the periphery of the notch 32, and a nozzle moving device 30 for moving the water jet nozzles 35a to 35c to change the direction of injection.

  That is, as shown in FIG. 4, a pair of upper and lower front plates 26 a are fixed to the cutting head portion 31 at the front portion in the outer shell plate of the slide frame 26 at a predetermined interval. The notch 32 is formed from the front surface of the part plate 26a toward the back side, and the notch 32 is formed in a U-shape to which the copy cutter 15 can be fitted with a predetermined gap. Further, arcuate guide recesses 33 centered on the notch center P of the notch 32 are formed at opposing positions on the outer peripheral side of the notch 32 of the front plate 26a, respectively. The movable block (cut movable member) 34 is slidably disposed. The movable block 34 is formed with three penetrating portions, for example, 45 ° apart from the notch center P, and water jet nozzles 35a to 35c are disposed in these penetrating portions, respectively. Further, there is provided a nozzle turning drive device 36 for turning the movable block 34 along the guide recess 33 within a predetermined angle range to change the direction of injection of the water jet nozzles 35a to 35c. As described above, the nozzle moving device 30 includes the guide recess 33, the movable block 34, and the nozzle turning drive device 36.

  The water jet nozzles 35a to 35c are connected to a flexible high-pressure water hose 37 and an abrasive hose 38, respectively, and are configured as an abrasive type that mixes and injects an abrasive into ultrahigh-pressure high-speed water. Yes. Of course, you may comprise in the hydro type only of an ultrahigh pressure high-speed water.

  Further, a cutter positioning member 39 is attached to the notch portion 32 so that the axis of the copy cutter 15 coincides with the notch center P. The cutter positioning member 39 allows the discharge ports of the water jet nozzles 35a to 35c and the copy cutter 15 to be aligned. It is comprised so that the distance with the outer peripheral surface may become constant.

  The nozzle turning drive device 36 has two hydraulic cutting and turning cylinders 36a. The tube bodies of the cutting and turning cylinders 36a are rotatably supported by the slide frame 26, and the output rods are respectively movable blocks 34. The movable block (cutting movable member) 34 is arcuate along the guide recess 33 by being connected to a passive arm 36b projecting on the left and right sides at the rear by a pin and extending and retracting two cutting turning cylinders 36a. Can slide in the direction. Of course, the nozzle turning drive device 36 may be constituted by a hydraulic or electric rotary drive device and a gear device such as a rack and pinion.

  As shown in FIG. 6, among the water jet nozzles 35 a to 35 c, the central water jet nozzle 35 b is configured as a fixed type fixed to the movable block 34, but the left and right water jet nozzles 35 a and 35 c are respectively injected. Injectable, which is configured to be movable so that the direction can be changed, and rotates the injection directions of the left and right water jet nozzles 35a, 35c from the notch center P toward the front side in the vicinity of the limit of the turning movement of the movable block 34. A direction changing mechanism 41 is provided.

  The jet direction changing mechanism 41 supports the nozzle main bodies of the water jet nozzles 35a and 35c in a predetermined range via the radial support pins 41a of the shield main body 1 in the penetrating portions of the movable block 34. A compression coil spring 41b that urges the nozzle body outward in the turning direction is provided inside the rear part of the nozzle body, and a stopper 41c that restricts the rotation of the nozzle body inward is provided inside the front part of the nozzle body. ing. As a result, during normal times, the nozzle body of the water jet nozzles 35a, 35c is urged to rotate outward in the turning direction by the compression coil spring 41b, and the positioning is regulated by the stopper 41c. The basic posture of spraying toward the notch center P is maintained. Further, in the vicinity of the front portion 26a of the front plate 26a in the vicinity of the swivel movement limit, there is a direction changing dog 41d that abuts on the rear part of the water jet nozzles 35a, 35c and can change the injection direction of the water jet nozzles 35a, 35c. Each is provided. Therefore, when the movable block 34 is moved by the nozzle turning drive device 36 to a position before the turning movement limit, the turning dock 41d comes into contact with the rear portion of the nozzle body, and the movable block 34 is turned by the nozzle turning drive device 36. Then, the deflection dock 41d pushes the rear part of the nozzle body and rotates the nozzle body against the compression coil spring 41b, thereby changing the injection direction of the water jet nozzles 35a and 35c from the notch center P in the direction of arrow a. It is possible to cut the front side cross section of the copy cutter 15 by turning to the front side shown.

  The operation of the main body retracting device 24, the head retracting device 27, and the nozzle turning drive device 36, and the injection and stop of the abrasive high-pressure high-speed water from the water jet nozzles 35a to 35c are performed in the atmospheric chamber of the shield main body 1. 6 can be performed remotely from within.

  In the above configuration, the cutter head 4 is rotated to excavate a tunnel, and when the tunnel widening portion is reached, the cutter cutter drive device 16 causes the copy cutter 15 to protrude from the storage chamber 13 to excavate the outer peripheral portion. When excavation of the widened part of the tunnel is completed, the copy cutter 15 is moved backward by the cutter extension / retraction drive device 16 and stored in the storage chamber 13.

  When the copy cutter 15 cannot be retracted and stored for some reason, the cutter head 4 is rotated, and the copy cutter 15 that cannot be retracted is stopped at a facing position in front of the copy cutter cutting device 21.

  Then, by remote operation from within the shield body 1, the body retracting device 24 is advanced to project the body frame 23 from the housing position of the housing space 22 to a projecting position in the space excavated by the copy cutter 15. . Further, the head retracting device 27 is advanced to cause the slide frame 26 to project forward, and the notch 32 of the cutting head portion 31 is externally fitted to the base end of the projecting portion 15 a of the copy cutter 15.

  As shown in FIG. 5A, high pressure water and abrasive are supplied from the high pressure water hose 37 and abrasive hose 38 to the water jet nozzles 35a to 35c, and the ultra high pressure and high speed water containing abrasive is cut off from the discharge ports. Injecting toward the notch center P, the cutting of the protruding portion 15a of the copy cutter 15 is started. Then, the nozzle turning drive device 36 is driven to turn the movable block 34 to change the spray direction of the water jet nozzles 35a to 35c to sequentially move the cutting parts. Then, as shown in FIG. 5B, when the movable block 34 is approached before the turning movement limit, the water jet nozzle 35a is rotated by the injection direction changing mechanism 41 until the turning movement limit. Thus, the ejection direction is moved forward in the direction of arrow a from the notch center P, and the front portion of the protruding portion 15a of the copy cutter 15 is cut.

  When one movement limit is reached, the movable block 34 is swung in the reverse direction by the nozzle swivel driving device 36 and cutting of the copy cutter 15 is continued. As shown in FIG. The water jet nozzles 35a to 35c are swung up and down, and the entire cross section of the base end of the projecting portion 15a of the copy cutter 15 is cut and cut by one or more swiveling motions, and the projecting portion 15a is removed from the cutter head 4. To separate. The time required for cutting the copy cutter 15, the rotational movement speed of the movable block 34, and the like are set in advance according to conditions such as the cutting ability of the water jet nozzles 35a to 35c.

  After cutting the projecting portion 15a of the copy cutter 15, the head retracting device 27 is contracted to accommodate the slide frame 26 having the cutting head portion 31 in the main body frame 23, and the main body retracting device 24 is contracted to the main body frame. 23 is stored in the storage space 22. Then, the cutter head 4 is rotationally driven to resume excavation. The protruding portion 15a of the cut copy cutter 15 is left in the ground.

  According to the above-described embodiment, the water jet nozzle 35a provided in the cutting head portion 31 is moved toward the cutting head portion 31 by moving the slide frame 26 forward from the shield body 1 to the copy cutter 15 that cannot be retracted and retracted. ~ 35c spray high-pressure high-speed water containing abrasives toward the copy cutter 15 to cut the projection 15a of the copy cutter 15 and separate it from the cutter head 4. The projecting portion 15a of the copy cutter 15 can be separated from the cutter head 4 at a low cost and with a short construction period, and the work performed by the operator entering the pressure chamber 3 is not required. Since it can be performed remotely, it is highly safe.

In addition, by ejecting the super high pressure and high speed water containing the abrasive from the water jet nozzles 35a to 35c, the copy cutter 15 can be efficiently cut in a short time.
Furthermore, since the copy cutter cutting device 21 including the cutting head unit 31 is accommodated in the accommodation space 22 in a watertight state at normal times, the copy cutter cutting device 21 does not become an obstacle to tunnel excavation. Further, since the copy cutter cutting device 21 is provided in the shield main body 1, it is possible to avoid an increase in size and complexity of the cutter head 4 as compared with the case where the copy cutter cutting device 21 is provided in the cutter head 4. A plurality of copy cutters 15 can be cut and separated by the copy cutter cutting device 21.

  Furthermore, in the cutting head portion 31, the nozzle moving device 30 causes the water jet nozzles 35a to 35c to pivot along the outer periphery of the copy cutter 15 fitted in the notch portion 32, so that the copy cutter 15 Even large sections can be cut efficiently.

  In addition, since the ejection direction changing mechanism 41 is provided in the cutting head unit 31, the cutting range can be extended with a simple structure. Therefore, the rear cross section of the protrusion 15a of the copy cutter 15 is cut by the nozzle moving device 30, and the rear cross section of the protrusion 15a is cut by the injection direction changing mechanism 41, so that the copy cutter 15 having a large cross section or a deformed cross section can be used. can do.

FIG. 7 shows another embodiment in which the cutting head portion 31 is provided with a cutting head follower mechanism 50 that can allow the positional deviation of the stop position of the copy cutter 15.
That is, in the cutting head following mechanism 50, a large notch portion 32 ′ is formed in the outer shell plate of the slide frame 26, and a pair of upper and lower movable plates 51 having the notch portion 32 are formed in the radial direction of the shield body 1. It is supported so as to be swingable within a predetermined range around the support shaft portion 52. The movable plate 51 is formed with a guide recess 33 for slidably guiding the movable block 34, and a cutting turning cylinder 36a of a nozzle turning drive device 36 is supported. Further, the movable plate 51 is provided with coil springs 53 on the left and right sides at the front and is urged to rotate in opposite directions, and is held at a neutral reference position where the notch 32 opens forward. Further, tapered guide surfaces 54 are formed on the left and right opening edges of the notch 32 so as to extend forward.

  Therefore, even if the stop position of the cutter head 4 is displaced with respect to the cutout portion 32 of the cutting head portion 31, the copy cutter 15 is brought into contact with the guide surface 54 of the cutout portion 32, and the movable plate 51. Is pivoted about the support shaft portion 52, so that the copy cutter 15 can be fitted into the notch center P of the notch portion 32 satisfactorily.

  Further, in the cutting head following mechanism 60 shown in FIG. 8, a pair of upper and lower movable plates 61 in which the cutout portions 32 are formed are slidably arranged within a predetermined range in the tangential direction of the shield body 1 via a plurality of guide members 62. Is. The movable plate 61 is urged by a plurality of coil springs 63 disposed on both the left and right sides, and is held at a neutral reference position where the notch 32 opens forward. Tapered guide surfaces 64 are formed on the left and right opening edges of the notch 32 so as to expand toward the front.

  According to the cutting head follow-up mechanism 60, the same operational effects as those of the previous cutting head follow-up mechanism 50 can be achieved.

1 is a schematic longitudinal sectional view of a shield machine having a copy cutter cutting device according to an embodiment of a copy cutter cutting device according to the present invention. The longitudinal cross-sectional view of a copy cutter cutting device is shown, (a) is an accommodation state, (b) shows a cutting state. It is a partially cutaway plan view of a copy cutter cutting device. It is sectional drawing of planar view which shows the cutting head part of a copy cutter cutting device. It is sectional drawing of planar view which shows operation | movement of a cutting | disconnection head part, (a) is a right rotation limit, (b) is a neutral position, (c) shows a left rotation limit. It is an expanded sectional view of the plane view explaining an injection direction change mechanism in the right rotation limit of a cutting head part. It is sectional drawing of the planar view of the cutting head follower mechanism provided in the cutting head part which shows other embodiment of a copy cutter cutting device. It is sectional drawing of planar view which shows other embodiment of a cutting head tracking mechanism.

Explanation of symbols

O Shield shaft center P Notch center 1 Shield body 1a Skin plate 2 Pressure bulkhead 4 Cutter head 12 Radial frame 13 Storage chamber 14 Excavation device 15 Copy cutter 15a Protruding portion 16 Cutter extension / retraction drive device 21 Copy cutter cutting device 22 Space 23 Body frame 24 Body retracting device (cutting head moving device)
25 Guide passage 26 Slide frame 26a Front plate 27 Head retracting device (cutting head moving device)
30 Nozzle moving device 31 Cutting head portion 32 Notch portion 33 Guide recess 34 Movable block (cutting movable member)
35a to 35c Water jet nozzle 36 Nozzle turning drive device 37 High-pressure water hose 38 Abrasive hose 39 Cutter positioning member 41 Injection direction diverting mechanism 50, 60 Cutting head following mechanism

Claims (5)

The cutter head provided at the front of the shield body is driven to rotate to excavate the tunnel, and the excavation excavation is performed to extend the tunnel by projecting the copy cutter from the retracted position inside the cutter head to the outer peripheral side. When the copy cutter cannot be retracted and stored after
Move the water jet nozzle closer to the protruding part of the copy cutter from the shield body side,
A method of processing a non-retractable copy cutter in a shield machine that injects ultra-high-pressure, high-speed water from a water jet nozzle to cut off the protruding portion of the copy cutter and separate it from the cutter head. The method for processing a non-retractable copy cutter in a shield machine according to claim 1, wherein ultrahigh-pressure high-speed water containing an abrasive is jetted from a water jet nozzle. A copy cutter cutting device for carrying out the method of processing a non-retractable copy cutter in the shield machine according to claim 1 or 2,
A shield machine comprising a shield body, a cutting head portion that is arranged so as to be movable forward and backward from the shield body and is accessible to the protruding portion of the copy cutter, and a water jet nozzle provided in the cutting head portion Copy cutter cutting device. The cutting head portion is housed in a housing space formed at a predetermined position on the outer periphery of the front portion of the shield body,
The copy cutter cutting device in the shield machine according to claim 3, further comprising a cutting head moving device that protrudes forward from the storage space and pushes out of the outer periphery of the shield main body and is accessible forward to the copy cutter. A cutting head portion is provided with a notch portion that is formed so as to be able to be externally fitted to the protruding portion of the copy cutter, and a nozzle moving device that moves the water jet nozzle along the periphery of the notch portion to change the injection direction. The copy cutter cutting device in the shield machine according to claim 3 or 4.

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