JP4437910B2 - Cutter changing device and method and tunnel excavator - Google Patents

Description

  The present invention relates to a cutter exchanging apparatus and method that can replace a cutter such as a leading bit and a cutter bit from the inside of the machine, and a tunnel excavator equipped with the cutter exchanging apparatus.

In general tunnel excavators , a cutter head is rotatably mounted on the front of a cylindrical excavator body, and a number of leading bits and cutter bits are attached to the cutter head, while the excavator body is attached to the rear. A large number of shield jacks for advancing the vehicle are mounted, and an erector device for assembling the segments to the inner wall surface of the existing tunnel is mounted. Therefore, by extending the shield jack while rotating the cutter head, the excavator body moves forward by obtaining the excavation reaction force from the existing segment, and the cutter bit or the like can excavate the ground in front and form a tunnel. .

  In recent years, tunnels tend to be long distances, and the leading bits and cutter bits attached to the cutter head are worn during tunnel excavation work. Since the excavation efficiency of the ground decreases when the preceding bit or the cutter bit is worn, excavation work must be stopped and each worn cutter must be replaced. However, this cutter replacement work suppresses the collapse of the face by discharging the mud and excavated sediment in the space including the chamber between the face and the bulkhead to the outside, and supplying air to the space for pressure. In this state, the worker enters the pressure space and replaces the preceding bit and the cutter bit.

Therefore, it takes a long time to replace the bit, and the safety of the worker must be fully taken into consideration, and the work efficiency is not good. Therefore, for example, Patent Document 1 shown below discloses a technique in which an operator can replace a preceding bit or cutter bit worn from the inside of the machine with a new one without leaving the face or chamber. In the shield machine described in Patent Document 1, an exchange bit provided on a cutter pork is pulled into the machine by a jack together with its support part from the rear of the shield machine, and the exchange bit is closed after the shutter is closed and water is stopped. Exchange.
JP 11-022383

  However, in the above-described conventional bit exchange device using a shield machine, the shutter is closed and the water is stopped after the exchange bit is pulled into the machine. It is necessary to give sufficient consideration to the structure of the support part and the close contact part. Therefore, there is a problem that the support structure of the shutter becomes complicated and the apparatus becomes large.

  The present invention solves such a problem, and provides a cutter exchanging apparatus and method and a tunnel excavator that improve the workability and safety of cutter exchanging work and simplify the apparatus. Objective.

In order to achieve the above-mentioned object, a cutter exchanging device according to the present invention comprises a guide hole provided in a cutter head along the front-rear direction, a movably supported along the guide hole, and a front end portion of the cutter exchanging device. A cutter that can be held in a position protruding forward from the head, a cutter moving means that moves the cutter back and forth, a seal insertion hole that communicates with the guide hole, and the guide hole in which the cutter has retracted from the seal insertion hole A seal member which is inserted into the front portion of the seal member and is capable of stopping water, seal insertion means for inserting the seal member into the guide hole from the seal insertion hole, and the seal member inserted into the guide hole from the seal insertion hole And a seal moving means for moving the lens forward and in close contact with the peripheral surface of the guide hole .

The cutter exchanging apparatus according to the present invention is characterized in that a sealant filling means for filling a sealant is provided in the front portion of the guide hole in which the cutter has been retracted.

The cutter exchanging apparatus according to the present invention is characterized in that seal positioning means for preventing the seal member that has moved to the front of the guide hole from moving backward is provided.

In the cutter exchanging apparatus according to the present invention, the seal insertion means has an extrusion rod that pushes the seal member from the seal insertion hole into the guide hole, and the seal positioning means has moved forward from the inside of the extrusion rod. It has the positioning rod which protrudes behind the said sealing member, It is characterized by the above-mentioned.

In the cutter exchanging device according to the present invention, the seal insertion means includes a seal support cylinder that holds the seal member and is detachable from the seal insertion hole, and is movably fitted in the seal support cylinder. An extrusion rod for extruding the seal member from the seal insertion hole into the guide hole; a positioning rod for movably fitting in the extrusion rod to prevent the seal member from retreating in the guide hole; and the extrusion rod And rod moving means for moving the positioning rod.

In the cutter exchanging apparatus according to the present invention, the cutter moving means includes a cutter exchanging screw rod that is rotatably supported behind the cutter and has a tip portion that enters and is screwed into the cutter. Yes.

In the cutter exchanging device according to the present invention, a movable pin whose tip is projectable into the guide hole is movably attached to the guide cylinder in which the guide hole is formed, and the tip of the movable pin is the tip of the cutter. The seal member which functions as a cutter fixing means capable of holding the cutter in a position protruding forward from the cutter head by pressing against a side surface, and having a tip portion protruding into the guide hole and moving forward of the guide hole It functions as a seal positioning means for preventing the retreat of the seal.

In the cutter exchanging device according to the present invention, a guide cylinder in which the guide hole is formed is fixed at a predetermined position of the cutter head, and the cutter has a cutter housing portion communicating with the guide hole at the rear of the guide cylinder. The storage container is detachably provided.

In the cutter replacement method according to the present invention , the cutter supported by the cutter head is retracted along the guide hole, and a seal member is inserted in front of the cutter from the seal insertion hole communicating with the side of the guide hole. The cutter is pulled out of the cutter head and replaced in a state where the seal member is moved forward and brought into close contact with the peripheral surface of the guide hole to stop water.

The cutter replacement method according to the present invention is characterized in that the cutter replacement operation is performed in a state in which the seal member is moved forward to stop water and then the retreat of the seal member is prevented.

In the cutter replacement method according to the present invention, after the cutter is pulled out from the guide hole to the rear, a new cutter is inserted into the guide hole to move forward, and the seal member in the guide hole is moved outward by the cutter. The cutter is pushed and moved to a predetermined mounting position.

A tunnel excavator according to the present invention includes a tubular excavator main body, a propulsion jack that advances the excavator main body, and a plurality of radial excavators that are rotatably mounted on the front portion of the excavator main body. A cutter head having a cutter pork, a guide hole provided in the cutter pork along the front-rear direction, a movably supported along the guide hole, and a front end portion protruding forward from the cutter head. A cutter that can be held in position, a cutter moving means that moves the cutter back and forth, a seal insertion hole that communicates with the guide hole, and a cutter that is retracted from the seal insertion hole and inserted into a front portion of the guide hole and water shut-off possible sealing member is a sealing insert means for inserting the sealing member into the guide hole from the seal insertion hole, is inserted into the guide hole from the seal insertion hole Move the serial seal member forward and is characterized in that comprises a seal moving means for close contact with the peripheral surface of the guide hole.

According to the cutter exchanging device according to the present invention , the cutter head is provided with the guide hole along the front-rear direction, and the cutter moving means supports the cutter along the guide hole so as to be movable back and forth, and the front end portion from the cutter head. A seal insertion hole is provided that can be held at a position protruding forward, and is provided with a seal insertion hole that communicates with the guide hole. Since the seal insertion means for inserting the seal member into the guide hole from the seal insertion hole is provided, the cutter replacement work is performed with the seal member inserted in front of the cutter after the cutter is retracted along the guide hole and water is stopped. It is possible to improve the workability and safety of the cutter replacement work, and to stop water easily by simply bringing the seal member into close contact with the peripheral surface of the guide hole. Can, it is possible to simplify the apparatus.

According to the cutter exchanging device according to the present invention, since the sealant filling means for filling the sealant is provided in the front part of the guide hole where the cutter is retracted, the sealant is applied to the front part of the guide hole when the cutter is retracted. By filling, the water stop performance by the seal member can be improved.

According to the cutter exchanging device according to the present invention, the seal moving means for moving the seal member inserted into the guide hole from the seal insertion hole forward and closely contacting the peripheral surface of the guide hole is provided. The water stop performance by the seal member can be improved by securely contacting the peripheral surface.

According to the cutter exchanging device according to the present invention, since the seal positioning means for preventing the seal member moved to the front of the guide hole is provided, the movement of the seal member in close contact with the peripheral surface of the guide hole is prevented. Thus, reliable water stop can be performed.

According to the cutter exchanging device according to the present invention, an extrusion rod that pushes the seal member from the seal insertion hole to the guide hole is provided as the seal insertion means, and protrudes rearward from the seal member moved forward from the inside of the extrusion rod as the seal positioning means. Since the positioning rod is provided, the seal member can be pushed out into the guide hole with a simple configuration, and the seal member can be positioned.

According to the cutter exchanging device according to the present invention , the seal insertion means holds the seal member and is detachably attached to the seal insertion hole, and the seal insertion means is movably fitted in the seal support cylinder and sealed. Rod that pushes the seal from the seal insertion hole into the guide hole, a positioning rod that movably fits in the extrusion rod to prevent the seal member in the guide hole from moving backward, and a rod moving means that moves the extrusion rod and the positioning rod Therefore, when replacing the cutter, the seal insertion means can be attached to perform the cutter replacement operation, so that the workability can be improved and the apparatus can be simplified.

According to the cutter exchanging device according to the present invention, as the cutter moving means, the cutter exchanging screw rod that is rotatably supported at the rear of the cutter and the tip portion enters into the cutter and is screwed is provided. With this configuration, the cutter can be easily moved, and it is not necessary to form the cutter moving means in a long shape, so that the size and cost of the apparatus can be reduced.

According to the cutter exchanging device according to the present invention, a movable pin whose tip portion can protrude into the guide hole is movably attached to the guide cylinder in which the guide hole is formed, and the movable pin is attached to the side surface of the cutter. The seal functions to function as a cutter fixing means capable of holding the cutter in a position protruding forward from the cutter head by being pressed against the seal head, and preventing the retraction of the seal member whose front end portion protrudes into the guide hole and moves forward of the guide hole Since it is made to function as a positioning means, it becomes possible to hold the position of the cutter and prevent the seal member from retreating with only the moving pin, and it is possible to simplify the apparatus and reduce the cost.

According to the cutter exchanging device according to the present invention, a cutter storage container having a cutter storage portion that fixes a guide cylinder having a guide hole formed at a predetermined position of the cutter head and communicates with the guide hole behind the guide cylinder. Since it is detachably provided, the cutter can be replaced with a new one while being stored in the cutter storage container, the cutter replacement work is facilitated, the replacement time can be shortened, and workability can be improved. it can.

According to the cutter replacement method of the present invention, the cutter supported by the cutter head is retracted along the guide hole, and the seal member is inserted in front of the cutter from the seal insertion hole communicating with the side of the guide hole. Since the cutter is pulled out from the cutter head and replaced while the member is moved forward and brought into close contact with the peripheral surface of the guide hole, the workability and safety of the cutter replacement work can be improved. In addition, it is possible to easily stop the water simply by bringing the seal member into close contact with the peripheral surface of the guide hole, and the apparatus can be simplified.

According to the cutter replacement method of the present invention , the cutter replacement operation is performed in a state in which the seal member is moved forward and stopped to stop water, and then the seal member is prevented from moving backward. The close seal member is prevented from moving, and water can be reliably stopped .

According to the cutter replacement method of the present invention, after the cutter is pulled backward from the guide hole, a new cutter is inserted into the guide hole to move forward, and the seal member in the guide hole is pushed outward by the cutter to cut the cutter. Since the device is moved to a predetermined mounting position, it is possible to always stop water using a new seal member without collecting an inexpensive seal member, thereby enabling simplification of the apparatus and cost reduction. In addition, the cutter replacement operation can be repeated with a single device.

According to the tunnel excavator according to the present invention , a cylindrical excavator main body can be advanced by a propulsion jack, and a cutter head having a plurality of cutter spokes radially attached to the front portion is mounted so as to be driven to rotate, A guide hole is provided in the cutter pork along the front-rear direction, and the cutter moving means supports the cutter so that it can move back and forth along the guide hole, and the front end can be held at a position protruding forward from the cutter head. In addition, a seal insertion hole communicating with the guide hole is provided, and a seal member capable of stopping water is provided by being inserted into the front portion of the guide hole where the cutter is retracted from the seal insertion hole, and the seal member is guided from the seal insertion hole. a sealing insert means for inserting into the hole, sealing the inserted seal member from the seal insertion hole in the guide hole and moves forward to close contact with the peripheral surface of the guide hole transfer Is provided with the means, from the retracted along the cutter guide hole by inserting a sealing member in front at water stop state, can be performed cutter replacement, the cutter replacement workability and safety In addition to improving the performance, water can be easily stopped by simply bringing the seal member into close contact with the peripheral surface of the guide hole, thereby simplifying the device and reducing the cost.

  The best mode of the cutter exchanging apparatus, cutter exchanging method, and tunnel excavator of the present invention is to support the cutter movably back and forth along the guide hole in the cutter pork, and to provide a seal insertion hole communicating with the guide hole, The cutter is exchanged in a state where the seal member is inserted into the front portion of the guide hole where the cutter is retracted from the seal insertion hole and the water is stopped, and the embodiment of the present invention will be described in detail below with reference to the drawings. Explained.

  FIG. 1 is a schematic cross-sectional view of a tunnel excavator equipped with a cutter exchanging apparatus according to a first embodiment of the present invention, FIG. 2 is a front view of the tunnel excavator of the first embodiment, and FIG. Section III-III of FIG. 2, FIG. 4 shows a cross section of the cutter pork at the time of cutter replacement, and FIGS. 5 and 6 show a cross section of the cutter pork representing the work of replacing the preceding bit by the cutter replacement apparatus of the first embodiment.

  In the tunnel excavator of the first embodiment, as shown in FIGS. 1 and 2, the excavator main body 11 has a cylindrical front cylinder 12 and a rear cylinder 13 that are flexibly connected via a spherical bearing 14. It can be bent by a plurality of intermediate folding jacks 15. A rotating ring 16 is rotatably supported on the front portion of the front barrel 12, and a cutter head 18 is connected to the rotating ring 16 via a connecting beam 17. The cutter head 18 is configured by connecting cutter spokes 19 provided radially from the center by a connecting ring 20, and a plurality of leading bits 21 are attached to the front surface of each cutter spoke 19 along the longitudinal direction thereof. At the same time, a plurality of cutter bits 22 are mounted along the longitudinal direction on both sides of each cutter pork 19.

  A ring gear 23 is fixed to the rear portion of the rotating ring 16, and a plurality of cutter turning motors 24 are attached to the excavator main body 11 (front trunk 12). It meshes with the ring gear 23. Therefore, when the cutter turning motor 24 is driven to drive the drive gear 25 to rotate, the cutter head 18 can be rotated via the ring gear 23, the rotating ring 16, and the connecting beam 17.

  A bulkhead 26 is attached to the front portion of the front cylinder 12 so as to be located behind the cutter head 18, and a chamber 27 is formed between the cutter head 18 and the bulkhead 26. A plurality of stirring rods 28 are fixed toward the front. A screw conveyor 29 is disposed in the excavator main body 11 in a forwardly inclined state, and a front end passes through the bulkhead 26 and opens into the chamber 27.

  A plurality of shield jacks (propulsion jacks) 30 are juxtaposed along the circumferential direction on the inner peripheral surface of the front portion of the rear barrel 13, and the spreader 31 is pressed against the existing segment S by extending the shield jack 30 rearward. Thus, the excavator body 11 can be moved forward by the reaction force. In addition, the rear trunk 13 is provided with an erector device 32 for assembling the segment S on the inner wall surface of the existing tunnel.

  By the way, in the first embodiment, the leading bit 21 attached to the cutter head 18 can be exchanged from the inside of the machine by the cutter exchange device. That is, as shown in FIGS. 1 to 3, the cutter pork 19 in the cutter head 18 has a hollow square cross-sectional shape, and a plurality of leading bits 21 are replaceably mounted on the front surface portion, while a work port is disposed on the rear surface portion. 33 is formed and can be opened and closed by the work door 34.

  In the cutter exchanging apparatus of the present embodiment, the flange portion 42 of the guide tube 41 is fixed to the front surface portion of the cutter spoke 19 with a bolt 43 via the seal 40, and the guide tube 41 has a guide hole having a circular cross section. 44 is formed along the front-rear direction, the front end portion is open to the outside of the cutter pork 19, and the rear end portion is open to the cutter pork 19. The leading bit (cutter) 21 is configured such that a bit 46 for excavating the ground is integrally fixed to a front end portion of a bit body 45 having a cylindrical shape, and a through hole 47 is formed in the center portion along the longitudinal direction. . In the preceding bit 21, the bit main body 45 is movably fitted in the guide hole 44 of the guide cylinder 41 via a seal 48, and the bit 46 projects forward from the cutter spoke 19. A bit exchange jack (cutter moving means) 49 is detachably attached to the flange portion 42 of the guide cylinder 41, and a connecting plate 50 is fixed to the rear end portion of the preceding bit 21, so that the bit exchange can be performed. The tip of the drive rod 51 of the jack 49 is fastened to the end of the connecting plate 50.

  Accordingly, the leading bit 21 can be moved along the guide hole 44 of the guide cylinder 41 by expanding and contracting the bit exchanging jack 49. By contracting the bit exchanging jack 49, the bit 46 is cut by the bit 46. While the head can be moved to the projecting position projecting forward from the head 18 and can be held, the leading bit 21 can be retracted and pulled into the cutter pork 19 by extending the bit exchange jack 49. When the leading bit 21 is retracted, a spacer 52 (see FIG. 5) is interposed between the flange portion 42 of the guide tube 41 and the bit replacing jack 49 in accordance with the expansion and contraction of the bit replacing jack 49, so that the leading bit is 21 can be moved beyond the stroke of the bit exchange jack 49.

  Further, a seal insertion hole 53 that communicates with the guide hole 44 from the outside is formed at a substantially central portion in the longitudinal direction of the guide tube 41. The seal insertion hole 53 is used to prevent water from entering the cutter pork 19 by inserting a water stop rubber ball 54 as a seal member, which will be described later, into the guide hole 44 when the leading bit 21 is replaced. is there. In addition, since the seal insertion hole 53 is not required during normal tunnel excavation work, a lid member 55 for closing the seal insertion hole 53 is attached.

  As shown in FIG. 4, when replacing the worn leading bit 21, a seal insertion mechanism 56 that inserts the water-stopping rubber ball 54 into the front portion of the guide hole 44 in which the leading bit 21 has retreated from the seal insertion hole 53. The guide tube 41 can be mounted. That is, in the seal insertion mechanism 56, the seal support cylinder 57 is formed with a support hole 58 adapted to the seal insertion hole 53, and can be attached to the side of the guide cylinder 41 with a bolt (not shown) via a seal. ing. In this case, the guide hole 44, the seal insertion hole 53, and the support hole 58 have the same diameter, and the water-stopping rubber ball 54 is a sphere formed slightly larger than the diameter of the hole, and the outer peripheral surface is in close contact and water-stopping is possible. In addition, it can be moved by a predetermined pressing force.

  In the seal support cylinder 57, the water stop rubber ball 54 is fitted and held on the distal end side of the support hole 58, while the water stop rubber ball 54 is attached to the seal insertion hole 53 on the base end side of the support hole 58. An extrusion rod 59 that is pushed out from the guide hole 44 to the guide hole 44 is movably fitted. The push rod 59 includes an outer cylinder 61 that fits into the support hole 58 via a seal 60, and a positioning rod (seal positioning means) 63 that fits inside the outer cylinder 61 via a seal 62 so as to be movable. Has been. The positioning rod 63 prevents the water stop rubber ball 54 inserted in the guide hole 44 from retreating. An extrusion jack (rod moving means) 64 for independently moving the extrusion rod 59 and the positioning rod 63 can be mounted in the cutter pork 19, and the tip of the drive rod 65 is connected to the lid portion 59 a of the extrusion rod 59, Alternatively, it can be connected to the rear end of the positioning rod 63 from which the lid 59a has been removed.

  In the above-described through-hole 47 of the preceding bit 21, the water-stopping rubber ball 54 inserted into the guide hole 44 from the seal insertion hole 53 is moved forward so that the outer peripheral portion is in close contact with the peripheral surface of the guide hole 44. A rod (seal moving means) 66 is movably fitted. A seal moving jack 67 for moving the moving rod 66 can be mounted in the cutter pork 19, and the tip of the drive rod 68 can be connected to the connecting portion 66a of the moving rod 66 penetrating the connecting portion rate 50. It has become.

  Therefore, the water stop rubber ball 54 is guided from the seal insertion hole 53 by extending the push-out jack 64 and moving the push-out rod 59 in a state where the bit exchange jack 49 is extended and the preceding bit 21 is retracted by a predetermined stroke. The hole 44 can be pushed out. In this state, by extending the seal moving jack 67 and moving the moving rod 66 forward, the water stop rubber ball 54 can be pushed forward of the guide hole 44 and the outer peripheral portion can be brought into close contact with the peripheral surface of the guide hole 44. . Thereafter, the push-out jack 64 is extended to advance only the positioning rod 63, so that the positioning rod 63 protrudes to the rear of the water-stopping rubber ball 54 that has moved forward, thereby preventing the water-stopping rubber ball 54 from retreating due to earth pressure. be able to.

  In the guide tube 41, a filling hole (sealant filling means) 69 for filling the guide hole 44 with grease (sealant) is formed in a side portion in front of the seal insertion hole 53. A grease supply device is connected to the filling hole 69 via a connection hose (not shown). Accordingly, when the bit replacement jack 49 is extended to retract the preceding bit 21 and at the same time, the filling of the grease from the filling hole 69 to the guide hole 44 is started, the leading bit 21 is retracted in front of the guide hole 44 formed. Since the partial space is filled with grease, water intrusion into the guide hole 44 can be suppressed.

  Here, the tunnel excavation work by the tunnel excavator of the first embodiment and the exchanging work of the leading bit 21 by the cutter exchanging device will be described.

  In order to form a tunnel by excavation, as shown in FIGS. 1 and 2, the cutter head 18 is rotated by the cutter turning motor 24 and a plurality of shield jacks 30 are extended to excavate by pressing reaction force against the existing segment S. The machine body 11 is moved forward. Then, a number of preceding bits 21 and cutter bits 22 attached to the cutter head 18 excavate the ground in front, thereby forming a tunnel. And the earth and sand generated by the ground excavation of the cutter head 18 are taken into the chamber 27 from the opening of the cutter head 18 and discharged to the outside by the screw conveyor 29. On the other hand, any one of the shield jacks 30 is operated in the contracting direction to form a space with the existing segment S, and a new segment S is inserted into this space by the erector device 32. By assembling the ring in a ring shape, a tunnel of a predetermined length is continuously constructed.

  In the course of carrying out such tunnel excavation work, when the leading bit 21 is worn out by tunnel excavation work over a long period of time and the excavation efficiency decreases, it is necessary to replace it with a new one. When the replacement work of the leading bit 21 is performed, the cutter head 18 is turned and the excavator body 11 is stopped, but the cutter head 18 is moved at an angle at which the cutter pork 19 is in a vertical state or a horizontal state in consideration of workability. It is desirable to stop it. Then, after all the earth and sand in the periphery of the cutter head 18 and the chamber 27 are discharged, the operator opens the work door 34 from the excavator body 11, enters the cutter head 18 through the work port 33, and leads the bit 21. Perform replacement work.

  As shown in FIGS. 3 and 4, the operator first removes the cover member 55 attached to the guide cylinder 41 of the preceding bit 21 to be replaced in the cutter pork 19 of the cutter head 18 while exposing the seal. A seal insertion mechanism 56 is attached to the guide tube 41 corresponding to the insertion hole 53, and an extrusion jack 64 is attached in the cutter spoke 19. At this time, as the seal insertion mechanism 56, the water stop rubber ball 54 is attached to the distal end side of the seal support cylinder 57, while the push rod 59 and the positioning rod 63 are attached to the proximal end side.

  Then, after releasing the positioning lock (not shown) of the preceding bit 21, the bit replacement jack 49 is extended, and the preceding bit 21 is retracted along the guide hole 44. In this case, as shown in FIG. 5 (a), after the bit exchange jack 49 is extended, the connection with the guide tube 41 is released and contracted, and a spacer 52 is interposed therebetween to connect the bit exchange jack 49 again. The preceding bit 21 can be pulled into the guide hole 44 by a predetermined distance by repeating the operation of elongating. At this time, by injecting grease from the filling hole 69 toward the guide hole 44, the front space of the guide hole 44 formed by retreating the leading bit 21 is filled with grease, and into the guide hole 44. Suppresses flooding.

  When the leading end of the leading bit 21 moves backward in the guide hole 44 from the seal insertion hole 53 and the front space of the guide hole 44 is filled with grease, the drive rod 65 of the push jack 64 is moved to the push rod 59. By connecting to the lid portion 59 a and extending it to advance the push rod 59, the water stop rubber ball 54 is pushed out from the seal insertion hole 53 to the guide hole 44. Subsequently, as shown in FIG. 5 (b), a seal moving jack 67 is mounted in the cutter spoke 19 to connect the drive rod 68 to the connecting portion 66a of the moving rod 66, and this is extended to move the moving rod 66. By moving forward and pushing the water stop rubber ball 54 forward of the guide hole 44, the outer peripheral portion of the water stop rubber 54 is brought into close contact with the peripheral surface of the guide hole 44, so that water can be reliably immersed into the guide hole 44 from the outside. Stop. Then, the connection between the drive rod 65 of the extrusion jack 64 and the lid portion 59a of the extrusion rod 59 is released, the lid portion 59a is removed from the extrusion rod 59, and the drive rod 65 of the extrusion jack 64 is coupled to the positioning rod 63. In this state, the push-out jack 64 is extended to advance only the positioning rod 63, and the tip of the positioning rod 63 protrudes to the rear of the water-stopping rubber ball 54 that has moved forward. The rubber ball 54 is prevented from moving backward.

  When the tip end portion of the guide hole 44 supporting the leading bit 21 is reliably stopped in this way, as shown in FIG. After returning to the position, the seal moving jack 67 is removed from the cutter pork 19. Then, using the bit exchange jack 49 and the spacer 52 again, the preceding bit 21 is moved backward by the same operation as described above, and is completely pulled out from the guide hole 44 of the guide cylinder 41. Then, the connection between the drive rod 51 of the bit exchange jack 49 and the connecting plate 50 is released, the worn leading bit 21 is removed, and a new leading bit 21 is mounted.

  When the new leading bit 21 is mounted, as shown in FIG. 6A, the bit replacement jack 49 is contracted and the spacer 52 is removed to advance the leading bit 21, and the tip reaches the front side of the seal insertion hole 53. Stop at position. Here, the push-out jack 64 is contracted to retract the positioning rod 63, and is pulled back from the guide hole 44 into the push-out rod 59 through the seal insertion hole 53. Then, when the bit exchange jack 49 is contracted again and the spacer 52 is removed and the preceding bit 21 is advanced, the water stop with the leading end of the preceding bit 21 in the guide hole 44 as shown in FIG. The rubber ball 54 moves while being pushed outward, and the bit 46 moves outward of the cutter pork 19. Here, as shown in FIG. 3, the new leading bit 21 is fixed at a predetermined protruding position, the seal insertion mechanism 56 is removed from the guide tube 41, and the lid member 55 is fixed to close the seal insertion hole 53. The cutter replacement work is completed. Then, the shield jack 30 is extended while rotating the cutter head 18 again, and the excavator body 11 is advanced to excavate the ground in front to form a tunnel.

  The cutter pork 19 is provided with a plurality of preceding bits 21, and all the preceding bits 21 can be exchanged continuously by one cutter exchanging device simply by replenishing the water stop rubber balls 54.

  As described above, in the cutter exchanging apparatus and the tunnel excavator of the first embodiment, the guide cylinder 41 having the guide hole 44 is fixed in the cutter pork 19 of the cutter head 18, and the leading bit 21 is placed in the guide hole 44. A seal insertion hole 53 communicating with the guide hole 44 is formed in the guide cylinder 41, and a water-stopping rubber ball 54, an extrusion rod 59, and a positioning rod 53 are inserted into the seal insertion hole 43. The seal insertion mechanism 56 can be mounted, and the water stop rubber ball 54 is inserted into the front portion of the guide hole 44 in which the preceding bit 21 has been retracted to enable water stop.

Therefore, when the leading bit 21 is replaced, the leading bit 21 is retracted by the bit replacing jack 49 , and the water blocking rubber ball 54 is inserted into the guide hole 44 through the pushing rod 59 by the pushing jack 64, and the water is stopped. The leading bit 21 can be pulled out into the cutter pork 19 and the replacement work can be performed, so that the workability in the cutter replacement work and the safety of the operator can be improved, and the water stop rubber ball 54 is placed around the guide hole 44. Water can be easily stopped just by bringing it into close contact with the surface, and the cutter changing device can be simplified and miniaturized.

  Further, the filling hole 69 for filling the grease in the front space of the guide hole 44 in which the preceding bit 21 has retreated is formed on the side portion of the guide cylinder 41, so that the grease is applied to the guide hole 44 when the preceding bit 21 is retreated. Filling can prevent flooding and improve water stop performance.

  Further, the water stop rubber ball 54 inserted into the guide hole 44 from the seal insertion hole 53 is moved forward to be brought into close contact with the peripheral surface of the guide hole 44, so that the water stop rubber ball 54 is guided. It is possible to improve the water stopping performance by securely adhering to the peripheral surface of the hole 44 without any gap. Further, the positioning rod 63 that prevents the water-stopping rubber ball 54 that has moved to the front of the guide hole 44 from being provided in the push rod 59 can prevent the water-stopping rubber ball 54 from moving back due to water pressure or the like. In addition, it is possible to prevent the water stop performance from being lowered and to reduce the size of the apparatus.

  Further, since the seal insertion mechanism 56 including the seal support cylinder 57, the water stop rubber ball 54, the push rod 59, the positioning rod 63, and the like can be attached to and detached from the seal insertion hole 53 of the guide cylinder 41, the cutter can be replaced. Therefore, it is possible to replace the leading bit 21 by mounting the seal insertion mechanism 56, and to reduce the size of the cutter pork 19 and contribute to the weight reduction of the cutter head 18.

  When the new leading bit 21 is mounted, the leading bit 21 is advanced through the guide hole 44 and pushed out of the water stop rubber ball 54 to move to a predetermined mounting position. The water can always be stopped using a new one without collecting 54, the apparatus can be simplified and the cost can be reduced, and the water stop rubber ball 54 can be replenished with a single device. The cutter replacement operation can be performed repeatedly. In this case, since a new water-stopping rubber ball 54 is always used, a sufficient water-stopping performance can be ensured to ensure work safety.

  FIG. 7 is a cross-sectional view of a cutter pork representing a cutter exchanging apparatus according to a second embodiment of the present invention, FIG. 8 is a cross-sectional view of the cutter pork during cutter replacement, FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG. The cross section of the cutter pork showing the exchanging operation of the preceding bit by the cutter exchanging apparatus of the embodiment is shown. In addition, the same code | symbol is attached | subjected to the member which has the same function as what was demonstrated in the Example mentioned above, and the overlapping description is abbreviate | omitted.

  In the cutter exchanging device mounted on the tunnel excavator of the second embodiment, as shown in FIGS. 7 to 9, the flange portion 72 of the guide cylinder 71 is bolted to the front surface portion of the cutter pork 19 constituting the cutter head 18. 73, a guide hole 74 having a circular cross section is formed along the front-rear direction in the guide tube 71, the front end portion is opened outward from the cutter pork 19, and the rear end portion Is open in the cutas pork 19. The guide cylinder 71 has front and rear cylinder parts 71 a and 71 b that are detachably connected by bolts 75. The leading bit (cutter) 76 is configured by integrally fixing a bit 78 for excavating the ground to a front end portion of a bit body 77 having a cylindrical shape, and a rear end of a through hole 79 formed in the center portion of the bit body 77. A female screw part 80 is formed in the part. In the preceding bit 76, the bit body 77 is movably fitted in the guide hole 74 of the guide cylinder 71 via the seal 81, and the bit 78 protrudes forward from the cutter spoke 19. In addition, two screw holes 82 are formed in the guide tube 71 along the direction orthogonal to the guide hole 74 at positions facing the circumferential direction, and the tip of the screw hole 82 projects into the guide hole 74. Possible moving pins 83 are screwed together. The moving pin 83 can be moved in the axial direction by being rotated by a tool (not shown), and the cutter pin can be held at a position where the tip portion presses against the side surface of the preceding bit 76 and protrudes forward from the cutter head 18. It can function as a means, and also functions as a seal positioning means for preventing a water-stopping rubber ball 92 as a seal member, which will be described later, having a distal end projecting into the guide hole 74 and moving in front of the guide hole 74. Is possible.

  The rear end portion of the guide hole 74 of the guide cylinder 71 is opened in the cutter pork 19 and is used for pulling out the leading bit 76 into the cutter pork 19 when the leading bit 76 is replaced. In some cases, as shown in FIG. 7, a lid member 84 is attached to the rear end portion of the guide hole 74 so as to be closed. On the other hand, when the worn leading bit 76 is replaced, a bit storage container 85 that can accommodate the pulled leading bit 76 can be attached to the guide cylinder 71 as shown in FIG. The bit storage container 85 is detachably attached to the rear end portion of the guide tube 41 with the flange portion 86 from which the lid member 84 is removed by a bolt 87, and a storage portion 88 of the same diameter communicating with the guide hole 74 is formed inside. Has been. In addition, a bit exchange screw rod (cutter moving means) 89 that penetrates the center portion from the outside is rotatably supported in the bit storage container 85, and the tip portion is screwed into the female screw portion 80 of the preceding bit 76. On the other hand, the base end portion protrudes to the outside of the cutter storage container 85, and two nuts 90 are screwed together.

  Therefore, in a state where the bit storage container 85 is fixed to the rear end portion of the guide cylinder 41, each nut 90 is loosened, and the bit replacement screw rod 89 is rotated by a tool (not shown), whereby the tip end portion of the bit replacement screw rod 89 is obtained. Can be moved along the guide hole 74 of the guide cylinder 71. By rotating this bit replacement screw rod 89 in one direction, the leading bit 76 can be 78 can move to the projecting position projecting forward from the cutter head 18, while the bit replacement screw rod 89 is rotated in the other direction, so that the preceding bit 76 is retracted and inside the accommodating portion 88 of the bit accommodating container 85. Can be drawn into.

  Further, a seal insertion hole 91 communicating with the guide hole 74 from the outside is formed at a substantially central portion in the longitudinal direction of the guide cylinder 71. This seal insertion hole 91 is for inserting a water stop rubber ball 92 into the guide hole 74 when the leading bit 76 is replaced to stop the water and preventing water from entering into the cutter pork 19. In addition, since the seal insertion hole 91 is unnecessary during normal tunnel excavation work, a lid member 93 that closes the seal insertion hole 91 is attached.

  Then, as shown in FIG. 8, when the worn leading bit 76 is replaced, a seal insertion mechanism 94 that inserts the water-stopping rubber ball 92 into the front portion of the guide hole 74 in which the leading bit 76 has retreated from the seal insertion hole 91. The guide tube 71 can be mounted. That is, in this seal insertion mechanism 94, the seal support cylinder 95 is formed with a support hole 96 that fits into the seal insertion hole 91, and can be attached to the side of the guide cylinder 71 with a bolt (not shown) via a seal. ing. In this case, the guide hole 74, the seal insertion hole 91, and the support hole 96 have the same diameter, and the water stop rubber ball 92 is a sphere formed slightly larger than the diameter of the hole, and the outer peripheral surface is in close contact and water stop is possible. In addition, it can be moved by a predetermined pressing force.

  In the seal support cylinder 95, the water stop rubber ball 92 is fitted and held on the tip end side of the support hole 96, while the water stop rubber ball 92 is attached to the seal insertion hole 91 on the base end side of the support hole 96. An extrusion rod 97 that is pushed out from the guide hole 74 to the guide hole 74 is movably fitted through a seal member 98. The extrusion rod 97 has a tip that is in close contact with the outer peripheral surface of the water-stopping rubber ball 92 so that it is properly attached. It has a concave curved shape that can be extruded. The push rod 97 is attached to the rear end portion with mounting brackets 99 projecting on both sides, and the base end portions of a pair of push screw rods (rod moving means) 100 are rotatably supported on both sides of the mounting bracket 99. The distal end portion of each extruded screw rod 100 is screwed into a connection bracket 101 protruding from the seal support tube 95 on both sides.

  Therefore, in the state where the leading bit 76 is retracted by a predetermined stroke by the bit replacement screw rod 89, each push screw rod 100 is rotated by using a tool (not shown) to advance the push rod 97, whereby the water stop rubber ball 92 is moved. It can be pushed out from the seal insertion hole 91 into the guide hole 74. In this state, by rotating the bit replacement screw rod 89 to advance the preceding bit 76, the water stop rubber ball 92 can be pushed forward of the guide hole 74 and the outer peripheral portion can be brought into close contact with the peripheral surface of the guide hole 74. . In this case, the leading bit 76 and the bit replacement screw rod 89 function as seal moving means. Thereafter, by rotating each moving pin 83 and moving forward, the tip of the moving pin 83 protrudes from the rear part of the water-stopping rubber ball 92 that has moved forward to prevent the water-stopping rubber ball 92 from retreating due to earth pressure. be able to.

  Further, in the guide cylinder 71, a filling hole (sealant filling means) 102 for filling the guide hole 74 with grease (sealant) is formed in a side portion in front of the seal insertion hole 91. A grease supply device is connected to the filling hole 102 via a connection hose (not shown). Therefore, when the bit replacement screw rod 89 is rotated to retract the preceding bit 76 and at the same time filling of the grease from the filling hole 102 to the guide hole 74 is started, the leading bit 76 is retracted and the guide hole 74 is formed. The front space is filled with grease, so that water intrusion into the guide hole 74 can be suppressed.

  Here, the replacement work of the leading bit 76 by the cutter replacement apparatus of the second embodiment will be described.

  In the middle of tunnel excavation work by the tunnel excavator, when the leading bit 76 is worn and the excavation efficiency is lowered, it is necessary to replace it with a new one. As shown in FIGS. 7 and 8, the operator first removes the lid member 84 attached to the rear end portion of the guide cylinder 71 of the preceding bit 76 to be replaced in the cutter spoke 19 of the cutter head 18. The bit storage container 85 is attached to the guide cylinder 71 corresponding to the exposed preceding bit 76, and the tip of the bit replacement screw rod 89 is screwed into the female screw portion 80 of the preceding bit 76. Further, the lid member 93 attached to the side portion of the guide cylinder 71 of the preceding bit 76 to be replaced is removed, and the seal insertion mechanism 94 is attached to the guide cylinder 71 corresponding to the exposed seal insertion hole 91. At this time, as the seal insertion mechanism 94, the water stop rubber ball 92 is attached to the distal end side of the seal support cylinder 95, while the extrusion rod 97 and the extrusion screw rod 100 are attached to the proximal end side.

  Next, the two moving pins 83 are rotated and retracted with a predetermined tool to release the holding of the position of the preceding bit 76 with respect to the cutter pork 18, and then the bit replacement screw rod 89 is rotated with the predetermined tool to guide the guide hole 74. The leading bit 76 is moved back along the line. At this time, by injecting grease from the filling hole 102 toward the guide hole 74, the front space of the guide hole 74 formed by retreating the preceding bit 76 is filled with grease, and water is immersed in the guide hole 74. Suppress.

  Then, as shown in FIG. 10 (a), when the leading end of the leading bit 76 moves backward in the guide hole 74 from the seal insertion hole 91 and the front space of the guide hole 74 is filled with grease, The push screw rod 100 (see FIG. 9) is rotated by a predetermined tool to advance the push rod 97, thereby pushing out the water stop rubber ball 92 from the seal insertion hole 91 to the guide hole 74. Subsequently, as shown in FIG. 10B, the bit replacement screw rod 89 is rotated in the opposite direction to that described above, and the leading bit 76 is advanced along the guide hole 74 so that the water blocking rubber ball 92 is moved into the guide hole 74. By pushing forward, the outer peripheral portion of the water stop rubber 92 is brought into close contact with the peripheral surface of the guide hole 74 to reliably prevent water from entering the guide hole 74 from the outside. In this state, the two moving pins 83 are rotated in the opposite direction to the above and moved forward so that the tip portion protrudes into the guide hole 74 and is positioned at the rear portion of the water-stopping rubber ball 92 moved forward. The water stop rubber ball 92 is prevented from moving backward due to earth pressure or the like.

  When the leading end of the guide hole 74 that supports the leading bit 76 is reliably stopped in this way, the bit replacement screw rod 89 is rotated again to move the leading bit 76 backward from the guide hole 74 of the guide cylinder 71. Pulling backward, the preceding bit 76 is stored in the bit storage container 85. In this case, the preceding bit 76 is positioned in the rear cylinder portion 71 b of the guide cylinder 71 and the bit storage container 85 at the retracted position of the preceding bit 76. Therefore, by loosening the bolt 75 and removing the rear cylinder part 71 b and the bit storage container 85 from the front cylinder part 71 a of the guide cylinder 71, the preceding bit 76 that has been worn out from the cutter pork 19 can be removed.

When the rear cylinder portion 71b of the guide cylinder 71 and the bit storage container 85 containing the new leading bit 76 are attached to the rear end of the guide cylinder 71, as shown in FIG. Rotate to advance the leading bit 76, stop once at the position where the tip reaches the front of the seal insertion hole 91, rotate the two moving pins 83, retreat, and then rotate the bit replacement screw rod 89 again Then, when the leading bit 76 is advanced, the leading end of the leading bit 76 moves while pushing the water stop rubber ball 91 in the guide hole 74 outward, and the bit 78 moves outward of the cutter pork 19. Here, as shown in FIG. 9 , each moving pin 83 is rotated and moved forward and pressed against a new preceding bit 76 to hold the position at a predetermined protruding position, and the bit storage container 85 and the seal are inserted from the guide tube 71. While removing the mechanism 94 and fixing the lid members 84 and 93, the cutter replacement operation is completed.

  As described above, in the cutter exchanging apparatus and the tunnel excavator according to the second embodiment, the guide cylinder 71 having the guide hole 74 is fixed in the cutter pork 19 of the cutter head 18, and the leading bit 76 is inserted in the guide hole 74. And a cutter replacement screw rod 89 for moving the leading bit 76 is provided inside the rear end portion of the guide tube 71 so that the bit storage container 85 can be mounted, and the guide tube 71 communicates with the guide hole 74. The seal insertion hole 91 is formed, and a seal insertion mechanism 94 having a water stop rubber ball 92 and an extrusion rod 97 can be attached to the seal insertion hole 91, and the water stop rubber ball 92 is moved backward by the preceding bit 76. The water can be stopped by being inserted into the front portion of the guide hole 74.

  Accordingly, when the leading bit 76 is replaced, the leading bit 76 is retracted by the bit replacing screw rod 89, and the water blocking rubber ball 92 is inserted into the guide hole 74 through the pushing rod 97 by the pushing screw rod 100 to stop the water. Thus, the leading bit 76 can be pulled into the cutter container 85 to perform the replacement work, and the workability in the cutter replacement work and the safety of the operator can be improved, and the water stop rubber ball 92 is inserted into the guide hole. It is possible to stop the water easily by simply bringing it into close contact with the peripheral surface of 74, and the leading bit 76 and the water stopping rubber ball 92 can be moved only by rotating the screw rods 89 and 100. It can be simplified and downsized.

  Further, the position of the leading bit 76 protruding forward by the plurality of moving pins 83 can be maintained, and the water stop rubber ball 92 can be prevented from moving backward in the guide hole 74 when the bit is exchanged. Cost can be reduced.

  Further, when the bit is exchanged, the leading bit 76 is retracted by the bit replacing screw rod 89 and pulled into the cutter container 85, and the leading bit 76 is exchanged together with the bit container 85, so that the worn leading bit is worn. Since the removal of 76 and the attachment of the new leading bit 76 are performed as a unit, the workability in the cutter replacement work can be improved. In this case, the guide tube 71 can be divided into the front and the rear, and the rear tube portion 71b is used as a part of the bit storage container 85, whereby the storage portion of the leading bit 76 and the stroke to be pulled out can be shortened. This can contribute to downsizing.

  In each of the above-described embodiments, the water stop rubber balls 54 and 92 are moved forward by the moving rod 66 and the bit replacement screw rod 89 so as to be in close contact with the peripheral surfaces of the guide holes 44 and 74. The tip surfaces of 59 and 97 are formed so as to fit the water-stopping rubber balls 54 and 92, or are formed in a tapered shape, and the extrusion rods 59 and 97 push the water-stopping rubber balls 54 and 92 into the guide holes 44 and 74. Then, the positioning rod 63, the moving rod 66, etc. may be omitted by configuring so as to stop and hold the water later.

  In the above-described embodiment, the cutter replacement device for exchanging the preceding bits 21 and 76 has been described. However, the present invention can also be applied as a device for exchanging the cutter bit 22.

  The cutter exchanging apparatus and method according to the present invention can be applied to tunnel excavators such as earth pressure type, mud pressure type and mud type shield excavators, tunnel boring machines, and can be applied to various construction machines. It is.

1 is a schematic sectional view of a tunnel excavator equipped with a cutter exchanging apparatus according to a first embodiment of the present invention. It is a front view of the tunnel excavator of 1st Example. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. It is sectional drawing of a cutter pork at the time of cutter exchange. It is sectional drawing of the cutter pork showing the replacement | exchange operation | work of the preceding bit by the cutter replacement | exchange apparatus of 1st Example. It is sectional drawing of the cutter pork showing the replacement | exchange operation | work of the preceding bit by the cutter replacement | exchange apparatus of 1st Example. It is sectional drawing of the cutter pork showing the cutter exchange apparatus which concerns on 2nd Example of this invention. It is sectional drawing of a cutter pork at the time of cutter exchange. It is IX-IX sectional drawing of FIG. It is sectional drawing of the cutter pork showing the replacement | exchange operation | work of the preceding bit by the cutter replacement | exchange apparatus of 2nd Example.

Explanation of symbols

11 Excavator body 18 Cutter head 19 Cutter pork 21, 76 Leading bit (cutter)
22 Cutter bit 24 Cutter turning motor 30 Shield jack 32 Elector device 33 Work port 41, 71 Guide tube 44, 74 Guide hole 49 Bit replacement jack (cutter moving means)
53, 91 Seal insertion hole 54, 92 Water stop rubber ball (seal member)
55, 84, 93 Lid member 56, 94 Seal insertion mechanism 59, 97 Extrusion rod 63 Positioning rod (seal positioning means)
64 Extrusion jack (rod moving means)
66 Moving rod (seal moving means)
67 Seal moving jack 69,102 Grease filling hole (sealing agent filling means)
83 Moving pin (cutter fixing means, seal positioning means)
85 bit storage container (cutter storage container)
89 Bit exchange screw rod (cutter moving means, seal moving means)
100 Extrusion screw rod (rod moving means)

Claims (12)

A guide hole provided in the cutter head along the front-rear direction;
A cutter that is supported movably along the guide hole and can be held at a position where the front end projects forward from the cutter head;
Cutter moving means for moving the cutter back and forth;
A seal insertion hole communicating with the guide hole;
A seal member that is inserted into the front portion of the guide hole in which the cutter is retracted from the seal insertion hole and is capable of stopping water;
Seal insertion means for inserting the seal member from the seal insertion hole into the guide hole ;
A cutter exchanging device, comprising: seal moving means for moving the seal member inserted into the guide hole from the seal insertion hole forward and closely contacting the peripheral surface of the guide hole . The cutter exchanging apparatus according to claim 1,
A cutter replacement device characterized in that a sealant filling means for filling a sealant in a front portion of the guide hole in which the cutter is retracted is provided. The cutter exchanging apparatus according to claim 1 ,
A cutter exchanging apparatus, comprising: seal positioning means for preventing the seal member moved to the front of the guide hole from moving backward. In the cutter exchanging device according to claim 3 ,
The seal insertion means has an extrusion rod that pushes the seal member from the seal insertion hole into the guide hole,
The cutter exchanging apparatus, wherein the seal positioning means includes a positioning rod that protrudes rearward of the seal member that has moved forward from within the push rod. The cutter exchanging apparatus according to claim 1,
The seal insertion means includes
A seal support tube that holds the seal member and is detachable from the seal insertion hole;
An extrusion rod that is movably fitted into the seal support cylinder and pushes the seal member from the seal insertion hole to the guide hole;
A positioning rod that is movably fitted in the push rod to prevent the seal member from retreating in the guide hole;
A cutter exchanging device comprising: a rod moving means for moving the push rod and the positioning rod. The cutter exchanging apparatus according to claim 1,
The cutter moving device includes a cutter replacement screw rod that is rotatably supported behind the cutter and that has a tip portion that enters the cutter and is screwed therein. The cutter exchanging apparatus according to claim 1,
A moving pin is attached to the guide cylinder in which the guide hole is formed, and a movable pin whose tip can protrude into the guide hole is movably mounted.
The moving pin functions as a cutter fixing means whose tip is pressed against the side surface of the cutter and can hold the cutter in a position protruding forward from the cutter head, and the tip is projected into the guide hole. The cutter exchanging device, which functions as a seal positioning unit that prevents the seal member that has moved in front of the guide hole from moving backward. The cutter exchanging apparatus according to claim 1,
A guide cylinder in which the guide hole is formed is fixed at a predetermined position of the cutter head, and a cutter storage container having a cutter storage portion communicating with the guide hole is detachably provided behind the guide cylinder. A cutter exchanging device characterized by that. The cutter supported by the cutter head is retracted along the guide hole, the seal member is inserted in front of the cutter from the seal insertion hole communicating with the side of the guide hole, and the seal member is moved forward to A cutter exchanging method, wherein the cutter is pulled out and exchanged with the cutter head in a state where water is stuck to the peripheral surface of the guide hole. The cutter replacement method according to claim 9 , wherein
A cutter exchanging method characterized in that the cutter exchanging operation is carried out in a state where the seal member is moved forward to stop water and the seal member is prevented from retracting. The cutter replacement method according to claim 9 , wherein
After the cutter is pulled backward from the guide hole, a new cutter is inserted into the guide hole and moved forward, and the seal member in the guide hole is pushed outward by the cutter to move the cutter to a predetermined mounting position. The cutter changing method characterized by moving to A tubular excavator body,
A propulsion jack that advances the excavator body;
A cutter head having a plurality of cutter spokes mounted on the front portion of the excavator main body so as to be driven to rotate and mounted radially;
A guide hole provided along the front-rear direction in the cutter pork;
A cutter that is supported movably along the guide hole and can be held at a position where the front end projects forward from the cutter head;
Cutter moving means for moving the cutter back and forth;
A seal insertion hole communicating with the guide hole;
A seal member that is inserted into the front portion of the guide hole in which the cutter is retracted from the seal insertion hole and is capable of stopping water;
Seal insertion means for inserting the seal member from the seal insertion hole into the guide hole ;
A tunnel excavator comprising: seal moving means for moving the seal member inserted into the guide hole from the seal insertion hole forward and closely contacting the peripheral surface of the guide hole .

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