Tunnel excavator

Abstract

To provide a tunnel excavator capable of easily replacing a bit by suppressing the retreat of the tunnel excavator.SOLUTION: A tunnel excavator comprises an outer periphery exchange bit body 6 mounted on a rotating head 2 of the tunnel excavator, which is rotatable about a rotation axis along the tangent direction of the rotation circle of the rotating head 2 and has multiple exchange bits 61 in the circumferential direction of the rotation axis, and a movable bit body 10 mounted on the rotating head 2 and having a movable bit 101 that can move outward from the rotating head 2. The movable bit body 10 is positioned so that it can excavate an exchange bit trajectory range, which is the range of the trajectory along which the multiple exchange bits 61 move as the rotating axis rotates, when the tunnel excavator is stopped in the fore-aft direction of the tunnel.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a tunnel boring machine having a rotating head. [Background technology]

[0002] In recent years, tunnel construction using tunnel boring machines such as shield machines has become noticeably larger in diameter, longer in distance, and deeper. When excavating long-distance tunnels, there is a concern that the bit attached to the rotating head will wear out during the excavation.

[0003] In particular, when drilling long distances through sand or gravel layers, the carbide tip at the end of the bit will wear down or chip, making it necessary to replace the bit.

[0004] To change the bit, the ground in front of the drilling face had to be improved and workers had to enter the chamber between the cutter and the bulkhead to change the bit manually. However, not only was the ground improvement process expensive and time-consuming, but transporting and fixing a heavy bit in a small space was hard work that was dangerous.

[0005] In addition, when using mud shield tunneling machines under riverbeds or the seabed, divers had to enter the chamber and replace the bit using high pressure. However, working under high pressure has time limitations and carries a high risk of decompression sickness, so bit replacement work increases costs and extends construction time.

[0006] Patent document 1 discloses a bit switching device comprising: a cutter head having a head member arranged to rotate relative to the cutting face and extend radially; a rotating shaft that is rotatable around an axis extending along the rotation direction of the head member and has at least one end protruding from the side of the head member to outside the head member; a plurality of bits provided on the end of the rotating shaft protruding to the outside of the head member at a predetermined interval in the rotation direction; a rotation restraint means for restraining the rotation of the rotating shaft; and a rotation means for rotating the rotating shaft while the rotation restraint of the rotating shaft by the rotation restraint means is released. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4891661 Summary of the Invention [Problem to be solved by the invention]

[0008] Such rotatable multi-bit devices allow for easy replacement of worn bits without the need for dangerous and costly replacement procedures. When replacing a bit, the tunneling machine is stopped and a rotating shaft on which a plurality of bits are mounted is rotated to position a new, unworn bit on the excavation surface.

[0009] However, the surface of the ground has not been excavated to the extent that the bit has become shorter due to wear, and the new, longer bit cannot be rotated to the appropriate position because it is interfered with by the surface of the ground. Therefore, when replacing a bit positioned in front of the tunnel face, it is necessary to move the tunnel boring machine back by the amount that the bit has worn, i.e., the amount that the new bit interferes with the surface of the ground.

[0010] In contrast to this, in the bit switching device described in the above Patent Document 1, the height of the bit used initially is made larger than the height of the bit used next. In this way, the next bit used will be short, and so will have a short useful life.

[0011] On the other hand, if such a bit switching device is applied to a cutter head that excavates not only the front of the face, such as a dome-shaped face, but also the side of the face in an arc-shaped cross section, the height of the bit used next will be lower than the height of the bit used initially, making it impossible to ensure an amount of overcut that exceeds the amount of worn bit.

[0012] For this reason, it is conceivable to use a copy cutter to excavate the ground to the extent that the new bit would interfere, but the copy cutter is installed for curve construction and is not installed with consideration for such a bit switching device; it is installed behind the bit switching device, so in order to excavate the side of the tunnel face with the copy cutter and switch the bit (replace the bit), it is necessary to move the tunnel boring machine far back and align the position of the bit switching device with the side of the tunnel face excavated by the copy cutter. It is desirable to avoid retracting the tunnel boring machine as much as possible from the standpoint of face stability and sealing.

[0013] The problem to be solved by the present invention is to provide a tunnel boring machine that is capable of suppressing backward movement of the tunnel boring machine and allowing easy replacement of a bit. [Means for solving the problem]

[0014] The invention of claim 1 is a tunnel boring machine having a rotating head, comprising: an exchangeable bit body mounted on the rotating head and rotatable about a rotational axis along a tangent direction of the rotation circle of the rotating head, the exchangeable bit body having a plurality of exchangeable bits in the circumferential direction of the rotational axis; and a movable bit body mounted on the rotating head and having movable bits movable outward from the rotating head, the movable bit body being positioned so that when the tunnel boring machine is stopped in the forward / backward direction of the tunnel, it is possible to excavate an exchangeable bit trajectory range, which is the range of the trajectory along which the plurality of exchangeable bits move by the rotation of the rotational axis of the exchangeable bit body.

[0015] The invention of claim 2 is the tunnel boring machine described in claim 1, characterized in that at least one of the multiple replacement bits of the replacement bit body is positioned so as to be able to excavate the face side, and the movable bit body has a movable bit that is movable outside the rotating head toward the face side.

[0016] The invention of claim 3 is the tunnel boring machine described in claim 1, characterized in that at least one of the multiple replacement bits of the replacement bit body is positioned so as to be able to excavate the front of the face, and the movable bit body has a movable bit that is movable outside the rotating head toward the front of the face.

[0017] The invention of claim 4 is a tunnel boring machine as described in any one of claims 1 to 3, characterized in that the movable bit body is provided in multiple units on the rotating head, and each of the movable bits is arranged so that it can excavate in a different range within the replacement bit trajectory range.

[0018] The invention of claim 5 is a tunnel boring machine having a rotating head, the tunnel boring machine comprising an exchange bit body provided on the rotating head and rotatable about a rotation axis along a tangent direction of the rotation circle of the rotating head, the exchange bit body having a plurality of exchange bits in the circumferential direction of the rotation axis, the exchange bit body being capable of moving the exchange bits outward from a normal excavation position of the rotating head, the exchange bit body being arranged so that when the exchange bit body has moved outward from the normal excavation position, it is possible to excavate an exchange bit trajectory range, which is the range of the trajectory along which the plurality of exchange bits move by the rotation of the rotation axis of the exchange bit body at the normal excavation position.

[0019] The invention of claim 6 is the tunnel boring machine described in claim 5, characterized in that at least one of the multiple replacement bits of the replacement bit body is arranged so as to be able to excavate the face side, and the replacement bit body has a replacement bit that is movable outside the rotating head toward the face side.

[0020] The invention of claim 7 is the tunnel boring machine described in claim 5, characterized in that at least one of the multiple replacement bits of the replacement bit body is arranged so as to be able to excavate the front of the face, and the replacement bit body has a replacement bit that is movable outside the rotating head toward the front of the face. Effect of the Invention

[0021] According to the present invention, when the replacement bit used to cut the replacement bit body becomes worn and short, the moving bit moves outward from the rotating head to excavate the replacement bit trajectory range, and a space for accommodating a longer replacement bit is formed in the ground outside the worn replacement bit. Therefore, when the replacement bit body is rotated to replace the worn replacement bit with a new replacement bit, the tunnel boring machine is prevented from being moved backwards significantly, and therefore the sealing properties of the tunnel boring machine and the stability of the face are less likely to be adversely affected.

[0022] In addition, since the replacement bit of the replacement bit body is positioned so as to be able to excavate the side of the face, and the movable bit body has a movable bit that can be moved toward the side of the face, retreat of the tunnel boring machine is suppressed, the replacement bit body which excavates the side of the face can be rotated, and worn replacement bits can be easily replaced.

[0023] In addition, by positioning the replacement bit of the replacement bit body so that it can excavate the front of the face, and by having a movable bit body that can move toward the front of the face, retreat of the tunnel boring machine is suppressed, the replacement bit body that cuts the front of the face can be rotated, and worn replacement bits can be easily replaced.

[0024] In addition, if multiple movable bit bodies are provided on the rotating head and each movable bit is arranged so that it can excavate in a different range within the replacement bit trajectory range, the face can be excavated over a wide range, and the amount of retreat of the tunnel boring machine can be further reduced.

[0025] According to the present invention, when the replacement bit used to cut the replacement bit body becomes worn, the replacement bit body itself is moved outward to excavate the replacement bit trajectory range, and when the replacement bit is returned to its original position, a space for accommodating a long replacement bit is formed in the ground outside the worn replacement bit. This prevents the tunnel boring machine from having to retreat significantly when the replacement bit body is rotated to replace the worn replacement bit with a new replacement bit, so that the sealing properties of the tunnel boring machine and the stability of the face are less likely to be adversely affected and there is no need for a movable bit separate from the replacement bit body.

[0026] In addition, the replacement bit of the replacement bit body is positioned so that it can excavate the side of the face, and the replacement bit body has a replacement bit that can be moved toward the side of the face, thereby preventing the tunnel boring machine from retreating, rotating the replacement bit body that excavates the side of the face, and easily replacing worn replacement bits.

[0027] In addition, the replacement bit of the replacement bit body is positioned so that it can excavate the front of the face, and the replacement bit body has a replacement bit that can be moved toward the front of the face, thereby preventing the tunnel boring machine from retreating, rotating the replacement bit body that excavates the front of the face, and easily replacing worn replacement bits. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a front view of a tunnel boring machine showing a first embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view of a main part of a tunnel boring machine showing a first embodiment of the present invention. [Diagram 3] 3A and 3B are diagrams showing an outer periphery replacement bit body attachment portion of a cutter spoke of a rotating head according to a first embodiment of the present invention, in which FIG. 3A is a side view and FIG. 3B is a front view. [Figure 4] 4A and 4B are diagrams showing an inner replacement bit body attachment portion of a cutter spoke of a rotating head according to a first embodiment of the present invention, in which FIG. 4A is a side view and FIG. 4B is a front view. [Diagram 5]FIG. 2 is a side view showing the replacement bit body rotating mechanism according to the first embodiment of the present invention. [Figure 6] FIG. 2 is a side view showing the replacement bit body rotation stopping mechanism according to the first embodiment of the present invention. [Figure 7] 7A and 7B are cross-sectional views showing the movable bit body mounting portion of the cutter spoke of the rotating head in the first embodiment of the present invention, where FIG. 7(A) is a side view when the movable bit is stored, and FIG. 7(B) is a side view when the movable bit is extended. [Figure 8] FIG. 2 is a side view of the outer periphery exchange bit body according to the first embodiment of the present invention during excavation in a tunnel. [Figure 9] FIG. 2 is a side view of an outer periphery replacement bit body in a tunnel according to the first embodiment of the present invention when the replacement bit is worn. [Figure 10] FIG. 2 is a side view of the moving bit body in the tunnel according to the first embodiment of the present invention when the moving bit is stored. [Figure 11] FIG. 2 is a side view of the moving bit body in the tunnel according to the first embodiment of the present invention when the moving bit is extended. [Figure 12] FIG. 2 is a side view of the moving bit body in the tunnel according to the first embodiment of the present invention when the moving bit is stored. [Figure 13] FIG. 2 is a side view of an outer periphery exchange bit body in a tunnel according to the first embodiment of the present invention when the tunnel boring machine is retreating. [Figure 14] FIG. 2 is a side view of an outer-periphery exchange bit body during rotation in a tunnel according to the first embodiment of the present invention. [Figure 15] FIG. 4 is a front view of a tunnel boring machine showing a second embodiment of the present invention. [Figure 16] FIG. 11 is a side view of a moving bit body in a tunnel according to a second embodiment of the present invention when the moving bit is extended. [Figure 17] FIG. 11 is a front view of a tunnel boring machine showing a third embodiment of the present invention. [Figure 18] FIG. 11 is a side view of a moving bit body in a tunnel according to a third embodiment of the present invention when the moving bit is extended. [Figure 19] FIG. 13 is a side view of an outer periphery exchange bit body in a tunnel according to a fourth embodiment of the present invention. [Figure 20] FIG. 13 is a side view of an inner replacement bit body in a tunnel according to a fourth embodiment of the present invention. [Figure 21] FIG. 11 is a front view of a tunnel boring machine showing a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. It goes without saying that the present invention is not limited to the embodiments.

[0030] [First embodiment] A first embodiment of the present invention will be described with reference to FIGS.

[0031] FIG. 1 is a front view of a tunnel excavation machine, FIG. 2 is a cross-sectional view of key parts of the tunnel excavation machine, FIG. 3 is a diagram showing the attachment portion of the outer peripheral replacement bit body to the cutter spokes of the rotating head, FIG. 4 is a diagram showing the attachment portion of the inner peripheral replacement bit body to the cutter spokes of the rotating head, FIG. 5 is a side view showing the replacement bit body rotation mechanism, FIG. 6 is a side view showing the replacement bit body rotation stop mechanism, FIG. 7 is a cross-sectional view showing the attachment portion of the movable bit body to the cutter spokes of the rotating head, FIG. 8 is a side view of the outer peripheral replacement bit body when excavating, FIG. 9 is a side view of the outer peripheral replacement bit body when the replacement bit is worn, FIG. 10 is a side view of the movable bit body when the moving bit is stored, FIG. 11 is a side view of the moving bit of the movable bit body when it is extended, FIG. 12 is a side view of the moving bit of the movable bit body inside the tunnel when it is stored, FIG. 13 is a side view of the outer peripheral replacement bit body when the tunnel excavation machine is retracting, and FIG. 14 is a side view of the outer peripheral replacement bit body when rotating.

[0032] As shown in Figures 1 and 2, the tunnel boring machine of this embodiment is a shield machine 1 which has a circular rotating head 2 and a chamber 3 formed on the back side of the rotating head 2, and moves forward while excavating the natural ground by rotating the rotating head 2.

[0033] The rotating head 2 can rotate in both clockwise and counterclockwise directions.

[0034] The excavated soil is taken into the chamber 3 and discharged rearward via the soil discharge device 4. The rotating head 2 is provided on the front end surface of the shield tunneling machine 1, and rotates around the central axis of the shield tunneling machine 1 by driving a rotating head drive unit 5 connected to the rotating head 2.

[0035] The rotary head 2 includes eight cutter spokes 20 arranged radially from the center of rotation at equal intervals, and a cutter ring 21 that connects the tips of the cutter spokes 20 to form the outer periphery of the rotary head 2.

[0036] The cutter spokes 20 are composed of, in clockwise order from the first cutter spoke 201 located directly at the top in Figure 1, a second cutter spoke 202, a third cutter spoke 203, a fourth cutter spoke 204, a fifth cutter spoke 205, a sixth cutter spoke 206, a seventh cutter spoke 207, and an eighth cutter spoke 208.

[0037] Of the eight cutter spokes 20, three cutter spokes 20 (the first cutter spoke 201, the fifth cutter spoke 205, and the eighth cutter spoke 208) have a pair of outer periphery replacement bit bodies 6 provided at one location on both side surfaces of their tip portions.

[0038] A pair of inner replacement bit bodies 7 are provided on both sides of each cutter spoke 20 at opposing positions from the tip end to the inner peripheral side.

[0039] Specifically, a pair of inner replacement bit bodies 7 are provided at three locations on the first cutter spoke 201, the fourth cutter spoke 204, the sixth cutter spoke 206, the seventh cutter spoke 207 and the eighth cutter spoke 208, at four locations on the second cutter spoke 202 and the third cutter spoke 203, and at two locations on the fifth cutter spoke 205.

[0040] The copy cutter 22 is housed at the tip of the third cutter spoke 203 .

[0041] The outer periphery replacement bit body 6 provided on the first cutter spoke 201 will be described with reference to Fig. 3. The outer periphery replacement bit bodies 6 provided on the other cutter spokes 20 have the same configuration, so description thereof will be omitted.

[0042] As shown in Fig. 3(A), the outer periphery replacement bit body 6 is formed by arranging nine rectangular replacement bits 61 at equal intervals (at an angle of 40 degrees) around the outer periphery of a circular disk 60. A bit tip 63 with high hardness is provided at the tip of the replacement bit 61.

[0043] 3(B), the bit tips 63 are provided at the tip of the replacement bit 61 on both sides in the rotation direction of the rotating head 2. Therefore, drilling can be performed with one replacement bit 61 whether the rotating head 2 is rotated clockwise or counterclockwise.

[0044] Since outer circumferential replacement bit bodies 6 are provided on both sides of one cutter spoke 20, and each replacement bit 61 is provided opposite each other, excavation can be performed in two passes using these replacement bits 61 (Figures 1 and 3(B)).

[0045] The outer periphery replacement bit body 6 is attached to the cutter spokes 20 so as to be rotatable around a rotation axis 62 provided along the tangential direction of the rotation circle of the rotating head 2. A pair of outer periphery replacement bit bodies 6 provided on both side surfaces of the tip of the first cutter spoke 201 share the rotation axis 62.

[0046] At least one of the multiple replacement bits 61 of the outer circumferential replacement bit body 6 is arranged so as to be able to excavate the side surface of the face, and at least one of the multiple replacement bits 61 is arranged so as to be able to excavate the front surface of the face. Of the replacement bits 61, one replacement bit 61a protrudes forward of the rotating head 2, the adjacent replacement bit 61b protrudes diagonally forward toward the outer periphery of the rotating head 2, and the adjacent replacement bit 61c is positioned so as to protrude slightly forward from the outer periphery of the rotating head 2.

[0047] Therefore, when the rotating head 2 rotates, the outer peripheral replacement bit body 6 moves in the circumferential direction in conjunction with the rotation of the rotating head 2, and the replacement bits 61a, 61b, and 61c cut the ground (the front and side surfaces of the working face) in a generally arc-shaped cross section from the front to the side of the rotating head 2. Replacement bits 61d, 61e, 61f, 61g, 61h, and 61i other than the replacement bits 61a, 61b, and 61c are positioned in positions that do not contribute to excavation.

[0048] In addition, if the outer periphery replacement bit bodies 6 provided on the left and right side surfaces of the cutter spokes 20 are shifted in phase from each other by about 20 degrees, incomplete digging is less likely to occur in the arc-shaped corners of the face.

[0049] The inner replacement bit body 7 provided on the first cutter spoke 201 will be described with reference to Fig. 4. The inner replacement bit bodies 7 provided on the other cutter spokes 20 have the same configuration, so description thereof will be omitted.

[0050] 4(A), the inner replacement bit body 7 is formed by arranging a plurality of (four in this embodiment) angular replacement bits 71 at equal intervals (at 90 degree angles) in the circumferential direction around the outer periphery of a circular disk 70. A bit tip 73 with high hardness is provided at the tip of the replacement bit 71.

[0051] 4(B), the bit tips 73 are provided at the tip of the replacement bit 71 on both sides in the rotation direction of the rotating head 2. Therefore, drilling can be performed with one replacement bit 71 whether the rotating head 2 is rotated clockwise or counterclockwise.

[0052] Inner replacement bit bodies 7 are provided on both sides of one cutter spoke 20, and each replacement bit 71 is provided opposite each other, so that excavation can be performed in two passes using these replacement bits 71 (Figures 1 and 4(B)).

[0053] The inner replacement bit body 7 is attached to the cutter spokes 20 so as to be rotatable around a rotation axis 72 that is provided along the tangential direction of the rotation circle of the rotating head 2. A pair of inner replacement bit bodies 7 provided on both inner side surfaces of the first cutter spoke 201 share the rotation axis 72.

[0054] At least one of the multiple replacement bits 71 of the inner replacement bit body 7 is disposed so as to be able to excavate the front surface of the face. Of the replacement bits 71, one replacement bit 71a protrudes outward from the front surface of the rotary head 2.

[0055] Therefore, when the rotary head 2 rotates, the inner replacement bit body 7 moves in the circumferential direction in conjunction with the rotation of the rotary head 2, and the replacement bit 71a cuts the natural ground (the front surface of the drilling face) in front of the rotary head 2. The replacement bits 71b, 71c, and 71d other than the replacement bit 71a are positioned so as not to contribute to excavation.

[0056] The inner peripheral replaceable bit bodies 7 attached to the multiple cutter spokes 20 are arranged offset from one another so that the entire area in front of the rotary head 2 can be excavated.

[0057] The outer circumferential replacement bit body 6 and the inner circumferential replacement bit body 7 are connected to an replacement bit body rotation mechanism which rotates the replacement bit body when replacing a bit, and an replacement bit body stopping mechanism which stops the replacement bit body from rotating when drilling.

[0058] In the following, the replacement bit body rotating mechanism and replacement bit body stopping mechanism of the outer replacement bit body 6 will be described with reference to Figs. 5 and 6, and the mechanism for the inner replacement bit body 7 will not be described since it has the same mechanism.

[0059] As shown in Fig. 5, an exchange bit body rotation mechanism 8 housed in a cutter spoke 20 is connected to the outer periphery exchange bit body 6. In Fig. 5, the right side of the paper surface is the traveling direction of the shield machine 1.

[0060] The replacement bit body rotation mechanism 8 has a worm gear 80 fixed to the outer periphery of the rotating shaft 62 of the outer replacement bit body 6, a worm 81 meshing with the worm gear 80, a worm shaft 82 to which the worm 81 is fixed, and a worm shaft drive motor 83 whose output end is connected to the worm shaft 82.

[0061] When the worm shaft drive motor 83 is driven, the worm shaft 82 and the worm 81 rotate, the worm gear 80 and the rotating shaft 62 rotate, and the outer periphery exchange bit body 6 provided at the end of the rotating shaft 62 rotates about the rotating shaft 62. By controlling this drive, the outer periphery exchange bit body 6 is rotated a predetermined angle.

[0062] This allows the replacement bit 61 protruding to the outside of the rotary head 2 of the outer periphery replacement bit body 6 to be replaced with another replacement bit 61.

[0063] As shown in FIG. 6, a replacement bit body rotation stopping mechanism 9 housed in a cutter spoke 20 is connected to the outer circumferential replacement bit body 6 .

[0064] The replacement bit body rotation stopping mechanism 9 has a rotation stopping disk 90 fixed to the outer periphery of the rotation shaft 62 of the outer periphery replacement bit body 6, a jack holding tube 91 installed in a position opposite to the outer periphery of the rotation stopping disk 90, and a jack 92 stored in the jack holding tube 91.

[0065] On the outer periphery of the rotation stop disk 90, for example, tooth grooves 900 are formed in the same number as the replacement bits 61 of the outer periphery replacement bit body 6.

[0066] The jack 92 has a cylinder 920 , a rod 921 which extends and retracts from the cylinder 920 toward the outer periphery of the rotation stop disk 90 , and a locking tooth 922 which protrudes from the tip of the rod 921 .

[0067] When the rod 921 is extended toward the rotation stop disc 90 and the locking teeth 922 are locked into the tooth grooves 900 of the rotation stop disc 90, the rotation of the rotation stop disc 90 and the rotating shaft 62 to which the rotation stop disc 90 is fixed is restricted, and the outer periphery replacement bit body 6 can no longer rotate.

[0068] When the rod 921 is retracted to cause the locking tooth 922 to escape from the tooth groove 900, the rotation restriction of the rotation stop disk 90 and the rotating shaft 62 is released, and the outer periphery replacement bit body 6 becomes rotatable by the operation of the replacement bit body rotation mechanism 8.

[0069] As shown in FIG. 7, a moving bit body 10 is provided at the tip end of one cutter spoke 20. Specifically, the moving bit body 10 is provided at the tip of the seventh cutter spoke 207 (FIG. 1).

[0070] The moving bit body 10 has a base 10a provided on the frame of the seventh cutter spoke 207, a moving bit cylinder 100, and a moving bit 101 that can be housed in the moving bit cylinder 100 and moves from the moving bit cylinder 100 to extend and retract.

[0071] The movable bit cylinder 100 and the movable bit 101 of the movable bit body 10 are inclined at the same angle, via the base 10a, facing the replacement bit 61c of the outer periphery replacement bit body 6, which protrudes slightly forward from the outer periphery and excavates the outermost periphery of the rotating head 2.

[0072] The movable bit body 10 needs to be positioned as far forward as possible of the cutter spoke 20 to match the replacement bit 61c, but in order to prevent the base on the base 10a side from protruding forward from the front frame of the cutter spoke 20, it is positioned at an angle so as to protrude forward as described above.

[0073] Further, the copy cutter 22 is provided at the center position in the front-rear direction of the cutter spoke 20 (the third cutter spoke 203) (not shown), and the movable bit body 10 is provided on the front side of the cutter spoke 20 (the seventh cutter spoke 207) facing the replacement bit 61c as described above. In other words, the copy cutter 22 is provided behind the replacement bit 61c and is located in a position that does not affect the excavation range of the replacement bit 61 during normal excavation or when stopped.

[0074] 7, the movable bit 101 is wider than the replacement bit 61, and can move outward from the rotary head 2 through openings (not shown) formed in the cutter spokes 20 until it reaches the same height as the tip of the replacement bit 61c before its tip becomes worn. The movable bit body 10 is extended and retracted by a hydraulic mechanism (not shown).

[0075] Fig. 7(A) shows the state when the shield machine 1 is excavating and the moving bit 101 has moved into and been stored in the moving bit cylinder 100, and Fig. 7(B) shows the state when the shield machine 1 is stopped excavating and the moving bit 101 has moved outward from the moving bit cylinder 100 and away from the cutter spokes 20. In this way, the moving bit body 10 is extendable and retractable.

[0076] The tip of the movable bit 101 has a shape corresponding to the tip shape of the replacement bit 61 of the outer circumferential replacement bit body 6. The tip of the movable bit 101 is provided with a bit tip (not shown).

[0077] The following describes a method for replacing the replacement bits 61, 71 of the outer-periphery replacement bit body 6 and the inner-periphery replacement bit body 7 during tunnel excavation by the shield machine 1. Note that replacement of the outer-periphery replacement bit body 6 will be described with reference to the drawings, and replacement of the inner-periphery replacement bit body 7 will be described without the drawings.

[0078] As shown in Figure 8, while the shield machine 1 is excavating, as the rotating head 2 rotates, the replacement bits 61a, 61b, 61c of the outer peripheral replacement bit bodies 6 attached to the cutter spokes 20 excavate the cross-sectional corner portion of the face of the ground G (from the front to the side of the face (in front and to the side of the rotating head 2)).

[0079] At this time, although not shown, the replacement bit 71a of the inner peripheral replacement bit body 7 excavates the front surface of the face (in front of the rotary head 2).

[0080] As shown in Figure 9, when the shield machine 1 excavates a long distance, for example, the replacement bits 61a, 61b, 61c that excavate the natural ground wear out and become shorter, and the excavation surface A of the face when worn is located further rearward and inward (towards the rotating head 2) than the excavation surface B of the face when the replacement bits 61a, 61b, 61c are not worn.

[0081] Although not shown, the replacement bit 71a of the inner peripheral replacement bit body 7 also wears, and a worn excavation surface A of the face is generated.

[0082] As shown in FIG. 10, the moving bit 101 of the moving bit body 10 is stored inside the rotating head 2 (seventh cutter spoke 207) until the replacement bits 61a, 61b, 61c are worn down by excavation by the shield machine and need to be replaced.

[0083] When the replacement bits 61 a , 61 b ​​, 61 c become worn, it is necessary to rotate the outer periphery replacement bit body 6 forward so that a new replacement bit 61 protrudes to the outside of the rotary head 2 .

[0084] However, since all replacement bits 61 are the same length when new, the new replacement bits 61d, 61e, 61f are longer than the worn replacement bits 61a, 61b, 61c, so the new replacement bit 61d will hit the rear end of the excavation surface A of the worn face that reaches the tips of the replacement bits 61a, 61b, 61c, and the outer periphery replacement bit body 6 cannot be rotated forward.

[0085] Therefore, as shown in Figure 11, the shield tunneling machine 1 is stopped in the fore-and-aft direction of the tunnel, and the movable bit 101 of the movable bit body 10 is moved along the replacement bit 61c toward the side of the face, so that it protrudes outside the rotating head 2 until it reaches the same height as the tip of the replacement bit 61c before its tip became worn.

[0086] When the rotating head 2 is rotated in this state, the movable bit 101 cuts the side of the face, which is a portion that could not be cut by the worn replacement bit 61c, in the replacement bit trajectory range, which is the range of the trajectory along which the replacement bit 61 moves as the outer periphery replacement bit body 6 rotates. In other words, the movable bit body 10 is arranged so that it can excavate the replacement bit trajectory range, which is the range of the trajectory along which the multiple replacement bits 61 move as the rotating shaft 62 of the outer periphery replacement bit body 6 rotates, while the shield machine 1 is stopped in the fore-aft direction of the tunnel.

[0087] In addition, if it is difficult to protrude the tip of the moving bit 101 to the same height as the tip of the replacement bit 61c before it became worn while the rotating head 2 is stopped, the moving bit 101 may be moved while the rotating head 2 is rotated to gradually widen the width.

[0088] Next, as shown in FIG. 12, the moving bit 101 is retreated and stored in the moving bit cylinder 100 inside the rotating head 2.

[0089] Next, as shown in Figure 13, the shield machine 1 is slightly retreated (the retreat amount S is the amount of wear on the replacement bit 61a that excavates the front of the face plus the amount that is sufficient for widening excavation with the movable bit 101), and the outer replacement bit body 6 and the inner replacement bit body 7 are moved away from the surface of the ground.

[0090] Next, as shown in Figure 14, the outer periphery replacement bit body 6 is rotated forward by 120 degrees to move the worn replacement bits 61a, 61b, 61c away from the face, and the three new replacement bits 61d, 61e, 61f are caused to protrude to the positions where the replacement bits 61a, 61b, 61c were located, i.e., forward, forward-side and to the side of the rotating head 2.

[0091] In addition, the inner peripheral replacement bit body 7 is rotated forward by 90 degrees to move the worn replacement bit 71 a away from the face, and a new replacement bit 71 b adjacent to the replacement bit 71 a is caused to protrude forward of the rotary head 2 .

[0092] In order to rotate the outer periphery replacement bit body 6 and the inner periphery replacement bit body 7, the shield tunneling machine 1 needs to be retreated, but since most of the face side has been excavated by the movable bit 101, and even if a small amount remains, it can be destroyed by the rotation of the outer periphery replacement bit body 6, the retreat amount S of the shield tunneling machine 1 need only be small, and the sealing material provided on the shield tunneling machine 1 will not be turned over.

[0093] In this embodiment, three sets of replacement bits 61 are provided on the outer replacement bit body 6, allowing for two replacements from the beginning, and four sets of replacement bits 71 are provided on the inner replacement bit body 7, allowing for three replacements from the beginning.

[0094] [Second embodiment] A second embodiment of the present invention will be described with reference to Figures 15 and 16. Note that a description of the same parts as in the first embodiment will be omitted, and differences will be mainly described.

[0095] The second embodiment is the same as the first embodiment except that a second moving bit body 10' is further provided.

[0096] The second movable bit body 10' is provided for excavating the ground G which can no longer be excavated due to wear of the replacement bit 61b located at a position protruding obliquely to the front side of the face of the outer circumferential replacement bit body 6.

[0097] The second moving bit body 10 ′ has a structure similar to that of the moving bit body 10 of the first embodiment, and is provided on a cutter spoke 20 different from that of the moving bit body 10 . Specifically, the second moving bit body 10' is provided at the tip of the sixth cutter spoke 206 (FIG. 15).

[0098] As shown in Figure 16, the movable bit cylinder 100' and movable bit 101' of the second movable bit body 10' are inclined at the same angle via a base (not shown) facing the replacement bit 61b of the outer periphery replacement bit body 6, which is one bit inward from the one that excavates the outermost periphery of the rotating head 2 and protrudes diagonally forward and to the side from the outer periphery.

[0099] The movable bit 101' is wider than the replacement bit 61 in the side view of Figure 16, and can move outward from the rotating head 2 through openings (not shown) formed in the cutter spokes 20 until it reaches the same height as the tip of the replacement bit 61b before its tip becomes worn.

[0100] When the movement of the shield tunneling machine 1 in the forward and backward directions of the tunnel is stopped, and the moving bit 101 of the moving bit body 10 and the moving bit 101' of the second moving bit body 10' are extended outside the rotating head 2 and the rotating head 2 is rotated, the side of the face and its front are continuously excavated within the replacement bit trajectory range of the outer replacement bit body 6.

[0101] This further reduces the amount of retreat of the shield machine 1 required to rotate the outer periphery replacement bit body 6 and the inner periphery replacement bit body 7 forward during replacement.

[0102] [Third embodiment] A third embodiment of the present invention will be described with reference to Figures 17 and 18. Note that a description of the same parts as in the first and second embodiments will be omitted, and differences will be mainly described.

[0103] The third embodiment is obtained by providing a third moving bit body 10'', which is another moving bit body, to the second embodiment.

[0104] The third movable bit body 10'' is provided for excavating the ground G that can no longer be excavated due to wear of the replacement bit 61a located in a position protruding forward of the face of the outer circumferential replacement bit body 6.

[0105] The third moving bit body 10'' has a structure similar to that of the moving bit body 10 of the first embodiment and the second moving bit body 10' of the second embodiment, and is provided on a cutter spoke 20 different from that of the moving bit body 10 and the second moving bit body 10' of the second embodiment. Specifically, the third moving bit body 10'' is provided at the tip of the fourth cutter spoke 204 (FIG. 17).

[0106] As shown in Figure 18, the movable bit cylinder 100" and movable bit 101" of the third movable bit body 10" are arranged horizontally at the same angle, via a base (not shown), facing the replacement bit 61a of the outer periphery replacement bit body 6, which is two bits inward from the one that excavates the outermost periphery of the rotating head 2 and protrudes forward of the face.

[0107] The movable bit 101'' is wider than the replacement bit 61 in the side view of FIG. 18, and can move outward from the rotary head 2 through openings (not shown) formed in the cutter spokes 20 until the tip of the movable bit 101'' is at the same height as the tip of the replacement bit 61a before it becomes worn.

[0108] When the movement of the shield tunneling machine 1 in the forward and backward directions of the tunnel is stopped, and the moving bits 101 of the moving bit body 10, the moving bits 101' of the second moving bit body 10' and the moving bits 101" of the third moving bit body 10" are extended outward from the rotating head 2 and the rotating head 2 is rotated, continuous excavation is performed from the side of the face to the front thereof within the replacement bit trajectory range of the outer replacement bit body 6.

[0109] Although not shown, a third movable bit body 10'' is also provided at a position corresponding to the replacement bit 71a of the inner peripheral replacement bit body 7. The movable bit 101 ″ of this third movable bit body 10 ″ is movable along the replacement bit 7 a protruding forward from the rotating head 2 of the inner peripheral replacement bit body 7 , outward from the rotating head 2 toward the front surface of the face.

[0110] When the movable bit 101 ″ of the third movable bit body 10 ″ is protruded forward of the rotary head 2 and the rotary head 2 is rotated, the front surface of the face is excavated within the replacement bit trajectory range of the inner peripheral replacement bit body 7 .

[0111] As a result, during replacement, not only the outer periphery of the face but also the front face of the face are cut within the replacement bit trajectory range, so there is no need to retreat the shield tunneling machine 1 in order to rotate the outer periphery replacement bit body 6 and the inner periphery replacement bit body 7 forward.

[0112] [Fourth embodiment] The fourth embodiment of the present invention will be described with reference to Figures 19 and 20. Note that a description of the same parts as in the first to third embodiments will be omitted, and differences will be mainly described.

[0113] In the fourth embodiment, no movable bit body is provided on the rotating head 2, and as shown in Figure 19, at least one outer periphery replacement bit body 6 is movable from a normal digging position 6A on the rotating head 2 toward the outside (as an example, an outer digging position 6B).

[0114] The movement direction may be, for example, three directions, i.e., in front, in front-side, and to the side, of the outer face from the normal excavation position 6A. It is preferable that the outer replacement bit body 6 is movable in a plurality of directions to a position where the tips of the worn replacement bits 61a, 61b, 61c can cover all the same positions as the tips of the replacement bits 61a, 61b, 61c before wear.

[0115] The outer periphery replacement bit body 6 is moved relative to the cutter spokes 20 together with the rotating shaft 62, the replacement bit body rotating mechanism 8, and the replacement bit body rotation stopping mechanism 9 using a hydraulic cylinder or the like.

[0116] As the shield tunneling machine 1 progresses in excavation, and the replacement bits 61a, 61b, 61c of the outer periphery replacement bit body 6 wear down to the point where the bit tips at the ends still remain, the shield tunneling machine 1 stops moving in the forward and backward directions of the tunnel, and the outer periphery replacement bit body 6 is moved toward the face side, front face side and front face.

[0117] When the rotary head 2 is rotated in each of these states, the cross-sectional corner portion of the face, which is within the replacement bit trajectory range of the outer periphery replacement bit body 6 at the normal drilling position 6A, is drilled.

[0118] Next, when the outer periphery replacement bit body 6 is returned to the normal drilling position 6A, a space is formed between the cross-sectional corner portion of the drilling face and the replacement bits 61 protruding forward and outward from the rotating head 2, so that the outer periphery replacement bit body 6 can be rotated to replace the worn replacement bits 61a, 61b, 61c with new replacement bits 61d, 61e, 61g.

[0119] In addition, at least one of the inner replacement bit bodies 7 arranged at the same circumferential distance from the center of the rotating head 2 (following the same path) is capable of moving from the normal drilling position 7A on the rotating head 2 toward the front of the outer face, as shown in Figure 20.

[0120] The inner circumference replacement bit body 7 is moved relative to the cutter spokes 20 together with the rotating shaft 72, the replacement bit body rotating mechanism 8, and the replacement bit body rotation stopping mechanism 9 by using a hydraulic cylinder or the like.

[0121] When the replacement bit 71a of the inner replacement bit body 7 wears down to the point where the bit tip at the tip still remains, the movement of the shield machine 1 in the forward and backward directions of the tunnel is stopped, and the inner replacement bit body 7 is moved toward the front of the face.

[0122] The inner replacement bit body 7 moves to the outer excavation position 7B where the tip of the worn replacement bit 71a is the same position as the tip of the replacement bit 71a before it was worn. Note that, taking into consideration that the inner replacement bit body 7 will later be rotated forward to place a new replacement bit 7b, it may be made movable slightly diagonally toward the outer periphery so that the part along that path can be excavated.

[0123] When the rotary head 2 is rotated in this state, the front surface of the face, which is within the range of the replacement bit locus of the inner peripheral replacement bit body 7 at the normal drilling position 7A, is drilled.

[0124] Next, when the inner replacement bit body 7 is returned to the normal drilling position 7A, a space is created between the front of the drilling face and the replacement bit 71 protruding forward and outward from the rotating head 2, so that the inner replacement bit body 7 can be rotated to replace the worn replacement bit 71a with a new replacement bit 71b. In this embodiment, the outer replacement bit body 6 and the inner replacement bit body 7 are moved outward from the normal excavation position at the rotating head 2 while the shield tunneling machine 1 is stopped from moving in the fore-and-aft direction of the tunnel, but this is not limited to the above and the movement may also be performed while the shield tunneling machine 1 is moving in the fore-and-aft direction of the tunnel.

[0125] [Fifth embodiment] A fifth embodiment of the present invention will be described with reference to Fig. 21. Note that a description of the same parts as in the first to fourth embodiments will be omitted, and differences will be mainly described.

[0126] In the fifth embodiment, as shown in FIG. 21, the rotary head 2 has four cutter spokes 20 arranged radially at equal intervals.

[0127] The cutter spokes 20 are made up of a first cutter spoke 201 located directly above in FIG. 21, a second cutter spoke 202, a third cutter spoke 203, and a fourth cutter spoke 204, arranged in clockwise order.

[0128] Of the four cutter spokes 20, three cutter spokes 20 each have an outer periphery replacement bit body 6 provided at one location on one side surface of the tip portion thereof.

[0129] Specifically, an outer circumferential replacement bit body 6 is provided on the side of the tip of the first cutter spoke 201 facing in a clockwise direction to the rotating head 2, and on the side of the tip of the second cutter spoke 202 and the third cutter spoke 203 facing in a counterclockwise direction to the rotating head 2.

[0130] A plurality of inner replacement bit bodies 7 are provided on the side surface of each cutter spoke 20 from the tip portion to the inner peripheral side.

[0131] Specifically, the inner replacement bit bodies 7 are provided at one location on the first cutter spokes 201, two locations on the second cutter spokes 202, three locations on the third cutter spokes 203, and two locations on the fourth cutter spokes 204 on the clockwise facing side of the cutter spokes 20, and at three locations on the first cutter spokes 201, two locations on the second cutter spokes 202, two locations on the third cutter spokes 203, and two locations on the fourth cutter spokes 204 on the counterclockwise facing side of the cutter spokes 20.

[0132] The moving bit body 10 is provided at the tip of the fourth cutter spoke 204 . In this embodiment, a copy cutter is not attached, but it may be provided separately.

[0133] Since the number of cutter spokes 20 is as small as four, the inner peripheral replacement bit bodies 7 are arranged at different positions so as to form different passes, that is, to form one pass.

[0134] Therefore, the inner replacement bit body 7 is positioned so that different paths are formed on both sides of each cutter spoke 20, so that there are no bits on the front of the cutter spoke 20 in either direction of the rotation of the rotating head 2, making it difficult for soil and sand to adhere to the front of the cutter spoke 20 or for gravel to become trapped. In this embodiment, the rotary drive unit can be arranged in a compact manner, and is therefore suitable for medium-diameter shields in which the cutter spokes are relatively thin.

[0135] [Other Modifications] The present invention is not limited to the above-mentioned embodiment, and may also include the following, for example.

[0136] In this embodiment, the tunnel boring machine is a shield machine, but is not limited to this and is not particularly limited as long as it has a rotating head. For example, it may be a tunnel boring machine such as a tunnel jacking machine or a TBM (tunnel boring machine).

[0137] In this embodiment, both the outer periphery replacement bit body and the inner periphery replacement bit body are used, but it is also possible to use only one of them. In this case, a movable bit body is used for at least one of the respective bodies. In addition, it is not necessary to apply at least one of the outer periphery replacement bit body and the inner periphery replacement bit body to all bits, and it may be applied partially to some bits. In this case, too, a movable bit body is adopted for at least one of the respective bits.

[0138] In this embodiment, eight cutter spokes are provided, but the number can be increased or decreased depending on the dimensions of the rotary head, etc. In addition, although the outer replacement bit bodies are attached to the tips of the three cutter spokes, the number of cutter spokes to which the outer replacement bit bodies are attached is not limited to three, and the number of passes is also not limited. The same is true for the inner replacement bit body.

[0139] In this embodiment, the outer peripheral replacement bit body has nine replacement bits and three sets are replaced twice, while the inner peripheral replacement bit body has four replacement bits and one is replaced three times, but this is not limited to this and it is also possible to increase or decrease the number of replacement bits and the number of replacements.

[0140] In this embodiment, the replacement bit body rotation mechanism consists of a worm gear fixed to the rotating shaft and a worm that is meshed with the worm gear and rotated by the worm shaft drive motor, but other mechanisms, for example a rotating wheel fixed to the outer periphery of the rotating shaft and the tip of an extendable jack connected by an arm, can also be used. Furthermore, the replacement bit body rotation stopping mechanism is not limited to that in the above embodiment, and can also be composed, for example, of a plurality of pin holes formed circumferentially around the rotating shaft and a pin that can be inserted and removed into any of the pin holes.

[0141] In the fourth embodiment, the inner replacement bit body is capable of being moved outward from the normal excavation position on the rotating head, but it is also possible to make only the outer replacement bit body movable, and after the outer replacement bit body has been moved outward from the normal excavation position to cut the cross-sectional corner portion of the face and then returned to the original normal excavation position, the shield tunneling machine is slightly retreated to a degree that does not impair sealing properties, and the outer replacement bit body and the inner replacement bit body are rotated.

[0142] In the fourth embodiment, the outer replacement bit body and the inner replacement bit body are movable outward from the normal drilling position of the rotating head, but at least one of the outer replacement bit body and the inner replacement bit body may be movable inward from the normal drilling position of the rotating head. During normal excavation, at least one of the outer periphery replacement bit body and the inner periphery replacement bit body is moved inside the rotating head, and when the replacement head used to cut the other outer periphery replacement bit body and the inner periphery replacement bit body becomes worn, the movement of the tunnel boring machine in the fore-and-aft direction of the tunnel is stopped, the outer periphery replacement bit body and the inner periphery replacement bit body that were retracted inside the rotating head are moved to the normal excavation position on the outside, and the rotating head is rotated to cut the side and front of the face with the outer periphery replacement bit body and the inner periphery replacement bit body. This allows the other outer periphery replacement bit bodies and the inner periphery replacement bit body to be rotated, and the worn replacement bit can be replaced with a new replacement bit.

[0143] In the first to fourth embodiments, a movable bit body is provided separately from the copy cutter, and the exchange bit trajectory range, which is the range of the trajectory along which the multiple exchange bits move by the rotation of the rotating shaft of the outer periphery exchange bit body, is excavated while the tunnel boring machine is stopped in the forward and backward directions of the tunnel. However, the copy cutter may be arranged in the same manner as the movable bit body, instead of the usual arrangement, to excavate the exchange bit trajectory range, which is the range of the trajectory along which the multiple exchange bits move by the rotation of the rotating shaft of the outer periphery exchange bit body. In other words, the copy cutter has an over-excavation function for curve construction and a function for excavating the exchange bit trajectory range. In other words, in addition to the function of excavating the exchange bit trajectory range of the movable bit body, the copy cutter has an over-excavation function for curve construction.

[0144] Each technical matter in any of the embodiments including the modified examples may be applied to other embodiments to serve as examples. [Explanation of symbols]

[0145] 1. Shield tunneling machine 2 Rotating Head 20 Cutter Spokes 21 Cutter Ring 3. Chamber 4 Earth removal equipment 5 Rotating head drive unit 6 Outer replacement bit body 60 Disc 61 Exchange Bits 62 Rotational Axis 63-bit chip 7 Inner replacement bit body 70 Disc 71 Exchange Bits 72 Rotational Axis 73 bit chip 8. Replacement bit body rotation mechanism 80 Worm Gear 81 Warm 82 Worm shaft 83 Worm shaft drive motor 9 Replacement bit body rotation stop mechanism 90 Rotating disc 900 Tooth space 91 Jack holder 92 Jack 920 Cylinder 921 Rod 922 Locking teeth 10 Moving Bit Body 100 Moving Bit Cylinder 101 Moving Bits 10' Second moving bit body 101' Moving Bit 10” 3rd moving bit body 101” Moving Bit

Claims

1. 1. A tunnel boring machine having a rotating head, comprising: a replacement bit body provided on the rotary head, rotatable about a rotation axis along a tangential direction of a rotation circle of the rotary head, the replacement bit body having a plurality of replacement bits in a circumferential direction of the rotation axis; A moving bit body provided on the rotary head and having a moving bit movable outward from the rotary head, The movable bit body is disposed so as to be capable of excavating an exchange bit trajectory range, which is a range of a trajectory along which the plurality of exchange bits move by rotation of the rotation shaft of the exchange bit body, while the tunnel boring machine is stopped in the forward and backward directions of the tunnel. A tunnel boring machine characterized by:

2. At least one of the plurality of replacement bits of the replacement bit body is arranged so as to be able to excavate a face side surface, The moving bit body has a moving bit that is movable outward from the rotary head toward the face side surface. A tunnel boring machine according to claim 1.

3. At least one of the plurality of replacement bits of the replacement bit body is arranged so as to be able to excavate a front surface of a face, The moving bit body has a moving bit that is movable outward from the rotary head toward the front surface of the face. A tunnel boring machine according to claim 1.

4. The movable bit body is provided in plurality on the rotary head, and each of the movable bits is arranged so as to be able to excavate in a different range within the replacement bit trajectory range. A tunnel boring machine according to any one of claims 1 to 3.

5. 1. A tunnel boring machine having a rotating head, comprising: a replacement bit body provided on the rotary head, rotatable around a rotation axis along a tangential direction of a rotation circle of the rotary head, the replacement bit body having a plurality of replacement bits in a circumferential direction of the rotation axis; The replacement bit body is capable of moving the replacement bit outward from a normal drilling position in the rotary head, The replacement bit body is disposed so that, when the replacement bit body has moved outward from a normal excavation position, a replacement bit trajectory range, which is a range of a trajectory along which the multiple replacement bits move as a result of rotation of the rotation shaft of the replacement bit body at the normal excavation position, can be excavated. A tunnel boring machine characterized by:

6. At least one of the plurality of replacement bits of the replacement bit body is arranged so as to be able to excavate a face side surface, The replaceable bit body has a replaceable bit that is movable outward from the rotary head toward a face side surface. A tunnel boring machine as claimed in claim 5.

7. At least one of the plurality of replacement bits of the replacement bit body is arranged so as to be able to excavate a front surface of a face, The replaceable bit body has a replaceable bit that is movable outward from the rotary head toward the front face of the face. A tunnel boring machine as claimed in claim 5.

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