JP2016169557A - Shield drilling machine and tunnel excavation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drilling machine, which ensures sediment flowability at a chamber central part and has downsized rotation driving means to drive rotation of a central part cutter head.SOLUTION: A shield drilling machine comprises: a central part cutter head 3A and a periphery cutter head 3B; an annular first cutter drum 20, which is rotatably mounted on a partition wall 8 that partitions a chamber 7; a first connection member 21, which connects the periphery cutter head 3B to the first cutter drum 20; an annular second cutter drum 23, which is rotatably mounted on the first cutter drum 20; a second connection member 24, which connects the central part cutter head 3A to the second cutter drum 23; first rotation driving means 22 to drive rotation of the first cutter drum 20 to a drilling machine body 2; and second rotation driving means 25 which is mounted on the first cutter drum 20 to drive rotation of the second cutter drum 23 to the first cutter drum 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shield machine in which a cutter head is divided into a central cutter head and an annular outer peripheral cutter head on the outer peripheral side of the central cutter head.

The shield machine includes a machine main body including a trunk member, an internal structure member, and equipment, and a circular cutter head disposed on the front side of the machine main body. The excavator main body includes a chamber formed in the front end portion of the excavator main body at the rear side of the cutter head, a partition partitioning the rear end side of the chamber, an annular cutter drum mounted on the partition, and a cutter A connecting member for connecting the head to the cutter drum, a rotation driving means for rotating the cutter drum, a plurality of shield jacks, a mud discharging mechanism or a soil discharging mechanism are provided.
While the cutter head is driven to rotate by the rotation driving means, the cutting face is excavated while generating the digging thrust with a plurality of shield jacks.

  Here, when excavating with one circular cutter head, the circumferential rotational speed of the cutter bit in the central part of the cutter head (hereinafter referred to as the peripheral speed) is the peripheral speed of the cutter bit in the outer peripheral part of the cutter head. Since it is slower than this, the excavation efficiency of the central portion of the cutter head is lowered, which is an impediment to increasing the excavation efficiency of the shield machine.

  In view of this, a shield machine has been proposed in which the cutter head is divided into a central cutter head and an outer peripheral cutter head, and each of them can be rotated by a rotation driving means.

  In the shield machine described in Patent Document 1, the cutter head is divided into a central cutter and an outer cutter, the outer cutter is connected to the cutter drum equipped on the partition wall via an intermediate beam, and the cutter drum is driven to rotate. A drive motor is provided, the partition is equipped with a central rotary shaft, a central cylinder extending forward from the central rotary shaft is provided, a rotary drive means for rotationally driving the central cutter is provided inside the central cylinder, The inner peripheral part is connected to the central cylinder via a plurality of central beams.

JP 2007-239402 A

  In the shield machine of Patent Document 1, the central cylindrical body and a plurality of central beams are arranged in the central portion of the chamber, so that the chamber space in the central portion of the chamber is narrowed, and the fluidity of the excavated sediment is reduced. Stagnation is likely to occur.

  As shown in FIGS. 1 and 2 of Patent Document 2, while the diameter of the central cutter of the cutter head is small, the inclination angle of the central beam with respect to the excavator shaft center does not increase so much, so the central beam causes the flow of excavated sediment. Even if the fluidity degradation due to the hindrance is acceptable, if the actual machine is equipped with a central cutter with a larger diameter, the tilt angle of the central beam becomes large, so a large central beam is required. The decrease in fluidity that hinders the flow of excavated soil will be significant, impairing practicality.

  Moreover, although the central cutter is also rotationally driven by the driving force for rotationally driving the cutter drum, the rotational driving means for rotationally driving the central cutter meshes the pinion at the tip of the output shaft of the drive motor with the gear, and its relatively small diameter In order to rotationally drive the central cutter via the gear, it is necessary to increase the size of the rotational driving means for the central cutter.

  An object of the present invention is a shield machine in which a cutter head is divided into a central cutter head and an annular outer cutter head, and the central cutter while ensuring fluidity of earth and sand in the chamber central portion. It is an object of the present invention to provide a shield machine capable of reducing the size of a rotation driving means for rotating a head.

  The shield machine according to claim 1 is a shield machine in which the cutter head is divided into a central cutter head and an annular peripheral cutter head on the outer peripheral side of the central cutter head. An annular first cutter drum rotatably mounted on a partition wall that partitions a chamber on the back side of the front cutter head, a first connecting member that connects an outer peripheral cutter head to the first cutter drum, and the first cutter drum An annular second cutter drum having an outer diameter smaller than the outer diameter of the first cutter drum and rotatably mounted on the first cutter drum, a second connecting member for connecting the central cutter head to the second cutter drum, A first rotation driving means for rotating the first cutter drum with respect to the main body of the excavator, and the first cutter drum; One and a second cutter drum is characterized in that a second rotary drive means for rotatably driving the first cutter drum.

  The shield excavator according to claim 2 is characterized in that, in the invention according to claim 1, the second connecting member is composed of a plurality of high-rigidity members elongated in the front-rear direction and arranged at a plurality of circumferentially equally divided positions. It is said.

  The shield machine according to claim 3 is the invention according to claim 1, wherein the second connecting member is a cylindrical member having a partial cone whose diameter decreases from the second cutter drum toward the face. It is characterized by.

  A shield machine according to a fourth aspect is the invention of any one of the first to third aspects, wherein hydraulic pressure is supplied to the central portion of the partition wall to the copy cutter of the outer peripheral cutter head and the second rotational drive means. It is equipped with a rotary joint that connects multiple hydraulic passages.

  A shield excavator according to a fifth aspect is the invention according to any one of the first to fourth aspects, wherein an annular recess is formed in an inner peripheral portion of the first cutter drum, and a second cutter drum is attached to the annular recess. It is characterized by that.

The tunnel excavation method according to claim 6 is a shield excavator formed by dividing the cutter head into a central cutter head and an annular outer peripheral cutter head on the outer peripheral side of the central cutter head, wherein the central cutter head And an annular first cutter drum rotatably mounted on a partition wall that partitions the chamber on the back side of the outer cutter head, a first connecting member that connects the outer cutter head to the first cutter drum, and the first An annular second cutter drum having an outer diameter smaller than the outer diameter of the cutter drum and rotatably mounted on the first cutter drum, and a second connecting member for connecting the central cutter head to the second cutter drum When,
A first rotation driving means for rotating the first cutter drum with respect to the excavator body, and a second cutter drum mounted on the first cutter drum and for rotating the second cutter drum with respect to the first cutter drum; When preparing a shield machine equipped with a second rotation driving means in advance and excavating a tunnel using the tunnel excavator, the average peripheral speed of the plurality of cutter bits of the central cutter head and the outer cutter The excavation is performed by setting so that the average peripheral speed of a plurality of cutter bits of the head is substantially equal.

  A tunnel excavation method according to a seventh aspect is the invention according to the sixth aspect, wherein the second connecting member is composed of a plurality of high-rigidity members that are elongated in the front-rear direction and arranged at a plurality of circumferentially equally divided positions. Yes.

  The tunnel excavation method according to an eighth aspect is the invention according to the sixth aspect, wherein the second connecting member is constituted by a cylindrical member having a partial cone whose diameter decreases from the second cutter drum toward the face side. It is characterized by.

  A tunnel excavation method according to a ninth aspect is the invention according to any one of the sixth to eighth aspects, wherein hydraulic pressure is supplied to the center side portion of the partition wall to the copy cutter of the outer peripheral cutter head and the second rotation driving means. It is equipped with a rotary joint that connects a plurality of hydraulic passages.

  A tunnel excavation method according to a tenth aspect is the invention according to any one of the sixth to ninth aspects, wherein an annular recess is formed in an inner peripheral portion of the first cutter drum, and a second cutter drum is attached to the annular recess. It is characterized by that.

Since the invention of the present application has the configuration described in the section of the problem solving means, the following effects can be obtained.
According to the first aspect of the present invention, the cutter head is divided into the central cutter head and the outer cutter head, and the first cutter and the outer cutter head through the first cutter drum and the first connecting member by the first rotation driving means. The center cutter head can be rotated with respect to the excavator body, and the center cutter head can be rotated with respect to the first cutter drum via the second cutter drum and the second connecting member by the second rotation driving means. can do.

Since the second cutter drum is annular and can be formed to have a certain diameter, the second cutter drum can be strongly rotated even if the driving force for rotating the second cutter drum by the second rotation driving means is reduced. . Therefore, it is possible to reduce the size of the second rotation driving unit.
And since it is not necessary to arrange | position the connection member which connects the member of the chamber center side which supports a center part cutter head to an outer peripheral part cutter head in the center part of a chamber, the sediment accumulation in the center part of a chamber can be prevented.

  According to the invention of claim 2, since the second connecting member is composed of a plurality of high-rigidity members elongated in the front-rear direction, the fluidity of the earth and sand at the center of the chamber is not hindered, and the center of the chamber Sediment accumulation can be prevented.

  According to invention of Claim 3, since the 2nd connecting member was constituted by the cylindrical member which has the partial cone which decreases in diameter toward the face side from the 2nd cutter drum, in the neighborhood of the rear surface of the central part cutter head, Since the diameter of the partial cone is also reduced, the fluidity of the earth and sand in the vicinity of the rear surface of the central cutter head can be ensured.

  According to the fourth aspect of the present invention, since the space can be provided in the central side portion of the partition wall on the inner peripheral side of the second cutter drum, the copy cutter of the outer peripheral cutter head and the second rotation are provided in the central side portion of the partition wall. A rotary joint for connecting a plurality of hydraulic passages for supplying hydraulic pressure to the driving means can be provided.

  According to the invention of claim 5, since the second cutter drum is mounted in the annular recess provided in the inner peripheral portion of the first cutter drum, the support rigidity for supporting the second cutter drum can be increased.

  According to the invention of claim 6, when excavating the tunnel, the average peripheral speed of the plurality of cutter bits of the central part cutter head and the average peripheral speed of the plurality of cutter bits of the outer peripheral part cutter head are substantially equal. Since excavation is performed so as to be equal, the excavation efficiency of the central portion of the cutter head can be increased to the same extent as the excavation efficiency of the outer peripheral portion of the cutter head.

According to the invention of claim 7, the same effect as that of claim 2 can be obtained.
According to the invention of claim 8, the same effect as that of claim 3 can be obtained.
According to the invention of claim 9, the same effect as that of claim 4 can be obtained.
According to the invention of claim 10, the same effect as that of claim 5 can be obtained.

It is a front view of the cutter head of the shield machine according to Embodiment 1 of the present invention. It is a longitudinal cross-sectional view of the principal part of the shield machine of FIG. It is a front view of the cutter head of the shield machine of Example 2. It is a longitudinal cross-sectional view of the principal part of the shield machine of FIG.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

The shield machine of Example 1 is demonstrated based on FIG. 1, FIG.
The shield machine 1 includes an excavator body 2 and a cutter head 3 disposed on the front side of the excavator body 2. The excavator main body 2 is the same as the excavator main body of a general shield excavator except for the peripheral structure of the cutter head 3, and will be described briefly.

  The excavator main body 2 includes a front barrel 4, a rear barrel 5, a middle folding portion 6 and a plurality of middle folding jacks, a partition wall 8 that partitions a rear end of the chamber 7 on the rear side (back side) of the cutter head 3, A plurality of shield jacks 9, a water supply pipe 10, a muddy water discharge pipe 11, an annular web 12, an erector device 13 for assembling the segment, a shape holding device for holding the shape of the segment, a work deck, and the like are provided.

  The shield machine 1 is a shield machine in which the cutter head 3 is divided into a central cutter head 3A and an annular outer cutter head 3B on the outer peripheral side of the central cutter head 3A. The central cutter head 3A is circular, the outer peripheral cutter head 3B is annular, and the central center (center) of the central cutter head 3A and the outer peripheral cutter head 3B is common. The outer periphery of the center cutter head 3A is close to the inner periphery of the outer cutter head 3B.

  In order to increase the excavation efficiency of the central portion of the cutter head, where d is the outer diameter of the center cutter head 3A of the excavator and D is the outer diameter of the outer cutter head 3B, (1/3) D ≦ It is desirable to set so that d ≦ (1/2) D. However, it is not limited to this. The front surface of the central cutter head 3A and the front surface of the outer peripheral cutter head 3B are substantially the same surface, but the front surface of the central cutter head 3A is located slightly in front of the front surface of the outer peripheral cutter head 3B.

  The central cutter head 3A is provided with a plurality of cutter frames 14 having a rectangular cross section, the outer peripheral ends of the cutter frames 14 are joined to the outer ring 3a, and a plurality of cutter bits 14a are formed on both side edges of the cutter frame 14. A face plate 15 is provided between adjacent cutter frames 14, 14, and openings 16 for introducing excavated material (such as earth and sand, gravel, rock fragments, etc.) into the chamber 7 are formed on both sides of the cutter frame 14. Yes.

  A plurality of cutter frames 17 having a rectangular cross section are provided radially on the outer peripheral cutter head 3B. The outer peripheral ends of these cutter frames 17 are joined to the outer peripheral ring 3b, and a plurality of cutter bits 17a are provided on both side edges of the cutter frame 17. A face plate 18 is provided between the cutter frame 17 and the cutter frame 17, and openings 19 for introducing excavated material into the chamber 7 are formed on both sides of the cutter frame 17. The outer peripheral cutter head 3B is provided with a plurality of stirring members 3c for stirring the earth and sand in the chamber 7.

  The chamber 7 is formed on the back side of the center cutter head 3A and the outer peripheral cutter head 3B inside the front end portion of the front cylinder 4, and the chamber 7 is located at the front end of the front cylinder 4 on the back side of the center cutter head 3A. It swells to the front side. Since the longitudinal length of the cutter frame 14 of the central cutter head 3A is smaller than the longitudinal length of the cutter frame 17 of the outer peripheral cutter head 3B, the longitudinal length of the chamber 7 on the back side of the central cutter head 3A is large and a wide chamber Space is reserved. The central cutter head 3 </ b> A is provided with a plurality of stirring members 3 d that stir the excavated material in the chamber 7.

  The partition wall 8 that partitions the rear end of the chamber 7 includes an outer peripheral side annular wall 8a whose outer peripheral end is joined to the inner surface of the front barrel 4, and a cylindrical wall 8b that extends rearward from the inner peripheral end of the annular wall 8a. A small-diameter annular wall 8c extending inward from the rear end of the cylindrical wall 8b, a short cylindrical wall 8d extending rearward from the small-diameter annular wall 8c, and a circular central circular wall 8e closing the rear end of the short cylindrical wall 8d; It has.

  An annular first cutter drum 20 is disposed in the chamber 7 and is rotatably mounted on the partition wall 8. The outer peripheral part of the first cutter drum 20 is located behind the inner peripheral part of the outer cutter head 3B, and the inner peripheral part of the first cutter drum 20 is formed with a smaller diameter than the central cutter drum 3A. Yes. The 1st connection member 21 which connects the inner peripheral side part of the outer peripheral part cutter head 3B and the outer peripheral side part of the 1st cutter drum 20 is provided, and this 1st connection member 21 is shifted so that it may move to a large diameter side, so that it is ahead. It is composed of a plurality of (for example, four) square tube members 21a slightly inclined.

  The first cutter drum 20 includes an annular front wall 20a, an outer cylindrical wall 20b extending rearward from the outer peripheral end of the front wall 20a, an annular wall 20c extending inward from the rear end of the outer cylindrical wall 20b, and the annular A short cylindrical wall 20d extending rearward from the inner peripheral end of the wall 20c, an annular rear end wall 20e extending inward from the rear end of the short cylindrical wall 20d, and an inner side extending forward from the inner peripheral end of the rear end wall 20e A peripheral cylindrical wall 20f, a small-diameter annular plate 20g extending outward from the front end of the inner peripheral-side cylindrical wall 20f, and a cylindrical portion 20h connecting the outer peripheral end of the small-diameter annular plate 20g to the inner peripheral end of the front wall 20a. It is formed in an annular hollow body. A sealing cylinder 20i extending forward from the inner peripheral cylinder wall 20f is also provided.

  An outer peripheral cylindrical wall 20b of the first cutter drum 20 is rotatably supported by the cylindrical wall 8b of the partition wall 8 via a seal member and a bearing. In addition, the diameter of the inner peripheral side cylinder wall 20f of the first cutter drum 20 is about 1/4 of the outer diameter of the central cutter head 3A. However, it is not limited to the above.

  First rotation driving means 22 for rotating the first cutter drum 20 with respect to the excavator main body 2 is provided, and the first rotation driving means 22 is fixed to the annular wall 20c of the first cutter drum 20 and A slewing bearing including a ring gear member 22a having outer teeth on the outer periphery and a plurality of drive motors 22b (hydraulic motors) are provided, and pinions 22c fixed to output shafts of the drive motors 22b mesh with the ring gear members 22a. doing. Each drive motor 22b is attached to the small-diameter annular wall 8c of the partition wall 8 and its peripheral members.

  An annular second cutter drum 23 for rotating the center cutter head 3A is rotatably mounted on the first cutter drum 20. The second cutter drum 23 has an outer diameter smaller than the outer diameter of the first cutter drum 20, and in the case of the present embodiment, the outer diameter of the second cutter drum 23 is equal to the outer diameter of the first cutter drum 20. About 1/3. However, it is not limited to the above.

An annular recess is formed by the sealing cylinder 20i and the cylinder 20h on the inner peripheral portion of the front end portion of the first cutter drum 20, and a second cutter drum 23 made of an annular hollow body is attached to the annular recess, 2 The inner peripheral surface of the cutter drum 23 is supported by the sealing cylinder 20i via a seal member and a bearing, and the outer peripheral surface of the second cutter drum 23 is supported by the cylinder portion 20h via a seal member and a bearing. Yes. Therefore, the support rigidity which supports the 1st cutter drum 20 can be improved. A second connecting member 24 for connecting the central cutter head 3A to the second cutter drum 23 is provided, and the second connecting member 24 has a plurality of (for example, four) tapered H-shaped members having an H-shaped cross section elongated in the front-rear direction. It is comprised by the highly rigid members 24a. The plurality of high-rigidity members 24a are disposed at circumferentially equally divided positions.

  A second rotation driving means 25 for rotating the second cutter drum 23 with respect to the first cutter drum 20 is provided, and the second rotation driving means 25 is provided on the first cutter drum 20. Similar to the first rotation driving means 22, the second rotation driving means 25 is fixed to the rear end wall of the second cutter drum 23 and includes a slewing bearing including a ring gear member having external teeth on the outer periphery, and a plurality of driving A motor (hydraulic motor) is provided, and a pinion fixed to the output shaft of each drive motor meshes with the ring gear member. Each drive motor is disposed in the first cutter drum 20 and attached to the small-diameter annular plate 20g and its peripheral members.

  The central part of the central circular wall 8e of the partition wall 8 is equipped with a rotary joint 27 for connecting a plurality of hydraulic passages for supplying hydraulic pressure to the copy cutter 26 of the outer peripheral cutter head 3B and the second rotation driving means 25 and the like. ing. A plurality of pipe members 28 for connecting the front end portion of the rotary joint 27 to the inner peripheral side cylinder wall 20f of the first cutter drum 20 are provided in the chamber 7, and hydraulic pipes (or hydraulic hoses) are provided inside these pipe members 28. Is installed. A hydraulic pipe (or a hydraulic hose) for supplying hydraulic pressure to the copy cutter 26 is led into the cutter frame 17 of the outer cutter head 3B through the first cutter drum 20 and the rectangular tube member 21a.

Next, the operation and effect of the shield machine 1 will be described.
By rotating the first cutter drum 20 by the first rotation driving means 22, the outer peripheral cutter head 3 </ b> B can be driven to rotate via the first connecting member 21.
At this time, since the second cutter drum 23 is mounted on the first cutter drum 20, when the first cutter drum 20 is driven to rotate, the second cutter drum 23 is also driven to rotate via the second connecting member 24. The central cutter head 3A is also rotationally driven.

  And when the 2nd cutter drum 23 is rotationally driven with respect to the 1st cutter drum 20 by the 2nd rotational drive means 25, since the 2nd cutter drum 23 is rotationally driven by the rotational driving force, The rotational speed of the central cutter head 3A can be made larger than the rotational speed of the outer peripheral cutter head 3B, and can be increased to a desired rotational speed.

  Thus, the average peripheral speed of the plurality of cutter bits 14a of the central cutter head 3A is set high so as to be substantially equal to the average peripheral speed of the plurality of cutter bits 17a of the outer peripheral cutter head 3B. It shall be excavated. As a result, the excavation efficiency of the central portion of the cutter head 3 can be increased to the same extent as the excavation efficiency of the outer peripheral portion of the cutter head 3, the excavation efficiency of the tunnel excavator 1 can be increased, and the tunnel excavation time can be shortened. Can be planned.

  Since the second cutter drum 23 is annular and can be formed to have a certain diameter, the second cutter drum 25 is made large even if the driving force for rotationally driving the second cutter drum 23 by the second rotation driving means 25 is reduced. Powerful rotation drive with torque. Therefore, the second rotation drive means 25 (drive motor) can be reduced in size (including a reduction in the number of drive motors).

  In addition, since the second connecting member 24 that connects the central cutter head 3A to the second cutter drum 23 is composed of a highly rigid member that is elongated in the front-rear direction and is arranged at multiple circumferential positions, the central cutter Since it is not necessary to arrange the member on the chamber center side that supports the head in the center portion of the chamber connected to the outer peripheral cutter head, sediment convection in the center portion of the chamber can be prevented.

  In particular, in the shield machine 1 according to the present embodiment, the front surface of the central cutter head 3A protrudes forward from the front surface of the outer peripheral cutter head 3B, and the front and rear thicknesses of the central cutter head 3A are set to those of the outer peripheral cutter head 3B. Since it is formed smaller than the front and rear thicknesses and a large chamber space is secured on the back side of the central cutter head 3A, it is possible to reliably prevent sediment accumulation in the center of the chamber 7.

The shield machine of Example 2 is demonstrated based on FIG. 3, FIG.
This shield machine 51 has a machine body 52 and a cutter head 53, and the portions other than the partition walls of the machine body 52 are the same as those of the machine body of the first embodiment, and are the same as those of the first embodiment. The same reference numerals are given to the constituent elements and the description thereof is omitted, and the peripheral structure of the partition wall and the cutter head 53 will be mainly described.

  The cutter head 53 is divided into a central cutter head 53A and an annular outer peripheral cutter head 53B on the outer peripheral side of the central cutter head 53A. The central cutter head 53A is circular, the outer peripheral cutter head 53B is annular, and the central center (center) of the central cutter head 53A and the outer peripheral cutter head 53B is common. The outer periphery of the central cutter head 53A is close to the inner periphery of the outer cutter head 53B. The front surface of the central cutter head 53A and the front surface of the outer peripheral cutter head 53B are substantially the same surface, but the front surface of the central cutter head 53A is located slightly in front of the front surface of the outer peripheral cutter head 53B.

  The outer peripheral portion of the central cutter head 53A is formed in a curved shape so as to approach the outer peripheral cutter head 53B toward the outer peripheral side, and the front and back positions of the outer cutter head 53B coincide with each other at the outer peripheral end. An angle-shaped center cutter 53c is also provided at the center of the center cutter head 53A. Similar to the first embodiment, the central cutter head 53A is provided with a plurality of cutter frames 64, a plurality of cutter bits 64a, a plurality of face plates 65, a plurality of openings 66, and the like. Similar to the first embodiment, the outer cutter head 53B is provided with a plurality of cutter frames 67, a plurality of cutter bits 67a, a plurality of face plates 68, a plurality of openings 69, and the like.

  The chamber 57 is formed inside the front end portion of the front cylinder 4 on the back side of the center cutter head 53A and the outer peripheral cutter head 53B, and the chamber 57 is located on the back side of the center cutter head 53A. It is slightly swollen to the front side. Therefore, the space at the center of the chamber 57 can be increased.

  A partition wall 58 for partitioning the rear end of the chamber 57 is provided. The partition wall 58 includes an annular wall 58 a on the outer peripheral side whose outer peripheral end is joined to the inner surface of the front barrel 4, and a rear side from the inner peripheral end of the annular wall 58 a. A cylindrical wall 58b that extends, a thick cylindrical body 58c inside thereof, a medium-diameter annular wall 58d that extends inward from the rear end of this cylindrical wall 58b, and a short that extends rearward from the inner peripheral end of this medium-diameter annular wall 58d. A cylindrical wall 58e and a circular wall 58f joined to the rear end of the short cylindrical wall 58e are provided.

  An annular first cutter drum 70 is disposed in the chamber 57 and is rotatably mounted on the partition wall 58. The outer peripheral side portion of the first cutter drum 70 is positioned behind the inner peripheral side portion of the outer peripheral cutter head 53B, and the inner peripheral portion of the first cutter drum 70 is formed to have a smaller diameter than the central cutter drum 53A. . The 1st connection member 71 which connects the inner peripheral side part of the outer peripheral part cutter head 53B and the outer peripheral side part of the 1st cutter drum 70 is provided, This 1st connection member 71 is a several (for example, four) square tube member. 71a.

  The first cutter drum 70 includes an annular body 70a having a “day” cross section forming an outer peripheral portion, a cylindrical wall 70b extending rearward from the vicinity of the inner periphery of the annular body 70a, and a rear end of the cylindrical wall 70b. An annular rear end wall 70c extending inwardly from the inner side, an inner peripheral cylindrical wall 70d extending forward from the inner peripheral end of the rear end wall 70c, and an L-shaped L-section extending inwardly from the inner peripheral front end of the annular body 70a. An annular hollow body is formed by the shaped wall 70e and the like. The outer peripheral surface of the annular body 70a of the first cutter drum 70 is rotatably supported by the thick cylindrical body 58c of the partition wall 58 via a seal member and a bearing. The first cutter drum 70 is provided with a plurality of stirring members 70m.

  First rotation driving means 72 for rotating the first cutter drum 70 with respect to the excavator main body 52 is provided, and the first rotation driving means 72 is fixed to the annular body 70a of the first cutter drum 70 and A slewing bearing including a ring gear member 72a having outer teeth on the outer periphery and a plurality of drive motors 72b (hydraulic motors) are provided, and pinions 72c fixed to the output shafts of the drive motors 72b mesh with the ring gear members 72a. doing. Each drive motor 72b is attached to the medium-diameter annular wall 58d of the partition wall 58 and its peripheral members.

  A second cutter drum 73 formed of an annular hollow body for rotationally driving the central cutter head 53A is rotatably mounted on the first cutter drum 70. The second cutter drum 73 has an outer diameter that is smaller than the outer diameter of the first cutter drum 70.

  An annular recess is formed in the inner peripheral portion of the front end portion of the first cutter drum 70, and a second cutter drum 73 is mounted in the annular recess, and the inner peripheral surface of the second cutter drum 73 is formed through a seal member and a bearing. The outer peripheral surface of the second cutter drum 73 is supported by the cylindrical portion of the L-shaped wall 70e via a seal member and a bearing.

  A circular plate 73a is joined to the front surface of the second cutter drum 73 in a watertight manner. The second cutter drum 73 is provided with a second connecting member 74 for connecting the central cutter head 53A, and the second connecting member 74 is joined to the circular plate 73a of the second cutter drum 73 at the rear end and to the face side. It is composed of a cylindrical member having a partial cone 74a that decreases in diameter and a cylindrical body 74b that extends from the front end of the partial cone 74a and is joined to the center of the center cutter head 53A.

  A second rotation driving means 75 for rotating the second cutter drum 73 with respect to the first cutter drum 70 is provided, and the second rotation driving means 75 is provided on the first cutter drum 70. Similar to the first rotation driving means 72, the second rotation driving means 75 includes a slewing bearing including a ring gear member fixed to the rear end wall of the second cutter drum 73 and having external teeth on the outer peripheral portion, and a plurality of drives. And a pinion fixed to the output shaft of each drive motor meshes with the ring gear member. Each drive motor is disposed in the first cutter drum 70 and is attached to a member that connects the annular body 70a and the inner peripheral side cylinder wall 70d.

  The central part of the central circular wall 58h of the partition wall 58 is equipped with a rotary joint 77 that connects a plurality of hydraulic passages for supplying hydraulic pressure to the copy cutter of the outer peripheral cutter head 53B and the second rotation driving means 75 and the like. Yes. The rotary joint 77 is fixed through the central portion of the circular wall 58f, and the distal end portion of the rotary shaft portion of the rotary joint 77 is connected and supported to the inner peripheral side cylindrical wall 70d by a plurality of tube members 70n.

Next, the operation and effect of the shield machine 51 will be described.
By rotating the first cutter drum 70 by the first rotation driving means 72, the outer peripheral cutter head 53 </ b> B can be driven to rotate via the first connecting member 71.
At this time, since the second cutter drum 73 is mounted on the first cutter drum 70, when the first cutter drum 70 is driven to rotate, the second cutter drum 73 is also driven to rotate via the second connecting member 74. The central cutter head 53A is also rotationally driven.

  When the second cutter drum 73 is rotationally driven with respect to the first cutter drum 70 by the second rotational driving means 75, the second cutter drum 73 is rotationally driven in a superimposed manner by the rotational driving force. The rotational speed of the cutter head 53A can be made larger than the rotational speed of the outer peripheral cutter head 53B, and can be increased to a desired rotational speed.

  In this way, the average peripheral speed of the plurality of cutter bits 64a of the central cutter head 53A is set high so as to be substantially equal to the average peripheral speed of the plurality of cutter bits 67a of the outer peripheral cutter head 53B. It shall be excavated. Thereby, the excavation efficiency of the center side part of the cutter head 53 can be improved, the excavation efficiency of the tunnel machine 51 can be increased, and the construction period of the tunnel excavation can be shortened.

  Since the second cutter drum 73 is annular and can be formed to have a certain diameter, the second cutter drum 75 is made large even if the driving force for rotationally driving the second cutter drum 73 by the second rotation driving means 75 is reduced. Powerful rotation drive with torque. Therefore, it is possible to reduce the size of the second rotation drive means 75 (drive motor) (including reduction in the number of drive motors).

Next, an example in which the above embodiment is partially changed will be described.
1) Although the above-mentioned shield machine has been described by taking a muddy water type shield machine as an example, the present invention can be similarly applied to an earth shield type shield machine.
2) The cross-sectional shape of the first cutter drum is not limited to that of the above embodiment, and first cutter drums having various cross-sectional shapes can also be employed.

  3) The circular plate 73a in FIG. 4 is omitted, and an operator enters the second connecting member 74 from the open / close door formed in the partition wall 58 by arranging the rotary joint 77 behind the illustrated position, and the cutter of the cutter head. You may comprise so that a bit exchange can be performed.

4) The cylindrical wall 70b, the rear end wall 70c, and the rear part about 2/3 of the inner peripheral side cylindrical wall 70d shown in FIG. 4 may be omitted. In this case, the circular plate 73a functions as a part of the partition wall 58, and earth and sand do not enter the rear side of the first cutter drum 70 and the circular plate 73a.
5) It should be noted that those skilled in the art can implement the present invention in a form in which various modifications are added without departing from the spirit of the present invention, and the present invention includes them.

1,51 Shield machine 2,52 Engraver body 3,53 Cutter head 3A, 53A Cutter head 3B, 53B Outer cutter head 7, 57 Chamber 8, 58 Bulkhead
20, 70 First cutter drums 21, 71 First connecting members 22, 72 First rotation driving means 23, 73 Second cutter drums 24, 74 Second connecting members 25, 75 Second rotation driving means 26 Copy cutters 27, 77 Rotary joint 74a Partial cone

Claims (10)

In a shield machine that divides and forms a cutter head into a central cutter head and an annular outer peripheral cutter head on the outer peripheral side of the central cutter head,
An annular first cutter drum rotatably mounted on a partition wall that divides the chamber on the back side of the central cutter head and the outer cutter head;
A first connecting member that connects the outer cutter head to the first cutter drum;
An annular second cutter drum having an outer diameter smaller than the outer diameter of the first cutter drum and rotatably mounted on the first cutter drum;
A second connecting member for connecting the center cutter head to the second cutter drum;
First rotational drive means for rotationally driving the first cutter drum with respect to the machine body;
A shield machine equipped with the first cutter drum and comprising a second rotation driving means for rotating the second cutter drum with respect to the first cutter drum.   2. The shield excavator according to claim 1, wherein the second connecting member includes a plurality of high-rigidity members that are elongated in the front-rear direction and are arranged at a plurality of circumferentially equally divided positions.   2. The shield machine according to claim 1, wherein the second connecting member is formed of a cylindrical member having a partial cone whose diameter decreases from the second cutter drum toward the face.   A rotary joint that connects a plurality of hydraulic passages for supplying hydraulic pressure to the copy cutter of the outer peripheral cutter head and the second rotation driving means is provided at the center side portion of the partition wall. The shield machine according to any one of 3 above.   The shield machine according to any one of claims 1 to 4, wherein an annular recess is formed in an inner peripheral portion of the first cutter drum, and a second cutter drum is attached to the annular recess. A shield machine formed by dividing a cutter head into a central cutter head and an annular outer peripheral cutter head on the outer peripheral side of the central cutter head,
An annular first cutter drum rotatably mounted on a partition wall that divides the chamber on the back side of the central cutter head and the outer cutter head;
A first connecting member that connects the outer cutter head to the first cutter drum;
An annular second cutter drum having an outer diameter smaller than the outer diameter of the first cutter drum and rotatably mounted on the first cutter drum;
A second connecting member for connecting the center cutter head to the second cutter drum;
First rotational drive means for rotationally driving the first cutter drum with respect to the machine body;
Preparing in advance a shield machine equipped with the first cutter drum and having a second rotational drive means for rotationally driving the second cutter drum with respect to the first cutter drum;
When excavating a tunnel using the shield machine, the average peripheral speed of the plurality of cutter bits of the central cutter head is substantially equal to the average peripheral speed of the plurality of cutter bits of the outer peripheral cutter head. A tunnel excavation method characterized in that the excavation is set up as described above.   The tunnel excavation method according to claim 6, wherein the second connecting member includes a plurality of high-rigidity members that are elongated in the front-rear direction and are arranged at a plurality of equal circumferential positions.   The tunnel excavation method according to claim 6, wherein the second connecting member is configured by a cylindrical member having a partial cone whose diameter decreases from the second cutter drum toward the face side.   The rotary joint for connecting a plurality of hydraulic passages for supplying hydraulic pressure to the copy cutter of the outer peripheral cutter head and the second rotation driving means is provided at the center side portion of the partition wall. The tunnel excavation method according to any one of 8. The tunnel excavation method according to any one of claims 6 to 9, wherein an annular recess is formed in an inner peripheral portion of the first cutter drum, and a second cutter drum is mounted in the annular recess.