JP2002295183A - Shield machine for free section tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To overcome a problem such that earth removal performance and mud discharge performance are decreased because excavated soil sucking-in parts of earth removal equipment and mud discharge equipment cannot be made to face onto a bottom of a chamber due to location of a cutter drum, a drum storage part and a planet gear mechanism near an outer periphery of a shield machine, which excavates a free-section tunnel by a main cutter and a planetary cutter, in a structure wherein a planetary shaft is disposed near the outer periphery of the shield machine so that the planetary cutter can be rotated on the planetary shaft. SOLUTION: A ring gear 29 and of the planet gear mechanism 5 and the first planet gear 30 are disposed in the drum storage part 27 housing the cutter drum 28. The planetary shaft 31 is provided in such a manner as to be inserted into the chamber 21. The second planet gear 32, an idle gear 33 and the third planet gear 34 are provided inside a cutter head 4. The planetary cutter 15 is rotated on the planet gear 34 serving as a center of rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator for a free-section tunnel, and more particularly, to a free-section tunnel or a free-section tunnel provided with a planetary cutter that revolves and rotates while being linked to the rotation of the main cutter in addition to a main cutter. The present invention relates to a shield excavator for excavating a tunnel having a rectangular cross section, in which a structure of a planetary gear mechanism and an improved structure related thereto are improved.

[0002]

2. Description of the Related Art There is a shield excavator as a drilling device used for constructing a tunnel such as a subway or water and sewage system by a shield method. Although a shield machine is generally capable of excavating a tunnel with a circular section, a shield machine for a rectangular tunnel capable of excavating a tunnel with a rectangular section has recently been proposed. Note that the rectangular cross section includes a square cross section.

A polygonal hole drilling apparatus (shield tunneling machine for free-section tunnel) described in Japanese Patent Application Laid-Open No. 10-61382.
Is a body member and a shield frame having a rectangular cross section, and a disk body (bit body) arranged at the front end side of the shield frame.
And a cutter disk provided with a pair of planetary cutters mounted on the disk body, a cutter driving mechanism, and a planetary gear mechanism that revolves while rotating the planetary cutter in synchronization with the disk body. The planetary gear mechanism includes a sun gear, a planetary idle gear, and a planetary gear that is concentric with the rotation center of the planetary cutter. The planetary gear mechanism is mounted on a disk body.

When the disk drive is driven to rotate by the cutter driving mechanism, the planetary idle gear rotates while revolving around the sun gear, and the planetary gear rotates through the planetary idle gear, and the planetary cutter rotates around the sun gear. Revolves integrally with the planetary gear while revolving. In this shield excavator with a planetary cutter, since the entire planetary gear mechanism is incorporated in the disk body, the aperture ratio of the cutter disk is reduced, and the excavated soil cannot be efficiently taken into the rear chamber of the cutter disk. .

[0005] The applicant of the present application has disclosed in
No. 8781 proposes a shield excavator for a free-section tunnel in which the aperture ratio is increased and the driving force transmission system for rotating the planetary cutter is simplified. In this shield machine, a structure including a planetary gear mechanism for rotating the planetary cutter in association with the rotation of the disk main body is configured as follows. A partition that defines a chamber is provided on the rear side of the cutter disk, and an annular drum housing that houses the cutter drum is provided near the outer periphery of the partition, and an outer peripheral surface of an inner peripheral wall of the drum housing includes a planetary gear mechanism. A sun gear is fixed, a pair of planetary gears are meshed with the sun gear via a pair of idle gears, and the front ends of the planetary shafts spline-connected to the planetary gears are fixedly connected to the planetary cutter. ing.

On the other hand, Japanese Unexamined Patent Publication No. 9-170399 proposes a shield tunneling machine for a rectangular section tunnel for excavating a flat rectangular large section tunnel. In this shield machine, three main cutter discs, a mechanism for driving the main cutter discs, four auxiliary cutter discs arranged at four corners of a rectangle, and a non-excavated area which cannot be excavated by these cutter discs are provided. Equipped with eight roller-shaped cutter drums (drum cutters),
The three main cutter discs are arranged on the front side of the two main cutter discs on both sides thereof and are partially overlapped with them.

[0007]

[Problems to be Solved by the Invention] JP-A-10-6
In the shield machine described in Japanese Patent No. 1382, a planetary gear mechanism is incorporated in the cutter disk on the front side of the chamber, so that the intake of excavated soil into the chamber is reduced and the aperture ratio of the cutter disk is reduced. JP-A-2000-
In the shield excavator for free section tunnel of 8781,
Since the planetary gear mechanism is provided in the drum accommodating portion of the partition wall, the aperture ratio of the cutter disk can be increased, and the rotation drive mechanism for driving the planetary cutter can be simplified.

However, since the planetary shaft is arranged concentrically with the rotation center of the planetary cutter, and because the rotation center of the planetary cutter needs to be provided near the outer periphery of the shield excavator, the planetary shaft is not connected to the shield excavator. Will be located in the vicinity of the outer periphery. For this reason, the drum accommodating section must be provided near the outer periphery of the shield machine.Therefore, it becomes impossible to provide the excavated soil suction section of the screw conveyor of the earth removal equipment near the outer periphery of the shield machine, and the drum accommodating section cannot be provided. Parts must be disposed on the inner peripheral side of the part. Therefore, the excavated soil suction part of the screw conveyor cannot be arranged so as to face the bottom of the chamber, and the position of the excavated soil suction part is increased. It is difficult to be discharged,
It becomes difficult to enhance the soil removal performance.

In the shield tunneling machine for a tunnel having a rectangular cross section disclosed in Japanese Patent Application Laid-Open No. 9-170399, a main cutter disk,
The number of excavating members such as auxiliary cutter discs and cutter drums (drum cutters) is large, and the structure of their rotary drive system becomes complicated, resulting in high manufacturing costs.

An object of the present invention is to provide a shield excavator for a free-section tunnel in which a planetary shaft is disposed closer to the axial center than the vicinity of the outer periphery to enhance the performance of discharging excavated soil from a chamber. An object of the present invention is to provide a shield excavator for a free section tunnel having a cutter head rotation drive mechanism having a simple structure capable of excavating a flat rectangular tunnel having a large section without leaving a tunnel.

[0011]

According to the first aspect of the present invention, there is provided a shield excavator for a tunnel having a free section, a cutter head having a main cutter and a planetary cutter, a cutter driving means for driving the cutter head to rotate, and a rotation of the cutter driving means. Equipped with a planetary gear mechanism that rotates the planetary cutter in conjunction with the rotation of the main cutter by the driving force, and freely forms the contour shape of the planetary cutter according to the ratio between the revolution speed and the revolution speed of the planetary cutter. In a shield machine capable of excavating a cross-section tunnel, a rotary driving force for rotating a planetary cutter, wherein the planetary shaft is inserted through a chamber on the rear side of a cutter head on an axial center side from a portion near an outer periphery of the shield machine. And a first planetary gear and a planetary gear respectively mounted in the cutter head. And a gear mechanism having a second planetary gear concentric with the rotation axis of the planetary gear and transmitting the rotational driving force of the planetary shaft to the planetary cutter.

The cutter driving means rotates the main cutter and the planetary cutter of the cutter head to excavate into a circular cross section, and rotates the planetary cutter in synchronization with the rotation of the main cutter, and the planetary cutter rotates out of the free cross section. Excavate the outer part and the corner part that protrude from the circle,
Drill a free section tunnel. The “free cross section” is a non-circular cross section or irregular cross section such as a square, a rectangle, a polygon, an ellipse, and an oval.

The rotational driving force for rotating the planetary cutter is:
The power is transmitted from the planetary shaft to the second planetary gear via the first planetary gear and the idle gear, and the planetary cutter rotates. Since the rotation axis of the planetary cutter is arranged near the outer periphery of the shield machine, the second planetary gear is also arranged near the outer periphery of the cutter head. Therefore, the positions of the first planetary gear and the planetary shaft are set. Is located at a position closer to the axis than the portion near the outer periphery of the shield machine. Therefore, the mechanism that generates the rotational driving force applied to the planetary shaft can be arranged at a position closer to the axis than the outer periphery of the shield machine, with an annular space between the shield body and the front body member of the shield machine. Become. Therefore, at the bottom of the shield machine, the excavated soil suction portion of the soil discharging facility or the mud discharging facility can be disposed at the bottom of the annular space.

According to a second aspect of the present invention, there is provided a shield excavator having a configuration similar to that of the first aspect, further comprising a partition wall located behind the cutter head with a chamber therebetween. An annular drum accommodating section constituted by the partition wall is provided, and a cutter drum rotatably driven by cutter driving means is rotatably mounted in the drum accommodating section, and a plurality of connecting members for connecting the cutter drum to the cutter head are provided. The planetary gear mechanism includes a ring gear fixed to an inner surface of an outer peripheral wall of the drum housing, a first planetary gear meshed with the ring gear, a second planetary gear, an idle gear, and a planetary cutter provided respectively on a cutter head. A third planetary cutter concentric with the rotation axis of
A planetary shaft for transmitting the rotational driving force of the first planetary gear to the second planetary gear, and transmitting the rotational driving force of the planetary shaft from the second planetary gear to the third planetary gear via the idle gear; Is configured to rotate.

The main cutter and the planetary cutter of the cutter head are rotationally driven by the cutter driving means to excavate a circular section, and the planetary cutter is rotated in conjunction with the rotation of the main cutter, and the planetary cutter is rotated in the circular section of the free section. Excavate the outside and corner portions that protrude, and excavate a free-section tunnel. When the cutter head rotates,
The first planetary gear meshing with the ring gear rotates while revolving, and this rotational force is transmitted to the third planetary gear via the planetary shaft, the second planetary gear, and the idle gear, and the third planetary gear, the planetary cutter, Rotates.

Since the rotation axis of the planetary cutter is disposed near the outer periphery of the cutter head, the third planetary gear is also disposed near the outer periphery of the cutter head. Therefore, the positions of the second planetary gear and the planetary shaft are located on the axial center side (inner peripheral side) with respect to the vicinity of the outer periphery, and are slightly located on the outer peripheral side with respect to the vicinity of the shaft center of the shield machine. As a result, the mechanism (the ring gear or the first planetary gear) for generating the rotational driving force applied to the planetary shaft, the drum accommodating portion, and the cutter drum are moved to a position closer to the axis than the outer periphery of the shield excavator. It can be arranged with an annular space between it and the front fuselage of the machine. Therefore, at the bottom of the shield machine, the excavated soil suction portion of the earth discharging facility or the mud discharging facility is disposed at the bottom of the annular space, and the excavated soil can be sucked from the bottom of the chamber.

According to a third aspect of the present invention, there is provided a shield excavator having a configuration similar to that of the first aspect, further comprising a partition wall located behind the cutter head and separated by a chamber. An annular drum accommodating section constituted by the partition wall is provided, and a cutter drum rotatably driven by cutter driving means is rotatably mounted in the drum accommodating section, and a plurality of connecting members for connecting the cutter drum to the cutter head are provided. The planetary gear mechanism includes a sun gear fixed to an outer surface of an inner peripheral wall of the drum housing, a first planetary gear meshed with the sun gear, a second planetary gear, an idle gear, and a planetary cutter provided respectively on a cutter head. A third planetary cutter concentric with the rotation axis of the
A planetary shaft for transmitting the rotational driving force of the planetary gear to the second planetary gear, and transmitting the rotational driving force of the planetary shaft to the second planetary gear.
The planetary cutter is configured to rotate from the planetary gear to the third planetary gear via the idle gear to rotate.

The shield machine of the third aspect of the present invention is different from the device of the second aspect only in that a sun gear is provided in place of the ring gear, and the first planetary gear meshes with the sun gear. When the cutter head rotates, the first planetary gear meshing with the sun gear revolves and revolves, and this rotational force is transmitted to the third planetary gear via the planetary shaft, the second planetary gear, and the idle gear,
The third planetary gear and the planetary cutter rotate. Other operations are the same as those of the second aspect.

According to a fourth aspect of the present invention, in the tunnel machine according to any one of the first to third aspects, the ratio between the revolution speed and the revolution speed of the planetary cutter is set to 1: 4, It is characterized in that a square section tunnel can be excavated. Therefore, the planetary cutter rotates four times when the main cutter makes one rotation, and excavates the outer part including the four corners of the square cross section.

According to a fifth aspect of the present invention, there is provided a shield excavator for a free section tunnel according to the second or third aspect of the present invention, wherein the outer peripheral wall of the annular drum accommodating portion is arranged with an annular space between the outer peripheral wall and the front body member. It is characterized by having been done. Therefore, the excavated soil taken into the chamber can be sucked and discharged into the excavated soil suction portion of the earth discharging facility or the mud discharging facility introduced into the annular space.

According to a sixth aspect of the present invention, there is provided a shield excavator for a free section tunnel, wherein the shield excavator is connected to both sides of the shield excavator for a free section tunnel according to claim 4, and the cutter head of the central shield excavator is attached to both sides. And the cutter head of the shield excavator on both sides is partially wrapped with respect to the cutter head of the central shield excavator. It is. Therefore, although it is a shield excavator with a structure in which a plurality of shield excavators are connected in parallel, a flat vertical or horizontal rectangular cross-section tunnel (may be a large cross-section tunnel) without leaving an unexcavated area Is excavable. Each of the shield excavators on both sides of the free section tunnel shield excavator may be the same free section tunnel shield excavator as the central free section tunnel shield excavator. Machine.

According to a seventh aspect of the present invention, there is provided a shield excavator for a free section tunnel, wherein the shield excavator having substantially the same structure as the shield excavator is connected to both sides of the shield excavator for a free section tunnel according to the fourth aspect. The cutter heads of the shield excavators are arranged in the excavation direction ahead of the cutter heads of the shield excavators on both sides, and the cutter heads of the shield excavators on both sides are partially arranged with respect to the cutter head of the central shield excavator. It is characterized by being wrapped. Therefore, as in the case of the sixth aspect, it is possible to excavate a flat vertical or horizontal rectangular section tunnel (sometimes a large section tunnel) without leaving an unexcavated area.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is an example in which the present invention is applied to a shield tunneling machine for a free-section tunnel that excavates a square-section tunnel. Note that the front, rear, left and right in the excavation direction will be described as front, rear, left and right. As shown in FIGS. 1 and 2, the shield machine 1 includes a front body member 2 and a rear body member 3 having a square cross section, a cutter head 4,
It includes a planetary gear mechanism 5, a cutter driving mechanism 6, a plurality of shield jacks 7, an earth discharging facility 8, an erector 9, and the like.

The front body member 2 and the rear body member 3 will be described. As shown in FIG. 1, a rear trunk member 3 is connected to a rear end of the front trunk member 2 via a center bent portion 10 and a plurality of center bending jacks 11. A row of tail grout seals 12 is provided.

Next, the cutter head 4 will be described. As shown in FIGS. 1 to 3, the cutter head 4 is
The cutter head 4 includes a center frame 13, a main cutter 14, planetary cutter spokes 18, and a planetary cutter 15 mounted on the planetary cutter spokes 18. The center frame 13 is formed in a laterally substantially cylindrical body, and a main cutter 14 is provided on the front half of the outer periphery of the center frame 13.
The two main cutter spokes 14a are 18 in front view.
It is welded to the 0-degree symmetric position. Each of the main cutter spokes 14a is formed in a substantially sector shape that is wider toward the outer diameter side, and the length from the rotation center to the outer diameter portion is formed to be の 長 of one side of the square cross section. A large number of cutter bits 16 are attached to the front of 14a, and a mud dispensing port 17 is also formed.

At the rear of the center frame 13, a pair of planetary cutter spokes 18 that are 90 degrees out of phase with the main cutter spokes 14a are fixed. Each of the planetary cutter spokes 18 has a substantially leaf-shaped planetary cutter 15 pivotably attached thereto. Each of the planetary cutter spokes 18 is formed in a substantially fan shape so that a second planetary gear 32, an idle gear 33, and a third planetary gear 34 can be pivotally connected, and each of the planetary cutters 15 is disposed in front of the planetary cutter spokes 18. Have been.

Each of the planetary cutter spokes 18 is formed to have a half length of one side of the square section tunnel, similarly to the main cutter spokes 14a. The contour shape of the planetary cutter 15 in a front view is formed in a substantially leaf shape according to the ratio of the revolution speed and the revolution speed of the planetary cutter 15. A number of bits 20 are attached to the outer peripheral portion of the front surface of each planetary cutter 15. Each planetary cutter 1
5, a shaft portion 3 of the third planetary gear 34
5 is fixed, and this shaft portion 35 is a rotation shaft of the planetary cutter 15. The pair of planetary cutters 15 are symmetrically arranged with respect to the center of revolution of the cutter head 4.

Next, the chamber 21, the partition 22, the cutter drum 28 and the like will be described. As shown in FIGS. 1 and 3, a chamber 21 is formed on the rear side of the cutter head 4, and a partition 22 located on the front body member 2 with the chamber 21 interposed therebetween, and partitions a rear end of the chamber 21. The partition 22 is welded to the front body member 2. The partition wall 22 has a cylindrical portion 23 concentric with the tunnel axis, a central wall portion 24 for closing the front end of the cylindrical portion 23,
An opening wall 25 welded to the rear end of the cylindrical portion 23 and the front body member 2, and an annular wall having an L-shaped cross section that forms an annular drum housing portion 27 in cooperation with the opening wall 25 and the cylindrical portion 23. Part 26
It is composed of An annular space 52 having a square outer shape is formed between the cylindrical wall 26a of the annular wall portion 26 and the front body member 2. The outer periphery of the annular plate portion 26b of the annular wall portion 26 is welded to the front body member 2, and the rear end of the cylindrical wall 26a is welded to the opening wall portion 25.

The annular drum housing portion 27 is formed on the outer peripheral side with respect to the portion near the axis of the shield machine 1 and on the inner peripheral side with respect to the vicinity of the outer peripheral portion, and the front end of the drum housing portion 27 is opened to the chamber 21. ing. A cutter drum 28 is rotatably mounted on the drum accommodating portion 27, and a plurality of seal members / bearing members 28a and 28b are mounted in annular gaps inside and outside the cutter drum 28.

Next, the planetary gear mechanism 5 will be described.
The planetary gear mechanism 5 includes a ring gear 29, a pair of first planetary gears 30, a pair of planetary shafts 31, a pair of second planetary gears 32, a pair of idle gears 33, and a pair of 3
And a planetary gear 34. The ring gear 29 is fixed to the inner surface of the outer peripheral wall of the drum housing 27 (the cylindrical portion 26 a of the annular wall 26), and the first planetary gear 30 meshes with the ring gear 29 in the drum housing 27. The axis of the rotating member (30 to 34) of the planetary gear mechanism 5 is parallel to the axis of the tunnel.

The second planetary gear 32, the idle gear 33, and the third planetary gear 34 are provided in the planetary cutter spokes 18, and the second planetary gear 32 meshes with the third planetary gear 34 via the idle gear 33, Shaft 35 of third planetary gear 34
The planetary cutter 15 is fixed to the front end of the. The shaft portion 35 is rotatably supported via a pair of bearings 36 at a position near three equal parts on the outer peripheral side among two points dividing the planetary cutter spoke 18 into three equal parts in the length direction. .

The planetary shaft 31 is located at the same radial position as the drum accommodating portion 27 and is disposed so that the chamber 21 is inserted into the front side of the drum accommodating portion 27, and is rotatable by a pair of bearings 37a and 37b. It is supported by. The rear part of the planetary shaft 31 is inserted through the front part of the cutter drum 28, the first planetary gear 30 is connected to the rear end of the planetary shaft 31 so as to be able to transmit rotational force, and the second planetary gear 32 is connected to the front end of the planetary shaft 31. Are connected so as to be able to transmit a rotational force.

The rear end of the planetary shaft 31 is mounted on a planetary carrier 38 which forms the rear of the cutter drum 28.
It is rotatably supported via 7a. The front end of the planetary shaft 31 is connected to the front wall 3 of the planetary cutter spoke 18.
9 is rotatably supported via a bearing 37b, and is configured to transmit the rotational driving force of the first planetary gear 30 to the second planetary gear 31. In addition, sealing plates 40 and 41 for preventing intrusion of earth and sand into the planetary cutter spokes 18 are also provided.

The chamber 21 of the planetary shaft 32
A cylindrical connecting member 42 for covering the planetary shaft 32 is provided on the inner part, a rear end of the connecting member 42 is fixed to the cutter drum 28, and a front end of the connecting member 42 is fixed to the planetary cutter spoke 18. ing. Each main cutter spoke 14 a is connected to the cutter drum 28 via a connecting member 43 that is slightly longer than the connecting member 42. The rotational driving force input to the cutter drum 28 is transmitted to the cutter head 4 via a pair of connecting members 42 and a pair of connecting members 43, so that the cutter drum 28 and the cutter head 4 rotate integrally. Has become.

Next, the cutter driving mechanism 6 will be described. The cutter driving mechanism 6 includes an annular gear 44 and a plurality of cutter driving motors 45 for driving the annular gear 44 to rotate. A pinion gear 46 fixed to the motor shaft of each cutter drive motor 45 meshes with the annular gear 44, and the annular gear 44 is connected to the cutter drum 28 and the planetary carrier 38.
, And the cutter drive motor 45 is laid on the opening wall 25. The ring gear 44 is supported by the opening wall 25 via a pivot bearing (not shown).

When the plurality of cutter driving motors 45 operate, the annular gear 44 and the cutter drum 28 (including the planetary carrier 38) revolve around the center of the shield machine 1 (tunnel axis) as a rotation center, and a plurality of couplings are formed. The cutter head 4 (including the main cutter 14 and the planetary cutter 15) and the planetary gear mechanism 5 via the members 42 and 43
Revolves integrally with the cutter drum 28. Since the first planetary gear 30 revolves with the cutter drum 28, the first planetary gear 30 rotates by itself, and the planetary shaft 31 and the second planetary gear 32 also rotate by rotation. The power is transmitted to the planetary gear 34, the planetary cutter 15 rotates and rotates integrally with the third planetary gear 34, and the planetary cutter 19 revolves integrally with the cutter head 4 while rotating at a rotational speed of, for example, four times the rotational speed. It rotates on its own.

Next, the plurality of shield jacks 7 will be described. As shown in FIG. 1, a plurality of shield jacks 7 for generating thrust for excavation are arranged in front and rear directions at appropriate intervals in the circumferential direction inside the rear portion of the front body member 2 and the front end of the rear body member 3. Has been established. Each shield jack 7
An annular frame 47 fixed to the inner surface of the front end of the rear trunk member 3
A spreader 49 is connected to the distal end of the rod of the shield jack 7 via an eccentric fitting 48, and the reaction force of the plurality of shield jacks 7 is excavated for the segment 50 which has been lining the inner surface of the tunnel. Generate thrust.

Next, the earth discharging facility 8 will be described. Figure 1
As shown in FIG. 5, a screw conveyor 51 is disposed in a manner inclined upward and backward from the lower end of the opening wall 25 of the partition wall 22. The bottom of the annular space 52 defined by the annular wall portion 26, the opening wall portion 25, and the front body member 2, has a communication hole 2
A discharge portion 52 a communicating with the chamber 21 through the through hole 6 a is formed, and the excavated soil suction portion 51 of the screw conveyor 51 is formed.
a is disposed in the discharge part 52a, and the screw conveyor 51
Sucks the excavated soil that has flowed into the discharge portion 52a from the chamber 21, transfers the excavated soil to the rear, and transfers the excavated soil to the belt conveyor extending rearward from within the rear trunk member 3. The excavated soil sent to the belt conveyor is conveyed to the rear in the tunnel by a belt conveyor (not shown) and conveyed to the ground.

Next, the erector 9 will be described. As shown in FIG. 1, the erector 9 is a device for assembling a segment 50 on the inner surface of a tunnel having a square cross section. The annular frame 47 is provided with a plurality of brackets 56 in a ring shape.
Are rotatably supported, respectively. The ring-shaped erector drum 53 is rotatably supported by the guide rollers 58, and the erector drum 53 is provided with an erector main body 54 so as to protrude rearward, and the erector drum 53 is a rotary drive motor mounted on a bracket 59. At 55, it can be driven to rotate. That is, a chain member or a rack is fixed to the inner peripheral surface of the electret drum 53, and a pinion of an output shaft of the rotary drive motor 55 meshes with the chain member or the rack.

A rotary joint 60 is connected to the center wall 24 of the partition wall 22.
The outer cylinder member 61 is fixed to the central wall portion 24, and the rotary joint 60 is provided with a humidifier passage, a grease introduction passage, and the like.

In the above-described planetary gear mechanism 5, the ratio between the revolution speed and the rotation speed of the planetary cutter 15 is determined by the ring gear 29, the first planetary gear 30, the second planetary gear 32, the idle gear 33, and the third planetary gear. 34 can be set arbitrarily by appropriately setting the number of teeth. In this shield machine 1, the ratio between the revolution speed and the revolution speed of the planetary cutter disk 19 is set to 1: 4, and
The planetary cutter 15 rotates four times during rotation, and is configured to be able to excavate a square section tunnel (rectangular section tunnel).

The outline shape of the planetary cutter disc 19 when viewed from the front is substantially a leaf shape. The outline shape will be described with reference to FIG. The rectangular cross section of the tunnel is a square h as shown by a virtual line. In order to excavate this tunnel with the shield machine 1, the planetary cutter 15 is used.
When the planetary gear rotates while revolving, it is necessary to draw a locus such that the planetary cutter 15 is always inscribed in the square h. When the planetary cutter disk 19 rotates four times while revolving once, the contour shape of the planetary cutter disk 19 is determined so that the locus of the farthest point portion farthest from the revolving center O of the planetary cutter 15 draws a square h. I have.

Here, assuming that the outer shape of the circular area excavated by the main cutter 14 is a circle J and the revolving locus of the rotation center Ob of the planetary cutter 15 is a circle K (shown by a virtual line), the circle K
The upper points m1, m2,... Indicate the position of the rotation center Ob of the planetary cutter 15 at each angle when the planetary cutter 15 is rotated by an angle θ (θ = 15 °). The points P1, P2,... On the square h are the points m1, m on the circle K.
.. And the orbital center O are points where the straight line intersects the square h.

The rotation center Ob of the planetary cutter 15 is at the point m1.
In order for the planetary cutter disc 19 to be inscribed in the square h, the radius of the planetary cutter disc 19 is
It must be a straight line length n1 connecting the point m1 on the circle K and the point P1 on the square h. Next, when the planetary cutter 15 moves from the position of the point m1 to the position of the point m2 by revolving at an angle θ, the radius of the planetary cutter 15 must be on the circle K in order for the planetary cutter 15 to be inscribed in the square h. It must be a straight line length n2 connecting the point m2 and the point P2 on the square h.

Similarly, when the planetary cutter 15 moves to the position of the point m3, the radius of the planetary cutter 15 becomes the circle K
The straight line length n3 connecting the upper point m3 and the point P3 on the square h
Must. On the other hand, the planetary cutter 15 rotates by an angle of 4θ while revolving by an angle of θ. Therefore, as described above, the radius length of the planetary cutter 15 is sequentially set to n1, n2,
, The contour shape of the planetary cutter 15 is determined. Therefore, the contour shape of the planetary cutter 15 is substantially leaf-shaped. By setting the outline shape of the planetary cutter 15 in the front view as described above, a corner having a square cross section can be excavated by each planetary cutter 15, so that a tunnel having a square cross section can be excavated.

Next, the operation of the shield machine 1 described above will be described. When excavating a tunnel having a square cross section with the shield excavator 1, a plurality of shield jacks 7 are used.
When the cutter driving motor 45 is rotationally driven while generating the thrust for excavation, the cutter drum 28 rotates via the pinion gear 46 and the annular gear 44, and is integrated with the cutter drum 28 via the plurality of connecting members 42 and 43. The cutter head 4 rotates. The rotation of the cutter head 4 causes the main cutter 14 and the planetary cutter 15 to rotate, and the rotation of the main cutter 14 mainly excavates a circular cross-section (the portion indicated by the circle J in FIG. 4) in the square cross-section tunnel.

On the other hand, the planetary cutter 15 revolves around the center of the cutterhead 4 by the rotation of the cutterhead 4, but the rotation of the cutter drum 28 causes the first planetary gear 30 to rotate due to the above-described operation of the planetary gear mechanism 5. , Planet shaft 31, second planetary gear 32, idle gear 33,
The third planetary gears 34 respectively rotate, and the planetary cutter 15 rotates concentrically with the third planetary gears 34. Planetary cutter 15
Since the ratio between the revolution speed and the rotation speed of the motor is 1: 4,
During one rotation of the cutter head 4, the planetary cutter disk 19 rotates in a direction opposite to the rotation direction of the cutter head 4.
Rotate and spin.

As described above, by rotating the planetary cutter 15 while revolving, the planetary cutter 15 always revolves while rotating while inscribed in the square K. Therefore,
The four corners of the tunnel having a circular cross section are excavated by the planetary cutter 15 revolving while rotating, and a tunnel having a square cross section is excavated by cooperation of the main cutter 14 and the planetary cutter 15. Then, the excavation is stopped every time one ring is excavated, the segments 50 are assembled on the inner surface of the tunnel using the erector 9, and thereafter the excavation is resumed.

According to the shield machine 1 described above,
The ring gear 29 and the first planetary gear 30 of the planetary gear mechanism 5 are disposed in the drum housing portion 27, and the planetary shaft 31 is located closer to the axis of the shield excavator 1 than the vicinity of the outer periphery of the shield excavator 1 (the inner peripheral side). ), The second planetary gear 32, the idle gear 33, and the third planetary gear 34 are arranged in the planetary cutter spoke 18 of the cutter head 4, and the third planetary gear 34
Is disposed near the outer periphery of the shield machine 1, so that the drum housing 2
7, the cutter drum 28, the ring gear 29, and the first planetary gear 30 can be arranged on the axial center side of the shield excavator 1 near the outer periphery thereof, with the annular space 52 being provided between the front excavator member 2 and the shield body 2.

As a result, the excavated soil suction section 51a of the earth discharging facility or the mud discharging facility is arranged at the bottom of the annular space 52, and the excavated soil can be sucked from the bottom of the chamber 21. Performance can be ensured. Further, since the ring gear 29 of the planetary gear mechanism 5 is provided on the inner surface of the outer peripheral wall of the drum housing 27, it is advantageous in terms of integrally connecting the annular gear 44, the planetary carrier 38 and the cutter drum 28. Further, since the cutter head 4 having the main cutter 14 and the planetary cutter 15 is provided, and only a part of the planetary gear mechanism 5 is provided on the cutter head 4, the aperture ratio of the cutter head 4 can be sufficiently secured.

Next, a modified embodiment in which this embodiment is partially modified and another embodiment will be described. However, members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. 1] Modification (see FIG. 5) This shield machine 1C employs a planetary gear mechanism 5C in which the structure of the planetary gear mechanism 5 of the shield machine 1 is partially modified. In the planetary gear mechanism 5C, a sun gear 29C fixed to the inner peripheral wall of the drum housing 27 is provided instead of the ring gear 29, and the first planetary gear 30 meshes with the sun gear 29C.

The planetary carrier 38C, which is a part of the cutter drum 28C, extends forward through the outer peripheral side of the first planetary gear 30 and is integrally connected to the cutter drum 28C. The planetary gear mechanism 5C operates in substantially the same manner as the planetary gear mechanism 5. That is, the cutter drum 2
When the gear 8C is driven to rotate, the first planetary gear 30 rotates while revolving around the sun gear 29C, and its rotation is
Planet shaft 31, second planetary gear 32, idle gear 3
The rotation of the planetary cutter 15 is transmitted to the third planetary gear 34 through the third planetary gear 3, and the planetary cutter 15 revolves while revolving. The number of gear teeth is set so that the ratio of the revolution speed of the planetary cutter 15 to the revolution speed thereof is 1: 4.

2) In the shield machine 1, the case where the ratio between the revolution speed and the revolution speed of the planetary cutter 15 is set to 1: 4 and a tunnel having a square cross section is excavated has been described as an example. The ratio between the revolution speed and the revolution speed of the cutter 15 is not limited to the above example. When the ratio between the revolution speed and the revolution speed is set to 1: 3, a triangular section, 1: 2 When it is set to, a tunnel having a rectangular section can be excavated, and when set to 1: 5, a tunnel having a regular pentagonal section can be excavated. However, the contour shape of the planetary cutter disc 19 is appropriately set according to the cross-sectional shape of the tunnel to be excavated, that is, the ratio between the revolution speed and the revolution speed of the planetary cutter disc 19.

3) In the shield machine 1, the cutter head 4 is provided with a pair of planetary cutters 15. However, the cutter head 4 may be provided with one planetary cutter 15, and three or more planetary cutters may be provided. 15 may be equipped.
Further, the idle gear 33 provided in the planetary cutter spoke 18 is omitted, and the second planetary gear 32 is replaced with the third planetary gear 34.
It may be configured to directly mesh with the shaft.

4] Another embodiment 1 (see FIGS. 6 to 9) This shield excavator 1 for a rectangular section (free section) tunnel
A is a shield excavator 70 for a free section tunnel similar to the shield excavator 1 described in the above embodiment, and a pair of right and left shield excavators 71 and 7 connected in parallel on both sides thereof.
2 and is configured to be able to excavate a flat, horizontally long rectangular section tunnel having a large section. Shield machine 71, 72
Is also substantially the same as the shield machine 1 of the embodiment.

The front body member 2A of the shield machine 1A is formed in a flat rectangular shape as shown in FIGS. 7 and 8, but the front body member 2 is provided between the shield machine 70 and 71. Corresponding partitions are also provided. Shield machine 1A
The rear trunk member 3A is formed in a thick flat rectangular shape as shown in FIG. The cutter head 4 of the center shield excavator 70 is arranged ahead of the cutter heads 4 of the shield excavators 71 and 72 on both sides in the excavation direction,
The cutter heads 4 of the shield excavators 71 and 72 on both sides are arranged so as to partially overlap with the cutter head 4 of the central shield excavator 70.

A portion of the annular space 52 of the shield excavators 71 and 72 on both sides on the center shield excavator 70 side is not provided, and the left and right shield excavators 71 and 72 are not provided.
Of the partition walls 73 and 74 are asymmetrical with respect to the axis. Similarly to the shield machine 1, a large number of shield jacks 7 are provided inside the shield machine 1A.

Referring to the earth discharging facility 75, FIG.
As shown in FIG. 7, a merging screw conveyor 78 is provided at a central portion in the rear part of the shield machine 1A. The merging screw conveyor 78 branches into a pair of left and right slightly smaller diameter screw conveyors 76 and 77. Excavated soil suction portions at the front ends of the small-diameter screw conveyors 76 and 77 project into the right bottom portion and the left bottom portion of the annular space 52 of the central shield machine 70, respectively.

Next, the erector 81 will be described.
As shown in FIGS. 6 and 9, the erector 81 includes a pair of upper and lower guide frames 82, an erector frame 83, an erector main body 84, a movement drive motor 85, a rotation drive motor 86, and the like. A pair of upper and lower guide frames 82
Are installed in parallel at regular intervals up and down over substantially the entire width from the left end to the right end. Electa frame 83
Are movably supported by the guide frames 82 and are configured to be movable in the left-right direction by a movement drive motor 85 connected to the annular frame 47.

This rectangular section tunnel shield machine 1
According to A, the cutter head 4 of the central shield excavator 70 is arranged ahead of the cutter heads 4 of the shield excavators 71 and 72 on both sides in the excavation direction, and the cutter head 4 of the central shield excavator 70 is On the other hand, by partially wrapping the cutter heads 4 of the shield excavators 71 and 72 on both sides, the shield excavators 70 and 7 are
There is no unexcavated region that cannot be excavated between the shield excavator 70 and the shield excavator 70, 72, and efficient excavation can be performed even with hard soil.

5] Alternative Embodiment 2 (See FIGS. 10 to 13) This rectangular section (free section) tunnel shield machine 1
B is a shield excavator 90 for a free section tunnel having the same structure as the shield excavator for a free section tunnel of the above-described main embodiment, and a pair of shield excavators 91 and 92 connected in parallel on upper and lower sides thereof. The tunnel is configured to be able to excavate a rectangular tunnel having a large cross section and a flat vertical length.
The cutter head 4 of the central shield excavator 90 is disposed forward of the cutter heads 4 of the shield excavators 91 and 92 on both sides in the excavation direction. The cutter heads 4 of the excavators 91 and 92 are partially wrapped and arranged.

The front fuselage member 2B of the shield machine 1B is formed in a flat rectangular shape as shown in FIGS. 11 and 12, but the front machine member 2 is located between the shield machine 90 and 91. Corresponding partitions are also provided. Shield machine 1
The rear body member 3B of B is formed in a thick flat rectangular shape as shown in FIG. The cutter head 4 and the planetary gear mechanism 5 of the central shield excavator 90 are the same as those of the shield excavator 1 except for the shield excavator 9.
Because the space between the upper and lower partition walls of 0 is narrowed,
Those corresponding to the annular space 52 of the shield machine 1 are omitted.

The uppermost shield excavator 91 and the lowermost shield excavator 92 are shield excavators having a structure different from that of the shield excavator 1 of the embodiment, and are disclosed in Japanese Patent Application Laid-Open No. 2000-8781 proposed by the present applicant. This is the same as the shield machine described in (1). This shield machine 91, 92
In, the drum housing portion 27B is formed near the inside of the front trunk member 2B, and the cutter drum 28 is rotatably mounted on the drum housing portion 27B. Since the shield machines 91 and 92 are symmetrical with respect to the axis of the shield machine 90, the shield machine 91 will be described as an example.

As shown in FIGS. 10 to 12, the planetary gear mechanism 5B has a sun gear 93 and a first gear meshed with the sun gear 93.
It has a pair of idle gears 94 and a pair of planetary gears 95 meshed with the pair of idle gears 94, respectively. The sun gear 93 is fixed to the outer surface of the inner peripheral wall of the drum housing 27B. Are rotatably supported by a planetary carrier forming a part of the cutter drum 28 via bearings.

The planetary shaft 96 is disposed near the outer periphery of the shield machine 91 so as to be concentric with the center of rotation of the planetary cutter 15, and the planetary gear 95 is spline-connected to the rear end of the planetary shaft 96, and The front end of the shaft 96 is fixedly connected to the planetary cutter 15. When the cutter drum 28 is driven to rotate, the planetary gear 95 revolves around the sun gear 93 while revolving around. The rotational force of the planetary gear 95 is transmitted to the planetary cutter 15 via the planetary shaft 96, and the planetary cutter 15 is rotated. While revolving around the axis of the shield machine 91, it revolves around the center of the planet shaft 96 in the direction opposite to the revolving direction.

The cutter drum 28 and the cutter head 4 are connected to each other, and a pair of connecting members 97 for transmitting a rotational driving force from the cutter drum 28 to the cutter head 4 are provided on a pair of planetary shafts 96, respectively. Connecting member 4
2 is also provided. 10, 12, and 13, the excavated soil suction portion of the screw conveyor 98 is connected to the partition wall 22 of the shield machine 92 as shown in FIGS. 10, 12, and 13.
The screw conveyor 98 penetrates the lower portion of the central wall portion 24 and protrudes into the vicinity of the lower end of the chamber 21. The screw conveyor 98 is disposed in an upwardly inclined rearward direction, and the excavated soil sucked from the chamber 21 is transported by a belt conveyor or a conveyor (not shown). It is transported to a trolley, and then transported backward in the tunnel and transported to the ground.

According to the shield excavator 1B, the cutter heads 4 of the shield excavators 90 to 92 are arranged in the same manner as the shield excavator 1A.
As in A, there is no unexcavated area that cannot be excavated between the shield excavators 90 and 91 and between the shield excavators 90 and 92, and efficient excavation can be performed even with hard soil.

An example in which the shield machines 1A and 1B are partially changed will be described. Each shield machine may be equipped with one planetary cutter 15 or three or more planetary cutters 15. In the shield excavator 1A, shield excavators similar to the shield excavators 91 and 92 in the shield excavator 1B may be provided instead of the shield excavators 717 and 72 on both sides of the central shield excavator 70. In the shield excavator 1B, the shield excavators 91 on both sides of the central shield excavator 90,
Instead of 92, a shield machine similar to the shield machines 71 and 72 of the shield machine 1A may be provided. In addition, various changes can be made to each part of the shield machine 1, 11A, 1B without departing from the spirit of the present invention.

[0069]

According to the first aspect of the present invention, the rotation of the planetary shaft is transmitted to the planetary cutter via the gear mechanism including the first and second planetary gears, and the planetary cutter is rotated. The planetary shaft can be arranged closer to the axis than the vicinity of the outer periphery of the shield machine.

Since the planetary shaft is on the axial center side of the vicinity of the outer periphery of the shield machine, a mechanism for generating a rotational driving force applied to the planetary shaft is provided on the axial center side of the outer periphery of the shield machine. And a space can be provided between the shield machine and the front trunk member of the shield machine. Therefore,
At the bottom of the shield machine, the excavated soil suction part of the soil discharging equipment and the mud discharging equipment can be arranged at the bottom of the space,
The soil discharging performance and the mud discharging performance can be secured. Since only a part of the planetary gear mechanism is provided in the cutter head, the aperture ratio of the cutter head does not decrease.

According to the second aspect of the present invention, similarly to the first aspect, the second planetary gear, the idle gear, and the third planetary gear are provided on the cutter head to rotate the planetary shaft, and the rotation of the planetary shaft is controlled by the second planetary gear. And the planetary shaft is disposed closer to the center of the shield excavator than the outer periphery of the shield machine, as in the first embodiment. it can.

As a result, the drum housing, the cutter drum, the ring gear and the first planetary gear of the planetary gear mechanism,
A space can be provided between the shield excavator and the trunk member of the shield excavator closer to the axis than the vicinity of the outer periphery of the shield excavator.
Therefore, in the same manner as in the first aspect, at the bottom of the shield machine, the excavated soil suction portion of the soil discharging facility and the mud discharging facility can be disposed at the bottom of the space, and the soil discharging performance and the mud discharging performance are secured. be able to. In addition, since only a part of the planetary gear mechanism is provided on the cutter head, the aperture ratio of the cutter head does not decrease.

According to the third aspect of the invention, basically the same effects as those of the second aspect can be obtained.

According to the fourth aspect of the present invention, since the ratio of the revolution speed of the planetary cutter to the revolution speed thereof is set to 1: 4, the planetary cutter can rotate while the main cutter and the planetary cutter make one revolution. 4 times to excavate the outer portion including the four corners of the square cross section, thereby excavating the tunnel of the square cross section.

According to the fifth aspect of the present invention, since the outer peripheral wall of the annular drum accommodating portion is arranged between the front drum member and the annular space for discharging the excavated soil from the chamber, An excavated soil suction section of a soil discharging facility or a mud discharging facility is arranged at the bottom of the annular space, and the excavated soil can be sucked from the bottom of the chamber.

According to the invention of claim 6, the shield excavator is connected to both sides of the shield excavator for a free-section tunnel according to claim 4, and the cutter head of the central shield excavator is connected to the cutter head of the shield excavator on both sides. In addition, since the cutter heads are arranged forward in the excavation direction and the cutter heads on both sides are partially wrapped with respect to the central cutter head, an unexcavated area does not occur at the excavation boundary of the shield excavator. In particular, the central shield excavator is the shield excavator for a free-section tunnel according to claim 4, and the planetary shaft is located on the axial center side from the vicinity of the outer periphery. The structure for partially wrapping the cutter head is simplified.

According to a seventh aspect of the present invention, a shield excavator having substantially the same structure as the shield excavator is connected to both sides of the shield excavator for a free-section tunnel according to the fourth aspect, and the central shield excavator is provided. Since the cutter heads of both sides were arranged ahead of the cutter heads of the shield excavators on both sides in the excavation direction, and the cutter heads of the shield excavators on both sides were partially wrapped with respect to the cutter head of the central shield excavator. Therefore, no unexcavated area is formed at the excavation boundary of the shield machine.

In particular, the central shield excavator is the shield excavator for a free-section tunnel according to claim 4, and the planetary shaft is located closer to the axial center than the vicinity of the outer periphery. The structure for partially wrapping the cutter heads on both sides is simplified. Further, since all three shield excavators are shield excavators for a free-section tunnel as described in claim 4, when excavating a vertical rectangular cross-section tunnel, as in claims 1 to 3, It becomes easy to secure soil performance or sludge performance.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a shield excavator for a free-section tunnel according to an embodiment of the present invention.

FIG. 2 is a front view of the shield machine.

FIG. 3 is an enlarged vertical sectional side view of a main part of a planetary gear mechanism, a cutter driving mechanism, and the like.

FIG. 4 is an explanatory diagram of a contour shape of a planetary cutter.

FIG. 5 is a diagram corresponding to FIG. 3 according to a modified embodiment.

FIG. 6 is a cross-sectional plan view of a shield excavator for a rectangular section tunnel according to another embodiment.

FIG. 7 is a front view of the shield machine shown in FIG. 6;

FIG. 8 is a cross-sectional view showing a cross section at a plurality of positions for explaining the structure of the planetary gear mechanism of the shield machine shown in FIG. 6;

9 is a vertical sectional front view of the shield machine shown in FIG. 6;

FIG. 10 is a cross-sectional side view of a shield excavator for a rectangular section tunnel according to another embodiment.

FIG. 11 is a front view of the shield machine shown in FIG. 10;

FIG. 12 is a cross-sectional view showing a cross section at a plurality of positions for explaining the structure of the planetary gear mechanism of the shield machine shown in FIG. 10;

FIG. 13 is a vertical sectional front view of the shield machine shown in FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shield excavator 4 Cutter head 5 Planetary gear mechanism 6 Cutter drive mechanism 14 Main cutter 15 Planetary cutter 21 Chamber 22 Partition wall 27 Drum accommodating part 28 Cutter drum 29 Ring gear 30 First planetary gear 31 Planetary shaft 32 Second planetary gear (first) 33 idle gear 34 third planetary gear (second planetary gear) 42, 43 connecting member 52 annular space

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Ukegawa 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (72) Inventor Takeshi Yagura 1-7-1 Kyobashi, Chuo-ku, Tokyo Inside Toda Construction Co., Ltd. (72) Minoru Motoki 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (72) Toshihiro Okumura 1-1-1 Kyobashi, Chuo-ku, Tokyo Toda (72) Inventor Mitsuo Shimizu 8 Harima-cho, Harima-cho, Kako-gun, Hyogo Prefecture Inside Harima Plant, Kawasaki Heavy Industries, Ltd. Harima Factory (72) Inventor Tamotsu Munakata 8 Harima-machi, Harima-cho, Kako-gun, Hyogo Kawasaki Heavy Industries, Ltd. Harima Factory F-term (reference) 2D054 AB01 AB05 AC04 BA09 BB02 BB09 CA02 DA03

Claims (7)

[Claims] 1. A cutter head having a main cutter and a planetary cutter, a cutter driving means for rotationally driving the cutter head, and a planetary gear for rotating the planetary cutter in synchronization with the rotation of the main cutter by the rotational driving force of the cutter driving means. A gear mechanism, wherein the contour shape of the planetary cutter is formed in accordance with the ratio between the revolution speed and the rotation speed of the planetary cutter so that a tunnel with a free cross section can be excavated. A planetary shaft that penetrates the chamber on the rear side of the cutter head on the axial center side from the vicinity of the outer periphery of the planetary shaft and transmits a rotational driving force for rotating the planetary cutter, and a planetary shaft provided in the cutter head. A planetary shaft having a first planetary gear and a second planetary gear concentric with the rotation axis of the planetary cutter; Free cross section for tunnel shield machine to a gear mechanism for transmitting the rotational driving force to the planetary cutter, comprising the. 2. A cutter head having a main cutter and a planetary cutter, a cutter driving means for driving the cutter head to rotate, and a planetary gear for rotating the planetary cutter in conjunction with the rotation of the main cutter by the rotational driving force of the cutter driving means. A gear mechanism, wherein the contour shape of the planetary cutter is formed in accordance with the ratio between the revolution speed and the rotation speed of the planetary cutter, so that a tunnel having a free section can be excavated. On the rear side, a partition wall separated by a chamber and an annular drum accommodating section composed of the partition wall are provided, and a cutter drum rotatably driven by cutter driving means is rotatably mounted on the drum accommodating section, and the cutter drum is mounted. A plurality of connecting members connected to the cutter head, wherein the planetary gear mechanism includes an outer peripheral wall of the drum housing portion; A ring gear fixed to the inner surface, the meshed with the ring gear 1
A planetary gear, a second planetary gear and an idle gear provided on the cutter head, a third planetary cutter concentric with the rotation axis of the planetary cutter, and a rotational driving force of the first planetary gear are transmitted to the second planetary gear. A planetary shaft, wherein the rotational driving force of the planetary shaft is transmitted from the second planetary gear to the third planetary gear via the idle gear to rotate the planetary cutter, and the free-section tunnel is characterized in that: For shield excavators. 3. A cutter head having a main cutter and a planetary cutter, a cutter driving means for driving the cutter head to rotate, and a planetary gear for rotating the planetary cutter in conjunction with the rotation of the main cutter by the rotational driving force of the cutter driving means. A gear mechanism, wherein the contour shape of the planetary cutter is formed in accordance with the ratio between the revolution speed and the rotation speed of the planetary cutter, so that a tunnel having a free section can be excavated. On the rear side, a partition wall separated by a chamber and an annular drum accommodating section composed of the partition wall are provided, and a cutter drum rotatably driven by cutter driving means is rotatably mounted on the drum accommodating section, and the cutter drum is mounted. A plurality of connecting members connected to the cutter head, wherein the planetary gear mechanism includes an inner peripheral wall of the drum housing portion; A sun gear fixed to the outer surface, a first planetary gear meshed with the sun gear, a second planetary gear, an idle gear provided on the cutter head, and a third planetary cutter concentric with the rotation axis of the planetary cutter; 1 The rotational driving force of the planetary gear is
A planetary shaft for transmitting the planetary gear to the planetary gear, and transmitting the rotational driving force of the planetary shaft from the second planetary gear to the third planetary gear via the idle gear to rotate the planetary cutter. Shield excavator for free section tunnels. 4. The planetary cutter according to claim 1, wherein a ratio between a revolution speed and a revolution speed of the planetary cutter is set to ４, and a tunnel having a square cross section can be excavated. Shield tunneling machine for free-section tunnels as described in (1). 5. The shield for a free-section tunnel according to claim 2, wherein an outer peripheral wall of the annular drum accommodating portion is disposed with an annular space provided between the outer peripheral wall and the front body member. Excavator. 6. A shield excavator connected to both sides of the shield excavator for a free-section tunnel according to claim 4, wherein a cutter head of the central shield excavator is excavated in a direction in which the cutter heads of the shield excavators on both sides are extended. A shield excavator for a free-section tunnel, wherein the cutter excavator on both sides is partially wrapped with respect to the cutter head of the central shield excavator. 7. A shield excavator having substantially the same structure as the shield excavator is connected to both sides of the shield excavator for free-section tunnel according to claim 4, and the cutter head of the central shield excavator is shielded on both sides. A free-section tunnel characterized by being arranged ahead of the cutter head of an excavator in the excavation direction and partially wrapping the cutter heads of both shield excavators with respect to the central shield excavator cutter head. For shield excavators.