JPH06105033B2 - Free section shield machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a free-section shield machine capable of continuously excavating a tunnel having a desired cross-sectional shape, not limited to a circular shape.

[Conventional technology]

Conventionally, various types of shield machines as described above have been proposed and implemented. Generally, a cutter placed on the front surface of the shield machine body is rotated around the central axis of the shield machine to excavate the front surface in the propulsion direction of the shield machine, and the shield machine is propelled by the excavated amount to make the segment ring. It is used to move forward by adding the.

Further, Japanese Patent Laid-Open No. 59-102090 discloses an enlarged shield construction method for forming an expanded diameter portion such as a retreat portion or a station portion in a part of a tunnel excavated by the shield machine.

[Problems to be Solved by the Invention]

Since the conventional shield construction method and shield machine excavate by rotating the front cutter, the excavation cross-sectional shape is limited to a circular shape, and it is difficult to excavate a tunnel having another irregular cross-sectional shape. On the other hand, most of the actual cross-sectional shapes such as sewage, power lines, subway tunnels, etc., other than the circular shape, have been conventionally used for excavation of large circular cross-sections including such irregular cross-sectional shapes. Must be performed, and an extra excavation work and a work for processing the excavation shear are required. Such extra work has a greater influence on the tunnel construction cost as the cross section of the subway tunnel has a larger diameter, which is also a constraint when applying the shield construction method.

In order to solve this problem, the invention disclosed in the above publication is constructed by excavating a tunnel with a normal diameter once to assemble a segment ring, then removing the segment ring of the target portion and performing special excavation work in the radial direction. The diameter portion and the like are partially formed, and the cross section having a desired shape other than the circular shape is not continuously excavated.

In view of such circumstances, an object of the present invention is to provide a shield machine capable of continuously excavating a tunnel having a desired sectional shape, not limited to a circular shape.

[Means for Solving the Problems]

The present invention relates to a shield machine main body, a rotary body rotatably supported by the shield machine main body around an axis extending in the propulsion direction, and having a center cutter on the front surface, drive means for driving the rotary body, and a front-back direction. And a plurality of torsion bars rotatably supported by the rotating body at a position deviated from the rotation axis thereof, a cutter arm fixed to the front portion of each torsion bar and rotating together with the torsion bar, and each torsion bar. A control lever fixed to the rear part of the bar, which rotates together with the torsion bar and the cutter arm,
A forming cutter that is integrally fixed to the cutter arm and scrapes the front soil with the rotation of the rotating body, a guide member having a guide shape corresponding to a desired excavation shape, and the guide during rotation of the rotating body. The control means is provided with a control means for pressing the rotating end of the control lever against the member to control the revolution trajectory of the forming cutter in the cutter arm connected to the control lever via the torsion bar.

[Action]

According to the above shield machine, the central portion of the face, which is the excavation front surface, is excavated by drivingly rotating the rotating body and the center cutter by the drive means. Further, during the rotation of the center cutter and the rotating body, the forming cutter rotatably supported by the rotating body revolves around a unique trajectory corresponding to the guide shape of the guide member, thereby revolving around the outer peripheral portion of the face. Is scraped off, and excavation having a desired cross-sectional shape is performed as a whole.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

First Embodiment (FIGS. 1 to 3) The shield machine shown here comprises a skin plate (shield machine body) 1 in the shape of a rectangular tube, and this skin plate 1
A cutting wheel (rotating body) 2 is built in at the tip of the.

This cutting wheel 2 includes a front plate 3 and a rear plate 10.
And is configured to be rotatable about the central axis (axis extending in the propulsion direction) G of the skin plate 1. A plurality of slits 3a are radially formed on the front plate 3, and a center bit 4 is formed at the center of the front plate 3.
Is provided, and a large number of cutter bits 5 are arranged on the peripheral portion of the slit 3a, and a center cutter 6 is constituted by both bits 4 and 5. Forming cutters 7 for shaving the front soil are provided at a plurality of positions in front of the peripheral edge of the cutting wheel 2.

As shown in FIG. 2, the rear outer peripheral surface of the cutting wheel 2 is joined to the inner ring of the slewing bearing 9 fixed to the bracket 8a on the side of the skin plate 1, and the rear plate 10 of the cutting wheel 2 has a ring. 11 is extended to the rear. On the other hand, a hollow fixing ring 15 is installed in the central portion of the skin plate 1, and the ring 11 is rotatably fitted to the outside of the fixing ring 15 with a seal 16 interposed therebetween.

A cutting wheel driving gear 12 is fixed to the rear end of the ring 11. Behind the ring 11, a reduction gear motor (driving means) 35 is fixed to a bracket 8c provided on the skin plate 1. This reduction gear motor
A pinion 18b provided on the drive shaft of 35 is meshed with the cutting wheel drive gear 12.

Incidentally, reference numeral 16a in FIG. 2 denotes a seal, which, together with the seal 16, prevents earth and sand from flowing backward. The inner circumference of a part of the skin plate 1 corresponding to the seat on which the seal 16a is provided is formed in a circular shape.

Next, the structure of the rotating member to which the forming cutter 7 is fixed (P portion in FIG. 2) will be described.

The rear plate 10 of the cutting wheel 2 includes the rear plate 10
A plurality of (72 in this case) housings 72 are supported in the front-rear direction by brackets 73 and brackets 73, and a torsion bar 23 extending in the front-rear direction is rotatably supported in the housing 72 via bearings 71. ing. A cutter arm 70 is fixed to the front end of the torsion bar 23, and a control lever 29 is fixed to the rear of the torsion bar 23, which constitute a rotating member that can rotate about the torsion bar 23. The forming cutter 7 is fixed to the turning end (front turning end) of the cutter arm 70, and the forming cutter 7 and the turning member turn together. A notch 2b (FIG. 1) is formed in the cutting wheel 2 to prevent interference with the forming cutter 7.

The control lever 29 is connected to the rear end of the torsion bar 23 via a spline, and a roller 28 is rotatably attached to a pivot end (rear pivot end) of the control lever 29 about a pin 27a. ing.

As shown in FIG. 3, a plurality of brackets 8e are arranged on the outer periphery of the ring 11, and each bracket 8e has a pin 27b.
An expansion / contraction member (regulating means) 33 is attached so as to be swingable about the center of the expansion / contraction center, and the control lever 29 is rotatably connected to the movable end of the expansion / contraction member 33 via a pin 27c.
The elastic member 33 is attached in a contracted state, and always applies a force in the extension direction to the control lever 29.

On the other hand, a guide rail (guide member) 34 is fixed to the inner surface of the skin plate 1 at a position where it contacts the roller 28. The guide rail 34 has an inner peripheral surface (guide surface) corresponding to a desired excavation shape (here, a rectangular shape), and the roller 28 is pressed against the inner peripheral surface by the urging force of the elastic member 33.

In FIG. 2, 66 is a screw conveyor that carries the excavated soil in the chamber 2a backward, 37 is an erector that lays a segment 36 on the inner wall of the tunnel excavated by a shield machine, and 38 is a reaction force from the segment 36. A shield jack for propelling the shield machine, and 39 are tail seals for preventing the inflow of earth and sand or water from the outer peripheral portion of the segment 36 into the shield machine.

Next, the operation of this shield machine will be described.

By driving the motor 35 with a reducer in the skin plate 1, the cutting wheel drive gear 12 meshed with the pinion 18b fixed to the drive shaft thereof rotates,
The ring 11 and the cutting wheel 2 also rotate integrally with this.

With the rotation of the cutting wheel 2, the forming cutter 7 and the entire drive device thereof revolve around the central axis G, but the roller 28 at the tip of the control lever 29 is urged by the elastic member 33 to guide the guide rail 34. Since the guide rail 34 is pressed against the inner peripheral surface of the guide rail 34, it revolves around a trajectory according to the inner peripheral shape of the guide rail 34. Since the torsion bar 23 and the cutter arm 70 are integrally connected to the control lever 29, the forming cutter 7 fixed to the tip end of the cutter arm 70 also has a locus corresponding to the inner peripheral shape of the guide rail 34. That is, the trajectory corresponding to the desired excavation shape is drawn and revolves around the central axis G.

Therefore, while the cutting wheel 2 and the forming cutter 7 are rotationally driven by the motor 35 with a reduction gear, the entire shield machine is propelled by the operating force of the shield jack 38 to rotate the center bit 4 at the center.
And the central circular portion is excavated by the cutter bit 5, and the earth and sand of the outer peripheral portion can be excavated by the forming cutter 7 that revolves around the periphery while drawing a unique trajectory, and a tunnel having a desired sectional shape as a whole is excavated. be able to.

The earth and sand excavated in this way has slits 3a formed in the front plate 3 and notches 2b in the cutting wheel 2.
It is taken into the chamber 2a through the above, is sequentially carried out rearward by the screw conveyor 66, and is finally carried out to the ground by the belt conveyor 40 and the like shown by the one-dot chain line in FIG.

At this time, the excavated earth and sand are filled in the chamber 2a,
If the amount of earth and sand pulled out by the screw conveyor 66 is adjusted so that the pressure in 2a is kept within a certain range, the earth and sand in the chamber 2a and in front of the chamber 2a will have its tip intake port due to the pressure difference caused by the operation of the screw conveyor 66. It will flow smoothly.

According to such a shield machine, the tunnel having a desired sectional shape can be continuously and easily excavated by the center cutter 6 fixed to the cutting wheel 2 and the forming cutter 7 arranged around the center cutter 6. it can.

Moreover, in this shield machine, both the cutting wheel 2 and each forming cutter 7 are rotated by the motor 35 with a reduction gear that is a single drive source, and a special mechanism for driving the forming cutter 7 is not required. Therefore, the above effect can be obtained with a simple structure that has few failure factors, is light in weight, and is low in cost. Further, by controlling the orbit of the forming cutter 7 by the guide rail 34 having a fixed shape, even if an external force acts on the forming cutter 7, the trajectory is less likely to be disturbed.

Further, as shown in this embodiment, if a hollow fixing ring 15 is provided in the central portion of the shield machine main body and an elastic member 33 and the like are provided on the outer peripheral portion of the fixing ring 15, this fixing ring 15 It is possible to install the screw conveyor 66 at a suitable inclination angle by utilizing the internal space of the.

Second Embodiment (FIGS. 4 and 5) Here, the forming cutter 7 in the first embodiment is arranged behind the cutting wheel 2.

Specifically, the cutting wheel 2 is divided into a spoke-shaped front plate 3 and a rear plate 10, and both plates 3 and 10 are connected by a torque arm (not shown) extending in the front-rear direction. A housing 74 is fixed to the front plate 3 at a position corresponding to each torsion bar 23, and a front end of the torsion bar 23 is rotatably supported by a bearing 74a provided in the housing 74.

According to such a structure, first, the center bit 4 and the cutter bit 5 provided on the front plate 3 excavate the earth and sand, and then the forming cutter 7 excavates the peripheral portion thereof. As compared to the case in which the forming cutter 7 is arranged in front of the front plate 3 as in the example, the excavation area by the forming cutter 7 is significantly reduced, and accordingly, the following effects are obtained.

(1) Since the forming cutter 7 is for excavating the outer peripheral sediment in the excavation area by the center cutter 6,
The amount of excavation work is greater than it seems. Therefore,
In the structure in which the forming cutter 7 has a heavy load as in the first embodiment, the blade of the forming cutter 7 is worn before the center cutter 6. On the other hand, if the forming cutter 7 is arranged rearward as in this embodiment, the excavation area is reduced, and since the earth and sand are loosened by the excavation by the center cutter 6, the burden on the forming cutter 7 is reduced and both cutters are reduced. The wear degree of the shield machine is averaged, and the life of the entire shield machine is extended.

(2) While the forming cutter 7 revolves, a large torsional load acts on the rotating member to which the forming cutter 7 is fixed. Therefore, by reducing the load on the forming cutter 7, the structure of the rotating member is improved. It is possible to simplify the manufacturing cost and reduce the size of the shield machine. Particularly, by reducing the size of the rotating member located in the chamber 2a, the fluidity of the sediment in the chamber 2a is enhanced, and the soil excavated by the forming cutter 7 is easily taken into the chamber 2a.

(3) Since the forming cutter 7 is located on the front side of the cutting wheel 2 when viewed from the inside of the skin plate 1, when the forming cutter 7 has an abnormality such as a breakage during excavation, the repair can be easily performed. It can be carried out.

The present invention is not limited to the embodiments described above, and the following aspects can be taken as examples.

(1) In the present invention, regardless of the number of forming cutters and the arrangement position, the forming cutters may be arranged at an appropriate place depending on the soil quality. As for the structure of the forming cutter, it is sufficient if the front soil is scraped along with the rotation of the cutting wheel 2. For example, a cutter bit divided into a plurality of pieces like a forming cutter 7'shown in FIG. The same effect as described above can be obtained with the one having 7a.

(2) The shape of the guide member in the present invention is not limited to the rectangular shape like the guide rail 34, and may be appropriately set according to a desired excavation shape such as a circle, an egg shape, a horseshoe shape, or the like.

FIG. 7 is a small circle which is an excavated cross-sectional shape obtained by rotating the outer periphery 1a of the skin plate 1 and the cutting wheel 2.
100 (dashed-dotted line), large circle that is the excavation cross-sectional shape obtained when the cutting wheel is rotated with the center of the forming cutter farthest from the center of the small circle 100.
Although 101 (one-dot chain line) is shown, in this device, the revolution trajectory of the forming cutter can be freely set within the range surrounded by the small circle 100 and the large circle 101.
In any case, excellent excavation can be performed by using a skin plate having a sectional shape corresponding to each excavated sectional shape. For example, the figure shows the outer periphery 1a of the skin plate 1 in the shape of a rectangular tube, but as is clear from this figure, the outer periphery shape of the skin plate 1 is within the above range.

Similarly, FIGS. 8 and 9 show examples in which horseshoe-shaped and oval-shaped outer peripheral shapes are accommodated within the above-described range. In these cases as well, the skin plate 1 having the horseshoe-shaped or oval outer peripheral shape may be used, and the guide rail may be shaped so that the revolution trajectory of the forming cutter matches these shapes.

That is, according to this shield machine, various excavation cross-sections can be easily obtained by a single shield machine simply by appropriately changing the shapes of the guide rail and the skin plate.

On the other hand, as for the structure of the guide member, in addition to the rail as described above, for example, an internal gear may be used, and instead of using the roller 28, a pinion gear that meshes with the internal gear may be used.

(3) In the first embodiment, the roller 28 and the guide rail 34 are
Although the elastic member 33 is used as a means for pressing the elastic member 33, the elastic member 33 can be omitted if, for example, the guide rail 34 has an inner / outer double structure and the roller 28 passes between them.

(4) In each of the above embodiments, the cutting wheel 2 is supported by the inner surface of the skin plate 1,
For example, a bearing may be fixed to the outer periphery of the fixing ring 15 shown in FIG. 2, and the cutting wheel 2 may be supported by this bearing.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention rotates the rotating body having the center cutter, and revolves the forming cutter supported by the rotating body via the rotating member along the guide member to meet a desired excavation shape. Since the center circular portion of the face is excavated by the center cutter and the outer peripheral portion is excavated by the forming cutter that draws a unique trajectory, the desired cross-sectional shape is obtained as a whole. It is possible to freely excavate a tunnel having.

Moreover, since a special mechanism for driving the forming cutter is unnecessary, the above effect can be obtained with a simple and low-cost structure with few failure factors.

Further, since the revolving locus of the forming cutter is regulated by pressing the rotation axis of the forming cutter against the guide surface of the guide member having a predetermined shape, the above locus is less likely to be disturbed even when an external force is applied to the forming cutter.

[Brief description of drawings]

1 is a front view of a shield machine according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 7 is a front view of a shield machine according to the second embodiment, FIG. 5 is a sectional view taken along line VV of FIG. 4, FIG. 6 is a front view of a forming cutter according to another embodiment, and FIG. 7 is a view of the forming cutter. FIGS. 8 and 9 are explanatory diagrams showing the revolution locus and the setting range of the outer peripheral shape of the skin plate, and FIGS. 8 and 9 are explanatory diagrams showing other examples of the outer peripheral shape of the skin plate. 1 ... Skin plate (shield machine body), 2 ... Cutting wheel (rotating body), 6 ... Center cutter, 7, 7 '
... forming cutter, 23 ... torsion bar, 29 ... control lever, 33 ... expansion / contraction member (regulating means), 34 ... guide rail (guide member), 35 ... motor with reduction gear (driving means), G
… Center axis (axis extending in the direction of propulsion).

Claims (1)

[Claims] 1. A shield machine main body, a rotary body rotatably supported by the shield machine main body around an axis extending in its propulsion direction, and having a center cutter on the front surface, drive means for driving the rotary body, and front and rear. Direction, and a plurality of torsion bars rotatably supported on the rotating body at a position deviated from its rotation axis, and fixed to the front portion of each torsion bar,
A cutter arm that rotates with this torsion bar,
A control lever fixed to the rear of each torsion bar, which rotates together with the torsion bar and the cutter arm, and a forming cutter which is integrally fixed to the cutter arm and scrapes off the earth and sand in front of the rotary body as the rotor rotates,
A guide member having a guide shape corresponding to a desired excavation shape, and by pressing the rotating end portion of the control lever against the guide member during rotation of the rotating body, the control lever is passed through the torsion bar. A free-section shield machine, comprising: a restricting unit that restricts an orbit of a forming cutter in a connected cutter arm.