JP2569275B2 - Free section shield machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a free-section shield machine capable of continuously excavating a tunnel having a desired sectional shape, not limited to a circular shape.

[0002]

2. Description of the Related Art Conventionally, various types of shield machines as described above have been proposed and implemented. In general, a cutter placed in front of the shield machine body is rotated around the center axis of the shield machine to excavate the front of the shield machine in the propulsion direction. Digging by adding is used.

[0003] Also, Japanese Patent Publication No. Sho 42-6712 discloses that
During the rotation of the circular digging cutter disk, the electromagnetic clutch is switched so that the overcutting rotary cutter is appropriately protruded and retracted in the radial direction from the peripheral edge of the disk to overcut only in a specific direction, and utilizing this overcut portion. Shown is an apparatus that allows the shield machine to make a curve.

[0004]

Since the conventional shield method and shield machine excavate by rotating the front cutter, the excavated cross-sectional shape is limited to a circular shape, and other excavated tunnels having an irregular cross-sectional shape are excavated. It is difficult. On the other hand, most of the cross-sectional shapes actually required other than circular, such as sewers, power lines, and subway tunnels, are conventionally excavated with large circular cross-sections including such irregular cross-sectional shapes. In such a case, an extra excavation operation and an excavation shearing operation are required. Such extra work has a greater effect on the tunnel construction cost as the diameter of the cross section becomes larger, such as in a subway tunnel, and is a constraint in applying the shield method.

On the other hand, the apparatus disclosed in the above publication enables excavation of a portion slightly protruding from the circular excavation section, but has the following disadvantages.

1) The overcut rotary cutter must be driven by a special means such as a motor, and the size and cost of the apparatus are correspondingly increased.

[0007] 2) Only turning the overcut rotary cutter in and out in the radial direction by turning on and off the electromagnetic clutch.
Although it is possible to supplementally excavate a portion slightly protruding from the circle in order to realize the curve progression, it is extremely difficult to accurately obtain an excavation shape that is far from the circle. Even more, it is virtually impossible to obtain various excavation shapes such as a rectangle, a horseshoe, and an ellipse with a single shield machine.

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

[0009]

As a means for solving the above-mentioned problems, the present invention relates to a shield machine main body, and the shield machine body is supported rotatably around an axis extending in the propulsion direction, and has a center on a front surface thereof. A rotating body having a cutter, driving means for driving the rotating body, a plurality of rotating members rotatably supported by the rotating body at positions off the rotation axis, and a front portion of the rotating member A forming cutter integrally fixed to a rotating end and shaving earth and sand in front of the rotating body, an actuating means for rotating the rotating member, and a rotating displacement for detecting a rotating displacement amount of the rotating body; Quantity detection means;
The target operation amount corresponding to the operation amount of the rotating member necessary to obtain the revolving locus of each forming cutter corresponding to the preset excavation shape is set to the rotation amount of the rotating body detected by the rotation amount detection unit. Calculating means for calculating the operating amount of the rotating member, and an operating amount detecting means for detecting the actual operating amount of the rotating member; and a detected operating amount detected by the operating amount detecting means and a target operating amount calculated by the calculating means. And operation control means for controlling the driving of the rotating member by the operation means in a direction in which the two are made equal to each other.

[0010]

According to the shield machine, while the rotating body is rotating, the amount of rotational displacement is detected, and the corresponding operating amount of the rotating member is calculated by the calculating means. By detecting the operation amount, comparing the detected operation amount with the target operation amount, and performing drive control of the rotating member in a direction to make them equal, a predetermined desired excavation sectional shape can be accurately determined. Obtainable. In addition, since the forming cutter is rotated integrally with the rotating body and the earth and sand in front is shaved by the forming cutter by the rotation force, it is not necessary to newly provide a driving unit for excavation by the forming cutter. That is, the driving means of the rotating body is also used as the driving means for excavation by the forming cutter. Further, it is possible to easily change the finally obtained excavation sectional shape only by changing the calculation content of the calculation means. Also, since the amount of the tip of the forming cutter that is actually displaced in the radial direction is small compared to the amount by which the pivot end of the pivot member is pivoted, compared to a shield machine that directly moves the auxiliary cutter and the like in the radial direction. It is also possible to finely control the orbit of the forming cutter.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.

The shield machine shown here includes a skin plate (shield machine body) 1 in the form of a rectangular cylinder, and a cutting wheel (rotating body) 2
Built-in.

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

As shown in FIG. 2, a rear outer peripheral surface of the cutting wheel 2 is provided with a bracket 8 on the skin plate 1 side.
The ring 11 is joined to the inner ring of the slewing bearing 9 fixed to a, and a rear surface plate 10 of the cutting wheel 2 has a ring 11 extending rearward. On the other hand, a hollow fixing ring 15 is provided at the center of the skin plate 1, and the ring 11 is rotatably fitted outside 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. Ring 11
A motor (drive means) 35 with a speed reducer is fixed to a bracket 8c provided on the skin plate 1, and a pinion 18b provided on a drive shaft of the motor 35 with a speed reducer is used to drive the cutting wheel. Gear 12
Are engaged.

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

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

The rear plate 10 of the cutting wheel 2 is provided with a plurality of housings 72 (3 in this case) supported in the front and rear by the rear plate 10 and the bracket 73 in the front-rear direction.
The torsion bar 23 extending in the front-rear direction via the bearing 71 is rotatably supported in the housing 72. A cutter arm 70 is fixed to a front end of the torsion bar 23, and a control lever 29 is fixed to a rear portion of the torsion bar 23.
Is formed around the pivot member. The forming cutter 7 is fixed to a turning end (a front turning end) of the cutter arm 70, and the forming cutter 7 and the turning member turn integrally. The cutting wheel 2 has a notch 2b
(FIG. 1) is formed, and the forming cutter 7 is formed.
The interference with is prevented.

The control lever 29 is connected to the torsion bar 2
3 is connected to the rear end through a spline. FIG.
As shown in the figure, a plurality of brackets 8e are arranged on the outer periphery of the ring 11, and a telescopic member (operating means) 33 is attached to each bracket 8e so as to be swingable about a pin 27b. Then, the drive control system shown in FIG. 4 controls the expansion / contraction stroke of the expansion / contraction member (operating means) 33 so that the rotating member rotates by an appropriate angle at an appropriate timing, so that the forming cutter 7 can move to a desired shape. The orbit is drawn.

In FIG. 4, a cutting wheel rotational position detector 90 sets a reference rotational position of the cutting wheel 2 to an appropriate position (for example, the position shown in FIG. 3), and an amount of rotational displacement of the cutting wheel 2 with respect to this reference rotational position ( For example, an angle).

The telescopic member expansion / contraction detector 94 is provided with the telescopic member 3.
The reference length of No. 3 is set to an appropriate value, and the actual amount of expansion and contraction of the expandable member 33 with respect to this length is detected, and is constituted by a potentiometer or the like. In addition, what is necessary is just to set the length of the expansion-contraction member 33 when the control lever 29 is in the position of FIG.

The arithmetic unit 91 incorporates a program for calculating the required amount of expansion and contraction of the expandable member 33 in accordance with the amount of rotational displacement of the cutting wheel 2 in order to obtain a predetermined excavation section. The instantaneous calculation of the required amount of expansion and contraction of the expandable member 33 corresponding to the amount of rotational displacement of the cutting wheel 2 input from the cutting wheel rotation position detector 90 is performed. The details of the operation will be described later in detail.

The comparator 92 compares the displacement amounts input from the arithmetic unit 91 and the expansion / contraction member expansion / contraction detector 94, and gives an expansion / contraction command to the expansion / contraction member controller 93 so that the two become equal. When the difference between the two disappears, a stop command is given.

The expansion / contraction member controller 93 controls the actual amount of expansion / contraction of the expansion / contraction member 33. For example, the elastic member 33
When a hydraulic cylinder is used, a servo valve for controlling oil supplied to the hydraulic cylinder and a set of control devices for the servo valve correspond to the telescopic member controller 93.

In FIG. 2, reference numeral 66 denotes a chamber 2a.
Screw conveyor for transporting excavated earth and sand backwards, 3
7 is segment 3 on tunnel inner wall excavated by shield machine
6 is a shield jack for propelling the shield machine by taking a reaction force from the segment 36;
Reference numeral 9 denotes a tail seal that prevents earth and sand, water, and the like from flowing into the shield machine from the outer peripheral portion of the segment 36.

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

Motor 35 with reduction gear in skin plate 1
Is driven, the cutting wheel driving gear 12 meshed with the pinion 18b fixed to the drive shaft rotates, and the ring 11 and the cutting wheel 2 also rotate integrally therewith. With the rotation of the cutting wheel 2, the forming cutter 7 and the entire driving device also revolve integrally around the central axis G.

On the other hand, in the drive control system, first, the arithmetic unit 91
With respect to the rotational position of the cutting wheel 2, the amount of expansion and contraction of the expandable member 33 necessary to obtain a desired cross-sectional shape is calculated. From the comparison between this amount of expansion and contraction and the actual amount of expansion and contraction,
The expansion / contraction drive of the expansion / contraction member 33, that is, the rotation drive of the rotation member including the control lever 29 and the like is controlled.

The control will be described in detail. For example, when the forming cutter 7 is located at a position corresponding to the corner portion of the skin plate 1, the expanding and contracting member 33 is extended to move the forming cutter 7 from the center axis G.
The distance to the tip (that is, the orbital radius) is increased, thereby expanding the excavation area by the forming cutter 7 to the corner. Conversely, when the forming cutter 7 is at a position corresponding to the midpoint of each side of the square skin plate 1, the elastic member 33 is contracted, and the distance from the central axis G to the tip of the forming cutter 7 is reduced. By such control, the forming cutter 7 revolves while drawing a trajectory corresponding to a desired excavation shape (here, a substantially square shape).

Accordingly, while the cutting wheel 2 and the forming cutter 7 are driven to rotate by the motor 35 with the speed reducer, the whole of the shield machine is propelled by the operating force of the shield jack 38 so that the center bit 4 and the cutter which rotate at the center are rotated. The center circular part is excavated by the bit 5, and the surrounding area can be shaved by the forming cutter 7 revolving while drawing a peculiar trajectory around the central circular part, so that a tunnel having a desired cross-sectional shape as a whole can be excavated. it can.

The excavated earth and sand is taken into the chamber 2a through the slit 3a formed in the front plate 3 and the notch 2b of the cutting wheel 2.
After being sequentially conveyed backward by the screw conveyor 66, it is finally conveyed to the ground by the belt conveyor 40 or the like shown by a dashed line in FIG.

At this time, if the excavated earth and sand is filled in the chamber 2a and the amount of earth and sand drawn out by the screw conveyor 66 is adjusted so as to maintain the pressure in the chamber 2a within a certain range, the excavated earth and sand are located in the chamber 2a and in front thereof. The earth and sand flows smoothly to the tip intake port due to the pressure difference generated by the operation of the screw conveyor 66.

According to such a shield machine, a tunnel having a desired cross-sectional shape is easily and continuously excavated by the center cutter 6 fixed to the cutting wheel 2 and the forming cutter 7 disposed therearound. can do.

Moreover, in this shield machine, both the cutting wheel 2 and each forming cutter 7 are rotated by the motor 35 with a speed reducer, which is a single driving source, and a special mechanism for driving the forming cutter 7 is provided. Is unnecessary, the above-mentioned effects can be obtained with a simple structure that is light in weight and low in cost, with few causes of failure.

Further, in this shield machine, the turning control of the turning member is controlled by the drive control system so that the forming cutter 7 draws a desired revolving locus. Not only that, it is also possible to accurately excavate irregularly shaped cross sections, such as rectangles, which are greatly separated from circles, and the applicable range is extremely wide. Of course, it is needless to say that so-called overcut can be performed using such a modified cross section excavation function.

This overcut will be described with reference to FIG. In the figure, regions J, K, L, and M indicated by hatching outside the outer periphery 1a of the skin plate 1 are overcut zones. In the normal excavation, the forming cutter 7 is controlled by a program incorporated in the arithmetic unit 91 so as to move along the outer peripheral shape of the skin plate 1. In addition to the above program, a program for moving the forming cutter 7 along the outer peripheral shape 96a obtained by adding the region J to the outer peripheral shape of the skin plate 1, and the outer peripheral shape 96b obtained by adding the region K and the outer peripheral shape 96c obtained by adding the region L ,
A program for moving the forming cutter 7 along the outer peripheral shape 96d including the region M is incorporated. At the same time, a selection circuit for arbitrarily selecting the above five types of programs is added to the arithmetic unit 91 so that one of the five types of excavation sections can be arbitrarily selected as needed. With such a configuration, it is possible to obtain the effect of overcut as described below.

For example, while a normal excavation section program is being selected and excavated, this program is applied to the outer peripheral shape 9.
When the program is switched to the excavation section program corresponding to 6a, the portion of the earth and sand protruding upward from the upper side of the skin plate 1 is also excavated (overcut). When excavation proceeds in this state, a sectional space corresponding to the region J above the skin plate 1 is formed, and the frictional resistance between the skin plate 1 and the earth and sand at this portion is reduced. On the other hand, since the lower part of the skin plate 1 is still in contact with earth and sand, the difference between the frictional resistance of the upper part of the skin plate 1 and the frictional resistance of the lower part of the skin plate 1 gradually increases. As a result, the shield machine tries to escape to the upper side where the frictional resistance is small, and the propulsion direction of the shield machine gradually turns upward.

As described above, since the direction of the shield machine is changed in the direction of the overcut, the traveling direction of the shield machine can be changed by appropriately selecting the excavation section program corresponding to the outer peripheral shapes 96a to 96d in FIG. It can be easily changed up, down, left and right, and it becomes possible to excavate a sharp curve. If a program capable of overcutting each of the four corners is incorporated, it is possible to easily carry out the control of the posture recovery for rolling.

Further, in this shield machine, the tip position of the forming cutter is displaced in the radial direction by the rotation of the rotating member, and thus the actual amount of displacement in the radial direction is equal to the rotation of the rotating end of the rotating member. Since it is smaller than the amount of movement (that is, the expansion and contraction stroke of the expansion and contraction member 33), more delicate control of the radial position of the tip of the forming cutter 7 is possible as compared with the conventional case where the auxiliary cutter is directly driven in the radial direction. Therefore, the excavated cross-sectional shape can be obtained with higher accuracy.

Further, as shown in this embodiment, if a hollow fixing ring 15 is provided at the center of the shield machine main body, and an elastic member 33 or the like is provided on the outer periphery of the fixing ring 15, this fixing is achieved. The screw conveyor 66 can be installed at a suitable inclination angle by utilizing the internal space of the ring 15.

Second Embodiment (FIGS. 6 and 7) Here, the forming cutter 7 in the first embodiment is arranged behind the cutting wheel 2.

More specifically, the cutting wheel 2 is divided into a spoke-shaped front plate 3 and a rear plate 10, and the two plates 3, 10 are connected by a torque arm (not shown) extending forward and backward. In addition, each torsion bar 23 is provided on the front plate 3.
A housing 74 is fixed at a position corresponding to the above. The 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 front plate 3
Since the center bit 4 and the cutter bit 5 provided in the hole excavate earth and sand, and then the forming cutter 7 excavates the surrounding area, the forming cutter 7 is moved forward of the front plate 3 as in the first embodiment. The area of excavation by the forming cutter 7 is significantly reduced as compared with the one arranged in the above, and the following effects can be obtained accordingly.

(1) Since the forming cutter 7 excavates the earth and sand at the outer peripheral portion of the excavation area by the center cutter 6, the excavation work is larger than the apparent amount. Therefore, in the structure in which the burden on the forming cutter 7 is large 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 disposed rearward as in this embodiment, the excavated area is reduced, and the earth and sand is loosened by the excavation by the center cutter 6, so that
The burden on the forming cutter 7 is reduced, the degree of wear of both cutters is averaged, and the life of the entire shield machine is extended.

(2) During the revolution of the forming cutter 7, a large torsional load acts on the rotating member to which the forming cutter 7 is fixed. Therefore, the burden on the forming member 7 is reduced by reducing the load on the forming cutter 7. The structure can be further simplified, the production cost can be reduced, and the shield machine can be downsized. In particular, by reducing the size of the rotating member located in the chamber 2a, the fluidity of the earth and sand in the chamber 2a is increased, and the earth and sand excavated by the forming cutter 7 is easily taken into the chamber 2a.

(3) Since the forming cutter 7 is located closer to the front side than the cutting wheel 2 when viewed from the inside of the skin plate 1, when the forming cutter 7 has an abnormality such as breakage during excavation, the repair is performed. Can be easily performed.

The present invention is not limited to the embodiments described above, but may take the following forms as examples.

(1) In the present invention, regardless of the number and arrangement position of the forming cutters, the forming cutters may be arranged at an appropriate place according to the soil properties. As for the structure of the forming cutter, any structure may be used as long as it can remove the earth and sand in the forward direction in the rotation direction. For example, a forming cutter having a cutter bit 7a divided into a plurality of pieces, such as a forming cutter 7 'shown in FIG. However, the same effect as above can be obtained.

(2) In the present invention, regardless of the specific shape of the excavated cross section, skin plates having various outer peripheral shapes such as the horseshoe shape and the oval shape are used, and the revolving locus of the forming cutter conforms to these shapes. Various excavation shapes can be obtained by incorporating a matching program into the arithmetic unit. That is, according to this shield machine, various excavation sections can be easily formed by a single shield machine only by changing the program of the arithmetic unit and changing the shape of the skin plate to a shape corresponding to the program of the arithmetic unit. Can be obtained.

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

(4) In the present invention, the operating means for rotating the rotating member is not limited to the type, and for example, the rotating member is driven by a motor with a speed reducer, similarly to the driving of the cutting wheel 2 described above. It is also possible.

[0052]

As described above, according to the present invention, the rotating body having the center cutter is rotated, and the forming cutter supported by the rotating body via the rotating member forms a trajectory corresponding to a desired excavation shape. Since the turning of the turning member is controlled as described, a tunnel having a desired sectional shape can be freely excavated with a simple and low-cost structure.

Also, unlike the conventional one in which the overcut rotary cutter protrudes and retracts in the radial direction when the electromagnetic clutch is turned on and off, the operation amount of the rotary member and the rotational displacement amount of the rotary body are detected sequentially. A target operation amount corresponding to the detected rotational displacement amount (i.e., an operation amount of the rotating member necessary to obtain a desired excavation shape) is calculated, and based on a comparison between the target operation amount and an actual detected operation amount, Since the driving control of the rotating member is performed, not only overcutting, but also tunnel excavation of a deformed cross-section that is far from a circle can be accurately performed. It can be changed freely just by changing the contents. Furthermore, since the amount of the tip of the forming cutter that is actually displaced in the radial direction is smaller than the amount that the pivot end of the pivot member is pivoted, it is compared with a shield machine that directly moves the auxiliary cutter and the like in the radial direction. Also, it is possible to finely control the orbit of the forming cutter, and it is possible to obtain a desired excavation cross-sectional shape with higher accuracy.

[Brief description of the drawings]

FIG. 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 AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a block diagram of a drive control system provided in the shield machine.

FIG. 5 is an explanatory diagram of an overcut performed by the shield machine.

FIG. 6 is a front view of a shield machine according to a second embodiment.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

FIG. 8 is a front view of a forming cutter according to another embodiment.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 skin plate (shield machine body) 2 cutting wheel (rotating body) 6 center cutter 7, 7 ′ forming cutter (forming cutter) 23 torsion bar (constituting rotating member) 29 control lever (constituting rotating member) 33 telescopic Member (operating means) 35 Motor with reduction gear (driving means) 70 Cutter arm (constituting rotating member) 90 Cutting wheel rotational position detector (rotational displacement detecting means) 91 Computing device (computing means) 92 Comparator (operating) Control means) 93 Telescopic member controller (operation control means) 94 Telescopic member expansion / contraction amount detector (operation amount detection means) G Central axis (axis extending in the propulsion direction)

Claims (1)

(57) [Claims] 1. A shield machine main body, and supported by the shield machine main body so as to be rotatable around an axis extending in a propulsion direction thereof.
A rotating body having a center cutter on the front surface, a driving means for driving the rotating body, a plurality of rotating members rotatably supported by the rotating body at positions off the rotation axis, and the rotating member A forming cutter that is integrally fixed to a front rotating end of the cutting body, and that cuts forward soil with rotation of the rotating body;
Actuating means for rotating the rotating member, rotational displacement amount detecting means for detecting a rotational displacement amount of the rotating body, and necessary for obtaining a revolving locus of each forming cutter corresponding to a preset excavation shape. Calculating means for calculating a target actuation amount corresponding to the actuation amount of the rotating member according to the rotational displacement amount detected by the rotational displacement amount detecting means; and an actuation amount for detecting the actual actuation amount of the rotating member Detecting means for comparing the detected operating amount detected by the operating amount detecting means with the target operating amount calculated by the calculating means, and controlling the driving of the rotating member by the operating means in a direction to make them equal. A free-section shield machine comprising an operation control means.