JP7165477B1 - Cutter board for shield machine and shield machine equipped with the same - Google Patents

Abstract

A cutter head for a shield excavator in which the excavation capacity does not decrease on the inner peripheral side of the spoke portion where scraper teeth are not arranged. SOLUTION: A plurality of spoke portions 2b radially extending from a hub portion 2a, through holes 2e formed between the plurality of spoke portions 2b for taking in excavated earth and sand, and a plurality of spoke portions 2b extending in an extending direction. An outer peripheral ring portion 2d connecting the outer peripheral end portions, a plurality of leading bits 4b provided on the front surfaces of the plurality of spoke portions 2b, and formed only inward from the central portion in the extending direction of the plurality of spoke portions 2b. Slanted surfaces TS, which are both side surfaces in the width direction of the spokes 2b that are inclined in the direction toward which they approach each other from the front to the rear of the spokes 2b, and the width of only the outer side from the central portion in the extending direction of the plurality of spokes 2b. First scraper teeth 4sa provided on both outer edges in the direction of spokes 2b, and second scraper teeth 4sb provided on both outer edges in the width direction at outer peripheral ends in the extending direction of the plurality of spokes 2b. . [Selection drawing] Fig. 4

Description

TECHNICAL FIELD The present invention relates to a shield machine and a shield machine equipped with the shield machine.

A shield tunneling machine is a device that forms an excavation hole in the natural ground by moving forward while pressing a cutter board provided on the front surface of the machine body against the face of the natural ground and rotating it.

Shield machines include mud pressure shield machines and slurry shield machines. The former shield machine has a structure that stabilizes the face by injecting additives into the chamber to turn the excavated soil into mud (fluidization) and apply a predetermined pressure. is filled between the face and the partition wall, and the additive material is injected and kneaded to make the earth and sand into mud (mixture of gravel and additive material) with high fluidity and water stoppage, and the soil pressure stabilizes the face. It is a shield machine that digs while digging. The earth and sand mixed with the additive in the chamber are taken into the screw conveyor and discharged from the rear of the equipment body. The latter shield machine has a structure in which the face is stabilized by applying a predetermined pressure to the muddy water in the chamber, and the muddy water is circulated to transport the excavated soil as a fluid.

Here, the cutter board of the earth pressure shield tunneling machine includes a hub portion located at the center of rotation, a plurality of spoke portions radially extending from the hub portion, and outer peripheral end portions in the extending direction of the plurality of spoke portions. and a connecting peripheral ring portion. Further, a through hole is formed between the spokes for taking earth and sand excavated by the cutter board into a chamber formed behind the cutter board.

Disposed on each spoke are various excavating means such as roller cutters, leading bits and scraper teeth. The roller cutter is arranged in front of each spoke portion and mainly crushes boulders, boulders, etc. (hereinafter sometimes simply referred to as "boulders"). A plurality of preceding bits are arranged on the front surface of each spoke portion to perform preliminary excavation and protect the scraper tooth. Furthermore, a plurality of scraper teeth are arranged along the extending direction of each spoke portion at both outer edge portions in the width direction of each spoke portion, that is, at the outer peripheral corner portions of the intake port for excavated earth and sand, and excavate the ground. The excavated earth and sand are taken into the chamber (see Patent Documents 1 to 5, for example).

JP 2012-122257 A JP 2012-122258 A JP 2012-122259 A JP 2012-122260 A JP-A-10-140984

By the way, in the earth pressure shield tunneling machine, if there is a boulder with a diameter larger than the maximum that can be taken in through the through-hole formed in the cutter board, the boulder is crushed by a bit before being taken in. This is because if cobbles that cannot be conveyed by the screw conveyor are taken in, they cannot be crushed in the chamber, so they will remain until they are agitated in the chamber and worn down to a diameter that can be conveyed by the screw conveyor. This is because it leads to damage to the stirring rod, torque arm, etc. Therefore, the maximum diameter of the boulders to be taken in from the cutter disc must be less than or equal to the diameter that can be conveyed by the screw conveyor.

In a mud pressure shield tunneling machine, when excavating a gravel layer with a very high gravel ratio and including boulders, large-diameter boulders are placed on the ground on the inner peripheral side of the cutter board (inside from the center in the extending direction of the spokes). If there is, after the boulder comes off the face ground, it should roll toward the outer periphery of the spoke (outside from the center in the extension direction of the spoke) where there is a through hole large enough to take in the boulder. Moving. Then, until the cobblestone is taken in from the through hole on the outer peripheral side, it collides with the spoke portion and the bit attached to the spoke portion many times, causing wear and damage to the bit and spoke portion.

Such a tendency is particularly greater in shield machines with relatively small shield diameters of about 2000 mm to 4500 mm than in shield machines with relatively large shield diameters of 6000 mm or more.

Here, if the scraper teeth protruding from the side surface of the spoke portion are arranged only on both outer edge portions in the width direction of the outer peripheral side of the spoke portion and are not arranged on the inner peripheral side, the penetration formed on the inner peripheral side can be removed. Since the maximum diameter of cobbles that can be taken into the hole is increased, the wear and breakage of the bit and spokes described above are suppressed.

However, on the inner peripheral side of the spoke portion where the scraper tooth is not arranged, there is a possibility that the ability to excavate the ground may be reduced.

The present invention has been made in view of the above-mentioned technical background, and provides a cutter board for a shield machine that does not impair the ability to excavate the ground on the inner peripheral side of the spoke portion where the scraper teeth are not arranged. The purpose is to provide technology.

In order to solve the above-mentioned problems, a cutter board for a shield machine according to claim 1 of the present invention includes a hub portion positioned at the center of rotation, a plurality of spoke portions radially extending from the hub portion, and a through hole formed between the spokes for taking in excavated earth and sand; an outer peripheral ring portion connecting outer peripheral ends of the plurality of spokes in the extending direction; and a plurality of leading bits formed only inside from the center position of the distance from the center of rotation of the cutter disk in the extending direction of the plurality of spokes when viewed from the front to the outer end of the spoke, and on the face side Slanted surfaces that are both side surfaces in the width direction of a certain spoke portion that are inclined in a direction toward each other from the front to the rear, and only outside from the center position in the extending direction of the plurality of spoke portions . First scraper teeth provided on both outer edges in the width direction of the spokes, and second scraper teeth provided on both outer edges in the width direction of the outer peripheral ends in the extending direction of the plurality of spokes and the pitch of the preceding bit arranged inside from the central position of the plurality of spokes with respect to the extending direction of the spoke is equal to that of the spoke of the preceding bit arranged outside from the central position. It is narrower than the pitch in the extending direction, and the inclined surface is attached with a wear-resistant steel plate coated to prevent adhesion of excavated earth and sand, or has a coating to prevent adhesion of excavated earth and sand. It is characterized by being processed .

According to claim 2 of the present invention, there is provided a cutter board for a shield machine according to claim 1, wherein an angle formed by a line perpendicular to the front plate of the spoke portion and the inclined surface is 5°. It is characterized by

According to a third aspect of the present invention, there is provided a cutter board for a shield machine according to the first or second aspect of the invention, which is provided only inside from the central portion of the plurality of spoke portions in the extending direction, and It further has a protective member that protects the inner side from the central portion in the extending direction of the.

According to a fourth aspect of the present invention, there is provided a cutter board for a shield machine according to the third aspect of the invention, wherein the protective member is a front view of the cutter board inside the center position in the extending direction of the spoke portion. and wear-resistant steel plates provided between the edge portions on both sides in the width direction and the preceding bit .

According to a fifth aspect of the present invention, there is provided a cutter board for a shield machine according to the third aspect of the invention, wherein the protective member is positioned in front of the spoke portion inside from the center position in the extending direction of the spoke portion. It is characterized in that it is a built-up weld formed on the entire side surface of the face plate in the width direction.

According to claim 6 , the shield machine of the present invention is characterized in that the cutter board according to any one of claims 1 to 5 is rotatably provided on the front surface of the machine body.

According to the present invention, both side surfaces in the width direction only on the inner peripheral side of each spoke portion are slanted surfaces that are slanted toward each other from the front to the rear of the spoke portion. As a result, the ground on the face face crushed into grooves by the leading bit on the inner peripheral side is scooped up by the spoke portion on the inner peripheral side and taken into the machine.

Therefore, even on the inner peripheral side of the spoke portion where the scraper tooth is not arranged, the ability to excavate the natural ground is not impaired.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a configuration diagram showing the inside of a mud pressure shield machine according to an embodiment of the present invention seen through from the side; FIG. 2 is a front view of a cutter head of the earth pressure shield machine of FIG. 1; FIG. 3 is a side view of the cutter head of FIG. 2 as seen from the direction of arrow A1; 3 is a cross-sectional view as seen from arrow X in FIG. 2; FIG. 5 is a cross-sectional view showing an enlarged Z portion of FIG. 4; FIG. 3 is a cross-sectional view seen from arrow Y in FIG. 2; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment as an example of the present invention will be described in detail below with reference to the drawings. In the drawings for describing the embodiments, in principle, the same components are denoted by the same reference numerals, and repeated description thereof will be omitted.

FIG. 1 is a configuration diagram showing the inside of the earth pressure shield machine of this embodiment seen through from the side, FIG. 2 is a front view of the cutter head of the earth pressure shield machine of FIG. 1, and FIG. 3 is the cutter of FIG. FIG. 4 is a cross-sectional view of the head viewed from the direction of arrow A1, FIG. 4 is a cross-sectional view of FIG. 2 viewed from arrow X, FIG. 5 is a cross-sectional view of FIG. 1 is a cross-sectional view seen from .

A mud pressure shield tunneling machine (shield tunneling machine) 1 according to the present embodiment has impermeability and plastic flow generated by injecting and kneading an additive into soil excavated by a cutter head (cutter board) 2 . The chamber between the cutter head 2 and the equipment main body 3 is filled with mud that has flexibility (the property of being able to be deformed and moved freely) to generate mud pressure, and the mud pressure is used as the earth pressure of the face. It is a device that builds a borehole against the

This mud pressure shield tunneling machine 1 is particularly suitable for excavating a ground containing a cobblestone-mixed gravel layer or a cobblestone layer in which boulders are mixed. It may be applied to gravel layers.

The excavation outer diameter of the mud pressure shield machine 1 is, for example, about 4500 mm. Further, the machine length of the earth pressure shield machine 1 is, for example, about 6400 mm. Further, the operation of the earth pressure shield machine 1 is controlled by an operator in the driver's cab in a trailing truck (not shown) arranged behind it.

The cutter head 2 is a member for excavating the face of the ground, and is installed on the front surface of the equipment body 3 in a freely rotatable state along the circumferential direction of the equipment body 3 . The cutter head 2 employs, for example, a disk-shaped spoke type. That is, as shown in FIG. 2, the cutter head 2 includes a hub portion 2a located at the center of rotation, six spoke portions 2b radially extending from the hub portion 2a toward the outer circumference, and extensions of the spoke portions 2b. An intermediate ring portion 2c that connects the middle portions in the direction, an outer ring portion 2d that connects the tip portions of the spoke portions 2b, and a penetration formed between the spoke portions 2b for taking excavated earth and sand into the chamber 6. and a hole 2e.

A center bit (bit) 4a is attached to the hub portion 2a of the cutter head 2. As shown in FIG. In some cases, other excavating members such as a cone-head roller bit are attached to the hub portion 2a.

As shown in the figure, each spoke portion 2b has a dimension in the width direction (rotation direction of the cutter head 2) that extends from the rotation center of the cutter head 2 in the front view in the extension direction of the spoke portion 2b to the outside of the spoke portion 2b. From the center position of the distance to the end (here, slightly closer to the hub portion 2a than the mounting position of the intermediate ring portion 2c) to the inner side (hereinafter referred to as the “inner peripheral side”), it becomes thinner as it approaches the hub portion 2a. , and the widthwise dimension is the same on the outer side (hereinafter referred to as "peripheral side") from the center position in the extending direction of the spoke portion 2b.

On the inner peripheral side of the spoke portion 2b, the spoke portion 2b is formed so as to gradually widen from the hub portion 2a. This is because it is possible to That is, if the width direction of the inner peripheral side of the spoke portion 2b is narrowed, the opening area of the through hole 2e can be widened, but the strength is lowered. This is because the opening area of the hole 2e is reduced.

Also, by forming the spokes 2b so that their widthwise dimensions are the same on the outer peripheral side, the opening area of the through-holes 2e, in other words, the opening ratio can be increased.

In the present embodiment, the central position of the spoke portion 2b in the extending direction is slightly closer to the hub portion 2a than the mounting position of the intermediate ring portion 2c, but the position is the same as the mounting position of the intermediate ring portion 2c. Alternatively, it may be closer to the outer ring portion 2d than the mounting position of the intermediate ring portion 2c.

Further, in the present embodiment, the spokes 2b are formed such that the inner peripheral side of the spokes 2b becomes narrower in the width direction as it approaches the hub portion 2a, and the outer side from the center position is formed so that the width direction dimensions are the same. However, the spoke portions 2b may be formed with the same width over the entire length, or may be formed so as to become thinner toward the hub portion 2a over the entire length of the spoke portions 2b.

A leading bit (bit) 4b, a scraper tooth 4s, and a wear-resistant steel plate (protective member) 4t are attached to each spoke portion 2b. In this embodiment, the height of the preceding bit 4b (the height from the surface of the spoke portion 2b) is 150 mm, the height of the scraper tooth 4s is 100 mm, and the amount of protrusion (the amount of protrusion from the side surface of the spoke portion 2b) is 100 mm. It has become. In addition to the leading bit 4b, other excavating member such as a roller bit may be attached to the front surface of the spoke portion 2b.

The preceding bit 4b has the role of preemptively crushing boulders and excavating the ground, and also protecting the scraper tooth 4s. As shown in FIG. facing each other) are arranged in a regular pattern. Each preceding bit 4b has a planar shape of, for example, a substantially rectangular shape, and is arranged with its long side along the width direction of the spoke portion 2b.

In this embodiment, the positions of the preceding bits 4b adjacent to each other in the rotational direction of the cutter head 2 are arranged on different rotational trajectories. You may

The scraper teeth 4s have the role of excavating the natural ground and taking the excavated earth and sand into the chamber 6 (FIG. 1), and are provided on both outer edges in the width direction only on the outer peripheral side of each spoke portion 2b. It consists of a first scraper tooth 4sa and a second scraper tooth 4sb provided on both outer edges in the width direction of the outer peripheral end portion in the extending direction of each spoke portion 2b. As will be described later, the attachment position of the first scraper tooth 4sa differs depending on the spoke portion 2b. The radially outer side from the first scraper tooth 4sa attached to the spoke portion 2b at the positions corresponding to 12 o'clock and 6 o'clock is the outer peripheral side of the spoke portion 2b.

In the present embodiment, the attachment positions of the first scraper teeth 4sa of the adjacent spoke portions 2b are offset from each other in the radial direction of the cutter head 2. As shown in FIG. Specifically, in FIG. and the first scraper tooth 4sa installed at the position corresponding to 6 o'clock, the first scraper tooth 4sa installed at the position corresponding to 2 o'clock and 8 o'clock, and the position corresponding to 4 o'clock and 10 o'clock The first scraper teeth 4sa are arranged alternately.

In addition, in this embodiment, two types of second scraper teeth 4sb having different lengths are provided. In FIG. The second scraper tooth 4sb is longer than the second scraper tooth 4sb installed at other positions, and the trajectory when the cutter head 2 rotates is installed at a position corresponding to 4 o'clock and 10 o'clock on the face of the clock. It slightly overlaps the trajectory of the first scraper tooth 4sa on the outer peripheral side.

By arranging the first scraper tooth 4sa and the second scraper tooth 4sb in this way, the natural ground located on the outer peripheral side of the cutter head 2 is evenly excavated.

As shown in FIGS. 4 and 6, both side surfaces in the width direction only on the inner peripheral side of each spoke portion 2b form inclined surfaces TS that are inclined in directions toward each other from the front to the rear of the spoke portion 2b. It's becoming As shown in the figure, in the present embodiment, the inclination angle of the inclined surface TS (the angle formed by the inclined surface TS and the line perpendicular to the front plate 2ba of the spoke portion 2b) is 5°. Such an inclined surface TS has the same function as the scraper tooth 4s on the outer peripheral side described above, and is excavated so that the ground on the face surface crushed into grooves by the leading bit 4b is scooped up into the chamber 6. taken inside. Note that the inclination angle of the inclined surface TS does not have to be 5°, and can be freely set.

Here, as shown in FIGS. 4 and 6, a wear-resistant steel plate 4t for protecting the inclined surface TS is attached to the inclined surface TS to prevent wear and damage of the spoke portion 2b due to ground excavation. is doing. The wear-resistant steel plate 4t attached to the inclined surface TS may be coated with a powder or liquid sediment-adhesion prevention agent. If the coating treatment for preventing adhesion of excavated earth and sand is performed, the amount of earth and sand excavated from the face surface is reduced due to the earth and sand adhering to the inclined surface TS, and the excavation efficiency is prevented from deteriorating.

Also, instead of the wear-resistant steel plate 4t, an anti-adhesion plate for preventing adhesion of excavated earth and sand may be attached to the inclined surface TS. Alternatively, instead of attaching the wear-resistant steel plate 4t or the anti-adhesion plate to the inclined surface TS, a coating process may be directly applied to prevent adhesion of excavated earth and sand. By attaching an anti-adhesion plate to the inclined surface TS or applying an anti-adhesion coating to the inclined surface TS, as described above, the excavation amount of the earth and sand on the face surface is reduced due to the earth and sand adhering to the inclined surface TS. Efficiency will not deteriorate.

Further, in the present embodiment, as shown in FIGS. 2, 4 and 5, both outer edge portions in the width direction on the inner peripheral side of each spoke portion 2b and a front surface on the inner peripheral side of each spoke portion 2b (details A wear-resistant steel plate 4t is attached to the surface of the front plate 2ba of the spoke portion 2b via a mounting plate 4v. By providing such a wear-resistant steel plate 4t, both outer edges in the width direction on the inner peripheral side and the surface of each spoke portion 2b are protected, and wear and damage of the spoke portions 2b due to ground excavation are prevented.

In the present embodiment, the wear-resistant steel plate 4t is attached to both outer edges in the width direction and the front surface of the inner peripheral side of each spoke portion 2b. may have been Alternatively, the wear-resistant steel plate 4t may be attached directly to the spoke portion 2b without using the mounting plate 4v.

Furthermore, as shown in FIGS. 4 to 6, on the inner peripheral side of each spoke portion 2b, a built-up welded portion (protective member) 4w is formed on the entire side surface in the width direction of the front plate 2ba of the spoke portion 2b. ing. This improves the wear resistance of the inner peripheral side of the spoke portion 2b during ground excavation.

Here, the maximum diameter of the boulders taken into the through hole 2e is determined by the size (diameter) of the screw conveyor 10, but in the earth pressure shield machine 1 of the present embodiment, boulders having a diameter of about 700 mm×600 mm are used. , and the through hole 2e formed in the cutter head 2 is sized to take in a cobblestone having a maximum diameter of 700 mm.

This is because if a boulder of a size that cannot be conveyed by the screw conveyor 10 is taken in from the through hole 2e, it cannot be crushed in the chamber 6, so it is conveyed by the screw conveyor 10 while being agitated in the chamber 6. It will remain until it is worn out to the maximum diameter. In this case, the kneading blades 15 and 16 (to be described later) will be damaged, so the maximum diameter of the boulders taken into the chamber 6 must be kept below the diameter that can be conveyed by the screw conveyor 10 .

An additive material injection port 5a is provided in the hub portion 2a and the spoke portion 2b. The additive material injection port 5 a is a component for injecting a sludge material such as a bentonite-based additive toward the front face of the cutter head 2 . As the additive injected from each of the additive injection ports 5a, a foaming material may be used instead of the bentonite-based additive, or both the bentonite-based additive and the foaming material may be used. good.

Earth and sand excavated by the cutter head 2 are taken into a chamber 6 (see FIG. 1) described later through the through holes 2e. By regulating the opening area of , the size of the boulder taken in from the through hole 2e is regulated. If the excavation outer diameter of the mud pressure shield machine 1 is small (for example, 2000 mm), the intermediate ring portion 2c can be omitted.

A plurality of peripheral bits (bits) 4c are mounted side by side on the face-side front surface of the peripheral ring portion 2d. This peripheral bit 4c also has a height of 150 mm. The heights of the peripheral bits 4c adjacent to each other in the rotation direction of the cutter head 2 can be made different such that they alternately rise and fall along the rotation direction of the cutter head 2. FIG. By doing so, the impact and load applied to the outer peripheral bit 4c can be distributed, the durability of the outer peripheral bit 4c can be improved, and the replacement time of the outer peripheral bit 4c of the cutter head 2 can be extended. In addition, by changing the height of the outer peripheral bit 4c on the same rotational locus, it is possible to cut down the cobbles and the like of the face well.

Also, two copy bits 4d, for example, are provided at opposite pole positions on the outer peripheral surface of the outer peripheral ring portion 2d. This copy bit 4d has a role of performing over-digging at the time of construction of a sharp curve, attitude control of the earth pressure shield machine 1, and the like.

As shown in FIG. 1, the equipment body 3 includes a front body plate 3a of the girder portion and a rear body plate 3b of the tail portion behind it. The front body plate 3 a and the rear body plate 3 b are formed of, for example, cylindrical steel plates, and are members that form the outer shape of the device body 3 and form a hollow space inside the device body 3 . The front body plate 3a and the rear body plate 3b are engaged with each other by inserting the spherical bearing portion at the front end of the rear body plate 3b into contact with the inner peripheral surface of the front body plate 3a on the rear end side of the front body plate 3a. It is

On the front side of the forward body plate 3a, a partition wall 7 is provided at a position recessed inward from the front surface of the equipment body 3a to divide the hollow space inside the equipment body 3 into a face side and an inside side. A chamber 6 is provided on the face side of the partition wall 7 (that is, between the cutter head 2 and the partition wall 7). 9a, a shield jack 9b, a screw conveyor 10, and an earth pressure detector (not shown) are provided.

The additive material injection part 5b is a device for injecting an additive material toward the outer circumference of the device main body 3 or into the chamber 6. It is provided in the vicinity of the outer periphery of 7. The additive injected from the additive injection part 5b is, for example, a sludge material such as a bentonite-based additive. As the additive injected from the additive injection part 5b, a foaming material may be used instead of the bentonite-based additive, or both the bentonite-based additive and the foaming material may be used.

The chamber 6 is a space into which earth and sand excavated by the cutter head 2 are taken. Inside the chamber 6 , a columnar kneading blade 15 protruding into the chamber 6 is provided on the front surface of the partition wall 7 , while a columnar kneading blade 15 protruding into the chamber 6 is provided on the rear surface of the cutter head 2 . A kneading blade 16 is provided. These kneading blades 15 and 16 are displaced from each other in the radial direction of the cutter head 2, and when the cutter head 2 rotates, they agitate the sand that has entered the chamber 6 and the additive material that has been injected into the chamber 6. It has a mixed role.

The cutter driving body 8 is a driving source that rotates the cutter head 2 . Here, an intermediate support driving method is exemplified as the cutter driving method, and the cutter driving body 8 is positioned approximately in the middle between the center in the front surface of the cutter head 2 and the outer periphery thereof, as shown in FIG. 2 are arranged side by side along the circumferential direction.

The center-folding jack 9a is a device that connects the front body plate 3a and the rear body plate 3b and corrects the propelling direction of the earth pressure shield machine 1. As shown in FIG. A plurality of them are arranged side by side along the circumferential direction of the earth pressure shield machine 1 at a position straddling the boundary between the trunk plate 3a and the rear trunk plate 3b. By supplying pressurized oil to the folding jack 9a and propelling the earth pressure shield excavator 1 in a state in which the front body plate 3a and the rear body plate 3b are bent in a predetermined direction and angle, a mud pressure shield is formed. It is possible to control the driving direction of the excavator 1 .

The shield jack 9b is a device that generates a propulsive force for advancing the earth pressure shield machine 1 by receiving reaction force from the segment SG installed behind the machine body 3. As shown in FIG. A plurality of earth pressure shield machines are arranged side by side along the circumferential direction of the earth pressure shield machine 1 at positions straddling the boundary between the front body plate 3 a and the rear body plate 3 b in the main body 3 .

The screw conveyor 10 is a device for discharging the earth and sand taken in the chamber 6 to the outside of the machine, and as shown in FIG. It is provided in a state in which it continuously extends obliquely upward from the earth and sand intake end 10a toward the discharge end 10b located behind the equipment body 3 at a position slightly higher than the center in the height direction of the equipment body 3. there is

For this screw conveyor 10, for example, a ribbon-type screw conveyor is used in which a spiral blade 10c having no rotating shaft is provided inside a tube. In the case of a screw conveyor having a rotating shaft, clogging is likely to occur due to boulders. It is possible to transport cobbles that are too large to be transported by the screw conveyor. As a result, in the earth pressure shield machine 1 of the present embodiment, it is possible to take cobbles or the like of a size that can be discharged by the screw conveyor 10 into the chamber 6 without crushing them.

A discharge pipe (not shown) is connected to the discharge end portion 10b of the screw conveyor 10, and the earth and sand conveyed to the discharge end portion 10b of the screw conveyor 10 are conveyed to a cart or the like through the discharge pipe. It has become.

The earth pressure detection part is a sensor part that converts the pressure of mud in the chamber 6 into an electric signal via a strain gauge, and is provided with the earth pressure detection surface facing the inside of the chamber 6 . The earth pressure shield tunneling machine 1 controls the earth pressure in the chamber 6 detected by the earth pressure detector so that it falls within a predetermined value range, thereby proceeding with the excavation process while maintaining the stability of the face. It's like

Next, an earth pressure shield construction method using the earth pressure shield tunneling machine 1 of FIG. 1 will be described. Here, the excavation target is a ground consisting of a gravel layer with a very high gravel ratio and containing boulders.

When excavating such ground, the earth pressure shield excavator 1 of the present embodiment constructs an excavation pit in the ground by pushing the machine main body 3 forward while rotating the cutter head 2 against the face.

During this excavation work, an additive is added to the earth and sand excavated by the cutter head 2, and the earth and sand and the additive are stirred and mixed by the rotation of the cutter head 2 and the operation of the kneading blade 16 following the rotation. It transforms excavated soil into mud with plastic flowability and impermeability. Then, the chamber 6 and the screw conveyor 10 are filled with the mud, and the filled mud is pressurized by the propulsive force of the shield jack 9b to generate mud pressure, which is opposed to the earth pressure of the face. to maintain the stability of the face. Further, for example, the rotation speed of the cutter head 2 is kept constant, the extension speed of the shield jack 9b and the rotation speed of the screw conveyor 10 are adjusted, and the earth pressure in the chamber 6 is measured by the earth pressure detector and becomes constant. to maintain the stability of the face.

The bentonite-based additive (sludge material) added as an additive has the effect of increasing the plastic fluidity and impermeability of the soil, and also wraps the crushed gravel and boulders together with the excavated soil. It has the effect of improving the integrity of the excavated soil and the gravel so that the gravel does not separate from the excavated soil.

Here, if the maximum diameter of the boulders that can be taken in the through holes 2e on the outer peripheral side of the cutter head 2 is larger than that of the through holes 2e on the inner peripheral side of the cutter head 2, they will not be taken in by the through holes 2e on the inner peripheral side. The boulder moves to the outer peripheral side of the spoke portion 2b and is taken in from the through hole 2e on the outer peripheral side. During this time, the boulders repeatedly collide with the spoke portion 2b and the preceding bit 4b attached to the spoke portion 2b, accelerating wear and breakage of the preceding bit 4b and the spoke portion 2b.

In contrast, in the earth pressure shield machine 1 of the present embodiment, as described above, the scraper tooth 4s projecting from the side surface of the spoke portion 2b is not provided on the inner peripheral side of each spoke portion 2b. Therefore, the maximum diameter of boulders that can be taken in through the through holes 2e is the same between the inner peripheral side and the outer peripheral side of the cutter head 2. FIG. Therefore, when a large-diameter boulder that can be taken in through the through-hole 2e is in the ground on the inner peripheral side of the cutter head 2, the boulder is taken in through the through-hole 2e on the inner peripheral side as it is after coming off the face ground. It is fed into the chamber 6.

At this time, both side surfaces in the width direction only on the inner peripheral side of each spoke portion 2b form inclined surfaces TS that are inclined in a direction toward each other from the front to the rear of the spoke portion 2b. As a result, the inclined surface TS has a function similar to that of the scraper tooth 4s on the outer peripheral side, so that the ground on the face surface crushed into grooves by the leading bit 4b on the inner peripheral side is applied to the spoke portion 2b on the inner peripheral side. It is excavated and taken into the chamber 6 (ie, inside the machine) so as to be scooped by the .

Therefore, even on the inner peripheral side of the spoke portion 2b where the scraper tooth 4s is not arranged, the ability to excavate the natural ground is not impaired.

As described above, the invention made by the present inventor was specifically described based on the embodiment, but the embodiment disclosed in this specification is an example in all respects, and is limited to the technology disclosed. should be considered nothing. That is, the technical scope of the present invention should not be construed in a restrictive manner based on the description of the above embodiments, but should be construed according to the description of the scope of claims. All modifications are included as long as they do not deviate from the description technology and equivalent technology and the gist of the claims.

For example, in the above-described embodiment, a case where a ribbon screw type screw conveyor is used has been described. may be used.

In the above description, the case where the present invention is applied to a mud pressure shield machine of an intermediate support drive system has been described, but the present invention is not limited to this. It is also applied to other shield excavators such as excavators.

1 Mud Pressure Shield Machine (Shield Machine)
2 Cutter head (cutter board)
2a hub portion 2b spoke portion 2c intermediate ring portion 2d outer ring portion 2e through hole 4a center bit (bit)
4b leading bit (bit)
4c peripheral bit (bit)
4s scraper tooth 4sa first scraper tooth 4sb second scraper tooth 4t wear-resistant steel plate (protective member)
4w Overlay weld (protective member)
6 chamber 7 partition wall 10 screw conveyor TS inclined surface

Claims (6)

a hub portion positioned at the center of rotation;
a plurality of spoke portions radially extending from the hub portion;
a through hole formed between each of the spokes for taking in excavated soil;
an outer ring portion that connects the outer peripheral end portions of the plurality of spoke portions in the extending direction;
a plurality of preceding bits provided on the front surfaces of the plurality of spokes ;
From the front of the spokes on the face side, which is formed only inside from the center position of the distance from the center of rotation of the cutter disc in the front view to the outer ends of the spokes in the extending direction of the plurality of spokes . slanted surfaces, which are both side surfaces in the width direction of the spoke portion, which are slanted in a direction toward which they approach each other toward the rear;
first scraper teeth provided on both outer edge portions in the width direction only outside from the central position in the extending direction of the plurality of spoke portions ;
second scraper teeth provided on both outer edge portions in the width direction of the outer peripheral end portions in the extending direction of the plurality of spoke portions ;
has
The pitch with respect to the extending direction of the spokes of the preceding bit arranged inside from the central position of the plurality of spokes is the extending direction of the spokes of the preceding bit arranged outside from the central position. is narrower than the pitch for
The inclined surface is attached with a wear-resistant steel plate coated to prevent adhesion of excavated earth and sand, or is coated to prevent adhesion of excavated earth and sand.
A cutter board for a shield machine characterized by: The angle formed by the line perpendicular to the front plate of the spoke and the inclined surface is 5°.
A cutter board for a shield machine according to claim 1, characterized in that: further comprising a protective member provided only inside from the central position in the extending direction of the plurality of spokes and protecting the inside from the central position in the extending direction of the spokes;
A cutter board for a shield machine according to claim 1 or 2 , characterized in that: The protective member is
Abrasion-resistant steel plates provided between both edge portions in the width direction of the cutter disc in the front view on the inner side from the center position in the extending direction of the spoke portion and between the preceding bits,
A cutter board for a shield machine according to claim 3 , characterized in that: The protective member is
A built-up weld formed on the entire side surface in the width direction of the front plate of the spoke portion inside from the center position in the extending direction of the spoke portion,
A cutter board for a shield machine according to claim 3 , characterized in that: The cutter board according to any one of claims 1 to 5 is provided in a rotatable state on the front surface of the equipment body,
A shield machine characterized by:

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